Un exemple d'étude dendrochronologique: la charpente de la chapelle Saint_hubert à Weweler (Burg-Reuland)

in Bulletin de la Fondation Vanhove-Vonneche (1991), 3

Question sociale et politique pontificale. L'itinéraire d'un démocrate chrétien: Antoine Pottier (1849-1923)

in Revue belge de philologie et d'histoire (1991), t. LXIX(n°2), 300-321

Interprétation et rectification des jugements répressifs

in Revue de Jurisprudence de Liège, Mons et Bruxelles (1991)

Le type toponymique "mouchenière"

in Nouvelle Revue d'Onomastique (1991), 17/18

Polarization correction to the electrostatic potential at the CNDO and theab initio level. Influence of the basis set expansion

in Theoretica Chimica Acta (1991), 79(2), 141-152

The influence of the basis set on the electrostatic potential corrected for polarization has been studied for H2S, CH3SH and COHCH2SH. The position and deepness of the minima and the height of the barrier ... [more ▼]

The influence of the basis set on the electrostatic potential corrected for polarization has been studied for H2S, CH3SH and COHCH2SH. The position and deepness of the minima and the height of the barrier between symmetric minima is discussed at both the deorthogonalized CNDO/2 and ab initio levels within STO-3G, 3-21G, 4-31G, 6-31G and 6-311G basis sets. The calculation of the electrostatic potential and corrected one using CNDO deorthogonalized coefficients including 3d orbitals has been applied at the first time on sulfur-containing molecules. The influence of polarization and diffuse functions has also been analysed and the incidence of the polarization correction on the relative proton affinity in NH2(CH2)3NHCH3 and in the adenine molecule has been investigated at the CNDO and ab initio levels. At both levels, the relative proton affinity of several basic sites in the same molecule can be qualitatively expressed without inclusion of the polarization correction except in the case of substituted amines. [less ▲]

Un témoignage antérieur à Celse sur l’opération du coloboma : P. bibl. univ. Giss. IV.44

in Chronique d'Egypte : Bulletin Périodique de la Fondation Egyptologique Reine Elisabeth (1991), 66

Le point sur l'evolution dans le domaine des formulations.

in Parasitica (1991), 47(2-3),

Importance de l'axe hypophyso-hepatique dans le regulation hormonale de la croissance chez le bovin.

in Bulletin des Recherches Agronomiques de Gembloux (1991), 26(2),

Generation of bovine multisite haplotypes using random cosmids

in Genomics (1991), 10

One hundred ten random cosmids were used to probe Southern blots of DNA from nine unrelated cattle digested with 12 restriction enzymes. Although only one-third of the expected fragments were explored, 85 ... [more ▼]

One hundred ten random cosmids were used to probe Southern blots of DNA from nine unrelated cattle digested with 12 restriction enzymes. Although only one-third of the expected fragments were explored, 85% of the cosmids revealed at least one polymorphism. The mean heterozygosity of the generated haplotypes was estimated at 51.9%. A surprisingly high proportion of polymorphisms (approximately 25%) was attributed to insertion-deletion events, compensating for the lower level of nucleotide diversity observed in cattle (pi approximately 0.0007) compared to that in human. The mutation rate at cytosines in the CpG dinucleotide was estimated approximately 10 times higher than that at other nucleotides. When used in linkage studies, the generated markers should cover approximately 50% of the bovine genome. [less ▲]

Biodegradation, drug release mechanism and physiological activity of a protein's sustained release system

in Proceedings International Symposium Control. Rel.Bioact. Mater. (1991)

Malitrah : Une formation en alternance dans l'enseignement professionnel spécial de plein exercice. Présentation d'un projet

in Education Permanente (1991), 222

Immunohistochemical expression of epidermal growth factor receptors in nuclei of a subpopulation of keratinocytes and sweat gland cells.

in Dermatologica (1991), 183(1), 7-9

We have raised a polyclonal antibody to the 170-kD epidermal growth factor receptor. We found an intercellular pattern of immunoreactivity in the epidermis as well as a positivity of the cytoplasm of ... [more ▼]

