Designer schools: the role of school space and architecture in obesity prevention

Spatial features of obesogenic environments studied on a broad community level have been associated with childhood overweight and obesity, but little research has focused on the effects of the design of micro spaces, such as schools, on individual health behaviors. This article aims to generate thinking and research on the link between school space and architecture and obesity prevention by reviewing and synthesizing available literature in architecture, environmental psychology, and obesity research, in an effort to propose promising ideas for school space design and redesign. The school environment is defined through 5 dimensions: physical, legal, policy, social, and cultural domains. Theories underlying environmental interventions and documented associations between the environment and health behaviors and outcomes are reviewed to illustrate how existing environmental research could translate to obesity prevention. Design strategies aimed at promoting physical activity and healthful eating are proposed, with particular emphasis on the design of cafeterias, activity spaces, connectivity with the larger community, and student health centers.     

Forecasting the obesity epidemic in the aging U.S. population

Objective: The objective was to forecast BMI distribution in the U.S. population along with demographic changes based on past race‐, sex‐, and birth cohort‐specific secular trends. Research Methods and Procedures: We compiled data from 44,184 subjects from 4 National Health and Nutrition Examination Surveys (NHANES; 1971 to 2004). By race and sex, we fit regression models to create smoothed mean BMI curves by age for 1970 to 2010. Linking corresponding birth cohorts across age‐ and year‐specific mean BMI projections, we estimated the trajectory of relative BMI throughout each cohort's lifetime. These projections were validated using actual cohorts in the Nurses’ Health Study and Health Professionals Follow‐up Study. Combined with U.S. census, we predicted BMI distributions in 2010 and examined the joint impact of the obesity epidemic and population aging. Results: BMI secular trends in the past 3 decades differ significantly by birth cohort, sex, and race. If these trends continue, the prevalence of obesity is expected to reach 35%, 36%, 33%, and 55% in 2010 among white men, white women, black men, and black women, respectively, far from the Healthy People 2010 goal of 15%. Such forecasts translate into 9.3 million more obese adults 20 to 74 years of age than in 2000, 8.3 million of whom would be 50 years of age or older, and 8.5 million of whom would be white. The mean age among obese men and women is also expected to rise from 47 to 49 years among whites and from 43 to 44 years among blacks. Discussion: As the baby boom generation approaches retirement age, the continuing obesity epidemic signals a likely expansion in the population with obesity‐related comorbidities. A framework to combine BMI and demographic trends is essential in evaluating the burden and disparity associated with the epidemic in the aging U.S. population.     

Fatness and fitness: exposing the logic of evolutionary explanations for obesity

To explore the logic of evolutionary explanations of obesity we modelled food consumption in an animal that minimizes mortality (starvation plus predation) by switching between activities that differ in energy gain and predation. We show that if switching does not incur extra predation risk, the animal should have a single threshold level of reserves above which it performs the safe activity and below which it performs the dangerous activity. The value of the threshold is determined by the environmental conditions, implying that animals should have variable ‘set points’. Selection pressure to prevent energy stores exceeding the optimal level is usually weak, suggesting that immediate rewards might easily overcome the controls against becoming overweight. The risk of starvation can have a strong influence on the strategy even when starvation is extremely uncommon, so the incidence of mortality during famine in human history may be unimportant for explanations for obesity. If there is an extra risk of switching between activities, the animal should have two distinct thresholds: one to initiate weight gain and one to initiate weight loss. Contrary to the dual intervention point model, these thresholds will be inter-dependent, such that altering the predation risk alters the location of both thresholds; a result that undermines the evolutionary basis of the drifty genes hypothesis. Our work implies that understanding the causes of obesity can benefit from a better understanding of how evolution shapes the mechanisms that control body weight.     

