Trends In Height Research Articles

Trends of adult height in India from 1998 to 2015: Evidence from the National Family and Health Survey.

The aim of the study is to investigate the trends in adult height between two consecutive surveys of NHFS and explore differences across variables such as gender, wealth, social groups etc. We used the NFHS-II (1998-99), NFHS-III (2005-2006) and NFHS-IV (2015-16) (all three for women and last two for men) data to examine the trends in average height. Comparison was done between the two age strata of 15-25 and 26-50 years, across both male and female, to assess the trends. Between NFHS-III and NFHS-IV, the average height of women in the age group of 15-25 showed a decline by 0.12 cm [95% CI, -0.24 to 0.00, p-0.051] while in the 26-50 years age strata it demonstrated significant improvement in the mean height by 0.13 cm [95% CI, 0.02 to 0.023, p-0.015]. However, Between NFHS III and IV, the average height of women in the poorest wealth index category registered a significant decline [-0.57cm, 95% CI, -076 to -0.37, p-0.000]. Between NFHS III and IV, the average height of Scheduled Tribe (ST) women in the age group of 15-25 years also exhibited a significant decline by 0.42 cm, [95% CI, -0.73 to -0.12, p-0.007]. Among men, between the two surveys, both the age groups of 15-25 years and 26-50 years showed significant decline in average height: 1.10 cm [95% CI, -1.31 to -.099 cm, p-0.00] and 0.86 cm [95% CI, -1.03 to -0.69, p-0.000], respectively. In the context of an overall increase in average heights worldwide the decline in average height of adults in India is alarming and demands an urgent enquiry. The argument for different standards of height for Indian population as different genetic group needs further scrutiny. However, the trends from India clearly underline the need to examine the non-genetic factors also to understand the interplay of genetic, nutritional and other social and environmental determinants on height.

Trends of Planetary Boundary Layer Height Over Urban Cities of China From 1980–2018

Boundary layer height (BLH) is an important parameter in climatology and air pollution research, especially in urban city. We calculated the BLH with a bulk Richardson number (Ri) method over urban cities of China during 1980–2018 using European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-interim data after carefully validation with sounding data obtained from two meteorology stations in eastern China during 2010–2018. The values of BLH between these two types of data have correlation coefficients in the range of 0.65–0.87, which indicates that it is reasonable to analyze long-term trends of the BLH from ERA data sets. Using ERA-interim calculated BLH, we found that there is an increasing trend in the daytime BLH in most cities of eastern China, particularly during the spring season. A correlation analysis between the BLH and temperature, wind speed, relative humidity and visibility revealed that the variability in meteorological parameters, as well as in aerosol concentrations over highly polluted eastern China, play important roles in the development of the BLH.

Strong extratropical cyclone generated ocean swells in the Northern Pacific from modeling and in-situ observations on the Hawaiian Islands

The Northern Pacific Ocean swell environment is generated by extratropical cyclones originating at mid-latitude regions that travel thousands of miles, unimpeded, across the Pacific Ocean. Some of these massive swells reach the Hawaiian Islands causing damage to the shoreline and coastal infrastructure. Understanding the cause and relation between extratropical (EX) cyclone trends and associated swells that affect the Hawaiian Islands is essential towards coastal mitigation from destructive flooding. The strong EX-cyclogenesis events are detected from the atmospheric reanalysis dataset during 1979–2017 and are used to hindcast swells in the North Pacific domain using modeling and in situ observations. Our results show a rise in the number and intensity of strong EX-cyclones during 1979–2017, and this increase accelerates during 2007–2017. The deseasonalized and Thiel–Sen trends show that poleward and westward movement and increment in the frequency of strong EX-cyclones cause a significant rise in swell generation and intensity during 2007–2017. Almost one-third of the strong EX-cyclone-generated waves reach the Hawaiian Islands during 1979–2017 and one-quarter of it during 2007–2017.​ The deseasonalized maximum daily significant wave height and peak period trend slightly decreased during 1979–2017; however, it significantly increased during 2007–2017. These trends show similarity with El Niño-Southern Oscillation events, which affect the EX-cyclone pattern.