We have raised a polyclonal antibody to the 170-kD epidermal growth factor receptor. We found an intercellular pattern of immunoreactivity in the epidermis as well as a positivity of the cytoplasm of keratinocytes and eccrine secretory cells. In some samples, a nuclear labelling was evidenced in these type of cells. There is a close resemblance in the topographical distribution of these cells with nuclear labelling and those synthesizing DNA under phytohaemagglutinin stimulation. [less ▲]

Fast double antibody radioimmunoassay of human granulocyte myeloperoxidase and its application to plasma.

in Journal of Immunological Methods (1991), 137(2), 181-191

The haem enzyme myeloperoxidase (MPO) (EC 1.11.1.7) with a spectral A430/A280 ratio greater than 0.7 and a specific activity of 125 U/mg was purified from isolated human neutrophils. To obtain a ... [more ▼]

The haem enzyme myeloperoxidase (MPO) (EC 1.11.1.7) with a spectral A430/A280 ratio greater than 0.7 and a specific activity of 125 U/mg was purified from isolated human neutrophils. To obtain a radioimmunoassay (RIA) for this enzyme, a specific antiserum against human neutrophil MPO was raised in rabbits and used at an initial dilution of 1/10,000. MPO labelled with 125iodine by a technique of self-labelling in the presence of H2O2, had a specific activity of 24 mCi/mg. After incubation at room temperature (2 h) and separation by double antibody precipitation in the presence of polyethylene glycol, the sensitivity of the RIA was 21 ng/ml. The RIA showed good precision and accuracy with intra- and interassay coefficients of variation of less than 7% for MPO concentrations ranging from 100 to 800 ng/ml, and satisfactory recoveries of known amounts of exogenous MPO in plasma. For the measurement of MPO in blood, the best sampling technique was to collect blood into EDTA. Rapid centrifugation (within 20 min) was necessary for blood collected into heparin. Mean MPO values in normal individuals were 340 +/- 98 ng/ml in EDTA plasma (n = 152) and 332 +/- 82 ng/ml in heparinized plasma (n = 34). When MPO was measured 12-6 h after injury in critically ill patients high values (above 1000 ng/ml) were found in 6/15 patients with multiple injuries. In patients with sepsis (n = 22), MPO values were always above 1000 ng/ml. [less ▲]

The Photoionization of Ammonia revisited. The Vibrational Autoionization of NH3 and its three Isotopomers in the 10-12 eV photon energy range.

in Chemical Physics (1991), 155

The photoionzation efficiency curves of NH3 and its three isotopomers have been investigated in the photon energy range of the first ionized state. From the analysis of the corresponding vibrational ... [more ▼]

The photoionzation efficiency curves of NH3 and its three isotopomers have been investigated in the photon energy range of the first ionized state. From the analysis of the corresponding vibrational structure, wavenumbers and anharmonicity constants are deduced. The detailed investigation of the abundant autoionization structure tends to show the adiabatic ionization energy to be 10.072+/-0.010 eV for NH3, NH2D and NHD2 and 10.083+/-0.010 eV for ND3. All autoionization features were classified in vibrational progressions (nu2 bending mode) belonging to nasa1 (or nd) and npe (n=5, 6, 7) Rydberg series. Vibrational autoionization occurs through Delta v transitions up to -9. A qualitative analysis of the intensity distribution of these series strongly supports that transitions involving odd Delta v values are favoured. This observation can be understood by applying group theoretical considerations to the theory of vibrational autoionization. [less ▲]

Neuroendocrine Control of the Onset of Puberty: Secretion of Gonadotrophin-Releasing Hormone from Rat Hypothalamic Explants

in Acta Paediatrica Scandinavica. Supplement (1991), 372

Aspects chirurgicaux du traitement des affections surrenaliennes.

in Acta Chirurgica Belgica (1991), 91(2), 107-11

With the greatly enhanced accuracy of current endocrinologic diagnosis assisted by precise diagnostic imaging, together with greatly enhanced preparation of patients with endocrinopathy for safer ... [more ▼]

With the greatly enhanced accuracy of current endocrinologic diagnosis assisted by precise diagnostic imaging, together with greatly enhanced preparation of patients with endocrinopathy for safer anesthetic and surgical procedure (e.g. adrenal cortical cancers, cortisol and aldosterone producing adenomas and pheochromocytomas), operative procedures can be planned and conducted more precisely. For the surgeon, the strategy for treatment of functional and neoplastic disorders of the adrenal glands has essentially to consider the anatomy of the suprarenal glands, the deleterious effects of hormone excess before and during operation, the presumed nature of incidentally discovered adrenal mass and the size of the tumor. [less ▲]

