This conceptual study proposes a pedagogical framework that integrates Generative Artificial Intelligence tools(AIGC)and Chain-of-Thought(CoT)reasoning,grounded in the cognitive apprenticeship model,for the Pragmatics...This conceptual study proposes a pedagogical framework that integrates Generative Artificial Intelligence tools(AIGC)and Chain-of-Thought(CoT)reasoning,grounded in the cognitive apprenticeship model,for the Pragmatics and Translation course within Master of Translation and Interpreting(MTI)programs.A key feature involves CoT reasoning exercises,which require students to articulate their step-by-step translation reasoning.This explicates cognitive processes,enhances pragmatic awareness,translation strategy development,and critical reflection on linguistic choices and context.Hypothetical activities exemplify its application,including comparative analysis of AI and human translations to examine pragmatic nuances,and guided exercises where students analyze or critique the reasoning traces generated by Large Language Models(LLMs).Ethically grounded,the framework positions AI as a supportive tool,thereby ensuring human translators retain the central decision-making role and promoting critical evaluation of machine-generated suggestions.Potential challenges,such as AI biases,ethical concerns,and overreliance,are addressed through strategies including bias-awareness discussions,rigorous accuracy verification,and a strong emphasis on human accountability.Future research will involve piloting the framework to empirically evaluate its impact on learners’pragmatic competence and translation skills,followed by iterative refinements to advance evidence-based translation pedagogy.展开更多
The rapid advancement of large language models(LLMs)has driven the pervasive adoption of AI-generated content(AIGC),while also raising concerns about misinformation,academic misconduct,biased or harmful content,and ot...The rapid advancement of large language models(LLMs)has driven the pervasive adoption of AI-generated content(AIGC),while also raising concerns about misinformation,academic misconduct,biased or harmful content,and other risks.Detecting AI-generated text has thus become essential to safeguard the authenticity and reliability of digital information.This survey reviews recent progress in detection methods,categorizing approaches into passive and active categories based on their reliance on intrinsic textual features or embedded signals.Passive detection is further divided into surface linguistic feature-based and language model-based methods,whereas active detection encompasses watermarking-based and semantic retrieval-based approaches.This taxonomy enables systematic comparison of methodological differences in model dependency,applicability,and robustness.A key challenge for AI-generated text detection is that existing detectors are highly vulnerable to adversarial attacks,particularly paraphrasing,which substantially compromises their effectiveness.Addressing this gap highlights the need for future research on enhancing robustness and cross-domain generalization.By synthesizing current advances and limitations,this survey provides a structured reference for the field and outlines pathways toward more reliable and scalable detection solutions.展开更多
This study explores the integration of ChatGPT and AI-generated content (AIGC) in engineering management. It assesses the impact of AIGC services on engineering management processes, mapping out the potential developm...This study explores the integration of ChatGPT and AI-generated content (AIGC) in engineering management. It assesses the impact of AIGC services on engineering management processes, mapping out the potential development of AIGC in various engineering functions. The study categorizes AIGC services within the domain of engineering management and conceptualizes an AIGC-aided engineering lifecycle. It also identifies key challenges and emerging trends associated with AIGC. The challenges highlighted are ethical considerations, reliability, and robustness in engineering management. The emerging trends are centered on AIGC-aided optimization design, AIGC-aided engineering consulting, and AIGC-aided green engineering initiatives.展开更多
In this study,it aims at examining the differences between humangenerated and AI-generated texts in IELTS Writing Task 2.It especially focuses on lexical resourcefulness,grammatical accuracy,and contextual appropriate...In this study,it aims at examining the differences between humangenerated and AI-generated texts in IELTS Writing Task 2.It especially focuses on lexical resourcefulness,grammatical accuracy,and contextual appropriateness.We analyzed 20 essays,including 10 human written ones by Chinese university students who have achieved an IELTS writing score ranging from 5.5 to 6.0,and 10 ChatGPT-4 Turbo-generated ones,using a mixed-methods approach,through corpus-based tools(NLTK,SpaCy,AntConc)and qualitative content analysis.Results showed that AI texts exhibited superior grammatical accuracy(0.4%–3%error rates for AI vs.20–26%for university students)but higher lexical repetition(17.2%to 23.25%for AI vs.17.68%for university students)and weaker contextual adaptability(3.33/10–3.69/10 for AI vs.3.23/10 to 4.14/10 for university students).While AI’s grammatical precision supports its utility as a corrective tool,human writers outperformed AI in lexical diversity and task-specific nuance.The findings advocate for a hybrid pedagogical model that leverages AI’s strengths in error detection while retaining human instruction for advanced lexical and contextual skills.Limitations include the small corpus and single-AI-model focus,suggesting future research with diverse datasets and longitudinal designs.展开更多
