615 research outputs found

    Preliminary genetic analyses of important musculoskeletal conditions of thoroughbred racehorses in Hong Kong

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    A retrospective cohort study of important musculoskeletal conditions of Thoroughbred racehorses was conducted using health records generated over a 15 year period (n = 5062, 1296 sires). The prevalence of each condition in the study population was: fracture, 13%; osteoarthritis, 10%; suspensory ligament injury, 10%; and tendon injury, 19%. Linear and logistic sire and animal regression models were built to describe the binary occurrence of these musculoskeletal conditions, and to evaluate the significance of possible environmental risk factors. The heritability of each condition was estimated using residual maximum likelihood (REML). Bivariate mixed models were used to generate estimates of genetic correlations between each pair of conditions.<p></p> Heritability estimates of fracture, osteoarthritis, suspensory ligament and tendon injury were small to moderate (range: 0.01–0.20). Fracture was found to be positively genetically correlated with both osteoarthritis and suspensory ligament injury. These results suggest that there is a significant genetic component involved in the risk of the studied conditions. Due to positive genetic correlations, a reduction in prevalence of one of the correlated conditions may effect a reduction in risk of the other condition.<p></p&gt

    Pathways to Drug Liberalization: Racial Justice, Public Health, and Human Rights

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    In our recent article, together with more than 60 of our colleagues, we outlined a proposal for drug policy reform consisting of four specific yet interrelated strategies: (1) de jure decriminalization of all psychoactive substances currently deemed illicit for personal use or possession (so-called “recreational” drugs), accompanied by harm reduction policies and initiatives akin to the Portugal model; (2) expunging criminal convictions for nonviolent offenses pertaining to the use or possession of small quantities of such drugs (and releasing those serving time for these offenses), while delivering retroactive ameliorative relief; (3) the ultimate legalization and careful regulation of currently illicit drugs; and (4) the delivery of a new “Marshall Plan” focused on community-building initiatives, expanded harm reduction programs, and social and health care support efforts (Earp et al. 2021). We were gratified to see so many thoughtful commentaries on our proposal, and we respond to them in part in this reply

    CMBfit: Rapid WMAP likelihood calculations with normal parameters

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    We present a method for ultra-fast confrontation of the WMAP cosmic microwave background observations with theoretical models, implemented as a publicly available software package called CMBfit, useful for anyone wishing to measure cosmological parameters by combining WMAP with other observations. The method takes advantage of the underlying physics by transforming into a set of parameters where the WMAP likelihood surface is accurately fit by the exponential of a quartic or sextic polynomial. Building on previous physics based approximations by Hu et.al., Kosowsky et.al. and Chu et.al., it combines their speed with precision cosmology grade accuracy. A Fortran code for computing the WMAP likelihood for a given set of parameters is provided, pre-calibrated against CMBfast, accurate to Delta lnL ~ 0.05 over the entire 2sigma region of the parameter space for 6 parameter ``vanilla'' Lambda CDM models. We also provide 7-parameter fits including spatial curvature, gravitational waves and a running spectral index.Comment: 14 pages, 8 figures, References added, accepted for publication in Phys.Rev.D., a Fortran code can be downloaded from http://space.mit.edu/home/tegmark/cmbfit

    Analysis of CMB polarization on an incomplete sky

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    The full sky cosmic microwave background polarization field can be decomposed into 'electric' and 'magnetic' components. Working in harmonic space we construct window functions that allow clean separation of the electric and magnetic modes from observations over only a portion of the sky. Our construction is exact for azimuthally symmetric patches, but should continue to perform well for arbitrary patches. From the window functions we obtain variables that allow for robust estimation of the magnetic component without risk of contamination from the probably much larger electric signal. For isotropic, uncorrelated noise the variables have a very simple diagonal noise correlation, and further analysis using them should be no harder than analysing the temperature field. For an azimuthally-symmetric patch, such as that obtained from survey missions when the galactic region is removed, the exactly-separated variables are fast to compute allowing us to estimate the magnetic signal that could be detected by the Planck satellite in the absence of non-galactic foregrounds. We also discuss the sensitivity of future experiments to tensor modes in the presence of a magnetic signal generated by weak lensing, and give lossless methods for analysing the electric polarization field in the case that the magnetic component is negligible.Comment: 27 pages, 8 figures. New appendix on weak signal detection and revised plots using a better statistic. Other changes to match version accepted by PRD. Sample source code now available at http://cosmologist.info/pola

