366 research outputs found
Amino acid catabolism by ribbed mussel (Modiolus demissus) gill tissue: studies on isolated mitochondria and the L-amino acid oxidase
Gill tissue from Modiolus demissus has a general L-amino acid oxidase (EC 1.4.3.2) associated with proteinaceous particles sedimenting at 15,000xg. The oxidase is most active between pH 4.5 and pH 5 in citrate buffer with L-(alpha)-amino acids having three or more carbons, with no hydroxyl or methyl substitutions for hydrogens on the (beta)-carbons, and no charged groups on the (gamma)-carbon. The apparent K(,m)s for L-leucine and L-ornithine were identical (2.5 mM). Glycine, taurine, L-proline, aminooxyacetic acid, L-cycloserine, and EDTA would not act as substrates or inhibitors;Preliminary experiments with 2,4-dinitrophenol (DNP), 2,4,6-trinitrophenol (TNP), and sodium azide indicated that most of the oxygen consumption by ribbed mussel gill tissue was the result of mitochondrial respiration. A procedure utilizing isoosmotic sucrose, EGTA, defatted serum albumin, and HEPES as the isolation medium was devised for the preparation of fully coupled ribbed mussel gill mitochondria. Optimal rates of respiration and respiratory coupling required substrate, ADP, inorganic phosphate and a fairly high KC1 concentration (90 mM) in the assay medium. Preparation of gill mitochondria in isoosmotic solutions containing high KC1 concentrations (150 mM) yielded mitochondria with state 2 respiration, partially uncoupled ATP synthesis during state 3 respiration and no state 4 respiration;The presence of arginase, ornithine aminotransferase, P-5-C reductase, and proline oxidase was demonstrated in gill tissue from the ribbed mussel, Modiolus demissus. Ornithine aminotransferase and proline oxidase were found in mitochondrial fractions, and indirect evidence is presented for a mitochondrial P-5-C dehydrogenase. The proline oxidase lost its rotenone sensitivity in mechanically disrupted metochondria but retained sensitivity to antimycin A. The apparent K(,m)\u27s for partially purified arginase and ornithine aminotransferase were 7 mM for arginine and 4.8 mM and 2 mM for ornithine and 2-oxoglutarate, respectively. Amino acid analysis and radiotracer experiments indicated that at low concentrations proline is catabolized primarily to glutamate, organic acids and CO(,2)
Analyzing Medication Documentation in Electronic Health Records: Dental Studentsâ Self-Reported Behaviors and Charting Practices
The aim of this two-part study was to assess third- and fourth-year dental studentsâ perceptions, self-reported behaviors, and actual charting practices regarding medication documentation in axiUm, the electronic health record (EHR) system. In part one of the study, in fall 2015, all 125 third- and 85 fourth-year dental students at one U.S. dental school were invited to complete a ten-item anonymous survey on medication history-taking. In part two of the study, the EHRs of 519 recent dental school patients were randomly chosen via axiUm query based on age >21 years and the presence of at least one documented medication. Documentation completeness was assessed per EHR and each medication based on proper medication name, classification, dose/frequency, indication, potential oral effects, and correct medication spelling. Consistency was evaluated by identifying the presence/absence of a medical reason for each medication. The survey response rate was 90.6% (N=187). In total, 64.5% of responding students reported that taking a complete medication history is important and useful in enhancing pharmacology knowledge; 90.4% perceived it helped improve their understanding of patientsâ medical conditions. The fourth-year students were more likely than the third-year students to value the latter (p=0.0236). Overall, 48.6% reported reviewing patient medications with clinic faculty 76-100% of the time. The respondentsâ most frequently cited perceived barriers to medication documentation were patientsâ not knowing their medications (68.5%) and, to a much lesser degree, axiUm limitations (14%). Proper medication name was most often recorded (93.6%), and potential oral effects were recorded the least (3.0%). Medication/medical condition consistency was 70.6%. In this study, most of the students perceived patient medication documentation as important; however, many did not appreciate the importance of all elements of a complete medication history, and complete medication documentation was low
Performance improvements of a highly integrated digital electronic control system for an F-15 airplane
The NASA highly integrated digital electronic control (HIDEC) program is structured to conduct flight research into the benefits of integrating an aircraft flight control system with the engine control system. A brief description of the HIDEC system installed on an F-15 aircraft is provided. The adaptive engine control system (ADECS) mode is described in detail, together with simulation results and analyses that show the significant excess thrust improvements achievable with the ADECS mode. It was found that this increased thrust capability is accompanied by reduced fan stall margin and can be realized during flight conditions where engine face distortion is low. The results of analyses and simulations also show that engine thrust response is improved and that fuel consumption can be reduced. Although the performance benefits that accrue because of airframe and engine control integration are being demonstrated on an F-15 aircraft, the principles are applicable to advanced aircraft such as the advanced tactical fighter and advanced tactical aircraft
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Patterns of Oral Microbiota Diversity in Adults and Children: A Crowdsourced Population Study.
