1,978 research outputs found

    Force, power, and string being?

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    Design Justice in Community-Oriented Engineering Pedagogy and Practice

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    While engineering service-learning projects are seen as a favorable way for students to reinforce curricular learning while gaining cultural awareness, the outcomes of these projects center student benefits over partner community wellbeing. For these projects, and in other engineering contexts, various scholar-activists have conceptualized numerous principles and methods to center justice and equity in engineering outcomes. This research project and its associated intervention involved collecting scholarship and methods in engineering and social justice, and attempted to integrate these ideas into the practices of a local humanitarian service-learning engineering team. The collected scholarship centered around the topics of Design Justice, feminist qualitative science & technology studies, and Latin American decolonial theory. In partnership with the Engineers Without Borders Cal Poly Local projects team, following the frameworks of critical participatory action research and community autoethnography, the author spent time with the team to build relationships and facilitated presentations, dialogues, and activities around the collected scholarship. Two sets of semi-structured interviews were conducted before and after the intervention, and qualitative data was analyzed using iterative thematic inquiry. This project found that a local humanitarian engineering-service learning environment was a suitable space to advocate alternative design principles and methods, and that students expressed a desire to learn more about these topics, as well as utilize and share these resources with their friends and in other contexts such as their professional careers. Students experienced moderate amounts of success in using the collected scholarship to modify their project practices, specifically their plans for community assessment. These results imply that other spaces and organizations with an explicit focus on service or social justice may be ideal environments to attempt to implement alternative design principles, and that more efforts to enable students to learn about and share alternative principles could have lasting effects

    Robust self-trapping of vortex beams in a saturable optical medium

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    We report the first observation of robust self-trapping of vortex beams propagating in a uniform condensed medium featuring local saturable self-focusing nonlinearity. Optical vortices with topological charge m=1, that remain self-trapped over ~ 5 Rayleigh lengths, are excited in carbon disulfide using a helical light beam at 532 nm and intensities from 8 to 10 GW/cm^2. At larger intensities, the vortex beams lose their stability, spontaneously breaking into two fragments. Numerical simulations based on the nonlinear Schr\"odinger equation including the three-photon absorption and nonpolynomial saturation of the refractive nonlinearity demonstrate close agreement with the experimental findings.Comment: 27 pages, 7 figures,to be published in Phys. Rev. A (2016

    Enabling Future Sustainability Transitions: An Urban Metabolism Approach to Los Angeles Pincetl et al. Enabling Future Sustainability Transitions

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    Summary: This synthesis article presents an overview of an urban metabolism (UM) approach using mixed methods and multiple sources of data for Los Angeles, California. We examine electric energy use in buildings and greenhouse gas emissions from electricity, and calculate embedded infrastructure life cycle effects, water use and solid waste streams in an attempt to better understand the urban flows and sinks in the Los Angeles region (city and county). This quantification is being conducted to help policy-makers better target energy conservation and efficiency programs, pinpoint best locations for distributed solar generation, and support the development of policies for greater environmental sustainability. It provides a framework to which many more UM flows can be added to create greater understanding of the study area's resource dependencies. Going forward, together with policy analysis, UM can help untangle the complex intertwined resource dependencies that cities must address as they attempt to increase their environmental sustainability

    Evaluation of Marker-Assisted Introgression of Yield QTL Alleles into Adapted Soybean

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    Genetic diversity is limited in southern elite soybean [Glycine max (L.) Merrill]. Introgression of diverse alleles for yield may increase the rate of yield improvement. Beneficial yield alleles at three quantitative trait loci (QTL) from the northern cultivar Archer have been tagged with molecular markers. The objective of this research was to assess the value of the three Archer alleles for increased yield in southern environments and genetic backgrounds. Four sets of near isogenic lines (NIL) for each quantitative trait locus (QTL) were derived from heterozygous F6 plants identified from the crosses of Archer X Asgrow A5403 and Archer X Pioneer 9641. The NIL sets were tested at four environments across 2 yr. Data was collected on yield, height, and maturity. None of the marker effects were significant for any of the three QTL for any trait, when averaged over all sets or for individual sets. The results suggest that the Archer alleles are not superior to the southern alleles when tested in southern environments. Archer has low relative yield in the South, while in the original mapping study ARcher was the high-yield adapted parent. The superior genetic value assigned to the Archer yield QTL to may not be readily transported to populations or environments where Archer is inferior. Recombination and epistasis may also have affected the ability of the Archer markers and QTL to improve yield. Our results indicate that it may be difficult to capture the value assigned to QTL alleles derived from diverse parents with variable relative genetic value when the alleles are introgressed into populations with different genetic backgrounds, or when tested in different environments

