820 research outputs found
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Effect of tempering upon the tensile properties of a nanostructured bainitic steel
The tensile properties of a nanostructured carbide-free bainitic steel formed at 200–250 °C are compared against those after tempering sufficiently to remove the retained austenite. Although significant ductility is observed following tempering, a comparison of tempered and untempered samples shows that it is in fact reduced when a comparison is made at identical strength. The shape of the stress–strain curves shows clear evidence that the capacity for work hardening is reduced with the loss of austenite. The nanostructure of the steel transformed at 250 °C is examined by transmission electron microscopy, to compare the as-transformed to the tempered structure. In this case after tempering at 500 °C the energy absorbed during the tensile test is lower, due to the lower strength. Reduction of strength is caused by the slight coarsening of the bainite plates, and lower dislocation density after tempering. Considering the formation of carbide particles in high strength steel, impressive ductility is exhibited even in the tempered condition.The authors would like to thank Professor A. L. Greer for the provision
of laboratory facilities at the University of Cambridge and also express their
gratitude to the Scholars Rescue Fund of International Institute of Education
in Washington DC, for supporting Hala Salman Hasan’s work in Cambridge.This is the accepted manuscript version. The final published version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0921509314009642
Entomological Surveillance of Behavioural Resilience and Resistance in Residual Malaria Vector Populations.
The most potent malaria vectors rely heavily upon human blood so they are vulnerable to attack with insecticide-treated nets (ITNs) and indoor residual spraying (IRS) within houses. Mosquito taxa that can avoid feeding or resting indoors, or by obtaining blood from animals, mediate a growing proportion of the dwindling transmission that persists as ITNs and IRS are scaled up. Increasing frequency of behavioural evasion traits within persisting residual vector systems usually reflect the successful suppression of the most potent and vulnerable vector taxa by IRS or ITNs, rather than their failure. Many of the commonly observed changes in mosquito behavioural patterns following intervention scale-up may well be explained by modified taxonomic composition and expression of phenotypically plastic behavioural preferences, rather than altered innate preferences of individuals or populations. Detailed review of the contemporary evidence base does not yet provide any clear-cut example of true behavioural resistance and is, therefore, consistent with the hypothesis presented. Caution should be exercised before over-interpreting most existing reports of increased frequency of behavioural traits which enable mosquitoes to evade fatal contact with insecticides: this may simply be the result of suppressing the most behaviourally vulnerable of the vector taxa that constituted the original transmission system. Mosquito taxa which have always exhibited such evasive traits may be more accurately described as behaviourally resilient, rather than resistant. Ongoing national or regional entomological monitoring surveys of physiological susceptibility to insecticides should be supplemented with biologically and epidemiologically meaningfully estimates of malaria vector population dynamics and the behavioural phenotypes that determine intervention impact, in order to design, select, evaluate and optimize the implementation of vector control measures
Control of Phomopsis Blight of Egg Plant through Fertilizer and Fungicide Management
The experiments were conducted at Laboratory of the Department of Plant Pathology and in the farm of Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh during Rabi season of the year 2007-2008. Four fungicides viz. Bavistin 50 WP (Carbendazim), Tilt 250 EC (Propiconazole), Cupravit 50 WP (Copperoxychloride) and Dithane M-45 (Mancozeb) and micronutrients (Gypsum, ZnO and Boric acid) were evaluated against Phomopsis vexans causing Phomopsis blight and fruit rot of eggplant. The fungicides and micronutrients either applied individually or in combination showed significant effect in terms of per cent leaf infection, fruit infection, leaf area diseased and fruit area diseased in comparison to control. Effect of each fungicide applied in combination with micronutrients always showed better performance in reducing disease incidence and disease severity than the fungicides applied alone. Among the fungicides, Bavistin 50 WP (0.1%) proved to be effective arresting the spore germination and mycelia growth of Phomopsis vexans assayed in in vitro test. Reduction of leaf area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 58.17, 67.37, 78.41 and 85.25%, respectively at preflowering, post-flowering, fruiting and fruit ripening stages while Bavistin 50 WP (0.1%) alone reduced by 52.22, 58.67, 74.19 and 83.09%, respectively at those stages. Similarly reduction of fruit area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 57.93 and 79.79%, respectively at fruiting and fruit ripening stages while Bavistin 50WP (0.1%) alone reduced by 56.93 and 76.14%, respectively at those stages. Micronutrients had little effect against the disease but significantly better than control.Int. J. Agril. Res. Innov. & Tech. 3 (1): 66-72, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.1609
