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See detailApplying the electronic nose in the environment : requirements for the sensors
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Andre, Philippe ULg

in Szuber, Jacek (Ed.) Papers from the 3rd international seminar on semiconductor gas sensors-SGS 2002, Ustron, Poland, 19-22 september 2002 (2002, September)

For few years, the department "Environmental monitoring" at FUL applies the principle of the electronic nose equipped with tin oxide sensors to recognise and to monitor real life malodours in the ... [more ▼]

For few years, the department "Environmental monitoring" at FUL applies the principle of the electronic nose equipped with tin oxide sensors to recognise and to monitor real life malodours in the environment and directly in the field. <br />For such emissions, the gas mixtures are very complex and only their odour should be of interest, and not their chemical composition. <br />Moreover, working in the field implies various constraints. <br />The obstacles of the monitoring of real life environmental odours with an electronic nose can be classified into three main areas : the final goal of the study (measuring an odorous annoyance), the analysed sample itself (influenced by the evolution of the process and of ambient parameters) and the operating conditions (necessity to transport the reference gas and the batteries in the field, influence of air humidity). <br />The paper describes the approach of FUL to the problem with various tests conducted in the field with home-made electronic noses based on tin oxide sensors and with very simple configurations. The conclusions, which can be extrapolated to any other sensor types, are promising, but the sensor performances (sensibility, reproducibility, electrical consumption, drift, etc.) should still be improved before reaching the final goal. [less ▲]

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See detailA diagnostic m-test for distributional specification of parametric conditional heteroscedasticity models for financial data
Lejeune, Bernard ULg

Conference (2002, August 26)

This paper proposes a convenient and generally applicable diagnostic m-test for checking the distributional specification of parametric conditional heteroscedasticity models for financial data such as the ... [more ▼]

This paper proposes a convenient and generally applicable diagnostic m-test for checking the distributional specification of parametric conditional heteroscedasticity models for financial data such as the customary student-t GARCH Model. The proposed test is based on the moments of the probability integral transform of the estimated innovations of the assumed model. Monte-Carlo evidence indicates that our suggested test performs well both in terms of size and power. [less ▲]

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See detailOxytocin synthesis and oxytocin receptor expression by cell lines of human small cell carcinoma of the lung stimulate tumor growth through autocrine/paracrine signaling
Pequeux, Christel ULg; Breton, Christophe; Hendrick, Jean-Claude et al

in Cancer Research (2002), 62(16), 4623-4629

The objective of the present work was to investigate the existence of an oxytocin (OT)-mediated autocrine/paracrine signaling upon small cell carcinoma of the lung (SCCL) cell growth. In that view, OT ... [more ▼]

The objective of the present work was to investigate the existence of an oxytocin (OT)-mediated autocrine/paracrine signaling upon small cell carcinoma of the lung (SCCL) cell growth. In that view, OT receptor (OTR) expression, concomitant with OT synthesis and secretion, was evidenced on three different SCCL cell lines (DMS79, H146, and H345) and related to the vasopressin (VP) system. Specific OT, VP, OTR, Via VP receptor (V1aR), and V1b/V3 VP receptor (V1bR/V3R) transcripts were identified by reverse transcription-.PCR in all cell lines studied. Binding of I-125-(d(CH2)(5)(1),Tyr(Me)(2), Thr(4), Orn(3),Tyr(9)-NH2)-vasotocin (OVTA) was observed on all SCCL cell lines, with a K-d (dissociation constant) ranging from 0.025-0.089 nm, depending; on the cell line and the analytical method. Selectivity of I-125-OVTA binding was confirmed by displacement curves obtained with various OTR and VP receptor agonists and antagonists (OT, OVTA, L-371,257, VP, F180). Immunocytochemistry identified cellular OT and VP, and peptide secretion was measured in supernatants of SCCL cultures. [H-3]Thymidine incorporations, applied on H345 cells, demonstrated a dose-dependent mitogenic effect of exogenous OT (1 and 100 nM) that was abolished by the OTR antagonist OVTA. A decrease of proliferation was also observed with OVTA alone, showing a functional mitogenic effect of tumor-derived OT. Taken together, these observations demonstrate the existence of a functional OT-mediated autocrine/paracrine signaling actively implicated in growth and development of SCCL tumors. Furthermore, these findings point to the potential of OT antagonists for development as therapeutic agents for the treatment of SCCL. [less ▲]

