Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolit...Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolites might have specific or novel functions and these diverse active compounds can be achieved by biosynthesis, semi-biosynthesis, or chemical synthesis. A strategy to exploit the biosynthesis potential of a fungal strain is to use various culture conditions and to evaluate the chemical profiles of the culture extracts. The value of this approach was demonstrated with the fungal strain Aigialus parvus BCC 5311, producer of hypothemycin, aigialospirol, and aigialomycin A-D. The optimization of hypothemycin production and its derivative diversity by Aigialus parvus BCC 5311 was carried out using qualitative (general factorial design) and quantitative analysis (two-level fractional factorial design). Qualitative analysis revealed that soluble starch and yeast extract were shown to be the best carbon and nitrogen source respectively for the production of hypothemycin, aigialospirol and aigialomycin A-D. Quantitative analysis showed that the initial pH of culture medium is the most important factor that affects the production of hypothemycin and its derivatives (aigialospirol and aigialomycin A-D) production. Optimal medium composition used in a 5 L bioreactor generated a specific growth rate of A. parvus BCC 5311 of 0.0295 h-1, biomass yield of 1.6 g×gstarch-1, hypothemycin yield of 13.6 mg×gbiomass-1, and hypothemycin production rate of 0.6 mg×L-1×day-1. The maximum concentration of 58.0 mg×L-1 of hypothemycin was obtained at 120 h of culturing. Furthermore, the Aigialomycin A-D and Aigialospirol obtained were diversified towards various cultural conditions used. The high amount of hypothemycin produced and the diversity of derivatives obtained from this study should be useful for future mass production.展开更多
This autumn fruitful autumn,Beijing International Studies University(BISU)is about to celebrate the54th anniversary since its foundation.Meanwhile,the Department of English established in1964turned into the School of ...This autumn fruitful autumn,Beijing International Studies University(BISU)is about to celebrate the54th anniversary since its foundation.Meanwhile,the Department of English established in1964turned into the School of English Language,Literature and Culture(SELLC)in2009.Are there any moving stories behind these name-changes,and did the teaching philosophy change accordingly?展开更多
In the wave of higher education internationalization,college students’career education is faced with problems such as inadequate integration of international elements in teaching content,insufficient depth of interna...In the wave of higher education internationalization,college students’career education is faced with problems such as inadequate integration of international elements in teaching content,insufficient depth of international cooperation in practical links,lack of international professional experience among the teaching staff,and insufficient emphasis on the cultivation of multicultural adaptability in the education model.Based on this,this paper deeply explores the new requirements put forward by internationalization for college students’career education and its diversified implementation paths from the perspective of higher education internationalization.It aims to build a comprehensive and multi-level career education system and improve students’international competitiveness through strategies such as constructing an internationalized curriculum system,expanding international cooperation practice projects,strengthening international exchanges and training for teachers,and integrating multicultural education.展开更多
Global challenges,including resource inefficiency,rising food demand,sustainability concerns,and climate change,necessitate more efficient and resilient agricultural systems.Conservation agriculture(CA),which is based...Global challenges,including resource inefficiency,rising food demand,sustainability concerns,and climate change,necessitate more efficient and resilient agricultural systems.Conservation agriculture(CA),which is based on the principles of the minimum mechanical soil disturbance,permanent soil organic cover,and species diversification,provides a promising solution.This study examined the principles and mechanisms of CA,assessed its benefits and constraints,and identified key research gaps.This study focused on CA outcomes related to soil health,biodiversity,productivity,and ecosystem services,considering factors such as climate,soil type,and management practices.CA has demonstrated the potential to improve soil health,enhance biodiversity,and boost productivity across diverse regions.However,its effectiveness has been found to vary across studies,emphasizing the need for a more critical understanding of its benefits and limitations.Moreover,variations in outcomes are evident due to differences in experimental methodologies,environmental conditions,and socioeconomic factors.For the widespread adoption of CA practices,it is necessary to make personalized adjustments to it,integrating the corresponding technologies,thereby meeting the needs of farmers.Interdisciplinary research is crucial to refining CA practices and addressing existing knowledge gaps.This study is practiced to enhance the understanding of the potential of CA to promote a sustainable global food production system.展开更多
