Search

OPREVENT2 was a multilevel, multicomponent (MLMC) adult obesity prevention that sought to improve access and demand for healthier food and physical activity opportunities in six Native American communities in the Southwest and Midwest. OPREVENT2 worked with worksites, food stores, schools (grades 2-6), through social media and mailings, and with a local community action committee (CAC), in each of the three intervention communities, and was implemented in six phases. We conducted a process evaluation to assess implementation of each intervention component in terms of reach, dose delivered and fidelity. Implementation of each component was classified as high, medium or low according to set standards, and reported back at the end of each phase, allowing for improvements. The school and worksite components were implemented with high reach, dose delivered and fidelity, with improvement over time. The school program had only moderate reach and dose delivered, as did the social media component. The CAC achieved high reach and dose delivered. Overall, study reach and dose delivered reached a high implementation level, whereas fidelity was medium. Great challenges exist in the consistent implementation of MLMC interventions. The detailed process evaluation of the OPREVENT2 trial allowed us to carefully assess the relative strengths and limitations of each intervention component.

We report on how external cavity III-V/SiN hybrid lasers operate in regimes of ultra-damped relaxation oscillations or in CW unstable dynamical regimes (self-pulsing or approaching turbulence) as a consequence of mirror dispersion, non-zero linewidth enhancement factor, and four-wave mixing in the gain medium. The impact of the dispersive mirror bandwidth and different mirror effective lengths on the laser tolerance to external optical feedback is also discussed.

We present a real-time approach for stabilizing a III-V/Si hybrid external-cavity laser implemented using microring monitoring and a feedback control loop. Laser mode stabilization over bias current and stage temperature variations are experimentally demonstrated. We achieved single-mode and mode-hop-free laser operation as the bias current was swept across 320 mA. The same feedback control also enabled wavelength-locked laser operation using an intracavity phase control. The feedback control was also applied to an integrated on-chip hybrid laser, and mode-hop-free laser operation was demonstrated over 23 °C substrate temperature variation.

A recent study using mapping techniques to analyse vulnerability over the next 20 to 30 years highlights potential ‘hotspots’ and offers insights for mitigating the effects.

Objective: To evaluate the impact of a multi-level, multi-component (MLMC) adult obesity intervention on beverage intake in Native American adults living in five geographically and culturally diverse tribal communities., Design: A 14-month, community-randomised, MLMC design was utilised, with three communities randomised to Intervention and two communities randomised to Comparison. FFQ were administered pre- and post-interventions, and difference-in-differences (DiD) analysis was used to assess intervention impact on beverage intake., Setting: The intervention took place within food stores, worksites, schools and selected media outlets located in the five communities. Key activities included working with store owners to stock healthy beverages, display and dispersal of educational materials, support of policies that discouraged unhealthy beverage consumption at worksites and schools and taste tests., Participants: Data were collected from 422 respondents between the ages of 18 and 75 living in the five communities pre-intervention; of those, 299 completed post-intervention surveys. Only respondents completing both pre- and post-intervention surveys were included in the current analysis., Results: The DiD for daily servings of regular, sugar-sweetened soda from pre- to post-intervention was significant, indicating a significant decrease in Intervention communities (P < 0·05). No other changes to beverage intake were observed., Conclusions: Large, MLMC obesity interventions can successfully reduce the intake of regular, sugar-sweetened soda in Native American adults. This is important within modern food environments where sugar-sweetened beverages are a primary source of added sugars in Native American diets.

Limited information on current dietary patterns of Native American (NA) adults exists. This paper describes the dietary intake of 582 NA adults, aged 19-75 years, living in six communities in New Mexico and Wisconsin in 2016-2017 and compares macronutrient and micronutrient intakes, estimated via a semi-quantitative 30-day Block Food Frequency Questionnaire, among different age and sex groups. NA adults consumed a diet high in % energy from total fat, saturated fat, added sugars, and sodium. A general trend of lower micronutrient intakes with increasing age was observed. Health professionals can apply this information to develop effective and culturally relevant nutrition interventions. Abbreviations: NA = Native American; CVD = Cardiovascular diseases; IOM = Institute of Medicine; IRB = Institutional Review Board; AIQ = Adult Impact Questionnaire; FFQ = Food Frequency Questionnaire; NHANES = National Health and Nutrition Examination Survey; NHNS : Navajo Health and Nutrition Survey.

