468 research outputs found
Coping with loss: cell adaptation to cytoskeleton disruption
Unravelling the role of cytoskeleton regulators may be complicated by adaptations to experimental manipulations. In this issue of Developmental Cell, Cerikan et al. (2016) reveal how acute effects of DOCK6 RhoGEF depletion on RAC1 and CDC42 activation are reversed over time by compensatory mechanisms that re-establish cellular homeostasis
A practical experience with independent verification and validation
One approach to reducing software cost and increasing reliability is the use of an independent verification and validation (IV & V) methodology. The Software Engineering Laboratory (SEL) applied the IV & V methodology to two medium-size flight dynamics software development projects. Then, to measure the effectiveness of the IV & V approach, the SEL compared these two projects with two similar past projects, using measures like productivity, reliability, and maintain ablilty. Results indicated that the use of the IV & V methodology did not help the overall process nor improve the product in these cases
Criteria for software modularization
A central issue in programming practice involves determining the appropriate size and information content of a software module. This study attempted to determine the effectiveness of two widely used criteria for software modularization, strength and size, in reducing fault rate and development cost. Data from 453 FORTRAN modules developed by professional programmers were analyzed. The results indicated that module strength is a good criterion with respect to fault rate, whereas arbitrary module size limitations inhibit programmer productivity. This analysis is a first step toward defining empirically based standards for software modularization
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Preference Heterogeneity and Insurance Markets: Explaining a Puzzle of Insurance
Standard theories of insurance, dating from Rothschild and Stiglitz (1976), stress the role of adverse selection in explaining the decision to purchase insurance. In these models, higher risk people buy full or near-full insurance, while lower risk people buy less complete coverage, if they buy at all. While this prediction appears to hold in some real world insurance markets, in many others, it is the lower risk individuals who have more insurance coverage. If the standard model is extended to allow individuals to vary in their risk tolerance as well as their risk type, this could explain why the relationship between insurance coverage and risk occurrence can be of any sign, even if the standard asymmetric information effects also exist. We present empirical evidence in five difference insurance markets in the United States that is consistent with this potential role for risk tolerance. Specifically, we show that individuals who engage in risky behavior or who do not engage in risk reducing behavior are systematically less likely to hold life insurance, acute private health insurance, annuities, long-term care insurance, and Medigap. Moreover, we show that the sign of this preference effect differs across markets, tending to induce lower risk individuals to purchase insurance in some of these markets, but higher risk individuals to purchase insurance in others. These findings suggest that preference heterogeneity may be important in explaining the differential patterns of insurance coverage in various insurance markets.Economic
A cell-permeable biscyclooctyne as a novel probe for the identification of protein sulfenic acids
Reactive oxygen species act as important second messengers in cell signaling and homeostasis through the oxidation of protein thiols. However, the dynamic nature of protein oxidation and the lack of sensitivity of existing molecular probes have hindered our understanding of such reactions; therefore, new tools are required to address these challenges. We designed a bifunctional variant of the strained bicyclo[6.1.0]nonyne (BCN-E-BCN) that enables the tagging of intracellular protein sulfenic acids for biorthogonal copper-free click chemistry. In validation studies, BCN-E-BCN binds the sulfenylated form of the actin-severing protein cofilin, while mutation of the cognate cysteine residues abrogates its binding. BCN-E-BCN is cell permeable and reacts rapidly with cysteine sulfenic acids in cultured cells. Using different azide-tagged conjugates, we demonstrate that BCN-E-BCN can be used in various applications for the detection of sulfenylated proteins. Remarkably, cycloaddition of an azide-tagged fluorophore to BCN-E-BCN labelled proteins produced in vivo can be visualized by fluorescence microscopy to reveal their subcellular localization. These findings demonstrate a novel and multifaceted approach to the detection and trapping of sulfenic acids
Catalytic and non-catalytic mechanisms involved in Glutathione S-transferase Pi mediated cytoprotection
Outcomes of thromboprophylaxis with enoxaparin vs. unfractionated heparin in medical inpatients
BACKGROUND: Clinical trials have shown low-molecular weight heparin (LMWH) to be at least as safe and efficacious as unfractionated heparin (UFH) for preventing venous thromboembolism (VTE) in acutely-ill medical inpatients. OBJECTIVE: To compare clinical and economic outcomes among acutely-ill medical inpatients receiving the LMWH enoxaparin versus UFH prophylaxis in clinical practice. METHODS: Using a large, multi-hospital, US database, we identified persons aged ≥40 years hospitalized for ≥6 days for an acute medical condition (including circulatory disorders, respiratory disorders, infectious diseases, or neoplasms) from Q4 1999 to Q1 2002. From these patients, those who received thromboprophylaxis with either enoxaparin or UFH were identified. Surgical patients and those requiring or ineligible for anticoagulation were excluded. We compared the incidence of deep-vein thrombosis (DVT), pulmonary embolism (PE), and all VTE (i.e., DVT and/or PE). Secondary outcomes were occurrence of side-effects, length of hospital stay and total costs. RESULTS: 479 patients received enoxaparin prophylaxis and 2,837 received UFH. The incidence of VTE was 1.7% with enoxaparin prophylaxis versus 6.3% with UFH (RR = 0.26; p < 0.001). Occurrence of side effects, length of stay (10.00 days with enoxaparin vs. 10.26 days with UFH; p = 0.348) and total costs (17,602; p = 0.463) were similar in the 2 groups. CONCLUSION: We observed a 74% lower risk of VTE among patients receiving enoxaparin prophylaxis versus UFH prophylaxis. There was no significant difference in side effects or economic outcomes. These results provide evidence that the LMWH enoxaparin is more effective than UFH in reducing the risk of VTE in current clinical practice
The NYU Survey Service: Promoting Value in Undergraduate Education
New York University\u27s Data Service Studio has recently launched the NYU Survey Service, whose ultimate aim is to support the development and administration of surveys of all types. For the web-based component, we utilize a product called Qualtrics, which allows university affiliates to develop and administer web-based surveys. This article describes the process by which we at NYU came to offer the service during a time when concerns abound about the ability of libraries to support and expand services while still meeting service imperatives such as robust data services. While many considerations went into this evaluation and the ultimate conclusion to pilot the service, we emphasize those most related to data and information literacy, undergraduate instruction, learning and research, library collaborations and application administration and support
Preference Heterogeneity and Insurance Markets: Explaining a Puzzle of Insurance
Standard theories of insurance, dating from Rothschild and Stiglitz (1976), stress the role of adverse selection in explaining the decision to purchase insurance. In these models, higher risk people buy full or near-full insurance, while lower risk people buy less complete coverage, if they buy at all. While this prediction appears to hold in some real world insurance markets, in many others, it is the lower risk individuals who have more insurance coverage. If the standard model is extended to allow individuals to vary in their risk tolerance as well as their risk type, this could explain why the relationship between insurance coverage and risk occurrence can be of any sign, even if the standard asymmetric information effects also exist. We present empirical evidence in five difference insurance markets in the United States that is consistent with this potential role for risk tolerance. Specifically, we show that individuals who engage in risky behavior or who do not engage in risk reducing behavior are systematically less likely to hold life insurance, acute private health insurance, annuities, long-term care insurance, and Medigap. Moreover, we show that the sign of this preference effect differs across markets, tending to induce lower risk individuals to purchase insurance in some of these markets, but higher risk individuals to purchase insurance in others. These findings suggest that preference heterogeneity may be important in explaining the differential patterns of insurance coverage in various insurance markets.
Microbiology of a multi-layer biosolid/desulfurized tailings cover on a mill tailings impoundment
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