Historical overview In 1975,Michel Mathieu became the head of the newly autonomous Department of Ophthalmology at the University of Montreal.Mathieu’s growing reputation as a skilled clinician and researcher attracte...Historical overview In 1975,Michel Mathieu became the head of the newly autonomous Department of Ophthalmology at the University of Montreal.Mathieu’s growing reputation as a skilled clinician and researcher attracted excellent candidates to the department(1).Under his direction,Suzanne Véronneau-Troutman became the first resident and,subsequently,the first female ophthalmic surgeon at University of Montreal.Her immense contribution to the field of strabismus later gained worldwide appreciation,as recognized by the annual American Academy of Ophthalmology award named after her(2).Mathieu’s work,and that of his recruits,led to major advances in the fields of corneal transplantation,retinal degenerations,electroretinography,and ophthalmic surgical instrumentation(3).展开更多
Background:Cognitive assessments,such as the Montreal Cognitive Assessment(MoCA),use components that assume intact sensory abilities,however,adults show concomitant decreases in visual acuity with increasing age.Score...Background:Cognitive assessments,such as the Montreal Cognitive Assessment(MoCA),use components that assume intact sensory abilities,however,adults show concomitant decreases in visual acuity with increasing age.Scores on cognitive assessments are typically lower for individuals with visual impairments compared to individuals with normal/corrected to normal vision.But it is not clear if lowers scores on cognitive assessments are due to the assessments relying on visual stimuli,or if individuals with visual impairments are actually more likely to have cognitive impairments.Therefore we simulated visual impairments,i.e.,reduced visual acuity and contrast sensitivity,in young healthy adults to determine how this impacts their scores on a measure of cognitive ability,i.e.,the MoCA.Methods:Participants(n=19)completed one of the three version of the MoCA under three conditions(20/20,simulated 20/80,simulated 20/200).The MoCA was administered following the clinical protocols.Only participants that scored>26(i.e.,normal cognitive function)at 20/20 were included in the analysis.For comparison,we included MoCA data from a sample of older adults with normal vision(n=19,Mage=74,Acuity M=0.04 logMAR,SD=0.16)or visual impairment(n=19,Mage=79,Acuity M=0.35 logMAR,SD=0.3).Results:Acuity of participants at 20/20(M=0.06 LogMAR,SD=0.1),simulated 20/80(M=0.63,SD=0.18)and simulated 20/200(M=0.88,SD=0.19)showed that the participants experienced simulated acuity loss with the goggles.For the MoCA scores,we found a main effect of acuity(F=16.22,P<0.001,η2=0.375,BF10=5,618).Planned post hoc comparisons showed a significant difference between scores with a 20/20 acuity(M=27.26,SD=0.93)and 20/80(M=24.74,SD=1.66,t=5.62,ptukey<0.001,d=1.88),and between 20/20 and 20/200(M=25.63,SD=1.46,t=3.63,ptukey=0.002,Cohen’s d=1.33).However,no difference was observed between 20/80 and 20/200(t=−1.99,ptukey=0.125,d=0.572).The MoCA scores in older adults with normal vision(M=27.32,SD=2.41)and with visual impairment(M=26.68,SD=2.52),did not differ significantly(t36=−0.787,P=0.436,d=0.26,BF10=0.4).Conclusions:Our findings show that simulated reductions in visual acuity and contrast sensitivity lead to lower scores on measures of cognitive ability,specifically the MoCA.However,it appears that older adults with actual visual impairments may have developed compensatory strategies to adapt to this loss in visual acuity as there were no significant differences in scores of older adults with and without visual impairments.Therefore,we would recommend that when assessing an individual with visual impairments to conduct the cognitive test by re-scoring it without the visual components,e.g.,the MoCA Blind,to magnify the visual components,or to substitue the visual component when possible using auditory alternatives,e.g.,the oral trail making task.展开更多
Alternative technologies have emerged to reduce the greenhouse gas (GHG) emissions of traditional commuter rail systems powered by diesel. Even larger reductions can be obtained with energy production from renewable r...Alternative technologies have emerged to reduce the greenhouse gas (GHG) emissions of traditional commuter rail systems powered by diesel. Even larger reductions can be obtained with energy production from renewable resources. This paper uses the commuter rail system in Montreal, Quebec, as a case study for implementing alternative technologies, namely, complete electrification of the network (only one of the existing five lines is electrified) and hydrogen fuel cell-powered trains. It is important to note that the main source of electricity generation in Quebec is hydropower which is offered at a relatively low cost. Several criteria were considered to determine the most suitable alternative including GHG emissions from operation and fuel production, operation and capital costs, and technological and commercial viability. Electrification of the commuter rail system would decrease annual emissions by 98% which is more than 27,000 tons. The GHG reductions for hydrogen trains are lower than electric trains but still substantial. The operation costs favor the electrification scenario;however, the high costs of electrical infrastructure make hydrogen trains more competitive since additional infrastructure is unnecessary. However, hydrogen trains remain a new and unproven technology;uncertainties associated with it should be settled before full implementation.展开更多
