2,843 research outputs found

    Incidental finding of a double orifice mitral valve in an elderly patient: value of 3D imaging.

    Get PDF
    A rare isolated double orifice mitral valve (DOMV) was diagnosed in a 77-year-old male patient, being assessed for surgical repair of the ascending aorta. This is a rare congenital abnormality, usually discovered as an incidental finding during investigation of other congenital heart defects. This case shows that a detailed assessment of all cardiac structures is necessary, not only in young patients, but also in the elderly population, to minimise the under-diagnosis of such rare anomalies. The use of 3D transthoracic echocardiography (TTE) has an increasingly significant role in establishing the diagnosis and extending the morphological and functional understanding of the anomaly. LEARNING POINTS: Thoroughly assessing all cardiac structures, in accordance with the minimum dataset guidelines for transthoracic echocardiography, ensures not only a comprehensive assessment of the primary indication for the scan, but also improves the detection of concomitant and otherwise unknown lesions. Despite falling under the category of congenital heart defects, several rare anomalies such as DOMV can be present in elderly patients, and the adult echocardiographer should have appropriate knowledge and awareness for detecting these conditions. 3D TTE provides a comprehensive assessment of the morphology of DOMV, over and above the information obtained by 2D imaging

    Lookback time bounds from energy conditions

    Full text link
    In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach to cosmological modeling, where the energy and matter components of the cosmic fluid are unknown, the energy conditions provide model-independent bounds on the behavior of the lookback time of cosmic sources as a function of the redshift for any value of the spatial curvature. We also confront such bounds with a lookback time sample which is built from the age estimates of 32 galaxies lying in the interval 0.11z1.840.11 \lesssim z \lesssim 1.84 and by assuming the total expanding age of the Universe to be 13.7±0.213.7 \pm 0.2 Gyr, as obtained from current cosmic microwave background experiments. In agreement with previous results, we show that all energy conditions seem to have been violated at some point of the recent past of cosmic evolution.Comment: 7 pages, 3 figures. v2: Minor changes, published in Phys.Rev.D in the present for

    Energy Conditions and Cosmic Acceleration

    Get PDF
    In general relativity, the energy conditions are invoked to restrict general energy-momentum tensors TμνT_{\mu\nu} in different frameworks, and to derive general results that hold in a variety of general contexts on physical grounds. We show that in the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) approach, where the equation of state of the cosmological fluid is unknown, the energy conditions provide model-independent bounds on the behavior of the distance modulus of cosmic sources as a function of the redshift for any spatial curvature. We use the most recent type Ia supernovae (SNe Ia) observations, which include the new Hubble Space Telescope SNe Ia events, to carry out a model-independent analysis of the energy conditions violation in the context of the standard cosmology. We show that both the null (NEC), weak (WEC) and dominant (DEC) conditions, which are associated with the existence of the so-called phantom fields, seem to have been violated only recently (z0.2z \lesssim 0.2), whereas the condition for attractive gravity, i.e., the strong energy condition (SEC) was firstly violated billions of years ago, at z1z \gtrsim 1.Comment: 6 pages, 3 figures. v2: References added, misprints corrected, published in Phys.Rev.D in the present for

    HIF-1 alpha-independent hypoxia-induced rapid PTK6 stabilization is associated with increased motility and invasion

    Get PDF
    © 2014 Landes Bioscience. PTK6/Brk is a non-receptor tyrosine kinase overexpressed in cancer. Here we demonstrate that cytosolic PTK6 is rapidly and robustly induced in response to hypoxic conditions in a HIF-1-independent manner. Furthermore, a proportion of hypoxic PTK6 subsequently re-localized to the cell membrane. We observed that the rapid stabilization of PTK6 is associated with a decrease in PTK6 ubiquitylation and we have identified c-Cbl as a putative PTK6 E3 ligase in normoxia. The consequences of hypoxia-induced PTK6 stabilization and subcellular re-localization to the plasma membrane include increased cell motility and invasion, suggesting PTK6 targeting as a therapeutic approach to reduce hypoxia-regulated metastatic potential. This could have particular significance for breast cancer patients with triple negative disease

    Triple Differential Dijet Cross Section at the LHC

    Get PDF
    The measurement of the triple-differential dijet production cross section as a function of the average transverse momentum pT,avgp_{T,\textrm{avg}}, half the rapidity separation yy^{*}, and the boost yby_{b} of the two leading jets in the event enables a kinematical scan of the underlying parton momentum distributions. We compute for the first time the second-order perturbative QCD corrections to this triple-differential dijet cross section, at leading color in all partonic channels, thereby enabling precision studies with LHC dijet data. A detailed comparison with experimental CMS 8 TeV data is performed, demonstrating how the shape of this differential cross section probes the parton densities in different kinematical ranges.info:eu-repo/semantics/publishedVersio

    Radiação fotossinteticamente ativa durante o período chuvoso em vegetação de Caatinga em regeneração na Chapada do Araripe, PE.

    Get PDF
    A radiação fotossinteticamente ativa (PAR) é importante para diferentes áreas relacionadas à fisiologia vegetal e ciências agrárias, pois está diretamente associada à produção de biomassa e a taxa de crescimento das plantas, sendo também um importante parâmetro para estudos ecológicos. Assim, o presente trabalho teve como objetivo analisar os componentes da radiação fotossinteticamente ativa (PAR) em uma área de caatinga em regeneração na Chapada do Araripe, PE. Foram utilizados dados micrometeorológicos do período de janeiro a abril de 2013 (estação chuvosa), coletados por sensores eletrônicos instalados em uma torre localizada em uma área de caatinga em regeneração em Araripina, PE. Com base nos dados medidos de radiação PAR incidente, refletida e transmitida, obteve-se a fração da radiação fotossinteticamente ativa absorvida (fPARa) e interceptada (fPARin), assim como suas relações com a radiação solar global (Rg). Observou-se que a precipitação do período foi de 473,45 mm, correspondendo a 79,62% do total anual. A radiação fotossinteticamente ativa (PARt) e a radiação global (Rg) apresentaram correlação linear, com coeficiente de determinação (r2) igual a 0,99. O valor médio de fPARa foi igual a 55%, com menor verificado em janeiro (32%) e maior no mês de abril (76%). Esses valores estão associados ao desenvolvimento vegetativo em decorrência das chuvas e podem ser utilizados para estimativa do fator de cobertura vegetal da área de estudo. Constatou-se que existe alta correlação entre a Rg e a PAR na área de caatinga em regeneração, estimando também o comportamento da fRFAi e fRAFa
    corecore