610 research outputs found

    Onward and Upward: The Legacy of Black Urologists in America

    Get PDF
    In partnership with the American Urological Association\u27s William P. Didusch Center for Urologic History, Henry Ford Health hosted a Grand Rounds event from 7 – 9 a.m. Wednesday, June 14, in the Buerki Auditorium at Henry Ford Hospital. The event highlights the contributions of Black urologists to the history of medicine despite systemic racism in the medical field and across the country. Covering the impact of exclusion and segregation in the past, as well as present day issues such as microaggressions and cultural insensitivity, the lecture and discussion calls for a future of successfully integrating medicine to achieve better outcomes for physicians and their patients. The schedule of the event is as follows: 7 a.m.: Welcome by Craig Rogers, M.D., Chair, Department of Urology, Vattikuti Urology Institute. Introductory remarks by Adnan Munkarah, M.D., President, Care Delivery System and Chief Clinical Officer and Steven Kalkanis, M.D., CEO of Henry Ford Medical Group and CEO of Henry Ford Hospital. 7:10 a.m.: Keynote speaker Arthur L. Burnett II, M.D., MBA., FACS., professor of urology, Johns Hopkins University School of Medicine will present “Onward and Upward: The Legacy of Black Urologists in America. 7:30 a.m.: Panel discussion moderated by Linda McIntire, M.D., President, R. Frank Jones Urological Society, and graduate of Henry Ford urology program, featuring the panelists listed below. Melvin Hollowell, M.D., FACS Dr. Hollowell earned his medical degree in 1959 and has practiced in Detroit for 64 years. At 93 years young, he is still practicing today. Isaac Powell, M.D. Dr. Powell graduated with his medical degree in 1969 and became the first African American graduate from the Henry Ford Hospital urology program in 1974. Conrad Maitland, M.D. Dr. Maitland has been practicing for 40 years and is himself a survivor of prostate cancer - a disease that disproportionately affects Black men. Ray Littleton, M.D. Dr. Littleton joined the senior staff at Henry Ford Hospital in 1980 and helped pioneer minimally invasive surgery by performing the first percutaneous kidney stone removal in Michigan in 1983

    Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies

    Get PDF
    Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However, one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences. This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment disturbance which would have implications for the established OSL chronology for the region

    Hydrogen-Helium Mixtures at High Pressure

    Full text link
    The properties of hydrogen-helium mixtures at high pressure are crucial to address important questions about the interior of Giant planets e.g. whether Jupiter has a rocky core and did it emerge via core accretion? Using path integral Monte Carlo simulations, we study the properties of these mixtures as a function of temperature, density and composition. The equation of state is calculated and compared to chemical models. We probe the accuracy of the ideal mixing approximation commonly used in such models. Finally, we discuss the structure of the liquid in terms of pair correlation functions.Comment: Proceedings article of the 5th Conference on Cryocrystals and Quantum Crystals in Wroclaw, Poland, submitted to J. Low. Temp. Phys. (2004

    Percolation model for structural phase transitions in Li1−x_{1-x}Hx_xIO3_3 mixed crystals

    Full text link
    A percolation model is proposed to explain the structural phase transitions found in Li1−x_{1-x}Hx_xIO3_3 mixed crystals as a function of the concentration parameter xx. The percolation thresholds are obtained from Monte Carlo simulations on the specific lattices occupied by lithium atoms and hydrogen bonds. The theoretical results strongly suggest that percolating lithium vacancies and hydrogen bonds are indeed responsible for the solid solution observed in the experimental range 0.22<x<0.360.22 < x < 0.36.Comment: 4 pages, 2 figure

    Transverse Fresnel-Fizeau drag effects in strongly dispersive media

    Full text link
    A light beam normally incident upon an uniformly moving dielectric medium is in general subject to bendings due to a transverse Fresnel-Fizeau light drag effect. In conventional dielectrics, the magnitude of this bending effect is very small and hard to detect. Yet, it can be dramatically enhanced in strongly dispersive media where slow group velocities in the m/s range have been recently observed taking advantage of the electromagnetically induced transparency (EIT) effect. In addition to the usual downstream drag that takes place for positive group velocities, we predict a significant anomalous upstream drag to occur for small and negative group velocities. Furthermore, for sufficiently fast speeds of the medium, higher order dispersion terms are found to play an important role and to be responsible for peculiar effects such as light propagation along curved paths and the restoration of the spatial coherence of an incident noisy beam. The physics underlying this new class of slow-light effects is thoroughly discussed

    Students as co-creators of teaching approaches, course design and curricula: implications for academic developers

    Get PDF
    Within higher education, students’ voices are frequently overlooked in the design of teaching approaches, courses and curricula. In this paper we outline the theoretical background to arguments for including students as partners in pedagogical planning processes. We present examples where students have worked collaboratively in design processes along with the beneficial outcomes of these examples. Finally we focus on some of the implications and opportunities for academic developers of proposing collaborative approaches to pedagogical planning

    Transmission of Human Immunodeficiency Virus Type 1 from a Seronegative Organ and Tissue Donor

