1,222 research outputs found

    Improving Forage Production Quantity and Quality Using Native Legume Species in Semi-Arid Agrosilvopastoral System

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    Agrosilvopastoral systems provide a range of livelihood services, either directly through forage production or indirectly by the beneficial effects on soil conservation, nutrient cycling, pollutant filtering, and biodiversity enhancement. Hence, improved silvopastoral systems have ample scope to rehabilitate degraded pastures to sustain livestock production, which remains a strong pillar for the livelihoods of the agrosilvopastoral communities. To evaluate the impact of Hedysarum coronarium L. (sulla) reseeding on pasture productivity, plant cover and plant density in semi-arid silvopastoral systems, an experiment was carried out in Sbaihia Site, Zaghouan Governorate, Tunisia during 2018-2019 growing season. The experiment was laid out under a randomized complete block design having 3 treatments including reseeding sulla; protection from grazing and control (free grazing) with three replications per treatment. Preliminary results showed that there were significant differences (p\u3c 0.05) among the three treatments. Reseeded sulla and protected plots recorded 100% plant cover while the control plots had less than 60%. The estimated biomass for the reseeded plots was four times higher than the biomass production in the protected plots and eleven times higher than the control plots. The highest plant density was recorded in the reseeded plots (163.2 plants/m2), followed by the protected plots (30.6 plants/m2) while the lowest value was recorded in the control plots (29.8 plants/m2). Based on these findings, it is concluded that reseeding well-adapted native forage species has a great potential to improve productivity of semi-arid silvopastoral systems, which would contribute towards reducing the feeding cost and, therefore, enhancing the income of the agrosilvopastoral communities

    Marqueurs chromosomiques: à propos d'un cas

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    Les marqueurs chromosomiques peuvent être définis comme des petits chromosomes de structure anormale présents en addition aux 46 chromosomes humains connus. C'est un groupe hétérogène d'anomalies de structure chromosomique pouvant être avec ou sans conséquence phénotypique. Plusieurs tentatives sont réalisées afin de retrouver une corrélation génotype-phénotype lors de la présence d'un marqueur chromosomique. L'identification du marqueur, son origine et sa structure suit une stratégie bien codifiée actuellement allant d'abord de l'orientation clinique suivie des techniques de cytogénétique conventionnelle (caryotype métaphasique standard, bandes C, NOR) et de cytogénétique moléculaire (M-FISH, CGH, CGH array) puis une détection par des techniques plus ciblées (painting, sondes locus spécifique). Cet ensemble permet une meilleure analyse et correspondance clinico-génétique. Nous rapportons le cas d'un nourrisson présentant une dysmorphie faciale avec un retard psychomoteur dont l'analyse cytogénétique a révélé la présence d'un marqueur chromosomique avec un caryotype métaphasique 47,XX,+mar. A travers cette observation, nous mettons en valeur le rôle de la cytogénétique conventionnelle et moléculaire dans le diagnostic des syndromes dysmorphiques permettant une meilleure prise en charge du patient et un conseil génétique adéquat pour sa familleKey words: Marqueurs chromosomiques, anomalie chromosomique, analyse cytogénétique, dysmorphi

    Salt effect on physiological, biochemical and anatomical structures of two Origanum majorana varieties (Tunisian and Canadian)

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    In this study, we evaluated the salt concentration effect on plant growth, mineral composition, antioxidant responses and anatomical structure of two varieties of Origanum majorana after exposure to NaCl treatment. Our results show an inclusive behaviour of the two varieties, since the majority of sodium was exported and accumulated in their aerial parts. The Canadian variety (CV) appeared relatively more tolerant to salt than the Tunisian one (TV). Transversal section of leaves showed a thickening of dorsal and ventral cuticle, more importantly in CV than in TV, in the presence and in absence of salt. This was accompanied by an increase in the length of palisade cells, and the width of spongy collenchyma lacuna. The stem had a subquadrangular shape in TV and quadrangular in the Canadian variety. At mature stage, the stem pit was reabsorbed in the TV and replaced by a large cavity, whereas it remained unchanged in CV. The relative salt tolerance of the CV was related to: (1) a good selectivity in favour of K+: (2) a strong peroxidase activity and (3) an increase in the lengthening of palisade cell accompanied with an increase of lacunae in spongy parenchyma in CV.Key words: Origanum majorana, salinity, growth, mineral nutrition, leaves, stems, anatomical, antioxidant

    The study of applying heat to enhance moisture transfer in knitted spacer structures

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    The aim of the article is to report the research of the Advanced Textiles Research Group on the application of heat to enhance the moisture transmission in knitted spacer structures. The current trend in the design and development of moisture management textiles is to use knitted spacer structures. Generally, in moisture management textiles, the moisture is transmitted through the fabric due to capillary forces, which are influenced by the hydrostatic pressure difference between the two fabric layers and the geometry and the dimensions of the capillaries of the sandwiched fibre layer of a knitted spacer structures. However, the hydrostatic pressure difference is also influenced by the outer environmental changes. The research has demonstrated that the moisture transfer rate of up to 30% per 100 cm2 of fabric area can be achieved by creating a temperature gradient between the two layers of a knitted spacer structures. This temperature gradient was achieved by application of heat at one layer of the knitted spacer structures, which influenced the hydrostatic pressure difference of the knitted spacer structures. Application of heat to the knitted spacer structures was achieved by knitting small heater elements on side of knitted spacer structures to create an active moisture management structure. Wash tests, temperature rise rates and moisture wettability experiments of the active moisture management structure were performed, and the results are discussed in the publication

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

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    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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