Visual Censuses of Fish Populations at the Florida Middle Ground

Logistical constraints and bottom-time restrictions form major Impediments to visual censusing of fish populations at depths such as are found at the Florida Middle Ground. A sampling strategy which incorporated multiple short duration point-diversity counts enabled estimation of population densities of a number of species present at the Florida Middle Ground. The method described is most accurate for substratum-oriented, site tenacious species such as damselfishes, gobies, and some wrasses, as well as slow-moving or sedentary larger species such as angel fishes and groupers. Numerical classification of count data revealed that fish distribution patterns at the Florida Middle Ground were loosely defined, although differences between biotopes and stations could be discerned. Subjective indices of substratum sand, rubble, hard coral, soft coral, and sponge coverages indicated that these factors had a discrete influence on observed fish distribution patterns

Pulse source for 80 Gb/s systems using a gain-wwitched laser diode followed by a nonlinearly chirped grating

This work presents the generation of 3.5 ps pulses at a repetition rate of 10 GHz and the optimization of the pulse spectrum. The output pulses are near transform limited and have pulse pedestals that are virtually eliminated to 35 dB down from the peak of the pulse, thus providing a source suitable for use in 80 Gb/s OTDM systems

Optimized pulse source employing an externally injected gain-switched laser diode in conjunction with a nonlinearly chirped grating

In this paper, we demonstrate the generation of transform-limited short optical pulses, which display excellent spectral and temporal qualities by employing a novel technology, based on an externally injected gain-switched laser in conjunction with a nonlinearly chirped grating. Using this technique, 3.5-ps optical pulses exhibiting a time-bandwidth product (TBP) of 0.45 are generated, which are suitable for use in high-speed 80 Gb/s optical time-division multiplexing (OTDM) communications systems. The numerical integration of a set of rate equations using suitable parameters for the devices used in the experiments were carried out to further confirm the feasibility of the proposed method for developing an optimized pulse source for high-speed photonic systems

High Spatial Resolution X-Ray Spectroscopy of the IC443 Pulsar Wind Nebula and Environs

Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222127, in the supernova remnant IC443 reveal an ~5$^{\prime\prime}$-radius ring-like structure surrounding the pulsar and a jet-like feature oriented roughly north-south across the ring and through the pulsar's location at 06$^{\rm h}$17$^{\rm m}$5.200$^{\rm s}$ +22$^{\circ}$21$^{\prime}$27.52$^{\prime\prime}$ (J2000.0 coordinates). The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind and, (3) the spectrum at greater distances is consistent with thermal emission from the supernova remnant. The cometary shape of the nebula, suggesting motion towards the southwest, appears to be subsonic: There is no evidence either spectrally or morphologically for a bow shock or contact discontinuity; the nearly circular ring is not distorted by motion through the ambient medium; and the shape near the apex of the nebula is narrow. Comparing this observation with previous observations of the same target, we set a 99% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 44 mas/yr (310 km/s for a distance of 1.5 kpc), with the best-fit (but not statistically significant) projected direction toward the west.Comment: Accepted for publication in the Astrophysical Journa

Core Outcome Set-STAndards for Development: The COS-STAD recommendations

Background The use of core outcome sets (COS) ensures that researchers measure and report those outcomes that are most likely to be relevant to users of their research. Several hundred COS projects have been systematically identified to date, but there has been no formal quality assessment of these studies. The Core Outcome Set-STAndards for Development (COS-STAD) project aimed to identify minimum standards for the design of a COS study agreed upon by an international group, while other specific guidance exists for the final reporting of COS development studies (Core Outcome Set-STAndards for Reporting [COS-STAR]). Methods and findings An international group of experienced COS developers, methodologists, journal editors, potential users of COS (clinical trialists, systematic reviewers, and clinical guideline developers), and patient representatives produced the COS-STAD recommendations to help improve the quality of COS development and support the assessment of whether a COS had been developed using a reasonable approach. An open survey of experts generated an initial list of items, which was refined by a 2-round Delphi survey involving nearly 250 participants representing key stakeholder groups. Participants assigned importance ratings for each item using a 1–9 scale. Consensus that an item should be included in the set of minimum standards was defined as at least 70% of the voting participants from each stakeholder group providing a score between 7 and 9. The Delphi survey was followed by a consensus discussion with the study management group representing multiple stakeholder groups. COS-STAD contains 11 minimum standards that are the minimum design recommendations for all COS development projects. The recommendations focus on 3 key domains: the scope, the stakeholders, and the consensus process. Conclusions The COS-STAD project has established 11 minimum standards to be followed by COS developers when planning their projects and by users when deciding whether a COS has been developed using reasonable methods

Parodie et carnavalisation : l’exemple de Hubert Aquin

One of the defining features of patient-centered outcomes research (PCOR) is the emphasis on reporting outcomes that are meaningful to patients. Accelerating progress toward this objective could be achieved through increased development and uptake of core outcome sets (COS), which are intended to represent a standardized minimum set of outcomes that should bemeasured and reported in all clinical trials in a specific condition. The level of activity around COS has increased significantly over recent years, however there are many important clinical conditions for which high quality COS havenot been developed. We believe that meaningful progress toward the goals behind the significant investments in PCOR will depend on sustained attention to the challenges of COS development and uptake

Optimized pulse source based on a gain-switched laser diode in conjuction with a non-linearly chirped grating for 40 Gbit/s systems

A technique based on the design of an optimized source of pico-second optical pulses, which exhibits excellent temporal and spectral purity, is presented. The procedure entails an initial complete intensity and chirp characterization of pulses, from an externally injected-gain switched laser (EI-GSL), using the technique of frequency resolved optical gating (FROG). This characterization yields the parameters that are required for the design of a non-linearly chirped fibre Bragg grating (NC FBG) with a chirp profile that is opposite to that measured across the pulse. By employing the tailor made NC FBG after the gain-switched laser, direct compression of the gain-switched pulses is achieved, to obtain pedestal-free, near transform-limited, 7 ps pulses. The system viability, characterized by simulations, portrays a 6 dB difference in performance between a pulse source with insufficient TPSR and one that exhibits adequate TPSR &(ge; 30 dB)

Opportunistic decision-making in government: concept formation, variety and explanation

The notion of opportunism is too often used loosely in policy and administrative research on executive decision-making: its various meanings are too rarely clearly distinguished. To make it useful for explanation, this article presents fresh concept formation work, clarifying the concept to recognize different kinds and degrees of opportunism. To illustrate the use of the refined concept, the article examines key decisions by British cabinets and core executives between 1945 and 1990. It proposes that neo-Durkheimian institutional theory can help to explain why different kinds of opportunism are cultivated in differently ordered administrations, so providing new insight into decision-making.This work was supported by the Leverhulme Trust (grant number: F01374I