The increasing fluency of advanced language models,such as GPT-3.5,GPT-4,and the recently introduced DeepSeek,challenges the ability to distinguish between human-authored and AI-generated academic writing.This situati...The increasing fluency of advanced language models,such as GPT-3.5,GPT-4,and the recently introduced DeepSeek,challenges the ability to distinguish between human-authored and AI-generated academic writing.This situation is raising significant concerns regarding the integrity and authenticity of academic work.In light of the above,the current research evaluates the effectiveness of Bidirectional Long Short-TermMemory(BiLSTM)networks enhanced with pre-trained GloVe(Global Vectors for Word Representation)embeddings to detect AIgenerated scientific Abstracts drawn from the AI-GA(Artificial Intelligence Generated Abstracts)dataset.Two core BiLSTM variants were assessed:a single-layer approach and a dual-layer design,each tested under static or adaptive embeddings.The single-layer model achieved nearly 97%accuracy with trainable GloVe,occasionally surpassing the deeper model.Despite these gains,neither configuration fully matched the 98.7%benchmark set by an earlier LSTMWord2Vec pipeline.Some runs were over-fitted when embeddings were fine-tuned,whereas static embeddings offered a slightly lower yet stable accuracy of around 96%.This lingering gap reinforces a key ethical and procedural concern:relying solely on automated tools,such as Turnitin’s AI-detection features,to penalize individuals’risks and unjust outcomes.Misclassifications,whether legitimate work is misread as AI-generated or engineered text,evade detection,demonstrating that these classifiers should not stand as the sole arbiters of authenticity.Amore comprehensive approach is warranted,one which weaves model outputs into a systematic process supported by expert judgment and institutional guidelines designed to protect originality.展开更多
[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricult...[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricultural products.[Methods]Thirty three representative townships in Xiayi County,Ningling County,and Yongcheng City were selected.Soil Se content and its impact on wheat Se level were measured.The effects of exogenous Se supplementation on the Se content of crops including soybean,wheat,peanut,corn,sweet potato,grape,crisp pear and apple were also investigated.[Results]Showed that the soil Se content in 18 townships of Xiayi County ranged from 0.08 to 0.34 mg/kg,and Se-adequate areas,Se-deficient areas and severely Se-deficient areas accounted for 27.78%,66.67%,and 0.055%of the total,respectively.In Ningling County,the soil Se content in 11 townships ranged from 0.13 to 0.23 mg/kg,and among them,Se-adequate areas and Se-deficient areas comprised 18.18%and 81.82%,respectively.In Yongcheng City,the soil Se content in 4 townships ranged from 0.16 to 0.23 mg/kg,and Se-adequate areas and Se-deficient areas constituted 75.00%and 25.00%,respectively.The soil Se content in 33 townships across Xiayi County,Ningling County,and Yongcheng City ranged from 0.07 to 0.34 mg/kg.However,the Se levels in wheat from all 33 townships fail to meet the standard for Se-enriched agricultural products.It indicates that relying solely on soil Se supply is insufficient for crops to achieve the Se level required for Se-enriched agricultural products.Exogenous Se supplementation could effectively increase the Se content in soybean,wheat,peanut,corn,sweet potato,grape,crisp pear,and apple.Among these,soybean,wheat and peanut showed the highest Se levels after supplementation,all exceeding 0.10 mg/kg and meeting the industry standard for Se-enriched agricultural products.[Conclusions]The results of this study indicates that exogenous Se supplementation can serve as a key measure for producing Se-enriched agricultural products.展开更多
The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain mod...The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain moderate to high total purine content(TP).Recent research revealed substantial variations within and across pig breeds,implying genetic factors influencing this trait.Thus,this study aimed to unravel the genetic underpinnings governing purine base content in pork.The heritability estimates(h~2)for the four purine traits ranged from 0.14 to 0.35.A total of 14,36,19 and 25 quantitative trait loci(QTLs)were identified for guanine,adenine,hypoxanthine,and TP,respectively.Our comprehensive gene set enrichment analysis and gene network analysis revealed 15 promising candidate genes intricately interwoven within diverse purine metabolism pathways,such as purine ribonucleotide metabolic process,purine nucleotide metabolism and transport,and purine salvage pathways,all contributing to TP.Strikingly,most genetic variants significantly associated with TP displayed analogous effects on multiple purine bases.Two distinct and highly significant QTLs(P<10^(–12))emerged on Sus scrofa chromosome(SSC)12:one impacting guanine content and the other concurrently influencing adenine and hypoxanthine levels.The peak of the guanine QTL on SSC12 resided 1.1 kb downstream of the transmembrane protein 238 like(TMEM238L)gene and is encapsulated within a genomic segment characterized by the histone modification H3K27me3.Focused fine-mapping for the SSC12 QTL associated with adenine and hypoxanthine levels narrowed its scope to around 172 kb,encompassing the growth arrest specific 7(GAS7)and myosin heavy chain 13(MYH13)genes.However,the observed QTL effect was not attributed to any missense mutations within the two genes.This pioneering study unveils the genetic variations and candidate genes associated with purine content in livestock,laying a robust foundation for the selective breeding of pig lines with reduced purine base content.展开更多
Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is ...Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is designed to assess physical activity(PA)across all key domains(i.e.,school,chores,work/volunteering,transport,free time,outdoor time).It aimed to address multiple gaps in global PA surveillance(e.g.,omission of important PA domains,insufficient cultural adaptation,underrepresentation of rural areas in questionnaire validation studies).The purpose of this study was to assess the content validity of the GAC-PAQ among PA experts,8-to 17-year-olds,and one of their parents/guardians,and to discuss changes made to the questionnaire based on participants'feedback.Methods:Sixty-two experts in PA measurement and/or surveillance from 24 countries completed an online survey that included both closed-and open-ended questions about the content validity of the GAC-PAQ.The proportion of experts who agreed or strongly agreed with the items was calculated.Child-parent/guardian dyads from 15 countries(n=250;10-40 per country)participated in a structured cognitive interview to assess the clarity of the questions and response options,and they were encouraged to provide suggestions to improve clarity and facilitate completion of the questionnaire.Participating countries are:Aotearoa New Zealand,Brazil,Canada,China,Colombia,Czech Republic,India,Malawi,Mexico,Nepal,Nigeria,Spain,Sweden,Thailand,and the United Arab Emirates.Interviews were conducted in 13 different languages and structured by PA domain.Generic images were included to help participants in answering questions about PA intensity.Results:Expert agreement with the items for each domain exceeded 75%,and their qualitative feedback was used to revise the questionnaire before cognitive interviews.In general,participants found the questionnaire to be comprehensive.Adolescents(12-17 years)found it easier than children(8-11 years)to answer the questions.Several children struggled to answer questions about the duration and intensity of activities and/or concepts related to travel modes,active trips,and organized activities.Many parents/guardians were unsure about the frequency,duration,and intensity of their children's or adolescents'PA at school and/or recommended using more culturally relevant and appropriate images.Some participants misunderstood the concept of activities that“make you stronger”(intended to assess resistance activities)and/or struggled to differentiate between work,volunteering,and chores.Conclusion:Participants'feedback was used to develop a revised,simplified,and culturally adapted GAC-PAQ,which will be pilot-tested in all15 countries in an App that will include country-specific images and narration in local languages.Further research is needed to assess the reliability and validity of the revised GAC-PAQ.展开更多
Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance b...Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance both yield potential and nutritional value.In this study,the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed,ranging from 9.02 to 50.60 mg/kg.The seed iron content of valencia type accessions was significantly higher than that of Peruvian,Virginia,and Irregular types.Landraces showed the highest average iron content,followed by advanced cultivars,breeding lines and interspecific hybrid cultivars.Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat.Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight(HSW),resveratrol and oleic acid.Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg,including two elite genotypes that Zh.h4280 showed high resveratrol levels(1057.34μg/kg)and Zh.h1976 exhibited large seeds(HSW over 90g).Association analysis identified four markers,one of which,AHGS2053 stably explained with 5.75%–5.84%phenotypic variation.Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles.The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts.展开更多
Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during fr...Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.展开更多
This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides...This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.展开更多
Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study invest...Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.展开更多
Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of ...Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.展开更多
The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in tempe...The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in temperature and ocean heat content(OHC)of the Yellow Sea and Bohai Sea caused by Super Typhoon Maysak in early September 2020,which is representative of northward/northeastward-bypassing typhoons with centers just to the east of the study area.Temperature shows spatially coherent cooling in the upper mixed layer but warming in the subsurface layer in the majority of the offshore waters,due to wind-enhanced vertical mixing.In lower layers from the thermocline to sea bottom,temperature experiences significant warming in northeastern coastal waters of the Shandong Peninsula and in regions just off the Subei Shoal,but significant cooling in western coastal waters of the Korean Peninsula and southern coastal waters of the Shandong Peninsula.Significant temperature warming/cooling in lower layers is caused by coastal downwelling/upwelling.The total OHC of the study area decreases rapidly during Typhoon Maysak(2020)’s passage,which is generated comparably by latent heat loss at the sea surface and southward heat advection out of the study area at the southern boundary.Reduced shortwave radiation contributes positively but secondarily to the decreasing OHC during the first day.A numerical experiment suggests that Typhoon Maysak(2020)-induced OHC decline could have greatly affected the regional climate evolution in the following seasons.More studies are needed to fully understand the impacts of typhoons on regional climate changes in shelf seas at different time scales.展开更多
Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automaticall...Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation.展开更多
Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify...Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.展开更多
Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droug...Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droughts on these processes have been widely evaluated,the effects of heatwaves on tree growth and soil water content(SWC)remain poorly understood,particularly those related to thinning treatment.In this study,we evaluated the impacts of the 2021 Pacific Northwest Heatwave and thinning on forest growth and SWC,as well as assessed how thinning might mitigate the heatwave's impacts in lodgepole pine forests in British Columbia,Canada.We measured meteorological data(air temperature,rainfall,solar radiation(SR),relative humidity(RH),and wind speed(W_(s)),sap flow,SWC,soil temperature(T_(s)),and tree diameters at the breast height(DBH)during the growing season(June–September)in the control(27,000 stems·ha^(-1)),lightly thinned(4,500 stems·ha^(-1)),and heavily thinned(1,100 stems·ha^(-1))experimental plots from 2018 to 2024.We found that thinning persistently and significantly(p<0.05)increased individual tree growth,with the most pronounced effects in the heavily thinned stands.The 2021 Pacific Northwest Heatwave led to an exceptionally hot growing season,significantly(p<0.05)reducing forest growth and SWC across all plots.Forest growth recovered in 2022 in the thinned plots but remained suppressed in the unthinned plots,suggesting that thinning effectively mitigated the impact of the heatwave on forest growth,while the heatwave's impacts were persistent in the unthinned plots.Our study highlights that thinning is a practical management strategy for improving tree growth and supporting climate change adaptation to extreme climate events.展开更多
By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of s...By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of shale gas.An improved evaluation method of shale gas content evolution in superimposed basins is proposed.This method incorporates the coupling effect of key geological factors such as temperature,pressure,organic matter abundance,maturity,and pore characteristics on the content and occurrence state of shale gas,as well as the configuration relationship between shale gas generation and storage throughout geological history.Using this approach,the gas evolution histories of the Longmaxi Formation shales in wells N201 and PY1 are reconstructed under varying geological conditions.The Longmaxi Formation shales in these wells are dominated by typeⅠkerogen,with original total organic carbon(TOC_(o))contents of 6.20 wt% and 4.92 wt%,respectively,indicating differences in the initial material basis for gas generation.At the maximum burial depth of approximately 5000 m,the Longmaxi Formation shale in well N201 exhibits a formation pressure coefficient of 2.05,an organic matter maturity of 2.2%,and organic pores accounting for 68%of the total porosity.The gas generation quantity(Q_(g))reaches 19.24 m^(3)/t,while the gas storage capacity(Q_(s))is 4.30 m^(3)/t.The actual total gas content(Q_(a)),constrained by Q_(s),is 4.30 m^(3)/t,with free gas comprising 94%.Following relatively moderate tectonic uplift,the Q_(a) in well N201 decreases to 4.03 m^(3)/t,with free gas accounting for 63%.In contrast,the Longmaxi Formation shale in well PY1 reached a maximum burial depth of 6300 m,associated with a formation pressure coefficient of 1.62,organic matter maturity of 2.5%,and organic pore proportion of 67%.Here,Q_(g) is 16.87 m^(3)/t,and both Q_(s) and Q_(a) are 3.65 m^(3)/t,with free gas accounting for 98%.After intense tectonic uplift,Q_(a) declines to 2.72 m^(3)/t,and the proportion of free gas drops to51%.Finally,a four-stage differential accumulation model of shale gas is established:Slow gas generation and only adsorbed gas occur in stageⅠ,which is primarily controlled by TOC content;both adsorbed gas and free gas present in stageⅡ,with free gas becoming dominant;rapid gas generation and free gas predominance are controlled by temperature and porosity in stageⅢ;and gas adjustment and accumulation are primarily controlled by temperature and pressure in stageⅣ.展开更多
Amylose content(AC)is a key determinant of rice eating and cooking quality(ECQ).Lower AC is generally associated with improved palatability and is therefore a desirable trait in rice breeding;however,effective manipul...Amylose content(AC)is a key determinant of rice eating and cooking quality(ECQ).Lower AC is generally associated with improved palatability and is therefore a desirable trait in rice breeding;however,effective manipulation of AC remains a challenge.In this study,we identified AC6,a novel endosperm-specific early nodulin-like(ENODL)gene,belonging to a 32-member ENODL family.Using CRISPR/Cas9 technology,we generated an ac6 knockout allele,which exhibited a significant decrease in AC and produced improved ECQ without compromising grain appearance or yield.Subcellular localization analysis demonstrated that AC6 is a plastid-localized protein that likely regulates AC by interacting with the Waxy(Wx)protein.Moreover,expression of starch metabolism-related genes was markedly altered in developing ac6 endosperm.Our study highlights AC6 as a novel target gene for engineering rice germplasm with enhanced ECQ.展开更多
Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and ...Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and secretary of the CPC Gulu Village Branch,better known as Cliff Village,in Hanyuan County,Ya’an City,Sichuan Province,was still dressed in his Yi ethnic waistcoat.展开更多
文摘This conceptual study proposes a pedagogical framework that integrates Generative Artificial Intelligence tools(AIGC)and Chain-of-Thought(CoT)reasoning,grounded in the cognitive apprenticeship model,for the Pragmatics and Translation course within Master of Translation and Interpreting(MTI)programs.A key feature involves CoT reasoning exercises,which require students to articulate their step-by-step translation reasoning.This explicates cognitive processes,enhances pragmatic awareness,translation strategy development,and critical reflection on linguistic choices and context.Hypothetical activities exemplify its application,including comparative analysis of AI and human translations to examine pragmatic nuances,and guided exercises where students analyze or critique the reasoning traces generated by Large Language Models(LLMs).Ethically grounded,the framework positions AI as a supportive tool,thereby ensuring human translators retain the central decision-making role and promoting critical evaluation of machine-generated suggestions.Potential challenges,such as AI biases,ethical concerns,and overreliance,are addressed through strategies including bias-awareness discussions,rigorous accuracy verification,and a strong emphasis on human accountability.Future research will involve piloting the framework to empirically evaluate its impact on learners’pragmatic competence and translation skills,followed by iterative refinements to advance evidence-based translation pedagogy.
基金supported in part by the Science and Technology Innovation Program of Hunan Province under Grant 2025RC3166the National Natural Science Foundation of China under Grant 62572176the National Key R&D Program of China under Grant 2024YFF0618800.
