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Research Findings: Few studies have examined second-born preschool children's empathy development under China's universal two-child policy. The purpose of this study was to explore the differences in empathy between Chinese preschool children with one older sibling and without siblings. A total of 180 children were purposively sampled from 14 preschools in Beijing to participate in the study, including 90 only children and 90 second-born children. We conducted tasks with children individually to assess their emotional empathy. The results suggest that second-born children exhibited higher levels of empathy than only children after controlling for demographic characteristics. Specifically, empathy of second-born children was significantly higher than that of only children in response to three emotions (i.e., sadness, fear, and anger). Practice or Policy: This study highlights the benefit of growing up with siblings. Interactions and relationships with siblings can enhance children's empathy. We should provide more opportunities and intentional instructions for only children to interact with and get along with peers. [ABSTRACT FROM AUTHOR]

Airborne particulate matter (PM) was collected in Beijing between 24 February and 12 March 2014 to investigate chemical characteristics and potential industrial sources of aerosols along with health risk of haze events. Results showed secondary inorganic aerosol was the major contributor to PM 2.5 during haze days. Utilizing specific elements, including Fe, La, Tl and As, as fingerprinting tracers, four emission sources, namely iron and steel manufacturing, petroleum refining, cement plant, and coal combustion were explicitly identified; their elevated contributions to PM during haze days were also estimated. The average cancer risk from exposure to inhalable PM toxic metals was 1.53 × 10 −4 on haze days, which is one order of magnitude higher than in other developed cities. These findings suggested heavy industries emit large amounts of not only primary PM but also precursor gas pollutants, leading to secondary aerosol formation and harm to human health during haze days. [ABSTRACT FROM AUTHOR]

The seasonal variations of raindrop size distribution (DSD) and rainfall are investigated using three-year (2016–2018) observations from a two-dimensional video disdrometer (2DVD) located at a suburban station (40.13° N, 116.62° E, ~30 m AMSL) in Beijing, China. The annual distribution of rainfall presents a unimodal distribution with a peak in summer with total rainfall of 966.6 mm, followed by fall. Rain rate (R), mass-weighted mean diameter (Dm), and raindrop concentration (Nt) are stratified into six regimes to study their seasonal variation and relative rainfall contribution to the total seasonal rainfall. Heavy drizzle/light rain (R2: 0.2~2.5 mm h−1) has the maximum occurrence frequency throughout the year, while the total rainfall in summer is primarily from heavy rain (R4: 10~50 mm h−1). The rainfall for all seasons is contributed primarily from small raindrops (Dm2: 1.0~2.0 mm). The distribution of occurrence frequency of Nt and the relative rainfall contribution exhibit similar behavior during four seasons with Nt of 10~1000 m−3 registering the maximum occurrence and rainfall contributions. Rainfall in Beijing is dominated by stratiform rain (SR) throughout the year. There is no convective rainfall (CR) in winter, i.e., it occurs most often during summer. DSD of SR has minor seasonal differences, but varies significantly in CR. The mean values of log10Nw (Nw: mm−1m−3, the generalized intercept parameter) and Dm of CR indicate that the CR during spring and fall in Beijing is neither continental nor maritime, at the same time, the CR in summer is close to the maritime-like cluster. The radar reflectivity (Z) and rain rate () relationship (Z = R) showed seasonal differences, but were close to the standard NEXRAD Z-R relationship in summer. The shape of raindrops observed from 2DVD was more spherical than the shape obtained from previous experiments, and the effect of different axis ratio relations on polarimetric radar measurements was investigated through T-matrix-based scattering simulations. [ABSTRACT FROM AUTHOR]

