In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradie...In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradient gel electrophoresis （16S-23S rRNA-ITS DGGE） and microscopic evaluation. Samples were collected quarterly at four sites （River Mouth, Meiliang Bay, Cross Area, and Lake Center） from August 2006 to April 2007. Results showed that Microcystis dominated total phytoplankton abundance at the four sites in all seasons except winter. The average annual abundance of Microcystis was relatively high at River Mouth and Meiliang Bay, reaching 81.22×10^6 and 61.32×10^6 cells/L, respectively. For temporal variations, Shannon-Wiener diversity index （H＇） according to DGGE profile revealed the richness of Microcystis in summer （H＇ = 1.375±0.034） and winter （H＇ = 1.650 ±0.032） was lower than that in spring （H＇ = 2.078 ±0.031） and autumn （H＇ = 2.365 ±0.032） （P 〈 0.05）. While for spatial variations, the richness of Microcystis at River Mouth （H＇ = 2.015± 0.074） was higher than at other sites during four seasons （P 〈 0.01）. Very few differences of Microcystis diversity in the same season were observed among the other three sites （P 〉 0.05）. Canonical correspondence analysis （CCA） was performed to elucidate the relationships between Microcystis operational taxonomic units （OTUs） composition and the environmental factors. Results of CCA revealed that temperature was strongly positively correlated with the first axis （r = 0.963）, while TSS was negative correlated with the second axis （r = -0.716）. Phylogenetic tree based on the sequencing results of target bands on DGGE gel indicated that samples collected in summer and winter constituted two separated clusters.展开更多
Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of to...Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of topological phases with particle-hole symmetry.In two dimensions,TDPs support propagating topological edge modes that simulate the elusive Majorana elementary particles.Furthermore,a piercing ofπ-flux Dirac-solenoids in TDPs stabilizes localized Majorana excitations that can be braided for the purpose of topological quantum computation.Such two-dimensional(2D)TDPs have been a focus in the research frontier,but their experimental realizations are still under debate.Here,with a novel design scheme,we realize 2D TDPs in an acoustic crystal by synthesizing both the particle-hole and fermion-like time reversal symmetries for a wide range of frequencies.The design scheme leverages an enriched unit cell structure with real-valued couplings that emulate the targeted Hamiltonian of TDPs with complex hoppings:A technique that could unlock the realization of all topological classes with passive metamaterials.In our experiments,we realize a pair of TDPs with opposite Chern numbers in two independent sectors that are connected by an intrinsic fermion-like timereversal symmetry built in the system.We measure the acoustic Majorana-like helical edge modes and visualize their robust topological transport,thus revealing the unprecedented D and DIII class topologies with direct evidence.Our study opens up a new pathway for the experimental realization of two fundamental classes of topological phases and may offer new insights in fundamental physics,materials science,and phononic information processing.展开更多
During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm ...During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence展开更多
This study explores the complex relationship between climate change and human development. The aim is to understand how climate change affects human development across countries, regions, and the global population. Vi...This study explores the complex relationship between climate change and human development. The aim is to understand how climate change affects human development across countries, regions, and the global population. Visual analytics were used to examine the impact of various climate change indicators on different aspects of human development. The study highlights the urgent need for climate change action and encourages policymakers to make decisive moves. Climate change adversely affects numerous aspects of daily life, leading to significant consequences that must be addressed through policy changes and global governance recommendations. Key findings include that regions with higher CO2 emissions experience a significantly higher incidence of life-threatening diseases compared to regions with lower emissions. Additionally, higher CO2 emissions correlate with consistent death rates. Increased pollution exposure is associated with a higher prevalence of life-threatening diseases and higher rates of malnutrition. Moreover, greater mineral depletion is linked to more frequent life-threatening diseases, suggesting that industrialization contributes to adverse health effects. These results provide valuable insights for policy and decision-making aimed at mitigating the impact of climate change on human development.展开更多
