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Hermitian geometry on the resolvent set(Ⅱ)

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Science China Mathematics 2021年第2期64卷 385-398页

作者： Ronald g.douglas Rongwei Yang Department of Mathematics Texas A&M UniversityCollege StationTX 77843USA School of Mathematical Sciences Tianjin Normal UniversityTianjin 300387China Department of Mathematics and Statistics State University of New York at AlbanyAlbanyNY 12222USA

For an element A in a unital C^(*)-algebra B,the operator-valued 1-formωA(z)=(z-A)^(-1) dz is analytic on the resolvent setρ(A),which plays an important role in the functional calculus of *** paper defines a class of Hermitian metrics onρ(A)through the coupling of the operator-valued(1,1)-formΩA=-ωA^(*)∧ωA with tracial and vector *** main goal is to study the connection between A and the properties of the metric concerning curvature,arc length,completeness and singularity.A particular example is when A is quasi-nilpotent,in which case the metric lives on the punctured complex plane C\{0}.The notion of the power set is defined to gauge the"blow-up"rate of the metric at 0,and examples are given to indicate a likely link with A’s hyper-invariant subspaces.

关键词： C^(*)-algebra Hermitian metric curvature arc length Fuglede-Kadison determinant quasi-nilpotent operator power set

The paternal epigenome and embryogenesis： poising mechanisms for development

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Asian Journal of Andrology 2011年第1期13卷 76-80页

作者： Timothy g Jenkins douglas T Carrell Andrology and IVF Laboratories Department of Surgery University of Utah Salt Lake City UT 84108 USA Department of Obstetrics and gynecology University of Utah School of Medicine Salt Lake City UT 84108 USA Department of Physiology University of Utah School of Medicine Salt Lake City UT 84108 USA

The scope of paternal contributions during early embryonic development has long been considered limited. Dramatic changes in chromatin structure throughout spermatogenesis have been thought to leave the sperm void of complex layers of epigenetic regulation over the DNA blueprint, thus leaving the balance of that regulation to the oocyte. However, recent work in the fields of epigenetics and male factor infertility has placed this long-held, and now controversial dogma, in a new light. Elegant studies investigating chromatin and epigenetic modifications in the developing sperm cell have provided new insights that may establish a more critical role for the paternal epigenome in the developing embryo. DNA methylation, histone tail modifications, targeted histone retention and protamine incorporation into the chromatin have great influence in the developing sperm cell. Perturbations in the establishment and/or maintenance of any of these epigenetic marks have been demonstrated to affect fertility status, ranging in severity from mild to catastrophic. Sperm require this myriad of chromatin structural changes not only to serve a protective role to DNA throughout spermatogenesis and future delivery to the egg, but also, it appears, to contribute to the developmental program of the future embryo. This review will focus on our current understanding of the epigenetics of sperm. We will discuss sperm-specific chromatin modifications that result in genes essential to development being poised for activation early in embryonic development, the disruption of which may result in reduced fecundity.

关键词： chromatin DNA methylation embryogenesis epigenetics histone modification male infertility

Solid state interfacial reactions in electrodeposited Ni/Sn couples

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International Journal of Minerals,Metallurgy and Materials 2010年第4期17卷 459-463页

作者： Wen-ming Tang An-qiang He Qi Liu douglas-g. Ivey Department of Materials Science and Engineering Hefei University of Technology Hefei 230009 China Department of Chemical and Materials Engineering University of Alberta Edmonton T6G 2G6 Canada

Ni/Sn couples, prepared by sequentially electroplating Ni layers and Sn layers on metallized Si wafers, were employed to study the microstructures and growth kinetics of Ni-Sn intermediate phases, when the Ni/Sn couples were aged at room temperature or armealed at temperatures from 150 to 225℃ for various times. The results show that the NiSn phase and Ni3Sn4 phase are formed, respectively, in the aged couples and annealed couples. The Ni3Sn4 layer is continuously distributed between the Ni and Sn sides in the annealed Ni/Sn couples. The Ni3Sn4 growth follows parabolic growth kinetics with an apparent activation energy of 39.0 kJ/mol.

关键词： electrodeposition solid state reaction diffusion microstructure kinetics

Enteral stents for the management of malignant colorectal obstruction

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World Journal of gastroenterology 2014年第37期20卷 13239-13245页

作者： Jeremy Kaplan Anna Strongin douglas g Adler Ali A Siddiqui Division of gastroenterology and Hepatology Department of Internal Medi-cineThomas Jefferson University Hospital Division of gastroenterology and Hepatology Department of Internal MedicineUniversity of Utah

Colorectal cancer (CRC) is the 3rd most common cancer in the United States with more than 10000 new cases diagnosed annually. Approximately 20% of patients with CRC will have distant metastasis at time of diagnosis, making them poor candidates for primary surgical resection. Similarly, 8%-25% of patients with CRC will present with bowel obstruction and will require palliative therapy. Emergent surgical decompression has a high mortality and morbidity, and often leads to a colostomy which impairs the patient’s quality of life. In the last decade, there has been an increasing use of colonic stents for palliative therapy to relieve malignant colonic obstruction. Colonic stents have been shown to be effective and safe to treat obstruction from CRC, and are now the therapy of choice in this scenario. In the setting of an acute bowel obstruction in patients with potentially resectable colon cancer, stents may be used to delay surgery and thus allow for decompression, adequate bowel preparation, and optimization of the patient’s condition for curative surgical intervention. An overall complication rate (major and minor) of up to 25% has been associated with the procedure. Long term failure of stents may result from stent migration and tumor ingrowth. In the majority of cases, repeat stenting or surgical intervention can successfully overcome these adverse effects.