Gene Engineering Principles is a fundamental professional course for majors such as bioengineering and biotechnology.It integrates theoretical knowledge with experimental practice and engineering applications.It is ch...Gene Engineering Principles is a fundamental professional course for majors such as bioengineering and biotechnology.It integrates theoretical knowledge with experimental practice and engineering applications.It is characterized by its comprehensive and highly practical nature.Aligning with the new-era higher education philosophy of‘competency-oriented,value-driven’teaching,this study presented a systematic exploration and practice based on undergraduate cohorts from 2018 to 2020 in Chengdu University.The reform focused on teaching methodology,formative assessment,and the integration of ideological and political education.Key strategies included the introduction of classical experimental cases,emphasis on pre-class preparation,enhancement of classroom interaction,focus on engineering-oriented applications,optimization of assessment mechanisms,and the incorporation of national strategic needs into the curriculum.These measures effectively stimulated students’learning motivation and research potential,thereby improving the overall teaching quality and educational effectiveness of the course.The results of the teaching reform demonstrate significant improvements in students’ability to apply theoretical knowledge to practical engineering problems,scientific thinking,experimental research skills,scientific reasoning,and professional identity.Reformed classes outperformed control groups across various instructional metrics,achieving notable educational outcomes.展开更多
The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
In order to better implement the“Three-Dimensional Education”and cultivate high-quality nursing talents,the integration of ideological and political education into the pathogen biology curriculum promotes curriculum...In order to better implement the“Three-Dimensional Education”and cultivate high-quality nursing talents,the integration of ideological and political education into the pathogen biology curriculum promotes curriculum reform and application.This article explores the use of various teaching methods and means in the teaching process of pathogen biology under the guidance of ideological and political education,aiming to stimulate students’learning interest,cultivate their autonomous learning ability,independent thinking,problem-analyzing and problem-solving abilities,and thus improve their comprehensive qualities and medical professional literacy.展开更多
The sub-forum on standardization of new energy and direct-current diversified applications was held on July 9,which gathered leaders and experts to discuss how to thoroughly implement the national green power direct c...The sub-forum on standardization of new energy and direct-current diversified applications was held on July 9,which gathered leaders and experts to discuss how to thoroughly implement the national green power direct connection policy proposed in the transformation of the energy landscape,pool wisdom to tackle bottlenecks in the industrialization of DC technology,and leverage the role of standardization in coordinating and regulating the diversified applications of DC technology.It was designed to promote the establishment of a collaborative,open,and advanced global standards system for DC technology.展开更多
To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuro...To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuronal diversity,and uncover the principles governing neuronal specification across different regions.Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed,leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge.In this review,we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes,including predetermined,stochastic,and cascade diversifying models,and elaborate how these strategies are implemented in distinct regions such as the neocortex,spinal cord,retina,and hypothalamus.Importantly,the identity of neural progenitors is defined by their spatial position and temporal patterning factors,and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes.Microenvironmental cues,spontaneous activity,and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions.The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy,as well as understanding the organization of functional neural circuits and the evolution of the nervous system.展开更多
Chemosensation is the most ubiquitous sense in animals,enacted by the products of complex gene families that detect environmental chemical cues and larger-scale sensory structures that process these cues.While there i...Chemosensation is the most ubiquitous sense in animals,enacted by the products of complex gene families that detect environmental chemical cues and larger-scale sensory structures that process these cues.While there is a general conception that olfactory receptor(OR)genes evolve rapidly,the universality of this phenomenon across vertebrates,and its magnitude,are unclear.The supposed correlation between molecular rates of chemosensory evolution and phenotypic diversity of chemosensory systems is largely untested.We combine comparative genomics and sensory morphology to test whether OR genes and olfactory phenotypic traits evolve at faster rates than other genes or traits.Using published genomes,we identified ORs in 21 tetrapods,including amphibia