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Endocrinology, Endocrinologie, Nutrition, obesity, metabolic disorders, Nutrition, obésité, maladies métaboliques, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: anatomie et physiologie, organisme dans son ensemble ou etude de plusieurs organes ou systemes, Vertebrates: anatomy and physiology, studies on body, several organs or systems, Alimentation. Comportement alimentaire, Feeding. Feeding behavior, Vertebres: endocrinologie, Vertebrates: endocrinology, Sciences medicales, Medical sciences, Endocrinopathies, Pancréas endocrine. Cellules apud (pathologie), Endocrine pancreas. Apud cells (diseases), Diabète. Anomalie tolérance glucose, Diabetes. Impaired glucose tolerance, Etiopathogénie. Dépistage. Explorations. Résistance tissu cible, Etiopathogenesis. Screening. Investigations. Target tissue resistance, Endocrinopathie, Endocrinopathy, Endocrinopatía, Maladie héréditaire, Genetic disease, Enfermedad hereditaria, Pathologie de l'appareil urinaire, Urinary system disease, Aparato urinario patología, Trouble de la nutrition, Nutrition disorder, Trastorno nutricíon, Diabète MODY, Maturity onset diabetes young, Diabetes MODY, Délétion, Deletion, Deleción, Endocrinologie, Endocrinology, Endocrinología, Etat nutritionnel, Nutritional status, Estado nutricional, Homme, Human, Hombre, Malade, Patient, Enfermo, Maladie métabolique, Metabolic diseases, Metabolismo patología, Nutrition, Nutrición, Néphropathie, Nephropathy, Nefropatía, Obésité, Obesity, Obesidad, Pathologie du rein, Kidney disease, and Riñón patología

Aims Hepatocyte nuclear factor 1β (HNF1B) mutations cause a syndrome of renal cysts and diabetes, with whole gene deletions accounting for approximately 50% of cases. The severity of the renal phenotype is variable, from enlarged cystic kidneys incompatible with life to normal renal development and function. We investigated the prevalence of HNF1B deletions in patients with diabetes but no known renal disease. Methods We tested 461 patients with familial diabetes diagnosed before 45 years, including 258 probands who met clinical criteria for maturity-onset diabetes of the young (two generations affected and at least one family member diagnosed under 25 years). A fluorescent polymerase chain reaction assay was used to analyse two intragenic polymorphic HNF1B markers and identify heterozygous patients who therefore did not have whole gene deletions. Those patients homozygous for both markers were then tested for an HNF1B deletion using multiplex ligation-dependent probe amplification. Results Heterozygous HNF1B intragenic polymorphisms were identified in 337/461 subjects. Multiplex ligation-dependent probe amplification analysis showed an HNF1B gene deletion in three of the remaining 124 probands, all of whom met the criteria for maturity-onset diabetes of the young. Testing of their relatives identified three additional deletion carriers and ultrasound scanning showed renal developmental abnormalities in three of these six patients. Conclusions We estimate that HNF1B mutations account for < 1% of cases of maturity-onset diabetes of the young. Although HNF1B mutations are a rare cause of diabetes in the absence of known renal disease, a genetic diagnosis of renal cysts and diabetes syndrome is important as it raises the possibility of subclinical renal disease and the 50% risk of renal cysts and diabetes syndrome in the patient's offspring.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, and Fundamental and applied biological sciences. Psychology

