1,577 research outputs found

    Probabilistic Modeling of Dietary Arsenic Exposure

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    Sociodemographic characteristics and patient and family experience survey response biases

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    Enhancing Patient and Family Experience (PFE) is vital to the delivery of quality healthcare services. Sociodemographic differences affect health outcomes and experiences, but research is limited on biases in PFE survey methodology. We sought to assess survey participation rates across sociodemographic characteristics. This retrospective study analyzed a health system’s ambulatory PFE survey data, collected January 1 – July 31, 2019. Outcomes of interest were rates of survey response, completion, and comments. Predictors included respondent-reported race, ethnicity, language, and measure of social deprivation attached to a respondent’s home address. Addresses were geocoded to census tracts. The tract’s degree of socioeconomic deprivation was defined using the Deprivation Index (DPI). Associations between outcomes and predictors were assessed using the Chi square test. 77,627 unique patient encounters were analyzed. Patients were predominantly White (76%); 5% were Hispanic; and 1% were Spanish-speaking. The overall response, completion, and comment rates were 20.1%, 17.6%, and 4.1%, respectively. There were significant differences across assessed sociodemographic characteristics in response, completion, and comment rates. White patients were most likely to respond, complete, and leave a comment. Spanish-speaking respondents and those living in the most deprived areas were more likely to respond and complete the survey, but less likely to comment than English-speaking respondents and those living in less deprived areas, respectively. PFE survey participation differs across a range of sociodemographic characteristics, potentially introducing noteworthy biases. Health systems should minimize differences in how they collect feedback and account for potential biases when responding to experience data. Experience Framework This article is associated with the Policy & Measurement lens of The Beryl Institute Experience Framework. (https://www.theberylinstitute.org/ExperienceFramework). Access other PXJ articles related to this lens. Access other resources related to this lens

    Gauge fixing and the Hamiltonian for cylindrical spacetimes

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    We introduce a complete gauge fixing for cylindrical spacetimes in vacuo that, in principle, do not contain the axis of symmetry. By cylindrically symmetric we understand spacetimes that possess two commuting spacelike Killing vectors, one of them rotational and the other one translational. The result of our gauge fixing is a constraint-free model whose phase space has four field-like degrees of freedom and that depends on three constant parameters. Two of these constants determine the global angular momentum and the linear momentum in the axis direction, while the third parameter is related with the behavior of the metric around the axis. We derive the explicit expression of the metric in terms of the physical degrees of freedom, calculate the reduced equations of motion and obtain the Hamiltonian that generates the reduced dynamics. We also find upper and lower bounds for this reduced Hamiltonian that provides the energy per unit length contained in the system. In addition, we show that the reduced formalism constructed is well defined and consistent at least when the linear momentum in the axis direction vanishes. Furthermore, in that case we prove that there exists an infinite number of solutions in which all physical fields are constant both in the surroundings of the axis and at sufficiently large distances from it. If the global angular momentum is different from zero, the isometry group of these solutions is generally not orthogonally transitive. Such solutions generalize the metric of a spinning cosmic string in the region where no closed timelike curves are present.Comment: 12 pages, accepted for publication in Physical Review

    Sequence-based prediction for vaccine strain selection and identification of antigenic variability in foot-and-mouth disease virus

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    Identifying when past exposure to an infectious disease will protect against newly emerging strains is central to understanding the spread and the severity of epidemics, but the prediction of viral cross-protection remains an important unsolved problem. For foot-and-mouth disease virus (FMDV) research in particular, improved methods for predicting this cross-protection are critical for predicting the severity of outbreaks within endemic settings where multiple serotypes and subtypes commonly co-circulate, as well as for deciding whether appropriate vaccine(s) exist and how much they could mitigate the effects of any outbreak. To identify antigenic relationships and their predictors, we used linear mixed effects models to account for variation in pairwise cross-neutralization titres using only viral sequences and structural data. We identified those substitutions in surface-exposed structural proteins that are correlates of loss of cross-reactivity. These allowed prediction of both the best vaccine match for any single virus and the breadth of coverage of new vaccine candidates from their capsid sequences as effectively as or better than serology. Sub-sequences chosen by the model-building process all contained sites that are known epitopes on other serotypes. Furthermore, for the SAT1 serotype, for which epitopes have never previously been identified, we provide strong evidence - by controlling for phylogenetic structure - for the presence of three epitopes across a panel of viruses and quantify the relative significance of some individual residues in determining cross-neutralization. Identifying and quantifying the importance of sites that predict viral strain cross-reactivity not just for single viruses but across entire serotypes can help in the design of vaccines with better targeting and broader coverage. These techniques can be generalized to any infectious agents where cross-reactivity assays have been carried out. As the parameterization uses pre-existing datasets, this approach quickly and cheaply increases both our understanding of antigenic relationships and our power to control disease

    Please Don't Move—Evaluating Motion Artifact From Peripheral Quantitative Computed Tomography Scans Using Textural Features

