2,446 research outputs found

    Colloquium: Statistical mechanics of money, wealth, and income

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    This Colloquium reviews statistical models for money, wealth, and income distributions developed in the econophysics literature since the late 1990s. By analogy with the Boltzmann-Gibbs distribution of energy in physics, it is shown that the probability distribution of money is exponential for certain classes of models with interacting economic agents. Alternative scenarios are also reviewed. Data analysis of the empirical distributions of wealth and income reveals a two-class distribution. The majority of the population belongs to the lower class, characterized by the exponential ("thermal") distribution, whereas a small fraction of the population in the upper class is characterized by the power-law ("superthermal") distribution. The lower part is very stable, stationary in time, whereas the upper part is highly dynamical and out of equilibrium.Comment: 24 pages, 13 figures; v.2 - minor stylistic changes and updates of references corresponding to the published versio

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Mapping post-glacial expansions: The peopling of Southwest Asia

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    Archaeological, palaeontological and geological evidence shows that post-glacial warming released human populations from their various climate-bound refugia. Yet specific connections between these refugia and the timing and routes of post-glacial migrations that ultimately established modern patterns of genetic variation remain elusive. Here, we use Y-chromosome markers combined with autosomal data to reconstruct population expansions from regional refugia in Southwest Asia. Populations from three regions in particular possess distinctive autosomal genetic signatures indicative of likely refugia: one, in the north, centered around the eastern coast of the Black Sea, the second, with a more Levantine focus, and the third in the southern Arabian Peninsula. Modern populations from these three regions carry the widest diversity and may indeed represent the most likely descendants of the populations responsible for the Neolithic cultures of Southwest Asia. We reveal the distinct and datable expansion routes of populations from these three refugia throughout Southwest Asia and into Europe and North Africa and discuss the possible correlations of these migrations to various cultural and climatic events evident in the archaeological record of the past 15,000 years

    Family physician views about primary care reform in Ontario: a postal questionnaire

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    BACKGROUND: Primary care reform initiatives in Ontario are proceeding with little information about the views of practicing family physicians. METHODS: A postal questionnaire was sent to 1200 randomly selected family physicians in Ontario five months after the initial invitation to join the Ontario Family Health Network. It sought information about their practice characteristics, their intention to participate in the Network and their views about the organization and financing of primary care. RESULTS: The response rate was 50.3%. While many family physicians recognize the need for change in the delivery of primary care, the majority (72%) did not expect to join the Ontario Family Health Network by 2004, or by some later date (60%). Nor did they favour capitation or rostering, 2 key elements of the proposed reforms. Physicians who favour capitation were 5.5 times more likely to report that they expected to join the Network by 2004, although these practices comprise 5% of the sample. CONCLUSIONS: The results of this survey, conducted five months after the initial offering of primary care reform agreements to all Ontario physicians, suggest that an 80% enrollment target is unrealistic

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Tracking family medicine graduates. Where do they go, what services do they provide and whom do they see?

