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This paper provides an analysis of China's land border cultural heritage, aiming to offer guidance for its protection and development. The study compiled a comprehensive database of heritage sites and analyzed their mathematical characteristics based on quantity, type, and quality. The spatial pattern of the cultural heritage was described using kernel density analysis, spatial variability, and spatial correlation, while the driving mechanism was measured based on Geo-Detector model. The findings revealed that the land border areas of China have a total of 1227 cultural heritage, comprising two main types and 18 subtypes. National cultural heritage accounted for 22.74%, with ancient city ruins being the largest type of cultural heritage. The Southwest and Northeast regions of China exhibited high-high clusters and low-low clusters, respectively. Moreover, the study identified history of administrative succession, evolution of historical and cultural, altitude, distance from the city, population density, minority population ratio, urbanization process, and per capita GDP as significant factors impacting the spatial pattern of land border cultural heritage in China. Based on these findings, the study suggests that the government should invest more in border cultural heritage, improve transportation infrastructure in border areas, ensure dynamic inheritance and protection of cultural heritage, and promote the joint development of different types of cultural heritage. The research results will provide data support and decision-making reference for the sustainable development of cultural heritage in land border areas, and can provide a new perspective for the management of cultural heritage in similar areas. [ABSTRACT FROM AUTHOR]

Key message: From 61 QTL mapped, a stable QTL cluster of 992 kb was discovered on chromosome 5 for folate content and a putative candidate gene, Glyma.05G237500, was identified. Folate (vitamin B9) is one of the most essential micronutrients whose deficiencies lead to various health defects in humans. Herein, we mapped the quantitative trait loci (QTL) underlying seed folate content in soybean using recombinant inbred lines developed from cultivars, ZH35 and ZH13, across four environments. We identified 61 QTL on 12 chromosomes through composite interval mapping, with phenotypic variance values ranging from 1.68 to 24.68%. A major-effect QTL cluster (qFo-05) was found on chromosome 5, spanning 992 kb and containing 134 genes. Through gene annotation and single-locus haplotyping analysis of qFo-05 in a natural soybean population, we identified seven candidate genes significantly associated with 5MTHF and total folate content in multiple environments. RNA-seq analysis showed a unique expression pattern of a hemerythrin RING zinc finger gene, Glyma.05G237500, between both parental cultivars during seed development, which suggest the gene might regulate folate content in soybean. This is the first study to investigate QTL underlying folate content in soybean and provides new insight for molecular breeding to improve folate content in soybean. [ABSTRACT FROM AUTHOR]

Summary: Isoflavones are a class of secondary metabolites produced by legumes and play important roles in human health and plant stress tolerance. The C2H2 zinc‐finger transcription factor (TF) functions in plant stress tolerance, but little is known about its function in isoflavone regulation in soybean (Glycine max).Here, we report a C2H2 zinc‐finger TF gene, GmZFP7, which regulates isoflavone accumulation in soybean. Overexpressing GmZFP7 increased the isoflavone concentration in both transgenic hairy roots and plants. By contrast, silencing GmZFP7 expression significantly reduced isoflavone levels. Metabolomic and qRT‐PCR analysis revealed that GmZFP7 can increase the flux of the phenylpropanoid pathway. Furthermore, dual‐luciferase and electrophoretic mobility shift assays showed that GmZFP7 regulates isoflavone accumulation by influencing the expression of Isoflavone synthase 2 (GmIFS2) and Flavanone 3 β‐hydroxylase 1 (GmF3H1).In this study, we demonstrate that GmZFP7 contributes to isoflavone accumulation by regulating the expression of the gateway enzymes (GmIFS2 and GmF3H1) of competing phenylpropanoid pathway branches to direct the metabolic flux into isoflavone. A haplotype analysis indicated that important natural variations were present in GmZFP7 promoters, with P‐Hap1 and P‐Hap3 being the elite haplotypes.Our findings provide insight into how GmZFP7 regulates the phenylpropanoid pathway and enhances soybean isoflavone content. [ABSTRACT FROM AUTHOR]

With the popularization of autonomous vehicle (AV) technology, mixed traffic flows that consist of AVs and human-driven vehicles (HDVs) will appear in the real world. Although many studies of the features of mixed traffic flow have been carefully evaluated, few studies have focused on the effect of aggressive driving performance on mixed traffic flow. This study aims to develop an approach to evaluate the effects of aggressive driving on the stability and capacity performance under the conditions of AV and HDV mixed traffic flow. First, since a car-following model can describe the relationship between vehicles, we calibrate a car-following model for aggressive driving and nonaggressive driving behaviors based on real traffic data and previous research results. Then, in a mixed traffic flow environment, a basic linear stability formula and capacity calculation expression are developed that consider the effects of vehicle order on the capacity. Finally, because the proportion of aggressive driving and aggressive driving parameters may change, nine combinations of three aggressive driving proportions and three driving parameter cases are used for the sensitivity analysis. The results indicate that the effect of aggressive driving on mixed traffic flow is complex. When the proportion of aggressive driving is less than 35%, the increase in the proportion of aggressive driving increases the traffic capacity and reduces the unstable part. However, when the proportion of aggressive driving is greater than 35%, the increase in the proportion of aggressive driving increases the unstable part. When the penetration rate of AVs exceeds 0.490, mixed traffic flow remains stable at all aggressive driving proportions. In addition, the capacity of a mixed traffic flow may be improved as the penetration rate of AVs increases. To a certain extent, these conclusions provide a theoretical basis for formulating different management modes of AVs and HDVs. [ABSTRACT FROM AUTHOR]

Key message: We identified four hub genes for isoflavone biosynthesis based on BSA-seq and WGCNA methods and validated that GmIE3-1 positively contribute to isoflavone accumulation in soybean. Soybean isoflavones are secondary metabolites of great interest owing to their beneficial impact on human health. Herein, we profiled the seed isoflavone content by HPLC in 1551 soybean accessions grown in two locations for two years and constructed two extreme pools with high (4065.1 µg g−1) and low (1427.23 µg g−1) isoflavone contents to identify candidate genes involved in isoflavone biosynthesis pathways using bulk segregant analysis sequencing (BSA-seq) approach. The results showed that the average sequencing depths were 50.3× and 65.7× in high and low pools, respectively. A total of 23,626 polymorphic SNPs and 5299 InDels were detected between both pools and 1492 genes with different variations were identified. Based on differential genes in BSA-seq and weighted gene co-expression network analysis (WGCNA), four hub genes, Glyma.06G290400 (designated as GmIE3-1), Glyma.01G239200, Glyma.01G241500, Glyma.13G256100 were identified, encoding E3 ubiquitin-protein ligase, arm repeat protein interacting with ABF2, zinc metallopeptidase EGY3, and dynamin-related protein 3A, respectively. The allelic variation in GmIE3-1 showed a significant influence on isoflavone accumulation. The virus-induced gene silencing (VIGS) and RNAi hairy root transformation of GmIE3-1 revealed partial suppression of this gene could cause a significant decrease (P < 0.0001) of total isoflavone content, suggesting GmIE3-1 is a positive regulator for isoflavones. The present study demonstrated that the BSA-seq approach combined with WGCNA, VIGS and hairy root transformation can efficiently identify isoflavone candidate genes in soybean natural population. [ABSTRACT FROM AUTHOR]

Folate deficiency is a significant global health issue that affects millions of people and causes severe adverse effects. Major staple crops, which provide significant amounts of calories, often contain inadequate folate levels. Synthetic fortification has contributed to a reduction in low-folate populations, but a more sustainable solution is needed. Biofortification, or the breeding of crops to naturally increase their nutrient content, is a promising alternative. Soybean is a highly nutritious crop and a good candidate for folate biofortification. However, studies on folate have been limited due to the challenges in folate analysis. The development of sensitive and selective tools, reference materials, and studies on the stability of folate vitamers in crops has facilitated the development of improved folate determination methods. Additionally, the soybean folate biofortification program can be improved by leveraging previous studies in major cereals, common bean and pea, as well as combining conventional breeding with new genomics approaches. In this review, we discuss the folate content, composition, and analytical challenges in soybean and suggest possible frameworks and strategies for folate biofortification in soybean. We also conducted an in silico analysis of key folate biosynthesis enzymes in soybean. [ABSTRACT FROM AUTHOR]

