Solar absorption chiller

In developing nations access to electricity is inconsistent at best, and food spoilage is a prevalent issue. The solar powered absorption chiller is a refrigeration system designed to provide refrigeration to these developing areas. This year, our team has worked to develop a system where the sun\u27s rays are collected as heat to power an absorption refrigerator. The goal of this project was to take an existing solar tracker system and use its collected heat to power a refrigerator. Our team designed and built heat exchangers to extract heat from the concentrated solar system; assembled components for a fluid circulation loop; and retrofitted an absorption chiller refrigerator to be powered by our heated fluid. Additionally, we redesigned an existing solar tracking system to improve function and decrease power consumption. By the end of this year we assembled the entire system and performed months of solar testing as well as proof-ofconcept testing that the refrigerator could receive necessary heat through a heated fluid. By the end of the school year, we concluded that the heated fluid would need to reach 150°C to begin the refrigeration cycle (with current heat exchanger design), which was 25° higher than our solar testing had achieved. With further improvements, the refrigerator could be designed to run with lower heat inputs and the tracker system could be designed to attain heat at higher temperatures. With these changes, a working refrigeration system could have dramatic impacts on farming communities in developing countries; reducing food spoilage, increasing family income, and preventing food-borne illnesses

LINKING THE PSYCHOSOCIAL AETIOLOGY AND NEUROBIOLOGY OF UNIPOLAR DEPRESSION

Psychosocial factors are an important contributor to the aetiology of unipolar depression. This paper reviews the evidence for the contribution of different psychosocial factors, and provides an overview of the proposed neurobiological mechanisms underlying the link between psychosocial factors and depression. Implicated psychosocial factors fall into three interrelated groups: life events, socioeconomic status, and social support. The life events most strongly linked with depression are bereavement, disability or medical illness, and childhood maltreatment. Others include refugee status, workplace stressors, and obesity. Studies linking low socioeconomic status with depression are conflicting. There is strong evidence for the association between lack of social support and depression. Multiple neurobiological mechanisms linking psychosocial factors to depression have been suggested, though evidence remains limited. The key foci of evidence point to increased activity in the hypothalamic-pituitary-adrenal axis, epigenetic modifications of key genes, and inflammatory processes. Other mechanisms being explored include structural changes to the limbic system, prefrontal cortex, cingulate cortex, and hippocampus, and the role of other molecules such as cholecystokinin, tachykinins, spinophillin, synaptophysin and myelin basic protein. There is overlap between these mechanisms

Incorporating metapopulation Dynamics to Inform Invasive Species Management: Evaluating Bighead and Silver Carp Control Strategies in the Illinois River

1. Invasive species management can benefit from predictive models that incorporate spatially explicit demographics and dispersal to guide resource allocation decisions. 2. We used invasive bigheaded carps (Hypophthalmichthys spp.) in the Illinois River, USA as a case study to create a spatially explicit model to evaluate the allocation of future management efforts. Specifically, we compared additional harvest (e.g. near the invasion front vs. source populations) and enhanced movement deterrents to meet the management goal of reducing abundance at the invasion front. 3. We found additional harvest in lower river pools (i.e. targeting source populations) more effectively limited population sizes upriver at the invasion front compared to allocating the same harvest levels near the invasion front. Likewise, decreasing passage (i.e. lock and dam structures) at the farthest, feasible downriver location limited invasion front population size more than placing movement deterrents farther upriver. 4. Synthesis and applications. Our work highlights the benefits of adopting a multipronged approach for invasive species management, combining suppression of source populations with disrupting movement between source and sink populations thereby producing compounding benefits for control. Our results also demonstrate the importance of considering metapopulation dynamics for invasive species control programs when achieving long-term management goals

Physical activity recommendations for early childhood: an international analysis of ten different countries’ current national physical activity policies and practices for those under the age of 5

