681 research outputs found

    Distributed Computing with Adaptive Heuristics

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    We use ideas from distributed computing to study dynamic environments in which computational nodes, or decision makers, follow adaptive heuristics (Hart 2005), i.e., simple and unsophisticated rules of behavior, e.g., repeatedly "best replying" to others' actions, and minimizing "regret", that have been extensively studied in game theory and economics. We explore when convergence of such simple dynamics to an equilibrium is guaranteed in asynchronous computational environments, where nodes can act at any time. Our research agenda, distributed computing with adaptive heuristics, lies on the borderline of computer science (including distributed computing and learning) and game theory (including game dynamics and adaptive heuristics). We exhibit a general non-termination result for a broad class of heuristics with bounded recall---that is, simple rules of behavior that depend only on recent history of interaction between nodes. We consider implications of our result across a wide variety of interesting and timely applications: game theory, circuit design, social networks, routing and congestion control. We also study the computational and communication complexity of asynchronous dynamics and present some basic observations regarding the effects of asynchrony on no-regret dynamics. We believe that our work opens a new avenue for research in both distributed computing and game theory.Comment: 36 pages, four figures. Expands both technical results and discussion of v1. Revised version will appear in the proceedings of Innovations in Computer Science 201

    Interstate Voter Registration Database Matching: The Oregon-Washington 2008 Pilot Project

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    Voter registration databases maintain lists of registered voters that are used to determine who is and is not eligible to vote in an election. As such, accurate voter registration databases form a cornerstone of the electoral process. In the United States, each state maintains its own voter registration database. It is not uncommon for a voter to become registered in two states, for example as a result of moving from one state to the other or of living in one state and working in one another. In this paper, we report on a pilot interstate voter registration database matching project between the two states of Oregon andWashington whose goal was to explore the feasibility of using database matching to identify voters registered in the two states, and to do so with as much openness and transparency as possible. We describe the matching algorithms used, the procedures taken with found matches, and the resulting actions taken on actual voter registrations. We also discuss several directions for improving matching algorithms and procedures

    Addressing Barriers to Universal Screening for Social, Emotional, and Behavioral Risk in Elementary Schools

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    Early identification of students in need of additional support in the classroom is an important structure for school districts to have in place. Universal screening for social-emotional and behavioral (SEB) risk is one method that schools can use to identify students in need of SEB support and to begin early intervention programing. Unfortunately, recommendations about universal screening and resources for universal screening for SEB risk are limited. As a result, barriers to screening are increased and interventions are delayed – sometimes indefinitely -- for those who need them most. This paper discusses the barriers and challenges experienced by elementary schools (grades K-5) in one school district in the South across a three-year consultative study. This district was supported by the researchers in identifying an appropriate SEB screener, in disseminating the screener, and in ensuring accuracy in its completion. Across the three years, data were evaluated from previous years, and recommendations to improve the district’s screening initiative were made by the lead consultant and school psychology graduate students. Over time, positive changes were noted in screening practices, but it is evident that more work needs to be done. Specific solutions and future implications for early childhood are discussed

    Lagged acute respiratory outcomes among children related to ambient pollutant exposure in a high exposure setting in South Africa

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    BACKGROUND : Acute ambient air pollution impacts on the respiratory health of children may be lagged across time. We determined the short-term lagged effects of particulate matter (PM2.5), sulphur dioxide (SO2), and oxides of nitrogen (NOx) on the respiratory health of children living in low-income communities. METHODS : A school-based study was conducted using a repeated measures design, across summer and winter, in four schools in each of four suburbs in the Vaal Triangle, South Africa. Data for PM2.5, NOx, and SO2 were obtained from monitoring stations within close proximity of the schools. Over 10 school days in each phase, grade 4 children completed a symptoms log and lung function tests. Parents completed a child respiratory questionnaire. Generalized estimation equations models adjusted for covariates of interest in relation to lung function outcomes and air pollutants including lag effects of 1–5 days. RESULTS : Daily PM2.5, NOx, and SO2 median concentration levels were frequently higher than international standards. Among the 280 child participants (mean age 9 years), the prevalence of symptoms based on probable asthma was 9.6%. There was a consistent increased pollutant-related risk for respiratory symptoms, except for NOx and shortness of breath. Lung function, associated with pollutant fluctuations across the different lags, was most pronounced for peak expiratory flow rate (PEFR) for PM2.5 and SO2. A preceding 5-day average SO2 exposure had the largest loss (7.5 L/minute) in PEFR. CONCLUSIONS : Lagged declines in daily lung function and increased odds of having respiratory symptoms were related to increases in PM2.5 and SO2 among a school-based sample of children.The South African National Department of Forestry, Fisheries and the Environment.https://journals.lww.com/environepidem/Pages/default.aspxam2023Geography, Geoinformatics and Meteorolog