The effects of secondary metabolites in different Vigna species on the development of Clavigralla tomentosicollis were investigated in an artificial seed system using different fractions of crude pod extracts, while the orientation response of this pod-bug to volatile extracts was studied using a dual-choice olfactometer. Feeding on the neutral fraction extracts, in contrast to the basic and acidic fractions, resulted in significantly higher mortalities, longer total developmental time, and lower growth index of the insects in comparison with controls. All volatile extracts elicited an avoidance reaction by C. tomentosicollis, except the volatile from the susceptible genotype IT84S-2246 which generally attracted as many insects as controls. Extracts from wild Vigna species showed higher activity than those from their cultivated relatives. The present study which has established that most secondary metabolites in cowpea pods were localized in the neutral fraction of the crude extract, could facilitate experiments on the separation and characterization of the toxic factors involved.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Sélection variétale. Amélioration spéciale, objectifs d'amélioration, Varietal selection. Specialized plant breeding, plant breeding aims, Résistance aux organismes nuisibles, Pest resistance, Déprédateurs, Pest animals, Amélioration génétique, Genetic improvement, Enriquecimiento genético, Angiospermae, Arthropoda, Coreidae, Culture tropicale, Tropical crop, Cultivo tropical, Dicotyledones, Déprédateur, Pest, Plaga, Fruit, Fruto, Heteroptera, Insecta, Invertebrata, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Plante sauvage, Wild plant, Planta salvaje, Spermatophyta, Comparaison interspécifique, Interspecific comparison, Comparación interespecífica, Cultivar, Dégât, Damage, Estrago, Effet dimensionnel, Size effect, Efecto dimensional, Etude en laboratoire, Laboratory study, Estudio en laboratorio, Gousse, Pod, Vaina, Graine, Seeds, Semillas, Infestation, Infestación, Lignée sélection, Breeding line, Línea selección, Mécanisme défense, Defense mechanism, Mecanismo defensa, Ressource génétique, Genetic resource, Recurso genético, Résistance insecte, Insect resistance, Resistencia insecto, Trichome, Tricoma, Vigna unguiculata, Clavigralla tomentosicollis, Péricarpe, Pericarp, and Vigna vexillata

Studies were conducted in the laboratory to investigate the different components of the resistance of Vigna vexillata A. Richards, TVnu 72, and several cultivars of cultivated Vigna spp. to infestation and damage by the brown cowpea coreid, Clavigralla tomentosicollis Stäl. The main objective was to determine the different roles of the pod wall and seeds, and the relationship between seed size, number, and damage by this insect. Results showed that both the pod wall and seed clearly contribute different components to the resistance of TVnu 72 to C. tomentosicollis. Analysis of the results suggests that the seed defences and the pod wall pericarp may be more important than are trichomes in this resistance. Seed number was found to influence the extent of damage in a more predictable manner than seed size. However, because both of these traits are generally inversely related and mutually exclusive, their individual effects cannot be completely separated. The implications of these traits in a breeding programme targeted at a specific consumer group are discussed.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Phytopathologie. Zoologie agricole. Protection des cultures et des forets, Phytopathology. Animal pests. Plant and forest protection, Protozoaires. Invertébrés, Protozoa. Invertebrates, Signalements, symptômes, dégâts, importance économique, surveillance des populations, Records, symptoms, damages, economic importance, population surveys, Angiospermae, Arthropoda, Coreidae, Dicotyledones, Déprédateur, Pest, Plaga, Heteroptera, Insecta, Invertebrata, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Relation animal végétal, Animal plant relation, Relación animal vegetal, Spermatophyta, Comportement alimentaire, Feeding behavior, Conducta alimenticia, Comportement déprédateur, Pest behavior, Conducta depredadora, Culture tropicale, Tropical crop, Cultivo tropical, Cycle développement, Life cycle, Ciclo desarrollo, Etude en laboratoire, Laboratory study, Estudio en laboratorio, Glycine max, Hôte substitution, Host substitution, Huesped sustitución, Plante hôte, Host plant, Planta huesped, Survie, Survival, Sobrevivencia, Vigna unguiculata, and Clavigralla tomentosicollis

