INTRODUÇÃO: Embora a mortalidade geral tenha diminuído na era da terapia antirretroviral de alta potência (TARVAP), o envolvimento do Sistema Nervoso Central (SNC) ainda é elevado nos pacientes com infecção pelo HIV. O estudo sobre possíveis correlações entre neuroinfecções, a presença de déficts neurocognitivos e o uso da TARVAP é importante para se avaliar os efeitos de longo prazo do tratamento com drogas antirretrovirais em uma população. Desta forma, são necessários estudos para se avaliar a neuropatologia da infecção pelo HIV e os efeitos do tratamento bem como a adesão ao mesmo. OBJETIVOS: Analisar a frequência e o tipo de infecções oportunistas e da infecção crônica pelo HIV no SNC na era pós-TARVAP, de pacientes necropsiados em um hospital universitário, no período de 2007 a 2014. Nestes casos, avaliar o substrato neuropatológico de pacientes com Aids e histórico clínico de demência. MATERIAIS E MÉTODOS: Foram analisados os achados dos exames neuropatológicos de 123 encéfalos de pacientes autopsiados com AIDS no Serviço de Patologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP/USP), seus dados clínicos e respectivos os laudos necroscópicos. RESULTADOS: Dos 123 casos analisados, 73 (59,3%) eram do sexo masculino e a média de idade foi de 40,56 anos. Destes, 69 (56,1%) tiveram neuroinfecções causadas por agentes oportunistas, sendo a neurotoxoplasmose a mais prevalente. Da correlação entre a contagem de células CD4 e o uso da TARVAP houve diferença significativa para uma delas, àquela que foi analisada como sendo a terceira mais próxima da data do óbito (p = 0,03). Apenas 6 pacientes fizeram uso regular da TARVAP no decorrer da doença e nenhum deles apresentaram neuroinfecções durante o tratamento. CONCLUSÕES: Podemos concluir que mesmo na era pós TARVAP as infecções no SNC causadas por agentes infecciosos permanecem presentes e no caso da população estudada podem estar correlacionadas com a baixa adesão ao tratamento. / RATIONALE: Although overall mortality has decreased in the era of highly active antiretroviral therapy (HAART), the involvement of the central nervous system (CNS) is still high in patients with HIV infection. The study of possible correlations between neuroinfections, the presence of neurocognitive payment deficits and the use of HAART is important to evaluate the long-term effects of treatment with antiretroviral drugs in a population. Thus, studies are needed to evaluate the neuropathology of infection by HIV and the treatment effects and it adhesion. OBJECTIVES: To analyze the changes caused by opportunistic infections and chronic HIV infection in the CNS in the post-HAART era of autopsied patients at a university hospital, from 2007 to 2014. In these cases, assess the neuropathologic of AIDS patients and clinical history of dementia. MATERIALS AND METHODS: The findings of neuropathological examinations of 123 brains of patients were analyzed autopsied AIDS in Hospital Pathology Service of the Clinics of Ribeirão Preto Medical School, University of São Paulo (HCFMRP / USP) clinical data and their postmortem reports. RESULTS: The 123 cases analyzed, 73 (59.3%) were male and the average age was 40.56 years. Of these 69 (56,1%) had neuroinfections caused by opportunistic agents, toxoplasmosis being the most prevalent. The correlation between CD4 cell count and use of HAART were no significant differences for one of them to that which was analyzed as being the closest third of the date of death (p = 0.03). Only 6 patients made regular use of HAART during the disease and none of them showed neuroinfections during treatment. CONCLUSIONS: We can conclude that even in the post HAART era CNS infections caused by infectious agents remain present and in the case of the studied population can be correlated with low adherence to the treatment.

