264 research outputs found

    New Eastern Record of \u3ci\u3ePtosima Walshii\u3c/i\u3e (Coleoptera: Buprestidae)

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    Ptosima walshii LeConte (Coleoptera: Buprestidae) is reported for the first time in Pennsylvania, being the eastern-most record of the species. Four specimens were captured in Lindgren funnel traps in Bedford and Fulton counties during invasive wood-destroying beetle surveys

    Fundamental Aspects of Black Holes

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    The literature study here seeks to present the foundations of black hole physics in General Relativity. The report includes a discussion of the Kerr black hole metric, black hole entropy, particle creation, the laws of black hole mechanics, and a bilinear mass formula for the Kerr-Newman black hole solution

    A Near Horizon Extreme Binary Black Hole Geometry

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    A new solution of four-dimensional vacuum General Relativity is presented. It describes the near horizon region of the extreme (maximally spinning) binary black hole system with two identical extreme Kerr black holes held in equilibrium by a massless strut. This is the first example of a non-supersymmetric, near horizon extreme binary black hole geometry of two uncharged black holes. The black holes are co-rotating, their relative distance is fixed, and the solution is uniquely specified by the mass. Asymptotically, the geometry corresponds to the near horizon extreme Kerr (NHEK) black hole. The binary extreme system has finite entropy

    Generalized Near Horizon Extreme Binary Black Hole Geometry

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    We present a new vacuum solution of Einstein’s equations describing the near horizon region of two neutral, extreme (zero-temperature), corotating, nonidentical Kerr black holes. The metric is stationary, asymptotically near horizon extremal Kerr (NHEK), and contains a localized massless strut along the symmetry axis between the black holes. In the deep infrared, it flows to two separate throats which we call “pierced-NHEK” geometries: each throat is NHEK pierced by a conical singularity. We find that in spite of the presence of the strut for the pierced-NHEK geometries the isometry group SL(2,R)×U(1) is restored. We find the physical parameters and entropy

    The RNA editing enzyme ADAR2 restricts L1 mobility

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    Adenosine deaminases acting on RNA (ADARs) are enzymes that convert adenosines to inosines in double-stranded RNAs (RNA editing A-to-I). ADAR1 and ADAR2 were previously reported as HIV-1 proviral factors. The aim of this study was to investigate the composition of the ADAR2 ribonucleoprotein complex during HIV-1 expression. By using a dual-tag affinity purification procedure in cells expressing HIV-1 followed by mass spectrometry analysis, we identified 10 non-ribosomal ADAR2-interacting factors. A significant fraction of these proteins was previously found associated to the Long INterspersed Element 1 (LINE1 or L1) ribonucleoparticles and to regulate the life cycle of L1 retrotransposons. Considering that we previously demonstrated that ADAR1 is an inhibitor of LINE-1 retrotransposon activity, we investigated whether also ADAR2 played a similar function. To reach this goal, we performed specific cell culture retrotransposition assays in cells overexpressing or ablated for ADAR2. These experiments unveil a novel function of ADAR2 as suppressor of L1 retrotransposition. Furthermore, we showed that ADAR2 binds the basal L1 RNP complex. Overall, these data support the role of ADAR2 as regulator of L1 life cycle

    The inhibition of the highly expressed miR-221 and miR-222 impairs the growth of prostate carcinoma xenografts in mice

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    MiR-221 and miR-222 are two highly homologous microRNAs whose upregulation has been recently described in several types of human tumors, for some of which their oncogenic role was explained by the discovery of their target p27, a key cell cycle regulator. We previously showed this regulatory relationship in prostate carcinoma cell lines in vitro, underlying the role of miR-221/222 as inducers of proliferation and tumorigenicity

    NF-kB and c-Jun induce the expression of the oncogenic miR-221 and miR-222 in prostate carcinoma and glioblastoma cells

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    MicroRNAs (miRNAs) are potent negative regulators of gene expression involved in all aspects of cell biology. They finely modulate virtually all physiological pathways in metazoans, and are deeply implicated in all main pathologies, among which cancer. Mir-221 and miR-222, two closely related miRNAs encoded in cluster from a genomic region on chromosome X, are strongly upregulated in several forms of human tumours. In this work, we report that the ectopic modulation of NF-kB modifies miR-221/222 expression in prostate carcinoma and glioblastoma cell lines, where we had previously shown their oncogenic activity. We identify two separate distal regions upstream of miR-221/222 promoter which are bound by the NF-kB subunit p65 and drive efficient transcription in luciferase reporter assays; consistently, the site-directed mutagenesis disrupting p65 binding sites or the ectopical inhibition of NF-kB activity significantly reduce luciferase activity. In the most distal enhancer region, we also define a binding site for c-Jun, and we show that the binding of this factor cooperates with that of p65, fully accounting for the observed upregulation of miR-221/222. Thus our work uncovers an additional mechanism through which NF-kB and c-Jun, two transcription factors deeply involved in cancer onset and progression, contribute to oncogenesis, by inducing miR-221/222 transcription

    TNF-a and IL-10 modulation induced by polyphenols extracted by olive pomace in a mouse model of paw inflammation

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    Polyphenols from olive are known to possess antioxidant and anti-inflammatory properties. The aim of this study was to study whether or not administration of olive (Olea europaeaL.) polyphenols could have an effect on cytokines as TNF-a and IL-10 in the mouse paw following inflammation induced by carrageenan injection. TNF-a and IL-10 were measured by enzyme-linked immunosorbent assay. Carrageenan decreased IL-10 in the paws, however, this reduction appeared to be less evident in mice treated with carrageenan but administered with polyphenols. As for TNF-a, our findings did not reveal differences between groups but an increase in polyphenol and carrageenan groups if compared to the carrageenan only group. No differences between groups in the serum Glutathione were found. Altogether, this investigation shows that olive polyphenols in the mouse may modulate the levels of cytokines having a role in the process of inflammation as TNF-a and IL-10
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