159 research outputs found

    Issues and special features of animal health research

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    In the rapidly changing context of research on animal health, INRA launched a collective discussion on the challenges facing the field, its distinguishing features, and synergies with biomedical research. As has been declared forcibly by the heads of WHO, FAO and OIE, the challenges facing animal health, beyond diseases transmissible to humans, are critically important and involve food security, agriculture economics, and the ensemble of economic activities associated with agriculture. There are in addition issues related to public health (zoonoses, xenobiotics, antimicrobial resistance), the environment, and animal welfare

    Towards a TEI compliant interchange format for Ancient Egyptian-Coptic textual resources

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    Sharing digital textual resources is an actual challenge for scholars working on Ancient Egyptian-Coptic (3000 BC-1350 AD). There are two types of reasons for this: first, the different writing systems that have been used throughout the history of this language (hieroglyphic and hieratic scripts, demotic, Coptic) led to various solutions as regards the encoding of texts; second, the diverging aims and scopes of the projects involved in creating annotated corpora of Ancient Egyptian-Coptic generated representation formats with few characteristics in common. As a result, the resources themselves cannot be shared, and no standard tool can be used for encoding, annotating, querying or analyzing these resources. In order to overcome these issues, several leading projects in the field join forces and introduce a TEI compliant interchange data model that has the following characteristics: 1) The ancient Egyptian-Coptic TEI interchange data model represents an agreement on a subset of the EpiDoc schema towards which the textual data of each project can be converted. Project specific annotations are dealt with either using stand-off markup that refers to tokens of transliterated texts (Bański 2010; Pose et al. 2014), or on the basis of data models that are true expansions of the kernel interchange data model. 2) The specialized metadata elements and attributes referring to Egyptological concepts are based on controlled vocabularies that are shared and enriched collaboratively by the projects. 3) These metadata apply either to physical text-bearing objects, inscribed physical features, witnesses (on documents) or texts (Morlock & Santin 2014). As the conceptualization of the relationship between these entities is shared between projects, coherence and precision when describing both the material, philological and linguistic dimensions of textual resources can be obtained

    Proteomic Analysis of Lipid Droplets from Arabidopsis Aging Leaves Brings New Insight into Their Biogenesis and Functions

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    Lipid droplets (LDs) are cell compartments specialized for oil storage. Although their role and biogenesis are relatively well documented in seeds, little is known about their composition, structure and function in senescing leaves where they also accumulate. Here, we used a label free quantitative mass spectrometry approach to define the LD proteome of aging Arabidopsis leaves. We found that its composition is highly different from that of seed/cotyledon and identified 28 proteins including 9 enzymes of the secondary metabolism pathways involved in plant defense response. With the exception of the TRIGALACTOSYLDIACYLGLYCEROL2 protein, we did not identify enzymes implicated in lipid metabolism, suggesting that growth of leaf LDs does not occur by local lipid synthesis but rather through contact sites with the endoplasmic reticulum (ER) or other membranes. The two most abundant proteins of the leaf LDs are the CALEOSIN3 and the SMALL RUBBER PARTICLE1 (AtSRP1); both proteins have structural functions and participate in plant response to stress. CALEOSIN3 and AtSRP1 are part of larger protein families, yet no other members were enriched in the LD proteome suggesting a specific role of both proteins in aging leaves. We thus examined the function of AtSRP1 at this developmental stage and found that AtSRP1 modulates the expression of CALEOSIN3 in aging leaves. Furthermore, AtSRP1 overexpression induces the accumulation of triacylglycerol with an unusual composition compared to wild-type. We demonstrate that, although AtSRP1 expression is naturally increased in wild type senescing leaves, its overexpression in senescent transgenic lines induces an over-accumulation of LDs organized in clusters at restricted sites of the ER. Conversely, atsrp1 knock-down mutants displayed fewer but larger LDs. Together our results reveal that the abundancy of AtSRP1 regulates the neo-formation of LDs during senescence. Using electron tomography, we further provide evidence that LDs in leaves share tenuous physical continuity as well as numerous contact sites with the ER membrane. Thus, our data suggest that leaf LDs are functionally distinct from seed LDs and that their biogenesis is strictly controlled by AtSRP1 at restricted sites of the ER

    Synthesis, Crystal Structure, Magnetic, and Electron Paramagnetic Resonance Properties of a Spiroconjugated Biradical. Evidence for Spiroconjugation Exchange Pathway

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    A spiroconjugated nitronyl nitroxide biradical, 6,6‘-(4,4,5,5-tetramethylimidazolidine-3-oxide-1-oxyl)-3,3,3‘,3‘-tetramethyl-1,1‘-spirobisindane (1), has been prepared by functionalization of a 3,3,3‘,3‘-tetramethyl-1,1‘-spirobisindane framework followed by Ullman condensation and subsequent oxidation. The biradical crystallizes in the monoclinic space group C2/c with four molecules in the unit cell of dimensions a = 24.861(10) Å, b = 12.129(3) Å, and c = 12.258(6) Å. X-ray analysis of a blue-plate single crystal has revealed dihedral angles of 28° between the nitronyl nitroxide moiety and aromatic ring with intramolecular through space radical−radical distances of 8.25 and 10.11 Å. In the solid state, the temperature dependence of the molar magnetic susceptibility reveals antiferromagnetic interactions. These interactions are best fit using a pair model, affording the value J = −4.0 cm^(-1) where J is the interaction parameter appearing in the spin Hamiltonian H = −JS_1·S_2. The field dependence of the magnetization measured at 2 K is consistent with a pair model. Frozen matrix EPR spectra of biradical 1 in CH_2Cl_2 at 100 K shows a half field transition at 1700 G. Temperature dependence of the half field transition intensity has been found to be consistent with a ground singlet state and thermally accessible triplet state. The magnetic interaction observed in the solid state is also observed in solution. Thus, room-temperature solution spectra display a nine-line pattern, with hyperfine coupling to four “equivalent” nitrogen atoms and a hyperfine coupling constant a_N = 3.8 G. Temperature dependence of the solution EPR spectra of biradical 1 displays alternating line width effects caused by conformational dynamics in solution. This behavior has been attributed to modulation of exchange and hyperfine interactions most likely caused by rotational motion about the nitronyl nitroxide−phenyl bond. Biradical 1 therefore exists as a ground-state singlet with a thermally accessible triplet at ca. 4 cm^(-1) higher in energy with a conformational dependence of intramolecular exchange in solution. This coupling may present evidence for spiroconjugation as an exchange pathway. Density functional calculations (B3/6-311G(D)) have been performed to investigate this possibility

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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    Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in pp collision data at s=8TeV\sqrt{s}=8\,\mathrm TeV{} with the ATLAS detector

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