176 research outputs found

    Parametric frequency conversion of coherent light by the electro-optic effect in KDP

    Get PDF
    We report an experiment in which interaction between an optical wave at frequency f0 and a microwave signal at fm was used to generate a coherent optical beam at f0 + fm. The interaction was provided by lossless electro-optic modulation of the dielectric constant within a laser resonator and can thus be viewed as a demonstration of parametric(3-5) interaction at optical frequencies

    Interferometry and Laser Control with Solid Fabry-Perot Etalons

    Get PDF
    The use and analysis of solid Fabry-Perot etalons for interferometry and laser control are discussed and supported with experimental data. Low angle scattering is found to be an important factor influencing finesse and peak transmission. Thermal tuning sensitivity and wedge-angle control with thermal gradients are analyzed and illustrated. Control of laser oscillations using a solid-state etalon as a laser cavity end mirror is discussed. The use of the solid etalon as an optical cavity coupler is applied to the problem. of sideband energy removal from an internally modulated laser

    Influence of Mindfulness Practice on Counseling Skills Development

    Get PDF
    This study assessed the impact of mindfulness practice, incorporated alongside a five-week counselor skills training model, on the counseling skills development of master’s-level trainees (N = 59). Three groups of counseling students were studied: those who engaged in no mindfulness practice; those who engaged in a brief amount of mindfulness practice (five mindfulness practice sessions); and those who engaged in an extended amount of mindfulness practice (11 mindfulness practice sessions). The results showed improvements in counseling skills associated with mindfulness practice, although the brief and extended intervention groups did not significantly differ from one another

    Pennsylvania Folklife Vol. 16, No. 1

    Get PDF
    • Indian Readers and Healers by Prayer • Bayard Taylor\u27s Portrait of Pennsylvania Quakerism • Gypsy Stories from the Swatara Valley • Stump-Pulling • Occult Tales from Union County • Beekeeping and Bee Lore in Pennsylvania • New Materials on the 18th Century Emigration from the Speyer State Archives • The Snake-Bitten Dutchman • Notes and Documents: A Letter to Germany (1806) ; Midwestern Diary of Joel Vale Garretson (1863-1864) • Questionnaire on Hominyhttps://digitalcommons.ursinus.edu/pafolklifemag/1025/thumbnail.jp

    Implicating Calpain in Tau-Mediated Toxicity In Vivo

    Get PDF
    Alzheimer's disease and other related neurodegenerative disorders known as tauopathies are characterized by the accumulation of abnormally phosphorylated and aggregated forms of the microtubule-associated protein tau. Several laboratories have identified a 17 kD proteolytic fragment of tau in degenerating neurons and in numerous cell culture models that is generated by calpain cleavage and speculated to contribute to tau toxicity. In the current study, we employed a Drosophila tauopathy model to investigate the importance of calpain-mediated tau proteolysis in contributing to tau neurotoxicity in an animal model of human neurodegenerative disease. We found that mutations that disrupted endogenous calpainA or calpainB activity in transgenic flies suppressed tau toxicity. Expression of a calpain-resistant form of tau in Drosophila revealed that mutating the putative calpain cleavage sites that produce the 17 kD fragment was sufficient to abrogate tau toxicity in vivo. Furthermore, we found significant toxicity in the fly retina associated with expression of only the 17 kD tau fragment. Collectively, our data implicate calpain-mediated proteolysis of tau as an important pathway mediating tau neurotoxicity in vivo

    Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at √s = 200 GeV

    Get PDF
    The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8 < η < 2.0 in polarized proton-proton collisions at √s = 200  GeV are presented. Neutral pions were detected using the end cap electromagnetic calorimeter in the STAR detector at RHIC. The cross section was measured over a transverse momentum range of 5 < p[subscript T] < 16  GeV/c and is found to agree with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry A[subscript LL] is measured in the same pseudorapidity range and spans a range of Bjorken-x down to x ≈ 0.01. The measured A[subscript LL] is consistent with model predictions for varying degrees of gluon polarization. The parity-violating asymmetry A[subscript L] is also measured and found to be consistent with zero. The transverse single-spin asymmetry A[subscript N] is measured over a previously unexplored kinematic range in Feynman-x and p[subscript T]. Such measurements may aid our understanding of the onset and kinematic dependence of the large asymmetries observed at more forward pseudorapidity (η ≈ 3) and their underlying mechanisms. The A[subscript N] results presented are consistent with a twist-3 model prediction of a small asymmetry over the present kinematic range.United States. Dept. of Energy. Office of Nuclear PhysicsUnited States. Dept. of Energy. Office of High Energy PhysicsNational Science Foundation (U.S.

    The Amsterdam Declaration on Fungal Nomenclature

    Get PDF
    The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19–20 April 2011 under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). The purpose of the symposium was to address the issue of whether or how the current system of naming pleomorphic fungi should be maintained or changed now that molecular data are routinely available. The issue is urgent as mycologists currently follow different practices, and no consensus was achieved by a Special Committee appointed in 2005 by the International Botanical Congress to advise on the problem. The Declaration recognizes the need for an orderly transitition to a single-name nomenclatural system for all fungi, and to provide mechanisms to protect names that otherwise then become endangered. That is, meaning that priority should be given to the first described name, except where that is a younger name in general use when the first author to select a name of a pleomorphic monophyletic genus is to be followed, and suggests controversial cases are referred to a body, such as the ICTF, which will report to the Committee for Fungi. If appropriate, the ICTF could be mandated to promote the implementation of the Declaration. In addition, but not forming part of the Declaration, are reports of discussions held during the symposium on the governance of the nomenclature of fungi, and the naming of fungi known only from an environmental nucleic acid sequence in particular. Possible amendments to the Draft BioCode (2011) to allow for the needs of mycologists are suggested for further consideration, and a possible example of how a fungus only known from the environment might be described is presented
    corecore