Suitability of the pods of cowpea (Vigna unguiculata (L.) Walp) and soybean (Glycine max (L.) Merrill) as food for Clavigralla tomentosicollis was determined in the laboratory using development, food substitution and host switch experiments. On soybean pods, nymphs survived for 8 days and adults for 12 days; on cowpea, all nymphal instars developed into adults and lived for 80-100 days. Teneral adults that were switched from cowpea to soybean lost weight, while adults that were moved from soybean to cowpea gained weight with slight differences between the sexes. The shortest critical survival threshold (duration with at least 50% survival) of adults on cowpea was greater than the longest on soybean. The likelihood of C. tomentosicollis exploiting soybean as a trophic niche in areas of tropical Africa where production of this crop is on the increase and usually contiguous with cowpea production, is discussed.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Invertebres, Invertebrates, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Autoécologie, Autoecology, Animaux, Animals, Protozoa. Invertebrata, Angiospermae, Arthropoda, Dicotyledones, Heteroptera, Insecta, Invertebrata, Leguminosae, Spermatophyta, Déprédateur, Pest, Plaga, Développement, Development, Desarrollo, Etude en laboratoire, Laboratory study, Estudio en laboratorio, Fécondité, Fecundity, Fecundidad, Lens culinaris, Longévité, Longevity, Longevidad, Pentatomidae, Pisum sativum, Plante hôte, Host plant, Planta huesped, Plante légumière, Vegetable crop, Planta leguminosa, Relation animal végétal, Animal plant relation, Relación animal vegetal, Reproduction, Reproducción, and Thyanta pallidovirens

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Agronomie. Sciences du sol et productions vegetales, Agronomy. Soil science and plant productions, Génétique et amélioration des plantes d'intérêt économique, Genetics and breeding of economic plants, Sélection variétale. Amélioration spéciale, objectifs d'amélioration, Varietal selection. Specialized plant breeding, plant breeding aims, Résistance aux organismes nuisibles, Pest resistance, Déprédateurs, Pest animals, Africa, Angiospermae, Arthropoda, Dicotyledones, Heteroptera, Insecta, Invertebrata, Leguminosae, Spermatophyta, Afrique, Coreidae, Criblage, Screening, Cernido, Déprédateur, Pest, Plaga, Etude en laboratoire, Laboratory study, Estudio en laboratorio, Etude en serre, Greenhouse study, Estudio en invernadero, Etude sur terrain, Field study, Estudio en campo, Lignée sélection, Breeding line, Línea selección, Méthode, Method, Método, Méthodologie, Methodology, Metodología, Nigéria, Nigeria, Origine végétale, Plant origin, Origen vegetal, Plante légumière, Vegetable crop, Planta leguminosa, Relation animal végétal, Animal plant relation, Relación animal vegetal, Résistance insecte, Insect resistance, Resistencia insecto, Sensibilité résistance, Sensitivity resistance, Sensibilidad resistencia, Vigna unguiculata, Pest resistance, Clavigralla tomentosicollis, and Résistance déprédateur

Description des procédures de criblage destinées à tester la résistance de nouvelles accessions de niébé, et qui peuvent être appliquées pour le criblage rapide de germoplasmes et la séparation des lignées de sélection.

Hygiene and public health, epidemiology, occupational medicine, Hygiène et santé publique, épidémiologie, médecine du travail, Microbiology, infectious diseases, Microbiologie, maladies infectieuses, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Microbiologie, Microbiology, Pathologie de l'appareil digestif, Digestive diseases, Aparato digestivo patología, Aliment, Food, Alimento, Epidémiologie, Epidemiology, Epidemiología, Homme, Human, Hombre, Intoxication alimentaire, Food poisoning, Intoxicación alimentaria, Microbiologie, Microbiology, and Microbiología

The Belgian data for foodborne norovirus (NoV) outbreaks became available for the first time with the introduction of an extraction and detection protocol for NoV in the National Reference Laboratory for foodborne outbreaks in September 2006. In 2007, 10 NoV foodborne outbreaks were reported affecting 392 persons in Belgium. NoV became the most detected agent in foodborne outbreaks followed by Salmonella (eight foodborne outbreaks). The major implicated foods were sandwiches (4/10), where food handlers reported a history of gastroenteritis in two outbreaks. A food handler was implicated in the limited number of Belgian NoV outbreaks which is in accord with internationally recorded data. Forty foodborne and waterborne outbreak events due to NoV, epidemiological and/or laboratory confirmed, from 2000 to 2007 revealed that in 42.5 % of the cases the food handler was responsible for the outbreak, followed by water (27·5%), bivalve shellfish (17·5%) and raspberries (10·0%).

