As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The ...As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.展开更多
Cultural symbols,a manifestation of cities’cultural resources,are not only signs that frame concepts but also forms that express meanings.Exploring the international communication of cities from the perspective of sy...Cultural symbols,a manifestation of cities’cultural resources,are not only signs that frame concepts but also forms that express meanings.Exploring the international communication of cities from the perspective of symbols,this paper analyzes in depth how cities create their cultural symbols in the dynamic process of international communication in an era of symbol-based digital media,and how they develop their narratives and explain meanings through the dissemination of symbols when telling their stories to international audiences,thus enhancing the efficiency and effectiveness of their international communication efforts.展开更多
The article takes the famous modern American Jewish writer Bernard Malamud’s novel The Magic Barrel as the object of study,and uses symbolism to interpret it,analyzing it one by one in terms of the magic barrel,the c...The article takes the famous modern American Jewish writer Bernard Malamud’s novel The Magic Barrel as the object of study,and uses symbolism to interpret it,analyzing it one by one in terms of the magic barrel,the colors,the seasons and the windows,respectively,so as to reveal the process of getting rid of the childishness within the novel’s male protagonist,Leo Finkel,who is maturing,as well as the novel’s Jewish theme of searching for the soul of the self.展开更多
BACKGROUND A progressive decrease in exclusive breastfeeding(BF)is observed in Latin America and the Caribbean compared with global results.The possibility of being breastfed and continuing BF for>6 months is lower...BACKGROUND A progressive decrease in exclusive breastfeeding(BF)is observed in Latin America and the Caribbean compared with global results.The possibility of being breastfed and continuing BF for>6 months is lower in low birth weight than in healthy-weight infants.AIM To identify factors associated with BF maintenance and promotion,with particular attention to low-and middle-income countries,by studying geographic,socioeconomic,and individual or neonatal health factors.METHODS A scoping review was conducted in 2018 using the conceptual model of social determinants of health published by the Commission on Equity and Health Inequalities in the United States.The extracted data with common characteristics were synthesized and categorized into two main themes:(1)Sociodemographic factors and proximal determinants involved in the initiation and maintenance of BF in low-birth-weight term infants in Latin America;and(2)individual characteristics related to the self-efficacy capacity for BF maintenance and adherence in low-birth-weight term infants.RESULTS This study identified maternal age,educational level,maternal economic capacity,social stratum,exposure to BF substitutes,access to BF information,and quality of health services as mediators for maintaining BF.CONCLUSION Individual self-efficacy factors that enable BF adherence in at-risk populations should be analyzed for better health outcomes.展开更多
The Altomani&Sons Collection owns a remarkable newly discovered portrait of Guidobaldo II della Rovere,Duke of Urbino(1514-1574),a historical military figure who was a condottiere,ruler of Urbino,Commander-in-chie...The Altomani&Sons Collection owns a remarkable newly discovered portrait of Guidobaldo II della Rovere,Duke of Urbino(1514-1574),a historical military figure who was a condottiere,ruler of Urbino,Commander-in-chief of the Papal Estate,and Perfect of Rome,as well as a collector and patron of the Fine Arts.Camilla Guerrieri Nati(1628-1694),a seventeenth-century Italian painter from Fossombrone(in the province of Pesaro and Urbino),portrayed this heroic personage surrounded by emblems associated with his military courage and leadership,including his plumed burgonet helmet,metal gilded armor,a necklace with the golden fleece,and batons of secular and religious dominions.This oil painting on copper-considered a precious metal at the time-emphasizes the importance of the commission.The material and technique also reveals a unique artistic achievement in that it provides the painting with a smooth,reflective surface and vibrant coloration,symbolizing precious imagery.展开更多
Traditional Chinese medicine(TCM) arrived from China to Latin America and the Caribbean in the 1840s due to the massive migration of Chinese people to the region. In a few years, the press noticed the presence of Chin...Traditional Chinese medicine(TCM) arrived from China to Latin America and the Caribbean in the 1840s due to the massive migration of Chinese people to the region. In a few years, the press noticed the presence of Chinese herbalists practicing in different cities and countries regardless of the demographic weight of the Chinese community. The fascination with Chinese doctors implicated not only the press but also the literature, a phenomenon particularly observed in Cuba. In the first decades of the 20th century, the reactivation of Chinese immigration to the region fostered an anti-Chinese climate that materialized in more significant migratory restrictions and control of their businesses, such as what happened with Chinese herbalists. These herbalists who practiced inside and outside the Chinese community started to object to criticism and persecution by the conservative press and professional doctors. Despite this, Chinese doctors will continue to maintain their support of a significant number of ill persons. This work seeks to illuminate the historical relevance of TCM in Latin America and the Caribbean, focusing on the cases of Peru, Chile, and Cuba. This last country was far from China culturally and geographically, but as in many other small towns in the region, Chinese medicine presented an alternative to the treatment of illnesses.展开更多