    Precision Primordial 4^4He Measurement with CMB Experiments

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    Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) are two major pillars of cosmology. Standard BBN accurately predicts the primordial light element abundances (4^4He, D, 3^3He and 7^7Li), depending on one parameter, the baryon density. Light element observations are used as a baryometers. The CMB anisotropies also contain information about the content of the universe which allows an important consistency check on the Big Bang model. In addition CMB observations now have sufficient accuracy to not only determine the total baryon density, but also resolve its principal constituents, H and 4^4He. We present a global analysis of all recent CMB data, with special emphasis on the concordance with BBN theory and light element observations. We find ΩBh2=0.025+0.00190.0026\Omega_{B}h^{2}=0.025+0.0019-0.0026 and Yp=0.250+0.0100.014Y_{p}=0.250+0.010-0.014 (fraction of baryon mass as 4^4He) using CMB data alone, in agreement with 4^4He abundance observations. With this concordance established we show that the inclusion of BBN theory priors significantly reduces the volume of parameter space. In this case, we find ΩBh2=0.0244+0.001370.00284\Omega_{B}h^2=0.0244+0.00137-0.00284 and Yp=0.2493+0.00060.001Y_p = 0.2493+0.0006-0.001. We also find that the inclusion of deuterium abundance observations reduces the YpY_p and ΩBh2\Omega_{B}h^2 ranges by a factor of \sim 2. Further light element observations and CMB anisotropy experiments will refine this concordance and sharpen BBN and the CMB as tools for precision cosmology.Comment: 7 pages, 3 color figures made minor changes to bring inline with journal versio

    Mometasone absorption in cultured airway epithelium

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    Background: Topical mometasone is frequently used as an intranasal spray, on drug-eluting stents, and compounded by specialty pharmacies as a sinus rinse. A typical sinus rinse contains 1.2 mg of mometasone dissolved in 240 mL of buffered saline and is flushed through the sinonasal cavity. The mometasone irrigation rapidly flows to the contralateral sinonasal cavity or the nasopharynx with a contact time on the order of 5 to 10 seconds. However, no information is available on the absorption rate of topical mometasone on the sinonasal surface. Methods: To determine the absorption characteristics of mometasone, we harvested nasal epithelium from 2 healthy donors and differentiated them into a mature ciliated epithelium on Millicell membranes. We applied mometasone to the apical surface for various time intervals and then rinsed off non-absorbed mometasone with phosphate-buffered saline. Millicell membranes with the adherent epithelial cells were then harvested and stored in guanidine hydrochloride for quantification using high-performance liquid chromatography–mass spectrometry. Results: Fifty percent of the maximal absorption occurred after an average of 38 minutes after application, and maximal absorption occurred after an average of 114 minutes. Conclusion: Our data provide an estimate for rates of absorption of mometasone applied to the sinonasal cavity and suggest that the absorption rates poorly match contact time during saline lavage

    Low Complexity Regularization of Linear Inverse Problems

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    Inverse problems and regularization theory is a central theme in contemporary signal processing, where the goal is to reconstruct an unknown signal from partial indirect, and possibly noisy, measurements of it. A now standard method for recovering the unknown signal is to solve a convex optimization problem that enforces some prior knowledge about its structure. This has proved efficient in many problems routinely encountered in imaging sciences, statistics and machine learning. This chapter delivers a review of recent advances in the field where the regularization prior promotes solutions conforming to some notion of simplicity/low-complexity. These priors encompass as popular examples sparsity and group sparsity (to capture the compressibility of natural signals and images), total variation and analysis sparsity (to promote piecewise regularity), and low-rank (as natural extension of sparsity to matrix-valued data). Our aim is to provide a unified treatment of all these regularizations under a single umbrella, namely the theory of partial smoothness. This framework is very general and accommodates all low-complexity regularizers just mentioned, as well as many others. Partial smoothness turns out to be the canonical way to encode low-dimensional models that can be linear spaces or more general smooth manifolds. This review is intended to serve as a one stop shop toward the understanding of the theoretical properties of the so-regularized solutions. It covers a large spectrum including: (i) recovery guarantees and stability to noise, both in terms of 2\ell^2-stability and model (manifold) identification; (ii) sensitivity analysis to perturbations of the parameters involved (in particular the observations), with applications to unbiased risk estimation ; (iii) convergence properties of the forward-backward proximal splitting scheme, that is particularly well suited to solve the corresponding large-scale regularized optimization problem

    Functional diversity of chemokines and chemokine receptors in response to viral infection of the central nervous system.

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    Encounters with neurotropic viruses result in varied outcomes ranging from encephalitis, paralytic poliomyelitis or other serious consequences to relatively benign infection. One of the principal factors that control the outcome of infection is the localized tissue response and subsequent immune response directed against the invading toxic agent. It is the role of the immune system to contain and control the spread of virus infection in the central nervous system (CNS), and paradoxically, this response may also be pathologic. Chemokines are potent proinflammatory molecules whose expression within virally infected tissues is often associated with protection and/or pathology which correlates with migration and accumulation of immune cells. Indeed, studies with a neurotropic murine coronavirus, mouse hepatitis virus (MHV), have provided important insight into the functional roles of chemokines and chemokine receptors in participating in various aspects of host defense as well as disease development within the CNS. This chapter will highlight recent discoveries that have provided insight into the diverse biologic roles of chemokines and their receptors in coordinating immune responses following viral infection of the CNS
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