866 research outputs found

    Interaction between two Fuzzy Spheres

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    We have calculated interactions between two fuzzy spheres in 3 dimension. It depends on the distance r between the spheres and the radii rho_1, rho_2. There is no force between the spheres when they are far from each other (long distance case). We have also studied the interaction for r=0 case. We find that an attractive force exists between two fuzzy sphere surfaces.Comment: Latex file, 13 page

    Introduction of d-Glutamate at a Critical Residue of Aβ42 Stabilizes a Prefibrillary Aggregate with Enhanced Toxicity.

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    The amyloid beta peptide 42 (Aβ42) is an aggregation-prone peptide that plays a pivotal role in Alzheimer's disease. We report that a subtle perturbation to the peptide through a single chirality change at glutamate 22 leads to a pronounced delay in the β-sheet adoption of the peptide. This was accompanied by an attenuated propensity of the peptide to form fibrils, which was correlated with changes at the level of the fibrillary architecture. Strikingly, the incorporation of d-glutamate was found to stabilize a soluble, ordered macromolecular assembly with enhanced cytotoxicity to PC12 cells, highlighting the importance of advanced prefibrillary Aβ aggregates in neurotoxicity

    Penyusunan Turp Syndrome Tool Assessment

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    Background: TURP syndrome is one of the complications in patients with post-TURP. The prevalence of this case in the fi rst PKU Muhammadiyah Hospital of Yogyakarta mortality rate was 4.7% of the 168 action TURP. This case requires preventive action by composing one tool for early detection of TURP syndrome. Objective: Develop a tool to detect the TURP syndrome. Methods: This mixed method research method. Qualitative action research method. Samples were seven nurses and one urologist. Research from April to June 2014 The instrument is FGD guide. Test the validity of using triangulation experts. Quantitative methods with validity and reliability. The sample was 21 nurses and conducted in July 2014 questionnaire Intrumennya are signs and symptoms of TURP syndrome. Test the validity of the Pearson product moment and reliability testing using Cronbach alpha. Two of these methods implemented in RS PKU Muhammadiyah Yogyakarta I and II. Results: Qualitative methods produce 15 items signs and symptoms of TURP syndrome. Quantitative methods to test the validity of the fi fteen items that generate valid because the count is greater r table (n = 21, 5% signifi cance value of 0.433). Reliability test results of 0.930, meaning that this tool reliable. This tool categorizes into three TURP syndrome is negative, mild, moderate, and heavy. Conclusion: It has been structured tool for early detection of TURP syndrome

    Neutron star properties in the quark-meson coupling model

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    The effects of internal quark structure of baryons on the composition and structure of neutron star matter with hyperons are investigated in the quark- meson coupling (QMC) model. The QMC model is based on mean-field description of nonoverlapping spherical bags bound by self-consistent exchange of scalar and vector mesons. The predictions of this model are compared with quantum hadrodynamic (QHD) model calibrated to reproduce identical nuclear matter saturation properties. By employing a density dependent bag constant through direct coupling to the scalar field, the QMC model is found to exhibit identical properties as QHD near saturation density. Furthermore, this modified QMC model provides well-behaved and continuous solutions at high densities relevant to the core of neutron stars. Two additional strange mesons are introduced which couple only to the strange quark in the QMC model and to the hyperons in the QHD model. The constitution and structure of stars with hyperons in the QMC and QHD models reveal interesting di erences. This suggests the importance of quark structure e ects in the baryons at high densities. PACS number(s): 26.60.+c, 21.65.+f, 12.39.Ba, 24.85.+

    Samarium(II) iodide promoted carbon-carbon bond fragmentation: a facile route to bridged eight membered rings and 1,3-disubstituted cyclopentanes

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    Samarium(II) iodide has been found to induce carbon-carbon bond cleavage in a number of bicyclo[2.2.1]heptane derivatives having a 1,4-dicarbonyl moiety under conditions at which the 1,4-dicarbonyl moiety undergoes intramolecular pinacol coupling

    Hot hypernuclear matter in the modified quark meson coupling model

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    Hot hypernuclear matter is investigated in an explicit SU(3) quark model based on a mean field description of nonoverlapping baryon bags bound by the self-consistent exchange of scalar sigma, zeta and vector omega,phi mesons. The sigma, omega mean fields are assumed to couple to the u, d-quarks while the zeta ,phi mean fields are coupled to the s-quark. The coupling constants of the mean fields with the quarks are assumed to satisfy SU(6) symmetry. The calculations take into account the medium dependence of the bag parameter on the scalar fields sigma, zeta. We consider only the octet baryons N,Lambda,Sigma, Xi in hypernuclear matter. An ideal gas of the strange mesons K and K is introduced to keep zero net strangeness density. Our results for symmetric hypernuclear matter show that a phase transition takes place at a critical temperature around 180 MeV in which the scalar mean fields sigma, zeta take nonzero values at zero baryon density. Furthermore, the bag contants of the baryons decrease significantly at and above this critical temperature indicating the onset of quark deconfinement. The present results imply that the onset of quark deconfinement in SU(3) hypernuclear matter is much stronger than in SU(2) nuclear matter. PACS:21.65.+f, 24.85.+p, 12.39B

    Influenza virus morphogenesis and budding.

