2,750 research outputs found

    Gastrointestinal symptom severity in irritable bowel syndrome, inflammatory bowel disease and the general population

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    BackgroundIrritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) patients report similar gastrointestinal (GI) symptoms, yet comparisons of symptom severity between groups and with the general population (GP) are lacking.MethodsWe compared Patient‐Reported Outcomes Measurement Information System (PROMISÂź) GI symptom scales measuring gastro‐esophageal reflux (GER), disrupted swallowing, diarrhea, bowel incontinence, nausea/vomiting, constipation, belly pain, and gas/bloating in: (i) USA GP sample, (ii) IBS patients, and (iii) IBD patients from tertiary care and community populations. Symptom severity scores were based on T‐score metric with mean 50±10 (standard deviation) relative to the GP.Key ResultsOf 1643 patients enrolled, there were 253 IBS patients (68% F, mean age 45±15 years), 213 IBD patients (46% F, mean age 41±14 years), and 1177 GP subjects (57% F, mean age 46±16 years). IBS patients reported greater severity of GER, disrupted swallowing, nausea/vomiting, belly pain, gas/bloating, and constipation symptoms than their IBD counterparts (all P<.05). Compared to the GP, IBD patients had worse belly pain, gas/bloating, diarrhea, and bowel incontinence, but less severe GER and disrupted swallowing (all P<.05), and IBS patients had more severe nausea/vomiting, belly pain, gas/bloating, and constipation (all P<.05). Women had more severe belly pain and gas/bloating than men, whereas men had more severe bowel incontinence (all P<.05).Conclusion & InferencesIBS and IBD are associated with more severe GI symptoms compared to the GP excluding esophageal symptoms. Unlike IBD, IBS is not characterized by observable GI inflammation but patients report more severe upper and lower GI symptoms.The PROMIS GI scales were used to determine gastrointestinal symptoms severity in patients. Unlike IBD, IBS is not characterized by observable gastrointestinal inflammation, but patients report more severe upper and lower gastrointestinal symptoms.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/1/nmo13003.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/2/nmo13003_am.pd

    Vacuum polarization for compactified QED4+1QED_{4+1} in a magnetic flux background

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    We evaluate one-loop effects for QED4+1QED_{4+1} compactified to R4×S1{\bf R}^4 \times S^1, in a non-trivial vacuum for the gauge field, such that a non-vanishing magnetic flux is encircled along the extra dimension. We obtain the vacuum polarization tensor and evaluate the exact parity breaking term, presenting the results from the point of view of the effective 3+1 dimensional theory.Comment: 8 pages no figures Revte

    A note on anti-coordination and social interactions

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    This note confirms a conjecture of [Bramoull\'{e}, Anti-coordination and social interactions, Games and Economic Behavior, 58, 2007: 30-49]. The problem, which we name the maximum independent cut problem, is a restricted version of the MAX-CUT problem, requiring one side of the cut to be an independent set. We show that the maximum independent cut problem does not admit any polynomial time algorithm with approximation ratio better than n1−ϔn^{1-\epsilon}, where nn is the number of nodes, and Ï”\epsilon arbitrarily small, unless P=NP. For the rather special case where each node has a degree of at most four, the problem is still MAXSNP-hard.Comment: 7 page

    Archiving scientific data

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    We present an archiving technique for hierarchical data with key structure. Our approach is based on the notion of timestamps whereby an element appearing in multiple versions of the database is stored only once along with a compact description of versions in which it appears. The basic idea of timestamping was discovered by Driscoll et. al. in the context of persistent data structures where one wishes to track the sequences of changes made to a data structure. We extend this idea to develop an archiving tool for XML data that is capable of providing meaningful change descriptions and can also efficiently support a variety of basic functions concerning the evolution of data such as retrieval of any specific version from the archive and querying the temporal history of any element. This is in contrast to diff-based approaches where such operations may require undoing a large number of changes or significant reasoning with the deltas. Surprisingly, our archiving technique does not incur any significant space overhead when contrasted with other approaches. Our experimental results support this and also show that the compacted archive file interacts well with other compression techniques. Finally, another useful property of our approach is that the resulting archive is also in XML and hence can directly leverage existing XML tools

    Positive Magneto-Resistance in Quasi-1D Conductors

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    We present here a simple qualitative model that interpolates between the high and low temperature properties of quasi-1D conductors. At high temperatures we argue that transport is governed by inelastic scattering whereas at low temperatures the conductance decays exponentially with the electron dephasing length. The crossover between these regimes occurs at the temperature at which the elastic and inelastic scattering times become equal. This model is shown to be in quantitative agreement with the organic conductor TTT2I3−ήTTT_2I_{3-\delta}. Within this model, we also show that on the insulating side, the positive magnetoresistance of the form (H/T)2(H/T)^2 observed in TTT2I3−ήTTT_2I_{3-\delta} and other quasi-1D conductors can be explained by the role spin-flip scattering plays in the electron dephasing rate.Comment: 4 pages, Latex, no figure

    Meson - nucleon vertex form factors at finite temperature

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    In this paper the dependence of meson-nucleon-nucleon vertex form factors is studied as a function of termperature. The results are obtained starting from a zero temperature Bonn potential. The temperature dependence of the vertex form factors and radii is studied in the thermofield dynamics, a real-time operator formalism of finite temperature field theory. It is anticipated that these results will have an impact on the study of relativistic heavy-ion collisions as the critical temperature for the phase transition from hadronic to quark-gluon system is approached.Comment: 19 pages, Revtex, 11 figures (Ps), 171k

    SU(3)_flavor analysis of two-body weak decays of charmed baryons

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    We study two-body weak decays of charmed baryons \Lambda_c and \Xi_c into an octet or decuplet baryon and a pseudoscalar meson employing the SU(3) flavor symmetry. Using certain measured Cabibbo-favored modes, we fix the reduced amplitudes and predict the branching ratios of various decays of charmed baryons in the Cabibbo-enhanced, -suppressed and -doubly suppressed modes.Comment: 25 pages, No figure, Phys. Rev. D (to appear

    Finite temperature amplitudes and reaction rates in Thermofield dynamics

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    We propose a method for calculating the reaction rates and transition amplitudes of generic process taking place in a many body system in equilibrium. The relationship of the scattering and decay amplitudes as calculated in Thermo Field Dynamics the conventional techniques is established. It is shown that in many cases the calculations are relatively easy in TFD.Comment: 32 pages, RevTex, 2 PS figures, to appear in Phys. Rev.

    On Coloring Resilient Graphs

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    We introduce a new notion of resilience for constraint satisfaction problems, with the goal of more precisely determining the boundary between NP-hardness and the existence of efficient algorithms for resilient instances. In particular, we study rr-resiliently kk-colorable graphs, which are those kk-colorable graphs that remain kk-colorable even after the addition of any rr new edges. We prove lower bounds on the NP-hardness of coloring resiliently colorable graphs, and provide an algorithm that colors sufficiently resilient graphs. We also analyze the corresponding notion of resilience for kk-SAT. This notion of resilience suggests an array of open questions for graph coloring and other combinatorial problems.Comment: Appearing in MFCS 201
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