Chinese cultural symbols have been widely transplanted in Chinese American literature.Those symbols bear different significance in different authors’works on different historical stages,which,in essence,reflect Chine...Chinese cultural symbols have been widely transplanted in Chinese American literature.Those symbols bear different significance in different authors’works on different historical stages,which,in essence,reflect Chinese American writers’difficult process of searching for and constructing their cultural identity.展开更多
Francis Scott Key Fitzgerald's famous novel The Great Gatsby tells us a story about a young man named Gatsby who from thebottom of society,he tries to pursue love and happiness through struggle and hard-working,bu...Francis Scott Key Fitzgerald's famous novel The Great Gatsby tells us a story about a young man named Gatsby who from thebottom of society,he tries to pursue love and happiness through struggle and hard-working,but finally the dream fails and he is mur-dered.In the novel Fitzgerald combines the symbol of colors with theme of the novel"the disillusion of American dream"tightly and wit-tingly creating an organic unity like nature itself.Via analyzing such writing skill,let readers have a better understanding of the essenceof American Dream and the luxurious and decadent living conditions and perplexed and blank mental states of the lost generations afterWWI.The Great Gatsby;展开更多
Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to pr...Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America.We also evaluated the contribution of three sets of determinants of the occurrence-and abundance-based subregions.We compiled data on tree species composition from 894 local assemblages based on species occurrences,and from 658 local assemblages based on species abundances.We used an unconstrained community-level modelling approach and clustering techniques to identify and map tree subregions for the occurrence and the abundance data sets,separately.Hierarchical clustering analyses were conducted to investigate floristic affinities between the subregions and to map broader floristic regions.We used multinomial logistic regression models,deviance partitioning,and rank-sum tests to assess the main subregion correlates.We identified 18 occurrence-and four abundance-based subregions in the Cerrado-Pantanal.The hierarchical classifications grouped the occurrence-based subregions into nine floristic zones and abundance-based subregions into two broad floristic zones.Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance data sets.The occurrence-and abundance-based subregions are complementary approaches to disentangle macroecological patterns and to plan conservation efforts in the Cerrado and the Pantanal.Our findings based on occurrence data revealed more complex and interdigitated boundaries between subregions of tree species than previously reported.The environment,historical stability,and human effects act in a synergetic way on the distribution of the subregions.Finally,the relevance of contemporary environmental factors to the subregion patterns we found alert us to the profound impact global warming may have on the spatial organization of the Cerrado-Pantanal tree flora.展开更多
In cellular systems,establishing the initial symbol timing of potential preambles is the first step of a cell search.The envelope fluctuation of the downlink signal hinders the successful timing of conventional symbol...In cellular systems,establishing the initial symbol timing of potential preambles is the first step of a cell search.The envelope fluctuation of the downlink signal hinders the successful timing of conventional symbol timing methods.To solve this problem,a hybrid timing strategy is proposed with two novel detectors,namely the normalized replica-based detector and normalized differential detector.The strategy first detects all potential preambles via the normalized replica-based detector and then employs the normalized differential detector to verify the target preamble,which comes from the target cell and has the highest power.The strategy is unaffected by envelope fluctuation and has computational complexity comparable to that of conventional methods.Simu-lations and real-data tests show that the hybrid timing strategy is robust and practical for initial symbol timing.展开更多
