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From contraction to gene expression:nanojunctions of the sarco/endoplasmic reticulum deliver site-and function-specific calcium signals

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Science China(Life Sciences) 2016年第8期59卷 749-763页

作者： a.mark evans Nicola Fameli Oluseye A.Ogunbayo Jingxian Duan Jorge Navarro-Dorado Centre for Integrative Physiology College of Medicine and Veterinary MedicineHugh Robson BuildingUniversity of EdinburghEdinburgh EH8 9XDUK Institute of Biophysics Medical University of GrazGraz 8010Austria

Calcium signals determine, for example, smooth muscle contraction and changes in gene expression. How calcium signals select for these processes is enigmatic. We build on the "panjunctional sarcoplasmic reticulum" hypothesis, describing our view that different calcium pumps and release channels, with different kinetics and affinities for calcium, are strategically positioned within nanojunctions of the SR and help demarcate their respective cytoplasmic nanodomains. SERCA2 b and Ry R1 are preferentially targeted to the sarcoplasmic reticulum(SR) proximal to the plasma membrane(PM), i.e., to the superficial buffer barrier formed by PM-SR nanojunctions, and support vasodilation. In marked contrast, SERCA2 a may be entirely restricted to the deep, perinuclear SR and may supply calcium to this sub-compartment in support of vasoconstriction. Ry R3 is also preferentially targeted to the perinuclear SR, where its clusters associate with lysosome-SR nanojunctions. The distribution of Ry R2 is more widespread and extends from this region to the wider cell. Therefore, perinuclear Ry R3 s most likely support the initiation of global calcium waves at L-SR junctions, which subsequently propagate by calcium-induced calcium release via Ry R2 in order to elicit contraction. Data also suggest that unique SERCA and Ry R are preferentially targeted to invaginations of the nuclear membrane. Site- and function-specific calcium signals may thus arise to modulate stimulus-response coupling and transcriptional cascades.

关键词： calcium nanojunction ryanodine receptor sarco/endoplasmic reticulum calcium ATPase smooth muscle gene expression contraction

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From contraction to gene expression: nanojunctions of the sarcoplasmic reticulum deliver function-specific calcium signals

From contraction to gene expression: nanojunctions of the sa...

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第十一届全国钙信号和细胞功能研讨会

作者： a.mark evans Centre for Integrative Physiology College of Medicine and Veterinary Medicine Hugh Robson Building University of Edinburgh

Calcium signals determine smooth muscle contraction and the switch from acontractile to a migratory-proliferative phenotype（s）, which requires changes in geneexpression. However the mechanism by which different calcium signals select for these processes is enigmatic. We have shown that SERCA2 b and Ry R1 arepreferentially targeted to the sarcoplasmic reticulum（SR） proximal to the plasmamembrane（PM;Clark et al., 2010）, i.e., to the superficial buffer barrier formed by PM-SR nanojunctions（van Breemen et al., 2013）, and support vasodilation. Here, increases in SERCA2 b activity may remove calcium from the deeper cytoplasm to the superficial SR, from which calcium sparks may be released into the PM-SR junction via Ry R1 to activate PM resident BKCa channels, driving hyperpolarisation（Boittin et al., 2003）, removal of calcium from the cell by forward mode NCX activity and ultimately vasodilation（Boittin et al., 2003;Clark et al., 2010）. In marked contrast, SERCA2 a is entirely restricted to the deep, perinuclear SR（Clark et al.,2010） and may function to recycle calcium into this subcompartment in support of vasoconstriction（Dipp ＆ evans, 2001;Kinnear et al., 2004;Clark et al., 2010）. Importantly, Ry R3 is also preferentially targeted to the perinuclear SR and associated lysosome-SR nanojunctions（Kinnear et al., 2004, Kinnear et al., 2008）, while the distribution of Ry R2 is more widespread and extends from this region to the wider cell（Kinnear et al., 2008;Clark et al., 2010）. We therefore proposed that perinuclear clusters of Ry R3 may act as an initiation site for propagating calcium waves and contraction（Dipp ＆ evans, 2001;Kinnear et al., 2008）. Thereafter, by calcium-induced calcium release, Ry R2 may carry propagating calcium waves away from perinuclear clusters of Ry R3 and across the myofilaments to enhance myocyte contraction（Kinnear et al., 2008;Clark et al., 2010）. A third subtype of SERCA pump in PASMCs, namely SERCA1, and Ry R1 preferentially lines invaginati

