503 research outputs found
alphabeta sequence of F is IS31
Previous studies have shown that there is a deoxyribonucleic acid (DNA) segment, of length 1.3 kb and denoted as the alphabeta sequence, which occurs twice on the F plasmid at corrdinates 93.2 to 94.5/OF kb and 13.7 to 15.0F kb. In the present investigation, heteroduplexes were prepared between a phage DNA carrying the insertion sequence IS3 and suitable F-prime DNAs. The hybrids formed show that IS3 is the same as alphabeta. This result plus previous studies support the view that: (i) the insertion sequence IS2 and IS3 occur on F and, in multiple copies, on the main bacterial chromosome of Escherichia coli K-12; and (ii)these IS sequences on the main bacterial chromosomes are hot spots for Hfr formation by reciprocal recombination with the corresponding sequences of F
Results from an Einstein@Home search for continuous gravitational waves from Cassiopeia A, Vela Jr. and G347.3
We report results of the most sensitive search to date for periodic
gravitational waves from Cassiopeia A, Vela Jr. and G347.3 with frequency
between 20 and 1500 Hz. The search was made possible by the computing power
provided by the volunteers of the Einstein@Home project and improves on
previous results by a factor of 2 across the entire frequency range for all
targets. We find no significant signal candidate and set the most stringent
upper limits to date on the amplitude of gravitational wave signals from the
target population, corresponding to sensitivity depths between 54 and 83 , depending on the
target and the frequency range. At the frequency of best strain sensitivity,
near Hz, we set 90% confidence upper limits on the gravitational wave
intrinsic amplitude of , probing ellipticity values
for Vela Jr. as low as , assuming a distance of 200 pc
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Sulfonylurea Use and Incident Cardiovascular Disease Among Patients With Type 2 Diabetes: Prospective Cohort Study Among Women
OBJECTIVE Evidence is inconsistent for the association between sulfonylurea use and risk of cardiovascular disease among patients with diabetes. We aimed to prospectively evaluate this association using the Nurses’ Health Study (NHS), a well-established cohort of U.S. women with long-term follow-up. RESEARCH DESIGN AND METHODS We followed 4,902 women (mean age 68 years) with diabetes (mean duration 11 years), but without cardiovascular disease at baseline. The use of sulfonylureas and other medications was self-reported at baseline and during the follow-up period of up to 10 years. Cox proportional hazards regression models were used to estimate the relative risk (RR) and 95% CI for the association between the sulfonylurea use and incident cardiovascular disease while accounting for potential confounders, including age, diabetes duration, diabetes-related complications, other antihyperglycemic medications, BMI, lifestyle factors, family history of cardiovascular diseases, and present chronic conditions. We also applied the propensity score stratification method to address the possibility of residual confounding. RESULTS We identified 339 incident cases of cardiovascular disease, including 191 cases of coronary heart disease (CHD) and 148 cases of stroke. A longer duration of sulfonylurea use was significantly associated with a higher risk of CHD (P for trend = 0.002); the RRs for CHD were 1.24 (95% CI 0.85–1.81) for patients who used sulfonylurea therapy for 1–5 years, 1.51 (0.94–2.42) for 6–10 years, and 2.15 (1.31–3.54) for >10 years, compared with nonusers. Compared with users of metformin monotherapy, the RR for CHD was 3.27 (1.31–8.17) for those who were treated with the combination of metformin and sulfonylurea. The analysis using propensity score stratification yielded similar results. We did not observe a significant association between sulfonylurea therapy and stroke risk. CONCLUSIONS Long-term use of sulfonylureas was associated with a significantly higher risk of developing CHD among women with diabetes
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Adherence to healthy lifestyle and risk of gestational diabetes mellitus: prospective cohort study
Objective: To quantify the association between a combination of healthy lifestyle factors before pregnancy (healthy body weight, healthy diet, regular exercise, and not smoking) and the risk of gestational diabetes. Design: Prospective cohort study. Setting: Nurses’ Health Study II, United States. Participants: 20 136 singleton live births in 14 437 women without chronic disease. Main outcome measure Self reported incident gestational diabetes diagnosed by a physician, validated by medical records in a previous study. Results: Incident first time gestational diabetes was reported in 823 pregnancies. Each lifestyle factor measured was independently and significantly associated with risk of gestational diabetes. The combination of three low risk factors (non-smoker, ≥150 minutes a week of moderate to vigorous physical activity, and healthy eating (top two fifths of Alternate Healthy Eating Index-2010 adherence score)) was associated with a 41% lower risk of gestational diabetes compared with all other pregnancies (relative risk 0.59, 95% confidence interval 0.48 to 0.71). Addition of body mass index (BMI) <25 before pregnancy (giving a combination of four low risk factors) was associated with a 52% lower risk of gestational diabetes compared with all other pregnancies (relative risk 0.48, 0.38 to 0.61). Compared with pregnancies in women who did not meet any of the low risk lifestyle factors, those meeting all four criteria had an 83% lower risk of gestational diabetes (relative risk 0.17, 0.12 to 0.25). The population attributable risk percentage of the four risk factors in combination (smoking, inactivity, overweight, and poor diet) was 47.5% (95% confidence interval 35.6% to 56.6%). A similar population attributable risk percentage (49.2%) was observed when the distributions of the four low risk factors from the US National Health and Nutrition Examination Survey (2007-10) data were applied to the calculation. Conclusions: Adherence to a low risk lifestyle before pregnancy is associated with a low risk of gestational diabetes and could be an effective strategy for the prevention of gestational diabetes
