University of Massachusetts Amherst

About: University of Massachusetts Amherst is a education organization based out in Amherst Center, Massachusetts, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 37274 authors who have published 83965 publications receiving 3834996 citations. The organization is also known as: UMass Amherst & Massachusetts State College.

Hormesis: The Dose-Response Revolution

Abstract: Hormesis, a dose-response relationship phenomenon characterized by low-dose stimulation and high-dose inhibition, has been frequently observed in properly designed studies and is broadly generalizable as being independent of chemical/physical agent, biological model, and endpoint measured. This under-recognized and -appreciated concept has the potential to profoundly change toxicology and its related disciplines with respect to study design, animal model selection, endpoint selection, risk assessment methods, and numerous other aspects, including chemotherapeutics. This article indicates that as a result of hormesis, fundamental changes in the concept and conduct of toxicology and risk assessment should be made, including (a) the definition of toxicology, (b) the process of hazard (e.g., including study design, selection of biological model, dose number and distribution, endpoint measured, and temporal sequence) and risk assessment [e.g., concept of NOAEL (no observed adverse effect level), low dose modeling, recognition of beneficial as well as harmful responses] for all agents, and (c) the harmonization of cancer and noncancer risk assessment.

Handbook of Layered Materials

Abstract: CLAY MINERALS Introduction: Clay Structure, Surface Acidity, and Catalysis, K.A. Carrado Molecular Modeling of Clay Mineral Structure and Surface Chemistry, S.-H. Park and G. Sposito Clay-Organic Interactions: Organoclay Complexes and Polymer-Clay Nanocomposites, E. Ruiz-Hitzky, P. Aranda, and J.M. Serratosa Sorption of Nitroaromatic Compounds on Clay Surfaces, C.T. Johnston, S.A. Boyd, B.J. Teppen, and G. Sheng Photoprocesses in Clay-Organic Complexes, M. Ogawa Pillared Clays and Porous Clay Heterostructures, P. Cool and E.F. Vansant OTHER LAYERED MATERIALS Layered alpha-Zirconium Phosphates and Phosphonates, C.V. Kumar, A. Bhambhani, and N. Hnatiuk Layered Double Hydroxides (LDHs), P.S. Braterman, Z.P. Xu, and F. Yarberry Layered Manganese Oxides: Synthesis, Properties, and Applications, J. Liu, J.P. Durand, L. Espinal, L.-J. Garces, S. Gomez, Y.-C. Son, J. Villegas, and S.L. Suib Layered Metal Chalcogenides, C.O. Oriakhi and M.M. Lerner Alkali Silicates and Crystalline Silicic Acids, W. Schweiger and G. Lagaly

PEG- and peptide-grafted aliphatic polyesters by click chemistry.

Abstract: Novel aliphatic polyesters with pendent acetylene groups were prepared by controlled ring-opening polymerization and subsequently used for grafting poly(ethylene glycol) and oligopeptide moieties by the Cu(I)-catalyzed addition of azides and alkynes, a type of “click” chemistry. These aliphatic polyesters possess an acetylene graft density that can be tailored by ring-opening copolymerization of α-propargyl-δ-valerolactone (1) with e-caprolactone. Since the mild conditions associated with the click reaction are shown to be compatible with the polyester backbone, this method is a generally useful means for grafting numerous types of functionality onto aliphatic polyesters. The amphiphilic graft polyesters prepared in this study are shown to be biocompatible by in vitro cytotoxicity evaluation, suggesting their suitability for a range of biomaterial applications.

The Role of Organizational Learning in the Opportunity-Recognition Process

Abstract: Firms engage in entrepreneurship to increase performance through both strategic renewal and the creation of new venture opportunities. Organizational learning (OL) has become an effective avenue fo...

How to lease the internet in your spare time

Abstract: Today's Internet Service Providers (ISPs) serve two roles: managing their network infrastructure and providing (arguably limited) services to end users. We argue that coupling these roles impedes the deployment of new protocols and architectures, and that the future Internet should support two separate entities: infrastructure providers (who manage the physical infrastructure) and service providers (who deploy network protocols and offer end-to-end services). We present a high-level design for Cabo, an architecture that enables this separation; we also describe challenges associated with realizing this architecture.