Prevalence and Demographic, Socioeconomic, and Behavioral Risk Factors of Self-Reported Symptoms of Sexually Transmitted Infections (STIs) among Ever-Married Women: Evidence from Nationally Representative Surveys in Bangladesh
Sexually transmitted infections (STI) symptoms (e.g., abnormal genital discharge and genital sores/ulcers) are a major public health concern in Bangladesh because the symptoms can indicate an STI and cause sexual and reproductive health complications in women of reproductive age. To our knowledge, no study examined the prevalence and risk factors of STI symptoms using a nationally representative sample. This study investigates the prevalence of STI symptoms among ever-married women in Bangladesh and the associations of STI symptoms with various demographic, socioeconomic, and behavioral risk factors using the most recent available data (2007, 2011, and 2014) of the Bangladesh Demographic and Health Surveys (BDHS). The BDHS employs a two-stage stratified sampling technique. The analytic sample comprised 41,777 women of reproductive age (15–49 years). Outcome variables included STI symptoms: abnormal genital discharge and genital sores/ulcers. Multivariate logistic regression was employed to find the adjusted odds ratio with a 95% confidence interval to assess the associations of outcome measures with explanatory variables. The study found that the prevalence of abnormal genital discharge and genital sores/ulcers among ever-married women aged 15–49 years was 10% and 6%, respectively. Multi-variable analysis revealed that for women aged 25–34 years, those who used contraceptives and married earlier had an increased likelihood of STI symptoms. Furthermore, women from the wealthiest wealth quintile and couple’s joint decision-making were less likely to have STI symptoms. Findings have implications for interventions efforts aiming to improve women’s sexual and reproductive health in Bangladesh
Smoking and Risk of Kidney Failure in the Singapore Chinese Health Study
Background:The relationship between smoking and risk of kidney failure, especially in people of Chinese origin, is not clear. We analyzed data from the Singapore Chinese Health Study to investigate whether smoking increases the risk of kidney failure.Methods:The Singapore Chinese Health Study is a population-based cohort of 63,257 Chinese adults enrolled between 1993 and 1998. Information on smoking status was collected at baseline. Incidence of kidney failure was identified via record linkage with the nationwide Singapore Renal Registry until 2008. Kidney failure was defined by one of the following: 1) serum creatinine level of more than or equal to 500 μmol/l (5.7 mg/dl), 2) estimated glomerular filtration rate of less than 15 ml/min/1.73 m2, 3) undergoing hemodialysis or peritoneal dialysis, 4) undergone kidney transplantation. Cox proportional hazard regression analysis was performed for the outcome of kidney failure after adjusting for age, education, dialect, herbal medications, body mass index, sex, physician-diagnosed hypertension and diabetes mellitus.Results:The mean age of subjects was 55.6 years at baseline, and 44% were men. Overall 30.6% were ever smokers (current or former) at baseline. A total of 674 incident cases of kidney failure occurred during a median follow-up of 13.3 years. Among men, smokers had a significant increase in the adjusted risk of kidney failure [hazard ratio (HR): 1.29; 95% CI: 1.02-1.64] compared to never smokers. There was a strong dose-dependent association between number of years of smoking and kidney failure, (p for trend = 0.011). The risk decreased with prolonged cessation (quitting ≥10 years since baseline). The number of women smokers was too few for conclusive relationship.Limitation:Information on baseline kidney function was not available.Conclusions:Cigarette smoking is associated with increased risk of kidney failure among Chinese men. The risk appears to be dose- and duration-dependent and modifiable after long duration of cessation. © 2013 Jin et al
Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV
A search for pair-produced charged Higgs bosons is performed with the L3
detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV,
corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a
charm and a strange quark or into a tau lepton and its associated neutrino are
considered. The observed events are consistent with the expectations from
Standard Model background processes. A lower limit of 65.5 GeV on the charged
Higgs mass is derived at 95 % confidence level, independent of the decay
branching ratio Br(H^{+/-} -> tau nu)
Democratization and the Diffusion of Shari'a Law: Comparative Insights from Indonesia
The democratization of politics has been accompanied by a rise of Islamic laws in many Muslim-majority countries. Despite a growing interest in the phenomenon, the Islamization of politics in democratizing Muslim-majority countries is rarely understood as a process that unfolds across space and time. Based on an original dataset established during years of field research in Indonesia, this article analyzes the spread of shari’a regulations across the world’s largest Muslim-majority democracy since 1998. The article shows that shari’a regulations in Indonesia diffused unevenly across space and time. Explanations put forward in the literature on the diffusion of morality policies in other countries such as geographic proximity, institutions, intergovernmental relations and economic conditions did not explain the patterns in the diffusion of shari’a regulations in Indonesia well. Instead, shari’a regulations in Indonesia were most likely to spread across jurisdictions where local Islamist groups situated outside the party system had an established presence. In short, the Islamization of politics was highly contingent on local conditions. Future research will need to pay more attention to local Islamist activists and networks situated outside formal politics as potential causes for the diffusion of shari’a law in democratizing Muslim-majority countries
