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Gaseous reactive nitrogen (Nr) emissions from agricultural soils to the atmosphere constitute an integral part of global N cycle, directly or indirectly causing climate change impacts. The extensive use of N fertilizer in crop production will compromise our efforts to reduce agricultural Nr emissions in China. A national inventory of fertilizer N‐induced gaseous Nr emissions from croplands in China remains to be developed to reveal its role in shaping climate change. Here we present a data‐driven estimate of fertilizer N‐induced soil Nr emissions based on regional and crop‐specific emission factors (EFs) compiled from 379 manipulative studies. In China, agricultural soil Nr emissions from the use of synthetic N fertilizer and manure in 2018 are estimated to be 3.81 and 0.73 Tg N yr−1, with a combined contribution of 23%, 20% and 15% to the global agricultural emission total of ammonia (NH3), nitrous oxide (N2O) and nitric oxide (NO), respectively. Over the past three decades, NH3 volatilization from croplands has experienced a shift from a rapid increase to a decline trend, whereas N2O and NO emissions always maintain a strong growth momentum due to a robust and continuous rise of EFs. Regionally, croplands in Central south (1.51 Tg N yr−1) and East (0.99 Tg N yr−1) of China exhibit as hotspots of soil Nr emissions. In terms of crop‐specific emissions, rice, maize and vegetable show as three leading Nr emitters, together accounting for 61% of synthetic N fertilizer‐induced Nr emissions from croplands. The global warming effect derived from cropland N2O emissions in China was found to dominate over the local cooling effects of NH3 and NO emissions. Our established regional and crop‐specific EFs for gaseous Nr forms provide a new benchmark for constraining the IPCC Tier 1 default EF values. The spatio‐temporal insight into soil Nr emission data from N fertilizer application in our estimate is expected to advance our efforts towards more accurate global or regional cropland Nr emission inventories and effective mitigation strategies. [ABSTRACT FROM AUTHOR]

Tropical and subtropical acidic soils have been well documented as hotspots of global soil nitrogen (N) oxide (i.e., nitrous oxide (N2O) and nitric oxide (NO) emissions). While the effectiveness of possible mitigation options has been extensively examined in croplands, little is known about their effectiveness in reducing N‐oxide emissions from acidic soils of rapidly expanding tea plantations in China. Here, we conducted a 2‐year field experiment to investigate how organic substitution for synthetic fertilizer and biochar amendment affect soil N‐oxide emissions from a subtropical tea plantation. Across the 2‐year measurement period, full organic substitution for synthetic fertilizer significantly increased N2O emissions by an average of 17% while had a lower NO emission compared to synthetic fertilizer alone. Our global meta‐analysis further revealed that full or partial organic fertilizer substitution resulted in a 29% (95% confidence interval: 5%–60%) increase of N2O emissions from acidic soils. In contrast, irrespective of fertilizer type, biochar amendment significantly reduced N2O emissions by 14% in the first but not second experimental year, suggesting a transient effect. The trade‐off effect of full organic substitution on N2O and NO emissions may be attributed to the favorable conditions for N2O production due to the stimulated activity of nitrifiers and denitrifiers. The suppression of N2O emission following biochar amendment was probably due to promoted further reduction of N2O to dinitrogen. The fertilizer‐induced emission factor (EF) of N2O (2.1%) in the tea plantation was greater than the current IPCC default value, but the EF of NO (0.8%) was comparable to the global estimate. Taken together, while biochar amendment could have mitigation potential, cautions are needed when applying organic substitution for synthetic fertilizer as mitigation options for acidic soils as hotspots of N‐oxide emissions. [ABSTRACT FROM AUTHOR]

Asymmetry has been proved to exist in the human brain structure, function and behavior. Most of the existing brain asymmetry findings are originated from the western populations, while studies about the brain structural and functional asymmetries in East Asians are limited. Extensive evidence suggested that cultural differences, e.g. education and language, may lead to differences in brain structure and function between races. Therefore, we hypothesized that differences in brain structural asymmetries exist between East Asians and Westerners. In this study, we performed a comprehensive surface-based morphometric (SBM) analysis of brain asymmetries in cortical thickness, volume and surface area in two well-matched groups of right-handed, Chinese (n = 45) and Caucasian (n = 45) young male adults (age = 22-29 years). Our results showed consistent inter-hemispheric asymmetries in the three brain morphological measures in multiple brain regions in the Chinese young adults, including the temporal, frontal, parietal, occipital, insular cortices and the cingulate gyrus. Comparing with the Caucasians, the Chinese group showed greater structural asymmetry in the frontal, temporal, occipital and insular cortices, and smaller asymmetry in the parietal cortex and cingulate gyrus. These findings could provide a new neuroanatomical basis for understanding the distinctions between East Asian and Caucasian in brain functional lateralization. [ABSTRACT FROM AUTHOR]

To evaluate the adsorption characteristics and effects of dissolved organic matter (DOM) from wheat straw (DOMW) and swine manure (DOMS) on mercury [Hg(II)] adsorption by soils, a series of experiments was conducted on 26 soils with different soil properties.Results showed that the values ofKd(a solid–liquid partition coefficient) of soils varied within a range of 0.768–14.386 L g−1.Kdvalues were mainly controlled by soil organic matter (SOM), cation exchange capacity (CEC), soil nitrogen (N), and soil sulfur (S). When DOMWand DOMSwere added to the soil samples, the amount of Hg(II) adsorbed by the soils decreased significantly. Furthermore, based on the decreased percentage of adsorption of Hg(II) by soil upon adding DOMW(PDOMW) or DOMS(PDOMS), about 73.08% soils, the values ofPDOMSwere smaller than those ofPDOMW. ThePDOMWvalues were related to SOM, pH, free Fe oxide content, and CEC, whereasPDOMSvalues were related to soil free Fe/Al oxide contents. Therefore, we should pay more attention about mercury risk caused by the addition of exogenous organic matter in soils, especially for the soils with low or high pH, less SOM, low CEC, and less free Fe/Al oxide. [ABSTRACT FROM AUTHOR]