Made available in DSpace on 2016-04-26T14:54:33Z (GMT). No. of bitstreams: 1 Cleber Jose de Toledo.pdf: 801722 bytes, checksum: a938546870d61a78f5b2459c45d48884 (MD5) Previous issue date: 2013-10-20 / This work is based on the political position changes of the unionists from Central Única dos Trabalhadores, from its begin in in 1983 until it has been recognized as citizen unionism activist in the nineties, more exactly since its V Congress in 1994. We will try to demonstrate all the process made by the Central and its metamorphoses, more specific the transformation of production, economy, politics and society that will really changes its political strategy in the union fight. Starting with a careful analysis of a consolidated bibliography, as well as the investigation of the congress resolutions that guided Central position s during the investigated period and the results of an interview made with Vicente Paulo da Silva (Vicentinho), a present Federal Representative, which is so important to reach the goal of this work. This way we will try to show the reader a study of internal and external causes that influenced Central s position during a very long period of its history, always trying to learn the totality of transformation process / Este trabalho tem por base o estudo das mudanças de posicionamento político da Central Única dos Trabalhadores (CUT) no período que compreende sua fundação, em 1983, até sua inserção na prática que ficou conhecida como sindicalismo cidadão na década de 1990, mais precisamente a partir de seu V Congresso em 1994. Procuraremos demonstrar o percurso percorrido pela central e seu processo de metamorfose que o acompanha, inserido nas transformações de ordem produtiva, econômica, política e social que mudarão substantivamente a condução de suas estratégias políticas na luta sindical. Partiremos da análise de um já consolidado aparato bibliográfico, bem como da investigação das resoluções congressuais, que nortearam o posicionamento da central, durante o período investigado, em conjunto com os resultados de uma pesquisa realizada com o atual deputado federal Vicente Paulo da Silva (Vicentinho), de fundamental importância ao objetivo deste trabalho. Assim, expor ao leitor um estudo conjugado de fatores endógenos e exógenos que influenciaram no posicionamento da central durante boa parte de sua história, na tentativa de apreender o processo de transformação em sua totalidade

在機會網路上，傳遞資料遠比一般網路困難。運用行動代理人於機會網路上， 可大幅提升機會網路的功能，其中的行動代理人平台，需要一個代理人的搜尋 機制，方能實現對代理人的控制。本篇論文以「山文誌登山資訊系統」為背景，探討行動代理人在機會網路上的應用。在此登山客追蹤與環境監控系統中，每個登山客都攜帶一個配備有 GPS 功能的小型設備，此設備會在登山客的移動過程中，自動收集位置資訊，並使用短程無線電來和鄰近的登山客交換彼此的資訊。由於行動代理人是附屬於登山客所攜帶的設備上，而且當靠近其他登山客時，才可藉此轉移到另一個設備，故其行動力受制於登山客的移動行為。因登山客行走速率差異不大、所在位置分佈不均，使得行動代理人的轉移極為緩慢且需仰賴不確定的碰面機會，導致行動代理人之搜尋效率極低，無法支援緊急任務。為此，我們提出控制網路的方法，及一個簡單的搜尋演算法，讓搜尋代理人藉此高速網路來快速移動，以提高目標代理人的搜尋效率。在不同的考量及目標下，我們提出幾個控制網路的建置模型，並在證明其為 NP-complete問題後，提出有效的啟發式演算法來解決此控制點選擇問題。 / Transmitting data on an opportunistic network is much more difficult than that on a general network. The communication capability of an opportunistic network can be greatly enhanced via mobile agent functionality. A mobile agent platform demands a search mechanism to locate and control its agents. In this thesis, we investigate the adoption of mobile agent to opportunistic networks using "CenWits" system as reference model. In CenWits system, each hiker carries a GPS enabled sensor node to collect and exchange movement statistics with its fellow hikers using a short range wireless links. Since mobile agents will be attached to the sensor nodes that hikers carry with, mobile agents can hop from one host to another only when two hosts (hikers) meet together such that their mobility is restrained by the moving behavior of hikers. The little difference in walking speed and the uneven distribution of hikers make the hopping of mobile agents extremely slow and opportunistic. As a consequence, the search of mobile agents is slow and inefficient crippling agility of urgent agent functionality. Therefore, we propose to construct a control network using high speed network for search agents to travel in high speed. Under different objectives and constraints, we propose several control point placement models. After proving them to be NP-Complete, we propose few efficient heuristic algorithms to solve the placement problem. We also propose a simple search algorithm for search agents to search target agents quickly by using a control network.

