4,721 research outputs found
The Impacts of Undergraduate Service-Learning on Post-Graduation Employment Outcomes
This article highlights the results of a study assessing service-learning’s impact on post-graduation employment for students from a large, public land-grant university who had completed their undergraduate degree. Survey data collected three years after graduation yielded 44 unique pairs matched for undergraduate major, graduation date, gender, and academic performance, but with only a single member of each pair having taken service-learning coursework. The study investigated employment outcomes including time needed to find a first job, starting salary, timing of promotions and raises, and type of employment. Paired t-tests found significantly higher starting salaries and significantly shorter time to receive a first raise for graduates with service-learning experience. No significant differences were found regarding (a) whether either set received a raise or promotion, (b) whether the job was in their desired field, (c) the overall time to find an initial job, or (d) the length of time from hiring to first promotion. These results represent the first empirical data assessing service-learning’s potential influence on economic aspects of post-university employment
Engine panel seals for hypersonic engine applications: High temperature leakage assessments and flow modelling
A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating horizontal engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the seal concept design and development of two new seal classes that show promise of meeting these demands will be presented. These seals include the ceramic wafer seal and the braided ceramic rope seal. Presented are key elements of leakage flow models for each of these seal types. Flow models such as these help designers to predict performance-robbing parasitic losses past the seals, and estimate purge coolant flow rates. Comparisons are made between measured and predicted leakage rates over a wide range of engine simulated temperatures and pressures, showing good agreement
Fluorescence Fluctuation Spectroscopy Enables Quantitative Imaging of Single mRNAs in Living Cells
AbstractImaging mRNA with single-molecule sensitivity in live cells has become an indispensable tool for quantitatively studying RNA biology. The MS2 system has been extensively used due to its unique simplicity and sensitivity. However, the levels of the coat protein needed for consistent labeling of mRNAs limits the sensitivity and quantitation of this technology. Here, we applied fluorescence fluctuation spectroscopy to quantitatively characterize and enhance the MS2 system. Surprisingly, we found that a high fluorescence background resulted from inefficient dimerization of fluorescent protein (FP)-labeled MS2 coat protein (MCP). To mitigate this problem, we used a single-chain tandem dimer of MCP (tdMCP) that significantly increased the uniformity and sensitivity of mRNA labeling. Furthermore, we characterized the PP7 coat protein and the binding to its respective RNA stem loop. We conclude that the PP7 system performs better for RNA labeling. Finally, we used these improvements to study endogenous β-actin mRNA, which has 24xMS2 binding sites inserted into the 3′ untranslated region. The tdMCP-FP allowed uniform RNA labeling and provided quantitative measurements of endogenous mRNA concentration and diffusion. This work provides a foundation for quantitative spectroscopy and imaging of single mRNAs directly in live cells
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Real-world heart rate norms in the Health eHeart study.
Emerging technology allows patients to measure and record their heart rate (HR) remotely by photoplethysmography (PPG) using smart devices like smartphones. However, the validity and expected distribution of such measurements are unclear, making it difficult for physicians to help patients interpret real-world, remote and on-demand HR measurements. Our goal was to validate HR-PPG, measured using a smartphone app, against HR-electrocardiogram (ECG) measurements and describe out-of-clinic, real-world, HR-PPG values according to age, demographics, body mass index, physical activity level, and disease. To validate the measurements, we obtained simultaneous HR-PPG and HR-ECG in 50 consecutive patients at our cardiology clinic. We then used data from participants enrolled in the Health eHeart cohort between 1 April 2014 and 30 April 2018 to derive real-world norms of HR-PPG according to demographics and medical conditions. HR-PPG and HR-ECG were highly correlated (Intraclass correlation = 0.90). A total of 66,788 Health eHeart Study participants contributed 3,144,332 HR-PPG measurements. The mean real-world HR was 79.1 bpm ± 14.5. The 95th percentile of real-world HR was ≤110 in individuals aged 18-45, ≤100 in those aged 45-60 and ≤95 bpm in individuals older than 60 years old. In multivariable linear regression, the number of medical conditions, female gender, increasing body mass index, and being Hispanic was associated with an increased HR, whereas increasing age was associated with a reduced HR. Our study provides the largest real-world norms for remotely obtained, real-world HR according to various strata and they may help physicians interpret and engage with patients presenting such data
COMIT: identification of noncoding motifs under selection in coding sequences
COMIT is presented; an algorithm for detecting functional non-coding motifs in coding regions, separating nucleotide and amino acid effects
