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We investigate how management quality moderates the impact of carbon pricing on Chinese firms. Based on interviews with managers and lead engineers at manufacturing firms in Hubei and Beijing, we construct a novel index of climate-change-related management practices and link it to firm data from various sources. We document higher average productivity and more green innovation among firms that are well managed according to the index. In an event study of the introduction of regional cap-and-trade schemes for CO2, we analyze how management quality interacts with treatment. While treated firms reduced coal consumption more than control firms, this effect is statistically significant only for well-managed firms. The reduction could have been 25% greater if badly managed firms had been well managed. Our study highlights that good management practices, in particular energy monitoring, enhance the effectiveness of market-based climate policies by enabling firms to rationally comply with those policies. [ABSTRACT FROM AUTHOR]

Chicken age contributes to the meat characteristics; however, knowledge regarding the pathways and proteins associated with meat quality and muscle development are still scarce, especially in chicken thigh meat. Hence, the objective of this study was to elucidate the intricate relationship between these traits by liquid chromatography mass spectrometry at three different ages. A total of 341 differential expressed proteins (DEPs) were screened out (fold change ≥ 1.50 or ≤0.67 and p < 0.05) among 45 thigh meat samples (15 samples per age) of Beijing-You chicken (BYC), collected at the age of 150, 300, or 450 days (D150, D300, and D450), respectively. Subsequently, based on the protein interaction network and Markov cluster algorithm (MCL) analyses, 91 DEPs were divided into 26 MCL clusters, which were associated with pathways of lipid transporter activity, nutrient reservoir activity, signaling pathways of PPAR and MAPK, focal adhesion, ECM-receptor interaction, the cell cycle, oocyte meiosis, ribosomes, taurine and hypotaurine metabolism, glutathione metabolism, muscle contraction, calcium signaling, nucleic acid binding, and spliceosomes. Overall, our data suggest that the thigh meat of BYC at D450 presents the most desirable nutritional value in the term of free amino acids (FAAs) and intramuscular fat (IMF), and a series of proteins and pathways associated with meat quality and development were identified. These findings also provide comprehensive insight regarding these traits across a wide age spectrum. [ABSTRACT FROM AUTHOR]

The molecular regulatory mechanism underlying meat quality between different chicken genotypes remains elusive. This study aimed to identify the differences in metabolites and pathways in pectoralis major (breast muscle) between a commercial fast‐growing chicken genotype (Cobb500) and a slow‐growing Chinese native chicken genotype (Beijing‐You chickens, BYC) at market ages respectively based on ultra‐high‐performance liquid chromatography‐quadrupole/time of flight mass spectrometry (UHPLC‐QTOF/MS). Eighteen metabolites were identified as potential biomarkers between BYC and Cobb500 at market ages. Among them, L‐cysteine exhibited a higher relative intensity in BYC compared with Cobb500 and was enriched into 10 potential flavor‐associated KEGG pathways. In addition, the glycerophospholipid metabolism pathway was found to be associated with chicken meat flavor and the accumulation of sn‐glycerol 3‐phosphate and acetylcholine was more predominant in BYC than that in Cobb500, which were catalyzed by glycerophosphocholine phosphodiesterase (GPCPD1, EC:3.1.4.2), choline O‐acetyltransferase (CHAT, EC:2.3.1.6), and acetylcholinesterase (ACHE, EC:3.1.1.7). Overall, the present study provided some metabolites and pathways for further investigating the roles of the differences in meat flavor quality in breast muscle between Cobb500 and BYC at market ages. [ABSTRACT FROM AUTHOR]

