182 research outputs found

    Comportement des dromadaires sur patures Sahelien et Subhumide au Mali : 2. Especes vegetales et quantites de fourrage ingerees

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    Trois expĂ©riences ont Ă©tĂ© conduites entre 2014 et 2015 sur 12 dromadaires mĂąles adultes Ă  Niono et 12 Ă  Sotuba pour identifier les espĂšces broutĂ©es et la quantitĂ© de matiĂšre sĂšche ingĂ©rĂ©e correspondante en zones sahĂ©lienne et subhumide. Les donnĂ©es ont Ă©tĂ© collectĂ©es par suivi quotidien de 4 dromadaires porteurs de sac de collecte de fĂšces choisis au hasard, conduits avec le reste du troupeau durant 12 jours. A Niono, 32 espĂšces vĂ©gĂ©tales ont Ă©tĂ© broutĂ©es et 71 espĂšces Ă  Sotuba. A Niono, les espĂšces les plus broutĂ©es ont Ă©tĂ© Acacia seyal (19 %), Acacia senegal 14,8%), Balanites aegyptiaca (12,6 %) pour les ligneux et Zornia glochidiata (12,6 %) et Schoenefeldia gracilis (6,1 %) pour les graminĂ©es. A Sotuba, ce sont Ziziphus mauritiana (14,9 %), Vitellaria paradoxum (10,5 %) et les graminĂ©es Cassia tora (7,4 %) et Hiptis suaveolens (6,2 %). Dans le menu figuraient les feuilles, les rameaux, les fleurs et les fruits des espĂšces vĂ©gĂ©tales consommĂ©es. Le taux moyen de protĂ©ines de l’ingĂ©rĂ© a Ă©tĂ© de 13,3 % Ă  Niono contre 8,7 % Ă  Sotuba. La digestibilitĂ© de la matiĂšre sĂšche a Ă©tĂ© de 47,9 % Ă  Niono contre 41,2 % Ă  Sotuba. La teneur en protĂ©ines digestibles a Ă©tĂ© de 66,8 ± 0,8 g/kg MS Ă  Niono contre 62,0 ± 0,7 g/kg MS Ă  Sotuba. La quantitĂ© de matiĂšre sĂšche ingĂ©rĂ©e a Ă©tĂ© de 5,6 ± 0,2 kg Ă  Niono et 5,1 ± kg Ă  Sotuba. La connaissance de ces informations permettra de mieux organiser la complĂ©mentation alimentaire des dromadaires afin d’optimiser  leurs productions en zones sahĂ©lienne et subhumide du Mali. Mots clĂ©s : dromadaires, ingestion pĂąturage, sahel, subhumide, Mali English Title: Dromedary behaviour on Sahelian and subhumid pasture of Mali: 2. Plant species and feed intake Three experiments were conducted on 30 adult male camels to identify species grazed and the amount of dry matter ingested in the Sahelian (Niono) and sub-humid (Sotuba), zones during the rainy, cold dry and hot dry, seasons. Data were collected by monitoring 4 camels carrying faeces collection bags conducted with the rest of the herd. In Niono, 32 plant species were grazed and 71 species in Sotuba. The menu included leaves, twigs, flowers and fruits of consumed plant species. The average protein level of ingest was 13.3% in Niono and 8.7% in Sotuba. The digestibility of the material was 47.9% in Niono and 41.2% in Sotuba. The digestible protein content was 66.8 ± 0.8 g / kg of dry matter (DM) at Niono and 62.0 ± 0.7 g / kg DM at Sotuba. The amount of dry matter ingested was 5.6 ± 0.2 kg at Niono and 5.1 ± kg at Sotuba. Knowledge of this information is a key element to better organize animal feed supplementation in order to optimize camel production in the sahelian and sub-humid zones of Mali. Keywords: camels, grazing ingestion, Sahel, subhumid, Mal

    Effects of proton versus photon irradiation on (lymph) angiogenic, inflammatory, proliferative and anti-tumor immune responses in head and neck squamous cell carcinoma