Birthplace, years of residence in the United States, and obesity among Mexican-American adults

Objective: To evaluate the association between birthplace (Mexico or U.S.) and obesity in men and women and to analyze the relationship between duration of U.S. residency and prevalence of obesity in Mexican immigrants. Research Methods and Procedures: We used cross‐sectional data from 7503 adults of Mexican descent residing in Harris County, TX, to evaluate the relationships among BMI, birthplace, and years of residency in the U.S., controlling for demographic characteristics, physical activity level, and acculturation level. Results: U.S.‐born adults had an increased risk (between 34% and 65%) of obesity compared with their Mexican‐born counterparts. After controlling for recognized confounders and risk factors, this association was maintained in the highly acculturated only. Among highly acculturated obese U.S.‐born men, 6% of the cases were attributable to the joint effect of birthplace and acculturation; in women, this proportion was 25%. Among Mexican‐born women, there was an increasing trend in mean BMI with increasing duration of residency in the U.S. Compared with immigrants who had lived in the U.S. for <5 years, Mexican‐born women who had resided in the U.S. for ≥15 years had an adjusted BMI mean difference of 2.12 kg/m² (95% confidence interval, 1.53–2.72). Discussion: Mexican‐born men and women have a lower risk of obesity than their U.S.‐born counterparts, but length of U.S. residency among immigrants, especially in women, is directly associated with risk of obesity. Development of culturally specific interventions to prevent obesity in recent immigrants may have an important public health effect in this population.     

Bio-oil from photosynthetic microalgae: Case study

Microalgae possess the potential to produce bio-oils, carbohydrates, protein, amino acids and other value added products, each of which increase its value as a crop. Unfortunately, proven systems do not yet exist for commercial scale production. System designs have generally not adequately accounted for water and energy use at scale, as well as byproduct markets, and thus yielded systems that are both unaffordable and unsustainable. We address energy and water use by presenting a straightforward microalga-to-bio-oil production process and then characterize system performance using steady-state water and energy balances. Practical limitations to commercial production of bio-oils from photosynthetic microalgae are proposed and conclusions drawn regarding system potential for assumed biomass productivities. As this is a theoretical analysis of a generic process and in practice many of the bottlenecks presented remain to be solved, it is our intent that the analysis framework presented herein can be applied to future systems that propose such solutions.     

Trends of selected malformations in relation to folic acid recommendations and fortification: an international assessment

BACKGROUND: Two crucial issues relative to the benefits and impact of folic acid in the prevention of birth defects are whether supplementation recommendations alone, without fortification, are effective in reducing the population-wide rates of neural tube defects (NTDs), and whether such policies can reduce the occurrence of other birth defects. Using data from 15 registries, we assessed rates and trends of 14 major defects, including NTDs, in areas with official recommendations or fortification to assess the effectiveness of recommendations and fortification on a wide range of major birth defects. METHODS: We evaluated surveillance data through 2003 on major birth defects from population-based registries from Europe, North America, and Australia. All included ascertainment of pregnancy terminations (where legal). Trends before and after policies or fortification were assessed via Poisson regression and were compared via rate ratios. RESULTS: Significant changes in trends were seen for NTDs in areas with fortification but not in areas with supplementation recommendations alone. For other major birth defects, there was an overall lack of major trend changes after recommendations or fortification. However, some significant declines were observed for select birth defects in individual areas. CONCLUSIONS: Recommendations alone remain an ineffective approach in translating the known protective effect of folic acid in population-wide decline in NTD rates. Fortification appears to be effective in reducing NTDs. The effect on other birth defects remains unclear.     

黄河小浪底人工混交林生长季能量平衡特征

利用涡度相关系统和小气候梯度观测系统,对黄河小浪底人工混交林2012年生长季(5—9月)各能量通量进行了连续观测,分析了该生态系统能量平衡各项的变化特征,讨论了能量闭合状况。结果表明:潜热通量、感热通量和土壤热通量均与净辐射有类似的日变化特征。各项的绝对值大小表现为净辐射潜热通量感热通量土壤热通量。受日照时数的影响,5—9月能量平衡各项正值的日持续时间逐渐缩短。生长季,净辐射、感热通量和土壤热通量在6月份最大,最大值分别为418.5、231.4和12.5 MJ m-2month-1);潜热通量在7月份达到最大,最大值为320.8 MJ m-2month-1)。潜热通量、感热通量和土壤热通量占净辐射的比例分别在0.48—0.62、0.15—0.55、0.02—0.05之间。人工混交林生长季的能量分配主要以潜热通量和感热通量为主,且潜热通量为感热通量的2倍。波文比呈单峰曲线:6月最大,8月最小。黄河小浪底人工混交林生长季全天能量闭合度为79%。其中,白天闭合程度较高(81%),夜晚较低(41%)。本研究站点存在21%的能量不闭合。其原因可能与通量源区面积不匹配、忽略冠层热储存、湍流能的相位差等有关。     

