Evidence that vulture restaurants increase the local abundance of mammalian carnivores in South Africa

Vulture restaurants are used worldwide as a conservation tool to provide threatened vultures with a source of supplementary carrion free from anthropogenic contaminants such as poisons and veterinary drugs. While the impacts of supplementary feeding sites on ecosystem and scavenging community dynamics have been investigated in Europe, no information is currently available for southern Africa. This study presents evidence that providing supplementary carrion for vultures stimulated an increase in local abundance of two species of mammalian carnivores, the brown hyaena (Hyaena brunnea) and the black-backed jackal (Canis mesomelas). These findings require that the wider impacts of providing supplementary carrion for conserving threatened species are fully investigated

Homogenised model linking microscopic and macroscopic dynamics of a biofilm: Application to growth in a plug flow reactor

International audienceWe propose a new "hybrid" model for the simulation of biofilm growth in a plug flow bioreactor. Our approach consists in combining three scales: a microscopic one for the individual bacteria, a mesoscopic or "coarse-grained" one that homogenises at an intermediate scale the quantities relevant to the attachment/detachment process, and a macroscopic one in terms of substrate concentration. We compare our simulations with the numerical solutions of an existing partial differential equations model at the macroscopic scale

Identification and quantification of PAH in bitumen by GC-Ion-Trap MS and HPLC-fluorescent detectors

Bitumen is a complex product with a large matrix of heavy aliphatic/naphthenic/aromatic hydrocarbons as well as a large number of isomeric compounds such as polycyclic aromatic compounds (PACs). Some PACs and derivatives are known to have a mutagenic and carcinogenic activity, and there is no generally satisfactory clean-up method for separating PACs from this very complex hydrocarbon matrix. Moreover, from an analytical point of view, the isomeric compounds usually co-elute in the same gas chromatography (GC) retention range, GC being one of the most widely used techniques in this area. However, the use of a suitable clean-up procedure for isolating the aromatic fractions, combined with two selective detection techniques such as mass spectrometry (GC-Ion Trap MS) and HPLC-Fluorescent detector (HPLC-FL), is expected to provide an effective tool for accurately determining certain PAC species in bitumen. In this paper we compare two quantitative extractions to analyse the 16 PAHs that occur in bitumen according to the US EPA reference list. Two clean-up protocols are assessed and compared by using both GC-Ion Trap MS and HPLC-FL chromatographic/detection techniques. The first extraction method combines well-established and proven clean-up operations with an automatic fractionation by semi-preparative HPLC (certification test program for PAHs in sewage sludge, in creosote-contaminated soil and in harbour sediment organised by the Community Bureau of Reference, BCR). The second method uses a multiple step-by-step liquid/liquid and liquid/solid extraction clean-up procedure. After the bitumen extracts are cleaned up, only the use of both GC-MS &amp; HPLC-FL can provide reliable results. The more sensitive FL provides enhanced fluorescent selectivity signals that facilitate identification of PAH compounds. However, for their quantification, the capillary GC-ion trap mass spectrometric technique is preferred because of the insufficient resolution of the HPLC column and the possible quenching or co-elution effect of matrix compounds. Both detection techniques are regarded as complementary. [Authors]]]> Polycyclic Hydrocarbons, Aromatic ; Gas Chromatography, Mass Spectrometry ; Spectrometry, Mass, Electrospray Ionization oai:serval.unil.ch:BIB_99E6734EF740 2022-05-07T01:23:31Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_99E6734EF740 Sleep and dreaming Siclari , Francesca Tononi, Giulio info:eu-repo/semantics/bookPart incollection 2015-11-05 The neurology of consciousness info:eu-repo/semantics/altIdentifier/isbn/0128009489 eng oai:serval.unil.ch:BIB_99E74779D4BD 2022-05-07T01:23:31Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_99E74779D4BD Julian Charrière http://www.sikart.ch/kuenstlerInnen.aspx?id=13342783 Gunti, Claus info:eu-repo/semantics/article article 2019-08-19 SIKART - Dictionnaire de l'art suisse, pp. en ligne Julian Charrière, art, écologie, géologie, Suisse fre oai:serval.unil.ch:BIB_99BA8179E536 2022-05-07T01:23:30Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_99BA8179E536 Anti-CD2 receptor antibodies activate the HIV long terminal repeat in T lymphocytes info:eu-repo/semantics/altIdentifier/pmid/1680914 Bressler, P. Pantaleo, G. Demaria, A. Fauci, A. S. info:eu-repo/semantics/article article 1991-10 Journal of Immunology, vol. 147, no. 7, pp. 2290-4 info:eu-repo/semantics/altIdentifier/pissn/0022-1767 <![CDATA[The CD2 T lymphocyte glycoprotein surface molecule mediates both cell to cell adhesion and T cell activation, two processes that are involved in the spread of HIV infection. Treatment of chronically HIV-infected PBMC with anti-CD2 mAb has been shown to induce the expression of infectious virus from these cultures. In this study we investigated the mechanisms whereby anti-CD2 antibodies stimulate viral production. We demonstrate that treatment of transiently transfected T lymphocytes with anti-CD2 antibodies results in activation of the HIV long terminal repeat. Furthermore, CAT assays using mutated HIV long terminal repeat-CAT constructs and gel shift assays demonstrate that this activation is dependent on the NF-kappa B enhancer. These studies suggest that interaction of CD2 with its natural ligand, LFA-3, may play a role in regulation of HIV expression