Inland freshwater ecosystems are of increasing concerns in global methane (CH 4) budget in the atmosphere. Agricultural irrigation watersheds are a potential CH 4 emission hotspot owing to the anthropogenic carbon and nutrients loading. However, large-scale spatial variations of CH 4 concentrations and fluxes in agricultural catchments remain poorly understood, constraining an accurate regional estimate of CH 4 budgets. Here, we examined the spatiotemporal variations of dissolved CH 4 concentrations and fluxes from typical freshwater types (ditch, reservoir and river) within an agricultural irrigation watershed from Hongze catchment, which is subjected to intensive agricultural and rural activities in Eastern China. The dissolved CH 4 concentrations and fluxes showed similar temporal variations among the three freshwater types, with the highest rates in summer and the lowest rates in winter. The total CH 4 emission from this agricultural irrigation watershed was estimated to be 0.002 Gg CH 4 yr−1, with annual mean CH 4 concentration and flux of 0.12 μmol L−1 and 0.58 mg m−2 d−1, respectively. Diffusive CH 4 fluxes varied in samples taken from different freshwater types, the annual mean CH 4 fluxes for ditch, reservoir and river were 0.31 ± 0.06, 0.71 ± 0.13 and 0.72 ± 0.25 mg m−2 d−1, respectively. Among three freshwater types, the CH 4 fluxes were the lowest in ditch, which was associated with the lowest responses of CH 4 fluxes to water dissolved oxygen (DO), nitrate nitrogen (NO 3 −-N) and sediment dissolved organic carbon (DOC) concentrations in ditch. In addition, water velocity and wind speed were significantly lower in ditch than in reservoir and river, suggesting that they also played important roles in explaining the spatial variability of dissolved CH 4 concentrations and fluxes. These results highlighted a need for more field measurements with wider spatial coverage and finer frequency, which would further improve the reliability of flux estimates for assessing the contribution of agricultural watersheds to the regional and global CH 4 budgets. [Display omitted] • CH 4 concentrations and fluxes showed similar temporal variations among water types. • The CH 4 fluxes were significantly lower in ditches than in reservoirs and rivers. • The most sensitive responses of CH 4 fluxes to water parameters were found in rivers. • Water velocity and wind speed are responsible for spatial variability of CH 4 fluxes. [ABSTRACT FROM AUTHOR]

Rice paddies and aquaculture wetlands are typical agricultural wetlands that constitute one of the important sources of atmospheric methane (CH). Traditional transplanted rice paddies have been experiencing conversion to pond aquaculture wetlands for pursuing higher economic benefits over the past decades in southeast China. A parallel field experiment was carried out to compare CH emissions from a transplanted rice paddy and its converted crab-fish farming wetland in southeast China. Over the rice-growing season, CH fluxes averaged 1.86 mg m h from rice paddies, and 1.14 and 0.50 mg m h for the treatments with or without aquatic vegetation present in the crab-fish farming wetlands, respectively. When averaged across the treatments, seasonal CH emissions from crab-fish framing wetlands were 52 % lower than those from rice paddies. The CH fluxes were negatively related to water dissolved oxygen (DO) concentration but positively related to soil/sediment dissolved organic carbon (DOC) content in crab-fish farming wetlands. Dependence of CH fluxes on DO or DOC was intensified by the aquatic vegetation presence. By extrapolating the present CH emission rate with the current rice paddy-converted aquaculture cultivation area, the seasonal CH emissions from inland aquaculture wetlands during the critical farming stage (20 June to 18 October) were estimated to be 33.6 Gg ha in southeast China in 2012. Rice paddies conversion to crab-fish farming wetlands might have reduced CH emissions by 22-54 % in mainland China. Results of this study suggest that the conversion of transplanted rice paddies to crab-fish aquaculture wetlands for higher economic benefits would also lead to a lower ecosystem CH release rate. [ABSTRACT FROM AUTHOR]

A full accounting of net greenhouse gas balance ( NGHGB) and greenhouse gas intensity ( GHGI) was examined in an annual coastal reclaimed saline Jerusalem artichoke-fallow cropping system under various soil practices including soil tillage, soil ameliorant, and crop residue amendments. Seasonal fluxes of soil carbon dioxide ( CO2), methane ( CH4), and nitrous oxide (N2O) were measured using static chamber method, and the net ecosystem exchange of CO2 ( NEE) was determined by the difference between soil heterotrophic respiration ( RH) and net primary production ( NPP). Relative to no-tillage, rotary tillage significantly decreased the NPP of Jerusalem artichoke while it had no significant effects on the annual RH. Rotary tillage increased CH4 emissions, while seasonal or annual soil N2O emissions did not statistically differ between the two tillage treatments. Compared with the control plots, soil ameliorant or straw amendment enhanced RH, soil CH4, and N2O emissions under the both tillage regimes. Annual NGHGB was negative for all the field treatments, as a consequence of net ecosystem CO2 sequestration exceeding the CO2-equivalents released as CH4 and N2O emissions, which indicates that Jerusalem artichoke-fallow cropping system served as a net sink of GHGs. The annual net NGHGB and GHGI were estimated to be 11-21% and 4-8% lower in the NT than in RT cropping systems, respectively. Soil ameliorant and straw amendments greatly increased NPP and thus significantly decreased the negative annual net NGHGB. Overall, higher NPP but lower climatic impacts of coastal saline bioenergy production would be simultaneously achieved by Jerusalem artichoke cultivation under no-tillage with improved saline soil conditions in southeast China. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study is to show the condition of laminar organization on 3.0T and 7.0T postmortem magnetic resonance imaging (MRI) and analyze developmental changes. Methods: Heads of 131 fetal specimens of 14-40 weeks gestational age (GA) were scanned by 3.0T MRI. Eleven fetal specimens of 14-27 weeks GA were scanned by 7.0T MRI. Clear images were chosen for analysis. Results: On T-weighted 3.0T MRI, layers could be visualized at 14 weeks GA and appeared clearer after 18 weeks GA. On 7.0T MRI, four zones could be recognized at 14 weeks GA. During 15-22 weeks GA, when laminar organization appeared typical, seven layers including the periventricular zone and external capsule fibers could be differentiated, which corresponded to seven zones in histological stained sections. At 23-28 weeks GA, laminar organization appeared less typical, and borderlines among them appeared obscured. After 30 weeks GA, it disappeared and turned into mature-like structures. The developing lamination appeared the most distinguishable at the parieto-occipital part of brain and peripheral regions of the hippocampus. The migrating thalamocortical afferents were probably delineated as a high signal layer located at the lower, middle, and upper part of the subplate zone at 16-28 weeks GA on T-weighted 3.0T MRI. Conclusions: T-weighted 3.0T MRI and T-weighted 7.0T MRI can well demonstrate the laminar organization. Development of the lamination follows a specific spatio-temporal regularity, and postmortem MRI of the parieto-occipital part of brain obtained with 3.0T or 7.0T is an effective way to show developmental changes. [ABSTRACT FROM AUTHOR]

