The influence of expertise and experimental paradigms on the visual behavior of tennis athletes in returning a serve

To return a serve, one must pick up information from the server’s kinematics and anticipate the ball trajectory. Although the perceptual requirements are important, the literature diverges in terms of the differences between experts and novices as well as the importance of the experimental paradigm (in-situ vs. video-based) for the results. This study aimed to address both concerns. We compared experts’ (n=7, 20.6±1.1 years of age) and novices’ (n=7, 20.0±0.4 years of age) visual pattern when returning a serve (Experiment 1) and the influence of the experimental paradigm in experts (Experiment 2). Experts fixated more and longer the upper body and ball, while novices showed a more distributed pattern and with longer fixations outside of the server’s body. Also, the pattern was different when comparing in-situ and laboratory settings, differing mainly in fixation frequency. The influence of expertise was observed in qualitative (relative) and quantitative (absolute) measures of visual behavior with the setting having an important influence. Thus, studies should be as close to the actual situation if trying to understand experts’ behavior

Oxygen radical-mediated oxidation reactions of an alanine peptide motif - density functional theory and transition state theory study

<p>Abstract</p> <p>Background</p> <p>Oxygen-base (O-base) oxidation in protein backbone is important in the protein backbone fragmentation due to the attack from reactive oxygen species (ROS). In this study, an alanine peptide was used model system to investigate this O-base oxidation by employing density functional theory (DFT) calculations combining with continuum solvent model. Detailed reaction steps were analyzed along with their reaction rate constants.</p> <p>Results</p> <p>Most of the O-base oxidation reactions for this alanine peptide are exothermic except for the bond-breakage of the C_α-N bond to form hydroperoxy alanine radical. Among the reactions investigated in this study, the activated energy of OH α-H abstraction is the lowest one, while the generation of alkylperoxy peptide radical must overcome the highest energy barrier. The aqueous situation facilitates the oxidation reactions to generate hydroxyl alanine peptide derivatives except for the fragmentations of alkoxyl alanine peptide radical. The C_α-C_βbond of the alkoxyl alanine peptide radical is more labile than the peptide bond.</p> <p>Conclusion</p> <p>the rate-determining step of oxidation in protein backbone is the generation of hydroperoxy peptide radical via the reaction of alkylperoxy peptide radical with HO₂. The stabilities of alkylperoxy peptide radical and complex of alkylperoxy peptide radical with HO₂are crucial in this O-base oxidation reaction.</p

The Taiwan Birth Panel Study: a prospective cohort study for environmentally- related child health

<p>Abstract</p> <p>Background</p> <p>The Taiwan Birth Panel Study (TBPS) is a prospective follow-up study to investigate the development of child health and disease in relation to in-utero and/or early childhood environmental exposures. The rationale behind the establishment of such a cohort includes the magnitude of potential environmental exposures, the timing of exposure window, fatal and children's susceptibility to toxicants, early exposure delayed effects, and low-level or unknown neurodevelopmental toxicants.</p> <p>Methods</p> <p>A total of 486 mother-infant paired was enrolled from April 2004 to January 2005 in this study. Maternal blood before delivery, placenta and umbilical cord blood at birth, and mothers' urine after delivery were collected. The follow-up was scheduled at birth, 4, 6 months, and 1, 2, 3 and 5 years. The children's blood, urine, hair, and saliva were collected at 2 years of age and children's urine was collected at 5 years of age as well. The study has been approved by the ethical committee of National Taiwan University Hospital. All the subjects signed the inform consent on entering the study and each of the follow up.</p> <p>Results</p> <p>Through this prospective birth cohort, the main health outcomes were focused on child growth, neurodevelopment, behaviour problem and atopic diseases. We investigated the main prenatal and postnatal factors including smoking, heavy metals, perfluorinated chemicals, and non-persistent pesticides under the consideration of interaction of the environment and genes.</p> <p>Conclusions</p> <p>This cohort study bridges knowledge gaps and answers unsolved issues in the low-level, prenatal or postnatal, and multiple exposures, genetic effect modification, and the initiation and progression of "environmentally-related childhood diseases."</p