Data breaches have massive consequences for companies, affecting them financially and undermining their reputation, which poses significant challenges to online security and the long-term viability of businesses. This...Data breaches have massive consequences for companies, affecting them financially and undermining their reputation, which poses significant challenges to online security and the long-term viability of businesses. This study analyzes trends in data breaches in the United States, examining the frequency, causes, and magnitude of breaches across various industries. We document that data breaches are increasing, with hacking emerging as the leading cause. Our descriptive analyses explore factors influencing breaches, including security vulnerabilities, human error, and malicious attacks. The findings provide policymakers and businesses with actionable insights to bolster data security through proactive audits, patching, encryption, and response planning. By better understanding breach patterns and risk factors, organizations can take targeted steps to enhance protections and mitigate the potential damage of future incidents.展开更多
Contamination of the Arctic by legacy polychlorinated biphenyls(PCB)is well documented,but the more recent discovery of unintentionally produced(UP)PCBs in the Arctic is a cause for concern.Legacy PCBs are covered by ...Contamination of the Arctic by legacy polychlorinated biphenyls(PCB)is well documented,but the more recent discovery of unintentionally produced(UP)PCBs in the Arctic is a cause for concern.Legacy PCBs are covered by existing international conventions and regular monitoring,and the UP congeners are covered by the Stockholm Convention and the U.S.Toxic Substances Control Act,but systematic monitoring and regulatory enforcement of UP-PCBs are lacking.Sources of UP-PCB are by-products of manufacturing(e.g.pigments)and from thermal sources(e.g.incinerators).Estimates of PCB emissions in China now show UP-PCB eclipsing emissions of legacy PCB.Here we discuss the 209 PCB-congener results from surface snow samples from Lomonosovfonna in 2010 and 2014,a glacial site on Svalbard which,in 2014,shows presence of PCB5,PCB11,and an unusually high amount of PCB52.While PCB5 and PCB11 may not be found in legacy PCB mixtures,PCB52 is in many PCB mixtures,yet dominates none of them as in the 2014 snow sample.Is it possible that these congeners are from UP-PCB processes?A search of the literature shows that PCB5,PCB11 and PCB52 are co-synthesis products of pigment production and that PCB5 and PCB11 are found in flue gas and ash from hazardous waste incineration.Of these,PCB11 has received greater attention in the literature.It has recently been consistently detected in the air,snow,soil and biota in the Arctic,evidence that PCB11 and possibly other UP-PCB congeners are global contaminants.Ice core measurements dating from 1957 to 2009 of PCBs in Svalbard reveal PCB11 presence throughout that period,indicating historic presence in the Arctic before being a focus of research elsewhere.Other UP-PCB need to be more fully investigated,especially from thermal sources.展开更多
The theory and experiment of quantum information have been studied extensively in recent years,and the feasibility of quantum communication has been proved.Although the fundamental technology is not yet mature,researc...The theory and experiment of quantum information have been studied extensively in recent years,and the feasibility of quantum communication has been proved.Although the fundamental technology is not yet mature,research on quantum internet should be conducted.To implement quantum internet,an architecture that describes how quantum nodes are linked to form networks and how protocol functions are vertically composed need to be developed urgently.In this paper,we present a novel design of a clusterbased structure to describe how quantum nodes are interconnected,and how the structure can improve the performance of qubit transmission and reduce the network complexity.The idea of the quantum local area network(QLAN)is proposed as an essential component of the quantum internet.Besides,each quantum repeater links to neighboring repeaters to form a core network,and multiple QLANs are connected through the core network.The core network can be grouped into different hierarchical quantum repeater networks according to needed service requirements.For the sake of interoperability and fast prototyping,we adopt the idea of OSI layering model of the current Internet in the design of quantum internet.Finally,we elaborate on the composition of quantum nodes and the realization of end-to-end communication.展开更多
As one of the major threats to the current DeFi(Decentralized Finance)ecosystem,reentrant attack induces data inconsistency of the victim smart contract,enabling attackers to steal on-chain assets from DeFi projects,w...As one of the major threats to the current DeFi(Decentralized Finance)ecosystem,reentrant attack induces data inconsistency of the victim smart contract,enabling attackers to steal on-chain assets from DeFi projects,which could terribly do harm to the confidence of the blockchain investors.However,protecting DeFi projects from the reentrant attack is very difficult,since generating a call loop within the highly automatic DeFi ecosystem could be very practicable.Existing researchers mainly focus on the detection of the reentrant vulnerabilities in the code testing,and no method could promise the non-existent of reentrant vulnerabilities.In this paper,we introduce the database lock mechanism to isolate the correlated smart contract states from other operations in the same contract,so that we can prevent the attackers from abusing the inconsistent smart contract state.Compared to the existing resolutions of front-running,code audit,andmodifier,our method guarantees protection resultswith better flexibility.And we further evaluate our method on a number of de facto reentrant attacks observed from Etherscan.The results prove that our method could efficiently prevent the reentrant attack with less running cost.展开更多