The genus Thuja is ideal for investigating the genetic basis of the East Asia-North America disjunction.The biogeographical background of the genus is debatable and an adaptive strategy is lacking.Through the analysis...The genus Thuja is ideal for investigating the genetic basis of the East Asia-North America disjunction.The biogeographical background of the genus is debatable and an adaptive strategy is lacking.Through the analysis and mining of comparative transcriptomes,species differentiation and positively selected genes(PSGs)were identified to provide information for understanding the environmental adaptation strategies of the genus Thuja.De novo assembly yielded 44,397-74,252 unigenes of the five Thuja species with contig N50length ranging from 1,559 to 1,724 bp.Annotations revealed a similar distribution of functional categories among them.Based on the phylogenetic trees constructed using the transcriptome data,T.sutchuenensis was divided first,followed by T.plicata and T.occidentalis.The final differentiation of T.koraiensis and T.standishii formed a clade.Enrichment analysis indicated that the PSGs of the North American Thuja species were involved in plant hormone signal transduction and carbon fixation of photosynthetic organisms pathways.The PSGs of East Asian Thuja were related to phenolic,alkaloid,and terpenoid synthesis,important stress-resistant genes and could increase plant resistance to external environmental stresses.This study discovered numerous aroma synthetic-related PSGs including terpene synthase(TPS)genes and lipid phosphate phosphatase 2(LPP2),associated with the synthetic aroma of T.sutchuenensis.Physiological indicators,such as the contents of soluble sugars,total chlorophyll,total phenolics,and total flavonoids were determined,which are consistent with the PSGs enrichment pathways associated with adaptive strategies in the five Thuja species.The results of this study provide an important basis for future studies on conservation genetics.展开更多
In order to reduce the physical impairment caused by signal distortion,in this paper,we investigate symbol detection with Deep Learning(DL)methods to improve bit-error performance in the optical communication system.M...In order to reduce the physical impairment caused by signal distortion,in this paper,we investigate symbol detection with Deep Learning(DL)methods to improve bit-error performance in the optical communication system.Many DL-based methods have been applied to such systems to improve bit-error performance.Referring to the speech-to-text method of automatic speech recognition,this paper proposes a signal-to-symbol method based on DL and designs a receiver for symbol detection on single-polarized optical communications modes.To realize this detection method,we propose a non-causal temporal convolutional network-assisted receiver to detect symbols directly from the baseband signal,which specifically integrates most modules of the receiver.Meanwhile,we adopt three training approaches for different signal-to-noise ratios.We also apply a parametric rectified linear unit to enhance the noise robustness of the proposed network.According to the simulation experiments,the biterror-rate performance of the proposed method is close to or even superior to that of the conventional receiver and better than the recurrent neural network-based receiver.展开更多
Understanding the mechanisms underlying plant responses to climate change is an important step toward developing effective mitigation strategies. Polyploidy is an important evolutionary trait that can influence the ca...Understanding the mechanisms underlying plant responses to climate change is an important step toward developing effective mitigation strategies. Polyploidy is an important evolutionary trait that can influence the capacity of plants to adapt to climate change. The environmental flexibility of polyploids suggests their resiliency to climate change, however, such hypotheses have not yet received empirical evidence. To understand how ploidy level may influence response to climate change, we modeled the current and future distribution of 54 Crataegus species under moderate to severe environments and compared the range change between diploids and polyploids. The majority of studied species are predicted to experience considerable range expansion. We found a negative interaction between ploidy and ecoregions in determining the response to climate change. In extreme environments, polyploids are projected to experience a higher range expansion than diploids with climate change, while the opposite is true for moderate environments. The range expansion of Crataegus species can be attributed to their tolerance for a wide range of environmental conditions. Despite the higher tolerance of polyploids to extreme environments, they do not necessarily outperform diploids in moderate environments, which can be attributed to the varying nature of species interactions along a stress gradient.展开更多
President Xi Jinping’s America trip from November 14 to 17,including his talks with U.S.President Joe Biden and his attendance at the 30th APEC Economic Leaders’Meeting in San Francisco,is widely believed to have ad...President Xi Jinping’s America trip from November 14 to 17,including his talks with U.S.President Joe Biden and his attendance at the 30th APEC Economic Leaders’Meeting in San Francisco,is widely believed to have added stability to China-U.S.relations,brought new impetus to Asia-Pacific cooperation and injected positive energy into the international and regional landscape.展开更多
