2,592 research outputs found
Effects of breaking up prolonged sitting following low and high glycaemic index breakfast consumption on glucose and insulin concentrations
Purpose: Breaking up prolonged sitting can attenuate the postprandial rise in glucose and insulin. Whether such effects are dependent of the glycaemic index (GI) of the consumed carbohydrate is unknown. This study examined the acute effects of breaking up prolonged sitting following a low GI and a high GI breakfast on postprandial glucose and insulin concentrations. Procedures: Fourteen adult males aged 22.1 ± 1.2 years completed four, 4 h experimental conditions: high GI breakfast followed by uninterrupted sitting (HGI-SIT), low GI breakfast followed by uninterrupted sitting (LGI-SIT), high GI breakfast followed by 2 min activity breaks every 20 min (HGI-ACT), and low GI breakfast followed by 2 min activity breaks every 20 min (LGI-ACT). Positive incremental area under the curve (iAUC) for glucose and insulin (mean [95% CI]) for each 4h experimental condition was calculated. Statistical analyses were completed using linear mixed models. Results: The sitting × breakfast GI interaction was not significant for glucose positive iAUC (P=0.119). Glucose positive iAUC (mmol/L4 h−1) was significantly lower in the activity breaks conditions than the uninterrupted sitting conditions (2.07 [2.24, 2.89] vs. 2.56 [1.74, 2.40], respectively, P=0.004) and significantly lower in the low GI conditions than the high GI conditions (2.13 [1.80, 2.45] vs. 2.51 [2.18, 2.84], respectively, P=0.022). Insulin concentrations did not differ between conditions (P ≥ 0.203). Conclusions: Breaking up prolonged sitting and lowering breakfast GI independently reduced postprandial glucose responses. This indicates that interrupting prolonged sitting and reducing dietary GI are beneficial approaches for reducing cardiometabolic disease risk
Gait analysis in a <i>Mecp2</i> knockout mouse model of Rett syndrome reveals early-onset and progressive motor deficits
Rett syndrome (RTT) is a genetic disorder characterized by a range of features including cognitive impairment, gait abnormalities and a reduction in purposeful hand skills. Mice harbouring knockout mutations in the <i>Mecp2</i> gene display many RTT-like characteristics and are central to efforts to find novel therapies for the disorder. As hand stereotypies and gait abnormalities constitute major diagnostic criteria in RTT, it is clear that motor and gait-related phenotypes will be of importance in assessing preclinical therapeutic outcomes. We therefore aimed to assess gait properties over the prodromal phase in a functional knockout mouse model of RTT. In male <i>Mecp2</i> knockout mice, we observed alterations in stride, coordination and balance parameters at 4 weeks of age, before the onset of other overt phenotypic changes as revealed by observational scoring. These data suggest that gait measures may be used as a robust and early marker of <i>Mecp2</i>-dysfunction in future preclinical therapeutic studies
MEME-LaB : motif analysis in clusters
Genome-wide expression analysis can result in large numbers of clusters of co-expressed genes. While there are tools for ab initio discovery of transcription factor binding sites, most do not provide a quick and easy way to study large numbers of clusters. To address this, we introduce a web-tool called MEME-LaB. The tool wraps MEME (an ab initio motif finder), providing an interface for users to input multiple gene clusters, retrieve promoter sequences, run motif finding, and then easily browse and condense the results, facilitating better interpretation of the results from large-scale datasets
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Graduation Rates, Student Goals, and Measuring Community College Effectiveness
The goal of this study is to determine the institutional characteristics that affect the success of community college students as measured by the individual student probability of completing a certificate or degree or transferring to a baccalaureate institution. While there is extensive research on the institutional determinants of educational outcomes for K-12 education and a growing literature on this topic for baccalaureate institutions, few researchers have attempted to address the issue for community colleges. Using individual level data from the National Education Longitudinal Study of 1988 (NELS:88) and institutional level data from the Integrated Postsecondary Education Data System (IPEDS), we address two methodological challenges associated with research on community college students: unobserved institutional effects and attendance at multiple institutions. The most consistent results across specifications are the negative relationship between individual success and larger institutional size, and the proportion of part-time faculty and minority students
High eccentricity planets from the Anglo-Australian Planet Search
We report Doppler measurements of the stars HD187085 and HD20782 which
indicate two high eccentricity low-mass companions to the stars. We find
HD187085 has a Jupiter-mass companion with a ~1000d orbit. Our formal `best
fit' solution suggests an eccentricity of 0.47, however, it does not sample the
periastron passage of the companion and we find that orbital solutions with
eccentricities between 0.1 and 0.8 give only slightly poorer fits (based on RMS
and chi^2) and are thus plausible. Observations made during periastron passage
in 2007 June should allow for the reliable determination of the orbital
eccentricity for the companion to HD187085. Our dataset for HD20782 does sample
periastron and so the orbit for its companion can be more reliably determined.