ns,reptiles,birds,and mammals and compared their rates of evolution to those of orthologous non-OR protein-coding genes.We found that,for all clades investigated,most OR genes evolve nearly an order of magnitude faster than other protein-coding genes,with many OR genes showing signatures of diversifying selection across nearly all taxa in this study.This rapid rate of evolution suggests that chemoreceptor genes are in "evolutionary overdrive,"perhaps evolving in response to the ever-changing chemical space of the environment.To obtain complementary morphological data,we stained whole fixed specimens with iodine,μCT-scanned the specimens,and digitally segmented chemosensory and nonchemosensory brain regions.We then estimated phenotypic variation within traits and among tetrapods.While we found considerable variation in chemosensory structures,they were no more diverse than nonchemosensory regions.We suggest chemoreceptor genes evolve quickly in reflection of an ever-changing chemical space,whereas chemosensory phe no types and processing regions are more conserved because they use a standardized or constrained architecture to receive and process a range of chemical cues.展开更多
Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climat...Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.展开更多
In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area,Inner Mongolia,China,organic amendments applied as straw,manure,green manure,and the combination of green manure and ...In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area,Inner Mongolia,China,organic amendments applied as straw,manure,green manure,and the combination of green manure and straw increased wheat and maize yield,soil aggregate stability,and soil microbial activity in comparison with chemical fertilizer,without changing greenhouse gas emission intensity.展开更多
The triboelectric nanogenerator(TENG)can effectively collect energy based on contact electrification(CE)at diverse interfaces,including solid–solid,liquid–solid,liquid–liquid,gas–solid,and gas–liquid.This enables...The triboelectric nanogenerator(TENG)can effectively collect energy based on contact electrification(CE)at diverse interfaces,including solid–solid,liquid–solid,liquid–liquid,gas–solid,and gas–liquid.This enables energy harvesting from sources such as water,wind,and sound.In this review,we provide an overview of the coexistence of electron and ion transfer in the CE process.We elucidate the diverse dominant mechanisms observed at different interfaces and emphasize the interconnectedness and complementary nature of interface studies.The review also offers a comprehensive summary of the factors influencing charge transfer and the advancements in interfacial modification techniques.Additionally,we highlight the wide range of applications stemming from the distinctive characteristics of charge transfer at various interfaces.Finally,this review elucidates the future opportunities and challenges that interface CE may encounter.We anticipate that this review can offer valuable insights for future research on interface CE and facilitate the continued development and industrialization of TENG.展开更多
Based on the concept and development process of green agriculture and green economy,the field survey and questionnaire investigation were carried out in Jincheng Specialized Planting Cooperative in Xinji Town,Changli ...Based on the concept and development process of green agriculture and green economy,the field survey and questionnaire investigation were carried out in Jincheng Specialized Planting Cooperative in Xinji Town,Changli County of Qinhuangdao City. The results show that there are still many problems in the development of green economy and the improvement of green farms in Hebei Province. On this basis,it came up with pertinent measures and recommendations,in the hope of providing theoretical basis and reference for establishment and development of green farms in Hebei Province and most of domestic areas.展开更多
The world in which we are now living is becoming economically globalized, politically multi-polarized and culturally diversified. In such a global trend, the discussion on oriental culture and human rights development...The world in which we are now living is becoming economically globalized, politically multi-polarized and culturally diversified. In such a global trend, the discussion on oriental culture and human rights development aims at stimulating Chinese and international human rights development, promoting China’s human rights exchanges and cooperation with the theme of peace and development. This is of theoretical and practical importance.展开更多
We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based ...We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based on 5G technology,which provides a view of common satellite network slicing and supports flexible network deployment between the satellite and the ground.Specifically,considering the limited satellite network resource and the characteristics of the satellite channel,we propose a novel satellite E2E network slicing architecture.Therein,the deployment of the network functions between the satellite and the ground is coordinately considered.Subsequently,the classification and the isolation technologies of satellite network sub-slices are proposed adaptively based on 5G technology to support resource allocation on demand.Then,we develop the management technologies for the satellite E2E network slicing including slicing key performance indicator(KPI) design,slicing deployment,and slicing management.Finally,the analysis of the challenges and future work shows the potential research in the future.展开更多
