62 research outputs found

    The Ultimate Flipped Classroom: Team-Based Learning

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    Have you heard the buzz about the “flipped classroom” but wondered how to set it up? While there are different variations, Team-Based Learning (TBL) is an engaging strategy that gives you the ultimate flipped classroom. TBL helps students learn critical thinking, solve real-world problems, and develop collaborative skills. This poster session will introduce and highlight Team-Based Learning and give you ideas for employing this powerful strategy for bringing about more motivation and deeper learning in your students.https://fuse.franklin.edu/ss2014/1038/thumbnail.jp

    Order effects in high stakes undergraduate examinations: an analysis of 5 years of administrative data in one UK medical school.

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    OBJECTIVE: To investigate the association between student performance in undergraduate objective structured clinical examinations (OSCEs) and the examination schedule to which they were assigned to undertake these examinations. DESIGN: Analysis of routinely collected data. SETTING: One UK medical school. PARTICIPANTS: 2331 OSCEs of 3 different types (obstetrics OSCE, paediatrics OSCE and simulated clinical encounter examination OSCE) between 2009 and 2013. Students were not quarantined between examinations. OUTCOMES: (1) Pass rates by day examination started, (2) pass rates by day station undertaken and (3) mean scores by day examination started. RESULTS: We found no evidence that pass rates differed according to the day on which the examination was started by a candidate in any of the examinations considered (p>0.1 for all). There was evidence (p=0.013) that students were more likely to pass individual stations on the second day of the paediatrics OSCE (OR 1.27, 95% CI 1.05 to 1.54). In the cases of the simulated clinical encounter examination and the obstetrics and gynaecology OSCEs, there was no (p=0.42) or very weak evidence (p=0.099), respectively, of any such variation in the probability of passing individual stations according to the day they were attempted. There was no evidence that mean scores varied by day apart from the paediatric OSCE, where slightly higher scores were achieved on the second day of the examination. CONCLUSIONS: There is little evidence that different examination schedules have a consistent effect on pass rates or mean scores: students starting the examinations later were not consistently more or less likely to pass or score more highly than those starting earlier. The practice of quarantining students to prevent communication with (and subsequent unfair advantage for) subsequent examination cohorts is unlikely to be required.University of Cambridge School of Clinical MedicineThis is the final version of the article. It first appeared from BMJ Group via http://dx.doi.org/10.1136/bmjopen-2016-01254

    Kepler Observations of V447 Lyr: An Eclipsing U Gem Cataclysmic Variable

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    We present the results of an analysis of data covering 1.5 years of the dwarf nova V447 Lyr. We detect eclipses of the accretion disk by the mass donating secondary star every 3.74 hrs which is the binary orbital period. V447 Lyr is therefore the first dwarf nova in the Kepler field to show eclipses. We also detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem type dwarf nova. We show that the orbital phase of the mid-eclipse occurs earlier during outbursts compared to quiescence and that the width of the eclipse is greater during outburst. This suggests that the bright spot is more prominent during quiescence and that the disk is larger during outburst than quiescence. This is consistent with an expansion of the outer disk radius due to the presence of high viscosity material associated with the outburst, followed by a contraction in quiescence due to the accretion of low angular momentum material. We note that the long outbursts appear to be triggered by a short outburst, which is also observed in the super-outbursts of SU UMa dwarf novae as observed using Kepler.Comment: Accepted by MNRA

    Actuation of Micro-Optomechanical Systems Via Cavity-Enhanced Optical Dipole Forces

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    We demonstrate a new type of optomechanical system employing a movable, micron-scale waveguide evanescently-coupled to a high-Q optical microresonator. Micron-scale displacements of the waveguide are observed for milliwatt(mW)-level optical input powers. Measurement of the spatial variation of the force on the waveguide indicates that it arises from a cavity-enhanced optical dipole force due to the stored optical field of the resonator. This force is used to realize an all-optical tunable filter operating with sub-mW control power. A theoretical model of the system shows the maximum achievable force to be independent of the intrinsic Q of the optical resonator and to scale inversely with the cavity mode volume, suggesting that such forces may become even more effective as devices approach the nanoscale.Comment: 4 pages, 5 figures. High resolution version available at (http://copilot.caltech.edu/publications/CEODF_hires.pdf). For associated movie, see (http://copilot.caltech.edu/research/optical_forces/index.htm

    An Early Beaker funerary monument at Porton Down, Wiltshire

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    Excavation of an Early Beaker-Early Bronze Age funerary monument at Porton Down revealed an unusually complex burial sequence of 12 individuals, spanning four centuries, including eight neonates or infants and only one probable male, surrounded by a segmented ring-ditch. In the centre was a large grave which contained the disturbed remains of an adult female, accompanied by a Beaker, which had probably been placed within a timber chamber and later ‘revisited’ on one or more occasions. This primary burial and an antler pick from the base of the ring-ditch provided identical Early Beaker radiocarbon dates. Two burials were accompanied by a Food Vessel and a miniature Collared Urn respectively, others were unaccompanied, and there was a single and a double cremation burial, both within inverted Collared Urns. A C-shaped enclosure nearby may have been contemporary with the funerary monument, but its date and function are uncertain. Other features included an Early Neolithic pit which contained a significant assemblage of worked flint, and several Middle Bronze Age ditches and a Late Bronze Age ‘Wessex Linear’ ditch that reflect later prehistoric land divisions probably related to stock control

