594 research outputs found

    Significant Predictors of Nonalcoholic Fatty Liver Disease in Texas Firefighters

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    Risk factors for Nonalcoholic Fatty Liver Disease (NAFLD) include obesity, hypertension, dyslipidemia, and diabetes mellitus. Not only are these prevalent in the general US population, but they are also present at high rates in a specific subset responsible for public safety – firefighters. PURPOSE: The aim of the present study is to use logistic regression to predict the likelihood of occurrence of NAFLD in firefighters using a subset of health-related factors associated with common cardiometabolic risk factors. METHODS: Data were collected on 136 firefighters (128 males, 8 females; 36.3 ± 9.0 yrs; 95.7 ± 17.0 kg; 178.9 ± 7.4 cm; 29.8 ± 4.2 kg/m2) participating in FITLIFE, a university-based fitness program at Texas A&M University. Nominal logistic regression with stepwise removal was used to estimate the best model to predict fatty liver disease. Stepwise removal identified resting systolic blood pressure (RSBP, mm HG), Body Mass Index (BMI, kg/m2), visceral adipose tissue (VAT, cm2), whether or not has hypertension or is on medication (HTNMED; 0=No,1=Yes), and plasma triglyceride concentrations (TG, mg/dL) as independent predictors (p\u3c0.05). Odds ratios (OR) were calculated to determine the change in the odds of NAFLD per unit increase in each predictor. RESULTS: Logistic regression yielded the following equation to predict the probability of developing NAFLD: Logit = -22.5176 + 0.0918(RSBP) + 0.2154(BMI) + 0.0065(TG) + 0.0161(VAT) + 1.830(HTNMED) (R2 = 0.4655, p \u3c 0.001). Of the predictors, the ORs from largest to smallest were 6.235, 1.240, 1.096, 1.016, and 1.002 for HTNMED, BMI, RSBP, VAT, and TG, respectively. CONCLUSION: Using RSBP, BMI, VAT, TG, and HTNMED as predictors, this study demonstrates that the probability of developing NAFLD in Texas firefighters can be reasonably predicted. This regression model and individual predictors may be used by health practitioners as a cost-effective screening tool to identify those at higher risk for NAFLD

    Aquatic Treadmill Training Reduces Blood Pressure Reactivity to Acute Graded Exercise in Previously Sedentary Adults

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    Endurance exercise may reduce blood pressure and improve vasodilatory capacity thereby blunting the hypertensive response to stress. To test the efficacy of a novel model of low-impact endurance training, the aquatic-based treadmill (ATM), to improve blood pressure parameters, we recruited 60 sedentary adults and randomized to 12-weeks of either ATM (n = 36 [19 men, 17 women] , 41±2 yr, 173.58 ±1.58cm, 93.19 ±3.15kg) or land-based treadmill (LTM, n = 24 [11 men, 13 women], 42 ±2yr, 170.39 ±1.94cm, 88.14 ±3.6kg) training; 3sessions·wk-1, progressing to 500 kcal·session-1, 85% VO2max. The maximal Bruce treadmill test protocol was performed before and after training with blood pressures measured prior to, at the end of each stage, and for 5 minutes following exercise testing. Twelve subjects (5 ATM, 7 LTM) volunteered for biopsies of the vastus lateralis before and after training, and muscle samples were assessed for eNOS content. Blood pressure data were analyzed using group by training ANCOVA repeated across training, α = 0.05. Data obtained from muscle sample analysis were analyzed using group by training ANOVA repeated across training α = 0.05. Training reduced systolic blood pressure (9- 18.2mmHg), diastolic blood pressure (3.2-8.1 mmHg), mean arterial pressure (4.8-8.3mmHg), pulse pressure (7.5-15mmHg), and rate pressure product (1.8-3.9 bpm·mm Hg·103) during exercise stress and recovery in the ATM group, but not in the LTM group. Additionally, the ATM group, but not the LTM group, displayed a 31% increase in skeletal muscle eNOS content following training. Both groups improved VO2max (+3.6mL O2·kg-1·min-1), but resting blood pressure was not changed following training. These data support the use of ATM training as a novel therapeutic modality to combat hypertension

    Associations between incident breast cancer and ambient concentrations of nitrogen dioxide from a national land use regression model in the Canadian National Breast Screening Study

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    Background: Air pollution has been classified as a human carcinogen based largely on epidemiological studies of lung cancer. Recent research suggests that exposure to ambient air pollution increases the risk of female breast cancer especially in premenopausal women. Methods: Our objective was to determine the association between residential exposure to ambient nitrogen dioxide (NO2) and newly diagnosed cases of invasive breast cancer in a cohort of 89,247 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985.