Nitrogen fertilizer-induced direct nitrous oxide (N2O) emissions depend on water regimes in paddy fields, such as seasonal continuous flooding (F), flooding–midseason drainage–reflooding (F-D-F), and flooding–midseason drainage–reflooding–moist intermittent irrigation but without water logging (F-D-F-M). In order to estimate the changes in direct N2O emission from paddy fields during the rice-growing season in Mainland of China between the 1950s and the 1990s, the country-specific emission factors of N2O-N under different water regimes combined with rice production data were adopted in the present study. Census statistics on rice production showed that water management and nitrogen input regimes have changed in rice paddies since the 1950s. During the 1950s–1970s, about 20–25% of the rice paddy was continuously waterlogged, and 75–80% under the water regime of F-D-F. Since the 1980s, about 12–16%, 77%, and 7–12% of paddy fields were under the water regimes of F, F-D-F, and F-D-F-M, respectively. Total nitrogen input during the rice-growing season has increased from 87.5 kg N ha−1 in the 1950s to 224.6 kg N ha−1 in the 1990s. The emission factors of N2O-N were estimated to be 0.02%, 0.42%, and 0.73% for rice paddies under the F, F-D-F, and F-D-F-M water regimes, respectively. Seasonal N2O emissions have increased from 9.6 Gg N2O-N each year in the 1950s to 32.3 Gg N2O-N in the 1990s, which is accompanied by the increase in rice yield over the period 1950s–1990s. The uncertainties in N2O estimate were estimated to be 59.8% in the 1950s and 37.5% in the 1990s. In the 1990s, N2O emissions during the rice-growing season accounted for 8–11% of the reported annual total of N2O emissions from croplands in China, suggesting that paddy rice development could have contributed to mitigating agricultural N2O emissions in the past decades. However, seasonal N2O emissions would be increased, given that saving-water irrigation and nitrogen inputs are increasingly adopted in rice paddies in China. [ABSTRACT FROM AUTHOR]

Agricultural nitrate leaching and runoff incurs high nitrogen loads in agricultural irrigation watersheds, constituting one of important sources of atmospheric nitrous oxide (N2O). Two independent sampling campaigns of N2O flux measurement over diel cycles and N2O flux measurements once a week over annual cycles were carried out in an agricultural irrigation watershed in southeast China using floating chamber (chamber-based) and gas transfer equation (model-based) methods. The diel and seasonal patterns of N2O fluxes did not differ between the two measurement methods. The diel variation in N2O fluxes was characterized by the pattern that N2O fluxes were greater during nighttime than daytime periods with a single flux peak at midnight. The diel variation in N2O fluxes was closely associated with water environment and chemistry. The time interval of 9:00-11:00 a.m. was identified to be the sampling time best representing daily N2O flux measurements in agricultural irrigation watersheds. Seasonal N2O fluxes showed large variation, with some flux peaks corresponding to agricultural irrigation and drainage episodes and heavy rainfall during the crop-growing period of May to November. On average, N2O fluxes calculated by model-based methods were 27% lower than those determined by the chamber-based techniques over diel or annual cycles. Overall, more measurement campaigns are highly needed to assess regional agricultural N2O budget with low uncertainties. [ABSTRACT FROM AUTHOR]

Grassland ecosystems are sensitive to invasions by plants from other functional groups which can alter soil greenhouse gas (GHG) fluxes. However, the effects of plant invasion on net GHG exchanges between soils and the atmosphere, plant production, and global warming potential (GWP) of annual grasslands is poorly understood. To evaluate the impacts of perennial forb invasions on GHG budgets of an annual grassland in China, we measured soil carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) fluxes over two years in replicated invaded (dominated by Alternanthera philoxeroides or Solidago canadensis ) and non-invaded (dominated by the annual grass Eragrostis pilosa or the annual forb Sesbania cannabina ) field sites. On average, soil CO 2 and N 2 O emissions from invaded sites were 30% and 76% higher, respectively, relative to sites dominated by native species. Emissions of N 2 O and CO 2 were especially high in Solidago and Alternanthera dominated sites, respectively. Soil CH 4 emissions did not vary with plant species. On average, total biomass C of invaded sites was higher than that of the native dominated sites but this reflected the high C in Solidago dominated sites. Global warming potential (GWP) was increased by Alternanthera invasions and decreased by Solidago invasions. Plant invasions affected GWP of these annual grasslands through higher emissions of some GHGs but also sometimes higher biomass C. Together, this suggests that perennial forb invasions could change the net source or sink role of annual grasslands for GHG budgets, but the effects on GWP vary among species depending on GHG responses and C storage. [ABSTRACT FROM AUTHOR]

