164 research outputs found
The impact of time and repeated exposure on famous person knowledge in amnestic Mild cognitive impairment and Alzheimerâs disease
Objective: Famous people knowledge has been shown to be impaired early in Alzheimerâs disease (AD) and amnestic mild cognitive impairment (aMCI). However, the question of whether recently acquired knowledge is more impaired than remotely acquired knowledge remains a matter of debate. The aim of this study was to investigate the patterns of semantic memory impairment in aMCI and AD by investigating two factors that may influence the retrieval of such knowledge, namely remoteness and frequency of repetition of information over time. Method: Three groups (19 controls, 20 aMCI and 20 AD patients) were compared on a test assessing general and specific biographical knowledge about famous people, where the period of acquired fame (remote vs recent) and the type of fame (enduring vs transient) were controlled for. Results: Global performance of aMCI and AD patients was significantly poorer than that of controls. However, different patterns of recall were observed as a function of time and type of fame. A temporal gradient was found in both patient groups for enduring names but not for transient ones, whereby knowledge about remote enduring famous persons was better recalled. Patients were more impaired at questions assessing specific biographical knowledge (unique to an individual) than more general knowledge. Conclusions: Tests of famous people knowledge offer a unique opportunity to investigate semantic deficits in aMCI and AD, because they make it possible to estimate the time at which memories were acquired, as well as the type of fame. Results are discussed in light of memory consolidation models.
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Variation saisonniĂšre des paramĂštres abiotiques de la lagune Aghien (CĂŽte dâIvoire)
Objectifs: Les autoritĂ©s dans la quĂȘte dâune source dâeau complĂ©mentaire pour alimenter en eau potable la population dâAbidjan (CĂŽte dâIvoire) sans cesse croissante ont envisagĂ© exploiter la lagune Aghien. Ce prĂ©sent travail a pour objectif dâamĂ©liorer les connaissances sur la variation spatiale et saisonniĂšre des paramĂštres abiotiques de la lagune Aghien.MĂ©thodologie et rĂ©sultats: Pour atteindre ce but, quatre campagnes dâĂ©chantillonnages ont Ă©tĂ© menĂ©es. Ainsi, les Ă©chantillons dâeau ont Ă©tĂ© prĂ©levĂ©s de maniĂšre saisonniĂšre dans onze (11) stations reparties sur lâensemble de la lagune. Les paramĂštres tels que la tempĂ©rature, le pH, la conductivitĂ©, lâoxygĂšne dissous, le potentiel redox ont Ă©tĂ© mesurĂ©s in situ. La matiĂšre en suspension, le phosphate, le nitrate, le nitrite, lâammonium, la demande chimique en oxygĂšne (DCO) et la demande biochimique en oxygĂšne cinq jours (DBO5) ont Ă©tĂ© mesurĂ©s selon les mĂ©thodes conventionnelles ou au laboratoire. Les rĂ©sultats ont montrĂ© que les eaux de la lagune Aghien prĂ©sentent un pH en gĂ©nĂ©ral proche du pH neutre (pH entre 6,94 et 7,85). Les teneurs en Plomb sont supĂ©rieures Ă la norme. Les concentrations Ă©levĂ©es du plomb dans la lagune Aghien constituent donc un danger potentiel. Lâanalyse saisonniĂšre a donnĂ© des valeurs Ă©levĂ©es en ammonium, en phosphate, en nitrite, en DCO, en DBO5, en conductivitĂ©, en oxygĂšne dissous respectivement en petite et grande saison des pluies ainsi que de faibles valeurs de potentiel redox pendant la petite saison pluvieuse. Les paramĂštres tels que les MES, la turbiditĂ© et le nitrate enregistrent des valeurs plus marquĂ©es en petite saison sĂšche.Conclusions et application des rĂ©sultats: Les rĂ©sultats de cette Ă©tude montrent que les eaux de la lagune Aghien sont menacĂ©es par les effluents domestiques Ă caractĂšre biodĂ©gradable. Les concentrations en sels nutritifs sont encore dans la limite de lâacceptabilitĂ©. Cependant, les zones sous influence continentale ont enregistrĂ© les concentrations les plus Ă©levĂ©es des paramĂštres de pollution. Il est nĂ©cessaire de mettre en place un mĂ©canisme de surveillance chimique en respectant toutes les normes de protection de la lagune Aghien.Mots clĂ©s: Lagune Aghien-paramĂštres abiotiques- saison-pollutionEnglish Title: Seasonal variation of the abiotic parameters of the waters of the Aghien lagoon (CĂŽte