Medical oncology, Cancérologie, Medical laboratory techniques, Techniques de laboratoire médical, General medicine general surgery, Médecine et chirurgie générales, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Gynecologie. Andrologie. Obstetrique, Gynecology. Andrology. Obstetrics, Pathologie de la glande mammaire, Mammary gland diseases, Tumeurs, Tumors, Techniques d'exploration et de diagnostic (generalites), Investigative techniques, diagnostic techniques (general aspects), Anatomopathologie. Exploration cytologique. Biochimie. Spectrométries. Méthodes cliniques et paracliniques diverses, Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques, Glande mammaire pathologie, Mammary gland diseases, Glándula mamaria patología, Tumeur maligne, Malignant tumor, Tumor maligno, Adjuvant, Coadyuvante, Anatomopathologie, Anatomic pathology, Anatomía patológica, Essai clinique, Clinical trial, Ensayo clínico, Paramètre, Parameter, Parámetro, Préménopause, Premenopause, Premenopausia, Tamoxifène, Tamoxifene, Tamoxifeno, Cancer sein, Breast cancer, and Cáncer pecho

Background: Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment. Aims: To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer. Materials/methods: Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression. Results: Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly. Conclusions: Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.

Medical laboratory techniques, Techniques de laboratoire médical, Microbiology, infectious diseases, Microbiologie, maladies infectieuses, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Physiologie vegetale et developpement, Plant physiology and development, Généralités, méthodes, General aspects, methods, Métabolisme, Metabolism, Réserves et sécrétions, pigments, phytochrome, Storage and secretion, pigments, phytochrome, Algae, Heterokontophyta, Thallophyta, Analyse statistique, Statistical analysis, Análisis estadístico, Arbre phylogénétique, Phylogenetic tree, Arbol filogenético, Bacillariophyta, Biofilm, Polymère, Polymer, Polímero, Spectrométrie masse, Mass spectrometry, Espectrometría masa, Sécrétion, Secretion, Secreción, Benthic diatoms, EPS, Extracellular polymeric substances, and ToF-SIMS

Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) was used to study compositional characteristics of Extracellular Polymeric Substances (EPS) and compared these to characteristics of the EPS-matrix of intact diatom biofilms. Three benthic diatoms species were investigated, Cylindrotheca closterium, Navicula mutica and Nitzschia cf. brevissima. Comparison of the ToF-SIMS spectra of sequentially extracted EPS-fractions by cluster analysis and multidimensional scaling analysis (MDS) indicated that soluble and bound EPS were not distinguishable based on their ion spectra. On the contrary the water insoluble bicarbonate soluble (WIBS)-EPS-fraction formed a distinct cluster showing that this material was compositionally different from the other EPS-fractions. Ion spectra of the EPS-fractions were dissimilar to results obtained from intact biofilms. This suggested that during the extraction procedure, the structure of the EPS irreversibly changed, which alters the fragmentation patterns of the extracellular surface layer. Furthermore, from the examination of the positive ion spectra it was shown that the overall composition of EPS in the intact biofilms was different between diatom species. In spite of these differences, several common peak patterns were shared between different species. This suggests the presence of common structural components in the EPS of these diatoms that may play a role in building the surface EPS-layer.

BIODIVERSITY, GRASSHOPPER behavior, BIOMES, PHYLOGENY, and SPECIES distribution

Abstract: The open vegetation biomes, within the limits of the Chacoan subregion, occur along a diagonal in eastern South America covering a large range of environmental conditions. In order to contribute to the knowledge on the biodiversity of these open biomes, we analysed the phylogenetic relationships of the grasshopper genus Zoniopoda to the remaining South American Romaleinae, and examined the biogeographical patterns of diversification of the genus. The study is based on morphological and molecular (COI and H3) evidence, including 12 species of Zoniopoda and 17 species of four tribes of South American Romaleinae. We describe a new species of Zoniopoda, and test its taxonomic placement within the group. Results of our phylogenetic analyses recovered Zoniopoda as a monophyletic group with high support values. According to the dispersion–vicariance analysis, the ancestor of Zoniopoda may have been distributed in an area corresponding to the Chacoan and Cerrado provinces. A vicariant event, that could be explained by the uplift of the Brazilian Plateau and the subsidence of the Chaco, is hypothesized to have occurred splitting the ancestral distribution of Zoniopoda, resulting in the independent evolution of the Tarsata group within the Cerrado and the Iheringi group in the Chacoan subregion. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:act:FCFB4C5D-1741-46F1-8E25-B37ED2B9D872. [ABSTRACT FROM AUTHOR]

