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See detailThe photospheric abundances of active binaries. II. Atmospheric parameters and abundance patterns for 6 single-lined RS CVn systems
Morel, Thierry ULg; Micela, G.; Favata, F. et al

in Astronomy and Astrophysics (2003), 412

Photospheric parameters and abundances are presented for a sample of single-lined chromospherically active binaries from a differential LTE analysis of high-resolution spectra. Abundances have been ... [more ▼]

Photospheric parameters and abundances are presented for a sample of single-lined chromospherically active binaries from a differential LTE analysis of high-resolution spectra. Abundances have been derived for 13 chemical species, including several key elements such as Li, Mg, and Ca. Two methods have been used. The effective temperatures, surface gravities and microturbulent velocities were first derived from a fully self-consistent analysis of the spectra, whereby the temperature is determined from the excitation equilibrium of the Fe I lines. The second approach relies on temperatures derived from the (B-V) colour index. These two methods give broadly consistent results for the stars in our sample, suggesting that the neutral iron lines are formed under conditions close to LTE. We discuss the reliability in the context of chromospherically active stars of various colour indices used as temperature indicators, and conclude that the (V-R) and (V-I) colours are likely to be significantly affected by activity processes. Irrespective of the method used, our results indicate that the X-ray active binaries studied are not as metal poor as previously claimed, but are at most mildly iron-depleted relative to the Sun (-0.41protect <~ [Fe/H]protect la +0.11). A significant overabundance of several chemical species is observed (e.g., the alpha -synthezised elements). These abundance patterns are discussed in relation to stellar activity. Based on observations collected at ESO (La Silla, Chile). Table A.1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/495 [less ▲]

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See detailKinetic properties of the alpha(2) homo-oligomeric glycine receptor impairs a proper synaptic functioning
Mangin, J. A.; Baloul, M.; de Carvalho, L. P. et al

in Journal of Physiology-London (2003), 553(2), 369-386

Ionotropic glycine receptors (GlyRs) are present in the central nervous system well before the establishment of synaptic contacts. Immature nerve cells are known, at least in the spinal cord, to express ... [more ▼]

Ionotropic glycine receptors (GlyRs) are present in the central nervous system well before the establishment of synaptic contacts. Immature nerve cells are known, at least in the spinal cord, to express alpha(2) homomeric GlyRs, the properties of which are relatively unknown compared to those of the adult synaptic form of the GlyR (mainly alpha(1)/beta heteromeres). Here, the kinetics properties of GlyRs at the single-channel level have been recorded in real-time by means of the patch-clamp technique in the outside-out configuration coupled with an ultra-fast flow application system (< 100 µs). Recordings were performed on chinese hamster ovary (CHO) cells stably transfected with the a, GlyR subunit. We show that the onset, the relaxation and the desensitisation of α(2) homomeric GlyR-mediated currents are slower by one or two orders of magnitude compared to synaptic mature GlyRs and to other ligand-gated ionotropic channels involved in fast synaptic transmission. First latency analysis performed on single GlyR channels revealed that their slow activation time course was due to delayed openings. When synaptic release of glycine was mimicked (1 mM glycine; 1 ms pulse duration), the opening probability of α(2) homomeric GlyRs was low (P-o ≈ 0.1) when compared to mature synaptic GlyRs (P-o = 0.9). This low P-o is likely to be a direct consequence of the relatively slow activation kinetics of α(2) homomeric GlyRs when compared to the activation kinetics of mature α(1)/β GlyRs. Such slow kinetics suggest that embryonic α(2) homomeric GlyRs cannot be activated by fast neurotransmitter release at mature synapses but rather could be suited for a non-synaptic paracrine-like release of agonist, which is known to occur in the embryo. [less ▲]

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See detailClinical outcome following combination of cutting balloon angioplasty and coronary β-radiation for in-stent restenosis: A report from the RENO registry
Coucke, Philippe ULg; Roguelov; Eeckhout

in Journal of Invasive Cardiology (The) (2003), 15(12), 706-709

At present, vascular brachytherapy is the only efficient therapy for in-stent restenosis. Nevertheless, edge restenosis often related to geographical miss has been identified as a major limitation of the ... [more ▼]

