542 research outputs found
Computer simulation of simultaneous evolution of individual texture components During recrystallization of an IF steel
Computer simulation of simultaneous evolution of individual texture components during recrystallization of an IF steel is carried out. A new methodology has been developed that takes as its starting point experimental data of each texture component evolving during recrystallization. In particular, Magnusson et al. data on IF steel was analyzed in a previous work with the help of the exact analytical tools developed by Rios and Villa for simultaneous transformations. From this analysis parameters such as number of nuclei of each texture component per unit of volume could be obtained and were employed as input for the present computer simulation. From this input 3-d microstructures could then be generated. The methodology proposed here combines experimental data, exact analytical methods and computer simulation and may be employed to extract the maximum information from the experimental data
Perinatal exposure to traffic-related air pollution and autism spectrum disorders
Background: Studies from the United States indicate that exposure to air pollution in early life
is associated with autism spectrum disorders (ASD) in children, but the evidence is not consistent
with European data.
Objective: We aimed to investigate the association between exposure to air pollution from road
traffic and the risk of ASD in children, with careful adjustment for socioeconomic and other
confounders.
Method: Children born and residing in Stockholm, Sweden, during 1993–2007 with an ASD
diagnosis were identified through multiple health registers and classified as cases (n = 5,136). A
randomly selected sample of 18,237 children from the same study base constituted controls. Levels
of nitrogen oxides (NOx) and particulate matter with diameter ≤ 10 μm (PM10) from road traffic
were estimated at residential addresses during mother’s pregnancy and the child’s first year of life by
dispersion models. Odds ratios (OR) and 95% confidence intervals (CI) for ASD with or without
intellectual disability (ID) were estimated using logistic regression models after conditioning on
municipality and calendar year of birth as well as adjustment for potential confounders.
Result: Air pollution exposure during the prenatal period was not associated with ASD overall
(OR = 1.00; 95% CI: 0.86, 1.15 per 10-ÎĽg/m3 increase in PM10 and OR = 1.02; 95% CI:
0.94, 1.10 per 20-μg/m3 increase in NOx during mother’s pregnancy). Similar results were seen for
exposure during the first year of life, and for ASD in combination with ID. An inverse association
between air pollution exposure and ASD risk was observed among children of mothers who moved
to a new residence during pregnancy.
Conclusion: Early-life exposure to low levels of NOx and PM10 from road traffic does not appear to increase the risk of ASD.Swedish Research Council for Health, Working Life and Welfare (FORTE), 2012-0573, 2015-00289Swedish Research Council, 2011-3060Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS)Swedish Innovation Agency (VINNOVA), 259-2012-24Swedish Research Council, Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM), 340-2013-5867HKH Kronprinsessan Lovisas förening for barnasjukvårdStrategic Research Program in Epidemiology at Karolinska InstitutetPublishe
Perinatal exposure to traffic-related air pollution and autism spectrum disorders
Background:
Studies from the United States indicate that exposure to air pollution in early life
is associated with autism spectrum disorders (ASD) in children, but the evidence is not consistent
with European data.
Objective: We aimed to investigate the association between exposure to air pollution from road
traffic and the risk of ASD in children, with careful adjustment for socioeconomic and other
confounders.
Method: Children born and residing in Stockholm, Sweden, during 1993–2007 with an ASD
diagnosis were identified through multiple health registers and classified as cases (n = 5,136). A
randomly selected sample of 18,237 children from the same study base constituted controls. Levels
of nitrogen oxides (NOx) and particulate matter with diameter ≤ 10 μm (PM10) from road traffic
were estimated at residential addresses during mother’s pregnancy and the child’s first year of life by
dispersion models. Odds ratios (OR) and 95% confidence intervals (CI) for ASD with or without
intellectual disability (ID) were estimated using logistic regression models after conditioning on
municipality and calendar year of birth as well as adjustment for potential confounders.
