25 research outputs found

    Security for constrained IoT devices

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    Tese de mestrado, Segurança InformĂĄtica, Universidade de Lisboa, Faculdade de CiĂȘncias, 2020In the recent past the Internet of Things has been the target of a great evolution, both in terms of applicability and of use. Society increasingly wants to use and massify the IoT to obtain information and act in the environment, for example, to remotely control an irrigation system. The reduction in the cost of devices and the constant evolution of personal mobile devices has largely contributed to their spread. However, its implementation is carried out in adverse environments and outside the typical information systems. The devices are, as a rule, limited in terms of resources, both computation and memory. The applicability to the IoT of the security techniques already known to conventional systems has therefore to be adapted, because it does not take into account the characteristics of the resources of the devices and require additional load when exchanging messages between these system elements. In addition, the development of applications is difficult because there is not yet developed tools and standards as there are for the traditional HTTPS or TLS when considering conventional systems. In this work, we intend to present a prototype of a low-cost solution (compared to existing equivalent solutions) that uses a secure communication channel based on standard protocols. An application is also developed based on technologies more familiar to programmers, similar to traditional Web development. We took into account the ”Green By Web” project as a case study. We have concluded that it is possible to have a secure communication, using UDP/DTLS over the CoAP protocol. With this approach we optimized the number of exchanged messages between the client and the server to be up to 8 times less and their size to be up to 10%, comparing against applications that use TCP/TLS connections, such as web applications that use HTTPS. This allows the energy spent by the low-cost components to be lower and increases their battery lifetime

    Retinopexia com "buckle" escleral e crioterapia guiada por ultrassom: relato de caso

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    If the ocular media are clear, indirect binocular ophthalmoscopy allows retinal detachment and retinal tear identification and treatment under direct visualization. However, if opacities are present preventing direct fundus examination, ultrasonography becomes the most important tool for evaluating the posterior segment. In addition, ultrasonography can be useful in retinal tear treatment by guiding cryotherapy. In this article we describe a rhegmatogenous retinal detachment treatment technique applied to a patient with corneal opacity. Cryopexy and circumferential and radial buckle positioning were guided by ultrasonography, resulting in retinal attachment during the 6-month follow-up period.Quando os meios oculares sĂŁo transparentes, oftalmoscopia binocular indireta permite a identificação de descolamento de retina e roturas, bem como seu tratamento sob visibilização direta. PorĂ©m, em olhos que apresentam opacidades de meios impedindo o exame oftalmoscĂłpico, a ultrassonografia constitui o exame mais importante do segmento posterior do olho. AlĂ©m disso, o tratamento de roturas retinianas tambĂ©m pode ser auxiliado pelo uso desse equipamento, orientando a crioterapia. Neste trabalho serĂĄ apresentada tĂ©cnica de tratamento de descolamento de retina regmatogĂȘnico, no qual a criopexia e o posicionamento dos "buckles" episclerais circunferencial e radial foram guiados pelo ultrassom em paciente com leucoma corneano. O tratamento resultou em aplicação retiniana durante o seguimento em seis meses

    Statement of Second Brazilian Congress of Mechanical Ventilarion : part I

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    Resumo nĂŁo disponĂ­ve

    EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe

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    AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Rapazes negros e socialização de gĂȘnero: sentidos e significados de "ser homem" Afro descendant boys and gender socialization: meanings of "being a man"

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    Este artigo discute os processos de socialização de rapazes negros e pobres da cidade de SĂŁo Paulo, problematizando como determinados sentidos e experiĂȘncias sobre a masculinidade sĂŁo construĂ­dos e reelaborados em suas trajetĂłrias. A partir de trabalho empĂ­rico realizado entre 2007 e 2008, argumentamos em torno da ideia de que a masculinidade Ă© uma experiĂȘncia que permeia a trajetĂłria dos sujeitos, nunca acabada e marcada por revezes.<br>This paper discusses the processes of socialization of young black and poor boys in the city of SĂŁo Paulo, questioning how certain meanings and experiences of masculinity are constructed and reworked in their lives. From empirical research conducted between 2007 and 2008, we base our paper on the idea that masculinity is an experience that penetrates the trajectory of individuals, never finished and marked by setbacks
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