Myelin,made by oligodendrocytes(OLs)in the central nervous system(CNS),is essential for neural transmission.In particular,myelin facilitates communication across the long connections between different brain regions th...Myelin,made by oligodendrocytes(OLs)in the central nervous system(CNS),is essential for neural transmission.In particular,myelin facilitates communication across the long connections between different brain regions that form the white matter.Myelinated segments also provide metabolic intermediates to axons,supporting their demanding energetic needs.Genetic disorders that disrupt myelin formation result in progressive neurologic degeneration.展开更多
To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction...To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction-Order(FO)sliding-mode Fault-Tolerant Cooperative Control(FTCC)strategy is proposed for multiple UAVs based on Event-Triggered Communication Mechanism(ET-COM-M)and Event-Triggered Control Mechanism(ET-CON-M).First,by considering the limited communication bandwidth of multiple UAVs in formation,an ET-COM-M is designed to significantly reduce communication times.Then,a distributed observer is skillfully constructed to estimate the reference signals for follower UAVs.Moreover,the adaptive strategy is incorporated into the Radial Basis Function Neural Network(RBFNN)to learn the lumped unknown terms for handling bias actuator faults and parameter uncertainties.Besides,the Nussbaum method is used to deal with the loss-of-effectiveness faults.To further achieve the refined control performance against faults,FO calculus is artfully integrated into the sliding-mode control protocol with ET-CON-M.Finally,Zeno behavior is excluded by rigorous theoretical analysis and Lyapunov stability is proved to show the effectiveness of the designed FTCC strategy.Simulation results show that the designed FTCC strategy with Event-Triggered Mechanism(ETM)can guarantee the safety of multiple UAVs and simultaneously reduce the communication and control frequencies,making the developed control scheme applicable in engineering.展开更多
Xylogenesis,the process through which wood cells are formed,results in the long-term storage of carbon in woody biomass,making it a key component of the global carbon cycle.Understanding how environmental drivers infl...Xylogenesis,the process through which wood cells are formed,results in the long-term storage of carbon in woody biomass,making it a key component of the global carbon cycle.Understanding how environmental drivers influence xylogenesis during the growing season is therefore of great interest.However,studying shortterm drivers of wood production using xylogenetic data is complicated by the usual sampling scheme and the influence of eccentric growth,i.e.,heterogeneous growth around the stem.In this study,we improve xylogenesis research by introducing a statistical approach that explicitly considers seasonal phenology,short-term growth rates,and growth eccentricity.To this end,we developed Bayesian models of xylogenesis and compared them with a conventional method based on the use of Gompertz functions.Our results show that eccentricity generated high temporal autocorrelation between successive samples,and that explicitly taking it into account improved both the representativeness of phenology and intra-ring variability.We observed consistent short-term patterns in the model residuals,suggesting the influence of an unaccounted-for environmental variable on cell production.The proposed models offer several advantages over traditional methods,including robust confidence intervals around predictions,consistency with phenology,and reduced sensitivity to extreme observations at the end of the growing season,often linked to eccentric growth.These models also provide a benchmark for mechanistic testing of short-term drivers of wood formation.展开更多
Understanding the spatial mach between water purification service supply and demand is crucial for optimizing watershed management and strengthening nature-society linkages,particularly in ecologically critical areas ...Understanding the spatial mach between water purification service supply and demand is crucial for optimizing watershed management and strengthening nature-society linkages,particularly in ecologically critical areas such as the Three Gorges Reservoir Area(TGRA).This study quantified the spatiotemporal patterns of water purification supply and demand by assessing the actual and potential non-point source pollution,and compared their mismatch ratio in the TGRA.Meanwhile,supply-demand reachability indicator was used to identify the water purification supply-demand relationship.Results showed that the TGRA generally