Examining the characteristics of planetary boundary layer height and its relationship with atmospheric parameters over Indian sub-continent

Planetary boundary layer plays a critical role in the monsoon circulation studies at regional scales through exchange of land surface fluxes (heat and moisture) with atmosphere. The objective of the present study is to identify the spatial variability of long-term seasonal trends of planetary boundary layer height (PBLH) over Indian subcontinent and its association with atmospheri parameters. Monthly atmospheric boundary layer height data obtained from European centre for medium range weather forecast ERA-5 reanalysis has been used for the study during 1980–2018. Statistically robust non-parametric Mann Kendall test is used to investigate the significance of trend at 95% confidence interval. From the results it has been observed that decreasing trend for PBLH is noticed during pre-monsoon and monsoon seasons over Indian region. PBLH over central and north-west India is deeper (1600–1800 m) during pre-monsoon season whereas PBLH is shallow during other seasons. Seasonal variation of PBLH shows a strong negative association with the relative humidity (r more than −0.8) whereas it shows strong positive association with surface temperature (r > 0.7) and surface zonal winds (r > 0.5) over Indian subcontinent. Evaporative fraction which acts as a dominant controlling factor for the variation in PBLH is positively associated (r > 0.7) with the PBLH during monsoon season. Decreasing trend of PBLH during monsoon season may be attributed to the decrease in latent heat flux and increase in relative humidity that results in entrap of moisture at lower levels and may enhance the formation of extreme events. Inter annual variability of PBLH over Indian subcontinent demonstrates in-phase relationship with the deficit and excess monsoon years. Further to this, PBLH is found to be strongly negatively correlated with PM2.5 (r more than −0.5) during pre-monsoon and monsoon seasons suggesting an opposite phase relationship between the two parameters.

Impact of Thermohaline Variability on Sea Level Changes in the Southern Ocean

AbstractThe Southern Ocean is responsible for the majority of the global oceanic heat uptake that contributes to global sea level rise. At the same time, ocean temperatures do not change at the same rate in all regions and sea level variability is also affected by changes in salinity. This study investigates 10 years of steric height variability (2008–2017) in the Southern Ocean (30°S to 70°S) by analyzing temperature and salinity variations obtained from the GLORYS‐031 model provided by the European Copernicus Marine Environment Monitoring Service. The thermohaline variability is decomposed into thermohaline modes using a functional Principal Component Analysis. Thermohaline modes provide a natural basis to decompose the joint temperature‐salinity vertical profiles into a sum of vertical modes weighted by their respective principal components that can be related to steric height. Interannual steric height trends are found to differ significantly between subtropical and subpolar regions, simultaneously with a shift from a thermohaline stratification dominated by the first “thermal” mode in the north to the second ’saline’ mode in the South. The Polar Front appears as a natural boundary between the two regions, where steric height variations are minimized. Despite higher melt rates and atmospheric temperatures, steric height in Antarctic waters (0–2,000 m) has dropped since 2008 due to higher salt content in the surface and upper intermediate layer and partially colder waters, while subtropical waters farther north have mostly risen due to increased heat storage.

민족 간 신장 차이와 Bergmann법칙의 적용 가능성

Bergmann’s rule(Bergmann, 1847)states that homeothermic animals that live in colder regions such as Northern Europe have larger body sizes with smaller surface area in proportion to body weight in order to minimize heat dissipation. Conversely, in tropical regions body surface area is larger to maximize heat dissipation. For this, shorter heights are advantageous. As to whether this rule applies to humans, surveys of peoples living in cold and tropical regions of the world show that heights tend to be taller in the north and shorter in the south, but simplistic application of Bergmann’s rule cannot always be done in recent years. This is from the effect on physical development of socioeconomic growth in recent years. In the Netherlands, for example, Bergmann’s rule does not apply to height. If one looks only at recent years in this way, a human environmental bias from socioeconomic development is seen and so judgments cannot be made with height alone in each country of Europe today. This human environmental bias can be eliminated applying the secular trend standardization chart for height proposed in this study. Judging the changes in height over the span of about 120 years from 1860 to 1980 with this method allows for evaluation of the height trends in countries located in Northern, Central, and Southern Europe. Heights can then be conveniently explained with Bergmann’s rule. Of course, scientific verification of Bergmann’s rule remains a task for the future.

Trends in Body Height, Body Weight, BMI, and Nutrition Status from 1979 to 1987: A Measurement-Based Analysis of 10,954 Male Adolescents from the Municipality of Bijelo Polje

Trends in Body Height, Body Weight, BMI, and Nutrition Status from 1979 to 1987: A Measurement-Based Analysis of 10,954 Male Adolescents from the Municipality of Bijelo Polje

Effects of Coated Cysteamine on Oxidative Stress and Inflammation in Weaned Pigs.

