In this paper, we concentrate on computing several critical budgets for interdiction of the multicommodity network flows, and studying the interdiction effects of the changes on budget. More specifically, we first propose general interdiction models of the multicommodity flow problem, with consideration of both node and arc removals and decrease of their capacities. Then, to perform the vulnerability analysis of networks, we define the function F(R) as the minimum amount of unsatisfied demands in the resulted network after worst-case interdiction with budget R. Specifically, we study the properties of function F(R), and find the critical budget values, such as , the largest value under which all demands can still be satisfied in the resulted network even under the worst-case interdiction, and , the least value under which the worst-case interdiction can make none of the demands be satisfied. We prove that the critical budget for completely destroying the network is not related to arc or node capacities, and supply or demand amounts, but it is related to the network topology, the sets of source and destination nodes, and interdiction costs on each node and arc. We also observe that the critical budget is related to all of these parameters of the network. Additionally, we present formulations to estimate both and . For the effects of budget increasing, we present the conditions under which there would be extra capabilities to interdict more arcs or nodes with increased budget, and also under which the increased budget has no effects for the interdictor. To verify these results and conclusions, numerical experiments on 12 networks with different numbers of commodities are performed.

Since 2004, the number of people living with HIV (PLWH) has steadily increased by about 5% and currently, the number in Texas is about 86,000. Though the National HIV/AIDS Strategic Plan seeks to ensure “unfettered access to quality healthcare”, barriers to access still exist especially among minority populations. This study examines the relationship between HIV infection rates and the geographic location of HIV service centers with a focus on 4 counties: namely, Dallas, Denton, Harris and Tarrant. The goal is to show whether there is a spatial mismatch between HIV rates and service providers. Are service facilities located in zip codes where they are most needed? Using the vulnerability framework and the Inverse Care Law (ICL), we address the research question using demographic variables (race/ethnicity, sex, poverty, education attainment) and HIV data. Our results show that extreme vulnerable zip codes have high HIV rates and closest proximity to HIV service providers.

The aim of this research is to examine the contextual environment in which farmers operate so as to improve our understanding of the factors shaping vulnerability to climate risk. A key focus is on the livelihoods of sugarcane farmers, using a case study of small-, medium-scale (emerging) and large-scale sugarcane farmers in the KwaZulu-Natal Midlands area of Eston and its surrounds. A social vulnerability assessment was undertaken under the Sustainable Livelihoods Framework (SLF) to test the hypothesis that climate risk is considered a major contributing factor to the vulnerability of commercial farmers in KwaZulu-Natal and needs to be effectively managed. This involved an investigation into the multiple stresses (both external and internal, on-farm and off-farm, climatic and non climatic) acting on the system. It is clear that climate change risk and variability is a major, but not the sole contributing factor to the vulnerability of commercial farmers in this part of KwaZulu-Natal. Climate change does need to be effectively managed but it will be best done in conjunction with the management of the other multiple and interacting threats and stresses identified in this study. Climate change and vulnerability, as well as the other multiple stresses, are acting on an already vulnerable system, exacerbating and compounding present risks. This research also explored a number of coping and response strategies that commercial farmers have adopted in response to the threats and stresses and investigated particularly, what elements enhance or restrict these strategies (both on-farm and off-farm). These strategies posses potential as possible future adaptation options. It was found that the issues of access to livelihood assets (social, financial, natural/environmental, physical, human, knowledge assets and capital under the SLF) are key to the adaptive capacity and the adaptation strategies that farmers employ. Institutions (both formal and informal) play a pivotal role in this access to livelihood assets both enabling and restricting access. In conclusion, this work determined that a focus on only one element, such as climate change, will not significantly reduce the vulnerability of commercial farmers. There is an interactive, dynamic and multifaceted network present with a number of factors acting within and from outside the system. Political, biophysical, social and economic factors interact and combine to compound vulnerability, requiring more integrative and multiple response strategies.

