235 research outputs found

    Studies of angle-resolved photoelectron spectra from oriented NiCO: A model for adsorbed CO

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    We present a study of angle-resolved photoelectron spectra from oriented, linear NiCO. We address the question: How well do simple cluster models such as oriented NiCO simulate adsorbate molecules with respect to photoemission? The photoemission cross sections are obtained using Hartree-Fock electronic continuum orbitals. For the bonding 5σ̃ orbital, we find oriented NiCO to be a better model than oriented CO. The large magnitude of the 5σ̃ photoionization cross sections relative to the 4σ̃ cross section cannot, however, be explained by our calculations without consideration of backscattering of the photoelectrons ejected "downward" into the detector

    Resonance effects in the 5σ photoionization of CO

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    We report vibrational branching ratios and vibrationally resolved photoelectron angular distributions for resonant photoionization of the 5sigma level of CO leading to X^2Σ+CO+. These results were obtained using frozen-core Hartree–Fock photoelectron continuum orbitals. These studies provide a clear quantitative picture of the role of the kσ shape resonance in the observed non-Franck–Condon behavior and useful insight into the interplay between this shape resonance and a valence-like autoionizing resonance around 23 eV

    Integrating Viral Hepatitis Screening and Prevention Services into an Urban Chemical Dependency Treatment Facility for American Indians and Alaska Natives

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    American Indian/Alaska Natives (AI/AN) patients at an urban residential chemical dependency treatment center participated in a viral hepatitis prevention project. Project activities integrated into patients’ treatment programs included viral hepatitis and human immunodeficiency virus (HIV) risk factor screening, education and counseling, laboratory testing, and hepatitis A and B vaccination. Of 928 AI/AN admissions, 585 (63%) completed risk factor screening assessment. Of these, 436 (75%) received at least one vaccination, viral hepatitis testing, or both. Of 322 patients tested, 91 (28%) were hepatitis C virus (HCV) antibody positive. Lack of pre-existing immunity to vaccine-preventable viral hepatitis infection was common: 132 (45%) were susceptible to hepatitis A and 224 (70%) were susceptible to hepatitis B infection. Chemical dependency treatment centers serving urban AI/AN provide important opportunities for implementing viral hepatitis prevention programs for high-risk populations and for improving ongoing efforts to reduce the disparate impact of chronic liver disease in AI/ AN people

    Understanding disparities in clinical trials for Native Hawaiian men

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    Understanding low rates of participation by minority populations in clinical trials is critical for reducing and eliminating disparities. We examined beliefs and attitudes of Native Hawaiian men related to illness and cancer to better understand their rates of participation in clinical trials. We conducted face-to-face interviews with Native Hawaiian key informants throughout the State of Hawai‘i using quota sampling methods to obtain a range of perspectives about attitudes towards health care seeking to provide insight into low clinical trials participation. Interviews were audio-taped, transcribed, and independently coded by researchers. Thematic analysis guided the extraction of relevant data from the discussions. Key informants (N=16) suggested the following beliefs and attitudes regarding clinical trials participation: 1) mistrust in the healthcare system, 2) external locus of control, 3) gender norms, and 4) the customary pono (righteousness, to make right) practice towards family/community to model and maintain good health, including participation in cancer clinical trials. Native Hawaiian men in this study expressed hesitation in the benefits of formalized health care. Many men described experiences of racism, inequity, and injustice associated their interactions with health care providers. These encounters were factors that influenced their healthcare practices and beliefs towards maintaining health and longevity

    CoastalImageLib: An open- source Python package for creating common coastal image products

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    CoastalImageLib is a Python library that produces common coastal image products intended for quantitative analysis of coastal environments. This library contains functions to georectify and merge multiple oblique camera views, produce statistical image products for a given set of images, and create subsampled pixel instruments for use in bathymetric inversion, surface current estimation, run-up calculations, and other quantitative analyses. This package intends to be an open-source broadly generalizable front end to future coastal imaging applications, ultimately expanding user accessibility to optical remote sensing of coastal environments. This package was developed and tested on data collected from the Argus Tower, a 43 m tall observation structure in Duck, North Carolina at the US Army Engineer Research and Development Center’s Field Research Facility that holds six stationary cameras which collect twice-hourly coastal image products. Thus, CoastalImageLib also contains functions designed to interface with the file storage and collection system implemented at the Argus Tower