How to achieve high soil organic carbon (SOC) sequestration and low greenhouse gases emissions but without compromising yields is the challenge of rice cultivation in China. This study explored the potential to simultaneously increase SOC stocks and reduce methane (CH 4) emissions by optimizing rice cropping rotation and fertilization based on a 2-year field experiment in southeast China. We tested five optimized N management practices including directly reducing chemical N fertilizer input and replacing chemical N fertilizers with organic and controlled-release fertilizers in double-rice cropping and Chinese milk vetch-rice cropping rotation systems. Results showed higher seasonal rice yields, nitrogen use efficiency (NUE) and SOC stocks for Chinese milk vetch-rice rotation systems (CR) as compared to double-rice cropping systems (DR). Seasonal rice yields were the highest in the 2019 single-rice season (2019-SR), followed by the 2018 late (2018-LR) and early rice seasons (2018-ER). SOC stocks of CR for the treatment receiving organic N fertilizer (OF) were the largest among all rice seasons and fertilization treatments. Seasonal CH 4 emissions were 8–12% greater in the OF than in the chemical N fertilizer treatments across all rice seasons, with the greatest in 2019-SR and lowest in 2018-ER. Fertilization stimulated CH 4 emissions through enhancing mcrA gene activity, but regulated by soil properties, while rice rotation models indirectly influenced CH 4 emissions through direct effects on soil properties. However, yield-scaled CH 4 emissions remained unaffected by N fertilization in the two-year rice rotation systems. The NUE was significantly enhanced in OF than in other fertilizer treatments over all seasons. Seasonal net ecosystem C budget (NECB) was 24–41% greater in OF than in chemical N fertilizer treatments across all rice seasons, with the greatest in 2019-SR and lowest in 2018-LR. The NECB was increased by 46% in CR as compared to DR. Our results revealed that the optimized rice cropping rotation by incorporation of Chinese milk vetch with organic N fertilization is beneficial for enhancing soil C sequestration and maintaining rice yields in southeast China. [Display omitted] • Green manure rotation benefits for the enhancement of paddy soil carbon sinks. • Green manure rotation stimulates CH 4 emissions during the rice growing season. • Yield-scaled CH 4 emissions remain unaffected by N fertilization and crop rotation. • Green manure rotation can reconcile low climatic impacts with high yield of rice. [ABSTRACT FROM AUTHOR]

• CH 4 and N 2 O emissions from rice-aquaculture systems remain poorly constrained. • Rice-crayfish co-culture production is beneficial to reduce CH 4 and N 2 O emissions. • Ditched culture areas release more CH 4 but less N 2 O relative to rice planted areas. • Lower emission factors of N 2 O in rice-crayfish co-culture than monoculture systems. Rice paddies and rice-aquaculture co-culture systems are important sources of methane (CH 4) and nitrous oxide (N 2 O) to the atmosphere. Due to the growing human demand of aquaculture protein and the rapid development of green agriculture, rice-aquaculture co-culture systems have been increasingly developed from rice paddies in southeast China. However, the strength of CH 4 and N 2 O emissions from rice-aquaculture co-culture systems remains poorly quantified, in particular the contribution of these emissions from different functional cultivation areas. Here, a two-year parallel field experiment was conducted to examine the changes in CH 4 and N 2 O fluxes following the conversion from rice paddies to rice-crayfish co-culture systems in southeast China. Over the two-year period, annual CH 4 and N 2 O fluxes from rice-crayfish co-culture systems averaged 4.59 mg m-2 h-1 and 39.50 μg m -2 h -1, amounting to 391.9 kg ha−1 and 3.46 kg ha−1, respectively. The conversion from rice paddies to rice-crayfish co-culture systems significantly reduced CH 4 and N 2 O emissions by 14% and 31%, respectively. The emission factors of N 2 O were estimated to be 1.25–1.61% in the rice-crayfish co-culture system. Relative to rice planted areas, CH 4 and N 2 O fluxes from crayfish ditched culture areas were three times higher and 50% lower, which contributed 26% and 5% to the total CH 4 and N 2 O emissions from rice-crayfish co-culture systems, respectively. Our results highlight that the conversion of paddy rice monoculture to rice-crayfish co-culture systems can benefit low greenhouse gas emissions and high ecosystem economic profits as a potential option to sustain agricultural development and achieve carbon neutrality. [Display omitted] [ABSTRACT FROM AUTHOR]

Rice paddies and rivers draining agricultural watersheds have been documented as two major sources of atmospheric methane (CH 4), while parallel flux measurements have been rarely taken on CH 4 from rice paddies against the drainage rivers in agricultural watersheds. Moreover, the drainage events during the rice growing season deliver sufficient organic and inorganic nutrients to rivers, which makes there an increasing concerned source of atmospheric CH 4. Here, we compared CH 4 emissions from rice paddies and the associated rivers draining agricultural watersheds by a parallel field experiment in southeast China. Over the whole rice–growing season (June–November), CH 4 fluxes from drainage rivers averaged 25 mg m–2 h–1, which were 82 % higher than those from rice paddies (13.7 mg m–2 h–1). Besides the dependence of riverine CH 4 fluxes on water dissolved oxygen (DO), both ecosystem CH 4 fluxes were significantly correlated with water/soil dissolved organic carbon (DOC), oxidation-reduction potential (Eh) and the microbial functional genes that drive CH 4 production or uptake [methanogens (mcrA and methanogenic archaeal 16S rRNA) and methanotrophs (pmoA)]. Our results highlighted that the CH 4 mitigation potential benefited from the drainage practice in rice paddies might have been totally offset by its induced increases in CH 4 emissions from rivers draining agricultural watersheds at the regional scale. ● Rivers draining agricultural watersheds are an important source of atmospheric CH 4. ● CH 4 fluxes from drainage rivers have been rarely related to the abundance of microbes. ● CH 4 fluxes from drainage rivers were 82 % greater than those from rice paddies. ● The increase in CH 4 emissions in rivers may offset the mitigation benefit of CH 4 in rice paddies. [ABSTRACT FROM AUTHOR]

The potential of biochar for mitigating climatic impacts of coastal saline bioenergy production is not well established. A full accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) affected by biochar amendment combined with or without nitrogen (N) fertilizer application was examined in an annual coastal reclaimed Jerusalem artichoke bioenergy cropping system. The net ecosystem exchange of CO 2 (NEE) was determined by the difference between soil heterotrophic respiration ( R H ) and net primary production (NPP) using static chamber method. Biochar amendment raised the seasonal R H but without suppressing the NPP during the Jerusalem artichoke cropping season. Soil CH 4 emissions were 72% and 80% lower in the biochar amended than unamended plots when combined with N fertilizer application during the Jerusalem artichoke cropping and non-cropping seasons, respectively. The biochar-induced soil N 2 O mitigation efficiency was weakened by N fertilizer input over the annual cycle. Annual NGHGB and GHGI were negative for all the field treatments and were significantly lower in biochar amended than in unamended soils, suggesting that Jerusalem artichoke cropping system served as a net sink of GHGs due to net ecosystem CO 2 and biochar-induced C sequestration exceeding CO 2 -equivalents released as CH 4 and N 2 O emissions. On average, biochar amendment significantly enhanced GHGs sink capacity by resulting in almost 4–5 folds decrease in annual NGHGB or GHGI when combined with N fertilizer application or not. Therefore, higher biomass gain as potential alternative source of biofuels but lower climatic impacts of bioenergy production would be reconciled by biochar use in southeast coastal China. [ABSTRACT FROM AUTHOR]

