The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In thi...The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In this study,a highly sensitive and selective ratiometric fluorescence platform for alkaline phosphatase(ALP)detection was established,only employing Prussian blue(PB)nanozymes and a commercially available chromogen of o-phenylenediamine(OPD).PB nanozymes with remarkable peroxidaselike(POD-like)activity can effectively catalyze OPD chromogen to yield 2,3-diaminophenazine(OPDox)with an intense yellow fluorescence at 573 nm emission peak.Target ALP can facilitate ascorbic acid 2-phosphate(AAP)dephosphorylation to generate phosphate and ascorbic acid(AA).Significantly,both these two resultant hydrolysis products could effectively decrease the OPDox generation via a dualpath based inhibition on the PB nanozymes POD-like activity.On the other hand,the generated dehydroascorbic acid(DHAA)from AA oxidation would exclusively react with OPD chromogen to yield3-(dihydroxyethyl)furo[3,4-b]quinoxaline-1-one(DFQ)with a strong blue fluorescent signal at 434nm,which further providing a significant enhancement on the sensing selectivity of ALP detection.As a result,an increased yellow fluorescence of OPDox and decreased blue fluorescence of DFQ could be clearly observed with different ALP addition.A robust linear relationship between the fluorescence ratio of F_(434)/F_(573)and ALP activity ranging from 0.25U/L to 6U/L was obtained,with a low detection limit of 0.112 U/L.This proposed method demonstrates high sensitivity,excellent selectivity,cost-effectiveness,and operational simplicity,yet enabling an effective detection of ALP levels in human serum.展开更多
Using the ERA5 wave reanalysis,the distributions and trends of global available wave energy storage during 1980−2019 are analyzed.The results show that the available wave energy storage is not only related to total wa...Using the ERA5 wave reanalysis,the distributions and trends of global available wave energy storage during 1980−2019 are analyzed.The results show that the available wave energy storage is not only related to total wave energy storage but is also affected by the local available wave probability.Different distributions and trends between the available wave energy and total wave energy storage are observed.Larger values of total wave energy storage are concentrated in the high-latitude westerlies zone,whereas available wave energy storage exhibits greater concentration in the middle-low latitude regions.In each basin,there is a notable upward trend in both total wave energy storage and available wave energy storage.However,the northern Hemisphere(NH)exhibits an increasing trend in available wave probability,whereas the southern Hemisphere(SH)experiences a decreasing trend.This divergence contributes to the spatial distributions of available wave energy storage becoming increasingly uniform.These trends in wave energy are primarily influenced by changes in significant wave height.Although the increasing trend of significant wave height across all frequency ranges induces the growth of total wave energy storage,only the increasing of wave heights falling in 1.3−4 m can cause the growth of available wave energy storage.The consistent increasing rates of wave height under different mean levels contribute to the divergent trends in available wave probability.展开更多
Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this ...Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this study,using questionnaire surveys and in-depth interviews,the development of accessible tourism in Mount Tai Scenic Area was investigated and analyzed.Some countermeasures were put forward,including strengthening information guidance services,enhancing awareness and skills in accessibility services,improving feedback mechanisms for continuous refinement,and strengthening collaborations in the fields of the disabled and accessibility development,aiming to further promote humanistic care and enhance service satisfaction at the scenic area.展开更多
Lightweight nodes are crucial for blockchain scalability,but verifying the availability of complete block data puts significant strain on bandwidth and latency.Existing data availability sampling(DAS)schemes either re...Lightweight nodes are crucial for blockchain scalability,but verifying the availability of complete block data puts significant strain on bandwidth and latency.Existing data availability sampling(DAS)schemes either require trusted setups or suffer from high communication overhead and low verification efficiency.This paper presents ISTIRDA,a DAS scheme that lets light clients certify availability by sampling small random codeword symbols.Built on ISTIR,an improved Reed–Solomon interactive oracle proof of proximity,ISTIRDA combines adaptive folding with dynamic code rate adjustment to preserve soundness while lowering communication.This paper formalizes opening consistency and prove security with bounded error in the random oracle model,giving polylogarithmic verifier queries and no trusted setup.In a prototype compared with FRIDA under equal soundness,ISTIRDA reduces communication by 40.65%to 80%.For data larger than 16 MB,ISTIRDA verifies faster and the advantage widens;at 128 MB,proofs are about 60%smaller and verification time is roughly 25%shorter,while prover overhead remains modest.In peer-to-peer emulation under injected latency and loss,ISTIRDA reaches confidence more quickly and is less sensitive to packet loss and load.These results indicate that ISTIRDA is a scalable and provably secure DAS scheme suitable for high-throughput,large-block public blockchains,substantially easing bandwidth and latency pressure on lightweight nodes.展开更多
