731 research outputs found
BioBot: Innovative Offloading of Astronauts for More Effective Exploration
The BioBot concept consists of a robotic rover which is capable of traversing the same terrain as a spacesuited human. It carries the primary life support system for the astronaut, including consumables, atmosphere revitalization systems (e.g., CO2 scrubbing, humidity and temperature management, ventilation fan), power system (e.g., battery, power management and distribution),and thermal control system (e.g., water sublimator, cooling water pump), along with umbilical lines to connect to the supported astronaut. Although not technically part of life support, it would be logical for the BioBot to also provide long-range communications, video monitoring, tool and sample transport, and other functions to enable and enhance EVA productivity in planetary surface exploration.The design reference scenario for this concept is that astronauts involved in future lunar or Mars exploration will be on the surface for weeks or months rather than days, and will be involved in regular EVA operations. It is not unreasonable to think of geologists spending several days inEVA exploration each week over a prolonged mission duration, with far more ambitious operational objectives than were typical of Apollo. In this scenario, each astronaut will be accompanied by a "BioBot", which will transport their life support system and consumables, an extended umbilical and umbilical reel, and robotic systems capable of controlling the position and motion of the umbilical. The astronaut will be connected to the robot via the umbilical, carrying only a small emergency open-loop life support system similar to those contained in every PLSS. The robotic mobility base will be designed to be capable of traveling anywhere the astronaut can walk, and will also be useful as a transport for the EVA tools, science instrumentation, and collected samples. In addition, the BioBot can potentially carry the astronaut on traverses as well. Such a system will also be a significant enhancement to public engagement in these future exploration missions, as the robotic vehicles can also support high-resolution cameras and high bandwidth communications gear to providehigh-definition video coverage of each crew throughout each EVA sortie
Successful Treatment of an MTBE-impacted Aquifer Using a Bioreactor Self-colonized by Native Aquifer Bacteria
A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 μg L−1), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes
Women at risk for sexually transmitted diseases: correlates of intercourse without barrier contraception
Objective: The purpose of this study was to evaluate the correlates of vaginal intercourse without barrier contraception (unprotected intercourse).
Study Design: Baseline data from a randomized trial were analyzed to evaluate factors that are associated with intercourse without barrier method use among women \u3c35 years old. Logistic regression models provided estimates of the association of demographic, reproductive, and sexual history variables with unprotected intercourse.
Results: Intercourse without barrier contraception was common; 65% of participants had ≥2 episodes of intercourse without barrier contraception use in the past month. Factors that were associated with increased odds of unprotected intercourse included the number of coital episodes, a male partner’s unwillingness to use condoms (adjusted odds ratio, 4.1; 95% CI, 2.3-6.9), and, among women \u3c20 years old, low condom use self-efficacy score (adjusted odds ratio, 1.6; 95% CI, 1.0-2.9).
Conclusion: Risk factors for unprotected intercourse included coital frequency and the male partner’s unwillingness to use condoms. Self-efficacy for condom use was especially important for women \u3c20 years old
Arginine methylation of yeast mRNA-binding protein Npl3 directly affects its function, nuclear export, and intranuclear protein interactions
Arginine methylation can affect both nucleocytoplasmic transport and protein-protein interactions of RNA-binding proteins. These effects are seen in cells that lack the yeast hnRNP methyltransferase (HMT1), raising the question of whether effects on specific proteins are direct or indirect. The presence of multiple arginines in individual methylated proteins also raises the question of whether overall methylation or methylation of a subset of arginines affects protein function. We have used the yeast mRNA-binding protein Npl3 to address these questions in vivo. Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry was used to identify 17 methylated arginines in Npl3 purified from yeast: whereas 10 Arg-Gly-Gly (RGG) tripeptides were exclusively dimethylated, variable levels off methylation were found for 5 RGG and 2 RG motif arginines. We constructed a set of Npl3 proteins in which subsets of the RGG arginines were mutated to lysine. Expression of these mutant proteins as the sole form of Npl3 specifically affected growth of a strain that requires Hmtl. Although decreased growth generally correlated with increased numbers of Arg-to-Lys mutations, lysine substitutions in the N terminus of the RGG domain showed more severe effects. Npl3 with all 15 RGG arginines mutated to lysine exited the nucleus independent of Hmtl, indicating a direct effect of methylation on Npl3 transport. These mutations also resulted in a decreased, methylation-independent interaction of Npl3 with transcription elongation factor Tho2 and inhibited Npl3 self-association. These results support a model in which arginine methylation facilitates Npl3 export directly by weakening contacts with nuclear proteins. © 2005 by The American Society for Biochemistry and Molecular Biology, Inc