Recension bibliographique de "Plisnier P.D., Micha J.C. et Frank V. : Biologie et exploitation des poissons du Lac Ihema (bassin Akagera, Rwanda)".

in Cahiers d'Ethologie (1991), 11(4), 522

Spatially continuous processing within a raster based GIS : some examples of geographical models

in Bulletin de la Société belge de Géographie - SOBEG (1991), 2

La représentation d'un territoire en mode raster introduit une discrétisation qui peut être considérée, en première approximation, comme le résultat d'un échantillonnage à deux dimensions de cette surface ... [more ▼]

La représentation d'un territoire en mode raster introduit une discrétisation qui peut être considérée, en première approximation, comme le résultat d'un échantillonnage à deux dimensions de cette surface. Sous cette forme, un attribut spatialement continu constitue une couche de données directement accessible aux systèmes d'information géographique (S.I.G.) hybrides (raster/vecteur). Les avantages de cette représentation sont déjà exploités pour visualiser et traiter des phénomènes physiques surfaciques, tels que les modèles numériques de terrain. Une procédure identique peut être appliquée aux surfaces théoriques issues de l'application de modèles géographiques. En outre, les propriétés du mode raster sont susceptibles d'offrir des solutions graphiques soit plus simples, soit en l'absence de solutions analytiques. Cet article illustre ces avantages sur quelques modèles bien connus de l'analyse spatiale. [less ▲]

Pulsatile insulin delivery has greater metabolic effects than continuous hormone administration in man: importance of pulse frequency.

in Journal of Clinical Endocrinology and Metabolism (1991), 72(3), 607-15

The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26 ... [more ▼]

The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26-min pulses. The study was performed on nine male healthy volunteers submitted to a 325 min glucose-controlled glucose iv infusion using the Biostator. The endogenous secretion of pancreatic hormones was inhibited by somatostatin. Three experiments were performed in each subject on different days and in random order. In all cases glucagon was replaced (58 ng min-1). The amounts of insulin infused were identical in all instances and were 0.2 mU kg-1 min-1 (continuous), 1.3 mU kg-1 min-1, 2 min on and 11 min off (13-min pulses) or 2.6 mU kg-1 min-1, 2 min on and 24 min off (26-min pulses). Blood glucose levels and glucose infusion rate were monitored continuously by the Biostator, and classic methodology using D-[3-3H] glucose infusion allowed to study glucose turnover. When compared with continuous insulin, 13-min insulin pulses induced a significantly greater inhibition of endogenous glucose production. This effect disappeared when insulin was delivered in 26-min pulses. We conclude that, in man, an adequate pulse frequency is required to allow the appearance of the greater inhibition of pulsatile insulin on endogenous glucose production. [less ▲]

Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy.

in Journal of Clinical Immunology (1991), 11(2), 78-94

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found ... [more ▼]

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies. In addition, we noted that this interaction was dose dependent, Ca2+ dependent, saturable, and not covalent, was inhibited by soluble FN, but not by a prior incubation of FN-coated plates with anti-human fibronectin antibodies, and appeared to involve on the dimeric FN other structures than its heparin-binding, collagen-binding, or C1q-binding domains. Similar experiments conducted with normal plasma indicated that plasma IgA, but not plasma IgG or IgM, was also capable of significant binding to FN-coated plates. In contrast, serum IgA did not significantly bind to those plates under otherwise identical experimental conditions. Thus, the coagulation process induces a strong decrease in the FN-BC of circulating IgA, which implies the necessity of using plasma rather than serum to study such interactions. The apparent molecular weight of plasma IgA interacting with FN-coated plates ranged between 450 and 900 kd, and its major binding characteristics were quite similar to those observed with purified polymeric IgA. The FN-BC of plasma IgA was then measured by the same ELISA in 30 patients with primary IgA nephropathy (IgAN) and in 23 healthy controls. The mean FN-BC of plasma IgA was significantly higher in patients than in normal controls. This enhancement was due mainly to the augmentation in the concentration of circulating "macromolecular" IgA and was significantly correlated with the plasma levels of IgA-FN complexes. However, the pathogenetic role of these findings was probably not determinant since similar observations were made in alcoholic liver cirrhosis without urinary abnormalities and since the FN-BC of plasma IgA or the plasma levels of IgA-FN complexes were not correlated with the various biological parameters of evolutivity of primary IgAN. In conclusion, these studies suggest that the ability of polymeric IgA to directly bind to FN is involved in the formation of circulating IgA-FN complexes and that this normal binding process, although enhanced in IgAN, is probably not responsible for kidney injury, at least in the patients studied. [less ▲]