dâIvoire)English AbstractObjectives: The government seeking to provide the population of Abidjan with clean water apply, envisioned to exploit the Aghien lagoon as a supplement source of water. The aim of this work is to improve the knowledge on the spatial and seasonal variation of the abiotic parameters of the Aghien lagoon.Methodology and results: Four sampling campaigns were conducted on a seasonal basis from February to November 2016 in eleven (11) stations spread over the lagoon. Parameters such as temperature, pH, conductivity, dissolved oxygen, redox potential were measured in situ and suspended solids, phosphate, nitrate, nitrite, ammonium, chemical oxygen demand (COD) and biochemical oxygen demand five days (BOD5) by conventional chemical methods. The results showed that the waters of the Aghien lagoon have a pH generally close to the neutral pH (pH between 6.94 and 7.85). The heavy metal studies are mainly absent in the water. The quantity of plumb is higher than normal. So the higher concentration of plumb in the Aghien lagoon constitutes a potential danger. Seasonal analysis yielded high values of ammonium, phosphate, nitrite, COD, BOD5 and conductivity, oxygen dissolved respectively in small and large rainy season as well as low values of redox potential during the short rainy season. Parameters such as suspended solids, turbidity and nitrate recorded higher values in the short dry season.Conclusion and applications of results: The results of this study also show that the waters of the Aghien lagoon are threatened by domestic biodegradable effluents. Concentrations of nutrient salts are still within the limits of acceptability. However, areas under continental influence have recorded the highest concentrations of pollution parameters. It is necessary to set up a chemical monitoring mechanism respecting all the protection standards of the Aghien lagoon.Keywords: Aghien lagoon, abiotic parameters, clean water, heavy meta
Vers une méthodologie de développement d'outils de réalité virtuelle pour faciliter la convergence métiers en conception de produits centrée sur l'homme
La conception concourante de produits matĂ©riels centrĂ©e sur l homme est basĂ©e sur une collaboration entre le concepteur mĂ©canicien, l ergonome et le designer industriel. Cette collaboration souvent difficile peut ĂȘtre facilitĂ©e par l utilisation d objets intermĂ©diaires de conception, tels que la RĂ©alitĂ© Virtuelle (RV). NĂ©anmoins, bien que largement utilisĂ©e dans l industrie, la RV souffre d un dĂ©ficit d acceptation de la part des concepteurs de produits. Dans le cadre de ces travaux, nous proposons d utiliser la RV sous la forme d outils immersifs d assistance Ă la convergence multidisciplinaire dĂ©veloppĂ©s selon une dĂ©marche anthropocentrĂ©e en fonction des besoins spĂ©cifiques Ă chaque projet de conception de produits. Afin d optimiser les dĂ©lais de dĂ©veloppement, nous proposons une mĂ©thodologie de conception d applications immersive dĂ©diĂ©e : la mĂ©thodologie ASAP(As Soon As Possible). Une premiĂšre sĂ©rie expĂ©rimentale a Ă©tĂ© conduite dans le cadre de contrats industriels d Ă©tudes et de recherche afin de valider la faisabilitĂ© de la mĂ©thodologie et l efficacitĂ© des outils dĂ©veloppĂ©s.Une deuxiĂšme sĂ©rie expĂ©rimentale a Ă©tĂ© effectuĂ©e sur plus de 50 sujets dans le cadre de projets, cette fois, pĂ©dagogiques qui ont nĂ©cessitĂ© le dĂ©veloppement de 12 applications. Elle a permis de valider quantitativement l influence des outils immersifs sur l efficacitĂ© perçue des phases de convergence interdisciplinaires ainsi que l influence de l approche proposĂ©e sur l acceptation de la RV par les concepteurs de produits. Ces travaux de thĂšse prĂ©sentent une premiĂšre approche qui, selon nous, permettra Ă terme, de faire Ă©voluer l usage de la RV vers une intĂ©gration plus forte au sein des processus de conception de produits avec, par exemple, une plus large utilisation des applications immersives de modĂ©lisation 3D, rĂ©elles sources d innovation.Human centered and concurring product design is based on the collaboration between mechanical engineers, human factor experts and industrial designers. This collaboration is often difficult and can be eased through the use of intermediary objects such as Virtual Reality (VR). Nevertheless, even though