    Statin Therapy Alters Lipid Storage in Diabetic Skeletal Muscle

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    While statins significantly reduce cholesterol levels and thereby reduce the risk of cardiovascular disease, the development of myopathy with statin use is a significant clinical side-effect. Recent guidelines recommend increasing inclusion criteria for statin treatment in diabetic individuals; however, the impact of statins on skeletal muscle health in those with diabetes (who already suffer from impairments in muscle health) is ill-defined. Here we investigate the effects of Fluvastatin treatment on muscle health in wild-type and streptozotocin (STZ)-induced diabetic mice. Wild-type and STZ-diabetic mice received diet enriched with 600 mg/kg Fluvastatin or control chow for 24 days. Muscle morphology, intra and extracellular lipid levels, and lipid transporter content was investigated. Our findings indicate that short-term Fluvastatin administration induced a myopathy that was not exacerbated by the presence of STZ-induced diabetes. Fluvastatin significantly increased ectopic lipid deposition within the muscle of STZ-diabetic animals, findings that were not seen with diabetes or statin treatment alone. Consistent with this observation, only Fluvastatin-treated diabetic mice downregulated protein expression of lipid transporters FAT/CD36 and FABPpm in their skeletal muscle. No differences in FAT/CD36 or FABPpm mRNA content were observed. Altered lipid compartmentalization resultant of a downregulation in lipid transporter content in STZ-induced diabetic skeletal muscle was apparent in the current investigation. Given the association between ectopic lipid deposition in skeletal muscle and the development of insulin-resistance, our findings highlight the necessity for more thorough investigations into the impact of statins in humans with diabetes

    Ecosystem engineers maintain a rare species of butterfl y and increase plant diversity

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    We evaluated whether ecosystem engineers can accomplish two conservation goals simultaneously: (1) indirectly maintain populations of an endangered animal through habitat modifi cation and (2) increase riparian plant diversity. We tested for eff ects of a prominent ecosystem engineer, the beaver Castor canadensis, on populations of St. Francis' satyr butterfl y Neonympha mitchellii francisci and plant species richness and composition. We performed our test by surveying riparian vegetation communities in all stages of beaver-infl uenced wetland succession. We found that beavers created wetland habitats that supported plant species not found elsewhere in riparian zones and increased plant species diversity across the landscape by creating a novel combination of patch types. Our results confi rmed what others have found about engineering eff ects on plant diversity, but these results further demonstrated a case where ecosystem engineers indirectly maintain populations of rare animals by modifying the composition and diversity of plant communities within wetlands. Our research demonstrates how an ecosystem engineer can infl uence habitat availability and composition of plant communities important for an endangered insect, and maintain overall plant species diversity by increasing habitat heterogeneity

    Sexual expression and cognitive function: gender-divergent associations in older adults

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    Prior research demonstrates a positive association between sexual activity and cognitive function in later life. However, the relationship between the type of sexual activity and cognitive function in older adulthood remains unclear. This study explores the associations between the frequency of engaging in different types of sexual activities (intercourse, masturbation, and kissing/petting/fondling) and cognitive function in older women and men. Using data from Wave 6 of the English Longitudinal Study of Ageing (ELSA), 1915 women and 2195 men (age range 50-89 years; n = 4110) reporting any type of sexual activity over the past 12 months, were included in the study. Multiple regression controlling for age, education, satisfaction with sex life, cohabiting, wealth, general health, physical activity, depression and loneliness, was used to explore the associations between the frequency of engagement in intercourse, masturbation and kissing/petting/fondling, and two measures of cognitive function; word recall and number sequencing. For women, masturbation was linked to better word recall (p = .008), whilst for men, kissing/petting/fondling was associated with better number sequencing (p = .035). In women (p = .016) and men (p = .018), dissatisfaction with sex life was associated with better number sequencing. The results point to gendered links between sexual activity and cognitive function. These gender-related divergences may reflect differences in biological/neurological mechanisms, or in cognitive lifestyle factors that could influence cognitive reserve in later life. This novel study underscores the need to delineate the underlying mechanisms of the association between sex and cognition in men and women

    The CAP cancer protocols – a case study of caCORE based data standards implementation to integrate with the Cancer Biomedical Informatics Grid

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    BACKGROUND: The Cancer Biomedical Informatics Grid (caBIG™) is a network of individuals and institutions, creating a world wide web of cancer research. An important aspect of this informatics effort is the development of consistent practices for data standards development, using a multi-tier approach that facilitates semantic interoperability of systems. The semantic tiers include (1) information models, (2) common data elements, and (3) controlled terminologies and ontologies. The College of American Pathologists (CAP) cancer protocols and checklists are an important reporting standard in pathology, for which no complete electronic data standard is currently available. METHODS: In this manuscript, we provide a case study of Cancer Common Ontologic Representation Environment (caCORE) data standard implementation of the CAP cancer protocols and checklists model – an existing and complex paper based standard. We illustrate the basic principles, goals and methodology for developing caBIG™ models. RESULTS: Using this example, we describe the process required to develop the model, the technologies and data standards on which the process and models are based, and the results of the modeling effort. We address difficulties we encountered and modifications to caCORE that will address these problems. In addition, we describe four ongoing development projects that will use the emerging CAP data standards to achieve integration of tissue banking and laboratory information systems. CONCLUSION: The CAP cancer checklists can be used as the basis for an electronic data standard in pathology using the caBIG™ semantic modeling methodology
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