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

Trois expériences ont été conduites entre 2014 et 2015 sur 12 dromadaires mâles adultes à Niono et 12 à Sotuba pour identifier les espèces broutées et la quantité de matière sèche ingérée correspondante en zones sahélienne et subhumide. Les données ont été collectées par suivi quotidien de 4 dromadaires porteurs de sac de collecte de fèces choisis au hasard, conduits avec le reste du troupeau durant 12 jours. A Niono, 32 espèces végétales ont été broutées et 71 espèces à Sotuba. A Niono, les espèces les plus broutées ont été 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 graminées. A Sotuba, ce sont Ziziphus mauritiana (14,9 %), Vitellaria paradoxum (10,5 %) et les graminées Cassia tora (7,4 %) et Hiptis suaveolens (6,2 %). Dans le menu figuraient les feuilles, les rameaux, les fleurs et les fruits des espèces végétales consommées. Le taux moyen de protéines de l’ingéré a été de 13,3 % à Niono contre 8,7 % à Sotuba. La digestibilité de la matière sèche a été de 47,9 % à Niono contre 41,2 % à Sotuba. La teneur en protéines digestibles a été de 66,8 ± 0,8 g/kg MS à Niono contre 62,0 ± 0,7 g/kg MS à Sotuba. La quantité de matière sèche ingérée a été de 5,6 ± 0,2 kg à Niono et 5,1 ± kg à Sotuba. La connaissance de ces informations permettra de mieux organiser la complémentation alimentaire des dromadaires afin d’optimiser  leurs productions en zones sahélienne et subhumide du Mali. Mots clés : dromadaires, ingestion pâturage, 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

Comportement des dromadaires adultes sur paturages sahelien et subhumide en station au Mali: 1. Description des principales activites

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Diet quality and colorectal tumor risk in persons with Lynch syndrome

Contains fulltext : 229397.pdf (Publisher’s version ) (Open Access)BACKGROUND: Persons with Lynch syndrome (LS) have an increased risk of developing colorectal tumors (CRTs). Adherence to diet quality indices associated with colorectal cancer (CRC) risk in the general population has not been studied before in LS. METHODS: Dietary habits of 490 participants with LS from a prospective cohort study was collected using a food frequency questionnaire. The Dutch Healthy Diet index 2015 (DHD15-index) and Dietary Approaches to Stop Hypertension (DASH) were used to score food-based diet quality. Diet quality scores were divided into tertiles where a higher tertile reflects a higher diet quality. Multivariable Cox proportional hazard regression models were used to estimate the association between the DHD15-index, DASH score and CRT risk. RESULTS: During a median follow-up time of 53.4 months, 210 participants (42.9%) developed CRTs. The DHD-index and DASH score were not associated with CRT risk; hazard ratios for highest vs. lowest tertile were 1.00 (95% Confidence Interval (CI): 0.67-1.48) and 1.11 (95% CI: 0.74-1.69), respectively. No linear trends across the DHD-index and DASH score tertiles were observed (P-trend = 0.97 and 0.83 respectively). CONCLUSION: In contrast to observations in the general population, no evidence for an association between the food-based DHD15-index or DASH score and CRT risk was observed in persons with LS. Further studies are needed investigating the association between diet quality and mechanisms leading to the development of LS-associated tumors

Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society

Pattern and process in Norwegian upland grasslands: a functional analysis

Four classes of functional and morphological plant traits (FMT) – established strategies (the CSR scheme sensu Grime 1979), life-forms (sensu Raunkiaer 1934), morphology, and regenerative strategies – are used as tools for explaining vegetation gradients at summer farms in the mountains of western Norway. These farms are assembly points for free-ranging domestic grazers, and differ floristically and ecologically from the surrounding heath or woodland vegetation. Detrended Correspondence Analysis and Two-Way INdicator SPecies ANalysis are used to relate major gradients in a floristic data set from 12 summer farms to two sets of explanatory variables: (1) environmental variables representing physical factors, plot position, soils, and land-use, and (2) the four FMT classification schemes. The main floristic gradient parallels a spatial gradient from the centres of the farms to the surrounding vegetation. A functional interpretation based on the concurrent use of the two sets of explanatory variables suggests that the gradient is one of decreasing disturbance and increasing environmental stress caused by decreasing grazing and manure effects away from farms. Partial Canonical Correspondence Analysis is used to investigate the relationships between the four FMT classes. The four classification schemes are partially redundant, and do not represent different trends of specialisation within the landscape. There is no strong evidence for decoupling of the traits of the vegetative and regenerative phases within the data. The combination of general process-based theories and specific plant attribute responses enhances the generality and interpretability of the study