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See detailEfficacy of raloxifene on vertebral fracture risk reduction in postmenopausal women with osteoporosis: Four-year results from a randomized clinical trial
Delmas, P. D.; Ensrud, K. E.; Adachi, J. D. et al

in Journal of Clinical Endocrinology and Metabolism (2002), 87(8), 3609-3617

The Multiple Outcomes of Raloxifene Evaluation trial studied 7705 postmenopausal women with osteoporosis randomized to placebo, or raloxifene 60 or 120 mg/d [JAMA 282(1999):6371. This report assesses the ... [more ▼]

The Multiple Outcomes of Raloxifene Evaluation trial studied 7705 postmenopausal women with osteoporosis randomized to placebo, or raloxifene 60 or 120 mg/d [JAMA 282(1999):6371. This report assesses the efficacy of raloxifene on the long-term cumulative incidence new vertebral fractures through 4 yr. New vertebral fractures was assessed from radiographs taken at baseline, yr 2-4. The primary analysis was the cumulative incidence of new vertebral fractures through 4 yr. A posthoc analysis compared the vertebral fracture risk in yr 4 alone with that observed in the first 3 yr. The 4-yr cumulative relative risks (RR) for one or more new vertebral fractures were 0.64 [95% confidence interval (CI) 0.53, 0.761 with raloxifene 60 mg/d and 0.57 (95% CI 0.48, 0.69) with raloxifene 120 mg/d. In yr 4 alone, raloxifene 60 mg/d reduced the new vertebral fracture risk by 39% [RR 0.61 (95% CI 0.43,0.88)], which was not found to be significantly different from the RR observed in the first 3 yr in both raloxifene groups, irrespective of prevalent fracture status. The nonvertebral fracture risk was not significantly reduced [RR 0.93 (95% CI 0.81, 1.06)]. The safety profile after 4 yr was similar to that observed after 3 yr. Raloxifene 60 and 120 mg/d through 4 yr decreased the cumulative risk of new vertebral fractures in postmenopausal women with osteoporosis. The decreased vertebral fracture risk in yr 4 alone was not different from that observed in the first 3 yr. [less ▲]

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See detailComparison between transrectal ultrasonography and pregnancy-associated glycoprotein determination for early pregnancy diagnosis in the goat
Quesada, E; Gonzalez, F; Calero, P et al

in Reproduction in Domestic Animals (2002), 37(4), 247

The aim of the present workwas to compare the efficiency of transrectal ultrasonography technique and the determination of the pregnancy-associated glycoproteins (PAG) concentrations in plasma samples for ... [more ▼]

The aim of the present workwas to compare the efficiency of transrectal ultrasonography technique and the determination of the pregnancy-associated glycoproteins (PAG) concentrations in plasma samples for pregnancy diagnosis in goats. Thirty nine Canary goats were synchronized and naturally mated every 12 hours throughout oestrous. Blood samples were collected on days 17, 18, 19, 20, 22, 24, 26 and 28 and transrectal ultrasonography was carried out on days 20, 22, 24, 26 and 28 (Day 0¼day of the last mating). PAG concentrations were analysed by a RIA method previously validated. There were 23 pregnant goats (10 single and 13 multiple pregnancies) and 16 nonpregnant goats. The pregnancy diagnosis was a little earlier by PAG determination than transrectal ultrasonography (sensitivity: 95 and 91% on Day 24 and 100 and 96% on Day 26, respectively). The ultrasonography allowed to discriminate between single and multiple pregnancies in 70% of goats (16/23) on Day 28 of pregnancy. The PAG concentrations were significantly higher in multiple than single pregnancies from Day 19 onwards, suggesting that it could also be used as a tool to discriminate between single and multiple gestations. (Supported by D.G. de Universidades del Gobierno de Canarias). [less ▲]

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See detailImplications pathologiques du systeme neuroendocrinien digestif
Piette, Caroline ULg; Polus, Marc ULg; Louis, Edouard ULg

in Revue Médicale de Liège (2002), 57(8), 509-18

The neuroendocrine system is made of endocrine cells disseminated in various organs. In this article, we will focus on the implication of the neuroendocrine system in digestive pathology. First of all, we ... [more ▼]

The neuroendocrine system is made of endocrine cells disseminated in various organs. In this article, we will focus on the implication of the neuroendocrine system in digestive pathology. First of all, we will review the neuroendocrine tumors in every location and then describe their classification, epidemiology, symptomatology, diagnosis and treatment. Finally, we will consider the implications of the neuroendocrine system in the inflammatory and functional pathology of the digestive tract. [less ▲]

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See detailNew trends in anti-malarial agents
Frederich, Michel ULg; Dogné, Jean-Michel ULg; Angenot, Luc ULg et al

in Current Medicinal Chemistry (2002), 9(15), 1435-1456

Malaria is the major parasitic infection in many tropical and subtropical regions, leading to more than one million deaths (principally young African children) out of 400 million cases each year (WHO ... [more ▼]

Malaria is the major parasitic infection in many tropical and subtropical regions, leading to more than one million deaths (principally young African children) out of 400 million cases each year (WHO world health report 2000). More than half of the world's population live in areas where they remain at risk of malaria infection. During last years, the situation has worsened in many ways, mainly due to malarial parasites becoming increasingly resistant to several antimalarial drugs. Furthermore, the control of malaria is becoming more complicated by the parallel spread of resistance of the mosquito vector to currently available insecticides. Discovering new drugs in this field is therefore a health priority. Several new molecules are under investigation. This review describes the classical treatments of malaria and the latest discoveries in antimalarial agents, especially artemisinin and its recent derivatives as well as the novel peroxidic compounds. [less ▲]

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See detailEvidence of mast-cell activation in a subset of patients with eosinophilic chronic obstructive pulmonary disease
Louis, Renaud ULg; Cataldo, Didier ULg; Buckley, M. G. et al

in European Respiratory Journal (2002), 20(2), 325-331

Although asthma has been viewed mainly, as an eosinophilic disease, and chronic obstructive pulmonary disease (COPD) as a neutrophilic disease, recent studies have shown increased neutrophil counts in ... [more ▼]

Although asthma has been viewed mainly, as an eosinophilic disease, and chronic obstructive pulmonary disease (COPD) as a neutrophilic disease, recent studies have shown increased neutrophil counts in severe asthma and sputum eosinophilia in sonic COPD patients. In an attempt to further characterise these two syndromes according to pathology, the current authors have conducted a study of induced sputum in 15 subjects with COPD, 17 asthmatics, and 17 nonatopic healthy individuals. Sputum was analysed for cytology and levels of eosinophil cationic protein (ECP), albumin, tryptase and soluble intercellular adhesion molecule-1. The COPD subjects differed from the asthmatics as they had higher sputum neutrophil and lower columnar epithelial cell counts, but there were no differences in any soluble marker studied. When compared to control subjects, both the asthmatic and COPD subjects had raised eosinophil counts and ECP levels. In a subset of COPD subjects with Sputum eosinophilia (>3% of total cells), significantly increased levels of tryptase were detected. In conclusion, although chronic obstructive pulmonary disease is a more neutrophilic disease than asthma, the two diseases are difficult to distinguish on the basis of sputum levels of the soluble markers traditionally associated with asthma. However, a subset of patients with chronic obstructive pulmonary disease with airway eosinophilia and mast-cell activation might represent a distinct pathological phenotype. [less ▲]

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See detailModulation of fibrinolytic and gelatinolytic activity during adipose tissue development in a mouse model of nutritionally induced obesity
Lijnen, Roger; Maquoi, Erik ULg; Demeulemeester, Désiré et al

in Thrombosis and Haemostasis (2002), 88(2), 345-353

A nutritionally induced obesity model was used to investigate the modulation of fibrinolytic and gelatinolytic activity during the development of adipose tissue. Five week old male mice were fed a ... [more ▼]

A nutritionally induced obesity model was used to investigate the modulation of fibrinolytic and gelatinolytic activity during the development of adipose tissue. Five week old male mice were fed a standard fat diet (SFD, 13% kcal as fat) or a high fat diet (HFD, 42% kcal as fat) for up to 15 weeks. The HFD resulted in body weights of 31 +/- 0.9 g, 38 +/- 2.0 g and 47 +/- 1.9 g at 5, 10 and 15 weeks, respectively; corresponding values for mice on the SFD were 26 +/- 0.6 g, 31 +/- 0.9 g and 31 +/- 1.2 g (all p < 0.001). The weight of the isolated subcutaneous (s.c.) or gonadal (GON) fat after 15 weeks of HFD was 1,870 +/- 180 mg or 1,470 +/- 160 mg, as compared to 250 +/- 58 mg or 350 +/- 71 mg for the SFD (p < 0.001). The HFD induced marked time-dependent hyperglycemia and elevated levels of triglycerides and total cholesterol. The HFD diet also induced a marked hypertrophy of the adipocytes as compared to the SFD, e.g. diameter of 83 +/- 3.0 microns versus 52 +/- 4.2 microns for GON adipocytes at 15 weeks (p < 0.005). Plasma plasminogen activator inhibitor-1 (PAI-1) levels were higher in mice on the HFD as compared to the SFD; they were comparable in extracts of s.c. or GON adipose tissue, whereas at different time points tissue-type (t-PA) and urokinase-type (u-PA) plasminogen activator activity was somewhat lower in the adipose tissues of mice on HFD. Gelatinolytic activity (mainly MMP-2) was detected in s.c. but not in GON adipose tissue of mice on SFD, and decreased on the HFD. In situ zymography on cryosections did not reveal different fibrinolytic activities in s.c. or GON adipose tissues of the HFD as compared to the SFD groups, whereas significantly lower gelatinolytic and higher caseinolytic activities were detected in s.c. and GON tissues of mice on the HFD (p < or = 0.05). The fibrillar collagen content was lower in adipose tissue of mice on HFD. Thus, in this model time-dependent development of adipose tissue appears to be associated with modulation of proteolytic activity. [less ▲]

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See detailFunctional brain imaging applications to differential diagnosis in the dementias
Salmon, Eric ULg

in Current Opinion in Neurology (2002), 15(4), 439-444

Purpose of review The diagnosis of dementia rests on an improved knowledge and a better detection of early impairments, to which functional imaging can certainly contribute. Recent findings Progress has ... [more ▼]

Purpose of review The diagnosis of dementia rests on an improved knowledge and a better detection of early impairments, to which functional imaging can certainly contribute. Recent findings Progress has been observed at different levels. First, the understanding of different dementias has benefited from explorations of the neural substrate of dementia symptoms and from research into new markers. Second, diverse variables (clinical, anatomical, biochemical) have been related to impaired cerebral activity in Alzheimer's disease and other dementias, and progress in image analysis and in multimodal data acquisition has allowed a better understanding of the significance of brain activity disturbances. Third, functional imaging has been applied in well-designed clinical studies, and has provided important arguments for the diagnosis of characteristic clinical syndromes in the dementias. Summary The functioning of neural networks responsible for clinical symptoms in dementia remains an important research topic for functional imaging. The development of new tracers and new techniques for image processing should also improve the usefulness of brain imaging as a diagnostic tool. [less ▲]

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See detailHST STIS observations of four QSO pairs
Aracil, B.; Petitjean, P.; Smette, A. et al

in Astronomy and Astrophysics (2002), 391(1), 1-12

We present HST STIS observations of four quasar pairs with redshifts 0.84<z(em)<1.56 and angular separation 2-3 arcmin corresponding to ∼1-1.5 h(50)(-1) Mpc transverse proper distance at zsimilar to0.9 ... [more ▼]

We present HST STIS observations of four quasar pairs with redshifts 0.84<z(em)<1.56 and angular separation 2-3 arcmin corresponding to ∼1-1.5 h(50)(-1) Mpc transverse proper distance at zsimilar to0.9. We study the distribution of velocity differences between nearest neighbor HI Lyman-alpha absorption lines detected in the spectra of adjacent QSOs in order to search for the possible correlation caused by the extent or the clustering properties of the structures traced by the absorption lines over such a scale. The significance of the correlation signal is determined by comparison with Monte-Carlo simulations of spectra with randomly distributed absorption lines. We find an excess of lines with a velocity separation smaller than DeltaV=500 km s(-1) significant at the 99.97% level. This clearly shows that the Lyman-alpha forest is correlated on scales larger than 1 h(50)(-1) Mpc at zsimilar to1. However, out of the 20 detected coincidences within this velocity bin, 12 have V>200 km s(-1). This probably reflects the fact that the scale probed by our observations is not related to the real size of individual absorbers but rather to large scale correlation. Statistics are too small to conclude about any difference between pairs separated by either 2 or 3 arcmin. A damped Lyman-alpha system is detected at z(abs)=1.2412 toward LBQS 0019-0145A with log N(HI)similar to20.5. From the absence of ZnII absorption, we derive a metallicity relative to solar [Zn/H]< -1.75. [less ▲]

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See detailOesophage de Barrett: mise au point
Delforge, M.; Plomteux, O.; Delfosse, Valérie ULg et al

in Revue Médicale de Liège (2002), 57(8), 535-45

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the ... [more ▼]

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the proximal margin of the gastric folds is the anatomic landmark. Another important feature of BE is the specialized intestinal metaplasia. In the aetiology of this condition, acid reflux is a primary event but there is evidence that other factors are causal. As BE is a well known premalignant condition, detection of dysplastic epithelium and its severity is the crucial element. Practical guidelines are presented for endoscopic surveillance program. The purpose is the early detection of high grade dysplasia and carcinoma to advise oesophagectomy or endoscopic ablation therapy for patients unfit to undergo surgery. [less ▲]

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See detailL'image du mois. Faux anevrysme du ventricule gauche
LANCELLOTTI, Patrizio ULg; Melon, Pierre ULg; Grenade, Thierry ULg et al

in Revue Médicale de Liège (2002), 57(8), 485

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See detailComparisons of two groups of sex-change applicants based on the MMPI
Michel, Aude; Ansseau, Marc ULg; Legros, Jean-Jacques ULg et al

in Psychological Reports (2002), 91(1), 233-240

Out of 29 men asking for a sex-change, 16 reported clinical anamnesis criteria for transsexualism according to the DSM-III-R, a more restrictive diagnosis than the DSM-IV gender dysphoria diagnosis. In ... [more ▼]

Out of 29 men asking for a sex-change, 16 reported clinical anamnesis criteria for transsexualism according to the DSM-III-R, a more restrictive diagnosis than the DSM-IV gender dysphoria diagnosis. In addition, all the subjects had taken an MMPI which, of course, did not contribute to the transsexualism diagnosis but which served to describe their personalities. The 16 subjects diagnosed as transsexual and the 13 who did not qualify for this diagnosis were compared on the basis of personality variables measured by the MMPI. Certain differences became evident. The transsexuals systematically complied to cultural stereotypes of femininity without any uneasiness, whereas the nontranssexuals could be subdivided into two groups, those with a vague sense of ill-being linked to a pronounced feminine identity or those with only a slight feminine identity and who showed no particular difficulties. [less ▲]

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See detailEffectiveness of bioremediation of crude oil contaminated subantarctic intertidal sediment: The microbial response
Delille, D.; Delille, Bruno ULg; Pelletier, E.

in Microbial Ecology (2002), 44(2), 118-126

A field study was initiated in February 1996 in a remote sandy beach of The Grande Terre (Kerguelen Archipelago, 69degrees 42' E, 49degrees 19' S) with the objective of determining the long-term effects ... [more ▼]