At present, vascular brachytherapy is the only efficient therapy for in-stent restenosis. Nevertheless, edge restenosis often related to geographical miss has been identified as a major limitation of the technique. The non-slippery cutting balloon has the potential to limit vascular barotraumas, which, together with low-dose irradiation at both ends of the radioactive source, are the prerequisite for geographical miss. This prospective study aimed to examine the efficacy of combining cutting balloon angioplasty and brachytherapy for in-stent restenosis. The Radiation in Europe NOvoste (RENO) registry prospectively tracked all patients who had been treated by coronary β-radiation with the Beta-Cath System (Novoste Corporation, Brussels, Belgium) but were not included in a randomized radiation trial. A subgroup of patients with in-stent restenosis treated by cutting balloon angioplasty and coronary β-radiation (group 1, n = 166) was prospectively defined, and clinical outcomes of patients at 6 months were compared with those of patients treated by conventional angioplasty and coronary β-radiation (group 2, n = 712). At 6-month follow-up, there was a significant difference between groups 1 and 2 in target vessel revascularization (10.2% versus 16.6% respectively; p = 0.04) and in the incidence of major adverse clinical events (MACE) including death, myocardial infarction, and revascularization (10.8% versus 19.2%; p = 0.01). This observation was confirmed by a multivariate analysis indicating a lower risk for MACE at 6 months (odds ratio: 0.49; confidence intervals: 0.27-0.88; p = 0.02). Compared to conventional angioplasty, cutting balloon angioplasty prior to coronary beta-radiation with the Beta-Cath System seems to improve the 6-month clinical outcome in patients with in-stent restenosis. [less ▲]

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See detailLa violence d'un choc sans destinataire
Servais, Christine ULg

in Communication et Langages (2003), 138

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See detailTreatment of urological complications related to aorto-iliac pathology and surgery
Bonnet, Pierre ULg; Vandeberg, Colette ULg; Limet, Raymond ULg

in European Journal of Vascular and Endovascular Surgery (2003), 26(6), 657-664

Objectives. Proximity of ureters with iliac arteries makes them prone to damage by aorto-iliac pathology or surgery. The aim of this retrospective study is to analyse the incidence, the predisposing ... [more ▼]

Objectives. Proximity of ureters with iliac arteries makes them prone to damage by aorto-iliac pathology or surgery. The aim of this retrospective study is to analyse the incidence, the predisposing factors, and the optimal treatment Of ureteral stenosis (US) or leakages (UL). Design. Retrospective study. Material. Fiftyone ureteral lesions in 41 patients referred to the urologist in a fourteen years period in the same institution. Methods. Lesions are classified in three groups: A, preoperative; B, less than 3 months postoperatively; and C, more than 3 months postoperatively. Group A comprises 10 abdominal aortic aneurysm (AAA) patients; eight of the AAA are of the inflammatory type. Group B comprises 16 patients, 11 US and 9 UL. Group C comprises 15 patients and 15 US. Results. Endoureteral treatment was successful in most of the group B patients. Some of them, however, had to be submitted to secondary open surgery, so that the global success rate is 70% in group B. In group C, the response is poor following endourological treatment alone (12.5% success) and open surgery is more often needed (3 ureterolyses and 1 nephrectomy). Global success rate is 40%. Conclusion. Early diagnosis is associated to better results with less invasive procedure, late diagnosis is accompanied by a lower success rate of endourological treatment and requires more often primary open surgery. [less ▲]

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See detailEndometriose stade I et II: implications physiopathologiques, cliniques et therapeutiques
Nisolle, Michelle ULg; Nervo, Patricia ULg

in Journal de Gynécologie, Obstétrique et Biologie de la Reproduction (2003), 32(8, Pt 2), 11-4

Stage I and II endometriosis is defined by a r-AFS score respectively ranging from 1 to 5 and from 6 to 15. This mild, superficial endometriosis is a very common pathology occurring in infertile women ... [more ▼]

