University of California, Irvine

About: University of California, Irvine is a education organization based out in Irvine, California, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 47031 authors who have published 113602 publications receiving 5521832 citations. The organization is also known as: UC Irvine & UCI.

SUMO modification of Huntingtin and Huntington's disease pathology

Abstract: Huntington's disease (HD) is characterized by the accumulation of a pathogenic protein, Huntingtin (Htt), that contains an abnormal polyglutamine expansion. Here, we report that a pathogenic fragment of Htt (Httex1p) can be modified either by small ubiquitin-like modifier (SUMO)-1 or by ubiquitin on identical lysine residues. In cultured cells, SUMOylation stabilizes Httex1p, reduces its ability to form aggregates, and promotes its capacity to repress transcription. In a Drosophila model of HD, SUMOylation of Httex1p exacerbates neurodegeneration, whereas ubiquitination of Httex1p abrogates neurodegeneration. Lysine mutations that prevent both SUMOylation and ubiquitination of Httex1p reduce HD pathology, indicating that the contribution of SUMOylation to HD pathology extends beyond preventing Htt ubiquitination and degradation.

Joint mixed logit models of stated and revealed preferences for alternative-fuel vehicles

Abstract: We compare multinomial logit and mixed logit models for data on California households' revealed and stated preferences for automobiles. The stated preference (SP) data elicited households' preferences among gasoline, electric, methanol, and compressed natural gas vehicles with various attributes. The mixed logit models provide improved fits over logit that are highly significant, and show large heterogeneity in respondents' preferences for alternative-fuel vehicles. The effects of including this heterogeneity are demonstrated in forecasting exercises. The alternative-fuel vehicle models presented here also highlight the advantages of merging SP and revealed preference (RP) data. RP data appear to be critical for obtaining realistic body-type choice and scaling information, but they are plagued by multicollinearity and difficulties with measuring vehicle attributes. SP data are critical for obtaining information about attributes not available in the marketplace, but pure SP models with these data give implausible forecasts.

Ion‐Current Rectification in Nanopores and Nanotubes with Broken Symmetry

Abstract: This article focuses on ion transport through nanoporous systems with special emphasis on rectification phenomena. The effect of ion-current rectification is observed as asymmetric current–voltage (I–V) curves, with the current recorded for one voltage polarity higher than the current recorded for the same absolute value of voltage of opposite polarity. This diode-like I–V curve indicates that there is a preferential direction for ion flow. Experimental evidence that ion-current rectification is inherent to asymmetric, e.g., tapered, nanoporous systems with excess surface charge is provided and discussed. The fabrication and operation of asymmetric polymer nanopores, gold nanotubes, glass nanocapillaries, and silicon nanopores are presented. The possibility of tuning the direction and extent of rectification is discussed in detail. Theoretical models that have been developed to explain the ion-current rectification effect are also presented.

The impact of boreal forest fire on climate warming.

Abstract: We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 ± 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (–2.3 ± 2.2 Watts per square meter) because multidecadal increases in surface albedo had a larger impact than fire-emitted greenhouse gases. This result implies that future increases in boreal fire may not accelerate climate warming.