    Get PDF
    Abstract BACKGROUND Since 1985, donors of organs or tissues for transplantation in the United States have been screened for human immunodeficiency virus type 1 (HIV-1), and more than 60,000 organs and 1 million tissues have been transplanted. We describe a case of transmission of HIV-1 by transplantation of organs and tissues procured between the time the donor became infected and the appearance of antibodies. The donor was a 22-year-old man who died 32 hours after a gunshot wound; he had no known risk factors for HIV-1 infection and was seronegative. METHODS We reviewed the processing and distribution of all the transplanted organs and tissues, reviewed the medical histories of the donor and HIV-1—infected recipients, tested stored donor lymphocytes for HIV-1 by viral culture and the polymerase chain reaction, and tested stored serum samples from four organ recipients for HIV-1 antigen and antibody. RESULTS HIV-1 was detected in cultured lymphocytes from the donor. Of 58 tissues and organs obtained from the donor, 52 could be accounted for by the hospitals that received them. Of the 48 identified recipients, 41 were tested for HIV-1 antibody. All four recipients of organs and all three recipients of unprocessed fresh-frozen bone were infected with HIV-1. However, 34 recipients of other tissues — 2 receiving corneas, 3 receiving lyophilized soft tissue, 25 receiving ethanol-treated bone, 3 receiving dura mater treated with gamma radiation, and 1 receiving marrow-evacuated, fresh-frozen bone — tested negative for HIV-1 antibody. Despite immunosuppressive chemotherapy, HIV-1 antibody appeared between 26 and 54 days after transplantation in the three organ recipients who survived more than 4 weeks. CONCLUSIONS Although rare, transmission of HIV-1 by seronegative organ and tissue donors can occur. Improvements in the methods used to screen donors for HIV-1, advances in techniques of virus inactivation, prompt reporting of HIV infection in recipients, and accurate accounting of distributed allografts would help to reduce further this already exceedingly low risk. (N Engl J Med 1992;326:726–32.

    Three-variable Mahler measures and special values of modular and Dirichlet LL-series

    Full text link
    In this paper we prove that the Mahler measures of the Laurent polynomials (x+x−1)(y+y−1)(z+z−1)+k(x+x^{-1})(y+y^{-1})(z+z^{-1})+k, (x+x−1)2(y+y−1)2(1+z)3z−2−k(x+x^{-1})^2(y+y^{-1})^2(1+z)^3z^{-2}-k, and x4+y4+z4+1+k1/4xyzx^4+y^4+z^4+1+k^{1/4}xyz, for various values of kk, are of the form r1Lâ€Č(f,0)+r2Lâ€Č(χ,−1)r_1 L'(f,0)+r_2 L'(\chi,-1), where r1,r2∈Qr_1,r_2\in \mathbb{Q}, ff is a CM newform of weight 3, and χ\chi is a quadratic character. Since it has been proved that these Maher measures can also be expressed in terms of logarithms and 5F4_5F_4-hypergeometric series, we obtain several new hypergeometric evaluations and transformations from these results

    Using the inertia of spacecraft during landing to penetrate regoliths of the Solar System

    Get PDF
    The high inertia, i.e. high mass and low speed, of a landing spacecraft has the potential to drive a penetrometer into the subsurface without the need for a dedicated deployment mechanism, e.g., during Huygens landing on Titan. Such a method could complement focused subsurface exploration missions, particularly in the low gravity environments of comets and asteroids, as it is conducive to conducting surveys and to the deployment of sensor networks. We make full-scale laboratory simulations of a landing spacecraft with a penetrometer attached to its base plate. The tip design is based on that used in terrestrial Cone Penetration Testing (CPT) with a large enough shaft diameter to house instruments for analysing pristine subsurface material. Penetrometer measurements are made in a variety of regolith analogue materials and target compaction states. For comparison a copy of the ACC-E penetrometer from the Huygens mission to Titan is used. A test rig at the Open University is used and is operated over a range of speeds from 0.9 to 3 m s−1 and under two gravitational accelerations. The penetrometer was found to be sensitive to the target’s compaction state with a high degree of repeatability. The penetrometer measurements also produced unique pressure profile shapes for each material. Measurements in limestone powder produced an exponential increase in pressure with depth possibly due to increasing compaction with depth. Measurements in sand produced an almost linear increase in pressure with depth. Iron powder produced significantly higher pressures than sand presumably due to the rough surface of the grains increasing the grain-grain friction. Impacts into foamglas produced with both ACC-E and the large penetrometer produced an initial increase in pressure followed by a leveling off as expected in a consolidated material. Measurements in sand suggest that the pressure on the tip is not significantly dependent on speed over the range tested, which suggests bearing strength equations could be applied to impact penetrometry in sand-like regoliths. In terms of performance we find the inertia of a landing spacecraft, with a mass of 100 kg, is adequate to penetrate regoliths expected on the surface of Solar System bodies. Limestone powder, an analogue for a dusty surface, offered very little resistance allowing full penetration of the target container. Both iron powder, representing a stronger coarse grained regolith, and foamglas, representing a consolidated comet crust, could be penetrated to similar depths of around two to three tip diameters. Speed tests suggest a linear dependence of penetration depth on impact speed
    • 

    corecore