A field study was initiated in February 1996 in a remote sandy beach of The Grande Terre (Kerguelen Archipelago, 69degrees 42' E, 49degrees 19' S) with the objective of determining the long-term effects of some bioremediation agents on the biodegradation rate and the toxicity of oil residues under severe subantarctic conditions. A series of 10 experimental plots were settled firmly into sediment. Each plot received 2L of Arabian light crude oil and some of them were treated with bioremediation agents: slow release fertilizer Inipol EAP-22 (Elf Atochem) or fish composts. Plots were sampled on a regular basis over a 3-year period. A two-order of magnitude increase of saprophytic and hydrocarbon-utilizing microorganisms occurred during the first month of the experiment in all treated enclosures, but no clear differences appeared between the plots. Very high microbial populations were present during the experiment. Biodegradation within treated spots was faster than within the untreated ones and appeared almost complete after 6 months as indicated by the degradation index of aliphatic hydrocarbons within all plots. The analysis of interstitial water collected below the oily residues presented no toxicity. However, a high toxicity signal, using Microtox solid phase, appeared for all oiled sand samples with a noticeable reduction with time even if the toxicity signal remained present and strong after 311 days of oil exposition. As a conclusion, it is clear that the microbial response was rapid and efficient in spite of the severe weather conditions, and the rate of degradation was improved in presence of bioremediation agents. However, the remaining residues had a relatively high toxicity. [less ▲]

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See detailStrictureplasty in Crohn's disease : Short- and long-term follow-up
Laurent, Stanislas; Detry, Olivier ULg; Detroz, Bernard ULg et al

in Acta Chirurgica Belgica (2002), 102(4, JUL-AUG), 253-255

Strictureplasty for obstructive Crohn's disease is still controversial because lesions are left in place and the suture is performed on a diseased bowel. Many surgeons prefer to perform bowel resection ... [more ▼]

Strictureplasty for obstructive Crohn's disease is still controversial because lesions are left in place and the suture is performed on a diseased bowel. Many surgeons prefer to perform bowel resection, hoping for fewer complications and a lower recurrence rate. In this paper, the authors reports their strictureplasty experience. They performed a systematic retrospective review of the patients suffering from Crohn's disease who underwent strictureplasties during a 10-year period in the abdominal surgery department of the University Hospital of Liege Sart Tilman, and studied the short- and long-term clinical results of 68 strictureplasties performed in 18 patients. Median follow-up was 63 months (range 12 to 144). Mortality was 0% and septic morbidity was 11% (one wound abscess and one leakage). Among the 16 patients available for the latest follow-up, symptomatic stenotic recurrence had to be medically treated in hospital for 4 patients (25%) with a recurrence delay range of 19 to 49 months. Stenosis recurrence needed re-intervention in one patient 48 months after surgery: stenosis occurred at a distance from the corrected site. These results confirmed that strictureplasty is a safe and efficient procedure in selected patients undergoing surgery for obstructive Crohn's disease. [less ▲]

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See detailThe beneficial role of different auxins and polyamines at successive stages of somatic embryo formation and development of Panax ginseng in vitro
Kevers, Claire ULg; Gaspar, Thomas ULg; Dommes, Jacques ULg

in Plant Cell, Tissue & Organ Culture (2002), 70(2), 181-188

The production of viable plantlets via somatic embryogenesis in Panax ginseng requires different culture media corresponding to successive developmental stages. The effects of several auxins and ... [more ▼]

The production of viable plantlets via somatic embryogenesis in Panax ginseng requires different culture media corresponding to successive developmental stages. The effects of several auxins and polyamines have been tested at various steps. Multiplication of the embryogenic root-derived callus has been optimized on half-strength MS medium supplemented with 3-(benzo[b]selenyl)acetic acid (BSAA, a synthetic auxin) and kinetin; exogenously applied polyamines were deleterious at this stage, causing browning of the callus, diminished capacity of embryo initiation, and an increased tendency to hyperhydricity. BSAA again appeared to be the most favourable auxin at the initiation stage, but here its action was reinforced by the presence of polyamines, spermidine being the most efficient. Among the auxin needed at the next step, i.e., for the regeneration of embryos, the two seleniated auxins BSAA and seleniated 2,4-dichlorophenoxyacetic acid (2,4-D-Se) were the more efficient. For the harmonious development of plantlets, i.e., the simultaneous outgrowth of shoots and roots, the polyamines were favourable, with a greater efficiency for spermine. [less ▲]

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See detailPAG profiles in postpartum dairy cows and newborn calves
Ropstad, E; Kalberg, K; Dahl, E et al

in Reproduction in Domestic Animals (2002), 37(4), 249

In ruminants, pregnancy associated glycoproteins (PAG), synthesized in the outer layers of the trophoblast, enter the maternal bloodstream. In this study, blood samples from cows in the postpartum period ... [more ▼]

In ruminants, pregnancy associated glycoproteins (PAG), synthesized in the outer layers of the trophoblast, enter the maternal bloodstream. In this study, blood samples from cows in the postpartum period, pregnant cows and calves were collected to determine 1) the clearance rate of PAG, 2) the accuracy of PAG measurements used for pregnancy diagnosis and 3) PAG concentrations and clearance rate in newborn calves. A curvilinear decline in PAG was found with increasing days from calving. Between day 70–80 pp 3 out of 11 samples (27%) had PAG concentrations > 4 ng/ml plasma. A cut-off value of 4 ng/ml was found to give the best accuracy for pregnancy diagnosis 28–36 days after service (n ¼58: sensitivity¼0.97; specificity ¼1.0). PAG concentrations in newborn calves (n¼10) varied between 78–880 ng/ml, declining with increasing age in a curvilinear pattern to < 1 ng/ml between 20–40 days pp. In two male twin calves PAG concentrations were 880 and 101 ng/ml, respectively, at one day of age. We conclude: 1) 4 ng PAG /ml provides the best cut-off value for pregnancy diagnosis. 2) Cows serviced before 60 days pp can produce false positive pregnancy diagnoses due to PAG originating from the previous pregnancy. 3) High PAG concentrations can be found in newborn calves. [less ▲]

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See detailTrace element and isotope (Sr, Nd) geochemistry of porphyry- and skarn-mineralising Late Cretaceous intrusions from Banat, western South Carpathians, Romania
Dupont, Alain; Vander Auwera, Jacqueline ULg; Pin, Christian et al

in Mineralium Deposita (2002), 37(6-7), 568-586

Geochemical and isotopic (strontium, neodymium) data have been obtained from 24 samples of seven Late Cretaceous intrusions associated with skarn (Tincova, Bocsa, Ocna de Fier - Dognecea) and porphyry ... [more ▼]

Geochemical and isotopic (strontium, neodymium) data have been obtained from 24 samples of seven Late Cretaceous intrusions associated with skarn (Tincova, Bocsa, Ocna de Fier - Dognecea) and porphyry copper-molybdenum/skarn deposits (Oravita, Ciclova, Sasca and Moldova Noua) in the South Carpathians of Romania. The intrusions cut the Supragetic-Getic nappes and form a 100-km-long, NNE-SSW-trending lineament in the Banat metallogenic province. The samples range in composition from gabbro to granodiorite and define, in major and trace element variation diagrams, a calc-alkaline to high-potassium calc-alkaline trend ranging from 50 to 67% SiO2. They are magnetite-bearing, I-type granitoids enriched in LILE/LREE and depleted in Nb, Ta and Zr, common features for magmas associated with subduction zones. The lack of cumulate textures and of positive europium anomalies seems to indicate that the samples represent liquid compositions. The observed trend thus approximates a liquid line of descent resulting from fractional crystallisation of parental magmas with similar major and trace element compositions. Initial strontium isotopic ratios (Sr-i) vary from 0.7042 to 0.7058 and epsilon(Nd(t)) values range from + 3.9 to -0.2. Variations of Sri and epsilon(Nd(t)) values with SiO2 show minor crustal assimilation. The generally positive epsilon(Nd(t)) values, together with moderate Sri, indicate that the parental magmas result from partial melting of a rubidium-enriched and LREE-depleted source, such as a heterogeneous lithospheric mantle or a young mafic lower crust derived from it. Selective rubidium enrichment probably occurred during a previous subduction event by metasomatism of the overlying mantle wedge, either in the Early Cretaceous or earlier, as suggested by T-DM model ages (ca. 600 Ma). The Cu-Mo(-Pb-Zn-Fe) deposits are intimately associated with the intrusions, and the Banat (Romania) region can be subdivided in two metallogenic zones. In northern Banat, Fe-Cu-Pb-Zn skarns occur whereas in southern Banat, porphyry-style copper and molybdenum deposits predominate. These differences result from a combination of several parameters: (1) magma composition, whereby copper- and molybdenum-rich deposits tend to be associated with calc-alkaline compositions; (2) an increase of the present-day erosion level, from south to north, as indicated by the presence of large equigranular plutons in northern Banat, and of porphyritic cupolas and apophyses associated with porphyry-style mineralisation in southern Banat; (3) the nature of the host rocks, with skarns preferentially developed in calcareous host rocks; and (4) local variations of conditions controlling the infiltration of fluids and the precipitation of ore minerals. [less ▲]

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See detailMatrix metalloproteinase-9 deficiency impairs cellular infiltration and bronchial hyperresponsiveness during allergen-induced airway inflammation
Cataldo, Didier ULg; Tournoy, K. G.; Vermaelen, K. et al

in American Journal of Pathology (2002), 161(2), 491-498

We investigated the specific role of matrix metalloproteinase (MMP)-9 in allergic asthma using a murine model of allergen-induced airway inflammation and airway hyperresponsiveness in MMP-9(-/-) mice and ... [more ▼]

We investigated the specific role of matrix metalloproteinase (MMP)-9 in allergic asthma using a murine model of allergen-induced airway inflammation and airway hyperresponsiveness in MMP-9(-/-) mice and their corresponding wild-type (WT) littermates. After a single intraperitoneal sensitization to ovalbumin, the mice were exposed daily either to ovalbumin (1%) or phosphate-buffered saline aerosols from days 14 to 21. Significantly less peribronchial mononuclear cell infiltration of the airways and less lymphocytes in the bronchoalveolar lavage fluid were detected in challenged MMP-9(-/-) as compared to WT mice. In contrast, comparable numbers of bronchoalveolar lavage fluid eosinophils; were observed in both genotypes. After allergen exposure, the WT mice developed a significant airway hyperresponsiveness to carbachol whereas the MMP-9(-/-) mice failed to do so. Allergen exposure induced an increase of MMP-9-related gelatinolytic activity in WT lung extracts. Quantitative reverse transcriptase-polymerase chain reaction showed increased mRNA levels of MMP-12, MMP-14, and urokinase-type plasminogen activator after allergen exposure in the lung extracts of WT mice but not in MMP-9-deficient mice. in contrast, the expression of tissue inhibitor of metalloproteinases-1 was enhanced after allergen exposure in both groups. We conclude that MMP-9 plays a key role in the development of airway inflammation after allergenexposure. [less ▲]

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See detailMolecular basis of cold adaptation
D'Amico, Salvino ULg; Claverie, P.; Collins, T. et al

in Philosophical Transactions of the Royal Society of London Series B-Biological Sciences (2002), 357(1423), 917-924

Cold-adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include ... [more ▼]

Cold-adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include both prokaryotic and eukaryotic organisms and thus represent a significant proportion of the living world. These organisms produce cold-evolved enzymes that are partially able to cope with the reduction in chemical reaction rates induced by low temperatures. As a rule, cold-active enzymes display a high catalytic efficiency, associated however, with a low thermal stability. In most cases, the adaptation to cold is achieved through a reduction in the activation energy that possibly originates from an increased flexibility of either a selected area or of the overall protein structure. This enhanced plasticity seems in turn to be induced by the weak thermal stability of psychrophilic enzymes. The adaptation strategies are beginning to be understood thanks to recent advances in the elucidation of the molecular characteristics of cold-adapted enzymes derived from X-ray crystallography, protein engineering and biophysical methods. Psychrophilic organisms and their enzymes have, in recent years, increasingly attracted the attention of the scientific community due to their peculiar properties that render them particularly useful in investigating the possible relationship existing between stability, flexibility and specific activity and as valuable tools for biotechnological purposes. [less ▲]

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See detailHysteretic behavior in metallic granular matter
Dorbolo, Stéphane ULg; Ausloos, Marcel ULg; Vandewalle, Nicolas ULg

in Applied Physics Letters (2002), 81(5), 936-938

Various packings made of metallic grains have been electrically characterized. Electrical breakdown is observed in I-V curves. A well defined critical point separates the insulating and the conducting ... [more ▼]

Various packings made of metallic grains have been electrically characterized. Electrical breakdown is observed in I-V curves. A well defined critical point separates the insulating and the conducting regime of the packing. The breakdown is reversible by submitting the packing to a small tap. This unusual property leads to hysteretic loops in I-V diagrams. The study of the behavior of I-V curves allows us to describe the system as a network of weak lossy contacts. The key parameter is the inner electrical field controlling the diode-like or diffusion-like state of the packing. (C) 2002 American Institute of Physics. [less ▲]

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See detailNon-linear generalization of principal component analysis: From a global to a local approach
Kerschen, Gaëtan ULg; Golinval, Jean-Claude ULg

in Journal of Sound & Vibration (2002), 254(5), 867-876

Principal component analysis (PCA), also known as proper orthogonal decomposition or Karhunen-Loeve transform, is commonly used to reduce the dimensionality of a data set with a large number of ... [more ▼]

Principal component analysis (PCA), also known as proper orthogonal decomposition or Karhunen-Loeve transform, is commonly used to reduce the dimensionality of a data set with a large number of interdependent variables. PCA is the optimal linear transformation with respect to minimizing the mean square reconstruction error but it only considers second-order statistics. If the data have non-linear dependencies, an important issue is to develop a technique which takes higher order statistics into account and which can eliminate dependencies not removed by PCA. Recognizing the shortcomings of PCA, researchers in the field of statistics and neural networks have developed non-linear extensions of PCA. The purpose of this paper is to present a non-linear generalization of PCA, called VQPCA. This algorithm builds local linear models by combining PCA with clustering of the input space. This paper concludes by observing from two illustrative examples that VQPCA is potentially a more effective tool than conventional PCA. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailAnnual nitrogen budget of the seagrass Posidonia oceanica as determined by in situ uptake experiments
Lepoint, Gilles ULg; Millet, S.; Dauby, Patrick ULg et al

in Marine Ecology. Progress Series (2002), 237

The uptake of nitrate and ammonium by the roots and leaves of Posidonia oceanica were determined between February 1993 and June 1999 by in situ experiments using the isotope 15 of nitrogen (N-15) as a ... [more ▼]

The uptake of nitrate and ammonium by the roots and leaves of Posidonia oceanica were determined between February 1993 and June 1999 by in situ experiments using the isotope 15 of nitrogen (N-15) as a tracer in a nutrient-poor coastal zone of the NW Mediterranean Sea (Revellata Bay, Corsica). Nitrate and ammonium leaf uptakes are recorded at 0.05 and 0.1 muM respectively. The high variability observed cannot be explained solely by the variation of the substrate concentrations in the water column. For leaves, mean specific uptake rates were 43 +/- 45 and 43 +/- 64 mug N g N-1 h(-1). Nitrate and ammonium leaf uptake fluxes (g N m(-2) yr(-1)) seem to have the same importance on an annual basis. :Nitrate uptake occurs mainly in winter and early spring, when nitrate concentrations in the water column are highest. The uptake of N, and mainly of ammonium, is significant throughout the year with maxima at the beginning of spring, but it is insufficient to meet the annual N requirement of the plant. Posidonia root biomass was very high and corresponded to high specific N uptake rates by the roots. Ammonium was incorporated by the roots 6 times faster than nitrate. In the sediment, this uptake capacity is limited by the nutrient diffusion rate, and the root uptake is therefore insufficient to meet the N requirements of the plant. In fact, P. oceanica of Revellata Bay have a complex N budget involving uptake and recycling processes and allowing the plants to meet their N requirements in one of the most nutrient-poor areas of the NW Mediterranean Sea. We calculated that leaf and root would contribute to 40 and 60% of the annual N uptake, respectively, and 60% of the annual N requirement of the plant. [less ▲]