Oral microbiome dysbiosis has been associated with various local and systemic human diseases such as dental caries, periodontal disease, obesity, and cardiovascular disease. Bacterial composition may be affected by age, oral health, diet, and geography, although information about the natural variation found in the general public is still lacking. In this study, citizen-scientists used a crowdsourcing model to obtain oral bacterial composition data from guests at the Denver Museum of Nature & Science to determine if previously suspected oral microbiome associations with an individual's demographics, lifestyle, and/or genetics are robust and generalizable enough to be detected within a general population. Consistent with past research, we found bacterial composition to be more diverse in youth microbiomes when compared to adults. Adult oral microbiomes were predominantly impacted by oral health habits, while youth microbiomes were impacted by biological sex and weight status. The oral pathogen Treponema was detected more commonly in adults without recent dentist visits and in obese youth. Additionally, oral microbiomes from participants of the same family were more similar to each other than to oral microbiomes from non-related individuals. These results suggest that previously reported oral microbiome associations are observable in a human population containing the natural variation commonly found in the general public. Furthermore, these results support the use of crowdsourced data as a valid methodology to obtain community-based microbiome data
A COMMUNITY OF PRACTICE ENABLING A RAPID RESPONSE IN TRANSFORMING BIOCHEMISTRY LABORATORY TEACHING
The emergence of the COVID-19 pandemic has meant the adoption of emergency remote teaching by many who teach at university. This has been a particular challenge for courses that include essential hands-on practical skill development. The prior establishment of our Community of Practice, aimed at transforming laboratory education, has meant we have been able to respond rapidly to the challenge of moving face-to-face laboratory teaching to online sessions.
Biochemistry students at University of Western Australia already complete their pre-laboratory reading and quiz asynchronously online, following the âPrepare, Do, Reviewâ model. Students then attend face-to-face laboratory and post-laboratory sessions. We have now developed online laboratory and post-lab sessions using Zoom and incorporating videos of laboratory procedures. Students deliver oral presentations in the post-lab and the summative quiz is now asynchronous and online.
The changes have provided the impetus for reviewing other laboratory sessions, and the introduction of electronic laboratory notebooks. We have also expanded our Community of Practice with a team of postdoctoral researchers to ensure the techniques students are learning are contemporary and relevant to research.
We will discuss the challenges in implementing the changes we have made, and the gains in the development of new resources and teaching strategies
Spatial risk modeling of cattle depredation by black vultures in the midwestern United States
ock operations through depredation of stock are a cause of humanâwildlife conflict. Management of such conflict requires identifying environmental and nonâenvironmental factors specific to a wildlife species\u27 biology and ecology that influence the potential for livestock depredation to occur. Identification of such factors can improve understanding of the conditions placing livestock at risk. Black vultures (Coragyps atratus) have expanded their historical range northward into the midwestern United States. Concomitantly, an increase in concern among agricultural producers regarding potential black vulture attacks on livestock has occurred. We estimated area with greater or lesser potential for depredation of domestic cattle by black vultures across a 6âstate region in the midwestern United States using an ensemble of small models (ESM). Specifically, we identified landscapeâscale spatial factors, at a zip code resolution, associated with reported black vulture depredation on cattle in midwestern landscapes to predict future potential livestock depredation. We hypothesized that livestock depredation would be greatest in areas with intensive beef cattle production close to preferred black vulture habitat (e.g., areas with fewer old fields and early successional vegetation paired with more direct edge between older forest and agricultural lands). We predicted that the density of cattle within the county, habitat structure, and proximity to anthropogenic landscape features would be the strongest predictors of black vulture livestockâdepredation risk. Our ESM estimated the relative risk of black vultureâcattle depredation to be between 0.154â0.631 across our entire study area. Consistent with our hypothesis, areas of greatest predicted risk of depredation correspond with locations that are favorable to vulture lifeâhistory requirements and increased potential to encounter livestock. Our results allow wildlife managers the ability to predict where black vulture depredation of cattle is more likely to occur in the future. It is in these areas where extension and outreach efforts aimed at mitigating this conflict should be focused. Researchers and wildlife managers interested in developing or employing tools aimed at mitigating livestockâvulture conflicts can also leverage our results to select areas where depredation is most likely to occur