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Soft drink intake and progression of radiographic knee osteoarthritis: data from the osteoarthritis initiative
Objectives: We examine the prospective association of soft drink consumption with radiographic progression of knee osteoarthritis (OA). Design: Prospective cohort study. Setting: This study used data from the osteoarthritis initiative (OAI). Participants: In OAI, 2149 participants with radiographic knee OA and having dietary data at baseline were followed up to 12, 24, 36 and 48 months. Measures The soft drink consumption was assessed with a Block Brief Food Frequency Questionnaire completed at baseline. To evaluate knee OA progression, we used quantitative medial tibiofemoral joint space width (JSW) based on plain radiographs. The multivariate linear models for repeated measures were used to test the independent association between soft drink intake and the change in JSW over time, while adjusting for body mass index and other potential confounding factors. Results: In stratified analyses by gender, we observed a significant dose–response relationship between baseline soft drink intake and adjusted mean change of JSW in men. With increasing levels of soft drink intake (none, ≤1, 2–4 and ≥5 times/week), the mean decreases of JSW were 0.31, 0.39, 0.34 and 0.60 mm, respectively. When we further stratified by obesity, a stronger dose–response relationship was found in non-obese men. In obese men, only the highest soft drink level (≥5 times/week) was associated with increased change in JSW compared with no use. In women, no significant association was observed. Conclusions: Our results suggest that frequent consumption of soft drinks may be associated with increased OA progression in men. Replication of these novel findings in other studies demonstrating the reduction in soft drink consumption leads to delay in OA progression is needed
Biodiversity and Ecosystem Informatics: Event and Process Tagging for Information Integration for the International Gulf of Main Watershed
This incubation proposal addresses the issue of integrating large, diverse, and autonomous collections of scientific data within a complex institutional setting. The goal is to convert these autonomous collections into a shareable repository that supports synthesis of data through new metadata structures based on events and processes. The institutional setting is the data and data-gathering activities of over 80 agencies, NGOS, and academic and research institutions operating within the Gulf of Maine watershed. The metadata development will be coordinated by library and spatial information scientists working jointly with domain scientists. An essential task of this incubation effort will be the development of a shared understanding of environmental processes and events that becomes a shareable ontology.Libraries play a vital role in organizing intellectual access to creative works. Scientific data has tended to be outside this traditional purview and has thus lacked the benefits of cataloging and indexing that promote shared access. We are proposing a new metadata structure that exploits common units of analysis in environmental studies: events and processes. Associating scientific data sets with event and process tags, in addition to other metadata elements, can substantially improve the ability to integrate and synthesize diverse scientific collections. The metadata initiative of this proposal will lay the foundation for specifying events and processes through the collaboration of data collections content specialists and information management specialists
Manipulation of Ovarian Function Significantly Influenced Sarcopenia in Postreproductive-Age Mice
Correlates of hyaluronic acid and corticosteroid injections among patients with radiographically confirmed osteoarthritis
Objective: Despite the rapid proliferation of hyaluronate (HA) and corticosteroid (CO) injections and clinical guidelines regarding their use in osteoarthritis (OA), information on the characteristics of people receiving them is scarce. We described use of injections among adults with radiographically confirmed knee OA and identified correlates of injection use.
Methods: We used publicly available data from Osteoarthritis Initiative and included participants with ≥ one radiographically confirmed knee OA (Kellgren-Lawrence grade (K-L) \u3e 2) at baseline. We matched 415 participants reporting HA and/or CO during the 6 month before one of the first 7 annual follow-up assessments to 1,841 non-injection users by randomly selecting a study visit to match the distribution observed in the injection users. Multinomial logistic regression models identified correlates of injection use including sociodemographics and clinical/functional factors.
