308 research outputs found

    Genome wide scan for quantitative trait loci affecting tick resistance in cattle (Bos taurus × Bos indicus)

    Get PDF
    <p><b>Abstract</b></p> <p><b>Background</b></p> <p>In tropical countries, losses caused by bovine tick <it>Rhipicephalus (Boophilus) microplus</it> infestation have a tremendous economic impact on cattle production systems. Genetic variation between <it>Bos taurus</it> and <it>Bos indicus</it> to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (<it>Bos indicus</it>) × Holstein (<it>Bos taurus</it>) cross.</p> <p>Results</p> <p>Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23.</p> <p>Conclusions</p> <p>The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.</p

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

    Get PDF
    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

    Get PDF
    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Barley sodium content is regulated by natural variants of the Na+ transporter HvHKT1;5

    Get PDF
    During plant growth, sodium (Na+) in the soil is transported via the xylem from the root to the shoot. While excess Na+ is toxic to most plants, non-toxic concentrations have been shown to improve crop yields under certain conditions, such as when soil K+ is low. We quantified grain Na+ across a barley genome-wide association study panel grown under non-saline conditions and identified variants of a Class 1 HIGH-AFFINITY-POTASSIUM-TRANSPORTER (HvHKT1;5)-encoding gene responsible for Na+ content variation under these conditions. A leucine to proline substitution at position 189 (L189P) in HvHKT1;5 disturbs its characteristic plasma membrane localisation and disrupts Na+ transport. Under low and moderate soil Na+, genotypes containing HvHKT1:5P189 accumulate high concentrations of Na+ but exhibit no evidence of toxicity. As the frequency of HvHKT1:5P189 increases significantly in cultivated European germplasm, we cautiously speculate that this non-functional variant may enhance yield potential in non-saline environments, possibly by offsetting limitations of low available K+

    Participation in biocultural diversity conservation : insights from five Amazonian examples

    Get PDF
    Unidad de excelencia MarĂ­a de Maeztu CEX2019-000940-MThe past three decades have seen the emergence of myriads of initiatives focused on conserving, revitalizing, and maintaining Indigenous and Local Knowledge (ILK) as part of biocultural approaches to conservation. However, the extent to which these efforts have been participatory has been often overlooked. In this chapter, we focus on five prominent ILK conservation initiatives in the Amazon Basin to examine the participation of Indigenous Peoples and Local Communities (IPLCs) in ILK conservation. Our review illustrates several examples of ILK conservation initiatives offering substantial opportunities for meaningful IPLC participation over the long term. Overall, our case studies suggest that the development of robust and inclusive decision-making processes is essential to optimize IPLC participation in ILK conservation, thereby increasing the legitimacy of these initiatives. Our review is not an exhaustive account of the breadth and depth of all initiatives promoting participatory biocultural conservation in this region, but it illustrates that there are many strategies that can help foster IPLC engagement and lead the participatory turn in biocultural conservation
    • 

    corecore