6,987 research outputs found

    Diagnosis of malaria parasitemia in children using a rapid diagnostic test

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    Aim: This cross-sectional study was conducted to evaluate the diagnostic performance of a new rapid immunochromatographic test named “Paracheck pf” in the diagnosis of malaria in Nigerian children.Materials and Methods: A total of 380 Nigerian children aged between 6 and 59 months who presented at the University of Nigeria Teaching Hospital (UNTH) Enugu with fever and no obvious focus of any other infection were consecutively recruited. Malaria parasitemia was determined using simple microscopy and “Paracheck pf”.Results: “Paracheck pf” has the following diagnostic performance characteristics: Sensitivity of 82%, specificity of 91.5%, negative predictive value of 91.5%, positive predictive value of 82%, a strong positive correlation between parasite density and test sensitivity, and a detection limit of 397 parasites/ml.Conclusions: The test is, therefore, recommended for the use in Nigerian children aged between 6 and 59 months in Enugu for the diagnosis of malaria, but negative results should be cautiously interpreted in infants because symptomatic malaria may occur in these children at parasite densities as low as 100/ml

    Magnetic hard-direction ordering in anisotropic Kondo systems

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    We present a generic mechanism that explains why many Kondo materials show magnetic ordering along directions that are not favoured by the crystal-field anisotropy. Using a renormalization-group (RG) analysis of single impurity Kondo models with single-ion anisotropy, we demonstrate that strong fluctuations above the Kondo temperature drive a moment re-orientation over a wide range of parameters, e.g. for different spin values SS and number of Kondo channels NN. In tetragonal systems this can happen for both easy-plane or easy axis anisotropy. The characteristic crossing of magnetic susceptibilities is not an artefact of the weak-coupling RG treatment but can be reproduced in brute-force perturbation theory. Employing numerical renormalization group (NRG), we show that for an under-screened moment (S=1S=1, N=1N=1) with easy-plane anisotropy, a crossing of magnetic susceptibilities can also occur in the strong-coupling regime (below the Kondo temperature). This suggests that collective magnetic ordering of such under-screened moments would develop along the magnetic hard axis

    Evolutionary testing supported by slicing and transformation

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    Evolutionary testing is a search based approach to the automated generation of systematic test data, in which the search is guided by the test data adequacy criterion. Two problems for evolutionary testing are the large size of the search space and structural impediments in the implementation of the program which inhibit the formulation of a suitable fitness function to guide the search. In this paper we claim that slicing can be used to narrow the search space and transformation can be applied to the problem of structural impediments. The paper presents examples of how these two techniques have been successfully employed to make evolutionary testing both more efficient and more effective

    Fracture patternsas seen at the accident and emergency department of the university of maiduguri teaching hospital Nigeria: - a five year prospective study

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    Most trauma resulting from vehicular accidents or otherwise, often involve the skeleton (made up of 206 bones), resulting into a fracture. Fractures are a cause of high morbidity and occasionally mortality. Objective: The aim of this study is to analyze the anatomical regions most involved, fracture types, their causes, outcome of treatment and the commonest complication of the fracture in our environment. Method: A five year prospective study (January 2005 to December 2009) was undertaken. All patients presented at the Accident and Emergency Unit of the University of Maiduguri Teaching Hospital, both fresh and old fractures were included. All were followed up to discharge from the hospital and some years after. Those that died were noted. A proforma was used to collect the data. Follow up was between 2 to5 years. Results: During the period of the study, there were 24, 041 emergencies that reported to UMTH, 6,535(27.2%) were due to RTA and 596 (2.5%) had fractures, presenting with 677 fractures. There were 477(80.2%) males and 189(19.8%) females, giving a ratio of 4:1. The lower limbs were affected in 247(41.5%) patients, upper limbs in 146(24.6%), more than one region 54(9.1%), maxillofacial 47(7.9%), skull 41(6.9%), spinal fractures 33(5.5%) andpelvic fractures 28(4.7%). There were 435(73.2%) motor vehicular cases, (3.4%) follows domestic accidents and11(1.9%) from assaults. There were 66 associated injuries. Conclusion: Fractures occurred in about 10% of RTAs with males more involved than Females (4:1) and motor vehicular accidents causing most of the fractures. The lower limbs were more involved and most of the fractures were closed. Association with head injury leads to more mortality

    Rosai-dorfman disease: report of a rare case of peripheral lymphadenopathy.

