36 research outputs found

    Reproductive Peformance of the Parasitoid Bracon Hebetor Say (Hymenoptera: Braconidae) on Various Host Species of Lepidoptera

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    The objective of this study was to investigate the reproductive performance of Bracon hebetor, a larval ecto-parasitiod of stored product moth species, on several species of lepidopteran insects, including Plodia interpunctella, Ephestia kuehniella, E. cautella, Corcyra cephalonica, Amyelois transitella, and Galleria mellonella. B. hebetor females were introduced singly into experimental arenas and allowed to sting and oviposit for five days with a fresh host given daily. Experiments were conducted using Petri dishes (100 15 mm). In life history studies, B. hebetor females were introduced singly into Petri dishes and given a single host larva every day throughout their life time. I also investigated the effect of parasitoid and host density, and size of rearing containers on progeny production and sex ratio of B. hebetor. Statistical analyses were done using PC SAS Version 9.1. The mean cumulative fecundity in five days was highest on A. transitella (106.42 5.19) and lowest on T. bisselliella (9.64 1.28Department of Entomology and Plant Patholog

    Efficient Reliability Estimation Approach for Analysis and Optimization of Composite Structures

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    The efficient evaluation of reliability index is of considerable importance in the assessment of component reliability and reliability-based structural optimization. In this thesis, the structural reliabiltiy analysis is performed using the random sampling techniques such as traditional Monte Carlo simulation and the analytical techniques such as first-order reliability method. The feasibility of Gauss quadrature points as means of target sampling of design space and generating accurate first- and second-order response surface models of failure functions is examined. Parametric uncertainty is considered by probabilistic modeling of design parameters. Various alternative approaches for estimation of component reliability index are examined with application to two structural problems: ply failure in a multidirectional composite laminate and axial buckling of a composite circular cylinder. The probabilistic sensitivity analysis is performed to measure the influence of each random variable on the estimated reliability index. The advantages and disadvantages of each approach are discussed and the approach considered the most efficient in terms of accuracy and computational requirements is identified. Furthermore, the most efficient approach is applied in reliability-based structural optimization of a composite circular cylinder with ply failure and axial buckling constraints. The optimization problem is solved using sequential quadratic programming based on sequential local response surface approximations of failure functions. The optimization results are presented for different geometric properties, laminate configurations, and coefficients of variation

    A Statistical Framework for Discrete Visual Features Modeling and Classification

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    Multimedia contents are mostly described in discrete forms, so analyzing discrete data becomes an important task in many image processing and computer vision applications. One of the most used approaches for discrete data modeling is the finite mixture of multinomial distributions, considering that the events to model are independent. It, however, fails to capture the true nature in the case of sparse data and leads generally to poor biased estimates. Different smoothing techniques that reflect prior background knowledge are proposed to overcome this issue. Generalized Dirichlet distribution has suitable covariance structure, so it offers flexibility in parameter estimation; therefore, it has become a favorable choice as a prior. This specific choice, however, has its problems mainly in the estimation of the parameters, which appears to be a laborious task and can deteriorate the estimates accuracy when we consider the maximum likelihood (ML) approach. In this thesis, we propose an unsupervised statistical approach to learn structures of this kind of data. The central ingredient in our model is the introduction of the generalized Dirichlet distribution mixture as a prior to the multinomial. An estimation algorithm for the parameters based on leave-one-out (LOO) likelihood and empirical Bayesian inference is developed. This estimation algorithm can be viewed as a hybrid expectation-maximization (EM) which alternates EM iterations with Newton-Raphson iterations using the Hessian matrix. We also propose the use of our model as a parametric basis for support vector machines (SVM) within a hybrid Generative/discriminative framework. Through a series of experiments involving scene modeling and classification using visual words and color texture modeling, we show the efficiency of the proposed approaches

    RelQ Mediates the Expression of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus

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    An induced stringent response, which is established by an increased level of (p)ppGpp, is required for the expression of β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA). However, it is not clear whether RSH (enzyme mediating stringent response to amino acid starvation) or small alarmone synthetases (SASs) are involved in the maintenance of (p)ppGpp level in response to β-lactams. Since the S. aureus genome encodes two active SASs (RelP and RelQ), their contribution to the expression of β-lactam resistance in MRSA was investigated. It was determined that relQ deletion renders community-associated MRSA (CA-MRSA) sensitive to β-lactams by negatively affecting the expression of mecA, and induction of (p)ppGpp synthesis by mupirocin bypasses the requirement of relQ for the expression of high-level β-lactam resistance. Surprisingly, relP deletion increased the level of β-lactam resistance. Such contradictory observations could be attributed to the fact that relQ promoter is ~5-fold stronger than the relP and is induced by oxacillin as well as deletion of either of the SASs, while relP promoter responds only to oxacillin. The stronger promoter activity of relQ, coupled with the inducibility of the relQ promoter in response to the lack of relP, results in efficient expression of relQ in the relP-deleted background. This positively affects mecA expression and renders the ΔrelP strain highly resistant. These findings indicate an important role for RelQ in the expression of high-level β-lactam resistance in MRSA

    Prospect of Protected Agricultural Structure and its Constraints for Utilizing in Nepal

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    Protected agricultural structures have been adopted by commercial farmers throughout the world including Nepal to cope with climate change and its adverse effects on agriculture. Technology based production system is important for sustainable agricultural development. It could be the tool for low-income countries like Nepal where agriculture is the priority of income generation for the rural people. A field study was conducted in 2021 and 2022 to understand the prospects of protected agriculture structures adaptation by farmers and agricultural entrepreneur in Nepal. The study was traversed with both physical observation and the user’s interviews. The opportunities and the constraints have been critically analysed based on these field study along with the review of different policy documents and success stories published. This study found that the protected cultivation practice has been rapidly increased with increasing number of protected structures like plastic house or tunnel framed with bamboo or GI pipe, Agri-net house, naturally ventilated poly house and semi or hi-tech green house. In contrary, the import of horticulture products has also been increased more than 200% in last 10 years. This study finds the gap mismatching between technology enhancement, production and import of horticulture crops

    MONOSODIUM GLUTAMATE POTENTIATES THE CONTRACTION OF THE VISCERAL SMOOTH MUSCLE OF DUODENUM BY AUGMENTING THE ACTIVITY OF INTRINSIC CHOLINERGIC EFFERENTS, INDUCING OXIDATIVE STRESS AND PROLIFERATING SMOOTH MUSCLE CELLS

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    Objective: The objective of the present study was to examine the effects of monosodium glutamate (MSG) on the contraction of visceral smooth muscle (VSM) of the duodenum in a rat model to understand the MSG-induced impairment of the function of the small intestine. Methods: Male albino rats of Charles Foster strain were exposed with MSG at three different dosages (632, 1264, and 2528 mg/kg BW/day) for 30-day duration. The records of the contraction of the duodenum were achieved with isotonic transducer (IT-2245) coupled with RMS-Polyrite D by our standard laboratory protocol. Results: We have observed potentiation of contraction of duodenum ex vivo dose-dependently in MSG exposed groups of rats compared to control. Furthermore, the enzymatic activity of acetylcholinesterase (AChE) in VSM tissue homogenate and expression of AChE protein in fixed duodenal muscle cell layers have been decreased in a dosage response manner comparing to control rats. We have found a significant decrease in the activities of some antioxidant enzymes such as Cu-Zn superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-s-transferase, and increase in the level of malondialdehyde in MSG exposed VSM tissue homogenate of the duodenum. We have also observed thickening of muscularis externa layer and increase in the number of muscle cells in circular and longitudinal muscle layers of the duodenal wall in transverse duodenal wall sections stained with eosin-hematoxylin. Conclusion: MSG potentiates the contraction of VSM of duodenum by augmenting the activity of intrinsic cholinergic efferents predominantly, and inducing oxidative stress and proliferating smooth muscle cells

    Protocol for the Addressing the Social Determinants and Consequences of Tuberculosis in Nepal (ASCOT) pilot trial.

