146 research outputs found

    Effects of fire-fighting on a fully developed compartment fire: temperatures and emissions

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    This study evaluates the effects and consequences of fire-fighting operations on the main characteristics of a fully-developed compartment fire. It also presents data and evaluation of the conditions to which fire-fighters are exposed. A typical room enclosure was used with ventilation through a corridor to the front access door. The fire load was wooden pallets. Flashover was reached and the fire became fully developed before the involvement of the fire-fighting team. The progression of the fire-fighters through the corridor and the main-room suppression attack - in particular the effect of short, medium and long water pulses on either the hot gas layer or the fire seat - was charted against the compartment temperatures, heat release rates, oxygen levels and toxic species concentrations. The fire fighting team was exposed to extreme conditions, heat fluxes in excess of 35 kW/m2 and temperatures of the order of 250 oC even at crouching level. The fire equivalence ratio showed rich burning with high toxic emissions in particular of CO and unburnt hydrocarbons very early in the fire history and a stabilisation of the equivalence ratio at about 1.8. The fire fighting operations made the combustion temporarily richer and the emissions even higher

    Physical activity and clustered cardiovascular disease risk factors in young children: a cross-sectional study (the IDEFICS study)

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    <p>Background The relevance of physical activity (PA) for combating cardiovascular disease (CVD) risk in children has been highlighted, but to date there has been no large-scale study analyzing that association in children aged ≤9 years of age. This study sought to evaluate the associations between objectively-measured PA and clustered CVD risk factors in a large sample of European children, and to provide evidence for gender-specific recommendations of PA.</p> <p>Methods Cross-sectional data from a longitudinal study in 16,224 children aged 2 to 9 were collected. Of these, 3,120 (1,016 between 2 to 6 years, 2,104 between 6 to 9 years) had sufficient data for inclusion in the current analyses. Two different age-specific and gender-specific clustered CVD risk scores associated with PA were determined. First, a CVD risk factor (CRF) continuous score was computed using the following variables: systolic blood pressure (SBP), total triglycerides (TG), total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-c) ratio, homeostasis model assessment of insulin resistance (HOMA-IR), and sum of two skinfolds (score CRFs). Secondly, another CVD risk score was obtained for older children containing the score CRFs + the cardiorespiratory fitness variable (termed score CRFs + fit). Data used in the current analysis were derived from the IDEFICS (‘Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS’) study.</p> <p>Results In boys <6 years, the odds ratios (OR) for CVD risk were elevated in the least active quintile of PA (OR: 2.58) compared with the most active quintile as well as the second quintile for vigorous PA (OR: 2.91). Compared with the most active quintile, older children in the first, second and third quintiles had OR for CVD risk score CRFs + fit ranging from OR 2.69 to 5.40 in boys, and from OR 2.85 to 7.05 in girls.</p> <p>Conclusions PA is important to protect against clustering of CVD risk factors in young children, being more consistent in those older than 6 years. Healthcare professionals should recommend around 60 and 85 min/day of moderate-to-vigorous PA, including 20 min/day of vigorous PA.</p&gt

    Hypertensive patients' use of blood pressure monitors stationed in pharmacies and other locations: a cross-sectional mail survey

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    <p>Abstract</p> <p>Background</p> <p>Blood pressure (BP) monitors are commonly stationed in public places such as pharmacies, but it is uncertain how many people with hypertension currently use them. We sought to estimate the proportion of hypertensive patients who use these types of monitors and examine whether use varies by demographic or health characteristics.</p> <p>Methods</p> <p>We conducted a cross-sectional mail survey of hypertensive adults enrolled in a practice based research network of 24 primary care practices throughout the state of North Carolina. We analyzed results using descriptive statistics and examined bivariate associations using chi-square and independent associations using logistic regression.</p> <p>Results</p> <p>We received 530 questionnaires (76% response rate). Of 333 respondents (63%) who reported checking their BP in locations other than their doctor's office or home, 66% reported using a monitor stationed in a pharmacy. Younger patients more commonly reported using pharmacy monitors (48% among those < 45 years vs 35% of those over 65, p = 0.04). Blacks reported using them more commonly than whites (48% vs 39%, p = 0.03); and high school graduates more often than those with at least some college (50% vs 37%, p = 0.02). In multivariate analysis, younger age (aOR 1.49; 95% CI 1.00–2.21 for those age 45 to 65 years vs those > 65 years old) and high school education (aOR 1.74; 95% CI 1.13–2.58) were associated with use of pharmacy-stationed monitors, but Black race was not. Patients with diabetes, heart disease, or stroke were not more likely to use pharmacy-stationed monitors.</p> <p>Conclusion</p> <p>Hypertensive patients' use of BP monitors located in pharmacies is common. Younger patients, Blacks, and those with high school education were slightly more likely to report using them. Because use of these monitors is so common, efforts to ensure their accuracy are important.</p