FaSTrack: a Modular Framework for Real-Time Motion Planning and Guaranteed Safe Tracking
Real-time, guaranteed safe trajectory planning is vital for navigation in
unknown environments. However, real-time navigation algorithms typically
sacrifice robustness for computation speed. Alternatively, provably safe
trajectory planning tends to be too computationally intensive for real-time
replanning. We propose FaSTrack, Fast and Safe Tracking, a framework that
achieves both real-time replanning and guaranteed safety. In this framework,
real-time computation is achieved by allowing any trajectory planner to use a
simplified \textit{planning model} of the system. The plan is tracked by the
system, represented by a more realistic, higher-dimensional \textit{tracking
model}. We precompute the tracking error bound (TEB) due to mismatch between
the two models and due to external disturbances. We also obtain the
corresponding tracking controller used to stay within the TEB. The
precomputation does not require prior knowledge of the environment. We
demonstrate FaSTrack using Hamilton-Jacobi reachability for precomputation and
three different real-time trajectory planners with three different
tracking-planning model pairs.Comment: Published in the IEEE Transactions on Automatic Contro
Potential Impact of Time Trend of Life-Style Factors on Cardiovascular Disease Burden in China
Cardiovascular disease (CVD) is a leading cause of death in China. Evaluation of risk factors and their impacts on disease burden is important for future public health initiatives and policy making
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Transcriptionally active HERV-H retrotransposons demarcate topologically associating domains in human pluripotent stem cells.
Chromatin architecture has been implicated in cell type-specific gene regulatory programs, yet how chromatin remodels during development remains to be fully elucidated. Here, by interrogating chromatin reorganization during human pluripotent stem cell (hPSC) differentiation, we discover a role for the primate-specific endogenous retrotransposon human endogenous retrovirus subfamily H (HERV-H) in creating topologically associating domains (TADs) in hPSCs. Deleting these HERV-H elements eliminates their corresponding TAD boundaries and reduces the transcription of upstream genes, while de novo insertion of HERV-H elements can introduce new TAD boundaries. The ability of HERV-H to create TAD boundaries depends on high transcription, as transcriptional repression of HERV-H elements prevents the formation of boundaries. This ability is not limited to hPSCs, as these actively transcribed HERV-H elements and their corresponding TAD boundaries also appear in pluripotent stem cells from other hominids but not in more distantly related species lacking HERV-H elements. Overall, our results provide direct evidence for retrotransposons in actively shaping cell type- and species-specific chromatin architecture
Do Chinese Traditional and Modern Cultures Affect Young Adults’ Moral Priorities?
Dramatic cultural change has occurred in Mainland China over the past four decades, yet little is known about how this cultural shift impacts Chinese peoples’ moral values. The present research aims to fill this gap by examining whether Chinese traditional and modern cultures influence young adults’ moral judgments. Study 1 investigated the relation between psychological traditionality/modernity and moral concerns. Results indicated that participants who strongly endorsed Chinese traditional culture prioritize relationship concern rather than justice concern. Study 2 used the cultural priming method and tested the effects of traditional and modern icons on moral concerns. Results suggested that participants who were primed with traditional or modern or neutral icons did not give priority to relationship or justice concern. Together, our findings provide initial empirical evidence on whether Chinese traditional and modern cultures shift the moral mindsets of bicultural young Chinese among alternative (and even competing) moral codes
Bacterial expression of mutant argininosuccinate lyase reveals imperfect correlation of in - vitro enzyme activity with clinical phenotype in argininosuccinic aciduria
Background: The urea cycle defect argininosuccinate lyase (ASL) deficiency has a large spectrum of presentations from highly severe to asymptomatic. Enzyme activity assays in red blood cells or fibroblasts, although diagnostic of the deficiency, fail to discriminate between severe, mild or asymptomatic cases. Mutation/phenotype correlation studies are needed to characterize the effects of individual mutations on the activity of the enzyme. Methods: Bacterial in-vitro expression studies allowed the enzyme analysis of purified mutant ASL proteins p.I100T (c.299T > C), p.V178M (c.532G > A), p.E189G (c.566A > G), p.Q286R (c.857A > G), p.K315E (c.943A > G), p.R379C (c.1135C > T) and p.R385C (c.1153C > T) in comparison to the wildtype protein. Results: In the bacterial in-vitro expression system, ASL wild-type protein was successfully expressed. The known classical p.Q286R, the novel classical p.K315E and the known mutations p.I100T, p.E189G and p.R385C, which all have been linked to a mild phenotype, showed no significant residual activity. There was some enzyme activity detected with the p.V178M (5 % of wild-type) and p.R379C (10 % of wild-type) mutations in which Km values for argininosuccinic acid differed significantly from the wild-type ASL protein. Conclusion: The bacterially expressed enzymes proved that the mutations found in patients and studied here indeed are detrimental. However, as in the case of red cell ASL activity assays, some mutations found in genetically homozygous patients with mild presentations resulted in virtual loss of enzyme activity in the bacterial system, suggesting a more protective environment for the mutant enzyme in the liver than in the heterologous expression system and/or in the highly dilute assays utilized her
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