803 research outputs found

    Function of Serum Complement in Drinking Water Arsenic Toxicity

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    Serum complement function was evaluated in 125 affected subjects suffering from drinking water arsenic toxicity. Their mean duration of exposure was 7.4 ± 5.3 yrs, and the levels of arsenic in drinking water and urine samples were 216 ± 211 and 223 ± 302 μg/L, respectively. The mean bactericidal activity of complement from the arsenic patients was 92% and that in the unexposed controls was 99% (P < 0.01), but heat-inactivated serum showed slightly elevated activity than in controls. In patients, the mean complement C3 was 1.56 g/L, and C4 was 0.29 g/L compared to 1.68 g/L and 0.25 g/L, respectively, in the controls. The mean IgG in the arsenic patients was 24.3 g/L that was highly significantly elevated (P < 0.001). Arsenic patients showed a significant direct correlation between C3 and bactericidal activity (P = 0.014). Elevated levels of C4 indicated underutilization and possibly impaired activity of the classical complement pathway. We conclude reduced function of serum complement in drinking water arsenic toxicity

    Fine-Grid Calculations for Stellar Electron and Positron Capture Rates on Fe-Isotopes

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    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (YeY_{e}) of the core material. It is suggested that the temporal variation of YeY_{e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly 54,55,56^{54,55,56}Fe, are considered to be key players in controlling YeY_{e} ratio via electron capture on these nuclide. Recently an improved microscopic calculation of weak interaction mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic \textit{state-by-state} calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the YeY_{e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on 54,55,56^{54,55,56}Fe. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.Comment: 21 pages, 6 ps figures and 2 table

    Fairness in Algorithmic Decision Making: An Excursion Through the Lens of Causality

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    As virtually all aspects of our lives are increasingly impacted by algorithmic decision making systems, it is incumbent upon us as a society to ensure such systems do not become instruments of unfair discrimination on the basis of gender, race, ethnicity, religion, etc. We consider the problem of determining whether the decisions made by such systems are discriminatory, through the lens of causal models. We introduce two definitions of group fairness grounded in causality: fair on average causal effect (FACE), and fair on average causal effect on the treated (FACT). We use the Rubin-Neyman potential outcomes framework for the analysis of cause-effect relationships to robustly estimate FACE and FACT. We demonstrate the effectiveness of our proposed approach on synthetic data. Our analyses of two real-world data sets, the Adult income data set from the UCI repository (with gender as the protected attribute), and the NYC Stop and Frisk data set (with race as the protected attribute), show that the evidence of discrimination obtained by FACE and FACT, or lack thereof, is often in agreement with the findings from other studies. We further show that FACT, being somewhat more nuanced compared to FACE, can yield findings of discrimination that differ from those obtained using FACE.Comment: 7 pages, 2 figures, 2 tables.To appear in Proceedings of the International Conference on World Wide Web (WWW), 201

    Study on the Structure vs Activity of Designed Non-Precious Metal electrocatalysts for CO2 Conversion

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    This work investigates Cu and Cu-Sn nanocatalysts with controlled composition and morphology for the electrochemical CO2 reduction reaction to value-added chemicals, showing that bimetallic materials possess active sites with increased specific activity toward activation and reduction of CO2 compared to monometallic ones. While Cu showed high selectivity for the competitive hydrogen evolution reaction, bimetallic Cu-Sn electrocatalysts were selective towards CO and formates. Nanoparticles were prepared via a straightforward chemical process, leading to small, well-define and crystalline nanoparticles, either mono or bimetallic, where Cu and Sn precursors are blended in one step to achieve alloyed or core–shell structures

    A survey of adherence to guidelines to prevent healthcare-associated infections in Iranian intensive care units

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    Background: Healthcare-associated infections (HAIs) are acquired by patients while receiving care. The highest incidence of HAIs has been documented in admissions to intensive care units. Adherence to evidence-based practices is the most important step for preventing HAIs. Objectives: To determine the rate of adherence to evidence-based post-insertion recommended care practices after admission into the intensive care unit for the following devices: central line catheter, indwelling urinary catheter, and mechanical ventilator. Patients and Methods: A structured observational cross-sectional research design was used. Data were collected using a checklist and a self-report questionnaire. The minimum sample size required for this study was 276 post-insertion care episodes, and 332 episodes were observed. TheANOVA test was used to identify any significant differences among themean scores of the three devices. Results: Overall observed adherence rates were 18.3, 59.1, and 43.1 for central line catheters, indwelling urinary catheter, and mechanical ventilator, respectively. Of the observed episodes of device care, only in 9.4 of the episodes was regular oral care performed for patients on mechanical ventilators and only in 19.3 of the episodes were indwelling urinary catheters properly secure after insertion. More so, in none (0.0) of the episodes was the central line catheter hub disinfected before being accessed. Conclusions: Evidence-based post-insertion recommended care practices were not consistently and uniformly implemented in the intensive care units. Establishment of a program for the surveillance of adherence to recommended guidelines is required for improving compliance by health professionals and the quality of preventive care. © 2016, Iranian Red Crescent Medical Journal