Objective： The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection an...Objective： The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection and IV infusion in animal experimentation to hone the core professional nursing competencies. Methods： Two classes from the 2012 senior graduating nursing class were randomly selected by a computer to conduct the diversified practical teaching methods based on animal experimentation. A hospital environment was simulated by requiring students to perform different types of injections and practical IV infusion techniques. A comprehensive evaluation of the core professional competencies, as well as other integrated competencies, was conducted to determine the effectiveness of the teaching methods. Results： Two-sampled, pairwise u-tests were performed between the scores of the experimental （nursing class 2） and control （nursing class 1） groups. These findings showed that the overall test scores were significantly higher in the experimental group compared to the control group and that the average P-values for the competencies in various categories were 〈0.01, which indicated statistically significant results. Conclusions： Based on the data from this project, diversified teaching methods for basic nursing training founded on animal experimentation can help nursing students perfect their core professional competencies and improve their overall professional standing. The introduction of animal experimentation requires further verification, and an increased acknowledgement of its benefits through the widespread dissemination of this information.展开更多
Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrospher...Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrosphere is mainly associated with the ocean which is crucial to the human survival and development,due to the difference heat capacities be-展开更多
文摘Many metabolites produced by various microorganisms have proven their usefulness in the area concerning human health. However, most of their diverse natural compound biosyntheses are hardly discovered. These metabolites might have specific or novel functions and these diverse active compounds can be achieved by biosynthesis, semi-biosynthesis, or chemical synthesis. A strategy to exploit the biosynthesis potential of a fungal strain is to use various culture conditions and to evaluate the chemical profiles of the culture extracts. The value of this approach was demonstrated with the fungal strain Aigialus parvus BCC 5311, producer of hypothemycin, aigialospirol, and aigialomycin A-D. The optimization of hypothemycin production and its derivative diversity by Aigialus parvus BCC 5311 was carried out using qualitative (general factorial design) and quantitative analysis (two-level fractional factorial design). Qualitative analysis revealed that soluble starch and yeast extract were shown to be the best carbon and nitrogen source respectively for the production of hypothemycin, aigialospirol and aigialomycin A-D. Quantitative analysis showed that the initial pH of culture medium is the most important factor that affects the production of hypothemycin and its derivatives (aigialospirol and aigialomycin A-D) production. Optimal medium composition used in a 5 L bioreactor generated a specific growth rate of A. parvus BCC 5311 of 0.0295 h-1, biomass yield of 1.6 g×gstarch-1, hypothemycin yield of 13.6 mg×gbiomass-1, and hypothemycin production rate of 0.6 mg×L-1×day-1. The maximum concentration of 58.0 mg×L-1 of hypothemycin was obtained at 120 h of culturing. Furthermore, the Aigialomycin A-D and Aigialospirol obtained were diversified towards various cultural conditions used. The high amount of hypothemycin produced and the diversity of derivatives obtained from this study should be useful for future mass production.
文摘This autumn fruitful autumn,Beijing International Studies University(BISU)is about to celebrate the54th anniversary since its foundation.Meanwhile,the Department of English established in1964turned into the School of English Language,Literature and Culture(SELLC)in2009.Are there any moving stories behind these name-changes,and did the teaching philosophy change accordingly?
文摘In the wave of higher education internationalization,college students’career education is faced with problems such as inadequate integration of international elements in teaching content,insufficient depth of international cooperation in practical links,lack of international professional experience among the teaching staff,and insufficient emphasis on the cultivation of multicultural adaptability in the education model.Based on this,this paper deeply explores the new requirements put forward by internationalization for college students’career education and its diversified implementation paths from the perspective of higher education internationalization.It aims to build a comprehensive and multi-level career education system and improve students’international competitiveness through strategies such as constructing an internationalized curriculum system,expanding international cooperation practice projects,strengthening international exchanges and training for teachers,and integrating multicultural education.