maintained a balanced supply and demand relationship for water purification.Spatial analysis revealed that the ecosystem service demand and reachability indicator peaked in regions with>1000 m and>25°.Water purification exhibited High-High in the central Yangtze River corridor and southwestern TGRA,whereas Low-Low in the northern and southern regions.Driving analysis indicated climate factors significantly enhanced both supply(0.41)and demand(0.54),whereas soil factors exerted negative impacts on both supply(−0.37)and demand(−0.23).Topographic and socioeconomic factors also showed adverse,albeit relatively minor,effects.Based on the observed spatial mismatches,we propose shifting water purification governance strategies from aggregate control towards spatially targeted coordination that explicitly addresses distinct supply-demand relationships across different zones.展开更多
This review comprehensively summarized the potential of artificial intelligence(AI)in the management of esophageal cancer.It highlighted the significance of AI-assisted endoscopy in Japan where endoscopy is central to...This review comprehensively summarized the potential of artificial intelligence(AI)in the management of esophageal cancer.It highlighted the significance of AI-assisted endoscopy in Japan where endoscopy is central to both screening and diagnosis.For the clinical adaptation of AI,several challenges remain for its effective translation.The establishment of high-quality clinical databases,such as the National Clinical Database and Japan Endoscopy Database in Japan,which covers almost all cases of esophageal cancer,is essential for validating multimodal AI models.This requires rigorous external validation using diverse datasets,including those from different endoscope manufacturers and image qualities.Furthermore,endoscopists’skills significantly affect diagnostic accuracy,suggesting that AI should serve as a supportive tool rather than a replacement.Addressing these challenges,along with country-specific legal and ethical considerations,will facilitate the successful integration of multimodal AI into the management of esophageal cancer,particularly in endoscopic diagnosis,and contribute to improved patient outcomes.Although this review focused on Japan as a case study,the challenges and solutions described are broadly applicable to other high-incidence regions.展开更多
In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact...In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact on global climate change.However,the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored.To address this research gap,we collected 306 upper layer(0–20 cm)soil samples from the Dongting Lake floodplain between 2013 and 2022.The random forest(RF)algorithm was used to analyze the spatial distribution of soil organic carbon(SOC)in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied.In 2022,the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^(-1),averaging 10.43 g kg^(-1),with a corresponding SOC density of(2.65±0.49)kg m^(-2) and total SOC stock of 6.82 Tg C(2.87–13.48 Tg C).From 2013 to 2022,the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 to 10.82 g kg^(-1).This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition.Above 21.4 m elevation,the amount of SOC loss increased with elevation,the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes.Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change.展开更多
Drought has the potential to induce extensive defoliation in forest trees.However,the responses of non-structural carbohydrates(NSCs,including soluble sugar and starch)to the combined effects of drought and defoliatio...Drought has the potential to induce extensive defoliation in forest trees.However,the responses of non-structural carbohydrates(NSCs,including soluble sugar and starch)to the combined effects of drought and defoliation remain to be elucidated,particularly in pine trees.In this study,we investigated the interactive effects of drought and defoliation on the contents of NSCs in five organs(new and old needles,twigs,stems,as well as roots)of Chinese pine(Pinus tabuliformis)seedlings.We sampled two batches of the seedlings at 30 and 50 days,respectively.Our results showed that Chinese pine could tolerate mild drought,but severe drought significantly decreased the content of soluble sugars in all organs.Defoliation initially suppressed the photosynthetic rate and significantly reduced the soluble sugar content in all organs.However,after 50 days,this effect was substantially mitigated by the new needle growth.Starch content in twigs,stems,and roots was found to be more vulnerable to defoliation than to drought.A significant interactive effect existed between drought and defoliation on NSCs,with defoliation exacerbating the negative impact of drought on the accumulation of NSCs,especially in new needles and roots.These findings highlight the complex effects of defoliation on NSCs during drought,underscoring critical implications for the management and economic value of Chinese pine forests.展开更多
Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for sign...Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.展开更多