Result: Air pollution exposure during the prenatal period was not associated with ASD overall
(OR = 1.00; 95% CI: 0.86, 1.15 per 10-ÎĽg/m3 increase in PM10 and OR = 1.02; 95% CI:
0.94, 1.10 per 20-μg/m3 increase in NOx during mother’s pregnancy). Similar results were seen for
exposure during the first year of life, and for ASD in combination with ID. An inverse association
between air pollution exposure and ASD risk was observed among children of mothers who moved
to a new residence during pregnancy.
Conclusion: Early-life exposure to low levels of NOx and PM10 from road traffic does not appear
to increase the risk of ASD.NonePublishe
Lower breast cancer survival in mothers of children with a malignancy: a national study
As it is unclear if hereditary factors affect breast cancer survival, this was compared using fertility and cancer registry data, among all women so diagnosed during 1961–1999 in Sweden, having a child with childhood cancer (⩽20 years of age; n=254) and with that of other women (n=74 781). Those having a child with a childhood malignancy had a significantly worse survival than other women, relative risk (RR)=1.25, 95% CI 1.02–1.55, P<0.04, adjusted for age at diagnosis, year of diagnosis, parity and time since last pregnancy. Childhood sarcomas or acute myeloid leukaemia seemed to be most associated with a worse survival in the mother (RR=1.38 and 1.69, respectively). The lower survival of the mother was present for breast cancer diagnosed both before and after 50 years of age. The Li–Fraumeni syndrome and possibly other genetic disorders may lower breast cancer survival
Using performance-based regulation to reduce childhood obesity
BackgroundWorldwide, the public health community has recognized the growing problem of childhood obesity. But, unlike tobacco control policy, there is little evidence about what public policies would work to substantially reduce childhood obesity. Public health leaders currently tend to support traditional "command and control" schemes that order private enterprises and governments to stop or start doing specific things that, is it hoped, will yield lower childhood obesity rates. These include measures such as 1) taking sweetened beverages out of schools, 2) posting calorie counts on fast-food menu boards, 3) labeling foods with a "red light" if they contain high levels of fat or sugar, 4) limiting the density of fast food restaurants in any neighborhood, 5) requiring chain restaurants to offer "healthy" alternatives, and 6) eliminating junk food ads on television shows aimed at children. Some advocates propose other regulatory interventions such as 1) influencing the relative prices of healthy and unhealthy foods through taxes and/or subsidies and 2) suing private industry for money damages as a way of blaming childhood obesity on certain practices of the food industry (such as its marketing, product composition, or portion size decisions). The food industry generally seeks to deflect blame for childhood obesity onto others, such as parents and schools
The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease
<p>Abstract</p> <p>Background</p> <p>Balance impairment is one of the most distressing symptoms in Parkinson's disease (PD) even with pharmacological treatment (levodopa). A complementary treatment is high frequency stimulation in the subthalamic nucleus (STN). Whether STN stimulation improves postural control is under debate. The aim of this study was to explore the effects of STN stimulation alone on balance performance as assessed with clinical performance tests, subjective ratings of fear of falling and posturography.</p> <p>Methods</p> <p>Ten patients (median age 66, range 59–69 years) with bilateral STN stimulation for a minimum of one year, had their anti-PD medications withdrawn overnight. Assessments were done both with the STN stimulation turned OFF and ON (start randomized). In both test conditions, the following were assessed: motor symptoms (descriptive purposes), clinical performance tests, fear of falling ratings, and posturography with and without vibratory proprioceptive disturbance.</p> <p>Results</p> <p>STN stimulation alone significantly (p = 0.002) increased the scores of the Berg balance scale, and the median increase was 6 points. The results of all timed performance tests, except for sharpened Romberg, were significantly (p ≤ 0.016) improved. The patients rated their fear of falling as less severe, and the total score of the Falls-Efficacy Scale(S) increased (p = 0.002) in median with 54 points. All patients completed posturography when the STN stimulation was turned ON, but three patients were unable to do so when it was turned OFF. The seven patients with complete data showed no statistical significant difference (p values ≥ 0.109) in torque variance values when comparing the two test situations. This applied both during quiet stance and during the periods with vibratory stimulation, and it was irrespective of visual input and sway direction.