Chronological age is one of the important factors influencing muscle development and meat quality in chickens. To evaluate the protein expression profiles during skeletal muscle development, we performed a tandem mass tag (TMT)-based quantitative proteomic strategy in pectoralis major (breast muscle) of Beijing-You chicken (BYC) at the chronological age of 90, 120, and 150 days. Each chronological age contained 3 pooling samples or 15 birds (five birds per pooling sample). A total of 1,413 proteins were identified in chicken breast muscle with FDR < 1% and 197 of them were differentially expressed (fold change ≥1.2 or ≤0.83 and p < 0.05). There were 110 up- and 71 down-regulated proteins in 120 d vs 90 d group, 13 up- and 10 down-regulated proteins in 150 d vs 120 d group. The proteomic profiles of BYC at 120 d were very similar to those at 150 d and highly different from those at 90 d, suggesting that 120 d might be an important chronological age for BYC. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these differentially expressed proteins were mainly involved in the pathway of glycolysis/gluconeogenesis, adrenergic signaling in cardiomyocytes, focal adhesion, oocyte meiosis and phagosome. Furthermore, some DEPs were quantified using parallel reaction monitoring (PRM) to validate the results from TMT analysis. In summary, these results provided some candidate protein-coding genes for further functional validation and contribute to a comprehensive understanding of muscle development and age-dependent meat quality regulation by proteins in chickens. [ABSTRACT FROM AUTHOR]

Atmospheric deposition of dissolved organic carbon (DOC) is equivalent to the magnitude of riverine export of organic carbon (OC) to the oceans. Interpreting the fluctuations of DOC in precipitation is therefore essential in understanding the global carbon balance. This study measured DOC in 137 rain events collected from November 2016 to November 2020 at a rural site in agricultural areas of Beijing on the North China Plain. Concentrations of DOC ranged from 0.09 to 19.69 mg C L−1 with a volume weighted mean value of 2.76 ± 0.27 mg C L−1, which is comparable with those measured in North China a decade ago (3.0 ± 0.4 mg C L−1) and the global mean level (2.64 ± 2.04 mg C L−1). While differences in these values were small, their overall mean values were statistically different (p < 0.05). When classified via air mass back-trajectories, precipitation events with trajectories from south demonstrated higher DOC concentrations than those from north, matching with the spatial distribution of OC emission in the region. The annual precipitation DOC fluxes varied from 6.60 to 15.85 kg C ha−1 yr−1, with an average of 11.05 ± 3.83 kg C ha−1 yr−1 in this study. Both the annual mean concentrations and fluxes of precipitation DOC decreased by approximately 60% between 2017 and 2020, coinciding with the declining trend in OC emissions and aerosol OC concentrations due to the clean air actions. These unique data will allow for a better understanding of current status of rainwater DOC deposition on the global scale and will be critical for evaluating the impacts of future changes, e.g., replacing coal with natural gas, on atmospheric composition. [Display omitted] • 4-year field study evaluating the impact of clean air polices in China on rain DOC. • Atmospheric DOC deposition decreased by 60% between 2017 and 2020 in rural Beijing. • The present DOC level is lower than 2010, but higher than the global mean value. [ABSTRACT FROM AUTHOR]

While atmospheric deposition plays a vital role in cleaning air pollutants, it also supplies toxic heavy metals and metalloids (MMs) to the receiving terrestrial and aquatic ecosystems and threatens human health through food chains. To characterize the input of atmospheric deposition to agricultural soils, bulk rain samples were collected on an event basis at a rural site in the North China Plain during 2016–2020. The results show that higher concentrations of MMs in bulk rain samples were associated with western and southern air masses passing polluted areas. In addition, the annual deposition flux of MMs tends to decline during the study period, coinciding with the inter-annual variations of particulate matter rather than the precipitation amounts. Of note, the deposition flux of MMs that exist entirely in fine particles declined significantly compared to those that exist in coarse particulate form, indicating that the clean air actions implemented in recent years were highly effective in reducing ambient MMs from anthropogenic emissions. The positive matrix factorization receptor model was also applied to the whole data set for bulk depositions and five sources were identified as agricultural (biomass burning and soil), dust, coal combustion, industrial and traffic emissions. These factors contributed 41%, 24%, 21%, 9% and 5% of the chemical components in bulk depositions, respectively. Future control strategies should tighten the emissions from combustion and soil/dust in the North China Plain to protect agriculture from atmospheric MMs depositions. [ABSTRACT FROM AUTHOR]