Freshwater aquaculture ponds constitute one of the important anthropogenic sources of atmospheric methane (CH 4). Nevertheless, estimates of global CH 4 emissions from freshwater aquaculture have large uncertainties due to a lack of data from different aquaculture types. Furthermore, despite that ebullition is a major pathway of CH 4 in aquatic systems, the quantification of ebullitive CH 4 fluxes from typical freshwater aquaculture ponds has been poorly represented. Here, field measurements of CH 4 fluxes over two years were taken to quantify ebullitive CH 4 fluxes from inland freshwater fish and crab aquaculture ponds in subtropical China. Ebullitive CH 4 fluxes averaged 15.97 ± 1.57 and 11.22 ± 1.26 mg m−2 d−1 in the fish and crab ponds in the first experimental year, respectively, and were 22.86 ± 2.30 and 21.95 ± 2.19 mg m−2 d−1 in the second year. During aquaculture period, ebullition dominated the emission pathways of CH 4 , accounting for 83% and 98% of the total CH 4 emissions in the fish and crab ponds, respectively. Ebullitive CH 4 fluxes exhibited considerable spatial variations, with the lowest flux rates captured at the aeration area due to aerator-use in both the fish and crab ponds. Dissolved oxygen and dissolved organic carbon were the two primary factors that drove ebullitive CH 4 fluxes in both aquaculture ponds. By incorporating global measurement data, we further assessed the CH 4 mitigation potential of aerator use in freshwater aquaculture and revealed the dominant role of ebullition in this mitigation contribution. Together with the rice-based aquaculture, aerator use could reduce CH 4 emissions from freshwater aquaculture ponds globally by 71% and in China by 63%. • Ebullition dominates the pathways of CH 4 emissions from inland aquaculture. • Ebullitive CH 4 fluxes differ with bioturbation to sediment in aquaculture ponds. • Aerator use could reduce global inland aquaculture CH 4 emissions by 71%. • Specific area aerator use benefits the whole aquaculture pond CH 4 mitigation. [ABSTRACT FROM AUTHOR]

Abstract: Structural sexual dimorphism and asymmetry in human cerebellum have been described in previous research, but results remain inconclusive or even conflicting. In this study, gender differences and hemispheric asymmetries in global and regional human cerebellum gray matter (GM) were estimated in an age-matched sample (n =112) of young Chinese adults. An optimized voxel-based morphometry (VBM) in spatial unbiased infratentorial template (SUIT) space together with an automated atlas-based volumetric approach were performed for mapping regional gray matter (GM) gender-related differences across the entire cerebellum. The two methods provided consistent findings on gender differences. The cerebellar GM volume was significantly larger in the anterior and middle posterior lobes of male group. In addition, a trend of greater GM volume in lateral posterior lobe of female group was observed. With the created symmetric cerebellar template, the asymmetric properties of cerebellar hemisphere were also assessed by VBM analysis, showing rightward asymmetry distributed in most cerebellar lobules and leftwards asymmetry distributed in the lobules around the medial posterior lobe. Gender differences in males showed higher leftward asymmetry sparsely within a few lobules and lower rightward asymmetry mainly within lobule Crus II, as compared with females. The acquired detailed morphologic knowledge of normal human cerebellum could establish a baseline for comparison with pathologic changes in the cerebellum. Moreover, our results might help to address controversies in thestudy of sexual dimorphisms and asymmetric patterns in human cerebellum. [Copyright &y& Elsevier]

Abstract: We developed a novel brain atlas template to facilitate computational brain studies of Chinese subjects and populations using high quality magnetic resonance imaging (MRI) and well-validated image analysis techniques. To explore the ethnicity-based structural brain differences, we used the MRI scans of 35 Chinese male subjects (24.03±2.06 years) and compared them to an age-matched cohort of 35 Caucasian males (24.03±2.06 years). Global volumetric measures were used to identify significant group differences in the brain length, width, height and AC–PC line distance. Using the LONI BrainParser, 56 brain structures were automatically labeled and analyzed for all subjects. We identified significant ethnicity differences in brain structure volumes, suggesting that a population-specific brain atlas may be more appropriate for studies involving Chinese populations. To address this, we constructed a 3D Chinese brain atlas based on high resolution 3.0T MRI scans of 56 right-handed male Chinese volunteers (24.46±1.81 years). All Chinese brains were spatially normalized by using linear and nonlinear transformation via the “AIR Make Atlas” pipeline workflow within the LONI pipeline environment. This high-resolution Chinese brain atlas was compared to the ICBM152 template, which was constructed using Caucasian brains. [Copyright &y& Elsevier]

• Soil N 2 O and NO emissions have been rarely linked to crop NUE in annual wheat-rice rotations. • Manure N fertilizer substitution reduced N 2 O and NO emissions while enhanced crop NUE. • Both N 2 O and NO emissions were positively correlated with N surplus. • The combined emission factor of N fertilizer for N 2 O + NO was negatively related to crop NUE. Nitrogen (N) fertilizer has shown to affect soil nitrous oxide (N 2 O) and nitric oxide (NO) emissions that contribute to global warming and stratospheric ozone depletion. However, soil N 2 O and NO emissions with a linkage to crop N use efficiency (NUE) under different fertilization strategies in winter wheat-summer rice rotation systems remain yet to be further examined. Here, we carried out a two-year field study to assess the response of soil N 2 O and NO emissions as an interplay with NUE to different fertilization strategies in a typical winter wheat-summer rice rotation cropland of subtropical China. Three fertilizer treatments were established consisting of phosphorus (P) and potassium (K) fertilizer application (PK), NPK fertilizer application (NPK), and NPK fertilizer application with N partially replaced with manure (NPKM). Annual N 2 O, NO and N 2 O + NO emissions averaged 0.96, 0.24 and 1.19 kg N ha−1 yr−1 for the PK plots and 6.54, 1.48 and 8.03 kg N ha−1 yr−1 for the NPK plots, respectively. Relative to the NPK plots, partially replacing chemical N fertilizer with manure decreased annual N 2 O and NO emissions and their combined emissions by 13–15%, while it significantly enhanced crop NUE as compared to the NPK plots. Annual mean emission factors (EFs) of N fertilizer for N 2 O and NO were estimated to be 1.17% and 0.26% for the NPK plots, and 0.99% and 0.22% for the NPKM plots, respectively. Both N 2 O and NO emissions were positively correlated with N surplus, while yield-scaled N 2 O + NO emissions and the fertilizer N-induced combined EF for N 2 O + NO were negatively related to crop NUE. Together, our results highlight that improving crop NUE while reducing soil N surplus constitutes an effective strategy to mitigate soil gaseous N loss through N 2 O and NO in the wheat-rice rotation cropping systems. [ABSTRACT FROM AUTHOR]

