Morphing Web Pages to Preclude Web Page Tampering Threats

O número de utilizadores da Internet continua a aumentar todos os anos e a Internet é cada vez mais uma ferramenta diária na vida de cada indivíduo, utilizada como instrumento de trabalho ou de entretenimento. Contudo, ao navegar na Internet, os utilizadores tornam-se possíveis alvos de ataques informáticos um vez que efetuam transações de dados, muitas vezes privados e sensíveis, com servidores remotos.Entre os diferentes ataques informáticos existentes, destaca-se o ataque MitB que deu origem ao tema desta dissertação. Os ataques MitB são realizados com recurso a Malware instalado e em execução nos computadores dos utilizadores, que tem acesso às informações das janelas dos navegadores de Internet - por exemplo através de bibliotecas de funções do sistema operativo ou até recorrendo a extensões dos navegadores de Internet. Estes ataques utilizam âncoras do DOM para identificar as secções de uma página web onde pretendem atacar - recolhendo dados ou modificando a própria página. O resultado do ataque será diretamente influenciado pela capacidade do Malware em identificar os pontos de ataque numa determinada página web.O Polimorfismo é um conceito geral que pode ser aplicado a páginas web como uma ferramenta para neutralizar e derrotar este tipo de ataques informáticos, tal como foi documentado pela empresa Shape Security, Inc. em 2014. Aplicando técnicas de polimorfismo a páginas web, as respostas de um servidor serão textualmente diferentes entre si, mas o resultado visual apresentado ao utilizador será sempre o mesmo. Concretamente, os valores dos atributos estáticos e a estrutura dos documentos HTML poderão ser modificados no servidor, criando assim versões polimorfas de uma página web. Estas transformações podem ser realizadas em tempo real no servidor ou pré-calculadas. Desta forma, nunca dois documentos HTML serão textualmente iguais, tornando as páginas em alvos em movimento, dificultando os ataques MitB. Este nível de proteção é necessário uma vez que todas as alterações da página realizadas pelo atacante são locais e portanto difíceis de detectar pelas estruturas de segurança e controlo implementadas nos servidores dos fornecedores dos serviços.Neste dissertação, pretende-se desenvolver uma ferramenta baseada em polimorfismo para proteger páginas web e os seus utilizadores dos ataques MitB que recorrem a âncoras do DOM. Esta ferramenta será avaliada em precisão e eficiência. A precisão será avaliada comparando a lista de erros e de avisos gerada pela navegador de Internet para a página original e as várias versões polimorfas produzidas, enquanto que a eficiência será calculada recorrendo a tentativas automáticas de alterações indevidas das páginas protegidas com a ferramenta desenvolvida.The number of Internet users keeps growing every year. Moreover, the Internet is becoming a daily tool, which impacts the individual's lives used either as a work tool or for entertainment purposes. However, by using it, people become possible targets for cyber attacks as they keep exchanging data, sometimes sensitive and private data, with remote servers.Among all the different attacks types, MitB is the reason behind the genesis of this thesis subject. MitB attacks are performed by a computer program running on user's computer that is commonly known as Malware, which has access to what happens inside a browser window. It can be a system library or even a browser extension programmed to, automatically, misrepresent the source code of the client-side server response, and other information stored in user's browsers. They rely on markup and DOM anchors to identify sections of a web page to attack. The end result of an attack will be dictated by the malware's ability to successfully identify the right location on the web page to perform the attack.Polymorphism is a broad concept that can be applied to web pages as a tool to both neutralize and defeat such kind of attacks, as documented by Shape Security, Inc. in 2014. Applying polymorphic techniques to web pages, the server response will be textually different between requests, but the visual display to the user will always be the same. That is, the values of static attributes and the structure of HTML documents may be modified on the server immediately before responses are sent off, creating a polymorphic version of the web page, or by pre-building this new versions on the server to decrease the real time computational costs. Therefore, no two HTML documents will be textually the same, turning web pages in somehow a moving target against MitB attacks. This level of protection is necessary since all changes are made locally, client side, making their detection difficult by control and security structures implemented on the service provider's servers.In this thesis, we aim to develop a tool based on polymorphism to protect web pages and users from MitB attacks based on markup and DOM anchors. This tool will be evaluated by accuracy and efficiency. The first metric will be evaluated by recording and comparing the list of errors and warnings generated by original web pages and by their polymorphic versions created with our tool. The efficiency will be evaluated by running automated attempts for tampering web pages protected by our tool

