摘要：
BACKGROUND: The plant microbiome can support plant health and fitness in the face of biotic and abiotic stress. Research has mostly focused on plant growth in natural and agricultural soils. However, as urban areas continue to expand and soils change in the Anthropocene, microbiome assembly during development of plants grown in urban area soil remains largely elusive. Here, we examined the effect of developmental stages on the phyllosphere and rhizosphere microbiomes of rice grown in soil from an urban area during the vegetative growth stages. RESULTS: We found that the microbial alpha and beta diversity, networks, and functions of the phyllosphere and rhizosphere microbiomes significantly differed among rice seedling, tillering, and elongation stages. Notably, we observed that bacteria assigned to potential animal parasites or symbionts not only exhibited significantly higher relative abundances in the phyllosphere compared to the rhizosphere but are also influenced by the developmental stages. Plants grown in the urban area soil had a higher relative abundance of Bacteroidales and enriched bacteria assigned to potential animal parasites or symbionts in the phyllosphere in contrast to plants grown in field. Some of these bacteria were shown to significantly influence the assembly of the phyllosphere microbiome and to prevalently engage in negative interactions with other microbes. CONCLUSION: Our study provides new insights into developmental stage-resolved microbiome assembly of plants grown in urban areas. The insights could help in the development of strategies for promoting 'One Health' by highlighting the role of plants as alternative host for bacterial groups that are prevalently associated with animals.
摘要：
KNOX genes play crucial roles in cell-fate determination and body plan specification during early embryogenesis. However, the specific gene structure and functional differentiation of KNOXs in Brassica napus is still unclear. We investigated KNOX genes in Brassica rapa (B. rapa), Brassica oleracea (B. oleracea), and Brassica napus (B. napus), which are polyploidy models with genome triplication after Arabidopsis-Brassiceae divergence. In total, 15, 14, and 32 KNOX genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis classified BnKNOXs (B. napus) into three classes with conserved domain organization. Synteny analysis indicated that BnKNOXs family expansion during allopolyploidization was mainly due to whole-gene and segmental duplications. Cis-element, gene structure, and expression pattern analyses showed high conservation within the same group. RNA-seq and qRT-PCR results divided BnKNOXs into three classes with distinct expression patterns: Class I exhibited moderate and specific expression in buds and inflorescence tips; Class III showed specific low expression in seeds and stamens; while the second class showed expression in most tissues. Sub-cellular localization results showed that the three candidate genes from the three classes exhibited distinct subcellular localizations, with BnSTM-C and BnKNAT3a-A predominantly in the nucleus and BnKNATM1-A in the cytoplasm indicating different expression patterns. Collectively, these findings provide a foundation for further functional studies of BnKNOX genes in B. napus.
摘要：
Hexavalent chromium (Cr(VI)) pollution poses significant health and ecological risks warranting cost-effective remediation. This study investigated the efficacy of zinc oxide nanoparticles (nZnO) and Miscanthus lutarioriparius synergism for Cr(VI) immobilization and stabilization. nZnO characterized by XRD, SEM-EDS and DLS was amended to 3 mg kg−1 Cr(VI) spiked soil pots at 0.5 % and 1 %. M. lutarioriparius seedlings were then transplanted and grown for 3 months. Results showed increase in residual soil Cr(III) from negligible to 68.9 % upon 1 % nZnO indicating reduction of Cr(VI). Maximum decline of 76.3 % in total Cr(VI) confirmed immobilization. Batch adsorption experiments revealed rising Cr(VI) removal from 61.3 % to 83.7 % by increase in nZnO dose from 0.2 to 1 g L−1. M. lutarioriparius demonstrated hyperaccumulator ability uptaking 208.3 and 156.8 mg kg−1 Cr in roots and shoots respectively. Restricted root-shoot translocation factor of 0.79 aided suitability for phytostabilization. The plant-nZnO synergy enhanced remediation efficiency as confirmed by tolerance index restoration from 38.6 % to 100 %. Increased growth performance reflected mitigation of toxicity by restricted bioavailability. Overall, the nanoremediation strategy displayed high potential for effective in situ stabilization of Cr(VI) contamination combining favorable properties of nZnO and plant tolerance mechanisms.
