7,541 research outputs found

    The Effect of Disease-induced Mortality on Structural Network Properties

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    As the understanding of the importance of social contact networks in the spread of infectious diseases has increased, so has the interest in understanding the feedback process of the disease altering the social network. While many studies have explored the influence of individual epidemiological parameters and/or underlying network topologies on the resulting disease dynamics, we here provide a systematic overview of the interactions between these two influences on population-level disease outcomes. We show that the sensitivity of the population-level disease outcomes to the combination of epidemiological parameters that describe the disease are critically dependent on the topological structure of the population's contact network. We introduce a new metric for assessing disease-driven structural damage to a network as a population-level outcome. Lastly, we discuss how the expected individual-level disease burden is influenced by the complete suite of epidemiological characteristics for the circulating disease and the ongoing process of network compromise. Our results have broad implications for prediction and mitigation of outbreaks in both natural and human populations.Comment: 23 pages, 6 figure

    An Investigation of Philadelphia's Youth Aid Panel: A Community-Based Diversion Program for First-Time Youthful Offenders

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    The formal justice system currently does not have the resources to effectively deal with nonviolent first-time offending youth, oftentimes leaving them with little punishment aside from a criminal record. This report offers a close examination of Philadelphia's Youth Aid Panels (YAP), which seeks to provide alternative sentencing for this high-risk population through the collaboration of volunteer community members, victims, parent(s)/guardian and a law enforcement official. YAP offers victims a better sense of restitution while also providing the youth with the real opportunity to reintegrate into society without a record. Our initial exploratory evaluation shows promising results, and we offer a several recommendations to strengthen YAP programs

    Quantum filtering for multiple measurements driven by fields in single-photon states

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    In this paper, we derive the stochastic master equations for quantum systems driven by a single-photon input state which is contaminated by quantum vacuum noise. To improve estimation performance, quantum filters based on multiple-channel measurements are designed. Two cases, namely diffusive plus Poissonian measurements and two diffusive measurements, are considered.Comment: 8 pages, 6 figures, submitted for publication. Comments are welcome

    Evolving Healthy Populations

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    On the generalization of linear least mean squares estimation to quantum systems with non-commutative outputs

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    The purpose of this paper is to study the problem of generalizing the Belavkin-Kalman filter to the case where the classical measurement signal is replaced by a fully quantum non-commutative output signal. We formulate a least mean squares estimation problem that involves a non-commutative system as the filter processing the non-commutative output signal. We solve this estimation problem within the framework of non-commutative probability. Also, we find the necessary and sufficient conditions which make these non-commutative estimators physically realizable. These conditions are restrictive in practice.Comment: 31 page

    Perceptions of the Texas State and Federal Closures Among Inshore Shrimpers in Galveston Bay, Texas and Calcasieu Lake, Louisiana

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    The inshore shrimp fisheries along the coast of the Gulf of Mexico represent a significant portion of the total shrimp harvest in the Gulf. The shrimp harvest is allocated to the offshore and inshore fisheries through the use of season closures. In 1981, the Gulf of Mexico Regional Fisheries Management Council began implementing a policy known as the Texas Closure; a seasonal closure of the waters of the Federal Conservation Zone concurrent with the traditional season closure of the state waters of Texas. One impact of the Texas Closure on the offshore fishery has been fleet displacement from Texas to Louisiana waters. When offshore shrimpers were surveyed as to their perceptions of the Texas Closure, the most discontent was expressed among those shrimpers closest to the Texas/Louisiana border. This thesis examines the perceived impacts of the Texas Closure on the inshore shrimpers of the two bays closest to the Texas;Louisiana border: Galveston Bay, Texas and Calcasieu Lake, Louisiana to ensure that the Texas Closure has not had negative side effects on these user groups. Surveys were administered to shrimp captains in both regions to determine socio-demographic trends occurring in the fisheries and to assess the perceptions of the Texas state and federal closures. In-depth interviews were conducted as well with a variety of participants in various levels of the fishery. The model of human ecology is used to describe the study area and generate predictions of impacts. The results indicate that, for the post part the Calcasieu Lake shrimpers were much less opinionated about the Texas Closure than the Galveston Bay population. In addition, the perceptions of shrimpers in both regions towards the Texas state closure and Texas Closure were very consistent, suggesting that the two closures are perceived as one large closure. This suggests that the Texas Closure has had no additional impacts than the state closure already has. Those Galveston Bay shrimpers who had an opinion were equally divided between approving and disapproving of the Texas Closure. This difference was related to vessel size. Larger inshore boat captains felt personally impacted by the Texas Closure presumably because they have been able to shrimp just beyond the state territorial sea when the state closure was implemented prior to the implementation of the Texas Closure. These captains of larger boats tended to disapprove of the Texas Closure. The captains of small boats who had an opinion expressed support for the Texas Closure because it serves as a conservation measure which enables more shrimp to spawn before being harvested. Due to geographical limitations, fleet displacement was not perceived to personally impact the inshore shrimpers from either bay

    A study of young volunteers and volunteering in a Cape Town based, international NGO

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    Includes bibliographical references.What motivates a group of young people from a disadvantaged community spend between 20 and 50 hours every week in a voluntary organisation in their area? This dissertation has studied young volunteers aged between 18 and 28, who are working in a non-govemmental organisation (NGO) operating in a disadvantaged local community on the Cape Flats in Cape Town, South Africa. The aim of this research was to gain knowledge of their motivations for being full-time volunteers for this NGO. This is a qualitative, ethnographic study, which seeks to provide information about the young volunteers and volunteering in a descriptive way. The methods used for data collection have been participative observation, interviews, personal conversations, drawings of social network maps and a questionnaire. The numbers of interviewees are 12 in total, viz. ll volunteers and the Manager of the NGO. Clary et al (1992) created an empirical instrument that can be used to map out an individual's reasons for volunteering, namely the 'volunteers function inventory' (VFI), which suggest 6 main motivations for volunteering. This functional approach for studying motivation applies to volunteers in high-risk communities because it relates the individual’s psychological functions to his/her experiences, current life situation and stage of development. The data analysis in this study indicates that there are several motivations at stake, which can operate at the same time as well as change over time. In Cole's recent study (2004), she found that there does not appear to be any one motivational reason for volunteering. People do volunteer work for different reasons, but for volunteers from high-risk communities, values are very important motivators: "I feel compassion toward people in need" seems to apply to the majority of the volunteers who participated in this study. In addition to value based motivations for volunteering, the following three motivations are to be found in this group of 11 volunteers: the social benefits of volunteering, the personal development of being a volunteer and, last but not least, the love for the work they are doing
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