Institution
Worcester Polytechnic Institute
Education•Worcester, Massachusetts, United States•
About: Worcester Polytechnic Institute is a education organization based out in Worcester, Massachusetts, United States. It is known for research contribution in the topics: Population & Data envelopment analysis. The organization has 6270 authors who have published 12704 publications receiving 332081 citations. The organization is also known as: WPI.
Topics: Population, Data envelopment analysis, Supply chain, Nonlinear system, Finite element method
Papers published on a yearly basis
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TL;DR: Testing both models, the delivery of Cu+ by Archaeoglobus fulgidus Cu+ chaperone CopZ to the corresponding Cu+-ATPase, CopA, was studied, and under nonturnover conditions, CopZ transferred Cu+ to the TM-MBS of a CopA lacking MBDs.
Abstract: As in other P-type ATPases, metal binding to transmembrane metal-binding sites (TM-MBS) in Cu+-ATPases is required for enzyme phosphorylation and subsequent transport. However, Cu+ does not access Cu+-ATPases in a free (hydrated) form but is bound to a chaperone protein. Cu+ transfer from Cu+ chaperones to regulatory cytoplasmic metal-binding domains (MBDs) present in these ATPases has been described, but there is no evidence of a proposed subsequent Cu+ movement from the MBDs to the TM-MBS. Alternatively, we postulate the parsimonious Cu+ transfer by the chaperone directly to TM-MBS. Testing both models, the delivery of Cu+ by Archaeoglobus fulgidus Cu+ chaperone CopZ to the corresponding Cu+-ATPase, CopA, was studied. As expected, CopZ interacted with and delivered the metal to CopA MBDs. Cu+-loaded MBDs, acting as metal donors, were unable to activate CopA or a truncated CopA lacking MBDs. Conversely, Cu+-loaded CopZ activated the CopA ATPase and CopA constructs in which MBDs were rendered unable to bind Cu+. Furthermore, under nonturnover conditions, CopZ transferred Cu+ to the TM-MBS of a CopA lacking MBDs. These data are consistent with a model where MBDs serve a regulatory function without participating in metal transport and the chaperone delivers Cu+ directly to transmembrane transport sites of Cu+-ATPases.
213 citations
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TL;DR: In this paper, the authors summarize recent contributions in the broad area of AoI and present general AoI evaluation analysis that are applicable to a wide variety of sources and systems, starting from elementary single-server queues, and applying these AoI methods to a range of increasingly complex systems, including energy harvesting sensors transmitting over noisy channels, parallel server systems, queueing networks, and various single-hop and multi-hop wireless networks.
Abstract: We summarize recent contributions in the broad area of age of information (AoI). In particular, we describe the current state of the art in the design and optimization of low-latency cyberphysical systems and applications in which sources send time-stamped status updates to interested recipients. These applications desire status updates at the recipients to be as timely as possible; however, this is typically constrained by limited system resources. We describe AoI timeliness metrics and present general methods of AoI evaluation analysis that are applicable to a wide variety of sources and systems. Starting from elementary single-server queues, we apply these AoI methods to a range of increasingly complex systems, including energy harvesting sensors transmitting over noisy channels, parallel server systems, queueing networks, and various single-hop and multi-hop wireless networks. We also explore how update age is related to MMSE methods of sampling, estimation and control of stochastic processes. The paper concludes with a review of efforts to employ age optimization in cyberphysical applications.
213 citations
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TL;DR: A novel loading approach to stably label human mesenchymal stem cells with quantum dot (QD) nanoparticles is developed and the optimization and validation of this long‐term tracking technique are reported and several important biological applications by delivering labeled cells to the mammalian heart are highlighted.
Abstract: Stem cells show promise for repair of damaged cardiac tissue. Little is known with certainty, however, about the distribution of these cells once introduced in vivo. Previous attempts at tracking delivered stem cells have been hampered by the autofluorescence of host tissue and limitations of existing labeling techniques. We have developed a novel loading approach to stably label human mesenchymal stem cells with quantum dot (QD) nanoparticles. We report the optimization and validation of this long-term tracking technique and highlight several important biological applications by delivering labeled cells to the mammalian heart. The bright QD crystals illuminate exogenous stem cells in histologic sections for at least 8 weeks following delivery and permit, for the first time, the complete three-dimensional reconstruction of the locations of all stem cells following injection into the heart. Disclosure of potential conflicts of interest is found at the end of this article.
212 citations
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TL;DR: In this paper, the authors investigated the mathematical well-posedness of the variational model of quasi-static growth for a brittle crack proposed by Francfort and Marigo in [15] and showed that the notion of minimizer of a Mumford and Shah type function for its own jump set is stable under weak convergence assumptions.
Abstract: This paper investigates the mathematical well-posedness of the variational model of quasi-static growth for a brittle crack proposed by Francfort and Marigo in [15]. The starting point is a time discretized version of that evolution which results in a sequence of minimization problems of Mumford and Shah type functionals. The natural weak setting is that of special functions of bounded variation, and the main difficulty in showing existence of the time-continuous quasi-static growth is to pass to the limit as the time-discretization step tends to 0. This is performed with the help of a jump transfer theorem which permits, under weak convergence assumptions for a sequence {un} of SBV-functions to its BV-limit u, to transfer the part of the jump set of any test field that lies in the jump set of u onto that of the converging sequence {un}. In particular, it is shown that the notion of minimizer of a Mumford and Shah type functional for its own jump set is stable under weak convergence assumptions. Furthermore, our analysis justifies numerical methods used for computing the time-continuous quasi-static evolution. © 2003 Wiley Periodicals, Inc.
211 citations
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TL;DR: In this paper, a thermodynamic model is proposed to describe the sorption of water in Nafion based on the Flory-Huggins activity model and an appropriate osmotic pressure correction term for the chemical potential of water within the swollen membrane.
Abstract: A thermodynamic model is proposed to describe the sorption of water in Nafion based on the Flory-Huggins activity model and an appropriate osmotic pressure correction term for the chemical potential of water within the swollen membrane. The key variables for sorption are equivalent weight of ionomer, acid strength of the ionic groups, modulus of polymer elasticity, and interaction between water and polymer. The water uptake per unit mass of dry Nafion increases with the increasing acid strength of the functional groups, decreasing Young’s modulus, and decreasing equivalent weight of Nafion. The model provides insights into the sorption and swelling behavior of ion-exchange membranes, and thus, may be useful in evaluating and designing alternate proton-exchange membranes for fuel cell applications. In a companion paper ~Part II!, a predictive model is presented for the transport of protons in Nafion.
211 citations
Authors
Showing all 6336 results
Name | H-index | Papers | Citations |
---|---|---|---|
Andrew G. Clark | 140 | 823 | 123333 |
Ming Li | 103 | 1669 | 62672 |
Joseph Sarkis | 101 | 482 | 45116 |
Arthur C. Graesser | 95 | 614 | 38549 |
Kevin J. Harrington | 85 | 682 | 33625 |
Kui Ren | 83 | 501 | 32490 |
Bart Preneel | 82 | 844 | 25572 |
Ming-Hui Chen | 82 | 525 | 29184 |
Yuguang Fang | 79 | 572 | 20715 |
Wenjing Lou | 77 | 311 | 29405 |
Bernard Lown | 73 | 330 | 20320 |
Joe Zhu | 72 | 231 | 19017 |
Y.S. Lin | 71 | 304 | 16100 |
Kevin Talbot | 71 | 268 | 15669 |
Christof Paar | 69 | 399 | 21790 |