315 research outputs found
Twisted topological structures related to M-branes II: Twisted Wu and Wu^c structures
Studying the topological aspects of M-branes in M-theory leads to various
structures related to Wu classes. First we interpret Wu classes themselves as
twisted classes and then define twisted notions of Wu structures. These
generalize many known structures, including Pin^- structures, twisted Spin
structures in the sense of Distler-Freed-Moore, Wu-twisted differential
cocycles appearing in the work of Belov-Moore, as well as ones introduced by
the author, such as twisted Membrane and twisted String^c structures. In
addition, we introduce Wu^c structures, which generalize Pin^c structures, as
well as their twisted versions. We show how these structures generalize and
encode the usual structures defined via Stiefel-Whitney classes.Comment: 20 page
Integral group actions on symmetric spaces and discrete duality symmetries of supergravity theories
For a split, simply connected, semisimple Lie group of rank
and the maximal compact subgroup of , we give a method for computing
Iwasawa coordinates of using the Chevalley generators and the Steinberg
presentation. When is a scalar coset for a supergravity theory in
dimensions , we determine the action of the integral form
on . We give explicit results for the action of the
discrete --duality groups and on the
scalar cosets and
for type IIB supergravity
in ten dimensions and 11--dimensional supergravity in dimensions,
respectively. For the former, we use this to determine the discrete U--duality
transformations on the scalar sector in the Borel gauge and we describe the
discrete symmetries of the dyonic charge lattice. We determine the
spectrum--generating symmetry group for fundamental BPS solitons of type IIB
supergravity in dimensions at the classical level and we propose an
analog of this symmetry at the quantum level. We indicate how our methods can
be used to study the orbits of discrete U--duality groups in general
Correlation of the Indoor Air Quality Santriwati Dormitory with Acute Respiratory Infection at Raudhatul Ulum Islamic Boarding Schools and Al-ittifaqiah Islamic Boarding Schools in Ogan Ilir on 2015
Background: The high number of acute respiratory infection found in two islamic boarding schools specifically at Raudhatul Ulum Islamic Boarding Schools are 178 cases and 231 cases at Al-Ittifaqiah. Method: It was an observational research using cross-sectional design. Research sites at Raudhatul Ulum Islamic Boarding Schools and Al-Ittifaqiah Islamic Boarding Schools in Ogan Ilir. The population research was all santriwati both Islamic boarding schools that total sample 72 santriwati. The dependent variable in this study was santriwati incidence of respiratory infection, the independent variable was the physical quality of the air (temperature, lighting, humidity, rate of ventilation), the quality of biological air (number of bacterial air), residential density, sanitize behavior, and the behavior of openning window.The sample collection technique namely random sampling with the methods of sampling stratified. Data would be analyzed using chi square test. Result: The research result showed that there is significant correlation between temperature p= 0,013, residential density p= 0,003, sanitize behavior p= 0,001, and the behavior of opening a window p= 0,012 on the acute respiratory infection. There is no significant relationship in lighting p= 0,401, humidity p= 0,170, ventilation rate p= 0,489, and the germ air p= 0,170 as the acute respiratory infection. Conclusion: This research concluded that temperatur, residential density, sanitize behavior, and the behavior of opening window have significant correlation
Hypermatrix factors for string and membrane junctions
The adjoint representations of the Lie algebras of the classical groups
SU(n), SO(n), and Sp(n) are, respectively, tensor, antisymmetric, and symmetric
products of two vector spaces, and hence are matrix representations. We
consider the analogous products of three vector spaces and study when they
appear as summands in Lie algebra decompositions. The Z3-grading of the
exceptional Lie algebras provide such summands and provides representations of
classical groups on hypermatrices. The main natural application is a formal
study of three-junctions of strings and membranes. Generalizations are also
considered.Comment: 25 pages, 4 figures, presentation improved, minor correction
Influence of Polymer Additives on Strength of Cement Stone
The article presents the results of strength tests of cement stone with polymer additives. It is established that polymer additives can both increase and decrease the strength and density of cement stone. It is shown that the polymer additive DLP2141 accelerates the set of strength of cement stone at the early stages of hardening
Twisted topological structures related to M-branes
Studying the M-branes leads us naturally to new structures that we call
Membrane-, Membrane^c-, String^K(Z,3)- and Fivebrane^K(Z,4)-structures, which
we show can also have twisted counterparts. We study some of their basic
properties, highlight analogies with structures associated with lower levels of
the Whitehead tower of the orthogonal group, and demonstrate the relations to
M-branes.Comment: 17 pages, title changed on referee's request, minor changes to
improve presentation, typos correcte
Complementarity of the Maldacena and Karch-Randall Pictures
We perform a one-loop test of the holographic interpretation of the
Karch-Randall model, whereby a massive graviton appears on an AdS_4 brane in an
AdS_5 bulk. Within the AdS/CFT framework, we examine the quantum corrections to
the graviton propagator on the brane, and demonstrate that they induce a
graviton mass in exact agreement with the Karch-Randall result. Interestingly
enough, at one loop order, the spin 0, spin 1/2 and spin 1 loops contribute to
the dynamically generated (mass)^2 in the same 1: 3: 12 ratio as enters the
Weyl anomaly and the 1/r^3 corrections to the Newtonian gravitational
potential.Comment: 20 pages, Revtex 3, Discussion on the absence of a scalar ghost
clarified; Additional details on the computation give
Central vein sign differentiates Multiple Sclerosis from central nervous system inflammatory vasculopathies.