The Covid-19 pandemic produced a complex combination of intense negative emotions among the general public,influencing people's coping reactions toward the pandemic.Yet each discrete emotion may affect people'...The Covid-19 pandemic produced a complex combination of intense negative emotions among the general public,influencing people's coping reactions toward the pandemic.Yet each discrete emotion may affect people's behaviors in different ways.Unveiling the specific emotion–behavior relationships can provide valuable implications for designing effective intervention programs.Through the lens of the appraisal theory of emotion,we assessed the relationships between negative emotions and pandemic-related behaviors among the Chinese population midst the early outbreak of the pandemic.An anonymous online survey was distributed to mainland of China participants(n=2976),which assessed individuals'emotional states and behavioral reactions to the pandemic.Consistent with the differential appraisal theme underlying each negative emotion as delineated by the appraisal theory,mixed relationships between emotions and pandemic-related behaviors were revealed.Specifically,anxiety was positively associated with behaviors of seeking pandemic-related information,sharing such information,and stockpiling preventive goods,yet,contrary to prediction,anxious people were reluctant to adopt preventive measures,which is maladaptive.Sad people sought information less frequently and exhibited lower intention to stockpile preventive goods;but,opposing prediction,they shared information less frequently.Angry people were more active in sharing information and in stockpiling preventive goods.These findings suggest that public health practitioners can utilize the emotion–behavior relationships to identify the vulnerable individuals who tend to adopt maladaptive coping behaviors,help them address emotional distress,and encourage their adoption of effective coping behaviors.展开更多
Recognition of psychological characteristics based on massive data and computer machine learning algorithms has gradually become a new way for psychological research. As we all know, person-job fit is an important con...Recognition of psychological characteristics based on massive data and computer machine learning algorithms has gradually become a new way for psychological research. As we all know, person-job fit is an important consideration in recruitment and selection. Most existing selection process can reliably measure skills fit, i.e., matching job seekers’ skills/work experience with job demand. What is often harder to assess is the compatibility between job seekers’ motivational needs/career aspirations and job characteristics, which will ultimately determine their career progress and job satisfaction. With the increasing application of machine learning methods in psychology, this paper constructed classification models to predict individuals’ needs, career aspiration, and occupation through their personality traits. This enables automatic access to individuals’ psychological indicators, with the MLP (Multi-Layer Perceptron) method showing the highest prediction accuracy. In addition, it conducted a comparative analysis of the distribution of personality characteristics in different occupations. Based on the study results, we put forward some countermeasures and suggestions for application in human resource management.展开更多
We give an elementary proof to the asymptotic expansion formula of Rochon and Zhang(2012)for the unique complete Kahler-Einstein metric of Cheng and Yau(1980),Kobayashi(1984),Tian and Yau(1987)and Bando(1990)on quasi-...We give an elementary proof to the asymptotic expansion formula of Rochon and Zhang(2012)for the unique complete Kahler-Einstein metric of Cheng and Yau(1980),Kobayashi(1984),Tian and Yau(1987)and Bando(1990)on quasi-projective manifolds.The main tools are the solution formula for second-order ordinary differential equations(ODEs)with constant coefficients and spectral theory for the Laplacian operator on a closed manifold.展开更多
A G-Frobenius graph F, as defined by Fang, Li, and Praeger, is a connected orbital graph of a Frobenius group G = K × H with Frobenius kernel K and Frobenius complement H. F is also shown to be a Cayley graph, F ...A G-Frobenius graph F, as defined by Fang, Li, and Praeger, is a connected orbital graph of a Frobenius group G = K × H with Frobenius kernel K and Frobenius complement H. F is also shown to be a Cayley graph, F = Cay（K, S） for K and some subset S of the group K. On the other hand, a network N with a routing function R, written as （N, R）, is an undirected graph N together with a routing R which consists of a collection of simple paths connecting every pair of vertices in the graph. The edge-forwarding index π（N） of a network （N, R）, defined by Heydemann, Meyer, and Sotteau, is a parameter to describe tile maximum load of edges of N. In this paper, we study the edge-forwarding indices of Frobenius graphs. In particular, we obtain the edge-forwarding index of a G-Frobenius graph F with rank（G） ≤ 50.展开更多
