26 research outputs found
Dramatic Increases in Obesity and Overweight Prevalence and Body Mass Index Among Ethnic-Immigrant and Social Class Groups in the United States, 1976–2008
This study examined trends in US obesity and overweight prevalence and body mass index (BMI) among 30 immigrant groups, stratified by race/ethnicity and length of immigration, and among detailed education, occupation, and income/poverty groups from 1976 to 2008. Using 1976–2008 National Health Interview Surveys, differentials in obesity, overweight, and BMI, based on self-reported height and weight, were analyzed by using disparity indices, logistic, and linear regression. The obesity prevalence for the US population aged ≥18 tripled from 8.7% in 1976 to 27.4% in 2008. Overweight prevalence increased from 36.9% in 1976 to 62.0% in 2008. During 1991–2008, obesity prevalence for US-born adults increased from 13.9 to 28.7%, while prevalence for immigrants increased from 9.5 to 20.7%. While immigrants in each ethnic group and time period had lower obesity and overweight prevalence and BMI than the US-born, immigrants’ risk of obesity and overweight increased with increasing duration of residence. In 2003–2008, obesity prevalence ranged from 2.3% for recent Chinese immigrants to 31–39% for American Indians, US-born blacks, Mexicans, and Puerto Ricans, and long-term Mexican and Puerto Rican immigrants. Between 1976 and 2008, the obesity prevalence more than quadrupled for those with a college education or sales occupation. Although higher prevalence was observed for lower education, income, and occupation levels in each period, socioeconomic gradients in obesity and overweight decreased over time because of more rapid increases in prevalence among higher socioeconomic groups. Continued immigrant and socioeconomic disparities in prevalence will likely have substantial impacts on future obesity trends in the US
Temperature responses of Rubisco from Paniceae grasses provide opportunities for improving C3 photosynthesis.
Enhancing the catalytic properties of the CO2-fixing enzyme Rubisco is a target for improving agricultural crop productivity. Here, we reveal extensive diversity in the kinetic response between 10 and 37 °C by Rubisco from C3 and C4 species within the grass tribe Paniceae. The CO2 fixation rate (kcatc) for Rubisco from the C4 grasses with nicotinamide adenine dinucleotide (NAD) phosphate malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PCK) photosynthetic pathways was twofold greater than the kcatc of Rubisco from NAD-ME species across all temperatures. The declining response of CO2/O2 specificity with increasing temperature was less pronounced for PCK and NADP-ME Rubisco, which would be advantageous in warmer climates relative to the NAD-ME grasses. Modelled variation in the temperature kinetics of Paniceae C3 Rubisco and PCK Rubisco differentially stimulated C3 photosynthesis relative to tobacco above and below 25 °C under current and elevated CO2. Amino acid substitutions in the large subunit that could account for the catalytic variation among Paniceae Rubisco are identified; however, incompatibilities with Paniceae Rubisco biogenesis in tobacco hindered their mutagenic testing by chloroplast transformation. Circumventing these bioengineering limitations is critical to tailoring the properties of crop Rubisco to suit future climates
Assessment of the health of Americans: the average health-related quality of life and its inequality across individuals and groups
BACKGROUND: The assessment of population health has traditionally relied on the population's average health measured by mortality related indicators. Researchers have increasingly recognized the importance of including information on health inequality and health-related quality of life (HRQL) in the assessment of population health. The objective of this study is to assess the health of Americans in the 1990s by describing the average HRQL and its inequality across individuals and groups. METHODS: This study uses the 1990 and 1995 National Health Interview Survey from the United States. The measure of HRQL is the Health and Activity Limitation Index (HALex). The measure of health inequality across individuals is the Gini coefficient. This study provides confidence intervals (CI) for the Gini coefficient by a bootstrap method. To describe health inequality by group, this study decomposes the overall Gini coefficient into the between-group, within-group, and overlap Gini coefficient using race (White, Black, and other) as an example. This study looks at how much contribution the overlap Gini coefficient makes to the overall Gini coefficient, in addition to the absolute mean differences between groups. RESULTS: The average HALex was the same in 1990 (0.87, 95% CI: 0.87, 0.88) and 1995 (0.87, 95% CI: 0.86, 0.87). The Gini coefficient for the HALex distribution across individuals was greater in 1995 (0.097, 95% CI: 0.096, 0.099) than 1990 (0.092, 95% CI: 0.091, 0.094). Differences in the average HALex between all racial groups were the same in 1995 as 1990. The contribution of the overlap to the overall Gini coefficient was greater in 1995 than in 1990 by 2.4%. In both years, inequality between racial groups accounted only for 4–5% of overall inequality. CONCLUSION: The average HRQL of Americans was the same in 1990 and 1995, but inequality in HRQL across individuals was greater in 1995 than 1990. Inequality in HRQL by race was smaller in 1995 than 1990 because race had smaller effect on the way health was distributed in 1995 than 1990. Analysis of the average HRQL and its inequality provides information on the health of a population invisible in the traditional analysis of population health