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See detailNoradrenergic control of auditory information processing in female canaries
Appeltants, D.; Del Negro, C.; Balthazart, Jacques ULg

in Behavioural Brain Research (2002), 133(2), 221-235

An ethological procedure, based on the study of the sexual responsiveness of female canaries (Serinus canaria) to song playbacks was used to investigate the function of central noradrenergic inputs in the ... [more ▼]

An ethological procedure, based on the study of the sexual responsiveness of female canaries (Serinus canaria) to song playbacks was used to investigate the function of central noradrenergic inputs in the processing of auditory information. The effects of a noradrenergic denervation on sexual responses was analyzed in females exposed to playbacks of biological relevant auditory stimuli, i.e. sexually stimulating songs, presented alone or masked by auditory distractors. A decrease in behavioral responsiveness was observed as a function of the amount of masking distractors indicating that female canaries have the perceptual ability to discriminate and selectively attend to biologically relevant songs. After the systemic administration of DSP-4, a specific noradrenergic neurotoxin, females exhibited an overall decrease in sexual responsiveness to songs masked or not by distractors. No effect of DSP-4 were detected on the motor activity nor on reproductive behaviors. These results indicate that central noradrenergic inputs modulate the sexual behavior of female canaries by affecting the auditory processing of relevant information contained in sexually stimulating songs. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailControlled synthesis and chemical modification of unsaturated aliphatic (co)polyesters based on 6,7-dihydro-2(3H)-oxepinone
Lou, Xudong; Detrembleur, Christophe ULg; Lecomte, Philippe ULg et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2002), 40(14), 2286-2297

A pure unsaturated cyclic ester, 6,7-dihydro-2(3H)-oxepinone (DHO2), was prepared by a new synthetic route. The copolymerization of DHO2 with epsilon-caprolactone (CL) was initiated by aluminum ... [more ▼]

A pure unsaturated cyclic ester, 6,7-dihydro-2(3H)-oxepinone (DHO2), was prepared by a new synthetic route. The copolymerization of DHO2 with epsilon-caprolactone (CL) was initiated by aluminum isopropoxide [Al(OiPr)3] at 0 °C as an easy way to produce unsaturated aliphatic polyesters with nonconjugated CC double bonds in a controlled manner. The chain growth was living, as certified by the agreement between the experimental molecular weight at total monomer conversion and the value predicted from the initial monomer/initiator molar ratio. The polydispersity was reasonably low (weight-average molecular weight/number-average molecular weight 1.2). The homopolymerization of DHO2 was, however, not controlled because of fast intramolecular transesterification. Copolymers of DHO2 and CL were quantitatively oxidized with the formation of epoxides containing chains. The extent of the epoxidation allowed the thermal properties and thermal stability of the copolyesters to be modulated. The epoxidized copolyesters were successfully converted into thioaminated chains, which were then quaternized into polycations. No degradation occurred during the chemical modification. [less ▲]

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See detailStratospheric HF column abundances above Kitt Peak (31.9 degrees N latitude): trends from 1977 to 2001 and correlations with stratospheric HCl columns
Rinsland, Curtis P.; Zander, Rodolphe ULg; Mahieu, Emmanuel ULg et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2002), 74(2), 205-216

Time series of stratospheric hydrogen fluoride (HF) column abundances have been derived from infrared solar absorption spectra recorded for 195 days between May 1977 and June 2001 at a spectral resolution ... [more ▼]

Time series of stratospheric hydrogen fluoride (HF) column abundances have been derived from infrared solar absorption spectra recorded for 195 days between May 1977 and June 2001 at a spectral resolution of typically 0.01 cm(-1). The measurements were made at the US National Solar Observatory facility on Kitt Peak, Arizona, USA (31.9degreesN, 111.6degreesW, 2.09 km altitude) and have been analyzed with the SFIT2 algorithm, which is based on a semi-empirical application of the optimal estimation method. The measurements show a continuous buildup of the stratospheric HF column over the 24-yr period superimposed on short-term variations and a seasonal cycle with spring maxima and autumn minima. The measured stratospheric HF columns increased by a factor of 4.7, from 2.03 x 10(14) molecule cm(-2) in May 1977 to 9.49 x 10(14) molecule cm(-2) in June 2001. A best fit with a model that assumes an exponential increase in the stratospheric HF column with time superimposed on a sinusoidal seasonal cycle yields an average rate of stratospheric HF column increase of (4.30 +/- 0.15% yr(-1)), 1 sigma. The rate of increase is nearly a factor of two less than that derived previously from 1977 to 1990 Kitt Peak total columns, which indicates a significant slowdown in the increase rate during the 1990s, consistent with the trends from recent near-global lower mesospheric satellite remote and surface in situ measurements. Day-to-day stratospheric HIT columns are highly correlated with the same day stratospheric HCl columns as a result of common transport of lower and higher latitude air to above the station. Extrapolation of the linear relation between the two sets of stratospheric columns indicates a background HCl column of 1 x 10(15) molecule cm(-2) for zero HF, consistent with a previous estimate from 1977 to 1990 HF and HCl Kitt Peak total column measurements and a 1973 HCl measurement above the station. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailPattern recognition with a digital holographic microscope working in partially coherent illumination
Dubois, Frank; Minetti, Christophe; Monnom, Olivier et al

in Applied Optics (2002), 41(20), 4108-4119

We describe the implementation of the automatic spatial-frequency-selection filter for recognition of patterns obtained with a digital holographic microscope working with a partially coherent source. The ... [more ▼]

We describe the implementation of the automatic spatial-frequency-selection filter for recognition of patterns obtained with a digital holographic microscope working with a partially coherent source. The microscope provides the complex-optical-amplitude field that allows a refocusing plane-by-plane of the sample under investigation by numerical computation of the optical propagation. By inserting a correlation filter in the propagation equation, the correlation between the filter and the propagated optical field is obtained. In this way, the pattern is located in the direction of the optical axis. Owing to the very weak noise level generated by the partially coherent source, the correlation process is shift invariant. Therefore the samples can be located in the three dimensions. To have a robust recognition process, a generalized version of the automatic spatial-frequency-selection filters has been implemented. The method is experimentally demonstrated in a two-class problem for the recognition of protein crystals. (C) 2002 Optical Society of America. [less ▲]

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See detailCumulative reaction probability by constrained dynamics: H transfer in HCN, H2CO, and H3CO
Baloitcha, Ezinvi; Lasorne, Benjamin; Lauvergnat, David et al

in Journal of Chemical Physics (2002), 117(2), 727-739

A strategy to obtain quantum corrections to the cumulative reaction probability from a subspace of active coordinates is analyzed. The kinetic energy operator exactly takes into account the constraints ... [more ▼]

A strategy to obtain quantum corrections to the cumulative reaction probability from a subspace of active coordinates is analyzed. The kinetic energy operator exactly takes into account the constraints due to inactive coordinates. The geometry of the inactive skeleton is adiabatically adjusted to the dynamical variables or simply frozen according to the coupling to the active space. Dynamics is carried out using the curvilinear coordinates of the Z-matrix so that computation of the potential energy surface and dynamics are coupled. The cumulative reaction probability N(E) is obtained directly in a large range of energy by a time independent formulation of the Zhang and Light transition state wave packet method. N-nD(E) is first computed in the active n-dimensional space and then convoluted with a bath. The efficiency of the Chebyshev expansion of the microcanonical projection operator delta(E-(H) over cap (nD)) appearing in the quantum expression of N-nD(E) is checked. The method is implemented for the study of tunneling effect in H transfer. The coordinates are three spherical coordinates referred to the frozen or adiabatic skeleton. We compare the quantum corrections brought about by different 2D groups of internal coordinates. (C) 2002 American Institute of Physics. [less ▲]

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See detailDifferential production of cytokines and activation of NF-kappa B in HPV-transformed keratinocytes
Havard, L.; Delvenne, Philippe ULg; Frare, P. et al

in Virology (2002), 298(2), 271-285

We have proposed that chronic infection of keratinocytes by HPV modifies the expression of potentially important cytokines by interfering with the NF-kappaB signal pathway We evaluated the constitutive ... [more ▼]

We have proposed that chronic infection of keratinocytes by HPV modifies the expression of potentially important cytokines by interfering with the NF-kappaB signal pathway We evaluated the constitutive and IL-1beta-induced expression of GM-CSF and TNF-alpha and the expression/activity of NF-kappaB in HPV+ and HPV- cell lines. Despite the enhanced expression of the functional components of the NF-kappaB signaling pathway in HPV+ cell lines by a mechanism implicating the HPV oncoprotein E6, the constitutive activity of NF-kappaB and the expression of GM-CSF/TNF-alpha were significantly reduced relative to the HPV- cell line and normal keratinocytes. In contrast, we observed a superactivation of NF-kappaB activity after IL-1beta stimulation, a strong and transient induction of GM-CSF/TNF-alpha mRNA, but undetectable levels of secreted proteins in HPV+ cell lines. Our data demonstrate that E6 modulates the NF-kappaB signaling pathway and suggest that other HPV proteins also interfere with GM-CSF/TNF-alpha expression by transcriptional and/or posttranscriptional mechanisms. (C) 2002 Elsevier Science (USA). [less ▲]

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See detailSubstrate-activated zinc binding of metallo-beta-lactamases - Physiological importance of the mononuclear enzymes
Wommer, S.; Rival, S.; Heinz, U. et al

in Journal of Biological Chemistry (2002), 277(27), 24142-24147

We have investigated the influence of substrate binding on the zinc ion affinity of representatives from the three metallo-g-lactamase subclasses, B1 (BcII from Bacillus cereus and BlaB from ... [more ▼]

We have investigated the influence of substrate binding on the zinc ion affinity of representatives from the three metallo-g-lactamase subclasses, B1 (BcII from Bacillus cereus and BlaB from Chryseobacterium meningosepticum), B2 (CphA from Aeromonas hydrophila), and B3 (L1 from Stenotrophomonas maltophilia). By competition experiments with metal-free apoenzymes and chromophoric zinc chelators or EDTA, we determined the dissociation constants in the absence and presence of substrates. For the formation of the monozine enzymes we determined constants of 1.8, 5.1, 0.007, and 2.6 nm in the absence and 13.6, 1.8, 1.2, and 5.7 pm in the presence of substrates for Bell, BlaB, CphA, and L1, respectively. A second zinc ion binds in the absence (presence) of substrates with considerably higher dissociation constants, namely 1.8 (0.8), 0.007 (0.025), 50 (1.9), and 0.006 (0.12) mum for BcII, BlaB, CphA, and L1, respectively. We have concluded that the apo form might be the prevailing state of most of the metallo-beta-lactamases under physiological conditions in the absence of substrates. Substrate availability induces a spontaneous self-activation due to a drastic decrease of the dissociation constants, resulting in the formation of active mononuclear enzymes already at picomolar free zinc ion concentrations. In the presence of substrates, the binuclear state of the enzymes only exists at unphysiologic high zinc concentrations and might be of no biological relevance. From the competition experiments with EDTA it is further concluded that the reactivation rate does not depend on the pool of free zinc ions but proceeds via the EDTA-Zn(II)-enzyme ternary complexes. [less ▲]

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See detailBulletin agrométéorologique - Juin 2002
Tychon, Bernard ULg; Ozer, Pierre ULg; Eerens, H. et al

in Bulletin Agrométéorologique (2002)

Le mois de juin a été caractérisé par des précipitations généralement normales à déficitaires dans l’Est et le Sud du pays. Les températures furent supérieures à la moyenne. Les autres paramètres ... [more ▼]

Le mois de juin a été caractérisé par des précipitations généralement normales à déficitaires dans l’Est et le Sud du pays. Les températures furent supérieures à la moyenne. Les autres paramètres météorologiques étaient proches de la normale. Par rapport au bulletin précédent (mai 2002), les prévisions de rendement n’ont pas changé. La situation des cultures est globalement favorable, avec des rendements qui s’annoncent supérieurs à ceux de 2001 à la possible exception du colza et du maïs fourrager. [less ▲]

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See detailProton aurora in the cusp
Frey, H. U.; Mende, S. B.; Immel, T. J. et al

in Journal of Geophysical Research. Space Physics (2002), 107

Frequently, the Far Ultraviolet Instrument (FUV) on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft observes intense ultraviolet emission from a localized dayside region ... [more ▼]

Frequently, the Far Ultraviolet Instrument (FUV) on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft observes intense ultraviolet emission from a localized dayside region poleward of the general auroral oval location. This emission is especially distinct in the Doppler-shifted emission of hydrogen atoms produced by precipitating protons. We interpret this as a direct signature of proton precipitation into the cusp after reconnection of magnetospheric lobe field lines. This cusp signature appears only when the interplanetary magnetic field (IMF) has a positive northward B[SUB]z[/SUB] component. However, the intensity of the precipitation, and hence the intensity of UV emission, is not controlled by the magnitude of B[SUB]z[/SUB] but rather by the solar wind dynamic pressure. A statistical analysis of 18 cases observed in summer and fall 2000 shows good correlation between the UV intensity and the dynamic pressure and between the location in local time and the IMF B[SUB]y[/SUB] component. A quantitative analysis of observations from all three FUV subinstruments allows for an estimate of proton and electron energy fluxes during these times. In general, these estimates agree with results from in situ measurements by spacecraft and show that during these times, protons may contribute significantly to the overall energy deposition into the cusp. [less ▲]

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See detailTransient modifications of respiratory capacity in thymic cells during murine radioleukemogenesis
Verlaet, Myriam ULg; Duyckaerts, Claire ULg; Rahmouni, Souad ULg et al

in Free Radical Biology & Medicine (2002), 33(1), 76-82

The evolution of mitochondrial oxidative phosphorylation was studied during cancer induction in a model of thymic radiolymphomagenesis in C57BL/Ka mice. During the preneoplastic period, thymuses displayed ... [more ▼]

The evolution of mitochondrial oxidative phosphorylation was studied during cancer induction in a model of thymic radiolymphomagenesis in C57BL/Ka mice. During the preneoplastic period, thymuses displayed an increase of the cytochrome c oxidase activity and oxygen consumption together with oxidative DNA damage assessed by the presence of the 8-hydroxydeoxyguanine DNA base modification. These transient changes in mitochondrial functional activity were not observed in thymuses of mice rescued from lymphoma development by a bone marrow graft, suggesting an important role of mitochondria for neoplastic transformation in this model. which might therefore be of interest to test the utilization of antioxidants for the prevention of radiation-induced malignancies. (C) 2002 Elsevier Science Inc. [less ▲]

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See detailSources of Labrador Sea sediments since the last glacial maximum inferred from Nd-Pb isotopes
Fagel, Nathalie ULg; Innocent, Christophe; Gariepy, Clément et al

in Geochimica et Cosmochimica Acta (2002), 66(14), 2569-2581

Pb isotopes have been measured in the clay-size fraction of Late Glacial and Holocene deep-sea sediments recovered from two Labrador Sea piston cores that have been previously analyzed for Nd isotopes ... [more ▼]