Fire is a fundamental ecological driver shaping natural vegetation patterns.In the semi-arid southern Espinal-Monte ecotone of Argentina,the spatiotemporal patterns of fire occurrence related to and modulated by clima...Fire is a fundamental ecological driver shaping natural vegetation patterns.In the semi-arid southern Espinal-Monte ecotone of Argentina,the spatiotemporal patterns of fire occurrence related to and modulated by climatic gradients and antecedent conditions are not well researched.This study examined fire occurrence in the semi-arid southern Espinal-Monte ecotone(southeastern La Pampa,northeastern Río Negro,and southwestern Buenos Aires with an area of 68×103 km2)of Argentina,a key environmental transition zone with pronounced climatic and vegetation gradients.The objective was to identify the spatiotemporal patterns of fire occurrence and their relationship with climatic variables.Thermal anomaly(TA)data from the MODIS(Moderate Resolution Imaging Spectrometer;MOD14)sensor(November 2000–March 2020)with confidence levels>65.0%were analyzed.Climatic variables(rainfall isohyets and aridity indices)were obtained from the WorldClim datasets,and annual meteorological conditions(rainfall and potential evapotranspiration)were calculated using the climatic research unit(CRU)database.Monthly data and moving averages of rainfall and aridity indices from distinct periods(two and three years preceding fire events)were integrated.Spatial analysis was conducted using kernel density estimation on a 10 km×10 km grid to correlate TA with climatic gradients,while linear regression examined relationships between summer TA and meteorological variables over different periods.Results showed that the highest fire occurrence was recorded in summer,with peaks in December and January.Spatially,55.0%of TA occurred in areas with annual rainfall of 300–400 mm,and 64.5%in areas with an aridity index of 0.3–0.4,forming an arc-like distribution in the center of the ecotone.The highest TA densities were observed in southeastern La Pampa and northeastern Río Negro,decreasing toward southwestern Buenos Aires.Significant correlations(R2>0.700)were found among TA accumulation,aridity index values,and cumulative rainfall from previous two and three years,at both vegetation unit and provincial levels.Summer was the critical season for fire occurrence,with spatial distribution primarily determined by the interaction between climatic conditions and woody biomass availability.The lower fire incidence in southwestern Buenos Aires was linked to sparse woody vegetation and agricultural expansion,which reduced fuel load.These findings reinforce that fuel availability,modulated by climatic conditions from previous years,is a key limiting factor for fire dynamics in this area,and that human activities such as agriculture and grazing alter fire regimes by affecting fuel structure and continuity.展开更多
Land-use change and associated landscape pattern modifications are key drivers of biodiversity dynamics.However,the influence of landscape heterogeneity on soil microbial diversity remains poorly understood.This study...Land-use change and associated landscape pattern modifications are key drivers of biodiversity dynamics.However,the influence of landscape heterogeneity on soil microbial diversity remains poorly understood.This study analyzed soil microbial communities(bacteria and fungi)and soil properties(organic carbon,pH,available potassium,nitrogen,and phosphorus)across 74 sites in Hainan,China,covering six land-use types(rubber,areca,banana,farmland,longan,and mango).We evaluated the effects of both landscape composition(habitat coverage and patch richness)and configuration heterogeneity(patch density and largest patch index)on soil microbial community structure and diversity.Results show that land-use types and landscape patterns weakly affect microbial composition but strongly shape diversity in a taxon-specific way.Bacterial Chao1 richness and fungal Shannon diversity varied significantly among land-use types,mainly due to soil available phosphorus.Rubber coverage positively correlated with bacterial and fungal diversity,while the largest patch index negatively affected only fungal diversity.Available phosphorus reduced this negative effect.This study demonstrates that land-use change and landscape heterogeneity differentially influence soil microbial composition and diversity,with available phosphorus emerging as a key determinant.Our findings highlight the need for careful landscape planning and soil nutrient management to preserve soil microbial diversity.展开更多
In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and m...In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and multiple user detection techniques,our scheme can reach a high throughput of 0.98 without feedback under finite frame size settings,where the upper bound on performance is 1.Moreover,a lower bound on throughput performance is derived,which is tight in some parameter settings and can be used to approximate theoretical performance.Simulation results validate our analysis and confirm the advantages of our proposed scheme.展开更多
The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,...The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,allowing users to operate on already restored files while other files are still being restored.This approach improves availability during restoration tasks but suffers from a critical limitation:inconsistencies between the access sequence and the restore sequence.In many cases,the file a user needs to access at a given moment may not yet be restored,resulting in significant delays and poor user experience.To this end,we present Histore,which builds on the user’s historical access sequence to schedule the restore sequence,in order to reduce users’access delayed time.Histore includes three restore approaches:(i)the frequency-based approach,which restores files based on historical file access frequencies and prioritizes ensuring the availability of frequently accessed files;(ii)the graph-based approach,which preferentially restores the frequently accessed files as well as their correlated files based on historical access patterns,and(iii)the trie-based approach,which restores particular files based on both users’real-time and historical access patterns to deduce and restore the files to be accessed in the near future.We implement a prototype of Histore and evaluate its performance from multiple perspectives.Trace-driven experiments on two datasets show that Histore significantly reduces users’delay time by 4-700×with only 1.0%-14.5%additional performance overhead.展开更多
Avery significant event in China’s political calendar took place in Beijing in early March,and,as usual,it was more than optics.The fourth sessions of the 14th National People’s Congress(NPC)and the 14th National Co...Avery significant event in China’s political calendar took place in Beijing in early March,and,as usual,it was more than optics.The fourth sessions of the 14th National People’s Congress(NPC)and the 14th National Committee of the Chinese People’s Political Consultative Conference(CPPCC),the country’s top legislative and advisory bodies,are expected to set the course for China’s direction over the year and beyond.展开更多
Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope...Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope of oxidative modifications on these molecules is crucial for increasing their synthetic structural diversity and unlocking new potential pharmacological activities.However,the progress has been limited by the scarcity of suitable tailoring enzymes.Here,we reported a break-through in achieving targeted and remote dual-site oxidation of licorice triterpenoids using a single P450 mutant.This approach successfully enabled the selective synthesis of the rare triterpenoid,liquiritic acid and 24-OH-liquiritic acid.Our findings demonstrate that microenvironmental accessibility engineering of triterpenoid substrates within the P450 enzyme is essential for continuous and regioselective oxidation.This study not only sheds light on the mechanistic aspects of P450 catalysis but also expands the enzymatic toolkit for selective oxidative modifications in triterpenoid biosynthesis.展开更多
As an important resource in data link,time slots should be strategically allocated to enhance transmission efficiency and resist eavesdropping,especially considering the tremendous increase in the number of nodes and ...As an important resource in data link,time slots should be strategically allocated to enhance transmission efficiency and resist eavesdropping,especially considering the tremendous increase in the number of nodes and diverse communication needs.It is crucial to design control sequences with robust randomness and conflict-freeness to properly address differentiated access control in data link.In this paper,we propose a hierarchical access control scheme based on control sequences to achieve high utilization of time slots and differentiated access control.A theoretical bound of the hierarchical control sequence set is derived to characterize the constraints on the parameters of the sequence set.Moreover,two classes of optimal hierarchical control sequence sets satisfying the theoretical bound are constructed,both of which enable the scheme to achieve maximum utilization of time slots.Compared with the fixed time slot allocation scheme,our scheme reduces the symbol error rate by up to 9%,which indicates a significant improvement in anti-interference and eavesdropping capabilities.展开更多
Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,...Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,developing nations like China face unique challenges in program design and implementation.Objective:This study conducts a systematic comparative analysis of home accessibility modification policies across China,Japan,Germany,and Sweden,identifying key policy dimensions and proposing evidence-based recommendations for strengthening China’s policy framework.Methods:We employed a multi-dimensional analytical framework examining legislative foundations,eligibility criteria,funding mechanisms,and service delivery models.Data were collected from primary legislation,governmental regulations,official statistics,and peer-reviewed literature.Results:Significant cross-national variations exist in policy approaches.Japan and Germany utilize social insurance models with standardized assessments,Sweden adopts a universal rights-based approach,while China employs a targeted assistance model focused on economically disadvantaged households.China completed 1.28 million household renovations during its 14th Five-Year Plan,demonstrating strong implementation capacity;future policy refi nement could draw on international experience to strengthen assessment standardization,broaden eff ective coverage,and improve the sustainability of fi nancing.Conclusions:China can benefi t from international experience in developing standardized assessment protocols,diversifying funding mechanisms,and establishing professional service delivery systems,while acknowledging contextual constraints unique to developing country settings.展开更多
Background Endometrial receptivity(ERE)is a transient uterine state that determines the success of blastocyst implantation;however,the epigenomic regulation underlying ERE establishment in goats remains unclear.Here,w...Background Endometrial receptivity(ERE)is a transient uterine state that determines the success of blastocyst implantation;however,the epigenomic regulation underlying ERE establishment in goats remains unclear.Here,we profiled transcriptional and epigenomic features of endometrial tissues from pregnant goats during the peri-implantation window and nonpregnant control goats in the regressed luteal phase to uncover the transcriptional regulatory networks responsible for ERE establishment in goats,utilizing RNA-seq,ATAC-seq,and H3 K27 ac CUT&Tag.Results A total of 3,143 differentially expressed genes(DEGs)were identified,accompanied by significant alterations in chromatin accessibility and H3 K27 ac modifications between receptive and non-receptive endometria.The targeted genes associated with these epigenetic changes were significantly enriched in pathways related to cell adhesion,immune tolerance,and embryo attachment.Motif enrichment and transcription factor(TF)footprinting analyses identified members of the FOS/JUN,SOX,HNF1,CEBP,and BATF families as candidate regulators,implicating downstream genes involved in ERE establishment,including SPP1,FOXO1,KLF4/6,STAT1,IFI6,ITGB8,PLAC8,DUSP4,NR1D1,ISG15,RUFY4,and PIK3R3.In addition,numerous super-enhancers were identified,indicating regions of high regulatory activity and potential long-range gene-enhancers interactions in the endometrium.Integration of multi-omics datasets revealed a strong correlation(r>0.7)among chromatin accessibility,H3 K27 ac activation,and the expression of 172 DEGs.Furthermore,a set of hub genes(KLF6,IFI6,MCL1,SDC4,SUSD6,MAFF,and IL6R)that appear to coordinate TF binding and distal super-enhancers activity associated with ERE establishment.Conclusions Our data provided an integrated epigenomic atlas of endometrial receptivity establishment in goats and identify candidate regulatory elements and transcription factors that may orchestrate uterine preparation for implantation.These findings offer valuable insights and testable targets for improving fertility in ruminant livestock.展开更多