The Evolutionary Pathway to Obligate Scavenging in Gyps Vultures

The evolutionary pathway to obligate scavenging in Gyps vultures remains unclear. We propose that communal roosting plays a central role in setting up the information transfer network critical for obligate scavengers in ephemeral environments and that the formation of a flotilla-like foraging group is a likely strategy for foraging Gyps vultures. Using a spatial, individual-based, optimisation model we find that the communal roost is critical for establishing the information network that enables information transfer owing to the spatial-concentration of foragers close to the roost. There is also strong selection pressure for grouping behaviour owing to the importance of maintaining network integrity and hence information transfer during foraging. We present a simple mechanism for grouping, common in many animal species, which has the added implication that it negates the requirement for roost-centric information transfer. The formation of a flotilla-like foraging group also improves foraging efficiency through the reduction of overlapping search paths. Finally, we highlight the importance of consideration of information transfer mechanisms in order to maximise the success of vulture reintroduction programmes

Anthropogenic contributions to global carbonyl sulfide, carbon disulfide and organosulfides fluxes

Previous studies of the global sulfur cycle have focused almost exclusively on oxidized species and just a few sulfides. This focus is expanded here to include a wider range of reduced sulfur compounds. Inorganic sulfides tend to be bound into sediments, and sulfates are present both in sediments and the oceans. Sulfur can adopt polymeric forms that include S-S bonds. This review examines the global anthropogenic sources of reduced sulfur, updating emission inventories and widening the consideration of industrial sources. It estimates the anthropogenic fluxes of key sulfides to the atmosphere (units Gg S a-1) as: carbonyl sulfide (total 591: mainly from pulp and pigment 171, atmospheric oxidation of carbon disulfide 162, biofuel and coal combustion, 133, natural 898 Gg S a-1), carbon disulfide (total 746: rayon 395, pigment 205, pulp 78, natural 330 Gg S a-1), methanethiol (total 2119: pulp 1680, manure 330, rayon and wastewater 102, natural 6473 Gg S a-1), dimethyl sulfide (total 2197: pulp 1462, manure 660 and rayon 36, natural 31 657 Gg S a-1), dimethyl disulfide (total 1103: manure 660, pulp 273; natural 1081 Gg S a-1). The study compares the magnitude of the natural sources: marine, vegetation and soils, volcanoes and rain water with the key anthropogenic sources: paper industry, rayon-cellulose manufacture, agriculture and pigment production. Industrial sources could be reduced by better pollution control, so their impact may lessen over time. Anthropogenic emissions dominate the global budget of carbon disulfide, and some aromatic compounds such as thiophene, with emissions of methanethiol and dimethyl disufide also relatively important. Furthermore, industries related to coal and bitumen are key sources of multi-ringed thiophenes, while food production and various wastes may account for the release of significant amounts of dimethyl disulfide and dimethyl trisulfide