文摘Global challenges,including resource inefficiency,rising food demand,sustainability concerns,and climate change,necessitate more efficient and resilient agricultural systems.Conservation agriculture(CA),which is based on the principles of the minimum mechanical soil disturbance,permanent soil organic cover,and species diversification,provides a promising solution.This study examined the principles and mechanisms of CA,assessed its benefits and constraints,and identified key research gaps.This study focused on CA outcomes related to soil health,biodiversity,productivity,and ecosystem services,considering factors such as climate,soil type,and management practices.CA has demonstrated the potential to improve soil health,enhance biodiversity,and boost productivity across diverse regions.However,its effectiveness has been found to vary across studies,emphasizing the need for a more critical understanding of its benefits and limitations.Moreover,variations in outcomes are evident due to differences in experimental methodologies,environmental conditions,and socioeconomic factors.For the widespread adoption of CA practices,it is necessary to make personalized adjustments to it,integrating the corresponding technologies,thereby meeting the needs of farmers.Interdisciplinary research is crucial to refining CA practices and addressing existing knowledge gaps.This study is practiced to enhance the understanding of the potential of CA to promote a sustainable global food production system.
基金Supported by Sichuan Province Germplasm Resource Precision Identification Project(2025 Provincial Finance Agricultural High Quality Development Joint Financial Transfer Payment Fund Project)Longquanyi District Science and Technology Plan Project in 2025(2081923007)School Level Horizontal Project in 2025(2502180).
文摘Gene Engineering Principles is a fundamental professional course for majors such as bioengineering and biotechnology.It integrates theoretical knowledge with experimental practice and engineering applications.It is characterized by its comprehensive and highly practical nature.Aligning with the new-era higher education philosophy of‘competency-oriented,value-driven’teaching,this study presented a systematic exploration and practice based on undergraduate cohorts from 2018 to 2020 in Chengdu University.The reform focused on teaching methodology,formative assessment,and the integration of ideological and political education.Key strategies included the introduction of classical experimental cases,emphasis on pre-class preparation,enhancement of classroom interaction,focus on engineering-oriented applications,optimization of assessment mechanisms,and the incorporation of national strategic needs into the curriculum.These measures effectively stimulated students’learning motivation and research potential,thereby improving the overall teaching quality and educational effectiveness of the course.The results of the teaching reform demonstrate significant improvements in students’ability to apply theoretical knowledge to practical engineering problems,scientific thinking,experimental research skills,scientific reasoning,and professional identity.Reformed classes outperformed control groups across various instructional metrics,achieving notable educational outcomes.
文摘The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
文摘In order to better implement the“Three-Dimensional Education”and cultivate high-quality nursing talents,the integration of ideological and political education into the pathogen biology curriculum promotes curriculum reform and application.This article explores the use of various teaching methods and means in the teaching process of pathogen biology under the guidance of ideological and political education,aiming to stimulate students’learning interest,cultivate their autonomous learning ability,independent thinking,problem-analyzing and problem-solving abilities,and thus improve their comprehensive qualities and medical professional literacy.
文摘The sub-forum on standardization of new energy and direct-current diversified applications was held on July 9,which gathered leaders and experts to discuss how to thoroughly implement the national green power direct connection policy proposed in the transformation of the energy landscape,pool wisdom to tackle bottlenecks in the industrialization of DC technology,and leverage the role of standardization in coordinating and regulating the diversified applications of DC technology.It was designed to promote the establishment of a collaborative,open,and advanced global standards system for DC technology.
基金supported by the National Key R&D Program of China(2019YFA0801900 and 2018YFA0801104)the National Natural Science Foundation of China(81891002,32070972,31921002,and 31771131)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB32020000)the Hundred-Talent Program(Chinese Academy of Sciences)the Beijing Municipal Science&Technology Commission(Z210010 and Z181100001518001).