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    Most imaging methods, including peripheral quantitative computed tomography (pQCT), are susceptible to motion artifacts particularly in fidgety pediatric populations. Methods currently used to address motion artifact include manual screening (visual inspection) and objective assessments of the scans. However, previously reported objective methods either cannot be applied on the reconstructed image or have not been tested for distal bone sites. Therefore, the purpose of the present study was to develop and validate motion artifact classifiers to quantify motion artifact in pQCT scans. Whether textural features could provide adequate motion artifact classification performance in 2 adolescent datasets with pQCT scans from tibial and radial diaphyses and epiphyses was tested. The first dataset was split into training (66% of sample) and validation (33% of sample) datasets. Visual classification was used as the ground truth. Moderate to substantial classification performance (J48 classifier, kappa coefficients from 0.57 to 0.80) was observed in the validation dataset with the novel texture-based classifier. In applying the same classifier to the second cross-sectional dataset, a slight-to-fair (κ = 0.01–0.39) classification performance was observed. Overall, this novel textural analysis-based classifier provided a moderate-to-substantial classification of motion artifact when the classifier was specifically trained for the measurement device and population. Classification based on textural features may be used to prescreen obviously acceptable and unacceptable scans, with a subsequent human-operated visual classification of any remaining scans

    Simulations of small-scale turbulent dynamo

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    We report an extensive numerical study of the small-scale turbulent dynamo at large magnetic Prandtl numbers Pm. A Pm scan is given for the model case of low-Reynolds-number turbulence. We concentrate on three topics: magnetic-energy spectra and saturation levels, the structure of the field lines, and the field-strength distribution. The main results are (1) the folded structure (direction reversals at the resistive scale, field lines curved at the scale of the flow) persists from the kinematic to the nonlinear regime; (2) the field distribution is self-similar and appears to be lognormal during the kinematic regime and exponential in the saturated state; and (3) the bulk of the magnetic energy is at the resistive scale in the kinematic regime and remains there after saturation, although the spectrum becomes much shallower. We propose an analytical model of saturation based on the idea of partial two-dimensionalization of the velocity gradients with respect to the local direction of the magnetic folds. The model-predicted spectra are in excellent agreement with numerical results. Comparisons with large-Re, moderate-Pm runs are carried out to confirm the relevance of these results. New features at large Re are elongation of the folds in the nonlinear regime from the viscous scale to the box scale and the presence of an intermediate nonlinear stage of slower-than-exponential magnetic-energy growth accompanied by an increase of the resistive scale and partial suppression of the kinetic-energy spectrum in the inertial range. Numerical results for the saturated state do not support scale-by-scale equipartition between magnetic and kinetic energies, with a definite excess of magnetic energy at small scales. A physical picture of the saturated state is proposed.Comment: aastex using emulateapj; 32 pages, final published version; a pdf file (4Mb) of the paper containing better-quality versions of figs. 5, 8, 12, 15, 17 is available from http://www.damtp.cam.ac.uk/user/as629 or by email upon request

    An investigation into the prevalence of dog bites to primary school children in Trinidad

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    <p>Abstract</p> <p>Background</p> <p>To estimate the prevalence of dog bites to primary school children between the ages of 8–12 years using a semi-structured interview process. With the increase in the pet population and popularity of dangerous breeds of dog and a high stray dog population combined with a dearth of information on the risk of dog attacks to children in Trinidad, a semi-structured interview process was used to determine risk factors associated with dog attacks.</p> <p>Methods</p> <p>A questionnaire survey of 1109 primary school children between the ages of 8–12 years was conducted in Trinidad from November 2002 to September 2003. The survey was conducted to determine the risk factors such as age, gender, size of dog and relationship of dog and victim, in dog bite incidents. The chi-square statistic and odds ratios were used to estimate risk factors for a bite incident.</p> <p>Results</p> <p>Twenty-eight percent of children were bitten at least once by a dog. Gender (male) and owning a dog were statistically significant risk factors (p = 0.003 and 0.008 respectively, χ<sup>2 </sup><it>df</it>, 95% confidence). Most attacks occurred outside of the home (58.0%) followed by the victims' home (42.0%) and were by a dog known but not owned (54.6%) by the victim. Many victims (33.0%) were bitten without having any interaction with the dog and the majority (61.9%) of victims did not receive professional medical assistance. Overall, the lower leg or foot was most often injured (39.3%).</p> <p>Conclusion</p> <p>A public educational campaign is needed on responsible pet ownership. In addition, children must be taught effective ways of avoiding attacks or reducing injury in the event of a dog attack. The Dangerous dogs Act 2000 must be proclaimed in parliament by the Government of Trinidad and Tobago to exert more pressure on pet owners to safeguard the public from the menace of dog attacks.</p

    Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition

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    Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie

    Overweight and obese adult humans have a defective cellular immune response to pandemic H1N1 influenza A virus

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    ObjectiveObese adults have a greater risk of morbidity and mortality from infection with pandemic H1N1 influenza A virus (pH1N1). The objective of the present study was to elucidate the specific mechanisms by which obesity and overweight impact the cellular immune response to pH1N1.Design and MethodsWe stimulated peripheral blood mononuclear cells from healthy weight, overweight, and obese individuals ex vivo with live pH1N1 and then measured markers of activation and function using flow cytometry and cytokine secretion using cytometric bead array assays.ResultsOur data indicate that CD4+ and CD8+ T cells from overweight and obese individuals expressed lower levels of CD69, CD28, CD40 ligand, and interleukin-12 receptor, as well as, produced lower levels of interferon-γ and granzyme B, compared to healthy weight individuals, suggesting deficiencies in activation and function. Dendritic cells from the three groups expressed similar levels of major histocompatibility complex-II, CD40, CD80, and CD86, as well as, produced similar levels of interleukin-12.ConclusionsThe defects in CD4+ and CD8+ T cells may contribute to the increased morbidity and mortality from pH1N1 in obese individuals. These data also provide evidence that both overweight and obesity cause impairments in immune function

    Measurement of the Branching Fraction for B- --> D0 K*-

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    We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications
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