Les inventaires forestiers nationaux en Europe: tentative de synthèse.

in Silva Belgica (1991), 98(4), 13-19

Dans de nombreux pays, la forêt est une ressource naturelle importante et au niveau mondial, les problèmes d'approvisionnement en bois se posent avec de plus en plus d'acuité. Le développement des ... [more ▼]

Dans de nombreux pays, la forêt est une ressource naturelle importante et au niveau mondial, les problèmes d'approvisionnement en bois se posent avec de plus en plus d'acuité. Le développement des populations et de leurs besoins en bois a fait prendre conscience de la nécessité de gérer ce patrimoine de façon responsable, sous peine de le voir s'appauvrir, voire même disparaître dans des proportions inquiétantes. Assez paradoxalement, ce sont les pays riches en "or vert" qui ont innové dans ce domaine (Suède, Finlande, Canada,...). Mais comment gérer une ressource aussi étendue et diversifiée sans se doter des moyens de la connaître ? A ce titre, un inventaire réalisé à l'échelle des nations est devenu indispensable. Dans les lignes qui suivent, nous tenterons de faire le point sur les approches méthodologiques propres aux inventaires forestiers nationaux (ou régionaux) et nous évoquerons différentes réalisations concrètes actuellement en vigueur dans plusieurs pays, principalement ceux à tradition forestière. [less ▲]

Laparoscopic management of large ovarian endometrial cyst: use of fibrin sealant.

in Journal of Gynecologic Surgery (1991), 7(3), 163-6

In order to prevent postoperative adhesions often present after CO 2 laser vaporization of large endometriomas, 62 patients with endometriomas greater than 3 cm diameter were treated with a new procedure ... [more ▼]

In order to prevent postoperative adhesions often present after CO 2 laser vaporization of large endometriomas, 62 patients with endometriomas greater than 3 cm diameter were treated with a new procedure. Partial cystectomy was performed using the CO 2 laser. Residual endometrial cyst was then vaporized. After laparoscopic vaporization of the interior cyst wall, a fibrin glue (Tissucol) was injected onto the vaporized area to close laparoscopically the ovarian cyst cavity. When performed, second-look laparoscopy demonstrated healing of the ovary without any periovarian adhesions. The incidence of periovarian adhesions was significantly lower (p less than 0.01) than in the group of women treated by laparoscopy and in whom the glue was not used to close the ovarian cyst cavity. [less ▲]

Management of small woods in Belgium.

in Quarterly Journal of Forestry (1991), 85(1), 37-42

In Belgium, forest occupies 20 per cent of the total land area. Private forests account for about 52 per cent; they are generally small (averaging about three ha) and their owners are not accustomed to ... [more ▼]

In Belgium, forest occupies 20 per cent of the total land area. Private forests account for about 52 per cent; they are generally small (averaging about three ha) and their owners are not accustomed to basing their decisions on a management plan. However, some attempts to develop co-operation through forestry associations exist and the regional authorities tend to encourage them. Whatever the details of any possible future legislation may be, the principal aim must be the development and introduction of an extremely simple form of management plan (the so-called 'plan simple de gestion') in exchange for assistance to the private owner. [less ▲]

Soya oil in diet for growing fattening bulls : effects on animal performance and fatty acid composition

in Animal Production (1991), 53

Analyse du coût d'exploitation des navires sur les voies d'eau intérieures

in Bulletin de l’Association Internationale Permanente des Congrès de Navigation [Bulletin de l'AIPCN] (1991), (supplément au Bulletin n°74), 20

