402 research outputs found

    Prenatal Diagnosis of Thoracoschisis and Review of Literature

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    Thoracoschisis is a rare congenital malformation characterized by herniation of the abdominal content through a defect in the thorax. There are previously 12 reported cases, most discussing the postnatal findings and management. Here we describe a case of left thoracoschisis with associated upper limb abnormality which was diagnosed antenatally with the aid of 3D ultrasound

    asking the same questions but expecting different answers

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    Piecewise Approximate Analytical Solutions of High-Order Singular Perturbation Problems with a Discontinuous Source Term

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    A reliable algorithm is presented to develop piecewise approximate analytical solutions of third- and fourth-order convection diffusion singular perturbation problems with a discontinuous source term. The algorithm is based on an asymptotic expansion approximation and Differential Transform Method (DTM). First, the original problem is transformed into a weakly coupled system of ODEs and a zero-order asymptotic expansion of the solution is constructed. Then a piecewise smooth solution of the terminal value reduced system is obtained by using DTM and imposing the continuity and smoothness conditions. The error estimate of the method is presented. The results show that the method is a reliable and convenient asymptotic semianalytical numerical method for treating high-order singular perturbation problems with a discontinuous source term

    Epidemic malaria and warmer temperatures in recent decades in an East African highland

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    Climate change impacts on malaria are typically assessed with scenarios for the long-term future. Here we focus instead on the recent past (1970–2003) to address whether warmer temperatures have already increased the incidence of malaria in a highland region of East Africa. Our analyses rely on a new coupled mosquito–human model of malaria, which we use to compare projected disease levels with and without the observed temperature trend. Predicted malaria cases exhibit a highly nonlinear response to warming, with a significant increase from the 1970s to the 1990s, although typical epidemic sizes are below those observed. These findings suggest that climate change has already played an important role in the exacerbation of malaria in this region. As the observed changes in malaria are even larger than those predicted by our model, other factors previously suggested to explain all of the increase in malaria may be enhancing the impact of climate change

    Rapid antigen testing as a reactive response to surges in nosocomial SARS-CoV-2 outbreak risk

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    Healthcare facilities are vulnerable to SARS-CoV-2 introductions and subsequent nosocomial outbreaks. Antigen rapid diagnostic testing (Ag-RDT) is widely used for population screening, but its health and economic benefits as a reactive response to local surges in outbreak risk are unclear. We simulate SARS-CoV-2 transmission in a long-term care hospital with varying COVID-19 containment measures in place (social distancing, face masks, vaccination). Across scenarios, nosocomial incidence is reduced by up to 40-47% (range of means) with routine symptomatic RT-PCR testing, 59-63% with the addition of a timely round of Ag-RDT screening, and 69-75% with well-timed two-round screening. For the latter, a delay of 4-5 days between the two screening rounds is optimal for transmission prevention. Screening efficacy varies depending on test sensitivity, test type, subpopulations targeted, and community incidence. Efficiency, however, varies primarily depending on underlying outbreak risk, with health-economic benefits scaling by orders of magnitude depending on the COVID-19 containment measures in place

    Bringing COVID-19 home for Christmas: a need for enhanced testing in healthcare institutions after the holidays

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    Festive gatherings this 2020 holiday season threaten to cause a surge in new cases of novel coronavirus disease 2019 (COVID-19). Hospitals and long-term care facilities are key hotspots for COVID-19 outbreaks, and may be at elevated risk as patients and staff return from holiday celebrations in the community. Some settings and institutions have proposed fortified post-holiday testing regimes to mitigate this risk. We use an existing model to assess whether implementing a single round of post-holiday screening is sufficient to detect and manage holiday-associated spikes in COVID-19 introductions to the long-term care setting. We show that while testing early helps to detect cases prior to potential onward transmission, it likely to miss a substantial share of introductions owing to false negative test results, which are more probable early in infection. We propose a two-stage post-holiday testing regime as a means to maximize case detection and mitigate the risk of nosocomial COVID-19 outbreaks into the start of the new year. Whether all patients and staff should be screened, or only community-exposed patients, depends on available testing capacity: the former will be more effective, but also more resource-intensive