    Racial Disparity in Police Stop and Searches in England and Wales

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    Data published by the United Kingdom's Ministry for Justice clearly shows that, compared to persons who were White, members of racial minorities in England, particularly Blacks, were far more likely to be stopped and searched by the police. The question is whether such racial disparity in stops and searches could be justified by racial disparities in offending? Or whether the disparity in stop and searches exceeded the disparity in offending? This paper proposes a method for measuring the amount of excess in racial disparity in police stop and searches. Using the most recently published Ministry of Justice data (for 2007/08) for Police Areas in England and Wales it concludes that while in several Areas there was no excess to racial disparity in police stop and searches, there was, on the basis of the methodology proposed in the paper, evidence of such excess in some Police Areas of England and Wales

    Physical Stress, Not Biotic Interactions, Preclude an Invasive Grass from Establishing in Forb-Dominated Salt Marshes

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    Biological invasions have become the focus of considerable concern and ecological research, yet the relative importance of abiotic and biotic factors in controlling the invasibility of habitats to exotic species is not well understood. Spartina species are highly invasive plants in coastal wetlands; however, studies on the factors that control the success or failure of Spartina invasions across multiple habitat types are rare and inconclusive.We examined the roles of physical stress and plant interactions in mediating the establishment of the smooth cordgrass, Spartina alterniflora, in a variety of coastal habitats in northern China. Field transplant experiments showed that cordgrass can invade mudflats and low estuarine marshes with low salinity and frequent flooding, but cannot survive in salt marshes and high estuarine marshes with hypersaline soils and infrequent flooding. The dominant native plant Suaeda salsa had neither competitive nor facilitative effects on cordgrass. A common garden experiment revealed that cordgrass performed significantly better when flooded every other day than when flooded weekly. These results suggest that physical stress rather than plant interactions limits cordgrass invasions in northern China.We conclude that Spartina invasions are likely to be constrained to tidal flats and low estuarine marshes in the Yellow River Delta. Due to harsh physical conditions, salt marshes and high estuarine marshes are unlikely to be invaded. These findings have implications for understanding Spartina invasions in northern China and on other coasts with similar biotic and abiotic environments

    High blood pressure in school children: prevalence and risk factors

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    BACKGROUND: The purpose of this study was to determine the prevalence of high blood pressure (HBP) and associated risk factors in school children 8 to 13 years of age. METHODS: Elementary school children (n = 1,066) were examined. Associations between HBP, body mass index (BMI), gender, ethnicity, and acanthosis nigricans (AN) were investigated using a school based cross-sectional study. Blood pressure was measured and the 95(th )percentile was used to determine HBP. Comparisons between children with and without HBP were utilized. The crude and multiple logistic regression adjusted odds ratios were used as measures of association. RESULTS: Females, Hispanics, overweight children, and children with AN had an increased likelihood of HBP. Overweight children (BMI ≥ 85(th )percentile) and those with AN were at least twice as likely to present with HBP after controlling for confounding factors. CONCLUSION: Twenty one percent of school children had HBP, especially the prevalence was higher among the overweight and Hispanic group. The association identified here can be used as independent markers for increased likelihood of HBP in children

    Cardiovascular magnetic resonance in systemic hypertension

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    Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR) provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue characterization of diffuse and focal fibrosis. In addition, CMR is well suited for exclusion of common secondary causes for hypertension. We review the current and emerging clinical and research applications of CMR in hypertension
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