Aller en pèlerinage à Saint-Martin de Tours au XVIIIe siècle

in Bulletin de la Société Royale Le Vieux-Liège (1991), t. XII, n° 261

Nutritive-Value Of Triticale Cultivars In Pigs As A Function Of Their Chemical-Composition

in Animal Feed Science & Technology (1991), 35(1-2), 49-53

Approche physique des phénomènes hydrodynamiques

in Revue de l'AIRH (1991)

Les courants excito moteurs de basses fréquences. Détermination des durées d'impulsions optimales de stimulation

in Kinésitherapie, les Annales (1991), 18(10), 483-484

Miscellaneous spectroscopic observations of quasars and quasar candidates

in Astronomy and Astrophysics. Supplement Series (1990), 86

Spectroscopic observations are presented for 11 quasar candidates, as well as 19 quasars with uncertain redshift, three BL Lac candidates, and 11 objects located within a few arcsec of a quasar. The ... [more ▼]

Spectroscopic observations are presented for 11 quasar candidates, as well as 19 quasars with uncertain redshift, three BL Lac candidates, and 11 objects located within a few arcsec of a quasar. The spectra indicate than nine of the 11 quasar candidates are stars, while the remaining two are low-redshift galaxies. The individual objects studied and commented on include KPNO 1, CFHT 2, Q 0010+023, UM 232, UM 473, WEE 124, UM 644, PKS 1514+197, MC3 1639+155, and WEE 185. [less ▲]

Characterization of an Enterococcus Hirae Penicillin-Binding Protein 3 with Low Penicillin Affinity

in Journal of Bacteriology (1990), 172(12), 6856-6862

Enterococcus hirae S185, a clinical isolate from swine intestine, exhibits a relatively high resistance to penicillin and contains two 77-kDa penicillin-binding proteins 3 of high (PBP 3s) and low (PBP 3r ... [more ▼]

Enterococcus hirae S185, a clinical isolate from swine intestine, exhibits a relatively high resistance to penicillin and contains two 77-kDa penicillin-binding proteins 3 of high (PBP 3s) and low (PBP 3r) affinity to penicillin, respectively. A laboratory mutant S185r has been obtained which overproduces PBP 3r and has a highly increased resistance to penicillin. Peptide fragments specifically produced by trypsin and SV8 protease digestions of PBP 3r were isolated, and the amino acid sequences of their amino terminal regions were determined. On the basis of these sequences, oligonucleotides were synthesized and used as primers to generate, by polymerization chain reaction, a 233-bp DNA fragment the sequence of which translated into a 73-amino-acid peptide segment of PBP 3r. These structural data led to the conclusion that the E. hirae PBP 3r and the methicillin-resistant staphylococcal PBP 2' are members of the same class of high-Mr PBPs. As shown by immunological tests, PBP 3r is not related to PBP 3s but, in contrast, is related to the 71-kDa PBP 5 of low penicillin affinity which is responsible for penicillin resistance in E. hirae ATCC 9790 and R40. [less ▲]

Perspectives à l'horizon 1992 de la mobilité des biens et des personnes dans la CEE. Conclusions du congrès "Transports à l'Horizon 1992" GTU-AIL

in Bulletin de l'AILG (1990), (12), 3

Effects of the Nonsteroidal Inhibitor R76713 on Testosterone-Induced Sexual Behavior in the Japanese Quail (Coturnix Coturnix Japonica)

in Hormones & Behavior (1990), 24(4), 510-31

A new triazole derivative, R76713 (6-[4-chlorophenyl)(1H-1,2,4-triazol-1-yl)methyl]-1-methyl-1H- benzotriazole), was recently shown to inhibit aromatase selectively without affecting other steroid ... [more ▼]

