76 research outputs found
The Use of Smart Devices for the Detection of Aflatoxin in Ground Corn Feeds
Aflatoxin contaminates agricultural commodities, plants or animal-derived food, in warm and humid conditions primarily in tropical countries such as the Philippines. Although the type and degree of contamination are dependent on its concentration, its effect becomes critical when biomagnified. In this study, a rapid, simple, and portable detection was developed. A smart-device sensor was used to measure the pH of the samples with aflatoxin and compared it with the pH of pure samples. Concentrations in parts per billion (ppb) were calculated for each of the samples from the obtained pH readings; Cyclic voltammetry was also conducted to further study the electrochemical properties of the mixture with aflatoxin
The Use of Smart Devices for the Detection of Aflatoxin in Ground Corn Feeds
Aflatoxins are toxic and carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus (Gourama, H., & Bullerman, L., 1995). These fungal species are contaminants of food crops as well as animal feeds, and are responsible for aflatoxin contamination of these agricultural products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds (Gourama, H., & Bullerman, L., 1995). Determination of aflatoxins concentration in food crops and animal feeds is thus very important for Food Safety Regulatory Agencies (FRSA) to create effective policies (Shane, S.H. & Groopman, J.D., 1994). However, the current mechanism of aflatoxin detection does not provide an immediate result, requires technical expertise, and are costly (Paniel, N., Radoi, A. & Marty, J., 2010
Effect of Applied Magnetic Field on Surface Morphology, Optical and Electrical Property of Tin (IV) Oxide (SnO2) Nanomaterial for Meat Spoilage Detection
The specter of botcha or “double dead” meat is a persistent, if not underestimated, threat in Filipino markets. In 2014, the National Meat Inspection Service (NMIS) recorded the confiscation of more than 12 metric tons of so-called hot meat, unfit for human consumption. The hazard that consuming this and other forms of spoiled meat poses to human health cannot be overstated, especially because spoiled meat can harbor dangerous pathogens or parasites such as Salmonella, Staphylococcus, Pseudomonas Aeroginosa, and Trichinella
Nanocomposite Material Synthesized Via Horizontal Vapor Phase Growth Technique: Evaluation and Application Perspective
The synthesis of nanomaterials has been reported by many researchers using different methods. One of the methods that can be used with perfect pureness and have less pollution in the synthesized materials results is the vapor phase growth technique (VPGT). Several types of nano shapes materials were reported such as nanoparticles, nanorods, nano triangular, nanosphere, and nanocrystal. The synthesis method has a fundamental process where the nanomaterials evaporated and condensed based on the temperature difference. There are three important variables, i.e., stochiometric ratio of source materials, temperature and baking time. The synthesis was occured in the quartz tube and sealed in the vacuum condition. This create the material was synthesis in pure and isolated conditions. The application of the nanomaterials synthesized via Horizontal Vapor Phase Growth (HVPG) can be implemented in anti-pathogen, anti-bacterial, gas sensing and coating applications
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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
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Global fertility in 204 countries and territories, 1950–2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
Background
Accurate assessments of current and future fertility—including overall trends and changing population age structures across countries and regions—are essential to help plan for the profound social, economic, environmental, and geopolitical challenges that these changes will bring. Estimates and projections of fertility are necessary to inform policies involving resource and health-care needs, labour supply, education, gender equality, and family planning and support. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 produced up-to-date and comprehensive demographic assessments of key fertility indicators at global, regional, and national levels from 1950 to 2021 and forecast fertility metrics to 2100 based on a reference scenario and key policy-dependent alternative scenarios.