During the last two decades there have been growing interests on recommendations for children’s physical activity. The World Health Organization (WHO) launched the first global international recommendations for children in 2010, focusing on children and youth aged 5-17 year olds. The recommendations were based on the dose-response relationship between the frequency, duration, intensity, type and amount of physical activity needed for prevention of non-communicable diseases. There remains however, at time of writing, (2019) a gap in the recommendations, as the WHO did not offer global recommendations for those children under the age of 5 (early years). An international policy and practice analysis, (not previously undertaken), of ten sample countries, was completed of current national physical activity practices. Also an international comparison of early years’ education settings were examined, specifically for those under the age of 5, to investigate current curricula, as well as the qualifications, knowledge and understanding of those supporting children’s learning in different cultural contexts. The sample of ten countries (Belgium, China, Denmark, Finland, Germany, Ireland, Italy, Norway, United Kingdom and United States of America) questioned whether the global daily physical activity recommendations (WHO, 2010) are costumed and used for to the early years’ age group on a national level or if they need to be adjusted. The analysis revealed that eight countries have developed their own national recommendations for children below the age of 5, while only two countries do not have any early years’ specific physical activity recommendations. National authorities seem to be the most common executive sources behind the recommendations. The content of physical activity for children under the age of 5, mostly included the total amount and intensity of physical activity. The total daily amount of physical activity in these ten countries varies between 60 minutes moderate to vigorous intensity physical activity up to 180 min total light to moderate intensity physical activity and for some countries the daily recommendations are only from age 1 year, not between birth and 1 year, this age range remains unsupported. The conclusions from the analysis of national recommendations, underlined the need to see the global recommendations be developed for the younger age group, to support all countries. It is proposed a need for universally new recommendations to go beyond just physical activity intensity levels and to consider how young children’s development can be supported in a versatile way by physically active play. Also age specific recommendations are offered for appropriate and purposeful physical activity to support early years and school aged children’s overall development. The findings also suggest educational recommendations for staff members of early childhood education and care settings to know appropriate and age specific recommendations to ensure they are able to support young children to reach the national and global recommendations. Research recommendations are also proposed

Robust spatial frameworks for leveraging research on sustainable crop intensification

Meeting demand for food, fiber, feed, and fuel in a world with 9.7 billion people by 2050 without negative environmental impact is the greatest scientific challenge facing humanity. We hypothesize that this challenge can only be met with current and emerging technologies if guided by proactive use of a broad array of relevant data and geospatial scaling approaches to ensure local to global relevance for setting research priorities and implementing agricultural systems responsive to real-time status of weather, soils, crops, and markets. Despite increasing availability of field-scale agricultural data, robust spatial frameworks are lacking to convert these data into actionable knowledge. This commentary article highlights this knowledge gap and calls attention to the need for developing robust spatial frameworks that allow appropriate scaling to larger spatial domains by discussing a recently developed example of a data-driven strategy for estimating yield gaps of agricultural systems. To fully leverage research on sustainable intensification of cropping systems and inform policy development at different scales, we call for new approaches combining the strengths of top-down and bottom-up approaches which will require coordinated efforts between field scientists, crop modelers, and geospatial researchers at an unprecedented level

Biological consequences of nanoscale energy deposition near irradiated heavy atom nanoparticles

Gold nanoparticles (GNPs) are being proposed as contrast agents to enhance X-ray imaging and radiotherapy, seeking to take advantage of the increased X-ray absorption of gold compared to soft tissue. However, there is a great discrepancy between physically predicted increases in X-ray energy deposition and experimentally observed increases in cell killing. In this work, we present the first calculations which take into account the structure of energy deposition in the nanoscale vicinity of GNPs and relate this to biological outcomes, and show for the first time good agreement with experimentally observed cell killing by the combination of X-rays and GNPs. These results are not only relevant to radiotherapy, but also have implications for applications of heavy atom nanoparticles in biological settings or where human exposure is possible because the localised energy deposition high-lighted by these results may cause complex DNA damage, leading to mutation and carcinogenesis.</p