A symbol is an expression of meaning,while blank symbols express special meanings.By focusing on the application of blank symbols in Japanese architecture and indoor designs,we analyzed the aesthetic principles in Jap...A symbol is an expression of meaning,while blank symbols express special meanings.By focusing on the application of blank symbols in Japanese architecture and indoor designs,we analyzed the aesthetic principles in Japanese architecture and indoor designs from the perspective of semiotics,such as“Kongji,”“Emptiness,”and“Dying out,”and their minimalist and pure design concepts.Traditional Chinese culture was also further explored,especially the profound influence of the“Chan sect”and the philosophy of“unity of heaven and mankind”on Japanese architecture and designs.This study aims to facilitate the coexistence and mutual appreciation of Chinese and Japanese architectural designs.展开更多
Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are diffi...Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are difficult to apply in engineering practice.Symbolic regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for datasets.In this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate model.Three terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate models.Based on the FCG rate test data from other literature,the SR model was constructed using Al-7055-T7511.It was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear regression.Compared with the three semi-empirical FCG rate models,the SR model yielded higher prediction accuracy.This result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.展开更多
In the Italian novel Lacci,the young husband abandoned his wife and lived with another woman.Although the marriage has been maintained under the stress of tense relations,friction and cracks have long existed and brok...In the Italian novel Lacci,the young husband abandoned his wife and lived with another woman.Although the marriage has been maintained under the stress of tense relations,friction and cracks have long existed and broken their peaceful life.This betrayal story restores the whole story from three perspectives through the eyes of the husband,the wife,and the memory of two children.It also reveals the indifferent and uncommunicable situations experienced by everyone in the family.The shoelace that appeared repeatedly in this article not only symbolizes the entangled and chaotic relationship between husband and wife,but also symbolizes the parent-child relationship that has long been broken but still tied up with each other;another image,the cat,not only symbolizes the seductive lover in the eyes of the husband,but also represents himself who pursues the satisfaction of desire.At the same time,cat also implies the disintegration of this marriage from inside to outside.In short,in this suffocating marriage novel,shoelace symbolizes order,while cat symbolizes chaos.The cat who keeps breaking in wore away their trust and emotion,and in the end,the two people in marriage can only bind reluctantly with shoelaces and hurt each other.展开更多
South America’s climatic diversity is a product of its vast geographical expanse, encompassing tropical to subtropical latitudes. The variations in precipitation and temperature across the region stem from the influe...South America’s climatic diversity is a product of its vast geographical expanse, encompassing tropical to subtropical latitudes. The variations in precipitation and temperature across the region stem from the influence of distinct atmospheric systems. While some studies have characterized the prevailing systems over South America, they often lacked the utilization of statistical techniques for homogenization. On the other hand, other research has employed multivariate statistical methods to identify homogeneous regions regarding temperature and precipitation, but their focus has been limited to specific areas, such as the south, southeast, and northeast. Surprisingly, there is a lack of work that compares various multivariate statistical techniques to determine homogeneous regions across the entirety of South America concerning temperature and precipitation. This paper aims to address this gap by comparing three such techniques: Cluster Analysis (K-means and Ward) and Self Organizing Maps, using data from different sources for temperature (ERA5, ERA5-Land, and CRU) and precipitation (ERA5, ERA5-Land, and CPC). Spatial patterns and time series were generated for each region over the period 1981-2010. The results from this analysis of spatially homogeneous regions concerning temperature and precipitation have the potential to significantly benefit climate analysis and forecasts. Moreover, they can offer valuable insights for various climatological studies, guiding decision-making processes in diverse fields that rely on climate information, such as agriculture, disaster management, and water resources planning.展开更多
基金supported by the Meteorological Soft Science Project(Grant No.2023ZZXM29)the Natural Science Fund Project of Tianjin,China(Grant No.21JCYBJC00740)the Key Research and Development-Social Development Program of Jiangsu Province,China(Grant No.BE2021685).