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    The World Health Organization's End TB (tuberculosis) Strategy advocates social and economic support for TB-affected households but evidence from low-income settings is scarce. We will evaluate the feasibility and acceptability of a locally-appropriate socioeconomic support intervention for TB-affected households in Nepal. We will conduct a pilot randomised-controlled trial with mixed-methods process evaluation in four TB-endemic, impoverished districts of Nepal: Pyuthan, Chitwan, Mahottari, and Morang. We will recruit 128 people with TB notified to the Nepal National TB Program (NTP) and 40 multisectoral stakeholders including NTP staff, civil-society members, policy-makers, and ASCOT (Addressing the Social Determinants and Consequences of Tuberculosis) team members. People with TB will be randomised 1:1:1:1 to four study arms (n=32 each): control; social support; economic support; and combined social and economic (socioeconomic) support. Social support will be TB education and peer-led mutual-support TB Clubs providing TB education and stigma-reduction counselling. Economic support will be monthly unconditional cash transfers during TB treatment with expectations (not conditions) of meeting NTP goals. At 0, 2, and 6 months following TB treatment initiation, participants will be asked to complete a survey detailing the social determinants and consequences of TB and their feedback on ASCOT. Complementary process evaluation will use focus group discussions (FGD), key informant interviews (KII), and a workshop with multi-sectoral stakeholders to consider the challenges to ASCOT's implementation and scale-up. A sample of ~100 people with TB is recommended to estimate TB-related costs. Information power is estimated to be reached with approximately 25 FGD and 15 KII participants.  The ASCOT pilot trial will both generate robust evidence on a locally-appropriate, socioeconomic support intervention for TB-affected households in Nepal and inform a large-scale future ASCOT trial, which will evaluate the intervention's impact on catastrophic costs mitigation and TB outcomes. The trial is registered with the ISRCTN ( ISRCTN17025974). [Abstract copyright: Copyright: © 2022 Rai B et al.

    Comparing cross-sectional and longitudinal approaches to Tuberculosis Patient Cost Surveys using Nepalese data.

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    The World Health Organization has supported the development of national tuberculosis (TB) patient cost surveys to quantify the socio-economic impact of TB in high-burden countries. However, methodological differences in study design (e.g. cross-sectional vs longitudinal) can generate different estimates making the design and impact evaluation of socioeconomic protection strategies difficult. The objective of the study was to compare the socio-economic impacts of TB estimated by applying cross-sectional or longitudinal data collections in Nepal. We analysed data from a longitudinal costing survey (patients interviewed at three-time points) conducted between April 2018 and October 2019. We calculated both mean and median costs from patients interviewed during the intensive (cross-sectional 1) and continuation phases of treatment (cross-sectional 2). We then compared costs, the prevalence of catastrophic costs and the socio-economic impact of TB generated by each approach. There were significant differences in the costs and social impacts calculated by each approach. The median total cost (intensive plus continuation phases) was significantly higher for the longitudinal compared to cross-sectional 2 (US$119.42 vs 91.63, P < 0.001). The prevalence of food insecurity, social exclusion and patients feeling poorer or much poorer were all significantly higher applying a longitudinal approach. In conclusion, the longitudinal design captured important aspects of costs and socioeconomic impacts which were missed by applying a cross-sectional approach. If a cross-sectional approach is applied due to resource constraints, our data suggest the start of the continuation phase is the optimal timing for a single interview. Further research to optimize methodologies to report patient incurred expenditure during TB diagnosis and treatment is needed

    Comparing cross-sectional and longitudinal approaches to Tuberculosis Patient Cost Surveys using Nepalese data : Tuberculosis cost survey approaches

