6,108 research outputs found

    Adjustable mount for electro-optic transducers in an evacuated cryogenic system

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    The invention is an adjustable mount for positioning an electro-optic transducer in an evacuated cryogenic environment. Electro-optic transducers are used in this manner as high sensitivity detectors of gas emission lines of spectroscopic analysis. The mount is made up of an adjusting mechanism and a transducer mount. The adjusting mechanism provided five degrees of freedom, linear adjustments and angular adjustments. The mount allows the use of an internal lens to focus energy on the transducer element thereby improving the efficiency of the detection device. Further, the transducer mount, although attached to the adjusting mechanism, is isolated thermally such that a cryogenic environment can be maintained at the transducer while the adjusting mechanism remains at room temperature. Radiation shields also are incorporated to further reduce heat flow to the transducer location

    Glycoprotein IIb/IIIa Inhibitors Use and Outcome after Percutaneous Coronary Intervention for Non-ST Elevation Myocardial Infarction

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    Aims. We investigate the effect of glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors on long-term outcomes following percutaneous coronary intervention (PCI) after non-ST elevation myocardial infarction (NSTEMI). Meta-analyses indicate that these agents are associated with improved short-term outcomes. However, many trials were undertaken before the routine use of P2Y12 inhibitors. Recent studies yield conflicting results and registry data have suggested that GP IIb/IIIa inhibitors may cause more bleeding than what trials indicate. Methods and Results. This retrospective observational study involves 3047 patients receiving dual-antiplatelet therapy who underwent PCI for NSTEMI. Primary outcome was all-cause mortality. Major adverse cardiac events (MACE) were a secondary outcome. Mean follow-up was 4.6 years. Patients treated with GP IIb/IIIa inhibitors were younger with fewer comorbidities. Although the unadjusted Kaplan-Meier analysis suggested that GP IIb/IIIa inhibitor use was associated with improved outcomes, multivariate analysis (including propensity scoring) showed no benefit for either survival (P=0.136) or MACE (P=0.614). GP IIb/IIIa inhibitor use was associated with an increased risk of major bleeding (P=0.021). Conclusion. Although GP IIb/IIIa inhibitor use appeared to improve outcomes after PCI for NSTEMI, patients who received GP IIb/IIIa inhibitors tended to be at lower risk. After multivariate adjustment we observed no improvement in MACE or survival and an increased risk of major bleeding

    IMBES pre-conference: using insight from research to improve education

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    In September 2016, the International Mind, Brain, and Education Society (IMBES) biennial conference took place in Toronto, Canada. The pre-conference (organized by the Wellcome Trust) was designed to share new findings, lessons learned, and inspirational innovation within the field, and to encourage the community to not only identify current challenges, but to start planning potential ways to address them. This article provides a brief summary of the discussions from the day, and suggests steps that members of the community, conference organizers, and funders can take in helping to move the field forward. Finally, it outlines new work Wellcome has commissioned since the conference in response to some of the challenges defined on the day

    A Hot Uranus Orbiting the Super Metal-rich Star HD77338 and the Metallicity - Mass Connection

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    We announce the discovery of a low-mass planet orbiting the super metal-rich K0V star HD77338 as part of our on-going Calan-Hertfordshire Extrasolar Planet Search. The best fit planet solution has an orbital period of 5.7361\pm0.0015 days and with a radial velocity semi-amplitude of only 5.96\pm1.74 m/s, we find a minimum mass of 15.9+4.7-5.3 Me. The best fit eccentricity from this solution is 0.09+0.25-0.09, and we find agreement for this data set using a Bayesian analysis and a periodogram analysis. We measure a metallicity for the star of +0.35\pm0.06 dex, whereas another recent work (Trevisan et al. 2011) finds +0.47\pm0.05 dex. Thus HD77338b is one of the most metal-rich planet host stars known and the most metal-rich star hosting a sub-Neptune mass planet. We searched for a transit signature of HD77338b but none was detected. We also highlight an emerging trend where metallicity and mass seem to correlate at very low masses, a discovery that would be in agreement with the core accretion model of planet formation. The trend appears to show that for Neptune-mass planets and below, higher masses are preferred when the host star is more metal-rich. Also a lower boundary is apparent in the super metal-rich regime where there are no very low-mass planets yet discovered in comparison to the sub-solar metallicity regime. A Monte Carlo analysis shows that this, low-mass planet desert, is statistically significant with the current sample of 36 planets at around the 4.5\sigma\ level. In addition, results from Kepler strengthen the claim for this paucity of the lowest-mass planets in super metal-rich systems. Finally, this discovery adds to the growing population of low-mass planets around low-mass and metal-rich stars and shows that very low-mass planets can now be discovered with a relatively small number of data points using stable instrumentation.Comment: 25 pages, 15 figures, 5 tables, accepted for publication in Ap

    Scientific collaboration with educators: practical insights from an in‐class noise‐reduction intervention

