Income shocks and HIV in Sub-Saharan Africa:

Poverty is commonly cited as a key driver of the HIV/AIDS epidemic, yet little causal evidence exists linking economic conditions to actual disease outcomes. Using data on more than 200,000 individuals across 19 Sub-Saharan African countries, we present evidence that negative income shocks can lead to substantial increases in HIV prevalence, particularly for women in rural areas. Building on recent work showing that income shortfalls can induce some women to engage in higher-risk sex, we match data on individuals' HIV status from the Demographic and Health Surveys to data on recent variation in local rainfall, a primary (and exogenous) source of variation in income for rural households in Africa. We find that infection rates for women (men) in HIV-endemic rural areas increase significantly by 14 percent (11 percent) for every drought event experienced in the previous 10 years. Further analysis suggests that women most affected by the shocks (that is, those engaged in agriculture) are driving the women's results; these women are partnering with men least affected (those employed outside agriculture). Our findings suggest a role for formal insurance and social safety nets in tackling the HIV/AIDS epidemic.HIV/AIDS, Income shocks,

Internet and ITC Use Among Agricultural SMEs: Evidence from Hawaii

Much of the SME research examining adoption and use of Internet and information and communication technologies (ICT) to date has argued that firms adopt and use the Internet and related ICTs to different extents depending on firm size, industry type and CEO education. To understand these issues studies tend to compare firms across industry sectors. The results though are mixed. Moreover, only a small percentage of SME ICT studies target agricultural firms. The study presented here surveyed SME farm operators in a narrow set of grower/producer sectors. Results indicate wide use of computers and the Internet, especially for functions like email, online purchasing, and online business-related research. Website ownership is less widespread. The study also surveyed the firms about their use of emerging social technologies like instant messaging, chat, blogs, etc. Perceptions of ICT benefits and reasons for not investing in them are discussed. Implications for future research and farm operators are also discussed

AN ANALYSIS OF ALBERTA\u27S FIRST NATIONS, METIS, AND INUIT SCHOOL-COMMUNITY LEARNING ENVIRONMENT PROJECT

The First Nations, Métis, and Inuit School-Community Learning Environment Project was one of the programs through which the Aboriginal Branch of Alberta Education attempted to increase the academic success rate of First Nation, Métis, and Inuit students. Sixteen school jurisdictions in Alberta were asked to choose one school within their district on which to focus the resources offered by the Project. These resources included a large amount of money and print materials prepared by the Aboriginal Branch. The schools were asked to consult with the school community and area residents, including elders, to prepare strategies they believed would fulfill the goals of the First Nations, Métis, and Inuit School-Community Learning Environment Project. The first goal of the Project, and the one this quantitative study examines, was to increase the number of students who obtained the acceptable standard on the Provincial Achievement Tests. The Project was initiated in the 2003-2004 school year and ended in 2004-2005. This study compares the means of the numbers of students who obtained the acceptable standard on the Provincial Achievement Tests in the two years before the Project began, 2001-2002 and 2002-2003; two years during the Project, 2003-2004 and 2004-2005; and two years after the Project ended, 2005-2006 and 2006-2007. This study also compares the strategies each school used to achieve the goal of increasing the numbers of students attaining the acceptable standard on the Provincial Achievement Tests. In addition, 12 schools were purposefully quota sampled that were not part of the Project; the numbers of students who obtained the acceptable standard on the Provincial Achievement Tests in these schools were compared with the numbers of students who obtained the acceptable standard in schools that were part of the Project. Analysis of the results indicated that, generally speaking, the First Nations, Métis, and Inuit School-Community Learning Environment Project resulted in only nominal improvements in increasing the academic success of First Nation, Métis, and Inuit students attending schools that took part in the Project

Examining sponsorship and cosponsorship in the U.S. House of Representatives, 1973-2002

The purpose of this paper is to uncover the effects of background characteristics on members of Congress\u27 legislative activity. I intend to measure legislative activity using the total number of bills sponsored and cosponsored during each Congress. Beginning in 1973, this original dataset includes over 6,000 observations and is the most comprehensive study of this subject. Because my dataset begins in 1973, I will be able to identify any effect that the unrestricted ability to cosponsor, which began in 1978, had on legislative activeness. It is my intention to contribute to our scholarly understanding of sponsorship and cosponsorship activity in the U.S. House of Representatives and help shape future studies. I find empirical support for the signaling perspective which posits that political actors use legislative activity as a means for internal, rather than external, communication

