On the origin of the reactor antineutrino anomalies in light of a new summation model with parameterized β−\beta^{-} transitions

We investigate the possible origins of the norm and shape reactor antineutrino anomalies in the framework of a summation model (SM) where $\beta^{-}$ transitions are simulated by a phenomenological Gamow-Teller $\beta$-decay strength model. The general trends of the discrepancies to the Huber-Mueller model on the antineutrino side can be reproduced both in norm and shape. From the exact electron-antineutrino correspondence of the SM model, we predict similar distortions in the electron spectra, suggesting that biases on the reference fission-electron spectra could be at the origin of the anomalies

An elaborated feeding cycle model for reductions in vectorial capacity of night-biting mosquitoes by insecticide-treated nets

BACKGROUND: Insecticide Treated Nets (ITNs) are an important tool for malaria control. ITNs are effective because they work on several parts of the mosquito feeding cycle, including both adult killing and repelling effects. METHODS: Using an elaborated description of the classic feeding cycle model, simple formulas have been derived to describe how ITNs change mosquito behaviour and the intensity of malaria transmission, as summarized by vectorial capacity and EIR. The predicted changes are illustrated as a function of the frequency of ITN use for four different vector populations using parameter estimates from the literature. RESULTS: The model demonstrates that ITNs simultaneously reduce mosquitoes' lifespans, lengthen the feeding cycle, and by discouraging human biting divert more bites onto non-human hosts. ITNs can substantially reduce vectorial capacity through small changes to all of these quantities. The total reductions in vectorial capacity differ, moreover, depending on baseline behavior in the absence of ITNs. Reductions in lifespan and vectorial capacity are strongest for vector species with high baseline survival. Anthropophilic and zoophilic species are affected differently by ITNs; the feeding cycle is lengthened more for anthrophilic species, and the proportion of bites that are diverted onto non-human hosts is higher for zoophilic species. CONCLUSION: This model suggests that the efficacy of ITNs should be measured as a total reduction in transmission intensity, and that the quantitative effects will differ by species and by transmission intensity. At very high rates of ITN use, ITNs can generate large reductions in transmission intensity that could provide very large reductions in transmission intensity, and effective malaria control in some areas, especially when used in combination with other control measures. At high EIR, ITNs will probably not substantially reduce the parasite rate, but when transmission intensity is low, reductions in vectorial capacity combine with reductions in the parasite rate to generate very large reductions in EIR

Mercury exposure, malaria, and serum antinuclear/antinucleolar antibodies in amazon populations in Brazil: a cross-sectional study

BACKGROUND: Mercury is an immunotoxic metal that induces autoimmune disease in rodents. Highly susceptible mouse strains such as SJL/N, A.SW, B10.S (H-2(s)) develop multiple autoimmune manifestations after exposure to inorganic mercury, including lymphoproliferation, elevated levels of autoantibodies, overproduction of IgG and IgE, and circulating immune complexes in kidney and vasculature. A few studies have examined relationships between mercury exposures and adverse immunological reactions in humans, but there is little evidence of mercury-associated autoimmunity in humans. METHODS: To test the immunotoxic effects of mercury in humans, we studied communities in Amazonian Brazil with well-characterized exposures to mercury. Information was collected on diet, mercury exposures, demographic data, and medical history. Antinuclear and antinucleolar autoantibodies (ANA and ANoA) were measured by indirect immunofluorescence. Anti-fibrillarin autoantibodies (AFA) were measured by immunoblotting. RESULTS: In a gold mining site, there was a high prevalence of ANA and ANoA: 40.8% with detectable ANoA at ≥1:10 serum dilution, and 54.1% with detectable ANA (of which 15% had also detectable ANoA). In a riverine town, where the population is exposed to methylmercury by fish consumption, both prevalence and levels of autoantibodies were lower: 18% with detectable ANoA and 10.7% with detectable ANA. In a reference site with lower mercury exposures, both prevalence and levels of autoantibodies were much lower: only 2.0% detectable ANoA, and only 7.1% with detectable ANA. In the gold mining population, we also examined serum for AFA in those subjects with detectable ANoA (≥1:10). There was no evidence for mercury induction of this autoantibody. CONCLUSIONS: This is the first study to report immunologic changes, indicative of autoimmune dysfunction in persons exposed to mercury, which may also reflect interactions with infectious disease and other factors