Pb isotopes have been measured in the clay-size fraction of Late Glacial and Holocene deep-sea sediments recovered from two Labrador Sea piston cores that have been previously analyzed for Nd isotopes. The newly acquired Pb isotopic data allow us to better constrain the different source areas that supplied clay-size material during the last deglaciation, until 8.6 kyr (calendar ages). Nd-Pb data can be modeled mainly as a mixture between a Precambrian crust and Lower Palcozoic material originating from the denudation of the pan-African orogen. The old material originates mainly from the Archean, Lower Proterozoic, or both terranes of Greenland (and also probably corresponding terranes of Labrador), although minor input of other Precambrian material is recorded in some detrital carbonate-rich deglacial samples from Orphan Knoll. The Phanerozoic crustal end member consists of sediment material mainly originating from northwestern Europe. This source area is found to be the only significant source of young crustal material in early Holocene sediments from the Greenland Rise. No significant input from the mid-Atlantic volcanism is apparent. This study puts further constraints on the deep circulation pattern during the last deglaciation. It is concluded that at that time, European Phanerozoic material was carried from the Norwegian Sea through the Wyville Thompson Ridge into the Iceland Basin by the North East Atlantic Deep Water. No evidence for an overflow is found either south of the Iceland (Iceland-Scotland Ridge) or through the Denmark Strait. Copyright (C) 2002 Elsevier Science Inc. [less ▲]

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See detailParticularities of the bucco-pharyngeal apparatus in Zenarchopterus kampeni (Pisces : Hemiramphidae) and their probable significance in feeding
Vandewalle, Pierre ULg; Lambert, Vincianne; Parmentier, Eric ULg

in Belgian Journal of Zoology (2002), 132(2), 125-132

The present study shows several new anatomical particularities of the buccal and pharyngeal parts of the halfbeak Zenarchopterus kampeni. The upper buccal jaw consists of premaxillaries and maxillaries ... [more ▼]

The present study shows several new anatomical particularities of the buccal and pharyngeal parts of the halfbeak Zenarchopterus kampeni. The upper buccal jaw consists of premaxillaries and maxillaries tightly joined by ligaments. A 10degrees lowering of the mandible leads to a 30degrees elevation of the upper jaw. The adductor mandibulae is reduced to bundles A(2) and Aomega. As in the Labridae, the lower pharyngeal jaw articulates with the scapular girdle. The upper pharyngeal jaw consists of distinct second pharyngobranchials followed by the third pharyngobranchials fused into a powerful posterior component. This part fits into and slides along a longitudinal ventral gutter of the neuroranium, thanks not only to the dorsal retractor muscles but also to specific retractors of the second pharyngobranchials. The power and dentition of the pharyngeal parts contrasts with the fragility of the buccal elements. [less ▲]

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See detailApoptosis of HL-60 leukemia cells induced by the bisindole alkaloids sungucine and isosungucine from Strychnos icaja
Lansiaux, A.; Bailly, Christian; Houssier, Claude ULg et al

in Planta Medica (2002), 68(7), 591-595

Sungucine and isosungucine are two bisindole alkaloids isolated from the roots of the African plant Strychnos icaja Baillon. They both exhibit antiplasmodial activities but also show cytotoxic effects ... [more ▼]

Sungucine and isosungucine are two bisindole alkaloids isolated from the roots of the African plant Strychnos icaja Baillon. They both exhibit antiplasmodial activities but also show cytotoxic effects against human cancer cell lines. In order to elucidate their mechanism of action, we have investigated the interaction of the alkaloids with DNA and their capacity to inhibit nucleic acids and protein synthesis in the human HL-60 promyelocytic leukemia cell line. Cell treatment with both sungucine and isosungucine leads to the appearance of a hypo-diploid DNA content peak. Western blotting analysis reveals that the two alkaloids induce cleavage of the poly(ADP-ribose) polymerase (PARP) and promote the cleavage of a caspase-3 DEVD peptide substrate. The activation of the caspase cascade is accompanied with a fragmentation of DNA in cells, as revealed by the TUNEL assay. Altogether, the results shed light on the mechanism of action of these two plant alkaloids and identify signaling factors involved in (iso)sungucine-induced apoptosis in HL-60 cells. [less ▲]

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See detailCentral cord syndrome - Response
Martin, Didier ULg

in Journal of Neurosurgery (2002), 97(1, Suppl. S), 159-159

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See detailVers une agrégation en sciences : images d'une collaboration
Hindryckx, Marie-Noëlle ULg; Collignon, Viviane ULg; Cornélis, André ULg

in Puzzle (2002), 12

Bilan d'une collaboration entre les didacticiens des sciences physiques, biologiques et chimiques dans le cadre de la réforme de l'agrégation de l'enseignement secondaire supérieur. Deux expériences de ... [more ▼]

Bilan d'une collaboration entre les didacticiens des sciences physiques, biologiques et chimiques dans le cadre de la réforme de l'agrégation de l'enseignement secondaire supérieur. Deux expériences de formation sont racontées et analysées : représentations et démarche expérimentale sur les fruits et légumes en biologie et sur le fonctionnement d'une pile en chimie [less ▲]

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See detailVila Maria Formation (Silurian, Parana Basin, Brazil): integrated radiometric and palynological age determinations
Mizusaki, A. M. P.; Melo, J. H. G.; Vignol-Lelarge, M. L. et al

in Geological Magazine (2002), 139(4), 453-463

Fresh shale samples taken from a well-known outcrop section of the Silurian Vila Maria Formation, located on the northeastern margin of the Parana Basin (Tres Barras Farm, Goias State, central-western ... [more ▼]

Fresh shale samples taken from a well-known outcrop section of the Silurian Vila Maria Formation, located on the northeastern margin of the Parana Basin (Tres Barras Farm, Goias State, central-western Brazil), have been analysed for both palynological and radiometric age determinations. The rocks yielded a fairly diverse, age-definitive cryptospore assemblage, and the same samples proved suitable for Rb-Sr analysis, despite Silurian sedimentary rocks being rarely suited to radiometric dating techniques. This study thus introduces an alternative, independent method for estimating the minimum depositional age of the Vila Maria Formation. The Rb-Sr age value has been calculated via an isochron diagram that yields 435.9 +/- 7.8 Ma. Accordingly, the latter value is interpreted as the minimum depositional age of the analysed Vila Maria strata, implying their deposition during Llandovery times. This concurs with the palynological results, which indicate an age no older than Early Silurian and, more particularly, favour an Early to Middle Llandovery (Rhuddanian-Early Aeronian) attribution. [less ▲]

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See detailL'architecture Art nouveau à Liège
Charlier, Sébastien ULg

in Nouvelles du Patrimoine (Les) (2002), 97

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See detailA positive response to infliximab in Crohn disease: Association with a higher systemic inflammation before treatment but not with-308 TNF gene polymorphism
Louis, Edouard ULg; Vermeire, S.; Rutgeerts, P. et al

in Scandinavian Journal of Gastroenterology (2002), 37(7), 818-824

Background: Two-thirds to three-fourths of patients with either refractory luminal or fistulizing Crohn disease respond to infliximab treatment. The ability or inability to respond seems to persist over ... [more ▼]

Background: Two-thirds to three-fourths of patients with either refractory luminal or fistulizing Crohn disease respond to infliximab treatment. The ability or inability to respond seems to persist over time. Biological characteristics and/or genetic background can influence the response to treatment. The aim was to assess the value of C-reactive protein and TNF-alpha serum levels before treatment as well as the TNF -308 gene polymorphism in the prediction of response to infliximab treatment in Crohn disease. Methods: Two-hundred-and-twenty-six Crohn disease patients treated in the setting of an expanded access programme to infliximab in Belgium were studied. There were 136 refractory luminal diseases and 90 refractory fistulizing diseases. Luminal diseases were treated with one single infusion; fistulizing diseases with three infusions at weeks 0, 2 and 6. A clinical response to treatment was defined as either a Crohn disease activity index <150 (complete) or a drop of 70 points (partial) at week 4, for luminal disease, and as either complete fistula healing (complete) or a decrease of at least 50% of the number of draining fistulas on two consecutive visits between weeks 0 and 18, for fistulizing disease. CRP and serum TNF-α levels were measured at week 0 before treatment and were compared between responders and non- responders. Patients were genotyped for the -308 TNF gene polymorphism, and allelic as well as genotype frequencies were compared between responders and non- responders. Results: There were 73.2% responders (46.4% complete and 26.8% partial) and 26.8% non- responders. Response rates were similar in luminal and fistulizing diseases. CRP level before treatment was significantly higher in responders than in non-responders (16.8 mg/l (5-160) versus 9.6 mg/l (5-143); P = 0.02). Furthermore, response rate was significantly higher in patients with elevated CRP (> 5 mg/l) than in patients with a normal CRP value (< 5 mg/l) before treatment (76% versus 46%; P = 0.004; OR: 0.26 (0.11-0.63)). Allelic and genotype frequencies for -308 TNF gene polymorphis m were not significantly different between responders and non- responders - with the exception of a slightly higher TNF2 frequency in nonresponders in luminal disease (22.1% versus 11.6%; P = 0.04). However, this was not associated with a significant difference in genotype frequencies. Conclusion: A positive clinical response to infliximab was associated with a higher CRP level before treatment in our population of Crohn disease patients, but there was no relevant association with -308 TNF gene polymorphism. We therefore suggest that CRP level may help to identify better candidates for infliximab treatment. [less ▲]

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See detailRemplacement valvulaire mitral par homogreffe
RADERMECKER, Marc ULg; Canivet, J. L.; Tambwe, W. et al

in Revue Médicale de Liège (2002), 57(7), 459-62

The total homograft replacement of the left AV valve and subvalvular apparatus constitutes a delicate operation, which may prove beneficial in young patients with extensive bacterial endocarditis. The ... [more ▼]

The total homograft replacement of the left AV valve and subvalvular apparatus constitutes a delicate operation, which may prove beneficial in young patients with extensive bacterial endocarditis. The case of a staphylococcal endocarditis in a young drug addicted patient, operated three years previously of mitral valve repair for the same pathology, is presented. In addition to the complete excision of infected tissues and valvular substitution with biological material, this technique has the advantage of avoiding long term anticoagulation. The history, technical key points, and current indications of mitral homograft in the surgery of the left atrio-ventricular valves are reviewed. [less ▲]

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See detailExperimental study of cracking induced by desiccation in 1-dimensional systems
Lecocq, N.; Vandewalle, Nicolas ULg

in European Physical Journal E -- Soft Matter (2002), 8(4), 445-452

We designed a simple experiment to study both the dynamical and statistical properties of cracking that occurs in a one-dimensional system composed of wet clay (or similar material) exposed to shrinkage ... [more ▼]

We designed a simple experiment to study both the dynamical and statistical properties of cracking that occurs in a one-dimensional system composed of wet clay (or similar material) exposed to shrinkage induced by desiccation. We study both the dynamical formation of cracks and the statistical characteristics of the final cracks pattern. We observe that the drying rate has a strong influence on the way cracks appear and grow. We find that the final crack width is related to the order of apparition of the cracks. We discuss the statistical distributions of cracks width and separation between two adjacent cracks. We also study the correlations between these two quantities. Our results are compared to the predictions of existing models. Finally, a comparison with another kind of clay is made. [less ▲]

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See detailComparison of sampling procedures for isolating pulmonary mycoplasmas in cattle
Thomas, Anne; Dizier, Isabelle ULg; Trolin, A. et al

in Veterinary Research Communications (2002), 26(5), 333-339

Three sampling procedures were compared to determine the optimal technique for isolating mycoplasmas in cattle with respiratory diseases. The prevalence of mycoplasmas isolated from these animals is also ... [more ▼]

Three sampling procedures were compared to determine the optimal technique for isolating mycoplasmas in cattle with respiratory diseases. The prevalence of mycoplasmas isolated from these animals is also reported. In the first group, bronchoalveolar lavage (BAL) and nasal swab cultures were compared with the corresponding lung cultures from cattle necropsied for fatal respiratory diseases (n = 20). In a second group, nasal swabs were compared with corresponding BAL cultures in living animals with recurrent respiratory pathologies (n = 49). There was complete agreement between the paired BAL and lung cultures. In contrast, nasal cultures were not representative of the mycoplasmas present in the lower respiratory airways. The relative sensitivity and specificity of the nasal swab technique compared to BAL in living animals confirmed that the nasal swab cultures were not predictive of lower respiratory airway pathogens, such as Mycoplasma bovis. BAL is considered to be the best method for isolating M. bovis in cattle with respiratory diseases as it combines reliability and feasibility under field sampling conditions. In the present study, Mycoplasma dispar (43%) and M. bovis (29%) were mainly isolated in mixed infections. This confirms the need to search for mycoplasmas in routine examinations and to take them into account in therapeutic strategies for respiratory diseases in cattle. [less ▲]

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See detailLevels and congener distributions of PCDDs, PCDFs and non-ortho PCBs in Belgian foodstuffs - Assessment of dietary intake
Focant, Jean-François ULg; Eppe, Gauthier ULg; PIRARD, Catherine ULg et al

in Chemosphere (2002), 48(2), 167-179

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 197 ... [more ▼]

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 197 foodstuffs samples of animal origin from Belgium during years 2000 and 2001. All investigated matrices (except horse) present background levels lower than the Belgian non-commercialization value of 5 pg TEQ/g fat. Pork was the meat containing the lowest concentration of both PCDD/Fs and cPCBs. The mean background concentration of 2,3,7,8-TCDD toxicity equivalent in milk was 1.1 pg/g of fat, with a congener distribution typical of non-contaminated milk. The relative contribution of 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF to the PCDD/Fs TEQ was 85 +/- 7.9% for all investigated matrices. The cPCBs contribution to the total TEQ was 47 +/- 19.0% for products of terrestrial species and 69 +/- 20.0% for aquatic species. Once the contribution of cPCBs was added to the TEQ, few foodstuffs such as horse, sheep, beef, eggs and cheese presented levels above the future European guidelines that currently only include PCDD/Fs but will be re-evaluated later in order to include 'dioxin-like' PCBs. Based on levels measured in the samples, the estimation of the dietary intake was 65.3 pg WHO-TEQ/day for PCDD/Fs only (1.00 pg WHO-TEQ/kg bw/day, for a 65 kg person) and 132.9 pg WHO-TEQ/day if cPCBs were included (2.04 pg WHO-TEQ/kg bw/day, for a 65 kg person). Meat (mainly beef), dairy products, and fish each account for roughly one third of the intake. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailColloque "Ecrire Ferney"
Tilkin, Françoise ULg

in Bulletin de la Société Voltaire (2002), 3

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See detailRevascularisation arterielle et transfert de lambeau libre pour le sauvetage des membres ischemiques avec perte de tissus mous: une alternative a l'amputation
Heymans, O.; LEMAIRE, Vincent ULg; Nelissen, Xavier ULg et al

in Revue Médicale de Liège (2002), 57(7), 453-4455-8

Severe limb ischemia is a common problem encountered in medical practice. Aggressive attempts at revascularization have extended the limits of limb salvage. However, in certain cases, extended tissue loss ... [more ▼]

Severe limb ischemia is a common problem encountered in medical practice. Aggressive attempts at revascularization have extended the limits of limb salvage. However, in certain cases, extended tissue loss compromises the healing process. It often results in amputation despite bypass graft patency. Microvascular free tissue transfer combined with arterial revascularization allows healing of these wounds and limb preservation. This combined approach is the ultimate alternative to amputation. [less ▲]

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See detailComment je traite.... Le cancer avance du pancreas par une approche innovante dirigee contre les nouvelles cibles
Polus, Marc ULg; Bours, Vincent ULg; Jerusalem, Guy ULg et al

in Revue Médicale de Liège (2002), 57(7), 428-32

A better knowledge of fundamental mechanisms of carcinogenesis allows the development of novel therapeutic tools specifically targeting the cancer cell. Our understanding of cellular and molecular ... [more ▼]

A better knowledge of fundamental mechanisms of carcinogenesis allows the development of novel therapeutic tools specifically targeting the cancer cell. Our understanding of cellular and molecular mechanisms controlling cellular cycle and cell survival is an important step for new anti-cancer treatments. This review will focus on new therapeutic's strategies in advanced pancreatic cancer. [less ▲]