Stage I and II endometriosis is defined by a r-AFS score respectively ranging from 1 to 5 and from 6 to 15. This mild, superficial endometriosis is a very common pathology occurring in infertile women. Nevertheless, these women with stage I/II endometriosis have usually few pelvic pain. This review summarizes the recent literature concerning new data on the pathogenesis of peritoneal endometriosis and its clinical management. Retrograde menstruation, peritoneal adhesion of shed endometrial tissue, and outgrowth of endometrial cells, glands and stroma, are essential elements in the pathogenesis of endometriosis according to Sampson's classic implantation theory. Nevertheless, exact pathophysiology of endometriosis remains unknown. Superficial endometriotic lesions observed by laparoscopy have to be treated. Surgical procedure is not difficult for stage I and II of endometriosis. Surgical procedure remains controversial. Carbon dioxide (CO2) Laser can be used for laparoscopic destruction of endometriosis. Newer procedures, such as SurgiTouch (Lumenis), are more effective in vaporization and decrease the risk thermal damage of contiguous structures. The monopolar scissors can also be used in order to excise the peritoneal endometriotic lesions. Medical treatment may be usefull if surgical treatment is not complete or if the pelvic cavity is hypervascularized. In these cases, Gonadotropin-Releasing Hormone agonists (Gn-RHa) are the most common and effective treatment. [less ▲]

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See detailL'image du mois. Myxome de l'oreillette gauche
Tombeux, Christophe ULg; Davin, Laurent ULg; PIERARD, Luc ULg et al

in Revue Médicale de Liège (2003), 58(12), 723

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See detailTowards a consistant safety format of steel beam-columns: application of the new interaction formulae for ambient temperature to elevated temperatures
Vila Real, Paulo; Lopes, Nuno; da Silva, Luis et al

in Steel & Composite Structures (2003), 3(6), 383-401

Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed ... [more ▼]

Two new formulae for the design of beam-columns at room temperature have been proposed into Eurocode 3, prEN 1993-1-1 (2002), and are the result of great efforts made by two working groups that followed different approaches, a French-Belgian team and an Austrian-German one. Under fire conditions the prEN 1993-1-2 (structural fire design) presents formulae, for the design of beam-columns based on the prENV 1993-1-1 (1992). In order to study the possibility of having, in part 1-1 and part 1-2 of the Eurocode 3, the same approach, a numerical research was made using the finite element program SAFIR, developed at the University of Liege for the study 4 structures subjected to fire. [less ▲]

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See detailLes fondations belges d'utilité publique : entre permanence et changements
Pirotte, Gautier ULg; Heuschen, Laurence

Report (2003)

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See detailSite-directed mutagenesis of conserved inverted repeat sequences in the xylanase C promoter region from Streptomyces sp EC3
Giannotta, F.; Georis, J.; Rigali, Sébastien ULg et al

in Molecular Genetics & Genomics (2003), 270(4), 337-346

Streptomyces sp. EC3, a strain which was originally isolated from cattle manure compost, was shown to possess a strong xylanolytic activity. One of the genes responsible for this activity, xlnC, encodes a ... [more ▼]

Streptomyces sp. EC3, a strain which was originally isolated from cattle manure compost, was shown to possess a strong xylanolytic activity. One of the genes responsible for this activity, xlnC, encodes a secreted xylanase. In the native strain, as in the heterologous host S. lividans, expression of xlnC was detectable in the presence of xylan but not in the presence of glucose. Induction by xylan was shown to take place at the transcriptional level. The transcriptional start site of xlnC was mapped and likely -35 (5'-TTGACA-3') and -10 (5'-GAGAAC-3') motifs were identified. In order to localise putative conserved regulatory sequences, the promoter regions of xylanase-encoding genes from various Streptomyces species were aligned. This alignment revealed the existence of three sets of quite well conserved palindromic AT rich sequences called boxes 1, 2 and 3. Box 3 (5'-CGAAA N TTTCG-3') is the farthest away from the promoter region (150-200 bp). A shorter version of this palindrome (5'-GAAA NN TTTC-3') or (5'-CGAAA-3') constitutes box 1, which is located just upstream of the putative -35 promoter sequence. Box 2, located 5-7 bp upstream of box 1, comprises a shorter palindrome than box 3, with inverted polarity [5'-(G/C)TTTC (N) GAAA(G/C)-3']. The putative regulatory role of the conserved inverted repeats in boxes 2 and 3 in the promoter region of the xlnC gene from Streptomyces sp. EC3, was assessed. These boxes were modified by site-directed mutagenesis, and the mutant promoter regions, as well as the wild-type promoter region, were separately fused to a beta-lactamase reporter gene. Analysis of the expression patterns of these fusions in cultures grown in the presence of glucose, xylan or both carbon sources demonstrated that these motifs were cis -acting negative regulatory elements, each playing a specific role in the regulation of xlnC expression. Box 3 was shown to be critical for the establishment of repression of xlnC expression by glucose, whereas box 2 was shown to play an important role in the induction of xlnC expression by xylan. [less ▲]