    Yearling bulls have reduced sperm concentration and increased seminal plasma interleukin-8 after a 28-day breeding season

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    We hypothesized that yearling bulls selected for a 28-d breeding season would have reduced sperm concentrations and morphology, and have increased seminal plasma concentrations of pro-inflammatory cytokine interleukin-8 (IL-8). Yearling bulls were selected based on a breeding soundness examination (BSE) at approximately 415 d of age and contained at least 750 million sperm in the ejaculate, with 12 bulls randomly selected for breeding (BREEDERS) and 12 bulls not selected for breeding (NON-BREEDERS). After a 28-d breeding period, all bulls underwent a BSE. Plasma and seminal plasma were collected at each time point for analysis. Data were analysed utilizing either the MIXED or GLIMMIX procedures with repeated measures in SAS with breeding group, age and the interaction as fixed effects. Sperm concentration per ml of ejaculate was reduced (p \u3c .05) in yearling bulls used for breeding compared with those not used for breeding at the end of the breeding season. Seminal plasma IL-8 concentrations in yearling bulls used for breeding were increased (p \u3c .05) after the breeding season compared with bulls not used for breeding. Taken together, yearling bulls selected for a 28-d breeding season have reduced sperm production per ml of an ejaculate and increased inflammatory response in the seminal plasma that can lead to impaired breeding response if they are to be used for more than 30 d of breeding

    Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden:a cross sectional study using whole body magnetic resonance angiography

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    Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA).50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005).ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is primarily due to a strong correlation with ilio-femoral atheroma burden

    Utilization of a mobile medical van for delivering pediatric care in the bateys of the Dominican Republic

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    Background Bateys are impoverished areas of housing for migrant Haitian sugar cane workers in the Dominican Republic (DR). In these regions, preventative health care is almost non-existent, public service accessibility is limited, and geographic isolation prevents utilization of care even by those families with resources. Consequently, the development of a viable mobile system is vital to the delivery of acute and preventative health care in this region. Aims This study evaluated an existing mobile medical system. The primary goal was to describe the population served, diseases treated, and resources utilized. A secondary goal was to determine qualitatively an optimal infrastructure for sustainable health care delivery within the bateys. Methods Information on basic demographic data, diagnosis, chronicity of disease, and medications dispensed was collected on all pediatric patients seen in conjunction with an existing mobile medical system over a 3-month period in the DR. Health statistics for the region were collected and interviews were conducted with health care workers (HCWs) and community members on existing and optimal health care infrastructure. Results Five hundred eighty-four pediatric patients were evaluated and treated. Median age was 5 years (range 2 weeks to 20 years), and 53.7% of patients seen were 5 years of age or younger. The mean number of complaints per patient was 2.8 (range 0 to 6). Thirty-six percent (373) of all diagnoses were for acute complaints, and 64% (657) were chronic medical problems. The most common pediatric illnesses diagnosed clinically were gastrointestinal parasitic infection (56.6%), skin/fungal infection (46.2%), upper respiratory tract infections (URIs) (22.8%), previously undiagnosed asthma and allergies (8.2%), and symptomatic anemia (7.2%). Thirty HCWs and community members were interviewed, and all cited the need for similar resources: a community clinic and hospital referral site, health promoters within each community, and the initiation of pediatric training for community HCWs. Conclusion A mobile medical system is a sustainable, efficient mechanism for delivering acute and preventive care in the Haitian bateys of the Dominican Republic. The majority of patients served were 8 years of age or younger with multiple presenting symptoms. A pediatric protocol for identifying the most appropriate drugs and supplies for mobile units in the DR can be created based upon diseases evaluated. Qualitative data from HCWs and community members identified the need for an integrative health care delivery infrastructure and community health promoters versed in pediatric care who can aid in education of batey members and monitor chronic and acute illnesses. We are planning follow-up visits to implement these programs

    CHEMICAL TECHNOLOGY DIVISION, CHEMICAL DEVELOPMENT SECTION C PROGRESS REPORT FOR DECEMBER 1959 AND JANUARY 1960

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    The recovery of Th from Blind River ion exchange barrens with di(2- ethylhexyl)phosphoric acid was investigated. The recovery of Tc and Np from fluorination plant residues with tertiary amine was studied. The extraction of Np/sup 4+/ by quaternary ammonium nitrates is reported. A solvent recovery procedure involving successive use of Na/sub 2/CO/sub 3/washing and Al/sub 2/O/ sub 3/- adsorption was demonstrated in laboratory tests as a possible method for the purification and decontamaination of organophosphorus process solvents. The effect of nitrated fractions of Annsco 125-82 on Zr-Nb extractions by TBP was investigated. Treatnnent of TBPAmsco 125-82 solutions with 2 M HNO/sub 3/ at 60 ction prod- C for 1 to 48 hr showed that under these mild conditions the TBP degradation products were more important than those from Amsco as contributors to Zr-Nb extraction and as affecting efficiency of solvent clean-up. The interfacial tensions between benzene solutions of several amine salt and alkyl phosphate extractants and aqueous solutions were examined as functions of the solute concentrations. (For preceding period see CF-59-11-132.) (W.L.H.