Accurate estimates of relative pollen productivity (RPP) values are fundamental to the use of fossil pollen records to quantitatively reconstruct paleovegetation. Based on a pollen dataset from moss polster and related vegetation data for 34 sites in the central part of the Ziwuling Mountains (central Chinese Loess Plateau, with a temperate–warm temperate climate), we estimated the relevant source area of pollen (RSAP) and the RPP values of 8 major woody plant taxa in deciduous broadleaved forest, using the Extended R-Value (ERV) model. The best results were obtained with ERV sub-model 2 and the inverse distance (1/d) method to distance weight the vegetation data. The RSAP was estimated to be 855 m and the rank order of the RPP values for the 8 major woody plant taxa is as follows: Betula (2.083 ± 0.091), Syringa (1.367 ± 0.087), Quercus (1 ± 0, the reference taxon), Pinus (0.791 ± 0.036), Ulmus (0.643 ± 0.062), Carpinus (0.621 ± 0.122), Malus (0.035 ± 0.015), and Acer (0.035 ± 0.025). Repeatability tests using the leave-one-out and K-fold methods showed that the RPP values of all 8 major woody plant taxa have a good reproducibility, which indicates that the RPP values are consistent in the study area. Comparison of the RPP values of the major plant taxa from deciduous broadleaved forest in temperate and warm temperate regions shows that the RPP values for the same pollen taxon may differ significantly between different areas. For example, the RPP for Pinus in areas with dominantly natural vegetation is much lower than for areas where the vegetation has been substantially altered by human activity. We suggest that differences in vegetation/landscape characteristics (including community structure and species composition/abundance) are the major causes of the difference. Therefore, changes in the regional landscape should be considered when choosing suitable RPP values for quantitative paleovegetation reconstruction. [ABSTRACT FROM AUTHOR]

Since nitrate nitrogen (NO 3 −-N) input has proved an effective approach for the treatment of black and odorous river waterbody, it was controversial whether the total nitrogen concentration standard should be raised when the effluent from the sewage treatment plant is discharged into the polluted river. To reveal the effect of exogenous nitrate (NO 3 −-N) on black odorous waterbody, sediments with different features from contaminated rivers were collected, and the changes of physical and chemical characteristics and microbial community structure in sediments before and after the addition of exogenous NO 3 −-N were investigated. The results showed that after the input of NO 3 −-N, reducing substances such as acid volatile sulfide (AVS) in the sediment decreased by 80 % on average, ferrous (Fe2+) decreased by 50 %, yet the changing trend of ammonia nitrogen (NH 4 +-N) in some sediment samples increased while others decreased. High-throughput sequencing results showed that the abundance of Thiobacillus at most sites increased significantly, becoming the dominant genus in the sediment, and the abundance of functional genes in the metabolome increased, such as soxA, soxX, soxY, soxZ. Network analysis showed that sediment microorganisms evolved from a single sulfur oxidation ecological function to diverse ecological functions, such as nitrogen cycle nirB, nirD, nirK, nosZ, and aerobic decomposition. In summary, inputting an appropriate amount of exogenous NO 3 −-N is beneficial for restoring and maintaining the oxidation states of river sediment ecosystems. • The microbial community under different pollution conditions was studied. • The original sediment is mainly characterized by sulfur oxidation functions. • Community increased the ecological functions such as nitrogen cycle and aerobic decomposition. • After exogenous NO 3 −-N input, Thiobacillus became the dominant genus. • The sites of microorganisms with NO 3 −-N reduction function occurred DNRA. [ABSTRACT FROM AUTHOR]

Since frequent traffic accidents bring great losses to people's safety and social property, this paper takes the results of traffic accident risk prediction as the basis so that it can help city managers to reasonably deploy police force, relieve traffic pressure, avoid traffic accidents and provide safe guidance to pedestrians. Based on this paper, a deep learning framework including spatiotemporal attention mechanism is proposed to solve the problem of traffic accident prediction in urban areas, and the experimental simulation shows that the accuracy of traffic accident risk prediction proposed in this paper reaches 94%. [ABSTRACT FROM AUTHOR]

Exploring the spatial pattern of tourism resources and tourism economy is vital to improve the utilization efficiency of tourism resources and promote sustainable tourism development. This research investigated the quantity and types of tourism resources and analyzed the spatial patterns of tourism resources on Hainan Island from the perspectives of spatial variation and spatial association. The spatial and temporal pattern of the number of tourists and tourism revenue during 2010–2019 were further analyzed. The influencing factors of tourism development were explored based on the geographic detector. The results showed that 10425 tourism resources exist on Hainan Island, and the type of buildings and facilities had the largest number of tourism resources. The geological landscape, astronomical phenomena and meteorological landscapes, buildings and facilities, ruins and remains, tourism commodities, and human activities showed significant spatial agglomeration. Domestic tourism was far more developed than inbound tourism in terms of the number of tourists and tourism revenue. However, the spatial difference of tourism resources and tourism economy was apparent on Hainan Island. Factor analysis showed that the quantity of hotels, the proportion of tertiary industry in the GDP, and the regional population were the most influential factors for the distribution of tourism resources, while the density of the road network, the quantity of hotels, the per capita GDP, the proportion of tertiary industry in GDP, the regional population, and the quantity of tourism resources showed obvious influences on the tourism economy of Hainan Island. Interactions of the factors mainly fell into three types: synergistic increases, single factor weakening, and nonlinear weakening. It is suggested that the local government should fully exploit diversity types of tourism resources on Hainan Island to attract more tourists and improve the tourism revenue; improving the inbound tourism, and to strengthen the construction of road network on Hainan Island. [ABSTRACT FROM AUTHOR]

With the development of the social economy, the level of motorization has been greatly improved, and the traffic safety problem has been paid more and more attention. In recent years, China's road traffic accident rate showed a trend of decline after rising first, suggests that the Chinese road traffic safety level is on the decline. Road traffic safety evaluation has a positive effect in found risk factors of road traffic safety in time and reduce the traffic accident rate, so the study of traffic safety evaluation method is imperative. And the urban road traffic safety evaluation is frequently viewed as the multi-attribute group decision-making (MAGDM) problem. Depending on the conventional VIKOR method and interval-valued intuitionistic fuzzy sets (IVIFSs), this paper designs a novel IVIF-VIKOR method to assess the urban road traffic safety. In addition, since subjective randomness frequently exists in determining criteria weights, the weights of criteria is [Z1] decided objectively by utilizing CRITIC method. Eventually, an application and some comparative analysis are given. The results show that the designed algorithms are useful for assessing the urban road traffic safety. [ABSTRACT FROM AUTHOR]

We investigate the dynamic performance of traffic flow using a modified optimal velocity car-following model. In the car-following scenarios, the following vehicle must continuously adjust the following distance to the preceding vehicle in real time. A new optimal velocity function incorporating the desired safety distance instead of a preset constant is presented first to describe the abovementioned car-following behavior dynamically. The boundary conditions of the new optimal velocity function are theoretically analyzed. Subsequently, we propose an improved car-following model by combining the heterogeneity of driver's sensitivity based on the new optimal velocity function and previous car-following model. The stability criterion of the improved model is obtained through the linear analysis method. Finally, numerical simulation is performed to explore the effect of the desired safety distance and the heterogeneity of driver's sensitivity on the traffic flow. Results show that the proposed model has considerable effects on improving traffic stability and suppressing traffic congestion. Furthermore, the proposed model is compatible with the heterogeneity of driver's sensitivity and can enhance the average velocity of traffic flow compared with the conventional model. In conclusion, the dynamic performance of traffic flow can be improved by considering the desired safety distance and the heterogeneity of driver's sensitivity in the car-following model. [ABSTRACT FROM AUTHOR]

With the implementation of the Belt and Road Initiative and the national strategy of "Ecological Protection and High-Quality Development in the Yellow River Basin", the tourism development of the Yellow River basin of China is facing important opportunity. However, the spatial differences of tourism economy and the unbalanced development of interprovincial resources has become a threat for the sustainable development of the basin. By using the statistical data from 2003 to 2018, this paper aims to identify the numerical feature and spatial patterns of tourism development in the Yellow River Basin from the aspects of tourist volume (domestic tourists and inbound tourists) and tourism income (income from domestic tourism and inbound tourism) at provincial and prefectural scales. Analysis of spatial autocorrelation reveals significant clusters and outliers of tourist volume and tourism income at prefectural scale. Location condition, terrain condition, culture resources, regional policies, the interregional relationship and tourism infrastructure were the main factors influencing the spatial differences of tourism development in the Yellow River Basin. The study could offer useful information for the regional tourism management in the Yellow River Basin. [ABSTRACT FROM AUTHOR]