A new triazole derivative, R76713 (6-[4-chlorophenyl)(1H-1,2,4-triazol-1-yl)methyl]-1-methyl-1H- benzotriazole), was recently shown to inhibit aromatase selectively without affecting other steroid-metabolizing enzymes and without interacting with estrogen, progestin, or androgen receptors. This compound was tested for its capacity to intefere with the induction of copulatory behavior by testosterone (T) in castrated Japanese quail (Coturnix coturnix japonica). In a first experiment, R76713 inhibited (range 0.01 to 1 mg/kg) the activation of sexual behavior by T silastic implants and hypothalamic aromatase activity in castrated male quail in a dose-dependent manner. The 5 alpha- and 5 beta- reductases of T were not systematically affected. Stereotaxic implantation of R76713 in the medial preoptic area similarly blocked the behavior activated by systemic treatment with T, demonstrating that central aromatization of androgen is implicated in the activation of behavior. These inhibiting effects of R76713 on behavior were observed when implants were placed in the medial part of the nucleus preopticus medialis, confirming the implication of this brain area in the control of male copulatory behavior. Finally, the behavioral inhibition produced by R76713 could be reversed by simultaneous treatment with a dose of estradiol, which was not behaviorally effective by itself. This suggests that the behavioral deficit induced by the inhibitor was specifically due to the suppression of estrogen production. This also shows that the activation of copulatory behavior probably results from the interaction of androgens and estrogens at the brain level, as the two treatments separately providing these hormonal stimuli (T with the aromatase inhibitor on one hand and a low dose of estradiol on the other hand) had almost no behavioral effects but they synergized to activate copulation when given concurrently. These data confirm the critical role of preoptic aromatase in the activation of reproductive behavior and demonstrate that R76713 is a useful tool for the in vivo study of estrogen-dependent processes. [less ▲]

Heparin-induced thrombocytopenia: A case report

in Angiology (1990), 41(12), 1075-1081

The authors report a case of heparin-induced thrombocytopenia, in whom massive pulmonary embolism occurred in spite of heparin anticoagulation. Successful pulmonary thrombectomy was carried out under ... [more ▼]

The authors report a case of heparin-induced thrombocytopenia, in whom massive pulmonary embolism occurred in spite of heparin anticoagulation. Successful pulmonary thrombectomy was carried out under cardiopulmonary bypass, with limitation of platelet clumping during bypass by aggregation inhibitors. This report is a comprehensive contribution to a better understanding of this rare immunoallergic complication of heparin administration, with a high incidence of serious thromboembolic events. The optimal management for cases of unavoidable reexposure to heparin is discussed. [less ▲]

Diurnal Rhythmicity in the Pattern of Mrnas in the Leaves of Sinapis Alba

in Plant Physiology (1990), 94(4), 1590-1597

Previous studies have shown that certain specific leaf mRNAs exhibit a diurnal rhythmicity in their quantity in higher plants. To determine whether this situation is restricted to a few mRNAs, or affects ... [more ▼]

Previous studies have shown that certain specific leaf mRNAs exhibit a diurnal rhythmicity in their quantity in higher plants. To determine whether this situation is restricted to a few mRNAs, or affects a large number, we have used in vitro translation and two-dimensional polyacrylamide gel electrophoresis to analyze the mRNA complement in leaves of Sinapis alba at different times during an 8-hour/16-hour day/night cycle. A method for the visual analysis of two-dimensional polyacrylamide gel electrophoresis was also developed. This method selected, at each sampling time, spots that were significant. It then selected, between two sampling times, intensity changes that were significant at the 0.02 confidence level. During a day/night cycle, complex rhythmic changes affected about 10% of the mRNAs. Nineteen different rhythm patterns were found. These 19 patterns fell into four main classes: mRNAs that increase during the light period and decrease during the dark, mRNAs that increase and then decrease during the light period, mRNAs that decrease during the light period and increase during the dark period, and mRNAs that increase and then decrease during the dark period. [less ▲]

An automatic remeshing technique for finite element simulation of forming processes

in International Journal for Numerical Methods in Engineering (1990), 30(8), 1503-1525

Indications actuelles de la greffe hétérotopique en transplantation cardiaque

in Revue Médicale de Liège (1990), 45(12), 614-9

Pour une production ligneuse de qualité : impératifs écologiques et sylvicoles.

in Agricontact (1990), (223), 1-7

New observations and gravitational lens models of the Cloverleaf quasar H1413 + 117

in Astrophysical Journal (1990), 364

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong ... [more ▼]