Friend/foe Identification Accuracy And Shooting Performance: Effects Of Prior Task Loading And Time Pressure

The current dismounted soldier and the soldier of the future will be loaded with more information processing tasks while they perform shooting tasks. It is conceivable that some increased level of cognitive tasking may be performed simultaneously with required shooting tasks. The effect of cognitive load on shooting performance has been previously examined (Scribner and Harper, 2001). This study concentrated on the effect of various cognitive workload demands on a friend-foe discrimination shooting task in a single- and dual-task scenario. In light of this, it is imperative that the soldier not be overburdened mentally, which may result in decreased survivability and lethality. Specifically, this study was designed to examine the ability of the soldier to perform friend-foe target discrimination and shooting accuracy, with varying target exposure times, friendly target signatures, and varying cognitive load demands (working memory recall task). Using the Small Arms Simulator Testbed (SAST) we examined the effects of manipulations of working memory load and sustained information transfer, on shooting performance (as measured by target acquisition and friend/foe discrimination indices). Additionally, we investigated subjective measures of workload and stress. A secondary task, administered aurally, was given to subjects to attend to while they performed shooting (friend/foe discrimination task) scenarios: working memory recall task. Each type of task consisted of three levels of difficulty. Analysis of variance revealed significant differences for the memory recall task during shooting and non-shooting conditions. Furthermore, results showed that workload increased as a function of task demand, with associated decreases in shooting performance

Perceptions Over Time Related to Meeting Procedures in Partially Distributed Groups

Groups use different procedural structures to organize their efforts in group meetings. These structures are affected by the group members\u27 preferences for the degree of procedural order they want in a meeting, as well as by the communication media available in the meeting environment. Analysis of thirty partially distributed experimental groups that met over a period of time indicates that members\u27 preferences for procedural order affect their perceptions of outcome satisfaction and participation. Further analysis of video tapes of the sessions should indicate how media and other factors affect the members\u27 actual attempts at providing structure to the meetings

Burnout Syndrome in Critical Care Nurses

Burnout syndrome among nurses, especially within the critical care setting, has been a persistent and increasingly prevalent problem in the healthcare field. This systematic review aims to explore the common causes of burnout among nurses associated with working in a critical care setting. Twenty-five peer-reviewed articles, published between the years of 2000 and 2018, were selected for analysis and synthesis using the databases PubMed and CINAHL. The group included research studies conducted in the United States, Spain, France, China and Iran with sample sizes ranging from 42 to 2,392 intensive care unit (ICU) nurses. The articles included in this review were from systematic reviews and individual experimental studies that used Maslach Burnout Inventory, General Health Questionnaire, Integrative Literature Reviews, Depression Screenings, Cross-Sectional studies, and the Connor-David Resilience Scale. Findings demonstrate a high incidence of burnout among critical care nurses, with common causes related to environmental, situational and personal factors