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See detailBlood flow variation in human muscle during electrically stimulated exercise bouts
Vanderthommen, Marc ULg; Depresseux, J. C.; Dauchat, L. et al

in Archives of Physical Medicine & Rehabilitation (2002), 83(7), 936-941

OBJECTIVES: To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the ... [more ▼]

OBJECTIVES: To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the mechanisms of muscle spatial recruitment during NMES. DESIGN: One thigh was submitted to 3 stimulation bouts of different durations (S1=4min, S2=8min, S3=12min) with a workload corresponding to 10% of quadriceps maximal isometric voluntary torque. SETTING: A cyclotron research center at a Belgian university. PARTICIPANTS: Ten healthy male volunteers. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were studied with positron emission tomography and H(2)(15)O. Tissue blood flow was evaluated during the last 4 minutes of each stimulation bout in multiple regions of interest (ROIs) selected in the transverse section of the stimulated thigh. RESULTS: Mean tissue blood flow was significantly lower during S1 (5.9+/-1.3mL. min(-1). 100g(-1)) than during S2 (10.6+/-3.4mL. min(-1). 100g(-1)) and S3 (11.6+/-3.7mL. min(-1). 100g(-1)) (P<.05). For each ROI, an arbitrary tissue blood flow activation level of 5mLmin(-1)100g(-1) was fixed. The mean percentage of activated ROIs reached 42.4%, 62.7%, and 63.6% during S1, S2, and S3, respectively. Between S1 and S3, the newly recruited ROIs were preferentially located far from the electrode. CONCLUSION: During NMES, new muscular regions situated far from the stimulation site are recruited. These recruitment mechanisms are particular and contrast with the recruitment of motor units seen during voluntary contraction. [less ▲]

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See detailExperimental and theoretical studies of DyIII: radiative lifetimes and oscillator strengths of astrophysical interest
Zhang, Z. G.; Svanberg, S.; Palmeri, P. et al

in Monthly Notices of the Royal Astronomical Society (2002), 334(1), 1-10

The lifetimes of three short-lived levels belonging to the 4f(9) 6p configuration and of two long-lived levels of the 4f(9) 5d configuration of Dy iii have been measured for the first time using time ... [more ▼]

The lifetimes of three short-lived levels belonging to the 4f(9) 6p configuration and of two long-lived levels of the 4f(9) 5d configuration of Dy iii have been measured for the first time using time-resolved laser-induced fluorescence techniques. They are in good agreement with theoretical values calculated within the framework of a pseudo-relativistic configuration interaction approximation. Using the experimental lifetimes and the theoretical branching fractions, a first set of transition probabilities of astrophysical interest has been obtained for Dy III. [less ▲]

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See detailLes interférences entre le divorce et les pensions de retraite et de survie: le point de la question
Michiels, Olivier ULg

in Divorce : Actualité Juridique, Sociale et Fiscale (2002), 7

L'article examine les conséquences du divorce sur le droit à la pension de retraite et à la pension de survie.

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See detailUse of municipal solid waste incineration residues in the precasting of concrete paving
Courard, Luc ULg; Degeimbre, Robert ULg; Darimont, Anne ULg et al

in Materials and Structures (2002), 35(250), 365-372

Valorisation of Municipal Solid Waste Incineration Residues - excluding ashes - is a positive advance in sustainable development: saving natural resources, decrease in wastes volume stored, reduction of ... [more ▼]

Valorisation of Municipal Solid Waste Incineration Residues - excluding ashes - is a positive advance in sustainable development: saving natural resources, decrease in wastes volume stored, reduction of energy consumption. If good conditions of incineration can be ensured and post-combustion treatments are realised, solid residues are in the form of granular materials usable in construction and civil engineering. Uses in road structures are classical; application for the precasting of paving is quite new and interesting due to the quantity of recycled materials. Mechanical and physical performances of municipal solid waste incineration residues let us to replace a part of the granular skeleton and to obtain similar behaviour as with reference granular composition: splitting resistance, water absorption and resistance to abrasion are optimised. Leaching behaviour is also verified in order to avoid detrimental effect on the environment; it is shown that post-combustion treatments and compacting energy combined with vibration are essential for a good quality product fabrication. [less ▲]

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See detailLayered silicate/polyester nanohybrids by controlled ring-opening polymerization
Lepoittevin, Bénédicte; Pantoustier, Nadège; Alexandre, Michaël ULg et al

in Macromolecular Symposia (2002), 183

In this study, layered silicate/aliphatic polyester nanohybrids were synthesized by ring-opening polymerization of c-caprolactone as promoted by the so-called coordination-insertion mechanism. These ... [more ▼]

In this study, layered silicate/aliphatic polyester nanohybrids were synthesized by ring-opening polymerization of c-caprolactone as promoted by the so-called coordination-insertion mechanism. These nanocomposites were formed in presence of montmorillortite surface-modified by ammonium cations bearing hydroxyl group(s), such as bis(2-hydroxyethyl)methyl (hydrogenated tallow alkyl) ammonium. The lactone polymerization could in initiated by all the hydroxyl functions available at the clay surface, after activation into either tin(II) or AI(III) alkoxide active species. Hybrid nanocomposites were accordingly generated through the covalent grafting of every polyester chain onto the filler surface. Surface-grafted polycaprolactone (PCL) chains were untied and isolated by ionic exchange reaction with LiCl in THF solution and molar masses were measured by size exclusion chromatography. The PCL molar masses could be controlled and readily tuned by the content of hydroxyl groups available at the clay surface. Interestingly, initiation reaction by aluminum trialkoxide active species yielded grafted PCL chains characterized by very narrow molecular weight distribution (M-w/M(n)similar to1.2). These polyester-grafted layered silicate nanohybrids displayed complete exfoliation of silicate sheets as shown by X-ray diffraction (XRD) and transmission electron microscopy (TEM). [less ▲]

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See detailRisk indices and osteoporosis screening: Scope and limits
Ben Sedrine, Wafa ULg; Reginster, Jean-Yves ULg

in Mayo Clinic Proceedings (2002), 77(7), 622-623

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See detailMultiyear infrared solar spectroscopic measurements of HCN, CO, C2H6,and C2H2 tropospheric columns above Lauder, New Zealand (45 degrees S latitude)
Rinsland, Curtis P.; Jones, Nicholas B.; Connor, Brian J. et al

in Journal of Geophysical Research. Atmospheres (2002), 107(D14),

[1] Near-simultaneous, 0.0035 or 0.007 cm(-1) resolution infrared solar absorption spectra of tropospheric HCN, C2H2, CO, and C2H6 have been recorded from the Network for the Detection of Stratospheric ... [more ▼]

[1] Near-simultaneous, 0.0035 or 0.007 cm(-1) resolution infrared solar absorption spectra of tropospheric HCN, C2H2, CO, and C2H6 have been recorded from the Network for the Detection of Stratospheric Change station in Lauder, New Zealand (45.04degreesS, 169.68degreesE, 0.37 km altitude). All four molecules were measured on over 350 days with HCN and C2H2 reported for the first time based on a new analysis procedure that significantly increases the effective signal-to-noise of weak tropospheric absorption features in the measured spectra. The CO measurements extend by 2.5 years a database of measurements begun in January 1994 for CO with improved sensitivity in the lower and middle troposphere. The C2H6 measurements lengthen a time series begun in July 1993 with peak sensitivity in the upper troposphere. Retrievals of all four molecules were obtained with an algorithm based on the semiempirical application of the Rodgers optimal estimation technique. Columns are reported for the 0.37- to 12-km-altitude region, approximately the troposphere above the station. The seasonal cycles of all four molecules are asymmetric, with minima in March-June and sharp peaks and increased variability during August-November, which corresponds to the period of maximum biomass burning near the end of the Southern Hemisphere tropical dry season. Except for a possible HCN column decrease, no evidence was found for a statistically significant long-term trend. [less ▲]

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See detailHematies Hyperdenses et Sphérocytose
Bricteux, Guy ULg; Panagopoulos, A.; Paulus, Jean-Michel ULg

in Revue Médicale de Liège (2002), 57(7), 443-8

A 12-year old female, suffering from recurring episodes of icterus and abdominal pain, is hospitalized in emergency. She is not anemic but her hemogram reveals a high level of hyperdense red blood cells ... [more ▼]

A 12-year old female, suffering from recurring episodes of icterus and abdominal pain, is hospitalized in emergency. She is not anemic but her hemogram reveals a high level of hyperdense red blood cells (32%; controls 0-2.5%) and an abnormal reticulocyte count (201 x 10(3)/microL; controls 29-84 x 10(3)/microL), indicating a 3.5 fold increase in RBC production. The same abnormalities are found in the patient's mother. The blood smear shows few spherocytes. RBC osmotic fragility is increased only after incubation. Hereditary spherocytosis is diagnosed following electrophoresis of membrane proteins which reveals a deficiency in band 3, a protein which links the lipid bilayer to the cytoskeleton. This case of hemolytic anemia-illustrates the physiopathologic and diagnostic significance of hyperdense RBC, which reflect the cell dehydration associated with the membrane disorder. [less ▲]

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See detailAnionic polymerisation of methyl methacrylate with complex initiator system
Nugay, Turgut; Nugay, Nihan; Jérôme, Robert ULg

in Polymer Bulletin (2002), 48(6), 457-462

Polymerisation of methyl methacrylate was conducted by using alkyl lithium/dimethylsulfoxide (DMSO) system as initiator in toluene. A special attention was focused on using some lithium polyetheralkoxides ... [more ▼]

Polymerisation of methyl methacrylate was conducted by using alkyl lithium/dimethylsulfoxide (DMSO) system as initiator in toluene. A special attention was focused on using some lithium polyetheralkoxides as polymerisation promoters at ambient temperatures. Poly(methyl methacrylate) samples were characterized with Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance Spectroscopy (H-1 NMR) and Differential Scanning Calorimetry (DSC). The positive effect of the mu/sigma type ligands such as lithium 2-(2-methoxyethoxy)ethoxide (LiOEEM), 2-(methoxy)ethoxide (LiOEM) on controlling the living character, molecular weight, stereo regularity and the yield of the produced polymers was demonstrated. It has been found that this approach provided high polymerisation yields and low polydispersity but low initiator efficiency. [less ▲]

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See detailAnatomically informed basis functions for EEG source localization : Combining functional and anatomical constraints
Phillips, Christophe ULg; Rugg, Michael D; Friston, Karl J

in Neuroimage (2002), 16(3), 678-6951

Distributed linear solutions have frequently been used to solve the source localization problem in EEG. Here we introduce an approach based on the weighted minimum norm (WMN) method that imposes ... [more ▼]

Distributed linear solutions have frequently been used to solve the source localization problem in EEG. Here we introduce an approach based on the weighted minimum norm (WMN) method that imposes constraints using anatomical and physiological information derived from other imaging modalities. The anatomical constraints are used to reduce the solution space a priori by modeling the spatial source distribution with a set of basis functions. These spatial basis functions are chosen in a principled way using information theory. The reduced problem is then solved with a classical WMN method. Further (functional) constraints can be introduced in the weighting of the solution using fMRI brain responses to augment spatial priors. We used simulated data to explore the behavior of the approach over a range of the model's hyperparameters. To assess the construct validity of our method we compared it with two established approaches to the source localization problem, a simple weighted minimum norm and a maximum smoothness (Loreta-like) solution. This involved simulations, using single and multiple sources that were analyzed under different levels of confidence in the priors. (C) 2002 Elsevier Science (USA). [less ▲]

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See detailThe anti-epileptic drug levetiracetam reverses the inhibition by negative allosteric modulators of neuronal GABA- and glycine-gated currents
Rigo, Jean-Michel; Hans, Grégory ULg; Nguyen, Laurent ULg et al

in British Journal of Pharmacology (2002), 136(5), 659-672

1 In this study in vitro and in vivo approaches were combined in order to investigate if the anti-epileptic mechanism(s) of action of levetiracetam (LEV; Keppra(R)) may involve modulation of inhibitory ... [more ▼]

1 In this study in vitro and in vivo approaches were combined in order to investigate if the anti-epileptic mechanism(s) of action of levetiracetam (LEV; Keppra(R)) may involve modulation of inhibitory neurotransmission. 2 GABA- and glycine-gated currents were studied in vitro using whole-cell patch-clamp techniques applied on cultured cerebellar granule, hippocampal and spinal neurons. Protection against clonic convulsions was assessed in vivo in sound-susceptible mice. The effect of LEV was compared with reference anti-epileptic drugs (AEDs): carbamazepine, phenytoin, valproate, clonazepam, phenobarbital and ethosuximide. 3 LEV contrasted the reference AEDs by an absence of any direct effect on glycine-gated currents. At high concentrations, beyond therapeutic relevance, it induced a small reduction in the peak amplitude and a prolongation of the decay phase of GABA-gated currents. A similar action on GABA-elicited currents was observed with the reference AEDs, except ethosuximide. 4 These minor direct effects contrasted with a potent ability of LEV (EC50 = 1-10 muM) to reverse the inhibitory effects of the negative allosteric modulators zinc and beta-carbolines on both GABA(A) and glycine receptor-mediated responses. 5 Clonazepam, phenobarbital and valproate showed a similar ability to reverse the inhibition of beta-carbolines on GABA-gated currents. Blockade of zinc inhibition of GABA responses was observed with clonazepam and ethosuximide. Phenytoin was the only AED together with LEV that inhibited the antagonism of zinc on glycine-gated currents and only clonazepam and phenobarbital inhibited the action of DMCM. 6 LEV (17 mg kg(-1)) produced a potent suppression of sound-induced clonic convulsions in mice. This protective effect was significantly abolished by co-administration of the beta-carboline FG 7142, from a dose of 5 mg kg(-1). In contrast, the benzodiazepine receptor antagonist flumazenil (up to 10 mg kg(-1)) was without any effect on the protection afforded by LEV. 7 The results of the present study suggest that a novel ability to oppose the action of negative modulators on the two main inhibitory ionotropic receptors may be of relevance for the anti-epileptic mechanism(s) of action of LEV. [less ▲]

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See detailComment j'explore.... Une hypertension resistante
Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (2002), 57(7), 475-478

Hypertension is a cardiovascular risk factor which needs a good evaluation before treatment. When this latter is decided, the target is to normalize high blood pressure. This requires a complete ... [more ▼]

Hypertension is a cardiovascular risk factor which needs a good evaluation before treatment. When this latter is decided, the target is to normalize high blood pressure. This requires a complete information of the patient; the latter will also receive individualized non pharmacological advices and, also, possibly different antihypertensive drugs. When blood pressure does not normalize, one must check the blood pressure measurement technique, the compliance to treatment and potential pharmacologic interferences. Secondary hypertension is only considered if resistance to therapy cannot be found. It should be remembered that obesity and sleep apnea disorders are responsible of many instances of refractory hypertension. [less ▲]

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See detailLandgrebe et Fink sur l’universalité de la philosophie phénoménologique
Seron, Denis ULg

in Les Etudes philosophiques (2002)

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See detailLocation adjustment for the minimum volume ellipsoid estimator
Croux, C.; Haesbroeck, Gentiane ULg; Rousseeuw, P. J.

in Statistics and Computing (2002), 12(3), 191-200

Estimating multivariate location and scatter with both affine equivariance and positive breakdown has always been difficult. A well-known estimator which satisfies both properties is the Minimum Volume ... [more ▼]

