987 research outputs found

    Virtual HSM: Building a Hardware-backed Dependable Cryptographic Store

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    Cloud computing is being used by almost everyone, from regular consumer to IT specialists, as it is a way to have high availability, geo-replication, and resource elasticity with pay-as-you-go charging models. Another benefit is the minimal management effort and maintenance expenses for its users. However, security is still pointed out as the main reason hindering the full adoption of cloud services. Consumers lose ownership of their data as soon as it goes to the cloud; therefore, they have to rely on cloud provider’s security assumptions and Service Level Agreements regarding privacy and integrity guarantees for their data. Hardware Security Modules (HSMs) are dedicated cryptographic processors, typically used in secure cloud applications, that are designed specifically for the protection of cryptographic keys in all steps of their life cycles. They are physical devices with tamperproof resistance, but rather expensive. There have been some attempts to virtualize HSMs. Virtual solutions can reduce its costs but without much success as performance is incomparable and security guarantees are hard to achieve in software implementations. In this dissertation, we aim at developing a virtualized HSM supported by modern attestation-based trusted hardware in commodity CPUs to ensure privacy and reliability, which are the main requirements of an HSM. High availability will also be achieved through techniques such as cloud-of-clouds replication on top of those nodes. Therefore virtual HSMs, on the cloud, backed with trusted hardware, seem increasingly promising as security, attestation, and high availability will be guaranteed by our solution, and it would be much cheaper and as reliable as having physical HSMs

    Translations, betrayals and controversies in the articulation of the uncertainty principle : potentialities and challenges of a symmetrical history of physics

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    In this paper, we discuss the potentialities and challenges of historical approaches related to the Symmetrical Anthropology proposed by Bruno Latour and collaborators. To accomplish this goal, first, we provide a brief account about how Sociology and Anthropology of Science evolved, stressing how these different movements correlate with historiographical approaches. Second, we introduce the metaphysical scheme of Symmetrical Anthropology and discuss which characteristics a historical narrative should have to be consistent with this world vision. Third, we briefly describe the articulation of the Uncertainty Principle focusing on appropriating such characteristics. Based on this concrete historical account, we discuss the potentialities and challenges of this approach to History of Physics

    Dietary Leucine Supplementation Minimises Tumour-induced Damage In Placental Tissues Of Pregnant, Tumour-bearing Rats

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The occurrence of cancer during pregnancy merges two complex, poorly understood metabolic and hormonal conditions. This association can exacerbate the conditions of both the mother and the foetus. The branched-chain amino acid leucine enhances cellular activity, particularly by increasing protein synthesis. This study aimed to analyse the modulatory effect of a leucine-rich diet on direct and indirect tumour-induced placental damage. This was accomplished by evaluating the expression of genes involved in protein synthesis and degradation and assessing anti-oxidant enzyme activity in placental tissues collected from pregnant, tumour-bearing rats. Results: Pregnant rats were either implanted with Walker 256 tumour cells or injected with ascitic fluid (to study the indirect effects of tumour growth) and then fed a leucine-rich diet. Animals in a control group underwent the same procedures but were fed a normal diet. On the 20th day of pregnancy, tumour growth was observed. Dams fed a normoprotein diet showed the greatest tumour growth. Injection with ascitic fluid mimicked the effects of tumour growth. Decreased placental protein synthesis and increased protein degradation were observed in both the tumour-bearing and the ascitic fluid-injected groups that were fed a normoprotein diet. These effects resulted in low placental DNA and protein content and high lipid peroxidation (measured by malondialdehyde content). Decreased placental protein synthesis-related gene expression was observed in the tumour group concomitant with increased expression of genes encoding protein degradation-associated proteins and proteolytic subunits. Conclusions: Consumption of a leucine-rich diet counteracted the effects produced by tumour growth and injection with ascitic fluid. The diet enhanced cell signalling, ameliorated deficiencies in DNA and protein content, and balanced protein synthesis and degradation processes in the placenta. The improvements in cell signalling included changes in the mTOR/eIF pathway. In conclusion, consumption of a leucine-rich diet improved placental metabolism and cell signalling in tumour-bearing rats, and these changes reduced the deleterious effects caused by tumour growth.1658FAPESP [2010/00209-9, 2011/08276-0, 2013/16115-1]CNPq [302863/2013-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Iron Overload Favors the Elimination of Leishmania

