A Benthic chamber with electric stirrer mixing

Benthic chambers incorporating electric stirrer mixing have been designed and tested and have proven reliable during seven 18-31 day, 4300m ocean deployments. The chambers are 21 cm diameter by 31 cm long acrylic tubes sealed with pvc lids. A stepper motor and pressure tolerant electronics contained within the lids are magnetically coupled to stirring paddles to provide mixing within the chambers. The stirrers exhibit stable mixing rates and uniform speeds between chambers, require less than 1/3 watt of power, and are maintenance free. Laboratory calibration of stirring and mixing characteristics demonstrate that areal averaged equivalent seawater-sediment boundary layer thickness can be set to agree with in situ measured values.Funding was provided by the National Science Foundation through Grant No. OCE87-11962

Implications of not matching to a first-choice discipline: a family medicine perspective

Background: Family medicine is often selected as an alternate career choice by medical students who do not match to their first choice discipline. Consequently, family medicine residency programs accept and train some residents who prepared for and intended a career in another specialty. The implications of this warrant investigation.Methods: Graduates (2006-2011) of Albertan family medicine residency programs were surveyed to examine differences between physicians who indicated family medicine was their first choice discipline and those who indicated that it was not their first choice. Survey questions targeted practice location, preparedness for practice, perceptions of family medicine, lifestyle satisfaction, and well-being. Principal components analysis was used to examine the factor structure of our survey items and ANOVA and Chi square were used to compare mean scores and proportions, respectively.Results: The overall response rate was 47.2% (307/651). Most (263) respondents reported that family medicine was their first choice discipline (yes-group); 42 respondents indicated that it was not (no-group) and two did not answer. The two groups were similar demographically. The no-group reported significantly lower mean scores on perceptions of family medicine. There were no significant differences between the two groups in their preparedness for practice and measures of lifestyle satisfaction and well-being.Conclusion: Irrespective of their perceptions of the discipline, the respondents who did not match to their first choice discipline found family medicine to be a viable career option

Book Reviews

This is a book that every lawyer should read and every law student should be required to read. It is the culminating work of a masterly mind that for over fifty years has been studying governments, ancient and modern,\u27 and meantime the writer has had the practical advantage of holding high and responsible offices, including that of British Ambassador to the United States. Viscount Bryce speaks plainly of American national, state and municipal shortcomings in government, especially the last, but it is done in a kindly vein. He is a friend of America and gives us credit for much

Experiencing Simulated Confrontations in Virtual Reality

The use of virtual reality (VR) to simulate confrontational human behaviour has significant potential for use in training, where the recreation of uncomfortable feelings may help users to prepare for challenging real-life situations. In this paper we present a user study (n=68) in which participants experienced simulated confrontational behaviour performed by a virtual character either in immersive VR, or on a 2D display. Participants reported a higher elevation in anxiety in VR, which correlated positively with a perceived sense of physical space. Character believability was influenced negatively by visual elements of the simulation, and positively by behavioural elements, which complements findings from previous work.We recommend the use of VR for simulations of confrontational behaviour, where a realistic emotional response is part of the intended experience. We also discuss incorporation of domain knowledge of human behaviours, and carefully crafted motion-captured sequences, to increase users’ sense of believability

Observing the Evolution of the Universe

How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed. One may in addition track the evolution of the dark energy and discover the net neutrino mass. We are at the dawn of a new era in which hundreds of square degrees of sky can be mapped with arcminute resolution and sensitivities measured in microKelvin. Acquiring these data requires the use of special purpose telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and the South Pole Telescope (SPT). These new telescopes are outfitted with a new generation of custom mm-wave kilo-pixel arrays. Additional instruments are in the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey. Full list of 177 author available at http://cmbpol.uchicago.ed

The recycling and transcytotic pathways for IgG transport by FcRn are distinct and display an inherent polarity

The Fc receptor FcRn traffics immunoglobulin G (IgG) in both directions across polarized epithelial cells that line mucosal surfaces, contributing to host defense. We show that FcRn traffics IgG from either apical or basolateral membranes into the recycling endosome (RE), after which the actin motor myosin Vb and the GTPase Rab25 regulate a sorting step that specifies transcytosis without affecting recycling. Another regulatory component of the RE, Rab11a, is dispensable for transcytosis, but regulates recycling to the basolateral membrane only. None of these proteins affect FcRn trafficking away from lysosomes. Thus, FcRn transcytotic and recycling sorting steps are distinct. These results are consistent with a single structurally and functionally heterogeneous RE compartment that traffics FcRn to both cell surfaces while discriminating between recycling and transcytosis pathways polarized in their direction of transport

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo