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.

Litter quality and the temperature sensitivity of decomposition

Abstract: The temperature sensitivity of litter decomposition will influence the rates of ecosystem carbon sequestration in a warmer world. A number of studies have shown that the temperature sensitivity of litter decomposition can vary depending on litter type and extent of decomposition. However, the underlying causes of this variation are not well understood. According to fundamental principles of enzyme kinetics, the temperature sen- sitivity of microbial decomposition should be inversely related to litter carbon quality. We tested the accuracy of this hypothesis by adding ground plant shoot and root material to soils incubated under controlled conditions and measuring the temperature sensitivities of decomposition at three time points throughout a 53-d incubation. As the overall quality of the litter organic C declined, litter decomposition became more sensitive to temperature. This was true regardless of whether differences in C quality were due to inherent differences in litter chemistry or due to differences in the extent of decomposition. The same pattern was observed when specific C compounds of varying quality were added to soil, suggesting that substrate C quality has a significant and predictable influence on the temperature sensitivity of microbial decomposition.

New formalism for two-photon quantum optics. I. Quadrature phases and squeezed states.

Abstract: This paper introduces a new formalism for analyzing two-photon devices (e.g., parametric amplifiers and phase-conjugate mirrors), in which photons in the output modes are created or destroyed two at a time. The key property of a two-photon device is that it excites pairs of output modes independently. Thus our new formalism deals with two modes at a time; a continuum multimode description can be built by integrating over independently excited pairs of modes. For a pair of modes at frequencies \ensuremath{\Omega}\ifmmode\pm\else\textpm\fi{}\ensuremath{\epsilon}, we define (i) quadrature-phase amplitudes, which are complex-amplitude operators for modulation at frequency \ensuremath{\epsilon} of waves ``cos[\ensuremath{\Omega}(t-x/c)]'' and ``sin[\ensuremath{\Omega}(t-x/c)]'' and (ii) two-mode squeezed states, which are the output states of an ideal two-photon device. The quadrature-phase amplitudes and the two-mode squeezed states serve as the building blocks for our formalism; their properties and their physical interpretation are extensively investigated.

Information and American Democracy: Technology in the Evolution of Political Power

Abstract: This book assesses the consequences of new information technologies for American democracy in a way that is theoretical and also historically grounded. The author argues that new technologies have produced the fourth in a series of 'information revolutions' in the US, stretching back to the founding. Each of these, he argues, led to important structural changes in politics. After re-interpreting historical American political development from the perspective of evolving characteristics of information and political communications, the author evaluates effects of the Internet and related new media. The analysis shows that the use of new technologies is contributing to 'post-bureaucratic' political organization and fundamental changes in the structure of political interests. The author's conclusions tie together scholarship on parties, interest groups, bureaucracy, collective action, and political behavior with new theory and evidence about politics in the information age.

Bioluminescence in the Sea

Abstract: Bioluminescence spans all oceanic dimensions and has evolved many times— from bacteria to fish—to powerfully influence behavioral and ecosystem dynamics. New methods and technology have brought great advances in understanding of the molecular basis of bioluminescence, its physiological control, and its significance in marine communities. Novel tools derived from understanding the chemistry of natural light-producing molecules have led to countless valuable applications, culminating recently in a related Nobel Prize. Marine organisms utilize bioluminescence for vital functions ranging from defense to reproduction. To understand these interactions and the distributions of luminous organisms, new instruments and platforms allow observations on individual to oceanographic scales. This review explores recent advances, including the chemical and molecular, phylogenetic and functional, community and oceanographic aspects of bioluminescence.