University of California, Santa Barbara

About: University of California, Santa Barbara is a education organization based out in Santa Barbara, California, United States. It is known for research contribution in the topics: Population & Laser. The organization has 30281 authors who have published 80852 publications receiving 4626827 citations. The organization is also known as: UC Santa Barbara & UCSB.

Predation and Population Stability

Abstract: Publisher Summary This chapter discusses predation and population stability. It describes some potentially stabilizing features that have been found in real systems and shows the main stabilizing features discovered in the field of studies—refuges, spatial heterogeneity—or probably can be modified to incorporate them, for example, invulnerable classes of prey. It also touches two obvious features of reality, namely time lags, which destabilize the interaction, and density dependence (for example, resource limitation) in the prey, which is stabilizing. General model (the Lotka-Voltema equations) is also discussed and a criterion for estimating its stabilizing effect is presented. The chapter discusses the relationship between learning and functional response, and indicates the importance of two features, developmental response and numerical response, of the interaction. The chapter examines other aspects, namely the consequences for stability arising from the response of the individual predator to changes in the density of its prey (or to changes in the densities of two or more prey).

Perspective on the Development of High‐Toughness Ceramics

Abstract: The science governing the strength and fracture of structural ceramics has developed from a mostly empirical topic in 1965 into a mature discipline that now sets the standards in the field of mechanical behavior. The intent of this review is to provide a perspective regarding this evolution, followed by succinct descriptions of current understanding. The rapid developments in the field are considered to have commenced upon the first concerted attempt to apply fracture mechanics concepts to ceramics, beginning in the middle 1960s. This allowed a distinction between the separate contributions to strength from the flaws in the material and from the microstructure, as manifest in the fracture toughness. Another contribution that accelerated the learning process was the development of indentation techniques, which allowed trends in the damage resistance of new ceramics to be assessed on a routine basis. However, the most important development, which originated at about the same time, was the discovery of toughened zirconia alloys. The ensuing research on these alloys established two vital precedents.

Using circuit theory to model connectivity in ecology, evolution, and conservation.

Abstract: Connectivity among populations and habitats is important for a wide range of ecological processes. Understanding, preserving, and restoring connectivity in complex landscapes requires connectivity models and metrics that are reliable, efficient, and process based. We introduce a new class of ecological connectivity models based in electrical circuit theory. Although they have been applied in other disciplines, circuit-theoretic connectivity models are new to ecology. They offer distinct advantages over common analytic connectivity models, including a theoretical basis in random walk theory and an ability to evaluate contributions of multiple dispersal pathways. Resistance, current, and voltage calculated across graphs or raster grids can be related to ecological processes (such as individual movement and gene flow) that occur across large population networks or landscapes. Efficient algorithms can quickly solve networks with millions of nodes, or landscapes with millions of raster cells. Here we review basic circuit theory, discuss relationships between circuit and random walk theories, and describe applications in ecology, evolution, and conservation. We provide examples of how circuit models can be used to predict movement patterns and fates of random walkers in complex landscapes and to identify important habitat patches and movement corridors for conservation planning.

Microtubule-binding agents: a dynamic field of cancer therapeutics

Abstract: Microtubules are dynamic filamentous cytoskeletal proteins composed of tubulin and are an important therapeutic target in tumour cells. Agents that bind to microtubules have been part of the pharmacopoeia of anticancer therapy for decades and until the advent of targeted therapy, microtubules were the only alternative to DNA as a therapeutic target in cancer. The screening of a range of botanical species and marine organisms has yielded promising new antitubulin agents with novel properties. In the current search for novel microtubule-binding agents, enhanced tumour specificity, reduced neurotoxicity and insensitivity to chemoresistance mechanisms are the three main objectives.