On the validity of the definition of angular momentum in general relativity

We exam the validity of the definition of the ADM angular momentum without the parity assumption. Explicit examples of asymptotically flat hypersurfaces in the Minkowski spacetime with zero ADM energy-momentum vector and finite non-zero angular momentum vector are presented. We also discuss the Beig-\'O Murchadha-Regge-Teitelboim center of mass and study analogous examples in the Schwarzschild spacetime.Comment: References are updated, and typos and computational errors are corrected. Accepted by Ann. Henri Poincar

Research Performance, Collaboration, and Movement of Researchers in the Field of Business and Management: A Comparison between International and Domestic Migrants in East Asia

This study examines differences in research performance, international collaboration, and migration moves between two types of migrant researchers: international and domestic migrant researchers. The investigation focuses on 929 researchers in the field of business and management in four East Asian countries—China, Japan, South Korea, and Taiwan—and explores their scientific output and movements across types of institutions. The study uses bibliographic data from the Web of Science and Scopus author ID to disambiguate information across databases. The findings reveal that both international and domestic migrants demonstrate comparable productivity. Concerning publication quality, international migrants exhibit a higher citation impact, and researchers from Taiwan demonstrate the highest average number of citations per paper among the four countries. For international collaboration, international migrants report a higher rate of international collaboration than domestic migrants. The United States serves as the primary collaborative partner for migrant researchers from Taiwan, Japan, and South Korea, whereas China has a closer partnership with Hong Kong. Finally, international migrants demonstrate a higher frequency of migration, with an average of two moves per capita. This study provides empirical evidence for the value of scientific migration from the perspectives of international and domestic migrants in East Asian countries

Coarse-Grain Model for Lipid Bilayer Self-Assembly and Dynamics: Multiparticle Collision Description of the Solvent

A mesoscopic coarse-grain model for computationally-efficient simulations of biomembranes is presented. It combines molecular dynamics simulations for the lipids, modeled as elastic chains of beads, with multiparticle collision dynamics for the solvent. Self-assembly of a membrane from a uniform mixture of lipids is observed. Simulations at different temperatures demonstrate that it reproduces the gel and liquid phases of lipid bilayers. Investigations of lipid diffusion in different phases reveals a crossover from subdiffusion to normal diffusion at long times. Macroscopic membrane properties, such as stretching and bending elastic moduli, are determined directly from the mesoscopic simulations. Velocity correlation functions for membrane flows are determined and analyzed

Specifying angular momentum and center of mass for vacuum initial data sets

We show that it is possible to perturb arbitrary vacuum asymptotically flat spacetimes to new ones having exactly the same energy and linear momentum, but with center of mass and angular momentum equal to any preassigned values measured with respect to a fixed affine frame at infinity. This is in contrast to the axisymmetric situation where a bound on the angular momentum by the mass has been shown to hold for black hole solutions. Our construction involves changing the solution at the linear level in a shell near infinity, and perturbing to impose the vacuum constraint equations. The procedure involves the perturbation correction of an approximate solution which is given explicitly.Comment: (v2) a minor change in the introduction and a remark added after Theorem 2.1; (v3) final version, appeared in Comm. Math. Phy

BIBLIOMETRIC ANALYSIS OF ACUPUNCTURE RESEARCH FRONTS AND THEIR WORLDWIDE DISTRIBUTION OVER THREE DECADES

Background: Considerable research has been conducted on acupuncture worldwide. This study chronologically examined the changing features and research fronts of acupuncture and elucidated the differences among the six most productive countries. Methods: Bibliographic coupling is a powerful tool for identifying the research fronts of a field. Acupuncture-related publications worldwide and from the six most productive countries during 1983–2012 were retrieved from the Science Citation Index Expanded and Social Science Citation Index. To form the research fronts, the 100 most highly cited papers (HCPs) were clustered in terms of references shared. Results: The United States had the highest proportion of HCPs. The effectiveness of acupuncture in areas such as relieving neck and back pain, migraines and headaches, and knee osteoarthritis symptoms was a predominant topic. Initially, the endogenous opioid peptide system was the primary research focus in the acupuncture mechanism research; however, during 1993–2012, researchers focused more on the functional magnetic resonance imaging of brain activity. In addition, acupuncture use and prevalence, the attitudes of health practitioners, and the effects of expectancy and belief were also major topics. Researches from Western countries, including the United States, England, and Germany, showed more interest in clinical trials and economic- and ethics-related studies, whereas those from East Asian countries including China, Japan, and South Korea focused more on mechanism research. Conclusion: Western countries dominated the research fronts of acupuncture. The patterns of the research fronts varied worldwide, indicating continuity and innovation in research in each country

TCMGeneDIT: a database for associated traditional Chinese medicine, gene and disease information using text mining

<p>Abstract</p> <p>Background</p> <p>Traditional Chinese Medicine (TCM), a complementary and alternative medical system in Western countries, has been used to treat various diseases over thousands of years in East Asian countries. In recent years, many herbal medicines were found to exhibit a variety of effects through regulating a wide range of gene expressions or protein activities. As available TCM data continue to accumulate rapidly, an urgent need for exploring these resources systematically is imperative, so as to effectively utilize the large volume of literature.</p> <p>Methods</p> <p>TCM, gene, disease, biological pathway and protein-protein interaction information were collected from public databases. For association discovery, the TCM names, gene names, disease names, TCM ingredients and effects were used to annotate the literature corpus obtained from PubMed. The concept to mine entity associations was based on hypothesis testing and collocation analysis. The annotated corpus was processed with natural language processing tools and rule-based approaches were applied to the sentences for extracting the relations between TCM effecters and effects.</p> <p>Results</p> <p>We developed a database, TCMGeneDIT, to provide association information about TCMs, genes, diseases, TCM effects and TCM ingredients mined from vast amount of biomedical literature. Integrated protein-protein interaction and biological pathways information are also available for exploring the regulations of genes associated with TCM curative effects. In addition, the transitive relationships among genes, TCMs and diseases could be inferred through the shared intermediates. Furthermore, TCMGeneDIT is useful in understanding the possible therapeutic mechanisms of TCMs via gene regulations and deducing synergistic or antagonistic contributions of the prescription components to the overall therapeutic effects. The database is now available at <url>http://tcm.lifescience.ntu.edu.tw/</url>.</p> <p>Conclusion</p> <p>TCMGeneDIT is a unique database that offers diverse association information on TCMs. This database integrates TCMs with biomedical studies that would facilitate clinical research and elucidate the possible therapeutic mechanisms of TCMs and gene regulations.</p