This paper introduces an improved car-following speed (CFS) model that simultaneously considers speed of the lead vehicle, vehicle spacing, and driver's sensitivity to them. Specifically, the proposed model extends the Helbing-Tilch model and Yang et al. model developed based on the principle of grey relational analysis where vehicle spacing is considered as the primary factor contributing to car-following speed choices. A computational experiment is conducted for model calibration using vehicle spacing, speed, and acceleration data derived from vehicle trajectory data of the Next Generation Simulation (NGSIM) project sponsored by the Federal Highway Administration (FHWA). It shows that speed of the lead vehicle and vehicle spacing significantly affect speed of the lag vehicle. Further, model validation is carried out using an independent NGSIM dataset by comparing vehicle speed predictions made by the calibrated CFS model with Helbing-Tilch model and Yang et al. model as benchmarks. Compared with speed prediction results of the benchmark models, mean relative errors, root mean square errors, and equal coefficient of speed predictions of the CFS model have reduced by 72.41% and 61.85%, 70.14% and 57.99%, and 33.15% and 14.48%, respectively. The findings of model validation reveal that the CFS model could improve the accuracy of speed predictions in the car-following process. [ABSTRACT FROM AUTHOR]

The 4.2 ka event has attracted worldwide interest since it was suggested to be a possible cause for the collapse of ancient civilizations. With the accumulation of proxy records, however, both the nature of the 4.2 ka event itself and the manner of societal responses to climate change have become controversial. Here we present a climatic record of Daihai Lake spanning 5–3 cal ka BP, together with a cultural series for the lake basin around 4 cal ka BP, to explore the regional nature of the 4.2 ka event and the relationship between climatic variation and cultural evolution. The climatic record reflects a dry event at the interval of 4060–3690 cal yr BP that could be a regional manifestation of the 4.2 ka event. The cultural series suggests an interruption between two different cultures during the period of 4300–4000 cal yr BP. Taking into consideration the dating errors and especially the uncertainties resulting from dating cultural layers of the archaeological sections, we suggest that the cultural interruption in the Daihai Lake basin might have been caused by a monsoon-related dry event. Humans primarily engaged in agriculture likely left the lake basin because the drainage basin became unsuitable for agrarian activities as the climate became too dry, thus leaving a cultural vacancy of several centuries in the lake basin. A significant decline in the intensity of the East Asian summer monsoon on centennial to multi-decadal timescales could be associated with dramatic cooling of surface waters of both the North Atlantic and western tropical Pacific. [ABSTRACT FROM AUTHOR]

Reconstructing the spatial patterns of regional climate and vegetation during specific intervals in the past is important for assessing the possible responses of the ecological environment under future global warming scenarios. In this study, we reconstructed the history of regional vegetation and climate based on six radiocarbon-dated pollen records from the North China Plain. Combining the results with existing pollen records, we reconstruct the paleoenvironment of the North China Plain during the Last Glacial Maximum (LGM) and the Holocene Climatic Optimum (HCO). The results show that changes in the regional vegetation since the LGM were primarily determined by climatic conditions, the geomorphic landscape and by human activity. During the LGM, the climate was cold and dry; mixed broadleaf-coniferous forest and deciduous-evergreen broadleaf forest developed in the southern mountains, and cold-resistant coniferous forest and mixed broadleaf-coniferous forest were present in the northern mountains. The forest cover was relatively low, with mesophytic and hygrophilous meadow occupying the southern part of the plain, and temperate grassland and desert steppe were distributed in the north; Chenopodiaceae-dominated halophytes grew on the exposed continental shelf of the Bohai Sea and Yellow Sea. During the HCO, the climate was warm and wet; deciduous broadleaf forest and deciduous-evergreen broadleaf forest, with subtropical species, developed in the southern mountains, and deciduous broadleaf forest with thermophilic species was present in northern mountains. Although the degree of forest cover was greater than during the LGM, the vegetation of the plain area was still dominated by herbs, while halophytes had migrated inland due to sea level rise. In addition, the expansion of human activities, especially the intensification of cultivation, had a significant influence on the natural vegetation. Our results provide data and a scientific basis for paleoclimate modelling and regional carbon cycle assessment in north China, with implications for predicting changes in the ecological environment under future global warming scenarios. [ABSTRACT FROM AUTHOR]

We compared the pollen assemblages of surface moss samples and corresponding vegetation inventory data from 34 sites in the Huangling region of the central Loess Plateau. Our aims were to determine the characteristics of the pollen assemblages from the deciduous broadleaved forest climax community and its significance in terms of vegetation type and species composition. The pollen assemblages are dominated by woody plants such as Quercus (42% of total terrestrial pollen), Betula (16%) and Pinus (12%), with minor differences between different plant communities. The pollen assemblages of individual sampling sites differed from the vegetation composition within the 0–100 m scope and were more similar to the vegetation coverage within the 0–1000 m scope. This indicates that the surface pollen assemblages mainly reflect the comprehensive information from the vegetation composition of a large area, rather than the vegetation composition close to the sampling site. The contents of Quercus, Betula and Pinus pollen are high, and close to their vegetation coverage; whereas the contents of deciduous broadleaved arbor taxa (such as Malus and Acer) are lower, but their corresponding regional vegetation cover is higher. This suggests that the vegetation information conveyed by poorly-represented pollen taxa should be considered when interpreting stratigraphic pollen assemblages. Using the observed quantitative relationships between pollen and vegetation of the main taxa, we reconstructed the regional vegetation composition in the Gonghai Lake area of the northeastern Loess Plateau during the middle Holocene (7300–5000 yr BP). The results indicated that Quercus-dominated deciduous broadleaved forest climax community developed in the mountains surrounding the lake. [ABSTRACT FROM AUTHOR]

Attempts to alter seed oil content in soybean have been hampered by the complicated genetic architecture as being controlled by multiple genes. In order to investigate the genetic basis of oil content, bulk segregant analysis based on next generation resequencing (BSA-seq) was performed on a soybean natural population comprising 1551 acessions with diverse worldwide origins conferring wide diversity for seed oil content. Firstly, we identified a total of 2030 genes using the delta SNP-index method from the two phenotypic bulks showing extreme high and low oil content with significant differences. Secondly, using a stringent criterion of delta index greater than 0.9 or lower than −0.9, 130 candidate genes were further identified, including Glyma.04G047000, which encodes a lipid metabolism enzyme lecithin:cholesterol acyltransferase 1 (LCAT1). A 1-bp insertion was detected in LCAT1 gene leading to a truncated protein,and was found to be significantly correlating with seed oil content both in this natural population and also in another validation population containing 182 cultivars. Finally, high oil alleles for 130 candidate genes were shown to be more prevalent in cultivars than in landraces, and were particularly abundant in the accessions originated from the North ecoregion in China, which are recognized for their high oil content. This result demonstrates that these oil-associated alleles can be employed as selective markers for soybean breeding with high oil content. The BSA-seq strategy used in our study identified candidate genes for oil content and, therefore, may contribute to improving soybean seed oil content. • Bulk segregant analysis sequencing (BSA-seq) was applied to improve soybean oil. • A panel of 1551 soybean accessions with wide diversity in oil content were used. • A total of 130 candidate genes were detected to control oil accumulation. • Natural variation in LCAT-L1 gene may involve in high oil content in soybean. • Natural variation in candidate genes conferred geographical distribution pattern. [ABSTRACT FROM AUTHOR]

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500–11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment. [ABSTRACT FROM AUTHOR]

Abstract Accurate understanding urban leisure spaces (ULS) is crucial for optimizing the allocation of leisure resources. This paper aims to provide a detailed classification of ULS and derive its spatial distribution and morphological characteristics using geographical technology. We constructed a hierarchical classification system for leisure functions and identified 11 types of ULS in Qingdao based on the domination and combination of these functions. Single-function spaces are mainly concentrated in the suburbs with relatively large plots, while multi-function zones are primarily distributed in downtown areas with relatively small plots. Natural-recreational leisure spaces are more complex in shape, while cultural-special leisure spaces are less complex. The uneven distribution of different types of leisure spaces suggests that the government should focus on improving natural leisure spaces in downtown areas and developing diversified leisure spaces in the suburban areas. [ABSTRACT FROM AUTHOR]

Selenocysteine (Sec) carries out the majority of the functions of the various Se-containing species in vivo. Thus, it is of great importance to develop sensitive and selective assays to detect Sec. Herein, a carbon-dot-based fluorescent turn-on probe for highly selective detection of selenol in living cells is presented. The highly photoluminescent carbon dots that emit yellow-green fluorescence (Y-G-CDs; λmax = 520 nm in water) were prepared by using m-aminophenol as carbon precursor through a facile solvothermal method. The surface of Y-G-CDs was then covalently functionalized with 2,4-dinitrobenzenesulfonyl chloride (DNS-Cl) to afford the 2,4-dinitrobenzene-functionalized CDs (CD-DNS) as a nanoprobe for selenol. CD-DNS is almost nonfluorescent. However, upon treating with Sec, the DNS moiety of CD-DNS can be readily cleaved by selenolate through a nucleophilic substitution process, resulting in the formation of highly fluorescent Y-G-CDs and hence leads to a dramatic increase in fluorescence intensity. The proposed nanoprobe exhibits high sensitivity and selectivity toward Sec over biothiols and other biological species. A preliminary study shows that CD-DNS can function as a useful tool for fluorescence imaging of exogenous and endogenous selenol in living cells. [ABSTRACT FROM AUTHOR]

