917 research outputs found
In-Situ Colloidal MnO2 Deposition and Ozonation of 2,4-Dinitrotoluene
Laboratory experiments are presented that demonstrate a novel in situ semipassive reactive barrier for the degradation of 2,4 dinitrotoluene created by coating aquifer surfaces by deposition of colloidal MnO2, which catalyzes ozone degradation and enhances contaminant oxidation. Ozone is added to the reactive barrier and is transported through the zone with the contaminants by existing hydraulic gradients. The communication presents the preliminary laboratory investigation demonstrating the viability of this method. Studies were conducted by coating Ottawa sand with colloidal MnO2. Results show that concentrations of MnO2 in the range of 0.2 mg/g can be deposited with no measurable change in hydraulic conductivity, that there is significant coverage of the sand material by MnO2, and the deposition was not reversible under a wide range of chemical conditions. Ozonation of 2,4-dinitrotoluene in the presence of MnO2- coated sand was demonstrated to result in pseudo-first-order degradation kinetics with respect to DNT with half-lives ranging from 28 to 22 min (at pH 6 and 7, respectively), approximately 25% faster than experiments performed in the absence of MnO2
Political Economy of Electricity Reform: A Case Study in Gujarat, India
In India, the supply of electricity relies heavily on a virtually bankrupt and sometimes corrupt system of state electricity boards (SEBs), which have failed to bring electricity to approximately 40% of rural households. High subsidy levels to agriculture and domestic customers and widespread electricity theft have resulted in weak financial conditions for the SEBs; and thus-top down remedies for improving the electricity system are not likely to be successful. The problems are particularly acute in Gujarat state, which represents a microcosm of the key issues faced throughout India, where a complicated and overlapping regulatory structure and new entrant prohibitions have stifled new electricity sector investment. This paper identifies and analyses the political and economic factors that have hindered progress. The main finding is that government may meet with greater success if it encourages and facilitates local private investment in small-scale electricity production, as a ‘bottom-up’ solution, rather than continuing attempts to force through ‘top-down’ reform of the existing state-owned electricity sector against entrenched interest groups.power sector, reform, liberalisation, electricity
Short communication: NKG2C+ NK cells contribute to increases in CD16+CD56- cells in HIV type 1+ individuals with high plasma viral load.
Chronic HIV-1 infection results in the expansion of both NKG2C+ and CD16+CD56- human natural killer cells. NKG2C+ cells proliferate in response to human cytomegalovirus (HCMV) and expansion of the dysfunctional CD56-CD16+ natural killer (NK) cells is associated with HIV-1 viremia. Here we report an association between increased proportions of CD56-CD16+ NK cells in viremic HIV-1+ individuals and an increased contribution of NKG2C+ cells to this subset. These data, in addition to anti-HCMV IgG serology, indicate a potential contribution of both HCMV and HIV-1 to NK cell dysfunction in HIV-1-infected individuals
Developing Compassionate and Socially Responsible Global Citizens through Interdisciplinary, International Service-Learning
Interdisciplinary, international service-learning experiences provide transformative experiences that develop students’ capacities as socially responsible global citizens. In this article the authors, a team of two professors and three students, share the results of a self-study in which we explored the narrative inquiry question: How does an interdisciplinary service-learning experience influence student understanding of common human dignity, social responsibility, and citizenship in a global context? The findings and reflections from this partnership between faculty and students provide insights and recommendations for faculty seeking to develop sustainable, interdisciplinary, international service-learning experiences.
