Proposta e Estudo de Soluções para Otimização de Rotas em Ambientes de Mobilidade de Redes

Tese de doutoramento em Engenharia Informática, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraNo mundo de hoje, no qual se acentua a tendência para que todo o tipo de comunicações recorra à arquitetura TCP/IP e crescem, em número e tipo, os dispositivos que utilizam ligações sem fios, a mobilidade em ambiente IP assume um papel de extrema importância. Por esse facto, tem sido grande a atenção da comunidade científica à proposta e desenvolvimento de soluções de mobilidade IP de nós individuais e de redes. O NEMO Basic Support Protocol, IETF RFC 3963, foi desenvolvido com o objetivo de fornecer mobilidade de redes de forma imediata e transparente para a Internet atual. Contudo, a sua simplicidade está na génese das suas maiores limitações, que resultam em claros problemas de desempenho. Por outro lado, nenhuma das alternativas propostas com o intuito de resolver estas limitações conseguiu reunir consenso. Nesta tese é apresentada uma mudança de paradigma, que consiste em envolver os dispositivos finais nos processos de mobilidade de redes. A proposta Optimised Mobility for Enhanced Networking, OMEN, faculta os mecanismos necessários para que os dispositivos finais tomem consciência da sua condição de mobilidade e possam recorrer aos mecanismos de otimização de rotas já previstos no MIPv6, de forma a não estarem sujeitos às limitações do RFC 3963. Com esta medida consegue-se resolver o problema da decisão da altura ideal para otimizar a rota de um determinado fluxo e, ao mesmo tempo, permitir que os elementos da infraestrutura de rede móvel fiquem dedicados às suas funções de encaminhamento de pacotes, resultando num incremento acentuado do desempenho da rede e num decréscimo do consumo de energia. As simulações realizadas mostram que a proposta OMEN apresenta valores de desempenho de comunicação e de perda de pacotes substancialmente melhores que as restantes soluções existentes, corroborando as vantagens da mudança de paradigma. Para a realização dos diversos estudos de comparação das soluções foi necessário desenvolver um emulador que permitisse resolver as limitações de falta de implementação das soluções de mobilidade de redes e, ao mesmo tempo, permitir simulações de larga escala e de carga na rede. O emulador desenvolvido, denominado mobSim, foi executado num cluster de grandes dimensões, dado o tamanho e complexidade dos cenários de simulação.In the current world, in which there is a growing trend to use the TCP/IP protocol suite in all types of communication networks, and the number and type of devices using wireless connections is growing, IP mobility of both nodes and networks is of extreme importance. This is the main reason why the scientific community has paid and is paying special attention to the proposal and development of IP mobility solutions. The NEMO Basic Support Protocol, IETF RFC 3963, was developed with the objective of readily allowing transparent network mobility in the current Internet. Nevertheless, the simplicity of this solution is at the basis of its limitations, which severely affect its performance. On the other hand, none of the proposed alternatives is gathering enough consensus of the community. In this thesis, a paradigm shift is proposed, consisting of involving end nodes in the network mobility process. The proposal, named Optimised Mobility for Enhanced Networking, OMEN, establishes the necessary means for informing end nodes of their mobility condition, which can then use existing MIPv6 route optimisation mechanisms in order for them not to be subject to the limitations of RFC 3963. In this way, the problem of deciding which and when to optimise flows is left to the end nodes, which are in the best position to decide. At the same time, mobile routers are freed from all tasks concerning the mobility management of a potentially large number of flows, making them lighter and with lower power requirements. The performed simulations show that the OMEN proposal leads to better performance then existing network mobility solutions, confirming the advantages of the paradigm shift. The performed studies were carried out using a specially built network mobility emulator, in order to overcome the lack of support for this type of mobility and the scalability limitations of existing simulators. The developed emulator, named mobSim, ran in a large cluster, due to the size and complexity of the simulated scenarios.IST-FP6-0384239: CONTENT – Network of Excellence on Content Networks and Services for Home UsersFCT PTDC/EIA –EIA/116173/2009: CoFiMoM - Combate a Incêndios com Multihoming e Mobilidad

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Proposta e Estudo de Soluções para Otimização de Rotas em Ambientes de Mobilidade de Redes

