Extended phenotypes can underlie trade-offs: a case of social spiders.

Extended phenotypes engineered by animals can potentially improve safety and/or foraging. Whether the well-known trade-off between safety and foraging applies for extended phenotypes, and if so, how it is resolved has not been determined. Spiders build elaborate silk structures that serve as traps for their insect prey and often attach silken retreats (nests) to their capture webs. These extended phenotypes of spiders are made of silk that is considered costly since it is made of protein. Using the Indian social spider, Stegodyphus sarasinorum, we examined how simple proximal factors, like colony hunger state and group size, shape trade-offs in collectively built extended phenotypes that offer shelter and food. We found that well-fed colonies showed greater investment in retreat silk than starved colonies. However, the two groups did not differ in their investment in capture webs. Hence, our findings validate the starvation-risk taking hypothesis in an extended phenotypic paradigm by showing that hungry colonies trade-off retreat size for capture web, irrespective of group size.

Personalizing the Dietary Guidelines: Use of a feedback report to help adolescent students plan health behaviors using a SMART goal approach.

BACKGROUND: School health curricula should help students choose health goals related to the Dietary Guidelines (DG) recommendations addressing obesity. We aimed to identify characteristics associated with choice of DG recommendation items. METHODS: In 12 HealthCorps affiliated high schools, students completed a 19-item web-based questionnaire that provided a personalized health-behavior feedback report to guide setting SMART (Specific, Measurable, Action-oriented, Realistic, Time-bound) goals. We examined if gender, weight-status, and personalized feedback report messages were related to student-selected SMART Goals. RESULTS: The most frequent SMART Goals focused on breakfast (22.4%), physical activity (21.1%), and sugary beverages (20.4%). Students were more likely to choose a SMART goal related to breakfast, sugary beverages, fruit/vegetable intake or physical activity if their feedback report suggested that health behavior was problematic (p<0.0001). Males were more likely than females to set sugary beverage goals (p<0.05). Females tended to be more likely than males to set breakfast goals (p=0.051). Students, who had obesity, were more likely than normal weight students to set physical activity goals (p<0.05). CONCLUSION: SMART goals choice was associated with gender and weight status. SMART goal planning with a web-based questionnaire and personalized feedback report appears to help students develop goals related to the Dietary Guidelines recommendations.

Correction to: Effective nationwide school-based participatory extramural program on adolescent body mass index, health knowledge and behaviors.

CORRECTION: Following the publication of the original article [1], it was brought to our attention that author Judith Wylie-Rosett was erroneously included as Judith Wylie.

Effective nationwide school-based participatory extramural program on adolescent body mass index, health knowledge and behaviors.

BACKGROUND: Adolescent obesity is a major public health concern. Open to all high school students regardless of weight status, HealthCorps is a nationwide program offering a comprehensive high school-based participatory educational program to indirectly address obesity. We tested a hypothesis that the HealthCorps program would decrease BMI z-scores among overweight or obese students, and reduce obesity rates, and evaluated its effects on health knowledge and behaviors. METHODS: HealthCorps aimed to improve student knowledge and behaviors regarding nutrition quality, physical activity, sleep, breakfast intake, and mental resilience. Participating students received through HealthCorps coordinators weekly or bi-weekly classroom lessons either for a semester or a year in addition to various during- and after-school health-promoting activities and mentorship. Self-reported height and weight were collected along with questionnaires assessing knowledge and behaviors during 2013-2014 academic year among 14 HealthCorps-participating New York City high schools. This quasi experimental two-arm pre-post trial included 611 HealthCorps and 221 comparison arm students for the analytic sample. Sex-specific analyses stratified by weight status were adjusted for age and Hispanic ethnicity with clustering effects of schools and students taken into account. RESULTS: HealthCorps female overweight/obese and obese student had a significant decrease in BMI z-scores (post-pre delta BMI z-score = -0.16 (95%CI = (-0.26, -0.05), p = 0.004 for the former; and = -0.23 (-0.44, -0.03), p = 0.028, for the latter) whereas comparison female counterparts did not. The HealthCorps students, but not the comparison students, had a significant increase for all knowledge domains except for the breakfast realm, and reported a greater number of significant behavior changes including fruit and vegetable intake and physical activities. CONCLUSIONS: The HealthCorps program was associated with reduced BMI z-score in overweight/obese and obese female adolescents, with enhanced health knowledge and behavior for both sexes. With its wide reach, this may be a promising program to help combat adolescent obesity in schools. TRIAL REGISTRATION: This study is registered as a clinical trial at the ClinicalTrials.gov registry with trial number NCT02277496 on September 10, 2014 (Retrospectively registered).

Spatially explicit modeling of 1992-2100 land cover and forest stand age for the conterminous United States.

Information on future land-use and land-cover (LULC) change is needed to analyze the impact of LULC change on ecological processes. The U.S. Geological Survey has produced spatially explicit, thematically detailed LULC projections for the conterminous United States. Four qualitative and quantitative scenarios of LULC change were developed, with characteristics consistent with the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES). The four quantified scenarios (A1B, A2, B1, and B2) served as input to the forecasting scenarios of land-use change (FORE-SCE) model. Four spatially explicit data sets consistent with scenario storylines were produced for the conterminous United States, with annual LULC maps from 1992 through 2100. The future projections are characterized by a loss of natural land covers in most scenarios, with corresponding expansion of anthropogenic land uses. Along with the loss of natural land covers, remaining natural land covers experience increased fragmentation under most scenarios, with only the B2 scenario remaining relatively stable in both the proportion of remaining natural land covers and basic fragmentation measures. Forest stand age was also modeled. By 2100, scenarios and ecoregions with heavy forest cutting had relatively lower mean stand ages compared to those with less forest cutting. Stand ages differed substantially between unprotected and protected forest lands, as well as between different forest classes. The modeled data were compared to the National Land Cover Database (NLCD) and other data sources to assess model characteristics. The consistent, spatially explicit, and thematically detailed LULC projections and the associated forest stand-age data layers have been used to analyze LULC impacts on carbon and greenhouse gas fluxes, biodiversity, climate and weather variability, hydrologic change, and other ecological processes.