    Structured Sparsity: Discrete and Convex approaches

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    Compressive sensing (CS) exploits sparsity to recover sparse or compressible signals from dimensionality reducing, non-adaptive sensing mechanisms. Sparsity is also used to enhance interpretability in machine learning and statistics applications: While the ambient dimension is vast in modern data analysis problems, the relevant information therein typically resides in a much lower dimensional space. However, many solutions proposed nowadays do not leverage the true underlying structure. Recent results in CS extend the simple sparsity idea to more sophisticated {\em structured} sparsity models, which describe the interdependency between the nonzero components of a signal, allowing to increase the interpretability of the results and lead to better recovery performance. In order to better understand the impact of structured sparsity, in this chapter we analyze the connections between the discrete models and their convex relaxations, highlighting their relative advantages. We start with the general group sparse model and then elaborate on two important special cases: the dispersive and the hierarchical models. For each, we present the models in their discrete nature, discuss how to solve the ensuing discrete problems and then describe convex relaxations. We also consider more general structures as defined by set functions and present their convex proxies. Further, we discuss efficient optimization solutions for structured sparsity problems and illustrate structured sparsity in action via three applications.Comment: 30 pages, 18 figure

    A national study of the association between traffic-related air pollution and adverse pregnancy outcomes in Canada, 1999–2008

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    AbstractNumerous studies have examined the association of air pollution with preterm birth and birth weight outcomes. Traffic-related air pollution has also increasingly been identified as an important contributor to adverse health effects of air pollution. We employed a national nitrogen dioxide (NO2) exposure model to examine the association between NO2 and pregnancy outcomes in Canada between 1999 and 2008. National models for NO2 (and particulate matter of median aerodynamic diameter <2.5µm (PM2.5) as a covariate) were developed using ground-based monitoring data, estimates from remote-sensing, land use variables and, for NO2, deterministic gradients relative to road traffic sources. Generalized estimating equations were used to examine associations with preterm birth, term low birth weight (LBW), small for gestational age (SGA) and term birth weight, adjusting for covariates including infant sex, gestational age, maternal age and marital status, parity, urban/rural place of residence, maternal place of birth, season, year of birth and neighbourhood socioeconomic status and per cent visible minority. Associations were reduced considerably after adjustment for individual covariates and neighbourhood per cent visible minority, but remained significant for SGA (odds ratio 1.04, 95%CI 1.02–1.06 per 20ppb NO2) and term birth weight (16.2g reduction, 95% CI 13.6–18.8g per 20ppb NO2). Associations with NO2 were of greater magnitude in a sensitivity analysis using monthly monitoring data, and among births to mothers born in Canada, and in neighbourhoods with higher incomes and a lower proportion of visible minorities. In two pollutant models, associations with NO2 were less sensitive to adjustment for PM2.5 than vice versa, and there was consistent evidence of a dose-response relationship for NO2 but not PM2.5. In this study of approximately 2.5 million Canadian births between 1999 and 2008, we found significant associations of NO2 with SGA and term birth weight which remained significant after adjustment for PM2.5, suggesting that traffic may be a particularly important source with respect to the role of air pollution as a risk factor for adverse pregnancy outcomes

    Statistical modeling of ground motion relations for seismic hazard analysis

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    We introduce a new approach for ground motion relations (GMR) in the probabilistic seismic hazard analysis (PSHA), being influenced by the extreme value theory of mathematical statistics. Therein, we understand a GMR as a random function. We derive mathematically the principle of area-equivalence; wherein two alternative GMRs have an equivalent influence on the hazard if these GMRs have equivalent area functions. This includes local biases. An interpretation of the difference between these GMRs (an actual and a modeled one) as a random component leads to a general overestimation of residual variance and hazard. Beside this, we discuss important aspects of classical approaches and discover discrepancies with the state of the art of stochastics and statistics (model selection and significance, test of distribution assumptions, extreme value statistics). We criticize especially the assumption of logarithmic normally distributed residuals of maxima like the peak ground acceleration (PGA). The natural distribution of its individual random component (equivalent to exp(epsilon_0) of Joyner and Boore 1993) is the generalized extreme value. We show by numerical researches that the actual distribution can be hidden and a wrong distribution assumption can influence the PSHA negatively as the negligence of area equivalence does. Finally, we suggest an estimation concept for GMRs of PSHA with a regression-free variance estimation of the individual random component. We demonstrate the advantages of event-specific GMRs by analyzing data sets from the PEER strong motion database and estimate event-specific GMRs. Therein, the majority of the best models base on an anisotropic point source approach. The residual variance of logarithmized PGA is significantly smaller than in previous models. We validate the estimations for the event with the largest sample by empirical area functions. etc
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