1,259 research outputs found

    Modifications et stabilité du phosphore échangeable d'un ferralsol ingéré par un ver géophage

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    L'un des paramètres des cinétiques de dilution isotopique du phosphore est modifié par l'ingestion, du ferralsol étudié, par le ver géophage #Pontoscolex corethrurus (#Glossoscolecidae, #Oligochaeta$). La concentation d'ions phosphate de la solution du sol et le compartiment d'ions immédiatement échangeables associé au sol sont nettement augmentés. Divers mécanismes pouvant expliquer ces modifications sont discutés. La minéralisation du phosphore organique s'effectue au profit des formes les plus rapidement échangeables. (Résumé d'auteur

    Further evidence of response by leukaemia patients in remission to antigen(s) related to acute myelogenous leukaemia.

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    Fifteen patients with acute myelogenous leukaemia were studied to determine if their remission blood leucocytes could be stimulated into taking up [3H] thymidine after in vitro culture with their own cryo-preserved irradiated AML leukaemia cells. In 6/15 patients it was possible to show autologous recognition and equal recognition of their stored leukaemia cells, even when they had previously been maintained in in vitro proliferative cultures in liquid suspension and undergoing myeloid maturation for one week. After in vitro proliferative culture, 4 populations of leukaemia cells produced material in the supernatant media between 3 and 7 days capable of inducing [3H] thymidine uptake in autologous (2 pts, 5 supernatants) and allogeneic (2 pts, 2 supernatants) AML remission lymphocytes, but not in normal donor lymphocytes. The relevance of these observations to tumour-associated AML antigen is discussed

    Produção e avaliação da qualidade do leite na microrregião de Castanhal.

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    Effects of a primary rehabilitation programme on arterial vascular adaptations in an individual with paraplegia

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    AbstractObjectiveEvaluation of the effects of 6 weeks of wheelchair endurance training on arterial stiffness in an individual with paraplegia.MethodsA 22-year-old male patient with complete (ASIA A) paraplegia (T11) was tested before and after training (30minutes three times per week). Physical performance and cardiorespiratory response were evaluated during a maximal progressive test. Heart rate (HR), blood pressure, stroke volume and arterial carotid–wrist and carotid–ankle pulse wave velocity (PWV) were measured at rest.ResultsMaximal responses registered (maximal tolerated power, V˙O2 peak) during the exercise test were increased after training. At rest, HR as PWV decreased, whereas cardiac output and blood pressure remained constant.ConclusionContinuous exposure of the subject to a repeated high intensity exercise bout for 6 weeks elevated fitness level. Such a regular practice might also constitute a major way to trigger vascular remodelling beyond to the trained body part

    Tuneable Capacitor based on dual picks profile of the sacrificial layer

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    In this paper, we present a novel dual gap tuneable capacitor process based on the profile of the sacrificial layer. This profile involves a tri-layer photo-resist process with only one mask level. This realization is based on a special profile of the sacrificial layer designed by two picks. The mechanism of the sacrificial layer realisation is dependent on resist thickness, resist formulation (viscosity, type of polymer and/or solvent, additives...), design of the patterned layer (size or width) and the conditions under which this layer is prepared: thermal treatment, etch back processes... In this communication we demonstrate influence of the later parameters and discuss how a dual pick profile was achieved.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    Éradication de mammifères introduits en milieux insulaires : questions préalables et mise en application