Friends and Foes from an Ant Brain's Point of View – Neuronal Correlates of Colony Odors in a Social Insect

Background: Successful cooperation depends on reliable identification of friends and foes. Social insects discriminate colony members (nestmates/friends) from foreign workers (non-nestmates/foes) by colony-specific, multi-component colony odors. Traditionally, complex processing in the brain has been regarded as crucial for colony recognition. Odor information is represented as spatial patterns of activity and processed in the primary olfactory neuropile, the antennal lobe (AL) of insects, which is analogous to the vertebrate olfactory bulb. Correlative evidence indicates that the spatial activity patterns reflect odor-quality, i.e., how an odor is perceived. For colony odors, alternatively, a sensory filter in the peripheral nervous system was suggested, causing specific anosmia to nestmate colony odors. Here, we investigate neuronal correlates of colony odors in the brain of a social insect to directly test whether they are anosmic to nestmate colony odors and whether spatial activity patterns in the AL can predict how odor qualities like ‘‘friend’’ and ‘‘foe’’ are attributed to colony odors. Methodology/Principal Findings: Using ant dummies that mimic natural conditions, we presented colony odors and investigated their neuronal representation in the ant Camponotus floridanus. Nestmate and non-nestmate colony odors elicited neuronal activity: In the periphery, we recorded sensory responses of olfactory receptor neurons (electroantennography), and in the brain, we measured colony odor specific spatial activity patterns in the AL (calcium imaging). Surprisingly, upon repeated stimulation with the same colony odor, spatial activity patterns were variable, and as variable as activity patterns elicited by different colony odors. Conclusions: Ants are not anosmic to nestmate colony odors. However, spatial activity patterns in the AL alone do not provide sufficient information for colony odor discrimination and this finding challenges the current notion of how odor quality is coded. Our result illustrates the enormous challenge for the nervous system to classify multi-component odors and indicates that other neuronal parameters, e.g., precise timing of neuronal activity, are likely necessary for attribution of odor quality to multi-component odors

Imagerie ultrarapide pour l'étude de la stabilité de plasmas obtenus avec une torche ICP et la visualisation d'arcs glissants dans des échelles de Jacobs

La torche à plasma à couplage inductif du LAEPT est actuellement dédiée à l'étude des rentrées atmosphériques (atmosphère terrestre, martienne ou encore de Titan). Ce type de dispositif offre l'opportunité de travailler avec des plasmas relativement stables (équilibre thermique et chimique). Les résultats obtenus sur la caractérisation du plasma (température, densité électronique, propriétés radiatives) [1,2], dans des conditions de pression et d'enthalpie fixées, servent de données de référence (cas test) à tous les différents codes de calculs relatifs aux propriétés radiatives des plasmas. Les données principales étant des spectres étalonnés, il faut pouvoir confirmer qu'il n'existe aucune fluctuation au niveau de l'émission lors de l'enregistrement spectrométrique. L'utilisation d'une caméra ultra-rapide serait ainsi de toute première importance pour d'une part mettre en évidence ou non la présence de fluctuations résultant d'instabilités dans les zones de circulation de la torche ICP ou issues du générateur HF et d'autre part visualiser les échanges initiaux d'énergie lors du démarrage de la torche. Ce dernier point a pour objectif de fournir des informations à la modélisation de la torche préparée actuellement au laboratoire. Le glidarc est un procédé simple permettant d'obtenir un plasma froid à pression atmosphérique. Ce procédé est largement utilisé dans des applications de conversion chimique mais peu d'études fondamentales existent sur ce sujet. L'utilisation de la caméra ultra-rapide permet de définir précisément la forme et la position de la colonne d'arc en fonction du temps et des données expérimentales: courant, tension, débit de gaz... La visualisation directe de l'arc est ensuite confrontée à une vision indirecte obtenue à l'aide d'une caméra magnétique en voie de développement au LAEPT. Les caractéristiques géométriques de l'arc sont également comparées aux données courant-tension pour affiner les modèles existants au laboratoire, notamment sur les coefficients de transport dans un plasma froid à pression atmosphérique