在機會網路上，訊息的遞送遠比一般網路來得困難許多，溝通交換資訊效率很低。本篇論文以山文誌資訊系統為背景，假設在山區中已佈建完成控制節點並組成控制網路，以及行動代理人機制已導入在控制網路上用來搜尋移動的目標節點。其中行動代理人附屬於登山客所攜帶的設備上，欲搜尋的目標節點會沿著登山路徑不斷移動造成搜尋上的困難，若搜尋失敗不只拉長延後了搜尋時間，也可能錯失黃金救難時間造成極大的損失，如何增進搜尋效率是機會網路上相當重要的議題。為此，本文提出一個搜尋方法，在任意的時間點計算目標行動節點落在每個控制節點之間路段的機率，預測目標代理人的位置，就可依機率高低逐次搜尋各路段，以提高搜尋效率。我們以山文誌登山資訊系統，作為參考的機會網路，提出兩個模型，使用機率預測搜尋法，預測行動節點可能所在位置優先搜尋此路段來降低整體搜尋時間，透過一連串的實驗驗證機率模型之準確度，並評估本法之搜尋效率以及當各路段花費時間的機率分佈假設有誤時，搜尋效率的受損程度。在我們的實驗中，機率模型之準確度極高，誤差不超過7.59%，搜尋效率都在44.44以上，即使機率分佈錯誤，搜尋效能仍高於二分搜尋法約2倍。 / Since transmitting data on an opportunistic network is more difficult than that on a general network, information exchanging is less efficient. Based on “CenWits” system, we assume that control point has entirely construed all over the mountains and a control network has completed altogether; meanwhile, the mobile agent mechanism has applied in the searching of mobile target nodes. With mobile agent attached on the equipment of hikers, the target agent moving constantly along the hiking path grows the difficulties in searching. The failure in locating the mobile agent possibly not only prolongs the searching time, but also misses the golden time of life saving, and causes enormously damages eventually. Therefore, figuring that “improving the efficiency of searching” is a major issue in opportunistic network, in this thesis we develop a searching method which enables us to calculate the probability where a mobile target agent locates in every edge between control points in any arbitrary time point. Through forecasting the location of the target agent, we can start searching from the edge with the highest probability, thus enhance the efficiency of searching. Using “CenWits” system as reference opportunistic network, we designed two probability models as well as associated search methods. We conducted a series of experiments to evaluate the accuracy of probabilistic models and the performance of the proposed search methods. In our experiments, the error of probability models is no more than 7.59%. Our proposed methods out perform Basic Binary Search by 44.44 in average. Furthermore, assuming that there is a discrepancy between the probability assumptions and the real distribution of the traveling time spent on each edge, we evaluate the performance degradation too. The experimental results show that under such circumstance, our Probabilistic Prediction Method can even outperform Basic Binary Search by approximately 200%.

Mobile communication devices may be used for spreading multimedia data without support of an infrastructure. Such a scheme, where the data is carried by people walking around and relayed from device to device by means of short range radio, could potentially form a public content distribution system that spans vast urban areas. The transport mechanism is the flow of people and it can be studied but not engineered. We study the efficiency of pedestrian content distribution by modeling the mobility of people moving around in a city, constrained by a given topology. The model is supplemented by simulation of similar or related scenarios for validation and extension. The results show that contents spread well with pedestrian speeds already at low arrival rates into a studied region. Our contributions are both the queuing analytic model that captures the flow of people and the results on the feasibility of pedestrian content distribution. / <p>QC 20130109</p>