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    Iron plays a central role in host-parasite interactions, since both intervenients need iron for survival and growth, but are sensitive to iron-mediated toxicity. The host’s iron overload is often associated with susceptibility to infection. However, it has been previously reported that iron overload prevented the growth of Leishmania major, an agent of cutaneous leishmaniasis, in BALB/c mice. In order to further clarify the impact of iron modulation on the growth of Leishmania in vivo, we studied the effects of iron supplementation or deprivation on the growth of L. infantum, the causative agent of Mediterranean visceral leishmaniasis, in the mouse model. We found that dietary iron deficiency did not affect the protozoan growth, whereas iron overload decreased its replication in the liver and spleen of a susceptible mouse strain. The fact that the iron-induced inhibitory effect could not be seen in mice deficient in NADPH dependent oxidase or nitric oxide synthase 2 suggests that iron eliminates L. infantum in vivo through the interaction with reactive oxygen and nitrogen species. Iron overload did not significantly alter the mouse adaptive immune response against L. infantum. Furthermore, the inhibitory action of iron towards L. infantum was also observed, in a dose dependent manner, in axenic cultures of promastigotes and amastigotes. Importantly, high iron concentrations were needed to achieve such effects. In conclusion, externally added iron synergizes with the host’s oxidative mechanisms of defense in eliminating L. infantum from mouse tissues. Additionally, the direct toxicity of iron against Leishmania suggests a potential use of this metal as a therapeutic tool or the further exploration of iron anti-parasitic mechanisms for the design of new drugs

    O que aconteceu aos Kaxarari: um estudo etnográfico de (In) sustentabilidade ambiental

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    Dissertação de mestrado apresentada ao Programa de Pós-Graduação em Desenvolvimento Regional e Meio Ambiente (PGDRA) da Universidade Federal de Rondônia, dentro da linha de pesquisa Políticas Públicas e Desenvolvimento Sustentável para obtenção do Titulo de Mestre em Desenvolvimento Regional e Meio Ambiente. Orientador Prof. Dr. Ari Miguel Teixeira OttA etnia Kaxarari marca a sua história do contato interétinco com segmentos das frentes extrativistas da seringa e do caucho em três períodos distintos: o tempo das correrias o tempo do cativeiro e o tempo dos direitos. A Terra indígena Kaxarari está localizada nas proximidades dos distritos de Califórnia e Extrema nas divisas de Rondônia, Acre e Amazonas este povo pertencente à família lingüística Pano, tem sua organização dividida em clãs de acordo com cada família e/ou povo. Habitam atualmente em cinco aldeias: Marmelinho, Paxiúba, Pedreira, Barrinha e Central, reunidas em um território de aproximadamente 145.000 hectares e uma população estimada em 317 indivíduos. Este estudo avaliou a relação da comunidade com o seu meio e o processo de utilização dos recursos naturais das comunidades da reserva indígena Kaxarari (RO). A partir dos contatos iniciais deste povo, sob a perspectiva etnográfica, procurando evidenciar as múltiplas resistências diante dos impactos decorrentes do contato com a sociedade nacional e as formas e meios como eles vêm construindo seus processos de (in)sustentabilidade. Para a realização do estudo foi utilizado o método etnográfico. O contato inicial com caucheiros peruanos e seringalistas brasileiros revelou-se extremamente desastroso para os Kaxarari. A conseqüência mais grave foi, sem duvida, a depopulação deste povo, que de dois mil habitantes, em 1910, ficaram reduzidos hoje em dia a menos de 400 indivíduos. Entretanto, mesmo tendo seus valores modificados no contato com o não índio, ainda constituem um exemplo de resistência, pois apesar da violência mantém uma língua, o território e a capacidade de reconstruírem seus valores e a luta pela existência

    Costo económico del tratamiento de las úlceras por presión : una aproximación teórica