Simple SummaryOxidative stress and inflammation are common problems in livestock and poultry production, and have a serious impact on animal welfare and profitability. Finding an effective way to deal with oxidative stress and inflammation is an urgent problem for the modern pig industry. Cysteamine has been shown to play a crucial role in the growth performance, digestive metabolism, immune function, and fecundity of animals. In this study, we found that dietary supplementation of coated cysteamine could enhance the level of immunoglobulin and the expression of intestinal immune factors in the weaned pigs induced by diquat. It is proved that dietary supplementation with coated cysteamine can improve the intestine barrier function and immune function.This study aimed to explore the effects of dietary coated cysteamine on oxidative stress and inflammation in diquat-induced weaning pigs. Twenty-four pigs were randomly assigned to three dietary groups with eight replicates: the control (fed base diet), diquat (fed base diet), and coated cysteamine + diquat groups (fed 80 mg/kg cysteamine). The experiment was conducted for 21 d, and consisted of a pre-starter period (14 d) and a starter period (7 d). Coated cysteamine treatment significantly increased (p < 0.05) the final weight and average daily gain (ADG) in pigs. The contents of alkaline phosphatase (ALP), immunoglobulin G (IgG), serine (Ser), and isoleucine (Ile) were elevated (p < 0.05) while the contents of albumin (ALB) and aspartic acid (Asp) were reduced (p < 0.05) in the serum after coated cysteamine supplementation. Coated cysteamine supplementation resulted in greater (p < 0.05) serum superoxide dismutase (SOD) activity, the expression of interleukin-10 (IL-10) mRNA in the colon, and the CuSOD mRNA expression in the jejunum (p < 0.05) and colon (p = 0.073). Coated cysteamine supplementation showed an increasing trend in villus height (p = 0.060), villus height/crypt depth (V/C) (p = 0.056), the expression levels of zonula occludens-1 (ZO-1) mRNA (p = 0.061), and Occludin mRNA (p = 0.074) in the jejunum. In summary, dietary supplementation with coated cysteamine improves the intestinal barrier function of the jejunum by increasing the immunoglobulin content and the relative expression of intestinal immune factor mRNA in pigs while alleviating oxidative stress and inflammatory reactions caused by diquat.

The age at which adult height is achieved during adolescence in the Birth to Twenty Cohort, Johannesburg, South Africa

Background. The core of the study involves comparing the secular trends in height among self-reported black and white racial groups in South Africa (SA). The white group represents that part of the population that has always been affluent and therefore has growth trends comparable with those of developed nations of the world. In comparing the groups, we wanted to see the extent to which the black population has caught up, if it all, since the introduction of democracy in 1994. Objectives. To establish the age at which linear growth plateaus; to compare the age of growth cessation and the achieved adult height between sexes and racial groups in SA; and to compare data from the Bone Health Cohort with previous similar studies to ascertain the secular trend. Methods. We analysed prospective data of 569 individuals who had annual anthropometric assessments from age nine until 20 years (1999 - 2010). The SuperImposition by Translation and Rotation (SITAR) statistical programme was used to model height and age at growth cessation. Results. There was a total of 183 black females, 93 white females, 205 black males and 88 white males. Black and white females achieved adult height at a similar age (15.1 and 15.3 years), but black females were 5.7 cm shorter. Black and white males achieved their adult height at 17.5 and 16.5 years, respectively, black males being 4.6 cm shorter. Mean adult black male height is currently 170.7 cm v. 166.9 cm in 1971, while there were no significant secular changes in the other groups. Conclusions. There has been a positive secular growth trend in height over 30 years among black males, but no changes in the other groups.

