Evaluation of Three Different Selective Media for Enumeration of Clostridium perfringens in Untreated and Treated Wastewater

Current and emerging legislation in North Carolina and other regions calls for the enumeration of Clostridium perfringens as a surrogate indicator for protozoan parasites in various types of waters. Past studies that have evaluated selective media for the detection of this bacterium have provided limited, conflicting, and inconclusive results. In this study membrane filtration was used to enumerate C. perfringens as culturable spores or total culturable cells in 19 samples of untreated and 25 samples of partially treated wastewaters on three candidate media, Tryptose Sulfite Cycloserine Agar (TSC), CP ChromoSelect Agar (CCP), and membrane Clostridium perfringens Agar (m-CP) in parallel, and the results were compared. Presumptive isolates from each agar were further subjected to phenotypic confirmation tests for acid phosphatase production and stormy fermentation to determine the performance of each agar. The CCP agar was determined to have the highest enumerative capacity of total C. perfringens cells when compared to both TSC agar and m-CP agar (p-value 0.05). The overall specificity of CCP agar as determined by agreement of results from both confirmation tests was 0.81, while the specificity of TSC agar was only 0.28. Based on its performance, ease of preparation and use and consistency of colony characteristics, CCP agar is recommended as the preferred medium for C. perfringens enumeration in wastewater.Master of Science in Public Healt

Community-Led Total Sanitation: A Mixed-Methods Systematic Review of Evidence and Its Quality

Background: Community-led total sanitation (CLTS) is a widely applied rural behavior change approach for ending open defecation. However, evidence of its impact is unclear. Objectives: We conducted a systematic review of journal-published and gray literature to a) assess evidence quality, b) summarize CLTS impacts, and c) identify factors affecting implementation and effectiveness. Methods: Eligible studies were systematically screened and selected for analysis from searches of seven databases and 16 websites. We developed a framework to appraise literature quality. We qualitatively analyzed factors enabling or constraining CLTS, and summarized results from quantitative evaluations. Discussion: We included 200 studies (14 quantitative evaluations, 29 qualitative studies, and 157 case studies). Journal-published literature was generally of higher quality than gray literature. Fourteen quantitative evaluations reported decreases in open defecation, but did not corroborate the widespread claims of open defecation–free (ODF) villages found in case studies. Over one-fourth of the literature overstated conclusions, attributing outcomes and impacts to interventions without an appropriate study design. We identified 43 implementation- and community-related factors reportedly affecting CLTS. This analysis revealed the importance of adaptability, structured posttriggering activities, appropriate community selection, and further research on combining and sequencing CLTS with other interventions. Conclusions: The evidence base on CLTS effectiveness available to practitioners, policy makers, and program managers to inform their actions is weak. Our results highlight the need for more rigorous research on CLTS impacts as well as applied research initiatives that bring researchers and practitioners together to address implementation challenges to improve rural sanitation efforts

Temperature effects on the physiological status and reflex impairment in European grayling Thymallus thymallus from catch-and release angling

There is a growing body of research communicating how angler behaviour can be adjusted and optimised to reduce fish injury and impairment resulting from the capture of recreationally angled fishes. However, few studies have focused on how individual and interacting abiotic variables influence the outcomes of catch and release (C&R) angling. A population of European grayling Thymallus thymallus at their upper thermal limit of their geographic distribution provided a model cold-water species that was representative of other fishes sensitive to climate warming impacts and that are subjected to C&R across different seasons. Here, C&R angling for T. thymallus was conducted during summer (>15 °C) and winter (15 °C, fish took significantly longer to regain equilibrium (178 ± 44 s) than at 15 °C versus <10 °C, In entirety, these results suggest that stress responses and post-release mortality risk in cold-water fishes subjected to C&R could be reduced via temperature-informed fishery management practises, and by minimising, or ideally eliminating, air exposur

Learning and identifying haptic icons under workload

This work addresses the use of vibrotactile haptic feedback to transmit background information with variable intrusiveness, when recipients are engrossed in a primary visual and/or auditory task. Our testbed will be a novel urgency-based turn-taking protocol for remote collaboration, and our setup uses inexpensive off-the-shelf technology. We describe two studies designed to (a) perceptually optimize a set of vibrotactile &amp;quot;icons &amp;quot; for our protocol and (b) evaluate users &apos; ability to identify them in the presence of varying degrees of workload. We found that 7 icons learned in approximately 3 minutes were each typically identified within 2.5 s and at 95 % accuracy in the absence of workload. With added visual and auditory distractor tasks, the time required to detect a change in haptic icon increased from 1.9 s to an average of 4.3 s. We further provide initial parameters to help designers intelligently balance the need to support communication while minimizing disruption. 1