3,650 research outputs found
Supporting the automated generation of modular product line safety cases
Abstract The effective reuse of design assets in safety-critical Software Product Lines (SPL) would require the reuse of safety analyses of those assets in the variant contexts of certification of products derived from the SPL. This in turn requires the traceability of SPL variation across design, including variation in safety analysis and safety cases. In this paper, we propose a method and tool to support the automatic generation of modular SPL safety case architectures from the information provided by SPL feature modeling and model-based safety analysis. The Goal Structuring Notation (GSN) safety case modeling notation and its modular extensions supported by the D-Case Editor were used to implement the method in an automated tool support. The tool was used to generate a modular safety case for an automotive Hybrid Braking System SPL
Automatic allocation of safety requirements to components of a software product line
Safety critical systems developed as part of a product line must still comply with safety standards. Standards use the concept of Safety Integrity Levels (SILs) to drive the assignment of system safety requirements to components of a system under design. However, for a Software Product Line (SPL), the safety requirements that need to be allocated to a component may vary in different products. Variation in design can indeed change the possible hazards incurred in each product, their causes, and can alter the safety requirements placed on individual components in different SPL products. Establishing common SILs for components of a large scale SPL by considering all possible usage scenarios, is desirable for economies of scale, but it also poses challenges to the safety engineering process. In this paper, we propose a method for automatic allocation of SILs to components of a product line. The approach is applied to a Hybrid Braking System SPL design
O Parque Anauá sob uma análise multifuncional no contexto urbano de Boa Vista
O artigo tem por finalidade destacar as relações que as obras arquitetônicas e o paisagismo do Parque Anauá exercem no contexto atual da capital de Roraima, levando-se em conta as alterações de sua proposta inicial, datada de 1980, que influenciaram em sua presente utilização. Considerado como maior parque urbano da região Norte, o mesmo se sobressai no contexto urbano de Boa Vista por seu conjunto arquitetônico representativo da Arquitetura Moderna roraimense, composto por antigos e novos edifÃcios de evidente plasticidade, resultantes da integração entre materiais tÃpicos da região, como a madeira acariquara, com o posterior uso do concreto e aço. Ademais, a ênfase e a compreensão dessas obras arrojadas se fazem necessárias para ilustrar o elo que as mesmas formam com a natureza do local, visando revelar sua intrÃnseca significância na correlação entre os âmbitos sociais, paisagÃsticos e arquitetônicos. O estudo foi realizado por meio de revisão bibliográfica, registros fotográficos e entrevistas que apontam a expressiva potencialidade do parque para a população boa-vistense. Desse modo, a relevância desse trabalho se faz pelo levantamento de análises sob diversos parâmetros de um dos mais importantes espaços públicos de Roraima
Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling
<p>Abstract</p> <p>Background</p> <p>With nearly 1,100 species, the fish family Characidae represents more than half of the species of Characiformes, and is a key component of Neotropical freshwater ecosystems. The composition, phylogeny, and classification of Characidae is currently uncertain, despite significant efforts based on analysis of morphological and molecular data. No consensus about the monophyly of this group or its position within the order Characiformes has been reached, challenged by the fact that many key studies to date have non-overlapping taxonomic representation and focus only on subsets of this diversity.</p> <p>Results</p> <p>In the present study we propose a new definition of the family Characidae and a hypothesis of relationships for the Characiformes based on phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes (4,680 base pairs). The sequences were obtained from 211 samples representing 166 genera distributed among all 18 recognized families in the order Characiformes, all 14 recognized subfamilies in the Characidae, plus 56 of the genera so far considered <it>incertae sedis </it>in the Characidae. The phylogeny obtained is robust, with most lineages significantly supported by posterior probabilities in Bayesian analysis, and high bootstrap values from maximum likelihood and parsimony analyses.</p> <p>Conclusion</p> <p>A monophyletic assemblage strongly supported in all our phylogenetic analysis is herein defined as the Characidae and includes the characiform species lacking a supraorbital bone and with a derived position of the emergence of the hyoid artery from the anterior ceratohyal. To recognize this and several other monophyletic groups within characiforms we propose changes in the limits of several families to facilitate future studies in the Characiformes and particularly the Characidae. This work presents a new phylogenetic framework for a speciose and morphologically diverse group of freshwater fishes of significant ecological and evolutionary importance across the Neotropics and portions of Africa.</p