    Optical and mechanical design of a "zipper" photonic crystal optomechanical cavity

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    Design of a doubly-clamped beam structure capable of localizing mechanical and optical energy at the nanoscale is presented. The optical design is based upon photonic crystal concepts in which patterning of a nanoscale-cross-section beam can result in strong optical localization to an effective optical mode volume of 0.2 cubic wavelengths ((\lambda_{c})^3). By placing two identical nanobeams within the near field of each other, strong optomechanical coupling can be realized for differential motion between the beams. Current designs for thin film silicon nitride beams at a wavelength of 1.5 microns indicate that such structures can simultaneously realize an optical Q-factor of 7x10^6, motional mass m~40 picograms, mechanical mode frequency ~170 MHz, and an optomechanical coupling factor (g_{OM}=d\omega_{c}/dx = \omega_{c}/L_{OM}) with effective length L_{OM} ~ \lambda = 1.5 microns.Comment: 16 pages, 10 figure

    Characterization of radiation pressure and thermal effects in a nanoscale optomechanical cavity

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    Optical forces in guided-wave nanostructures have recently been proposed as an effective means of mechanically actuating and tuning optical components. In this work, we study the properties of a photonic crystal optomechanical cavity consisting of a pair of patterned silicon nitride nanobeams. Internal stresses in the stoichiometric silicon nitride thin-film are used to produce inter-beam slot-gaps ranging from 560 to 40nm. A general pump-probe measurement scheme is described which determines, self-consistently, the contributions of thermo-mechanical, thermo-optic, and radiation pressure effects. For devices with 40nm slot-gap, the optical gradient force is measured to be 134fN per cavity photon for the strongly coupled symmetric cavity supermode, producing a static cavity tuning greater than five times that of either the parasitic thermo-mechanical or thermo-optic effects.Comment: 6 pages, 4 figure

    BOKS 45906: a CV with an orbital period of 56.6 min in the Kepler field?

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    BOKS 45906 was found to be a blue source in the Burrell-Optical-Kepler Survey which showed a 3 mag outburst lasting ∌5 d. We present the Kepler light curve of this source which covers nearly 3 years. We find that it is in a faint optical state for approximately half the time and shows a series of outbursts separated by distinct dips in flux. Using data with 1 min sampling, we find clear evidence that in its low state BOKS 45906 shows a flux variability on a period of 56.5574 ± 0.0014 min and a semi-amplitude of ∌3 per cent. Since we can phase all the 1 min cadence data on a common ephemeris using this period, it is probable that 56.56 min is the binary orbital period. Optical spectra of BOKS 45906 show the presence of Balmer lines in emission indicating it is not an AM CVn (pure Helium) binary. Swift data show that it is a weak X-ray source and is weakly detected in the bluest of the UVOT filters. We conclude that BOKS 45906 is a cataclysmic variable with a period shorter than the ‘period-bounce’ systems and therefore BOKS 45906 could be the first helium-rich cataclysmic variable detected in the Kepler field

    Surgical Treatment for Recurrent Bulbar Urethral Stricture: A Randomised Open-label Superiority Trial of Open Urethroplasty Versus Endoscopic Urethrotomy (the OPEN Trial)

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    BackgroundUrethral stricture affects 0.9% of men. Initial treatment is urethrotomy. Approximately, half of the strictures recur within 4 yr. Options for further treatment are repeat urethrotomy or open urethroplasty.ObjectiveTo compare the effectiveness and cost-effectiveness of urethrotomy with open urethroplasty in adult men with recurrent bulbar urethral stricture.Design, setting, and participantsThis was an open label, two-arm, patient-randomised controlled trial. UK National Health Service hospitals were recruited and 222 men were randomised to receive urethroplasty or urethrotomy.InterventionUrethrotomy is a minimally invasive technique whereby the narrowed area is progressively widened by cutting the scar tissue with a steel blade mounted on a urethroscope. Urethroplasty is a more invasive surgery to reconstruct the narrowed area.Outcome measurements and statistical analysisThe primary outcome was the profile over 24 mo of a patient-reported outcome measure, the voiding symptom score. The main clinical outcome was time until reintervention.Results and limitationsThe primary analysis included 69 (63%) and 90 (81%) of those allocated to urethroplasty and urethrotomy, respectively. The mean difference between the urethroplasty and urethrotomy groups was –0.36 (95% confidence interval [CI] –1.74 to 1.02). Fifteen men allocated to urethroplasty needed a reintervention compared with 29 allocated to urethrotomy (hazard ratio [95% CI] 0.52 [0.31–0.89]).ConclusionsIn men with recurrent bulbar urethral stricture, both urethroplasty and urethrotomy improved voiding symptoms. The benefit lasted longer for urethroplasty.Patient summaryThere was uncertainty about the best treatment for men with recurrent bulbar urethral stricture. We randomised men to receive one of the following two treatment options: urethrotomy and urethroplasty. At the end of the study, both treatments resulted in similar and better symptom scores. However, the urethroplasty group had fewer reinterventions
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