Electro-optic modulation of 1.5μm light in an active InGaAsP/InP quantum well waveguide

We report an InGaAsP/InP phase modulator operating in the 1.5μm wavelength band. Phase modulation of 7.5°/mA and 1.7°/mA of injected current have been measured for TE and TM polarised light respectively at a signal wavelength of 1.52 μm.

An experimental investigation of RoF-enabled MIMO das in a non-light-of-sight environment

The performance of a 3 × 3 MIMO system using RoF-enabled DAS technology is experimentally investigated in a Non-Line-Of-Sight environment. Reduced spatial correlation and improved SNR are achieved due to the larger antenna separation. © 2011 OSA.

Temporal trends (2000–2011) and influences on fishery-independent catch rates for loggerhead sea turtles (Caretta caretta) at an important coastal foraging region in the southeastern United States

Seasonal trawling was conducted randomly in coastal (depths of 4.6–17 m) waters from St. Augustine, Florida, (29.9°N) to Winyah Bay, South Carolina (33.1°N), during 2000–03, 2008–09, and 2011 to assess annual trends in the relative abundance of sea turtles. A total of 1262 loggerhead sea turtles (Caretta caretta) were captured in 23% (951) of 4207 sampling events. Capture rates (overall and among prevalent 5-cm size classes) were analyzed through the use of a generalized linear model with log link function for the 4097 events that had complete observations for all 25 model parameters. Final models explained 6.6% (70.1–75.0 cm minimum straight-line carapace length [SCLmin]) to 14.9% (75.1–80.0 cm SCLmin) of deviance in the data set. Sampling year, geographic subregion, and distance from shore were retained as significant terms in all final models, and these terms collectively accounted for 6.2% of overall model deviance (range: 4.5–11.7% of variance among 5-cm size classes). We retained 18 parameters only in a subset of final models: 4 as exclusively significant terms, 5 as a mixture of significant or nonsignificant terms, and 9 as exclusively nonsignificant terms. Four parameters also were dropped completely from all final models. The generalized linear model proved appropriate for monitoring trends for this data set that was laden with zero values for catches and was compiled for a globally protected species. Because we could not account for much model deviance, metrics other than those examined in our study may better explain catch variability and, once elucidated, their inclusion in the generalized linear model should improve model fits.

Pixelated liquid-crystal light valve for neural network application.

The liquid-crystal light valve (LCLV) is a useful component for performing integration, thresholding, and gain functions in optical neural networks. Integration of the neural activation channels is implemented by pixelation of the LCLV, with use of a structured metallic layer between the photoconductor and the liquid-crystal layer. Measurements are presented for this type of valve, examples of which were prepared for two specific neural network implementations. The valve fabrication and measurement were carried out at the State Optical Institute, St. Petersburg, Russia, and the modeling and system applications were investigated at the Institute of Microtechnology, Neuchâtel, Switzerland.

Characterization and monitoring of temperature, chlorophyll, and light availability patterns in National Marine Sanctuary waters: final report

This project provides a framework for developing the capabilities of using satellite and related oceanographic and climatological data to improve environmental monitoring and characterization of physical, biological, and water quality parameters in the National Marine Sanctuaries (NMS). The project sought to: 1) assemble satellite imagery datasets in order to extract spatially explicit time series information on temperature, chlorophyll, and light availability for the Cordell Bank, Gulf of the Farallones, and Monterey Bay National Marine Sanctuaries. 2) perform preliminary analyses with these data in order to identify seasonal, annual, inter-annual, and event-driven patterns.

Fisheries databases for assessing habitat functions of Cape Romain NWR

The US Fish and Wildlife Service Cape Romain National Wildlife Refuge (CRNWR) and the Center for Coastal Environmental Health and Biomolecular Research (CCEHBR) at Charleston are interested in assessing the status of our coastal resources in light of increased coastal development and recreational use. Through an Interagency Agreement (FWS #1448-40181-00-H-001), an ecological characterization was undertaken to describe the status of and potential impacts to resources at CRNWR. This report describes historic fisheries-independent or non-commercial data relevant to CRNWR that can be used to evaluate the role of the Refuge as habitat for nearshore and offshore fish species. The purpose of this document is two-fold, first to give resource managers an understanding of fisheries data that have been collected over the years and, second, to illustrate how these data can be applied to address specific management issues. This report provides an overview of historic fisheries data collected along the southeast coast, as well as basic summaries of that data relevant to CRNWR, indicating how these data can be used to address specific questions of interest to Refuge managers and biologists.

Heat-stress and light-stress induce different cellular pathologies in the symbiotic dinoflagellate during coral bleaching

Coral bleaching is a significant contributor to the worldwide degradation of coral reefs and is indicative of the termination of symbiosis between the coral host and its symbiotic algae (dinoflagellate; Symbiodinium sp. complex), usually by expulsion or xenophagy (symbiophagy) of its dinoflagellates. Herein, we provide evidence that during the earliest stages of environmentally induced bleaching, heat stress and light stress generate distinctly different pathomorphological changes in the chloroplasts, while a combined heat- and light-stress exposure induces both pathomorphologies; suggesting that these stressors act on the dinoflagellate by different mechanisms. Within the first 48 hours of a heat stress (32°C) under low-light conditions, heat stress induced decomposition of thylakoid structures before observation of extensive oxidative damage; thus it is the disorganization of the thylakoids that creates the conditions allowing photo-oxidative-stress. Conversely, during the first 48 hours of a light stress (2007 µmoles m−2 s−1 PAR) at 25°C, condensation or fusion of multiple thylakoid lamellae occurred coincidently with levels of oxidative damage products, implying that photo-oxidative stress causes the structural membrane damage within the chloroplasts. Exposure to combined heat- and light-stresses induced both pathomorphologies, confirming that these stressors acted on the dinoflagellate via different mechanisms. Within 72 hours of exposure to heat and/or light stresses, homeostatic processes (e.g., heat-shock protein and anti-oxidant enzyme response) were evident in the remaining intact dinoflagellates, regardless of the initiating stressor. Understanding the sequence of events during bleaching when triggered by different environmental stressors is important for predicting both severity and consequences of coral bleaching