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    Rosai-Dorfman disease (RDD), also called Sinus histiocytosis is an uncommon proliferative disorder of unknown aetiology. Though, the lymph node is the revelation mode of several diseases particularly in the tropics, RDD typically presents with painless bilateral lymphadenopathy in the neck associated with fever and leukocytosis, sometimesmimics lympho-proliferative disorders. Recently research has unveiled gene mutation in the tumour with potential of malignant transformation. Case report:We report case of 4 year old boy who had massive cervical lymphadenopathy with extranodal manifestation of fever. Sepsis screening was negative, while imagingshowed hilar,mediastenal andmesenteric lymph nodes enlargement in addition to massive hepatomegaly. The histology is suggestive of the diagnosis of RDD. The patient was treated with corticosteroids, with remarkable remission. Conclusion: We report the clinicopathological characteristics of RDD in order to increase our awareness of its diagnosis and treatment and to re-emphasize that the disease is rare in our environment

    A post-placement side-effect removal algorithm

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    Side-effects are widely believed to impede program comprehension and have a detrimental effect upon software maintenance. This paper introduces an algorithm for side-effect removal which splits the side-effects into their pure expression meaning and their state-changing meaning. Symbolic execution is used to determine the expression meaning, while transformation is used to place the state-changing part in a suitable location in a transformed version of the program. This creates a program which is semantically equivalent to the original but guaranteed to be free from side-effects. The paper also reports the results of an empirical study which demonstrates that the application of the algorithm causes a significant improvement in program comprehension

    Monolithic semiconductor lasers with dynamically tunable linear-to-circular polarization

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    The ability to control the polarization state of emission from semiconductor lasers is essential for many applications in spectroscopy, imaging, and communications, inter alia, with monolithic integration approaches being extremely beneficial. Although manipulating the output polarization of radiation from a laser can be achieved through a number of approaches, obtaining continuous dynamic control, e.g., from linear to circular, remains extremely challenging. In this paper, we demonstrate that the polarization of terahertz (THz) frequency radiation can be continuously tuned electronically from linear to circular polarization by monolithically integrating in-plane metasurfaces with two phase-locked semiconductor-based THz quantum cascade lasers. Moreover, the metasurfaces—metal antenna arrays in this case—also act as efficient beam collimators, yielding a collimated beam divergence of ∼10° × 10°. Our results, however, have broad applicability to a wide range of semiconductor lasers operating from the visible to THz regions of the electromagnetic spectrum

    SN 2005hj: Evidence for Two Classes of Normal-Bright SNe Ia and Implications for Cosmology

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    HET Optical spectra covering the evolution from about 6 days before to about 5 weeks after maximum light and the ROTSE-IIIb unfiltered light curve of the "Branch-normal" Type Ia Supernova SN 2005hj are presented. The host galaxy shows HII region lines at redshift of z=0.0574, which puts the peak unfiltered absolute magnitude at a somewhat over-luminous -19.6. The spectra show weak and narrow SiII lines, and for a period of at least 10 days beginning around maximum light these profiles do not change in width or depth and they indicate a constant expansion velocity of ~10,600 km/s. We analyzed the observations based on detailed radiation dynamical models in the literature. Whereas delayed detonation and deflagration models have been used to explain the majority of SNe Ia, they do not predict a long velocity plateau in the SiII minimum with an unvarying line profile. Pulsating delayed detonations and merger scenarios form shell-like density structures with properties mostly related to the mass of the shell, M_shell, and we discuss how these models may explain the observed SiII line evolution; however, these models are based on spherical calculations and other possibilities may exist. SN 2005hj is consistent with respect to the onset, duration, and velocity of the plateau, the peak luminosity and, within the uncertainties, with the intrinsic colors for models with M_shell=0.2 M_sun. Our analysis suggests a distinct class of events hidden within the Branch-normal SNe Ia. If the predicted relations between observables are confirmed, they may provide a way to separate these two groups. We discuss the implications of two distinct progenitor classes on cosmological studies employing SNe Ia, including possible differences in the peak luminosity to light curve width relation.Comment: ApJ accepted, 31 page
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