Siberian-Arctic heatwaves(SAHs)disrupt ecosystems by increasing wildfires,thawing permafrost,and threatening Arctic communities.As SAHs become more frequent and intense,accurate prediction is crucial for preparedness ...Siberian-Arctic heatwaves(SAHs)disrupt ecosystems by increasing wildfires,thawing permafrost,and threatening Arctic communities.As SAHs become more frequent and intense,accurate prediction is crucial for preparedness and mitigating their impacts.We demonstrate that April surface temperatures in the Siberian Arctic can be predicted one month in advance with a skill of 0.75(1979-2022)using a regression model based on Arctic stratospheric ozone,the Arctic Oscillation,and sea ice in the Kara Sea.This model successfully predicts six of seven SAHs,identifying three driven by extreme ozone depletion and three by significant sea-ice loss.Additionally,from 1979 to 1997,warming was primarily caused by ozone depletion,while from 1998 to 2022,sea-ice loss became the main factor.Our findings indicate that SAHs are predictable and recommend this model for real-time monitoring and forecasting,highlighting its potential to enhance preparedness and reduce adverse effects.展开更多
Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related dea...Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related deaths.However,the utility of the integrated“deaths of despair”framework,which views alcohol,drug,and suicide deaths as a unified socio-economic phenomenon,remains under-explored in this context.Crucially,the long-term evolution of the composition of despair within the region remains a largely unexplored area of inquiry.Therefore,this study aims to analyze the long-term trends,changing composition,and regional heterogeneity of deaths from despair in the CEECA region from 1980 to 2021.Methods:Using 2021 Global Burden of Disease(GBD)data(1980–2021),we analyzed deaths of despair mortality trends in 29 CEECA countries.We employed Joinpoint regression to identify significant trend changes and conducted stratified analyses by cause,gender,and age group.Results:The CEECA deaths of despair crisis began as an alcohol and suicide driven phenomenon concentrated in middle-aged men(50–74 years)during the 1990s,with mortality rates for alcohol use disorders and self-harm surging annually by 30.35%(p=0.002)and 13.44%(p=0.001),respectively,between 1991 and 1994.It has since evolved,marked by a contrasting and emerging threat in the 21st century:a rising proportion of drug-related deaths among the younger(15–49 years)male cohort,where the share of drug use disorders increased from 6.9%in 2000 to 11.8%in 2008.Conclusion:The deaths of despair crisis in the CEECA region is not a past event but an ongoing,evolving phenomenon.Its changing nature demands a shift in public health focus from solely historical drivers to new,generation-specific threats,particularly the rise of drug-related despair among youth.展开更多
The rapid advancement of machine learning based tight-binding Hamiltonian(MLTB)methods has opened new avenues for efficient and accurate electronic structure simulations,particularly in large-scale systems and long-ti...The rapid advancement of machine learning based tight-binding Hamiltonian(MLTB)methods has opened new avenues for efficient and accurate electronic structure simulations,particularly in large-scale systems and long-time scenarios.This review begins with a concise overview of traditional tight-binding(TB)models,including both(semi-)empirical and first-principles approaches,establishing the foundation for understanding MLTB developments.We then present a systematic classification of existing MLTB methodologies,grouped into two major categories:direct prediction of TB Hamiltonian elements and inference of empirical parameters.A comparative analysis with other ML-based electronic structure models is also provided,highlighting the advancement of MLTB approaches.Finally,we explore the emerging MLTB application ecosystem,highlighting how the integration of MLTB models with a diverse suite of post-processing tools from linear-scaling solvers to quantum transport frameworks and molecular dynamics interfaces is essential for tackling complex scientific problems across different domains.The continued advancement of this integrated paradigm promises to accelerate materials discovery and open new frontiers in the predictive simulation of complex quantum phenomena.展开更多
文摘Historical overview In 1975,Michel Mathieu became the head of the newly autonomous Department of Ophthalmology at the University of Montreal.Mathieu’s growing reputation as a skilled clinician and researcher attracted excellent candidates to the department(1).Under his direction,Suzanne Véronneau-Troutman became the first resident and,subsequently,the first female ophthalmic surgeon at University of Montreal.Her immense contribution to the field of strabismus later gained worldwide appreciation,as recognized by the annual American Academy of Ophthalmology award named after her(2).Mathieu’s work,and that of his recruits,led to major advances in the fields of corneal transplantation,retinal degenerations,electroretinography,and ophthalmic surgical instrumentation(3).
