1,941 research outputs found

    Treatment-seeking rates in malaria endemic countries

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    BACKGROUND: The proportion of individuals who seek treatment for fever is an important quantity in understanding access to and use of health systems, as well as for interpreting data on disease incidence from routine surveillance systems. For many malaria endemic countries (MECs), treatment-seeking information is available from national household surveys. The aim of this paper was to assemble sub-national estimates of treatment-seeking behaviours and to predict national treatment-seeking measures for all MECs lacking household survey data. METHODS: Data on treatment seeking for fever were obtained from Demographic and Health Surveys, Malaria Indicator Surveys and Multiple Cluster Indicator Surveys for every MEC and year that data were available. National-level social, economic and health-related variables were gathered from the World Bank as putative covariates of treatment-seeking rates. A generalized additive mixed model (GAMM) was used to estimate treatment-seeking behaviours for countries where survey data were unavailable. Two separate models were developed to predict the proportion of fever cases that would seek treatment at (1) a public health facility or (2) from any kind of treatment provider. RESULTS: Treatment-seeking data were available for 74 MECs and modelled for the remaining 24. GAMMs found that the percentage of pregnant women receiving prenatal care, vaccination rates, education level, government health expenditure, and GDP growth were important predictors for both categories of treatment-seeking outcomes. Treatment-seeking rates, which varied both within and among regions, revealed that public facilities were not always the primary facility type used. CONCLUSIONS: Estimates of treatment-seeking rates show how health services are utilized and help correct reported malaria case numbers to obtain more accurate measures of disease burden. The assembled and modelled data demonstrated that while treatment-seeking rates have overall increased over time, access remains low in some malaria endemic regions and utilization of government services is in some areas limited

    A First Analysis of the Potential Impact of Climate Change on the Efficiency and Reliability of Solar and Hydro Energy Sources

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    Climate change impacts our electric power system in several ways, affecting both the load and generation. Here we investigate one part of these impacts, the effect of climate change on the supply of renewable energy. Analyzing 60 years of data, climate change is found to impact both the total supply available and its variability. This impact is found to vary significantly with location. Here we focus on and compare two disparate locations, Palma de Mallorca in the Balearic Islands and Cordova, Alaska. Using novel metrics, this analysis demonstrates the feasibility of a process to evaluate the changing needs for energy storage as well as the ability to evaluate the impact on grid reliability regarding both penetration of the increasing renewable resources and changes in the variability of the resource. This framework can be used to quantify the impact on both transmission grids and microgrids and can guide possible mitigation paths

    Role of Tc-99m MDP bone scan in evaluation of osteoid osteoma at varied locations

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    Background: Osteoid osteoma is a benign bone tumor; diagnosed using x-ray and Computer Tomography (CT). It shows a nidus and cortical thickening. When the nidus is not well visualised especially in uncommon locations; Bone Scan (BS) can be performed for evaluation of osteoid osteoma.Methods: A retrospective observational study was done where 21 subjects presenting with suspicion of osteoid osteoma underwent BS using 10-20mCi (370 to 740MBq) of Technetium-99m Pertechnetate with perfusion, delayed cortical and Single Photon Emission Tomography/Computer Tomography (SPECT/CT). Increased perfusion and delayed focal cortical uptake was assessed on BS to locate osteoid osteoma. Response evaluation to Radiofrequency ablation (RFA) was also performed using BS.Results: Osteoid osteoma was detected in femur (8), spine (3), forearm bones (2), humerus (2), tibia (2), fibula in one and iliac bone in one patient using BS. BS detected more lesions (18) than CT scan where nidus as confirmatory sign was seen in 13 lesions. The McNemar test showed no significant difference (p=0.22) in the detection of osteoid osteoma using CT and BS in common location of femur. However there was significant difference noted between BS and CT in uncommon site (p=0.023). 3/8 patients showed persistent increased cortical activity after RFA ablation on BS.Conclusions: BS was more useful for confirmation of diagnosis of Osteoid osteoma for lesions in uncommon sites. BS also helped to assess response to RFA ablation therapy. SPECT/CT improved interpretation of BS to locate the osteoid osteoma

    An Initial Analysis of the Impact of Future Climate Change on the Efficiency and Reliability of Solar, Wind and Hydro Energy Sources

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    Climate change will impact our electric power system, affecting both the load and generation and thereby the grid reliability. Here we investigate one part of these impacts, the effect of future climate change on the supply of renewable energy. Analyzing model output data through 2100, climate change is found to impact both the total supply available and its variability. This impact is however found to vary significantly with location. Here we focus on and compare a few disparate locations, Palma de Mallorca in the Balearic Islands, Cordova Alaska, McAllen TX and Oroville CA. Using developed metrics, this analysis applies a developed process to evaluate the changing needs for energy storage as well as the ability to evaluate the impact on grid reliability from both penetration of increasing renewable resources and changes in the variability of the resource on both transmission grids and microgrids in order to guide possible mitigation paths

