89 research outputs found
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Genomic Approaches to Enhance Stress Tolerance for Productivity Improvements in Pearl Millet
Pearl millet [Pennisetum glaucum (L.) R. Br.], the sixth most important cereal crop (after rice, wheat, maize, barley, and sorghum), is grown as a grain and stover crop by the small holder farmers in the harshest cropping environments of the arid and semiarid tropical regions of sub-Saharan Africa and South Asia. Millet is grown on ~31 million hectares globally with India in South Asia; Nigeria, Niger, Burkina Faso, and Mali in western and central Africa; and Sudan, Uganda, and Tanzania in Eastern Africa as the major producers. Pearl millet provides food and nutritional security to more than 500 million of the world’s poorest and most nutritionally insecure people. Global pearl millet production has increased over the past 15 years, primarily due to availability of improved genetics and adoption of hybrids in India and expanding area under pearl millet production in West Africa. Pearl millet production is challenged by various biotic and abiotic stresses resulting in a significant reduction in yields. The genomics research in pearl millet lagged behind because of multiple reasons in the past. However, in the recent past, several efforts were initiated in genomic research resulting into a generation of large amounts of genomic resources and information including recently published sequence of the reference genome and re-sequencing of almost 1000 lines representing the global diversity. This chapter reviews the advances made in generating the genetic and genomics resources in pearl millet and their interventions in improving the stress tolerance to improve the productivity of this very important climate-smart nutri-cereal
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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
Effect of Al doping on structural and dielectric properties of PLZT ceramics
yPolycrystalline samples of Al modified lead lanthanum zirconate titanate [PLZT] with Zr = 55% and Ti = 45%, have been synthesized by a high-temperature solid-state reaction technique. X-ray diffraction analysis of the compounds suggests the formation of a single-phase compound with tetragonal structure. Dielectric studies of the compounds as a function of temperature (from 30 to 350 degrees C) at frequency (1, 10 and 100 kHz) show that the compounds undergo a phase transition of diffuse type. The transition temperature shifts towards higher side with increase in frequency a typical characteristic of a relaxor material. Diffusivity (gamma) study of phase transition of these compounds provided its value between 1 and 2, indicating the variation of degree of disordering in the system. Measurement of dc resistivity (rho) as a function of temperature (Room temperature, RT to 350 degrees C) at a constant biasing field suggests the compounds have negative temperature coefficient of resistance (NTCR)
Investigation of structural and dielectric properties of (La, Fe)-doped PZT ceramics
Polycrystalline samples of iron doped lead lanthanum zirconium titanate (PLFZT) with a general formula Pb-0.9(La1-yFey)(0.1) (Zr0.55Ti0.45)(0.975)O-3, [y = 0.0,0.3,0.5,0.7] near the morphotropic phase boundary have been synthesized by a high-temperature, solid-state reaction technique. Preliminary X-ray structural study of the compounds show the formation of tetragonal structure. Detailed studies of dielectric constant (e) and tangent loss (tan 6) as a function of frequency (102 Hz to 10 kHz) at room temperature (RT) and temperature (RT-350 degrees C) at 10 kHz suggest that compounds undergo ferroelectric-paraelectric phase transition of diffuse type. The activation energy (Ea) of the samples was calculated from the plot of AC conductivity versus inverse of absolute temperature. The temperature dependence of resistivity shows that the compounds have negative temperature coefficient of resistance
Spectroscopic analysis and temperature-dependent dielectric properties of bulk Ni–Zn ceramics
In the present work, series of Zn ion-doped Ni1−xZnxFe2O4 (0.0≤x≤0.5) ceramics were prepared by the double sintered solid-state reaction route to find out the influence of Zn2+ ions on the crystal structure, lattice structure and dielectric behavior of parent NiFe2O4. X-ray diffraction (XRD) study favors that all the prepared compounds belong to the cubic spinel structure. Lattice parameters found to have increasing value with increased Zn2+ ion substitution. The Raman scattering measurement discerns optical-active modes with blue shift as the doping increases. The dielectric constant (ε′) and dielectric tangent loss (tan δ) decrease with an increase in frequency and at higher frequency, both become constant. Dielectric parameters observe nonlinear behavior with increasing Zn2+ ion substitution. Room temperature dielectric constant of 10% Zn ion-doped NiFe2O4 [Ni0.9Zn0.1Fe2O4] is much higher as compared to other prepared ceramics. The room temperature ac conductivity is found to increase with increase in frequency and temperature-dependent ac conductivity increases with increase in temperature