APPROVISIONNEMENT SOCIAL ET PRÉVISIBILITÉ DES RESSOURCES : MODÉLISATION DU COMPORTEMENT DES VAUTOURS

Foraging individuals may use either personal information derived from their own previous experience or social information based on conspecific observation. Which kind of information is used depends largely on food predictability. When resources are unpredictable, personal information may be of little use, as illustrated by Gyps vultures that mostly rely on social foraging strategies to find carrion. Some human activities increase resource predictability, e.g. supplying feeding stations makes food patches more predictable for scavengers. In this thesis, I explore the impact of different levels of resource predictability on the use of personal or social information in foraging strategies and on the ecological service provided by vultures. I developed an individual-based spatially explicit model of foraging Gyps vultures at a daily scale to explore different behavioural hypotheses as well as different management scenarios. The results show that individuals using previously acquired personal information provided a less efficient scavenging service, tended to be more aggregated on resources and thus suffered more strongly from competition while feeding than individuals foraging in groups. Then, I discuss the consequences of this work in terms of conservation and population management. This work will also be used to help analyse GPS tracking data. Finally, it will be integrated in a study that takes into account socio-economical aspects to better understand all sides of the vultures' ecological service and its sensitivity to human interventions.Pour trouver leur nourriture, les individus peuvent utiliser des informations qu'ils ont recueillies eux-mêmes précédemment ou des informations obtenues par l'observation de leurs congénères. Le type d'information utilisé dépend beaucoup de la prévisibilité de leur nourriture. Quand la nourriture n'est pas prévisible, l'information personnelle n'a que peu de valeur. C'est le cas des vautours Gyps qui s'approvisionnent socialement pour trouver des carcasses. Certaines activités humaines changent la prévisibilité des ressources, par exemple en installant des charniers qui rendent la nourriture plus prévisible pour les nécrophages. Dans cette thèse, j'étudie l'impact de la prévisibilité des ressources alimentaires sur la stratégie d'approvisionnement et sur le service écologique rendu par les vautours. J'ai créé un modèle individu-centré spatialement explicite du comportement journalier des vautours proposant plusieurs stratégies de recherche et différents contextes de gestion. Le modèle montre que les individus favorisant les charniers rendent un service d'équarrissage plus faible et souffrent plus de la compétition lors de l'exploitation car ils s'agrègent davantage sur les ressources que des individus recherchant en groupe. Je discute des conséquences de ce travail sur le plan de la conservation et de la gestion des populations de vautours. Ce travail sera utilisé à court terme pour aider à l'analyse d'un suivi GPS. Enfin, il sera intégré dans une étude incluant des aspects socio-économiques afin d'avoir une vue d'ensemble du service rendu par les vautours et de sa sensibilité aux activités humaines

9 juin 1978. Circulaire n° 78-193 relative aux conditions d'admission au cycle préparatoire des écoles élémentaires.

Deygout Jean. 9 juin 1978. Circulaire n° 78-193 relative aux conditions d'admission au cycle préparatoire des écoles élémentaires. In: La petite enfance à l'école, XIXe-XXe siècles. Paris : Institut national de recherche pédagogique, 1982. pp. 336-338. (Bibliothèque de l'Histoire de l'Education, 1

9 juin 1978. Circulaire n° 78-193 relative aux conditions d'admission au cycle préparatoire des écoles élémentaires.

Deygout Jean. 9 juin 1978. Circulaire n° 78-193 relative aux conditions d'admission au cycle préparatoire des écoles élémentaires. In: La petite enfance à l'école, XIXe-XXe siècles. Paris : Institut national de recherche pédagogique, 1982. pp. 336-338. (Bibliothèque de l'Histoire de l'Education, 1

Introduction

Je travaille à la direction des Opérations qui fait partie de la DGAC et plus particulièrement de la direction des Services de la navigation aérienne : pour mémoire, la direction des Opérations regroupe l’ensemble des services du contrôle aérien français, et en particulier l’ensemble de ses contrôleurs. Il a été beaucoup question, précédemment, d’un triptyque pilote-contrôleur-automate et du rôle de l’ingénieur. L’idée de cette conférence est d’aborder des aspects concernant d’autres particip..