文摘Background:Cognitive assessments,such as the Montreal Cognitive Assessment(MoCA),use components that assume intact sensory abilities,however,adults show concomitant decreases in visual acuity with increasing age.Scores on cognitive assessments are typically lower for individuals with visual impairments compared to individuals with normal/corrected to normal vision.But it is not clear if lowers scores on cognitive assessments are due to the assessments relying on visual stimuli,or if individuals with visual impairments are actually more likely to have cognitive impairments.Therefore we simulated visual impairments,i.e.,reduced visual acuity and contrast sensitivity,in young healthy adults to determine how this impacts their scores on a measure of cognitive ability,i.e.,the MoCA.Methods:Participants(n=19)completed one of the three version of the MoCA under three conditions(20/20,simulated 20/80,simulated 20/200).The MoCA was administered following the clinical protocols.Only participants that scored>26(i.e.,normal cognitive function)at 20/20 were included in the analysis.For comparison,we included MoCA data from a sample of older adults with normal vision(n=19,Mage=74,Acuity M=0.04 logMAR,SD=0.16)or visual impairment(n=19,Mage=79,Acuity M=0.35 logMAR,SD=0.3).Results:Acuity of participants at 20/20(M=0.06 LogMAR,SD=0.1),simulated 20/80(M=0.63,SD=0.18)and simulated 20/200(M=0.88,SD=0.19)showed that the participants experienced simulated acuity loss with the goggles.For the MoCA scores,we found a main effect of acuity(F=16.22,P<0.001,η2=0.375,BF10=5,618).Planned post hoc comparisons showed a significant difference between scores with a 20/20 acuity(M=27.26,SD=0.93)and 20/80(M=24.74,SD=1.66,t=5.62,ptukey<0.001,d=1.88),and between 20/20 and 20/200(M=25.63,SD=1.46,t=3.63,ptukey=0.002,Cohen’s d=1.33).However,no difference was observed between 20/80 and 20/200(t=−1.99,ptukey=0.125,d=0.572).The MoCA scores in older adults with normal vision(M=27.32,SD=2.41)and with visual impairment(M=26.68,SD=2.52),did not differ significantly(t36=−0.787,P=0.436,d=0.26,BF10=0.4).Conclusions:Our findings show that simulated reductions in visual acuity and contrast sensitivity lead to lower scores on measures of cognitive ability,specifically the MoCA.However,it appears that older adults with actual visual impairments may have developed compensatory strategies to adapt to this loss in visual acuity as there were no significant differences in scores of older adults with and without visual impairments.Therefore,we would recommend that when assessing an individual with visual impairments to conduct the cognitive test by re-scoring it without the visual components,e.g.,the MoCA Blind,to magnify the visual components,or to substitue the visual component when possible using auditory alternatives,e.g.,the oral trail making task.
文摘Alternative technologies have emerged to reduce the greenhouse gas (GHG) emissions of traditional commuter rail systems powered by diesel. Even larger reductions can be obtained with energy production from renewable resources. This paper uses the commuter rail system in Montreal, Quebec, as a case study for implementing alternative technologies, namely, complete electrification of the network (only one of the existing five lines is electrified) and hydrogen fuel cell-powered trains. It is important to note that the main source of electricity generation in Quebec is hydropower which is offered at a relatively low cost. Several criteria were considered to determine the most suitable alternative including GHG emissions from operation and fuel production, operation and capital costs, and technological and commercial viability. Electrification of the commuter rail system would decrease annual emissions by 98% which is more than 27,000 tons. The GHG reductions for hydrogen trains are lower than electric trains but still substantial. The operation costs favor the electrification scenario;however, the high costs of electrical infrastructure make hydrogen trains more competitive since additional infrastructure is unnecessary. However, hydrogen trains remain a new and unproven technology;uncertainties associated with it should be settled before full implementation.
基金support held by JPA,Collaborative Network Award BRAVEinMS,Grant/Award Number:PA-1604-08492(MG)from the Multiple Sclerosis Society of Canada,Grant/Award Number:1038154(to TEK).
文摘Myelin,made by oligodendrocytes(OLs)in the central nervous system(CNS),is essential for neural transmission.In particular,myelin facilitates communication across the long connections between different brain regions that form the white matter.Myelinated segments also provide metabolic intermediates to axons,supporting their demanding energetic needs.Genetic disorders that disrupt myelin formation result in progressive neurologic degeneration.
基金supported in part by National Natural Science Foundation of China(Nos.62373188,62003162)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20240182,BK20222012)+2 种基金the Industry-University Research Innovation Foundation for the Chinese Ministry of Education(No.2021ZYA02005)the Aeronautical Science Foundation of China(Nos.20220007052003,20200007018001)the Fundamental Research Funds for the Central Universities,China(Nos.NE2024004,NI2024001)。
文摘To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction-Order(FO)sliding-mode Fault-Tolerant Cooperative Control(FTCC)strategy is proposed for multiple UAVs based on Event-Triggered Communication Mechanism(ET-COM-M)and Event-Triggered Control Mechanism(ET-CON-M).First,by considering the limited communication bandwidth of multiple UAVs in formation,an ET-COM-M is designed to significantly reduce communication times.Then,a distributed observer is skillfully constructed to estimate the reference signals for follower UAVs.Moreover,the adaptive strategy is incorporated into the Radial Basis Function Neural Network(RBFNN)to learn the lumped unknown terms for handling bias actuator faults and parameter uncertainties.Besides,the Nussbaum method is used to deal with the loss-of-effectiveness faults.To further achieve the refined control performance against faults,FO calculus is artfully integrated into the sliding-mode control protocol with ET-CON-M.Finally,Zeno behavior is excluded by rigorous theoretical analysis and Lyapunov stability is proved to show the effectiveness of the designed FTCC strategy.Simulation results show that the designed FTCC strategy with Event-Triggered Mechanism(ETM)can guarantee the safety of multiple UAVs and simultaneously reduce the communication and control frequencies,making the developed control scheme applicable in engineering.