• IndirectN2Oemissions from rivers draining agricultural watersheds are of increasing concerns. • Seasonal dissolved N2O concentrationsand N2O fluxes showed a similar variation pattern. • Annual mean model-based N2O fluxes werecomparable with chamber-based N2O fluxes. • The indirect riverine EFof N2O dependedlargely on surface water NO3–N concentrations. • Annual mean riverine indirect EF of N2O was significant lower than the IPCC default value. Indirect nitrous oxide (N 2 O) emissions from rivers draining agricultural watersheds are of increasing concerns due to riverine abundant sources of nitrogen loaded through leaching and runoff. However, the seasonal variation of N 2 O emissions from agricultural drainage rivers is poorly explored, especially the uncertainty in quantifying indirect N 2 O emission factors (EFs) from these aquatic environments. Here, a two-year study (2014-2016) was conducted to quantify indirect N 2 O emissions from a river draining a rice paddy watershed in subtropical China. Indirect N 2 O fluxes were simultaneously determined using the floating chamber method (chamber-based) and the gas exchange modeling approach (model-based) based on the measurement of dissolved N 2 O concentration. Results showed that seasonal dissolved N 2 O concentration and N 2 O fluxes had a similar variation pattern, with the highest and the lowest levels in summer and winter, respectively. The annual mean of model-based N 2 O fluxes (20.24 ± 3.34 μmol m−2 d−1) was generally in agreement with chamber-based N 2 O fluxes (18.70 ± 3.56 μmol m−2 d−1). The indirect emission factor of N 2 O was highly dependent on the surface water NO 3 −-N concentration. Annual mean indirect EF of N 2 O from the drainage river was estimated to be 0.00051, which was significantly lower than the default EF 5r value (0.0025) proposed by the Intergovernmental Panel on Climate Change (IPCC). These results suggest that the use of IPCC default value might have overestimated indirect N 2 O emissions from agricultural impacted riverine systems. Our study also highlights that more extensive in-situ measurements are required for monitoring indirect N 2 O emissions from agricultural impacted waters with different drainage characteristics, which would benefit for refining the IPCC EF 5r default value to further constrain global N 2 O budget. [ABSTRACT FROM AUTHOR]

• Soil N 2 O emissions have been rarely linked to N-related functional genes in wheat cropland. • Manure N substitution of chemical N fertilizer reduced N 2 O emissions from wheat cropland. • Manure N combination decreased the abundance of AOB while increased that of nosZ. • The abundance of AOB was significantly increased, relative to that of AOA unaltered by N input. Fertilization has been shown to affect nitrogen (N) cycling and its related functional microbes in agricultural soils. However, the linkage between soil N 2 O emissions and N-related functional genes under different fertilization strategies from wheat in a wheat-rice double cropping system is rarely examined. Here, we carried out a two-year field study to examine the response of soil N 2 O emissions driven by N cycling functional genes [archaeal and bacterial amoA (AOA + AOB), nirS , nirK and nosZ to different fertilization strategies in a wheat cropland of subtropical China. Three fertilizer treatments were established consisting of chemical phosphorus (P) and potassium (K) fertilizer application (PK), chemical N (urea) and PK fertilizer application (NPK), and chemical NPK fertilizer application with chemical N partially replaced with manure (composted pig manure) (NPKM). Over the two wheat seasons, seasonal total N 2 O emissions averaged 0.66, 3.60 and 3.11 kg N ha−1 for PK, NPK and NPKM plots, respectively. Relative to the NPK treatment, the NPKM treatment significantly decreased N 2 O emissions by 14 % without compromising grain yield, with a lowered combined fertilizer-induced emission factor (EF) of 1.02 %. Compared with the PK treatment, N fertilization consistently and significantly increased the abundance of ammonium-oxidation bacteria (AOB), nirS , nirK and nosZ genes. The nosZ gene, which drives N 2 O reduction during denitrification, showed a greater extent under NPKM with manure N combination. The AOB had a more sensitive response than ammonium-oxidation archaea (AOA) to chemical N fertilization. Seasonal N 2 O emissions showed significant positive correlations with AOB gene abundance and the ratio of (nirK + nirS)/ nosZ , while had a negative correlation with nosZ gene abundance across N fertilized treatments. The N 2 O-related microbial composition of functional genes was significantly changed by N fertilizer application and also showed contrasting patterns between treatments of chemical N fertilizer with and without manure N substitution. Together, partially replacing chemical N fertilizer with manure reduced N 2 O emissions from wheat in a wheat-rice double cropping system, mainly through decreasing AOB associated-nitrifying potential, and particularly stimulating N 2 O reduction. [ABSTRACT FROM AUTHOR]