关键词： Colorectal cancer Colonic obstruction Self expanding metal stents Intestinal obstruction/etiology Intestinal obstruction/mortality Intestinal obstruction/surgery Survival rate

Forests,atmospheric water and an uncertain future: the new biology of the global water cycle

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Forest Ecosystems 2018年第3期5卷 236-257页

作者： douglas Sheil Faculty of Environmental Sciences and Natural Resource Management(MINA) Norwegian University of Life Sciences (NMBU)

Theory and evidence indicate that trees and other vegetation influence the atmospheric water-cycle in various *** influences are more important, more complex, and more poorly characterised than is widely *** there is little doubt that changes in tree cover will impact the water-cycle, the wider consequences remain difficult to predict as the underlying relationships and processes remain poorly characterised. Nonetheless, as forests are vulnerable to human activities, these linked aspects of the water-cycle are also at risk and the potential consequences of large scale forest loss are severe. Here, for non-specialist readers, I review our knowledge of the links between vegetation-cover and climate with a focus on forests and rain(precipitation). I highlight advances, uncertainties and research opportunities. There are significant shortcomings in our understanding of the atmospheric hydrological cycle and of its representation in climate models. A better understanding of the role of vegetation and tree-cover wil reduce some of these shortcomings. I outline and il ustrate various research themes where these advances may be *** themes include the biology of evaporation, aerosols and atmospheric motion, as well as the processes that determine monsoons and diurnal precipitation cycles. A novel theory—the ‘biotic pump’—suggests that evaporation and condensation can exert a major influence over atmospheric dynamics. This theory explains how high rainfall can be maintained within those continental land-masses that are sufficiently forested. Feedbacks within many of these processes can result in non-linear behaviours and the potential for dramatic changes as a result of forest loss(or gain): for example, switching from a wet to a dry local climate(or visa-versa). Much remains unknown and multiple research disciplines are needed to address this: forest scientists and other biologists have a major role to *** ideas, methods and data offer opportun

关键词： Biotic pump Climate Condensation Evaporation Ice-nucleation Transpiration gCM Vapour Water-cycle

Assessing the effects of surface-bound humic acid on the phototoxicity of anatase and rutile TiO_2 nanoparticles in vitro

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Journal of Environmental Sciences 2016年第4期28卷 50-60页

作者： Xiaojia He Sabrieon Sanders Winfred g.Aker Yunfeng Lin Jessica douglas Huey-min Hwang Department of Biology Jackson State University Department of Biological Sciences Alcorn State University Environmental Science Ph.D.Program Jackson State University Department of Chemistry and Biochemistry Jackson State University School of Polymers and High Performance Materials The University of Southern Mississippi

In this study,the cytotoxicity of two different crystal phases of TiO2 nanoparticles,with surface modification by humic acid（HA）,to Escherichia coli,was *** physicochemical properties of TiO2 nanoparticles were thoroughly *** different initial concentrations,namely 50,100,and 200 ppm,of HA were used for synthesis of HA coated TiO2 nanoparticles（denoted as A/RHA50,A/RHA100,and A/RHA200,respectively）.Results indicate that rutile（LC50（concentration that causes 50%mortality compared the control group）=6.5）was more toxic than anatase（LC50=278.8）under simulated sunlight（SSL）irradiation,possibly due to an extremely narrow band *** is noted that HA coating increased the toxicity of anatase,but decreased that of ***,AHA50 and RHA50had the biggest differences compared to uncoated anatase and rutile with LC50of 201.9 and21.6,*** then investigated the formation of reactive oxygen species（ROS）by TiO2 nanoparticles in terms of hydroxyl radicals（OH）and superoxide anions（O2^-）.Data suggested that O2^- was the main ROS that accounted for the higher toxicity of rutile upon SSL *** also observed that HA coating decreased the generation of OH and O2^- on rutile,but increased O2^- formation on *** from TEM analysis also indicated that HA coated rutile tended to be attached to the surface of *** more than anatase.