CCR5-∆32, CCR2-64I, SDF1-3'A, and IFNλ4 rs12979860 and rs8099917 gene polymorphisms in individuals with HIV-1, HIV/HTLV-1, and HIV/HTLV-2 in São Paulo, Brazil
Background. Chemokine and chemokine-receptor polymorphisms have been associated with protection against HIV infection and delayed progression to AIDS, whereas polymorphisms in IFNλ4 (formerly IL28B) have been associated with human T-lymphotropic virus 1 (HTLV-1)-associated myelopathy (HAM) development. Evolutionary selection against ancestral genes differs among human populations, resulting in varying risks of acquiring and developing viral diseases. Methods. DNA samples from 434 patients infected with HIV-1 and/or co-infected with HTLV-1/-2, and samples from 74 HIV and HTLV non-infected individuals from São Paulo, Brazil, were divided into five groups: HIV-naïve, n=160; HIV-ART, n=180; HIV/HTLV-1, n=53; HIV/HTLV-2, n=41; and control, n=74. These samples were analyzed for CCR5-∆32 deletion, CCR2-64I, SDF1-3'A, and IFNλ4 rs12979860 and rs8099917 single nucleotide polymorphisms using PCR and PCR-RFLP techniques. These polymorphisms' genotype and allele frequencies were calculated and compared among groups using logistic regression analysis. Results. All polymorphism profiles described in the literature were detected in this study. The wild-type genotype predominated in all genes analyzed except for IFNλ4 rs12979860. Statistical differences in allele frequencies among groups were detected in the CCR5 and CCR2 genes, with a high frequency of ∆32 in HIV-naïve vs. HIV-ART (OR 2.45, P=0.037) and a minus mutant allele A (CCR2-64I) in HIV-naïve vs. HIV/HTLV-1 (OR 1.90, P=0.048), HIV-ART vs. HIV/HTLV-1 (OR 2.62, P=0.003), and HIV/ART vs. HIV/HTLV-2 (OR 2.42, P=0.016). Conclusions. The polymorphism profiles detected in the study groups corroborate the profiles described in racial admixed populations. High CCR2-64I mutant allele frequencies were detected in HIV/HTLV-1/-2 co-infected individuals, and CCR5-∆32 showed predictive value for ART initiation
Percepção, uso e afetividade de frequentadores de praças públicas na cidade de São Paulo, Brasil
The present study analyzed the perception of regulars about five squares of the city of São Paulo and the use of these spaces. Exploratory interviews were conducted with attendees. The results indicate that green areas, safety, location, leisure, physical activity are among the items that contribute to positive feelings, as well as the decision to use these spaces. Infrastructure such as the presence of benches, bins, bathrooms and other elements that prolong the stay of the visitor in the square and increase their comfort when visiting the space is perceived, used and considered very important by the regulars. There is no standard in planning structures and equipment in different squares, since management is decentralized. The perceptions of the squares by the regulars can help in the creation of base projects, with similar elements, that meet these common expectations. In this way, it becomes relevant to be considered by public managers, weak and strong points perceived by regulars.O presente trabalho analisou a percepção de frequentadores sobre cinco praças da cidade de São Paulo e o uso destes espaços. Foram realizadas entrevistas exploratórias com frequentadores. Os resultados indicam que áreas verdes, segurança, localização, lazer, atividade fÃsica estão entre os itens que contribuem para sentimentos positivos, assim como a decisão de usar estes espaços. Infraestrutura como, presença de bancos, lixeiras, banheiros e outros elementos que prolonguem a estadia do visitante na praça e aumente seu conforto ao visitar o espaço é percebido, utilizado e considerado muito importante pelos frequentadores. Não há padrão no planejamento das estruturas e equipamentos em diferentes praças, uma vez que a gestão é descentralizada. As percepções das praças pelos frequentadores podem auxiliar na criação de projetos bases, com elementos semelhantes, que atendam a essas expectativas em comum. Dessa forma, torna-se relevante ser considerado pelos gestores públicos, pontos fracos e fortes percebidos por frequentadores
Covalently interconnected transition metal dichalcogenide networks via defect engineering for high-performance electronic devices.