Atualmente, estimativas da Organização das Nações Unidas para Prevenção e Controle da Aids (UNAids), apontam para a existência de mais de 40 milhões de soropositivos no mundo. Sendo a adolescência uma fase que se caracteriza pela expressão mais efetiva da sexualidade e dos impulsos sexuais em função da maturidade sexual, estes vêm constituindo-se grupo prioritário nas ações de prevenção. Nesse contexto, a Coordenação Nacional de Doenças Sexualmente Transmissíveis/AIDS (CN-DST/AIDS) e o Ministério do Exército do Brasil, firmaram em 1996, um convênio visando ações na área de Infecções Sexualmente Transmissíveis (IST)/aids junto às Forças Armadas. O presente estudo objetivou investigar e compreender aspectos relacionados à vulnerabilidade às IST/aids entre atiradores do serviço militar obrigatório, bem como caracterizar a população nos aspectos pertinentes às condições socioeconômicas, práticas sexuais, ocorrência de IST e prevenção às IST/aids, com vistas a uma apreciação sociocomportamental. Para tanto o presente estudo constitui-se do tipo survey, o qual permite a obtenção de informações quanto à prevalência, distribuição e inter-relação de variáveis no âmbito de uma população. Dentre os resultados, destacam-se: 36,5% com idade de 18 anos; 64,7% com segundo grau de escolaridade completo; 23,5% pertencem aos estratos sociais “C" e “D"; 88,2% referem já ter vivenciada a primeira relação sexual; 53,3% não fizeram uso do preservativo na última vez que praticaram coito oral; 28% não utilizaram preservativo na última vez que praticaram coito vaginal ou anal; 3,5% já apresentaram corrimento, feridas, verrugas ou bolhas em seus órgãos genitais; 56,5% desejam receber orientações sobre IST/aids de profissionais de saúde; 54,1% consideram o fato de manter relações sexuais com quem confiam uma barreira no uso do preservativo; 71,8% percebem como sendo nula ou baixa a vulnerabilidade pessoal ao HIV. Os dados sociocomportamentais apresentados demonstram a vulnerabilidade às IST/aids entre os atiradores estudados, assim evidenciando a necessidade de ações de educação em saúde junto aos mesmos. / Nowadays, the estimations of the United Nations Agency on Aids show the existence of more than 40 million persons infected in the world. As the adolescence is the phase characterized by the most effective expression of sexuality and sexual impulses in the function of sexual maturity, the prevention actions prioritize this group. In this sense, the National Coordination for Sexually Transmitted Diseases/AIDS (CN-DST/AIDS) and the Brazilian Army established in 1996 an agreement with the purpose to develop actions in the area of Sexually Transmitted Infections/aids with the Brazilian Forces. This study aimed to examine and understand aspects of vulnerability to STI/aids among shooters in obligatory military service, as well as to characterize the population with respect to socio-economic conditions, sexual practices, occurrence of STI and prevention of STI/aids, with a view to obtaining a socio-behavioral evaluation. Hence, this survey allowed us to collect information on the prevalence, distribution and interrelation among variables in the sphere of a population. Results showed: 36.5% are 18 years old; 64.7% completed high school; 23.5% are from “C" and “D" social classes; 88.2% have had their first sexual intercourse; 53.3% did not use preservatives during their last oral sex ; 28% did not use preservative in their last vaginal or anal intercourse; 3.5% already presented discharge, wounds, warts or blister in their genital organs; 56.5% would like to receive orientations on STI/aids from health professionals; 54,1% consider that the fact that they maintain sexual intercourse with some one they trust is a barrier to use preservatives; 71.8% perceive as zero or low their personal vulnerability to HIV. The socio behavioral data showed a vulnerability to STI/aids among the shooters studied, confirming the need for health education directed to them.