Marine biology, limnology, Biologie marine, limnologie, Ecology, Ecologie, Environment, Environnement, Oceanography, Océanographie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Synécologie, Synecology, Ecosystèmes saumâtres, Brackish water ecosystems, Milieu saumâtre, Brackish water environment, Medio salobre, Estuaire, Estuaries, Estuario, Etude comparative, Comparative study, Estudio comparativo, Extracellulaire, Extracellular, Extracelular, Glucide, Carbohydrate, Glúcido, Phytobenthos, Fitobentos, Répartition spatiale, Spatial distribution, Distribución espacial, Vasière, Mud flats, Fondo fangoso, Zone intertidale, Intertidal zone, Zona intertidal, Ems-Dollard estuary, Extracellular carbohydrate, Grain size distribution, Humber estuary, Marennes-Oléron Bay, Microphytobenthos, Monosaccharide distribution, and Tidal flats

In this study, the spatial distribution of two operationally defined extracellular carbohydrate fractions (water- and EDTA-extractable carbohydrates) were examined in three intertidal mudflats in Western Europe (Dollard, the Netherlands; Marennes, France; Humber, UK). The three mudflats were sampled along cross-shore transects and sediment cores were sliced to a depth of 5 cm. In these mudflats diatoms were the dominant component of the microphytobenthos. Carbohydrate content showed little variation with depth but varied along transects within each mudflat. Carbohydrate contents were also significantly different between mudflats and the carbohydrate contents of the stations within a mudflat grouped together resulting in separate clusters. This was also observed when the Marennes mudflat was investigated on a temporal scale. These results suggest that processes that act on the scale of whole mudflats determine the variations in extracellular carbohydrate contents In the surface 0.5 cm of the sediment, water-extractable carbohydrates showed a correlation with both chlorophyll a content and median grain size while EDTA-extractable carbohydrates were only correlated with median grain size. Incubation experiments also showed the importance of microphytobenthos as a source of extracellular carbohydrate especially when subjected to the light. Analyses of the monosaccharide distribution of the carbohydrate fractions revealed that the carbohydrate composition was largely similar between the areas investigated. Structurally. the carbohydrates found in these sediments seem to represent a biorefractory part of the freshly produced carbohydrates that remained after rapid degradation of the mare labile component.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Ecology, Ecologie, Geology, Géologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie microbienne, Microbial ecology, Milieux divers (espace extraatmosphérique, air, eau), Various environments (extraatmospheric space, air, water), Bactérie, Bacteria, Article synthèse, Review, Artículo síntesis, Cyanobacteria, Cycle biogéochimique, Biogeochemical cycle, Ciclo biogeoquímico, Diazotrophie, Diazotrophy, Diazotrofía, Fixation azote, Nitrogen fixation, Fijación nitrogeno, Milieu marin, Marine environment, Medio marino, Océan, Ocean, Océano, and Trichodesmium