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    Influenza viruses are enveloped, negative stranded, segmented RNA viruses belonging to Orthomyxoviridae family. Each virion consists of three major sub-viral components, namely (i) a viral envelope decorated with three transmembrane proteins hemagglutinin (HA), neuraminidase (NA) and M2, (ii) an intermediate layer of matrix protein (M1), and (iii) an innermost helical viral ribonucleocapsid [vRNP] core formed by nucleoprotein (NP) and negative strand viral RNA (vRNA). Since complete virus particles are not found inside the cell, the processes of assembly, morphogenesis, budding and release of progeny virus particles at the plasma membrane of the infected cells are critically important for the production of infectious virions and pathogenesis of influenza viruses as well. Morphogenesis and budding require that all virus components must be brought to the budding site which is the apical plasma membrane in polarized epithelial cells whether in vitro cultured cells or in vivo infected animals. HA and NA forming the outer spikes on the viral envelope possess apical sorting signals and use exocytic pathways and lipid rafts for cell surface transport and apical sorting. NP also has apical determinant(s) and is probably transported to the apical budding site similarly via lipid rafts and/or through cortical actin microfilaments. M1 binds the NP and the exposed RNAs of vRNPs, as well as to the cytoplasmic tails (CT) and transmembrane (TM) domains of HA, NA and M2, and is likely brought to the budding site on the piggy-back of vRNP and transmembrane proteins. Budding processes involve bud initiation, bud growth and bud release. The presence of lipid rafts and assembly of viral components at the budding site can cause asymmetry of lipid bilayers and outward membrane bending leading to bud initiation and bud growth. Bud release requires fusion of the apposing viral and cellular membranes and scission of the virus buds from the infected cellular membrane. The processes involved in bud initiation, bud growth and bud scission/release require involvement both viral and host components and can affect bud closing and virus release in both positive and negative ways. Among the viral components, M1, M2 and NA play important roles in bud release and M1, M2 and NA mutations all affect the morphology of buds and released viruses. Disassembly of host cortical actin microfilaments at the pinching-off site appears to facilitate bud fission and release. Bud scission is energy dependent and only a small fraction of virus buds present on the cell surface is released. Discontinuity of M1 layer underneath the lipid bilayer, absence of outer membrane spikes, absence of lipid rafts in the lipid bilayer, as well as possible presence of M2 and disassembly of cortical actin microfilaments at the pinching-off site appear to facilitate bud fission and bud release. We provide our current understanding of these important processes leading to the production of infectious influenza virus particles

    Opposed-Flow Flame Spreading in Reduced Gravity

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    Experimental results obtained in drop towers and in Space Shuttle based experiments coupled with modelling efforts are beginning to provide information that is allowing an understanding to be developed of the physics of opposed-flow flame spread at reduced gravity where the spread rate and flow velocity are comparable and of the role played by radiative and diffusive processes in flame spreading in microgravity. Here we describe one Space Shuttle based experiment on flame spreading in a quiescent environment, the Solid Surface Combustion Experiment, SSCE, one planned microgravity experiment on flame spreading in a radiatively-controlled, forced opposing flow environment, the Diffusive and Radiative Transport in Fires Experiment, DARTFire, modelling efforts to support these experiments, and some results obtained to date

    Comparing Virtue, Consequentialist, and Deontological Ethics-Based Corporate Social Responsibility: Mitigating Microfinance Risk in Institutional Voids

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    Due to the nature of lending practices and support services offered to the poor in developing countries, portfolio risk is a growing concern for the microfinance industry. Though previous research highlights the importance of risk for microfinance organizations, not much is known about how microfinance organizations can mitigate risks incurred from providing loans to the poor in developing countries. Further, though many microfinance organizations practice corporate social responsibility (CSR) to help create economic and social wealth in developing countries, the impact of such CSR practices remains an underdeveloped area of inquiry. We use a normative ethics lens to develop an ethics-based CSR theory that differentiates between three forms of ethics-based CSR—virtue, consequentialist, and deontological. We argue that while all three forms can help mitigate risk, virtue ethics-based CSR is potentially the most useful form of CSR toward mitigating microfinance portfolio risk. We test our hypotheses using a sample of microfinance organizations from across the world. Our findings suggest that virtue ethics-based CSR is not just an important philosophical paradigm; it can actually help mitigate microfinance portfolio risk when implemented in practice
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