Orientador: José Augusto de Lollo / Resumo: A erosão, especialmente do tipo acelerada, é um fenômeno com grande potencial de causar degradação ambiental, diminuindo a produção de alimentos, provocando a desertificação de áreas, o assoreamento de rios, o deslizamento de solo, entre outros. Dessa forma, o estudo dos processos erosivos e suas consequências é de fundamental importância em diversas áreas do conhecimento, exatamente para que possam ser propostas formas de remediar os casos já existentes e prevenir possíveis próximas ocorrências. Dentre os tipos de erosão existentes destaca-se a hídrica, e os parâmetros envolvidos nesse cenário podem ser diversos, envolvendo tanto fatores naturais, como as propriedades do solo, o clima e o relevo, quanto antropogênicos, como a ocupação do solo e técnicas de manejo. Além disso, uma ferramenta muito utilizada nos estudos de suscetibilidade à erosão é o SIG, ou Sistemas de Informações Geográficas, devido à sua capacidade de armazenar, manipular, analisar e apresentar dados distribuídos espacialmente e georreferenciados. O uso dessa ferramenta proporciona tanto a melhora na precisão dos valores obtidos, quanto diminui o tempo consumido durante os cálculos. Assim, o objetivo deste trabalho foi avaliar os resultados de diferentes abordagens de avaliação do potencial de ocorrência de erosão na Bacia Hidrográfica do Córrego do Jaú, em Aparecida D’Oeste – SP, envolvendo diversos parâmetros naturais e antrópicos, e utilizando sistemas de informações geográficas, de forma a verificar a ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Erosion, especially the accelerated type, is a phenomenon with high potential to cause environmental degradation, declining food production, causing desertification of areas, siltation of rivers, landslides, among others. Thus, the study of erosion and its consequences is of fundamental importance in many areas of knowledge, so that ways to remedy existing cases of it and prevent possible subsequent occurrences can be proposed. Among the existing types of erosion, the one caused by water stands out, and the parameters involved in this scenario may be diverse, involving both natural factors, such as soil properties, climate and relief, and anthropogenic ones, such as soil occupation and management. In addition, a tool widely used in erosion susceptibility studies is GIS, due to its ability to store, manipulate, analyze and present spatially distributed and geo-referenced data. The use of this tool provides both the improvement in the accuracy of the values obtained and the reduction of time consumed during calculations. So, the objective of this study was to evaluate the results of different approaches to assess the potential for erosion occurrence in the Córrego do Jaú watershed, in Aparecida D'Oeste – SP, involving several natural and anthropic parameters, and using geographic information systems, in order to verify the applicability of these methods in the study basin. For the proposed study, the methods of the Natural Vulnerability to Erosion (VNE) and adaptations of the U... (Complete abstract click electronic access below) / Mestre

