549 research outputs found
Hybrid technology for the use of solar energy : the challenge towards green energy / S. I. Hossain ... [et al.]
Large areas in many countries are populated but have no connection to a national electricity grid. Centralized
electricity generating facilities burning fossil fuels have been the normal. Renewable energy resources, especially
solar energy is now penetrating this sector. Long-term energy storage is the universal challenge in providing
renewables-based electricity with high availability across the seasons. Solar domestic hot water system is widely
used and developing fast in recent years. However many problems occur at the same time, for example more energy
consumption by circulation pump, water reheating, long investment payback period, and etc. The motivation for the
development of a combined hot water and sorption store is to complement the advantages and to reduce the
disadvantages of the two particular storage technologies. Hot water stores offer high heat supply rates but are
particularly suitable for short term storage due to heat losses whereas for a sorption store the power drain is low but it shows the advantage of a high storage density and long-term heat storage almost without losses. We investigated the demonstration project and discuss the need for authoritative system modelling in order to size the system components for minimum cost at a designated availability of supply
Water Purification and Disinfection by Using Solar Energy: Towards Green Energy Challenge
The aim of this work was to design a solar water treatment plant for household purpose. Water purification is the process of eradicating detrimental chemicals, biological poisons, suspended solids and gases from contaminated water. In this work we have reported an investigation of compact filter which is cost effective for developing countries and ease of maintenance. We have arranged a solar water disinfection system that improves the microbiological quality of drinking water at household level. We get 14 L pure water and 16 ml water vapour within 240 min by using filtration method. From our work we get hot water up to 49°C. The efficiency of the system at sunny days and cloudy days are 18.23% and 18.13% respectively. This simple solar hybrid system helps to remove turbidity as well as chemical and pathogenic contaminants from water sources in the most affordable, and expedient manner possibly
Time trends, projections, and spatial distribution of low birthweight in Australia, 2009–2030: Evidence from the National Perinatal Data Collection
Introduction: Infants with low birthweight (LBW, birthweight <2500 g) have increased in many high-resource countries over the past two decades. This study aimed to investigate the time trends, projections, and spatial distribution of LBW in Australia, 2009–2030.
Methods: We used standard aggregate data on 3 346 808 births from 2009 to 2019 from Australia's National Perinatal Data Collection. Bayesian linear regression model was used to estimate the trends in the prevalence of LBW in Australia.
Results: We found that the prevalence of LBW was 6.18% in 2009, which has increased to 6.64% in 2019 (average annual rate of change, AARC = +0.76%). If the national trend remains the same, the projected prevalence of LBW in Australia will increase to 7.34% (95% uncertainty interval, UI = 6.99, 7.68) in 2030. Observing AARC across different subpopulations, the trend of LBW was stable among Indigenous mothers, whereas it increased among non-Indigenous mothers (AARC = +0.81%). There is also an increase among the most disadvantaged mothers (AARC = +1.08%), birthing people in either of two extreme age groups (AARC = +1.99% and +1.53% for <20 years and ≥40 years, respectively), and mothers who smoked during pregnancy (AARC = +1.52%). Spatiotemporal maps showed that some of the Statistical Area level 3 (SA3) in Northern Territory and Queensland had consistently higher prevalence for LBW than the national average from 2014 to 2019.
Conclusion: Overall, the prevalence of LBW has increased in Australia during 2009–2019; however, the trends vary across different subpopulations. If trends persist, Australia will not achieve the Sustainable Development Goals (SDGs) target of a 30% reduction in LBW by 2030. Centering and supporting the most vulnerable subpopulations is vital to progress the SDGs and improves perinatal and infant health in Australia
Internet use impact on physical health during COVID-19 lockdown in Bangladesh : a web-based cross-sectional study
Previous studies on internet use frequency were focused on mental health impact, with little known about the impact on physical health during the COVID-19 lockdown. This study examined the impact of internet use frequency on self reported physical health during the COVID-19 lockdown in Bangladesh. A web-based cross-sectional study on 3242 individuals was conducted from 2 August–1 October 2020. The survey covered demographics, internet use frequency and self-reported physical health questions. Linear regression analyses were used to examine the impact of internet use frequency on physical health. 72.5%, 69.9%, 65.1% and 55.3% respondents reported headache, back pain, numbness of the fingers and neck pain, respectively. The analyses showed increased physical health impact among regular (coefficient β = 0.52, 95% confidence interval [CI]: 0.18–0.85, p = 0.003), frequent (β = 1.21, 95% CI: 0.88–1.54, p < 0.001) and intense (β = 2.24,
95% CI: 1.91–2.57, p < 0.001) internet users. Other important predictors were gender, income, occupation, regions, and working status. Frequent and extensive uses of the internet were strong predictors of physical health problems, and our findings suggest the need for increased awareness about the physical health problems that can be triggered by excessive internet usage
CD200-CD200R1 inhibitory signaling prevents spontaneous bacterial infection and promotes resolution of neuroinflammation and recovery after stroke
Abstract
Background
Ischemic stroke results in a robust inflammatory response within the central nervous system. As the immune-inhibitory CD200-CD200 receptor 1 (CD200R1) signaling axis is a known regulator of immune homeostasis, we hypothesized that it may play a role in post-stroke immune suppression after stroke.
Methods
In this study, we investigated the role of CD200R1-mediated signaling in stroke using CD200 receptor 1-deficient mice. Mice were subjected to a 60-min middle cerebral artery occlusion and evaluated at days 3 and 7, representing the respective peak and early resolution stages of neuroinflammation in this model of ischemic stroke. Infarct size and behavioral deficits were assessed at both time points. Central and peripheral cellular immune responses were measured using flow cytometry. Bacterial colonization was determined in lung tissue homogenates both after acute stroke and in an LPS model of systemic inflammation.