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    International audienceThe proximity of organs at risk makes the treatment of head and neck squamous cell carcinoma (HNSCC) challenging by standard radiotherapy. The higher precision in tumor targeting of proton (P) therapy could promote it as the treatment of choice for HNSCC. Besides the physical advantage in dose deposition, few is known about the biological impact of P versus photons (X) in this setting. To investigate the comparative biological effects of P versus X radiation in HNSCC cells, we assessed the relative biological effectiveness (RBE), viability, proliferation and mRNA levels for genes involved in (lymph)angiogenesis, inflammation, proliferation and anti-tumor immunity. These parameters, particularly VEGF-C protein levels and regulations, were documented in freshly irradiated and/or long-term surviving cells receiving low/high-dose, single (SI)/multiple (MI) irradiations with P/X. The RBE was found to be 1.1 Key (lymph)angiogenesis and inflammation genes were downregulated (except for vegf-c) after P and upregulated after X irradiation in MI surviving cells, demonstrating a more favorable profile after P irradiation. Both irradiation types stimulated vegf-c promoter activity in a NF-ÎșB-dependent transcriptional regulation manner, but at a lesser extent after P, as compared to X irradiation, which correlated with mRNA and protein levels. The cells surviving to MI by P or X generated tumors with higher volume, anarchic architecture and increased density of blood vessels. Increased lymphangiogenesis and a transcriptomic analysis in favor of a more aggressive phenotype were observed in tumors generated with X-irradiated cells. Increased detection of lymphatic vessels in relapsed tumors from patients receiving X radiotherapy was consistent with these findings. This study provides new data about the biological advantage of P, as compared to X irradiation. In addition to its physical advantage in dose deposition, P irradiation may help to improve treatment approaches for HNSCC

    Genome Wide Transcriptome Analysis of Dendritic Cells Identifies Genes with Altered Expression in Psoriasis

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    Activation of dendritic cells by different pathogens induces the secretion of proinflammatory mediators resulting in local inflammation. Importantly, innate immunity must be properly controlled, as its continuous activation leads to the development of chronic inflammatory diseases such as psoriasis. Lipopolysaccharide (LPS) or peptidoglycan (PGN) induced tolerance, a phenomenon of transient unresponsiveness of cells to repeated or prolonged stimulation, proved valuable model for the study of chronic inflammation. Thus, the aim of this study was the identification of the transcriptional diversity of primary human immature dendritic cells (iDCs) upon PGN induced tolerance. Using SAGESeq approach, a tag-based transcriptome sequencing method, we investigated gene expression changes of primary human iDCs upon stimulation or restimulation with Staphylococcus aureus derived PGN, a widely used TLR2 ligand. Based on the expression pattern of the altered genes, we identified non-tolerizeable and tolerizeable genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (Kegg) analysis showed marked enrichment of immune-, cell cycle- and apoptosis related genes. In parallel to the marked induction of proinflammatory mediators, negative feedback regulators of innate immunity, such as TNFAIP3, TNFAIP8, Tyro3 and Mer are markedly downregulated in tolerant cells. We also demonstrate, that the expression pattern of TNFAIP3 and TNFAIP8 is altered in both lesional, and non-lesional skin of psoriatic patients. Finally, we show that pretreatment of immature dendritic cells with anti-TNF-α inhibits the expression of IL-6 and CCL1 in tolerant iDCs and partially releases the suppression of TNFAIP8. Our findings suggest that after PGN stimulation/restimulation the host cell utilizes different mechanisms in order to maintain critical balance between inflammation and tolerance. Importantly, the transcriptome sequencing of stimulated/restimulated iDCs identified numerous genes with altered expression to date not associated with role in chronic inflammation, underlying the relevance of our in vitro model for further characterization of IFNprimed iDCs

    Probing Mechanical Properties of Graphene with Raman Spectroscopy

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    The use of Raman scattering techniques to study the mechanical properties of graphene films is reviewed here. The determination of Gruneisen parameters of suspended graphene sheets under uni- and bi-axial strain is discussed and the values are compared to theoretical predictions. The effects of the graphene-substrate interaction on strain and to the temperature evolution of the graphene Raman spectra are discussed. Finally, the relation between mechanical and thermal properties is presented along with the characterization of thermal properties of graphene with Raman spectroscopy.Comment: To appear in the Journal of Materials Scienc

    Autophagy mediates degradation of nuclear lamina

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    Z.D. is supported by a fellow award from the Leukemia & Lymphoma Society. B.C.C. is supported by career development awards from the Dermatology Foundation, Melanoma Research Foundation, and American Skin Association. S.L.B., P.D.A. and R.M. are supported by NIA P01 grant (P01AG031862). S.L.B. is also supported by NIH R01 CA078831. R.D.G. is supported by R01 GM106023 and the Progeria Research Foundation