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    The World Health Organization has supported the development of national tuberculosis (TB) patient cost surveys to quantify the socio-economic impact of TB in high-burden countries. However, methodological differences in study design (e.g. cross-sectional vs longitudinal) can generate different estimates making the design and impact evaluation of socioeconomic protection strategies difficult. The objective of the study was to compare the socioeconomic impacts of TB estimated by applying cross-sectional or longitudinal data collections in Nepal. We analysed data from a longitudinal costing survey (patients interviewed at three-time points) conducted between April 2018 and October 2019. We calculated both mean and median costs from patients interviewed during the intensive (cross-sectional 1) and continuation phases of treatment (cross-sectional 2). We then compared costs, the prevalence of catastrophic costs and the socio-economic impact of TB generated by each approach. There were significant differences in the costs and social impacts calculated by each approach. The median total cost (intensive plus continuation phases) was significantly higher for the longitudinal compared to cross-sectional 2 (US$119.42 vs 91.63,

    Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016

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    Background: A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. Methods Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita. Findings In 2016, HAQ Index performance spanned from a high of 97\ub71 (95% UI 95\ub78-98\ub71) in Iceland, followed by 96\ub76 (94\ub79-97\ub79) in Norway and 96\ub71 (94\ub75-97\ub73) in the Netherlands, to values as low as 18\ub76 (13\ub71-24\ub74) in the Central African Republic, 19\ub70 (14\ub73-23\ub77) in Somalia, and 23\ub74 (20\ub72-26\ub78) in Guinea-Bissau. The pace of progress achieved between 1990 and 2016 varied, with markedly faster improvements occurring between 2000 and 2016 for many countries in sub-Saharan Africa and southeast Asia, whereas several countries in Latin America and elsewhere saw progress stagnate after experiencing considerable advances in the HAQ Index between 1990 and 2000. Striking subnational disparities emerged in personal health-care access and quality, with China and India having particularly large gaps between locations with the highest and lowest scores in 2016. In China, performance ranged from 91\ub75 (89\ub71-93\ub76) in Beijing to 48\ub70 (43\ub74-53\ub72) in Tibet (a 43\ub75-point difference), while India saw a 30\ub78-point disparity, from 64\ub78 (59\ub76-68\ub78) in Goa to 34\ub70 (30\ub73-38\ub71) in Assam. Japan recorded the smallest range in subnational HAQ performance in 2016 (a 4\ub78-point difference), whereas differences between subnational locations with the highest and lowest HAQ Index values were more than two times as high for the USA and three times as high for England. State-level gaps in the HAQ Index in Mexico somewhat narrowed from 1990 to 2016 (from a 20\ub79-point to 17\ub70-point difference), whereas in Brazil, disparities slightly increased across states during this time (a 17\ub72-point to 20\ub74-point difference). Performance on the HAQ Index showed strong linkages to overall development, with high and high-middle SDI countries generally having higher scores and faster gains for non-communicable diseases. Nonetheless, countries across the development spectrum saw substantial gains in some key health service areas from 2000 to 2016, most notably vaccine-preventable diseases. Overall, national performance on the HAQ Index was positively associated with higher levels of total health spending per capita, as well as health systems inputs, but these relationships were quite heterogeneous, particularly among low-to-middle SDI countries. Interpretation GBD 2016 provides a more detailed understanding of past success and current challenges in improving personal health-care access and quality worldwide. Despite substantial gains since 2000, many low-SDI and middle- SDI countries face considerable challenges unless heightened policy action and investments focus on advancing access to and quality of health care across key health services, especially non-communicable diseases. Stagnating or minimal improvements experienced by several low-middle to high-middle SDI countries could reflect the complexities of re-orienting both primary and secondary health-care services beyond the more limited foci of the Millennium Development Goals. Alongside initiatives to strengthen public health programmes, the pursuit of universal health coverage hinges upon improving both access and quality worldwide, and thus requires adopting a more comprehensive view-and subsequent provision-of quality health care for all populations
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