VR is widely used in the industry, it suffers from a lack of acceptance by product designers. In the context of this research work, we suggest to use VR in the form of immersive multidisciplinary convergence support tools. These tools are developed in accordance with an anthropocentered approach, as a function of each specific product design project s needs. In order to optimize development times, we propose a dedicated immersive software design methodology : the ASAP methodology (As Soon As Possible). A first experiment, aiming to demonstrate the feasibility of the ASAP methodology and the effectiveness of the implemented immersive tools, has been conducted in the context of industrial product design projects. A second experiment, involving more than 50 participants, has been conducted in the context of educational product design projects and led to the development of 12 immersivetools. It demonstrated quantitatively the contribution of immersive tools to the perceived effectiveness of interdisciplinary convergence phases and the contribution of the ASAP methodology on the acceptation of VR by product designers. This research work describes a first approach that could, according to us, allow abetter integration of VR within product design processes.BELFORT-UTBM-SEVENANS (900942101) / SudocSudocFranceF
Physico-chemical and biological characterization of an aquifer polluted with ETBE
International audiencePetroleum compounds and among them, gasoline, is the most massively used chemicals worldwide and, as a consequence gasoline derives compounds are the most frequently found contaminants in groundwate
The one year fate of iron oxide coated gold nanoparticles in mice
Safe implementation of nanotechnology and nanomedicine requires an in-depth understanding of the life cycle of nanoparticles in the body. Here, we investigate the long-term fate of gold/iron oxide heterostructures after intravenous injection in mice. We show these heterostructures degrade in vivo and that the magnetic and optical properties change during the degradation process. These particles eventually eliminate from the body. The comparison of two different coating shells for heterostructures, amphiphilic polymer or polyethylene glycol, reveals the long lasting impact of initial surface properties on the nanocrystal degradability and on the kinetics of elimination of magnetic iron and gold from liver and spleen. Modulation of nanoparticles reactivity to the biological environment by the choice of materials and surface functionalization may provide new directions in the design of multifunctional nanomedicines with predictable fate
HIF1α is required for NK cell metabolic adaptation during virus infection
Natural killer (NK) cells are essential for early protection against virus infection and must metabolically adapt to the energy demands of activation. Here, we found upregulation of the metabolic adaptor hypoxia-inducible factor-1α (HIF1α) is a feature of mouse NK cells during murine cytomegalovirus (MCMV) infection in vivo. HIF1α-deficient NK cells failed to control viral load, causing increased morbidity. No defects were found in effector functions of HIF1αKO NK cells; however, their numbers were significantly reduced. Loss of HIF1α did not affect NK cell proliferation during in vivo infection and in vitro cytokine stimulation. Instead, we found that HIF1α-deficient NK cells showed increased expression of the pro-apoptotic protein Bim and glucose metabolism was impaired during cytokine stimulation in vitro. Similarly, during MCMV infection HIF1α-deficient NK cells upregulated Bim and had increased caspase activity. Thus, NK cells require HIF1α-dependent metabolic functions to repress Bim expression and sustain cell numbers for an optimal virus response
Cholinesterase activities as potential biomarkers: Characterization in two freshwater snails, Potamopyrgus antipodarum (Mollusca, Hydrobiidae, Smith 1889) and Valvata piscinalis (Mollusca, Valvatidae, MĂŒller 1774)
Fine-scale population structure and connectivity of bottlenose dolphins, Tursiops truncatus, in European waters and implications for conservation