The determination of both stable nitrogen (δ15N–NO 3 -) and stable oxygen (δ18O–NO 3 -) isotopic signatures of nitrate in PM 2.5 has shown potential for an approach of assessing the sources and oxidation pathways of atmospheric NO x (NO+NO 2). In the present study, daily PM 2.5 samples were collected in the megacity of Beijing, China during the winter of 2017–2018, and this new approach was used to reveal the origin and oxidation pathways of atmospheric NO x. Specifically, the potential of field δ15N–NO 3 - signatures for determining the NO x oxidation chemistry was explored. Positive correlations between δ18O–NO 3 - and δ15N–NO 3 - were observed (with R 2 between 0.51 and 0.66, p < 0.01), and the underlying environmental significance was discussed. The results showed that the pathway-specific contributions to NO 3 − formation were approximately 45.3% from the OH pathway, 46.5% from N 2 O 5 hydrolysis, and 8.2% from the NO 3 +HC channel based on the δ18O-δ15N space of NO 3 −. The overall nitrogen isotopic fractionation factor (εN) from NO x to NO 3 − on a daily scale, under winter conditions, was approximately +16.1‰±1.8‰ (consistent with previous reports). Two independent approaches were used to simulate the daily and monthly ambient NO x mixtures (δ15N-NO x), respectively. Results indicated that the monthly mean values of δ15N-NO x compared well based on the two approaches, with values of −5.5‰ ± 2.6‰, −2.7‰ ± 1.9‰, and −3.2‰ ± 2.2‰ for November, December, and January (2017–2018), respectively. The uncertainty was in the order of 5%, 5‰ and 5.2‰ for the pathway-specific contributions, the εN, and δ15N-NO x , respectively. Results also indicated that vehicular exhaust was the key contributor to the wintertime atmospheric NO x in Beijing (2017–2018). Our advanced isotopic perspective will support the future assessment of the origin and oxidation of urban atmospheric NO x. [Display omitted] • Positive correlations between δ18O–NO 3 - and δ15N–NO 3 - were observed in PM 2.5 during winter in Beijing. • Contribution of daytime (45.3%) and nocturnal channels (54.7%) to NO 3 − formation was comparable. • The mean nitrogen isotopic fractionation factor from NO x to NO 3 − in winter Beijing was +16.1‰ ±1.8‰. • Vehicular exhaust dominated the wintertime NO x emissions in Beijing. [ABSTRACT FROM AUTHOR]

Rapid accumulation of aerosol nitrate (NO 3 −) contributes to haze pollution; however, studies quantifying NO 3 − formation mechanisms remain scarce. To explore aerosol nitrate formation pathways, total suspended particulate (TSP) samples were collected in Beijing during the spring of 2013, and the concentration of NO 3 − and δ18O- NO 3 − value were analyzed. The NO 3 − concentrations on polluted days (PD) were higher than those on non-polluted days (NPD). Furthermore, higher δ18O- NO 3 − values were observed on PD (86.8 ± 8.1‰) as compared with NPD (73.7 ± 11.0‰) suggest that more nitrate was produced by pathways with relative high δ18O–HNO 3 values during PD. Based on the calculated δ18O–HNO 3 values from different formation pathways and the observed δ18O- NO 3 − values, the possible fractional contributions of HNO 3 formed via various pathways to TSP NO 3 − were estimated using the Bayesian isotope mixing model. The δ18O- NO 3 − constrained calculations suggest that the pathways of N 2 O 5 + H 2 O/Cl−, NO 3 + VOCs, and ClNO 3 + H 2 O possibly contributed 53%–89% to nitrate production during PD. During NPD, the NO 2 + OH pathway produced 37%–69% of the NO 3 −. Using the δ18O- NO 3 − value combined with the isotope mixing model is a promising approach for exploring NO 3 − formation pathways. Image 1 • Higher δ18O- NO 3 − values were observed on polluted days than non-polluted days. • Oxygen isotopic equilibrium fractionation between NO x and O 3 affect δ18O–HNO 3 value. • Less contributions of NO 3 − were produced by the NO 2 + OH pathway on PD than NPD. [ABSTRACT FROM AUTHOR]