• Biochar amendment decreased N 2 O and NO emissions from acidic soils. • Biochar amendment stimulated both nitrification and denitrification processes. • Soil N 2 O was produced mainly through denitrification in acidic soils. • Soil DOC and pH were key factors to N 2 O and NO emissions from acidic soils. • Soil N 2 O emissions were negatively related to nosZ gene abundances. Acidic soils are hotspots of nitrous oxide (N 2 O) and nitric oxide (NO) and biochar is documented to have the potential for mitigating N 2 O and NO. The N 2 O and NO emissions associated with soil functional genes and physicochemical properties under biochar amendment remains unclear in acidic soils. Here, we carried out a two-year field study to examine the responses of soil N 2 O and NO emissions to biochar amendment in a subtropical tea plantation in China. Measurements of N 2 O and NO fluxes were taken from inter-row soils using the static chamber method. We also measured the seasonal changes in soil key nitrogen (N)-cycling functional genes and physicochemical properties. Annual N 2 O and NO emissions averaged 27.31 kg N 2 O-N ha−1 yr−1 and 8.75 kg NO-N ha−1 yr−1 for the N fertilizer applied plots, which were decreased by 24% and 16% due to biochar application, respectively. In addition, both potential nitrification (PNR) and denitrification (PDR) rates were stimulated by biochar amendment, which significantly increased the abundances of bacterial amoA (AOB), nirK and nosZ genes. Changes in the composition of the N 2 O-related microbial functional community were closely associated with soil PNR, pH, DOC, and NO 3 −-N contents. The ratios of NO/N 2 O were mainly lower than 1, suggesting that N 2 O was produced mostly through denitrification rather than nitrification. There were negative correlations between soil N 2 O and NO emissions and soil PDR and pH, and soil N 2 O emissions were negatively correlated with nosZ gene abundances. Together, the decrease in N 2 O and NO emissions following biochar application could be largely attributed to the enhanced denitrification process, in which biochar enriched the nirK and nosZ genes abundance, resulting from the enhancement of soil DOC and pH in acidic soils. [ABSTRACT FROM AUTHOR]

To gain insight into the microbial mechanisms associated with the replacement of chemical fertilizers with organic or bio-organic fertilizers to mitigate soil nitrous oxide (N 2 O) emissions, we measured N 2 O emissions from greenhouse vegetable soils through field observations and pot experiments. Results showed that organic substitution suppressed N 2 O emissions by reducing soil mineral N content and stimulating the abundance of the nosZII gene. The trade-off effect of bio-organic substitution on N 2 O emissions may be due to the stimulated activity of the AOA-amoA gene, resulting in unfavorable conditions for N 2 O production and thus reduced N 2 O loss. We also linked the inhibitory effect of organic and bio-organic substitution on N 2 O emissions to the increased abundance of key species in bacterial co-occurrence networks represented by Patescibacteria as they were significantly and negatively correlated with N 2 O emissions. However, the mitigation effect of bio-organic substitution on N 2 O emissions was conteracted by an increase in Bacillus abundance due to the direct negative effect of Bacillus on the nosZII gene abundance. These findings suggest that conventional or bio-organic substitution is a promising strategy for alleviating the environmental costs of crop production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Inland freshwater ecosystems are of increasing concerns in global methane (CH 4 ) budget in the atmosphere. Agricultural irrigation watersheds are a potential CH 4 emission hotspot owing to the anthropogenic carbon and nutrients loading. However, large-scale spatial variations of CH 4 concentrations and fluxes in agricultural catchments remain poorly understood, constraining an accurate regional estimate of CH 4 budgets. Here, we examined the spatiotemporal variations of dissolved CH 4 concentrations and fluxes from typical freshwater types (ditch, reservoir and river) within an agricultural irrigation watershed from Hongze catchment, which is subjected to intensive agricultural and rural activities in Eastern China. The dissolved CH 4 concentrations and fluxes showed similar temporal variations among the three freshwater types, with the highest rates in summer and the lowest rates in winter. The total CH 4 emission from this agricultural irrigation watershed was estimated to be 0.002 Gg CH 4 yr -1 , with annual mean CH 4 concentration and flux of 0.12 μmol L -1 and 0.58 mg m -2 d -1 , respectively. Diffusive CH 4 fluxes varied in samples taken from different freshwater types, the annual mean CH 4 fluxes for ditch, reservoir and river were 0.31 ± 0.06, 0.71 ± 0.13 and 0.72 ± 0.25 mg m -2 d -1 , respectively. Among three freshwater types, the CH 4 fluxes were the lowest in ditch, which was associated with the lowest responses of CH 4 fluxes to water dissolved oxygen (DO), nitrate nitrogen (NO 3 - -N) and sediment dissolved organic carbon (DOC) concentrations in ditch. In addition, water velocity and wind speed were significantly lower in ditch than in reservoir and river, suggesting that they also played important roles in explaining the spatial variability of dissolved CH 4 concentrations and fluxes. These results highlighted a need for more field measurements with wider spatial coverage and finer frequency, which would further improve the reliability of flux estimates for assessing the contribution of agricultural watersheds to the regional and global CH 4 budgets., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Gaseous reactive nitrogen (Nr) emissions from agricultural soils to the atmosphere constitute an integral part of global N cycle, directly or indirectly causing climate change impacts. The extensive use of N fertilizer in crop production will compromise our efforts to reduce agricultural Nr emissions in China. A national inventory of fertilizer N-induced gaseous Nr emissions from croplands in China remains to be developed to reveal its role in shaping climate change. Here we present a data-driven estimate of fertilizer N-induced soil Nr emissions based on regional and crop-specific emission factors (EFs) compiled from 379 manipulative studies. In China, agricultural soil Nr emissions from the use of synthetic N fertilizer and manure in 2018 are estimated to be 3.81 and 0.73 Tg N yr -1 , with a combined contribution of 23%, 20% and 15% to the global agricultural emission total of ammonia (NH 3 ), nitrous oxide (N 2 O) and nitric oxide (NO), respectively. Over the past three decades, NH 3 volatilization from croplands has experienced a shift from a rapid increase to a decline trend, whereas N 2 O and NO emissions always maintain a strong growth momentum due to a robust and continuous rise of EFs. Regionally, croplands in Central south (1.51 Tg N yr -1 ) and East (0.99 Tg N yr -1 ) of China exhibit as hotspots of soil Nr emissions. In terms of crop-specific emissions, rice, maize and vegetable show as three leading Nr emitters, together accounting for 61% of synthetic N fertilizer-induced Nr emissions from croplands. The global warming effect derived from cropland N 2 O emissions in China was found to dominate over the local cooling effects of NH 3 and NO emissions. Our established regional and crop-specific EFs for gaseous Nr forms provide a new benchmark for constraining the IPCC Tier 1 default EF values. The spatio-temporal insight into soil Nr emission data from N fertilizer application in our estimate is expected to advance our efforts towards more accurate global or regional cropland Nr emission inventories and effective mitigation strategies., (© 2021 John Wiley & Sons Ltd.)