Fossil pollen, as a direct proxy record of past vegetation, and indirect proxy record of past climate, plays an essential role in revealing and reconstructing past vegetation and climate. However, relationships between pollen, vegetation and climate are not linear, hence quantitative reconstructions of past vegetation and climate based on pollen records are not straightforward, and results may be highly contradictory and difficult to interpret. One of the main causes of discrepancies between results has been the lack of comprehensive and systematical studies on modern pollen dispersal and deposition processes, particularly on the quantification of these processes. Based on empirical studies performed in China over the last 30 years, this paper provides the state-of-the-art of the understanding of pollen dispersal and deposition processes in China and the remaining questions to be investigated. We show that major progress has been achieved in the study of modern pollen dispersal and deposition processes, and in the application of models of the pollen-vegetation-climate relationships for quantitative reconstruction of past vegetation and climate. However, several issues are not entirely solved or understood yet, such as how to quantify the reworking and re-deposition of pollen grains in quaternary alluvial sediments, the influence of pollen preservation on pollen assemblages, and human impact on vegetation. Even so, the progress made during the last decades makes it possible to achieve significantly more precise and informative reconstructions of past vegetation, land-use and climate in China than was possible earlier. [ABSTRACT FROM AUTHOR]

• A novel strategy reconstructs the regional land cover from fossil pollen data. • Two records of Holocene land cover clearly reveal human activities in North China. • Human activities may contribute to the regional pattern of vegetation succession. • Human impacts on the environment showed a predatory pattern in the late Holocene. Beginning in the middle to late Holocene, anthropogenic land cover change has had a profound impact on both regional and continental environments. Hence, assessing temporal and spatial differences in the intensity of human activity in different regions and geomorphologic contexts has become a focus of current global change research. Here we use two representative pollen records from different geomorphologic units in North China (Lake Gonghai in the mountains, and Lake Daihai in a large basin) together with a novel methodology to quantitatively reconstruct Holocene land cover changes. The results indicate diverse vegetation succession patterns in different regions and geomorphologic contexts. In the Daihai basin, the vegetation cover changed relatively little, maintaining values of 45–50%, and only increased during the interval of 8–5.1 ka, when it attained a maximum of 67%. In the Gonghai area, the vegetation cover remained at a higher level at 70–80% for an extended interval, before decreasing substantially to 58% after 1.4 ka. We propose that changes in the intensity of human activities was a major cause of the observed regional disparities in vegetation succession. Comparison of the results with records of prehistoric human activity shows that, prior to 5.1 ka, land cover change (especially of the vegetation composition) in the Daihai basin evolved naturally, under the influence of climate. Then, during ∼ 5.1–2.8 ka, a transitional stage occurred, driven by both climate change and human activities. Finally, from ∼ 2.8 ka to the present, human activities dominated the pattern of vegetation change. In contrast, land cover change in the alpine Gonghai area was controlled by natural processes until 1.4–1.3 ka, when human activities exceeded the influence of natural variability and became the dominant factor controlling local vegetation development. In larger basin/plain areas, the favorable climatic conditions of the mid-Holocene promoted increased human activity; while later, population pressure, the increased demand for resources, and political factors may have triggered the diffusion of human populations from basins to the mountains or previously undeveloped areas, with resulting effects on their vegetation succession. The anthropogenic impacts have dominated the natural environment of mountainous areas in north-central China for at least the last 1,300 years. [ABSTRACT FROM AUTHOR]

• Conjugase treatment was sufficient for soybean folate extraction. • 10-fold variation was observed for soybean folates, from 64.51 − 691.24 μg/100 g. • 5-CHO-H 4 folate was the most dominant folate vitamer in soybean. • Folates are affected by accession type, ecoregion, and seed morphological traits. • Soybean is a key candidate for folate biofortification. Soybean is a rich source of folates. We optimised the extraction and detection of folates from soybean seeds by HPLC-MS/MS and analysed the folate content and composition of 1074 accessions. Total folate content ranged from 64.51 to 691.24 μg/100 g fresh weight, with 10-fold variation, and 60 elite accessions with over 400 μg/100 g of total folate were identified. The most abundant component was 5-CHO-H 4 folate, which accounted for an average of 60% of total folate content. Seed-coat colour, seed weight, ecoregion, and accession type significantly affected soybean folate content. Furthermore, 5-CH 3 -H 4 folate correlated positively with seed protein (r = 0.24***) and negatively with oil (r = -0.26***). The geographical distribution of folate according to accession origin revealed that accessions from Northeast China contain higher amounts of total folate and 5-CHO-H 4 folate. This study provides comprehensive and novel insights into the folate profile of soybean, which will benefit soybean breeding for folate enhancement. [ABSTRACT FROM AUTHOR]

The chemical compositions, sizes and fluorescent properties of synthesized carbon nanoparticles (CNPs) were characterized. Escherichia coli ( E. coli ) cells were used as a model to study the cytotoxicity of CNPs, and the results of the cellular uptake of CNPs yielded excellent results: the CNPs demonstrated good biocompatibility and were non-toxic to the growth of the E. coli cells. Moreover, to assess the potential toxicity of CNPs to human health, the binding behavior of CNPs with human immunoglobulin G (HIgG) was examined by fluorescence quenching spectroscopy, synchronous fluorescence spectroscopy and circular dichroism spectroscopy under physiological conditions. The fluorescence quenching constants and parameters for the interaction at different temperatures had been calculated according to Scatchard. The thermodynamic parameters, such as enthalpy change (Δ H ), entropy change (Δ S ) and free energy change (Δ G ), were calculated, and the results indicated strong static quenching and showed that van der Waals forces, hydrogen bonds and hydrophobic interactions were the predominant intermolecular forces stabilizing the CNP–HIgG complex. Synchronous fluorescence and circular dichroism spectra provided information regarding the conformational alteration of HIgG in the presence of CNPs. These findings help to characterize the interactions between CNPs and HIgG, which may clarify the potential risks and undesirable health effects of CNPs, as well as the related cellular trafficking and systemic translocation. [ABSTRACT FROM AUTHOR]

Pollen influx (number of pollen grains cm year) can objectively reflect the dispersal and deposition features of pollen within a certain time and space, and is often used as a basis for the quantitative reconstruction of palaeovegetation; however, little is known about the features and mechanisms of vertical dispersal of pollen. Here we present the results from a 5 year (2006-2010) monitoring program using pollen traps placed at different heights from ground level up to 60 m and surface soil samples in a mixed coniferous and deciduous broad-leaved woodland in the Changbai mountains, northeastern China. The pollen percentages and pollen influx from the traps have very similar characteristics to the highest values for Betula, Fraxinus, Quercus and Pinus, among the tree taxa and Artemisia, Chenopodiaceae and Asteraceae among the herb taxa. Pollen influx values vary significantly with height and show major differences between three distinct layers, above-canopy (≥32 m), within the trunk layer (8 ≤ 32 m) and on the ground (0 m). These differences in pollen influx are explained by differences in (i) the air flows in each of these layers and (ii) the fall speed of pollen of the various taxa. We found that the pollen recorded on the ground surface is a good representation of the major part of the pollen transported in the trunk space of the woodland. Comparison of the pollen influx values with the theoretical, calculated 'characteristic pollen source area' (CPSA) of 12 selected taxa indicates that the pollen deposited on the ground surface of the woodland is a fair representation with 85-90 % of the total pollen deposited at a wind speed of 2.4 m s coming from within ca. 1-5 km for Pinus and Quercus, ca. 5-10 km for Ulmus, Tilia, Oleaceae and Betula, ca. 20-40 km for Fraxinus, Poaceae, Chenopodiaceae, Populus and Salix, and ca. 30-60 km for Artemisia; it is also a good representation with 90-98 % of the total pollen deposited coming from within 60 km at a wind speed of 2.4 m s, or 100 km at a wind speed: 6 m s, for the 12 selected taxa used in the CPSA calculation. Furthermore, comparison with the vegetation map of the area around the sampling site shows that the pollen deposited on the ground represents all plant communities which grow in the study area within 70 km radius of the sampling site. In this study, the pollen percentages obtained from the soil surface samples are significantly biased towards pollen taxa with good preservation due to thick and robust pollen walls. Therefore, if mosses are available instead, soil samples should be avoided for pollen studies, in particular for the study of pollen-vegetation relationships, the estimation of pollen productivities and quantitative reconstruction of past vegetation. The results also indicate that the existing model of pollen dispersal and deposition, Prentice's model, provides a fair description of the actual pollen dispersal and deposition in this kind of woodland, which suggests that the application of the landscape reconstruction algorithm would be relevant for reconstruction of this type of woodland in the past. [ABSTRACT FROM AUTHOR]

