3,806 research outputs found

    Disciplined doctors: Does the sex of a doctor matter? A cross-sectional study examining the association between a doctor's sex and receiving sanctions against their medical registration.

    Get PDF
    To examine the association between doctors' sex and receiving sanctions on their medical registration, while controlling for other potentially confounding variables

    Detection of cold pain, cold allodynia and cold hyperalgesia in freely behaving rats

    Get PDF
    BACKGROUND: Pain is elicited by cold, and a major feature of many neuropathic pain states is that normally innocuous cool stimuli begin to produce pain (cold allodynia). To expand our understanding of cold induced pain states we have studied cold pain behaviors over a range of temperatures in several animal models of chronic pain. RESULTS: We demonstrate that a Peltier-cooled cold plate with ± 1°C sensitivity enables quantitative measurement of a detection withdrawal response to cold stimuli in unrestrained rats. In naïve rats the threshold for eliciting cold pain behavior is 5°C. The withdrawal threshold for cold allodynia is 15°C in both the spared nerve injury and spinal nerve ligation models of neuropathic pain. Cold hyperalgesia is present in the spared nerve injury model animals, manifesting as a reduced latency of withdrawal response threshold at temperatures that elicit cold pain in naïve rats. We also show that following the peripheral inflammation produced by intraplantar injection of complete Freund's adjuvant, a hypersensitivity to cold occurs. CONCLUSION: The peltier-cooled provides an effective means of assaying cold sensitivity in unrestrained rats. Behavioral testing of cold allodynia, hyperalgesia and pain will greatly facilitate the study of the neurobiological mechanisms involved in cold/cool sensations and enable measurement of the efficacy of pharmacological treatments to reduce these symptoms

    poolMC: Smart pooling of mRNA samples in microarray experiments

    Get PDF
    Background: Typically, pooling of mRNA samples in microarray experiments implies mixing mRNA from several biological-replicate samples before hybridization onto a microarray chip. Here we describe an alternative smart pooling strategy in which different samples, not necessarily biological replicates, are pooled in an information theoretic efficient way. Further, each sample is tested on multiple chips, but always in pools made up of different samples. The end goal is to exploit the compressibility of microarray data to reduce the number of chips used and increase the robustness to noise in measurements. Results: A theoretical framework to perform smart pooling of mRNA samples in microarray experiments was established and the software implementation of the pooling and decoding algorithms was developed in MATLAB. A proof-of-concept smart pooled experiment was performed using validated biological samples on commercially available gene chips. Conclusions: The theoretical developments and experimental demonstration in this paper provide a useful starting point to investigate smart pooling of mRNA samples in microarray experiments. Important conditions for its successful implementation include linearity of measurements, sparsity in data, and large experiment size.

    Sex differences in medico-legal action against doctors: a systematic review and meta-analysis

    Get PDF
    The relationship between male sex and poor performance in doctors remains unclear, with high profile studies showing conflicting results. Nevertheless, it is an important first step towards understanding the causes of poor performance in doctors. This article aims to establish the robustness of the association between male sex and poor performance in doctors, internationally and over time

    Production and evaporation of higher dimensional black holes

    Get PDF
    This thesis is a study of the theory and phenomenology of trans-Planckian black holes, in TeV gravity extra-dimensional theories. The introduction starts with the motivation for this beyond the Standard Model scenario (chapter 1), a summary of the theoretical tools to formulate the theory, and a summary of the best bounds from experiment (chapter 2). In chapter 3, after setting up some notation and describing well known solutions in 4 + n-dimensional general relativity, we construct an approximate effective background for a brane charged rotating higher-dimensional black hole. This is achieved by solving Maxwell’s equations perturbatively on the brane to obtain the electromagnetic field. A brief study of the effect of rotation on the absorption of classical particles is also provided. Chapter 4 is a review of methods to model black hole production focusing on the trapped surface method. A model for the mass and angular momentum loss into gravitational radiation is described. A detailed study of the effects of particle mass and charge, for fermions and scalars on the effective brane charged background, is presented in chapters 5 and 6. After coupling the fields to the background, the separated radial wave equations for both perturbations are obtained (chapter 5) and they are integrated using a detailed numerical method as well as analytic approximations (chapter 6). Similarly, a method is described to obtain high accuracy angular functions based on series expansions. We conclude the theoretical study by evaluating the Hawking spectra for various combinations of spin, mass, charge and rotation parameters, and discuss them comparatively. The last part of the thesis is on the implementation of the theoretical results in the new CHARYBDIS2 Monte Carlo simulation of black hole production and decay (chapter 7), and on the analysis of the phenomenological consequences (chapter 8). The main new features implemented in CHARYBDIS2 are: a full treatment of the spin-down phase using the angular and energy distributions of the associated Hawking radiation; an improved model for energy and angular momentum loss in the production process, and a wider range of options for the Planck-scale termination of the decay. The main conclusions of this thesis and an outlook on future directions are summarised in the final chapter.This work was funded by Fundação para a Ciência e Tecnologia (FCT) - Portugal grant SFRH/BD/23052/2005 co-financed by POPH/FSE

    The MultiSite Spectroscopic Telescope campaign: 2m spectroscopy of the V361 Hya variable PG1605+072

    Full text link
    We present results and analysis for the 2m spectroscopic part of the MultiSite Spectroscopic Telescope (MSST) campaign undertaken in May/June 2002. The goal of the project was to observe the pulsating subdwarf B star PG1605+072 simultaneously in velocity and photometry and to resolve as many of the >50 known modes as possible, which will allow a detailed asteroseismological analysis. We have obtained over 150 hours of spectroscopy, leading to an unprecedented noise level of only 207m/s. We report here the detection of 20 frequencies in velocity, with two more likely just below our detection threshold. In particular, we detect 6 linear combinations, making PG1605+072 only the second star known to show such frequencies in velocity. We investigate the phases of these combinations and their parent modes and find relationships between them that cannot be easily understood based on current theory. These observations, when combined with our simultaneous photometry, should allow asteroseismology of this most complicated of sdB pulsators.Comment: 9 pages, 5 figures, accepted for publication in A&A; Figure 1 at lower resolution than accepted versio

    The Rise and Fall of Debris Disks: MIPS Observations of h and chi Persei and the Evolution of Mid-IR Emission from Planet Formation

    Full text link
    We describe Spitzer/MIPS observations of the double cluster, h and χ\chi Persei, covering a ∼\sim 0.6 square-degree area surrounding the cores of both clusters. The data are combined with IRAC and 2MASS data to investigate ∼\sim 616 sources from 1.25-24 μm\mu m. We use the long-baseline KsK_{s}-[24] color to identify two populations with IR excess indicative of circumstellar material: Be stars with 24 μm\mu m excess from optically-thin free free emission and 17 fainter sources (J∼\sim 14-15) with [24] excess consistent with a circumstellar disk. The frequency of IR excess for the fainter sources increases from 4.5 μm\mu m through 24 μm\mu m. The IR excess is likely due to debris from the planet formation process. The wavelength-dependent behavior is consistent with an inside-out clearing of circumstellar disks. A comparison of the 24 μm\mu m excess population in h and χ\chi Per sources with results for other clusters shows that 24 μm\mu m emission from debris disks 'rises' from 5 to 10 Myr, peaks at ∼\sim 10-15 Myr, and then 'falls' from ∼\sim 15/20 Myr to 1 Gyr.Comment: 48 pages, 15 figures, accepted for publication in The Astrophysical Journa
    • …
    corecore