Estimating multivariate location and scatter with both affine equivariance and positive breakdown has always been difficult. A well-known estimator which satisfies both properties is the Minimum Volume Ellipsoid Estimator (MVE). Computing the exact MVE is often not feasible, so one usually resorts to an approximate algorithm. In the regression setup, algorithms for positive-breakdown estimators like Least Median of Squares typically recompute the intercept at each step, to improve the result. This approach is called intercept adjustment. In this paper we show that a similar technique, called location adjustment, can be applied to the MVE. For this purpose we use the Minimum Volume Ball (MVB), in order to lower the MVE objective function. An exact algorithm for calculating the MVB is presented. As an alternative to MVB location adjustment we propose L-1 location adjustment, which does not necessarily lower the MVE objective function but yields more efficient estimates for the location part. Simulations compare the two types of location adjustment. We also obtain the maxbias curves of both L-1 and the MVB in the multivariate setting, revealing the superiority of L-1. [less ▲]

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See detailComparative sequence analysis of the INS-IGF2-H19 gene cluster in pigs
Amarger, V.; Nguyen, Minh Ngoc ULg; Van Laere, Anne-Sophie ULg et al

in Mammalian Genome (2002), 13(7), 388-398

IGF2 is the major candidate gene for a paternally expressed Quantitative Trait Locus (QTL) in the pig primarily affecting muscle development. Here we report two sequence contigs together comprising almost ... [more ▼]

IGF2 is the major candidate gene for a paternally expressed Quantitative Trait Locus (QTL) in the pig primarily affecting muscle development. Here we report two sequence contigs together comprising almost 90 kb containing the INS-IGF2 and H19 genes. A comparative sequence analysis of the pig, human, and mouse genomic sequences was conducted to identify the exon/intros organization, all promoters, and other evolutionarily conserved elements. RT-PCR analysis showed that IGF2 transcripts originated from four different promoters and included various combinations of seven untranslated exons together with three coding exons, in agreement with previous findings in other mammals. The observed sequence similarity in intronic and intragenic regions among the three species is remarkable and is most likely explained by the complicated regulation of imprinting and expression of these genes. The general trend was, as expected, a higher sequence similarity between human and pig than between these species and the mouse, but a few exceptions to this rule were noted. This genomic region exhibits several striking features, including a very high GC content, many CpG islands, and a low amount of interspersed repeats. The high GC and CpG content were more pronounced in the pig than in the two other species. The results will facilitate the further characterization of this important QTL in the pig. [less ▲]

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See detailConcepts in plant stress physiology. Application to plant tissue cultures
Gaspar, Thomas ULg; Franck, Thierry ULg; Bisbis, Badia et al

in Plant Growth Regulation (2002), 37(3), 263-285

Because the term stress is used, most often subjectively, with various meanings, this paper first attempts to clarify the physiological definition, and the appropriate terms as responses in different ... [more ▼]

Because the term stress is used, most often subjectively, with various meanings, this paper first attempts to clarify the physiological definition, and the appropriate terms as responses in different situations. The flexibility of normal metabolism allows the development of responses to environmental changes which fluctuate regularly and predictably over daily and seasonal cycles. Thus every deviation of a factor from its optimum does not necessarily result in stress. Stress begins with a constraint or with highly unpredictable fluctuations imposed on regular metabolic patterns that cause bodily injury, disease, or aberrant physiology. Stress is the altered physiological condition caused by factors that tend to alter an equilibrium. Strain is any physical and/or chemical change produced by a stress, i.e. every established condition, which forces a system away from its thermodynamic optimal state. The paper secondly summarises the Strasser's state-change concept which is precisely that suboptimality is the driving force for acclimation (genotype level) or adaptation (population level) to stress. The paper continues with the actual knowledge on the mechanisms of stress recognition and cell signalling. Briefly: plasma membranes are the sensors of environmental changes; phytohormones and second messengers are the transducers of information from membranes to metabolism; carbon balance is the master integrator of plant response; betwixt and between, some genes are expressed more strongly, whereas others are repressed. Reactive oxygen species play key roles in up- and down-regulation of metabolism and structure. The paper shows finally that the above concepts can be applied to plant tissue cultures where the accumulating physiological and genetical deviations (from a normal plant behaviour) are related to the stressing conditions of the in vitro culture media and of the confined environment. The hyperhydrated state of shoots and the cancerous state of cells, both induced under conditions of stress in in vitro cultures, are identified and detailed, because they perfectly illustrate the stress-induced state-change concept. It is concluded that stress responses include either pathologies or adaptive advantages. Stress may thus contain both destructive and constructive elements: it is a selection factor as well as a driving force for improved resistance and adaptive evolution. [less ▲]

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See detailLevel lifetimes in 3p and 3d configurations of Fe XII
Biémont, Emile ULg; Palmeri, P.; Quinet, Pascal ULg et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2002), 20(1), 37-44

Transitions between the five fine-structure levels in the 3s(2)3p(3) ground configuration of Fe XII (P-like) are of interest in astrophysics and terrestrial plasma diagnostics. The decay rates give rise ... [more ▼]

Transitions between the five fine-structure levels in the 3s(2)3p(3) ground configuration of Fe XII (P-like) are of interest in astrophysics and terrestrial plasma diagnostics. The decay rates give rise to level lifetimes in the millisecond range, which have been measured recently at a heavy-ion storage ring. While most of the 3s(2)3p(2)3d levels are short-lived, two of these levels have no El decay channels and may also have millisecond lifetimes. We present HFR and MCDF calculations of the El, M1, E2 and M2 transition rates between the 3s(2)3p(3), 3s3p(4) and 3s(2)3p(2)3d levels and compare the lifetime results to most recent experimental data as well as to other predictions. [less ▲]

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See detailEDDIE C. CAMPBELL live
Sacré, Robert ULg

in Soul Bag (2002), (167), 47-48

Concert au Sang-A-Klang, Luxembourg, 8 mars 2002: compte rendu + Photo WILLIE BLACK (basse)

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See detailNOD2/CARD15 does not influence response to infliximab in Crohn's disease
Vermeire, S.; Louis, Edouard ULg; Rutgeerts, P. et al

in Gastroenterology (2002), 123(1), 106-111

Background

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See detailMeasurements of the ground-state ionization energy and wavelengths for the 1snp P-1(1)*-1s(2) S-1(0) (n=4-9) lines of Mg XI and FVIII
Pal'chikov, V. G.; Faenov, A. Y.; Skobelev, I. Y. et al

in Journal of Physics B-Atomic Molecular and Optical Physics (2002), 35(12), 2741-2754

The wavelengths of the 1snp P-1(1)0-1s(2) S-1(0) transitions in the He-like Mg XI (n = 4-9) and F VIII (n = 4-8) have been measured in laser-produced plasmas. The accuracy of the present measurements (0.4 ... [more ▼]

The wavelengths of the 1snp P-1(1)0-1s(2) S-1(0) transitions in the He-like Mg XI (n = 4-9) and F VIII (n = 4-8) have been measured in laser-produced plasmas. The accuracy of the present measurements (0.4-1.6 mAngstrom) is a large improvement over previous results. The Rydberg series is used to determine the ground-state ionization energy of F VIII and Mg XI: E-ion (F VIII) = 953.96 +/- 0.11 eV, E-ion (Mg XI) = 1761.88 +/- 0.15 eV. These experimental results are compared with theoretical data calculated by the 1/Z-expansion method and the HFR and MCDF approaches. Fairly good agreement between theory and experiment is observed with a precision up to 5 x 10(-5). Radiative corrections to the 1s(2) S-1(0) state are analysed and compared with experiments. It is found that QED corrections to the ground-state ionization energy are significant at the present level of experimental accuracy. [less ▲]

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See detailFull electrochemical synthesis of conducting polymer films chemically grafted to conducting surfaces
Labaye, David E; Jérôme, Christine ULg; Gueskin, V. M. et al

in Langmuir (2002), 18(13), 5222-5230

This paper reports on the full electrochemical synthesis of electrically conducting polymers chemically grafted to conducting surfaces (e.g., glassy carbon, stainless steel, nickel, gold). It is based on ... [more ▼]

This paper reports on the full electrochemical synthesis of electrically conducting polymers chemically grafted to conducting surfaces (e.g., glassy carbon, stainless steel, nickel, gold). It is based on new functional acrylate monomers, i.e., 3-(2-acryloyloxyethyl)thiophene and N-(2-acryloyloxyethyl)pyrrole, whose the synthesis is reported in this work. The polymerization process consists of two electrochemical steps. The first one is the cathodic electrografting of polyacrylate chains bearing a precursor of the conducting polymer in the ester group, either thiophene or pyrrole. In the second step, this precursor is polymerized under anodic polarization, in the presence or not of additional unsubstituted monomer in the electrochemical bath. Cyclic voltammetry was used to confirm that the two-component film is conducting and electrochemically active (reversible doping and dedoping). The chemical composition and the microscopic morphology of these composites were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. [less ▲]

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See detailImpact of mutations affecting ND mitochondria-encoded Subunits on the activity and assembly of complex I in chlamydomonas. Implication for the structural organization of the enzyme
Cardol, Pierre ULg; Matagne, René-Fernand ULg; Remacle, Claire ULg

in Journal of Molecular Biology (2002), 319(5), 1211-1221

The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex 1) comprises more than 35 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five ... [more ▼]

The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex 1) comprises more than 35 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components (ND1, ND2, ND4, ND5 and ND6) are coded for by the mitochondrial genome. Here, we characterize two mitochondrial mutants (dum5 and dum17) showing strong reduction or inactivation of complex I activity: dum5 is a IT deletion in the 3' UTR of nd5 whereas dum17 is a IT deletion in the coding sequence of nd6. The impact of these mutations and of mutations affecting nd1, nd4 and nd4/nd5 genes on the assembly of complex I is investigated. After separation of the respiratory complexes by blue native (BN)-PAGE or sucrose gradient centrifugation, we demonstrate that the absence of intact ND1 or ND6 subunit prevents the assembly of the 850 kDa whole complex, whereas the loss of ND4 or ND4/ND5 leads to the formation of a subcomplex of 650 kDa present in reduced amount. The implications of our findings for the possible role of these ND subunits on the activity of complex I and for the structural organization of the membrane arm of the enzyme are discussed. In mitochondria from all the strains analyzed, we moreover detected a 160210 kDa fragment comprising the hydrophilic 49 kDa and 76 kDa subunits of the complex I peripheral arm and showing NADH dehydrogenase activity. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailQSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring
Alcalde, D.; Mediavilla, E.; Moreau, O. et al

in Astrophysical Journal (2002), 572(2, Part 1), 729-734

We present VR observations of QSO 2237+ 0305 conducted by the Gravitational Lensing International Time Project collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2 ... [more ▼]

We present VR observations of QSO 2237+ 0305 conducted by the Gravitational Lensing International Time Project collaboration from 1999 October 1 to 2000 February 3. The observations were made with the 2.56 m Nordic Optical Telescope at Roque de los Muchachos Observatory, La Palma ( Spain). The pointspread function ( PSF) fitting method and an adapted version of the ISIS subtraction method have been used to derive the VR light curves of the four components ( A D) of the quasar. The mean errors range in the intervals 0.01-0.04 mag ( PSF fitting) and 0.01-0.02 mag ( ISIS subtraction), with the faintest component ( D) having the largest uncertainties. We address the relatively good agreement between the A and D light curves derived using different filters, photometric techniques, and telescopes. The new VR light curves of component A extend the time coverage of a high-magnification microlensing peak, which was discovered by the OGLE team. [less ▲]

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See detailVesicular nanostructures prepared by reactive melt blending
Koulic, Christian; Yin, Zhihui; Pagnoulle, Christophe et al

in Angewandte Chemie (International ed. in English) (2002), 41(12), 2154-2156

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See detailA synopticity test of a sampling pattern in the Alboran Sea
Rixen, M.; Beckers, Jean-Marie ULg

in Journal of Marine Systems (2002), 35(1-2), 111-130

Hydrographic surveys are usually considered as synoptic, as if the corresponding data set had been sampled at the same time. However, this assumption might lead to strong biases in subsequent analyses. To ... [more ▼]

Hydrographic surveys are usually considered as synoptic, as if the corresponding data set had been sampled at the same time. However, this assumption might lead to strong biases in subsequent analyses. To obtain synoptic data at a given moment, we integrate a Lagrangian motion equation towards a 'modal sampling time', to relocate the sampling stations both in time and space, by combining objective analysis and geostrophic velocities, assumed to be either stationary or unstationary over the period of integration. The relocation algorithms are applied to a data set covering the entire Alboran Sea. The relocation of data points leads to a significant change on vertical velocities computed with the OMEGA equation. For validation purpose, the algorithm is also applied to a synthetic data set obtained from a 3D Primitive Equation (PE) model output. Raw and pseudosynoptic analysed temperature-salinity (T/S) fields and derived quasigeostrophic (QG) vertical velocities are compared. It is shown that the relocation method might correct significantly the errors arising from the synopticity hypothesis and that the sensitivity to the level of no-motion and the analysis parameters is less important than the nonsynopticity. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailConstruction of regular languages and recognizability of polynomials
Rigo, Michel ULg

in Discrete Mathematics (2002), 254(1-3), 485-496

A generalization of numeration systems in which NI is recognizable by finite automata can be obtained by describing a lexicographically ordered infinite regular language. We show that if P is an element ... [more ▼]

A generalization of numeration systems in which NI is recognizable by finite automata can be obtained by describing a lexicographically ordered infinite regular language. We show that if P is an element of Q[x] is a polynomial such that P(N) subset of N then there exists a numeration system in which the set of representations of P(N) is regular. The main issue is to construct a regular language with a complexity function equals to P(n + 1) - P(n) for n large enough. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailPhosphorylation of varicella-zoster virus IE63 protein by casein kinases influences its cellular localization and gene regulation activity
Bontems, Sébastien ULg; Di Valentin, Emmanuel ULg; Baudoux, Laurence et al

in Journal of Biological Chemistry (2002), 277(23), 21050-21060

During the early phase of varicella-zoster virus (VZV) infection, Immediate Early protein 63 (IE63) is expressed rapidly and abundantly in the nucleus, while during latency, this protein is confined ... [more ▼]

During the early phase of varicella-zoster virus (VZV) infection, Immediate Early protein 63 (IE63) is expressed rapidly and abundantly in the nucleus, while during latency, this protein is confined mostly to the cytoplasm. Because phosphorylation is known to regulate many cellular events, we investigated the importance of this modification on the cellular localization of IE63 and on its regulatory properties. We demonstrate here that cellular casein kinases I and II are implicated in the in vitro and in vivo phosphorylation of IE63. A mutational approach also indicated that phosphorylation of the protein is important for its correct cellular localization in a cell type-dependent fashion. Using an activity test, we demonstrated that IE63 was able to repress the gene expression driven by two VZV promoters and that phosphorylation of the protein was required for its full repressive properties. Finally, we showed that IE63 was capable of exerting its repressive activity in the cytoplasm, as well as in the nucleus, suggesting a regulation at the transcriptional and/or post-transcriptional level. [less ▲]

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See detailBulletin agrométéorologique
Tychon, Bernard ULg; Ozer, Pierre ULg; Eerens, H. et al

in Bulletin Agrométéorologique (2002)

Le mois de mai a été caractérisé par des conditions climatiques normales tant pour les précipitations que pour les températures. En revanche, le rayonnement a été largement déficitaire. La situation des ... [more ▼]

Le mois de mai a été caractérisé par des conditions climatiques normales tant pour les précipitations que pour les températures. En revanche, le rayonnement a été largement déficitaire. La situation des cultures est globalement favorable, avec des rendements qui s’annoncent supérieurs à ceux de 2001 à la possible exception du colza et du maïs fourrager. [less ▲]

