CFD Study of a Tunnel-Ventilated Compost-Bedded Pack Barn Integrating an Evaporative Pad Cooling System.

Evaporative cooling is one of the most efficient techniques to reduce heat stress in cows in agricultural facilities. Additionally, compost-bedded pack barn has been shown to improve the welfare and production of cows. Two techniques were combined and analysed by developing a computational fluid dynamics (CFD) model of a tunnel-ventilated compost-bedded packed barn that integrated the heat and airflow dynamics of an evaporative pad cooling system. This allowed us to study the distribution of dry-bulb temperature, relative humidity and airflow velocity inside the barn based on the external environmental conditions, thickness of the pad, water temperature and specific manufacturer characteristics of the pad, providing optimal cooling pad location, size and operating conditions in the barn. Employing experimental data the CFD model was validated showing good agreement. The Equivalent Temperature Index for dairy Cattle (ETIC) was used to determine the level of stress of the cows considering the airflow velocity. It was found a moderate stress due to high relative humidity and low airflow velocity. From the predicted results, it was recommended to increase the airflow velocity above 3 m s-1 when simultaneously the external dry-bulb temperature and relative humidity exceed 30 °C and 55%, respectively, simultaneously. Additionally, installation of baffles at the pad outlet to drive the airflow to the floor was suggested to improve the drying of the compost-bedded closed to the pads, where a low airflow velocity region was established.

Social cohesion emerging from a community-based physical activity program: A temporal network analysis.

Community-based physical activity programs, such as the Recreovía, are effective in promoting healthy behaviors in Latin America. To understand Recreovías' challenges and scalability, we characterized its social network longitudinally while studying its participants' social cohesion and interactions. First, we constructed the Main network of the program's Facebook profile in 2013 to determine the main stakeholders and communities of participants. Second, we studied the Temporal network growth of the Facebook profiles of three Recreovía locations from 2008 to 2016. We implemented a Time Windows in Networks algorithm to determine observation periods and a scaling model of cities' growth to measure social cohesion over time. Our results show physical activity instructors as the main stakeholders (20.84% nodes of the network). As emerging cohesion, we found: (1) incremental growth of Facebook users (43-272 nodes), friendships (55-2565 edges), clustering coefficient (0.19-0.21), and density (0.04-0.07); (2) no preferential attachment behavior; and (3) a social cohesion super-linear growth with 1.73 new friendships per joined user. Our results underscore the physical activity instructors' influence and the emergent cohesion in innovation periods as a co-benefit of the program. This analysis associates the social and healthy behavior dimensions of a program occurring in natural environments under a systemic approach.

Quality of public urban parks for physical activity practice in Bucaramanga, Colombia / Qualidade dos parques públicos urbanos para a prática de atividades físicas em Bucaramanga, Colômbia

Abstract The characteristics of parks (availability, accessibility, conservation, quality, safety, etc.) are important predictors of their use for physical activity practices. The aim of this study was to verify the association among the socioeconomic level of neighborhoods, the characteristics and quality of urban public parks for physical activity in Bucaramanga, Colombia. Cross-sectional study, conducted in 2015, in which 10 parks with structures for physical activity were evaluated. The socioeconomic level of the district was evaluated based on the neighborhoods around the parks and classified in "low" and "high". The number of residents in the surrounding area of parks were evaluated with Geographic Information System (GIS), site characteristics and quality with the System for Observing Play and Recreation in Communities (SOPARC) and the Physical Activity Resource Assessment (PARA), respectively. The association was analyzed with Mann Whitney U test and Spearman correlation (rho) on STATA 14 and the significance level was maintained at 5%. A positive association was found between the socioeconomic level and the presence of walking paths (marginal, p=0.056), accessibility (rho=0.875; p=0.001) and general quality of parks (rho=0.657; p=0.039). The low socioeconomic level was associated with the presence of sports courts (p=0.032). These results can guide the actions of public managers for the modification of the built environment and structures of the parks for physical activity.