In multiple sclerosis (MS), magnetic resonance imaging (MRI) is a sensitive tool for detecting white matter lesions, but its diagnostic specificity is still suboptimal; ambiguous cases are frequent in clinical practice. Detection of perivenular lesions in the brain (the "central vein sign") improves the pathological specificity of MS diagnosis, but comprehensive evaluation of this MRI biomarker in MS-mimicking inflammatory and/or autoimmune diseases, such as central nervous system (CNS) inflammatory vasculopathies, is lacking. In a multicenter study, we assessed the frequency of perivenular lesions in MS versus systemic autoimmune diseases with CNS involvement and primary angiitis of the CNS (PACNS).
In 31 patients with inflammatory CNS vasculopathies and 52 with relapsing-remitting MS, 3-dimensional T2*-weighted and T2-fluid-attenuated inversion recovery images were obtained during a single MRI acquisition after gadolinium injection. For each lesion, the central vein sign was evaluated according to consensus guidelines. For each patient, lesion count, volume, and brain location, as well as fulfillment of dissemination in space MRI criteria, were assessed.
MS showed higher frequency of perivenular lesions (median = 88%) than did inflammatory CNS vasculopathies (14%), without overlap between groups or differences between 3T and 1.5T MRI. Among inflammatory vasculopathies, Behçet disease showed the highest median frequency of perivenular lesions (34%), followed by PACNS (14%), antiphospholipid syndromes (12%), Sjögren syndrome (11%), and systemic lupus erythematosus (0%). When a threshold of 50% perivenular lesions was applied, central vein sign discriminated MS from inflammatory vasculopathies with a diagnostic accuracy of 100%.
The central vein sign differentiates inflammatory CNS vasculopathies from MS at standard clinical magnetic field strengths. Ann Neurol 2018;83:283-294
Differential expression of collectins in human placenta and role in inflammation during spontaneous Labor.
© 2014 Yadav et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Collectins, collagen-containing Ca2+ dependent C-type lectins and a class of secretory proteins including SP-A, SP-D and MBL, are integral to immunomodulation and innate immune defense. In the present study, we aimed to investigate their placental transcript synthesis, labor associated differential expression and localization at feto-maternal interface, and their functional implication in spontaneous labor. The study involved using feto-maternal interface (placental/decidual tissues) from two groups of healthy pregnant women at term (≥37 weeks of gestation), undergoing either elective C-section with no labor ('NLc' group, n = 5), or normal vaginal delivery with spontaneous labor ('SLv' group, n = 5). The immune function of SP-D, on term placental explants, was analyzed for cytokine profile using multiplexed cytokine array. SP-A, SP-D and MBL transcripts were observed in the term placenta. The 'SLv' group showed significant up-regulation of SP-D (p = 0.001), and down-regulation of SP-A (p = 0.005), transcripts and protein compared to the 'NLc' group. Significant increase in 43 kDa and 50 kDa SP-D forms in placental and decidual tissues was associated with the spontaneous labor (p<0.05). In addition, the MMP-9-cleaved form of SP-D (25 kDa) was significantly higher in the placentae of 'SLv' group compared to the 'NLc' group (p = 0.002). Labor associated cytokines IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α and MCP-1 showed significant increase (p<0.05) in a dose dependent manner in the placental explants treated with nSP-D and rhSP-D. In conclusion, the study emphasizes that SP-A and SP-D proteins associate with the spontaneous labor and SP-D plausibly contributes to the pro-inflammatory immune milieu of feto-maternal tissues.Funding provided by BT/PR15227/BRB/10/906/2011) Department of Biotechnology (DBT), Government of India http://dbtindia.nic.in/index.asp (TM) and Indian Council of Medical Research (ICMR) Junior Research Fellowship (JRF)/Senior Research Fellowship (SRF), Government of India, www.icmr.nic.in (AKY)
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