    Structural analysis of the role of the (β)3 subunit of the (α)V(β)3 integrin in IGF-I signaling

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    The disintegrin echistatin inhibits ligand occupancy of the (α)V(β)3 integrin and reduces Insulin-like growth factor I (IGF-I) stimulated migration, DNA synthesis, and receptor autophosphorylation in smooth muscle cells. This suggests that ligand occupancy of the (α)V(β)3 receptor is required for full activation of the IGF-I receptor. Transfection of the full-length (β)3 subunit into CHO cells that have no endogenous (β)3 and do not migrate in response to IGF-I was sufficient for IGF-I to stimulate migration of these anchorage dependent cells. In contrast, transfection of either of two truncated mutant forms of (β)3 (terminating at W(715) or E(731)) or a mutant with substitutions for Tyr(747) Tyr(759) (YY) into either CHO or into porcine smooth muscle cells did not restore the capacity of these cells to migrate across a surface in response to IGF-I. This effect was not due to loss of IGF-I receptor autophosphorylation since the response of the receptor to IGF-I was similar in cells expressing either the full-length or any of the mutant forms of the (β)3 subunit. Echistatin reduced IGF-I receptor phosphorylation in cells expressing the full-length or the YY mutant forms of (β)3 subunit, but it had no effect in cells expressing either of two truncated forms of (β)3. A cell-permeable peptide homologous to the C-terminal region of the (β)3 subunit (amino acids 747–762) reduced IGF-I stimulated migration and receptor autophosphorylation of non-transfected porcine smooth muscle cells. These results demonstrate that the full-length (β)3 with intact tyrosines at positions 747 and 759 is required for CHO cells to migrate in response to IGF-I. Furthermore, a region of critical amino acids between residues 742–762 is required for echistatin to induce its regulatory effect on receptor phosphorylation. Since the IGF-I receptor does not bind to (α)V(β)3 the results suggest that specific but distinct regions of the (β)3 subunit interact with intermediary proteins to facilitate IGF-I stimulated cell migration and echistatin induced inhibition of IGF-I signal transduction

    Innate Immune Cell Recovery Is Positively Regulated by NLRP12 during Emergency Hematopoiesis

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    With enhanced concerns of terrorist attacks, dual exposure to radiation and thermal combined injury (RCI) has become a real threat with devastating immunosuppression. NLRP12, a member of the NOD-like receptor family, is expressed in myeloid and bone marrow cells and has been implicated as a checkpoint regulator of inflammatory cytokines as well as an inflammasome activator. We show that NLRP12 has a profound impact on hematopoietic recovery during RCI by serving as a checkpoint of TNF signaling and preventing hematopoietic apoptosis. Using a mouse model of RCI, increased NLRP12 expression was detected in target tissues. Nlrp12−/− mice exhibited significantly greater mortality, inability to fight bacterial infection, heightened levels of pro-inflammatory cytokines, overt granulocyte/monocyte progenitor cell apoptosis and failure to reconstitute peripheral myeloid populations. Anti-TNF antibody administration improved peripheral immune recovery. These data suggest that NLRP12 is essential for survival after RCI by regulating myelopoiesis and immune reconstitution

    Disruption of the association of integrin-associated protein (IAP) with tyrosine phosphatase non-receptor type substrate-1 (SHPS)-1 inhibits pathophysiological changes in retinal endothelial function in a rat model of diabetes

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    Our studies have shown that the association between integrin-associated protein (IAP) and SHPS-1 regulates the response of cells including osteoclasts, osteoblasts, smooth muscle and retinal endothelial cells to Insulin-like growth factor-I (IGF-I). The aims of this study were to determine whether the regulation of IGF-I responsiveness by IAP/SHPS-1 association is a generalized response of endothelial cells, to identify the mechanism by which IAP/SHPS-1 association contributes to changes in endothelial cell responses to IGF-I and to determine whether inhibiting their association alters pathophysiologic changes that occur in vivo
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