51 research outputs found
High-Resolution Denitrification Kinetics in Pasture Soils Link N2O Emissions to pH, and Denitrification to C Mineralization
peer-reviewedDenitrification in pasture soils is mediated by microbial and physicochemical processes leading to nitrogen loss through the emission of N2O and N2. It is known that N2O reduction to N2 is impaired by low soil pH yet controversy remains as inconsistent use of soil pH measurement methods by researchers, and differences in analytical methods between studies, undermine direct comparison of results. In addition, the link between denitrification and N2O emissions in response to carbon (C) mineralization and pH in different pasture soils is still not well described. We hypothesized that potential denitrification rate and aerobic respiration rate would be positively associated with soils. This relationship was predicted to be more robust when a high resolution analysis is performed as opposed to a single time point comparison. We tested this by characterizing 13 different temperate pasture soils from northern and southern hemispheres sites (Ireland and New Zealand) using a fully automated-high-resolution GC detection system that allowed us to detect a wide range of gas emissions simultaneously. We also compared the impact of using different extractants for determining pH on our conclusions. In all pH measurements, soil pH was strongly and negatively associated with both N2O production index (IN2O) and N2O/(N2O+N2) product ratio. Furthermore, emission kinetics across all soils revealed that the denitrification rates under anoxic conditions (NO+N2O+N2 μmol N/h/vial) were significantly associated with C mineralization (CO2 μmol/h/vial) measured both under oxic (r2 = 0.62, p = 0.0015) and anoxic (r2 = 0.89, p<0.0001) conditions.This work was funded by the New Zealand Government through the New Zealand Fund for Global Partnerships in Livestock Emissions Research to support the objectives of the Livestock Research Group of the Global Research Alliance on Agricultural Greenhouse Gases (Agreement number: 16084) awarded to SEM and the University of Otago
The potential of plasma-derived hard carbon for sodium-ion batteries
Sodium-ion batteries (SIB) are receiving wider attention due to sodium abundance and lower cost. The application of hard carbon to SIB electrodes has shown their significant potential to increase rates, capacities, stability, and overall performance. This article describes the significance of hard carbon, its structural models, and mechanisms for SIB applications. Further, this work unveils the potential of plasma methods as a scalable and sustainable manufacturing source of hard carbon to meet its increasing industrial demands for energy storage applications. The working mechanisms of major plasma technologies, the influence of their parameters on carbon structure, and their suitability for SIB applications are described. This work summarises the performance of emerging plasma-driven hard carbon solutions for SIB, including extreme environments, and revolves around the flexibilities offered by plasma methods in a wider spectrum such as multi-materials doping, in-situ multilayer fabrication, and a broad range of formulations and environments to deposit hard carbon-based electrodes for superior SIB performance. It is conceived the challenges around the stable interface, capacity fading, and uplifting SIB capacities and rates at higher voltage are currently being researched, Whereas, the development of real-time monitoring and robust diagnostic tools for SIB are new horizons. This work proposes a data-driven framework for plasma-driven hard carbon to make high-performance energy storage batteries
Photocatalytic response in water pollutants with addition of biomedical and anti-leishmanial study of iron oxide nanoparticles
Public health is a major concern globally, owing to the presence of industrial dyes in the effluent. Nanoparticles with green synthesis are an enthralling research field with various applications. This study deals with investigating the photocatalytic potential of Fe-oxide nanoparticles (FeO-NPs) for the degradation of methylene blue dye and their potential biomedical investigations. Biosynthesis using Anthemis tomentosa flower extract showed to be an effective method for the synthesis of FeO-NPs. The freshly prepared FeO-NPs were characterized through UV/Vis spectroscopy showing clear peak at 318 nm. The prepared FeO-NPs were of smaller size and spherical shape having large surface area and porosity with no aggregations. The FeO-NPs were characterized using XRD, FTIR, HRTEM, SEM and EDX. The HRTEM results showed that the particle size of FeO-NPs was 60–90 nm. The antimicrobial properties of FeO-NPs were investigated against two bacterial Staphylococcus aureus 13 (±0.8) and Klebsiella pneumoniae 6(±0.6) and three fungal species Aspergillus Niger, Aspergillus flavus, and Aspergillus fumigatus exhibiting a maximum reduction of 57% 47% and 50%, respectively. Moreover, FeO-NPs exhibited high antioxidant properties evaluated against ascorbic acid. Overall, this study showed high photocatalytic, antimicrobial, and antioxidant properties of FeO-NPs owing to their small size and large surface area. However, the ecotoxicity study of methylene blue degradation products showed potential toxicity to aquatic organisms