关键词： TiO2nanoparticles Escherichia coli Humic acid Crystallinity Surface coating

IMPROVINg THE LINK BETWEEN THE LEED gREEN BUILDINg LABEL AND A BUILDINg’S ENERgY-RELATED ENVIRONMENTAL METRICS

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Journal of green Building 2008年第2期3卷 85-105页

作者： g.Christopher Wedding douglas Crawford-Brown Cherokee Investment Services 111 East Hargett StreetSuite 300RaleighNorth CarolinaUSA 27601. Pell Frischmann 5 Manchester SquareLondonUK W1A 1AU

The US green Building Council’s (USgBC) Leadership in Energy and Environmental Design (LEED) green buildingrating program has grown from a little known tool for market change to a label and brand relied upon by many ofthe largest players in real estate. It now serves as an indicator of sustainability and an instrument for environmentalmanagement. While LEED-certifi ed buildings tend to offer greater environmental benefi ts than their conventionalcounterparts, research and experience shows that the variation in and magnitude of these benefi ts varies, even amongbuildings of the same LEED certifi cation level. In light of growing concerns about “greenwashing” and the liabilityassociated with questionable environmental declarations, it is important to ensure that users of LEED and similarcertifi cation programs receive a set of benefi ts comparable to those expected. With a focus on energy-related issues, thisresearch (1) highlights evidence of the inconsistency between the expected and actual benefi ts of LEED buildings, (2)suggests revisions to LEED’s Energy & Atmosphere (EA) section to reduce the variation and magnitude in the energyrelatedenvironmental impacts from LEED buildings, (3) quantifi es this reduction in variation and magnitude ofimpacts using Monte Carlo analyses and probabilistic models created specifi cally for this research, (4) compares carbondioxide emissions from LEED buildings to the Architecture 2030 Challenge goals and (5) quantifi es the importanceof scoring LEED buildings on a per capita normalized basis. This research is a follow-up piece to the authors’ previouswork published in the Journal of green Building (Wedding and Crawford-Brown 2007).

关键词： green building USgBC LEED Monte Carlo analysis greenwashing probabilistic modeling carbon offsets green power Architecture 2030 Challenge

AN ANALYSIS OF VARIATION IN THE ENERgY-RELATED ENVIRONMENTAL IMPACTS OF LEED CERTIFIED BUILDINgS

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Journal of green Building 2007年第4期2卷 151-170页

作者： g.Christopher Wedding douglas Crawford-Brown Cherokee Investment Services USA Institute for the Environment University of North Carolina at Chapel HillUSA

The US green Building Council’s(USgBC)LEED guidelines have become the dominant third-party certification program for“green”buildings in the *** that buildings use 37%of all energy and 68%of all electricity while contributing substantially to air emission,waste generation,and water consumption issues in the US,one of LEED’s purposes is to address the environmental impacts of energy use in *** research analyzes(1)how well the LEED guidelines measure these impacts and(2)which parameters create the most variation among these *** impacts here refer to emissions of carbon dioxide,nitrogen oxides,sulfur dioxide,mercury,and par-ticulate matter(PM10);solid waste;nuclear waste;and water *** data from the US Department of Energy,the National Renewable Energy Laboratory,the US EPA Energy Star program,and the USgBC,among others,models using Monte Carlo analysis were created to simulate the range of impacts of LEED-certified *** metrics and statistics were calculated to highlight the significance of variation in these *** re-search needs and implications of the results for LEED version 3.0 are also discussed.

关键词： LEED USgBC green building Monte Carlo analysis energy environmental impacts carbon dioxide particulate matter nitrogen oxides sulfur dioxides mercury nuclear waste solid waste water consumption

Interpreting forest diversity-productivity relationships:volume values,disturbance histories and alternative inferences

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Forest Ecosystems 2020年第1期7卷 64-75页

作者： douglas Sheil Frans Bongers Faculty of Environmental Sciences and Natural Resource Management(MINA) Norwegian University of Life Sciences(NMBU)Box 50031432 AsNorway Forest Ecology and Forest Management group Wageningen University&ResearchPO Box 476700 AA WageningenThe Netherlands

Understanding the relationship between stand-level tree diversity and productivity has the potential to inform the science and management of *** shows that plant diversity-productivity relationships are challenging to interpret—and this remains true for the study of forests using non-experimental field *** we highlight pitfalls regarding the analyses and interpretation of such *** examine three themes:1)the nature and measurement of ecological productivity and related values;2)the role of stand history and disturbance in explaining forest characteristics;and 3)the interpretation of any *** show that volume production and true productivity are distinct,and neither is a demonstrated proxy for economic *** stand characteristics,including diversity,volume growth and productivity,vary intrinsically with succession and stand *** should be characterising these relationships rather than ignoring or eliminating *** to do so may lead to misleading *** illustrate,we examine the study which prompted our concerns—Liang et al.(Science 354:aaf8957,2016)—which developed a sophisticated global analysis to infer a worldwide positive effect of biodiversity(tree species richness)on“forest productivity”(stand level wood volume production).Existing data should be able to address many of our *** evaluations will improve understanding.

关键词： Causation Correlation Diversity Inference Productivity Richness Tree-growth Wood-density