8,022 research outputs found

    Machine Assisted Proof of ARMv7 Instruction Level Isolation Properties

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    In this paper, we formally verify security properties of the ARMv7 Instruction Set Architecture (ISA) for user mode executions. To obtain guarantees that arbitrary (and unknown) user processes are able to run isolated from privileged software and other user processes, instruction level noninterference and integrity properties are provided, along with proofs that transitions to privileged modes can only occur in a controlled manner. This work establishes a main requirement for operating system and hypervisor verification, as demonstrated for the PROSPER separation kernel. The proof is performed in the HOL4 theorem prover, taking the Cambridge model of ARM as basis. To this end, a proof tool has been developed, which assists the verification of relational state predicates semi-automatically

    Social network analysis of a chimpanzee (Pan troglodytes) group in captivity following the integration of a new adult member

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    Management of primates in captivity often presents the challenge of introducing new individuals into a group, and research investigating the stability of the social network in the medium-term after the introduction can help inform management decisions. We investigated the behavior of a group of chimpanzees (Pan troglodytes) housed at Chester Zoo, UK over 12 months (divided into three periods of four months) following the introduction of a new adult female. We recorded grooming, proximity, other affiliative behaviors and agonistic behaviors and used Social Network Analysis to investigate the stability, reciprocity and structure of the group, to examine the effect of rearing history on grooming network position and the role of sex in agonistic behavior. Both the grooming and agonistic networks correlated across all three periods, while affiliative networks correlated only between periods two and three. Males had significantly higher out-degree centrality in agonistic behaviors than females, indicating that they carried out agonistic behaviors more often than females. There was no significant difference in centrality between hand-reared and mother-reared chimpanzees. Overall, the group structure was stable and cohesive during the first year after the introduction of the new female, suggesting that this change did not destabilize the group. Our findings highlight the utility of Social Network Analysis in the study of primate sociality in captivity, and how it can be used to better understand primate behavior following the integration of new individuals

    The development of RAPTA compounds for the treatment of tumors

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    © 2015 Elsevier B.V. Ruthenium(II)-arene RAPTA-type compounds have been extensively explored for their medicinal properties. Herein a comprehensive review of this class of compounds is provided. A discussion of the basic RAPTA structure is given together with the ways it has been modified to elucidate the key role of each part and to afford targeted derivatives. The various mechanistic studies conducted on RAPTA compounds are described and these are linked to the observed macroscopic biological properties. Ultimately, the review shows that certain RAPTA compounds display quite unique properties that point towards a clinical investigation

    Prosthesis use is associated with reduced physical self-disgust in limb amputees

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    Self-disgust is an emotion schema negatively affecting people’s body image and is triggered by bodily imperfections and deviations from the “normal” body envelope. In this study, we explore the idea that “normalising” the body in those with limb amputations via the prosthesis would be linked to reduced self-directed disgust. An international clinical community sample (N = 83) with mostly lower limb amputations completed measures about their demographics, prosthesis, adjustment, body image disturbance, psychological distress, and self-directed disgust in a survey design. Consistent with the “normalising” hypothesis, correlation and bootstrapped regression models revealed, first, that frequency of prosthesis use was significantly and negatively associated with physical self-disgust. Second, prosthesis use significantly mediated the exogenous effect of time since amputation on physical self-disgust. These results emphasise the psychological value of the prosthesis beyond its functional use, and stress its importance in normalising the body envelope in those with limb amputations, which may in turn promote psychological well-being

    A Younger Demographic Defines Hepatitis C Patient Profiles in the Recent Direct-Acting Antiviral Era

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    A Younger Demographic Defines Hepatitis C Patient Profiles in the Recent Direct-Acting Antiviral Era Authors: Minawala, Ria1; Naylor, Paul H.2; Ehrinpreis, Murray N.2; Mutchnick, Milton G.2 Institutions: 1. Wayne State University School of Medicine, Detroit, MI, United States. 2. Wayne State University School of Medicine, Division of Gastroenterology, Detroit, MI, United States. Background: Highly effective and safe direct-acting antivirals (DAAs) against hepatitis C virus (HCV) combined with U.S. Preventive Services Task Force recommendation to screen for HCV in individuals born between 1945 and 1965 (age cohort; 54-79 years of age in 2019) was expected to reduce the number of actively infected patients via identification and treatment. Nevertheless, HCV infections remain a significant health concern. A study of HCV infected patients in our urban internal medicine practice, during the interferon era and prior to the introduction of DAAs, demonstrated a population within the age cohort. The objective of this study was to characterize the current patient population seen in the same practice with respect to age, race, and treatment status to determine the impact of DAA therapy on patient profiles and to test the hypothesis that there would be an increase in younger population among those infected. Methods: Using electronic medical records, we identified patients who presented to our urban GI practice in 2019. Data collected from patient charts included demographics, liver function tests, HCV genotype, viral load, imaging studies, and treatment history. Results: There were 601 patients with HCV seen in 2019 and the majority were African American (AA) (85%) and male (66%). Comparison of age alongside gender and race revealed that non-AA patients (51 years, SEM = 0.9) were significantly younger than AA patients (63 years, SEM = 0.4; p Conclusion: The primary shift in patient demographics as compared to the interferon era has been toward younger, non- AA females. In contrast, the predominant AA patients are still within the age cohort. The emergence of younger patients has important implications for screening, patient outreach, and treatment plans. A more intensive evaluation for risk factors and the role of COVID-19 in treatment is warranted. Many AA and non- AA patients were not started on any treatment in 2019, signifying a need for continued follow-up after initial visit to close the linkage to care gap

    FAILURE TO TREAT HCV IN PATIENTS SEEN IN A PREDOMINATELY AFRICAN AMERICAN SOCIOECONOMICALLY CHALLENGED POPULATION

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    The research objective of this proposal is to investigate the impediment with respect to moving a patient from initial antibody/PCR positive to successful completion of treatment. Secondary objectives include determining the most effective way for patients to progress from initial antibody/PCR positive to treatment and identifying the roadblocks for HCV antibody/PCR positive patients to be treated effectively. Data was collected from 2019 HCV patient EMR charts, including demographics, laboratory studies, and treatment history. Concerning treatment, we evaluated linkage to the care; we defined success as treatment within six months of the initial visit. Thus, data on treatment initiation was collected through the first six months of 2020
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