Tocopherol plays an important role as a powerful antioxidant in human beings and in plants. This study investigated the genetic basis of tocopherol content in soybean. A RIL population of 192 lines derived from 2 cultivars, ZH13 and ZH35, was evaluated for tocopherol content across 3 environments. QTL mapping identified 38 QTL for tocopherol, with stable QTL identified on Chromosomes 5 and 12. Ninety polymorphic genes were identified from these regions. Further SNP variation of a natural population identified 47 SNPs, with missense variants in 19 genes, including the heat shock transcription factor gene (GmHSFA8) and gamma-tocopherol methyltransferase (GmVTE4), potentially related to tocopherol accumulation in soybean. Haplotype analysis revealed significant variations in these missense variants in the natural population. This study provides insights into the genetic mechanisms underlying tocopherol content in soybean, which is important for breeding high tocopherol soybean cultivars. [ABSTRACT FROM AUTHOR]

The North China Plain is climatically sensitive and is also noted as one of the principal regions in East Asia experiencing pronounced climatic warming. We reconstructed the paleoclimate and paleoenvironment of a lake site in North China Plain during the mid-Holocene warm period, in order to provide reference data for assessing possible futures changes in the ecological environment in the context of ongoing climate change. The reconstruction is based on the chronology, sedimentology and pollen assemblages of two sedimentary sequences from the Lake Baiyangdian area, which are used to determine the regional vegetation composition and paleotemperature of the hinterland of the North China Plain during the mid-Holocene. The results show that the extent and distribution of Lake Baiyangdian varied due to river channel changes, which also affected the sedimentary facies and the patterns of erosion and accumulation. The pollen assemblages from the lacustrine deposits are derived from the entire catchment of Lake Baiyangdian and they reflect regional patterns of climatic and environmental change. During the mid-Holocene, mixed broadleaf-coniferous forest dominated the western mountains and hills, intrazonal grassland developed on the alluvial fans, and lake-swamp-floodplain environments developed in the hinterland of the North China Plain. Statistical analysis of the modern distribution and climate thresholds of Ceratopteris were used to estimate the mean annual temperature (MAT) and mean January temperature (MJaT) of the Lake Baiyangdian area during the mid-Holocene, which were respectively 3.5 °C and 7.7 °C higher than today. Our findings provide a scientific basis for landscape reconstruction and paleoclimate modelling in North China. • Characteristics of sedimentary strata in Lake Baiyangdian area during the Holocene • Environmental implications of sedimentary pollen assemblages from Lake Baiyangdian • Regional vegetation composition of the Lake Baiyangdian area during the mid-Holocene • Estimates of the mid-Holocene paleotemperature in the hinterland of North China Plain [ABSTRACT FROM AUTHOR]

The response characteristics of East Asian summer monsoon (EASM) precipitation to abrupt climatic events during the early to middle Holocene transition may provide insights into the response of EASM precipitation to possible extreme climatic events under future global warming scenarios. We present a high-resolution (∼10 yr) pollen record from a hydrologically closed alpine lake (Yazihai Lake) in North China spanning the interval of 9000–7500 cal yr BP. The results reveal two significant weak monsoon events during 8830–8730 cal yr BP and 8100–8000 cal yr BP. Based on a comparison with the GRIP δ18O ice core record from Greenland and the stalagmite δ18O record from Dongge Cave in South China, we suggest that the second weak monsoon event (8100–8000 cal yr BP) recorded at Yazihai Lake corresponds to the 8.2 ka event that originated in the North Atlantic region, it is spatially and temporally synchronous between the northern and the southern parts of the EASM region and is characterized by a significant decrease in EASM precipitation. For the first weak monsoon event (8830–8730 cal yr BP) recorded at Yazihai Lake, it was also captured by pollen, stalagmite δ18O, and marine sedimentary records from middle to low latitudes of the Northern Hemisphere, and its nature and amplitude resemble the 8.2 ka event. We infer that the possible cause of these two significant weak monsoon events was related to the southward shift of the intertropical convergence zone (ITCZ) due to the collapse of the Atlantic Meridional Overturning Circulation (AMOC), triggered by meltwater influx to the North Atlantic Ocean, and that the abrupt climate signals were transmitted via the monsoon circulation from low latitudes to middle–high latitudes in the EASM region. • Two significant weak monsoon events occurred in North China during 9000–7500 cal yr BP. • Details are given on the effects and structure of the 8.2 ka event in North China. • Possible causes of two significant weak monsoon events are discussed. [ABSTRACT FROM AUTHOR]

Due to the scarcity of long, high-resolution paleoclimate records, the effects of abrupt climatic events on regional climate variations in middle to high latitudes of East Asia are unclear. We present a detailed pollen record for the past 35,000 years, with an AMS 14C chronology, from Hulun Lake in northern China. The results reveal four episodes of regional vegetation change during the Last Glaciation, characterized by increases in cold-resistant and drought-tolerant plants and decreased regional vegetation cover. These episodes coincided with Heinrich events (H3, H2 and H1) and the Younger Dryas event (YD) that originated in the North Atlantic region. Additionally, during the warm intervals of the Dansgaard-Oeschger (D-O) cycles and the Bølling-Allerød (B/A) interstadial recorded in Greenland ice cores, patches of broadleaved deciduous forest expanded in the surrounding mountains while typical steppe vegetation expanded in the vicinity of Hulun Lake. Overall, the structure and amplitude of regional vegetation change in the Hulun Lake region during abrupt climatic events differ from the registration of these events in the oxygen isotope records from Greenland ice cores; however, they are similar to coeval stalagmite oxygen isotope records from East Asia. Thus, we suggest that the regional climate variations were characterized by increased or decreased precipitation during H events and D-O cycles in the Hulun Lake region, which was mainly controlled by changes in the intensity of the East Asian summer monsoon (EASM). Our results suggest that the variability of the EASM was physically linked to the North Atlantic climate system on centennial- to millennial-scale. In addition, the amplitude of regional precipitation variations during H events and D-O cycles was low during the interstadial of the Last Glaciation and the Last Glacial Maximum; however, the amplitude of regional precipitation variations during H1 event and B/A warming event was substantially greater during the Last Deglaciation. We suggest that differences in NHSI and land surface conditions (ice sheets and sea level) were responsible for the contrasting responses of EASM precipitation to these abrupt climatic events during different intervals. • Detailed pollen record for the past 35,000 years from the northern EASM region of China. • Characteristics of regional precipitation variations during H events and D-O cycles. • NHSI and land surface changes affected the EASM response to abrupt climatic events. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) were synthesized by the nitric acid oxidation of activated carbon. The experimental measurements showed that the resulting particles exhibited an average diameter of 50nm and tunable emission wavelength. The fluorescence intensity of CDs was effectively quenched by copper ion (Cu2+) (turn-off) and restored reversibly by the addition of oxalate (turn-on). Based on this phenomenon, an “off–on” approach for detection of Cu2+ and oxalate using CDs as fluorescent probes was performed. The quantitative detection of Cu2+ ranged from 1.0×10−5 to 9.0×10–5 mol/L was allowed, and the concentrations of oxalate in the range of 1.0×10−5–7.0×10–5 mol/L exhibited a linear relationship with the relative fluorescence intensity with a correlation coefficient R 2=0.9945. Furthermore, the detection limit for oxalate was as low as 1.0×10−6 mol/L, and the influences of 14 kind potential interference ions on oxalate determination were examined. [ABSTRACT FROM AUTHOR]