文摘As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.
文摘Cultural symbols,a manifestation of cities’cultural resources,are not only signs that frame concepts but also forms that express meanings.Exploring the international communication of cities from the perspective of symbols,this paper analyzes in depth how cities create their cultural symbols in the dynamic process of international communication in an era of symbol-based digital media,and how they develop their narratives and explain meanings through the dissemination of symbols when telling their stories to international audiences,thus enhancing the efficiency and effectiveness of their international communication efforts.
文摘The article takes the famous modern American Jewish writer Bernard Malamud’s novel The Magic Barrel as the object of study,and uses symbolism to interpret it,analyzing it one by one in terms of the magic barrel,the colors,the seasons and the windows,respectively,so as to reveal the process of getting rid of the childishness within the novel’s male protagonist,Leo Finkel,who is maturing,as well as the novel’s Jewish theme of searching for the soul of the self.
文摘BACKGROUND A progressive decrease in exclusive breastfeeding(BF)is observed in Latin America and the Caribbean compared with global results.The possibility of being breastfed and continuing BF for>6 months is lower in low birth weight than in healthy-weight infants.AIM To identify factors associated with BF maintenance and promotion,with particular attention to low-and middle-income countries,by studying geographic,socioeconomic,and individual or neonatal health factors.METHODS A scoping review was conducted in 2018 using the conceptual model of social determinants of health published by the Commission on Equity and Health Inequalities in the United States.The extracted data with common characteristics were synthesized and categorized into two main themes:(1)Sociodemographic factors and proximal determinants involved in the initiation and maintenance of BF in low-birth-weight term infants in Latin America;and(2)individual characteristics related to the self-efficacy capacity for BF maintenance and adherence in low-birth-weight term infants.RESULTS This study identified maternal age,educational level,maternal economic capacity,social stratum,exposure to BF substitutes,access to BF information,and quality of health services as mediators for maintaining BF.CONCLUSION Individual self-efficacy factors that enable BF adherence in at-risk populations should be analyzed for better health outcomes.
文摘The Altomani&Sons Collection owns a remarkable newly discovered portrait of Guidobaldo II della Rovere,Duke of Urbino(1514-1574),a historical military figure who was a condottiere,ruler of Urbino,Commander-in-chief of the Papal Estate,and Perfect of Rome,as well as a collector and patron of the Fine Arts.Camilla Guerrieri Nati(1628-1694),a seventeenth-century Italian painter from Fossombrone(in the province of Pesaro and Urbino),portrayed this heroic personage surrounded by emblems associated with his military courage and leadership,including his plumed burgonet helmet,metal gilded armor,a necklace with the golden fleece,and batons of secular and religious dominions.This oil painting on copper-considered a precious metal at the time-emphasizes the importance of the commission.The material and technique also reveals a unique artistic achievement in that it provides the painting with a smooth,reflective surface and vibrant coloration,symbolizing precious imagery.