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    O presente artigo consiste numa abordagem teórica sobre a problemática dos custos económicos das úlceras por pressão. Parte-se do conhecimento do problema, numa perspetiva conceptual, para, de seguida, apresentar resultados de estudos de prevalência, a partir dos quais foram delineados estudos de impacto económico. O objectivo deste artigo é o de reflectir sobre os custos económicos associados às úlceras por pressão, quer numa perspetiva global, considerando a repercussão financeira, quer numa vertente personalista, atendendo aos custos intangíveis. Relativamente ao impacto económico das úlceras por pressão, foi efectuada uma estimativa ao nível da Região Autónoma dos Açores do custo total do tratamento por ambiente de cuidados. Nos cuidados domiciliários o custo com o tratamento de todas as categorias é calculado em 7.086.415 euros; nos cuidados hospitalares, em 1.723.509 euros, e nos cuidados prestados em lares de idosos, em 1.002.562 euros. Nos Açores, a estimativa do custo total do tratamento das úlceras por pressão, considerando todas as suas categorias, ronda os 9.812.486 euros. Quanto ao impacto emocional associado, este tem elevados custos para pessoa e para os familiares, nomeadamente pelo sofrimento gerado. De facto, as úlceras por pressão acarretam elevados custos económicos associados ao tratamento, bem como custos intangíveis pelo sofrimento vivenciado por pessoas e cuidadores.RESUMEN: El presente artículo consiste en una reflexión teórica sobre el problema de los costos económicos de las úlceras por presión. Se empieza por el conocimiento del problema, desde una perspectiva conceptual, y, a continuación, se presentan los resultados de estudios de prevalencia, a partir de los cuales se diseñaron estudios de impacto económico. El objetivo del artículo es reflexionar sobre los costos económicos asociados a las úlceras por presión tanto en una perspectiva global, considerando la repercusión financiera, como en una vertiente personalista, de acuerdo a los costos intangibles. En cuanto al impacto económico de las úlceras por presión, se realizó una estimación de la Región Autónoma de Açores del costo total del tratamiento por ámbito de atención. En la atención domiciliaria el costo con el tratamiento de todas las categorías se estima en € 7.086.415, en la atención hospitalaria, se estima € 1.723.509 y en la atención en los asilos se estima en €1.002.562. En Açores, el costo total estimado del tratamiento de las úlceras por presión en todas las categorías, es de alrededor de € 9.812.486. En cuanto al impacto emocional asociado, éste tiene elevados costos para la persona y para los familiares, principalmente, por el sufrimiento causado. De hecho, las úlceras por presión implican altos costos económicos asociados con el tratamiento, así como, costos intangibles generados por el sufrimiento experimentado por los individuos y los cuidadores.ABSTRACT: The present study consisted of a theoretical approach to the problem posed by the economic costs associated with pressure ulcers (PUs). The initial aim was to assess the target problem from a conceptual perspective and then to report the results of prevalence studies that formed the basis for investigations of the disease’s economic impact. The purpose of the present article is to discuss the economic costs associated with PUs from both the global point of view (appraising their financial repercussion) and the individual point of view (addressing the intangible costs). Regarding the economic impact of the costs associated with PUs, the total cost of treatment per healthcare setting was estimated relative to the Autonomous Community of Azores. The total cost of all the PU categories was EUR 7,086,415 in the homecare setting, EUR 1,723,509 in the hospital setting, and EUR 1,002,562 in older people’s homes. Therefore, the estimated total treatment cost of all the PU categories was approximately EUR 9,812,486 in Azores. However, the emotional impact of this disease imposes high costs on patients and their relatives as a function of the resultant suffering. Indeed, PUs impose high costs not only related to the treatment but also related to the intangible costs of the suffering caused to patients and their caregivers.Project ICE 2 – Investigação Científica em Enfermagem – Estudo do “Custo Económico das Úlceras por Pressão na Macaronésia” (MAC/1/A029) de Iniciativa Comunitária – Programa de Cooperação Transnacional Madeira-Açores-Canárias 2007-2013info:eu-repo/semantics/publishedVersio

    Dietary leucine supplementation minimises tumour-induced damage in placental tissues of pregnant, tumour-bearing rats

