Transaction Entropy: An Alternative Metric of Market Performance.

Market uncertainty has a significant impact on market performance. Previous studies have dedicated much effort towards investigations into market uncertainty related to information asymmetry and risk. However, they have neglected the uncertainty inherent in market transactions, which is also an important aspect of market performance, besides the quantity of transactions and market efficiency. In this paper, we put forward a concept of transaction entropy to measure market uncertainty and see how it changes with price. Transaction entropy is defined as the ratio of the total information entropy of all traders to the quantity of transactions, reflecting the level of uncertainty in making successful transactions. Based on the computational and simulated results, our main finding is that transaction entropy is the lowest at equilibrium, it will decrease in a shortage market, and increase in a surplus market. Additionally, we make a comparison of the total entropy of the centralized market with that of the decentralized market, revealing that the price-filtering mechanism could effectively reduce market uncertainty. Overall, the introduction of transaction entropy enriches our understanding of market uncertainty and facilitates a more comprehensive assessment of market performance.

Integrated Transcriptomic and Metabolomic Analyses Reveal the Effects of Grafting on Special Metabolites of Acanthopanax senticosus Leaves.

Acanthopanax senticosus (A. senticosus) is a member of Acanthopanax Miq. and is used in traditional Chinese medicine, and it has been found that grafting technology can be used to alter plant metabolite composition and transcriptome characteristics. In this study, shoots of A. senticosus were grafted onto the rootstocks of the vigorous Acanthopanax sessiliflorus (A. sessiliflorus) to improve its varietal characteristics. In order to investigate the changes in metabolites and transcriptional patterns in grafted A. senticosus leaves (GSCL), fresh leaves were collected from 2-year-old grafted A. senticosus scions, while self-rooted seedling A. senticosus leaves (SCL) were used as controls to analyse the transcriptome and metabolome. Metabolic profiles and gene expression patterns were further identified and correlated in special metabolite target pathways. The content of chlorogenic acid and triterpenoids in the GSCL was higher than in the control, while the quercetin content was lower. All these metabolic changes were associated with changes in the expression pattern of transcripts. Our results revealed the transcriptome and metabolome characteristics of GSCL. This may help to improve leaf quality in A. senticosus cultivation, suggesting that it is feasible to improve the medicinal quality of GSCL through asexual propagation, but the long-term effects need further investigation. In conclusion, this dataset provides a useful resource for future studies on the effects of grafting on medicinal plants.

Impactful scientists have higher tendency to involve collaborators in new topics.

In scientific research, collaboration is one of the most effective ways to take advantage of new ideas, skills, and resources and for performing interdisciplinary research. Although collaboration networks have been intensively studied, the question of how individual scientists choose collaborators to study a new research topic remains almost unexplored. Here, we investigate the statistics and mechanisms of collaborations of individual scientists along their careers, revealing that, in general, collaborators are involved in significantly fewer topics than expected from a controlled surrogate. In particular, we find that highly productive scientists tend to have a higher fraction of single-topic collaborators, while highly cited-i.e., impactful-scientists have a higher fraction of multitopic collaborators. We also suggest a plausible mechanism for this distinction. Moreover, we investigate the cases where scientists involve existing collaborators in a new topic. We find that, compared to productive scientists, impactful scientists show strong preference of collaboration with high-impact scientists on a new topic. Finally, we validate our findings by investigating active scientists in different years and across different disciplines.

Fresh teams are associated with original and multidisciplinary research.

Teamwork is one of the most prominent features in modern science. It is now well understood that team size is an important factor that affects the creativity of the team. However, the crucial question of how the character of research studies is related to the freshness of a team remains unclear. Here, we quantify the team freshness according to the absence of prior collaboration among team members. Our results suggest that papers produced by fresher teams are associated with greater originality and a greater multidisciplinary impact. These effects are even stronger in larger teams. Furthermore, we find that freshness defined by new team members in a paper is a more effective indicator of research originality and multidisciplinarity compared with freshness defined by new collaboration relationships among team members. Finally, we show that the career freshness of team members is also positively correlated with the originality and multidisciplinarity of produced papers.

Quantifying financial market dynamics: Scaling law in rank mobility of Chinese stock prices.

Rank mobility, which was designed to measure the average variation of relative rank positions with respect to any absolute variable over a given time period, can be used to explore how the memory of stock price ranking orders fades over time. We investigate the variation in rank order of the closing prices of stocks registered at the Shanghai A-share market over a long period of 16 years. And we find that rank mobility increases as a power law with increasing time scale, and eventually converges to a constant level. This power-law relationship can be observed not only over a long period of 16 years but also for each consecutive year, especially their power law exponents are very close. The empirical evidence indicates a fundamental dynamics of Chinese stock price movements.

The education-chasing labor rush in China identified by a heterogeneous migration-network game.

