University of California

About: University of California is a education organization based out in Oakland, California, United States. It is known for research contribution in the topics: Population & Layer (electronics). The organization has 55175 authors who have published 52933 publications receiving 1491169 citations. The organization is also known as: UC & University of California System.

Compact Intermediate States in Protein Folding

Abstract: Recently there has been growing recognition of the existence and importance of compact intermediate states of proteins. Such species have been observed under both transient (refolding kinetics) and equilibrium conditions. It is clear that for many proteins most denaturing conditions do not lead to a fully unfolded protein (random coil), but rather to species with substantial secondary structure and substantial compactness, relative to the fully unfolded state. In addition, there is now good experimental data to demonstrate the existence of two classes of compact denatured states of proteins: compact intermediates, in the thermodynamic sense (i.e., a minimum in the free energy profile for the reaction), and compact substates of the unfolded state (Palleros et al., 1993). It is important to note that it is often experimentally difficult to distinguish between these two types of compact denatured states, especially by spectral methods. Recent reviews of compact denatured states, and particularly the molten globule, include those of Dill and Shortle (1991), Ptitsyn (1987, 1992), Kuwajima (1989), Christensen and Pain (1991), and Baldwin and Roder (1991). Theoretical models for the existence of two classes of denatured states have been presented by Dill and co-workers (Alonso et al., 1991), Ptitsyn (1987, 1992), and Finkelstein and Shakhnovich (1989).

A bridge between worlds: understanding network structure to understand change strategy

Abstract: A number of scholars are exploring district and site relations in organizational change efforts in the larger policy context of No Child Left Behind. These studies suggest the importance of the central office as a support to the work of reform and offer strategies for building relations between district offices and sites in order to implement and sustain change efforts. What is frequently overlooked in these studies is that organizational change efforts are often socially constructed. Therefore, examining the underlying social networks may provide insight into structures that support or constrain efforts at change. This exploratory case study uses social network analysis and interviews to examine the communication and knowledge network structures of central office and site leaders in an ‘in need of improvement’ district facing sanctions under No Child Left Behind. Findings indicate sparse ties among and between school site and central office administrators, as well as a centralized network structure that may constrain the exchange of complex information and ultimately inhibit efforts at change.

Language Barriers, Physician-Patient Language Concordance, and Glycemic Control Among Insured Latinos with Diabetes: The Diabetes Study of Northern California (DISTANCE)

Abstract: BACKGROUND A significant proportion of US Latinos with diabetes have limited English proficiency (LEP). Whether language barriers in health care contribute to poor glycemic control is unknown.

Stable complete minimal surfaces in $R^3$ are planes

Abstract: A proof of the statement in the title is given.

Nonlinear Force-Free Modeling of Coronal Magnetic Fields. II. Modeling a Filament Arcade and Simulated Chromospheric and Photospheric Vector Fields

Abstract: We compare a variety of nonlinear force-free field (NLFFF) extrapolation algorithms, including optimization, magneto-frictional, and Grad – Rubin-like codes, applied to a solar-like reference model. The model used to test the algorithms includes realistic photospheric Lorentz forces and a complex field including a weakly twisted, right helical flux bundle. The codes were applied to both forced “photospheric” and more force-free “chromospheric” vector magnetic field boundary data derived from the model. When applied to the chromospheric boundary data, the codes are able to recover the presence of the flux bundle and the field’s free energy, though some details of the field connectivity are lost. When the codes are applied to the forced photospheric boundary data, the reference model field is not well recovered, indicating that the combination of Lorentz forces and small spatial scale structure at the photosphere severely impact the extrapolation of the field. Preprocessing of the forced photospheric boundary does improve the extrapolations considerably for the layers above the chromosphere, but the extrapolations are sensitive to the details of the numerical codes and neither the field connectivity nor the free magnetic energy in the full volume are well recovered. The magnetic virial theorem gives a rapid measure of the total magnetic energy without extrapolation though, like the NLFFF codes, it is sensitive to the Lorentz forces in the coronal volume. Both the magnetic virial theorem and the Wiegelmann extrapolation, when applied to the preprocessed photospheric boundary, give a magnetic energy which is nearly equivalent to the value derived from the chromospheric boundary, but both underestimate the free energy above the photosphere by at least a factor of two. We discuss the interpretation of the preprocessed field in this context. When applying the NLFFF codes to solar data, the problems associated with Lorentz forces present in the low solar atmosphere must be recognized: the various codes will not necessarily converge to the correct, or even the same, solution.