In order to ensure an ongoing and long-term breeding progress of soybean, stable sources of major quality traits across multi-environments need to be identified. Here, a panel of 135 soybean genotypes was tested in three different Chinese environments, including Beijing, Anhui, and Hainan during the 2017 and 2018 growing seasons to identify stable genotypes for cultivation under varying environmental conditions. The weighted average of absolute scores biplot (WAASB) for the best linear unbiased predictions of the genotype-environment interaction and multi-trait stability index (MTSI) were utilized to determine the stability of the soybeans for seven seed composition traits viz; protein content, oil content, and five fatty acids (palmitic, stearic, oleic, linoleic, and linolenic acids). Based on the WAASB index, the following genotypes were identified as stable genotypes for some specific traits; ZDD12828 and ZDD12832 for protein content, WDD01583 and WDD03025 for oil content, ZDD23040 for palmitic acid, WDD00033 for stearic acid, ZDD23822 for oleic acid, ZDD11183 for linoleic acid, and ZDD08489 for linolenic acid. Furthermore, based on MTSI at a selection intensity of 10%, 14 soybean genotypes were selected for their average performance and stability. Overall, the MTSI was shown to be a powerful and simple tool for identifying superior genotypes in terms of both performance and stability, hence, identifying stable soybean genotypes for future breeding programs of quality traits. [ABSTRACT FROM AUTHOR]

The Qaidam Basin is one of the most sensitive areas to climate change in China, owing to its unique geographical position and ecological condition. In this study, 32 surface-soil pollen samples were collected to reveal the relationship between modern pollen assemblages, vegetation and precipitation in the eastern region of the Qaidam Basin. The results show that Chenopodiaceae (3.8-87%, average 48%), Artemisia (1.7-64.2%, average 17.5%) and Ephedra (0-90%, average 16.3%) are the dominant pollen types in all samples, and that different pollen assemblages correspond to different vegetation types. DCA and CCA of major pollen types demonstrate that precipitation is an important factor in the control of the distribution of vegetation in the study area. The content and concentration of the three major pollen types ( Artemisia, Chenopodiaceae and Ephedra) change with the mean annual precipitation, and the optimum mean annual precipitation for Ephedra, Chenopodiaceae and Artemisia is <80, 80-200 and >160 mm, respectively. Correlation analysis between the variation in grain size of the three major pollen types and the main environmental variables shows that the grain size of the three pollen types is positively correlated with precipitation in the Qaidam Basin. The results confirm that precipitation is the most important environmental factor in the Qaidam Basin, and that it has an important effect on pollen grain size in the study area. [ABSTRACT FROM AUTHOR]

Based on 74 fossil pollen records and relative pollen productivity estimates for 29 plant taxa, we produced a quantitative reconstruction of regional vegetation change in North China over the past 6,000 years, using the combined MAT-REVEALS approach. The results include the spatial dynamics of the five main land cover types (Pinus , coniferous trees excluding Pinus , deciduous trees, grassland and bare ground) for three time slices: 6 ka, 3 ka and 0.05 ka. From 6 ka to the present, the total vegetation cover decreased from 64% to 61% (i.e., bare ground increased from 36% to 39%), mainly because of decreases in the cover of deciduous trees (from 19% to 14%). At the same time, the cover of coniferous trees increased (from 10% to 14%), and that of herb plants was largely unchanged (from 34% to 33%). The vegetation cover was greater at high latitudes and altitudes than at lower latitudes and in lowland areas. On the regional scale, temperate coniferous forest with Larix and Betula was dominant in the Greater Khingan Mountains, while in the Changbai Mountains, deciduous forest (decreasing from 72% to 56%) gradually transitioned to coniferous-deciduous mixed forest (Pinus and coniferous trees increased from 1% to 18%). The deciduous forest was dominated by Quercus , Betula and Pinus and occurred mainly in the warm temperate mountains of North China, where the vegetation cover was relatively high before 3 ka (>70%), before decreasing substantially to 55% at 0.05 ka. Grassland with Artemisia and Poaceae was the main land cover type in the North China Plain and in the temperate steppe region where forest vegetation was relatively sparse. The spatial dynamics of the land cover types appear to have been affected by climate change; climatic cooling in the second half of the Holocene led to the southward migration of coniferous trees. At the same time, human activities were likely the cause of the reduction of the regional vegetation cover, especially the tree cover. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seed tocopherols were profiled in 1,151 Chinese soybean accessions. • Tocopherol level was affected by genotype, ecoregion of origin, and accession type. • The correlations among quality traits could facilitate soybean breeding. • The geographical distribution provided hotspot regions for higher tocopherols. • Soybean accessions with high tocopherols could be used as elite breeding materials. Soybean seeds are primary sources of natural tocopherols used by food and pharmaceutical industries owing to their beneficial impacts on human health. Here, we profiled the seed tocopherol compositions of 1151 Chinese soybean accessions that originated from different ecoregions, grown in three locations for two years in China. Thus, this study aimed to evaluate the effect of accessions, ecoregions of origin, accession types and geographical factors on tocopherol content of soybean as well as unveil the correlations among tocopherols and other important seed quality traits. The highest average contents of α- and γ-tocopherols (15.43 μg g−1 and 151.44 μg g−1, respectively) were observed in the Northern Region (NR) accessions of China. Also, α-, γ-, and total tocopherol contents were higher in cultivars than landraces. The correlation analysis showed that tocopherols were significantly associated with other seed quality traits. α- and γ-tocopherols had significant positive correlations with latitude and longitude, while δ-tocopherol showed a contrary trend. Taken together, we identified novel soybean accessions that can be utilized as raw materials for food industries and in breeding programs to improve the tocopherols contents of soybean seeds. [ABSTRACT FROM AUTHOR]

• Soybean seed nutritional characteristics are affected by the origin of cultivar. • Chinese and USA soybean cultivars exhibit different seed nutritional profiles. • Protein, oil, isoflavone, oleic and linoleic acids are major discriminative traits. • Elite soybean cultivars could be utilized in breeding programs and food industries. Soybean is an important oilseed crop both in China and the USA owing to its nutritional and functional characteristics. The formation of nutritional components in soybean is influenced by the genetic background of cultivar as well as environmental factors. Here, we profiled protein, oil, fatty acids, soluble sugars and isoflavone in 218 Chinese and 115 USA soybean cultivars which were grown across three locations for two years in China. Significant differences (p < 0.05) were observed among the cultivars, countries of origin and maturity groups for all the nutritional characteristics measured. Higher levels of oil (20.5%), linoleic acid (56.4%), sucrose (58.6 mg g−1), total soluble sugars (109 mg g−1) and total isoflavone (3,161.8 μg g−1) were observed in USA cultivars, while higher levels of protein (42.4%) and oleic acid (23.2%) were observed in Chinese cultivars. From the principal component analysis, protein, oil, oleic acid, linoleic acid and isoflavone were identified as the major discriminative characteristics in the soybean cultivars. Furthermore, correlation analysis presented various beneficial associations among the different nutritional traits. The nutritional characteristics varied in their associations with the geographical factors (latitude, longitude and altitude), indicating that the origin of the cultivars has a pronounced effect on the nutritional characteristics. This study reveals the profiles of nutritional characteristics of Chinese and USA soybean cultivars and also identified unique cultivars that can be utilized for various industrial uses and breeding programs aimed at improving soybean nutritional characteristics. [ABSTRACT FROM AUTHOR]

Soybean contains nutritional bioactive compounds, including carotenoids associated with human health benefits. Carotenoids are applicable in pharmaceuticals/nutreceuticals, cosmetic, and mainly food industries. However, an efficient and accurate method for carotenoid and chlorophyll detection and quantification has not yet been developed and validated for soybean seeds. The need for a rapid and reliable analysis method has become increasingly important. Thus, this study was initiated to develop and validate a simple, rapid, and selective reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of lutein, zeaxanthin, α-carotene, β–carotene, β–cryptoxanthin, and chlorophyll–a and –b in soybean flour sample (100.00 mg) extracted using ethanol-acetone (1:1) solvents at a volume of 1.50 mL. Interestingly, the effective separation technique was achieved using the mobile phases of methyl tert-butyl ether, methanol containing 10 mM ammonium acetate, and water delivered at a 0.90 mL min−1 flow rate through a C30YMC Carotenoid (250 × 4.6 mm I.D., S-5 µm) column coupled with a UV-VIS detector set at 450 nm. The detector response was linear from 0.05–30.00 μg mL−1 with a coefficient of determination (R2) of 0.9993–0.9999. The validated method was sensitive with a detection limit (LOD) of 0.0051–0.0300 μg mL−1 and 0.0155–0.0909 μg mL−1 for the quantification limit (LOQ). The recovery values were from 83.12–106.58%, and the repeatability precision ranged from 1.25–4.20% and 0.15–0.81% for the method and system, respectively. The method showed adequate precision with a relative standard deviation smaller than 3.00%. This method was also found to be applicable for profiling carotenoids and chlorophylls in other legumes. In summary, this method was successfully implemented for qualitative and quantitative determination of major carotenoids and chlorophylls in soybean and other legume seeds, which are beneficial to food industry and quality breeding programs to meet human nutrition demands globally. [ABSTRACT FROM AUTHOR]