Resumo As características dos parques (disponibilidade, acessibilidade, conservação, qualidade, segurança, etc.) são importantes preditores da sua utilização para a prática de atividades físicas. O objetivo deste estudo foi verificar a associação entre o nível socioeconômico dos bairros com as características e a qualidade dos parques públicos urbanos para a prática de atividades físicas em Bucaramanga, Colômbia. Estudo transversal, realizado em 2015, no qual foram avaliados 10 parques com estruturas para atividades físicas. O nível socioeconômico da região foi avaliado com base nos bairros próximos aos parques e classificado em "baixo" e "alto". O número de residentes próximos foi avaliado com o Sistema de Informação Geográfica (SIG), as características do local e a qualidade foram avaliadas, respectivamente, com o System for Observing Play and Recreation in Communities (SOPARC) e o Physical Activity Resource Assessment (PARA). A associação foi analisada com o teste U de Mann Whitney e a correlação de Spearman (rho) no STATA 14 e o nível de significância mantido em 5%. Foi verificada associação positiva entre o nível socioeconômico e a presença de pistas de caminhada (marginal, p=0,056), acessibilidade (rho=0,875; p=0,001) e qualidade geral dos parques (rho=0,657; p=0,039). O baixo nível socioeconômico foi associado à presença de quadras para esportes (p=0,032). Esses resultados podem orientar as ações dos gestores públicos para a modificação do ambiente construído e estruturas dos parques para a atividade física.

The Recreovía of Bogotá, a Community-Based Physical Activity Program to Promote Physical Activity among Women: Baseline Results of the Natural Experiment Al Ritmo de las Comunidades.

Community-based physical activity (PA) programs in Latin America have been recognized because of the use of available environmental resources to offer PA classes. Yet, the evaluation of programs focused on PA classes involving dancing in public spaces is limited. The aim of this study was to assess the physical activity levels, park use, and the contextual characteristics of public parks with and without the Recreovía in Bogotá in Colombia. Al Ritmo de las Comunidades is a natural experiment conducted in nine parks (3 parks implementing new Recreovías, 3 control parks and 3 parks with existing Recreovías) during 2013. We used the System for Observing Play and Recreation in Communities to evaluate park use (gender, age, and physical activity level) and target areas. A total of 4925 people were observed during 702 observation visits to parks. The percentage of women was higher in parks with Recreovía, compared to parks without Recreovía (53% vs. 40% vs. 33%; p < 0.001). Women using parks with Recreovía compared to women in parks without Recreovía were less likely to be sedentary (25% vs. 39%; p < 0.0001) and more likely to engage in moderate-to-vigorous activity (75% vs. 61%; p < 0.0001). Among men, the activity pattern was the opposite. The Recreovía is a promising strategy to promote park use and PA, especially among women who are less likely to meet PA recommendations during their leisure time. The provision of a cost-free community program may be an effective approach and a good investment for health.

Start small, dream big: Experiences of physical activity in public spaces in Colombia.

Multi-sectoral strategies to promote active recreation and physical activity in public spaces are crucial to building a "culture of health". However, studies on the sustainability and scalability of these strategies are limited. This paper identifies the factors related to the sustainability and scaling up of two community-based programs offering physical activity classes in public spaces in Colombia: Bogotá's Recreovía and Colombia's "Healthy Habits and Lifestyles Program-HEVS". Both programs have been sustained for more than 10years, and have benefited 1455 communities. We used a mixed-methods approach including semi-structured interviews, document review and an analysis of data regarding the programs' history, characteristics, funding, capacity building and challenges. Interviews were conducted between May-October 2015. Based on the sustainability frameworks of Shediac-Rizkallah and Bone and Scheirer, we developed categories to independently code each interview. All information was independently analyzed by four of the authors and cross-compared between programs. Findings showed that these programs underwent adaptation processes to address the challenges that threatened their continuation and growth. The primary strategies included flexibility/adaptability, investing in the working conditions and training of instructors, allocating public funds and requesting accountability, diversifying resources, having community support and champions at different levels and positions, and carrying out continuous advocacy to include physical activity in public policies. Recreovía and HEVS illustrate sustainability as an incremental, multi-level process at different levels. Lessons learned for similar initiatives include the importance of individual actions and small events, a willingness to start small while dreaming big, being flexible, and prioritizing the human factor.