The surface water of the marine environment has traditionally been viewed as a nitrogen (N) limited habitat, and this has guided the development of conceptual biogeochemical models focusing largely on the reservoir of nitrate as the critical source of N to sustain primary productivity. However, selected groups of Bacteria, including cyanobacteria, and Archaea can utilize dinitrogen (N2) as an alternative N source. In the marine environment, these microorganisms can have profound effects on net community production processes and can impact the coupling of C-N-P cycles as well as the net oceanic sequestration of atmospheric carbon dioxide. As one component of an integrated 'Nitrogen Transport and Transformations' project, we have begun to re-assess our understanding of (I) the biotic sources and rates of N2 fixation in the world's oceans, (2) the major controls on rates of oceanic N2 fixation, (3) the significance of this N2 fixation for the global carbon cycle and (4) the role of human activities in the alteration of oceanic N2 fixation. Preliminary results indicate that rates of N2 fixation, especially in subtropical and tropical open ocean habitats, have a major role in the global marine N budget. Iron (Fe) bioavailability appears to be an important control and is, therefore, critical in extrapolation to global rates of N2 fixation. Anthropogenic perturbations may alter N2 fixation in coastal environments through habitat destruction and eutrophication, and open ocean N2 fixation may be enhanced by warming and increased stratification of the upper water column. Global anthropogenic and climatic changes may also affect N2 fixation rates, for example by altering dust inputs (i.e. Fe) or by expansion of subtropical boundaries. Some recent estimates of global ocean N2 fixation are in the range of 100-200 Tg N (1-2 x 1014 g N) yr-1, but have large uncertainties. These estimates are nearly an order of magnitude greater than historical, pre-1980 estimates, but approach modern estimates of oceanic denitrification.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Ecology, Ecologie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géochimie, Geochemistry, Géochimie des sols et des roches, Soil and rock geochemistry, Formations superficielles, Surficial geology, Quaternaire marin et continental, Marine and continental quaternary, Europe, Europa, Actuel, modern, Actual, Calcium, calcium, Calcio, Carbohydrate, carbohydrates, Matière particulaire, particulate matters, Partícula elemental, Milieu intertidal, intertidal environment, Medio intertidal, Particule, particles, Rhéologie, rheology, Reología, Sorption, sorption, Sorción, Stabilisation, stabilization, Estabilización, Sédimentation estuaire, estuarine sedimentation, Sedimentación estuario, Vasière, mud flats, and Marisma

Extracellular Polymeric Substances (EPS) are considered to play an important role in the stabilization of intertidal mudflats. In this study the role of EPS as a binding agent in intertidal sediments was investigated. For this purpose two EPS fractions (termed coll-SF and EDTA-SF) were isolated from intertidal sediment and characterized in terms of monosaccharide- and size distribution. In slurry addition experiments the sorption characteristics of these EPS-fractions as well as their effect on sediment properties were examined under varying Ca2+-concentrations. Results showed more EDTA-SF adsorbed to the sediment compared to coll-SF. For both fractions more EPS adsorbed to the sediment when Ca2+-concentration increased. This effect was stronger for EDTA-SF. The differences in sorption between the two fractions could not be explained in terms of monosaccharide- and size distribution, which were largely similar. The addition of EPS in the presence or absence of Ca2+ did not alter the rheology of the sediment slurries indicating that there was no effect of EPS on the sediment properties. This contradicts results of experiments with bacterial EPS as well as field observations in which the presence of EPS/ biofilms leads to an increase in the erosion resistance of the sediment. Possible causes for this discrepancy in results are discussed.

Marine biology, limnology, Biologie marine, limnologie, Ecology, Ecologie, Environment, Environnement, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Autoécologie, Autoecology, Végétaux et champignons, Plants and fungi, Synécologie, Synecology, Ecosystèmes marins, Sea water ecosystems, Algae, Bacillariophyta, Facteur photique, Light effect, Factor fótico, Heterokontophyta, Milieu marin, Marine environment, Medio marino, Thallophyta, Eclairement énergétique, Irradiance, Aclaramiento energético, Extracellulaire, Extracellular, Extracelular, Photosynthèse, Photosynthesis, Fotosíntesis, Phytobenthos, Fitobentos, Polymère, Polymer, Polímero, Productivité biologique, Biological productivity, Productividad biológica, Cylindrotheca closterium, Extracellular polymeric substances, Microphytobenthos, and P/E curves