Hexavalent chromium (Cr(VI)) pollution poses significant health and ecological risks warranting cost-effective remediation. This study investigated the efficacy of zinc oxide nanoparticles (nZnO) and Miscanthus lutarioriparius synergism for Cr(VI) immobilization and stabilization. nZnO characterized by XRD, SEM-EDS and DLS was amended to 3 mg kg−1 Cr(VI) spiked soil pots at 0.5 % and 1 %. M. lutarioriparius seedlings were then transplanted and grown for 3 months. Results showed increase in residual soil Cr(III) from negligible to 68.9 % upon 1 % nZnO indicating reduction of Cr(VI). Maximum decline of 76.3 % in total Cr(VI) confirmed immobilization. Batch adsorption experiments revealed rising Cr(VI) removal from 61.3 % to 83.7 % by increase in nZnO dose from 0.2 to 1 g L−1. M. lutarioriparius demonstrated hyperaccumulator ability uptaking 208.3 and 156.8 mg kg−1 Cr in roots and shoots respectively. Restricted root-shoot translocation factor of 0.79 aided suitability for phytostabilization. The plant-nZnO synergy enhanced remediation efficiency as confirmed by tolerance index restoration from 38.6 % to 100 %. Increased growth performance reflected mitigation of toxicity by restricted bioavailability. Overall, the nanoremediation strategy displayed high potential for effective in situ stabilization of Cr(VI) contamination combining favorable properties of nZnO and plant tolerance mechanisms.
摘要：
Marginal lands, such as those with saline soils, have potential as alternative resources for cultivating dedicated biomass crops used in the production of renewable energy and chemicals. Optimum utilization of marginal lands can not only alleviate the competition for arable land use with primary food crops, but also contribute to bioenergy products and soil improvement. Miscanthus sacchariflorus and M. lutarioriparius are prominent perennial plants suitable for sustainable bioenergy production in saline soils. However, their responses to salt stress remain largely unexplored. In this study, we utilized 318 genotypes of M. sacchariflorus and M. lutarioriparius to assess their salt tolerance levels under 150 mM NaCl using 14 traits, and subsequently established a mini-core elite collection for salt tolerance. Our results revealed substantial variation in salt tolerance among the evaluated genotypes. Salt-tolerant genotypes exhibited significantly lower Na+ content, and K+ content was positively correlated with Na+ content. Interestingly, a few genotypes with higher Na+ levels in shoots showed improved shoot growth characteristics. This observation suggests that M. sacchariflorus and M. lutarioriparius adapt to salt stress by regulating ion homeostasis, primarily through enhanced K+ uptake, shoot Na+ exclusion, and Na+ sequestration in shoot vacuoles. To evaluate salt tolerance comprehensively, we developed an assessment value (D value) based on the membership function values of the 14 traits. We identified three highly salt-tolerant, 50 salt-tolerant, 127 moderately salt-tolerant, 117 salt-sensitive, and 21 highly salt-sensitive genotypes at the seedling stage by employing the D value. A mathematical evaluation model for salt tolerance was established for M. sacchariflorus and M. lutarioriparius at the seedling stage. Notably, the mini-core collection containing 64 genotypes developed using the Core Hunter algorithm effectively represented the overall variability of the entire collection. This mini-core collection serves as a valuable gene pool for future in-depth investigations of salt tolerance mechanisms in Miscanthus.
关键词：
Social capital;agricultural credit guarantee;participation behavior;social network;trust;entrepreneurs
摘要：
Agricultural credit guaranteed loans were effective in alleviating the challenges of securing funding and obtaining costly finance for new agricultural enterprises. This research utilized the Probit model to empirically analyze the impact and influence of social capital on the participation behavior of agricultural credit guaranteed loans, based on survey data from 503 newly established agricultural businesses in Hunan Province. The findings indicated that social capital, social network, social trust, and social involvement all exert a favorable and substantial influence on the behavior of participating in agricultural credit guaranteed loans. Additional analysis revealed that the impression of value had a role in moderating the impact of social capital on the behavior of participating in agricultural credit guaranteed loans. Furthermore, the influence of social capital on engagement patterns varies across distinct demographic categories, including age, educational attainment, and years of business experience.
摘要：
The bonding performance between new and old concrete affects the reliability and service life of the repair structure. However, the bonding interface is complex and has many influencing factors, so selecting appropriate repair materials and evaluation methods for repair structures under different service environments is important. This paper presents a comprehensive overview of the factors that influence bonding properties. These include the choice of repair materials, the condition of the existing concrete, the type of interfacial agents used, the service environment, and the testing methods employed. The paper concludes by examining the challenges and opportunities in developing interface bonding properties to provide insights and research directions for future theoretical analysis and experimental research.