基金funded by ANID—Millennium Science Initiative Program (No. NCS2022_053)。
文摘Traditional Chinese medicine(TCM) arrived from China to Latin America and the Caribbean in the 1840s due to the massive migration of Chinese people to the region. In a few years, the press noticed the presence of Chinese herbalists practicing in different cities and countries regardless of the demographic weight of the Chinese community. The fascination with Chinese doctors implicated not only the press but also the literature, a phenomenon particularly observed in Cuba. In the first decades of the 20th century, the reactivation of Chinese immigration to the region fostered an anti-Chinese climate that materialized in more significant migratory restrictions and control of their businesses, such as what happened with Chinese herbalists. These herbalists who practiced inside and outside the Chinese community started to object to criticism and persecution by the conservative press and professional doctors. Despite this, Chinese doctors will continue to maintain their support of a significant number of ill persons. This work seeks to illuminate the historical relevance of TCM in Latin America and the Caribbean, focusing on the cases of Peru, Chile, and Cuba. This last country was far from China culturally and geographically, but as in many other small towns in the region, Chinese medicine presented an alternative to the treatment of illnesses.
文摘Chinese cultural symbols have been widely transplanted in Chinese American literature.Those symbols bear different significance in different authors’works on different historical stages,which,in essence,reflect Chinese American writers’difficult process of searching for and constructing their cultural identity.
文摘Francis Scott Key Fitzgerald's famous novel The Great Gatsby tells us a story about a young man named Gatsby who from thebottom of society,he tries to pursue love and happiness through struggle and hard-working,but finally the dream fails and he is mur-dered.In the novel Fitzgerald combines the symbol of colors with theme of the novel"the disillusion of American dream"tightly and wit-tingly creating an organic unity like nature itself.Via analyzing such writing skill,let readers have a better understanding of the essenceof American Dream and the luxurious and decadent living conditions and perplexed and blank mental states of the lost generations afterWWI.The Great Gatsby;
基金This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil(CAPES)-Finance Code 001.
文摘Clear and data-driven bioregionalizations can provide a framework to test hypotheses and base biodiversity conservation.Here we used occurrence and abundance data in combination with objective analytical methods to propose two bioregionalization schemes for tree species of the Cerrado and the Pantanal in South America.We also evaluated the contribution of three sets of determinants of the occurrence-and abundance-based subregions.We compiled data on tree species composition from 894 local assemblages based on species occurrences,and from 658 local assemblages based on species abundances.We used an unconstrained community-level modelling approach and clustering techniques to identify and map tree subregions for the occurrence and the abundance data sets,separately.Hierarchical clustering analyses were conducted to investigate floristic affinities between the subregions and to map broader floristic regions.We used multinomial logistic regression models,deviance partitioning,and rank-sum tests to assess the main subregion correlates.We identified 18 occurrence-and four abundance-based subregions in the Cerrado-Pantanal.The hierarchical classifications grouped the occurrence-based subregions into nine floristic zones and abundance-based subregions into two broad floristic zones.Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance data sets.The occurrence-and abundance-based subregions are complementary approaches to disentangle macroecological patterns and to plan conservation efforts in the Cerrado and the Pantanal.Our findings based on occurrence data revealed more complex and interdigitated boundaries between subregions of tree species than previously reported.The environment,historical stability,and human effects act in a synergetic way on the distribution of the subregions.Finally,the relevance of contemporary environmental factors to the subregion patterns we found alert us to the profound impact global warming may have on the spatial organization of the Cerrado-Pantanal tree flora.
基金supported in part by the National Natural Science Foundation of China(61931015,62071335)in part by the Natural Science Foundation of Hubei Province of China(2021CFA002)+2 种基金in part by the Fundamental Research Funds for the Central Universitiesin part by the Technological Innovation Project of Hubei Province of China(2019AAA061)in part by the Science and Technology Program of Shenzhen(JCYJ20170818112037398).
