infection in wildfowl: a continental-scale study across Africa Understanding the ecological drivers of avian influenza virus

Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non-Anas species even when we account for differences in their foraging behaviour (primarily dabbling or not) or their geographical origin (Eurasian or Afro-tropical), suggesting the existence of intrinsic differences between wildfowl taxonomic groups in receptivity to infection. Birds were found infected as often in oropharyngeal as in cloacal samples, but rarely for both types of sample concurrently, indicating that both respiratory and digestive tracts may be important for AIV replication. Keywords: influenza A virus; pathogen transmission; disease ecology; wild birds; tropical; migratio

Polarization Diagnostics for Cool Core Cluster Emission Lines

The nature of the interaction between low-excitation gas filaments at ~104 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~107 K in the centers of galaxy clusters remains a puzzle. The presence of a strong, empirical correlation between the two gas phases is indicative of a fundamental relationship between them, though as yet of undetermined cause. The cooler filaments, originally thought to have condensed from the hot gas, could also arise from a merger or the disturbance of cool circumnuclear gas by nuclear activity. Here, we have searched for intrinsic line emission polarization in cool core galaxy clusters as a diagnostic of fundamental transport processes. Drawing on developments in solar astrophysics, direct energetic particle impact induced polarization holds the promise to definitively determine the role of collisional processes such as thermal conduction in the ISM physics of galaxy clusters, while providing insight into other highly anisotropic excitation mechanisms such as shocks, intense radiation fields, and suprathermal particles. Under certain physical conditions, theoretical calculations predict of the order of 10% polarization. Our observations of the filaments in four nearby cool core clusters place stringent upper limits ( 0.1%) on the presence of emission line polarization, requiring that if thermal conduction is operative, the thermal gradients are not in the saturated regime. This limit is consistent with theoretical models of the thermal structure of filament interfacesPeer reviewe

Mission N.M.A./PRIFAS d´etude et de prospective dans le Nordeste Bresilien: 7 au 23 juillet 1990.

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Efeito do fungo Metarhizium anisopliae var. acridum sobre artrópodes não-alvo.

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What Should a Clinician Do When Spreading Depolarizations are Observed in a Patient?

Abstract: The International Conference on Spreading Depolarizations (iCSD) held in Boca Raton, Florida, in the September of 2018 devoted a section to address the question, “What should a clinician do when spreading depolarizations are observed in a patient?” Discussants represented a wide range of expertise, including neurologists, neurointensivists, neuroradiologists, neurosurgeons, and pre-clinical neuroscientists, to provide both clinical and basic pathophysiology perspectives. A draft summary of viewpoints offered was then written by a multidisciplinary writing group of iCSD members, based on a transcript of the session. Feedback of all discussants was formally collated, reviewed, and incorporated into the final document which was subsequently approved by all authors

BASECOL2012: A collisional database repository and web service within the Virtual Atomic and Molecular Data Centre (VAMDC)

The BASECOL2012 database is a repository of collisional data and a web service within the Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu). It contains rate coefficients for the collisional excitation of rotational, ro-vibrational, vibrational, fine, and hyperfine levels of molecules by atoms, molecules, and electrons, as well as fine-structure excitation of some atoms that are relevant to interstellar and circumstellar astrophysical applications. Submissions of new published collisional rate coefficients sets are welcome, and they will be critically evaluated before inclusion in the database. In addition, BASECOL2012 provides spectroscopic data queried dynamically from various spectroscopic databases using the VAMDC technology. These spectroscopic data are conveniently matched to the in-house collisional excitation rate coefficients using the SPECTCOL sofware package (http:// vamdc.eu/software), and the combined sets of data can be downloaded from the BASECOL2012 website. As a partner of the VAMDC, BASECOL2012 is accessible from the general VAMDC portal (http://portal.vamdc.eu) and from user tools such as SPECTCOL

Turnover élevé et fidélité modérée de la Cigogne blanche Ciconia ciconia à un site européen d'hivernage

International audienceAlthough the number of wintering White storks almost doubled between the winters of 2002/2003 and 2004/2005, only 15% of the birds wintering in 2004/2005 had been recorded in 2002/2003. Assuming a yearly survival of 0.8, only c.60% of the birds surviving from one winter to the next one would have been faithful to the wintering site. Potential causes and consequences pf this high turnover and moderate site fidelity rates are discussed.Bien que le nombre de Cigognes hivernantes a pratiquement doublé entre les hivers 2002/03 et 2004/05, seulement 15% des oiseaux hivernants en 2004/05 étaient déjà présents en 2002/03. En supposant une survie annuelle de l'ordre de 0.8, environ 60% des oiseaux survivant d'une année sur l'autre seraient fidèles au site d'hivernage. Les causes et les conséquences potentielles de ce turnover élevé et de ce niveau modéré de fidélité sont discutés

Essai de caractérisation des opérations de lutte chimique contre les saute-riaux au nord du Burkina Faso (1990-1992)

Characterisation of Grasshopper Chemical Control in Northern Burkina Faso (1990-1992). Description forms of 393 Chemical grasshoppers control operations between 1990 and 1992 in the north of Burkina Faso are analysed. It is shown that the campaign could be divided in two parts. During the first one (mainly July), farmers carry out numerous treatments on small plots in cultivated areas to protect recently planted crops (pearl millet and sorghum). Sprayers installed on trucks are used during the second part of the campaign, mainly in October, in cultivated and fallow areas to protect crops at the critical period of grain maturation

Wintering of white storks in Mediterranean France

International audienceThe establishment of regular wintering of the White Stork (Ciconia ciconia) in southern France ha been documented by regular census data and individual identification of banded birds. The number of wintering storks rose from eight in 1996-1997 to 172 in 2003-2004. Most records (87%) came from the Montpellier region (43degrees34'N, 3degrees54'E). The birds mainly originated from western Germany. eastern France and western Switzerland and about half were probably immature. Compared to storks observed on autumn and spring migration. first-winter birds were under-represented. We discuss the factors likely to explain the settlement of this new wintering area: its location on the migration route of the increasing northwest European stork population, the presence of a rubbish dump and adverse effects of wintering in Africa