This paper empirically investigates the role of social trust in the long-term performance of the initial public offerings(IPOs)in China,controlling for the formal institutional environment.We find that privately owned...This paper empirically investigates the role of social trust in the long-term performance of the initial public offerings(IPOs)in China,controlling for the formal institutional environment.We find that privately owned or smaller IPO firms experience signifi-cantly better post-IPO performance when they are incorporated in regions with more social trust.The state-owned and bigger IPO firms,on the other hand,experience better long-term post-IPO performance when they are incorporated in regions with stronger formal institutions(e.g.court enforcement and contract holding).Political pluralism turns out to benefit all IPOs in the long term.In addition,our evidence shows that stronger social trust substitutes for the quality of court enforcement but complements the role of contract holding.These results are robust after controlling for alternative definitions of ownership,outliers,non-linear effects of institutions,and the potential endogeneity of institutions in the model.展开更多
The objective of this study was to evaluate the impact of Break Free from Depression(BFFD),a school-based depression awareness curriculum,in comparison to a wait list control group.A total of 13 eighth grade classroom...The objective of this study was to evaluate the impact of Break Free from Depression(BFFD),a school-based depression awareness curriculum,in comparison to a wait list control group.A total of 13 eighth grade classrooms participated in either an intervention or control group and completed pre-,post-,and three-month follow-up surveys.Students participating in BFFD(N=6 classrooms,166 students)demonstrated enhanced knowledge of and more adaptive attitudes towards depression compared to the control group(N=7 classrooms,155 students).Participants in the BFFD intervention also demonstrated increases in their confidence in knowing how to seek help for depression and in their intent to seek this help if needed.Slight decreases were found at a three-month follow-up in all scales except for intent to seek help.BFFD was effective regardless of gender,ethnicity,or identification as a member of the LGBTQ community.There was a delayed effect on measured constructs for Black students with gains apparent at three-month follow-up.The findings demonstrated that BFFD had a small but significant positive impact on students’knowledge,skills,and attitudes in seeking support for themselves and for others when faced with signs of depression.The implementation of depression awareness curricula in schools hold promise in promoting student mental health,and it is important to consider factors that might have an impact on outcomes.展开更多
Political connections are an increasingly important part of firms’strategies to develop relationships with the government and poli-ticians.This study examines the impact of transactional and rela-tional political con...Political connections are an increasingly important part of firms’strategies to develop relationships with the government and poli-ticians.This study examines the impact of transactional and rela-tional political connections on firm value.The results show that transactionally connected firms are more likely to exhibit greater firm value than their relationally connected and non-connected counterparts.This study further finds evidence of a long-term value-enhancing effect of the transactional approach to political connections.A variety of robustness tests with alternative model specifications continue to show that transactional political con-nections lead to higher firm value.The findings indicate that firms with transactional political connections are provided with better networks with the political regime in power compared with those with relational political connections.These transactionally con-nected firms may enjoy preferential treatment from the govern-ment,in the form of lower taxes,and the access to government loans,subsidies,bailouts,and/or procurement contracts.展开更多
This paper shows that signals from the offshore China spot market for the Chinese renminbi of the Hong Kong SAR(listed as CNH)directly affect the volatility of share prices of Chinese banks and the overall risks of Ch...This paper shows that signals from the offshore China spot market for the Chinese renminbi of the Hong Kong SAR(listed as CNH)directly affect the volatility of share prices of Chinese banks and the overall risks of Chinese banking stability.This is especially so amid heightened uncertainty about global trade or the People’s Republic of China.Thus,the CNH market volatility is a leading indicator of onshore Chinese banking sector volatility.Our results suggest that further offshore exchange market movements arising out of news such as increasing trade friction with the United States will generate greater volatility in the Chinese banking sector.Far from being a shock absorber for the Chinese financial system,the CNH market appears to be a shock transmitter of risk from offshore economic policy uncertainty to the Chinese banking system.展开更多
基金supported by the State Key Fun- damental Research and Development Program (No. 2008CB418000)the National Natural Science Foundation of China (No. 40671068)the Special Program for Lake Taihu Water Pollution Governing of Jiangsu Province (No. BK2007748)
