Collection efficiency and design of microbial air samplers

The variables affecting the physical collection efficiency of air samplers of the type that impact microbe-carrying particles onto agar were investigated using a simplified analytical method and computational fluid dynamics. The results from these two techniques were compared, as were the effect of jet velocity, nozzle size, and nozzle distance from the agar surface; also considered was the optimisation of these variables to obtain an efficient design of sampler. A technique is described that calculates the proportion of microbe-carrying particles that a sampler will collect from a typical size distribution of microbe-carrying particles found in an occupied room; the three air samplers studied were found to collect from about 22% to over 99% of the micro-organisms in the room air

Connection of ES cell-derived collecting ducts and ureter-like structures to host kidneys in culture

Work toward renal generation generally aims either to introduce suspensions of stem cells into kidneys in the hope that they will rebuild damaged tissue, or to construct complete new kidneys from stem cells with the aim of transplanting the engineered organs. In principle, there might be a third approach; to engineer renal tissue ‘modules’ in vitro and to use them to replace sections of damaged host kidney. This approach would require the urine collecting system or ureter of the new tissues to connect to those of the host. In this report, we demonstrate a method that allows collecting duct trees or ureters, engineered from ES cells, to connect to the collecting duct system or ureter, respectively, of fetal kidneys in culture

Letter sent to the members and associates of the American Institute of Accountants

https://egrove.olemiss.edu/aicpa_assoc/1340/thumbnail.jp

Renal engineering:strategies to address the problem of the ureter

Current techniques for making renal organoids generate tissues that show function when transplanted into a host, but they have no ureter through which urine can drain. There are at least 4 possible strategies for adding a ureter: connecting to ta host ureter; inducing an engineered kidney to make a ureter; making a stem-cell derived ureter; and replacement of only damaged cortex and outer medulla, using remaining host calyces, pelvis and ureter. Here we review progress: local BMP4 can induce a collecting duct tubule to become a ureter; a urothelial tube can be produced directly from pluripotent cells, and connect to the collecting duct system of a renal organoid; it is possible to graft ES cell-derived ureters into host kidney rudiments and see connection, smooth muscle development and spontaneous contraction, but this has not yet been achieved with all components being derived from ES cells. Remaining problems are discussed

The potential of a stratified ontology for developing materials in community-based coastal marine environmental education processes

This study set out to explore the possibilities that the Critical Realist concept of a stratified ontology might have for environmental learning and materials development processes. This involved processes of ongoing contextual profiling; the use of picture-based resources and storytelling to support the engagement with the marine harvesting contexts of the villages of Hamburg and Ngqinisa, in the former Ciskei. At the heart of the study was the process of uncovering the empirical, the actual and the real in the context of a community of coastal marine harvesters whose lives and livelihoods are affected by poverty and a history of inequality, and more recently by issues such as HIV/AIDS. Their stories of existing practice changed as we engaged with picture-based narratives, gaining depth and focus in relation to sustainability issues. The learning processes associated with and emerging out of the research processes were enhanced through abductive use of metaphors and graphic illustrations, and through intra- and inter community exchanges, again using picture based narratives. As the study unfolded, the development of environmental education materials receded. Focus turned to how conceptual abstraction processes (of abduction (metaphor) and retroduction) and the stratified ontological framework allowed for learning across epistemological divides