1,668 research outputs found

    Update on drowning

    Get PDF
    Drowning is defined as the process of experiencing respiratory impairment from either submersion or immersion in liquid. Drowning morbidity and mortality are an under-recognised public health burden in southern Africa. Continuous concerted efforts are underway to improve awareness among recreational water users, but the prevention and management of drowning remain difficult to achieve owing to poor reporting and limited resources. Priorities for both prehospital and emergency department management of drowning victims include ensuring airway patency, adequate ventilation, supplemental oxygenation and rewarming for a pulsatile patient, and cardiopulmonary resuscitation with rewarming for a pulseless patient

    Raising Permutations to Powers in Place

    Get PDF
    Given a permutation of n elements, stored as an array, we address the problem of replacing the permutation by its kth power. We aim to perform this operation quickly using o(n) bits of extra storage. To this end, we first present an algorithm for inverting permutations that uses O(lg^2 n) additional bits and runs in O(n lg n) worst case time. This result is then generalized to the situation in which the permutation is to be replaced by its kth power. An algorithm whose worst case running time is O(n lg n) and uses O(lg^2 n + min{k lg n, n^{3/4 + epsilon}}) additional bits is presented

    Perspectives and Researcher Experiences of Undergraduate Research

    Get PDF
    Extracurricular undergraduate research seems to improve student success in academic programs, but little research has been conducted in aviation settings to support this phenomenon. This study aims to address the gap in the body of research by investigating the experiences of aviation students who have participated in extracurricular research at the undergraduate level. This case study, conducted within a large aviation program at a mid-sized Midwestern university, qualitatively examines the perceptions and experiences of these students

    An Empirically Derived Three-Dimensional Laplace Resonance in the Gliese 876 Planetary System

    Get PDF
    We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our dataset incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, HARPS, and Keck HIRES as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian MCMC algorithm to perform a Bayesian analysis of the planet masses and orbits using an n-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99% credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φcb<6.20\Phi_{cb}<6.20^\circ for the "c" and "b" pair and Φbe<28.5\Phi_{be}<28.5^\circ for the "b" and "e" pair). Subsequent dynamical integrations of our posterior sample find that the GJ 876 planets must be roughly coplanar (Φcb<2.60\Phi_{cb}<2.60^\circ and Φbe<7.87\Phi_{be}<7.87^\circ), suggesting the amount of planet-planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model supports the idea of the outer-three planets having undergone significant past disk migration.Comment: 19 pages, 11 figures, 8 tables. Accepted to MNRAS. Posterior samples available at https://github.com/benelson/GJ87

    Immune reconstitution syndrome in HIV: validating a case definition and identifying clinical predictors in persons initiating antiretroviral therapy

    Get PDF
    Background: Clinical deterioration after initiation of antiretroviral therapy may result from restored immunity. There is no standard clinical definition for immune reconstitution syndrome. The objectives of this study were to validate a proposed definition and to identify factors predictive of immune reconstitution syndrome. Methods: This was a retrospective case-control study from an academic university medical practice. Cases were matched to &#10878;2 control subjects by CD4+ cell count at the time of initiation of antiretroviral therapy. Cases and “mock cases” were blindly reviewed by 2 human immunodeficiency virus (HIV) experts. Results: Twenty possible cases of immune reconstitution syndrome were identified; HIV experts excluded all cases of herpes zoster (shingles), with agreement on real and mock cases of 92%. For 14 confirmed case patients (compared with 40 control subjects), immune reconstitution syndrome was associated with a higher number of prior opportunistic infections (P = .003) and higher CD8+ cell counts at baseline (P = .05) and at week 12 (P = .02). Immune reconstitution syndrome was associated with lower baseline levels of alanine aminotransferase (P = .05) and hemoglobin (P = .02). On multivariate analysis, the number of prior opportunistic infections (odds ratio, 2.7; P = .007) and lower hemoglobin level at baseline (odds ratio, 0.8; P = .003) were independently associated with development of immune reconstitution syndrome. A predictive model was defined by classification and regression tree analysis with a sensitivity and specificity of 78.57% and 87.50%, respectively, for an importance score of &#10878;4 (on a scale of 0.0 to 100.0), and 92.86% and 80.00%, respectively, for a score of &#10878;2, using the number of prior opportunistic infections, CD8+ cell count, and hemoglobin level. Conclusions: A standard definition for immune reconstitution syndrome is possible. Patients with a greater severity of illness at initiation of antiretroviral therapy are at risk for immune reconstitution syndrome. The model defined by classification and regression tree analysis may provide a basis for risk stratification before initiation of antiretroviral therapy

    Virus-Phomopsis interactions on soybean and the effects of insect and disease management practices

    Get PDF
    Soybean (Glycine max (L.) Merr.) is affected by several seed-borne pathogens that reduce seed quality, affecting both marketability (Gergerich, 1999; Koning et al. 2001) and germination (Sinclair, 1999). One of the most common seedborne diseases is Phomopsis seed decay, primarily caused by Phomopsis longicolla T. W. Hobbs, a member of the Diaporthe-Phomopsis complex (Sinclair, 1999). Fungi of this complex are widespread throughout most of the soybean producing areas around the world, and the biggest impacts on seed and grain quality are physical damage, reduction in germination, alteration in protein content and reduction of oil quality (Meriles et al., 2004; Sinclair, 1999)

