929 research outputs found

    Land surface phenological response to decadal climate variability across Australia using satellite remote sensing

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    © 2014 Author(s). Land surface phenological cycles of vegetation greening and browning are influenced by variability in climatic forcing. Quantitative spatial information on phenological cycles and their variability is important for agricultural applications, wildfire fuel accumulation, land management, land surface modeling, and climate change studies. Most phenology studies have focused on temperature-driven Northern Hemisphere systems, where phenology shows annually recurring patterns. However, precipitation-driven non-annual phenology of arid and semi-arid systems (i.e., drylands) received much less attention, despite the fact that they cover more than 30% of the global land surface. Here, we focused on Australia, a continent with one of the most variable rainfall climates in the world and vast areas of dryland systems, where a detailed phenological investigation and a characterization of the relationship between phenology and climate variability are missing. To fill this knowledge gap, we developed an algorithm to characterize phenological cycles, and analyzed geographic and climate-driven variability in phenology from 2000 to 2013, which included extreme drought and wet years. We linked derived phenological metrics to rainfall and the Southern Oscillation Index (SOI). We conducted a continent-wide investigation and a more detailed investigation over the Murray-Darling Basin (MDB), the primary agricultural area and largest river catchment of Australia. Results showed high inter-and intra-annual variability in phenological cycles across Australia. The peak of phenological cycles occurred not only during the austral summer, but also at any time of the year, and their timing varied by more than a month in the interior of the continent. The magnitude of the phenological cycle peak and the integrated greenness were most significantly correlated with monthly SOI within the preceding 12 months. Correlation patterns occurred primarily over northeastern Australia and within the MDB, predominantly over natural land cover and particularly in floodplain and wetland areas. Integrated greenness of the phenological cycles (surrogate of vegetation productivity) showed positive anomalies of more than 2 standard deviations over most of eastern Australia in 2009-2010, which coincided with the transition from the El Niño-induced decadal droughts to flooding caused by La Niña

    Endometrioza apendicelui vermicular ce a simulat apendicita acută

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    Catedra 2 Chirurgie, USMF „Nicolae Testemiţanu”Autorii relatează un caz clinic de endometioza apendicelui vermicular. Pacienta în vârstă de 22 ani s-a internat cu acuze clasice de apendicită acută. Examenul paraclinic efectuat a stabilit modificări caracteristice. A fost efectuată laparotomia Mc-Burney pe dreapta, intraoperator fiind depistate congestia apendicelui şi o formaţiune de volum mobilă, de 1,5 cm. Examenul histomorfologic a confirmat diagnosticul anterior. Este necesar consultația medicului ginecolog pentru un tratament hormonal complex.The authors report a clinical case of endometriosis of the appendix. 22 year old patient was admitted with acute appendicitis classic blame. Paraclinical examination established characteristic changes. A laparotomy was performed on the right Mc-Burney. Appendix congestion and mobile formation volume of 1,5 cm were detected intraoperatively. Histomorfologic examination confirmed the previous diagnosis. Gynecologist consultation is necessary for complex hormonal treatment

    Data on lithofacies, sedimentology and palaeontology of South Rifian Corridor sections (Morocco)

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    We provide lithological, sedimentological and micropalaeontological descriptions of 39 sections and boreholes crossing the upper Miocene deposits of the Rifian Corridor. These deposits represent the sedimentary remnants of the marine gateway that connected the Atlantic to the Mediterranean in the late Miocene. Results from these 39 sites were adopted to reconstruct the palaeogeographic evolution of the gateway presented in the associated research article (Capella et al., 2018) [1]. For each outcrop we present a synthesis of field observations, lithofacies, key sedimentological features, planktic and benthic assemblages

    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 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

    Contourite depositional system after the exit of a strait: Case study from the late Miocene South Rifian Corridor, Morocco