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong radio source between images B and D. Gravitational lens models of H1413 + 117 using (1) a single elliptical galaxy and (2) two spherical galaxies are presented, which fit the positions of the four images of the quasar remarkably well. The models suggest that the strong radio source is a feature of the quasar, e.g., an ejected blob, which lies right on the caustic of the lens and is thereby strongly amplified. The time delays predicted by these models are sufficiently short to allow for their determination within one observational season, making H1413 + 117 an exceptionally well suited object for gravitational lens research. [less ▲]

Distribution of Aromatase in the Brain of the Japanese Quail, Ring Dove, and Zebra Finch: An Immunocytochemical Study

in Journal of Comparative Neurology (1990), 301(2), 276-88

An immunocytochemical peroxidase-antiperoxidase procedure using a purified polyclonal antibody raised against human placental aromatase was used to localize aromatase-containing cells in the brain of ... [more ▼]

An immunocytochemical peroxidase-antiperoxidase procedure using a purified polyclonal antibody raised against human placental aromatase was used to localize aromatase-containing cells in the brain of three avian species: the Japanese quail, the ring dove, and the zebra finch. In quail and dove, immunoreactive cells were found only in the preoptic area and hypothalamus, with a high density of positive cells being present in the medial preoptic area, in the septal area above the anterior commissure, in the ventromedial nucleus of the hypothalamus, and in rostral part of the infundibulum. Immunoreactivity was weaker in zebra finches, and no signal could therefore be detected in the ventromedial and tuberal hypothalamus. The positive material was localized in the perikarya and in adjacent cytoplasmic processes, including the full length of axons always leaving a clear unstained cell nucleus. These features could be observed in more detail on sections cut from perfused brains and stained with an alkaline phosphatase procedure. The distribution of aromatase immunoreactivity was similar in the three species although minor differences were observed in the preoptic area. The localization of labelled neurons coincided with the distribution of aromatase activity as studied by in vitro radioenzyme assays on brain nuclei dissected by the Palkovits punch method. There was one striking exception to this rule: no immunoreactivity was detected in the zebra finch telencephalon, while assays had shown the presence of an active enzyme in several nuclei such as the robustus archistriatalis, the hyperstriatum ventrale pars caudale, and the hippocampus and area parahippocampalis. The origins of this discrepancy and the functional role of the aromatase observed in the axons are discussed. [less ▲]

Core velocity dispersion and mass-to-light ratio of the old Magellanic globular cluster NGC 1835

in Astronomy and Astrophysics (1990), 239

Abstract image available at: http://adsabs.harvard.edu/abs/1990A&A...239..142D

Beta-lactamase expression in Streptomyces cacaoi

in Journal of Bacteriology (1990), 172(11), 6427-6434

Plasmids were prepared by inserting genomic DNA fragments from Streptomyces cacaoi within the mel gene of plasmid pIJ702. The inserted DNA fragments contain the beta-lactamase-encoding bla gene and ... [more ▼]

Plasmids were prepared by inserting genomic DNA fragments from Streptomyces cacaoi within the mel gene of plasmid pIJ702. The inserted DNA fragments contain the beta-lactamase-encoding bla gene and upstream nucleotide sequences of various lengths. The transcription start point of bla was identified by nuclease S1 mapping. Upstream nucleotide sequences of sufficient lengths had an enhancing effect on beta-lactamase production by the Streptomyces host. The dot blot hybridization assay revealed that this effect was exerted at the transcriptional level. Experimental evidence strongly suggests that the underlying mechanism involves, at least in part, one or several trans-acting elements. In one of the constructs, in which the upstream nucleotide sequence was reduced to 0.3 kb, the bla promoter was present but the bla gene was expressed by readthrough from a promoter, possibly the mel promoter, of the pIJ702 vector. [less ▲]

The chemical composition of the extreme halo stars. III - Equivalent widths of 20 dwarfs

in Astronomy and Astrophysics. Supplement Series (1990), 86

In the first two papers of this series the chemical composition of 20 extreme halo stars was discussed. The abundances of a number of elements were determined using model atmosphere analysis of equivalent ... [more ▼]

In the first two papers of this series the chemical composition of 20 extreme halo stars was discussed. The abundances of a number of elements were determined using model atmosphere analysis of equivalent widths. In this paper a tabulation of the equivalent width data is presented. A comparison of the measurements with the equivalent widths from different sources is used to assess the quality of the data. [less ▲]

Détermination du degré de réticulation du collagène par sa solubilité thermique et par analyse calorimétrique différentielle (ACD).

in Viandes et Produits Carnés (1990), 11

De la valeur d'une entreprise à la détermination de son prix de cession : le problème du "Goodwill"

in La Vie au Bureau (1990), 1990(Novembre), 12-20

This paper discusses key aspects linked to the valuation of "Goodwill" in the Belgian accounting context and discusses some important questions specific to the valuation of SMEs.

