Taille de la population d’Avahi laniger dans la réserve d’Ambodiriana-Manompana, Nord-est de Madagascar

Avahi laniger est le seul lémurien nocturne appartenant à la famille des Indriidae qui habite les forêts humides de l’est de Madagascar (Mittermeier et. al., 2010) dont une partie disparaît chaque année (exploitation du bois, pratique du «tavy» ou culture sur brûlis) (Beaucent and Fayolle, 2011; Lehman and Wright, 2000). La fragmentation et la destruction de leur habitat ainsi que la chasse menacent la survie de nombreuses espèces de lémuriens incluant celle de A. laniger (Jenkins et. al., 2011; Rakotondravony and Rabenandrasana, 2011; Anderson, Rowcliffe and Cowlishaw, 2007). Nous avons réalisé, entre fin Avril et Mai 2012, une étude de densité de la population de A. laniger au sein de l’aire protégée de Manompana-Ambodiriana afin d’estimer la taille de la population totale et de déterminer l’impact du projet de conservation menée par l’Association de Défense de la Forêt d’Ambodiriana (ADEFA) qui recherche l’évolution démographique à moyen terme de cette espèce."LABEX" TULIP: (ANR-10-LABX-41), fct fellowship: (SFRH/BD/64875/2009)

Neutron Stars in a Varying Speed of Light Theory

We study neutron stars in a varying speed of light (VSL) theory of gravity in which the local speed of light depends upon the value of a scalar field $\phi$. We find that the masses and radii of the stars are strongly dependent on the strength of the coupling between $\phi$ and the matter field and that for certain choices of coupling parameters, the maximum neutron star mass can be arbitrarily small. We also discuss the phenomenon of cosmological evolution of VSL stars (analogous to the gravitational evolution in scalar-tensor theories) and we derive a relation showing how the fractional change in the energy of a star is related to the change in the cosmological value of the scalar field.Comment: 15 pages, 2 figures. Added solutions with a more realistic equation of state. To be published in PR

On spontaneous scalarization

We study in the physical frame the phenomenon of spontaneous scalarization that occurs in scalar-tensor theories of gravity for compact objects. We discuss the fact that the phenomenon occurs exactly in the regime where the Newtonian analysis indicates it should not. Finally we discuss the way the phenomenon depends on the equation of state used to describe the nuclear matter.Comment: 41 pages, RevTex, 10 ps figures, submitted to Phys. Rev.

Daraina sportive lemur (Lepilemur milanoii) density and population size estimates in most of its distribution range: the Loky-Manambato region.

The population of the Daraina sportive lemur (Lepilemur milanoii) is believed to be mostly confined to the Loky-Manambato region (Louis et al., 2006). Very little is known about L. milanoii and it is classified as “Data Deficient” by the IUCN (IUCN, 2013; Schwitzer et al., 2013). Despite the management of the area by the NGO Fanamby since 2005, no study had been conducted to determine the presence and the abundance of L. milanoii in the main forest fragments of the region. During the 2011 dry season we surveyed the ten main forest fragments of the Loky-Manambato region and estimated L. milanoii densities and population sizes using line transect distance sampling (Buckland, 2001) and the DISTANCE software (Thomas et al., 2010). The results suggest that sportive lemur densities are reasonably high in the region, but with important discrepancies between forest fragments, with densities ranging from 49.8 ind./km² in Antsaharaingy to 590.5 ind./km² in Ampondrabe. For the region Loky-Manambato we were able to estimate a population size of 52,000 individuals. This is the first estimate for the total population size and we argue that similar studies should be repeated to monitor environmental changes and anthropogenic pressures (hunting, deforestation, mining, etc.).FCT grant: (SFRH/BD/64875/2009); the Groupement de Recherche International (GDRI); "Laboratoire d’Excellence" (LABEX) entitled TULIP : (ANR-10-LABX-41); Rufford Small Grant Foundation grant: (10941-1)

Survey of the critically endangered Perrier’s sifaka (Propithecus Perrieri) across most if its distribution range.

Propithecus perrieri (Perrier’s sifaka) is one of the most endangered lemur species due to its small and fragmented distribution range. Despite a Critically Endangered (CR) conservation and flagship species status, there are still many uncertainties regarding its actual distribution and its presence in some forests of its putative distribution range. We report the results of diurnal and nocturnal surveys carried out in 2012 across most forest fragments of its putative distribution range, namely the Ankarana National Park, the Analamerana Special Reserve and Andrafiamena-Andava-koera Protected Area. During our surveys the species was only observed in Andrafiamena and Analamerana protected areas.FCT fellowship: (SFRH/BD/64875/2009), Institut Français de la Biodiversité, the GDRI Madagascar, the “Laboratoire d'Excellence” (LABEX) entitled TULIP (ANR-10-LABX-41), Instituto Gulbenkian de Ciência, “Optimus Alive!” Biodiversity grant, The Rufford Small Grant for Nature Conservation: (ref. 10941-1), Département de Biologie Animale et Ecologie (D.B.A.E.), Faculté des Sciences, University of Mahajanga, the University of Antsiranana, and the Fanamby NGO (in particular S. Rajaobelina), Madagascar National Park, Analamerana Special Reserve, Ankarana National Park

Estimation des densités et tailles de population du Microcèbe Roux du Nord de (Microcebus tavaratra) dans la région Loky-Manambato (Daraina)