基金supported by the Discovery Grants program of the Natural Sciences and Engineering Research Council of Canada(No.RGPIN-2021-03553)the Canadian Research Chair in dendroecology and dendroclimatology(CRC-2021-00368)+3 种基金the Ministère des Ressources Naturelles et des Forèts(MRNF,Contract no.142332177-D)the Natural Sciences and Engineering Research Council of Canada(Alliance Grant No.ALLRP 557148-20,obtained in partnership with the MRNF and Resolute Forest Products)the Fonds de recherche du Qu ebec–Nature et technologies(Partnership Research Program on the Contribution of the Forestry Sector to Climate Change MitigationGrant No.2022-0FC-309064)。
文摘Xylogenesis,the process through which wood cells are formed,results in the long-term storage of carbon in woody biomass,making it a key component of the global carbon cycle.Understanding how environmental drivers influence xylogenesis during the growing season is therefore of great interest.However,studying shortterm drivers of wood production using xylogenetic data is complicated by the usual sampling scheme and the influence of eccentric growth,i.e.,heterogeneous growth around the stem.In this study,we improve xylogenesis research by introducing a statistical approach that explicitly considers seasonal phenology,short-term growth rates,and growth eccentricity.To this end,we developed Bayesian models of xylogenesis and compared them with a conventional method based on the use of Gompertz functions.Our results show that eccentricity generated high temporal autocorrelation between successive samples,and that explicitly taking it into account improved both the representativeness of phenology and intra-ring variability.We observed consistent short-term patterns in the model residuals,suggesting the influence of an unaccounted-for environmental variable on cell production.The proposed models offer several advantages over traditional methods,including robust confidence intervals around predictions,consistency with phenology,and reduced sensitivity to extreme observations at the end of the growing season,often linked to eccentric growth.These models also provide a benchmark for mechanistic testing of short-term drivers of wood formation.
基金sponsored by the National Natural Science Foundation of China(Grant number 42471510,42001218)National Major Water Conservancy Project Construction(follow up to the Three Gorges Project)(No.12620202700221 J001,NO.102126222020270029030)General Project of Hubei Social Science Fund(No.2021211,HBSK2022YB357,HBSKJJ20233269,HBSKJJ20243233).
文摘Understanding the spatial mach between water purification service supply and demand is crucial for optimizing watershed management and strengthening nature-society linkages,particularly in ecologically critical areas such as the Three Gorges Reservoir Area(TGRA).This study quantified the spatiotemporal patterns of water purification supply and demand by assessing the actual and potential non-point source pollution,and compared their mismatch ratio in the TGRA.Meanwhile,supply-demand reachability indicator was used to identify the water purification supply-demand relationship.Results showed that the TGRA generally maintained a balanced supply and demand relationship for water purification.Spatial analysis revealed that the ecosystem service demand and reachability indicator peaked in regions with>1000 m and>25°.Water purification exhibited High-High in the central Yangtze River corridor and southwestern TGRA,whereas Low-Low in the northern and southern regions.Driving analysis indicated climate factors significantly enhanced both supply(0.41)and demand(0.54),whereas soil factors exerted negative impacts on both supply(−0.37)and demand(−0.23).Topographic and socioeconomic factors also showed adverse,albeit relatively minor,effects.Based on the observed spatial mismatches,we propose shifting water purification governance strategies from aggregate control towards spatially targeted coordination that explicitly addresses distinct supply-demand relationships across different zones.
基金Supported by Japan Society for the Promotion of Science,No.24K11935.