Ethanol extracts of mango as antioxidants for broiler chicken

O objetivo deste trabalho foi avaliar o efeito da inclusão de extratos etanólicos, obtidos do caroço e da casca da manga, na ração de frangos de corte sobre o seu desempenho e a oxidação lipídica da carne. Foram utilizados 360 pintos machos da linhagem Ross 308, de um dia de idade, distribuídos em um delineamento inteiramente casualizado, com seis tratamentos e seis repetições de dez aves. Os tratamentos consistiram de: ração sem adição de antioxidante (controle); ração com adição de 200 ppm do antioxidante butilato de hidroxitolueno (BHT); ração com 200 ou 400 ppm de extrato da casca da manga (ECAS); e ração com 200 ou 400 ppm de extrato do caroço da manga (ECAR). A adição de BHT ou dos extratos da manga não influenciou significativamente o consumo de ração, o ganho de peso e a conversão alimentar. A adição de BHT e 400 ppm de ECAR proporcionou maior estabilidade lipídica da carne fresca, mensurada pelas substâncias reativas ao ácido tiobarbitúrico antes do armazenamento. O extrato etanólico do caroço da manga, na dosagem de 200 e 400 ppm, retarda a oxidação lipídica da carne de frangos armazenada por 15 dias.The objective of this work was to evaluate the effect of the inclusion of ethanol extracts, obtained from mango seed and peel, in the diet of broilers on their performance and on the lipid oxidation of meat. Three hundred and sisty one‑day‑old male chicks of the strain Ross 308 were distributed in a completely randomized design, with six treatments and six replicates of ten birds. Treatments consisted of: diet without antioxidant (control); diet with addition of 200 ppm of the antioxidant butylhydroxytoluene (BHT); diet with 200 or 400 ppm extract of mango peel (ECAS); and diet with 200 or 400 ppm extract of mango seed (ECAR). The addition of BHT or mango extracts did not significantly affect feed intake, weight gain, and feed conversion. The addition of BHT and 400 ppm of ECAR provided low lipid oxidation in fresh meat, measured by thiobarbituric acid reactive substances before storage. Ethanol extract of mango seed, at 200 and 400 ppm dosage, delays lipid oxidation of chicken meat stored for 15 days

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

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Using taxonomically unbiased criteria to prioritize resource allocation for oceanic island species conservation

Copyright © Springer Science+Business Media B.V. 2010.Oceanic islands have been the grand stage of documented extinctions. In view of limited resources, efficient prioritization is crucial to avoid the extinction of taxa. This work lists the top 100 management priority species for the European archipelagos of the Macaronesian region (Azores, Madeira and the Canary Islands), taking into account both their protection priority and their management feasibility. Bryophytes, vascular plants, molluscs, arthropods and vertebrates were scored by species experts following two sets of criteria: (i) protection priority, including ecological value, singularity, public institutions’ management responsibilities and social value; (ii) management feasibility, including threats knowledge and control feasibility, external socio-economical support for management and biological recovery potential. Environmental managers weighted the same criteria according to their management importance. Final species scores were determined by the combination of both species valuation and criteria weighting. Vascular plants dominate the Top 100 list, followed by arthropods and vertebrates. The majority of listed taxa are endemic to one archipelago or even to a single island. The management feasibility criteria did not dictate that all taxa must be eminently endangered, as for most of the species it should be relatively easy to control threats. The main advantages of this process are the independent participation of scientists and conservation managers, the inclusion of criteria on both protection priority and management feasibility and the taxonomically unbiased nature of the process. This study provides a potentially useful biodiversity conservation tool for the Macaronesian archipelagos that could be readily implemented by the respective regional governments in future legislation