文摘The rapid advancement of large language models(LLMs)has driven the pervasive adoption of AI-generated content(AIGC),while also raising concerns about misinformation,academic misconduct,biased or harmful content,and other risks.Detecting AI-generated text has thus become essential to safeguard the authenticity and reliability of digital information.This survey reviews recent progress in detection methods,categorizing approaches into passive and active categories based on their reliance on intrinsic textual features or embedded signals.Passive detection is further divided into surface linguistic feature-based and language model-based methods,whereas active detection encompasses watermarking-based and semantic retrieval-based approaches.This taxonomy enables systematic comparison of methodological differences in model dependency,applicability,and robustness.A key challenge for AI-generated text detection is that existing detectors are highly vulnerable to adversarial attacks,particularly paraphrasing,which substantially compromises their effectiveness.Addressing this gap highlights the need for future research on enhancing robustness and cross-domain generalization.By synthesizing current advances and limitations,this survey provides a structured reference for the field and outlines pathways toward more reliable and scalable detection solutions.
文摘This study explores the integration of ChatGPT and AI-generated content (AIGC) in engineering management. It assesses the impact of AIGC services on engineering management processes, mapping out the potential development of AIGC in various engineering functions. The study categorizes AIGC services within the domain of engineering management and conceptualizes an AIGC-aided engineering lifecycle. It also identifies key challenges and emerging trends associated with AIGC. The challenges highlighted are ethical considerations, reliability, and robustness in engineering management. The emerging trends are centered on AIGC-aided optimization design, AIGC-aided engineering consulting, and AIGC-aided green engineering initiatives.
基金supported by the Macao Science and Technology Development Fund(FDCT)(No.0071/2023/RIB3)Joint Research Funding Program between the Macao Science and Technology Development Fund(FDCT)and the Department of Science and Technology of Guangdong Province(FDCTGDST)(No.0003-2024-AGJ).
文摘In this study,it aims at examining the differences between humangenerated and AI-generated texts in IELTS Writing Task 2.It especially focuses on lexical resourcefulness,grammatical accuracy,and contextual appropriateness.We analyzed 20 essays,including 10 human written ones by Chinese university students who have achieved an IELTS writing score ranging from 5.5 to 6.0,and 10 ChatGPT-4 Turbo-generated ones,using a mixed-methods approach,through corpus-based tools(NLTK,SpaCy,AntConc)and qualitative content analysis.Results showed that AI texts exhibited superior grammatical accuracy(0.4%–3%error rates for AI vs.20–26%for university students)but higher lexical repetition(17.2%to 23.25%for AI vs.17.68%for university students)and weaker contextual adaptability(3.33/10–3.69/10 for AI vs.3.23/10 to 4.14/10 for university students).While AI’s grammatical precision supports its utility as a corrective tool,human writers outperformed AI in lexical diversity and task-specific nuance.The findings advocate for a hybrid pedagogical model that leverages AI’s strengths in error detection while retaining human instruction for advanced lexical and contextual skills.Limitations include the small corpus and single-AI-model focus,suggesting future research with diverse datasets and longitudinal designs.
文摘The increasing fluency of advanced language models,such as GPT-3.5,GPT-4,and the recently introduced DeepSeek,challenges the ability to distinguish between human-authored and AI-generated academic writing.This situation is raising significant concerns regarding the integrity and authenticity of academic work.In light of the above,the current research evaluates the effectiveness of Bidirectional Long Short-TermMemory(BiLSTM)networks enhanced with pre-trained GloVe(Global Vectors for Word Representation)embeddings to detect AIgenerated scientific Abstracts drawn from the AI-GA(Artificial Intelligence Generated Abstracts)dataset.Two core BiLSTM variants were assessed:a single-layer approach and a dual-layer design,each tested under static or adaptive embeddings.The single-layer model achieved nearly 97%accuracy with trainable GloVe,occasionally surpassing the deeper model.Despite these gains,neither configuration fully matched the 98.7%benchmark set by an earlier LSTMWord2Vec pipeline.Some runs were over-fitted when embeddings were fine-tuned,whereas static embeddings offered a slightly lower yet stable accuracy of around 96%.This lingering gap reinforces a key ethical and procedural concern:relying solely on automated tools,such as Turnitin’s AI-detection features,to penalize individuals’risks and unjust outcomes.Misclassifications,whether legitimate work is misread as AI-generated or engineered text,evade detection,demonstrating that these classifiers should not stand as the sole arbiters of authenticity.Amore comprehensive approach is warranted,one which weaves model outputs into a systematic process supported by expert judgment and institutional guidelines designed to protect originality.
基金Supported by Shangqiu Science and Technology Project(20240036).
