513 research outputs found

    Diablo Canyon power plant site ecological study annual report; July 1, 1973 - June 30, 1974

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    We completed surveys of 11 permanent subtidal stations, 17 random subtidal stations, 4 permanent intertidal stations, and 29 random intertidal stations during the period. In addition, we conducted studies on the sea otter, Enhydra lutris, herd located between Diablo Cove and Point Buchon, continued the annual count of the mature bed of the bull kelp, Nereocystis luetkeana, within Diablo Cove, and interviewed commercial abalone and sea urchin divers for catch-per-unit-of-effort data. During the year, sea otters moved south into the cove east of Lion Rock and then into Diablo Cove. (107pp.) The commercial abalone fishery showed signs of decline, while the commercial sea urchin fishery continued to expand. Several diving surveys were conducted inside Intake Cove to check on dredging progress; the cove appears to have become a haven for juvenile rockfish (Sebastes). The red abalone temperature tolerance studies were completed at the Department's marine culture laboratory at Granite Canyon

    Baseline Needs Assessment for a Hospital-Based Violence Intervention Program 1-Year Pilot

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    The objectives of the present study were to measure and describe the baseline participant needs of a hospital-based violence intervention 1-year pilot program, assess differences in expected hospital revenue based on changes in health insurance coverage resulting from program implementation and discuss the program’s limitations. Methods: Between September 2020 and September 2021 Encompass Omaha enrolled 36 participants. A content analysis of 1199 progress notes detailing points of contact with participants was performed to determine goal status. Goals were categorized and goal status was defined as met, in process, dropped, or participant refusal. Results: The most frequently identified needs were help obtaining short-term disability assistance or completing FMLA paperwork (86.11%), immediate financial aid (86.11%), legal aid (83.33%), access to food (83.3%), and navigating medical issues other than the primary reason for hospitalization (83.33%). Conclusions: Meeting the participants’ short-term needs is critical for maintaining their engagement in the long-term. Further, differences in expected hospital revenue for pilot participants compared with a control group were examined, and this analysis found a reduction in medical and facility costs for program participants. The pilot stage highlighted how complex the needs and treatment of victims of violence are. As the program grows and its staff become more knowledgeable about social work, treatment, and resource access processes, the program will continue to improve

    Defense, Disrespect, and #Deadly: A Qualitative Exploration of Precursors to Youth Violence Informed Through Hospital-Based Violence Prevention Program Follow Up

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    Success of youth violence intervention and prevention effects, particularly for gun violence, will be enhanced when efforts are appropriately informed by the antecedents and context of violence. Youth violence is guided by social and cultural norms that are shifting with the rise of technology. Bullying, gang violence, and self-directed violence is increasingly found to occur in the online space influencing peer groups across contexts. Through focus groups with youth at risk for violence and victimization, this study finds three themes emerge as common precursors to violence: defense of self or others, disrespect of self or family occurring in traditional community-based interactions, and threats or disrespect occurring through social media platforms. Youth violence prevention programs should consider how using social cognitive intervention framework could build knowledge, attitudes, and skills needed for violence intervention and prevention informed by precursors to violence found in this analysis

    Infrared spectroscopy of phytochrome and model pigments

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    Fourier-transform infrared difference spectra between the red-absorbing and far-red-absorbing forms of oat phytochrome have been measured in H2O and 2H2O. The difference spectra are compared with infrared spectra of model compounds, i.e. the (5Z,10Z,15Z)- and (5Z,10Z,15E)-isomers of 2,3,7,8,12,13,17,18-octaethyl-bilindion (Et8-bilindion), 2,3-dihydro-2,3,7,8,12,13,17,18-octaethyl-bilindion (H2Et8-bilindion), and protonated H2Et8-bilindion in various solvents. The spectra of the model compounds show that only for the protonated forms can clear differences between the two isomers be detected. Since considerable differences are present between the spectra of Et8-bilindion and H2Et8-bilindion, it is concluded that only the latter compound can serve as a model system of phytochrome. The 2H2O effect on the difference spectrum of phytochrome supports the view that the chromophore in red-absorbing phytochrome is protonated and suggests, in addition, that it is also protonated in far-red-absorbing phytochrome. The spectra show that protonated carboxyl groups are influenced. The small amplitudes in the difference spectra exclude major changes of protein secondary structure

