1,376 research outputs found

    The Technicolor Higgs in the Light of LHC Data

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    We consider scenarios in which the 125 GeV resonance observed at the Large Hadron Collider is a Technicolor (TC) isosinglet scalar, the TC Higgs. By comparison with quantum chromodynamics, we argue that the couplings of the TC Higgs to the massive weak bosons are very close to the Standard Model (SM) values. The couplings to photons and gluons are model-dependent, but close to the SM values in several TC theories. The couplings of the TC Higgs to SM fermions are due to interactions beyond TC, such as Extended Technicolor: if such interactions successfully generate mass for the SM fermions, we argue that the couplings of the latter to the TC Higgs are also SM-like. We suggest a generic parameterization of the TC Higgs interactions with SM particles that accommodates a large class of TC models, and we perform a fit of these parameters to the Higgs LHC data. The fit reveals regions of parameter space where the form factors are of order unity and consistent with data at the 95% CL, in agreement with expectations in TC theories. This indicates that the discovered Higgs boson is consistent with the TC Higgs hypothesis for several TC theories.Comment: 26 pages, 8 figure

    Parametrized post-Newtonian virial theorem

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    Using the parametrized post-Newtonian equations of hydrodynamics, we derive the tensor form of the parametrized post-Newtonian virial theorem.Comment: 10 pages, submitted to CQ

    Integrability of Two Coupled Oscillators using Complex Coordinates

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    Numerical Studies on Laser Welded Top-Hat Column under Axial Collision Based on the Concept of Super-Folding Element

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    Extruded longitudinal double-skinned aluminium body plates with integrated stiffeners are recently used for manufacturing in automobile industry like front rails and railway carriages. These extrusions provide light and heavy rigid structures. However, since it is not feasible to produce large parts by extrusion, these plates need to be connected, mostly by welding techniques. The crashworthiness performance of laser welded columns is evaluated using finite element (FE) analysis. This is very important in automobiles, since more attention is being paid to crashworthiness of the structures in recent years. The analysis method is based on the Superfolding Element (SE) concept, which originates from experimentally observed folding patterns of crushed shell elements. The FE model is used to predict accurately the progressive axial collapse of the lased welded columns and impact strength is greatly improved by laser welding technique

    Localized modes in defective multilayer structures

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    In this paper, the localized surface modes in a defective multilayer structure has been investigated. It is shown that the defective multilayer structures can support two different kind of localized modes depending on the position and the thickness of the defect layer. One of these modes is localized at the interface between the multilayer structure and a homogeneous medium (the so-called surface mode) and the other one is localized at the defect layer (defect localized mode). We reveal that the presence of defect layer pushes the dispersion curve of surface modes to the lower or the upper edge of the photonic bandgap depending on the homogeneous medium is a left-handed or right-handed medium (e.g. vacuum), respectively. So, the existence region of the surface modes restricted. Moreover, the effect of defect on the energy flow velocity of the surface modes is discussed.Comment: 5 pages, 7 figure

    Renal Hyperfiltration and the Development of Microalbuminuria in Type 1 Diabetes

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    OBJECTIVE: The purpose of this study was to examine prospectively whether renal hyperfiltration is associated with the development of microalbuminuria in patients with type 1 diabetes, after taking into account known risk factors. RESEARCH DESIGN AND METHODS: The study group comprised 426 participants with normoalbuminuria from the First Joslin Kidney Study, followed for 15 years. Glomerular filtration rate was estimated by serum cystatin C, and hyperfiltration was defined as exceeding the 97.5th percentile of the sex-specific distribution of a similarly aged, nondiabetic population (134 and 149 ml/min per 1.73 m2 for men and women, respectively). The outcome was time to microalbuminuria development (multiple albumin excretion rate >30 μg/min). Hazard ratios (HRs) for microalbuminuria were calculated at 5, 10, and 15 years. RESULTS: Renal hyperfiltration was present in 24% of the study group and did not increase the risk of developing microalbuminuria. The unadjusted HR for microalbuminuria comparing those with and without hyperfiltration at baseline was 0.8 (95% CI 0.4–1.7) during the first 5 years, 1.0 (0.6–1.7) during the first 10 years, and 0.8 (0.5–1.4) during 15 years of follow-up. The model adjusted for baseline known risk factors including A1C, age at diagnosis of diabetes, diabetes duration, and cigarette smoking resulted in similar HRs. In addition, incorporating changes in hyperfiltration status during follow-up had minimal impact on the HRs for microalbuminuria. CONCLUSION;S Renal hyperfiltration does not have an impact on the development of microalbuminuria in type 1 diabetes during 5, 10, or 15 years of follow-up.National Institutes of Health Grant (DK 041526

    The use of complementary and alternative medicine among california adults with and without cancer.