Despite persistent efforts in understanding the motives and patterns of human migration behaviors, little is known about the microscopic mechanism that drives migration and its association with migrant types. To fill the gap, we develop a population game model in which migrants are allowed to be heterogeneous and decide interactively on their destination, the resulting migration network emerges naturally as an Nash equilibrium and depends continuously on migrant features. We apply the model to Chinese labor migration data at the current and expected stages, aiming to quantify migration behavior and decision mode for different migrant groups and at different stages. We find the type-specific migration network differs significantly for migrants with different age, income and education level, and also differs from the aggregated network at both stages. However, a deep analysis on model performance suggests a different picture, stability exists for the decision mechanism behind the "as-if" unstable migration behavior, which also explains the relative invariance of low migration efficiency in different settings. Finally, by a classification of cities from the estimated game, we find the richness of education resources is the most critical determinant of city attractiveness for migrants, which gives hint to city managers in migration policy design.

Increasing trend of scientists to switch between topics.

Despite persistent efforts in understanding the creativity of scientists over different career stages, little is known about the underlying dynamics of research topic switching that drives innovation. Here, we analyze the publication records of individual scientists, aiming to quantify their topic switching dynamics and its influence. We find that the co-citing network of papers of a scientist exhibits a clear community structure where each major community represents a research topic. Our analysis suggests that scientists have a narrow distribution of number of topics. However, researchers nowadays switch more frequently between topics than those in the early days. We also find that high switching probability in early career is associated with low overall productivity, yet with high overall productivity in latter career. Interestingly, the average citation per paper, however, is in all career stages negatively correlated with the switching probability. We propose a model that can explain the main observed features.

An index of Chinese surname distribution and its implications for population dynamics.

OBJECTIVE: We propose an index to characterize the key feature of Chinese surname distributions and investigate its implications for population structure and dynamics. MATERIALS AND METHODS: The surname dataset was obtained from the National Citizen Identity Information Center, which contains 1.28 billion Chinese citizens enrolled in 2007, excluding those of Hong Kong, Macao, and Taiwan. An index, the coverage ratio of stretched exponential distribution (CRSED), is proposed based on the crossover point of stretched exponential truncated power-law distribution, where the stretched exponential term and the power-law term contribute equally. We use multidimensional scaling technique to demonstrate the dependence of the similarity of one prefecture to the others on the CRSED. RESULTS: The CRSEDs of 362 prefectures exhibit an uneven distribution. The consistency of this index is evident by strong positive correlations of CRSEDs at the three administrative levels. This new index has a strong negative correlation with the proportion of the rare surnames. The prefectures with similar CRSEDs tend to adjoin each other on the administrative map, resulting in several distinct regions, each of which shares similar terrain features or historical migrations. The prefectures with lower CRSEDs are more dissimilar to the other prefectures, while the ones with higher CRSEDs are more similar to the others. DISCUSSION: The population dynamics of the prefectures with higher CRSEDs are more likely dominated by migratory movements, the dominant evolutionary forces of the prefectures with lower CRSEDs can be attributed to drift and mutation.

Regional surname affinity: A spatial network approach.

OBJECTIVE: We investigate surname affinities among areas of modern-day China, by constructing a spatial network, and making community detection. It reports a geographical genealogy of the Chinese population that is result of population origins, historical migrations, and societal evolutions. MATERIALS AND METHODS: We acquire data from the census records supplied by China's National Citizen Identity Information System, including the surname and regional information of 1.28 billion registered Chinese citizens. We propose a multilayer minimum spanning tree (MMST) to construct a spatial network based on the matrix of isonymic distances, which is often used to characterize the dissimilarity of surname structure among areas. We use the fast unfolding algorithm to detect network communities. RESULTS: We obtain a 10-layer MMST network of 362 prefecture nodes and 3,610 edges derived from the matrix of the Euclidean distances among these areas. These prefectures are divided into eight groups in the spatial network via community detection. We measure the partition by comparing the inter-distances and intra-distances of the communities and obtain meaningful regional ethnicity classification. DISCUSSION: The visualization of the resulting communities on the map indicates that the prefectures in the same community are usually geographically adjacent. The formation of this partition is influenced by geographical factors, historic migrations, trade and economic factors, as well as isolation of culture and language. The MMST algorithm proves to be effective in geo-genealogy and ethnicity classification for it retains essential information about surname affinity and highlights the geographical consanguinity of the population.

Thermo- and mechanical-grinding-triggered color and luminescence switches of the diimine-platinum(II) complex with 4-bromo-2,2'-bipyridine.

