636 research outputs found

    Checking Interaction-Based Declassification Policies for Android Using Symbolic Execution

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    Mobile apps can access a wide variety of secure information, such as contacts and location. However, current mobile platforms include only coarse access control mechanisms to protect such data. In this paper, we introduce interaction-based declassification policies, in which the user's interactions with the app constrain the release of sensitive information. Our policies are defined extensionally, so as to be independent of the app's implementation, based on sequences of security-relevant events that occur in app runs. Policies use LTL formulae to precisely specify which secret inputs, read at which times, may be released. We formalize a semantic security condition, interaction-based noninterference, to define our policies precisely. Finally, we describe a prototype tool that uses symbolic execution to check interaction-based declassification policies for Android, and we show that it enforces policies correctly on a set of apps.Comment: This research was supported in part by NSF grants CNS-1064997 and 1421373, AFOSR grants FA9550-12-1-0334 and FA9550-14-1-0334, a partnership between UMIACS and the Laboratory for Telecommunication Sciences, and the National Security Agenc

    Brazilian Bidens pilosa Linne´ yields fraction containing quercetin-derived flavonoid with free radical scavenger activity and hepatoprotective effects

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    Bidens pilosa is a plant used by Amazonian and Asian folks for some hepatopathies. The hydroethanol crude extract and three fractions were assessed for antioxidant and hepatoprotective effects. Higher levels of scavenger activity on the 1,1-diphenyl-2-picrylhydrazyl radical, inhibition of deoxyribose oxidation and lipid peroxidation in vitro were detected for the ethyl acetate fraction (IC50∼4.3-32.3 mg/ml) followed by the crude extract (IC50∼14.2-98.0 mg/ml). The ethyl acetate fraction, again followed by the crude extract, showed high contents of total soluble polyphenols (3.6±0.2 and 2.1±0.2 GAE/mg, respectively) and presence of a quercetin-derived flavonoid identified as quercetin 3,3′-dimethyl ether 7-Ο-β-D-glycopyranoside. Both products were assayed for hepatoprotector effects against CCl4-induced liver injury in mice. Markers of oxidative stress and hepatic injury were evaluated. The results showed that the 10-day pretreatments (15 mg/kg, p.o.) protected the livers against injury by blocking CCl4-induced lipid peroxidation and protein carbonylation and the DNA fragmentation was decreased (∼60%). The pretreatments avoided the loss of the plasma ferric reducing/antioxidant power and the elevation of serum transaminases and lactate dehydrogenase activities. The results suggest that the main constituents responsible for the hepatoprotective effects with free radical scavenger power associated are well extracted by performing fractionation with ethyl acetate. The findings support the Brazilian traditional use of this plant and justify further evaluations for the therapeutic efficacy and safety of the constituents of the ethyl acetate fraction to treat some liver diseases.Keywords: Bidens pilosa L.; hydroethanol maceration; ethyl acetate fractionation; free radical scavenger; hepatoprotection; CCl4 toxicit

    Realizing Omega-regular Hyperproperties

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    We studied the hyperlogic HyperQPTL, which combines the concepts of trace relations and ω\omega-regularity. We showed that HyperQPTL is very expressive, it can express properties like promptness, bounded waiting for a grant, epistemic properties, and, in particular, any ω\omega-regular property. Those properties are not expressible in previously studied hyperlogics like HyperLTL. At the same time, we argued that the expressiveness of HyperQPTL is optimal in a sense that a more expressive logic for ω\omega-regular hyperproperties would have an undecidable model checking problem. We furthermore studied the realizability problem of HyperQPTL. We showed that realizability is decidable for HyperQPTL fragments that contain properties like promptness. But still, in contrast to the satisfiability problem, propositional quantification does make the realizability problem of hyperlogics harder. More specifically, the HyperQPTL fragment of formulas with a universal-existential propositional quantifier alternation followed by a single trace quantifier is undecidable in general, even though the projection of the fragment to HyperLTL has a decidable realizability problem. Lastly, we implemented the bounded synthesis problem for HyperQPTL in the prototype tool BoSy. Using BoSy with HyperQPTL specifications, we have been able to synthesize several resource arbiters. The synthesis problem of non-linear-time hyperlogics is still open. For example, it is not yet known how to synthesize systems from specifications given in branching-time hyperlogics like HyperCTL^*.Comment: International Conference on Computer Aided Verification (CAV 2020