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    Idealized facies of bottom current deposits (contourites) have been established for fine-grained contourite drifts in modern deep-marine sedimentary environments. Their equivalent facies in the ancient record however are only scarcely recognized due to the weathered nature of most fine-grained deposits in outcrop. Facies related to the erosional elements (i.e. contourite channels) of contourite depositional systems have not yet been properly established and related deposits in outcrop appear non-existent. To better understand the sedimentary facies and facies sequences of contourites, the upper Miocene contourite depositional systems of the South Rifian Corridor (Morocco) is investigated. This contourite depositional system formed by the dense palaeo-Mediterranean Outflow Water. Foraminifera assemblages were used for age-constraints (7.51 to 7.35 Ma) and to determine the continental slope depositional domains. Nine sedimentary facies have been recognized based on lithology, grain-size, sedimentary structures and biogenic structures. These facies were subsequently grouped into five facies associations related to the main interpreted depositional processes (hemipelagic settling, contour currents and gravity flows). The vertical sedimentary facies succession records the tectonically induced, southward migration of the contourite depositional systems and the intermittent behaviour of the palaeo-Mediterranean Outflow Water, which is mainly driven by precession and millennial-scale climate variations. Tides substantially modulated the palaeo-Mediterranean Outflow Water on a sub-annual scale. This work shows exceptional examples of muddy and sandy contourite deposits in outcrop by which a facies distribution model from the proximal continental slope, the contourite channel to its adjacent contourite drift, is proposed. This model serves as a reference for contourite recognition both in modern environments and the ancient record. Furthermore, by establishing the hydrodynamics of overflow behaviour a framework is provided that improves process-based interpretation of deep-water bottom current deposits

    Search for additional heavy neutral Higgs and gauge bosons in the ditau final state produced in 36 fb−1 of pp collisions at √s=13 TeV with the ATLAS detector

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    A search for heavy neutral Higgs bosons and Z′ bosons is performed using a data sample corresponding to an integrated luminosity of 36.1 fb−1 from proton-proton collisions at √s=13 TeV recorded by the ATLAS detector at the LHC during 2015 and 2016. The heavy resonance is assumed to decay to τ+τ− with at least one tau lepton decaying to final states with hadrons and a neutrino. The search is performed in the mass range of 0.2-2.25 TeV for Higgs bosons and 0.2-4.0 TeV for Z′ bosons. The data are in good agreement with the background predicted by the Standard Model. The results are interpreted in benchmark scenarios. In the context of the hMSSM scenario, the data exclude tan β > 1.0 for mA= 0.25 TeV and tan β > 42 for mA=1.5 TeV at the 95% confidence level. For the Sequential Standard Model, ZSSM′ with mZ′< 2.42 TeV is excluded at 95% confidence level, while Z NU′ with mZ ′ < 2.25 TeV is excluded for the non-universal G(221) model that exhibits enhanced couplings to third-generation fermions

    Measurements of long-range azimuthal anisotropies and associated Fourier coefficients for pp collisions at √s=5.02 and 13 TeV and p+Pb collisions at √sNN=5.02 TeV with the ATLAS detector

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    ATLAS measurements of two-particle correlations are presented for √s=5.02 and 13 TeV ppcollisions and for √sNN=5.02 TeV p+Pb collisions at the LHC. The correlation functions are measured as a function of relative azimuthal angle Δϕ, and pseudorapidity separation Δη, using charged particles detected within the pseudorapidity interval |η|2, is studied using a template fitting procedure to remove a “back-to-back” contribution to the correlation function that primarily arises from hard-scattering processes. In addition to the elliptic, cos (2Δϕ), modulation observed in a previous measurement, the pp correlation functions exhibit significant cos (3Δϕ) and cos (4Δϕ) modulation. The Fourier coefficients vn, n associated with the cos (nΔϕ) modulation of the correlation functions for n=2–4 are measured as a function of charged-particle multiplicity and charged-particle transverse momentum. The Fourier coefficients are observed to be compatible with cos (nϕ) modulation of per-event single-particle azimuthal angle distributions. The single-particle Fourier coefficients vn are measured as a function of charged-particle multiplicity, and charged-particle transverse momentum for n=2–4. The integrated luminosities used in this analysis are, 64nb−1 for the √s=13 TeV pp data, 170 nb−1 for the √ s = 5.02 TeV pp data, and 28 nb−1 for the √sNN = 5.02 TeV p+Pb data
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