    Entropic Tension in Crowded Membranes

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    Unlike their model membrane counterparts, biological membranes are richly decorated with a heterogeneous assembly of membrane proteins. These proteins are so tightly packed that their excluded area interactions can alter the free energy landscape controlling the conformational transitions suffered by such proteins. For membrane channels, this effect can alter the critical membrane tension at which they undergo a transition from a closed to an open state, and therefore influence protein function \emph{in vivo}. Despite their obvious importance, crowding phenomena in membranes are much less well studied than in the cytoplasm. Using statistical mechanics results for hard disk liquids, we show that crowding induces an entropic tension in the membrane, which influences transitions that alter the projected area and circumference of a membrane protein. As a specific case study in this effect, we consider the impact of crowding on the gating properties of bacterial mechanosensitive membrane channels, which are thought to confer osmoprotection when these cells are subjected to osmotic shock. We find that crowding can alter the gating energies by more than 2  kBT2\;k_BT in physiological conditions, a substantial fraction of the total gating energies in some cases. Given the ubiquity of membrane crowding, the nonspecific nature of excluded volume interactions, and the fact that the function of many membrane proteins involve significant conformational changes, this specific case study highlights a general aspect in the function of membrane proteins.Comment: 20 pages (inclduing supporting information), 4 figures, to appear in PLoS Comp. Bio

    Euclid: Fast two-point correlation function covariance through linear construction

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    We present a method for fast evaluation of the covariance matrix for a two-point galaxy correlation function (2PCF) measured with the Landy- Szalay estimator. The standard way of evaluating the covariance matrix consists in running the estimator on a large number of mock catalogs, and evaluating their sample covariance. With large random catalog sizes (random-to-data objects'ratio M≫ 1) the computational cost of the standard method is dominated by that of counting the data-random and random-random pairs, while the uncertainty of the estimate is dominated by that of data-data pairs. We present a method called Linear Construction (LC), where the covariance is estimated for small random catalogs with a size of M = 1 and M = 2, and the covariance for arbitrary M is constructed as a linear combination of the two. We show that the LC covariance estimate is unbiased. We validated the method with PINOCCHIO simulations in the range r = 20-200 h-1 Mpc. With M = 50 and with 2 h-1 Mpc bins, the theoretical speedup of the method is a factor of 14. We discuss the impact on the precision matrix and parameter estimation, and present a formula for the covariance of covariance.</p

    Helix movement is coupled to displacement of the second extracellular loop in rhodopsin activation

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    The second extracellular loop (EL2) of rhodopsin forms a cap over the binding site of its photoreactive 11-cis retinylidene chromophore. A crucial question has been whether EL2 forms a reversible gate that opens upon activation or acts as a rigid barrier. Distance measurements using solid-state 13C NMR spectroscopy between the retinal chromophore and the β4 strand of EL2 show that the loop is displaced from the retinal binding site upon activation, and there is a rearrangement in the hydrogen-bonding networks connecting EL2 with the extracellular ends of transmembrane helices H4, H5 and H6. NMR measurements further reveal that structural changes in EL2 are coupled to the motion of helix H5 and breaking of the ionic lock that regulates activation. These results provide a comprehensive view of how retinal isomerization triggers helix motion and activation in this prototypical G protein-coupled receptor. © 2009 Nature America, Inc. All rights reserved

    Site-Directed Mutations and the Polymorphic Variant Ala160Thr in the Human Thromboxane Receptor Uncover a Structural Role for Transmembrane Helix 4

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    The human thromboxane A2 receptor (TP), belongs to the prostanoid subfamily of Class A GPCRs and mediates vasoconstriction and promotes thrombosis on binding to thromboxane (TXA2). In Class A GPCRs, transmembrane (TM) helix 4 appears to be a hot spot for non-synonymous single nucleotide polymorphic (nsSNP) variants. Interestingly, A160T is a novel nsSNP variant with unknown structure and function. Additionally, within this helix in TP, Ala1604.53 is highly conserved as is Gly1644.57. Here we target Ala1604.53 and Gly1644.57 in the TP for detailed structure-function analysis. Amino acid replacements with smaller residues, A160S and G164A mutants, were tolerated, while bulkier beta-branched replacements, A160T and A160V showed a significant decrease in receptor expression (Bmax). The nsSNP variant A160T displayed significant agonist-independent activity (constitutive activity). Guided by molecular modeling, a series of compensatory mutations were made on TM3, in order to accommodate the bulkier replacements on TM4. The A160V/F115A double mutant showed a moderate increase in expression level compared to either A160V or F115A single mutants. Thermal activity assays showed decrease in receptor stability in the order, wild type>A160S>A160V>A160T>G164A, with G164A being the least stable. Our study reveals that Ala1604.53 and Gly1644.57 in the TP play critical structural roles in packing of TM3 and TM4 helices. Naturally occurring mutations in conjunction with site-directed replacements can serve as powerful tools in assessing the importance of regional helix-helix interactions
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