We find the companion to HD20782 has M sin i=1.77+/-0.22M_JUP, an orbital
period of 595.86+/-0.03d and an orbit with an eccentricity of 0.92+/-0.03. The
detection of such high-eccentricity (and relatively low velocity amplitude)
exoplanets appears to be facilitated by the long-term precision of the
Anglo-Australian Planet Search. Looking at exoplanet detections as a whole, we
find that those with higher eccentricity seem to have relatively higher
velocity amplitudes indicating higher mass planets and/or an observational bias
against the detection of high eccentricity systems.Comment: to appear in MNRA
Beneficial postprandial lipaemic effects of interrupting sedentary time with high-intensity physical activity versus a continuous moderate-intensity physical activity bout: a randomised crossover trial
Objectives
To compare the postprandial cardiometabolic response to prolonged sitting, continuous moderate-intensity physical activity (PA) followed by prolonged sitting, and interrupting prolonged sitting with hourly high-intensity PA breaks.
Design
Three-condition randomised crossover trial.
Methods
Fourteen sedentary and inactive adults aged 29 ± 9 years took part in three, 8-h conditions: (1) prolonged sitting (SIT), (2) a continuous 30-min moderate-intensity PA bout followed by prolonged sitting (CONT-SIT), and (3) sitting interrupted hourly with 2 min 32 s high-intensity PA bouts (SIT-ACT). The treadmill PA in conditions 2 and 3 were matched for energy expenditure. Two standardised test meals were consumed during each condition. Incremental area under the curve (iAUC) for each 8-h condition was calculated for glucose, insulin, triglyceride, and high-density lipoprotein cholesterol (HDL-C) concentrations. Statistical analyses were completed using linear mixed models.
Results
Compared with SIT, SIT-ACT lowered triglyceride iAUC by 2.23 mmol/L ∙ 8 h (95% CI −4.33, −0.13) and raised HDL-C iAUC by 0.99 mmol/L ∙ 8 h (0.05, 1.93) (all p ≤ 0.038). There was no significant difference in triglyceride or HDL-C iAUC between CONT-SIT and SIT or SIT-ACT (p ≥ 0.211). There were no significant differences between conditions for glucose or insulin iAUC (p ≥ 0.504).
Conclusions
This study suggests that interrupting prolonged sitting with hourly high-intensity PA breaks acutely improves postprandial triglyceride and HDL-C concentrations compared with prolonged sitting, whereas a continuous moderate-intensity PA bout does not
Polymer Brush‐Modified Microring Resonators for Partition‐Enhanced Small Molecule Chemical Detection
Silicon photonic microring resonators have emerged as a promising technology for the sensitive detection of biological macromolecules, including proteins and nucleic acids. However, not all species of interest are large biologics that can be targeted by highly specific capture agents. For smaller organic chemicals, including many toxic and regulated species, a general approach to improving sensitivity would be desirable. By functionalizing the surface of silicon photonic microring resonators with polymer brushes, small molecules can selectively partition into the surface‐confined sensing region of the optical resonators. This in turn leads to response enhancements in excess of 1000% percent, relative to non‐functionalized sensors, for representative targets including 4‐methylumbelliferyl phosphate, a simulant for highly toxic organophosphates, Bisphenol A, an industrial pollutant, as well as other small organic analytes of interest. There are many polymer brush chemistries compatible with silicon resonators, making this a general strategy towards tuning sensor selectivity and specificity by optimizing interactions between the agent(s) of interest and the polymer construct.Polymer brush‐modified microring resonators sensors can be utilized to enhance sensitivity and specificity for the detection of small molecule organic chemicals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136268/1/slct201700082.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136268/2/slct201700082-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136268/3/slct201700082_am.pd
The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study
Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3
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Beyond Student Right-to-Know Data: Factors That Can Explain Community College Graduation Rates
Policymakers, educators, and researchers recognize the importance of community colleges as open door institutions that provide a wide range of students with access to college. At the same time, competing demands for the state funds that would support community colleges have resulted in reduced public allocations and higher student tuition fees. Understandably, therefore, both state policymakers and parents are increasingly focused on the returns to their public or private investments in education, and the outcomes of community college attendance are now under greater scrutiny. To facilitate the evaluation of the colleges, there are now available data, through the Student Right-to-Know and Campus Security Act (1990), which amended the Higher Education Act, on every college’s graduation rate for fall semester cohorts of first-time, fulltime (FTFT) students in degree programs. This information is known as the Student Right-to-Know (SRK) data. A related public concern is how the outcomes of community college students can be improved. Therefore, attempts are now being made to clarify the way that specific students define success and to identify the college policies and practices that can promote success for all students. For
some community college students, college completion, defined as earning a degree or certificate, is the appropriate measure of success. For other students, success is demonstrated by transferring to a baccalaureate institution. Still others are satisfied with completing courses that increase their knowledge or skill level in a particular area even though their educational experience is not considered successful as defined by traditional educational outcomes
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The Effects of Institutional Factors on the Success of Community College Students
Community colleges are the gateway to higher education for many students who would otherwise have limited access to college, particularly those who are from low-income households or are ethnic minorities, first generation college students, or immigrants. Yet only about one-third of all community college students receives any degree or certificate even eight years after initial college enrollment. And credit accumulation and completion rates are even lower for minority and low-income students. Meanwhile, community college student outcomes, as measures of college effectiveness, are of increasing concern for institutional accountability. The Bush administration and many legislators in Congress would like to hold postsecondary institutions to higher standards of accountability, just as they have done with elementary and secondary schools. Institutional reporting requirements to the Department of Education now include data for graduation rates overall and broken out by gender and race/ethnicity. More than half of all states take into account the performance of public colleges when determining higher education appropriations
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