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Not AvailableThe microbial diversity in the rhizosphere of different biotypes is influenced by different factors like plant species, root exudates and soil environment. Culturable microbial diversity in the rhizosphere of six biotypes (Chenopodium murale (CM), Spergula arvensis (SA), Launaea nudicaulis (LN), Brassica juncea (BJ), Phalaris minor (PM) and Triticum aestivum (TA)) growing in variable saline environment (ECe 8.0 dS m−1) was assessed and compared with the diversity of bulk soils (BS) of same environments. The significantly (P < 0.0001) highest bacterial and actinomycetes population were found in the rhizosphere of BJ whereas SA possessed higher fungal population. Phosphorus and zinc solubilizing bacteria was also found highest in BJ and TA rhizosphere, respectively. High saline soils had greater endospore forming bacterial population. The TA (0.88) and LN (0.87) rhizospheres showed significantly greater Shannon–Weiner diversity index compared to bulk soils (0.45–0.61). Pielou’s index of evenness of different samples ranged from 0.13 to 0.43. Discriminant function analysis revealed that rhizospheres of SA, CM and TA were clearly distinct. The rhizospheric soil of PM and BJ were similar to each other but clearly distinct from others. The observed separation of different biotypes was regulated by dimorphic fungi, nitrogen fixing bacteria, Pseudomonas, and fungi. Thus, our study clearly suggests that culturable microbial populations are influenced by different biotypes and salinity levels.Not Availabl
Carbon mineralization in soil as influenced by crop residue type and placement in an Alfisols of Northwest India
Carbon (C) mineralization of crop residues is an important process occurring in soil which is helpful in predicting CO2 emission to the atmosphere and nutrient availability to plants. A laboratory experiment was conducted in which C mineralization of residues of rice (Oryza sativa), wheat (Triticum aestivum), maize (Zea mays), mungbean (Vigna radiata) and their mixtures was applied to the soil surface or incorporated into an Alfisols from Northwest India. C mineralization was significantly affected by residue placement and type and their interactions. Rice residue had a higher decomposition rate (k = 0.121 and 0.076 day−1) than wheat (0.073 and 0.042 day−1) and maize residues (0.041 day−1) irrespective of placements. Higher decomposition rates of rice and wheat were observed when placed on soil surface than incorporated in the soils. Additive effects of the contribution of each residue type to C mineralization of the residue mixture were observed. When mungbean residue was added to the rice/wheat or maize/wheat mixture, decomposition of the residue mixture was enhanced. Crop residues with low N and high C/N ratio such as maize, wheat, rice and their mixtures can be applied on the soil surface for faster C and N mineralization, thereby helping to manage high volumes of residues under conservation agriculture-based practices in northwest India
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Not AvailableTillage is an important agricultural operation which influences soil properties, crop yield and environment. Nine combinations of three tillage practices including conventional tillage (CT), minimum tillage (MT) and zero tillage (ZT) were evaluated in fodder sorghum (Sorghum bicolor) + cowpea (Vigna unguiculata) – wheat (Triticum durum) cropping system for 5 years (2009–2014) on clay loam soil under limited irrigation. Continuous ZT practices significantly improved surface soil organic carbon, bulk density, infiltrationrateandmaximumwaterholdingcapacity.Carbonsequestration rate, soil organic carbon stock and soil enzymatic activities were relatively moreunderZTthanCT-CTpractice.Higherfodder yieldofsorghum+cowpea was recorded with CT (kharif) while wheat grain yield with ZT (rabi). However, the system productivity was statistically similar in all the tillage treatments on pooled data basis. The economic benefits were also maximum under ZT-ZT practice. The ZT-ZT practice recorded significantly lowest energy input (17.1 GJ ha−1) which resulted in highest energy use efficiency (13.6) and energy productivity (518 kg GJ−1). Thus, adoption of ZT significantly improved soil health, stabilized crop yield, increased profitability and energy use efficiency in the semi-arid agro-ecosystem.Not Availabl
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