文摘[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricultural products.[Methods]Thirty three representative townships in Xiayi County,Ningling County,and Yongcheng City were selected.Soil Se content and its impact on wheat Se level were measured.The effects of exogenous Se supplementation on the Se content of crops including soybean,wheat,peanut,corn,sweet potato,grape,crisp pear and apple were also investigated.[Results]Showed that the soil Se content in 18 townships of Xiayi County ranged from 0.08 to 0.34 mg/kg,and Se-adequate areas,Se-deficient areas and severely Se-deficient areas accounted for 27.78%,66.67%,and 0.055%of the total,respectively.In Ningling County,the soil Se content in 11 townships ranged from 0.13 to 0.23 mg/kg,and among them,Se-adequate areas and Se-deficient areas comprised 18.18%and 81.82%,respectively.In Yongcheng City,the soil Se content in 4 townships ranged from 0.16 to 0.23 mg/kg,and Se-adequate areas and Se-deficient areas constituted 75.00%and 25.00%,respectively.The soil Se content in 33 townships across Xiayi County,Ningling County,and Yongcheng City ranged from 0.07 to 0.34 mg/kg.However,the Se levels in wheat from all 33 townships fail to meet the standard for Se-enriched agricultural products.It indicates that relying solely on soil Se supply is insufficient for crops to achieve the Se level required for Se-enriched agricultural products.Exogenous Se supplementation could effectively increase the Se content in soybean,wheat,peanut,corn,sweet potato,grape,crisp pear,and apple.Among these,soybean,wheat and peanut showed the highest Se levels after supplementation,all exceeding 0.10 mg/kg and meeting the industry standard for Se-enriched agricultural products.[Conclusions]The results of this study indicates that exogenous Se supplementation can serve as a key measure for producing Se-enriched agricultural products.
基金support from the National Natural Science Foundation of China(32272855)STI 2030-Major Projects,China(2023ZD0404501)。
文摘The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain moderate to high total purine content(TP).Recent research revealed substantial variations within and across pig breeds,implying genetic factors influencing this trait.Thus,this study aimed to unravel the genetic underpinnings governing purine base content in pork.The heritability estimates(h~2)for the four purine traits ranged from 0.14 to 0.35.A total of 14,36,19 and 25 quantitative trait loci(QTLs)were identified for guanine,adenine,hypoxanthine,and TP,respectively.Our comprehensive gene set enrichment analysis and gene network analysis revealed 15 promising candidate genes intricately interwoven within diverse purine metabolism pathways,such as purine ribonucleotide metabolic process,purine nucleotide metabolism and transport,and purine salvage pathways,all contributing to TP.Strikingly,most genetic variants significantly associated with TP displayed analogous effects on multiple purine bases.Two distinct and highly significant QTLs(P<10^(–12))emerged on Sus scrofa chromosome(SSC)12:one impacting guanine content and the other concurrently influencing adenine and hypoxanthine levels.The peak of the guanine QTL on SSC12 resided 1.1 kb downstream of the transmembrane protein 238 like(TMEM238L)gene and is encapsulated within a genomic segment characterized by the histone modification H3K27me3.Focused fine-mapping for the SSC12 QTL associated with adenine and hypoxanthine levels narrowed its scope to around 172 kb,encompassing the growth arrest specific 7(GAS7)and myosin heavy chain 13(MYH13)genes.However,the observed QTL effect was not attributed to any missense mutations within the two genes.This pioneering study unveils the genetic variations and candidate genes associated with purine content in livestock,laying a robust foundation for the selective breeding of pig lines with reduced purine base content.
基金supported by a Project Grant(Grant No.PJT183705)an Early Career Investigator Prize(Grant No.ECP 184184)from the Canadian Institutes of Health Research+7 种基金a Prentice Institute Research Affiliate Fund Grant from the Prentice Institute for Global Population and Economy(Grant No.G00004116)a Te Herenga Waka Victoria University of Wellington Division of Science Health Engineering Architecture and Design Innovation Faculty Strategic Research Grant(Grant No.FSRG-SHEADI-10724)The Thailand Physical Activity Knowledge Development Centre(TPAK)/Thai Health Promotion Foundation provided funding for the cognitive interviews and pilot study in Thailand(Grant No.66-P1-0473)The University Pablo de Olavide provided a scholarship for 2 undergraduate students working on the project(codes PPI2207 and PPI2308)In the Czech Republicthe study was supported by Palacky University IGA(Grant No.IGA_FTK_2023_017)supported by the Division of Intramural Research at the National Institute on Minority Health and Health Disparities of the National Institutes of Healthsupported by the Key Project of the National Philosophy and Social Science Foundation of China(23&ZD197)。
文摘Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is designed to assess physical activity(PA)across all key domains(i.e.,school,chores,work/volunteering,transport,free time,outdoor time).It aimed to address multiple gaps in global PA surveillance(e.g.,omission of important PA domains,insufficient cultural adaptation,underrepresentation of rural areas in questionnaire validation studies).The purpose of this study was to assess the content validity of the GAC-PAQ among PA experts,8-to 17-year-olds,and one of their parents/guardians,and to discuss changes made to the questionnaire based on participants'feedback.Methods:Sixty-two experts in PA measurement and/or surveillance from 24 countries completed an online survey that included both closed-and open-ended questions about the content validity of the GAC-PAQ.The proportion of experts who agreed or strongly agreed with the items was calculated.Child-parent/guardian dyads from 15 countries(n=250;10-40 per country)participated in a structured cognitive interview to assess the clarity of the questions and response options,and they were encouraged to provide suggestions to improve clarity and facilitate completion of the questionnaire.Participating countries are:Aotearoa New Zealand,Brazil,Canada,China,Colombia,Czech Republic,India,Malawi,Mexico,Nepal,Nigeria,Spain,Sweden,Thailand,and the United Arab Emirates.Interviews were conducted in 13 different languages and structured by PA domain.Generic images were included to help participants in answering questions about PA intensity.Results:Expert agreement with the items for each domain exceeded 75%,and their qualitative feedback was used to revise the questionnaire before cognitive interviews.In general,participants found the questionnaire to be comprehensive.Adolescents(12-17 years)found it easier than children(8-11 years)to answer the questions.Several children struggled to answer questions about the duration and intensity of activities and/or concepts related to travel modes,active trips,and organized activities.Many parents/guardians were unsure about the frequency,duration,and intensity of their children's or adolescents'PA at school and/or recommended using more culturally relevant and appropriate images.Some participants misunderstood the concept of activities that“make you stronger”(intended to assess resistance activities)and/or struggled to differentiate between work,volunteering,and chores.Conclusion:Participants'feedback was used to develop a revised,simplified,and culturally adapted GAC-PAQ,which will be pilot-tested in all15 countries in an App that will include country-specific images and narration in local languages.Further research is needed to assess the reliability and validity of the revised GAC-PAQ.