文摘To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuronal diversity,and uncover the principles governing neuronal specification across different regions.Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed,leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge.In this review,we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes,including predetermined,stochastic,and cascade diversifying models,and elaborate how these strategies are implemented in distinct regions such as the neocortex,spinal cord,retina,and hypothalamus.Importantly,the identity of neural progenitors is defined by their spatial position and temporal patterning factors,and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes.Microenvironmental cues,spontaneous activity,and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions.The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy,as well as understanding the organization of functional neural circuits and the evolution of the nervous system.
基金L.R.Y.was supported by the National Science Foundation Postdoctoral Research Fellowship in Biology(NSF-DBI 1812035)and the Linnean Society of London and the Systematics Association Systematics Research Fund.M.H.was supported by the Yale Institute for Biospheric Studies Small Grants Program Doctoral Pilot Award.B.A.S.B.was supported by Yale University and the Yale Institute for Biospheric Studies.
文摘Chemosensation is the most ubiquitous sense in animals,enacted by the products of complex gene families that detect environmental chemical cues and larger-scale sensory structures that process these cues.While there is a general conception that olfactory receptor(OR)genes evolve rapidly,the universality of this phenomenon across vertebrates,and its magnitude,are unclear.The supposed correlation between molecular rates of chemosensory evolution and phenotypic diversity of chemosensory systems is largely untested.We combine comparative genomics and sensory morphology to test whether OR genes and olfactory phenotypic traits evolve at faster rates than other genes or traits.Using published genomes,we identified ORs in 21 tetrapods,including amphibia ns,reptiles,birds,and mammals and compared their rates of evolution to those of orthologous non-OR protein-coding genes.We found that,for all clades investigated,most OR genes evolve nearly an order of magnitude faster than other protein-coding genes,with many OR genes showing signatures of diversifying selection across nearly all taxa in this study.This rapid rate of evolution suggests that chemoreceptor genes are in "evolutionary overdrive,"perhaps evolving in response to the ever-changing chemical space of the environment.To obtain complementary morphological data,we stained whole fixed specimens with iodine,μCT-scanned the specimens,and digitally segmented chemosensory and nonchemosensory brain regions.We then estimated phenotypic variation within traits and among tetrapods.While we found considerable variation in chemosensory structures,they were no more diverse than nonchemosensory regions.We suggest chemoreceptor genes evolve quickly in reflection of an ever-changing chemical space,whereas chemosensory phe no types and processing regions are more conserved because they use a standardized or constrained architecture to receive and process a range of chemical cues.
基金Projects (Nos. 30228005, 39870143 and 30030030) supported by the National Natural Science Foundation of China Author for correspondence
文摘Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.
基金supported by the National Key Research and Development Program of China (2021YFD1700200)the earmarked fund for CARS-Green manure (CARS-22)+2 种基金the Inner Mongolia Natural Science Foundation (2022QN03032)the National Natural Science Foundation of China (32101852, 42207388)the Inner Mongolia Science and Technology Plan Project (2023YFHH0011)
文摘In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area,Inner Mongolia,China,organic amendments applied as straw,manure,green manure,and the combination of green manure and straw increased wheat and maize yield,soil aggregate stability,and soil microbial activity in comparison with chemical fertilizer,without changing greenhouse gas emission intensity.
基金the National Natural Science Foundation of China for Excellent Young Scholar(Grant No.52322313)National Key R&D Project from Minister of Science and Technology(2021YFA1201601)+6 种基金National Science Fund of China(62174014)Beijing Nova program(Z201100006820063)Youth Innovation Promotion Association CAS(2021165)Innovation Project of Ocean Science and Technology(22-3-3-hygg-18-hy)State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(KFZD202202)Fundamental Research Funds for the Central Universities(292022000337)Young Top-Notch Talents Program of Beijing Excellent Talents Funding(2017000021223ZK03).