文摘In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradient gel electrophoresis （16S-23S rRNA-ITS DGGE） and microscopic evaluation. Samples were collected quarterly at four sites （River Mouth, Meiliang Bay, Cross Area, and Lake Center） from August 2006 to April 2007. Results showed that Microcystis dominated total phytoplankton abundance at the four sites in all seasons except winter. The average annual abundance of Microcystis was relatively high at River Mouth and Meiliang Bay, reaching 81.22×10^6 and 61.32×10^6 cells/L, respectively. For temporal variations, Shannon-Wiener diversity index （H＇） according to DGGE profile revealed the richness of Microcystis in summer （H＇ = 1.375±0.034） and winter （H＇ = 1.650 ±0.032） was lower than that in spring （H＇ = 2.078 ±0.031） and autumn （H＇ = 2.365 ±0.032） （P 〈 0.05）. While for spatial variations, the richness of Microcystis at River Mouth （H＇ = 2.015± 0.074） was higher than at other sites during four seasons （P 〈 0.01）. Very few differences of Microcystis diversity in the same season were observed among the other three sites （P 〉 0.05）. Canonical correspondence analysis （CCA） was performed to elucidate the relationships between Microcystis operational taxonomic units （OTUs） composition and the environmental factors. Results of CCA revealed that temperature was strongly positively correlated with the first axis （r = 0.963）, while TSS was negative correlated with the second axis （r = -0.716）. Phylogenetic tree based on the sequencing results of target bands on DGGE gel indicated that samples collected in summer and winter constituted two separated clusters.
基金the support from the National Key R&D Program of China(2022YFA1404400)the National Natural Science Foundation of China(12125504 and 12074281)+5 种基金the support from the National Natural Science Foundation of China(12047541)the Gusu Leading Innovation Scientists Program of Suzhou City,and the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology(2020B1212030010)support from the US National Science Foundation(CMMI2131759)support from the US National Science Foundation(DMR-1823800 and CMMI-2131760)the U.S.Army Research Office through contract W911NF-23-1-0127。
文摘Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties.Topological D-class phases(TDPs)are archetypes of the ten-fold classification of topological phases with particle-hole symmetry.In two dimensions,TDPs support propagating topological edge modes that simulate the elusive Majorana elementary particles.Furthermore,a piercing ofπ-flux Dirac-solenoids in TDPs stabilizes localized Majorana excitations that can be braided for the purpose of topological quantum computation.Such two-dimensional(2D)TDPs have been a focus in the research frontier,but their experimental realizations are still under debate.Here,with a novel design scheme,we realize 2D TDPs in an acoustic crystal by synthesizing both the particle-hole and fermion-like time reversal symmetries for a wide range of frequencies.The design scheme leverages an enriched unit cell structure with real-valued couplings that emulate the targeted Hamiltonian of TDPs with complex hoppings:A technique that could unlock the realization of all topological classes with passive metamaterials.In our experiments,we realize a pair of TDPs with opposite Chern numbers in two independent sectors that are connected by an intrinsic fermion-like timereversal symmetry built in the system.We measure the acoustic Majorana-like helical edge modes and visualize their robust topological transport,thus revealing the unprecedented D and DIII class topologies with direct evidence.Our study opens up a new pathway for the experimental realization of two fundamental classes of topological phases and may offer new insights in fundamental physics,materials science,and phononic information processing.
基金supported by a series of awards from New Jersey Sea Grantsupport from the U.S. Army Corps of Engineers, Philadelphia Districtsupported by National Park Service Grants Nos.CA518099049 and PS 180060016
文摘During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence
文摘This study explores the complex relationship between climate change and human development. The aim is to understand how climate change affects human development across countries, regions, and the global population. Visual analytics were used to examine the impact of various climate change indicators on different aspects of human development. The study highlights the urgent need for climate change action and encourages policymakers to make decisive moves. Climate change adversely affects numerous aspects of daily life, leading to significant consequences that must be addressed through policy changes and global governance recommendations. Key findings include that regions with higher CO2 emissions experience a significantly higher incidence of life-threatening diseases compared to regions with lower emissions. Additionally, higher CO2 emissions correlate with consistent death rates. Increased pollution exposure is associated with a higher prevalence of life-threatening diseases and higher rates of malnutrition. Moreover, greater mineral depletion is linked to more frequent life-threatening diseases, suggesting that industrialization contributes to adverse health effects. These results provide valuable insights for policy and decision-making aimed at mitigating the impact of climate change on human development.