The effect of different design concepts in lumbar total disc arthroplasty on the range of motion, facet joint forces and instantaneous center of rotation of a L4-5 segment
Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. For the different implant designs, a three-dimensional finite element model was created and subsequently inserted into a validated model of a L4-5 lumbar spinal segment. The unconstrained design was represented by two implants, the Charité® disc and a newly developed disc prosthesis: Slide-Disc®. The constrained design was obtained by a modification of the Slide-Disc® whereby the inner core was rigidly connected to the lower metallic endplate. The models were exposed to an axial compression preload of 1,000 N. Pure unconstrained moments of 7.5 Nm were subsequently applied to the three anatomical main planes. Except for extension, the models predicted only small and moderate inter-implant differences. The calculated values were close to those of the intact segment. For extension, a large difference of about 45% was calculated between both Slide-Disc designs and the Charité® disc. The models predicted higher facet forces for the implants with an unconstrained core compared to an implant with a constrained core. All implants caused a moving center of rotation. Except for axial rotation, the unconstrained and constrained configurations mimicked the intact situation. In axial rotation, only the Slide-Disc® with mobile core reproduced the intact behavior. Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location of center of rotations. In contrast, facet forces appeared to be strongly dependent on the implant design. However, due to the great variability in facet forces reported in the literature, together with our results, we could speculate that these forces may be more dependent on the individual spine geometry rather than a specific implant design
Racial and geographic variation in coronary heart disease mortality trends
<p>Abstract</p> <p>Background</p> <p>Magnitudes, geographic and racial variation in trends in coronary heart disease (CHD) mortality within the US require updating for health services and health disparities research. Therefore the aim of this study is to present data on these trends through 2007.</p> <p>Methods</p> <p>Data for CHD were analyzed using the US mortality files for 1999–2007 obtained from the US Centers for Disease Control and Prevention. Age-adjusted annual death rates were computed for non-Hispanic African Americans (AA) and European Americans (EA) aged 35–84 years. The direct method was used to standardize rates by age, using the 2000 US standard population. Joinpoint regression models were used to evaluate trends, expressed as annual percent change (APC).</p> <p>Results</p> <p>For both AA men and women the magnitude in CHD mortality is higher compared to EA men and women, respectively. Between 1999 and 2007 the rate declined both in AA and in EA of both sexes in every geographic division; however, relative declines varied. For example, among men, relative average annual declines ranged from 3.2% to 4.7% in AA and from 4.4% to 5.5% in EA among geographic divisions. In women, rates declined more in later years of the decade and in women over 54 years. In 2007, age-adjusted death rate per 100,000 for CHD ranged from 93 in EA women in New England to 345 in AA men in the East North Central division. In EA, areas near the Ohio and lower Mississippi Rivers had above average rates. Disparities in trends by urbanization level were also found. For AA in the East North Central division, the APC was similar in large central metro (−4.2), large fringe metro (−4.3), medium metro urbanization strata (−4.4), and small metro (−3.9). APC was somewhat higher in the micropolitan/non-metro (−5.3), and especially the non-core/non-metro (−6.5). For EA in the East South Central division, the APC was higher in large central metro (−5.3), large fringe metro (−4.3) and medium metro urbanization strata (−5.1) than in small metro (−3.8), micropolitan/non-metro (−4.0), and non-core/non-metro (−3.3) urbanization strata.</p> <p>Conclusions</p> <p>Between 1999 and 2007, the level and rate of decline in CHD mortality displayed persistent disparities. Declines were greater in EA than AA racial groups. Rates were greater in the Ohio and Mississippi River than other geographic regions.</p