22,776 research outputs found
Note on restoring manifest rotational symmetry in hyperfine and fine structure in light-front QED
We study the part of the renormalized, cutoff QED light-front Hamiltonian
that does not change particle number. The Hamiltonian contains interactions
that must be treated in second-order bound state perturbation theory to obtain
hyperfine structure. We show that a simple unitary transformation leads
directly to the familiar Breit-Fermi spin-spin and tensor interactions, which
can be treated in degenerate first-order bound-state perturbation theory, thus
simplifying analytic light-front QED calculations. To the order in momenta we
need to consider, this transformation is equivalent to a Melosh rotation. We
also study how the similarity transformation affects spin-orbit interactions.Comment: 17 pages, latex fil
Optical and Infrared Spectroscopy
Contains report on one research project.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)U. S. Air Force (ESD Contract AF 19(628)-6066)M. I. T. Sloan Fund for Basic Researc
Echinocandin inhibition of 1,3-β-D-glucan synthase from Candida albicans
AbstractThe cyclic peptide antibiotic echinocandin was found to inhibit 1,3-β-D-glucan synthase activity present in a mixed membrane fraction from Candida albicans. Addition of antibiotic reduced the Vmax of the enzyme, but the Km was unaffected. GTP stimulated enzyme activity ~ 4-fold, but did not affect the percentage inhibition of the enzyme by echinocandin. Treatment of the reaction products with α-amylase and β-glucanase confirmed that the polymer synthesised was 1,3-β-D-glucan, not glycogen
Photoluminescence Detected Doublet Structure in the Integer and Fractional Quantum Hall Regime
We present here the results of polarized magneto-photoluminescence
measurements on a high mobility single-heterojunction. The presence of a
doublet structure over a large magnetic field range (2>nu>1/6) is interpreted
as possible evidence for the existence of a magneto-roton minima of the charged
density waves. This is understood as an indication of strong electronic
correlation even in the case of the IQHE limit.Comment: submitted to Solid State Communication
Indicators for comparing performance of irrigated agricultural systems
Irrigated farming / Irrigation systems / Indicators / Performance indexes / Financing / Crop production / Water demand / Water requirements / Prices
Immunohistochemical localization of a macrophage-specific antigen in developing mouse retina:phagocytosis of dying neurons and differentiation of microglial cells to form a regular array in the plexiform layers
In the developing mouse retina degenerating neurons can be observed initially in the ganglion cell layer followed by a phase of cell death in the inner nuclear layer. Using an immunohistochemical method to localize the mouse macrophage specific antigen F4/80, we show that macrophages migrate from the vascular supply overlying the developing retina and phagocytose the degenerating neurons. The macrophages subsequently differentiate to become the microglia of the retina and form a regularly spaced distribution across the retina in the inner and outer plexiform layers. These experiments provide strong evidence for the mesodermal origin of central nervous system microglia.</p
Initial bound state studies in light-front QCD
We present the first numerical QCD bound state calculation based on a
renormalization group-improved light-front Hamiltonian formalism. The QCD
Hamiltonian is determined to second order in the coupling, and it includes
two-body confining interactions. We make a momentum expansion, obtaining an
equal-time-like Schrodinger equation. This is solved for quark-antiquark
constituent states, and we obtain a set of self-consistent parameters by
fitting B meson spectra.Comment: 38 pages, latex, 5 latex figures include
Effectiveness, Acceptability, and Feasibility of Digital Health Interventions for LGBTIQ+ Young People: Systematic Review
Background: Young people (aged 12-25 years) with diverse sexuality, gender, or bodily characteristics, such as those who identify as lesbian, gay, bisexual, transgender, intersex, or queer (LGBTIQ+), are at substantially greater risk of a range of mental, physical, and sexual health difficulties compared with their peers. Digital health interventions have been identified as a potential way to reduce these health disparities.
Objective: This review aims to summarize the characteristics of existing evidence-based digital health interventions for LGBTIQ+ young people and to describe the evidence for their effectiveness, acceptability, and feasibility.
Methods: A systematic literature search was conducted using internet databases and gray literature sources, and the results were screened for inclusion. The included studies were synthesized qualitatively.
Results: The search identified 38 studies of 24 unique interventions seeking to address mental, physical, or sexual health–related concerns in LGBTIQ+ young people. Substantially more evidence-based interventions existed for gay and bisexual men than for any other population group, and there were more interventions related to risk reduction of sexually transmitted infections than to any other health concern. There was some evidence for the effectiveness, feasibility, and acceptability of these interventions overall; however, the quality of evidence is often lacking.
Conclusions: There is sufficient evidence to suggest that targeted digital health interventions are an important focus for future research aimed at addressing health difficulties in LGBTIQ+ young people. Additional digital health interventions are needed for a wider range of health difficulties, particularly in terms of mental and physical health concerns, as well as more targeted interventions for same gender–attracted women, trans and gender-diverse people, and people with intersex variations
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