文摘Data breaches have massive consequences for companies, affecting them financially and undermining their reputation, which poses significant challenges to online security and the long-term viability of businesses. This study analyzes trends in data breaches in the United States, examining the frequency, causes, and magnitude of breaches across various industries. We document that data breaches are increasing, with hacking emerging as the leading cause. Our descriptive analyses explore factors influencing breaches, including security vulnerabilities, human error, and malicious attacks. The findings provide policymakers and businesses with actionable insights to bolster data security through proactive audits, patching, encryption, and response planning. By better understanding breach patterns and risk factors, organizations can take targeted steps to enhance protections and mitigate the potential damage of future incidents.
基金Hayley Hung,Environment Canada,generously contributed information on Arctic air monitoring of PCB.We thank the editors and anonymous reviewers of an earlier AMAP assessment,Cynthia de Wit,Derek Muir,and Jennifer Balmer,for editing and suggestions for improvements.
文摘Contamination of the Arctic by legacy polychlorinated biphenyls(PCB)is well documented,but the more recent discovery of unintentionally produced(UP)PCBs in the Arctic is a cause for concern.Legacy PCBs are covered by existing international conventions and regular monitoring,and the UP congeners are covered by the Stockholm Convention and the U.S.Toxic Substances Control Act,but systematic monitoring and regulatory enforcement of UP-PCBs are lacking.Sources of UP-PCB are by-products of manufacturing(e.g.pigments)and from thermal sources(e.g.incinerators).Estimates of PCB emissions in China now show UP-PCB eclipsing emissions of legacy PCB.Here we discuss the 209 PCB-congener results from surface snow samples from Lomonosovfonna in 2010 and 2014,a glacial site on Svalbard which,in 2014,shows presence of PCB5,PCB11,and an unusually high amount of PCB52.While PCB5 and PCB11 may not be found in legacy PCB mixtures,PCB52 is in many PCB mixtures,yet dominates none of them as in the 2014 snow sample.Is it possible that these congeners are from UP-PCB processes?A search of the literature shows that PCB5,PCB11 and PCB52 are co-synthesis products of pigment production and that PCB5 and PCB11 are found in flue gas and ash from hazardous waste incineration.Of these,PCB11 has received greater attention in the literature.It has recently been consistently detected in the air,snow,soil and biota in the Arctic,evidence that PCB11 and possibly other UP-PCB congeners are global contaminants.Ice core measurements dating from 1957 to 2009 of PCBs in Svalbard reveal PCB11 presence throughout that period,indicating historic presence in the Arctic before being a focus of research elsewhere.Other UP-PCB need to be more fully investigated,especially from thermal sources.
基金supported in part by Anhui Initiative in Quantum Information Technologies under grant No.AHY150300Youth Innovation Promotion Association Chinese Academy of Sciences(CAS)under grant No.Y202093。
文摘The theory and experiment of quantum information have been studied extensively in recent years,and the feasibility of quantum communication has been proved.Although the fundamental technology is not yet mature,research on quantum internet should be conducted.To implement quantum internet,an architecture that describes how quantum nodes are linked to form networks and how protocol functions are vertically composed need to be developed urgently.In this paper,we present a novel design of a clusterbased structure to describe how quantum nodes are interconnected,and how the structure can improve the performance of qubit transmission and reduce the network complexity.The idea of the quantum local area network(QLAN)is proposed as an essential component of the quantum internet.Besides,each quantum repeater links to neighboring repeaters to form a core network,and multiple QLANs are connected through the core network.The core network can be grouped into different hierarchical quantum repeater networks according to needed service requirements.For the sake of interoperability and fast prototyping,we adopt the idea of OSI layering model of the current Internet in the design of quantum internet.Finally,we elaborate on the composition of quantum nodes and the realization of end-to-end communication.
基金supported byNationalKeyResearch andDevelopment Plan(Grant No.2018YFB1800701)Key-Area Research and Development Program of Guangdong Province 2020B0101090003,CCF-NSFOCUS Kunpeng Scientific Research Fund(CCF-NSFOCUS 2021010)+2 种基金National Natural Science Foundation of China(Grant Nos.61902083,62172115,61976064)Guangdong Higher Education Innovation Group 2020KCXTD007 and Guangzhou Higher Education Innovation Group(No.202032854)Guangzhou Fundamental Research Plan of“Municipalschool”Jointly Funded Projects(No.202102010445).
