1,947 research outputs found

    The Drosophila Caspase DRONC Cleaves following Glutamate or Aspartate and Is Regulated by DIAP1, HID, and GRIM

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    The caspase family of cysteine proteases plays important roles in bringing about apoptotic cell death. All caspases studied to date cleave substrates COOH-terminal to an aspartate. Here we show that the Drosophila caspase DRONC cleaves COOH-terminal to glutamate as well as aspartate. DRONC autoprocesses itself following a glutamate residue, but processes a second caspase, drICE, following an aspartate. DRONC prefers tetrapeptide substrates in which aliphatic amino acids are present at the P2 position, and the P1 residue can be either aspartate or glutamate. Expression of a dominant negative form of DRONC blocks cell death induced by the Drosophila cell death activators reaper, hid, and grim, and DRONC overexpression in flies promotes cell death. Furthermore, the Drosophila cell death inhibitor DIAP1 inhibits DRONC activity in yeast, and DIAP1's ability to inhibit DRONC-dependent yeast cell death is suppressed by HID and GRIM. These observations suggest that DRONC acts to promote cell death. However, DRONC activity is not suppressed by the caspase inhibitor and cell death suppressor baculovirus p35. We discuss possible models for DRONC function as a cell death inhibitor

    Gluon Fragmentation into 3PJ^3P_J Quarkonium

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    The functions of the gluon fragmentation into 3PJ^3P_J quarkonium are calculated to order αs2\alpha_s^2. With the recent progress in analysing quarkonium systems in QCD we show explicitly how the socalled divergence in the limit of the zero-binding energy, which is related to PP-wave quarkonia, is treated correctly in the case of fragmentation functions. The obtained fragmentation functions satisfy explicitly at the order of αs2\alpha_s^2 the Altarelli-Parisi equation and when z0z\rightarrow 0 they behave as z1z^{-1} as expected. Some comments on the previous results are made.Comment: Type-errors in the text and equations are eliminated. Several sentences are added in Sect.4. The file is compressed and uuencoded (E-Mail contact [email protected]

    Mental Health, Substance Use, and the Importance of Religion during the COVID-19 Pandemic

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    COVID-19 impacted multiple facets of life, with implications on physical, mental, and societal health. Specifically, long COVID and related losses have exacerbated complex and prolonged grief responses and mental disorders including depression and anxiety. These mental health concerns are in turn associated with increased detrimental coping strategies including substance use disorders (SUD). The social and interpersonal implications of SUD are varied. Secondary data analyses from the National Survey on Drug Use and Health (NSDUH) collected during the COVID-19 pandemic revealed an increase in substance use behaviors and mental health problems. Self-reported religious activities had a positive meditating effect on reducing substance use behaviors. Accordingly, we explored the importance of one\u27s religion and faith in coping with stress, grief, and mental health challenges during the COVID-19 pandemic, highlighting the impact of religion and faith in bringing hope and purpose during periods of loss, grief, mental health challenges, and SUD

    Penicillium menonorum, a new species related to P. pimiteouiense

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    Penicillium menonorum is described as a new monoverticillate, non-vesiculate species that resembles P. restrictum and P. pimiteouiense. On the basis of phylogenetic analysis of DNA sequences from four loci, P. menonorum occurs in a clade with P. pimiteouiense, P. vinaceum, P. guttulosum, P. rubidurum, and P. parvum. Genealogical concordance analysis was applied to P. pimiteouiense and P. parvum, substantiating the phenotypically defined species. The species P. rubidurum, P. guttulosum, and P. menonorum were on distinct branches statistically excluded from inclusion in other species and have distinct phenotypes

    Perturbative QCD Fragmentation Functions for BcB_c and BcB_c^* Production

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    The dominant production mechanism for bˉc{\bar b} c bound states in high energy processes is the production of a high energy bˉ{\bar b} or cc quark, followed by its fragmentation into the bˉc{\bar b} c state. We calculate the fragmentation functions for the production of the S-wave states BcB_c and BcB_c^* to leading order in the QCD coupling constant. The fragmentation probabilities for bˉBc{\bar b} \rightarrow B_c and bˉBc{\bar b} \rightarrow B_c^* are approximately 2.2×1042.2 \times 10^{-4} and 3.1×1043.1 \times 10^{-4}, while those for cBcc \rightarrow B_c and cBcc \rightarrow B_c^* are smaller by almost two orders of magnitude.Comment: Latex, 12 pages, 3 figures available upon request, NUHEP-TH-93-

    Energy Preserved Sampling for Compressed Sensing MRI

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    The sampling patterns, cost functions, and reconstruction algorithms play important roles in optimizing compressed sensing magnetic resonance imaging (CS-MRI). Simple random sampling patterns did not take into account the energy distribution in k-space and resulted in suboptimal reconstruction of MR images. Therefore, a variety of variable density (VD) based samplings patterns had been developed. To further improve it, we propose a novel energy preserving sampling (ePRESS) method. Besides, we improve the cost function by introducing phase correction and region of support matrix, and we propose iterative thresholding algorithm (ITA) to solve the improved cost function. We evaluate the proposed ePRESS sampling method, improved cost function, and ITA reconstruction algorithm by 2D digital phantom and 2D in vivo MR brains of healthy volunteers. These assessments demonstrate that the proposed ePRESS method performs better than VD, POWER, and BKO; the improved cost function can achieve better reconstruction quality than conventional cost function; and the ITA is faster than SISTA and is competitive with FISTA in terms of computation time

    The Connection between 3.3 {\mu}m PAH Emission and AGN Activity

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    We investigate the connection between starburst and AGN activity by comparing the 3.3 {\mu}m PAH eimission with AGN properties. Utilizing the slit-less spectroscopic capability of the AKARI space telescope, we observe moderate-luminosity Type I AGN at z~0.4 to measure global starburst activity. The 3.3 {\mu}m PAH emissions are detected for 7 out of 26 target galaxies. We find no strong correlation between the 3.3 {\mu}m PAH emission and AGN luminosity in the limted range of the observed AGN luminosity, suggesting that global star formation may not be tightly related with AGN activity. Combining our measurements with the previous 3.3 {\mu}m measurements of the low redshift Type I AGN in the literature, we investigate the connection between nuclear starburst and AGN activity. In contrast to global star formation, the 3.3 {\mu}m PAH luminosity measured from the central part of galaxies correlates with AGN luminosity, implying that starburst and AGN activity are directly connected at the nuclear region.Comment: 8 pages, 6 figures, accepted for publication in AJ, minor typos and references correcte

    The Cleo Rich Detector

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    We describe the design, construction and performance of a Ring Imaging Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones with a novel ``sawtooth''-shaped exit surface. Photons in the wavelength interval 135--165 nm are detected using multi-wire chambers filled with a mixture of methane gas and triethylamine vapor. Excellent pion/kaon separation is demonstrated.Comment: 75 pages, 57 figures, (updated July 26, 2005 to reflect reviewers comments), to be published in NIM
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