Solution-processed semiconducting transition metal dichalcogenides are at the centre of an ever-increasing research effort in printed (opto)electronics. However, device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity. Here, we report a new molecular strategy to boost the electrical performance of transition metal dichalcogenide-based devices via the use of dithiolated conjugated molecules, to simultaneously heal sulfur vacancies in solution-processed transition metal disulfides and covalently bridge adjacent flakes, thereby promoting percolation pathways for the charge transport. We achieve a reproducible increase by one order of magnitude in field-effect mobility (µFE), current ratio (ION/IOFF) and switching time (τS) for liquid-gated transistors, reaching 10-2 cm2 V-1 s-1, 104 and 18 ms, respectively. Our functionalization strategy is a universal route to simultaneously enhance the electronic connectivity in transition metal disulfide networks and tailor on demand their physicochemical properties according to the envisioned applications.European Commission through the Graphene Flagship, the ERC Grants SUPRA2DMAT (GA-833707), FUTURE-PRINT (GA-694101), Hetero2D, GSYNCOR, the EU Grant Neurofibres, the Agence Nationale de la Recherche through the Labex projects CSC (ANR-10-LABX-0026 CSC) and NIE (ANR-11-LABX-0058 NIE) within the Investissement d’Avenir program (ANR-10-120 IDEX-0002-02), the International Center for Frontier Research in Chemistry (icFRC), EPSRC Grants EP/K01711X/1, EP/K017144/1, EP/N010345/1, EP/L016057/1, and the Faraday Institution. The HAADF-STEM characterization was carried out in the Advanced Microscopy Laboratory (Dublin), a Science Foundation Ireland (SFI) supported centre
Drug-cured experimental Trypanosoma cruzi infections confer long-lasting and cross-strain protection.
BACKGROUND: The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-?+ T cell response. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response
BIOTRANSFORMAÇÃO IN VITRO DE UM COMPOSTO ANTITUMORAL (LQFM 018)
Introdução e objetivos: O composto LQFM 018 foi sintetizado no Laboratório de QuímicaFarmacêutica Medicinal/FF/UFG, é um potente agente antitumoral que em ensaiostoxicológicos agudos in vitro, no modelo de vermelho neutro, não apresentou efeito tóxicosignificativo para as células basais. Estudos do metabolismo são de grande importânciapara o desenvolvimento de novos fármacos. O principal objetivo deste trabalho foi aaplicação de metodologia utilizando fungos filamentosos para mimetizar o metabolismohumano do LQFM 018 e possibilitar a preparação in vitro de metabólitos. Metodologia:LQFM 018 solubilizado em etanol/DMSO foi adicionado ao meio reacional PDSM, napresença de fungos filamentosos e foi incubados por 96 h a 27ºC sob agitação de 200rpm. Acinética reacional foi realizada por Cromatografia em Camada Delgada (CCD). Osderivados obtidos foram extraídos com acetato de etila e purificados por Cromatografia emColuna (CC) com Sílica-gel, para em seguida serem caracterizados por RessonânciaMagnética Nuclear (RMN). Resultados e discussões: Foram identificados vários fungoscapazes de catalisar a reação dando origem a cinco prováveis metabólitos Mortierellaisabelina foi a cepa mais promissora. Quantidade suficiente dos metabólitos para ensaios deatividade antitumoral foram obtidos e serão realizados posteriormente. Conclusões: Osfungos filamentosos foram capazes de biotransformar o LQFM 018, produzindo prováveismetabólitos
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