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The Inspection of Level Crossing Rails Using Guided Waves

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Journal of Traffic and Transportation Engineering 2023年第1期11卷 29-35页

作者： mark evans Guided Ultrasonic Ltd Brentford TW88HQUK

Level crossing rails are high risk areas due to the combination of the limited effectiveness of current inspection methods and high corrosion rates which often *** paper discusses the current UK standard practices for the periodic inspection of level crossing rails using visual(VT)and conventional ultrasonic(UT)*** limitations of these methods are discussed and how these limitations affect the overall maintenance program for level crossings.A new inspection method,guided wave testing(GWT)is then described with particular emphasis on its advantages for inspecting level ***,a review is given of the current Network Rail trial of GWT on level crossings using the G-Scan system,with representative results which demonstrate the effectiveness of GWT for this application.

关键词： Rails guided waves GWT

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Searching for a route to synthesize in situ epitaxial Pr_(2)Ir_(2)O_(7) thin films with thermodynamic methods

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npj Computational Materials 2021年第1期7卷 1320-1325页

作者： Lu Guo Shun-Li Shang Neil Campbell Paul G.evans mark Rzchowski Zi-Kui Liu Chang-Beom Eom Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWisconsinUSA Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA Department of Physics University of Wisconsin-MadisonMadisonWisconsinUSA

In situ growth of pyrochlore iridate thin films has been a long-standing challenge due to the low reactivity of Ir at low temperatures and the vaporization of volatile gas species such as IrO_(3)(g)and IrO_(2)(g)at high temperatures and high PO_(2).To address this challenge,we combine thermodynamic analysis of the Pr-Ir-O_(2)system with experimental results from the conventional physical vapor deposition(PVD)technique of *** results indicate that only high growth temperatures yield films with crystallinity sufficient for utilizing and tailoring the desired topological electronic properties and the in situ synthesis of Pr_(2)Ir_(2)O_(7)thin films is fettered by the inability to grow with PO_(2)on the order of 10 Torr at high temperatures,a limitation inherent to the PVD ***,we suggest techniques capable of supplying high partial pressure of key species during deposition,in particular chemical vapor deposition(CVD),as a route to synthesis of Pr_(2)Ir_(2)O_(7).

关键词： process thermodynamic synthesis

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New Identities for Weak KAM Theory(For Haim Brezis,in continuing admiration)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 379-392页

作者： Lawrence Craig evans Department of Mathematics University of CaliforniaBerkeleyUSA.

This paper records for the Hamiltonian H =1/2|p|~2+ W(x) some old and new identities relevant for the PDE/variational approach to weak KAM theory.

关键词： Weak KAM theory, Effective Hamiltonian, Hamiltonian dynamics

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Modeling the Spatial Distribution of Soil Heavy Metals Using Random Forest Model—A Case Study of Nairobi and Thirirka Rivers’ Confluence

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Journal of Geographic Information System 2020年第6期12卷 597-619页

作者： evans Omondi mark Boitt Department of Geomatic Engineering and Geospatial Information Systems Jomo Kenyatta University of Agriculture and Technology Nairobi Kenya

Modeling the spatial distribution of soil heavy metals is important in determining the safety of contaminated soils for agricultural use. This study utilized 60 topsoil samples (0 - 30 cm), multispectral images (Sentinel-2), spectral indices, and ancillary data to model the spatial distribution of heavy metals in the soils along the Nairobi River. The model was generated using the Random Forest package in R. Using R2 to assess the prediction accuracy, the Random Forest model generated satisfactory results for all the elements. It also ranked the variables in order of their importance in the overall prediction. Spectral indices were the most important variables within the rankings. From the predicted topsoil maps, there were high concentrations of Cadmium on the easterly end of the river. Cadmium is an impurity in detergents, and this section is in close proximity to the Nairobi water sewerage plant, which could be a direct source of Cadmium. Some farms had Zinc levels which were above the World Health Organization recommended limit. The Random Forest model performed satisfactorily. However, the predictions can be improved further if the spatial resolutions of the various variables are increased and through the addition of more predictor variables.

