This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere geometry.The emphasis is on results that relate Dupin h...This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere geometry.The emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in spheres.Along with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of S^(n)(or R^(n)),are described in detail.The paper also contains several important constructions of Dupin hypersurfaces with certain special properties.展开更多
This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolit...This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolithographic biofabrication method with a photomask featuring hexagonal units,liver cells,including a human hepatic cell line(HepG2-C3A)and a human hepatic stellate cell line(LX-2)were embedded in gelatin methacryloyl hydrogel.Hepatic steatosis was induced by supraphysiological concentration of free fatty acids;hepatic fibrosis was induced by transforming growth factor-β1.Induction of steatosis was confirmed by Oil Red O and BODIPY staining and was inhibited with toyocamycin and obeticholic acid.Induction of fibrosis was confirmed by immunostaining for collagen type I and alpha smooth muscle actin and inhibited by rapamycin and curcumin treatment.This model was further preliminarily validated using primary human hepatocytes in a similar setup.These constructs provide a viable,biologically relevant,and higher throughput model of hepatic steatosis and fibrosis and may facilitate the study of the mechanisms of disease and testing of liver-directed drugs.展开更多
Infinite sequences defined with a finite alphabet are studied and it is shown that the set of sequences with bounded run-length has measure zero with respect to the Borel measure.Such sequences arise in many applicati...Infinite sequences defined with a finite alphabet are studied and it is shown that the set of sequences with bounded run-length has measure zero with respect to the Borel measure.Such sequences arise in many applications including digitization of certain linear systems involving flows on the circle and 2-torus,large scale simulation,and cryptology.They are basic objects of study in ergodic theory.展开更多
Though well-known for its simplicity and efficiency, Newton’s method applied to a complex polynomial can fail quite miserably, even on a relatively large open set of initial guesses. In this work, we present some ana...Though well-known for its simplicity and efficiency, Newton’s method applied to a complex polynomial can fail quite miserably, even on a relatively large open set of initial guesses. In this work, we present some analytic and numerical results for Newton’s method applied to the complex quartic family where is a parameter. The symmetric location of the roots of?allows for some easy reductions. In particular, when λ is either real or purely imaginary, standard techniques from real dynamical systems theory can be employed for rigorous analysis. Classifying those λ-values where Newton’s method fails on an open set leads to complex and aesthetically intriguing geometry in the λ-parameter plane, complete with fractal-like figures such as Mandelbrot-like sets, tricorns and swallows.展开更多
The macroscopic and microscopic magnetic properties for amorphous and nanocrystalline Fe73.5Cu1Nb3-Si13.5B9 powder have been investigated and their giant mag-neto-impedance (GMI) effect is reported for the first time....The macroscopic and microscopic magnetic properties for amorphous and nanocrystalline Fe73.5Cu1Nb3-Si13.5B9 powder have been investigated and their giant mag-neto-impedance (GMI) effect is reported for the first time. The experimental results show that powder sample annealed at 510℃ possesses the optimum soft magnetic properties. However, the maximum longitudinally driven GMI (LDGMI) ratio (about 52%) is found in the sample annealed at 600℃. This means that the LDGMI ratio depends on not only their magnetic properties but also their electric properties.展开更多
We examine three simple linear systems from the viewpoint of ergodic theory.We digitize the output and record only the sign of the output at integer times.We show that even with this minimal output we can recover impo...We examine three simple linear systems from the viewpoint of ergodic theory.We digitize the output and record only the sign of the output at integer times.We show that even with this minimal output we can recover important information about the systems.In particular,for a two-dimensional system viewed as a fow on the circle,we can determine the rate of rotation.We then use these results to determine the slope of the trajectories for constant irrational fow on the two-dimensional torus.To achieve this,we randomize the system by partitioning the state space and only recording which partition the state is in at each integer time.We show directly that these systems have entropy zero.Finally,we examine two four-dimensional systems and reduce them to the study of linear fows on the two-dimensional torus.展开更多
This article explores the history of the Qingxi Ironworks in late Qing Guizhou.Instead of focusing on state-centered industrialization or technology transfer and scientific knowledge in Qing mining and coal enterprise...This article explores the history of the Qingxi Ironworks in late Qing Guizhou.Instead of focusing on state-centered industrialization or technology transfer and scientific knowledge in Qing mining and coal enterprises,this study focuses on the individual ambitions and identity construction of two returned diplomats——Chen Jitong and Chen Mingyuan—who sought to claim authority over a mining interest in China's southwest interior.By leveraging their knowledge of the West to serve as intermediaries between state and foreign commercial interests,these cosmopolitan yet marginalized elites sought to convert their foreign expertise and avowed commitment to "selCstrengthening" into new forms of social and political capital.An examination of the personal networks and written accounts surrounding their entrepreneurial ventures sheds light on the opportunities and challenges experienced by a generation of "foreign affkirs" experts in repositioning themselves within the transforming Qing polity through participation in industrialization projects.展开更多
