5,393 research outputs found

    The Impact of a National Science Foundation Collaborative for Excellence in Teacher Preparation on an Undergraduate Chemistry Course for Non-Chemistry Science Majors

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    In 1999 and 2000 Chemistry 312: Analytical Chemistry for non-chemistry science majors (taken in the junior or senior year), was revised as a result of the instructor’s involvements in the Center for Excellence in Teacher Preparation project and an NSF equipment grant. Changes included the introduction of a K-12 teaching requirement, more emphasis on co-operative learning and on inquiry-based exercises. These latter two pedagogical practices had more impact on the laboratory activities than on the classroom activities. Students in the laboratory were assigned defined roles in the groups and all groups undertook a three-week research project. Students’ responses to the teaching requirement were (with a few exceptions in a class of over forty) positive, and several students identified themselves as future teachers. Responses to the group work associated with the laboratory and several homework exercises were less uniformly positive, with a significant number of students articulating a concern that their grades were compromised by the presence of weaker students in the groups. The grades awarded, the overall percentages and the exam scores of the students were compared for the years 1998, 1999, and 2000. There was a significant improvement in the overall percentages (and the exam scores) between 1998 and 1999, and between 1998 and 2000. Had the thresholds for the awarding of letter grades not been increased for 2000, there would have been 31 A’s awarded to the 44 students who completed the course

    Optical Synoptic Telescopes: New Science Frontiers

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    Over the past decade, sky surveys such as the Sloan Digital Sky Survey have proven the power of large data sets for answering fundamental astrophysical questions. This observational progress, based on a synergy of advances in telescope construction, detectors, and information technology, has had a dramatic impact on nearly all fields of astronomy, and areas of fundamental physics. The next-generation instruments, and the surveys that will be made with them, will maintain this revolutionary progress. The hardware and computational technical challenges and the exciting science opportunities are attracting scientists and engineers from astronomy, optics, low-light-level detectors, high-energy physics, statistics, and computer science. The history of astronomy has taught us repeatedly that there are surprises whenever we view the sky in a new way. This will be particularly true of discoveries emerging from a new generation of sky surveys. Imaging data from large ground-based active optics telescopes with sufficient etendue can address many scientific missions simultaneously. These new investigations will rely on the statistical precision obtainable with billions of objects. For the first time, the full sky will be surveyed deep and fast, opening a new window on a universe of faint moving and distant exploding objects as well as unraveling the mystery of dark energy.Comment: 12 pages, 7 figure

    Sizing the European Shadow Banking System: A New Methodology

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    One of the critical unanswered questions relating to the shadow-banking system has been to quantify its scale in an industry where entities, by design, are opaque and often outside of regulated and publically shared frameworks. However almost all shadow banking entities, including hedge funds, private equity funds and special purpose vehicles ("SPVs"), interact with the financial markets via regulated investment banks. For example, many SPVs are in fact originated as part of investment banking business and hedge funds typically transact in financial markets exclusively via the "prime brokerage" division of investment banks. This interface with the regulated banking environment combines with the typical practise by investment banks of equalizing compensation (Including bonus) ratios to revenues globally which then allows identification of the implied difference in revenues and hence assets that represents the shadow banking system. The paper will present for critique the results of this methodology to estimate the UK shadow banking system including European business managed from the UK. The estimate will imply a larger scale of shadow banking than previous estimates at £548 billion which, when combined with hedge fund assets of £360 billion (FSA, 2011) gives total shadow banking assets of over £900 billion. It is proposed that the large gap between the estimates of this paper and other estimates reflects the huge, and previously unknown, scale of offshore activities of UK investment banks

    Management of a Capital Stock by Strotz's Naive Planner

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    A generalized version of the capital management problem posed in a classic paper by R. H. Strotz is analyzed for the case of the "naive" planner who fails to anticipate any impending change in his own preferences. By imposing progressively stronger restrictions on the primitives of the problem --- namely, the planner's discounting function, his utility index function, and the investment technology --- the path of the capital stock is characterized first implicitly as the solution to a differential equation and then explicitly via formulae that may or may not be expressible in closed form. Inasmuch as this procedure turns out to leave the discounting function essentially unrestricted, the theory can accommodate, in particular, decision makers who discount time according to the type of hyperbolic curve said to be suggested by psychological studies. Strategies for numerical computation of capital paths are discussed and are demonstrated in sample planning problems.consumption, computation, hyperbolic discounting, time preference.

    Bifurcation analysis of a model of the budding yeast cell cycle

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    We study the bifurcations of a set of nine nonlinear ordinary differential equations that describe the regulation of the cyclin-dependent kinase that triggers DNA synthesis and mitosis in the budding yeast, Saccharomyces cerevisiae. We show that Clb2-dependent kinase exhibits bistability (stable steady states of high or low kinase activity). The transition from low to high Clb2-dependent kinase activity is driven by transient activation of Cln2-dependent kinase, and the reverse transition is driven by transient activation of the Clb2 degradation machinery. We show that a four-variable model retains the main features of the nine-variable model. In a three-variable model exhibiting birhythmicity (two stable oscillatory states), we explore possible effects of extrinsic fluctuations on cell cycle progression.Comment: 31 pages,13 figure

    Coping with Stress: The Caulobacter Approach

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    The Mass distribution of the Cluster 0957+561 from Gravitational Lensing

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    Multiply gravitationally lensed objects with known time delays can lead to direct determinations of H0_0 independent of the distance ladder if the mass distribution of the lens is known. Currently, the double QSO 0957+561 is the only lensed object with a precisely known time delay. The largest remaining source of systematic error in the H0_0 determination results from uncertainty in the mass distribution of the lens which is comprised of a massive galaxy (G1) and the cluster in which it resides. We have obtained V-band CCD images from CFHT in order to measure the mass distribution in the cluster from its gravitional distorting effect on the appearance of background galaxes. We use this data to constuct a two-dimensional mass map of the field. A mass peak is detected at the 4.5σ4.5\sigma level, offset from, but consistent with, the position of G1. Simple tests reveal no significant substructure and the mass distribution is consistent with a spherical cluster. The peak in the number density map of bright galaxies is offset from G1 similarly to the mass peak. We constructed an azimuthally averaged mass profile centered on G1 out to 2 \arcmin (400h−1400 h^{-1} kpc). It is consistent with an isothermal mass distribution with a small core (r_c \approx 5 \arcsec = 17 h^{-1} kpc). The inferred mass within 1 Mpc is consistent with the dynamical mass estimate but 2σ2\sigma higher than the upper limits from a ROSAT X-ray study. We discuss implications for H0_0 in a future paper.Comment: LaTeX, aas version 4 macros. Calibration error in original led to overestimate of cluster mass. Seven out of twelve figures included. Complete paper is available at: http://www.astro.lsa.umich.edu:80/users/philf
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