Thanks to their increasing sophistication and popularity, mobile devices, in the form of smartphones and tablets, have become the fastest growing contributors to Internet traffic. Indeed, smartphones are projected to account for 50% of global Internet traffic by 2017, with the share of mobile video increasing to about 40% of total Internet traffic. As users embrace Internet streaming of video, several studies have found that a small decrease in video quality leads to a substantial increase in viewer abandonment and disengagement rates. To handle the explosive growth in video traffic, Adaptive HTTP streaming, which exploits the prevalence of commodity web servers and content distribution networks, has emerged as the key technology for delivering video to end users. Although a number of systems have been proposed for HTTP video streaming in traditional environments and for fixed clients, existing platforms for video streaming on mobile devices are still in their infancy and do not address the additional challenges often experienced by mobile clients: high fluctuations in network conditions, heterogeneous networking interfaces, multiple form-factors, and limited battery life. In this dissertation, we propose a number of solutions for improving the Quality of Experience of HTTP video streaming on mobile devices. We begin by evaluating the performance of several existing video quality adaptation schemes when deployed on mobile platforms. Through experiments with smartphones in wide-area environments, we assemble several key findings. First, we show that the high fluctuations in network throughput on cellular and Wi-Fi networks impose significant challenges for efficiently architecting the video adaptation scheme. Second, we find significant differences between the performance of the current state-of-the-art schemes in controlled experimental settings and their performance in mobile settings on key quality metrics such as inefficiency, instability, rebuffering ratio, and startup latency. We also find noticeable differences in the behavior of the schemes under Wi-Fi and cellular network access, with most of the schemes performing worse when the network access is cellular. Given these observations, we hypothesize on the possible causes of these inefficiencies. We also identify the best practices of existing schemes and key insights from experimental results that can serve as foundations for addressing many of the limitations. Armed with these measurement-driven insights, we propose a novel video quality adaptation scheme, called MASS, which is more robust to the vagaries of the wireless networking conditions. We implement and evaluate our solution on commodity Android smartphones, and demonstrate significant performance gains over existing schemes. To further improve the streaming experience, we introduce an extension to HTTP video streaming that leverages the synergy between social network participation and video streaming to optimize end-user Quality of Experience. Our system, called SDASH, integrates and applies well-known concepts such as cooperative caching, prefetching, and P2P streaming for reducing bitrate fluctuations and optimizing the viewing experience. Finally, we develop a general infrastructure for constructing temporally and spatially localized P2P communities of mobile devices sharing similar interests. The platform enables on-demand cooperation among mobile clients based on device context and client preferences. We use a concrete implementation of the mobile P2P infrastructure for evaluating the performance of SDASH. This dissertation addresses the challenges facing Adaptive HTTP Streaming under mobile networking conditions. Through experimentation with commodity mobile devices, we show that the proposed techniques for bitrate adaptation and cooperative streaming can significantly improve the video viewing experience.

Ultrawideband and cognitive radio are two of the most important approaches that are shaping the future of wireless communication systems. At a first glance, the aims of UWB and cognitive radio do not seem to be overlapping significantly, however, there is a strong synergy between the capabilities of UWB and the goals of cognitive radio. One of the objectives of this thesis is to shed the first light on the marriage of these two important approaches.Ultrawideband (UWB) is a promising technology for future short-range, high-data rate wireless communication networks. Along with its exciting features including achieving high data rates, low transmission power requirement, and immunity to multipath effects, UWB is unique in its coexistence capability with narrowband systems.In this thesis, the details of practical UWB implementation are provided. Regarding the coexistence of UWB with licensed narrowband systems, narrowband interference (NBI)avoidance and cancelation techniques in the literature are investigated. It is aimed to emphasize that UWB is a strong candidate for cognitive radio, and this fact is proven by providing two different approaches in which ultrawideband is combined with cognitive radio to maximize the performance of unlicensed communications.

Device-to-device communication has been suggested as a complement to traditional cellular networks as a means of offloading cellular traffic. In this thesis we explore a solution for device-to-device communication based on opportunistic content distribution in a content-centric network. Communication opportunities arise as mobile nodes roam around in an area and occasionally enter in direct communication range with one another. We consider a node to be a pedestrian equipped with a mobile device and explore the properties of opportunistic communication in the context of content dissemination in urban areas. The contributions of this thesis lie in three areas. We first study human mobility as one of the main enablers of opportunistic communication. We introduce traces collected from a realistic pedestrian mobility simulator and demonstrate that the performance of opportunistic networks is not very sensitive to the accurate estimation of the probability distributions of mobility parameters. However, capturing the space in which mobility occurs may be of high importance. Secondly, we design and implement a middleware for opportunistic content-centric networking, and we evaluate it via a small-scale testbed, as well as through extensive simulations. We conclude that energy-saving mechanisms should be part of the middleware design, while caching should be considered only as an add-on feature. Thirdly, we present and evaluate three different energy-saving mechanisms in the context of opportunistic networking: a dual-radio architecture, an asynchronous duty-cycling scheme, and an energy-aware algorithm which takes into account node selfishness. We evaluate our proposals analytically and via simulations. We demonstrate that when a critical mass of participants is available, the performance of the opportunistic network is comparable to downloading contents directly via the cellular network in terms of energy consumption while offloading large traffic volumes from the operator. / <p>QC 20151120</p>

