2,740 research outputs found

    Designed for Disease: The Link Between Local Food Environments and Obesity and Diabetes

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    Examines the link between a community's retail food environment -- the ratio of fast-food outlets and convenience stores to grocery stores and produce vendors, with income level as a factor -- and the prevalence of adult obesity and diabetes

    Advanced Placement Course-Taking and ACT Test Outcomes in Arkansas

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    Since 2008, Arkansas has sought to dramatically increase the number of students participating in Advanced Placement (AP) classes. This program, which allows students to access college -level content while still enrolled in high school, has been linked to higher student achievement and attainment. This brief shares recent research from the Office for Education Policy investigating whether students who take AP courses demonstrate better college readiness and examines how these trends vary for different demographic and socioeconomic groups in the state

    Does the Timing of Money Matter? A Case Study of the Arkansas Academic Challenge Scholarship

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    In 2008, legislation passed to dramatically increase a small merit-aid program—the Arkansas Academic Challenge Scholarship (ACS) using newly created funds from the Arkansas Lottery. The expansion of this program created three unique groups of students eligible for funding: Prior Recipients, Traditional Recipients, and Current Achievers. Recent research from the Department of Education Reform at the University of Arkansas investigates how the scholarship influenced student outcomes for Current Achievers, who were already enrolled in college at the time the money was distributed. The study also investigates whether GPA, credit accumulation, and graduation rates vary depending on which year of college students were in when they received funding

    Sex Differences in Left Ventricular Electrical Dyssynchrony and Outcomes with Cardiac Resynchronization Therapy

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    BACKGROUND: Women seem to derive more benefit from cardiac resynchronization therapy (CRT) than men, even after accounting for the higher burden of risk factors for nonresponse often observed in men. OBJECTIVE: To assess for sex-specific differences in left ventricular (LV) electrical dyssynchrony as a contributing electrophysiological explanation for the greater degree of CRT benefit among women. METHODS: We compared the extent of baseline LV electrical dyssynchrony, as measured by the QRS area (QRSA), among men and women with left bundle branch block (LBBB) undergoing CRT at Duke University (n = 492, 35% women) overall and in relation to baseline QRS characteristics using independent sample t tests and Pearson correlation coefficients. Cox regression analyses were used to relate sex, QRSA, and QRS characteristics to the risk of cardiac transplantation, LV assist device implant, or death. RESULTS: Although the mean QRS duration (QRSd) did not differ by sex, QRSA was greater for women vs men (113.8 μVs vs 98.2 μVs, P < .001), owing to differences in the QRSd <150 ms subgroup (92.3 ± 28.7 μVs vs 67.6 ± 26.2 μVs, P < .001). Among those with nonstrict LBBB, mean QRSd was similar but QRSA was significantly greater among women than men (96.0 ± 25.0 μVs vs 63.6 ± 26.2 μVs, P < .001). QRSA was similar among men and women with strict LBBB (P = .533). Female sex was associated with better long-term outcomes in an unadjusted model (hazard ratio 0.623, confidence interval 0.454–0.857, P = .004) but sex no longer predicted outcomes after accounting for differences in QRSA. CONCLUSIONS: Our study suggests that sex-specific differences in LV dyssynchrony contribute to greater CRT benefit among women. Standard QRSd and morphology assessments seem to underestimate the extent of LV electrical dyssynchrony among women with LBBB

    Statistical challenges in assessing potential efficacy of complex interventions in pilot or feasibility studies

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    Early phase trials of complex interventions currently focus on assessing the feasibility of a large RCT and on conducting pilot work. Assessing the efficacy of the proposed intervention is generally discouraged, due to concerns of underpowered hypothesis testing. In contrast, early assessment of efficacy is common for drug therapies, where phase II trials are often used as a screening mechanism to identify promising treatments. In this paper we outline the challenges encountered in extending ideas developed in the phase II drug trial literature to the complex intervention setting. The prevalence of multiple endpoints and clustering of outcome data are identified as important considerations, having implications for timely and robust determination of optimal trial design parameters. The potential for Bayesian methods to help to identify robust trial designs and optimal decision rules is also explored