Vehicular Internet ofThings(V-IoT)networks need intelligent and adaptive spectrum access methods for ensuring ultra-reliable and low-latency communication(URLLC)in highly dynamic environments.Traditional reinforcement...Vehicular Internet ofThings(V-IoT)networks need intelligent and adaptive spectrum access methods for ensuring ultra-reliable and low-latency communication(URLLC)in highly dynamic environments.Traditional reinforcement learning(RL)-based algorithms,such as Q-Learning and Double Q-Learning,are often characterized by unstable convergence and inefficient exploration in the presence of stochastic vehicular traffic and interference.This paper proposes Adaptive Reinforcement Q-learning with Upper Confidence Bound(ARQ-UCB),a lightweight and reliability-aware RL framework,which explicitly reduces interruption and blocking probabilities while improving throughput and delay across diverse vehicular traffic conditions.This proposed ARQ-UCB algorithm extends the basic Q-updates with an exploration confidence term able to dynamically balance exploration and exploitation based on uncertainty estimates,hence allowing faster convergence in case of bursty vehicular traffic.A comprehensive simulation framework evaluates throughput,delay,fairness,energy efficiency,and computational complexity in several V-IoT scenarios.Obtained results indicate that ARQ–UCB attains substantial gains in terms of throughput,fairness,and blocking/delay probabilities while retaining sub-20μs decision latency and O(1)complexity per decision,thus validating real-time feasibility for reliable spectrum access in 5G and beyond V-IoT networks.展开更多
After securing a market for their dried red chilli peppers in China,elated farmers in Uganda are expanding the spicy crop cultivation to thousands of acres.China’s increasing appetite for international cuisine and sp...After securing a market for their dried red chilli peppers in China,elated farmers in Uganda are expanding the spicy crop cultivation to thousands of acres.China’s increasing appetite for international cuisine and spices has created a most welcome demand for high-quality chillies.And given Uganda’s unique climate and soil conditions that allow for diverse chilli varieties,the East African country has a competitive edge.This has led to Uganda and China now having trade agreements in place,facilitating exports.展开更多
The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such...The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such as geography,economics,and urban planning.Although much existing research focuses on the impact of individual transportation facilities on housing prices,there is a notable gap in comprehensive analyses that assess the influence of overall urban transit accessibility on housing market dynamics.This study selected the main urban area of Hefei,China,as a case to investigate the spatial distribution of housing prices and evaluate public transit accessibility in 2022.Employing techniques such as the optimized parameter geographical detector and local spatial regression models,the study aimed to elucidate the effects and underlying mechanisms of urban transit accessibility on housing prices.The findings revealed that:1)housing prices in Hefei exhibited a clustered spatial pattern,with high prices concentrated in the city center and lower prices in peripheral areas,forming three distinct high-price hotspots with a‘belt-like’distribution;2)public transit accessibility showed a‘coreperiphery’structure,with accessibility declining in a‘circumferential’pattern around the city center.Based on the‘housing price-accessibility’dimension,four categories were identified:high price-high accessibility(37.25%),high price-low accessibility(19.07%),low price-high accessibility(21.95%),and low price-low accessibility(21.73%);3)the impact of transit accessibility on housing prices was spatially heterogeneous,with bus travel showing the strongest explanatory power(0.692),followed by automobile,subway,and bicycle travel.The interaction of these transportation modes generated a synergistic effect on housing price differentiation,with most influencing factors contributing more than 25%.These findings offer valuable insights for optimizing the spatial distribution of public transit infrastructure and improving both urban housing quality and residents’living standards.展开更多
基金supported by the National Natural Science Foundation of China(No.22064014)the Science and Technology Development Plan Project of Lanzhou(No.2021–1-146)+2 种基金the Science and Technology Project of Gansu Province(Nos.21YF5FA071,21JR7RA538)the Industrial Support Programme for Higher Education Institutions Project(Nos.2023CYZC-69,2024CYCZ-05)the 2023 Gansu Provincial Key Talent Project(No.2023RCXM26)。
文摘The traditional nanozymes-based ratiometric fluorescence sensing platforms usually necessitate the supplementary addition of fluorescent probes,therefore greatly restricting its convenient and broad application.In this study,a highly sensitive and selective ratiometric fluorescence platform for alkaline phosphatase(ALP)detection was established,only employing Prussian blue(PB)nanozymes and a commercially available chromogen of o-phenylenediamine(OPD).PB nanozymes with remarkable peroxidaselike(POD-like)activity can effectively catalyze OPD chromogen to yield 2,3-diaminophenazine(OPDox)with an intense yellow fluorescence at 573 nm emission peak.Target ALP can facilitate ascorbic acid 2-phosphate(AAP)dephosphorylation to generate phosphate and ascorbic acid(AA).Significantly,both these two resultant hydrolysis products could effectively decrease the OPDox generation via a dualpath based inhibition on the PB nanozymes POD-like activity.On the other hand,the generated dehydroascorbic acid(DHAA)from AA oxidation would exclusively react with OPD chromogen to yield3-(dihydroxyethyl)furo[3,4-b]quinoxaline-1-one(DFQ)with a strong blue fluorescent signal at 434nm,which further providing a significant enhancement on the sensing selectivity of ALP detection.As a result,an increased yellow fluorescence of OPDox and decreased blue fluorescence of DFQ could be clearly observed with different ALP addition.A robust linear relationship between the fluorescence ratio of F_(434)/F_(573)and ALP activity ranging from 0.25U/L to 6U/L was obtained,with a low detection limit of 0.112 U/L.This proposed method demonstrates high sensitivity,excellent selectivity,cost-effectiveness,and operational simplicity,yet enabling an effective detection of ALP levels in human serum.
