32 research outputs found

    Coherent structures in numerically simulated jets with and without off-source heating

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    Direct numerical solutions of the incompressible Navier-Stokes equations, under the Boussinesq approximation, for the temporal evolution of a jet-like flow have been analyzed to educe coherent structures. The eduction procedure involved both conventional image processing and the application of the wavelet transform - here used as a spatially delimited filter to smooth out fine scale discontinuities and reveal the underlying order. Attention has been focussed on the vorticity and its components (azimuthal, radial and streamwise). It is found that the nature of the coherent motion is most strongly evident in the azimuthal component of the vorticity, and is revealed to consist of a toroidal base supporting a thin conical sheath; the interior of the structure is nearly devoid of azimuthal vorticity. There is some evidence of a secondary structure in the radial and streamwise components of the vorticity, which show strips of opposite sign close to each other, suggesting vortex pairs, possibly helically organized. With addition of volumetric heat after the (unheated) jet has achieved self-similarity, the structures tend to telescope into each other because of the acceleration produced by the heating, and the coherence present in the unheated jet is severely disrupted

    Vitamin D kao sastojak luminalne tekućine pasjemenika važan je za sazrijevanje spermija u nerasta pasmine veliki bijeli jorkšir

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    Vitamin-D (VD) is known to modulate reproductive processes through the expression of VDR in the male reproductive tract. To understand its influence in the initiation of sperm motility in epididymis, VD concentration was measured in serum, epididymal luminal fluid (ELF) and sperm cytosolic fluid (SCF) from the caput, corpus and cauda epididymis of Large White Yorkshire (LWY) boars (n = 30) of around 3-4 years of age. The relationship of VD concentration with sperm motility in epididymal segments was then observed. A progressive increase in sperm motility from caput to cauda epididymis was found with highest in cauda followed by corpus. Motility was found absent in the caput region. VD levels in serum were positively correlated with spermatozoan motility from the corpus (r = 0.819) and cauda (r = 0.961), and this was highly significant (P0.05) from sections of caput to cauda epididymis was in concurrence with the increasing concentration of VD from the caput to cauda epididymis suggesting the influence of VD in the initiation of sperm motility in the excurrent duct. VD levels in serum may also pave the way for the development of specific marker(s) to assist in the prediction and early diagnosis of idiopathic infertility in males due to epididymal dysfunction resulting from VD deficiency. This will help clinically in improving treatment modalities of this idiopathic male infertility.vu mužjaka. Kako bismo razumjeli njegov utjecaj na pokretanje spermija u pasjemeniku, izmjerena je koncentracija vitamina D u serumu, luminalnoj tekućini pasjemenika (ELF) i citosolnoj tekućini spermija (SCF) uzetoj iz glave, tijela i repa pasjemenika nerasta pasmine veliki bijeli jorkšir (n = 30) dobi 3 - 4 godine. Promatran je odnos koncentracije vitamina D i pokretljivosti spermija u dijelovima pasjemenika. Uočeno je progresivno povećanje pokretljivosti spermija od glave (gdje su mirovali) preko tijela do repa pasjemenika. Razine vitamina D u serumu pozitivno su korelirale s pokretljivošću spermija iz tijela (r = 0,819) i repa (r = 0,961), što je bilo statistički znakovito (P0,05) iz dijelova od glave do repa pasjemenika porasla je istodobno s porastom koncentracije vitamina D što upućuje na utjecaj vitamina D na početak pokretljivosti spermija u odvodnim kanalima. Razine vitamina D u serumu mogle bi utrti put razvoju specifičnih markera koji bi mogli pomoći u ranom dijagnosticiranju idiopatske neplodnosti u mužjaka uzrokovane disfunkcijom pasjemenika zbog manjka vitamina D. To može klinički pomoći u unapređenju modaliteta liječenja idiopatske neplodnosti u mužjaka

    A Climate-Change Policy Induced Shift from Innovations in Energy Production to Energy Savings

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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

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    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

    The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

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    Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

    Time Profile of Climate Change Stabilization Policy

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