55 research outputs found

    Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

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    BackgroundHuman immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.MethodsWe performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.ResultsAll countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries-apart from Ecuador-across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups-the median age group among decedents ranged from 30 to 45years of age at the municipality level in Brazil, Colombia, and Mexico in 2017.ConclusionsOur subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.Peer reviewe

    Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

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    Background: Human immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico. Methods: We performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017. Results: All countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries�apart from Ecuador�across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50 or more HIV deaths were concentrated in fewer than 10 of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups�the median age group among decedents ranged from 30 to 45 years of age at the municipality level in Brazil, Colombia, and Mexico in 2017. Conclusions: Our subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths

    Efficient prediction of phishing websites using supervised learning algorithms

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    AbstractPhishing is one of the luring techniques used by phishing artist in the intention of exploiting the personal details of unsuspected users. Phishing website is a mock website that looks similar in appearance but different in destination. The unsuspected users post their data thinking that these websites come from trusted financial institutions. Several antiphishing techniques emerge continuously but phishers come with new technique by breaking all the antiphishing mechanisms. Hence there is a need for efficient mechanism for the prediction of phishing website. This paper employs Machine-learning technique for modelling the prediction task and supervised learning algorithms namely Multi layer perceptron, Decision tree induction and Naïve bayes classification are used for exploring the results. It has been observed that the decision tree classifier predicts the phishing website more accurately when comparing to other learning algorithms

    Study of rotating Bénard-Brinkman convection of Newtonian liquids and nanoliquids in enclosures

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    Taylor-Bénard convection of water and water-based nanoliquids confined in three different types of high porosity rectangular enclosures, viz., shallow, square and tall, is studied analytically using both infinitesimal and finite amplitude stability analyses. We make use of the modified-Buongiorno-Brinkman model(MBBM) for the governing equations concerning nanoliquid-saturated porous enclosures bounded by rigid-rigid boundaries and obtain analytical results. Among three types of enclosures, maximum and minimum heat transfers are observed in tall and shallow enclosures respectively. Water well dispersed with a dilute concentration of single-walled carbon nanotubes(SWCNTs) is considered as a working medium. The water-SWCNTs is able to flow in the porous medium because the medium is loosely-packed with porosity in the range 0.5 ≤ ϕ ≤ 1. In addition to this, the maximum volume fraction of nanoparticles considered in the system is 6% and thus this does not alter the fluidity of the system. We found from the study that the presence of low concentration(volume fraction-0.06) of SWCNTs in a water-saturated porous medium effectively improves the heat transport of the system due to its high thermal conductivity and large surface area. Due to the presence of a porous medium, however, the onset of convection gets delayed and heat transport in nanoliquids gets substantially reduced in a Bénard-Brinkman configuration resulting from the weak thermal conductivity of the porous medium. Thus the porous medium acts as the heat storage system. Also, in a rotating frame of reference the heat transport gets reduced and rotation serves as an external mechanism of regulating heat transport in the system. The nonlinear dynamics of the system is studied using the 6-mode Lorenz model. Chaotic motion in the system is studied using the maximum Lyapunov exponent(MLE). The Hofp-bifurcation point of the system along with the MLE is used to investigate periodic, nearly periodic and mildly chaotic behaviors of the system

    Embryo rescue and plant regeneration in banana (Musa spp.).

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    Bananas and plantains are giant monocotyledonous perennial herbs, belonging to the order Zingiberales (Scitamineae) and family Musaceae. Banana is one of the few fruit crops in which all of the cultivated varieties are human selections. Its recalcitrance to improvement through breeding is mainly due to parthenocarpy and male and/or female sterility among the most cultivated varieties. Diverse genomic constitutions like AA, AB, AAB, ABB etc. with varied ploidy levels (2×, 3× and 4×) have aggravated the problem of improvement through classical breeding. These incompatibility problems have manifested into improper seed formation, poor embryo development, endosperm malformation etc. The success of a breeding programme depends on compatibility among the parents and the production of a good number of fertile seeds. More often, the banana seeds, although complete in terms of embryo, endosperm and seed coat, fail to germinate due to various reasons (Chin 1996). Under such circumstances, embryo culture becomes vital. Failure of embryo germination is attributed to the activation of growth inhibitors at the advanced maturity stage of seed development, leading to seed coat dormancy (Le Page-Degivry and Garello 1973; Bewley and Black 1982; Fenner 1985). Therefore, it becomes essential to rescue the embryos before maturity in order to salvage the maximum number of hybrid progenies in a breeding programme.An efficient regeneration protocol for zygotic embryos at varying maturity stages was developed for wild banana (Pisang Jajee (AA)). Embryo ontogeny was studied to determine the best maturity stage for embryo rescue, suitable media and culture conditions (light and dark) for germination and regeneration. The conversion of endosperm from transparent fluid into a semi-solid state was followed by visible embryo development, which commenced only after 70% embryo maturity. Zygotic embryos of Pisang Jajee at different maturity levels were excised and cultured on medium fortified with different concentrations of 6-benzyl adenine (BA) and indole acetic acid (IAA). Zygotic embryos produced callus or plantlets 25 days after initiation. The frequency of callus induction was greater in immature embryos irrespective of the media composition and decreased with increasing maturity. Fully matured embryos regenerated directly into plantlets without producing callus. Immature embryos required medium supplemented with plant growth regulators (PGRs) for successful regeneration. Although the culture conditions had no influence, dark conditions favoured callus induction and plant regeneration

    Genetic algorithm based steganography using wavelets

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    Steganography has long been a means of secure communication. Security is achieved by camouflaging the secret message. In this par per, we present a Genetic Algorithm based Steganography using Discrete Cosine Transforms(GASDCT) and Genetic Algorithm based Steganography using Discrete Wavelets Transform(GASDWT). In our approach, the Discrete Cosine Transform and Discrete Wavelet Transform are applied to the payload. Genetic Algorithm is used to generate many stego-images based on Fitness functions; one of these which give least statistical evidence of payload is selected as the best stego image to be communicated to the destination. It is observed that GASDWT has an improvement in Bit Error Rate(BER), Peak Signal to Noise Ratio(PSNR) and embedding capacity as compared to GASDCT. © Springer-Verlag Berlin Heidelberg 2007

    Optimal control for an M^X/G/1/N+1 queue with two service modes

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    A finite-buffer queueing model is considered with batch Poisson input and controllable service rate. A batch that upon arrival does not fit in the unoccupied places of the buffer is partially rejected. A decision to change the service mode can be made at service completion epochs only, and vacation (switch-over) times are involved in preparing the new mode. During a switch-over time, service is disabled. For the control of this model, three optimization criteria are considered: the average number of jobs in the buffer, the fraction of lost jobs, and the fraction of batches not fully accepted. Using Markov decision theory, the optimal switching policy can be determined for any of these criteria by the value-iteration algorithm. In the calculation of the expected one-step costs and the transition probabilities, an essential role is played by the discrete fast Fourier transform
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