This paper analyzes the characteristics of rain drop size distributions (DSDs) and vertical profiles of hydrometeors for a severe rainstorm event that occurred in Beijing, northern China, from 19 to 21 July 2016 using in situ measurements from two disdrometers (OTT-Parsivel2 and 2D-Video-Distrometer) and remote sensing data collected by a second-generation Micro Rain Radar (MRR2). This rainstorm was characterized by stratiform precipitation with embedded strong convection on 19 July and widespread, intense mixed convective-stratified rainfall resulting in persistent rainfall between 20 and 21 July. The temporal and spatial variations in rainfall rate R , liquid water content W , reflectivity Z , DSDs and the gamma DSD parameters in different precipitation episodes of this event are derived and compared between two meteorological stations in Beijing. Rainfall throughout the entire event was characterized by large concentrations of small- to medium-sized raindrops (diameters between 2 and 4 mm) and few larger particles (D > 4 mm), resulting in small values of reflectivity Z (<40 dBZ) and liquid water content W (<1.0 g m−3). In addition, the log 10 N w -D m scatter pairs recorded during the convective phase of this rainstorm indicate maritime-like convection. The time evolution of DSDs shows that most single peak DSDs occurred during stratiform rainfall, and bimodal DSDs were observed when the convective rainfall cells passed by and collisional breakups occurred. The gamma DSD model with a single peak in the stratiform phase of the storm and the bimodal DSD in the convective episode of the storm are quantitatively evaluated. In addition, in each precipitation episode, the differences in exponent b and coefficient A of the Z - R relationship between the two stations are smaller for stratiform rainfall than for convective rainfall due to the more evident variability of drop size and number concentration in convective rain. The physical nature of this relationship and the possible mechanisms leading to diverse characteristics in different phases of this heavy rainstorm are discussed. • The variations of DSD during a great rainstorm in northern China were investigated using 2DVD, Parsivel and MRR observation. • Most single-peak DSDs occurred in the stratiform rainfall, and the bimodal DSDs were observed in the convective rainfall. • The gamma distribution does not represent well the bimodal DSDs in higher rain rate (R >10 mm h-1). • The influence of the DSD characteristics on the Z -R relationships is investigated. [ABSTRACT FROM AUTHOR]

The dual isotopic signatures of particulate nitrate (hereafter as δ15N–NO 3 - and δ18O–NO 3 -) have been extensively used to imprint the source and chemical transformation of atmospheric NO x (NO x = NO + NO 2). For instance, the δ18O–NO 3 - elevated proportionally when NO x converted by O 3. In the present study, daily PM 2.5 samples (n = 91) were collected in winter Beijing (December to February in 2017–2018) and a two-endmember linear isotopic mixing model was used to model the endmember δ18O values of NO 3 − oxidized by O 3 (termed as δ18O noct) and the contribution of the different pathways (i.e., daytime and nocturnal oxidation pathways). During the campaign, the NO 3 − concentrations in PM 2.5 varied from 0.3 to 46.3 μg m−3 (8.1 ± 9.8 μg m−3), δ15N–NO 3 - from +1.0‰ to +19.6‰ (12.5 ± 3.6‰) and δ18O–NO 3 - from +50.7‰ to +103.5‰ (74.9 ± 13.3‰). The Keeling plots indicated that the δ18O noct endmember value was within the ranges based on theoretical approaches. The contribution of the nocturnal pathway to NO 3 − in PM 2.5 ranged from 8.5 ± 3.2% in background days to approximately 100% in extremely polluted days, with a mean of 52.0 ± 25.5%. The determined δ15N–NO 3 - values (12.5 ± 3.6‰) were comparable with previous studies conducted in recent winter Beijing (2013–2017, i.e., average values of 11.9‰–13.8‰). Due to the optimization of energy structure in Beijing, we inferred that the dominant NO x source in recent wintertime was the vehicular exhaust. The Bayesian mixing model also confirmed that the contribution of vehicle exhaust/biomass burning sources to the NO 3 − was up to 70%. This study may further improve the understanding of NO x emission source and atmospheric processes in urban environments. • Two-endmember linear isotopic mixing model can simulate the δ18O values of NO 3 − oxidized by O 3. • OH channel accounted for 48% of the wintertime NO 3 − production in Beijing. • Vehicular exhaust was the major NO x source in winter 2017–2018 of Beijing. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine if there are any genetic changes with whole-exome sequencing associated with distal vaginal atresia. This was a retrospective genetics study of 5 patients who presented with distal vaginal atresia who were recruited between 2017 and 2018. Whole-exome sequencing was performed in each subject with distal vaginal atresia. Sanger sequencing was used to confirm the potential causative genetic mutation. Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China. The main outcome measure was the rare mutations potentially associated with distal vaginal atresia in 5 patients. A truncating mutation c.266delC (p.P89Rfs*5) in the T-box transcription factor 6 (TBX6) gene, which is highly expressed in the human vagina, was identified in 1 patient using whole-exome sequencing. The deletion of the 16p11.2 region containing the TBX6 locus has also been reported previously to have the clinical feature of Müllerian agenesis. This mutation was paternally inherited by the patient. This truncating mutation was absent from all of the databases we checked, suggesting that the variant is rare and pathogenic. We showed, to our knowledge, for the first time, that the mutation in TBX6 might be associated with human distal vaginal atresia. [ABSTRACT FROM AUTHOR]