Size-resolved aerosol organic carbon (OC) and water-soluble OC (WSOC) was determined weekly in urban Beijing between 2013 and 2018. The results showed that in winter, the concentrations of WSOC and OC in fine (<2.1 μm) and coarse (>2.1 μm) mode were highest in 2013. During the following years, the concentrations of WSOC and OC were lower but an increasing trend was found from 2014 to 2016, which might be due to the increasing precursor concentrations. From summer 2013 to 2018, the concentrations of OC and WSOC in both fine and coarse mode decreased, which might be affected by decreasing emission intensity and photochemical oxidation. To characterize the seasonality of WSOC, two intensive field observations were further performed in winter 2013 and summer 2018. In winter of 2013, WSOC was mainly enriched in PM 1 (<1 μm) on clean days and lightly polluted days. In addition, the fine mode maximum shifted from 0.43-0.65 μm to 1.1–2.1 μm with the haze development due to the hygroscopic growth of particles. In summer of 2018, the WSOC was mainly concentrated in PM 1 , but in a few samples, the maximum size appeared in coarse mode. This difference might due to the different relative humidity and air mass sources. While the formation process of WSOC in winter was affected by photochemical oxidation below 2.1 μm, in 1.1–2.1 μm, it tended to change from photochemical oxidation to aqueous-phase oxidation. For the coarse mode WSOC formation in winter, however, it was mainly affected by heterogeneous processes. The findings advanced our understanding of the annual trends, size distribution and formation processes of WSOC, with significant implications for air pollution control in Beijing and surrounding regions. Image 1 • Carbonaceous species in both fine and coarse modes decreased from 2013 to 2018. • The size distribution of WSOC shifted from fine to coarse during haze episodes. • In summer, coarse mode WSOC was mainly condensed on sea salt. • In winter, WSOC formation was affected by secondary processes. [ABSTRACT FROM AUTHOR]

Identifying the sources of increased ammonia (NH 3) in the atmosphere has important implications for air quality, ecosystems, and climate. While analysis of the nitrogen isotopic composition (δ15N) can aid in the apportionment of NH 3 emission sources, the widely-used passive collection methods have not been verified for their ability to accurately characterize δ15N-NH 3. In this study, three types of passive samplers (ALPHA, Analyst, and Radiello) were employed and collocated with a denuder based active sampler (DELTA, serves as a reference method) to compare and contrast their ability in collecting atmospheric NH 3 for subsequent concentration and δ15N-NH 3 analysis in urban Beijing during the summer of 2018. The results showed that NH 3 concentrations determined using passive collection samplers that included ALPHA (n = 11), Analyst (n = 12), and Radiello (n = 7) samplers were 13.4%, 14.4%, and 27.5% lower than that of the active sampler (n = 12), respectively. The low NH 3 concentration bias in the passive collection samplers was suggested to be the result of inaccurate effective sampling rates due to incorrect mass transfer correction factors for the environmental conditions of this study. The δ15N-NH 3 values did not show significant differences between passive samplers, with weekly means of −31.0 ± 1.0‰ (n = 4), −28.4 ± 5.5‰ (n = 4), and −29.1 ± 0.9‰ (n = 4) for the ALPHA, Analyst, and Radiello, respectively. Notably, the overall mean δ15N-NH 3 values collected by these passive samplers (−29.5 ± 3.2‰, n = 12) was significantly lower than that of the active sampler (−14.1 ± 1.6‰, n = 4), with a difference of 15.4 ± 3.5‰. The large underestimation of δ15N-NH 3 values by passive samplers can be explained by the diffusive isotope fractionation of NH 3 isotopologues, which is driven by relative mass differences of 14NH 3 and 15NH 3. Overall, these findings highlight a potential low bias in NH 3 concentrations and a substantial uncertainty in previous source interpretation using δ15N-NH 3 as previous studies have almost exclusively characterized δ15N-NH 3 using passive samplers. We suggest that the denuder-based active sampler should be used in the future for characterizing δ15N-NH 3 whether at the source or in an atmospheric environment with mixed sources. This work also has important implications for characterizing δ15N of other gaseous nitrogen compounds. Unlabelled Image • Nitrogen isotopic composition of ammonia (δ15N-NH 3) aids in source apportionment. • Conventional collection methods for δ15N-NH 3 were almost based on passive samplers. • δ15N-NH 3 obtained by passive and active samplers were respective −29.5‰ and −14.1‰. • The low bias of 15.4‰ by passive δ15N-NH 3 was due to diffusive isotope fractionation. • Source apportionment based on passive δ15N-NH 3 might mislead mitigation strategy. [ABSTRACT FROM AUTHOR]