Funding: Fyssen post-doctoral fellowship, Fondation Total, a bridge funding from the School of Biology of the University of St Andrews and Peopleâs Trust for Endangered Species (ML).1. Protecting species often involves the designation of protected areas, wherein suitable management strategies are applied either at the taxon or ecosystem level. Special Areas of Conservation (SACs) have been created in European waters under the Habitats Directive to protect bottlenose dolphins, Tursiops truncatus, which forms two ecotypes, pelagic and coastal. 2. The SACs have been designated in coastal waters based on photoâidentification studies that have indicated that bottlenose dolphins have relatively high site fidelity. However, individuals can carry out longâdistance movements, which suggests potential for demographic connectivity between the SACs as well as with other areas. 3. Connectivity can be studied using genetic markers. Previous studies on the species in this area used different sets of genetic markers and therefore inference on the fineâscale population structure and demographic connectivity has not yet been made at a large scale. A common set of microsatellite markers was used in this study to provide the first comprehensive estimate of genetic structure of bottlenose dolphins in European Atlantic waters. 4. As in previous studies, a high level of genetic differentiation was found between coastal and pelagic populations. Genetic structure was defined at an unprecedented fineâscale level for coastal dolphins, leading to identification of five distinct coastal populations inhabiting the following areas: Shannon estuary, west coast of Ireland, English Channel, coastal Galicia, east coast of Scotland and Wales/west Scotland. Demographic connectivity was very low among most populations with <10% migration rate, suggesting no demographic coupling among them. Each local population should therefore be monitored separately. 5. The results of this study have the potential to be used to identify management units for bottlenose dolphins in this region and thus offer a significant contribution to the conservation of the species in European Atlantic waters. Future studies should prioritize obtaining biopsies from freeâliving dolphins from areas where only samples from stranded animals were available, i.e. Wales, west Scotland and Galicia, in order to reduce uncertainty caused by sample origin doubt, as well as from areas not included in this study (e.g. Iroise Sea, France). Furthermore, future management strategies should include monitoring local population dynamics and could also consider other options, such as population viability analysis or the incorporation of genetic data with ecological data (e.g. stable isotope analysis) in the designation of management units.PostprintPeer reviewe
Cell Surface Remodeling of Mycobacterium abscessus under Cystic Fibrosis Airway Growth Conditions.
Understanding the physiological processes underlying the ability of Mycobacterium abscessus to become a chronic pathogen of the cystic fibrosis (CF) lung is important to the development of prophylactic and therapeutic strategies to better control and treat pulmonary infections caused by these bacteria. Gene expression profiling of a diversity of M. abscessus complex isolates points to amino acids being significant sources of carbon and energy for M. abscessus in both CF sputum and synthetic CF medium and to the bacterium undergoing an important metabolic reprogramming in order to adapt to this particular nutritional environment. Cell envelope analyses conducted on the same representative isolates further revealed unexpected structural alterations in major cell surface glycolipids known as the glycopeptidolipids (GPLs). Besides showing an increase in triglycosylated forms of these lipids, CF sputum- and synthetic CF medium-grown isolates presented as yet unknown forms of GPLs representing as much as 10% to 20% of the total GPL content of the cells, in which the classical amino alcohol located at the carboxy terminal of the peptide, alaninol, is replaced with the branched-chain amino alcohol leucinol. Importantly, both these lipid changes were exacerbated by the presence of mucin in the culture medium. Collectively, our results reveal potential new drug targets against M. abscessus in the CF airway and point to mucin as an important host signal modulating the cell surface composition of this pathogen
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