La région Loky-Manambato dans le Nord de Madagascar, est connue pour abriter le propithèque à couronne dorée (Propithecus tattersalli), un lémurien emblématique et endémique de la région. Néanmoins cette région composée d’une dizaine de fragments forestiers de taille moyenne et encore relativement peu étudiés, abrite aussi le microcèbe roux du nord (Microcebus tavaratra). Malgré la gestion des forêts de cette région par l’ONG Fanamby depuis 2005, aucune étude n’avait encore été menée dans chacun des fragments forestiers de la région pour déterminer la présence et quantifier la taille des populations de microcèbes de chacun d’entre eux. Lors de notre étude nous avons tenté d’estimer les densités et les tailles des populations de M. tavaratra dans neuf des dix principaux fragments forestiers de la région. Dans ce but nous avons utilisé la méthode de «line transect distance-sampling». Nos résultats montrent que les densités de microcèbes sont relativement élevées, et varient de 28 à 325 ind/km² entre fragments forestiers de la région. Desétudes plus approfondies des données collectées seront nécessaires pour déterminer les variables environnementales responsables des différences de densité observées.FCT grant: (SFRH/BD/64875/2009); l’Institut Français de la Biodiversité, GDRI Madagascar, “Laboratoire d’Excellence” (LABEX) TULIP: (ANR -10-LABX-41)

Estación de tratamiento de lodos - Orly (Francia)

The article describes the main problems facing the authors of the design, and the manner in which they have overcome them. The main feautures of the Station are — reception of mud from decantation plants, and preliminary concentration; — recuperation of alumina sulphate, by acid treatment, and decantation of acidified muds, and — treatment of muds with neutralizing agents and filtration in vacuum. Although It is too early to be certain, It appears the results so far obtained In this plant, perhaps unique in the world, are highly promising and indicate a positive development In the future.El artículo explica los problemas principales que se les han planteado a los autores del proyecto y cómo han tratado de resolverlos: - recepción de lodos procedentes de los decantadores y concentración preliminar; - recuperación del sulfato de alúmina por tratamiento al ácido con decantación de lodos acidificados; - tratamiento de lodos con neutralización y filtración en vacio. Aunque todavía es pronto, parece ser que los resultados obtenidos en esta instalación —tal vez la única del mundo— son muy alentadores y marcan un interesante camino a seguir

Past environmental changes affected lemur population dynamics prior to human impact in Madagascar

Quaternary climatic changes have been invoked as important drivers of species diversification worldwide. However, the impact of such changes on vegetation and animal population dynamics in tropical regions remains debated. To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record covering the past 25,000 years with demographic inferences of a forest-dwelling primate species (Microcebus arnholdi), in northern Madagascar. Result comparisons suggest that climate changes through the African Humid Period (15.2 - 5.5 kyr) strongly affected the demographic dynamics of M. arnholdi. We further inferred a population decline in the last millennium which was likely shaped by the combination of climatic and anthropogenic impacts. Our findings demonstrate that population fluctuations in Malagasy wildlife were substantial prior to a significant human impact. This provides a critical knowledge of climatically driven, environmental and ecological changes in the past, which is essential to better understand the dynamics and resilience of current biodiversity

An early developmental vertebrate model for nanomaterial safety:Bridging cell-based and mammalian toxicity assessment

Background. With the rise in production of nanoparticles for an ever-increasing number of applications, there is an urgent need to efficiently assess their potential toxicity. We propose a nanoparticle hazard assessment protocol that combines mammalian cytotoxicity data with embryonic vertebrate abnormality scoring to determine an overall toxicity index. Results. We observed that, after exposure to a range of nanoparticles, Xenopus phenotypic scoring showed a strong correlation with cell based in vitro assays. Magnetite-cored nanoparticles, negative for toxicity in vitro and Xenopus, were further confirmed as non-toxic in mice. Conclusion. The results highlight the potential of Xenopus embryo analysis as a fast screening approach for toxicity assessment of nanoparticles, which could be introduced for the routine testing of nanomaterials

Testing Scalar-Tensor Gravity with Gravitational-Wave Observations of Inspiralling Compact Binaries

Observations of gravitational waves from inspiralling compact binaries using laser-interferometric detectors can provide accurate measures of parameters of the source. They can also constrain alternative gravitation theories. We analyse inspiralling compact %binaries in the context of the scalar-tensor theory of Jordan, Fierz, Brans and Dicke, focussing on the effect on the inspiral of energy lost to dipole gravitational radiation, whose source is the gravitational self-binding energy of the inspiralling bodies. Using a matched-filter analysis we obtain a bound on the coupling constant $\omega_{\rm BD}$ of Brans-Dicke theory. For a neutron-star/black-hole binary, we find that the bound could exceed the current bound of $\omega_{\rm BD}>500$ from solar-system experiments, for sufficiently low-mass systems. For a $0.7 M_\odot$ neutron star and a $3 M_\odot$ black hole we find that a bound $\omega_{\rm BD} \approx 2000$ is achievable. The bound decreases with increasing black-hole mass. For binaries consisting of two neutron stars, the bound is less than 500 unless the stars' masses differ by more than about $0.5 M_\odot$. For two black holes, the behavior of the inspiralling binary is observationally indistinguishable from its behavior in general relativity. These bounds assume reasonable neutron-star equations of state and a detector signal-to-noise ratio of 10.Comment: 10 pages, (3 figures upon request), WUGRAV-94-