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See detailpH Dependence of the morphology of aqueous micelles formed by polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) copolymers
Gohy, Jean-François; Willet, Nicolas ULg; Varshney, Sunil K et al

in e-Polymers (2002), (35), 1-10

The morphology of micelles formed by two polystyrene-block-poly(2-vinylpyridine)- block-poly(ethylene oxide) (PS-b-P2VP-b-PEO) copolymers was studied in water by dynamic light scattering and transmission ... [more ▼]

The morphology of micelles formed by two polystyrene-block-poly(2-vinylpyridine)- block-poly(ethylene oxide) (PS-b-P2VP-b-PEO) copolymers was studied in water by dynamic light scattering and transmission electron microscopy. Spherical micelles were observed that consist of a PS core, a P2VP shell and a PEO corona. The characteristic size of core, shell and corona depends on the copolymer composition. An important increase in micellar size occurs at pH < 5 as a result of P2VP block protonation. The reversibility of this pH effect depends on copolymer composition, too. The conformation of the PEO block plays an important role in this pH driven morphological transition. [less ▲]

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See detailCampagne de mesure des odeurs sur le CET "Champ de Beaumont" à Monceau-sur-Sambre Estimation des nuisances olfactives Jacques NICOLAS – Anne-Sophie CHAPLAIN F.U.L. Arlon 12 Août
Nicolas, Jacques ULg; Chaplain, Anne-Sophie

Report (2002)

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection ... [more ▼]

The study is made in the frame of a follow-up monitoring of all landfill sites in Wallonia, initiated by the Ministry of Environment and managed by ISSeP. The research group applied a field inspection technique based on the perception of a panel of experts sniffing the air around the region of interest and trying to delineate the odour plume. In a second step, the recorded meteorological data are entered into an atmospheric dispersion model and the odour emission rate of the facility is adjusted until the predicted odour impact zone fits about exactly the one which is measured in the field. The present report concerns the site of Monceau-sur-Sambre. [less ▲]

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See detailNovel unsaturated epsilon-caprolactone polymerizable by ring-opening and ring-opening metathesis mechanisms
Lou, Xudong; Detrembleur, Christophe ULg; Lecomte, Philippe ULg et al

in e-Polymers (2002), (34), 1-12

Ring-opening polymerization (ROP) and ring-opening metathesis polymerization (ROMP) of an unsaturated epsilon-caprolactone, 6,7-dihydro-2(3H)-oxepinone (DHO2), are alternative routes to produce ... [more ▼]

Ring-opening polymerization (ROP) and ring-opening metathesis polymerization (ROMP) of an unsaturated epsilon-caprolactone, 6,7-dihydro-2(3H)-oxepinone (DHO2), are alternative routes to produce unsaturated aliphatic polyesters with the same molecular structure. Polymerization of DHO2 initiated by Al isopropoxide in toluene at room temperature or at 0°C proceeds by a coordination-insertion mechanism, although intramolecular transesterification takes place beyond complete monomer conversion. The molecular weight distribution is narrow as long as monomer conversion does not exceed 90%. Ring-opening metathesis polymerization of DHO2 initiated by Schrock's Mo-based catalyst, 1, at 60°C allows higher molecular weight unsaturated polyester to be prepared, even though an intramolecular side reaction also operates. The structure of poly(DHO2) synthesized by ROP and ROMP is the same, as confirmed by 1H, 13C NMR, and FT-IR spectra. Copolymers of DHO2 with norbornene, cis-cyclooctene, and 1,5-cyclooctadiene have been successfully prepared. [less ▲]

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

in Bulletin Agrométéorologique (2002)

Le mois de juillet a été caractérisé par des précipitations généralement normales à excédentaires. Les températures, la vitesse moyenne du vent et l’humidité furent proches de la normale. Par contre, le ... [more ▼]