A estimativa da vulnerabilidade natural de aqüíferos é uma das primeiras tarefas a ser realizada para o planejamento, controle e prevenção da qualidade das águas subterrâneas e criação de perímetros de proteção para as mesmas. Nesse estudo o modelo GOD (G - groundwater confinement, O - overlay strata e D - depth to groundwater) (FOSTER et al. 1998) foi adotado para a estimativa da vulnerabilidade natural dos aqüíferos pertencentes à Unidade de Gerenciamento dos Recursos Hídricos do Estado de São Paulo das Bacias Hidrográficas dos Rios Piracicaba, Capivari e Jundiaí, sendo realizada uma extensa pesquisa sobre as características fisiográficas e ambientais da área de estudo, e critérios hidrogeológicos adotados para a estimativa de vulnerabilidade de aqüíferos. O modelo GOD utiliza como parâmetros o tipo de confinamento da água subterrânea, a litologia da zona vadosa e a profundidade do nível da água. Para a elaboração do respectivo mapa, foram adotados como base de dados o Mapa Geológico do Brasil ao Milionésimo (CPRM, 2004) e o Mapa de Águas Subterrâneas do Estado de São Paulo (DAEE, IG, IPT e CPRM, 2005). Apesar da notoriedade do modelo GOD e de sua extensa aplicação no Brasil e América Latina, foi sugerido ao final dessa pesquisa a inclusão da pluviometria como quarto parâmetro a ser considerado ao modelo GOD para a elaboração de mapas de vulnerabilidade em escalas inferiores a 1:250.000. Como incremento à pesquisa acadêmica, foram aplicados métodos geoestatíscos como a krigagem residual para a interpolação dos dados de elevação de cinco imagens SRTM, a análise de regressão múltipla dos índices pluviométricos anuais obtidos pelas estações pluviométricas do DAEE presentes na região e, a krigagem com deriva externa dos dados de saída da análise de regressão múltipla. Os mapas de vulnerabilidade, assim como as figuras dos resultados da krigagem residual das imagens SRTM e krigagem por deriva externa dos índices pluviométricos médios anuais, foram desenvolvidos utilizando o software específico para integração de Sistemas de Informação Geográfica SIG. / The natural aquifer vulnerability estimative is one of the primary tasks to be accomplished for a groundwater planning, control and prevention program, that would for example aim a protection perimeter design for human use or environmental protection. In this study the GOD model (G from groundwater confinement; O from overlay strata; D from depth to groundwater) (FOSTER et al. 1998) was applied for the natural groundwater vulnerability estimative of Sao Paulo State Water Resource Management Unit of the Hydraulic Basins of Piracicaba, Capivari and Jundiaí. An intensive bibliographic research related to physiographic and environmental characteristics from the researched area, and hydrogeologic criteria used for aquifer vulnerability estimative were also included. The GOD model uses as parameters the type of groundwater confinement, the vadoze zone representative litology and depth to groundwater in meters. To perform the estimative analysis and map elaboration the Brazilian Geologic Map 1:1.000.000 (CPRM, 2004) and the Sao Paulo State Groundwater Map (DAEE, IG, IPT and CPRM, 2005) were used as input database. In spite of the fact that the GOD model is well known and have been extensively applied both in Brazil and South America, it was suggested in this study the insertion of a pluviometric index as a fourth parameter to be considerate in the GOD model, for a groundwater vulnerability estimative in scales lower than 1:250.000. As an increment for academic research, it was also applied geostatistic methods as residual krigage of five SRTM images, multiple regression analysis of annual mean pluviometric data obtained from DAEEs pluviometric stations and, krigage with external derivation from the multiple regression analysis output data. All maps, figures and GOD model input data were developed, designed and analyzed using specific software for Geographic Information System integration, better known as GIS.

Helen Post (1907-1978) was a twentieth century American photographer, whose images of the Navajo offer sensitive insight into the lives of individuals residing on the reservation from 1938-1942. An employee at the time for the Bureau of Indian Affairs, Post traveled to the West on numerous excursions, each time gaining perspective and understanding into the intricacies of Native life. Her ability to portray the Navajo in unguarded and intimate moments stands as a significant contribution to discourse on visual records of American Indians. Examining Post's work provides an opportunity to not only reexamine her work, which has largely been overlooked, but also acknowledge misrepresented facets of the Navajo. Unlike other well-known white photographers working prior to and concurrent with Post, she avoided portraying her sitters in the common tropes, instead choosing to humanize the Navajo. Theoretically this examination utilizes Post-colonial theory in order to better understand Post's position as both outsider and friend to her sitters. It also explores the social interactions and cultural differences between photographer and subject. She emphasized rather than neglected the many complexities evident among the Navajo in the late 1930s to early 1940s. Post documented the effects of crucial reform policies and by so doing comprised a poignant collection of images. In her photographs of the Navajo, one sees a celebration of character and emotion, underscored by the simplicity of Post's thoughtful compositions. As stated by John Collier, Sr., Post's employer and former commissioner of the Bureau of Indian Affairs, Post was one who, "willed above all that the Indian spirit... should live on."