High Density Faraday Cup Array or Other Open Trench Structures and Method of Manufacture Thereof
A detector array and method for making the detector array. The detector array includes a substrate including a plurality of trenches formed therein, and a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charged particles incident on respective ones of the collectors and to output from the collectors signals indicative of charged particle collection. In the detector array, adjacent ones of the plurality of trenches are disposed in a staggered configuration relative to one another. The method forms in a substrate a plurality of trenches across a surface of the substrate such that adjacent ones of the trenches are in a staggered sequence relative to one another, forms in the plurality of trenches a plurality of collectors, and connects a plurality of electrodes respectively to the collectors
Action Boundary Proximity Effects on Perceptual-Motor Judgments
INTRODUCTION: Designed as a more ecological measure of reaction times, the Perception-Action Coupling Task (PACT) has shown good reliability and within-subject stability. However, a lengthy testing period was required. Perceptual-motor judgments are known to be affected by proximity of the stimulus to the action boundary. The current study sought to determine the effects of action boundary proximity on PACT performance, and whether redundant levels of stimuli, eliciting similar responses, can be eliminated to shorten the PACT.METHODS: There were 9 men and 7 women who completed 4 testing sessions, consisting of 3 familiarization cycles and 6 testing cycles of the PACT. For the PACT, subjects made judgments on whether a series of balls presented on a tablet afford "posting" (can fit) through a series of apertures. There were 8 ratios of ball to aperture size (B-AR) presented, ranging from 0.2 to 1.8, with each ratio appearing 12 times (12 trials) per cycle. Reaction times and judgment accuracy were calculated, and averaged across all B-ARs. Ratios and individual trials within each B-AR were systematically eliminated. Variables were re-averaged, and intraclass correlation coefficients (ICC) and coefficients of variation (CVTE) were calculated in an iterative manner.RESULTS: With elimination of the 0.2 and 1.8 B-ARs, the PACT showed good reliability (ICC = 0.81-0.99) and consistent within-subject stability (CVTE = 2.2-14.7%). Reliability (ICC = 0.81-0.97) and stability (CVTE = 2.6-15.6%) were unaffected with elimination of up to 8 trials from each B-AR.DISCUSSION: The shortened PACT resulted in an almost 50% reduction in total familiarization/testing time required, significantly increasing usability.Johnson CD, LaGoy AD, Pepping G-J, Eagle SR, Beethe AZ, Bower JL, Alfano CA, Simpson RJ, Connaboy C. Action boundary proximity effects on perceptual-motor judgments. Aerosp Med Hum Perform. 2019; 90(12):1000-1008
Faraday Cup Array Integrated with a Readout IC and Method for Manufacture Thereof
A detector array and method for making the detector array. The array includes a substrate including a plurality of trenches formed therein, and includes a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charge particles incident on respective ones of the collectors and to output from said collectors signals indicative of charged particle collection. The array includes a plurality of readout circuits disposed on a side of the substrate opposite openings to the collectors. The readout circuits are configured to read charge collection signals from respective ones of the plurality of collectors
A fully automated procedure for the parallel, multidimensional purification and nucleotide loading of the human GTPases KRas, Rac1 and RalB
Small GTPases regulate many key cellular processes and their role in human disease validates many proteins in this class as desirable targets for therapeutic intervention. Reliable recombinant production of GTPases, often in the active GTP loaded state, is a prerequisite for the prosecution of drug discovery efforts. The preparation of these active forms can be complex and often constricts the supply to the reagent intensive techniques used in structure base drug discovery. We have established a fully automated, multidimensional protein purification strategy for the parallel production of the catalytic G-domains of KRas, Rac1 and RalB GTPases in the active form. This method incorporates a four step chromatography purification with TEV protease-mediated affinity tag cleavage and a conditioning step that achieves the activation of the GTPase by exchanging GDP for the non-hydrolyzable GTP analogue GMPPnP. We also demonstrate that an automated method is efficient at loading of KRas with mantGDP for application in a SOS1 catalysed fluorescent nucleotide exchange assay. In comparison to more conventional manual workflows the automated method offers marked advantages in method run time and operator workload. This reduces the bottleneck in protein production while generating products that are highly purified and effectively loaded with nucleotide analogues
How many clones need to be sequenced from a single forensic or ancient DNA sample in order to determine a reliable consensus sequence?
Forensic and ancient DNA (aDNA) extracts are mixtures of endogenous aDNA, existing in more or less damaged state, and contaminant DNA. To obtain the true aDNA sequence, it is not sufficient to generate a single direct sequence of the mixture, even where the authentic aDNA is the most abundant (e.g. 25% or more) in the component mixture. Only bacterial cloning can elucidate the components of this mixture. We calculate the number of clones that need to be sampled (for various mixture ratios) in order to be confident (at various levels of confidence) to have identified the major component. We demonstrate that to be >95% confident of identifying the most abundant sequence present at 70% in the ancient sample, 20 clones must be sampled. We make recommendations and offer a free-access web-based program, which constructs the most reliable consensus sequence from the user's input clone sequences and analyses the confidence limits for each nucleotide position and for the whole consensus sequence. Accepted authentication methods must be employed in order to assess the authenticity and endogeneity of the resulting consensus sequences (e.g. quantification and replication by another laboratory, blind testing, amelogenin sex versus morphological sex, the effective use of controls, etc.) and determine whether they are indeed aDNA
- …