    Evolution of emission line activity in intermediate mass young stars

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    We present optical spectra of 45 intermediate mass Herbig Ae/Be stars. Together with the multi-epoch spectroscopic and photometric data compiled for a large sample of these stars and ages estimated for individual stars by using pre-main sequence evolutionary tracks, we have studied the evolution of emission line activity in them. We find that, on average, the H_alpha emission line strength decreases with increasing stellar age in HAeBe stars, indicating that the accretion activity gradually declines during the PMS phase. This would hint at a relatively long-lived (a few Myr) process being responsible for the cessation of accretion in Herbig Ae/Be stars. We also find that the accretion activity in these stars drops substantially by ~ 3 Myr. This is comparable to the timescale in which most intermediate mass stars are thought to lose their inner disks, suggesting that inner disks in intermediate mass stars are dissipated rapidly after the accretion activity has fallen below a certain level. We, further find a relatively tight correlation between strength of the emission line and near-infrared excess due to inner disks in HAeBe stars, indicating that the disks around Herbig Ae/Be stars cannot be entirely passive. We suggest that this correlation can be understood within the frame work of the puffed-up inner rim disk models if the radiation from the accretion shock is also responsible for the disk heating.Comment: 39 pages, accepted for publication in Ap

    Exchange Monte Carlo Method and Application to Spin Glass Simulations

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    We propose an efficient Monte Carlo algorithm for simulating a ``hardly-relaxing" system, in which many replicas with different temperatures are simultaneously simulated and a virtual process exchanging configurations of these replica is introduced. This exchange process is expected to let the system at low temperatures escape from a local minimum. By using this algorithm the three-dimensional ±J\pm J Ising spin glass model is studied. The ergodicity time in this method is found much smaller than that of the multi-canonical method. In particular the time correlation function almost follows an exponential decay whose relaxation time is comparable to the ergodicity time at low temperatures. It suggests that the system relaxes very rapidly through the exchange process even in the low temperature phase.Comment: 10 pages + uuencoded 5 Postscript figures, REVTe

    Low Complexity Security Algorithm for CPS / IoT Networks

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    Due to its noisy nature, wireless channel plays a dominant role in deciding the performance of data communication between the smart objects in the cyberphysical systems (CPS) or the internet of things (IoT). Open and heterogeneous nature of these networks makes them susceptible to vulnerable attacks. So, to keep up the confidentiality and integrity of the transmitted data against the adversaries, it should be secured before transmission. However, issues such as power efficiency, low computational complexity need to be considered when designing security algorithms for CPS/IoT networks. Traditional encryption algorithms, such as Advanced Encryption Standard (AES), International Data Encryption Algorithm (IDEA) can be used for security purpose, but they do not satisfy power and complexity criteria as per CPS/IOT networks requirements. Moreover, they exhibit poor bit error ratio (BER) performance in a noisy wireless channel. This paper presents a modified security algorithm, AES-P, with X-OR mapping on AES to make them suitable for CPS/IoT applications. Simulation and analysis of the proposed algorithm showed that its power consumption and complexity are reduced as compared to traditional AES. It also performed better in the wireless channel, while maintaining the required security level satisfied by Avalanche effect

    Increasing of entanglement entropy from pure to random quantum critical chains

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    It is known that the entropy of a block of spins of size LL embedded in an infinite pure critical spin chain diverges as the logarithm of LL with a prefactor fixed by the central charge of the corresponding conformal field theory. For a class of strongly random spin chains, it has been shown that the correspondent block entropy still remains universal and diverges logarithmically with an "effective" central charge. By computing the entanglement entropy for a family of models which includes the NN-states random Potts chain and the ZNZ_N clock model, we give some definitive answer to some recent conjectures about the behaviour of the effective central charge. In particular, we show that the ratio between the entanglement entropy in the pure and in the disordered system is model dependent and we provide a series of critical models where the entanglement entropy grows from the pure to the random case.Comment: 4 pages, 2 eps figures, added reference

    Characterization of the three Arabidopsis thaliana RAD21 cohesins reveals differential responses to ionizing radiation

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    The RAD21/REC8 gene family has been implicated in sister chromatid cohesion and DNA repair in several organisms. Unlike most eukaryotes, Arabidopsis thaliana has three RAD21 gene homologues, and their cloning and characterization are reported here. All three genes, AtRAD21.1, AtRAD21.2, and AtRAD21.3, are expressed in tissues rich in cells undergoing cell division, and AtRAD21.3 shows the highest relative level of expression. An increase in steady-state levels of AtRAD21.1 transcript was also observed, specifically after the induction of DNA damage. Phenotypic analysis of the atrad21.1 and atrad21.3 mutants revealed that neither of the single mutants was lethal, probably due to the redundancy in function of the AtRAD21 genes. However, AtRAD21.1 plays a critical role in recovery from DNA damage during seed imbibition, prior to germination, as atrad21.1 mutant seeds are hypersensitive to radiation damag
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