文摘As one of the major threats to the current DeFi(Decentralized Finance)ecosystem,reentrant attack induces data inconsistency of the victim smart contract,enabling attackers to steal on-chain assets from DeFi projects,which could terribly do harm to the confidence of the blockchain investors.However,protecting DeFi projects from the reentrant attack is very difficult,since generating a call loop within the highly automatic DeFi ecosystem could be very practicable.Existing researchers mainly focus on the detection of the reentrant vulnerabilities in the code testing,and no method could promise the non-existent of reentrant vulnerabilities.In this paper,we introduce the database lock mechanism to isolate the correlated smart contract states from other operations in the same contract,so that we can prevent the attackers from abusing the inconsistent smart contract state.Compared to the existing resolutions of front-running,code audit,andmodifier,our method guarantees protection resultswith better flexibility.And we further evaluate our method on a number of de facto reentrant attacks observed from Etherscan.The results prove that our method could efficiently prevent the reentrant attack with less running cost.
基金supported by grants from the National Natural Science Foundation of China(No.71802198)University of South China Covid-19 epidemic prevention and control scientific research emergency project(2020-2-5),Hunan province 2020 innovative province construction special topic to combat Covid-19 epidemic emergency(2020SK3010)Major Program of the National Social Science Foundation of China(No.21ZDA036).
文摘The Covid-19 pandemic produced a complex combination of intense negative emotions among the general public,influencing people's coping reactions toward the pandemic.Yet each discrete emotion may affect people's behaviors in different ways.Unveiling the specific emotion–behavior relationships can provide valuable implications for designing effective intervention programs.Through the lens of the appraisal theory of emotion,we assessed the relationships between negative emotions and pandemic-related behaviors among the Chinese population midst the early outbreak of the pandemic.An anonymous online survey was distributed to mainland of China participants(n=2976),which assessed individuals'emotional states and behavioral reactions to the pandemic.Consistent with the differential appraisal theme underlying each negative emotion as delineated by the appraisal theory,mixed relationships between emotions and pandemic-related behaviors were revealed.Specifically,anxiety was positively associated with behaviors of seeking pandemic-related information,sharing such information,and stockpiling preventive goods,yet,contrary to prediction,anxious people were reluctant to adopt preventive measures,which is maladaptive.Sad people sought information less frequently and exhibited lower intention to stockpile preventive goods;but,opposing prediction,they shared information less frequently.Angry people were more active in sharing information and in stockpiling preventive goods.These findings suggest that public health practitioners can utilize the emotion–behavior relationships to identify the vulnerable individuals who tend to adopt maladaptive coping behaviors,help them address emotional distress,and encourage their adoption of effective coping behaviors.
基金supported by the key research project of National Party School (School of Administration) system, under grant No.2022DXXTZDDYKT002.
文摘Recognition of psychological characteristics based on massive data and computer machine learning algorithms has gradually become a new way for psychological research. As we all know, person-job fit is an important consideration in recruitment and selection. Most existing selection process can reliably measure skills fit, i.e., matching job seekers’ skills/work experience with job demand. What is often harder to assess is the compatibility between job seekers’ motivational needs/career aspirations and job characteristics, which will ultimately determine their career progress and job satisfaction. With the increasing application of machine learning methods in psychology, this paper constructed classification models to predict individuals’ needs, career aspiration, and occupation through their personality traits. This enables automatic access to individuals’ psychological indicators, with the MLP (Multi-Layer Perceptron) method showing the highest prediction accuracy. In addition, it conducted a comparative analysis of the distribution of personality characteristics in different occupations. Based on the study results, we put forward some countermeasures and suggestions for application in human resource management.
基金supported by National Natural Science Foundation of China(Grant Nos.11331001 and 11871265)the Hwa Ying Foundation for its financial support and thanks Professor Jian Song for his invitation。
文摘We give an elementary proof to the asymptotic expansion formula of Rochon and Zhang(2012)for the unique complete Kahler-Einstein metric of Cheng and Yau(1980),Kobayashi(1984),Tian and Yau(1987)and Bando(1990)on quasi-projective manifolds.The main tools are the solution formula for second-order ordinary differential equations(ODEs)with constant coefficients and spectral theory for the Laplacian operator on a closed manifold.