Le mois de juillet a été caractérisé par des précipitations généralement normales à excédentaires. Les températures, la vitesse moyenne du vent et l’humidité furent proches de la normale. Par contre, le rayonnement fut médiocre sur l’ensemble du pays. Par rapport au bulletin précédent (juin 2002), les prévisions de rendement n’ont pas changé. La situation des cultures est globalement favorable, avec des rendements qui s’annoncent supérieurs voire similaires à ceux de 2001 à l’exception du colza. [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 detailL'etude clinique du mois. Balance benefice/risque du traitement oestroprogestatif postmenopausique en peril dans l'etude Women's Health Initiative: attitude pratique du clinicien
Gaspard, Ulysse ULg; van den Brule, F.; PINTIAUX, Axelle ULg et al

in Revue Médicale de Liège (2002), 57(8), 556-62

The Women's Health Initiative (WHI) is sponsored by the NIH. The study focuses on risk and benefits of strategies that could potentially reduce the incidence of heart disease, breast and colon cancer, and ... [more ▼]

The Women's Health Initiative (WHI) is sponsored by the NIH. The study focuses on risk and benefits of strategies that could potentially reduce the incidence of heart disease, breast and colon cancer, and fractures in postmenopausal women. One arm of the study, a double-blind, placebo-controlled trial, looking at the effects of continuous combined estrogen-progestin regimen was stopped prematurely based on health risks which exceeded health benefits. The main reason for this decision was the increase in risk of invasive breast cancer, as well as a slight increase in the rate of myocardial infarction and stroke. In this paper, we inform our colleagues of the detailed results of the study. We comment on its limitation and discuss the new original observations. Finally, we integrate the others to previous world literature data that are confirmed by the WHI study. It is important for the individual prescribing practitioner to issue practical conclusions and therapeutic recommendations. The department of Obstetrics and Gynaecologic of the University of Liege, in agreement with the European Menopause Society and the International Menopause Society, is convinced that there is no alternative to the hormone replacement therapy for menopausal symptoms. We should stick to the traditional indications for hormones, namely vasomotor symptoms and osteoporosis. We should continue to recommend hormones for symptomatic women. One should realize that the risk for breast cancer appears only after several years of use, and the risk for cardiovascular events below age 60 is very small (the age of the patients was 63 at inclusion in the WHI study). We should encourage women to take the necessary measures for routine, periodic breast examinations (both manual, echographic and radiographic). Women who use HRT for more than 5 years should discuss the latest data of the WHI study with their physician, in order to consider their individual benefit-risk equation. Those who feel good on hormones and are fully satisfied with this treatment should learn of possible harm after long-term use. It is important to take into account the importance of quality of life. We should leave to the patient the final decision whether or not to continue the treatment. It is presently impossible to decide whether other estroprogestin associations, other administration routes and other molecules such as estradiol, natural progesterone or other progestins, SERMS and Tibolone could have an impact very different from that of the estroprogestin combination used in the WHI study. It is the duty of every physician to decide, from the complex epidemiological data obtained in the aged women (63-68 years) with a high cardiovascular risk in the WHI study, if it is possible or not in each individual case to recommend the initiation or pursue of an hormone replacement therapy. [less ▲]

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See detailAtmospheric perturbations on GNSS signals and their influence on time transfer
Warnant, René ULg

in Proceedings of the XXVII URSI General Assembly (2002, August)

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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 detailOperational model for real-time reconstruction of the electron density profile using GPS TEC measurements
Stankov, Stanimir; Warnant, René ULg; Jodogne, Jean-Claude

in Proceedings of the XXVII URSI General Assembly (2002, August)

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See detailHypertension artérielle et tachycardie: penser à regarder dans la pharmacie personnelle du patient
Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (2002), 57(8), 497-501

The case report of a young patient with an increase in blood pressure and heart rate offers the opportunity to discuss the clinical guidelines to explore and treat high blood pressure. The value of the 24 ... [more ▼]

The case report of a young patient with an increase in blood pressure and heart rate offers the opportunity to discuss the clinical guidelines to explore and treat high blood pressure. The value of the 24 h blood pressure monitoring and the need for precise information on all drugs taken are stressed. [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 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 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 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 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 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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