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See detailDétermination d'un rendement fromager de laboratoire en relation avec les caractéristiques chimiques de lairs de brebis.
Rondia, P.; Blecker, Christophe ULg; Romnée, Jean-Michel et al

Poster (2003, December)

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See detailImpact du Percussionaire® et de la kinésithérapie respiratoire conventionnelle après chirurgie cardiaque : étude randomisée contrôlée
Kellens, Isabelle ULg; Fraipont, V.; Weber, T. et al

in Réanimation (2003, December), 12(suppl 3), 243

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See detailA capillary action test for the investigation of adhesion in repair technology
Courard, Luc ULg; Degeimbre, Robert ULg

in Canadian Journal of Civil Engineering (2003), 30(6), 1101-1110

When repair material is laid down on a concrete substrate, the porosity of concrete allows it to penetrate the substrate, increasing the probability of physical interactions, and subsequently increasing ... [more ▼]

When repair material is laid down on a concrete substrate, the porosity of concrete allows it to penetrate the substrate, increasing the probability of physical interactions, and subsequently increasing adhesion. Water absorption by immersion or usual capillary action tests do not provide enough information to understand what happens when contact occurs between the concrete substrate and the cement slurries used as a bonding layer. An adaptation of the capillary action test is presented; this is based on a continuous measurement of mass change of the sample. Major differences according to the type of surface preparation are pointed out: absorption rates as well as mass changes are greater for polished concrete substrates than for sandblasted ones. Centrifuged solutions of cement slurries modified with plasticizers and superplasticizers are used for water replacement in the adapted capillary action test. Results clearly show the influence of these admixtures: the greater the adhesion tension, the greater the wetting of the concrete substrate. Determination of these thermodynamic characteristics and performance of an adapted capillary action test provide a better understanding of the mechanisms of interface creation and promotion of adhesion. [less ▲]

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See detailac magnetic behavior of large-grain magnetoresistive La0.78Ca0.22Mn0.90Ox materials
Vanderbemden, Philippe ULg; Vertruyen, Bénédicte ULg; Rulmont, André ULg et al

in Physical Review. B (2003), 68(22), 224418

We report a detailed set of ac magnetic measurements carried out on bulk large grain La-Ca-Mn-O samples extracted from a floating zone method-grown rod. Three samples with La0.78Ca0.22Mn0.90Ox ... [more ▼]

We report a detailed set of ac magnetic measurements carried out on bulk large grain La-Ca-Mn-O samples extracted from a floating zone method-grown rod. Three samples with La0.78Ca0.22Mn0.90Ox stoichiometry but differing in their microstructure were investigated by electrical resistivity and ac susceptibility measurements: (i) a single grain sample, (ii) a sample containing two grains, and (iii) a polycrystalline sample. We show that the superimposition of dc magnetic fields during ac magnetic susceptibility measurements is an efficient way for characterizing the magnetic transition of samples with different microstructures. Whereas both single grain and polycrystalline samples display a single susceptibility peak, an additional kink structure is observed in the case of the double grain sample. The temperature dependence of the ac susceptibility measured with superimposed dc magnetic fields is analyzed in the framework of second-order phase transition ideas. The relations between the critical exponents (beta+gamma ~ 1.5, delta ~ 2.5) are found to be close to those of the mean-field model for all samples. This is attributed to the disordering caused by unoccupied Mn sites. ©2003 The American Physical Society. [less ▲]

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See detailEffects of increased afterload on left ventricular performance and mechanical efficiency are not baroreflex-mediated
Kolh, Philippe ULg; Ghuysen, Alexandre ULg; Tchana-Sato, Vincent ULg et al

in European Journal of Cardio - Thoracic Surgery (2003), 24(6), 912-919

Objective: To assess baroreflex intervention during increase in left ventricular afterload, we compared the effects of aortic banding on the intact cardiovascular system and under hexamethonium infusion ... [more ▼]