基金The National Key R&D Program of China under contract No.2023YFE0126300the National Natural Science Foundation of China under contract No.41930538the Open Fund of China Meteorological Administration Hydro-Meteorology Key Laboratory,Hohai University,under contract No.23SWQXM049.
文摘Using the ERA5 wave reanalysis,the distributions and trends of global available wave energy storage during 1980−2019 are analyzed.The results show that the available wave energy storage is not only related to total wave energy storage but is also affected by the local available wave probability.Different distributions and trends between the available wave energy and total wave energy storage are observed.Larger values of total wave energy storage are concentrated in the high-latitude westerlies zone,whereas available wave energy storage exhibits greater concentration in the middle-low latitude regions.In each basin,there is a notable upward trend in both total wave energy storage and available wave energy storage.However,the northern Hemisphere(NH)exhibits an increasing trend in available wave probability,whereas the southern Hemisphere(SH)experiences a decreasing trend.This divergence contributes to the spatial distributions of available wave energy storage becoming increasingly uniform.These trends in wave energy are primarily influenced by changes in significant wave height.Although the increasing trend of significant wave height across all frequency ranges induces the growth of total wave energy storage,only the increasing of wave heights falling in 1.3−4 m can cause the growth of available wave energy storage.The consistent increasing rates of wave height under different mean levels contribute to the divergent trends in available wave probability.
基金Sponsored by Tai’an Science and Technology Innovation Development Project(Policy Guidance Category)(2024ZC042)Research Project of Inner Mongolia Autonomous Region Center for the Theoretical System of Socialism with Chinese Characteristics(2024ZZB018).
文摘Mount Tai Scenic Area has achieved certain results in the construction of accessible tourism facilities,realizing the exploration of digital and intelligent transformation in traditional mountain scenic areas.In this study,using questionnaire surveys and in-depth interviews,the development of accessible tourism in Mount Tai Scenic Area was investigated and analyzed.Some countermeasures were put forward,including strengthening information guidance services,enhancing awareness and skills in accessibility services,improving feedback mechanisms for continuous refinement,and strengthening collaborations in the fields of the disabled and accessibility development,aiming to further promote humanistic care and enhance service satisfaction at the scenic area.
基金supported in part by the Research Fund of Key Lab of Education Blockchain and Intelligent Technology,Ministry of Education(EBME25-F-08).
文摘Lightweight nodes are crucial for blockchain scalability,but verifying the availability of complete block data puts significant strain on bandwidth and latency.Existing data availability sampling(DAS)schemes either require trusted setups or suffer from high communication overhead and low verification efficiency.This paper presents ISTIRDA,a DAS scheme that lets light clients certify availability by sampling small random codeword symbols.Built on ISTIR,an improved Reed–Solomon interactive oracle proof of proximity,ISTIRDA combines adaptive folding with dynamic code rate adjustment to preserve soundness while lowering communication.This paper formalizes opening consistency and prove security with bounded error in the random oracle model,giving polylogarithmic verifier queries and no trusted setup.In a prototype compared with FRIDA under equal soundness,ISTIRDA reduces communication by 40.65%to 80%.For data larger than 16 MB,ISTIRDA verifies faster and the advantage widens;at 128 MB,proofs are about 60%smaller and verification time is roughly 25%shorter,while prover overhead remains modest.In peer-to-peer emulation under injected latency and loss,ISTIRDA reaches confidence more quickly and is less sensitive to packet loss and load.These results indicate that ISTIRDA is a scalable and provably secure DAS scheme suitable for high-throughput,large-block public blockchains,substantially easing bandwidth and latency pressure on lightweight nodes.