Methods
To estimate fertility indicators from 1950 to 2021, mixed-effects regression models and spatiotemporal Gaussian process regression were used to synthesise data from 8709 country-years of vital and sample registrations, 1455 surveys and censuses, and 150 other sources, and to generate age-specific fertility rates (ASFRs) for 5-year age groups from age 10 years to 54 years. ASFRs were summed across age groups to produce estimates of total fertility rate (TFR). Livebirths were calculated by multiplying ASFR and age-specific female population, then summing across ages 10–54 years. To forecast future fertility up to 2100, our Institute for Health Metrics and Evaluation (IHME) forecasting model was based on projections of completed cohort fertility at age 50 years (CCF50; the average number of children born over time to females from a specified birth cohort), which yields more stable and accurate measures of fertility than directly modelling TFR. CCF50 was modelled using an ensemble approach in which three sub-models (with two, three, and four covariates variously consisting of female educational attainment, contraceptive met need, population density in habitable areas, and under-5 mortality) were given equal weights, and analyses were conducted utilising the MR-BRT (meta-regression—Bayesian, regularised, trimmed) tool. To capture time-series trends in CCF50 not explained by these covariates, we used a first-order autoregressive model on the residual term. CCF50 as a proportion of each 5-year ASFR was predicted using a linear mixed-effects model with fixed-effects covariates (female educational attainment and contraceptive met need) and random intercepts for geographical regions. Projected TFRs were then computed for each calendar year as the sum of single-year ASFRs across age groups. The reference forecast is our estimate of the most likely fertility future given the model, past fertility, forecasts of covariates, and historical relationships between covariates and fertility. We additionally produced forecasts for multiple alternative scenarios in each location: the UN Sustainable Development Goal (SDG) for education is achieved by 2030; the contraceptive met need SDG is achieved by 2030; pro-natal policies are enacted to create supportive environments for those who give birth; and the previous three scenarios combined. Uncertainty from past data inputs and model estimation was propagated throughout analyses by taking 1000 draws for past and present fertility estimates and 500 draws for future forecasts from the estimated distribution for each metric, with 95% uncertainty intervals (UIs) given as the 2·5 and 97·5 percentiles of the draws. To evaluate the forecasting performance of our model and others, we computed skill values—a metric assessing gain in forecasting accuracy—by comparing predicted versus observed ASFRs from the past 15 years (2007–21). A positive skill metric indicates that the model being evaluated performs better than the baseline model (here, a simplified model holding 2007 values constant in the future), and a negative metric indicates that the evaluated model performs worse than baseline.
Findings
During the period from 1950 to 2021, global TFR more than halved, from 4·84 (95% UI 4·63–5·06) to 2·23 (2·09–2·38). Global annual livebirths peaked in 2016 at 142 million (95% UI 137–147), declining to 129 million (121–138) in 2021. Fertility rates declined in all countries and territories since 1950, with TFR remaining above 2·1—canonically considered replacement-level fertility—in 94 (46·1%) countries and territories in 2021. This included 44 of 46 countries in sub-Saharan Africa, which was the super-region with the largest share of livebirths in 2021 (29·2% [28·7–29·6]). 47 countries and territories in which lowest estimated fertility between 1950 and 2021 was below replacement experienced one or more subsequent years with higher fertility; only three of these locations rebounded above replacement levels. Future fertility rates were projected to continue to decline worldwide, reaching a global TFR of 1·83 (1·59–2·08) in 2050 and 1·59 (1·25–1·96) in 2100 under the reference scenario. The number of countries and territories with fertility rates remaining above replacement was forecast to be 49 (24·0%) in 2050 and only six (2·9%) in 2100, with three of these six countries included in the 2021 World Bank-defined low-income group, all located in the GBD super-region of sub-Saharan Africa. The proportion of livebirths occurring in sub-Saharan Africa was forecast to increase to more than half of the world's livebirths in 2100, to 41·3% (39·6–43·1) in 2050 and 54·3% (47·1–59·5) in 2100. The share of livebirths was projected to decline between 2021 and 2100 in most of the six other super-regions—decreasing, for example, in south Asia from 24·8% (23·7–25·8) in 2021 to 16·7% (14·3–19·1) in 2050 and 7·1% (4·4–10·1) in 2100—but was forecast to increase modestly in the north Africa and Middle East and high-income super-regions. Forecast estimates for the alternative combined scenario suggest that meeting SDG targets for education and contraceptive met need, as well as implementing pro-natal policies, would result in global TFRs of 1·65 (1·40–1·92) in 2050 and 1·62 (1·35–1·95) in 2100. The forecasting skill metric values for the IHME model were positive across all age groups, indicating that the model is better than the constant prediction.