    Coherent ac spin current transmission across an antiferromagnetic CoO insulator

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: Data are available from the corresponding author upon reasonable request.The recent discovery of spin current transmission through antiferromagnetic insulating materials opens up vast opportunities for fundamental physics and spintronics applications. The question currently surrounding this topic is: whether and how could THz antiferromagnetic magnons mediate a GHz spin current? This mismatch of frequencies becomes particularly critical for the case of coherent ac spin current, raising the fundamental question of whether a GHz ac spin current can ever keep its coherence inside an antiferromagnetic insulator and so drive the spin precession of another ferromagnet layer coherently? Utilizing element- and time-resolved x-ray pump-probe measurements on Py/Ag/CoO/Ag/Fe75Co25/MgO(001) heterostructures, here we demonstrate that a coherent GHz ac spin current pumped by the Py ferromagnetic resonance can transmit coherently across an antiferromagnetic CoO insulating layer to drive a coherent spin precession of the Fe75Co25 layer. Further measurement results favor thermal magnons rather than evanescent spin waves as the mediator of the coherent ac spin current in CoO.US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering DivisionNational Science Foundation (NSF)National Research Foundation of KoreaEngineering and Physical Sciences Research Council (EPSRC)National Key Research and Development Program of CHIN

    “Avoiding or approaching eyes”? Introversion/extraversion affects the gaze-cueing effect

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    We investigated whether the extra-/introversion personality dimension can influence processing of others’ eye gaze direction and emotional facial expression during a target detection task. On the basis of previous evidence showing that self-reported trait anxiety can affect gaze-cueing with emotional faces, we also verified whether trait anxiety can modulate the influence of intro-/extraversion on behavioral performance. Fearful, happy, angry or neutral faces, with either direct or averted gaze, were presented before the target appeared in spatial locations congruent or incongruent with stimuli’s eye gaze direction. Results showed a significant influence of intra-/extraversion dimension on gaze-cueing effect for angry, happy, and neutral faces with averted gaze. Introverts did not show the gaze congruency effect when viewing angry expressions, but did so with happy and neutral faces; extraverts showed the opposite pattern. Importantly, the influence of intro-/extraversion on gaze-cueing was not mediated by trait anxiety. These findings demonstrated that personality differences can shape processing of interactions between relevant social signals

    First light of VLT/HiRISE: High-resolution spectroscopy of young giant exoplanets

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    A major endeavor of this decade is the direct characterization of young giant exoplanets at high spectral resolution to determine the composition of their atmosphere and infer their formation processes and evolution. Such a goal represents a major challenge owing to their small angular separation and luminosity contrast with respect to their parent stars. Instead of designing and implementing completely new facilities, it has been proposed to leverage the capabilities of existing instruments that offer either high-contrast imaging or high-dispersion spectroscopy by coupling them using optical fibers. In this work, we present the implementation and first on-sky results of the High-Resolution Imaging and Spectroscopy of Exoplanets (HiRISE) instrument at the Very Large Telescope (VLT), which combines the exoplanet imager SPHERE with the recently upgraded high-resolution spectrograph CRIRES using single-mode fibers. The goal of HiRISE is to enable the characterization of known companions in the H band at a spectral resolution on the order of R = λ/∆λ = 100 000 in a few hours of observing time. We present the main design choices and the technical implementation of the system, which is constituted of three major parts: the fiber injection module inside of SPHERE, the fiber bundle around the telescope, and the fiber extraction module at the entrance of CRIRES. We also detail the specific calibrations required for HiRISE and the operations of the instrument for science observations. Finally, we detail the performance of the system in terms of astrometry, temporal stability, optical aberrations, and transmission, for which we report a peak value of ~3.9% based on sky measurements in median observing conditions. Finally, we report on the first astrophysical detection of HiRISE to illustrate its potential

    Detecting life outside our solar system with a large high-contrast-imaging mission

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    In this White Paper, which was submitted in response to the European Space Agency (ESA) Voyage 2050 Call, we recommend the ESA plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a mission will be needed to characterize a sizable sample of temperate Earth-like planets in the habitable zones of nearby Sun-like stars and to search for extraterrestrial biological activity. We provide an overview of relevant European expertise, and advocate ESA to start a technology development program towards detecting life outside the Solar System.Publisher PDFPeer reviewe
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