Results: Injections were common (16.9% -year 1, 13.7% -year 2, 16.6 % -year 3, 13.5% - year 4, 15.9% -year 5, 13.5 % -year 6 and 9.9% -year 7) with corticosteroid injections most common (68.4%). HA and CO were more commonly reported by those with higher income (e.g. adjusted Odds Ratio (aOR) HA \u3e 25k: 3.63; (95% CI: 1.20-10.99)) and less common among blacks (aOR HA: 0.19; 95% CI: 0.06-0.55). Greater K-L grade (grade 4 versus 2) was associated with increased odds of HA (aOR: 4.79; 95% CI: 2.47-9.30), CO (aOR: 1.56; 95% CI: 1.04-2.34), or both (aOR: 4.94; 95% CI: 1.99-12.27).
Conclusion: Hyaluronic acid or corticosteroid injections are associated with higher socioeconomic positioning and indicators of greater disease severity
A Decline in Walking Speed is Associated with Incident Knee Replacement in Adults with and at Risk for Knee Osteoarthritis
OBJECTIVE: To determine if a one-year change in walking speed is associated with receiving an incident knee replacement during the following year in adults with and at risk for knee osteoarthritis (OA).
METHODS: Using data from the Osteoarthritis Initiative, we determined a one-year change in 20- meter walk speed from three observation periods (i.e., 0-12, 12-24, and 24-36 month). We operationally defined one-year change in walking speed as either: 1) decline: \u3c -0.1 m/s change, 2) no change: between -0.1 and 0.1 m/s change, 3) increase: \u3e 0.1 m/s change. Incident knee replacement was defined using each subsequent one-year period (i.e., 12-24, 24- 36, and 36-48 month). Combining data from the three observation periods, we performed a Poisson regression with robust error variance to determine the relative risk between a change in walking speed (exposure) and incident knee replacement over the following year (outcome).
RESULTS: Of the 4,264 participants included within this analysis (11,311 total person visits), 115 (3%) adults received a knee replacement. Decline in walking speed was associated with a 104% increase in risk [adjusted relative risk (RR)=2.04; 95% confidence interval (CI)= 1.40-2.98], while an increase in walking speed associated with a 55% decrease in risk (RR=0.45; 95% CI=0.22-0.93) of incident knee replacement in the following year compared to a person with no change in walking speed.
CONCLUSION: A one-year decline in walking speed is associated with an increased risk, while one-year increase in walking speed is associated with a decreased risk of future incident knee replacement
Long-term Effects of Use of Prescription Non-steroidal Anti-inflammatory Agents on Symptoms and Disease Progression among Patients with Radiographically Confirmed Osteoarthritis of the Knee
Objective: To estimate the extent to which long-term use of prescription non-steroidal anti-inflammatory agents (NSAIDs) relieve symptoms and delay disease progression among patients with radiographically confirmed osteoarthritis (OA) of the knee.
Methods: Using Osteoarthritis Initiative data, we identified participants with confirmed OA at enrollment and evaluated changes in symptoms measured using the Western Ontario and McMaster Universities Arthritis Index, WOMAC (n=1,846) and joint space width measured using serial x-rays and a customized software tool (n=1,116) over 4 years. Covariates included sociodemographics, OA clinical characteristics, indices of general health status, body mass index, and use of other treatments. We adjusted for baseline and time-varying confounders using marginal structural modeling.
Results: Six percent initiated NSAID treatment at year one, with half of the initiators being regular users. After adjusting for time-varying confounders with marginal structural models, we found that compared to participants who never reported use of prescription NSAIDs, those reporting use for 3 years had on average 0.88 point decrease (95% Confidence Interval (CI): -0.46 to 2.22) in WOMAC Pain, 0.72 point decrease (95% CI: -0.12 to 1.56) in WOMAC Stiffness, 4.27 points decrease (95% CI: 0.31 to -8.84) in WOMAC Function, and 0.28mm increase (95% CI: -0.06 to 0.62) in joint space width.
Conclusions: Long term NSAID use was associated with a priori defined minimally important clinical improvements in stiffness, function and structural degeneration, but not in pain
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