    Mathematical Modeling of Heat-Transfer for a Moving Sheet in a Moving Fluid

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    A mathematical model was developed for determining the heat transfer between a moving sheet that passes through a moving fluid environment to simulate the fabrication process of sheet and fiber-like materials. Similarity transformations were introduced to reduce the governing equations to two nonlinear ordinary differential equations. For high values Prandtl number, the energy equation became much stiffer or singularly perturbed and the standard numerical methods failed to handle it. An innovative procedure combining shooting and singular perturbation technique was developed. The results show that the heat transfer depends on the relative velocity between the moving fluid and the moving sheet to a certain value after that value the relative velocity has no effect. If blowing effect is found the thermal layer becomes thinner and temperature profiles are backed together

    Re-Evaluating the Classical Falling Body Problem

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    This paper re-analyzes the falling body problem in three dimensions, taking into account the effect of the Earth’s rotation (ER). Accordingly, the analytic solution of the three-dimensional model is obtained. Since the ER is quite slow, the three coupled differential equations of motion are usually approximated by neglecting all high order terms. Furthermore, the theoretical aspects describing the nature of the falling point in the rotating frame and the original inertial frame are proved. The theoretical and numerical results are illustrated and discussed.The authors would like to thank the referees for their valuable comments and suggestions, which helped to improve the manuscript. Moreover, the first author thanks Prince Sattam bin Abdulaziz University and Deanship of Scientific Research at Prince Sattam bin Abdulaziz University for their continuous support and encouragement.info:eu-repo/semantics/publishedVersio

    Effect of storage temperature on the keeping quality of commercially pasteurized milk

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    Pour étudier l'effet de la température sur la durée de conservation du lait pasteurisé, du lait fraîchemf:'nt pasteurisé et non homogénéisé provenant de deux laiteries industrielles, a été conservé à 7 et à 25°C. L'évolution du pH, des caractéristiques sensorielles, et de la flore totale du lait a été étudiée durant la période de conservation. L'altération du lait dont le taux microbien initial était de 10 3 UFC/ml a été observée entre le 5 ème et 6ème jour de conservation à 7°C. A 25°C, cette durée n'a été que de 20 à 24 heures. Au début de l'altération, le taux microbien a dépassé 10 7 UFC/ml. Les deux laits ont montré les mêmes signes d'altération à savoir la putréfaction, l'amertume, le caractère fruité, et la rancidité à 7°C; tandis qu'à 25°C, les défauts détectés étaient l'acidité, le surissement, et la rancidité. Les échantillons de lait ont montré également le signe de coagulation après ébullition, 2 heures avant l'altération à 25°C alors qu'à 7°C la coagulation du lait a eu lieu le même jour du début de l'altération. To study the effect of temperature on the shelf-life, freshly pasteurized and unhomogenized whole milk from two dairy plants was stored at 7 and 25°C. Microbial, sensory, and pH changes were monitored during storage. Milk of 1000 CFU/ml, as initial microbial count, showed evidence of spoilage between 5th and 6th day of storage at 7°C. When stored at 25°C, the shelf-life was only 20 to 24 hours. The microbial count at the time of spoilage exceeded 10000000 CFU/ml. Both brands ofmilk showed similar spoilage characteristics of putrid, bitter, fruity and rancid at 7°C and acid, sour, and rancid defects at 25°C. Milk samples showed clotting on boiling 2 hours before evidence of spoilage at 25°C and simultaneously with spoilage at 7°C

    Segregation and charge-density-wave order in the spinless Falicov-Kimball model

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    The spinless Falicov-Kimball model is solved exactly in the limit of infinite-dimensions on both the hypercubic and Bethe lattices. The competition between segregation, which is present for large U, and charge-density-wave order, which is prevalent at moderate U, is examined in detail. We find a rich phase diagram which displays both of these phases. The model also shows nonanalytic behavior in the charge-density-wave transition temperature when U is large enough to generate a correlation-induced gap in the single-particle density of states.Comment: 10 pages, 10 figure
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