基金supported by the National Key Research and Development Program of China(2023YFD1200200)the earmarked funds for CARS(No.CARS-13)+2 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2025-OCRI)the National Program for Crop Germplasm Protection of China(22250402)the National Crop Germplasm Resources Center(NCGRC-2025-036)。
文摘Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance both yield potential and nutritional value.In this study,the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed,ranging from 9.02 to 50.60 mg/kg.The seed iron content of valencia type accessions was significantly higher than that of Peruvian,Virginia,and Irregular types.Landraces showed the highest average iron content,followed by advanced cultivars,breeding lines and interspecific hybrid cultivars.Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat.Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight(HSW),resveratrol and oleic acid.Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg,including two elite genotypes that Zh.h4280 showed high resveratrol levels(1057.34μg/kg)and Zh.h1976 exhibited large seeds(HSW over 90g).Association analysis identified four markers,one of which,AHGS2053 stably explained with 5.75%–5.84%phenotypic variation.Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles.The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts.
基金Supported by National Modern Agricultural Industry Technology System Sichuan Pig Innovation Team(SCCXTD-2026-8)Sichuan Science and Technology Program(2025ZYD0049)"Challenge and Leadership"Project for Key Core Technologies of Sui Ning in Sichuan(2025SNKBZ19).
文摘Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.
基金Supported by Open Fund Project of the Engineering Technology Research Center of Characteristic Medicinal Plants of Fujian(PP202003).
文摘This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.
基金funded by the Natural Science Foundation of China(Grants No 42277127)。
文摘Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.
基金supported by the grants from the National Key Research and Development Program of China(2023YFD1800804 and 2023YFD1801100)the National Natural Science Foundation of China(32172926)the China Agriculture Research System(CARS-36)。
文摘Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0801400 and 2021YFF0704002)the Shandong Provincial Natural Science Foundation(Grant No.ZR2024LQX002)the National Science Foundation of China(Grant No.42176016).
文摘The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in temperature and ocean heat content(OHC)of the Yellow Sea and Bohai Sea caused by Super Typhoon Maysak in early September 2020,which is representative of northward/northeastward-bypassing typhoons with centers just to the east of the study area.Temperature shows spatially coherent cooling in the upper mixed layer but warming in the subsurface layer in the majority of the offshore waters,due to wind-enhanced vertical mixing.In lower layers from the thermocline to sea bottom,temperature experiences significant warming in northeastern coastal waters of the Shandong Peninsula and in regions just off the Subei Shoal,but significant cooling in western coastal waters of the Korean Peninsula and southern coastal waters of the Shandong Peninsula.Significant temperature warming/cooling in lower layers is caused by coastal downwelling/upwelling.The total OHC of the study area decreases rapidly during Typhoon Maysak(2020)’s passage,which is generated comparably by latent heat loss at the sea surface and southward heat advection out of the study area at the southern boundary.Reduced shortwave radiation contributes positively but secondarily to the decreasing OHC during the first day.A numerical experiment suggests that Typhoon Maysak(2020)-induced OHC decline could have greatly affected the regional climate evolution in the following seasons.More studies are needed to fully understand the impacts of typhoons on regional climate changes in shelf seas at different time scales.
文摘Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation.
基金supported by the National Natural Science Foundation(32130068,32271634,and 32071597)CAS Key Laboratory of Forest Ecology and Silviculture,Institute of Applied Ecology,Chinese Academy of Sciences(KLFES-2025)。
文摘Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.