Obesity prevalence is high in Native American (NA) adults, and there is a critical need to establish and implement evidence-based social, behavioral, and policy interventions that are theoretically informed. The use of multilevel, multicomponent (MLMC) interventions has been shown to be an effective strategy for comprehensive health behavior change; however, there is little guidance available in the literature to facilitate implementation in this underserved and understudied population. To decrease obesity and related comorbidities in NA adults, an MLMC intervention called OPREVENT (Obesity Prevention and Evaluation of InterVention Effectiveness in NaTive North Americans) was implemented in 5 rural NA communities to modify the food-purchasing environment, improve diet, and increase physical activity (PA). Five NA communities across the Upper Midwest and Southwest United States were randomly assigned to Immediate ( n  = 3) or Delayed ( n  = 2) Intervention. OPREVENT was implemented in Immediate Intervention community food stores, worksites, schools, and media over 1 y. A community-randomized controlled trial was used to evaluate intervention impact in adults at the individual and institutional levels, with individual-level data being collected on diet, PA, and psychosocial variables at baseline and follow-up; and institutional-level data being collected on food stores, worksites, and schools, media, and process measures. The OPREVENT intervention was one of the first MLMC obesity interventions in this population and provides evidence-based practices for future program development. The purpose of this article is to describe the design, implementation, and evaluation of OPREVENT. This trial was registered at isrctn.com as ISRCTN76144389.

Background: Obesity and other nutrition-related chronic disease rates are high in American Indian (AI) populations, and an urgent need exists to identify evidence-based strategies for prevention and treatment. Multi-level, multi-component (MLMC) interventions are needed, but there are significant knowledge gaps on how to deliver these types of interventions in low-income rural AI communities., Methods: OPREVENT2 is a MLMC intervention targeting AI adults living in six rural reservations in New Mexico and Wisconsin. Aiming to prevent and reduce obesity in adults by working at multiple levels of the food and physical activity (PA) environments, OPREVENT2 focuses on evidence-based strategies known to increase access to, demand for, and consumption of healthier foods and beverages, and increase worksite and home-based opportunities for PA. OPREVENT2 works to create systems-level change by partnering with tribal stakeholders, multiple levels of the food and PA environment (food stores, worksites, schools), and the social environment (children as change agents, families, social media). Extensive evaluation will be conducted at each level of the intervention to assess effectiveness via process and impact measures., Discussion: Novel aspects of OPREVENT2 include: active engagement with stakeholders at many levels (policy, institutional, and at multiple levels of the food and PA system); use of community-based strategies to engage policymakers and other key stakeholders (community workshops, action committees); emphasis on both the built environment (intervening with retail food sources) and the social environment. This paper describes the design of the intervention and the evaluation plan of the OPREVENT2., Trial Registration: Clinical Trial Registration: NCT02803853 (June 10, 2016).

Objectives: To describe the food environments experienced by American Indians living on tribal lands in California., Methods: Geocoded statewide food business data were used to define and categorize existing food vendors into healthy, unhealthy, and intermediate composite categories. Distance to and density of each of the composite food vendor categories for tribal lands and nontribal lands were compared using multivariate linear regression. Quantitative results were concurrently triangulated with qualitative data from in-depth interviews with tribal members (n = 24)., Results: After adjusting for census tract-level urbanicity and per capita income, results indicate there were significantly fewer healthy food outlets per square mile for tribal areas compared to non-tribal areas. Density of unhealthy outlets was not significantly different for tribal versus non-tribal areas. Tribal members perceived their food environment negatively and reported barriers to the acquisition of healthy food., Conclusions: Urbanicity and per capita income do not completely account for disparities in food environments among American Indians tribal lands compared to nontribal lands. This disparity in access to healthy food may present a barrier to acting on the intention to consume healthy food., Competing Interests: The authors have declared that no competing interests exist.

The relationship between dietary patterns and chronic disease is underexplored in indigenous populations. We assessed diets of 424 American Indian (AI) adults living in 5 rural AI communities. We identified four food patterns. Increased prevalence for cardiovascular disease was highly associated with the consumption of unhealthy snacks and high fat-food patterns (OR 3.6, CI=1.06, 12.3; and OR 6.0, CI=1.63, 22.1), respectively. Moreover, the food-consumption pattern appeared to be different by community setting (p<.05). We recommend culturally appropriate community-intervention programs to promote healthy behavior and to prevent diet-related chronic diseases in this high-risk population.

The genetic composition of present day human populations is determined largely by the interaction between the human host and infective agents. Therefore, theoretical analysis of the host-infective-agent system is required in order for us to be able to understand human evolution. Classical population genetics has been confined largely to analysing the interplay of various mechanisms, such as selection, mutation and drift, in one species at a time. Unfortunately, there have been few studies of such interactive systems. In the present investigation, these studies have been enlarged, with problems of human genetics in mind, by mathematical examination of a model in which a diploid host with three alleles interacts with a haploid infective agent with two alleles. The results are compared with those obtained from simpler models analysed in the past. The assumptions inherent in such "gene for gene" models and our results are discussed. An increase in the number of alleles appears to enhance the chances for the establishment of permanent genetic polymorphisms, improving genetic "elasticity" of a population for coping with changing challenges by various infective agents. Interaction between two haploid species leads to a loss of polymorphism in both of them and, hence, to a severe loss of evolutionary elasticity. The hypothesis that the evolution of diploidy might have been favoured by a selective advantage of diploid organisms interacting with environmental challenges, such as infective agents, is supported.