463 research outputs found

    The Role of Eukaryotic ABC-Transporters in Eliciting Neutrophil infiltration during Streptococcus pneumoniae infection

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    Streptococcus pneumoniae (S. pneumoniae) is a Gram-positive, encapsulated bacterium capable of causing significant morbidity and mortality throughout the world. A hallmark of S. pneumoniae infection is infiltration of neutrophils (PMNs) that assist in controlling the spread infection but may also contribute to pathology. Paradoxically, studies have shown that limiting PMN infiltration into the lumen of the lung during infection actually betters clinical outcome in experimental S. pneumoniae infection. The final step in PMN luminal trafficking is a Hepoxilin A3 (HXA3)-dependent migration across the pulmonary epithelium. HXA3 is a PMN chemoattractant that forms gradients along the polarized epithelial face, drawing PMNs from the basolateral to the apical surface during proinflammatory responses. HXA3 requires assistance of an integral- membrane protein transporter to escape the cell and form the gradient. The pulmonary HXA3 transporter is currently unidentified. In this work, we identify the pulmonary HXA3 transporter as the ATP-Binding Cassette Transporter (ABC transporter) Multi-drug Resistance Associated Protein 2 (ABCC2, MRP2). We demonstrate that MRP1 and MRP2 are divergent ABC- transporters that control transepithelial PMN migration through efflux of a distinct anti-inflammatory substance and the pro-inflammatory HXA3 in the context of Streptococcus pneumoniae infection. Enrichment of MRP2 on the plasma membrane requires detection of the bacterial virulence factors pneumolysin (PLY) and hydrogen peroxide. PLY and hydrogen peroxide not only coordinate MRP2 apical membrane enrichment but also influence HXA3-dependent PMN transepithelial migration. They influence migration through stimulation of epithelial intracellular calcium increases that are crucial for HXA3 production as well as MRP2 translocation to the plasma membrane. PLY and hydrogen peroxide are not sufficient in their signaling alone, however, and require at least one additional bacterial signal to induce HXA3/MRP2 proinflammatory activities

    Evaluation of Statistical and Machine Learning Approaches to Evaluating Creativity in the Alternatives Uses Task

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    For the last 70 years, divergent thinking tasks have been important for measuring the creative process. Raters typically show high levels of interrater reliability; however, the task can be onerous. We compare alternative methods from human rating. Specifically, we recruited human raters from Amazon’s Mechanical Turk and the Loyola Psychology Subject Pool with two different sampling methods (i.e., Top 2 and Snap Shot) In addition, we will use SemDist, a computer algorithm that operationalizes creativity based on semantic distance. Measures from these three methods will be compared for data from approximately four hundred study participants

    Love and intersubjectivity : an inquiry into the personalism of Max Scheler

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    The purpose of this study is to investigate intersubjectivity in the work of Scheler, focusing primarily on writings of his middle or "Catholic" period. To do so, I consider the nature of the person as both the autonomous center of spiritual acts and as a vital ego immersed in a universal life stream with others. I then address the issue of intersubjectivity as it has been commonly formulated in phenomenology and demonstrate that for Scheler, true intersubjectivity is situated in love between persons and that it demands both a proximity and a distance that are positioned outside the bounds of theoretical formulations and cognitive knowledge. Following an exhibition of the role and forms of love in Scheler's philosophy, I address issues related to love and the order of material values as they pertain to the autonomy and uniqueness of the person, with reference to themes of "the same" and "the other" found in the work of Levinas. Ultimately we see that Scheler posits the person in such a way that it is the seat of absolute value, that the person cannot be limited by theoretical structures or language, and that for Scheler, the person as person is a phenomenon that lies outside the scope of philosophy

    Surface behaviour of nco species on Rh(111) and polycrystalline Rh surfaces

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    Quasi-phase-matching (QPM) is a method to get tailored efficient second order nonlinear interactions [1]. Several techniques exist for fabrication of periodic domain structures in ferroelectric crystals for QPM frequency conversion. By far, electric field poling using lithographically patterned electrodes on the z-face of the crystal is the most common one [2]. High-quality periodically inverted ferroelectric domain structures in flux grown KTiOP 4 (KTP) crystals were fabricated already in the late 90's using this technique [3], and recently periodic domain sizes of few hundred nanometers were fabricated in 1 mm thick samples thanks to the quasi-one dimensional structure of KTP. It has recently also been shown that a slight Rb doping of the KTP crystal (RKTP) facilitates the periodic poling [4]. However, fabrication of two-dimensional (2D) domain structures in RKTP has not yet been investigated. A disadvantage with the lithographic patterning is that each sample needs to be patterned individually, which is tedious and time consuming. Moreover, when it comes to the small domain features, which are required by the next generation of nonlinear optical devices, a more versatile poling technique has to be developed due to the limitations of conventional photolithography. Structured silicon has been investigated as an alternative electrode for formation of 1D domains by contact poling in LiNb3 [5]. However, these electrodes were fabricated by wet etching and the sample thickness was limited to ∌200 ÎŒm.QC 20140619</p

    The profile of Lithuanian manager

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    Microscopic modeling of photoluminescence of strongly disordered semiconductors

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    A microscopic theory for the luminescence of ordered semiconductors is modified to describe photoluminescence of strongly disordered semiconductors. The approach includes both diagonal disorder and the many-body Coulomb interaction. As a case study, the light emission of a correlated plasma is investigated numerically for a one-dimensional two-band tight-binding model. The band structure of the underlying ordered system is assumed to correspond to either a direct or an indirect semiconductor. In particular, luminescence and absorption spectra are computed for various levels of disorder and sample temperature to determine thermodynamic relations, the Stokes shift, and the radiative lifetime distribution.Comment: 35 pages, 14 figure

    An all-solid-state laser source at 671 nm for cold atom experiments with lithium

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    We present an all solid-state narrow line-width laser source emitting 670 mW670\,\mathrm{mW} output power at 671 nm671\,\mathrm{nm} delivered in a diffraction-limited beam. The \linebreak source is based on a fre-quency-doubled diode-end-linebreak pumped ring laser operating on the 4F3/2→4I13/2{^4F}_{3/2} \rightarrow {^4I}_{13/2} transition in Nd:YVO4_4. By using periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up cavity, doubling efficiencies of up to 86% are obtained. Tunability of the source over 100 GHz100\,\rm GHz is accomplished. We demonstrate the suitability of this robust frequency-stabilized light source for laser cooling of lithium atoms. Finally a simplified design based on intra-cavity doubling is described and first results are presented
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