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    <p>Abstract</p> <p>Background</p> <p>There are continued concerns over an adequate supply of family physicians (FPs) practicing in Canada. While most resource planning has focused on intake into postgraduate education, less information is available on what postgraduate medical training yields. We therefore undertook a study of Family Medicine (FM) graduates from the University of Toronto (U of T) to determine the type of information for physician resource planning that may come from tracking FM graduates using health administrative data. This study compared three cohorts of FM graduates over a 10 year period of time and it also compared FM graduates to all Ontario practicing FPs in 2005/06. The objectives for tracking the three cohorts of FM graduates were to: 1) describe where FM graduates practice in the province 2) examine the impact of a policy introduced to influence the distribution of new FM graduates in the province 3) describe the services provided by FM graduates and 4) compare workload measures. The objectives for the comparison of FM graduates to all practicing FPs in 2005/06 were to: 1) describe the patient population served by FM graduates, 2) compare workload of FM graduates to all practicing FPs.</p> <p>Methods</p> <p>The study cohort consisted of all U of T FM postgraduate trainees who started and completed their training between 1993 and 2003. This study was a descriptive record linkage study whereby postgraduate information for FM graduates was linked to provincial health administrative data. Comprehensiveness of care indicators and workload measures based on administrative data where determined for the study cohort.</p> <p>Results</p> <p>From 1993 to 2003 there were 857 University of Toronto FM graduates. While the majority of U of T FM graduates practice in Toronto or the surrounding Greater Toronto Area, there are FM graduates from U of T practicing in every region in Ontario, Canada. The proportion of FM graduates undertaking further emergency training had doubled from 3.6% to 7.8%. From 1993 to 2003, a higher proportion of the most recent FM graduates did hospital visits, emergency room care and a lower proportion undertook home visits. Male FM graduates appear to have had higher workloads compared with female FM graduates, though the difference between them was decreasing over time. A 1997 policy initiative to discount fees paid to new FPs practicing in areas deemed over supplied did result in a decrease in the proportion of FM graduates practicing in metropolitan areas.</p> <p>Conclusions</p> <p>We were able to profile the practices of FM graduates using existing and routinely collected population-based health administrative data. Further work tracking FM graduates could be helpful for physician resource forecasting and in examining the impact of policies on family medicine practice.</p

    Efficiency of Ontario primary care physicians across payment models : a stochastic frontier analysis

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    Objective The study examines the relationship between the primary care model that a physician belongs to and the efficiency of the primary care physician in Ontario, Canada. Methods Survey data were collected from 183 self-selected physicians and linked to administrative databases to capture the provision of services to the patients served for the 12 month period ending June 30, 2013, and the characteristics of the patients at the beginning of the study period. Two stochastic frontier regression models were used to estimate efficiency scores and parameters for two separate outputs: the number of distinct patients seen and the number of visits. Results Because of missing data, only 165 physicians were included in the analyses. The average efficiency was 0.72 for both outputs with scores varying from 4 % to 93 % for the visits and 5 % to 94 % for the number of patients seen. We observed that there were both very low and very high efficiency scores within each model. These variations were larger than variations in average scores across models

    Prostate Cancer-Specific and Potent Antitumor Effect of a DD3-Controlled Oncolytic Virus Harboring the PTEN Gene

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    Prostate cancer is a major health problem for men in Western societies. Here we report a Prostate Cancer-Specific Targeting Gene-Viro-Therapy (CTGVT-PCa), in which PTEN was inserted into a DD3-controlled oncolytic viral vector (OV) to form Ad.DD3.E1A.E1B(Δ55)-(PTEN) or, briefly, Ad.DD3.D55-PTEN. The woodchuck post-transcriptional element (WPRE) was also introduced at the downstream of the E1A coding sequence, resulting in much higher expression of the E1A gene. DD3 is one of the most prostate cancer-specific genes and has been used as a clinical bio-diagnostic marker. PTEN is frequently inactivated in primary prostate cancers, which is crucial for prostate cancer progression. Therefore, the Ad.DD3.D55-PTEN has prostate cancer specific and potent antitumor effect. The tumor growth rate was almost completely inhibited with the final tumor volume after Ad.DD3.D55-PTEN treatment less than the initial volume at the beginning of Ad.DD3.D55-PTEN treatment, which shows the powerful antitumor effect of Ad.DD3.D55-PTEN on prostate cancer tumor growth. The CTGVT-PCa construct reported here killed all of the prostate cancer cell lines tested, such as DU145, 22RV1 and CL1, but had a reduced or no killing effect on all the non-prostate cancer cell lines tested. The mechanism of action of Ad.DD3.D55-PTEN was due to the induction of apoptosis, as detected by TUNEL assays and flow cytometry. The apoptosis was mediated by mitochondria-dependent and -independent pathways, as determined by caspase assays and mitochondrial membrane potential
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