Interpretation
Fertility is declining globally, with rates in more than half of all countries and territories in 2021 below replacement level. Trends since 2000 show considerable heterogeneity in the steepness of declines, and only a small number of countries experienced even a slight fertility rebound after their lowest observed rate, with none reaching replacement level. Additionally, the distribution of livebirths across the globe is shifting, with a greater proportion occurring in the lowest-income countries. Future fertility rates will continue to decline worldwide and will remain low even under successful implementation of pro-natal policies. These changes will have far-reaching economic and societal consequences due to ageing populations and declining workforces in higher-income countries, combined with an increasing share of livebirths among the already poorest regions of the world
Synthesis and Characterization of Gallium Oxide/Tin Oxide Nanostructures via Horizontal Vapor Phase Growth Technique for Potential Power Electronics Application
The monoclinic β-gallium oxide (Ga2O3) was viewed as a potential candidate for power electronics due to its excellent material properties. However, its undoped form makes it highly resistive. The Ga2O3/SnO2 nanostructures were synthesized effectively via the horizontal vapor phase growth (HVPG) technique without the use of a magnetic field. Different concentrations of Ga2O3 and SnO2 were varied to analyze and describe the surface morphology and elemental composition of the samples using the scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy, respectively. Meanwhile, the polytype of the Ga2O3 was confirmed through the Fourier transform infrared (FTIR) spectroscopy. The current-voltage (I–V) characteristics were established using a Keithley 2450 source meter. The resistivity was determined using the van der Pauw technique. The mobility and carrier concentration was done through the Hall effect measurements at room temperature using a 0.30-Tesla magnet. It was observed that there was an increase in the size of the nanostructures, and more globules appeared after the concentration of SnO2 was increased. It was proven that the drop in the resistivity of Ga2O3 was due to the presence of SnO2. The data gathered were supported by the Raman peak located at 662 cm−1, attributed to the high conductivity of β-Ga2O3. However, the ε-polytype was verified to appear as a result of adding SnO2. All the samples were considered as n-type semiconductors. High mobility, low power loss, and low specific on-resistance were attained by the highest concentration of SnO2. Hence, it was clinched as the optimal n-type Ga2O3/SnO2 concentration and recommended to be a potential substrate for power electronics application
A standard method to synthesize Ag, Ag/Ge, Ag/TiO2, SnO2, and Ag/SnO2 nanomaterials using the HVPG technique
Nanotechnology is growing rapidly in the past few decades with the applications in several fields such as medicine, environment, energy, electronics, automotive, and aerospace. There are many methods used by researchers to synthesize nanomaterial. In this paper, Horizontal Vapor Phase Growth (HVPG) technique was successfully used to synthesize various nanomaterial and nanocomposite materials such as Ag, Ag/Ge, Ag/TiO2, SnO2, and Ag/SnO2. HVPG technique used a one-pot step to synthesize nanomaterials with 100 % purity of the results, affordable cost, and environmentally friendly. The method has two variables; growth temperature and curing time. Changing the variables create different shapes of nanomaterials. It also reported that the technique could be used to synthesize various nanomaterials consists of single or multi-material. This detailed method demonstrates the capability of the HVPG technique to synthesize nanomaterials, not only to grow the single shape of nanomaterials but also allow other nanomaterial shapes to grow in different parameter conditions. • HVPG technique successfully used to synthesize various nanomaterials. • Only 2 parameters used; curing time and growth temperature. • Purity result (100 %) with no pollutant. © 2019 The Author(s
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