文摘The triboelectric nanogenerator(TENG)can effectively collect energy based on contact electrification(CE)at diverse interfaces,including solid–solid,liquid–solid,liquid–liquid,gas–solid,and gas–liquid.This enables energy harvesting from sources such as water,wind,and sound.In this review,we provide an overview of the coexistence of electron and ion transfer in the CE process.We elucidate the diverse dominant mechanisms observed at different interfaces and emphasize the interconnectedness and complementary nature of interface studies.The review also offers a comprehensive summary of the factors influencing charge transfer and the advancements in interfacial modification techniques.Additionally,we highlight the wide range of applications stemming from the distinctive characteristics of charge transfer at various interfaces.Finally,this review elucidates the future opportunities and challenges that interface CE may encounter.We anticipate that this review can offer valuable insights for future research on interface CE and facilitate the continued development and industrialization of TENG.
文摘Based on the concept and development process of green agriculture and green economy,the field survey and questionnaire investigation were carried out in Jincheng Specialized Planting Cooperative in Xinji Town,Changli County of Qinhuangdao City. The results show that there are still many problems in the development of green economy and the improvement of green farms in Hebei Province. On this basis,it came up with pertinent measures and recommendations,in the hope of providing theoretical basis and reference for establishment and development of green farms in Hebei Province and most of domestic areas.
文摘The world in which we are now living is becoming economically globalized, politically multi-polarized and culturally diversified. In such a global trend, the discussion on oriental culture and human rights development aims at stimulating Chinese and international human rights development, promoting China’s human rights exchanges and cooperation with the theme of peace and development. This is of theoretical and practical importance.
文摘We investigate the design of satellite network slicing for the first time to provide customized services for the diversified applications,and propose a novel scheme for satellite end-to-end(E2E) network slicing based on 5G technology,which provides a view of common satellite network slicing and supports flexible network deployment between the satellite and the ground.Specifically,considering the limited satellite network resource and the characteristics of the satellite channel,we propose a novel satellite E2E network slicing architecture.Therein,the deployment of the network functions between the satellite and the ground is coordinately considered.Subsequently,the classification and the isolation technologies of satellite network sub-slices are proposed adaptively based on 5G technology to support resource allocation on demand.Then,we develop the management technologies for the satellite E2E network slicing including slicing key performance indicator(KPI) design,slicing deployment,and slicing management.Finally,the analysis of the challenges and future work shows the potential research in the future.
基金supported by 2012 Jiangxi Province Higher Education Reform Research Provincial Research Project(No.JXJG-12-29-3)
文摘Objective： The aim of this project was to train highly professional and specialized nursing students from medical colleges to adapt to bedside clinical care by exploring and discussing various methods of injection and IV infusion in animal experimentation to hone the core professional nursing competencies. Methods： Two classes from the 2012 senior graduating nursing class were randomly selected by a computer to conduct the diversified practical teaching methods based on animal experimentation. A hospital environment was simulated by requiring students to perform different types of injections and practical IV infusion techniques. A comprehensive evaluation of the core professional competencies, as well as other integrated competencies, was conducted to determine the effectiveness of the teaching methods. Results： Two-sampled, pairwise u-tests were performed between the scores of the experimental （nursing class 2） and control （nursing class 1） groups. These findings showed that the overall test scores were significantly higher in the experimental group compared to the control group and that the average P-values for the competencies in various categories were 〈0.01, which indicated statistically significant results. Conclusions： Based on the data from this project, diversified teaching methods for basic nursing training founded on animal experimentation can help nursing students perfect their core professional competencies and improve their overall professional standing. The introduction of animal experimentation requires further verification, and an increased acknowledgement of its benefits through the widespread dissemination of this information.
文摘Our blue planet is made of atmosphere,hydrosphere,lithosphere and biosphere,these four layers are interdependence and interaction,which effect the environment and life on the planet.In these four layers,the hydrosphere is mainly associated with the ocean which is crucial to the human survival and development,due to the difference heat capacities be-