Results
In wild-type (WT) animals, CD200R1 was expressed on infiltrating monocytes and lymphocytes after stroke but was absent on microglia. Early after ischemia (72 h), CD200R1-knockout (KO) mice had significantly poorer survival rates and an enhanced susceptibility to spontaneous bacterial colonization of the respiratory tract compared to wild-type (WT) controls, despite no difference in infarct or neurological deficits. While the CNS inflammation was resolved by day 7 post-stroke in WT mice, brain-resident microglia and monocyte activation persisted in CD200R1-KO mice, accompanied by a delayed, augmented lymphocyte response. At this time point, CD200R1-KO mice displayed greater weight loss, more severe neurological deficits, and impaired motor function compared to WT. Systemically, CD200R1-KO mice exhibited signs of persistent infection including lymphopenia, T cell activation and memory conversion, and narrowing of the TCR repertoire. These findings were confirmed in a second model of acute neuroinflammation induced by systemic endotoxin challenge.
Conclusion
This study defines an essential role of CD200-CD200R1 signaling in stroke. Loss of CD200R1 led to high mortality, increased rates of post-stroke infection, and enhanced entry of peripheral leukocytes into the brain after ischemia, with no increase in infarct size. This suggests that the loss of CD200 receptor leads to enhanced peripheral inflammation that is triggered by brain injury.https://deepblue.lib.umich.edu/bitstream/2027.42/148133/1/12974_2019_Article_1426.pd
Prevalence and risk of hepatitis e virus infection in the HIV population of Nepal
Background: Infection with the hepatitis E virus (HEV) can cause acute hepatitis in endemic areas in immune-competent hosts, as well as chronic infection in immune-compromised subjects in non-endemic areas. Most studies assessing HEV infection in HIV-infected populations have been performed in developed countries that are usually affected by HEV genotype 3. The objective of this study is to measure the prevalence and risk of acquiring HEV among HIV-infected individuals in Nepal. Methods: We prospectively evaluated 459 Human Immunodeficiency Virus (HIV)-positive individuals from Nepal, an endemic country for HEV, for seroprevalence of HEV and assessed risk factors associated with HEV infection. All individuals were on antiretroviral therapy and healthy blood donors were used as controls. Results: We found a high prevalence of HEV IgG (39.4%) and HEV IgM (15.3%) in HIV-positive subjects when compared to healthy HIV-negative controls: 9.5% and 4.4%, respectively (OR: 6.17, 95% CI 4.42-8.61, p < 0.001 and OR: 3.7, 95% CI 2.35-5.92, p < 0.001, respectively). Individuals residing in the Kathmandu area showed a significantly higher HEV IgG seroprevalance compared to individuals residing outside of Kathmandu (76.8% vs 11.1%, OR: 30.33, 95% CI 18.02-51.04, p = 0.001). Mean CD4 counts, HIV viral load and presence of hepatitis B surface antigen correlated with higher HEV IgM rate, while presence of hepatitis C antibody correlated with higher rate of HEV IgG in serum. Overall, individuals with HEV IgM positivity had higher levels of alanine aminotransferase (ALT) than IgM negative subjects, suggesting active acute infection. However, no specific symptoms for hepatitis were identified. Conclusions: HIV-positive subjects living in Kathmandu are at higher risk of acquiring HEV infection as compared to the general population and to HIV-positive subjects living outside Kathmandu
Clinical Application of Computer-Aided Diagnostic System for Harmonious Introduction of Complementary Dialysis Therapy
In chronic peritoneal dialysis (PD) therapy, peritoneal permeability is gradually enhanced over the duration of the therapeutic course, leading to a grave decline in the therapeutic efficiency. In recent years, a novel therapy (CD therapy), which integrates PD therapy with hemodialysis therapy, is being applied to end-stage PD patients to complement the decline of therapeutic efficiency caused by the grave degeneration of the peritoneal tissue. To realize a harmonious introduction of the CD therapy, this study developed a useful index (KAu/c), which evaluates both therapeutic efficiency and degeneration of peritoneal tissue. Using a mathematical model and KAu/c, we were able to validate the therapeutic efficiency in the PD patients, and, in one case, propose a better prescription for the patient by employing the CD therapy. The clinical implementation of this methodology is indispensable with regard to expanding the therapeutic monitoring system for renal replacement therapy
Pathways to ecstasy use in young adults: Anxiety, depression or behavioural deviance?
Aims: To investigate pathways to ecstasy use disorders from pre-birth to early adulthood with particular attention to the relationship between early depressive and anxiety symptoms and later ecstasy use disorders
Poverty and Wellbeing Impacts of Microfinance : What Do We Know?
Over the last 35 years, microfinance has been generally regarded as an effective policy tool in the fight against poverty. Yet, the question of whether access to credit leads to poverty reduction and improved wellbeing remains open. To address this question, we conduct a systematic review of the quantitative literature of microfinance’s impacts in the developing world, and develop a theory of change that links inputs to impacts on several welfare outcomes. Overall, we find that the limited comparability of outcomes and the heterogeneity of microfinance-lending technologies, together with a considerable variation in socio-economic conditions and contexts in which impact studies have been conducted, render the interpretation and generalization of findings intricate. Our results indicate that, at best, microfinance induces short-term dynamism in the financial life of the poor; however, we do not find compelling evidence that this dynamism leads to increases in income, consumption, human capital and assets, and, ultimately, a reduction in poverty
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