Analysis of experimental shaft seal data for high-performance turbomachines, as for Space Shuttle main engines
High-pressure, high-temperature seal flow (leakage) data for nonrotating and rotating Raleigh-step and convergent-tapered-bore seals were characterized in terms of a normalized flow coefficient. The data for normalized Rayleigh-steip and nonrotating tapered-bore seals were in reasonable agreement with theory, but data for the rotating tapered-bore seals were not. The tapered-bore-seal operational clearances estimated from the flow data were significantly larger than calculated. Although clearances are influenced by wear from conical to cylindrical geometry and errors in clearance corrections, the problem was isolated to the shaft temperature - rotational speed clearance correction. The geometric changes support the use of some conical convergence in any seal. Under these conditions rotation reduced the normalized flow coefficiently by nearly 10 percent
Astrophysical Reaction Rates for B(p,)Be and B(p,)Be From a Direct Model
The reactions B(p,)Be and B(p,)Be
are studied at thermonuclear energies using DWBA calculations. For both
reactions, transitions to the ground states and first excited states are
investigated. In the case of B(p,)Be, a resonance at
keV can be consistently described in the potential model, thereby
allowing the extension of the astrophysical -factor data to very low
energies. Strong interference with a resonance at about keV
require a Breit-Wigner description of that resonance and the introduction of an
interference term for the reaction B(p,)Be. Two
isospin resonances (at keV and keV)
observed in the B+p reactions necessitate Breit-Wigner resonance and
interference terms to fit the data of the B(p,)Be
reaction. -factors and thermonuclear reaction rates are given for each
reaction. The present calculation is the first consistent parametrization for
the transition to the ground states and first excited states at low energies.Comment: 27 pages, 5 Postscript figures, uses RevTex and aps.sty; preprint
also available at http://quasar.physik.unibas.ch/ Phys. Rev. C, in pres
A Hybrid Sensor Based Backstepping Control Approach with its application to Fault-Tolerant Flight Control
Recently, an incremental type sensor based backstepping (SBB) control approach, based on singular perturbation theory and Tikhonovâs theorem, has been proposed. This Lyapunov function based method uses measurements of control variables and less model knowledge, and it is not susceptible to the model uncertainty caused by fault scenarios. In this paper, the SBB method has been implemented on a fixed wing aircraft with its focus on handling structural changes caused by damages. A new hybrid autopilot flight controller has been developed for a Boeing 747-200 aircraft after combining nonlinear dynamic inversion (NDI) with SBB control approach. Two benchmarks for fault tolerant flight control (FTFC), named rudder runaway and engine separation, are employed to evaluate the proposed method. The simulation results show that the proposed control approach leads to a zero tracking-error performance in nominal condition and guarantees the stability of the closed-loop system under failures as long as the reference commands are located in the safe flight envelope
Total RNA Analysis of Bacterial Community Structural and Functional Shifts Throughout Vertebrate Decomposition
Multiple methods have been proposed to provide accurate time since death estimations, and recently, the discovery of bacterial community turnover during decomposition has shown itself to have predictable patterns that may prove useful. In this study, we demonstrate the use of metatranscriptomics from the postmortem microbiome to simultaneously obtain community structure and functional data across postmortem intervals (PMIs). We found that bacterial succession patterns reveal similar trends as detected through DNA analysis, such as increasing Clostridiaceae as decomposition occurs, strengthening the reliability of total RNA community analyses. We also provide one of the first analyses of RNA transcripts to characterize bacterial metabolic pathways during decomposition. We found distinct pathways, such as amino acid metabolism, to be strongly upâregulated with increasing PMIs. Elucidating the metabolic activity of postmortem microbial communities provides the first steps to discovering postmortem functional biomarkers since functional redundancy across bacteria may reduce host individual microbiome variability.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152033/1/jfo14083_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152033/2/jfo14083.pd
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