An analysis of high‐resolution modelled wave heights along the South African south coast suggests recent deterioration of sea state

AbstractUnderstanding climate variability and change together with fishing activities through high‐resolution scientific information and local observations can help implement and sustain improved coastal marine management strategies. Ethnographic data collected between 2010 and 2016 during previous studies with traditional handline fishers on South Africa's south coast suggest that fishers recently observed a deterioration in sea state and a reduction in sea days. Many fishers attributed this deterioration to increased climate variability. The fishers also suggested experiencing increased difficulty when leaving the nearshore through river mouths due to higher waves and stronger winds. The current study investigated these oceanic changes in terms of wave height variability and trends, using high resolution modelled wave data of the south coast for the period 1997–2013. Considering the fishers' perspectives, wave heights near their main launch sites during their main fishing season (austral summer) were focussed on. During the mid‐to‐late 2000s, a positive regime shift of summer nearshore wave heights occurred along the south coast and a statistically significant positive trend in summer nearshore wave heights occurred during the study period. These results support the local fishers’ observations suggesting that the sea state had been deteriorating, in terms of higher summer nearshore waves. While the magnitude of the observed change is not critical to small‐boat fisheries in the area at present, it may contribute to the decrease in available sea days and hence, adds to the stressors in the commercial and small‐scale sectors, further increasing their vulnerability to change.

Response of extreme significant wave height to climate change in the South China Sea and northern Indian Ocean

Abstract The frequency of extreme wave events is increasing with climate change. The temporal and spatial variations of extreme wave height affect both human livelihood and the usage of ocean resources. The South China Sea and northern Indian Ocean both support coastal communities of high population density, with varied terrain structures and extreme wind and wave systems. This study focuses on the temporal and spatial variations of the extreme significant wave height in the South China Sea and northern Indian Ocean. Using nonstationary generalized extreme value analysis, trends for a 100-year return period of significant wave height were obtained for both. The most rapid increase in the 100-year return was found to be 0.015 m yr-1 in the northern South China Sea and in the Arabian Sea; however, the 100-year return significant wave height fell in the mouth of the Bay of Bengal. After analyzing the possible causes and influence factors, we found that the increase in significant wave height in the northern South China Sea was dominated by local wind-waves and similarly, the Arabian Sea was affected by swell. The NINO3.4 index shows good correlation with the significant wave height in the northern South China Sea because typhoons are related to NINO3.4 in this area. The trends of the extreme wave height in the Arabian Sea and southern Bay of Bengal have good correlations with the South Asian summer monsoon index.

Longitudinal Association of Economic Growth with Lung Function of Chinese Children and Adolescents over 30 Years: Evidence from Seven Successive National Surveys.

(1) Background: Recent studies reported that decrease in lung function of Chinese children and adolescents continues to decline, although the change has been insignificant and has reached a plateau. However, studies have not explored the relationship between lung function and economic development in China. This study sought to explore the longitudinal association between socio-economic indicators and lung function; (2) Method: Data were obtained from seven successive national surveys conducted by the Chinese National Survey on Students’ Constitution and Health from 1985 to 2014. Lung function of school-age children (7–22 years) was determined using forced vital capacity (FVC). GDP per capita and urbanization ratio were used as economic indicators. A fixed-effects model was employed to examine the longitudinal association after adjusting for height, weight, and time trends; (3) Results: Socio-economic indicators showed a U-curve relationship with lung function of boys and girls from urban and rural areas. Lung function initially decreased with GDP per capita or urbanization ratio and reached a minimum. Lung function then increased with increase in GDP per capita or urbanization ratio. The findings indicate that the relationship between economic growth and lung function is different in different development stages. In less-developed provinces, economic growth was negatively correlated with lung function, whereas, in developed provinces, economic growth was positively correlated with lung function; (4) Conclusion: The findings of the current study show that economic growth has significantly different effects on lung function at different economic levels. Therefore, governments should improve lung health in children and adolescents from low and middle economic regions.

Regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014

Objective: To analyze the regional inequality of height among Chinese Han students aged 7 to 18 years from 1985 to 2014. Methods: The Chinese Han students aged 7 to 18 years with complete basic information and height data from 30 mainland provinces (excluding Hong Kong, Macao, Taiwan and Tibet in China) were extracted as participants from 6 successive cross-sectional surveys of the Chinese National Survey on Student's Constitution and Health (CNSSCH). After excluding extreme and illogical cases, a total of 1 495 182 students were included in the analysis. The data of gross domestic product (GDP) per capita of each province at each survey year were collected from the website of National Bureau of statistics of China. Mann-Kendall trend test was used to analyze the trend of mean height across years. Weighted linear regression model was used to analyze the association between mean height of students aged 7 to18 years and GDP per capita at provincial level. Height difference, height ratio, slope index of inequality (SII) and relative index of inequality (RII) were used to measure the height inequality by gender and age groups. Results: The mean height of Chinese Han students aged 7 to 18 years increased from 144.9 cm in 1985 to 151.8 cm in 2014 (P<0.05). The height difference between urban and rural students in all age groups was reducing (P<0.05). The height difference between urban and rural boys aged 13 to 15 years decreased from 5.3 cm in 1985 to 2.5 cm in 2014, and the difference between urban and rural girls aged 7 to 12 years decreased from 4.6 cm in 1985 to 2.4 cm in 2014. The mean height of students aged 7 to 18 years was positively associated with GDP per capita in all survey years for both genders (P<0.001). Taking Shanghai and Guizhou as the representatives of economically developed and underdeveloped provinces, from 1985 to 2014, the height differences between two provinces were 6.8-9.2 cm, 8.0-12.4 cm and 6.3-8.8 cm for boys aged 7 to 12 years, 13 to 15 years and 16 to 18 years, respectively, and the height ratios were stable at 1.05-1.07, 1.05-1.08 and 1.04-1.05 respectively. From 1985 to 2014, the SII of mean height for boys in three age groups were 4.4-6.2, 4.9-6.7 and 2.5-4.7, respectively. The RII of mean height of boys in three age groups were 1.03-1.05, 1.03-1.04 and 1.01-1.03, respectively. In the same period, the SII of mean height for girls in three age groups were 4.2-6.2, 2.8-4.5 and 2.5-3.9, and the RII were 1.03-1.05, 1.02-1.03 and 1.02, respectively. Conclusion: From 1985 to 2014, the urban-rural inequality of height development among Chinese Han students aged 7 to 18 years was narrowing, but the socio-economic inequality of height persisted and remained at a relatively stable level.

Regulatory measures significantly reduced air-pollutant concentrations in Seoul, Korea

The Government of the Republic of Korea has enforced strict regulations to improve air quality since the early 2000s. The regulations are mainly focused on reducing vehicle emissions in the Seoul metropolitan region by conforming to the European emissions standards, replacing diesel buses with compressed natural gas buses, incentives for installing diesel exhaust after-treatment systems and buying eco-friendly vehicles. There was a 20% reduction in 2010s compared to the 2000s in terms of the mean concentrations of particulate matter (PM) with mean aerodynamic diameters of ≤10 μm (PM10) and 2.5 μm (PM2.5) during cold seasons (October through following February) although the decrease may not be entirely attributable to the regulations. The influences of other external factors such as transboundary transport of air pollutants and regional meteorological conditions cannot be neglected.This study analyzes the change in the diurnal variations—two maxima at around 11 and 22 local time (LT) and two minima at around 6 and 16 LT—of air pollutant concentrations that may be closely related to the regulatory action in reducing local vehicle emissions. A reduction of over 40% for the amplitude of two PM concentrations at 11 LT was revealed when values from the 2010s were compared to those from the 2000s. There was a similar reduction for other vehicle exhaust gases including nitrogen dioxide, carbon monoxide, and sulfur dioxide. Additional analysis of the long-term trend in mixed layer height and surface wind speed showed that the change in environmental conditions in the diurnal time scale was either negligible or unfavorable for conditions which reduce PM concentrations. This study suggests that the mean concentration estimation may underestimate the regulatory effects, but the approach based on the diurnal variation may be a more accurate indicator.

Determination of Manganese in Human Whole Blood with Indium Tin Oxide Electrochemical Point-of-Care Sensor