Tese de doutoramento em Engenharia Informática, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraNo mundo de hoje, no qual se acentua a tendência para que todo o tipo de comunicações recorra à arquitetura TCP/IP e crescem, em número e tipo, os dispositivos que utilizam ligações sem fios, a mobilidade em ambiente IP assume um papel de extrema importância. Por esse facto, tem sido grande a atenção da comunidade científica à proposta e desenvolvimento de soluções de mobilidade IP de nós individuais e de redes. O NEMO Basic Support Protocol, IETF RFC 3963, foi desenvolvido com o objetivo de fornecer mobilidade de redes de forma imediata e transparente para a Internet atual. Contudo, a sua simplicidade está na génese das suas maiores limitações, que resultam em claros problemas de desempenho. Por outro lado, nenhuma das alternativas propostas com o intuito de resolver estas limitações conseguiu reunir consenso. Nesta tese é apresentada uma mudança de paradigma, que consiste em envolver os dispositivos finais nos processos de mobilidade de redes. A proposta Optimised Mobility for Enhanced Networking, OMEN, faculta os mecanismos necessários para que os dispositivos finais tomem consciência da sua condição de mobilidade e possam recorrer aos mecanismos de otimização de rotas já previstos no MIPv6, de forma a não estarem sujeitos às limitações do RFC 3963. Com esta medida consegue-se resolver o problema da decisão da altura ideal para otimizar a rota de um determinado fluxo e, ao mesmo tempo, permitir que os elementos da infraestrutura de rede móvel fiquem dedicados às suas funções de encaminhamento de pacotes, resultando num incremento acentuado do desempenho da rede e num decréscimo do consumo de energia. As simulações realizadas mostram que a proposta OMEN apresenta valores de desempenho de comunicação e de perda de pacotes substancialmente melhores que as restantes soluções existentes, corroborando as vantagens da mudança de paradigma. Para a realização dos diversos estudos de comparação das soluções foi necessário desenvolver um emulador que permitisse resolver as limitações de falta de implementação das soluções de mobilidade de redes e, ao mesmo tempo, permitir simulações de larga escala e de carga na rede. O emulador desenvolvido, denominado mobSim, foi executado num cluster de grandes dimensões, dado o tamanho e complexidade dos cenários de simulação.In the current world, in which there is a growing trend to use the TCP/IP protocol suite in all types of communication networks, and the number and type of devices using wireless connections is growing, IP mobility of both nodes and networks is of extreme importance. This is the main reason why the scientific community has paid and is paying special attention to the proposal and development of IP mobility solutions. The NEMO Basic Support Protocol, IETF RFC 3963, was developed with the objective of readily allowing transparent network mobility in the current Internet. Nevertheless, the simplicity of this solution is at the basis of its limitations, which severely affect its performance. On the other hand, none of the proposed alternatives is gathering enough consensus of the community. In this thesis, a paradigm shift is proposed, consisting of involving end nodes in the network mobility process. The proposal, named Optimised Mobility for Enhanced Networking, OMEN, establishes the necessary means for informing end nodes of their mobility condition, which can then use existing MIPv6 route optimisation mechanisms in order for them not to be subject to the limitations of RFC 3963. In this way, the problem of deciding which and when to optimise flows is left to the end nodes, which are in the best position to decide. At the same time, mobile routers are freed from all tasks concerning the mobility management of a potentially large number of flows, making them lighter and with lower power requirements. The performed simulations show that the OMEN proposal leads to better performance then existing network mobility solutions, confirming the advantages of the paradigm shift. The performed studies were carried out using a specially built network mobility emulator, in order to overcome the lack of support for this type of mobility and the scalability limitations of existing simulators. The developed emulator, named mobSim, ran in a large cluster, due to the size and complexity of the simulated scenarios.IST-FP6-0384239: CONTENT – Network of Excellence on Content Networks and Services for Home UsersFCT PTDC/EIA –EIA/116173/2009: CoFiMoM - Combate a Incêndios com Multihoming e Mobilidad

Brazilian recommendations of mechanical ventilation 2013. Part 2

O suporte ventilatório artificial invasivo e não invasivo ao paciente crítico tem evoluído e inúmeras evidências têm surgido, podendo ter impacto na melhora da sobrevida e da qualidade do atendimento oferecido nas unidades de terapia intensiva no Brasil. Isto posto, a Associação de Medicina Intensiva Brasileira (AMIB) e a Sociedade Brasileira de Pneumologia e Tisiologia (SBPT) - representadas pelo seus Comitê de Ventilação Mecânica e Comissão de Terapia Intensiva, respectivamente, decidiram revisar a literatura e preparar recomendações sobre ventilação mecânica objetivando oferecer aos associados um documento orientador das melhores práticas da ventilação mecânica na beira do leito, baseado nas evidencias existentes, sobre os 29 subtemas selecionados como mais relevantes no assunto. O projeto envolveu etapas visando distribuir os subtemas relevantes ao assunto entre experts indicados por ambas as sociedades que tivessem publicações recentes no assunto e/ou atividades relevantes em ensino e pesquisa no Brasil na área de ventilação mecânica. Esses profissionais, divididos por subtemas em duplas, responsabilizaram-se por fazer revisão extensa da literatura mundial sobre cada subtema. Reuniram-se todos no Forum de Ventilação Mecânica na sede da AMIB em São Paulo, em 03 e 04 de agosto de 2013 para finalização conjunta do texto de cada subtema e apresentação, apreciação, discussão e aprovação em plenária pelos 58 participantes, permitindo a elaboração de um documento final

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

ABC₂-SPH risk score for in-hospital mortality in COVID-19 patients

Objectives: The majority of available scores to assess mortality risk of coronavirus disease 2019 (COVID-19) patients in the emergency department have high risk of bias. Therefore, this cohort aimed to develop and validate a score at hospital admission for predicting in-hospital mortality in COVID-19 patients and to compare this score with other existing ones. Methods: Consecutive patients (≥ 18 years) with confirmed COVID-19 admitted to the participating hospitals were included. Logistic regression analysis was performed to develop a prediction model for in-hospital mortality, based on the 3978 patients admitted between March–July, 2020. The model was validated in the 1054 patients admitted during August–September, as well as in an external cohort of 474 Spanish patients. Results: Median (25–75th percentile) age of the model-derivation cohort was 60 (48–72) years, and in-hospital mortality was 20.3%. The validation cohorts had similar age distribution and in-hospital mortality. Seven significant variables were included in the risk score: age, blood urea nitrogen, number of comorbidities, C-reactive protein, SpO2/FiO2 ratio, platelet count, and heart rate. The model had high discriminatory value (AUROC 0.844, 95% CI 0.829–0.859), which was confirmed in the Brazilian (0.859 [95% CI 0.833–0.885]) and Spanish (0.894 [95% CI 0.870–0.919]) validation cohorts, and displayed better discrimination ability than other existing scores. It is implemented in a freely available online risk calculator (https://abc2sph.com/). Conclusions: An easy-to-use rapid scoring system based on characteristics of COVID-19 patients commonly available at hospital presentation was designed and validated for early stratification of in-hospital mortality risk of patients with COVID-19.</p

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data