Arsenic speciation and biotransformation pathways in the aquatic ecosystem: The significance of algae
© 2020 Elsevier B.V. The contamination of aquatic systems with arsenic (As) is considered to be an internationally-important health and environmental issue, affecting over 115 countries globally. Arsenic contamination of aquatic ecosystems is a global threat as it can enter the food chain from As-rich water and cause harmful impacts on the humans and other living organisms. Although different factors (e.g., pH, redox potential, iron/manganese oxides, and microbes) control As biogeochemical cycling and speciation in water systems, the significance of algal species in biotransformation of As is poorly understood. The overarching attribute of this review is to briefly elaborate various As sources and its distribution in water bodies and factors affecting As biogeochemical behavior in aqueous ecosystems. This review elucidates the intriguing role of algae in biotransformation/volatilization of As in water bodies under environmentally-relevant conditions. Also, we critically delineate As sorption, uptake, oxidation and reduction pathways of As by algae and their possible role in bioremediation of As-contaminated water (e.g., drinking water, wastewater). The current review provides the updated and useful framework for government and water treatment agencies to implement algae in As remediation programs globally
Potential of siltstone and its composites with biochar and magnetite nanoparticles for the removal of cadmium from contaminated aqueous solutions: Batch and column scale studies
© 2020 Elsevier Ltd The present study is the first attempt to evaluate the pilot and batch scale adsorption potential of siltstone (SS) and its nanocomposites with biochar (EDB/SS), magnetite nanoparticles (MNPs/SS) and MNPs/EDB/SS for Cd removal from contaminated water. The SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were characterized with FTIR, XRD, BET, SEM, TEM, TGA and point of zero charge (PZC). The effects of adsorbent dosage, contact time, initial Cd concentration, pH and presence of competing ions were evaluated on the Cd removal and its adsorption. The order for Cd removal was: MNPs/EDB/SS \u3e MNPs/SS \u3e EDB/SS \u3e SS (95.86–99.72% \u3e 93.10–98.5% \u3e 89.66.98–98.40% \u3e 74.90–90%). Column scale experiments yielded maximum retention (95%) of Cd even after 2 h of injection at 100 mg Cd/L. The exhausted SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were reused without losing significant adsorption potential. Similarly, maximum Cd adsorption (117.38 mg/g) was obtained with MNPs/EDB/SS at dose 1.0 g/L. The results revealed that coexisting cations reduced the Cd removal due to competition with Cd ions. The experimental results were better explained with Freundlich isotherm model and pseudo 2nd order kinetic models. The results revealed that SS and its composites can be used efficiently for the removal of Cd from contaminated water
Synthesis, characterization and application of novel MnO and CuO impregnated biochar composites to sequester arsenic (As) from water: Modeling, thermodynamics and reusability
© 2020 Elsevier B.V. The present study aimed at enhancing the adsorption potential of novel nanocomposites of Sesbania bispinosa biochar (SBC) with copper oxide (SBC/CuO) and manganese oxide nanoparticles (SBC/MnO) for the efficient and inexpensive removal of environmentally concerned contaminant arsenic (As) from contaminated water at batch scale. The scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray (EDX), X-ray diffraction (XRD) and point of zero charge (PZC) analyses proved successful impregnation of the metallic nanoparticles on SBC surface. The results revealed the maximum As removal (96 %) and adsorption (12.47 mg/g) by SBC/CuO composite at 10 mg As/L, optimum pH-4, dose 1.0 g/L and ambient temperature (25 ± 1.5 °C) as compared with SBC (7.33 mg/g) and SBC/MnO (7.34 mg/g). Among four types of adsorption isotherms, Freundlich isotherm demonstrated best fit with R2 \u3e 0.997. While pseudo second-order kinetic model revealed better agreement with kinetic experimental data as matched with other kinetic models. The thermodynamic results depicted that As adsorption on the as-synthesized adsorbents was endothermic and spontaneous in nature with increased randomness. The SBC/CuO displayed excellent reusability and stability over four adsorption/desorption cycles and proved that the as-synthesized SBC/CuO composite may be the efficient adsorbent for practical removal of As from contaminated water