The partitioning of photosynthetically fixed carbon (C) into different fractions of intracellular and extracellular C pools by an axenic culture of Cylindrotheca closterium (Ehrenberg) and a field sample of natural benthic diatoms was studied using short-term incubation with 14C at different irradiances. Hence, excretion was directly dependent on the level of irradiance. During the incubations, a comparable amount of about 70 and 75% of the fixed C, respectively, was excreted by the culture and the field sample. This excreted C was distinguished in 2 operational fractions of attached (closely bound to the cells) and colloidal (soluble) material. In the field sample, the percentage of excreted C decreased at irradiances higher than 300 pmol photons m-2 s-1, but it was constant for the culture over the whole range of different irradiances applied. The percentage of extracellular polymeric substances (EPS) in the attached and colloidal material, as obtained by ethanol precipitation, was constant over the range of the provided irradiances for both samples. Subsamples of natural benthic diatoms were treated with an antibiotic cocktail in order to exclude bacterial activity which resulted in unexpected higher values of incorporated C in the fractions of total C, intracellular C, colloidal C and EPS.

General chemistry, physical chemistry, Chimie générale, chimie physique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Structure et morphologie de couches minces, Thin film structure and morphology, Structure et morphologie; épaisseur, Structure and morphology; thickness, Diffraction RX, XRD, Dépôt physique phase vapeur, Physical vapor deposition, Etude expérimentale, Experimental study, Frottement, Friction, Magnétron, Magnetrons, Microscopie électronique balayage, Scanning electron microscopy, Microstructure, Molybdène sulfure, Molybdenum sulfides, Propriété mécanique, Mechanical properties, Pulvérisation irradiation, Sputtering, Revêtement, Coatings, Tribologie, Tribology, Usure, and Wear

MoSx coatings were prepared with an unbalanced DC magnetron-sputtering system by varying the DC power mode, target type and liquid nitrogen trap. The composition and surface morphology were examined by energy dispersive X-ray and scanning electron microscopy; structural characterization was determined by X-ray diffraction. The friction and wear properties were evaluated with a fretting tester in dry (< 10% relative humidity) and humid (50% and 90% relative humidity) air. MoSx coatings deposited by simple DC power tended to form rougher surfaces, and had a higher edge orientation of crystallites with worse tribological performance than those by bipolar pulsed DC power. MoSx coatings made by a cold pressed target had a lower deposition rate, and were inclined to form (002) basal orientations parallel to the surface especially at higher argon pressures. The contents of oxygen and carbon in the MoSx coating with the use of liquid nitrogen trap were greatly reduced, but MoSx coatings had lower coefficients of friction and shorter wear life at higher relative humidity. The role of these deposition variables in the formation process is discussed.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Dispositifs optoélectroniques, Optoelectronic devices, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Domaines d'application, Application fields, Caractéristique temporelle, Time curve, Característica temporal, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Diode électroluminescente, Light emitting diode, Diodo electroluminescente, Effet champ électrique, Electric field effect, Efecto campo eléctrico, Electroluminescence, Electroluminiscencia, Etude expérimentale, Experimental study, Estudio experimental, Mécanisme, Mechanism, Mecanismo, Phénylènevinylène polymère, Phenylenevinylene polymer, Fenilenovinileno polímero, Polymère conjugué, Conjugated polymer, Polímero conjugado, Vieillissement, Ageing, and Envejecimiento

Polymer light-emitting diodes (PLEDs) made with poly(p-phenylene vinylene) (PPV) using a non-ionic precursor route with indium-tin oxide (ITO) as anode and Al as cathode have been examined during continuous electrical stress in an oxygen-rich atmosphere. Three distinct regions in the time evolution of the equivalent electrical resistance and the light output of PLEDs are identified. Various electrical and analytical measurement results are presented to explain the main failure mechanisms. The most severe degradation mode can be identified as dielectric breakdown, resulting in 'hot spots' and ohmic leakage paths. The inhibition of the ohmic path formation by oxidation under ambient conditions results in a local delamination of the electrode, shrinking the active area of the device. This loss of active area caused by these oxidative burn-outs can clearly be observed by scanning electron microscopy ( SEM) and is consistent with secondary ion mass spectroscopy (SIMS) results. Emission microscopy (EMMI) inspection provides evidence for electric field induced ageing at defects present in the device. These defects are already present in the as-produced samples, e.g. particle impurities, interface roughness and structural weakness (edges of the Al electrodes).