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    Background: The occurrence of cancer during pregnancy merges two complex, poorly understood metabolic and hormonal conditions. This association can exacerbate the conditions of both the mother and the foetus. The branched-chain amino acid leucine enhances cellular activity, particularly by increasing protein synthesis. This study aimed to analyse the modulatory effect of a leucine-rich diet on direct and indirect tumour-induced placental damage. This was accomplished by evaluating the expression of genes involved in protein synthesis and degradation and assessing anti-oxidant enzyme activity in placental tissues collected from pregnant, tumour-bearing rats. Results: Pregnant rats were either implanted with Walker 256 tumour cells or injected with ascitic fluid (to study the indirect effects of tumour growth) and then fed a leucine-rich diet. Animals in a control group underwent the same procedures but were fed a normal diet. On the 20th day of pregnancy, tumour growth was observed. Dams fed a normoprotein diet showed the greatest tumour growth. Injection with ascitic fluid mimicked the effects of tumour growth. Decreased placental protein synthesis and increased protein degradation were observed in both the tumour-bearing and the ascitic fluid-injected groups that were fed a normoprotein diet. These effects resulted in low placental DNA and protein content and high lipid peroxidation (measured by malondialdehyde content). Decreased placental protein synthesis-related gene expression was observed in the tumour group concomitant with increased expression of genes encoding protein degradation-associated proteins and proteolytic subunits. Conclusions: Consumption of a leucine-rich diet counteracted the effects produced by tumour growth and injection with ascitic fluid. The diet enhanced cell signalling, ameliorated deficiencies in DNA and protein content, and balanced protein synthesis and degradation processes in the placenta. The improvements in cell signalling included changes in the mTOR/eIF pathway. In conclusion, consumption of a leucine-rich diet improved placental metabolism and cell signalling in tumour-bearing rats, and these changes reduced the deleterious effects caused by tumour growth16CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP302863/2013-32010/00209-9; 2011/08276-0; 2013/16115-

    A dive into the bath: embedded 3D bioprinting of freeform in vitro models

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    Designing functional, vascularized, human scale in vitro models with biomimetic architectures and multiple cell types is a highly promising strategy for both a better understanding of natural tissue/organ development stages to inspire regenerative medicine, and to test novel therapeutics on personalized microphysiological systems. Extrusion-based 3D bioprinting is an effective biofabrication technology to engineer living constructs with predefined geometries and cell patterns. However, bioprinting high-resolution multilayered structures with mechanically weak hydrogel bioinks is challenging. The advent of embedded 3D bioprinting systems in recent years offered new avenues to explore this technology for in vitro modeling. By providing a stable, cell-friendly and perfusable environment to hold the bioink during and after printing, it allows to recapitulate native tissues’ architecture and function in a well-controlled manner. Besides enabling freeform bioprinting of constructs with complex spatial organization, support baths can further provide functional housing systems for their long-term in vitro maintenance and screening. This minireview summarizes the recent advances in this field and discuss the enormous potential of embedded 3D bioprinting technologies as alternatives for the automated fabrication of more biomimetic in vitro models.The authors acknowledge the financial support from Project NORTE-01-0145-FEDER 000021 supported by Norte Portugal Regional Operational Program (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), the European Union Framework Program for Research and Innovation HORIZON 2020, under European Research Council Grant Agreement 772817 and 101069302, Fundação para a Ciência e a Tecnologia (FCT) for the for Contract 2020.03410.CEECIND (to R. M. A. D.) and Wi-Pi project 2022.05526.PTDC. The schematics of the Table of Contents graphic was created with BioRender.com

    Echocardiography and cardiovascular risk:The relationship in the renal transplant recipient

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    Introduction: Cardiovascular disease (CVD) is the major cause of death among renal transplant recipientes (RTR). It is not known whether echocardiographic abnormalities are useful to identify RTR at high risk of CVD. Methods: Retrospective review of RTR with functioning and stable graft and an echocardiography performed in the last year. Risk of major adverse cardiac events (MACE) and death using a risk calculator specific for RTR. Results: Among 107 patients (57.9% males, 50.4±13.9 years), 7-year risk of MACE was >10% in 30.9% of patients and 7-year risk of death >10% in 56.1%. Left ventricular hypertrophy (LVH) was found in 55.1%, diastolic dysfunction in 39.3%, dilated left atrium (LA) in 53.3%, high pulmonary artery systolic pressure (PASP) in 9.0%, valvular calcifications in 22.4% and moderate to severe mitral regurgitation (MR) in 3.7%. Mean Ejection fraction was 68.36±6.87%. Univariate analysis showed an increased risk of MACE and death in patients with LVH, diastolic dysfunction, dilated LA, high PASP, valvular calcifications and MR. Multivariate analysis identified an independente association between the risk of MACE >10% and valvular calcifications and high PASP. Risk of death>10% in multivariate analysis had an independent association with diastolic dysfunction and elevated PASP. Conclusion: Echocardiographic abnormalities identify RTR at increased risk of MACE and death. Valvular calcifications and high PASP are predictors of MACE whereas diastolic dysfunction and high PASP predict death.info:eu-repo/semantics/publishedVersio
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