    Retention and Efficacy of Citizen Scientist Volunteers of the Texas Quail Index

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    The Texas Quail Index (TQI) was a 5-year, science-based project that utilized citizen scientists to collect data in the field, including 5 indices of bobwhite abundance in the spring, and 3 indices of bobwhite abundance in the fall. Over the course of the study, 84% of all volunteers dropped out of the program and \u3c8% of all data sets were complete. Accordingly, we surveyed the volunteers by mail to determine the rate and cause of participation decline and to identify characteristics of a reliable volunteer. Results indicated that annual volunteer participation rate declined more rapidly as time and labor requirements increased. Similarly, 74.3% of survey respondents who dropped out of the study reported leaving because the project required too much time and work. Motives may have contributed to the volunteer attrition as 72% of volunteers joined the program to learn more about quail management; however 71% of those that left the program reported not gaining knowledge in that area. We recommend that project designs, for citizen-science projects, should incorporate the motives of volunteers and recruit those whose motives best align with project goals. We also recommend that citizen-science coordinators keep volunteer tasks short and within the interest of the volunteer, to increase retention. Finally, we recommend stipends for volunteers on large-scale, laborious projects

    Using online learning modules to fight against antibiotic resistance in Australia

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    © 2013 Jorge Reyna, Santosh Khanal and Tessa Morgan. NPS MedicineWise and the Australian Commission on Safety and Quality in Health Care (ACSQHC) have launched a series of online learning modules designed to help combat antibiotic resistance in hospitals. The aim of the modules is to fill a previously unmet need for an online teaching resource on a common curriculum for hospitals and universities. The modules address specific areas where antibiotic use in hospitals needs improvement. Problem Based Learning has been used as pedagogical approach for the modules. Clinical scenarios are presented with a logical progression of tasks including clinical assessment and diagnosis, investigations, interpretation of results, and antibiotic selection. Expert advice and feedback has been incorporated at each step, helping to improve learning outcomes. Learners can access the modules at their own pace and revisit them upon completion. We report, for the first time, participants’ perceptions of the antimicrobial modules as learning resource, usability issues, and possible areas of improvement

    Relationships between Meteorological and other Variables and Bobwhite Spring Call Counts

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    Accurate assessment of quail population trends is critical to the success of future conservation efforts. Financial considerations and time constraints often limit population trend estimates to indices, the most common of which are spring call counts and autumn covey counts. While all indices have limitations and caveats, spring call count data specifically possess variability that makes them ill-suited for detecting fine-scale trends. However, because spring call counts record calling males and are relatively easy to conduct, they are assumed to represent an index of breeding potential and produce the most data per unit cost. Here, we examine their variability, comparing the number of male northern bobwhites (Colinus virginianus; hereafter, bobwhite) calling and weather measurements recorded during \u3e4,000 spring call counts conducted May–July 2014–2017. The number of male bobwhites recorded per call count decreased \u3e2 hours after sunrise, as ambient temperatures increased, but increased with relative humidity. An increase in ambient noise was associated with recording fewer male bobwhites. There was no correlation with either wind speed/hour for 3 of 4 years, or with the Palmer Drought Severity Index. Comparing these results with other spring call counts in the literature highlights inconsistency in spring call count timing, and discrepancies between call count protocols and weather conditions that affect detection probability. We suggest incorporating these results into future call counts to more accurately assess bobwhite population trends

    Effect of Cadmium Exposure on Planarian Regeneration

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    Cadmium is a neurotoxic chemical widely distributed within our environments, persevering for long periods. It can be found in cigarettes, batteries, plastics, and other products used daily. Exposure to cadmium can have toxic effects, altering the balance between the production of reactive oxygen species (ROS) and the ability of cells to detoxify and repair the damage. Its accumulation can cause organ damage, cancer, respiratory and reproductive toxicity, and neurological defects. Planaria regeneration is a complex biological process that involves the activation of stem cells, called neoblasts, to regenerate lost tissues and organs. Neoblasts can divide and differentiate into various cell types, allowing planaria to rapidly regrow lost body parts, including the head and tail. Research has suggested that ROS play a critical role in this process. However, if an overproduction occurs, oxidative stress can inhibit regeneration. A trunk fragment assay will be conducted on Girardia dorotocephala to monitor the progression of head regeneration over a two-week period. This assay will be used in future work, exposing planarians to varying concentrations of cadmium chloride. Exposure to high levels of cadmium is said to inhibit blastema repair, so introducing the flatworms to an antioxidant should cause a rescuing effect and progress its regeneration. Antioxidants mitigate damages by neutralizing ROS by donating an electron to stabilize oxidative stress and enhance regenerative capacity. The study of planarian regeneration holds great promise for developing regenerative medicine approaches for humans
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