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Additive enhancement of wound healing in diabetic mice by low level light and topical CoQ10
Diabetes, a highly prevalent disease that affects 9.3% of Americans, often leads to severe complications and slow wound healing. Preclinical studies have suggested that low level light therapy (LLLT) can accelerate wound healing in diabetic subjects, but significant improvements must be made to overcome the absence of persuasive evidence for its clinical use. We demonstrate here that LLLT can be combined with topical Coenzyme Q10 (CoQ10) to heal wounds in diabetic mice significantly faster than LLLT alone, CoQ10 alone, or controls. LLLT followed by topical CoQ10 enhanced wound healing by 68~103% in diabetic mice in the first week and more than 24% in the second week compared with untreated controls. All wounds were fully healed in two weeks following the dual treatment, in contrast to only 50% wounds or a fewer being fully healed for single or sham treatment. The accelerated healing was corroborated by at least 50% higher hydroxyproline levels, and tripling cell proliferation rates in LLLT and CoQ10 treated wounds over controls. The beneficial effects on wound healing were probably attributed to additive enhancement of ATP production by LLLT and CoQ10 treatment. The combination of LLLT and topical CoQ10 is safe and convenient, and merits further clinical study
A single-cell multiomic analysis of kidney organoid differentiation
Kidney organoids differentiated from pluripotent stem cells are powerful models of kidney development and disease but are characterized by cell immaturity and off-target cell fates. Comparing the cell-specific gene regulatory landscape during organoid differentiation with human adult kidney can serve to benchmark progress in differentiation at the epigenome and transcriptome level for individual organoid cell types. Using single-cell multiome and histone modification analysis, we report more broadly open chromatin in organoid cell types compared to the human adult kidney. We infer enhancer dynamics by cis-coaccessibility analysis and validate an enhancer driving transcription o
Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves
Kepler provides light curves of 156,000 stars with unprecedented precision.
However, the raw data as they come from the spacecraft contain significant
systematic and stochastic errors. These errors, which include discontinuities,
systematic trends, and outliers, obscure the astrophysical signals in the light
curves. To correct these errors is the task of the Presearch Data Conditioning
(PDC) module of the Kepler data analysis pipeline. The original version of PDC
in Kepler did not meet the extremely high performance requirements for the
detection of miniscule planet transits or highly accurate analysis of stellar
activity and rotation. One particular deficiency was that astrophysical
features were often removed as a side-effect to removal of errors. In this
paper we introduce the completely new and significantly improved version of PDC
which was implemented in Kepler SOC 8.0. This new PDC version, which utilizes a
Bayesian approach for removal of systematics, reliably corrects errors in the
light curves while at the same time preserving planet transits and other
astrophysically interesting signals. We describe the architecture and the
algorithms of this new PDC module, show typical errors encountered in Kepler
data, and illustrate the corrections using real light curve examples.Comment: Submitted to PASP. Also see companion paper "Kepler Presearch Data
Conditioning II - A Bayesian Approach to Systematic Error Correction" by Jeff
C. Smith et a
Multi-level meta-analysis of physical activity interventions during childhood: effects of physical activity on cognition and academic achievement
There is evidence that physical activity positively influences cognition and academic outcomes in childhood. This systematic review used a three-level meta-analytic approach, which handles nested effect sizes, to assess the impact of physical activity interventions. Ninety-two randomised control trials in typically developing children (5-12 years old, N = 25,334) were identified. Control group type and intervention characteristics including duration, frequency and teacher qualification were explored as potential moderators. Results showed physical activity interventions improved on-task behaviour with a large effect size (g = 1.04, p = 0.03 (95% CI: 0.08 – 2.00), very low-certainty evidence) and led to moderate improvements in creativity (g = 0.70, p < 0.01 (0.20 – 1.20), low-certainty evidence). Small beneficial effects were found for fluid intelligence (g = 0.16, p = 0.03 (0.02, 0.30), moderate-certainty evidence) and working memory (g = 0.18, p = 0.01 (0.07 – 0.29) very low-certainty evidence) but no overall benefit was observed for attention, inhibitory control, planning, cognitive flexibility or academic outcomes. Heterogeneity was high and moderator analyses indicated beneficial effects of PA with academic instruction of 6 – 10-week duration with moderate or moderate to vigorous intensity on mathematics outcomes and enriched PA programmes on language outcomes. In contrast, aerobic PA with moderate to vigorous intensity benefitted executive function outcomes. These results therefore suggest differential mechanisms of impact of different types of PA on different aspects of cognition
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