6,356 research outputs found

    Information security compliance in a healthcare setting: A user behavior pilot study

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    Human behavior is known to be one of the weakest links to information security and a likely cause of incidents that may lead or contribute to the loss or compromise of sensitive information (Ahmad, & Ismail, 2010; Akhunzada, Kam, 2015; Aloul, 2012; Cain, Edwards, & Still, 2018; Long, 2013; Narayana, Sookhak, & Anuar, 2015; Pike, 2011; Seidenberger, 2016). The Health Insurance Portability and Accountability Act (1996) requires healthcare organizations to comply with national standards to reduce the likelihood of a privacy breach. Online stolen data markets, where cybercriminals operate in the dark web, advertise, sell, share, and trade sensitive personally identifiable information for nefarious purposes (Chertoff, 2017; Holt et al., 2016). The 29-statement pilot study survey replicates the Safa et al. (2015) survey and was administered to 39 UW Medicine (UWM) employees via the UWM Research Electronic Data Capture online survey application. The survey statements are based on the Theory of Planned Behavior, the Protection Motivation Theory, and the Safa et al. (2015) employee information security conscious care behavior model. The UWM pilot study statements were modified, and results are presented (n = 32). Descriptive statistics are provided, as well as lessons learned, which will be incorporated into a larger-scale survey deployment. This is a timely study to determine how best to reduce the likelihood of a user error or a cyber adversary exploiting a weakness that could lead to or cause a global catastrophic cyber event that could potentially trigger further political, economic, and social volatility

    Convergence of Wnt signalling on the HNF4a-driven transcription in controlling liver zonation

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    BACKGROUND & AIMS: In each hepatocyte, the specific repertoire of gene expression is influenced by its exact location along the portocentrovenular axis of the hepatic lobule and provides a reason for the liver functions compartmentalization defined "metabolic zonation." So far, few molecular players controlling genetic programs of periportal (PP) and perivenular (PV) hepatocytes have been identified; the elucidation of zonation mechanisms remains a challenge for experimental hepatology. Recently, a key role in induction and maintenance of the hepatocyte heterogeneity has been ascribed to Wnt/beta-catenin pathway. We sought to clarify how this wide-ranging stimulus integrates with hepatocyte specificity. METHODS: Reverse transcriptase polymerase chain reaction (RT-PCR) allowed the transcriptional profiling of hepatocytes derived from in vitro differentiation of liver stem cells. The GSK3beta inhibitor 6-bromoindirubin-3'-oxime (BIO) was used for beta-catenin stabilization. Co-immunoprecipitations were used to study biochemical protein interactions while ChIP assays allowed the in vivo inspection of PV and PP genes regulatory regions. RESULTS: We found that spontaneous differentiation of liver stem cells gives rise to PP hepatocytes that, after Wnt pathway activation, switch into PV hepatocytes. Next, we showed that the Wnt downstream player LEF1 interacts with the liver-enriched transcriptional factor HNF4alpha. Finally, we unveiled that the BIO induced activation of PV genes correlates with LEF1 binding to both its own and HNF4alpha consensus, and the repression of PP genes correlates with HNF4alpha displacement from its own consensus. CONCLUSION: Our data show a direct and hitherto unknown convergence of the canonical Wnt signaling on the HNF4alpha-driven transcription providing evidences of a mechanism controlling liver zonated gene expression

    The dynamics of cargo driven by molecular motors in the context of asymmetric simple exclusion processes

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    We consider the dynamics of cargo driven by a collection of interacting molecular motors in the context of an asymmetric simple exclusion processes (ASEP). The model is formulated to account for i) excluded volume interactions, ii) the observed asymmetry of the stochastic movement of individual motors and iii) interactions between motors and cargo. Items (i) and (ii) form the basis of ASEP models and have already been considered in the literature to study the behavior of motor density profile [Parmeggiani 03]. Item (iii) is new. It is introduced here as an attempt to describe explicitly the dependence of cargo movement on the dynamics of motors. The steady-state solutions of the model indicate that the system undergoes a phase transition of condensation type as the motor density varies. We study the consequences of this transition to the properties of cargo velocity.Comment: 20 pages, 2 figure

    Involvement of sperm acetylated histones and the nuclear isoform of Glutathione peroxidase 4 in fertilization

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    We previously demonstrated that the nuclear form of Glutathione peroxidase 4 (nGPx4) has a peculiar distribution in sperm head, being localized to nuclear matrix and acrosome and that sperm lacking nGPx4 are more prone to decondensation in vitro. In this study we have hypothesized that sperm retained acetylated histones and nGPx4 are implicated in paternal chromatin decondensation and male pronucleus formation at fertilization. Indeed, significant higher amounts of acetylated histone H4 and acetylated histone H3 were observed by both immunofluorescence and western blotting in nGPx4-KO sperm vs WT ones. In vitro fertilization of zona pellucida- deprived oocytes by WT sperm in the presence of trichostatin (TSA) also demonstrated that paternal histone acetylation was inversely related to the timing of sperm nucleus decondensation at fertilization. In contrast, TSA had no effect on nGPx4-KO sperm, indicating they had a maximal level of histone acetylation. Moreover the paternally imprinted gene Igf2/H19 was hypomethylated in KO sperm compared to WT ones. The lack of nGPx4 negatively affected male fertility, causing a marked decrease in total pups and pregnancies with delivery, a significant reduction in pronuclei (PN) embryos in in vitro fertilization assays and an approximately 2 h delay in egg fertilization in vivo. Because the zona pellucida binding and fusion to oolemma of nGPx4-KO and WT sperm were similar, the subfertility of nGPx4 sperm reflected a decreased sperm progression through egg cumulus/zona pellucida, pinpointing a defective acrosome in line with acrosomal nGPx4 localization. We conclude that paternal acetylated histones and acrosomal nGPx4 are directly involved in fertilization
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