Mental Health Through Movement
Children’s mental health: ‘has become an issue of real concern, in the media and to both politicians and NHS leaders, over the last five years in particular. It has prompted numerous inquiries, reports, recommendations and pledges by politicians and NHS leaders to improve the situation’: https://www.theguardian.com/society/2018/nov/22/what-is-happening-withchildrens-mental-health On July 1st 2019, the Local Government Association released statistics to show that: ‘There were 205,720 cases where a child was identified as having a mental health issue in 2017/18, compared with 133,600 in 2014/15- up 54%’: https://www.local.gov.uk/about/news/councils-seeing-more-560-child-mentalhealth-cases-every-day It is within this context that the All-Party Parliamentary Group on A Fit and Healthy Childhood presents its 14th Report: ‘Positive Mental Health Through Movement’. With 1 in 10 children now having a mental health diagnosis and 1 in 4 an undiagnosed mental health issue, this, our third Report on the issue of child mental health, addresses the link between positive mental health and physical activity and movement experiences at a time when, paradoxically, today’s children and young people are more inactive and play less than ever before. The growing recognition of a link between mental health and movement is fortuitous because from September 2019, health education in English schools will be statutory alongside the expectation that they will offer their pupils at least 30 ‘active minutes’ per day. The APPG on A Fit and Healthy Childhood welcomes the change whilst recognising that those responsible for implementing the new strategy (including practitioners and families) will need guidance as they help children to develop individual strategies to address future adverse events and foster the positive sense of self that will enable them to lead fulfilled, healthy lives. This Report is therefore presented as a practical contribution to an essential debate. It offers new strategies against the persistence of historical and traditional ways of thinking; examines and collates best practice in the devolved Home Countries as well as the wider world and discusses exactly what is required to ensure that future child mental health strategy is holistic. It is respectful of equalities and is aware that the successful outcome of policies is entirely dependent upon the expertise and confidence of those tasked with the responsibility of delivering them. As the 21st century advances, we consider the effects of the digital age and its impact on children and young people’s mental health and wellbeing and the crucial role of parents and carers who want the best for their children in a societal climate where, all too often, fears of ‘nanny state’ meddling serve to isolate families who suffer in silence – until a disaster that may have been all too predictable and preventable overtakes them, making a private grief a public concern. The trajectory of progress in mental health policy has been ‘stop start’ rather than linear, with legislative change in 1959 and 1983, an increase in spending from 1997- 2010 and radical changes to child and adolescent mental health services (CAMHS) in 2000. The Wessely Independent Review of the Mental Health Act is another such milestone: https://www.gov.uk/government/groups/independent-review-of-the-mentalhealth-act The APPG on A Fit and Healthy Childhood anticipates that the Government will fulfil its pledge to parents, children and practitioners by introducing much needed mental health legislation - and that our trio of Reports and the holistic theme of this one will help to inform a strategy that works for 21st century children
Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000-18 : a geospatial modelling study
Background More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels.Methods We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km x 5 km resolution in 98 LMICs based on 2.1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution.Findings Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205000 (95% uncertainty interval 147000-257000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution.Interpretation Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Peer reviewe
Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic
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