    Arachnidism, scorpionism and ophidism in Ouro Preto Municipality, Minas Gerais State, Brazil

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    Abstract: INTRODUCTION This retrospective study shows the profile of arachnidism, ophidism, and scorpionism in the Ouro Preto Municipality, Brazil, from January 2007 to December 2013. METHODS The data were gathered from forms of the Epidemiological Surveillance Sector of the town's Health's Municipal Secretary. RESULTS Of the 412 envenomations, 308 were caused by spiders, 78 by scorpions, and 26 by snakes. The highest number of incidents involved people aged 20-34 years. Females were more affected than males. There were no reports of death. CONCLUSIONS The results show that envenomations caused by spiders, scorpions and snakes have decreased in recent years

    Therapeutic communication between health workers and patients concerning diabetes mellitus care

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    The objective of this cross-sectional study was to analyze therapeutic communication techniques used by health workers with patients under care for diabetes mellitus. Data were collected in 2010 in a public facility in the interior of Ceará, Brazil using video camera equipment and direct observation. Results showed that the most frequently used techniques within the "expression" group were: asking questions, voicing interest, and using descriptive phrases. The most frequently used technique within the "clarification" group was: asking the patient to specify the agent of action. Finally, in regard to the "validation" group, only the technique "summarizing content of the interaction" was employed. The conclusion is that despite the use of communication techniques on the part of professionals, there is still an alarming gap concerning communication skills. Such skills should be allied with technical expertise to enable the delivery of qualified care to individuals with diabetes mellitus.Este estudio transversal tuvo como objetivo analizar las técnicas de comunicación terapéutica entre profesionales y pacientes en la atención en diabetes mellitus. Los datos se recogieron en una institución pública de Ceará-Brasil, en 2010, con equipos de video y observación directa. Los resultados mostraron que las técnicas del grupo de expresión más utilizadas fueron: hacer preguntas, expresar interés y usar frases descriptivas. Con relación a las del grupo de clarificación sobresalió solicitar al paciente que necesite el agente de la acción. Con relación a las de validación, apenas se utilizó las de organizar el contenido de la interacción. Se concluye que a pesar del uso de técnicas de comunicación por los profesionales, aun es preocupante la laguna con relación a la habilidad en comunicación, que debe ser aliada a la capacidad técnica, para así propiciar el cuidado calificado a las personas con diabetes mellitus.Objetivou-se, por este estudo transversal, analisar as técnicas de comunicação terapêutica entre profissionais e pacientes na atenção em diabetes mellitus. Os dados foram coletados em uma instituição pública de um município no interior do Ceará, Brasil, em 2010, por meio de equipamentos de vídeo e observação direta. Os resultados mostraram que as técnicas do grupo de expressão mais utilizadas foram: fazer perguntas, verbalizar interesse e usar frases descritivas. Quanto às do grupo de clarificação, sobressaiu solicitar ao paciente que precise o agente da ação. Em relação às de validação, apenas foi utilizada a técnica de sumarizar o conteúdo da interação. Conclui-se que, apesar do emprego de técnicas comunicacionais pelos profissionais, ainda é preocupante a lacuna referente à habilidade em comunicação, a qual deve ser aliada à competência técnica, para assim propiciar o cuidado qualificado às pessoas com diabetes mellitus

    Processos de medicação, carga de trabalho e a segurança do paciente em unidades de internação

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    RESUMO Objetivo Levantar pontos críticos do processo de medicação, suas repercussões nas demandas de trabalho da equipe de enfermagem e riscos para a segurança dos pacientes. Método Estudo descritivo, com abordagem qualitativa, na perspectiva ecológico-restaurativa. Os dados foram coletados por meio de grupos focais e fotografias. Participaram enfermeiros e técnicos de enfermagem. Resultados Três categorias emergiram da análise temática: Desafios nos processos de prescrição e dispensação de medicamentos; Administração de medicamentos – organização no turno de trabalho; Uso de novas tecnologias para diminuir erros de medicamentos. Os resultados apontam que o processo de medicação assume um caráter de centralidade na organização do trabalho da equipe de enfermagem, sendo que estes profissionais configuram-se como a última barreira para detectar falhas de prescrição e dispensação de medicamentos. Conclusão Para a identificação de vulnerabilidades na etapa de administração de medicamentos, o uso de tecnologias, sem dúvida, agrega valor para o processo de cuidado seguro
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