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.

Analysis of interacting BPEL web services

Abstract: This paper presents a set of tools and techniques for analyzing interactions of composite web services which are specified in BPEL and communicate through asynchronous XML messages. We model the interactions of composite web services as conversations, the global sequence of messages exchanged by the web services. As opposed to earlier work, our tool-set handles rich data manipulation via XPath expressions. This allows us to verify designs at a more detailed level and check properties about message content. We present a framework where BPEL specifications of web services are translated to an intermediate representation, followed by the translation of the intermediate representation to a verification language. As an intermediate representation we use guarded automata augmented with unbounded queues for incoming messages, where the guards are expressed as XPath expressions. As the target verification language we use Promela, input language of the model checker SPIN. Since SPIN model checker is a finite-state verification tool we can only achieve partial verification by fixing the sizes of the input queues in the translation. We propose the concept of synchronizability to address this problem. We show that if a composite web service is synchronizable, then its conversation set remains same when asynchronous communication is replaced with synchronous communication. We give a set of sufficient conditions that guarantee synchronizability and that can be checked statically. Based on our synchronizability results, we show that a large class of composite web services with unbounded input queues can be completely verified using a finite state model checker such as SPIN.

Plugging a hole in the ocean: the emerging science of marine reserves1

Abstract: 2Department of Zoology, Oregon State University, Corvallis, Oregon 97331-2914 USA 3Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 USA 4Department of Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California 93106 USA WNational Center for Ecological Analysis and'Synthesis, Santa Barbara, California 93101-5504 USA

Controllability of structural brain networks.

Abstract: Cognitive function is driven by dynamic interactions between large-scale neural circuits or networks, enabling behaviour. However, fundamental principles constraining these dynamic network processes have remained elusive. Here we use tools from control and network theories to offer a mechanistic explanation for how the brain moves between cognitive states drawn from the network organization of white matter microstructure. Our results suggest that densely connected areas, particularly in the default mode system, facilitate the movement of the brain to many easily reachable states. Weakly connected areas, particularly in cognitive control systems, facilitate the movement of the brain to difficult-to-reach states. Areas located on the boundary between network communities, particularly in attentional control systems, facilitate the integration or segregation of diverse cognitive systems. Our results suggest that structural network differences between cognitive circuits dictate their distinct roles in controlling trajectories of brain network function.

Non‐linearity in ecosystem services: temporal and spatial variability in coastal protection

Abstract: Natural processes tend to vary over time and space, as well as between species. The ecosystem services these natural processes provide are therefore also highly variable. It is often assumed that ecosystem services are provided linearly (unvaryingly, at a steady rate), but natural processes are characterized by thresholds and limiting functions. In this paper, we describe the variability observed in wave attenuation provided by marshes, mangroves, seagrasses, and coral reefs and therefore also in coastal protection. We calculate the economic consequences of assuming coastal protection to be linear. We suggest that, in order to refine ecosystem-based management practices, it is essential that natural variability and cumulative effects be considered in the valuation of ecosystem services.

A nomenclature for restriction enzymes, DNA methyltransferases, homing endonucleases and their genes

Abstract: A nomenclature is described for restriction endonucleases, DNA methyltransferases, homing endonucleases and related genes and gene products. It provides explicit categories for the many different Type II enzymes now identified and provides a system for naming the putative genes found by sequence analysis of microbial genomes.