Utilisation d'une caméra ultra-rapide pour le diagnostic plasma dans un Glidarc

Le glidarc est un procédé simple permettant d'obtenir un plasma froid à pression atmosphérique. Ce procédé est largement utilisé dans des applications de conversion chimique mais peu d'études fondamentales existent sur ce sujet. L'utilisation de la caméra ultrarapide de l'équipe ESPRITS de l'institut Jean Lamour permet de définir précisément la forme et la position de la colonne d'arc en fonction du temps et des données expérimentales: courant, tension, débit de gaz... La visualisation directe de l'arc est d'une grande importance pour améliorer une méthode d'imagerie magnétique en voie de développement au LAEPT. Les caractéristiques géométriques de l'arc sont également comparées aux données courant-tension pour affiner les modèles existants au laboratoire, notamment sur les coefficients de transport dans un plasma froid à pression atmosphérique

Comparison of the Micro-Nutrica Nutritional Analysis program and the Russian Food Composition Database using data from the Baltic Nutrition Surveys.

OBJECTIVE: The objective of this study was to compare the nutrient content of foods and diets based on data from two food composition databases used in the Baltic Nutrition Surveys (conducted in Estonia, Latvia and Lithuania in 1997): an adapted version of the Finnish Micro-Nutrica Nutritional Analysis program (used in Estonia) and the Russian Institute of Nutrition Food Composition Database (used in Latvia and Lithuania). DESIGN: The adapted Micro-Nutrica and Russian databases were used to estimate the energy and nutrient (protein, fat, carbohydrate, vitamin C, calcium and iron) content of 15 common foodstuffs in the region and the nutrient intakes of 32 Latvian respondents (based on 24-h recalls). Differences between databases were estimated. RESULTS: There were discrepancies in the energy and nutrient content of the 15 selected foods using the two databases. The adapted Micro-Nutrica database generally gave a lower energy content than the Russian database (median: -6%), and a lower fat content for typically fat-rich foods. Intakes of energy, fat, carbohydrate and calcium by the 32 selected respondents were significantly lower when the Micro-Nutrica database was used. Differences were particularly high for fat (difference=-23.5%, 95% confidence interval=-31.1 to -15.8%, P<0.0001). CONCLUSIONS: The results suggest that reported comparisons of nutrient intakes in the Baltic countries should be treated with caution and that more research is needed for the development of comparable national databases in the region. Potential differences between databases should be investigated early when international surveys of dietary intake are being planned

Origin of the visible absorption in radiation-resistant optical fibers

International audienceIn this work we investigated the point defects at the origin of the degradation of radiation-tolerant optical fibers used in the visible part of the spectrum for plasma diagnostics in radiation environments. For this aim, the effects of γ-ray irradiation up to the dose of 10 MGy(SiO2) and post-irradiation thermal annealing at 550°C were studied for a Fluorine-doped fiber. An absorption peaking around 2 eV is mainly responsible for the measured radiation-induced losses, its origin being currently debated in the literature. On the basis of the unchanging shape of this band with the radiation dose, its correlation with the 1.9 eV photoluminescent band and the thermal treatment results we assign the asymmetric absorption around 2 eV to an unique defect, the NBOHC, instead of a set of various defects

Utilisation d'une caméra ultra-rapide pour le diagnostic plasma dans une torche ICP et un Glidarc

La rentrée atmosphérique d'une sonde spatiale (sur Mars ou Titan par exemple) reste une prouesse technologique liée en partie à la bonne tenue du bouclier thermique. Une rentrée pouvant s'effectuer à Mach 37, la création de l'onde de choc va induire des échauffements convectifs et radiatifs. C'est sur ce dernier type d'échauffement que se penche la communauté scientifique dans le but de restreindre les marges de sécurité (diminution de l'épaisseur du bouclier et donc de la masse embarquée) au prix d'une meilleure connaissance des principes physiques. C'est dans cette optique que la torche ICP du LAEPT est utilisée comme cas test pour définir les propriétés radiatives des plasmas lors de rentrées atmosphériques. L'utilisation de la caméra ultra-rapide de l'équipe ESPRITS de l'institut Jean Lamour est de toute première importance pour mettre en évidence ou non la présence de fluctuations résultant soit d'instabilités dans les zones de circulation de la torche ICP, soit du générateur HF (64 MHz) susceptibles de perturber les mesures spectroscopiques