The square-planar diimine-platinum(II) complex, Pt(4-Brbpy)(C≡CC6H5)2 (1) (4-Brbpy = 4-bromo-2,2'-bipyridine), was prepared and characterized. Solid-state 1 exhibits reversible thermo- and mechanical-grinding-triggered color and luminescence changes. When crystalline 1·2(CH2Cl2) or 1·2(CHCl3) are heated or ground, the original bright yellow-green emission centered at 525 (549, sh) nm changed to 637 and 690 nm, corresponding to thermo- and mechanochromic response shifts of approximately 88-112 nm and 141-165 nm, respectively. Meanwhile the crystalline state changes into an amorphous phase in both processes. Once the amorphous sample absorbs organic vapors, it can be reverted to the original crystalline state, along with red luminescence turning back to yellow-green emission. The reversibility of thermo- and mechanical-grinding-triggered chromic luminescence properties has been dynamically monitored by emission spectra and X-ray diffraction patterns. The dramatic thermo- and mechanical-grinding-triggered emission red shifts are most likely due to the conversion of the (3)MLCT/(3)LLCT emission state into the (3)MMLCT triplet state.

A new sensor for detection of CH3CN and ClCH2CN vapors based on vapoluminescent platinum(II) complex.

The planar platinum(II) complex [Pt(Me3SiC≡CbpyC≡CSiMe3)(C≡CC6H4Et-4)2] (1) with 5,5-bis(trimethylsilylethynyl)-2,2'-bipyridine was prepared and characterized. Solid-state 1 exhibits unusual, selective and reversible luminescence vapochromism to CH3CN and ClCH2CN vapors, which is useful for the detection of these hazardous vapors. A vapochromic cycle was monitored by dynamic variations in emission spectra and X-ray diffraction (XRD) patterns. Both X-ray crystallographic and density functional theory studies suggest that the vapochromic and vapoluminescent behavior of 1 are induced by the variation in the intermolecular Pt-Pt interactions.

2-(5-Bromo-thio-phen-2-yl)-5-[5-(10-ethyl-phenothia-zin-3-yl)thio-phen-2-yl]-1,3,4-oxadiazole.

The mol-ecule of the title compound, C(24)H(16)BrN(3)OS(3), contains three approximately planar fragments, viz. an oxadiazole ring plus two adjacent thio-phene groups, and two phenothia-zine benzene rings, with largest deviations from the least-squares planes of 0.051 (3), 0.019 (4) and 0.014 (3) Å, respectively. The phenothia-zine unit adopts a butterfly conformation, with a dihedral angle of 38.06 (15)° between the terminal benzene rings. The dihedral angle between the 2,5-bis-(thio-phen-2-yl)oxadiazole unit and the attached benzene ring is 15.35 (11)°. In the crystal, mol-ecules form stacks along the b-axis direction; neighboring mol-ecules within the stack are related by inversion centers, with shortest inter-centroid separations of 3.741 (2) and 3.767 (2) Å.

10-Ethyl-3-(5-methyl-1,3,4-oxadiazol-2-yl)-10H-phenothia-zine.

In the title compound, C(17)H(15)N(3)OS, the phenothia-zine ring system is slightly bent, with a dihedral angle of 13.68 (7)° between the benzene rings. The dihedral angle between the oxadiazole ring and the adjacent benzene ring is 7.72 (7)°. In the crystal, a π-π inter-action with a centroid-centroid distance of 3.752 (2) Šis observed between the benzene rings of neighbouring mol-ecules.

Possible origin of efficient navigation in small worlds.

The small-world phenomenon is one of the most important properties found in social networks. It includes both short path lengths and efficient navigation between two individuals. It is found by Kleinberg that navigation is efficient only if the probability density distribution of an individual to have a friend at distance r scales as P(r) ∼ r(-1). Although this spatial scaling is found in many empirical studies, the origin of how this scaling emerges is still missing. In this Letter, we propose the origin of this scaling law using the concept of entropy from statistical physics and show that this scaling is the result of optimization of collecting information in social networks.

[The impact of different provocations on ERK translocation and c-fos expression in neonatal cultured cardiomyocytes].

OBJECTIVE: To study the nuclear translocation of extracellular signal regulated kinase (ERK) and expression of c-fos mRNA under stimulation of AngII as well as the influence on the nuclear translocation of ERK with different interferences in neonatal cultured cardiomyocytes. METHODS: ERK in the cytoplasm or nucleus was observed by immunocytochemistry using specific antibody and the expression of c-fos was evaluated with RT-PCR technique. RESULTS: AngII (10(-6) mol/L) had the effect in promoting activation of ERK and then appeared in nucleus rapidly. The translocation process of ERK induced by AngII was blocked distinctly by Valsartan (10(-5) mol/L) and PD98059 (5 x 10(-5) mol/L), but not by CGP42112A (10(-5) mol/L). It was also found that Valsartan and PD98059 could inhibit the expression of c-fos in that process. CONCLUSION: The nuclear translocation of ERK might be a precondition for the inducement of c-fos expression.