基金The first two authors are supported by the Natural Science Foundation(No.10571005)and RFDP of China
文摘A G-Frobenius graph F, as defined by Fang, Li, and Praeger, is a connected orbital graph of a Frobenius group G = K × H with Frobenius kernel K and Frobenius complement H. F is also shown to be a Cayley graph, F = Cay（K, S） for K and some subset S of the group K. On the other hand, a network N with a routing function R, written as （N, R）, is an undirected graph N together with a routing R which consists of a collection of simple paths connecting every pair of vertices in the graph. The edge-forwarding index π（N） of a network （N, R）, defined by Heydemann, Meyer, and Sotteau, is a parameter to describe tile maximum load of edges of N. In this paper, we study the edge-forwarding indices of Frobenius graphs. In particular, we obtain the edge-forwarding index of a G-Frobenius graph F with rank（G） ≤ 50.
文摘This paper empirically investigates the role of social trust in the long-term performance of the initial public offerings(IPOs)in China,controlling for the formal institutional environment.We find that privately owned or smaller IPO firms experience signifi-cantly better post-IPO performance when they are incorporated in regions with more social trust.The state-owned and bigger IPO firms,on the other hand,experience better long-term post-IPO performance when they are incorporated in regions with stronger formal institutions(e.g.court enforcement and contract holding).Political pluralism turns out to benefit all IPOs in the long term.In addition,our evidence shows that stronger social trust substitutes for the quality of court enforcement but complements the role of contract holding.These results are robust after controlling for alternative definitions of ownership,outliers,non-linear effects of institutions,and the potential endogeneity of institutions in the model.
文摘The objective of this study was to evaluate the impact of Break Free from Depression(BFFD),a school-based depression awareness curriculum,in comparison to a wait list control group.A total of 13 eighth grade classrooms participated in either an intervention or control group and completed pre-,post-,and three-month follow-up surveys.Students participating in BFFD(N=6 classrooms,166 students)demonstrated enhanced knowledge of and more adaptive attitudes towards depression compared to the control group(N=7 classrooms,155 students).Participants in the BFFD intervention also demonstrated increases in their confidence in knowing how to seek help for depression and in their intent to seek this help if needed.Slight decreases were found at a three-month follow-up in all scales except for intent to seek help.BFFD was effective regardless of gender,ethnicity,or identification as a member of the LGBTQ community.There was a delayed effect on measured constructs for Black students with gains apparent at three-month follow-up.The findings demonstrated that BFFD had a small but significant positive impact on students’knowledge,skills,and attitudes in seeking support for themselves and for others when faced with signs of depression.The implementation of depression awareness curricula in schools hold promise in promoting student mental health,and it is important to consider factors that might have an impact on outcomes.
文摘Political connections are an increasingly important part of firms’strategies to develop relationships with the government and poli-ticians.This study examines the impact of transactional and rela-tional political connections on firm value.The results show that transactionally connected firms are more likely to exhibit greater firm value than their relationally connected and non-connected counterparts.This study further finds evidence of a long-term value-enhancing effect of the transactional approach to political connections.A variety of robustness tests with alternative model specifications continue to show that transactional political con-nections lead to higher firm value.The findings indicate that firms with transactional political connections are provided with better networks with the political regime in power compared with those with relational political connections.These transactionally con-nected firms may enjoy preferential treatment from the govern-ment,in the form of lower taxes,and the access to government loans,subsidies,bailouts,and/or procurement contracts.
文摘This paper shows that signals from the offshore China spot market for the Chinese renminbi of the Hong Kong SAR(listed as CNH)directly affect the volatility of share prices of Chinese banks and the overall risks of Chinese banking stability.This is especially so amid heightened uncertainty about global trade or the People’s Republic of China.Thus,the CNH market volatility is a leading indicator of onshore Chinese banking sector volatility.Our results suggest that further offshore exchange market movements arising out of news such as increasing trade friction with the United States will generate greater volatility in the Chinese banking sector.Far from being a shock absorber for the Chinese financial system,the CNH market appears to be a shock transmitter of risk from offshore economic policy uncertainty to the Chinese banking system.