基金funded by the National University of Río Negro Research Project (40-C-658)
文摘Fire is a fundamental ecological driver shaping natural vegetation patterns.In the semi-arid southern Espinal-Monte ecotone of Argentina,the spatiotemporal patterns of fire occurrence related to and modulated by climatic gradients and antecedent conditions are not well researched.This study examined fire occurrence in the semi-arid southern Espinal-Monte ecotone(southeastern La Pampa,northeastern Río Negro,and southwestern Buenos Aires with an area of 68×103 km2)of Argentina,a key environmental transition zone with pronounced climatic and vegetation gradients.The objective was to identify the spatiotemporal patterns of fire occurrence and their relationship with climatic variables.Thermal anomaly(TA)data from the MODIS(Moderate Resolution Imaging Spectrometer;MOD14)sensor(November 2000–March 2020)with confidence levels>65.0%were analyzed.Climatic variables(rainfall isohyets and aridity indices)were obtained from the WorldClim datasets,and annual meteorological conditions(rainfall and potential evapotranspiration)were calculated using the climatic research unit(CRU)database.Monthly data and moving averages of rainfall and aridity indices from distinct periods(two and three years preceding fire events)were integrated.Spatial analysis was conducted using kernel density estimation on a 10 km×10 km grid to correlate TA with climatic gradients,while linear regression examined relationships between summer TA and meteorological variables over different periods.Results showed that the highest fire occurrence was recorded in summer,with peaks in December and January.Spatially,55.0%of TA occurred in areas with annual rainfall of 300–400 mm,and 64.5%in areas with an aridity index of 0.3–0.4,forming an arc-like distribution in the center of the ecotone.The highest TA densities were observed in southeastern La Pampa and northeastern Río Negro,decreasing toward southwestern Buenos Aires.Significant correlations(R2>0.700)were found among TA accumulation,aridity index values,and cumulative rainfall from previous two and three years,at both vegetation unit and provincial levels.Summer was the critical season for fire occurrence,with spatial distribution primarily determined by the interaction between climatic conditions and woody biomass availability.The lower fire incidence in southwestern Buenos Aires was linked to sparse woody vegetation and agricultural expansion,which reduced fuel load.These findings reinforce that fuel availability,modulated by climatic conditions from previous years,is a key limiting factor for fire dynamics in this area,and that human activities such as agriculture and grazing alter fire regimes by affecting fuel structure and continuity.
基金supported by the National Natural Science Foundation of China(grant no.U23A2016 and 42101094).
文摘Land-use change and associated landscape pattern modifications are key drivers of biodiversity dynamics.However,the influence of landscape heterogeneity on soil microbial diversity remains poorly understood.This study analyzed soil microbial communities(bacteria and fungi)and soil properties(organic carbon,pH,available potassium,nitrogen,and phosphorus)across 74 sites in Hainan,China,covering six land-use types(rubber,areca,banana,farmland,longan,and mango).We evaluated the effects of both landscape composition(habitat coverage and patch richness)and configuration heterogeneity(patch density and largest patch index)on soil microbial community structure and diversity.Results show that land-use types and landscape patterns weakly affect microbial composition but strongly shape diversity in a taxon-specific way.Bacterial Chao1 richness and fungal Shannon diversity varied significantly among land-use types,mainly due to soil available phosphorus.Rubber coverage positively correlated with bacterial and fungal diversity,while the largest patch index negatively affected only fungal diversity.Available phosphorus reduced this negative effect.This study demonstrates that land-use change and landscape heterogeneity differentially influence soil microbial composition and diversity,with available phosphorus emerging as a key determinant.Our findings highlight the need for careful landscape planning and soil nutrient management to preserve soil microbial diversity.
文摘In this paper,we propose a random access scheme termed sign-compute diversity slotted ALOHA(SCDSA).The SCDSA scheme combines diversity transmission with compute-and-forward.Without considering the capture effect and multiple user detection techniques,our scheme can reach a high throughput of 0.98 without feedback under finite frame size settings,where the upper bound on performance is 1.Moreover,a lower bound on throughput performance is derived,which is tight in some parameter settings and can be used to approximate theoretical performance.Simulation results validate our analysis and confirm the advantages of our proposed scheme.
基金supported in part by National Key R&D Program of China(2022YFB4501200),National Natural Science Foundation of China(62332018)Science and Technology Program(2024NSFTD0031,2024YFHZ0339 and 2025ZNSFSC0497).
文摘The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,allowing users to operate on already restored files while other files are still being restored.This approach improves availability during restoration tasks but suffers from a critical limitation:inconsistencies between the access sequence and the restore sequence.In many cases,the file a user needs to access at a given moment may not yet be restored,resulting in significant delays and poor user experience.To this end,we present Histore,which builds on the user’s historical access sequence to schedule the restore sequence,in order to reduce users’access delayed time.Histore includes three restore approaches:(i)the frequency-based approach,which restores files based on historical file access frequencies and prioritizes ensuring the availability of frequently accessed files;(ii)the graph-based approach,which preferentially restores the frequently accessed files as well as their correlated files based on historical access patterns,and(iii)the trie-based approach,which restores particular files based on both users’real-time and historical access patterns to deduce and restore the files to be accessed in the near future.We implement a prototype of Histore and evaluate its performance from multiple perspectives.Trace-driven experiments on two datasets show that Histore significantly reduces users’delay time by 4-700×with only 1.0%-14.5%additional performance overhead.