The emergence of autonomous vehicles (AVs) could transform traffic flow characteristics and affect energy consumption subsequently. The primary objective of this study is to propose an improved eco-driving strategy for the mixed platoons by exploring the impacts of AVs on energy consumption characteristics. Initially, leveraging precise AV control, this study utilizes a Model Predictive Control (MPC) system to optimize AV trajectories, aiming to minimize energy consumption within mixed platoons of AVs and human-driven vehicles (HDVs). Given the differing collaborative capabilities of HDVs and AVs in mixed platoons, exceptional situations may arise at intersections where not all platoon vehicles cross the stop line during the same green light cycle (GLC). To address these challenges, we then propose a splitting approach to optimize the platoon operation mode. This approach allows for flexible splitting decisions based on AVs market penetration and current traffic conditions. The simulation results indicate that the energy consumption reduction ranges from 15.35% to 35.39% and 2.75–3.64% compared to the traditional mode and the eco-driving mode, respectively. In addition, through an analysis of the energy consumption of various vehicle orders within a mixed platoon, we determined that positioning the second AV in the middle platoon maximizes stability, resulting in a more consistent energy consumption pattern. These findings highlight the advantages of the strategy in terms of energy consumption, providing theoretical support management of mixed platoons. • A splitting mode for mixed platoons is designed considering the characteristics. • A simulation experiment confirms potential energy savings from proposed strategy. • Placing the second autonomous vehicle in the mixed platoon center maximizes stability. • Establishing a foundation for mixed platoons in operation and energy management. [ABSTRACT FROM AUTHOR]

Coastal wetlands provide valuable ecosystem services and understanding their response to past climatic changes may help predict their possible future responses. In this paper, we obtained records of pollen, algae, sediment grain-size, and other environmental proxies, from a late Holocene sediment core (CFD-E) from the Caofeidian area, on the northwest coast of the Bay of Bohai, China. Our results indicate three major stages of environmental change. During Stage I (3500–2800 cal yr BP), arboreal pollen content was high (mostly >60%), especially for Pinus and Quercus , and the PCA sample scores on Axis 1 were negative indicating that regional vegetation was temperate broadleaved forest and the climate was wet. During Stage II (2800–2350 cal yr BP), the arboreal pollen content decreased substantially (mostly <40%), and the PCA Axis 1 sample scores were positive indicating a decrease in forest vegetation, grassland expansion, and a drier climate. During Stage III (2350–1400 cal yr BP), the arboreal pollen content increased again (mostly >40%), although it remained lower than during Stage I, indicating that forests expanded under a relatively humid climate while the wetland area decreased slightly. Our results also record the 2.8 ka and 2.4 ka events of monsoon weakening, which were characterized by increases in herbaceous pollen (indicating grassland expansion) and the drying of the regional climate. There are several differences in the regional expression of these two climatic events. During the 2.4 ka event, Chenopodiaceae pollen increased substantially (average of 42.0%), indicating the expansion of halophytes; whereas during the 2.8 ka event, an increase in Artemisia indicates the occurrence of a dry climate throughout the region. We suggest that the aridity during the 2.8 ka event was triggered by decreased solar activity and the resulting changes in the El Niño-Southern Oscillation, which weakened the East Asian summer monsoon. However, we suggest that the 2.4 ka event was driven by the weakening of the Atlantic Meridional Overturning Circulation. • Significant increase in halophytic vegetation during 3500–1400 cal yr BP • The 2.8 ka and 2.4 ka events were characterized by climate drying lasting ∼150 years. • During these two events the area of forest decreased and grassland expanded. [ABSTRACT FROM AUTHOR]

Highlights The booming development of mobile devices has remarkably improved the lives of people, but it also leads to severe electromagnetic radiation problems. Therefore, it has become significantly important to develop electromagnetic interference (EMI) shielding materials for electromagnetic protection. In recent years, MXenes have attracted much attention in the field of EMI shielding, owing to outstanding electrical conductivity, high specific surface area and hydrophilicity. Firstly, this review introduces EMI shielding mechanism and categorization of EMI shielding materials. Subsequently, the research progress of MXenes/polymer‐based EMI shielding materials is reviewed in detail, especially for preparation methods of MXenes/polymer‐based EMI shielding blocks. Finally, the key scientific problems in MXenes/polymer‐based EMI shielding materials are proposed, and their development trend are prospected. The EMI shielding mechanism and categorization of EMI shielding materials is presented. The latest research progress of MXenes/polymer‐based EMI shielding materials is reviewed. Scientific problems for MXenes/polymer‐based EMI shielding materials are proposed. Development trend of MXenes/polymer‐based EMI shielding materials is prospected. [ABSTRACT FROM AUTHOR]

Car-following behavior is strongly related to the dynamic performance and safety of vehicles, and these behaviors must be studied more comprehensively. This study first quantitatively analyzes the relationship between time to collision and car-following behavior, and then proposes the concept of collision sensitivity coefficient. Based on the full velocity difference model, we introduce the collision sensitivity coefficient into the car-following model to explore its effect on vehicle dynamic performance and safety from a different perspective. The stability of traffic flow is investigated using linear stability theory and obtain the neutral stability condition of the proposed model. Numerical simulation results show that the proposed model can improve the stability of traffic flow and successfully suppress traffic jams. The computation results using various safety evaluation indicators reveal that the proposed model not only has better dynamic performance than the full velocity difference model but also can effectively improve the safety of vehicles. We conclude that collision sensitivity substantially affects car-following behavior. • The concept of collision sensitivity coefficient is proposed and its properties are analyzed theoretically. • An extended car-following model considering collision sensitivity is proposed. • The stability of the proposed model is investigated using linear stability theory. • Numerical simulations are conducted to explore how collision sensitivity influences the dynamic performance and safety of vehicles. [ABSTRACT FROM AUTHOR]

• The CD-DNBS was constructed using DNBS group as the recognition unit. • The CD-DNBS was successfully applied to quantitative sense PhSH by naked-eye. • The CD-DNBS displays a high selectivity towards thiophenol over biothiols. • The CD-DNBS is applicable to the precise measurement of PhSH by the test strip. A colorimetric turn-on probe was developed for the selective naked-eye determination of thiophenols by using yellow-emissive carbon dots (Y-CDs) as the colorimetric reporter and 2, 4-dinitrobenzenesulfonamide (DNBS) group as the recognition unit. The surfaces of Y-CDs were covalently coated with 2, 4-dinitrobenzenesulfonyl chloride to afford the 2, 4-dinitrobenzene- functionalized carbon dots (CD-DNBS) as a novel probe for detecting thiophenols. CD-DNBS was nearly colorless. Upon addition of thiophenol, the DNBS moiety of CD-DNBS could be readily cleaved via nucleophilic substitution reactions, leading to a dramatic increase in absorbance at 400 nm. The established detection probe displays a high selectivity towards thiophenol over biothiols and other biologically related species. [ABSTRACT FROM AUTHOR]

The development of fluorescent probes for the sensitive and selective determination of highly toxic thiophenols is considerably important in the fields of biological and environmental sciences. Herein, a turn-on fluorescent probe for thiophenol, named MCSH, was constructed based on a p K a shift mechanism, employing merocyanine dye as the fluorophore and 2,-4-dinitrobenzenesulfonamide (DNBS) group as the recognition unit. The imine nitrogen of MCSH has a p K a value of 4.12, which renders its non-fluorescent Schiff base form exclusively under neutral conditions. However, after reacting with thiophenols, its DNBS group was removed to afford a merocyanine dye as the final product, whose p K a value upshifts to 8.11, and was present mainly as the fluorescent protonated Schiff base form under neutral media. Such drastic change in p K a values leads to a significant fluorescence enhancement and can be utilized for the detection of thiophenols. The fluorescence intensity at 627 nm increases linearly with thiophenol concentration in the range of 0.2–3 μM with a detection limit of 15 nM (S/N = 3). MCSH displays high selectivity for the detection of thiophenols over a wide range of other analytes, including aliphatic thiols. Furthermore, the preliminary applications of MCSH for monitoring thiophenols in living cells and environmental have been carried out. Image 1 • A turn-on fluorescent probe for thiophenol has been developed. • The probe was constructed based the pK a shift of a merocyanine Schiff base. • The probe employs 2, 4-dinitrobenzenesulfonamide group as the recognition unit. • The probe shows high selectivity for thiophenols over various other analytes including aliphatic thiols. [ABSTRACT FROM AUTHOR]