Climate change and extreme weather events are affecting the environment, and people’s livelihood in both developing and developed countries. Agriculture, forestry, fishing, livestock, water resources, human health, terrestrial ecosystems, biodiversity, and coastal zones are among the major sectors impacted by these shocks. The challenge of adaptation is particularly acute in the developing countries, as poverty and resource constraints limit their capacity to act. Bangladesh fits in this category, and thus I use data from Bangladesh to analyze the adaptation process in the first and second chapter of my dissertation. In the first chapter, I investigate whether transient shocks (flood, cyclone) or permanent shocks (e.g., river erosion that leads to permanent loss of lands) have more influence on interregional migration. Findings of the study suggest that the households prefer to move to the nearest city when the environmental shock is temporary, whereas they tend to relocate over a greater distance when the environmental shock is more permanent in nature. In the second chapter, I investigate the feasibility of a set of adaptation measures to cope with hydro-climatic shocks (e.g. floods, drought, cyclones, tidal waves) and epidemic shocks (emergence or re-emergence of infectious diseases on livestock and poultry) in the agricultural sector in Bangladesh. Findings suggest that a decrease in agricultural income due to climatic and/or epidemic shocks is likely to induce households to adapt more. Developed countries are also vulnerable to extreme weather events and climatic shocks. In 2017, United States was hit by three consecutive hurricanes: Harvey, Irma, and Maria. Given the rising exposure and the increasing need to manage coastal vulnerability, the third essay focusses on understanding household preferences for financing adaptation activities in the U. S. and analyzes which mechanism, i.e., state or federal adaptation fund approach, is better suited to managing exposure to such types of natural disaster in the future.

Hurricane Sandy made landfall in Brigantine, New Jersey on October 29th, 2012. The storm impacted the coastal regions of New Jersey and New York, especially the heavily populated area of New York City. This research, which analyzes secondary data obtained from a telephone survey, investigates the public response of residents before, during and after Hurricane Sandy. The survey consisted of questions regarding what the residents expected concerning the threat of Hurricane Sandy, whether it matched what they experienced, where they got their information and how they made their decision to evacuate or not. The results from the survey were statistically analyzed in order to answer important research questions about public perception of Sandy's impacts. A Vulnerability Assessment of New York City, where some of Sandy's impacts were felt the most, was completed in order to understand why this area was so vulnerable. The concern level of various hurricane related hazards was analyzed and correlated to demographic variables to determine a relationship among the variables. A qualitative analysis was performed on the survey questions "Why did you evacuate?" and "Why did you not evacuate?" in order to determine themes in relation to people's reasons for evacuating or not evacuating. Finally, differences in how the public perceived Hurricane Sandy before and after the storm were analyzed and may be used for improving communication of the forecast to the public. Interdisciplinary research in this area is needed in order to better understand the public's need for appropriate warnings to ensure safety. Results show that residents were most concerned about wind damage and that they mainly used their television to obtain their information about the storm. Also, the most common reasons respondents reported for evacuating were because of the threat of possible impacts (storm surge, flooding, wind, rain and waves), the forecast called for bad conditions, or being told, recommended or convinced to leave. The main reasons reported by respondents for not evacuating are thinking that the impacts would not be bad in their area, feeling prepared or safe and thinking they could handle the impacts. This research can be used in the future for improving hurricane warning communication to the public.

Flooding is a natural phenomenon and in the past Thai people have adapted to flood events. However over the years land degradation, deforestation and bad urban practices have exacerbated the impact of flood disasters. This study of flood management in Thailand shows how human activities and interventions have impacted on the river basin system. This research focuses on the vulnerability to flood hazard of the people living or working near the Chao Phraya River. The case study is of the community living or working in the proximity of Wat Bang Luang (Bang Luang Temple) of the Pathum Thani Province, Thailand. This research explores the capacity of communities to live with or cope with floods. Their adaptations to changes in flood regimes will depend on several factors: political (especially when Thailand has a long history of preoccupation with engineering and technological solutions as the main approach to disaster response), economic, ecological (human modification to flood plains), social (kin-based networks) and cultural factors. The data collected from the target community showed a power struggle between Thai culture and the dominant hazard management paradigm. This research put a human face on natural disaster and looked at the issue of flooding from the experiences of ordinary people. The findings showed that some members of the community are resilient while others are passive and are more vulnerable to floods. However, it is important not to label any individual or group as either vulnerable or resilient as people can be both at the same time and policy makers need to build on the strengths, rather than focus on the weaknesses and on offering emergency relief.