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    This article examines the extent and correlates of complementary and alternative medicine (CAM) use among a population-based sample of California adults that is highly diverse in terms of sociodemographic characteristics and health status. As a follow-up to a state-wide health survey of 55,428 people, 9187 respondents were interviewed by phone regarding their use of 11 different types of CAM providers, special diets, dietary supplements, mind-body interventions, self-prayer and support groups. The sample included all participants in the initial survey who reported a diagnosis of cancer, all the non-white respondents, as well as a random sample of all the white respondents. The relation of CAM use to the respondents' demographic characteristics and health status is assessed. CAM use among Californians is generally high, and the demographic factors associated with high rates of CAM use are the same in California as have been found in other studies. Those reporting a diagnosis of cancer and those who report other chronic health problems indicate a similar level of visits to CAM providers. However, those with cancer are less likely to report using special diets, and more likely to report using support groups and prayer. Health status, gender, ethnicity and education have an independent impact upon CAM use among those who are healthy as well as those who report suffering from chronic health problems, although the precise relation varies by the type of CAM used

    PLAST-ncRNA: Partition function Local Alignment Search Tool for non-coding RNA sequences

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    Alignment-based programs are valuable tools for finding potential homologs in genome sequences. Previously, it has been shown that partition function posterior probabilities attuned to local alignment achieve a high accuracy in identifying distantly similar non-coding RNA sequences that are hidden in a large genome. Here, we present an online implementation of that alignment algorithm based on such probabilities. Our server takes as input a query RNA sequence and a large genome sequence, and outputs a list of hits that are above a mean posterior probability threshold. The output is presented in a format suited to local alignment. It can also be viewed within the PLAST alignment viewer applet that provides a list of all hits found and highlights regions of high posterior probability within each local alignment. The server is freely available at http://plastrna.njit.edu

    Effect of Hydrostatic Pressure on Lone Pair Activity and Phonon Transport in Bi2_2O2_2S

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    Dibismuth dioxychalcogenides, Bi2_2O2_2Ch (Ch = S, Se, Te) are emerging class of materials for next generation electronics and thermoelectrics with an ultrahigh carrier mobility and excellent air stability. Among these, Bi2_2O2_2S is fascinating because of stereochemically active 6s2s^2 lone pair of Bi3+^{3+} cation, heterogeneous bonding and high mass contrast of constituent elements. In this work, we systematically investigate the effect of hydrostatic pressure and its implications on lattice dynamics and phonon transport properties of Bi2_2O2_2S by employing first principles calculations along with the Boltzmann transport theory. The ambient PnmnPnmn phase exhibits a low average lattice thermal conductivity (κl\kappa_l) of 1.71 W-m/K at 300 K. We also find that Bi2_2O2_2S undergoes a structural phase transition from low symmetry (PnmnPnmn) to a high symmetry (I4/mmmI4/mmm) structure around 4 GPa due to the Bi3+^{3+} cation centering. Upon compression the lone pair activity of Bi3+^{3+} cation is suppressed, which increases κl\kappa_l by nearly 3 times to 4.92 W-m/K at 5 GPa for I4/mmmI4/mmm phase. The calculated phonon lifetimes and Gr\"uneisen parameters show that anharmonicity reduces with increasing pressure due to further suppression of lone pair, strengthening of intra and inter molecular interactions, which raises the average room temperature κl\kappa_l to 12.82 W-m/K at 20 GPa. Overall, the present study provides a comprehensive understanding of hydrostatic pressure effects on stereochemical activity of the Bi3+^{3+} cation lone pair and its consequences on phonon transport properties of Bi2_2O2_2S.Comment: 19 pages, 7 figures and supporting informatio
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