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    During the last five centuries, along with the reduction of biogeographie barriers, a great number of alien species were introduced by men, intentionally or not, in nearly ali ecosystems throughout the world. Most of these introductions failed and a majority of the others didn't raise any problem. But some of them led to major economic losses and/or biological diversity reduction. The insular vegetal and animal communities are little diversified, often disharmonie, and characterized by an important rate of endemie species when compared with those of continental ecosystems. These communities are therefore particularly vulnerable to alien species. For these reasons and because of the small size of islands which allows experimental studies, most operations of eradication took place in this type of ecosystems si nee the 1960s, mammal species being the main target. This paper offers an approach to improve the decision and the technica1 implementation in view of the eradication of alien mammals on islands. These recommendations are founded on the experiences of brown rat eradication from ten Brittany Islands (1994-1996) and those of rabbit eradication from three islands of the Kerguelen Archipelago (1992-1999)Au cours de ces cinq derniers siècles, suite à la levée des barrières biogéographiques, un grand nombre d'espèces végétales et animales a été introduit par l'homme, volontairement ou non, dans la quasi totalité des écosystèmes du globe. La plupart de ces introductions ont été des échecs et la majorité des succès est réputée ne pas poser de problèmes. Cependant, certaines introductions réussies sont à 1'origine de pertes économiques importantes et de graves atteintes à la diversité biologique. Les écosystèmes insulaires, abritant des communautés animales et végétales peu diversifiées par rapport aux milieux continentaux, souvent disharmoniques et caractérisées par de forts taux d'endémisme, sont particulièrement vulnérables aux introductions d'espèces. Dès les années soixante, l'essentiel des éradications d'espèces introduites, en particulier de mammifères, a été réalisé dans les îles compte tenu de leur superficie souvent réduite, favorable à l'expérimentation, et de leur grand intérêt écologique. À partir de l'expérience acquise lors de l'élimination du Surmulot de dix îles des côtes bretonnes (1994-1996) et du Lapin de trois îles de l'Archipel de Kerguelen (1992-1999), cet article propose une démarche d'aide à la décision et à la réalisation technique d'éradications de Mammifères introduits en milieux insulaire

    Nonlinear Mixed-Effect Pharmacokinetic Modeling and Distribution of Doxycycline in Healthy Female Donkeys after Multiple Intragastric Dosing–Preliminary Investigation

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    Doxycycline (DXC) is a broad-spectrum antibacterial antimicrobial administered to horses for the treatment of bacterial infections which may also affect donkeys. Donkeys have a different metabolism than horses, leading to differences in the pharmacokinetics of drugs compared to horses. This study aimed to describe the population pharmacokinetics of DXC in donkeys. Five doses of DXC hyclate (10 mg/kg) were administered via a nasogastric tube, q12 h, to eight non-fasted, healthy, adult jennies. Serum, urine, synovial fluid and endometrium were collected for 72 h following the first administration. Doxycycline concentration was measured by competitive enzyme immunoassay. Serum concentrations versus time data were fitted simultaneously using the stochastic approximation expectation-maximization algorithm for nonlinear mixed effects. A one-compartment model with linear elimination and first-order absorption after intragastric administration, best described the available pharmacokinetic data. Final parameter estimates indicate that DXC has a high volume of distribution (108 L/kg) as well as high absorption (10.3 h-1) in donkeys. However, results suggest that oral DXC at 10 mg/kg q12 h in donkeys would not result in a therapeutic concentration in serum, urine, synovial fluid or endometrium by comparison to the minimum inhibitory concentration of common equine pathogens. Further studies are recommended to identify appropriate dosage and dosing intervals of oral DXC in donkeys

    Calibration Optimization Methodology for Lithium-Ion Battery Pack Model for Electric Vehicles in Mining Applications

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    Large-scale introduction of electric vehicles (EVs) to the market sets outstanding requirements for battery performance to extend vehicle driving range, prolong battery service life, and reduce battery costs. There is a growing need to accurately and robustly model the performance of both individual cells and their aggregated behavior when integrated into battery packs. This paper presents a novel methodology for Lithium-ion (Li-ion) battery pack simulations under actual operating conditions of an electric mining vehicle. The validated electrochemical-thermal models of Li-ion battery cells are scaled up into battery modules to emulate cell-to-cell variations within the battery pack while considering the random variability of battery cells, as well as electrical topology and thermal management of the pack. The performance of the battery pack model is evaluated using transient experimental data for the pack operating conditions within the mining environment. The simulation results show that the relative root mean square error for the voltage prediction is 0.7–1.7% and for the battery pack temperature 2–12%. The proposed methodology is general and it can be applied to other battery chemistries and electric vehicle types to perform multi-objective optimization to predict the performance of large battery packs

    How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour

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    This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scientific studies. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with recommendations of their effectiveness. Using a modified stereo-camera system, we quantified behavioural interactions between white sharks (Carcharodon carcharias) and a baited target in the presence of a commercially available, personal electric shark deterrent (Shark Shield Freedom7™). The stereo-camera system enabled an accurate assessment of the behavioural responses of C. carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error) proximity of 131 (± 10.3) cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9) V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5) V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial when in the presence of an active Shark Shield™. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C. carcharias, and an accurate method for testing other shark deterrent technologies
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