Cellular responses to culture substrates with programmable anisotropy

Physiologically relevant culture substrates are needed to accurately model cell and tissue function in vitro to characterize function in both healthy and altered (diseased) states. In addition to their use as model systems, exerting control over cellular function in a biochemical engineering process through cell-substrate interactions may reveal new ways to increase yield or efficiency. While knowledge of cellular responses to elastic substrates has advanced greatly, it was only recently recognized that cellular interactions with viscous components of networks alters mammalian cell spreading, migration, proliferation, and differentiation. Matrix studies have shown varying results in response to stress relaxation timescales however, indicating that multiple factors contribute to the cell\u27s interpretation of its mechanical microenvironment. We hypothesize that there is an additional, critical design parameter that has not been considered: the length scales over which cells sense mechanical properties. This work seeks to investigate these questions using a new type of culture substrate based on cytocompatible liquid crystalline (LC) polymers. This work focuses on the design, synthesis, and characterization of new biomaterial substrates whose viscoelastic properties can be manipulated by controlling the liquid crystalline (LC) ordering within the material. These materials also have the ability to morph in shape in response to an external stimulus (e.g. light), which may be applied during in vitro culture to result in dynamic culture substrates. A unique feature is that order can be programmed from the molecular scale to the macroscale, which permits study of how cells interact with the substrates across different length scales. To enable these studies, liquid crystallinity must be maintained in a hydrated network, which is inherently challenging because swelling of polymers tends to increase the distance between LC molecules to weaken their ordering. This work prepares new LC networks using Click chemistry, which was selected for its efficiency under mild reaction conditions that can be used to incorporate more sensitive biological molecules. This work seeks to combine the dynamic properties of these LC materials with their low cytotoxicity, stability in a hydrated phase, and ability to be processed into scaffolds and gels for use as hydrated and responsive culture substrates. The goals are to first characterize the impact of composition on liquid crystalline ordering and culture substrate properties before quantifying the impacts of substrate anisotropy and mechanics, programmed at different length scales, on mesenchymal stem cell differentiation. To prepare the materials, alkyne-terminated liquid crystalline monomers (mesogens) and azide-terminated polyether chain extenders (PEO poly(ethylene oxide); PPO poly(propylene oxide)) were synthesized and purified by modifying established reactions. Chain extender molecular weight and composition were varied to afford control over water uptake and LC organization. For one-step LC network synthesis, chemically crosslinked networks were synthesized by polymerizing the mesogens and chain extenders with a tetraazide crosslinker. To enable cell encapsulation, a two-step network synthesis was used, where azide-terminated LC prepolymers were crosslinked in water using multifunctional strained alkyne. Scaffolds were also prepared to enable 3D studies by polymerizing the reactive mixture in the presence of sodium chloride (sieved to 500-600 μm) and extracting the salt once the reaction was complete. All LC networks were found to organize into the smectic phase. By varying the composition and molecular weight of the chain extender, the material’s elastic modulus and stability of the LC phase was tailored. The networks were found to display reversible shape changing, where the films extended in the LC phase and contracted in the isotropic phase. Composition was found to impact the ability of the network to change shape and the amount of strain generated. Additionally, stress relaxation experiments conducted in the hydrated state showed that networks that were isotropic were found to respond elastically, but LC networks displayed more viscous responses. Mesenchymal stem cells incubated with extractable materials displayed no differences in cellular toxicity compared to tissue culture controls. Cells were found to attach and proliferate on the hydrated LC networks, but attachment was found to be about 50% that of the tissue culture plastic. Adsorption of gelatin with fibronectin onto the networks successfully increased cell attachment. Cell spreading and differentiation (adipogenic vs. osteogenic) studies are ongoing at the time of abstract submission. Ultimately, this work lays the synthetic groundwork for a new synthetic platform for LC biomaterials that can be adapted to include biological molecules as well as investigates LC network utility as a dynamic culture substrate. Please click Additional Files below to see the full abstract

Reversibility in Queueing Models

In stochastic models for queues and their networks, random events evolve in time. A process for their backward evolution is referred to as a time reversed process. It is often greatly helpful to view a stochastic model from two different time directions. In particular, if some property is unchanged under time reversal, we may better understand that property. A concept of reversibility is invented for this invariance. Local balance for a stationary Markov chain has been used for a weaker version of the reversibility. However, it is still too strong for queueing applications. We are concerned with a continuous time Markov chain, but dose not assume it has the stationary distribution. We define reversibility in structure as an invariant property of a family of the set of models under certain operation. The member of this set is a pair of transition rate function and its supporting measure, and each set represents dynamics of queueing systems such as arrivals and departures. We use a permutation {\Gamma} of the family menmbers, that is, the sets themselves, to describe the change of the dynamics under time reversal. This reversibility is is called {\Gamma}-reversibility in structure. To apply these definitions, we introduce new classes of models, called reacting systems and self-reacting systems. Using those definitions and models, we give a unified view for queues and their networks which have reversibility in structure, and show how their stationary distributions can be obtained. They include symmetric service, batch movements and state dependent routing.Comment: Submitted for publicatio