Ammonia (NH 3 ) emissions from fertilized soils to the atmosphere and the subsequent deposition to land surface exert adverse effects on biogeochemical nitrogen (N) cycling. The region- and crop-specific emission factors (EFs) of N fertilizer for NH 3 are poorly developed and therefore the global estimate of soil NH 3 emissions from agricultural N fertilizer application is constrained. Here we quantified the region- and crop-specific NH 3 EFs of N fertilizer by compiling data from 324 worldwide manipulative studies and focused to map the global soil NH 3 emissions from agricultural N fertilizer application. Globally, the NH 3 EFs averaged 12.56% and 14.12% for synthetic N fertilizer and manure, respectively. Regionally, south-eastern Asia had the highest NH 3 EFs of synthetic N fertilizer (19.48%) and Europe had the lowest (6%), which might have been associated with the regional discrepancy in the form and rate of N fertilizer use and management practices in agricultural production. Global agricultural NH 3 emissions from the use of synthetic N fertilizer and manure in 2014 were estimated to be 12.32 and 3.79 Tg N/year, respectively. China (4.20 Tg N/year) followed by India (2.37 Tg N/year) and America (1.05 Tg N/year) together contributed to over 60% of the total global agricultural NH 3 emissions from the use of synthetic N fertilizer. For crop-specific emissions, the NH 3 EFs averaged 11.13%-13.95% for the three main staple crops (i.e., maize, wheat, and rice), together accounting for 72% of synthetic N fertilizer-induced NH 3 emissions from croplands in the world and 70% in China. The region- and crop-specific NH 3 EFs of N fertilizer established in this study offer references to update the default EF in the IPCC Tier 1 guideline. This work also provides an insight into the spatial variation of soil-derived NH 3 emissions from the use of synthetic N fertilizer in agriculture at the global and regional scales., (© 2020 John Wiley & Sons Ltd.)

Rivers are of increasing concern as sources of atmospheric methane (CH 4 ), while estimates of global CH 4 emissions from rivers are poorly constrained due to a lack of representative measurements in tropical and subtropical latitudes. Measurements of complete CH 4 flux components from subtropical rivers draining agricultural watersheds are particularly important since these rivers are subject to large organic and nutrient loads. Two-year measurements of CH 4 fluxes were taken to assess the magnitude of CH 4 emissions from the Lixiahe River (a tributary of the Grand Canal) draining a subtropical rice paddy watershed in China. Over the two-year period, annual CH 4 emissions averaged 29.52 mmol m -2 d -1 , amounting to 10.78 mol m -2 yr -1 , making the river a strong source of atmospheric CH 4 . The CH 4 emissions from rivers during the rice-growing season (June-October) accounted for approximately 70% of the annual total, with flux rates at 1-2 orders of magnitude greater than those for rice paddies in this area. Ebullition contributed to 44-56% of the overall CH 4 emissions from the rivers and dominated the emission pathways during the summer months. Our data highlight that rivers draining agricultural watersheds may constitute a larger component of anthropogenic CH 4 emissions than is currently documented in China.

Morphological observation and measurements of endocasts have played a vital role in research on the evolution of the human brain. However, endocasts have never been used to investigate how the human brain has evolved since the Neolithic period. We investigated the evolution of the human brain during the Holocene by comparing virtual endocasts from Beiqian site (a Neolithic Chinese site) and a sample of Chinese modern-day humans. Standardized measurements and indices were taken to provide quantification of the overall endocast shape, including the length, breadth, height, frontal breadth, and the ratio of frontal breadth to breadth, as well as the cranial capacity. We found that the height of the endocasts and cranial capacity have decreased between our two samples, whereas the frontal breadth and sexual dimorphism have increased. We argue that these changes can be caused by random genetic mutation and epigenetic change in response to changes in the environment., (Copyright © 2014 Wiley Periodicals, Inc.)

Measurements of methane (CH(4)) and nitrous oxide (N(2)O) fluxes have been extensively taken following rice seedlings transplanted into paddy fields, while little is known about CH(4) and N(2)O fluxes from rice seedling nurseries. Fluxes of CH(4) and N(2)O were simultaneously measured in rice seedling nurseries under the water regimes of continuous flooding and moist irrigation without waterlogging in Southeast China in 2010. Fluxes of CH(4) and N(2)O from continuously flooded nurseries averaged 10.33-14.84 mg m(-2) h(-1) and 28.64-34.35 μg N(2)O-Nm(-2) h(-1) for the different fertilizer applied plots, respectively. Relative to continuous flooding, moist irrigation decreased total CH(4) by 14-50% but increased N(2)O by 72-186%, dependent on the fertilizer types. Compared with inorganic N fertilizer, organic manure application increased CH(4) by 44% and 148% in the continuously flooded and moist irrigation nurseries, respectively. Rice seedling growth parameters were the greatest in moist irrigation nurseries with inorganic N fertilizer application. Moist irrigation instead of continuous waterlogging and shifts from organic manure to combined organic/inorganic N fertilizer inputs have been increasingly experienced in Chinese rice seedling nurseries, which would benefit for mitigating the combined global warming potentials of CH(4) and N(2)O from rice seedling nurseries in China., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A complete accounting of net greenhouse gas balance (NGHGB) and greenhouse gas intensity (GHGI) affected by Fe(III) fertilizer application was examined in typical annual paddy rice-winter wheat rotation cropping systems in southeast China. Annual fluxes of soil carbon dioxide (CO(2)), methane (CH(4)) and nitrous oxide (N(2)O) were measured using static chamber method, and the net ecosystem exchange of CO(2) (NEE) was determined by the difference between soil CO(2) emissions (R(H)) and net primary production (NPP). Fe(III) fertilizer application significantly decreased R(H) without adverse effects on NPP of rice and winter wheat. Fe(III) fertilizer application decreased seasonal CH(4) by 27-44%, but increased annual N(2)O by 65-100%. Overall, Fe(III) fertilizer application decreased the annual NGHGB and GHGI by 35-47% and 30-36%, respectively. High grain yield and low greenhouse gas intensity can be reconciled by Fe(III) fertilizer applied at the local recommendation rate in rice-based cropping systems., (Copyright © 2012 Elsevier Ltd. All rights reserved.)