Objective: To assess baroreflex intervention during increase in left ventricular afterload, we compared the effects of aortic banding on the intact cardiovascular system and under hexamethonium infusion. Methods: Six open-chest pigs, instrumented for measurement of aortic pressure and flow, left ventricular pressure and volume, were studied under pentobarbital-sufentanil anesthesia. Vascular arterial properties were estimated with a four-element windkessel model. Left ventricular contractility was assessed by the slope of end-systolic pressure-volume relationship. Results: The effects of aortic banding on mechanical aortic properties were unaffected by autonomic nervous system inhibition. However, increase in peripheral arterial vascular resistance and in heart rate were prevented by hexamethonium. Aortic banding increased left ventricular contractility and stroke work. Left ventricular-arterial coupling remained unchanged, but mechanical efficiency was impaired. These ventricular changes were independent of baroreflex integrity. Conclusions: Our results demonstrate that an augmentation in afterload has a composite effect on left ventricular function. Left ventricular performance is increased, as demonstrated by increase in contractility and stroke work, but mechanical efficiency is decreased. These changes are observed independently of baroreflex integrity. Such mechanisms of autoregulation, independent of the autonomic nervous system, are of paramount importance in heart transplant patients. (C) 2003 Elsevier B.V. All fights reserved. [less ▲]

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See detailDoes sustained ERP activity in posterior lexico-semantic processing areas during short-term memory tasks only reflect activated long-term memory?
Majerus, Steve ULg; Van der Linden, Martial ULg; Collette, Fabienne ULg et al

in Behavioral and Brain Sciences (2003), 26(6), 746-747

We challenge Ruchkin et al.'s claim in reducing short-term memory (STM) to the active part of long-term memory (LTM), by showing that their data cannot rule out the possibility that activation of ... [more ▼]

We challenge Ruchkin et al.'s claim in reducing short-term memory (STM) to the active part of long-term memory (LTM), by showing that their data cannot rule out the possibility that activation of posterior brain regions could also reflect the contribution of a verbal STM buffer. [less ▲]

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See detailThe influence of an acid-base-equilibrium on the adsorption behaviour of a weak polyampholyte
Mahltig, Boris; Jérôme, Robert ULg; Stamm, Manfred

in Journal of Polymer Research (2003), 10(4), 219-223

A weak diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly((dimethylamino)ethyl methacrylate), was investigated as a model system for the influence of an acid-base-equilibrium of a ... [more ▼]

A weak diblock polyampholyte PMAA-b-PDMAEMA, poly(methacrylic acid)-block-poly((dimethylamino)ethyl methacrylate), was investigated as a model system for the influence of an acid-base-equilibrium of a phthalic acid buffer system on the polyelectrolyte adsorption behaviour. The adsorption of polyampholyte from aqueous solution onto silicon surfaces is known to be strongly influenced by the parameters of the polymer solution and the properties of the polyampholyte itself like block ratio or molecular weight. In the case of the investigated polyampholytes, the main parameter with the most significant influence on the adsorption is the pH. The big influence of pH on adsorption results from the charges of the polymer chains and the substrate, which are determined by the pH. Therefore, it should be useful to investigate the influence of a buffer system on the polyampholyte adsorption. On the one hand the buffer system enables to determine the pH of the aqueous polyampholyte solution more precisely. On the other hand the concentrations of different phthalic species like the phthalic acid, the hydrogen phthalate and the phthalate are strongly influenced by pH. These different species were observed to have a strong influence on the adsorption behaviour of the polyampholyte, so the adsorption as function of pH was observed to be also determined by the acid-base-equilibrium of the buffer system. The adsorbed amount of polyampholyte dried after the adsorption process was determined using ellipsometry, while the surface topography of these adsorbed layers were characterized by atomic force microscopy (AFM). [less ▲]

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See detailPreventive assessment and enhancement of power system voltage stability: an integrated approach of thermal and voltage security
Capitanescu, Florin ULg

Doctoral thesis (2003)

This thesis is devoted to the preventive assessment and enhancement of voltage stability and security in electric power systems. However, in the course of deriving all the proposed methods we have paid ... [more ▼]