文摘Avery significant event in China’s political calendar took place in Beijing in early March,and,as usual,it was more than optics.The fourth sessions of the 14th National People’s Congress(NPC)and the 14th National Committee of the Chinese People’s Political Consultative Conference(CPPCC),the country’s top legislative and advisory bodies,are expected to set the course for China’s direction over the year and beyond.
基金supported by grants from the National Natural Science Foundation of China(Nos.22108154,22138006,32171430).
文摘Triterpenoids are valuable medicinal scaffolds,characterized by excellent pharmacological properties and the presence of hydroxyl and carboxyl groups that allow for further structural modifications.Expanding the scope of oxidative modifications on these molecules is crucial for increasing their synthetic structural diversity and unlocking new potential pharmacological activities.However,the progress has been limited by the scarcity of suitable tailoring enzymes.Here,we reported a break-through in achieving targeted and remote dual-site oxidation of licorice triterpenoids using a single P450 mutant.This approach successfully enabled the selective synthesis of the rare triterpenoid,liquiritic acid and 24-OH-liquiritic acid.Our findings demonstrate that microenvironmental accessibility engineering of triterpenoid substrates within the P450 enzyme is essential for continuous and regioselective oxidation.This study not only sheds light on the mechanistic aspects of P450 catalysis but also expands the enzymatic toolkit for selective oxidative modifications in triterpenoid biosynthesis.
基金supported by the National Science Foundation of China(No.62171387)the Science and Technology Program of Sichuan Province(No.2024NSFSC0468)the China Postdoctoral Science Foundation(No.2019M663475).
文摘As an important resource in data link,time slots should be strategically allocated to enhance transmission efficiency and resist eavesdropping,especially considering the tremendous increase in the number of nodes and diverse communication needs.It is crucial to design control sequences with robust randomness and conflict-freeness to properly address differentiated access control in data link.In this paper,we propose a hierarchical access control scheme based on control sequences to achieve high utilization of time slots and differentiated access control.A theoretical bound of the hierarchical control sequence set is derived to characterize the constraints on the parameters of the sequence set.Moreover,two classes of optimal hierarchical control sequence sets satisfying the theoretical bound are constructed,both of which enable the scheme to achieve maximum utilization of time slots.Compared with the fixed time slot allocation scheme,our scheme reduces the symbol error rate by up to 9%,which indicates a significant improvement in anti-interference and eavesdropping capabilities.
基金funded by the China Disabled Persons’Federation under its 2024 research project(Grant No.2024CDPFAT-47)the Yancheng Social Science Foundation(Grant No.25skB252).
文摘Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,developing nations like China face unique challenges in program design and implementation.Objective:This study conducts a systematic comparative analysis of home accessibility modification policies across China,Japan,Germany,and Sweden,identifying key policy dimensions and proposing evidence-based recommendations for strengthening China’s policy framework.Methods:We employed a multi-dimensional analytical framework examining legislative foundations,eligibility criteria,funding mechanisms,and service delivery models.Data were collected from primary legislation,governmental regulations,official statistics,and peer-reviewed literature.Results:Significant cross-national variations exist in policy approaches.Japan and Germany utilize social insurance models with standardized assessments,Sweden adopts a universal rights-based approach,while China employs a targeted assistance model focused on economically disadvantaged households.China completed 1.28 million household renovations during its 14th Five-Year Plan,demonstrating strong implementation capacity;future policy refi nement could draw on international experience to strengthen assessment standardization,broaden eff ective coverage,and improve the sustainability of fi nancing.Conclusions:China can benefi t from international experience in developing standardized assessment protocols,diversifying funding mechanisms,and establishing professional service delivery systems,while acknowledging contextual constraints unique to developing country settings.