Roger Ames＇s Confucian Role Ethics.＂ A Vocabulary, is an ambitious and significant exposition of Confucianism. Despite my disagreements with some of Ames＇s interpretation of Confucius, I have both enjoyed this book...Roger Ames＇s Confucian Role Ethics.＂ A Vocabulary, is an ambitious and significant exposition of Confucianism. Despite my disagreements with some of Ames＇s interpretation of Confucius, I have both enjoyed this book and learned a lot from it. Due to the limited scope of this review, I restrict it to an evaluation of Ames＇s exposition of the highest Confucian virtue, ren 4Y-. By Ames＇s own account, this book does not offer an alternative ethical theory, but a Confucian account of human flourishing, which begins with the roles and relations in the family. These roles and relations provide the basis of morality for Ames, as they not only constitute us but also enable us to become virtuous, respond appropriately in any situation, and enhance our relationships. In Ames＇s own words, we are ＂interrelated persons living a multiplicity of roles that constitute who we are, and ... allow us to pursue a unique distinctiveness and virtuosity in our conduct＂ （122） and ＂Confucian role ethics takes the substance of morality to be nothing more or less than positive growth in the constitutive relations of any particular situation＂ （258）.展开更多
Aims The mechanism by which species richness affects variation in ecosystem functioning both within and among ecosystems remains a key question at the interface of community and ecosystem ecology.Statistical averaging...Aims The mechanism by which species richness affects variation in ecosystem functioning both within and among ecosystems remains a key question at the interface of community and ecosystem ecology.Statistical averaging(the smoothing of average system performance via consideration of additional components)and the insurance effect(reduced variation in system performance by inclusion of asynchronously varying components)predict that more diverse communities should vary less both between replicates and internally.We experimentally tested these theories in small plant assemblages.Methods We constructed plant assemblages modeled after old-field plant communities.We varied species richness,species composition and initial densities while holding functional group richness constant in replicate assemblages under glasshouse conditions.Important findings The inverse of the coefficient of variation of aboveground biomass production,a proxy measure of reliability,increased with higher diversity when examined at the level of the assemblage(i.e.among-replicate assemblages)but not at the levels of functional group or species.These stabilizing processes were weakest in low-diversity,low-density assemblages.This experiment demonstrates the utility of hierarchical analysis of ecosystem reliability at the assemblage,functional group and species level.展开更多
文摘This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere geometry.The emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in spheres.Along with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of S^(n)(or R^(n)),are described in detail.The paper also contains several important constructions of Dupin hypersurfaces with certain special properties.
基金YSZ received funding from National Institutes of Health(K99CA201603,R00CA201603,R21EB025270,R21EB026175,R01EB028143,R03EB027984)National Science Foundation(1935105)+1 种基金Brigham Research Institute New England Anti-Vivisection Foundation,and American Fund for Alternatives to Animal Research(AFAAR).AZ received funding from National Institutes of Health(K08DK113244,R01MD012579)SD received funding from National Institutes of Health(R01MD012579-UT20664DS).
文摘This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolithographic biofabrication method with a photomask featuring hexagonal units,liver cells,including a human hepatic cell line(HepG2-C3A)and a human hepatic stellate cell line(LX-2)were embedded in gelatin methacryloyl hydrogel.Hepatic steatosis was induced by supraphysiological concentration of free fatty acids;hepatic fibrosis was induced by transforming growth factor-β1.Induction of steatosis was confirmed by Oil Red O and BODIPY staining and was inhibited with toyocamycin and obeticholic acid.Induction of fibrosis was confirmed by immunostaining for collagen type I and alpha smooth muscle actin and inhibited by rapamycin and curcumin treatment.This model was further preliminarily validated using primary human hepatocytes in a similar setup.These constructs provide a viable,biologically relevant,and higher throughput model of hepatic steatosis and fibrosis and may facilitate the study of the mechanisms of disease and testing of liver-directed drugs.
文摘Infinite sequences defined with a finite alphabet are studied and it is shown that the set of sequences with bounded run-length has measure zero with respect to the Borel measure.Such sequences arise in many applications including digitization of certain linear systems involving flows on the circle and 2-torus,large scale simulation,and cryptology.They are basic objects of study in ergodic theory.
文摘Though well-known for its simplicity and efficiency, Newton’s method applied to a complex polynomial can fail quite miserably, even on a relatively large open set of initial guesses. In this work, we present some analytic and numerical results for Newton’s method applied to the complex quartic family where is a parameter. The symmetric location of the roots of?allows for some easy reductions. In particular, when λ is either real or purely imaginary, standard techniques from real dynamical systems theory can be employed for rigorous analysis. Classifying those λ-values where Newton’s method fails on an open set leads to complex and aesthetically intriguing geometry in the λ-parameter plane, complete with fractal-like figures such as Mandelbrot-like sets, tricorns and swallows.