Application au tilapia Oreochromis aureus d'une technique électronique d'identification individuelle

in Cahiers d'Ethologie (1990), 10(3-4), 441-446

Heat transport in dielectric crystals at low temperature: A variational formulation based on extended irreversible thermodynamics

in Physical Review (1990), 42

We propose a variational principle applicable to the heat-transport equations derived some years ago by Guyer and Krumhansl [Phys. Rev. 133, 1411 (1964); 148, 766 (1966); 148, 778 (1966)] to describe heat ... [more ▼]

We propose a variational principle applicable to the heat-transport equations derived some years ago by Guyer and Krumhansl [Phys. Rev. 133, 1411 (1964); 148, 766 (1966); 148, 778 (1966)] to describe heat-wave propagation in dielectric crystals at low temperature. The variational principle appears as a generalization of Prigogine's minimum-entropy production criterion. The analysis is based on extended irreversible thermodynamics, which is used to derive the Guyer-Krumhansl equations from macroscopic arguments. [less ▲]

Formation of P Cygni line profiles in relativistically expanding atmospheres

in Astrophysical Journal (1990), 361

The probabilistic approach of Surdej (1979) is followed to generalize the Sobolev (1958) formalism to the case of special relativity, in order to interpret accurately the P Cygni line profiles observed in ... [more ▼]

The probabilistic approach of Surdej (1979) is followed to generalize the Sobolev (1958) formalism to the case of special relativity, in order to interpret accurately the P Cygni line profiles observed in the spectrum of broad absorption-line quasars and supernovae. The expressions of the source function and of the line profile are derived, and it is shown that the relativistic P Cygni line profiles are significantly different from those computed in the framework of the classical theory. Thus, for increasing values of the terminal wind velocity, the red emission wing becomes definitely narrower than the blue one, while the line center emission increases. This is no longer symmetrical in accordance with the relativistic expression of the Doppler effect. [less ▲]

La prévention des faillites au sein des Petites et Moyennes Entreprises : application de modèles statistiques simples au cas belge

in La Vie au Bureau (1990)

Après avoir rappelé l'importance du phénomène de la faillite et la manière dont de nombreuses PME entrent insidieusement dans un processus de faillite et de défaillance, cet article présente quelques ... [more ▼]

Après avoir rappelé l'importance du phénomène de la faillite et la manière dont de nombreuses PME entrent insidieusement dans un processus de faillite et de défaillance, cet article présente quelques modèles statistiques simples qui s'avèrent à la fois utiles et calculables dans le contexte belge du début des années '90. [less ▲]

Engineering a Novel Beta-Lactamase by a Single Point Mutation

in Protein Engineering (1990), 4(1), 79-86

beta-Lactamases are widespread and efficient bacterial enzymes which play a major role in bacterial resistance to penicillins and cephalosporins. In order to elucidate the role of the residues lying in a ... [more ▼]

beta-Lactamases are widespread and efficient bacterial enzymes which play a major role in bacterial resistance to penicillins and cephalosporins. In order to elucidate the role of the residues lying in a conserved loop of the enzymatic cavity of the active-site serine Streptomyces albus G beta-lactamase, modified proteins were produced by oligo-directed mutagenesis. Mutation of Asn116, which lies on one side of the active site cavity pointing to the substrate-binding site, into a serine residue resulted in spectacular modifications of the specificity profile of the enzyme. That replacement yielded an enzyme with a nearly unchanged activity towards good penicillin substrates. In sharp contrast its efficiency in hydrolysing cephalosporins was drastically reduced, the best substrates suffering the largest decrease in the second-order rate constant for serine acylation. In fact that single mutation generated a truly new enzyme behaving exclusively as a penicillinase, a situation which is never encountered to the same degree in any of the numerous naturally occurring variants of class A beta-lactamases. [less ▲]