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

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

[[alternative]]Skill Level Differences under Task Constraints and the Effect of Training on Tennis Forehand Skills Performance

[[abstract]]The main objectives of this research were: 1) Compare mature individuals at different skill levels under different task constraints, evaluating their motor control and skills performance ability. 2) Investigate speed and accuracy levels under task constraints. 3) Investigate the effect of task constraints and the training process on skills control and skills performance ability. The participants in Experiment 1 of this study were university students at different skill levels, 40 from each of these three categories: 1) general science departments (Height, 171.52±4.78 cm, Weight, 68.73±4.48 kg), 2) the Dept. of Physical Education(Height, 173.23±3.35 cm, Weight, 71.27±5.32 kg), and 3) tennis team players(Height, 175.48±3.38 cm, Weight, 72.72±4.53 kg), for a total of 120 males. Experiment 2 extended the research of Experiment 1. The same participants (N= 120) were randomly assigned to four groups, 1) a short racket and small face area group, 2) a medium racket and face area group, 3) a long racket and large face area group, and 4) a control group. In the time period of Experiment 1, each participant had to perform 6 tests of forehand skills performance at 9 racket types of task constraints. There were 9 constraints by the following multiplication: 3 racket lengths (65 cm, 68 cm, and 71 cm) X 3 face surface areas (95 inches2, 110 inches2, and 120 inches2). 6 tests at nine constraints make a total of 54 tests per participant. By doing this, we could measure their scores should be analyzed by the three-way ANOVA. The objective was to investigate the effect of different skill levels and task constraints on the performance of tennis forehand skills. In Experiment 2, the 4 groups described above entered a four-week training program composed of video feedback teaching and practice hitting. By doing this, we could measure their scores should be analyzed by the three-way ANOVA. This was in order to investigate whether skills performance under task constraints can be improved through the course of training. The results of this study show that: 1) Different skill levels and different task constraints to a certain extent impact the results and quality of tennis forehand skills performance. In addition, there was a trend towards more ideal performance at a racket length more appropriate to the individual. However, although there were obvious differences between rackets of different face areas, there was an uneven relationship between this variable and skills performance. As well, the various components involved in the action of a tennis forehand did not develop simultaneously. 2) There was a clear negative correlation between the absolute variance of forehand speed and accuracy under different racket task constraints, proving the thesis that there is exchanging between speed and accuracy. 3) In terms of the results and quality of skills performance for the different groups under different task constraints, following the film analysis feedback and the practice hitting training, the effectiveness of this training was clear. There was a trend towards improvement in the quality of skills performance for each individual extremity. However, the range of improvement was not the same for each group, showing that the development of the components of each action is not synchronous.