文摘In cellular systems,establishing the initial symbol timing of potential preambles is the first step of a cell search.The envelope fluctuation of the downlink signal hinders the successful timing of conventional symbol timing methods.To solve this problem,a hybrid timing strategy is proposed with two novel detectors,namely the normalized replica-based detector and normalized differential detector.The strategy first detects all potential preambles via the normalized replica-based detector and then employs the normalized differential detector to verify the target preamble,which comes from the target cell and has the highest power.The strategy is unaffected by envelope fluctuation and has computational complexity comparable to that of conventional methods.Simu-lations and real-data tests show that the hybrid timing strategy is robust and practical for initial symbol timing.
基金supported by the National Natural Science Foundation of China(31870664)the 948 Program of National Forestry and Grassland Administration(2013-4-47)the National Key Research and Development Program of China(2022YFD2200103)。
文摘The genus Thuja is ideal for investigating the genetic basis of the East Asia-North America disjunction.The biogeographical background of the genus is debatable and an adaptive strategy is lacking.Through the analysis and mining of comparative transcriptomes,species differentiation and positively selected genes(PSGs)were identified to provide information for understanding the environmental adaptation strategies of the genus Thuja.De novo assembly yielded 44,397-74,252 unigenes of the five Thuja species with contig N50length ranging from 1,559 to 1,724 bp.Annotations revealed a similar distribution of functional categories among them.Based on the phylogenetic trees constructed using the transcriptome data,T.sutchuenensis was divided first,followed by T.plicata and T.occidentalis.The final differentiation of T.koraiensis and T.standishii formed a clade.Enrichment analysis indicated that the PSGs of the North American Thuja species were involved in plant hormone signal transduction and carbon fixation of photosynthetic organisms pathways.The PSGs of East Asian Thuja were related to phenolic,alkaloid,and terpenoid synthesis,important stress-resistant genes and could increase plant resistance to external environmental stresses.This study discovered numerous aroma synthetic-related PSGs including terpene synthase(TPS)genes and lipid phosphate phosphatase 2(LPP2),associated with the synthetic aroma of T.sutchuenensis.Physiological indicators,such as the contents of soluble sugars,total chlorophyll,total phenolics,and total flavonoids were determined,which are consistent with the PSGs enrichment pathways associated with adaptive strategies in the five Thuja species.The results of this study provide an important basis for future studies on conservation genetics.
基金supported by the National Key R&D Program of China under Grant 2018YFB1801500.
文摘In order to reduce the physical impairment caused by signal distortion,in this paper,we investigate symbol detection with Deep Learning(DL)methods to improve bit-error performance in the optical communication system.Many DL-based methods have been applied to such systems to improve bit-error performance.Referring to the speech-to-text method of automatic speech recognition,this paper proposes a signal-to-symbol method based on DL and designs a receiver for symbol detection on single-polarized optical communications modes.To realize this detection method,we propose a non-causal temporal convolutional network-assisted receiver to detect symbols directly from the baseband signal,which specifically integrates most modules of the receiver.Meanwhile,we adopt three training approaches for different signal-to-noise ratios.We also apply a parametric rectified linear unit to enhance the noise robustness of the proposed network.According to the simulation experiments,the biterror-rate performance of the proposed method is close to or even superior to that of the conventional receiver and better than the recurrent neural network-based receiver.
文摘Understanding the mechanisms underlying plant responses to climate change is an important step toward developing effective mitigation strategies. Polyploidy is an important evolutionary trait that can influence the capacity of plants to adapt to climate change. The environmental flexibility of polyploids suggests their resiliency to climate change, however, such hypotheses have not yet received empirical evidence. To understand how ploidy level may influence response to climate change, we modeled the current and future distribution of 54 Crataegus species under moderate to severe environments and compared the range change between diploids and polyploids. The majority of studied species are predicted to experience considerable range expansion. We found a negative interaction between ploidy and ecoregions in determining the response to climate change. In extreme environments, polyploids are projected to experience a higher range expansion than diploids with climate change, while the opposite is true for moderate environments. The range expansion of Crataegus species can be attributed to their tolerance for a wide range of environmental conditions. Despite the higher tolerance of polyploids to extreme environments, they do not necessarily outperform diploids in moderate environments, which can be attributed to the varying nature of species interactions along a stress gradient.
