Intracellular free sodium and potassium, post-carbachol hyperpolarization, and extracellular potassium-undershoot in rat sympathetic neurones

Double-barrelled ion-sensitive microelectrodes were used to record the free intracellular Na+- and K+-concentrations ([Na+]i, [K+]i) and to determine their relation to changes in membrane potential and extracellular K+ ([K+]e) in rat sympathetic ganglia. The application of 50 μmol/l carbachol resulted in an elevation of [K+]e followed by a post-carbachol [K+]e-undershoot. The membrane depolarization of the sympathetic neurones was associated with an increase in [Na+]i and a decrease in [K+]i. A membrane hyperpolarization and a recovery of [K+]i and [Na+]i to their baseline levels were observed during the [K+]e-undershoot. The time course of the [K+]e-undershoot correlated exactly with the duration of the rise in [Na+]i and decrease of [K+]i. No K+-reuptake occurred in the presence of ouabain. These data confirm, by direct measurements of intracellular ion concentration changes, the contribution of the Na+, K+-pump to the post-carbachol membrane hyperpolarization and [K+]e-undershoot

Serving Sophomore Students

College sophomores have been deemed invisible students. This label is the result of a combination of issues students typically face during their sophomore year. Problems include: integration into social networks, declaration of a major, decisions regarding study abroad and/or internships, and disenchantment with the university, among others. A review of survey data reveals that sophomores at Illinois Wesleyan University are no different and face all of these problems. In addition to the above, sophomores at Illinois Wesleyan University have some expectations of the University that are not being met, such as course availability, adequacy of food service, and advising. These combined forces are resulting directly in attrition of some sophomores from the university. This project aims to justify and design a program that would address both universal and specific issues for sophomores at Illinois Wesleyan University. By studying programs in place at other universities and surveying Illinois Wesleyan University students, I will propose recommendations to Illinois Wesleyan University which may effectively address sophomore-specific concerns

Corticotropin‐releasing hormone–induced seizures in infant rats originate in the amygdala

The neuroanatomical substrate of seizures induced by picomolar amounts of corticotropin‐releasing hormone in infant rats was investigated. Electrographic and behavioral phenomena were monitored in 42 rat pups aged 5 to 22 days. Rat pups carried bipolar electrodes implanted in subcortical limbic structures, as well as cortical electrodes and intracerebroventricular cannulae. The administration of corticotropin‐releasing hormone produced age‐specific seizures within minutes, which correlated with rhythmic amygdala discharges. Paroxysmal hippocampal and cortical discharges developed subsequently in some rats. Corticotropin‐releasing hormone–induced electrographic and behavioral seizures originate in the amygdala. Copyright © 1992 American Neurological Associatio

A North American Consortium on Rehabilitation Engineering and Technology for the Individual

The availability and accessibility of appropriate rehabilitative healthcare, medical technology and treatment is an important national and international issue of particular relevance due to recent national healthcare reform initiatives. The focus of this project was to increase global competencies and awareness among biomedical engineers of the differing rehabilitative healthcare needs in North America via student exchange with consortium institutions in the U.S., Canada and Mexico. The aim was to increase understanding of alternative healthcare delivery systems with respect to technology and interaction with diverse client populations in a clinical setting and to enhance the development and technology transfer of new scientific tools and techniques, medical devices, and related biomedical research. To date, more than 50 undergraduates have expressed interest in these programs, with over 30 students completing applications, and travel awards extended to 18 students (16 of whom opted to participate in study abroad experiences). Assessment tools included: a healthcare survey, two case study reports, global perspectives inventory documenting cultural differences, cultural comforts and the campus environment for culture and cultural tolerance, and interviews of the exchange participants and faculty research mentors by the external program evaluator

Astrocytic Ion Dynamics: Implications for Potassium Buffering and Liquid Flow

We review modeling of astrocyte ion dynamics with a specific focus on the implications of so-called spatial potassium buffering, where excess potassium in the extracellular space (ECS) is transported away to prevent pathological neural spiking. The recently introduced Kirchoff-Nernst-Planck (KNP) scheme for modeling ion dynamics in astrocytes (and brain tissue in general) is outlined and used to study such spatial buffering. We next describe how the ion dynamics of astrocytes may regulate microscopic liquid flow by osmotic effects and how such microscopic flow can be linked to whole-brain macroscopic flow. We thus include the key elements in a putative multiscale theory with astrocytes linking neural activity on a microscopic scale to macroscopic fluid flow.Comment: 27 pages, 7 figure

Comparison of Oxygen Transfer Between an Integrated Fixed-Film Activated Sludge (IFAS) Process and a Conventional Activated Sludge Process (ASP)

The T.Z. Osborne (TZO) Water Reclamation Facility (WRF) located in Greensboro, NC is a 40 million gallon per day (MGD) wastewater treatment plant that includes biological nutrient removal with surface-water discharge. Several process alternatives are being evaluated as strategies to meet forthcoming nutrient limits. Integrated fixed film activated sludge (IFAS) is one of the alternatives being considered for implementation. Due to the limited number of full-scaleo perating IFAS treatment facilities in the United States and the City of Greensboro's desire to experience operating the process, a thorough year-long study was conducted to quantify the nitrification kinetics, aeration requirements, process performance, and potential operational issues. As part of the full-scale evaluation, an off-gas test was performed in accordance with the American Society of Civil Engineers' (ASCE) Protocol. Previously, only one off-gas test had been performed, and it was conducted by another IFAS manufacturer. To our knowledge, the testing described in this report is the first independent off-gas test on an IFAS system to date. Results of the testing indicate that the IFAS process has higher air flux and air use per unit load treated compared to the activated sludge process (ASP), likely due to elevated mixing requirements and high dissolved oxygen (DO) specified by the process manufacturer, with associated lower oxygen transfer efficiency. The relative air use of the IFAS process is in the range of 1.3 to over 3.0 times that of the ASP, and the IFAS process has approximately 25 to 50% more air use for mixing when compared to the ASP.Master of Science in Environmental Engineerin