Manganese (Mn) is one of the most common elements in the earth’s crust, and its compounds are widely used in consumer products including gasoline, cell phone batteries, fertilizer, pigments, fireworks, etc. Although a trace metal in the human body and under tight homeostatic control, elevated levels of Mn due to occupational or environmental exposure can cause serious adverse health effects, such as manganism (a Parkinsonian-like syndrome), liver cirrhosis, and Behcet disease. The normal range of Mn in blood is 4.7-18.3 µg/L (5-20 ppb), and values greater than 36 µg/L correlate with disease. The current method for analyzing Mn in blood is via inductively coupled plasma mass spectrometry (ICP-MS) in centralized labs, which requires a venipuncture sample, can take 3-6 months for analyses, and can be costly. Electrochemical analysis can offer an attractive alternative, leading to developing a point-of-care system for Mn monitoring in blood, with the advantages of being inexpensive and easily miniaturized. Herein, we report the first Indium Tin Oxide (ITO) electrochemical microsensor capable of accurately measuring Mn levels in human blood with cathodic stripping voltammetry (CSV). As shown in Fig. 1 (a), the ITO microsensor was developed by integrating a screen-printed carbon auxiliary electrode and an Ag/AgCl reference electrode on an ITO coated glass slide (1 cm × 4 cm). A circular ITO film with 3 mm diameter was exposed and used as the working electrode. To start electrochemical analysis, blood sample was first microwave digested with nitric acid and hydrogen peroxide to release Mn2+ bound to the proteins. The acid-digested blood sample was then titrated with sodium hydroxide to pH 5. Square wave cathodic stripping voltammetry (SWCSV) with optimized parameters was carried out to construct the calibration curve in the digested & pH adjusted blood sample with the Mn concentration ranging from 1.2 ppb to 25 ppb (confirmed by ICP-MS). The voltammogram in Fig. 1(b) shows an increasing trend of peak height and area with Mn concentration; and the calibration curve in Fig. 1(c) shows a sensitivity of 38.6 nC/ppb and linearity of 0.997 from the sensor’s measurements. We used the same stripping parameters, while applying a 3-point standard addition method, to determine the Mn concentration in two blood samples. The concentrations of 10.5 ppb and 26.3 ppb from our measurements lead to an average accuracy of 90% in comparison to the ICP-MS results of 8.9 ppb and 27.6 ppb. Four 150 µl sample droplets with a total volume of 600 µl were used in the measurement. Considering the 10X dilution from the blood digestion and pH adjustment process, only 60 µl of whole blood is needed to determine the Mn level with our approach. The favorable results and the small blood volume required in this work suggests the feasibility of point-of-care monitoring Mn in blood and is expected to be very useful for monitoring Mn exposure in vulnerable populations like children. Figure 1

Long-term spatio-temporal trends in extreme wave events in the Niger delta coastlines.

Wave climate in the marginal seas and estuaries provide baseline information, risk assessments and essential insight into coastal design, structure and engineering projects. This paper investigates the Spatio-temporal trends in extreme Significant Wave Height (SWH) in the Niger Delta coastlines. For the study domain, European Centre for Medium-Range Weather Forecasts (ECMWF) global atmospheric reanalysis ERA-Interim and wave hindcast data covering 37 years (January 1, 1980–December 31, 2016), derived from WAVEWATCH III (WW3) model were used in the analysis. The largest 99th percentile approach was used to analyze extreme SWH values. Results showed near neutral and negative trends over the region. The trends are generally insignificant for the 100-year return period. The sharp variation in extreme SWH between 1998 and 2000 resulted from a strong El Nino and La Nina phenomenon, which is associated with the weakening and strengthening of the West-African Monsoon.

Modeling and statistical analysis of distribution parameters of random cable bundles based on image recognition technology

In this paper, a modeling method of actual bending random bundled wire harness is proposed. Firstly, based on image recognition technology, the three-dimensional coordinates of bending wire harness axis are reconstructed by using two photos of actual wire harness in side view and top view; then the random bundled wire harness is realized based on random transfer path method. Based on this modeling method, this paper analyzes the statistical characteristics of distribution parameters of bending random wire harness by Monte Carlo simulation, and finds that the variation trend of self inductance, mutual inductance and mutual capacitance along the line is consistent with the variation trend of wire harness height, while the trend of self capacitance is opposite; the coefficient of variation of self capacitance, self inductance and mutual inductance has negative correlation with wire harness height; the bundling randomness is not obvious It will change the mean value of self inductance and self capacitance, but reduce the mean value of mutual capacitance and mutual inductance.

Gender difference in secular trends of body height in Chinese Han adolescents aged 18 years, 1985-2014