Measurement of Cr (VI) in environmental water samples is essential for monitoring drinking water quality and the risks of industrial waste. In this study, we report the first use of a new type of label-free carbon dot-based nanosensor for ratiometric fluorescence detection of Cr (VI) in environmental water samples. By using a simple one-pot method based on the solvothermal treatment of o -phenylenediamine, bright-yellow-emissive carbon dots (Y-CDs) were synthesized, exhibiting two emission bands centered at 430 and 560 nm under a single-wavelength excitation at 345 nm. Fluorescence intensities of the two emission bands of the as-synthesized Y-CDs were found to be simultaneously Cr (VI)-sensitive. The ratio of intensity (I 560 nm / I 430 nm) was linear against Cr (VI) concentrations from 0.01 to 4.5 μM at pH 6.0, and the detection limit (S/N = 3: 1) was 2.3 nM, therefore having a propensity to be a suitable ratiometric probe for sensing Cr (VI). Furthermore, the nanosensor was successfully applied to quantitatively detect Cr (VI) in environmental water samples. Compared with the majority of current ratiometric Cr (VI) sensors, this label-free CD-based ratiometric probe has low toxicity, a simple synthesis route, and excellent photostability. Image 1 • The Y-CDs show dual emission bands at 430 and 560 nm under excitation at 345 nm. • The intensity ratio (I 560 nm / I 430 nm) is linear against Cr (VI) concentrations. • The nanosensor was applied for ratiometric sensing of Cr (VI) in water samples. • The ratiometric probe is low in toxicity, easy to synthesize, and free from labels. [ABSTRACT FROM AUTHOR]

The scientific evaluation of tourism resources provides the basic conditions for the rational development and utilization of tourism resources, which is significant for the sustainable development of tourism. On the basis of obtaining a large sample of tourism resource data, this study constructed an evaluation index system of regional tourism resources from four aspects: quantity, type, grade, and a combination of regional tourism resources, taking the township scale as the spatial evaluation unit. The combination weighting method was used to evaluate the grade of tourism resources in each township, and the hierarchical clustering method and spatial autocorrelation method were used to analyze the spatial patterns of the tourism resource values. On the basis of the evaluation's results and spatial pattern analysis, this paper analyzed the influencing factors of tourism resource patterns and puts forward a tourism development model suitable for Hainan tourism development. The results showed that the overall value of tourism resources on Hainan Island was low, and the spatial pattern was obviously different, showing that the northern piedmont plain area was higher than the southern hilly area, and the east coast area was higher than the west coast area. Based on the analysis of quantity density, type abundance, grade advantage, and spatial combination, the tourism resource values of Hainan Island was divided into four combination areas: the first area was diversity and good combination, the second area was large quantity and good combination, the third area was diversity and high-quality resources, and the fourth area was large quantity. In addition, from the analysis of the spatial agglomeration effect, the phenomena of high and low agglomerations of tourism resource values were obvious. Finally, this paper puts forward a tourism development model for Hainan Island by grading, classification, and zoning. The results of this study can determine the time sequence and mode of regional tourism resources development and provide spatial implications and suggestions for regional tourism planning and management. [ABSTRACT FROM AUTHOR]

Abstract: Luminescence carbon nanoparticles (CNPs) have been prepared by refluxing the combustion soot of kerosene in nitric acid, and this approach can be used for milligram-scale synthesis of water-soluble particles. These fluorescent CNPs were stable in water for more than 3months without fluorescence decreasing. Diameter of the water-soluble fluorescent CNPs obtained by scanning electron microscope was about 50nm. In order to improve CNPs'' properties, they were modified with thiocarbamide. The effect of adsorption and deposition for metal ions could be measured by inductively couple plasma atomic emission spectrometry. In addition, the responses to pH of thiocarbamide-modified CNPs were different from the responses of CNPs. [Copyright &y& Elsevier]

• The Y-CDs possessing a yellow-emissive wavelength display a large Stokes shift. • The intensity of Y-CDs was effectively quenched by TNP via an inner filter effect. • The Y-CDs exhibited brilliant photostability, and selectivity in TNP measurements. • The nanoprobe was successfully applied to quantitative sense TNP in water samples. A fluorescent nanoprobe based on yellow-emissive carbon dots (Y-CDs) has been constructed for selective and sensitive sensing of 2,4,6-trinitrophenol (TNP). Y-CDs with a large Stokes shift (115 nm) were obtained through a simple one-pot solvothermal method. Significantly, the addition of TNP induced remarkable quenching of fluorescence intensity of Y-CDs via an inner filter effect. There was a good linear relationship between the fluorescence of Y-CDs and TNP concentration (0.2–130 μM), displaying a limit of detection of 56 nM. The nanoprobe can selectively detect TNP without interference from other nitroaromatic explosives, and has been successfully used for determining TNP in environmental water samples, representing a convenient tool for TNP sensing in environmental samples. [ABSTRACT FROM AUTHOR]

A new nanoprobe based on yellow-emissive carbon dots (Y-CDs) was developed for sensing full-range intracellular pH values. By using o -phenylenediamine as the raw material, Y-CDs with a quantum yield of 31% were prepared through a one-pot solvothermal carbonization method. The Y-CDs exhibited a distinctive fluorescence emission peak at 570 nm with excitation at 450 nm, showing a very large Stokes shift (120 nm). Notably, the nanoprobe revealed a linear relationship between fluorescence intensity and pH value within the range of pH 4.0 to 8.2, exhibiting the ability of this probe to monitor full-range intracellular pH variations. In addition, the nanosensor possessed excellent photostability and fluorescence reversibility in pH measurements and showed excellent selective detection of the influences of other biological species. The CD-based nanoprobe was successfully used to perform quantitative fluorescence imaging of intracellular pH variation, demonstrating its promise for application in cellular systems. Image 1 • The Y-CDs possessing a yellow-emissive wavelength (570 nm) display a large Stokes shift (120 nm). • The Y-CDs meets the requirement for sensing of full-range intracellular pH values. • The Y-CDs exhibited brilliant photostability, reversibility and selectivity in pH measurements. • The nanoprobe was successfully used to quantitative sense intracellular pH values. [ABSTRACT FROM AUTHOR]

Distinctness, uniformity and stability (DUS) testing of cultivars through morphological descriptors is an important and compulsory part of soybean breeding. Molecular markers are usually more effective and accurate in describing the genetic features for the identification and purity assessment of cultivars. In the present study, we assessed the distinctness and uniformity of five soybean cultivars using both single nucleotide polymorphism (SNP) markers developed by specific-locus amplified fragment sequencing (SLAF-seq) technology, and simple sequence repeat (SSR) markers. The phylogenetic tree and principal component analysis (PCA) from both the SLAF-seq and SSR methods showed a clear distinction among cultivars Zhonghuang 18, Zhonghuang 68 and Zhonghuang 35, while no clear distinction was observed between cultivars Zhonghuang 13 and Hedou 13. Using the SLAF-seq method, we determined the proportion of homozygous loci for the five soybean cultivars. The heterozygosity of each individual plant was estimated for the assessment of cultivar purity and the purity levels of the five soybean cultivars ranged from 91.89% to 93.96%. To further validate the applicability of the SLAF-seq approach for distinctness testing, we used the SNP information of 150 soybean cultivars with different origins. The cultivars were also distinguished clearly. Taken together, SLAF-seq can be used as an accurate and reliable method in the assessment of the distinctness and uniformity of soybean cultivars. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max L. Merr.) is one of the most important crops in the world. Its major content of vegetable oil made it widely used for human consumption and several food industries. To investigate the variation in seed fatty acid composition of soybeans from different origins, a set of 633 soybean accessions originated from four diverse germplasm collections—including China, United States of America (USA), Japan, and Russia—were grown in three locations, Beijing, Anhui, and Hainan for two years. The results showed significant differences (P < 0.001) among the four germplasm origins for all fatty acid contents investigated. Higher levels, on average, of palmitic acid (PA) and linolenic acid (LNA) were observed in Russian germplasm (12.31% and 8.15%, respectively), whereas higher levels of stearic acid (SA) and oleic acid (OA) were observed in Chinese germplasm (3.95% and 21.95%, respectively). The highest level of linoleic acid (LA) was noticed in the USA germplasm accessions (56.34%). The largest variation in fatty acid composition was found in LNA, while a large variation was observed between Chinese and USA germplasms for LA level. Maturity group (MG) significantly (P < 0.0001) affected all fatty acids and higher levels of PA, SA, and OA were observed in early maturing accessions, while higher levels of LA and LNA were observed in late maturing accessions. The trends of fatty acids concentrations with different MG in this study further provide an evidence of the importance of MG in breeding for such soybean seed components. Collectively, the unique accessions identified in this study can be used to strengthen the soybean breeding programs for meeting various human nutrition patterns around the globe. [ABSTRACT FROM AUTHOR]