550 research outputs found

    Surface characterization of selected LDEF tray clamps

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    The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected

    General subtraction method for numerical calculation of one-loop QCD matrix elements

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    We present a subtraction scheme for eliminating the ultraviolet, soft, and collinear divergences in the numerical calculation of an arbitrary one-loop QCD amplitude with an arbitrary number of external legs. The subtractions consist of local counter terms in the space of the four-dimensional loop momentum. The ultraviolet subtraction terms reproduce MSbar renormalization. The key point in the method for the soft and collinear subtractions is that, although the subtraction terms are defined graph-by-graph and the matrix element is also calculated graph-by-graph, the sum over graphs of the integral of each the subtraction term can be evaluated analytically and provides the well known simple pole structure that arises from subtractions from real emission graphs, but with the opposite sign.Comment: 38 pages, 10 figures, axodraw styl

    Getting that female glance: Patterns and consequences of male nonverbal behavior in courtship contexts

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    Abstract Females apparently are the choosier sex in courtship contexts, but there still is limited information about female selection criteria in real courtship settings. Given that a female knows little about a heretofore unacquainted male, upon what dimensions can (and do) females base their initial courtship decisions? Here, we report findings from observational studies that investigated male nonverbal behavior in a bar context. Study 1 documented the body movements of males prior to making contact with a female. It was found that males who successfully made bcontactQ courtship initiation with females exhibited different body language in this precontact phase than did males who did not make contact with females, including significantly more glancing behaviors, space-maximization movements, intrasexual touching, and less closed-body movements. The findings from a second withinsubject study comparing the behavior of men in a bar when women were present or not present supported the initial study's findings and showed that males' emphasis on these behaviors increases in a mate-relevant context. We suggest that certain aspects of male nonverbal behavior in courtship contexts can serve as self-presentation and mate-value signals

    Severity of Depression Predicts Remission Rates Using Transcranial Magnetic Stimulation

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    Background: Multiple factors likely impact response and remission rates in the treatment of depression with repetitive transcranial magnetic stimulation (rTMS). Notably the role of symptom severity in outcomes with rTMS is poorly understood.Objective/Hypothesis: This study investigated the predictors of achieving remission in patients suffering from depression who receive ≥3 rTMS treatments per week. Methods: Available data on 41 patients treated at Walter Reed National Military Medical Center from 2009 to 2014 were included for analysis. Patients received a range of pulse sequences from 3,000 to 5,000 with left sided or bilateral coil placement. Primary outcome measures were total score on the Patient Health Questionnaire (PHQ-9) or the Quick Inventory of Depressive Symptomatology—Self Rated (QIDS-SR). Remission was defined as a total score less than five, and response was defined as a 50% decrease in the total score on both outcome metrics. Outcomes in patients diagnosed as suffering from mild or moderate depression were compared to those suffering from severe depression. Results: Of the 41 patients receiving treatment, 16 reached remission by the end of treatment. Remission rate was associated with the initial severity of depression, with patients with mild or moderate depression reaching remission at a significantly higher rate than those with severe depression. Total number of rTMS sessions or length of treatment were not predictors of remission. Conclusion: Patients with a baseline level of depression characterized as mild or moderate had significantly better outcomes following rTMS compared to patients with severe depression

    Next-to-leading order QCD calculations with parton showers II: soft singularities

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    Programs that calculate observables in quantum chromodynamics at next-to-leading order typically generate events that consist of partons rather than hadrons -- and just a few partons at that. These programs would be much more useful if the few partons were turned into parton showers, which could be given to one of the Monte Carlo event generators to produce hadron showers. In a previous paper, we have seen how to generate parton showers related to the final state collinear singularities of the perturbative calculation for the example of e+ + e- --> 3 jets. This paper discusses the treatment of the soft singularities.Comment: 26 pages with 5 figures. This version is close to the version to be publishe

    Electron-positron annihilation: Statistical and thermodynamic considerations

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    Lightcone considerations suggest that, in e+e- annihilation, the hadronic matter is initially created within a spatial volume in the c.m. frame of the order of E-3, where E/2 is the colliding beam energy. Its implications, within the statistical thermodynamic descriptions of Fermi and Landau, are conjectured. A distinctive result is that the multiplicity for e+e- annihilation is a constant.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22038/1/0000456.pd

    The KLN Theorem and Soft Radiation in Gauge Theories: Abelian Case

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    We present a covariant formulation of the Kinoshita, Lee, Nauenberg (KLN) theorem for processes involving the radiation of soft particles. The role of the disconnected diagrams is explored and a rearrangement of the perturbation theory is performed such that the purely disconnected diagrams are factored out. The remaining effect of the disconnected diagrams results in a simple modification of the usual Feynman rules for the S-matrix elements. As an application, we show that when combined with the Low theorem, this leads to a proof of the absense of the 1/Q1/Q corrections to inclusive processes (like the Drell-Yan process). In this paper the abelian case is discussed to all orders in the coupling.Comment: 27 pages, LaTeX, 14 figure

    The analysis of facial beauty: an emerging area of research in pattern analysis

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    Much research presented recently supports the idea that the human perception of attractiveness is data-driven and largely irrespective of the perceiver. This suggests using pattern analysis techniques for beauty analysis. Several scientific papers on this subject are appearing in image processing, computer vision and pattern analysis contexts, or use techniques of these areas. In this paper, we will survey the recent studies on automatic analysis of facial beauty, and discuss research lines and practical application
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