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See detailPrecipitation of auroral protons in detached arcs
Immel, Thomas J; Mende, Stephen B; Frey, Harald U et al

in Geophysical Research Letters (2002), 29

Recent global-scale observations by the IMAGE-FUV instrument demonstrate the existence of regions of particle precipitation at sub-auroral latitudes on the dayside. The signature of this precipitation is ... [more ▼]

Recent global-scale observations by the IMAGE-FUV instrument demonstrate the existence of regions of particle precipitation at sub-auroral latitudes on the dayside. The signature of this precipitation is seen infrequently, but when so, it is clear in all 3 channels of the FUV instrument. A conjugate hemisphere conjunction with the FAST satellite demonstrates the presence of precipitating protons and the notable absence of precipitating electrons in these arcs. With this knowledge, one can determine the mean energy and energy flux of the precipitating protons by intercomparison of the response in the three FUV channels. Assuming that the protons have a kappa energy distribution, the mean energy is found to be ~20 keV, with a peak in total energy flux of ~1 mW/m[SUP]2[/SUP]/sec, consistent with fits to the FAST ion measurements. These phenomena are observed mainly during times of high solar wind dynamic pressure and variable interplanetary magnetic field, and are associated with earlier nightside enhancements in the brightness and latitudinal extent of the proton aurora. [less ▲]

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See detailInfluence of a low magnetic field on the thermal diffusivity of Bi2Sr2CaCu2O8
Dorbolo, Stéphane ULg; Ausloos, Marcel ULg

in Physical Review B (2002), 65(21),

The thermal diffusivity of a Bi-2212 polycrystalline sample has been measured under a 1 T magnetic field applied perpendicularly to the heat flux. The magnetic contribution to the heat carrier mean free ... [more ▼]

The thermal diffusivity of a Bi-2212 polycrystalline sample has been measured under a 1 T magnetic field applied perpendicularly to the heat flux. The magnetic contribution to the heat carrier mean free path has been extracted and is found to behave as a simple power law. This behavior can be attributed to a percolation process of electrons in the vortex lattice created by the magnetic field. [less ▲]

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See detailGlobal comparison of magnetospheric ion fluxes and auroral precipitation during a substorm
Mende, S. B.; Frey, H. U.; Immel, T. J. et al

in Geophysical Research Letters (2002), 29

Integrated fluxes from global images taken by the High Energy Neutral Atom (HENA) and the far ultraviolet (FUV) imagers on the IMAGE spacecraft were compared for a six-hour period, during which a ... [more ▼]

Integrated fluxes from global images taken by the High Energy Neutral Atom (HENA) and the far ultraviolet (FUV) imagers on the IMAGE spacecraft were compared for a six-hour period, during which a reasonably intense substorm occurred. HENA and the FUV proton auroral imager (SI-12) monitor emissions which are representative of trapped and precipitating magnetospheric proton fluxes, respectively. For several hours prior to substorm onset, measurements of the fluxes of lower energy (10-16 and 16-27 keV) magnetospheric Energetic Neutral Atoms (ENA-s) by HENA and precipitating auroral protons by FUV SI-12 show strong similarities, with the implication that, in general, proton precipitation is controlled by a steady pitch angle diffusion process. Less similarity is seen between ENA-s and the auroral electron precipitation, which is monitored with the FUV Wideband Imaging Camera. Prior to substorm onset, ENA intensity at large radial distance (L > 8) is reduced while the overall integrated ENA flux increases signifying earthward motion and accumulation of the plasma. About 20 minutes before onset, the auroral fluxes decrease while the ENA intensity continues to grow. The observations are consistent with a pre-onset increase in plasma pressure in the inner magnetosphere without an increase in precipitation showing more efficient trapping perhaps by the distorted nightside magnetosphere. At substorm onset the increase in precipitation intensity is very sudden while the more gradual intensification of the energetic ENA-s continues. At onset the electron aurora shows an increase in intensity of one order of magnitude, while the increase in precipitating proton flux is only 50%. The intensification of the precipitation is relatively short lived (~10 minutes) while the ENA substorm enhancements last about an hour. [less ▲]

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See detailIMAGE and FAST observations of substorm recovery phase aurora
Mende, Stephen B; Frey, Harald U; Carlson, Charles W et al

in Geophysical Research Letters (2002), 29

Images from the IMAGE Wide-band Imaging Camera (WIC) and Spectrographic Imager (SI) channel SI12, were compared to in situ data taken by FAST. The IMAGE data segment began during the expansive phase of a ... [more ▼]

Images from the IMAGE Wide-band Imaging Camera (WIC) and Spectrographic Imager (SI) channel SI12, were compared to in situ data taken by FAST. The IMAGE data segment began during the expansive phase of a substorm and a double oval configuration evolved, consisting of a set of discrete poleward auroral forms and a separate more diffuse oval. The FAST data showed that a narrow (~1.5° latitude) region of downward currents separated the two ovals. The SI-12 optical observations showed a single oval of precipitating protons located on the equatorward side within the diffuse aurora. In agreement with IMAGE, the highest intensity proton flux measured by FAST was concentrated on the equatorward region although low flux protons were present throughout the entire double oval. In the lower latitude diffuse oval occasional structured auroras were embedded. These structured auroras were mostly created by inverted V type electrons but there were narrow regions in which intense beams of accelerated electrons were seen whose energy/pitch angle distribution and accompanying electric field data were consistent with Alfven wave acceleration. The poleward oval consisted of an intense inverted V precipitation event poleward of which a weak region of Alfven wave accelerated electrons was located. From the images it appears that the Alfven wave accelerated electron event in the diffuse auroral regions and the poleward features were part of short lived or rapidly moving auroral forms. [less ▲]

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See detailRecurring Outbursts and Nuclear Fragmentation of Comet C/2001 A2 (LINEAR)
Sekanina, Zdenek; Jehin, Emmanuel ULg; Boehnhardt, Hermann et al

in Astrophysical Journal (2002), 572

Analysis of the visual light curve and fragmentation sequence of comet C/2001 A2 (LINEAR) shows a strong temporal correlation between the onset of outbursts and separation of companion nuclei. This ... [more ▼]

Analysis of the visual light curve and fragmentation sequence of comet C/2001 A2 (LINEAR) shows a strong temporal correlation between the onset of outbursts and separation of companion nuclei. This scenario conforms to Sekanina's conceptual model for the release of sizable fragments of an inert dust mantle from the nucleus surface: an outburst is triggered as some of the mass rapidly disintegrates into fine dust. [less ▲]

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See detailModel intercomparison in the Mediterranean: MEDMEX simulations of the seasonal cycle
Beckers, Jean-Marie ULg; Rixen, M.; Brasseur, P. et al

in Journal of Marine Systems (2002), 33

The simulation of the seasonal cycle in the Mediterranean by several primitive equation models is presented. All models were forced with the same atmospheric data, which consists in either a monthly ... [more ▼]

The simulation of the seasonal cycle in the Mediterranean by several primitive equation models is presented. All models were forced with the same atmospheric data, which consists in either a monthly averaged wind-stress with sea surface relaxation towards monthly mean sea surface temperature and salinity fields, or by daily variable European Centre for Medium Range Weather Forecast (ECMWF) reanalysed wind-stress and heat fluxes. In both situations models used the same grid resolution. Results of the modelling show that the model behaviour is similar when the most sensitive parameter, vertical diffusion, is calibrated properly. It is shown that an unrealistic climatic drift must be expected when using monthly averaged forcing functions. When using daily forcings, drifts are modified and more variability observed, but when performing an EOF analysis of the sea surface temperature, it is shown that the basic cycle, represented similarly by the models, consists of the seasonal cycle which accounts for more than 90% of its variability. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailEffects of prodelphinidins isolated from Ribes nigrum on chondrocyte metabolism and COX activity
Garbacki, Nancy ULg; Angenot, Luc ULg; Bassleer, C. et al

in Naunyn-Schmiedeberg's Archives of Pharmacology (2002), 365(6), 434-441

Articular diseases. such as osteoarthritis, is the clinical expression of the loss of cartilage function. COX inhibitors are widely used in the treatment of such pathologies for their beneficial effects ... [more ▼]

Articular diseases. such as osteoarthritis, is the clinical expression of the loss of cartilage function. COX inhibitors are widely used in the treatment of such pathologies for their beneficial effects on inflammation but often produce a negative activity on cartilage synthesis. In this study, we determined the effect of different prodelphinidins, the major compounds isolated from Ribes nigrum leaves, on the proteoglycans (PGs), type II collagen (coll. II) and prostaglandin E-2 (PGE(2)) production by differentiated human chondrocytes cultivated in long term (12 days) and in clusters as well as their inhibition potential on COX-1 and COX-2 in vitro. Gallocatechin trimer (GC-GC-GC) showed the higher stimulation of PGs and coll. II production (1 mug ml(-1)) and the synthesis of PGE(2) was significantly reduced by gallocatechin dimer (GC-GC), gallocatechin-epigallocatechin (GC-EGC) and GC-GC-GC at 10 and 100 mug ml(-1). The inhibition of PGE(2) synthesis was confirmed by the in vitro test on purified COX enzymes, showing the selectivity of prodelphinidins on COX-2. However, the prodelphinidins had no effects on COX activity in the whole blood assay. Our studies suggest that the prodelphinidins fractions from R. nigrum may be useful as an additive agent in the prevention of osteoarthritis. [less ▲]

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See detail"Arrachez-moi ce coeur!": de la crainte du rejet au délire après transplantation cardiaque
Triffaux, Jean-Marc ULg; Demoulin, J. C.; Limet, Raymond ULg

in Revue Médicale de Liège (2002), 57(6), 389-92

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See detailThe effects of growth hormone replacement therapy on bone metabolism in adult-onset growth hormone deficiency: A 2-year open randomized controlled multicenter trial
Bex, M.; Abs, R.; Maiter, D. et al

in Journal of Bone and Mineral Research (2002), 17(6), 1081-1094

Adult hypopituitary patients with growth hormone deficiency (GHD) show a significant decrease in bone mass and an increased fracture rate. Replacement therapy with GH increases bone turnover. Most of the ... [more ▼]

Adult hypopituitary patients with growth hormone deficiency (GHD) show a significant decrease in bone mass and an increased fracture rate. Replacement therapy with GH increases bone turnover. Most of the long-term data on bone mineral content (BMC) and bone mineral density (BMD) have been acquired in open, noncontrolled trials involving limited numbers of patients. To determine whether long-term GH therapy is beneficial for bone despite the increased bone turnover, 100 patients (59 men and 41 women), aged 25-65 years (mean, 49.7 years) with adult-onset GHD were randomized to treatment with GH (40 men and 28 women; mean dose, 0.18 IU/kg per week) or to a nontreated control group (19 men and 13 women) for 24 months. Despite a similar increase in parameters of bone turnover (osteocalcin [OC], procollagen type I carboxy-terminal propeptide [PICP], and pyridinolines ([PYD]) in male and female GH-treated patients compared with controls, the effects on BMC and BMD as evaluated by dual-energy X-ray absorptiometry were gender specific. A significant increase in spine BMC and BMD and total hip BMD and a decrease in BMD at the ultradistal radius over time was observed in male GH-treated patients compared with the evolution in controls (mean +/- SEM change at 24 months: + 6.8 +/- 1.1% and p = 0.009, +5.1 +/- 0.8% and p = 0.005, +3.5 +/- 0.7% and p = 0.02, and -2.6 +/- 0.8% and p = 0.008, respectively). No significant treatment effects were observed in female patients. Despite the increase in the total remodeling space induced by GH treatment, prolonged GH therapy in adult-onset GHD has a positive effect on bone balance, maintaining bone mass in women, and even increasing it in men over a 2 year-period. [less ▲]

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See detailSerological markers for prediction of response to anti-tumor necrosis factor treatment in Crohn's disease
Esters, N.; Vermeire, S.; Joossens, S. et al

in American Journal of Gastroenterology (2002), 97(6), 1458-1462

OBJECTIVES: The use of monoclonal anti-tumor necrosis factor (TNF) antibodies (infliximab, Remicade) is a new therapeutic approach for severe refractory luminal or fistulizing, Crohn's disease (CD ... [more ▼]

OBJECTIVES: The use of monoclonal anti-tumor necrosis factor (TNF) antibodies (infliximab, Remicade) is a new therapeutic approach for severe refractory luminal or fistulizing, Crohn's disease (CD). However, up to 30% of patients do not respond to this treatment. So far, no parameters predictive of response to anti-TNT have been identified. Our aim was to determine whether serological markers ASCA (anti-Saccharomyces cerevisiae antibodies) or pANCA (perinuclear antineutrophil cytoplasmic antibodies) could identify Crohn's patients likely to benefit from anti-TNF therapy. METHODS: Serum samples of 279 CID patients were analyzed for ASCA and pANCA before anti-TNF therapy. A blinded physician determined clinical response at week 4 (refractory luminal CD) or week 10 (fistulizing CD) after the first infusion of infliximab (5 mg/kg). RESULTS: Overall, there was no relationship between ASCA or pANCA and response to therapy. However, lower response rates were observed for patients with refractory intestinal disease carrying the pANCA+/ASCA- combination, although this lacked significance (p = 0.067). CONCLUSIONS: In this cohort of infliximab-treated patients, neither ASCA nor pANCA could predict response to treatment. However, the combination pANCA+/ASCA- might warrant further investigation for its value in predicting nonresponse in patients with refractory luminal disease. [less ▲]

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See detailMaxbias curves of robust location estimators based on subranges
Croux, C.; Haesbroeck, Gentiane ULg

in Journal of Nonparametric Statistics (2002), 14(3), 295-306

A maxbias curve is a powerful tool to describe the robustness of an estimator. It tells us how much an estimator can change due to a given fraction of contamination. In this paper, maxbias curves are ... [more ▼]

A maxbias curve is a powerful tool to describe the robustness of an estimator. It tells us how much an estimator can change due to a given fraction of contamination. In this paper, maxbias curves are computed for some univariate location estimators based on subranges: midranges, trimmed means and the univariate Minimum Volume Ellipsoid (MVE) location estimators. These estimators are intuitively appealing and easy to calculate. [less ▲]

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See detailOverproduction and biochemical characterization of the Chryseobacterium meningosepticum BlaB metallo-beta-lactamase
Vessillier, S.; Docquier, J. D.; Rival, S. et al

in Antimicrobial Agents and Chemotherapy (2002), 46(6), 1921-1927

The BlaB metallo-beta-lactamase of Chryseobacterium meningosepticum CCUG4310 was overproduced in Escherichia coli by means of a T7 promoter-based expression system. The overproducing system, scaled up in ... [more ▼]

The BlaB metallo-beta-lactamase of Chryseobacterium meningosepticum CCUG4310 was overproduced in Escherichia coli by means of a T7 promoter-based expression system. The overproducing system, scaled up in a 15-liter fermentor, yielded approximately 10 mg of BlaB protein per liter, mostly released in the culture supernatant. The enzyme was purified by two ion-exchange chromatographic steps with an overall yield of 66%. Analysis of the kinetic parameters revealed efficient activities (k(cat)/K-m ratios of >10(6) M-1 s(-1)) toward most penam and carbapenem compounds, with the exception of the 6-alpha-methoxypenam derivative temocillin and of biapenem, which were poorer substrates. Hydrolysis of cephalosporins was overall less efficient, with a remarkable variability that was largely due to variable affinities of the BlaB enzyme for different compounds. BlaB was also able to hydrolyze serine-beta-lactamase inhibitors, including beta-iodopenicillanate, sulbactam and, although less efficiently, tazobactam. [less ▲]

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See detailA comparison of the training value of two types of anesthesia simulators: Computer screen-based and mannequin-based simulators
Nyssen, Anne-Sophie ULg; Larbuisson, Robert ULg; Janssens, Marc ULg et al

in Anesthesia and Analgesia (2002), 94(6), 1560-1565

In this study, we compared two different training simulators (the computer screen-based simulator versus the full-scale simulator) with respect to training effectiveness in anesthesia residents ... [more ▼]

