1,361 research outputs found

    Security in Dynamic Spectrum Access Systems: A Survey

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    Dynamic Spectrum Access (DSA) systems are being developed to improve spectrum utilization. Most of the research on DSA systems assumes that the participants involved are honest, cooperative, and that no malicious adversaries will attack or exploit the network. Some recent research efforts have focused on studying security issues in cognitive radios but there are still significant security challenges in the implementation of DSA systems that have not been addressed. In this paper we focus on security issues in DSA. We identify various attacks (e.g., DoS attacks, system penetration, repudiation, spoofing, authorization violation, malware infection, data modification, etc.) and suggest various approaches to address them. We show that significant security issues exist that should be addressed by the research community if DSA is to find its way into production systems. We also show that, in many cases, existing approaches to securing IT systems can be applied to DSA and identify other DSA specific security challenges where additional research will be required

    A Survey Study Evaluating and Comparing the Health Literacy Knowledge and Communication Skills Used by Nurses and Physicians

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    Health literacy (HL) is considered as an interaction between the demands of health systems and the skills of individuals. The current global approach demands health professionals to be more accountable for universal precautions approach and improve communication skills, and employ strategies to confirm patients' understanding. The aim of this study is to assess the knowledge and attitude of health care professionals (HCPs) about HL and their communication skills, and its effect on their practices, and to compare the findings among subgroups of HCPs. An online cross-sectional survey involving 29 items was developed for sociodemographic and professional characteristics and knowledge, attitude, and practices evaluation. Health care professionals reached by occupational organizations and social media platforms. Among the 277 participants that answered the questions, 184 were physicians and 78 were nurses, and 37.99% of physicians and 18.42% nurses heard about the term "HL" through this survey. Most of the participants stated their willingness to receive information/training on the subject and that knowing HL level would change their approach to and outcomes of the patients. Nurses were using a variety of methods that improve communication with patients and considered HCPs' lack of knowledge of the concept of "HL" and their neglect of HL as obstacles to its evaluation more than physicians. These results emphasize the urgent need of initiatives to be taken to improve the awareness of HCPs of HL and the subsequent incorporation of these initiatives into the daily health care services they provide. Nurses' awareness of HL is higher and they are already better at incorporating HL-sensitive items into their practices. Both graduate and continuing education programs need to be modified to improve HL knowledge of all HCPs and its positive effects on health care. The current structure of the roles and responsibilities of these professions needs to be improved to make it more HL sensitive

    Health literacy, health status, and healthcare utilization of Taiwanese adults: results from a national survey

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    Abstract Background Low health literacy is considered a worldwide health threat. The purpose of this study is to assess the prevalence and socio-demographic covariates of low health literacy in Taiwanese adults and to investigate the relationships between health literacy and health status and health care utilization. Methods A national survey of 1493 adults was conducted in 2008. Health literacy was measured using the Mandarin Health Literacy Scale. Health status was measured based on self-rated physical and mental health. Health care utilization was measured based on self-reported outpatient clinic visits, emergency room visits, and hospitalizations. Results Approximately thirty percent of adults were found to have low (inadequate or marginal) health literacy. They tended to be older, have fewer years of schooling, lower household income, and reside in less populated areas. Inadequate health literacy was associated with poorer mental health (OR, 0.57; 95% CI, 0.35-0.91). No association was found between health literacy and health care utilization even after adjusting for other covariates. Conclusions Low (inadequate and marginal) health literacy is prevalent in Taiwan. High prevalence of low health literacy is not necessarily indicative of the need for interventions. Systematic efforts to evaluate the impact of low health literacy on health outcomes in other countries would help to illuminate features of health care delivery and financing systems that may mitigate the adverse health effects of low health literacy.http://deepblue.lib.umich.edu/bitstream/2027.42/78252/1/1471-2458-10-614.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78252/2/1471-2458-10-614.pdfPeer Reviewe

    Effects of Thyroxine Exposure on Osteogenesis in Mouse Calvarial Pre-Osteoblasts

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    The incidence of craniosynostosis is one in every 1,800-2500 births. The gene-environment model proposes that if a genetic predisposition is coupled with environmental exposures, the effects can be multiplicative resulting in severely abnormal phenotypes. At present, very little is known about the role of gene-environment interactions in modulating craniosynostosis phenotypes, but prior evidence suggests a role for endocrine factors. Here we provide a report of the effects of thyroid hormone exposure on murine calvaria cells. Murine derived calvaria cells were exposed to critical doses of pharmaceutical thyroxine and analyzed after 3 and 7 days of treatment. Endpoint assays were designed to determine the effects of the hormone exposure on markers of osteogenesis and included, proliferation assay, quantitative ALP activity assay, targeted qPCR for mRNA expression of Runx2, Alp, Ocn, and Twist1, genechip array for 28,853 targets, and targeted osteogenic microarray with qPCR confirmations. Exposure to thyroxine stimulated the cells to express ALP in a dose dependent manner. There were no patterns of difference observed for proliferation. Targeted RNA expression data confirmed expression increases for Alp and Ocn at 7 days in culture. The genechip array suggests substantive expression differences for 46 gene targets and the targeted osteogenesis microarray indicated 23 targets with substantive differences. 11 gene targets were chosen for qPCR confirmation because of their known association with bone or craniosynostosis (Col2a1, Dmp1, Fgf1, 2, Igf1, Mmp9, Phex, Tnf, Htra1, Por, and Dcn). We confirmed substantive increases in mRNA for Phex, FGF1, 2, Tnf, Dmp1, Htra1, Por, Igf1 and Mmp9, and substantive decreases for Dcn. It appears thyroid hormone may exert its effects through increasing osteogenesis. Targets isolated suggest a possible interaction for those gene products associated with calvarial suture growth and homeostasis as well as craniosynostosis. © 2013 Cray et al

    Lateral Gene Expression in Drosophila Early Embryos Is Supported by Grainyhead-Mediated Activation and Tiers of Dorsally-Localized Repression

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    The general consensus in the field is that limiting amounts of the transcription factor Dorsal establish dorsal boundaries of genes expressed along the dorsal-ventral (DV) axis of early Drosophila embryos, while repressors establish ventral boundaries. Yet recent studies have provided evidence that repressors act to specify the dorsal boundary of intermediate neuroblasts defective (ind), a gene expressed in a stripe along the DV axis in lateral regions of the embryo. Here we show that a short 12 base pair sequence (“the A-box”) present twice within the ind CRM is both necessary and sufficient to support transcriptional repression in dorsal regions of embryos. To identify binding factors, we conducted affinity chromatography using the A-box element and found a number of DNA-binding proteins and chromatin-associated factors using mass spectroscopy. Only Grainyhead (Grh), a CP2 transcription factor with a unique DNA-binding domain, was found to bind the A-box sequence. Our results suggest that Grh acts as an activator to support expression of ind, which was surprising as we identified this factor using an element that mediates dorsally-localized repression. Grh and Dorsal both contribute to ind transcriptional activation. However, another recent study found that the repressor Capicua (Cic) also binds to the A-box sequence. While Cic was not identified through our A-box affinity chromatography, utilization of the same site, the A-box, by both factors Grh (activator) and Cic (repressor) may also support a “switch-like” response that helps to sharpen the ind dorsal boundary. Furthermore, our results also demonstrate that TGF-β signaling acts to refine ind CRM expression in an A-box independent manner in dorsal-most regions, suggesting that tiers of repression act in dorsal regions of the embryo
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