关键词： Random Forest Sentinel 2 Heavy Metals Spectral Indices Spatial Modeling

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Social Computing Unhinged

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Journal of Social Computing 2020年第1期1卷 1-13页

作者： James evans University of Chicago ChicagoIL 60637and Santa Fe InstituteSanta FeNM 87501USA.

Social computing is ubiquitous and intensifying in the 21st *** used to reference computational augmentation of social interaction through collaborative filtering,social media,wikis,and crowdsourcing,here I propose to expand the concept to cover the complete dynamic interface between social interaction and computation,including computationally enhanced sociality and social science,socially enhanced computing and computer science,and their increasingly complex combination for mutual *** recommends that we reimagine Computational Social Science as Social Computing,not merely using computational tools to make sense of the contemporary explosion of social data,but also recognizing societies as emergent computers of more or less collective intelligence,innovation and *** further proposes we imagine a socially inspired computer science that takes these insights into account as we build machines not merely to substitute for human cognition,but radically complement *** leads to a vision of social computing as an extreme form of human computer interaction,whereby machines and persons recursively combine to augment one another in generating collective intelligence,enhanced knowledge,and other social goods unattainable without each *** the example of science and technology,I illustrate how progress in each of these areas unleash advances in the others and the beneficial relationship between the technology and science of social computing,which reveals limits of sociality and computation,and stimulates our imagination about how they can reach past those limits together.

关键词： social computing complex systems computer supported cooperative work computational social science artificial intelligence human computer interaction human-centered computing

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Review： Sugar beets as a substitute for grain for lactating dairy cattle

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Journal of Animal Science and Biotechnology 2017年第3期8卷 539-548页

作者： Essi evans Ulrike Messerschmidt Technical Advisory Services Inc 64 Scugog St Bowmanville ON L1C3J Canada KWS SAAT SE Grimsehlstr. 31 P.O. Box 1463D-37555 Einbeck Germany

Dairy cows are customarily given grains and highly digestible byproduct ingredients as additions to forage to support milk production. In many parts of the world growing seasons are short, and the grain crops that can be grown may not provide adequate yields. Sugar beets, on the other hand are relatively hardy, and dry matter yields surpass the yields of most grain crops. There are however, perceptions that beets may not be suitable as a feed ingredient due to the fact that the storage form of carbohydrate is sugar rather than starch. With little analytical support, sugar has been rejected in many feeding programs with the view that sugar reduces rumen pH, fiber digestion and microbial yield. This review explores available facts revolving around these concerns. Information regarding the feeding of sugar beets is provided and the use of sugar beets as a partial replacement for grain is proposed.

关键词： Dairy cattle Feed beets Fodder beets Methane Sugar Sugar beets

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A CLASS OF ASYNCHRONOUS MATRIX MULTI-SPLITTING MULTI-PARAMETER RELAXATION ITERATIONS

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Journal of Computational Mathematics 1998年第3期16卷 221-238页

作者： Bai, ZZ Wang, DR evans, DJ Chinese Acad Sci ICMSEC Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Dept Comp Studies Loughborough LE11 3TU Leics England

A class of asynchronous matrix multi-splitting multi-parameter relaxation methods, including the asynchronous matrix multisplitting SAOR, SSOR and SGS methods as well. as the known asynchronous matrix multisplitting AOR, SOR and GS methods, etc., is proposed for solving the large sparse systems of linear equations by making use of the principle of sufficiently using the delayed information. These new methods can greatly execute the parallel computational efficiency of the MIMD-systems, and are shown to be convergent when the coefficient matrices are H-matrices. Moreover, necessary and sufficient conditions ensuring the convergence of these methods are concluded for the case that the coefficient matrices are L-matrices.

关键词： system of linear equations asynchronous iteration matrix multisplitting relaxation convergence

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ON THE CONVERGENCE OF ASYNCHRONOUS NESTEDMATRIX MULTISPLITTING METHODS FOR LINEARSYSTEMS

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Journal of Computational Mathematics 1999年第6期17卷 575-588页

作者： Bai, ZZ Wang, DR evans, DJ Acad Sinica State Key Lab Sci Engn Comp Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Parallel Algorithms Res Ctr Loughborough LE11 3TU Leics England

A class of asynchronous nested matrix multisplitting methods for solving large-scale systems of linear equations are proposed, and their convergence characterizations are studied in detail when the coefficient matrice... 详细信息

关键词： solution of linear systems asynchronous parallel iteration matrix multisplitting relaxation method convergence

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