基金supported by the British Columbia Ministry of Forces through long-term annual contracts with University of British Columbia(Okanagan)(No.RE25SIR242)the Natural Sciences and Engineering Research Council of Canada(NSERC),Discovery Grants Program(No.RGPIN-2021-02628)+1 种基金supported by the China Postdoctoral Science Foundation(No.2024M760387)Heilongjiang Postdoctoral Financial Assistance(No.LBH-Z24062)。
文摘Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droughts on these processes have been widely evaluated,the effects of heatwaves on tree growth and soil water content(SWC)remain poorly understood,particularly those related to thinning treatment.In this study,we evaluated the impacts of the 2021 Pacific Northwest Heatwave and thinning on forest growth and SWC,as well as assessed how thinning might mitigate the heatwave's impacts in lodgepole pine forests in British Columbia,Canada.We measured meteorological data(air temperature,rainfall,solar radiation(SR),relative humidity(RH),and wind speed(W_(s)),sap flow,SWC,soil temperature(T_(s)),and tree diameters at the breast height(DBH)during the growing season(June–September)in the control(27,000 stems·ha^(-1)),lightly thinned(4,500 stems·ha^(-1)),and heavily thinned(1,100 stems·ha^(-1))experimental plots from 2018 to 2024.We found that thinning persistently and significantly(p<0.05)increased individual tree growth,with the most pronounced effects in the heavily thinned stands.The 2021 Pacific Northwest Heatwave led to an exceptionally hot growing season,significantly(p<0.05)reducing forest growth and SWC across all plots.Forest growth recovered in 2022 in the thinned plots but remained suppressed in the unthinned plots,suggesting that thinning effectively mitigated the impact of the heatwave on forest growth,while the heatwave's impacts were persistent in the unthinned plots.Our study highlights that thinning is a practical management strategy for improving tree growth and supporting climate change adaptation to extreme climate events.
基金funded by the Sinopec Science and Technology Project(No.P23132)the AAPG Foundation Grants-inAid Program(No.18644937)。
文摘By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of shale gas.An improved evaluation method of shale gas content evolution in superimposed basins is proposed.This method incorporates the coupling effect of key geological factors such as temperature,pressure,organic matter abundance,maturity,and pore characteristics on the content and occurrence state of shale gas,as well as the configuration relationship between shale gas generation and storage throughout geological history.Using this approach,the gas evolution histories of the Longmaxi Formation shales in wells N201 and PY1 are reconstructed under varying geological conditions.The Longmaxi Formation shales in these wells are dominated by typeⅠkerogen,with original total organic carbon(TOC_(o))contents of 6.20 wt% and 4.92 wt%,respectively,indicating differences in the initial material basis for gas generation.At the maximum burial depth of approximately 5000 m,the Longmaxi Formation shale in well N201 exhibits a formation pressure coefficient of 2.05,an organic matter maturity of 2.2%,and organic pores accounting for 68%of the total porosity.The gas generation quantity(Q_(g))reaches 19.24 m^(3)/t,while the gas storage capacity(Q_(s))is 4.30 m^(3)/t.The actual total gas content(Q_(a)),constrained by Q_(s),is 4.30 m^(3)/t,with free gas comprising 94%.Following relatively moderate tectonic uplift,the Q_(a) in well N201 decreases to 4.03 m^(3)/t,with free gas accounting for 63%.In contrast,the Longmaxi Formation shale in well PY1 reached a maximum burial depth of 6300 m,associated with a formation pressure coefficient of 1.62,organic matter maturity of 2.5%,and organic pore proportion of 67%.Here,Q_(g) is 16.87 m^(3)/t,and both Q_(s) and Q_(a) are 3.65 m^(3)/t,with free gas accounting for 98%.After intense tectonic uplift,Q_(a) declines to 2.72 m^(3)/t,and the proportion of free gas drops to51%.Finally,a four-stage differential accumulation model of shale gas is established:Slow gas generation and only adsorbed gas occur in stageⅠ,which is primarily controlled by TOC content;both adsorbed gas and free gas present in stageⅡ,with free gas becoming dominant;rapid gas generation and free gas predominance are controlled by temperature and porosity in stageⅢ;and gas adjustment and accumulation are primarily controlled by temperature and pressure in stageⅣ.
基金supported by the Government of Jiangsu Province,China(Grant Nos.23KJA210001,BE2023331,KYCX21_3247,and BE2021334)the National Natural Science Foundation of China(Grant Nos.31971914 and 32472072).
文摘Amylose content(AC)is a key determinant of rice eating and cooking quality(ECQ).Lower AC is generally associated with improved palatability and is therefore a desirable trait in rice breeding;however,effective manipulation of AC remains a challenge.In this study,we identified AC6,a novel endosperm-specific early nodulin-like(ENODL)gene,belonging to a 32-member ENODL family.Using CRISPR/Cas9 technology,we generated an ac6 knockout allele,which exhibited a significant decrease in AC and produced improved ECQ without compromising grain appearance or yield.Subcellular localization analysis demonstrated that AC6 is a plastid-localized protein that likely regulates AC by interacting with the Waxy(Wx)protein.Moreover,expression of starch metabolism-related genes was markedly altered in developing ac6 endosperm.Our study highlights AC6 as a novel target gene for engineering rice germplasm with enhanced ECQ.
文摘Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and secretary of the CPC Gulu Village Branch,better known as Cliff Village,in Hanyuan County,Ya’an City,Sichuan Province,was still dressed in his Yi ethnic waistcoat.
