4,204 research outputs found

    Anomalous scaling and Lee-Yang zeroes in Self-Organized Criticality

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    We show that the generating functions of avalanche observables in SOC models exhibits a Lee-Yang phenomenon. This establishes a new link between the classical theory of critical phenomena and SOC. A scaling theory of the Lee-Yang zeroes is proposed including finite sampling effects.Comment: 33 pages, 19 figures, submitte

    Provider reimbursement following the Affordable Care Act

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    Decreasing healthcare expenditure has been one of the main objectives of the Affordable Care Act (ACA). To achieve this goal, the Centers for Medicare and Medicaid Services (CMS) has been tasked with experimenting with provider reimbursement methods in an attempt to increase quality, while decreasing costs. The purpose of this research was to study the effects of the ACA on physician reimbursement rates from CMS to determine the most cost effective method of delivering healthcare services. CMS has experimented with payment methods in an attempt to increase cost effectiveness. Medicare has offered shared cost savings incentives to reward quality care to both primary care providers and preventative services. CMS has determined fee-for- service payments obsolete, opting instead for a Value Based Purchasing (VBP) method of payment. Although a universal payment method has yet to be adopted, it has been evident that a VBP model and preventative care can be used to decrease healthcare expenditure

    Scaling and Universality in City Space Syntax: between Zipf and Matthew

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    We report about universality of rank-integration distributions of open spaces in city space syntax similar to the famous rank-size distributions of cities (Zipf's law). We also demonstrate that the degree of choice an open space represents for other spaces directly linked to it in a city follows a power law statistic. Universal statistical behavior of space syntax measures uncovers the universality of the city creation mechanism. We suggest that the observed universality may help to establish the international definition of a city as a specific land use pattern.Comment: 24 pages, 5 *.eps figure

    Perceptions of Clinical Research Participation among African American Women

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    Background: Recruiting minority women into clinical research remains a significant challenge to conducting ethnically representative research. The main objective of this Office on Women's Health, DHHS-funded e-health database evaluation project was to examine African American women 's thoughts and perceptions about the clinical research process and about participation in the University of Michigan Women's Health Registry research database. Methods: Thirty-one African American women were recruited from the community to participate in a total of five 90-minute focus group discussions. All sessions were audiotaped and transcribed verbatim. Thematic content analysis was used to identify relevant themes about participation in clinical research and the Women's Health Registry. Results: Ten common trends were identified. (1) Information about the Women's Health Registry is not reaching the community. (2) Research is perceived as biased to benefit Caucasians. (3) Community involvement by the research team is critical for trust to develop. (4) Research directly relevant to African Americans or their community will encourage participation. (5) Researchers should use existing networks and advertise in appropriate locations. (6) The community needs more information concerning research. (7) Compensation is important. (8) Research that addresses a personal or family medical problem encourages involvement. (9) Minority representation on the research team is a motivator to participation. (10) There is limited time for healthcare-related activities. Conclusions: Successful recruitment strategies for African American women should feature community-based, culturally appropriate approaches. Online research databases for subject recruitment will likely be successful only if implemented within a broader community-oriented program.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63122/1/jwh.2006.0124.pd

    Characterization of radial turbulent fluxes in the Santander linear plasma machine

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    It is shown that the statistical and correlation properties of the local turbulent flux measured at different radial locations of the cold, weakly ionized plasmas inside the Santander Linear Plasma Machine [Castellanos et al., Plasma Phys. Control. Fusion 47, 2067 (2005)] are consistent with diffusive-like transport dynamics. This is in contrast to the dynamical behavior inferred from similar measurements taken in hotter, fully ionized tokamak and stellarator edge plasmas, in which longterm correlations and other features characteristic of complex, non-diffusive transport dynamics have been reported in the past. These results may shed some light on a recent controversy regarding the possible universality of the dynamics of turbulent transport in magnetized plasma

    Atypical onset of diabetes in a teenage girl: a case report

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Microfinance and entrepreneurship:An introduction

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    As microfinance gains increasing attention and application as a financing mechanism for entrepreneurs at the base of the economic pyramid, this Special Issue of International Small Business Journal aims to enhance scholarly understanding of how microfinance fosters entrepreneurial activity. Microfinance brings a range of financial services, including microcredit loans, savings, and insurance, within the reach of millions of poor households not served by traditional banks. This introduction summarizes the articles in this Special Issue of International Small Business Journal on ‘Microfinance’, which address a range of topics in this important domain of research and practice

    Fracturing ranked surfaces

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    Discretized landscapes can be mapped onto ranked surfaces, where every element (site or bond) has a unique rank associated with its corresponding relative height. By sequentially allocating these elements according to their ranks and systematically preventing the occupation of bridges, namely elements that, if occupied, would provide global connectivity, we disclose that bridges hide a new tricritical point at an occupation fraction p=pcp=p_{c}, where pcp_{c} is the percolation threshold of random percolation. For any value of pp in the interval pc<p≤1p_{c}< p \leq 1, our results show that the set of bridges has a fractal dimension dBB≈1.22d_{BB} \approx 1.22 in two dimensions. In the limit p→1p \rightarrow 1, a self-similar fracture is revealed as a singly connected line that divides the system in two domains. We then unveil how several seemingly unrelated physical models tumble into the same universality class and also present results for higher dimensions

    Gene expression in BMPR2 mutation carriers with and without evidence of Pulmonary Arterial Hypertension suggests pathways relevant to disease penetrance

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    <p>Abstract</p> <p>Background</p> <p>While BMPR2 mutation strongly predisposes to pulmonary arterial hypertension (PAH), only 20% of mutation carriers develop clinical disease. This finding suggests that modifier genes contribute to FPAH clinical expression. Since modifiers are likely to be common alleles, this problem is not tractable by traditional genetic approaches. Furthermore, examination of gene expression is complicated by confounding effects attributable to drugs and the disease process itself.</p> <p>Methods</p> <p>To resolve these problems, B-cells were isolated, EBV-immortalized, and cultured from familial PAH patients with BMPR2 mutations, mutation positive but disease-free family members, and family members without mutation. This allows examination of differences in gene expression without drug or disease-related effects. These differences were assayed by Affymetrix array, with follow-up by quantitative RT-PCR and additional statistical analyses.</p> <p>Results</p> <p>By gene array, we found consistent alterations in multiple pathways with known relationship to PAH, including actin organization, immune function, calcium balance, growth, and apoptosis. Selected genes were verified by quantitative RT-PCR using a larger sample set. One of these, CYP1B1, had tenfold lower expression than control groups in female but not male PAH patients. Analysis of overrepresented gene ontology groups suggests that risk of disease correlates with alterations in pathways more strongly than with any specific gene within those pathways.</p> <p>Conclusion</p> <p>Disease status in BMPR2 mutation carriers was correlated with alterations in proliferation, GTP signaling, and stress response pathway expression. The estrogen metabolizing gene CYP1B1 is a strong candidate as a modifier gene in female PAH patients.</p

    Extended droplet theory for aging in short-ranged spin glasses and a numerical examination

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    We analyze isothermal aging of a four dimensional Edwards-Anderson model in detail by Monte Carlo simulations. We analyze the data in the view of an extended version of the droplet theory proposed recently (cond-mat/0202110) which is based on the original droplet theory plus conjectures on the anomalously soft droplets in the presence of domain walls. We found that the scaling laws including some fundamental predictions of the original droplet theory explain well our results. The results of our simulation strongly suggest the separation of the breaking of the time translational invariance and the fluctuation dissipation theorem in agreement with our scenario.Comment: 27 pages, 39 epsfiles, revised versio
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