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.

Experimentally determined hydrophobicity scale for proteins at membrane interfaces.

Abstract: The partitioning of membrane-active oligopeptides into membrane interfaces promotes the formation of secondary structure. A quantitative description of the coupling of structure formation to partitioning, which may provide a basis for understanding membrane protein folding and insertion, requires an appropriate free energy scale for partitioning. A complete interfacial hydrophobicity scale that includes the contribution of the peptide bond was therefore determined from the partitioning of two series of small model peptides into the interfaces of neutral (zwitterionic) phospholipid membranes. Aromatic residues are found to be especially favoured at the interface while charged residues, and the peptide bond, are disfavoured about equally. Reduction of the high cost of partitioning the peptide bond through hydrogen bonding may be important in the promotion of structure formation in the membrane interface.

Alternative states and positive feedbacks in restoration ecology

Abstract: There is increasing interest in developing better predictive tools and a broader conceptual framework to guide the restoration of degraded land. Traditionally, restoration efforts have focused on re-establishing historical disturbance regimes or abiotic conditions, relying on successional processes to guide the recovery of biotic communities. However, strong feedbacks between biotic factors and the physical environment can alter the efficacy of these successional-based management efforts. Recent experimental work indicates that some degraded systems are resilient to traditional restoration efforts owing to constraints such as changes in landscape connectivity and organization, loss of native species pools, shifts in species dominance, trophic interactions and/or invasion by exotics, and concomitant effects on biogeochemical processes. Models of alternative ecosystem states that incorporate system thresholds and feedbacks are now being applied to the dynamics of recovery in degraded systems and are suggesting ways in which restoration can identify, prioritize and address these constraints.