114 research outputs found

    Gender-related variations in hemolymph parameters of Carabus lefebvrei (Coleoptera: Carabidae): HPLC analysis and phenoloxidase activity

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    We characterized the enzymatic activity of basal and total phenoloxidase and HLPC and SDS-PAGE profiles in hemolymph of Carabus lefebvrei males and females at different reproductive status. The phenoloxidase activity was activated by trypsin and inhibited by phenoloxidase activity specific inhibitor phenylthiourea. Our results demonstrated that both in males and females, there were no significant differences in the basal phenoloxidase activity between reproductive and virgin beetles, while the total phenoloxidase activity increased significantly in virgin specimens. Thus, resources seem to be invested to increase the humoral response in pre-reproductive phase forming a barrier against pathogens and preserving the fecundity and longevity of both sexes. The hemolymph DOPA-MBTH assay on polyacrilamide gel electrophoresis showed a high activity of monomeric form with an apparent molecular weight of 90 kDa and a dimer of about 170 kDa, also multimeric bands were present in both sexes. In the SDS-PAGE general protein pattern, specific bands were evident for reproductive and virgin males and females as biochemical markers of sexual difference in immunocompetence. Reproducible differences in peaks were recorded in HPLC analysis performed on virgin and reproductive males and females

    Tensionless structure of glassy phase

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    We study a class of homogeneous finite-dimensional Ising models which were recently shown to exhibit glassy properties. Monte Carlo simulations of a particular three-dimensional model in this class show that the glassy phase obtained under slow cooling is dominated by large scale excitations whose energy ElE_l scales with their size ll as EllΘE_l\sim l^{\Theta} with Θ1.33(5)\Theta\sim 1.33(5). Simulations suggest that in another model of this class, namely the four-spin model, energy is concentrated mainly in linear defects making also in this case domain walls tensionless. Two-dimensinal variants of these models are trivial and energy of excitations scales with the exponent Θ=1.05(5)\Theta=1.05(5).Comment: 5 page

    Bosonization of non-relativstic fermions in 2-dimensions and collective field theory

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    We revisit bosonization of non-relativistic fermions in one space dimension. Our motivation is the recent work on bubbling half-BPS geometries by Lin, Lunin and Maldacena (hep-th/0409174). After reviewing earlier work on exact bosonization in terms of a noncommutative theory, we derive an action for the collective field which lives on the droplet boundaries in the classical limit. Our action is manifestly invariant under time-dependent reparametrizations of the boundary. We show that, in an appropriate gauge, the classical collective field equations imply that each point on the boundary satisfies Hamilton's equations for a classical particle in the appropriate potential. For the harmonic oscillator potential, a straightforward quantization of this action can be carried out exactly for any boundary profile. For a finite number of fermions, the quantum collective field theory does not reproduce the results of the exact noncommutative bosonization, while the latter are in complete agreement with the results computed directly in the fermi theory.Comment: references added and typos corrected; 21 pages, 3 figures, eps

    Interacting Open Wilson Lines in Noncommutative Field Theories

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    In noncommutative field theories, it was known that one-loop effective action describes propagation of non-interacting open Wilson lines, obeying the flying dipole's relation. We show that two-loop effective action describes cubic interaction among `closed string' states created by open Wilson lines. Taking d-dimensional noncommutative [\Phi^3] theory as the simplest setup, we compute nonplanar contribution at low-energy and large noncommutativity limit. We find that the contribution is expressible in a remarkably simple cubic interaction involving scalar open Wilson lines only and nothing else. We show that the interaction is purely geometrical and noncommutative in nature, depending only on sizes of each open Wilson line.Comment: v1: 27 pages, Latex, 7 .eps figures v2: minor wording change + reference adde

    Growing Correlation Length on Cooling Below the Onset of Caging in a Simulated Glass-Forming Liquid

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    We present a calculation of a fourth-order, time-dependent density correlation function that measures higher-order spatiotemporall correlations of the density of a liquid. From molecular dynamics simulations of a glass-forming Lennard-Jones liquid, we find that the characteristic length scale of this function has a maximum as a function of time which increases steadily beyond the characteristic length of the static pair correlation function g(r)g(r) in the temperature range approaching the mode coupling temperature from above

    Variational Mean Field approach to the Double Exchange Model

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    It has been recently shown that the double exchange Hamiltonian, with weak antiferromagnetic interactions, has a richer variety of first and second order transitions than previously anticipated, and that such transitions are consistent with the magnetic properties of manganites. Here we present a thorough discussion of the variational Mean Field approach that leads to the these results. We also show that the effect of the Berry phase turns out to be crucial to produce first order Paramagnetic-Ferromagnetic transitions near half filling with transition temperatures compatible with the experimental situation. The computation relies on two crucial facts: the use of a Mean Field ansatz that retains the complexity of a system of electrons with off-diagonal disorder, not fully taken into account by the Mean Field techniques, and the small but significant antiferromagnetic superexchange interaction between the localized spins.Comment: 13 pages, 11 postscript figures, revte

    Cross-sectional study of community serostatus to highlight undiagnosed HIV infections with oral fluid HIV-1/2 rapid test in non-conventional settings

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    The submerged portion of undiagnosed HIV infection in Italy is about 30% of subjects found seropositive. This fact represents one of the most important public health problems hindering the control of infection progression. This means we need to fight unawareness and social stigma and promote easy and friendly access to HIV test. We developed a Prevention Program called \u201cEASY test Project\u201d, offering a new rapid HIV test on oral fluid, to evaluate the acceptability of an alternative, free and anonymous test available in different settings (on board a \u201cMotor Home\u201d at public events, Points of Care, STDs outpatient prevention units and GP surgeries). From December 2008 to December 2012 we performed 7,865 HIV saliva tests, with 50 new infections found (0.6% of the total) out of 140,000 informed subjects. From the self-reported characteristics of respondents, the population approaching the EAST test project was represented by males (70%) aged between 20 and 50 years, 61% with a medium-high education level, 62% homosexuals (MSM), 88% reported unsafe sexual behaviours, and 48% had never undergone an HIV screening test. In five years of the Prevention Program, 100% of subjects interviewed gave a general favorable consent in approaching rapid and not invasive screening, immediate return of the result, and a timely specialized approach and treatment of HIV positive subjects. Results from our study confirm that the rapid and alternative test may contribute to HIV prevention strategies and to the control of the spread of infection and HIV disease progression by reaching a larger population, particularly when and where regular screening procedures are difficult to obtain or are not preferred

    PYTHIA 6.4 Physics and Manual

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    The PYTHIA program can be used to generate high-energy-physics `events', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, underlying events and beam remnants, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest.Comment: 576 pages, no figures, uses JHEP3.cls. The code and further information may be found on the PYTHIA web page: http://www.thep.lu.se/~torbjorn/Pythia.html Changes in version 2: Mistakenly deleted section heading for "Physics Processes" reinserted, affecting section numbering. Minor updates to take into account referee comments and new colour reconnection option
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