摘要：
Biomass energy, recognized for its potential to supplant traditional energy sources, finds a promising alternative in Miscanthus. Particularly, M. lutarioriparius, a species within the Miscanthus genus, stands out as the most suitable for application. This study focuses on the impact of harvest timing on the biomass and combustion quality of M. lutarioriparius in the coastal wetlands of Dongting Lake, Hunan. A comprehensive field experiment was conducted in this area. The findings reveal several key trends: Firstly, the biomass yield of M. lutarioriparius decreased from 18.42 tons per hectare to 11.25 tons per hectare with the delayed harvest. there is a notable increase in the stem-to-leaf ratio of M. lutarioriparius, primarily attributed to leaf shedding. Secondly, the water content had dropped to 22.33% by the time of harvest in February of the following year. Ash content decreased from 4.55% to 2.17% from October to February of the following year. The calorific value, cellulose and lignin content increased with delayed harvest, while hemicellulose content decreased. Notably, the calorific value exhibits a significant positive correlation with cellulose and lignin content, and a markedly negative correlation with hemicellulose. Thirdly, most mineral elements in the plant demonstrate a significant decrease with delayed harvesting, except for potassium (K) and calcium (Ca), which initially increase and then decrease. The ash content shows a positive correlation with the contents of potassium (K) and silicon (Si). Despite a reduction in biomass yield due to delayed harvesting, combustion quality significantly improves. Therefore, it is concluded that optimal fuel quality is achieved when M. lutarioriparius is harvested in February of the following year.
期刊：
Population Space and Place,2024年30(7):e2789- ISSN：1544-8444
通讯作者：
Liu, D
作者机构：
[Liu, Dan] Guangdong Univ Foreign Studies, Sch English Educ, Guangzhou 510006, Peoples R China.;[Liu, Qiuxi] Hunan Agr Univ, Orient Sci & Technol Coll, Changsha, Hunan, Peoples R China.;[Morgan, W. John] Cardiff Univ, Sch Social Sci, Cardiff, Wales.;[Morgan, W. John] Cardiff Univ, Wales Inst Social & Econ Res & Data, Cardiff, Wales.
通讯机构：
[Liu, D ] G;Guangdong Univ Foreign Studies, Sch English Educ, Guangzhou 510006, Peoples R China.
关键词：
Chinese doctoral migration;cultural norms;gender differences;gender equality;motivations;push-pull
摘要：
Abstract Although attention has been paid to return migration internationally, research studies on why Chinese overseas doctoral graduates return to China are few. A study that considers gendered motivations has yet to be found. Using a qualitative study with 31 Chinese overseas doctoral graduate returnees, this study examines factors influencing graduates' reasons for returning to China and how these relate to Chinese gender and gender role‐related cultural norms. Using the push‐pull theory and the concepts of gender (as an individual characteristic) and gender norms, the study shows that the reasons for return were gendered, with females motivated by family and emotional factors and males by economic and career benefits. The study identifies inequalities derived from traditional gender roles and cultural norms that persist in China. This has implications for state policy, higher education institutions and future research.
摘要：
The presence of microcracks in the structure of barite aggregates and the occurrence of heat generation during the radiation shielding process contribute to a certain degree of deterioration of barite concrete. To address these challenges, an aggregate preheating method was proposed in this study, and the effects of aggregate preheating, addition of different polymer fibers on the mechanical, thermal, and radiation shielding properties of barite concrete were investigated. The influence mechanisms of aggregate preheating, as well as type and content of polymer fibers were further investigated by SEM, XRD, TG, and other experimental techniques. The results shown that the aggregate preheating and the incorporation of an appropriate amounts of fibers significantly improve the mechanical properties and thermal stability of the barite concrete. Fibers with smaller length-diameter ratios are more suitable for preparation of concrete with high mechanical properties, nevertheless, excessive fiber decreases the mechanical properties of the barite concrete. The aggregate preheating facilitates the premature fracture of barite aggregate and improves the microcrack structure of the barite, reducing the defects of the aggregates themselves, and increasing the failure path of the aggregates during the concrete failure process. Furthermore, aggregate preheating has a slight decreased effect on neutron shielding properties of barite concrete, whereas this adverse effect is compensated by the incorporation of polymer fibers.