Objective: To analyze the gender difference in secular trends of body height in Chinese Han adolescents aged 18 years from 1985 to 2014. Methods: Data were extracted from 1985, 1995, 2000, 2005, 2010 and 2014 Chinese National Surveys in Students' Constitution and Health. A total of 124 099 Chinese Han adolescents aged 18 years were included in the analysis. ANOVA test was used to compare the body height between different subgroups stratified by gender and the mean difference and ratio in body height were calculated. Quantile regression model was used to assess the association between body height and gender over time in the adolescents stratified by region or area. Results: The mean body height of adolescents aged 18 years increased significantly from 1985 to 2014 with the rate of 1.3 cm/decade in male adolescents and 0.8 cm/decade in female adolescents, and the highest increment occurred from 1995 to 2005 in both groups. Male adolescents were taller than female adolescents at each subgroup (P<0.05). Gender difference in body height increased from 11.1 cm in 1985 to 12.6 cm in 2014 and ratio remained to be 1.07-1.08. The body height was taller in adolescents in urban area than in rural area (P<0.05) and in northeastern China than in other regions (P<0.05) in both male and female adolescents. The body height of obese male adolescents had been taller since 2000 and the body height of obese female adolescents had been taller since 2010 than other groups. When adjusted for urban-rural areas, region, socioeconomic status and nutritional status, the body height increased over time at P5, P25, P50, P75 and P95 in both male and female adolescents, and the increments of gender difference in body height at different percentile ranged from 0.45 cm/decade to 0.57 cm/decade. When stratified by region, the gender difference in body height showed similar trend with total sample except P5 and P95 in northeastern China, the difference of increments were not significant. Conclusions: From 1985 to 2014, the gender difference in body height of Chinese Han adolescents aged 18 years increased, and male adolescents showed greater increase than female adolescents. Moreover, the adolescents in northeastern and eastern China had larger increment in body height. It is necessary to paid more attention to the adolescents in central and western China to promote their physical development.

Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VII. The Stellar Disk Structure Revealed by the Mono-abundance Populations

Abstract Using a sample of 96,201 primary red clump stars selected from the LAMOST and Gaia surveys, we investigate the stellar structure of the Galactic disk. The sample stars show two separated sequences of high-[α/Fe] and low-[α/Fe] in the [α/Fe]–[Fe/H] plane. We divide the sample stars into five mono-abundance populations (MAPs) with different ranges of [α/Fe] and [Fe/H], named as the high-[α/Fe], high-[α/Fe] and high-[Fe/H], low-[Fe/H], solar, high-[Fe/H] MAPs, respectively. We present the stellar number density distributions in the R–Z plane, and the scale heights and scale lengths of the individual MAPs by fitting their vertical and radial density profiles. The vertical profiles, the variation trend of scale height with the Galactocentric radius, indicate that there is a clear disk flare in the outer disk both for the low-[α/Fe] and the high-[α/Fe] MAPs. While the radial surface-density profiles show a peak radius of 7 kpc and 8 kpc for the high-[α/Fe] and low-[α/Fe] MAPs, respectively. We also investigate the correlation between the mean rotation velocity and metallicity of the individual MAPs, and find that the mean rotation velocities are well separated and show different trends between the high-[α/Fe] and the low-[α/Fe] MAPs. Finally, we discuss the character of the high-[α/Fe] and high-[Fe/H] MAP and find that it is more similar to the high-[α/Fe] MAP either in the radial and vertical density profiles or in the rotation velocity.

The Contribution of Internal Variability to Asian Midlatitude Warming

AbstractThe tropospheric warming in the Northern Hemisphere (NH) midlatitudes has been an important factor in regulating weather and climate since the twentieth century. Apart from anthropogenic forcing leading to the midlatitude warming, this study investigates the possible contribution of internal variability to Asian midlatitude warming and its role in East Asian circulation changes in boreal summer, using four reanalysis datasets in the past century and a set of 1800-yr preindustrial control simulations of the Community Earth System Model version 1 large ensemble (CESM-LE). The surface and tropospheric warming in the Asian midlatitudes is associated with a strong upper-level geopotential height rise north of the Tibetan Plateau (TP). Linear trends of 200-hPa geopotential height (Z200) confirm a dipole of an anomalous high north of the TP and an anomalous low over the Iranian Plateau in 1958–2017. The leading internal circulation mode bears a striking resemblance to the Z200 trend in the past 60 and 111 years, indicating that the long-term trend may be partially of internal origin. The Asian midlatitude warming is also found in preindustrial simulations of CESM-LE, further suggesting that internal variability explains at least part of the temperature change in the Asian midlatitudes, which is in a chain of wave trains along the NH midlatitudes. The Asian warming decreases the meridional gradient of geopotential height, resulting in the weakening of westerly winds over the TP and the TP thermal forcing. Thus, it is essential to consider the role of internal variability in shaping East Asian surface temperature and East Asian summer monsoon changes in the past decades.