In this study, we compared two different training simulators (the computer screen-based simulator versus the full-scale simulator) with respect to training effectiveness in anesthesia residents. Participants were evaluated in the management of a simulated preprogrammed scenario of anaphylactic shock using two variables: treatment score and diagnosis time. Our results showed that simulators can contribute significantly to the improvement of performance but that learning in treating simulated crisis situations such as anaphylactic shock did not significantly vary between full-scale and computer screen-based simulators. Consequently, the initial decision on whether to use a full-scale or computer screen-based training simulator should be made on the basis of cost and learning objectives rather than on the basis of technical or fidelity criteria. Our results support the contention that screen-based simulators are good devices to acquire technical skills of crisis management. Mannequin-based simulators would probably provide better training for behavioral aspects of crisis management, such as communication, leadership, and interpersonal conflicts, but this was not tested in the current study. IMPLICATIONS: We compared two different training simulators (computer screen-based versus full-scale) for training anesthesia residents to better document the effectiveness of such devices as training tools. This is an important issue, given the extensive use and the high cost of mannequin-based simulators in anesthesiology. [less ▲]

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See detailNicolas, Diane, Tatiana et les autres
Leleu, Yves-Henri ULg

in 15e Jour du Mois (Le) (2002)

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See detailIn vitro antiplasmodial activity of Tithonia diversifolia and identification of its main active constituent: tagitinin C.
Goffin, Eric ULg; Ziemons, Eric ULg; De Mol, Patrick ULg et al

in Planta Medica (2002), 68(6), 543-5

The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum. The ether extract from ... [more ▼]

The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum. The ether extract from aerial parts of the plant collected in Sao Tome e Principe, demonstrated good antiplasmodial activity (IC 50 on FCA strain: 0.75 microg/ml). A bioassay guided fractionation of this extract led to the isolation of the known sesquiterpene lactone tagitinin C as an active component against Plasmodium (IC 50 on FCA strain: 0.33 microg/ml), but also possessing cytotoxic properties (IC 50 on HTC-116 cells: 0.706 microg/ml). [less ▲]

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See detailEffect of systemic nitroglycerin on CGRP and 5-HT afferents to rat caudal spinal trigeminal nucleus and its modulation by estrogen
Pardutz, A.; Multon, Sylvie ULg; Malgrange, Brigitte ULg et al

in European Journal of Neuroscience (2002), 15(11), 1803-1809

Systemic administration of nitroglycerin, a nitric oxide donor, triggers in migraine patients a delayed attack of unknown mechanism. After puberty migraine is more prevalent in women. Attacks can be ... [more ▼]

Systemic administration of nitroglycerin, a nitric oxide donor, triggers in migraine patients a delayed attack of unknown mechanism. After puberty migraine is more prevalent in women. Attacks can be triggered by abrupt falls in plasma estrogen levels, which accounts in part for sexual dimorphism, but lacks an established neurobiological explanation. We studied the effect of nitroglycerin on the innervated area of calcitonin gene-related peptide (CGRP) and serotonin-immunoreactive afferents to the superficial laminae of the spinal portion of trigeminal nucleus caudalis, and its modulation by estrogen. In male rats, nitroglycerin produced after 4 h a significant decrease of the area innervated by CGRP-immunoreactive afferents and an increase of that covered by serotonin-immunoreactive fibres. These effects were not observed in the superficial laminae of thoracic dorsal horns. The effect of nitroglycerin was similar in ovariectomized females. In estradiol-treated ovariectomized females the area in the spinal portion of trigeminal nucleus caudalis laminae I-II covered by CGRP-immunoreactive fibres was lower and that of serotonin-immunoreactive fibres was higher than in males and for both transmitters not significantly changed after nitroglycerin. The bouton size of CGRP profiles was smaller in estradiol-treated ovariectomized females, whereas after nitroglycerin it decreased significantly but only in males and ovariectomized females. Nitroglycerin, i.e. nitric oxide, is thus able to differentially influence afferent fibres in the superficial laminae of rat spinal trigeminal nucleus caudalis. Estradiol modulates the basal expression of these transmitters and blocks the nitroglycerin effect. These data may contribute to understanding the mechanisms by which estrogens influence migraine severity and the triggering of attacks by nitric oxide. [less ▲]

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See detailThe role of topography in small well-mixed bays, with application to the lagoon of Mururoa
Mathieu, Pierre-Philippe; Deleersnijder, Eric; Cushman-Roisin, Benoît et al

in Continental Shelf Research (2002), 22(9), 1379-1395

The present study aims to better understand how bathymetry and wind field interact to shape the circulation in well-mixed bays with particular emphasis on the lagoon of Mururoa. The simple model of ... [more ▼]

The present study aims to better understand how bathymetry and wind field interact to shape the circulation in well-mixed bays with particular emphasis on the lagoon of Mururoa. The simple model of Csanady (J. Phys. Oceanography 3 (1973) 429) is re-examined and some new analytical properties of the velocity distribution are derived. An extended version of the Csanady model, called the idealised model (IM), is then applied to the lagoon of Mururoa located in the Pacific. The circulation obtained by IM compares well with the circulation simulated by a three-dimensional hydrodynamic model. Our results show that IM provides a simple and powerful heuristic tool to gain more insight into the dominant dynamical regime of the lagoon. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailL'image du mois. Desinsertion d'anneau mitral prothetique dans les suites d'une plastie mitrale
Nellessen, Eric ULg; LANCELLOTTI, Patrizio ULg; Yans, T. et al

in Revue Médicale de Liège (2002), 57(6), 361-2

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See detailDevelopment and assessment of the Osteoporosis Index of Risk (OSIRIS) to facilitate selection of women for bone densitometry
Sedrine, W. B.; Chevallier, T.; Zegels, Brigitte ULg et al

in Gynecological Endocrinology : The Official Journal of the International Society of Gynecological Endocrinology (2002), 16(3), 245-250

A simple questionnaire would be useful to identify individuals most in need of bone mineral density (BMD) testing. We designed a new predictive model and risk assessment instrument based on an extensive ... [more ▼]

A simple questionnaire would be useful to identify individuals most in need of bone mineral density (BMD) testing. We designed a new predictive model and risk assessment instrument based on an extensive review of the literature evaluating risk factors for osteoporosis, and tested its performance in a large cohort of postmenopausal women in whom BMD was measured by dual x-ray absorptiometry. In total, 1303 postmenopausal women from an outpatient osteoporosis clinic participated in this study. The Osteoporosis Index of Risk (OSIRIS) is based on four variables: age, body weight, current hormone replacement therapy use and history of previous low impact fracture. The sensitivity and specificity for an OSIRIS value of +1 were respectively 78.5% and 51.4%. The AUC under the ROC curve of OSIRIS was 0.71. Three categories were arbitrarily created using OSIRIS, with cutoff of +1 and -3. The low risk category (OSIRIS > +1) represented 41% of all women; only 7% of the women in this category had osteoporosis. The prevalence of osteoporosis was very high (66%) among the group at high risk (OSIRIS < -3 representing 15% of all women). The prevalence of osteoporosis was 39% in the intermediate risk group (-3 < OSIRIS < +1, 44% of all women). In conclusion, OSIRIS is a simple index based on four easy-to-collect variables from postmenopausal women, it shows a high degree of accuracy, and performed well for classifying the degree of risk of osteoporosis in western European women of Caucasian lineage. Based on this instrument it is possible to propose a strategy that would initiate treatment in women with very high risk, postpone BMD measurement in women with low risk and limit BMD measurement to women with intermediate risk of osteoporosis, this would spare more than 55% of the densitometry bill compared with a mass screening scenario. [less ▲]

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See detailExperimental and theoretical investigation of radiative decay rates of metastable levels in LaII
Derkatch, A.; Ilyinsky, L.; Mannervik, S. et al

in Physical Review A (2002), 65(6),

An experimental and theoretical investigation of lifetimes of metastable levels in La II has been performed. The experimentally obtained results using the laser probing of a stored ion beam were tau=5.2 ... [more ▼]

An experimental and theoretical investigation of lifetimes of metastable levels in La II has been performed. The experimentally obtained results using the laser probing of a stored ion beam were tau=5.2+/-0.2 s for the a(1)G(4) and tau=2.1+/-0.3 s for the b(1)D(2) levels. Within the error bars, the results are in good agreement with the relativistic Hartree-Fock calculations including core polarization. [less ▲]

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See detailPoly(epsilon-caprolactone)/clay nanocomposites prepared by melt intercalation: mechanical, thermal and rheological properties
Lepoittevin, Bénédicte; Devalckenaere, Myriam; Pantoustier, Nadège et al

in Polymer (2002), 43(14), 4017-4023

(Nano)composites of poly(epsilon-caprolactone) (PCL) were prepared by melt blending the polymer with natural Na+ montmorillonite and montmorillonite modified by hydrogenated tallowalkyl (HTA)-based ... [more ▼]

(Nano)composites of poly(epsilon-caprolactone) (PCL) were prepared by melt blending the polymer with natural Na+ montmorillonite and montmorillonite modified by hydrogenated tallowalkyl (HTA)-based quaternary ammonium cations, such as dimethyl 2-ethylhexyl HTA ammonium and methyl bis(2-hydroxyethyl) HTA ammonium. Microcomposites or nanocomposites were prepared depending on whether neat or modified montmorillonites was used, as assessed by X-ray diffraction and transmission electron microscopy. Mechanical and thermal properties were studied as a function of the filter content by tensile testing, Izod impact testing, thermogravimetric analysis and differential scanning calorimetry. The rheological behaviour at 80 degreesC was also analysed in relation to the structure and content of the layered silicate. Effect of exfoliated silicates on the mechanical properties, thermal stability and flame resistance of PCL was considered. Stiffness and thermal stability improved with the filler loading until a content of 5 wt%. Further loading resulted in the levelling off and possibly in a decrease of these properties. A marked charring effect was observed upon exposure to a flame. [less ▲]

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See detailAdsorption and structure formation of the weak polyelectrolytic diblock copolymer, PVP-b-PDMAEMA
Mahltig, Boris; Gohy, Jean-François; Antoun, Sayed et al

in Colloid and Polymer Science (2002), 280(6), 495-502

This paper reports on the pH-dependent adsorption of weak the polyelectrolytic diblock copolymer poly(2-vinylpyridine)-block-poly(dimethylaminoethyl methacrylate), (PVP-b-PDMAEMA). Aqueous PVP-b-PDMAEMA ... [more ▼]

This paper reports on the pH-dependent adsorption of weak the polyelectrolytic diblock copolymer poly(2-vinylpyridine)-block-poly(dimethylaminoethyl methacrylate), (PVP-b-PDMAEMA). Aqueous PVP-b-PDMAEMA solutions have been adsorbed on alkaline pretreated silicon substrates. Altogether two copolymers differing in block ratio and molecular weight were used for the investigations. While the electrical charge of both samples in solution was investigated by electrophoretic measurements, the adsorbed polymer layers were studied with ellipsometry and atomic force microscopy (AFM). Depending on pH the electrical charge of both blocks of the diblock copolymer varied. Three different regimes have been identified. Under acidic conditions at pH < 5, both blocks are mainly positively charged. At medium pH between 5 and 8, only the PDMAEMA block is positively charged. At pH > 8, both blocks are nearly uncharged and a polymer precipitation occurred in solution. Each of these pH regimes was characterized by a specific adsorption behaviour leading to two adsorption maxima at acidic and alkaline pH values, while at medium pH a plateau in the adsorbed amount was observed. Moreover, the structures of the polyelectrolytes formed on the substrate after adsorption were specific to each of the three pH regimes. [less ▲]

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See detailAnomalies hypophysaires chez le sujet age avec insuffisance renale chronique
Valdes Socin, Hernan Gonzalo ULg; Magis, Delphine ULg; Betea, Daniela ULg et al

in Revue Médicale de Liège (2002), 57(6), 375-381

Chronic renal failure (CRF) in the elderly is a cause of multiple endocrine dysfunctions. The three most common pituitary axes involved are the thyrotrope, lactotrope and gonadotrope axes. Thyroid ... [more ▼]

Chronic renal failure (CRF) in the elderly is a cause of multiple endocrine dysfunctions. The three most common pituitary axes involved are the thyrotrope, lactotrope and gonadotrope axes. Thyroid dysfunction may be the consequence of thyroid or pituitary failure. Hyperprolactinemia results in gonadal failure and is present in 30% of patients. Early presentation of menopause and andropause are common in patients with CRF. Sexual hormonal replacement is controversial and must be individually tailored. We propose a systematic screening in the elderly with CRF: determination of TSH, TPO antibodies and cervical palpation, measures of PRL, LH, FSH and testosterone to explore lactotrope and gonadotrope axis. [less ▲]

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See detailStructural basis of alpha-amylase activation by chloride
Aghajari, N.; Feller, Georges ULg; Gerday, Charles ULg et al

in Protein Science : A Publication of the Protein Society (2002), 11(6), 1435-1441

To further investigate the mechanism and function of allosteric activation by chloride in some alpha-amylases, the structure of the bacterial alpha-amylase from the psychrophilic micro-organism ... [more ▼]

To further investigate the mechanism and function of allosteric activation by chloride in some alpha-amylases, the structure of the bacterial alpha-amylase from the psychrophilic micro-organism Pseudoalteromonas haloplanktis in complex with nitrate has been solved at 2.1 Angstrom, as well as the structure of the mutants Lys300Gln (2.5 Angstrom) and Lys300Arg (2.25 Angstrom). Nitrate binds strongly to alpha-amylase but is a weak activator. Mutation of the critical chloride ligand Lys300 into Gln results in a chloride-independent enzyme, whereas the mutation into Arg mimics the binding site as is found in animal alpha-amylases with, however, a lower affinity for chloride. These structures reveal that the triangular conformation of the chloride ligands and the nearly equatorial coordination allow the perfect accommodation of planar trigonal monovalent anions such as NO3-, explaining their unusual strong binding. It is also shown that a localized negative charge such as that of Cl-, rather than a delocalized charge as in the case of nitrate, is essential for maximal activation. The chloride-free mutant Lys300Gln indicates that chloride is not mandatory for the catalytic mechanism but strongly increases the reactivity at the active site. Disappearance of the putative catalytic water molecule in this weakly active mutant supports the view that chloride helps to polarize the hydrolytic water molecule and enhances the rate of the second step in the catalytic reaction. [less ▲]

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See detailSpatial filtering using a raster geographic information system: methods for scaling health and environmental data
Ali, M.; Emch, M.; Donnay, Jean-Paul ULg

in Health & Place (2002), 8(2), 85-92

Despite the use of geographic information systems (GIS) in academic research, it is still uncommon for public health officials to use such tools for addressing health and environmental issues ... [more ▼]

Despite the use of geographic information systems (GIS) in academic research, it is still uncommon for public health officials to use such tools for addressing health and environmental issues. Complexities in methodological issues for addressing relationships between health and environment, investigating spatial variation of disease, and addressing spatial demand and supply of health care service, hinder the use of GIS in the health sector. This paper demonstrates simple spatial filtering methods for analyzing health and environmental data using a raster GIS. Computing spatial moving average rates reduces individual affects and creates a continuous surface of phenomena. Another spatial analytical method discussed is computation of exposure status surfaces including neighbors' influences weighted by distance decay. These methods describe how health and environmental data can be scaled in order to better address health problems. Spatial filtering methods are demonstrated using health and population surveillance data within a GIS that were collected for approximately 210,000 people in Matlab, Bangladesh. (C) 2002 Published by Elsevier Science Ltd. [less ▲]

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