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    Moving the field of Mind, Brain, and Education forward requires researchers and educators to reframe the boundaries of their own discipline in order to create knowledge that is both scientifically based, and of practical relevance for education. We believe that this could be done by co‐constructing research projects from the start. We present a case study of a noise‐reduction intervention in elementary classrooms, in which teachers and researchers worked together from the onset of study design. We examine the processes behind: (1) selecting research questions and measures, (2) planning interventions, (3) receiving ethical approval and funding, (4) recruiting schools, and (5) collecting data. At each step, our study provides suggestions for future collaborative efforts, keeping in mind broader theoretical and methodological implications. We believe that our concrete examples and suggestions will be useful for beginning and confirmed researchers, as well as teachers aiming to know more about research projects

    Enhanced triage for patients with suspected cardiac chest pain: the History and Electrocardiogram-only Manchester Acute Coronary Syndromes decision aid.

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    OBJECTIVES: Several decision aids can 'rule in' and 'rule out' acute coronary syndromes (ACS) in the Emergency Department (ED) but all require measurement of blood biomarkers. A decision aid that does not require biomarker measurement could enhance risk stratification at triage and could be used in the prehospital environment. We aimed to derive and validate the History and ECG-only Manchester ACS (HE-MACS) decision aid using only the history, physical examination and ECG. METHODS: We undertook secondary analyses in three prospective diagnostic accuracy studies that included patients presenting to the ED with suspected cardiac chest pain. Clinicians recorded clinical features at the time of arrival using a bespoke form. Patients underwent serial troponin sampling and 30-day follow-up for the primary outcome of ACS. The model was derived by logistic regression in one cohort and validated in two similar prospective studies. RESULTS: The HE-MACS model was derived in 796 patients and validated in cohorts of 474 and 659 patients. HE-MACS incorporated age, sex, systolic blood pressure plus five historical variables to stratify patients into four risk groups. On validation, 5.5 and 12.1% (pooled total 9.4%) patients were identified as 'very low risk' (potential immediate rule out) with a pooled sensitivity of 99.5% (95% confidence interval: 97.1-100.0%). CONCLUSION: Using only the patient's history and ECG, HE-MACS could 'rule out' ACS in 9.4% of patients while effectively risk stratifying remaining patients. This is a very promising tool for triage in both the prehospital environment and ED. Its impact should be prospectively evaluated in those settings

    Correspondence between geometrical and differential definitions of the sine and cosine functions and connection with kinematics

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    In classical physics, the familiar sine and cosine functions appear in two forms: (1) geometrical, in the treatment of vectors such as forces and velocities, and (2) differential, as solutions of oscillation and wave equations. These two forms correspond to two different definitions of trigonometric functions, one geometrical using right triangles and unit circles, and the other employing differential equations. Although the two definitions must be equivalent, this equivalence is not demonstrated in textbooks. In this manuscript, the equivalence between the geometrical and the differential definition is presented assuming no a priori knowledge of the properties of sine and cosine functions. We start with the usual length projections on the unit circle and use elementary geometry and elementary calculus to arrive to harmonic differential equations. This more general and abstract treatment not only reveals the equivalence of the two definitions but also provides an instructive perspective on circular and harmonic motion as studied in kinematics. This exercise can help develop an appreciation of abstract thinking in physics.Comment: 6 pages including 1 figur

    Effects of Morning Versus Evening Statin Administration on Lipid Profile: A Systematic Review and Meta-Analysis

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    Background: Evidence about the optimal time of day at which to administer statins is lacking. Objective: To synthesize evidence about effects of morning versus evening statin administration on lipid profile. Methods: We searched PubMed, SCOPUS, Web of Science and Embase databases (from inception up to July 24th, 2016) to identify the relevant studies. Mean differences (MDs) between the change scores in lipid parameters were pooled using a fixed-effect model. Results: Eleven articles with 1034 participants were eligible for the analysis. The pooled analysis comparing effects of morning versus evening administration of statins on plasma total cholesterol (TC) (p=0.10), high density lipoprotein cholesterol (HDL-C) (p=0.90) and triglycerides (TG) (p=0.45) was not statistically significant. Low density lipoprotein cholesterol (LDL-C) lowering was statistically greater in the evening-dose group (MD: 3.24 mg/dl, 95%CI: 1.23, 5.25, p=0.002). Subgroup analysis according to statin half-lives showed that evening-dose of statins was significantly superior to morning-dose for lowering LDL-C in case of both short and long half-life statins (MD: 9.68 mg/dl, 95%CI: 3.32, 16.03, p=0.003, and 2.53 mg/dl, 95%CI: 0.41, 4.64, p=0.02, respectively), and also for TC reduction in case of short half-life statins only (p=0.0005). Conclusions: LDL-C and TC lowering were significantly greater in the evening-dose than in the morning-dose in case of short-acting statins. Besides slight but significant effect on LDL-C, the efficacy of long-acting statins was equivalent for both regimens. Therefore, long-acting statins should be given at a time that will best aid compliance. Short-acting statins should be given in the evening
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