基金This work was supported by the State Climbing Project(Grant No.95A-08NMS)the New Materials Center of Shanghai(Grant No.99JC14017).
文摘The macroscopic and microscopic magnetic properties for amorphous and nanocrystalline Fe73.5Cu1Nb3-Si13.5B9 powder have been investigated and their giant mag-neto-impedance (GMI) effect is reported for the first time. The experimental results show that powder sample annealed at 510℃ possesses the optimum soft magnetic properties. However, the maximum longitudinally driven GMI (LDGMI) ratio (about 52%) is found in the sample annealed at 600℃. This means that the LDGMI ratio depends on not only their magnetic properties but also their electric properties.
文摘We examine three simple linear systems from the viewpoint of ergodic theory.We digitize the output and record only the sign of the output at integer times.We show that even with this minimal output we can recover important information about the systems.In particular,for a two-dimensional system viewed as a fow on the circle,we can determine the rate of rotation.We then use these results to determine the slope of the trajectories for constant irrational fow on the two-dimensional torus.To achieve this,we randomize the system by partitioning the state space and only recording which partition the state is in at each integer time.We show directly that these systems have entropy zero.Finally,we examine two four-dimensional systems and reduce them to the study of linear fows on the two-dimensional torus.
文摘This article explores the history of the Qingxi Ironworks in late Qing Guizhou.Instead of focusing on state-centered industrialization or technology transfer and scientific knowledge in Qing mining and coal enterprises,this study focuses on the individual ambitions and identity construction of two returned diplomats——Chen Jitong and Chen Mingyuan—who sought to claim authority over a mining interest in China's southwest interior.By leveraging their knowledge of the West to serve as intermediaries between state and foreign commercial interests,these cosmopolitan yet marginalized elites sought to convert their foreign expertise and avowed commitment to "selCstrengthening" into new forms of social and political capital.An examination of the personal networks and written accounts surrounding their entrepreneurial ventures sheds light on the opportunities and challenges experienced by a generation of "foreign affkirs" experts in repositioning themselves within the transforming Qing polity through participation in industrialization projects.
文摘Roger Ames＇s Confucian Role Ethics.＂ A Vocabulary, is an ambitious and significant exposition of Confucianism. Despite my disagreements with some of Ames＇s interpretation of Confucius, I have both enjoyed this book and learned a lot from it. Due to the limited scope of this review, I restrict it to an evaluation of Ames＇s exposition of the highest Confucian virtue, ren 4Y-. By Ames＇s own account, this book does not offer an alternative ethical theory, but a Confucian account of human flourishing, which begins with the roles and relations in the family. These roles and relations provide the basis of morality for Ames, as they not only constitute us but also enable us to become virtuous, respond appropriately in any situation, and enhance our relationships. In Ames＇s own words, we are ＂interrelated persons living a multiplicity of roles that constitute who we are, and ... allow us to pursue a unique distinctiveness and virtuosity in our conduct＂ （122） and ＂Confucian role ethics takes the substance of morality to be nothing more or less than positive growth in the constitutive relations of any particular situation＂ （258）.
基金supported by the State Key Basic Research and Development Plan(2002CB412502)the Natural Science Foundation of China(90211016)+1 种基金with additional support from Harvard Forest LTER and the Andrew Mellon Foundation.B.S.was supported by the Swiss National Science Foundation(nr.31-65224.01)the Deutsche Forschungsgemeinschaft(nr.FOR 456-WE 2618/6-1 to WW Weisser).
文摘Aims The mechanism by which species richness affects variation in ecosystem functioning both within and among ecosystems remains a key question at the interface of community and ecosystem ecology.Statistical averaging(the smoothing of average system performance via consideration of additional components)and the insurance effect(reduced variation in system performance by inclusion of asynchronously varying components)predict that more diverse communities should vary less both between replicates and internally.We experimentally tested these theories in small plant assemblages.Methods We constructed plant assemblages modeled after old-field plant communities.We varied species richness,species composition and initial densities while holding functional group richness constant in replicate assemblages under glasshouse conditions.Important findings The inverse of the coefficient of variation of aboveground biomass production,a proxy measure of reliability,increased with higher diversity when examined at the level of the assemblage(i.e.among-replicate assemblages)but not at the levels of functional group or species.These stabilizing processes were weakest in low-diversity,low-density assemblages.This experiment demonstrates the utility of hierarchical analysis of ecosystem reliability at the assemblage,functional group and species level.
