University of Delaware

About: University of Delaware is a education organization based out in Newark, Delaware, United States. It is known for research contribution in the topics: Population & Catalysis. The organization has 22223 authors who have published 54810 publications receiving 2049136 citations. The organization is also known as: University of Delaware Emergency Care Unit & UD.

Review of Particle Physics: Particle data group

Abstract: This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 112 reviews are many that are new or heavily revised including those on Heavy-Quark and Soft-Collinear Effective Theory, Neutrino Cross Section Measurements, Monte Carlo Event Generators, Lattice QCD, Heavy Quarkonium Spectroscopy, Top Quark, Dark Matter, V-cb & V-ub, Quantum Chromodynamics, High-Energy Collider Parameters, Astrophysical Constants, Cosmological Parameters, and Dark Matter. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.

A point-charge force field for molecular mechanics simulations of proteins based on condensed-phase quantum mechanical calculations.

Abstract: Molecular mechanics models have been applied extensively to study the dynamics of proteins and nucleic acids. Here we report the development of a third-generation point-charge all-atom force field for proteins. Following the earlier approach of Cornell et al., the charge set was obtained by fitting to the electrostatic potentials of dipeptides calculated using B3LYP/cc-pVTZ//HF/6-31G** quantum mechanical methods. The main-chain torsion parameters were obtained by fitting to the energy profiles of Ace-Ala-Nme and Ace-Gly-Nme di-peptides calculated using MP2/cc-pVTZ//HF/6-31G** quantum mechanical methods. All other parameters were taken from the existing AMBER data base. The major departure from previous force fields is that all quantum mechanical calculations were done in the condensed phase with continuum solvent models and an effective dielectric constant of e = 4. We anticipate that this force field parameter set will address certain critical short comings of previous force fields in condensed-phase simulations of proteins. Initial tests on peptides demonstrated a high-degree of similarity between the calculated and the statistically measured Ramanchandran maps for both Ace-Gly-Nme and Ace-Ala-Nme di-peptides. Some highlights of our results include (1) well-preserved balance between the extended and helical region distributions, and (2) favorable type-II poly-proline helical region in agreement with recent experiments. Backward compatibility between the new and Cornell et al. charge sets, as judged by overall agreement between dipole moments, allows a smooth transition to the new force field in the area of ligand-binding calculations. Test simulations on a large set of proteins are also discussed. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 1999–2012, 2003

Studying Information Technology in Organizations: Research Approaches and Assumptions

Abstract: We examined 155 behavioral information systems research articles published from 1983-1988and found that while this research is not rooted in a single overarching theoretical perspective itdoes exhibit a single set of philosophical assumptions about the nature of valid evidence andthe phenomena of interest to information systems researchers. We argue in this paper that thesephilosophical assumptions draw on the natural science tradition, and hence may not always beappropriate for inquiry into the relationships between information technology and people or organizations. In particular, we suggest that the development and use of information technologywithin organizations is inherently processual and contextual, and that these characteristics are notalways adequately captured by the philosophical assumptions prevalent in information systemsresearch. Positing social process as central to information systems phenomena asserts theimportance of studying the ongoing interactions among people, information technology andorganizations, as these are situated historically and contextually.We argue in this paper that the dominant research perspective in information systems research isnot well-equipped to deal with situated interactions over time, and propose additional researchphilosophies to augment the one currently favored by behavioral information systemsresearchers. We outline the features of such additional research perspectives, the interpretive andthe critical, providing empirical examples to illustrate how and when they may be useful. Weconclude that multiple research perspectives can usefully be employed within the informationsystems community to enrich understanding of behavioral information systems phenomena.

Introduction To Composite Materials

Abstract: The combination of materials to form a new material system with enhanced material properties is a well documented historical fact. For example, the ancient Jewish workers during their tenure under the Pharaohs used chopped straws in bricks as a means of enhancing their structural integrity. The Japanese Samurai warriors were known to use laminated metals in the forging of their swords to obtain desirable material properties. Even certain artisans from the Mediterranean and Far East used a form of composite technology in molding art works which were fabricated by layering cut paper in various sizes for producing desired shapes and contours.

Toward a Theory of Organizational Creativity

Abstract: In this article we develop a theoretical framework for understanding creativity in complex social settings. We define organizational creativity as the creation of a valuable, useful new product, service, idea, procedure, or process by individuals working together in a complex social system. The starting point for our theoretical development is provided by the interactionist model of creative behavior developed by Woodman and Schoenfeldt (1989). This model and supporting literature on creative behavior and organizational innovation are used to develop an interactional framework for organizational creativity. The theoretical framework is summarized by three propositions that can effectively guide the development of testable hypotheses.