Monitoring the obesity epidemic in France: the Obepi surveys 1997-2006

The objective of the study was to describe the prevalences of obesity in French adults over a 9-year period. Mailed questionnaire surveys, in 1997, 2000, 2003, and 2006, sampled 20,000 representative French households by the method of quotas. Weight, height, and waist circumference were reported by all members of the selected households > or = 18-years. Obesity was defined according to the WHO criteria, BMI > 30 kg/m2. The prevalence of adult obesity increased progressively from 8.6% (95% confidence interval: 8.2-8.8) in 1997 to 13.1% (12.7-13.5) in 2006. The increase affected all ages, socioeconomic strata, and regions. Although the prevalence of obesity increased in parallel in men and women from 1997 to 2003, the rate of increase was lower in men between 2003 and 2006. These surveys showed a sharp increase in the prevalence of obesity in France in recent years contrasting with a stable prevalence in the 1980s. The results of the first Obepi surveys prompted the French government to implement a Nutrition and Health National Plan in 2001. Regular monitoring of obesity prevalence in France and neighboring countries is needed to compare future trends.     

Ethical models underpinning responses to threats to public health: a comparison of approaches to communicable disease control in Europe

Increases in international travel and migratory flows have enabled infectious diseases to emerge and spread more rapidly than ever before. Hence, it is increasingly easy for local infectious diseases to become global infectious diseases (GIDs). National governments must be able to react quickly and effectively to GIDs, whether naturally occurring or intentionally instigated by bioterrorism. According to the World Health Organisation, global partnerships are necessary to gather the most up-to-date information and to mobilize resources to tackle GIDs when necessary. Communicable disease control also depends upon national public health laws and policies. The containment of an infectious disease typically involves detection, notification, quarantine and isolation of actual or suspected cases; the protection and monitoring of those not infected; and possibly even treatment. Some measures are clearly contentious and raise conflicts between individual and societal interests. In Europe national policies against infectious diseases are very heterogeneous. Some countries have a more communitarian approach to public health ethics, in which the interests of individual and society are more closely intertwined and interdependent, while others take a more liberal approach and give priority to individual freedoms in communicable disease control. This paper provides an overview of the different policies around communicable disease control that exist across a select number of countries across Europe. It then proposes ethical arguments to be considered in the making of public health laws, mostly concerning their effectiveness for public health protection.     

Central rather than overall obesity is related to diabetes in the Chinese population: the InterASIA study

Objective: The objective was to compare central and overall obesity measurements for identifying diabetes mellitus (DM) and impaired fasting glucose (IFG) level in the Chinese population. Research Methods and Procedures: Data for 15,236 Chinese adults between the ages of 35 and 74 years, obtained by the InterASIA Study in 2000–2001, were used for the current analyses. We analyzed the areas under the receiver operating characteristic (ROC) curves (AUCs) for waist circumference (WC), waist‐to‐hip ratio (WHR), and BMI to determine the ability of these indices to identify DM and IFG in the study sample and bootstrapped samples. WC was used as a measure of central obesity and BMI as a measure of overall obesity. Results: The prevalence rates of central and overall obesity in the study population were 33.97% and 9.78%, respectively. The prevalence rates of IFG and DM were 7.34% and 5.51%, respectively. ROC analysis revealed significant differences between AUCs for WHR (0.666, 95% confidence interval, 0.647 to 0.685) and BMI (0.622, 95% confidence interval, 0.601 to 0.642) and for WC (0.661, 95% confidence interval, 0.643 to 0.682) and BMI for identifying DM (all p < 0.0001). The analysis also revealed significant differences between AUCs for WHR (0.638, 95% confidence interval, 0.619 to 0.655) and BMI (0.607, 95% confidence interval, 0.589 to 0.627) and for WC (0.637, 95% confidence interval, 0.615 to 0.654) and BMI for identifying IFG (all p < 0.001). Discussion: Central obesity is more related to DM and IFG than is overall obesity in the Chinese population, and both WC and WHR are equally able to identify DM.     