文摘This review comprehensively summarized the potential of artificial intelligence(AI)in the management of esophageal cancer.It highlighted the significance of AI-assisted endoscopy in Japan where endoscopy is central to both screening and diagnosis.For the clinical adaptation of AI,several challenges remain for its effective translation.The establishment of high-quality clinical databases,such as the National Clinical Database and Japan Endoscopy Database in Japan,which covers almost all cases of esophageal cancer,is essential for validating multimodal AI models.This requires rigorous external validation using diverse datasets,including those from different endoscope manufacturers and image qualities.Furthermore,endoscopists’skills significantly affect diagnostic accuracy,suggesting that AI should serve as a supportive tool rather than a replacement.Addressing these challenges,along with country-specific legal and ethical considerations,will facilitate the successful integration of multimodal AI into the management of esophageal cancer,particularly in endoscopic diagnosis,and contribute to improved patient outcomes.Although this review focused on Japan as a case study,the challenges and solutions described are broadly applicable to other high-incidence regions.
基金supported by the National Key Research and Development Program of China(2022YFC3204101 and 2023YFF0807202)the National Natural Science Foundation of China(U22A20570 and U2444221)+4 种基金the Youth Promotion Association of the Chinese Academy of Sciences(2021365)the Changsha Outstanding Innovative Youth Project,China(kq2305035)the Science,Technology and Innovation Platform Plan of Hunan Province,China(2022PT1010)the Major Scientific and Technological Projects of the Ministry of Water Resources,China(SKS-2022081)the Comprehensive Investigation and Potential Evaluation of Natural Resources Carbon Sink in Southern Hilly Region,China(DD20220880)。
文摘In floodplain wetlands,alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils,thereby having a negative impact on global climate change.However,the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored.To address this research gap,we collected 306 upper layer(0–20 cm)soil samples from the Dongting Lake floodplain between 2013 and 2022.The random forest(RF)algorithm was used to analyze the spatial distribution of soil organic carbon(SOC)in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied.In 2022,the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^(-1),averaging 10.43 g kg^(-1),with a corresponding SOC density of(2.65±0.49)kg m^(-2) and total SOC stock of 6.82 Tg C(2.87–13.48 Tg C).From 2013 to 2022,the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 to 10.82 g kg^(-1).This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition.Above 21.4 m elevation,the amount of SOC loss increased with elevation,the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes.Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change.
基金funded by the National Natural Science Foundation of China(42201064,32301381)the Joint Fund for Regional Innovation and Development of the National Science Foundation(U22A20570)+1 种基金the Science and Technology Innovation Program of Hunan Province of China(2022RC4027)Natural Science Foundation of Hunan Province of China(2023JJ40440).
文摘Drought has the potential to induce extensive defoliation in forest trees.However,the responses of non-structural carbohydrates(NSCs,including soluble sugar and starch)to the combined effects of drought and defoliation remain to be elucidated,particularly in pine trees.In this study,we investigated the interactive effects of drought and defoliation on the contents of NSCs in five organs(new and old needles,twigs,stems,as well as roots)of Chinese pine(Pinus tabuliformis)seedlings.We sampled two batches of the seedlings at 30 and 50 days,respectively.Our results showed that Chinese pine could tolerate mild drought,but severe drought significantly decreased the content of soluble sugars in all organs.Defoliation initially suppressed the photosynthetic rate and significantly reduced the soluble sugar content in all organs.However,after 50 days,this effect was substantially mitigated by the new needle growth.Starch content in twigs,stems,and roots was found to be more vulnerable to defoliation than to drought.A significant interactive effect existed between drought and defoliation on NSCs,with defoliation exacerbating the negative impact of drought on the accumulation of NSCs,especially in new needles and roots.These findings highlight the complex effects of defoliation on NSCs during drought,underscoring critical implications for the management and economic value of Chinese pine forests.
基金supported by the National Natural Science Foundation of China(NSFC/RGC/JRF N_HKU735/21)Research Grant Council of Hong Kong,China(17102120,17108821,17103922,C1024-22GF,C7074-21G)+1 种基金Health and Medical Research Fund(HMRF 09200966)(to CSWL)FRQS Postdoctoral Fellowship(to AHKF).
