University of Texas at Austin

About: University of Texas at Austin is a education organization based out in Austin, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 94352 authors who have published 206297 publications receiving 9070052 citations. The organization is also known as: UT-Austin & UT Austin.

The Common Land Model

Abstract: The Common Land Model (CLM) was developed for community use by a grassroots collaboration of scientists who have an interest in making a general land model available for public use and further development. The major model characteristics include enough unevenly spaced layers to adequately represent soil temperature and soil moisture, and a multilayer parameterization of snow processes; an explicit treatment of the mass of liquid water and ice water and their phase change within the snow and soil system; a runoff parameterization following the TOPMODEL concept; a canopy photo synthesis-conductance model that describes the simultaneous transfer of CO2 and water vapor into and out of vegetation; and a tiled treatment of the subgrid fraction of energy and water balance. CLM has been extensively evaluated in offline mode and coupling runs with the NCAR Community Climate Model (CCM3). The results of two offline runs, presented as examples, are compared with observations and with the simulation of three other la...

Current Status of the AMOEBA Polarizable Force Field

Abstract: Molecular force fields have been approaching a generational transition over the past several years, moving away from well-established and well-tuned, but intrinsically limited, fixed point charge models toward more intricate and expensive polarizable models that should allow more accurate description of molecular properties. The recently introduced AMOEBA force field is a leading publicly available example of this next generation of theoretical model, but to date, it has only received relatively limited validation, which we address here. We show that the AMOEBA force field is in fact a significant improvement over fixed charge models for small molecule structural and thermodynamic observables in particular, although further fine-tuning is necessary to describe solvation free energies of drug-like small molecules, dynamical properties away from ambient conditions, and possible improvements in aromatic interactions. State of the art electronic structure calculations reveal generally very good agreement with...

Global signatures of protein and mRNA expression levels

Abstract: Cellular states are determined by differential expression of the cell’s proteins. The relationship between protein and mRNA expression levels informs about the combined outcomes of translation and protein degradation which are, in addition to transcription and mRNA stability, essential contributors to gene expression regulation. This review summarizes the state of knowledge about large-scale measurements of absolute protein and mRNA expression levels, and the degree of correlation between the two parameters. We summarize the information that can be derived from comparison of protein and mRNA expression levels and discuss how corresponding sequence characteristics suggest modes of regulation.

Forward and Inverse Modeling of Low-Temperature Thermochronometry Data

Abstract: The thermochronometric systems discussed in this volume broadly share three features: parent isotopes, daughter products, and one or more time-dependent, temperature-sensitive processes by which daughter products are altered or lost. If these processes can be measured in the laboratory, and their behavior confidently extrapolated to geological time scales, it becomes possible to construct a forward model of the system that predicts how a given instance of it will evolve assuming a particular starting arrangement and subsequent time-temperature history. Once a forward model has been created and verified, it then becomes possible to apply it in the inverse sense: given a measured ending condition and an assumed starting one, find the intervening time-temperature history. In general, because of information loss, limited precision of measurements, and lack of system uniqueness, more than one history is consistent with a given ending condition. As a result, an inverse model solution usually consists of a set of thermal histories that are consistent with the measured data, as judged by some statistical criterion. This chapter will concentrate on two low-temperature thermochronometers: fission-track (primarily for apatite) and (U-Th)/He. All of the calculations described here are implemented in a computer program called “HeFTy,” which is available with this volume (see Ehlers et al. 2005). A theme that will be touched upon throughout this chapter is that forward and inverse models are only as good as the data and assumptions behind them. Although this principle of course holds for all scientific investigations, it is often obscured when such details are packaged in user-friendly software that produces publication-ready graphics. Fission tracks form continuously over time at a rate dependent solely upon the concentration of uranium present. Earlier-formed fission tracks tend to be shorter than later-formed tracks, as they will have had more time to anneal, and may have experienced …

Marketing, Business Processes, and Shareholder Value: An Organizationally Embedded View of Marketing Activities and the Discipline of Marketing

Abstract: The authors develop a framework for understanding the integration of marketing with business processes and shareholder value. The framework redefines marketing phenomena as embedded in three core b...