基金financially supported by the National Natural Science Foundation of China(No.32502862)the Collection,Utilization and Innovation of Animal Resources by Research Institutes and Enterprises of Chongqing(No.Cqnyncwkqlhtxm)+1 种基金the Chongqing Modern Agricultural Industry Technology System(CQMAITS202513)the Key Project of Chongqing Technology Innovation and Application Development Special Program(CTSB2025TIAD-KPX0079)。
文摘Background Endometrial receptivity(ERE)is a transient uterine state that determines the success of blastocyst implantation;however,the epigenomic regulation underlying ERE establishment in goats remains unclear.Here,we profiled transcriptional and epigenomic features of endometrial tissues from pregnant goats during the peri-implantation window and nonpregnant control goats in the regressed luteal phase to uncover the transcriptional regulatory networks responsible for ERE establishment in goats,utilizing RNA-seq,ATAC-seq,and H3 K27 ac CUT&Tag.Results A total of 3,143 differentially expressed genes(DEGs)were identified,accompanied by significant alterations in chromatin accessibility and H3 K27 ac modifications between receptive and non-receptive endometria.The targeted genes associated with these epigenetic changes were significantly enriched in pathways related to cell adhesion,immune tolerance,and embryo attachment.Motif enrichment and transcription factor(TF)footprinting analyses identified members of the FOS/JUN,SOX,HNF1,CEBP,and BATF families as candidate regulators,implicating downstream genes involved in ERE establishment,including SPP1,FOXO1,KLF4/6,STAT1,IFI6,ITGB8,PLAC8,DUSP4,NR1D1,ISG15,RUFY4,and PIK3R3.In addition,numerous super-enhancers were identified,indicating regions of high regulatory activity and potential long-range gene-enhancers interactions in the endometrium.Integration of multi-omics datasets revealed a strong correlation(r>0.7)among chromatin accessibility,H3 K27 ac activation,and the expression of 172 DEGs.Furthermore,a set of hub genes(KLF6,IFI6,MCL1,SDC4,SUSD6,MAFF,and IL6R)that appear to coordinate TF binding and distal super-enhancers activity associated with ERE establishment.Conclusions Our data provided an integrated epigenomic atlas of endometrial receptivity establishment in goats and identify candidate regulatory elements and transcription factors that may orchestrate uterine preparation for implantation.These findings offer valuable insights and testable targets for improving fertility in ruminant livestock.
基金support the findings of this study are available from the corresponding authors upon reasonable request.
文摘Vehicular Internet ofThings(V-IoT)networks need intelligent and adaptive spectrum access methods for ensuring ultra-reliable and low-latency communication(URLLC)in highly dynamic environments.Traditional reinforcement learning(RL)-based algorithms,such as Q-Learning and Double Q-Learning,are often characterized by unstable convergence and inefficient exploration in the presence of stochastic vehicular traffic and interference.This paper proposes Adaptive Reinforcement Q-learning with Upper Confidence Bound(ARQ-UCB),a lightweight and reliability-aware RL framework,which explicitly reduces interruption and blocking probabilities while improving throughput and delay across diverse vehicular traffic conditions.This proposed ARQ-UCB algorithm extends the basic Q-updates with an exploration confidence term able to dynamically balance exploration and exploitation based on uncertainty estimates,hence allowing faster convergence in case of bursty vehicular traffic.A comprehensive simulation framework evaluates throughput,delay,fairness,energy efficiency,and computational complexity in several V-IoT scenarios.Obtained results indicate that ARQ–UCB attains substantial gains in terms of throughput,fairness,and blocking/delay probabilities while retaining sub-20μs decision latency and O(1)complexity per decision,thus validating real-time feasibility for reliable spectrum access in 5G and beyond V-IoT networks.
文摘After securing a market for their dried red chilli peppers in China,elated farmers in Uganda are expanding the spicy crop cultivation to thousands of acres.China’s increasing appetite for international cuisine and spices has created a most welcome demand for high-quality chillies.And given Uganda’s unique climate and soil conditions that allow for diverse chilli varieties,the East African country has a competitive edge.This has led to Uganda and China now having trade agreements in place,facilitating exports.
基金Under the auspices of the National Natural Science Foundation of China(No.42271224,41901193)Ministry of Edu cation Humanities and Social Sciences Research Planning Fund Project of China(No.24YJAZH190)+1 种基金Anhui Province Excellent Youth Research Project in Universities(No.2022AH030019)Anhui Social Sciences Innovation Development Research Project(No.2024CXQ503)。
文摘The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such as geography,economics,and urban planning.Although much existing research focuses on the impact of individual transportation facilities on housing prices,there is a notable gap in comprehensive analyses that assess the influence of overall urban transit accessibility on housing market dynamics.This study selected the main urban area of Hefei,China,as a case to investigate the spatial distribution of housing prices and evaluate public transit accessibility in 2022.Employing techniques such as the optimized parameter geographical detector and local spatial regression models,the study aimed to elucidate the effects and underlying mechanisms of urban transit accessibility on housing prices.The findings revealed that:1)housing prices in Hefei exhibited a clustered spatial pattern,with high prices concentrated in the city center and lower prices in peripheral areas,forming three distinct high-price hotspots with a‘belt-like’distribution;2)public transit accessibility showed a‘coreperiphery’structure,with accessibility declining in a‘circumferential’pattern around the city center.Based on the‘housing price-accessibility’dimension,four categories were identified:high price-high accessibility(37.25%),high price-low accessibility(19.07%),low price-high accessibility(21.95%),and low price-low accessibility(21.73%);3)the impact of transit accessibility on housing prices was spatially heterogeneous,with bus travel showing the strongest explanatory power(0.692),followed by automobile,subway,and bicycle travel.The interaction of these transportation modes generated a synergistic effect on housing price differentiation,with most influencing factors contributing more than 25%.These findings offer valuable insights for optimizing the spatial distribution of public transit infrastructure and improving both urban housing quality and residents’living standards.