Blacks are more affected by Human Immunodeficiency Virus (HIV)/Acquired Immunodeficiency Syndrome (AIDS) than any other race or ethnicity in the United States. The purpose of this dissertation was to investigate potential race-based differences in cardiovascular disease (CVD)-related hospitalizations and use of opportunistic infection (OI) prophylaxis between Blacks and Whites with HIV/AIDS. This dissertation includes two systematic literature reviews that identified knowledge gaps in the areas of CVD diagnosis and OI prophylaxis use between Blacks and Whites with HIV/AIDS, as well as two independent studies that addressed some of the gaps identified in the literature. The first study evaluated the association between race and CVD-related hospitalization in Blacks and Whites with HIV/AIDS. Data were retrieved from the 1996-2008 National Hospital Discharge Surveys (NHDS). Approximately 1.5 million hospital discharges were identified. After controlling for confounders, the odds of CVD-related hospitalization were 45% higher for Blacks than Whites (OR=1.45, 95% CI, 1.39-1.51). There was a statistically significant difference in the proportions of CVD-related hospitalization type and race (x2=479.77; df=3; p<0.001). Compared to Whites with HIV/AIDS, Blacks with HIV/AIDS had greater proportions of heart failure and hypertension, but lower proportions of stroke and coronary heart disease. These results suggest that there is an influence of race on both the occurrence and type of CVD-related hospitalizations in patients with HIV/AIDS. The second study assessed if race was associated with the use of OI prophylaxis (Pneumocystis jiroveci pneumonia [PCP] and Mycobacterium avium complex [MAC]). Data for this study were retrieved from the 1996-2008 National Hospital Ambulatory Medical Care Surveys (NHAMCS). Approximately 9.1 million hospital ambulatory visits were identified. After controlling for confounders, the odds of PCP prophylaxis use were 16% higher for Blacks than for Whites (OR=1.16, 95% CI, 1.15-1.17). In a separate regression analysis, the odds of MAC prophylaxis use were 12% higher for Blacks than for Whites (OR=1.12, 95% CI, 1.10-1.13). These findings suggest that Blacks with HIV/AIDS may have increased odds for OI prophylaxis. Based on this work, there is a need for further research to confirm these findings and to identify the causes of these race-based disparities. / text

The wireless medium is lossy due to many reasons, such as signal attenuation, multi-path propagation, and collisions. Wireless losses degrade network throughput, reliability, and latency. The goal of this dissertation is to combat wireless losses by developing effective techniques and protocols across different network layers. First, a novel opportunistic routing protocol is developed to overcome wireless losses at the network layer. Opportunistic routing protocols exploit receiver diversity to route traffic in the face of loss. A distinctive feature of the protocol is the performance derived from its optimization can be achieved in real IEEE 802.11 networks. At its heart lies a simple yet realistic model of the network that captures wireless interference, losses, traffic, and MAC-induced dependencies. Then a model-driven optimization algorithm is designed to accurately optimize the end-to-end performance, and techniques are developed to map the resulting optimization solutions to practical routing configurations. Its effectiveness is demonstrated using simulation and testbed experiments. Second, an efficient retransmission scheme (ER) is developed at the link layer for wireless networks. Instead of retransmitting lost packets in their original forms, ER codes packets lost at different destinations and uses a single retransmission to potentially recover multiple packet losses. A simple and practical protocol is developed to realize the idea, and it is evaluated using simulation and testbed experiments to demonstrate its effectiveness. Third, detailed measurement traces are collected to understand wireless losses in dynamic and mobile environments. Existing wireless drivers are modified to enable the logging and analysis of network activity under varying end-host configurations. The results indicate that mobile clients can suffer from consecutive packet losses, or burst errors. The burst errors are then analyzed in more detail to gain further insights into the problem. With these insights, recommendations for future research directions to mitigate loss in mobile environments are presented. / text