[[alternative]]The Effects of Foreperiods and Compatibility of Tennis Serve on

[[abstract]]本研究的主要目的在探討不同網球發球方向(相容性)及不同發球前期對接 發球者整體反應時間、反應時間與動作時間的影響。本研究的受試者為國 立臺灣師範大學體育系修習過網球課之慣用右手者男生50名，分別觀看由 一位甲組球員發網球的錄影帶，此影片係經專業人士處理後使畫面形成五 種不同的發球前期畫面及兩種不同的發球方向，每種發球方向及發球前期 各出現5 次的發球動作，因此所有的受試者共觀看50個發球畫面。受試者 在觀看每個發球畫面後，需先判斷發球方向後再往發球方向移動並按鍵， 以測試受試者的RT與MT。將所得資料分別以二因子重複量數變異數分析及 杜凱氏HSD 法事後比較進行統計分析，以驗證假設。經研究結果討論後， 得到如下的結論：一、在整體反應時間 (TRT)上，不同的網球發球方向與 不同的發球前期間有交互作用的關係存在。在不同的發球方向上，受試者 面對發向右邊時的 TRT比發向左邊時的 TRT快；在不同的前期上，受試者 在較適中的前期長度(2.5∼5秒) 能產生較快的 TRT，但在較短的前 期(1.5秒)和較長的前期(8秒) 則產生較慢的 TRT。二、在反應時間(RT) 上，不同的網球發球方向與不同的發球前期間無交互作用的關係存在，且 受試者面對不同發球方向時的RT亦沒有顯著不同；但在不同的發球前期上 ，受試者在較適中的前期長度(2.5∼5秒)能產生較快的RT，但在較短的前 期(1.5秒)和較長的前期(8秒)則產生較慢的RT。三、在動作時間(MT)上， 不同的網球發球方向與不同的發球前期間有交互作用的關係存在。在不同 的發球方向上，受試者面對發向右邊時的MT比發向左邊時的MT快；在不同 的前期上，MT受前期的影響較小，僅在發球方向是左邊時，於前期1.5秒 與2秒時的MT比前期8秒時的MT快。 The purpose of this study was to investigate the effects of variable foreperiods and compatibility of tennis serve on total response time(TRT),reaction time(RT) and movement time(MT).Forty right-handed males of National Taiwan Normal University in the Department of Physical Education were studied.Each subject separately watched the film in which one senior-level tennis player was serving a ball.This film had been processed by a professional person into tennis services of 5 variable foreperiods,2 different orientations and had totally 50 pictures for serving a ball.After watching a designated picture for serving a ball,the subject had to decide whether the ball would be served to the left or right side.Upon deciging,the subject would press a button indicating which side the ball would be served to.By doing this,we could measure theirRT and MT which should be analyzed separately by the two-way ANOVA and Tukey methtod.As the result of this study the following conclusions were reached: 1.In the TRT circumstance there were mutual functions in tennis service between different orientations and variable foreperiods.In the different orientations,the right side was significantly faster than the left on TRT.In variable foreperiods,the foreperiods of 2.5-5sec. was a significantly faster than 1.5 sec. and 8 sec. on TRT. 2.In the RT circumstance there were not mutual functions in tennis service between different orientations and variable foreperiods. Furthermore there was not significant different orientations of both the right and left sides.In variable foreperiods,the foreperiods of 2.5-5sec. was a significantly faster than 1.5 sec. and 8 sec. on RT. 3.In the MT circumstance there were mutual functions in tennis service between differentorientations and variable foreperiods.In the different orientations,the right side was significantly faster than the left on MT.In variable foreperiods,the effects had no significant difference on MT,only serving a ball in the direction of the left,the foreperiods of 1.5sec. and 2 sec. was a significantly faster than 8 sec. on MT. The purpose of this study was to investigate the effects of

Polyalthia Clerodane Diterpene Potentiates Hypoglycemia via Inhibition of Dipeptidyl Peptidase 4

Serine protease dipeptidyl peptidase 4 (DPP-4) is involved in self/non-self-recognition and insulin sensitivity. DPP-4 inhibitors are conventional choices for diabetic treatment; however, side effects such as headache, bronchus infection, and nasopharyngitis might affect the daily lives of diabetic patients. Notably, natural compounds are believed to have a similar efficacy with lower adverse effects. This study aimed to validate the DPP-4 inhibitory activity of clerodane diterpene 16-hydroxycleroda-3,13-dien-15,16-olide (HCD) from Polyalthia longifolia, rutin, quercetin, and berberine, previously selected through molecular docking. The inhibitory potency of natural DPP-4 candidates was further determined by enzymatic, in vitro Caco-2, and ERK/PKA activation in myocyte and pancreatic cells. The hypoglycemic efficacy of the natural compounds was consecutively analyzed by single-dose and multiple-dose administration in diet-induced obese diabetic mice. All the natural-compounds could directly inhibit DPP-4 activity in enzymatic assay and Caco-2 inhibition assay, and HCD showed the highest inhibition of the compounds. HCD down-regulated LPS-induced ERK phosphorylation in myocyte but blocked GLP-1 induced PKA expression. For in vivo tests, HCD showed hypoglycemic efficacy only in single-dose administration. After 28-days administration, HCD exhibited hypolipidemic and hepatoprotective efficacy. These results revealed that HCD performed potential antidiabetic activity via inhibition of single-dose and long-term administrations, and could be a new prospective anti-diabetic drug candidate