    Lightweight Modular Steel Floor System For Rapidly Constructible And Reconfigurable Buildings

    Get PDF
    Rapid construction, modularity, deconstruction, and reconfiguration facilitate economy and sustainability allowing for changes in a building’s use over time. Typical one-way composite steel/concrete floor systems lend themselves to terminal construction practices that make assumptions about the occupancy and usage needs that must last through the life of the structure. To address this, a lightweight rapidly constructible and reconfigurable modular steel floor (RCRMSF) system that utilizes two-way bending behavior and cold-formed steel building materials has been developed. RCRMSF improves upon the efficiency benefits of traditional composite steel/concrete flooring systems, reducing beam and girder usage and size, and allowing for highly flexible building configurations and mobility. The system con- sists of a series of prefabricated panels composed of a grid of cold-formed steel channels running in orthogonal directions sandwiched together by steel plates. A simple performance assessment has been formulated and a finite element model parametric study has been carried out in the Abaqus finite ele- ment analysis (FEA) software. The results of the developed performance assessment and FEA study show that RCRMSF systems are suitable for rapidly constructible buildings in terms of strength and serviceability, providing an initial step to fully modular and reconfigurable steel buildings

    The Geometry of Resonant Signatures in Debris Disks with Planets

    Full text link
    Using simple geometrical arguments, we paint an overview of the variety of resonant structures a single planet with moderate eccentricity (e < ~0.6) can create in a dynamically cold, optically thin dust disk. This overview may serve as a key for interpreting images of perturbed debris disks and inferring the dynamical properties of the planets responsible for the perturbations. We compare the resonant geometries found in the solar system dust cloud with observations of dust clouds around Vega and other stars and we discuss a new model for the asymmetries in the Epsilon Eridani cloud.Comment: 27 pages, including 6 figures and 1 table, to appear in Ap

    The Cytokine Release Inhibitory Drug CRID3 Targets ASC Oligomerisation in the NLRP3 and AIM2 Inflammasomes

    Get PDF
    Background: The Inflammasomes are multi-protein complexes that regulate caspase-1 activation and the production of the pro-inflammatory cytokine IL-1 beta. Previous studies identified a class of diarylsulfonylurea containing compounds called Cytokine Release Inhibitory Drugs (CRIDs) that inhibited the post-translational processing of IL-1 beta. Further work identified Glutathione S-Transferase Omega 1 (GSTO1) as a possible target of these CRIDs. This study aimed to investigate the mechanism of the inhibitory activity of the CRID CP-456,773 (termed CRID3) in light of recent advances in the area of inflammasome activation, and to clarify the potential role of GSTO1 in the regulation of IL-1 beta production

    Upper gastrointestinal bleeding in Scotland 2000-2010: Improved outcomes but a significant weekend effect

    Get PDF
    Aim: To assess numbers and case fatality of patients with upper gastrointestinal bleeding (UGIB), effects of deprivation and whether weekend presentation affected outcomes. Methods: Data was obtained from Information Services Division (ISD) Scotland and National Records of Scotland (NRS) death records for a ten year period between 2000-2001 and 2009-2010. We obtained data from the ISD Scottish Morbidity Records (SMR01) database which holds data on inpatient and day-case hospital discharges from non-obstetric and non-psychiatric hospitals in Scotland. The mortality data was obtained from NRS and linked with the ISD SMR01 database to obtain 30-d case fatality. We used 23 ICD-10 (International Classification of diseases) codes which identify UGIB to interrogate database. We analysed these data for trends in number of hospital admissions with UGIB, 30-d mortality over time and assessed effects of social deprivation. We compared weekend and weekday admissions for differences in 30-d mortality and length of hospital stay. We determined comorbidities for each admission to establish if comorbidities contributed to patient outcome. Results: A total of 60643 Scottish residents were admitted with UGIH during January, 2000 and October, 2009. There was no significant change in annual number of admissions over time, but there was a statistically significant reduction in 30-d case fatality from 10.3% to 8.8% (P &lt; 0.001) over these 10 years. Number of admissions with UGIB was higher for the patients from most deprived category (P &lt; 0.05), although case fatality was higher for the patients from the least deprived category (P &lt; 0.05). There was no statistically significant change in this trend between 2000/01-2009/10. Patients admitted with UGIB at weekends had higher 30-d case fatality compared with those admitted on weekdays (P &lt; 0.001). Thirty day mortality remained significantly higher for patients admitted with UGIB at weekends after adjusting for comorbidities. Length of hospital stay was also higher overall for patients admitted at the weekend when compared to weekdays, although only reached statistical significance for the last year of study 2009/10 (P &lt; 0.0005). Conclusion: Despite reduction in mortality for UGIB in Scotland during 2000-2010, weekend admissions show a consistently higher mortality and greater lengths of stay compared with weekdays
    corecore