General chemistry, physical chemistry, Chimie générale, chimie physique, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Propriétés physiques non électroniques de couches minces, Physical properties of thin films, nonelectronic, Propriétés mécaniques et acoustiques, Mechanical and acoustical properties, Coefficient frottement, Friction factor, Dépôt physique phase vapeur, Physical vapor deposition, Essai usure, Wear testing, Etude expérimentale, Experimental study, Magnétron, Magnetrons, Microstructure, Molybdène sulfure, Molybdenum sulfides, Propriété mécanique, Mechanical properties, Propriété surface, Surface properties, Revêtement, Coatings, SEM, Tribologie, Tribology, Usure petit débattement, Fretting wear, Desgate pequinio desplazamiento, Usure, and Wear

MoSx coatings were prepared by bipolar pulse DC (balanced and unbalanced) magnetron-sputtering systems. Deposition parameters, cathode current density, argon pressure, bias voltage and magnetron sputtering conditions, were varied in order to obtain low friction and wear-resistant coatings. Composition and surface morphology were determined by energy dispersive X-rays and scanning electron microscopy, while the structure was investigated by X-ray diffraction. The friction and wear properties were investigated by fretting tests in ambient air of < 10% and 50% relative humidity. On proper selection of the argon pressure and the cathode current density, MoSx coatings characterised by a strong (002) basal plane orientation parallel to the substrate were obtained in a reproducible way. Such coatings deposited under optimised conditions exhibit very good lubricity and high wear-resistance, even in ambient air with a relative humidity of 50%. Conversely, when deposition parameters such as higher argon pressure and larger cathode current density result in the deposition of a MoSx coatings with a needle-like structure and preferential (100) and (110) plane orientations, a lower wear resistance is achieved especially in air of 50% relative humidity. Ion bombardment, achieved by applying a negative voltage bias or unbalanced sputtering conditions, improves the friction and wear performance. Conversely, a positive bias voltage deteriorates the tribological performance of the coatings. Experimental data on the friction and sliding wear resistance for MoSx coatings indicate that the best tribological properties are obtained with low sulfur and featureless MoSx coatings.

Marine biology, limnology, Biologie marine, limnologie, Ecology, Ecologie, Environment, Environnement, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Formations superficielles, Surficial geology, Quaternaire marin et continental, Marine and continental quaternary, Europe, Europa, Océan Atlantique, Atlantic Ocean, Océano Atlántico, Procaryote, prokaryotes, Bactérie, bacteria, Carbone organique, organic carbon, Carbono orgánico, Effet biogène, biogenic effects, Effet tampon, buffer effects, Efecto tampón, Fer, iron, Hierro, Milieu littoral, coastal environment, Medio litoral, Oxydation, oxidation, Oxidación, Porosité, porosity, Porosidad, Réduction chimique, chemical reduction, Reducción química, Sulfate, sulfates, Sulfato, Sulfure, sulfides, Sulfuro, Sédiment marin, marine sediments, Sedimento marino, Variation verticale, and vertical variations

The Bassin d'Arcachon (south-west France) was chosen as a model ecosystem to study the chemical and microbiological buffering towards free sulphide. Data were collected on the vertical distribution of oxygen, sulphur and iron compounds and the vertical distribution of colourless sulphur bacteria and sulphide-producing bacteria. In addition, data on the chemical and biological buffering capacity towards free sulphide were collected in sediment slurries from defined depth layers using a biological sulphide and oxygen monitor (BOSM) equipped with electrodes for oxygen, sulphide, redox and pH. The data showed that a substantial population of aerobic sulphide-oxidizing bacteria was present, yet buffering towards free sulphide could mainly be attributed to chemical processes: in particular, reactions with iron were of importance. Interestingly, the potential microbiological rate of sulphide oxidation was orders of magnitude higher than the rate of sulphate reduction reported for this ecosystem. The ecological implications of these observations for the Bassin d'Arcachon are that the powerful biological buffering capacity towards the free sulphide present will become effective after the chemical buffering capacity has been depleted. Under such conditions the colourless sulphur bacteria will no longer face the competition with iron, and thus may be expected to proliferate. The crucial factor then becomes the availability of oxygen.