</p> <p>Conclusion</p> <p>In this sample, STN stimulation alone significantly improved the results of the clinical performance tests that mimic activities in daily living. This improvement was further supported by the patients' ratings of fear of falling, which were less severe with the STN stimulation turned ON. Posturography could not be performed by three out of the ten patients when the stimulation was turned OFF. The posturography results of the seven patients with complete data showed no significant differences due to STN stimulation.</p
Plasma Homeostasis and Cloacal Urine Composition in Crocodylus porosus Caught Along a Salinity Gradient
Juveniles of the Estuarine or Saltwater Crocodile, Crocodylus porosus, maintain both osmotic pressure and plasma electrolyte homeostasis along a salinity gradient from fresh water to the sea. In fresh water (FW) the cloacal urine is a clear solution rich in ammonium and bicarbonate and containing small amounts of white precipitated solids with high concentrations of calcium and magnesium. In salt water (SW) the cloacal urine has a much higher proportion of solids, cream rather than white in colour, which are the major route for excretion of potassium in addition to calcium and magnesium. Neither liquid nor solid fractions of the cloacal urine represent a major route for excretion of sodium chloride. The solids are urates and uric acid, and their production probably constitutes an important strategy for water conservation by C. porosus in SW. These data, coupled with natural history observations and the recent identification of lingual salt glands, contribute to the conclusion that C. porosus is able to live and breed in either fresh or salt water and may be as euryhaline as any reptile
Reproductive performance in sows in relation to Japanese Encephalitis Virus seropositivity in an endemic area
Japanese Encephalitis Virus (JEV) is considered an important reproductive pathogen in pigs. Most studies of the reproductive impact of JEV have been conducted in areas where the disease occurs in seasonal epidemics. In this study, the associations between seropositivity for JEV, measured with an IgG ELISA, and the number of piglets born alive and stillborn were investigated in a tropical area endemic for JEV in Vietnam. Sixty percent of sows from four farms in the Mekong delta of Vietnam were seropositive to JEV and the Odds Ratio for a sow being infected was highest (6.4) in sows above 3.5 years (95% confidence interval 2.2–18.3). There was an association between increasing Optical Density (OD) values from the ELISA and the number of stillborn piglets in sows less than 1.5 years, but no effect of seropositivity could be shown when all sows were studied. OD values had an effect (p = 0.04) on the number of piglets born alive in the statistical analysis only when interacting with the effect of the breeds. An increase in mean OD value of the herd was correlated (p < 0.0001) with an increase in the number of piglets born alive. In this study, there was evidence of a negative association between seropositivity for JEV and the reproductive performance only in sows less than 1.5 years in endemic areas. This could be explained by a year-round infection with the virus, which would lead to immunity in many gilts before their first pregnancy. This, in turn, may imply that JEV infection in pigs is of minor importance for the reproductive performance in endemic areas
A Longitudinal Test of the Demand–Control Model Using Specific Job Demands and Specific Job Control
# The Author(s) 2010. This article is published with open access at Springerlink.com Background Supportive studies of the demand–control (DC) model were more likely to measure specific demands combined with a corresponding aspect of control. Purpose A longitudinal test of Karasek’s (Adm Sci Q. 24:285–308, 1) job strain hypothesis including specific measures of job demands and job control, and both selfreport and objectively recorded well-being. Method Job strain hypothesis was tested among 267 health care employees from a two-wave Dutch panel survey with a 2-year time lag. Results Significant demand/control interactions were found for mental and emotional demands, but not for physical demands. The association between job demands and job satisfaction was positive in case of high job control, whereas this association was negative in case of low job control. In addition, the relation between job demands and J. de Jonge (*
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