    Multimodality Characterization of Cancer-Associated Fibroblasts in Tumor Microenvironment and Its Correlation With Ultrasound Shear Wave-Measured Tissue Stiffness in Localized Prostate Cancer

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    INTRODUCTION: Growing evidence suggests that the tumor microenvironment (TME) represented by cellular and acellular components plays a key role in the multistep process of metastases and response to therapies. However, imaging and molecular characterization of the TME in prostate cancer (PCa) and its role in predicting aggressive tumor behavior and disease progression is largely unexplored. The study explores the PCa TME through the characterization of cancer-associated fibroblasts (CAFs) using both immunohistochemistry (IHC) and genomics approaches. This is then correlated with transrectal ultrasound shear wave elastography (USWE)-measured tissue stiffness. PATIENTS AND METHODS: Thirty patients with clinically localized PCa undergoing radical prostatectomy for different risk categories of tumor (low, intermediate, and high) defined by Gleason score (GS) were prospectively recruited into this study. Prostatic tissue stiffness was measured using USWE prior to surgery. The CAFs within the TME were identified by IHC using a panel of six antibodies (FAP, SMAα, FSP1, CD36, PDGFRα, and PDGFRβ) as well as gene expression profiling using TempO-sequence analysis. Whether the pattern and degree of immunohistochemical positivity (measured by Quick score method) and expression of genes characterizing CAFs were correlated with USWE- and GS-measured tissue stiffnesses were tested using Spearman’s rank correlation and Pearson correlation. RESULTS: There was a statistically significant correlation between GS of cancers, the pattern of staining for CAFs by immunohistochemical staining, and tissue stiffness measured in kPa using USWE (p < 0.001). Significant differences were also observed in immunohistochemical staining patterns between normal prostate and prostatic cancerous tissue. PDGFRβ and SMAα immunostaining scores increased linearly with increasing the USWE stiffness and the GS of PCa. There was a significant positive correlation between increasing tissue stiffness in tumor stroma and SMAα and PDGFRβ gene expression in the fibromuscular stroma (p < 0.001). CONCLUSION: USWE-measured tissue stiffness correlates with increased SMAα and PDGFRβ expressing CAFs and PCa GSs. This mechanistic correlation could be used for predicting the upgrading of GS from biopsies to radical surgery and response to novel treatments

    Tests of the random phase approximation for transition strengths

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    We investigate the reliability of transition strengths computed in the random-phase approximation (RPA), comparing with exact results from diagonalization in full 0ω0\hbar\omega shell-model spaces. The RPA and shell-model results are in reasonable agreement for most transitions; however some very low-lying collective transitions, such as isoscalar quadrupole, are in serious disagreement. We suggest the failure lies with incomplete restoration of broken symmetries in the RPA. Furthermore we prove, analytically and numerically, that standard statements regarding the energy-weighted sum rule in the RPA do not hold if an exact symmetry is broken.Comment: 11 pages, 7 figures; Appendix added with new proof regarding violation of energy-weighted sum rul

    Biosynthesis of Mitochondrial Porin and Insertion into the Outer Mitochondrial Membrane of Neuruspora crassa

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    Mitochondrial porin, the major protein of the outer mitochondrial membrane is synthesized by free cytoplasmic polysomes. The apparent molecular weight of the porin synthesized in homologous or heterologous cell-free systems is the same as that of the mature porin. Transfer in vitro of mitochondrial porin from the cytosolic fraction into the outer membrane of mitochondria could be demonstrated. Before membrane insertion, mitochondrial porin is highly sensitive to added proteinase; afterwards it is strongly protected. Binding of the precursor form to mitochondria occurs at 4°C and appears to precede insertion into the membrane. Unlike transfer of many precursor proteins into or across the inner mitochondrial membrane, assembly of the porin is not dependent on an electrical potential across the inner membrane
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