文摘President Xi Jinping’s America trip from November 14 to 17,including his talks with U.S.President Joe Biden and his attendance at the 30th APEC Economic Leaders’Meeting in San Francisco,is widely believed to have added stability to China-U.S.relations,brought new impetus to Asia-Pacific cooperation and injected positive energy into the international and regional landscape.
基金Department of Education in Yunnan Province Fund for Scientific Research,Research on the Origin Tracing of the Traditional Architectures of Limi People of Yunnan Yi Ethnic Group(No.2022Y658).
文摘A symbol is an expression of meaning,while blank symbols express special meanings.By focusing on the application of blank symbols in Japanese architecture and indoor designs,we analyzed the aesthetic principles in Japanese architecture and indoor designs from the perspective of semiotics,such as“Kongji,”“Emptiness,”and“Dying out,”and their minimalist and pure design concepts.Traditional Chinese culture was also further explored,especially the profound influence of the“Chan sect”and the philosophy of“unity of heaven and mankind”on Japanese architecture and designs.This study aims to facilitate the coexistence and mutual appreciation of Chinese and Japanese architectural designs.
基金Supported by Sichuan Provincial Science and Technology Program(Grant No.2022YFH0075)Opening Project of State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure(Grant No.HJGZ2021113)Independent Research Project of State Key Laboratory of Traction Power(Grant No.2022TPL_T03).
文摘Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are difficult to apply in engineering practice.Symbolic regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for datasets.In this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate model.Three terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate models.Based on the FCG rate test data from other literature,the SR model was constructed using Al-7055-T7511.It was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear regression.Compared with the three semi-empirical FCG rate models,the SR model yielded higher prediction accuracy.This result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.
文摘In the Italian novel Lacci,the young husband abandoned his wife and lived with another woman.Although the marriage has been maintained under the stress of tense relations,friction and cracks have long existed and broken their peaceful life.This betrayal story restores the whole story from three perspectives through the eyes of the husband,the wife,and the memory of two children.It also reveals the indifferent and uncommunicable situations experienced by everyone in the family.The shoelace that appeared repeatedly in this article not only symbolizes the entangled and chaotic relationship between husband and wife,but also symbolizes the parent-child relationship that has long been broken but still tied up with each other;another image,the cat,not only symbolizes the seductive lover in the eyes of the husband,but also represents himself who pursues the satisfaction of desire.At the same time,cat also implies the disintegration of this marriage from inside to outside.In short,in this suffocating marriage novel,shoelace symbolizes order,while cat symbolizes chaos.The cat who keeps breaking in wore away their trust and emotion,and in the end,the two people in marriage can only bind reluctantly with shoelaces and hurt each other.
文摘South America’s climatic diversity is a product of its vast geographical expanse, encompassing tropical to subtropical latitudes. The variations in precipitation and temperature across the region stem from the influence of distinct atmospheric systems. While some studies have characterized the prevailing systems over South America, they often lacked the utilization of statistical techniques for homogenization. On the other hand, other research has employed multivariate statistical methods to identify homogeneous regions regarding temperature and precipitation, but their focus has been limited to specific areas, such as the south, southeast, and northeast. Surprisingly, there is a lack of work that compares various multivariate statistical techniques to determine homogeneous regions across the entirety of South America concerning temperature and precipitation. This paper aims to address this gap by comparing three such techniques: Cluster Analysis (K-means and Ward) and Self Organizing Maps, using data from different sources for temperature (ERA5, ERA5-Land, and CRU) and precipitation (ERA5, ERA5-Land, and CPC). Spatial patterns and time series were generated for each region over the period 1981-2010. The results from this analysis of spatially homogeneous regions concerning temperature and precipitation have the potential to significantly benefit climate analysis and forecasts. Moreover, they can offer valuable insights for various climatological studies, guiding decision-making processes in diverse fields that rely on climate information, such as agriculture, disaster management, and water resources planning.