    Suicide Prevention in an Emergency Department Population: The ED-SAFE Study

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    Importance: Suicide is a leading cause of deaths in the United States. Although the emergency department (ED) is an opportune setting for initiating suicide prevention efforts, ED-initiated suicide prevention interventions remain underdeveloped. Objective: To determine whether an ED-initiated intervention reduces subsequent suicidal behavior. Design, Setting, and Participants: This multicenter study of 8 EDs in the United States enrolled adults with a recent suicide attempt or ideation and was composed of 3 sequential phases: (1) a treatment as usual (TAU) phase from August 2010 to December 2011, (2) a universal screening (screening) phase from September 2011 to December 2012, and (3) a universal screening plus intervention (intervention) phase from July 2012 to November 2013. Interventions: Screening consisted of universal suicide risk screening. The intervention phase consisted of universal screening plus an intervention, which included secondary suicide risk screening by the ED physician, discharge resources, and post-ED telephone calls focused on reducing suicide risk. Main Outcomes and Measures: The primary outcome was suicide attempts (nonfatal and fatal) over the 52-week follow-up period. The proportion and total number of attempts were analyzed. Results: A total of 1376 participants were recruited, including 769 females (55.9%) with a median (interquartile range) age of 37 (26-47) years. A total of 288 participants (20.9%) made at least 1 suicide attempt, and there were 548 total suicide attempts among participants. There were no significant differences in risk reduction between the TAU and screening phases (23% vs 22%, respectively). However, compared with the TAU phase, patients in the intervention phase showed a 5% absolute reduction in suicide attempt risk (23% vs 18%), with a relative risk reduction of 20%. Participants in the intervention phase had 30% fewer total suicide attempts than participants in the TAU phase. Negative binomial regression analysis indicated that the participants in the intervention phase had significantly fewer total suicide attempts than participants in the TAU phase (incidence rate ratio, 0.72; 95% CI, 0.52-1.00; P = .05) but no differences between the TAU and screening phases (incidence rate ratio, 1.00; 95% CI, 0.71-1.41; P = .99). Conclusions and Relevance: Among at-risk patients in the ED, a combination of brief interventions administered both during and after the ED visit decreased post-ED suicidal behavior

    In vivo characterization of connective tissue remodeling using infrared photoacoustic spectra

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    Premature cervical remodeling is a critical precursor of spontaneous preterm birth, and the remodeling process is characterized by an increase in tissue hydration. Nevertheless, current clinical measurements of cervical remodeling are subjective and detect only late events, such as cervical effacement and dilation. Here, we present a photoacoustic endoscope that can quantify tissue hydration by measuring near-infrared cervical spectra. We quantify the water contents of tissue-mimicking hydrogel phantoms as an analog of cervical connective tissue. Applying this method to pregnant women in vivo, we observed an increase in the water content of the cervix throughout pregnancy. The application of this technique in maternal healthcare may advance our understanding of cervical remodeling and provide a sensitive method for predicting preterm birth

    Aspects of holography for theories with hyperscaling violation

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    We analyze various aspects of the recently proposed holographic theories with general dynamical critical exponent z and hyperscaling violation exponent θ\theta. We first find the basic constraints on z,θz, \theta from the gravity side, and compute the stress-energy tensor expectation values and scalar two-point functions. Massive correlators exhibit a nontrivial exponential behavior at long distances, controlled by θ\theta. At short distance, the two-point functions become power-law, with a universal form for θ>0\theta > 0. Next, the calculation of the holographic entanglement entropy reveals the existence of novel phases which violate the area law. The entropy in these phases has a behavior that interpolates between that of a Fermi surface and that exhibited by systems with extensive entanglement entropy. Finally, we describe microscopic embeddings of some θ≠0\theta \neq 0 metrics into full string theory models -- these metrics characterize large regions of the parameter space of Dp-brane metrics for p≠3p\neq 3. For instance, the theory of N D2-branes in IIA supergravity has z=1 and θ=−1/3\theta = -1/3 over a wide range of scales, at large gsNg_s N.Comment: 35 pages; v2: new references added; v3: proper reference [14] added; v4: minor clarification
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