4,356 research outputs found

    Room temperature plasmon laser by total internal reflection

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    Plasmon lasers create and sustain intense and coherent optical fields below light's diffraction limit with the unique ability to drastically enhance light-matter interactions bringing fundamentally new capabilities to bio-sensing, data storage, photolithography and optical communications. However, these important applications require room temperature operation, which remains a major hurdle. Here, we report a room temperature semiconductor plasmon laser with both strong cavity feedback and optical confinement to 1/20th of the wavelength. The strong feedback arises from total internal reflection of surface plasmons, while the confinement enhances the spontaneous emission rate by up to 20 times.Comment: 8 Page, 2 Figure

    Top and Bottom Seesaw from Supersymmetric Strong Dynamics

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    We propose a top and bottom seesaw model with partial composite top and bottom quarks. Such composite quarks and topcolor gauge bosons are bound states from supersymmetric strong dynamics by Seiberg duality. Supersymmetry breaking also induces the breaking of topcolor into the QCD gauge coupling. The low energy description of our model reduces to a complete non-minimal extension of the top seesaw model with bottom seesaw. The non-minimal nature is crucial for Higgs mixings and the appearance of light Higgs fields. The Higgs fields are bound states of partial composite particles with the lightest one compatible with a 125 GeV Higgs field which was discovered at the LHC.Comment: Minor changes, Published Versio

    PGB pair production at LHC and ILC as a probe of the topcolor-assisted technicolor models

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    The topcolor-assisted technicolor (TC2) model predicts some light pseudo goldstone bosons (PGBs), which may be accessible at the LHC or ILC. In this work we study the pair productions of the charged or neutral PGBs at the LHC and ILC. For the productions at the LHC we consider the processes proceeding through gluon-gluon fusion and quark-antiquark annihilation, while for the productions at the ILC we consider both the electron-positron collision and the photon-photon collision. We find that in a large part of parameter space the production cross sections at both colliders can be quite large compared with the low standard model backgrounds. Therefore, in future experiments these productions may be detectable and allow for probing TC2 model.Comment: 26 pages, 16 figures. slight changes in the text; notations for curves changed; references adde

    Measuring indirect transmission-reducing effects in tuberculosis vaccine efficacy trials: why and how?

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    Tuberculosis is the leading bacterial cause of death globally. In 2021, 10·6 million people developed symptomatic tuberculosis and 1·6 million died. Seven promising vaccine candidates that aim to prevent tuberculosis disease in adolescents and adults are currently in late-stage clinical trials. Conventional phase 3 trials provide information on the direct protection conferred against infection or disease in vaccinated individuals, but they tell us little about possible indirect (ie, transmission-reducing) effects that afford protection to unvaccinated individuals. As a result, proposed phase 3 trial designs will not provide key information about the overall effect of introducing a vaccine programme. Information on the potential for indirect effects can be crucial for policy makers deciding whether and how to introduce tuberculosis vaccines into immunisation programmes. We describe the rationale for measuring indirect effects, in addition to direct effects, of tuberculosis vaccine candidates in pivotal trials and lay out several options for incorporating their measurement into phase 3 trial designs

    A Novel Stable Isotope Approach for Determining the Impact of Thickening Agents on Water Absorption

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    Research on the bioavailability of water from thickened fluids has recently been published and it concluded that the addition of certain thickening agents (namely, modified maize starch, guar gum, and xanthan gum) does not significantly alter the absorption of water from the healthy, mature human gut. Using xanthan gum as an example, our “proof of concept” study describes a simple, accurate, and noninvasive alternative to the methodology used in that first study, and involves the measurement and comparison of the dilution space ratios of the isotopes 2H and 18O and subsequent calculation of total body water. Our method involves the ingestion of a thickening agent labeled with 2H 1 day after ingestion of 18O. Analyses are based on the isotopic enrichment of urine samples collected prior to the administration of each isotope, and daily urine samples collected for 15 days postdosing. We urge that further research is needed to evaluate the impact of various thickening agents on the bioavailability of water from the developing gut and in cases of gut pathology and recommend our methodology

    Holographic Anomalous Conductivities and the Chiral Magnetic Effect

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    We calculate anomaly induced conductivities from a holographic gauge theory model using Kubo formulas, making a clear conceptual distinction between thermodynamic state variables such as chemical potentials and external background fields. This allows us to pinpoint ambiguities in previous holographic calculations of the chiral magnetic conductivity. We also calculate the corresponding anomalous current three-point functions in special kinematic regimes. We compare the holographic results to weak coupling calculations using both dimensional regularization and cutoff regularization. In order to reproduce the weak coupling results it is necessary to allow for singular holographic gauge field configurations when a chiral chemical potential is introduced for a chiral charge defined through a gauge invariant but non-conserved chiral density. We argue that this is appropriate for actually addressing charge separation due to the chiral magnetic effect.Comment: 17 pages, 1 figure. v2: 18 pages, 1 figure, discussion clarified throughout the text, references added, version accepted for publication in JHE

    Quark masses and mixings in the RS1 model with a condensing 4th generation

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    We study the hierarchy of quark masses and mixings in a model based on a 5-dimensional spacetime with constant curvature of Randall-Sundrum type with two branes, where the Electroweak Symmetry Breaking is caused dynamically by the condensation of a 4th generation of quarks, due to underlying physics from the 5D bulk and the first KK gluons. We first study the hierarchy of quark masses and mixings that can be obtained from purely adjusting the profile localizations, finding that realistic masses are not reproduced unless non trivial hierarchies of underlying 4-fermion interactions from the bulk are included. Then we study global U(1) symmetries that can be imposed in order to obtain non-symmetric modified Fritzsch-like textures in the mass matrices that reproduce reasonably well quark masses and CKM mixings.Comment: Minor changes. Version accepted for publication in JHE

    Aid conditionalities, international Good Manufacturing Practice standards and local production rights: a case study of local production in Nepal

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    © 2015 Brhlikova et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This work was supported by the Economic and Social Research Council and the Department for International Development [RES-167-25-0110] through the collaborative research project Tracing Pharmaceuticals in South Asia (2006 – 2009). In addition to the authors of this paper, the project team included: Soumita Basu, Gitanjali Priti Bhatia, Erin Court, Abhijit Das, Stefan Ecks, Patricia Jeffery, Roger Jeffery, Rachel Manners, and Liz Richardson. Martin Chautari (Kathmandu) and the Centre for Health and Social Justice (New Delhi) provided resources drawn upon in writing this paper but are not responsible for the views expressed, nor are ESRC or DFID. Ethical review was provided by the School of Social and Political Science at the University of Edinburgh, and ethical approval in Nepal for the study granted by the Nepal Health Research Council (NHRC)

    Increasing condom use in heterosexual men: development of a theory-based interactive digital intervention

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    Increasing condom use to prevent sexually transmitted infections is a key public health goal. Interventions are more likely to be effective if they are theory- and evidence-based. The Behaviour Change Wheel (BCW) provides a framework for intervention development. To provide an example of how the BCW was used to develop an intervention to increase condom use in heterosexual men (the MenSS website), the steps of the BCW intervention development process were followed, incorporating evidence from the research literature and views of experts and the target population. Capability (e.g. knowledge) and motivation (e.g. beliefs about pleasure) were identified as important targets of the intervention. We devised ways to address each intervention target, including selecting interactive features and behaviour change techniques. The BCW provides a useful framework for integrating sources of evidence to inform intervention content and deciding which influences on behaviour to target
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