This thesis is devoted to the preventive assessment and enhancement of voltage stability and security in electric power systems. However, in the course of deriving all the proposed methods we have paid attention to keeping them compatible with the (more traditional) handling of thermal overloads, thereby providing a unified treatment of voltage and thermal security. The approaches presented in this work apply to both deregulated environments and classical, vertically integrated ones. The heart of most methods developed in this thesis is : (i) the derivation of sensitivities indicating the relative efficiency of the various bus injections to restore voltage stability or increase an insufficient voltage security margin, and (ii) the use of these sensitivities in linearized security constraints that can be incorporated to various optimization problems. Using this formulation, we deal with three different problems of interest in preventive security analysis: 1) Congestion management. We propose two optimization-based approaches to manage congestions due to voltage instability and/or thermal overload. The control variables are either power injections (generation rescheduling and load curtailment) or power transactions; 2) Computation of Available Transfer Capabilities (ATCs). We determine the simultaneous ATCs of multiple transactions by means of a single optimization-based computation; 3) evaluation of security margins interval. To face the uncertainty affecting power transfers, we present an optimization-based computation of the minimal and maximal margins under the assumption that individual injections vary within specified bounds. Besides this main theme, the thesis offers additional reflections on the: 1) Filtering of contingencies. We propose a simple and reliable technique to filter out harmless contingencies when computing voltage security margins of a large set of contingencies; 2) Evaluation of reactive reserves with respect to a contingency, an important topic for voltage security reasons as well as within the context of a deregulated market where providing reactive reserves is an ancillary service which should be properly paid. Most of the methods proposed in this thesis were successfully tested on realistic power system models. From a practical viewpoint all the above computations have been coupled to the fast time-domain quasi steady-state simulation used in the ASTRE software developed at the University of Liège. [less ▲]

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See detailHigh intraepithelial expression of estrogen and progesterone receptors in the transformation zone of the uterine cervix
Remoue, Franck; Jacobs, Nathalie ULg; Miot, Valérie et al

in American Journal of Obstetrics and Gynecology (2003), 189(6), 1660-1665

OBJECTIVE: Because sex hormones may be involved in tumor initiation and progression, we analyzed the presence of hormone receptors in the transformation zone of the uterine cervix where the majority of ... [more ▼]

OBJECTIVE: Because sex hormones may be involved in tumor initiation and progression, we analyzed the presence of hormone receptors in the transformation zone of the uterine cervix where the majority of human papillomavirus infections and associated (pre)neoplastic lesions develop. STUDY DESIGN: By using 23 total hysterectomy samples from young women who underwent surgery for noncervical benign uterine disease, we analyzed, by immunohistologic techniques, the in situ expression of estrogen (E-2-R) and progesterone (P-4-R) receptors in the transformation zone and ectocervix of the same women. RESULTS: The expression of estrogen receptors and progesterone receptors is significantly higher in the transformation zone compared with the ectocervix. Immunohistochemical localization indicated that hormone receptor-positive cells are mainly observed in (para)basal and intermediate cell layers in both the transformation zone and ectocervical epithelium. When transformation zone samples were segregated into epithelial tissues with a predominantly mature (7/23 samples) or immature (16/23 samples) squamous metaplasia, only biopsy specimens with immature squamous metaplasia showed a significantly higher density of hormone receptor-positive cells compared with ectocervical epithelium (P < .01). CONCLUSION: Our results suggest that the cervical transformation zone may be at increased risk of the development of cancer because of a high sensitivity to sex hormone regulation. (Am J Obstet Gynecol 2003; 189:1660-5.) [less ▲]

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See detailSegmentation by adaptive prediction and region merging
Van Droogenbroeck, Marc ULg; Talbot, Hugues

in Digital Image Computing Techniques and Applications, Volume II (2003, December)

This paper presents a segmentation technique based on prediction and adaptive region merging. While many techniques for segmentation exist, few of them are suited for the segmentation of natural images ... [more ▼]

This paper presents a segmentation technique based on prediction and adaptive region merging. While many techniques for segmentation exist, few of them are suited for the segmentation of natural images containing regular textures defined on non-rectangular segments. In this paper, we propose a description of regions based on a deconvolution algorithm whose purpose is to remove the influence of the shape on region contents. The decoupling of shape and texture information is achieved either by adapting waveforms to the segment shape, which is a time-consuming task that needs to be repeated for each segment shape, or by the extrapolation of a signal to fit a rectangular window, which is the chosen path. The deconvolution algorithm is the key of a new segmentation technique that uses extrapolation as a prediction of neighbouring regions. When the prediction of a region fits the actual content of a connected region reasonably well, both regions are merged. The segmentation process starts with an over-segmented image. It progressively merges neighbouring regions whose extrapolations fit according to an energy criterion. After each merge, the algorithm updates the values of the merging criterion for regions connected to the merged region pair. It stops when no further gain is achieved in merging regions or when mean values of adjacent regions are too different. Simulation results indicate that, although our technique is tailored for natural images containing periodic signals and flat regions, it is in fact usable for a large set of natural images. [less ▲]

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