文摘Dendritic spines are small protrusions along dendrites that contain most of the excitatory synapses in principal neurons,playing a crucial role in neuronal function by creating a compartmentalized environment for signal transduction.The plasticity of spine morphologies provides a tunable handle to regulate calcium signal dynamics,allowing rapid regulation of protein expression necessary to establish and maintain synapses(Cornejo et al.,2022).If excitatory inputs were to be located primarily on dendritic shafts,dendrites would frequently short-circuit,preventing voltage signals from propagating(Cornejo et al.,2022).It is thus not surprising that the structural plasticity of dendritic spines is closely linked to synaptic plasticity and memory formation(Berry and Nedivi,2017).While comprehensive in vitro studies have been conducted,in vivo studies that directly tackle the mechanism of dendritic transport and translation in regulating spine plasticity spatiotemporally are limited.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0805104)the National Natural Science Foundation of China(NSFC)under Grant Nos.41925022,42105016 and 42375070+1 种基金supported by the NSFC under Grant No.41888101the Natural Sciences and Engineering Research Council of Canada(Grant No.RGPIN-2019-04511)。
文摘Siberian-Arctic heatwaves(SAHs)disrupt ecosystems by increasing wildfires,thawing permafrost,and threatening Arctic communities.As SAHs become more frequent and intense,accurate prediction is crucial for preparedness and mitigating their impacts.We demonstrate that April surface temperatures in the Siberian Arctic can be predicted one month in advance with a skill of 0.75(1979-2022)using a regression model based on Arctic stratospheric ozone,the Arctic Oscillation,and sea ice in the Kara Sea.This model successfully predicts six of seven SAHs,identifying three driven by extreme ozone depletion and three by significant sea-ice loss.Additionally,from 1979 to 1997,warming was primarily caused by ozone depletion,while from 1998 to 2022,sea-ice loss became the main factor.Our findings indicate that SAHs are predictable and recommend this model for real-time monitoring and forecasting,highlighting its potential to enhance preparedness and reduce adverse effects.
基金supported by grants from the National Research Foundation of Korea(NRF)under the Ministry of Science and Information and Communication Technology(grant number:RS-2023-00249082)Korea University(grant number:K2225791).
文摘Background:That Central and Eastern Europe and Central Asia(CEECA)experienced a major mortality crisis in the 1990s is a well-established finding,with most analyses focusing on singular causes like alcohol-related deaths.However,the utility of the integrated“deaths of despair”framework,which views alcohol,drug,and suicide deaths as a unified socio-economic phenomenon,remains under-explored in this context.Crucially,the long-term evolution of the composition of despair within the region remains a largely unexplored area of inquiry.Therefore,this study aims to analyze the long-term trends,changing composition,and regional heterogeneity of deaths from despair in the CEECA region from 1980 to 2021.Methods:Using 2021 Global Burden of Disease(GBD)data(1980–2021),we analyzed deaths of despair mortality trends in 29 CEECA countries.We employed Joinpoint regression to identify significant trend changes and conducted stratified analyses by cause,gender,and age group.Results:The CEECA deaths of despair crisis began as an alcohol and suicide driven phenomenon concentrated in middle-aged men(50–74 years)during the 1990s,with mortality rates for alcohol use disorders and self-harm surging annually by 30.35%(p=0.002)and 13.44%(p=0.001),respectively,between 1991 and 1994.It has since evolved,marked by a contrasting and emerging threat in the 21st century:a rising proportion of drug-related deaths among the younger(15–49 years)male cohort,where the share of drug use disorders increased from 6.9%in 2000 to 11.8%in 2008.Conclusion:The deaths of despair crisis in the CEECA region is not a past event but an ongoing,evolving phenomenon.Its changing nature demands a shift in public health focus from solely historical drivers to new,generation-specific threats,particularly the rise of drug-related despair among youth.
基金supported by the Advanced Materials-National Science and Technology Major Project(Grant No.2025ZD0618401)the National Natural Science Foundation of China(Grant No.12504285)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20250472)NFSG grant from BITS-Pilani,Dubai campus。
文摘The rapid advancement of machine learning based tight-binding Hamiltonian(MLTB)methods has opened new avenues for efficient and accurate electronic structure simulations,particularly in large-scale systems and long-time scenarios.This review begins with a concise overview of traditional tight-binding(TB)models,including both(semi-)empirical and first-principles approaches,establishing the foundation for understanding MLTB developments.We then present a systematic classification of existing MLTB methodologies,grouped into two major categories:direct prediction of TB Hamiltonian elements and inference of empirical parameters.A comparative analysis with other ML-based electronic structure models is also provided,highlighting the advancement of MLTB approaches.Finally,we explore the emerging MLTB application ecosystem,highlighting how the integration of MLTB models with a diverse suite of post-processing tools from linear-scaling solvers to quantum transport frameworks and molecular dynamics interfaces is essential for tackling complex scientific problems across different domains.The continued advancement of this integrated paradigm promises to accelerate materials discovery and open new frontiers in the predictive simulation of complex quantum phenomena.