Stress and Its Association with the Academic Performance of Undergraduate Fourth Year Medical Students at Universiti Kebangsaan Malaysia
Introduction: Student can be stressed due to different stressors such as academic, financial, health related or loss of close family member or friend, etc. Stress is the bodies’ reaction both neurologically and physiologically to adapt to the new condition. Stress has a negative effect on the academic performance of the students. This study was aimed to explore the stress and stressors and also to determine the association between stress levels and the academic performances in terms of cumulative grade point average (CGPA) of undergraduate medical students. Methods: It was a cross-sectional study conducted among all 234 year-4 medical students of Universiti Kebangsaan Malaysia (UKM), session 2011-2012. Sample size comprised of 179 students after fulfilling all inclusion and exclusion criteria. A validated Medical Students’ Stressor Questionnaire (MSSQ) was used to collect the data. Stress level and its association with CGPA of semester-1 examination were analysed. Results: Response rate was 76.49%, where 72% were female and 69% resided in the hostel. Academic Related and Social-related Stressors caused for severe and high stress in 84% and 49% respondents respectively, with insignificant differences between gender and residency. Respondents with a high and severe stress level were observed to have higher CGPA. Conclusion: UKM medical students are highly resourceful to manage their stress well and thus denying the negative effect of stress towards their academic performance. Medical schools should train students exposing various personal and professional developmental activities that able to face the everyday challenges and manage stress well and thereby achieve better academic performance
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Applying multi-temporal landsat satellite data and markov-cellular automata to predict forest cover change and forest degradation of sundarban reserve forest, Bangladesh
Overdependence on and exploitation of forest resources have significantly transformed the natural reserve forest of Sundarban, which shares the largest mangrove territory in the world, into a great degradation status. By observing these, a most pressing concern is how much degradation occurred in the past, and what will be the scenarios in the future if they continue? To confirm the degradation status in the past decades and reveal the future trend, we took Sundarban Reserve Forest (SRF) as an example, and used satellite Earth observation historical Landsat imagery between 1989 and 2019 as existing data and primary data. Moreover, a geographic information system model was considered to estimate land cover (LC) change and spatial health quality of the SRF from 1989 to 2029 based on the large and small tree categories. The maximum likelihood classifier (MLC) technique was employed to classify the historical images with five different LC types, which were further considered for future projection (2029) including trends based on 2019 simulation results from 1989 and 2019 LC maps using the Markov-cellular automata model. The overall accuracy achieved was 82.30%~90.49% with a kappa value of 0.75~0.87. The historical result showed forest degradation in the past (1989–2019) of 4773.02 ha yr−1, considered as great forest degradation (GFD) and showed a declining status when moving with the projection (2019–2029) of 1508.53 ha yr−1 and overall there was a decline of 3956.90 ha yr−1 in the 1989–2029 time period. Moreover, the study also observed that dense forest was gradually degraded (good to bad) but, conversely, light forest was enhanced, which will continue in the future even to 2029 if no effective management is carried out. Therefore, by observing the GFD, through spatial forest health quality and forest degradation mapping and assessment, the study suggests a few policies that require the immediate attention of forest policy-makers to implement them immediately and ensure sustainable development in the SRF.</jats:p
Candida glabrata : a review of its features and resistance
Candida species belong to the normal microbiota of the oral cavity and gastrointestinal and vaginal tracts, and are responsible for several clinical manifestations, from mucocutaneous overgrowth to bloodstream infections. Once believed to be non-pathogenic, Candida glabrata was rapidly blamable for many human diseases. Year after year, these pathological circumstances are more recurrent and problematic to treat, especially when patients reveal any level of immunosuppression. These difficulties arise from the capacity of C. glabrata to form biofilms and also from its high resistance to traditional antifungal therapies. Thus, this review intends to present an excerpt of the biology, epidemiology, and pathology of C. glabrata, and detail an approach to its resistance mechanisms based on studies carried out up to the present.The authors are grateful to strategic project PTDC/SAU-MIC/119069/2010 for the financial support to the research center and for Celia F. Rodrigues' grant
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