The dispersion of age differences between partners and the asymptotic dynamics of the HIV epidemic

In this paper, the effect of a change in the distribution of age differences between sexual partners on the dynamics of the HIV epidemic is studied. In a gender- and age-structured compartmental model, it is shown that if the variance of the distribution is small enough, an increase in this variance strongly increases the basic reproduction number. Moreover, if the variance is large enough, the mean age difference barely affects the basic reproduction number. We, therefore, conclude that the local stability of the disease-free equilibrium relies more on the variance than on the mean.     

青藏高原牧区家庭能源消费对生态环境和人体健康的影响研究现状与展望

探究家庭能源消费对生态环境和人体健康的研究是系统推进家庭能源绿色低碳转型和实现联合国2030可持续发展目标的关键。重点综述了目前家庭能源消费、影响因素及其对生态环境和居民健康影响的国际研究现状。目前研究不足主要聚焦在以下两个方面：一方面,影响家庭能源消费因素的贡献率和影响消费行为的驱动机制尚不清晰;另一方面,目前主要针对家庭能源消费或者生态系统或者环境或者居民健康其中的某一方面或者某两个方面开展研究,鲜有研究系统的考虑家庭能源消费对生态环境和人体健康影响的综合研究。基于上述研究现状,结合青藏高原的实际情况,提出未来需要在宏观层面和微观层面加强研究。宏观层面：(1)亟需厘清青藏高原家庭能源与生态环境和人体健康之间的内在联系与驱动机制,形成青藏高原牧区“家庭能源-生态效应-环境效应-健康效应”的理论分析框架;(2)构建模块化的牧区“能源-生态-环境-健康-经济”等多学科交叉的综合评估模型,形成完整的、系统的评估方法。微观层面：(1)迫切开展青藏高原家庭能源消费特征与变化规律的研究;(2)深入开展家庭能源消费特征和变化规律与生态系统的反馈机制与量化研究;(3)加强牧区室内空气污染物浓度测定,...     

The spatiotemporal trajectory of a dengue epidemic in a medium-sized city

Understanding the transmission dynamics of infectious diseases is important to allow for improvements of control measures. To investigate the spatiotemporal pattern of an epidemic dengue occurred at a medium-sized city in the Northeast Region of Brazil in 2009, we conducted an ecological study of the notified dengue cases georeferenced according to epidemiological week (EW) and home address. Kernel density estimation and space-time interaction were analysed using the Knox method. The evolution of the epidemic was analysed using an animated projection technique. The dengue incidence was 6.918.7/100,000 inhabitants; the peak of the epidemic occurred from 8 February-1 March, EWs 6-9 (828.7/100,000 inhabitants). There were cases throughout the city and was identified space-time interaction. Three epicenters were responsible for spreading the disease in an expansion and relocation diffusion pattern. If the health services could detect in real time the epicenters and apply nimbly control measures, may possibly reduce the magnitude of dengue epidemics.     

BMI and seatbelt use

Objective: Seatbelt use among obese persons may be reduced because seatbelts are uncomfortable. We investigated the association between obesity and seatbelt use with data from the 2002 Behavioral Risk Factor Surveillance System Survey. Research Methods and Procedures: Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals (CIs) for seatbelt use among overweight (BMI, 25.0 to 29.9), obese (BMI, 30.0 to 39.9), and extremely obese (BMI ≥ 40.0) persons, relative to a non‐overweight/non‐obese reference group (BMI ≤ 24.9), adjusted for age, race, gender, education, and state seatbelt law. Results: Adjusted odds ratios for seatbelt use were 0.89 (95% CI, 0.85 to 0.93) for overweight, 0.69 (0.66 to 0.73) for obese, and 0.45 (95% CI, 0.40 to 0.50) for extremely obese persons. Interaction effects were evident for all covariates, with stronger associations between increasing BMI and decreasing seatbelt use for women, increasing age, higher education, and residence in states with a secondary seatbelt law. There was a linear decrease in seatbelt use with increasing BMI for all subgroups except persons 18 to 24 years old. Discussion: Lack of seatbelt can be added to the list of risk factors associated with obesity. Effective preventive interventions are needed to promote seatbelt use among overweight and obese persons.