Development of the scientific requirements of an Environmental Management System (EMS) for the pearling (Pinctada maxima) industry

This project has been a successful collaboration between pearl farmers, academic scientists and museum taxonomists and has given the scientific community greater access to remote regions of Australia, facilitating the description of new species to science. It has highlighted the inherent variability and abundant biodiversity of shallow water benthic communities in northern Australia. The study employed an exhaustively designed sampling regime incorporating three spatial scales (10’s of metres, 1-5 km, >100’s km) and random sampling through time. A multi-control sampling strategy was undertaken to give an estimate of the natural variability of the region and to test for benthic impacts at three pearl farms that have been in use for up to 40 years. Multiple lines of evidence all conclude that the variability in benthic conditions at the farms is within the bounds of the natural variability at the reference locations. The main mechanisms that influence the impact of shellfish aquaculture are considered to be; the farming method, the density of the cultivated shellfish (or stocking rate), the water depth of the farm area and the hydrographical conditions in the area (Danovaro et al 2004). All these factors favor the northern Australian cultured pearl industry and would contribute to the lack of a benthic footprint documented by this study. The conclusion drawn from these studies is that current pearl oyster culture techniques in northern Australia have no detectable effect on the sediments of the lease sites. As ongoing or frequent benthic monitoring is logistically challenging and expensive in context of northern Australian pearl farms and cannot be expected to observe anything but natural variability it would not be a wise use of scarce industry funding to include benthic monitoring protocols in the standard EMS for this industry. If major changes to farming practice creates uncertainty in the future on this issue, or political climate requires revalidation of these findings, a further study such as this, conducted as corporate industry research, such as this project, could again test the issue

Discovery of Pulsed X-ray Emission from the SMC Transient RX J0117.6-7330

We report on the detection of pulsed, broad-band, X-ray emission from the transient source RX J0117.6-7330. The pulse period of 22 seconds is detected by the ROSAT/PSPC instrument in a 1992 Sep 30 - Oct 2 observation and by the CGRO/BATSE instrument during the same epoch. Hard X-ray pulsations are detectable by BATSE for approximately 100 days surrounding the ROSAT observation (1992 Aug 28 - Dec 8). The total directly measured X-ray luminosity during the ROSAT observation is 1.0E38 (d/60 kpc)^2 ergs s-1. The pulse frequency increases rapidly during the outburst, with a peak spin-up rate of 1.2E-10 Hz s-1 and a total frequency change 1.8%. The pulsed percentage is 11.3% from 0.1-2.5 keV, increasing to at least 78% in the 20-70 keV band. These results establish RX J0117.6-7330 as a transient Be binary system.Comment: 17 pages, Latex, aasms, accepted for publication in ApJ Letter

Optimality Theory as a Framework for Lexical Acquisition

This paper re-investigates a lexical acquisition system initially developed for French.We show that, interestingly, the architecture of the system reproduces and implements the main components of Optimality Theory. However, we formulate the hypothesis that some of its limitations are mainly due to a poor representation of the constraints used. Finally, we show how a better representation of the constraints used would yield better results

Agile Course Design: Multi-University Faculty Collaboration to Design the MIS Course for an Online MBA Program

This paper outlines a collaborative course design process to develop and implement a required IS course in an online cohort-based MBA program using principles of The Agile Manifesto. The primary goal of this study is to analyze how students in traditionally developed courses and those in collaboratively developed courses differ. Specifically, we sought to reduce variability in student satisfaction across multiple sections offered by instructors who hail from different universities. We compared three semesters of students who took the course before (n = 101) and after (n = 162) use of the agile course development process. We found less variability in student evaluations in the ‘after’ group as compared to the ‘before’ group, providing support that the agile course development process provided a more consistent and similar experience for students. The second goal is to evaluate changes in student evaluations, comparing ‘before’ and ‘after’ groups. We did not expect to see substantial improvement since all instructors already received very high evaluations. Scores for all questions on the student evaluations increased after using the agile process, but the increases were not statistically significant. The final goal is to prepare an agenda for future research on agile course development based on components of The Agile Manifesto that were not used in the course development process. Opportunities include: comparing the agile course development process to other methods; adding more targeted questions to the student survey to better gauge changes in student satisfaction; partnering with alumni, current students, and industry to develop more relevant course material; and extending the process to other contexts

Discrete mode laser diodes with ultra narrow linewidth emission <3kHz

Ex-facet, free-running ultra-low linewidth (<3 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide discrete mode Fabry-Perot laser diode chips

Improving the Sensitivity of LISA

It has been shown in the past, that the six Doppler data streams obtained LISA configuration can be combined by appropriately delaying the data streams for cancelling the laser frequency noise. Raw laser noise is several orders of magnitude above the other noises and thus it is essential to bring it down to the level of shot, acceleration noises. A rigorous and systematic formalism using the techniques of computational commutative algebra was developed which generates all the data combinations cancelling the laser frequency noise. The relevant data combinations form a first module of syzygies. In this paper we use this formalism for optimisation of the LISA sensitivity by analysing the noise and signal covariance matrices. The signal covariance matrix, averaged over polarisations and directions, is calculated for binaries whose frequency changes at most adiabatically. We then present the extremal SNR curves for all the data combinations in the module. They correspond to the eigenvectors of the noise and signal covariance matrices. We construct LISA `network' SNR by combining the outputs of the eigenvectors which improves the LISA sensitivity substantially. The maximum SNR curve can yield an improvement upto 70 % over the Michelson, mainly at high frequencies, while the improvement using the network SNR ranges from 40 % to over 100 %. Finally, we describe a simple toy model, in which LISA rotates in a plane. In this analysis, we estimate the improvement in the LISA sensitivity, if one switches from one data combination to another as it rotates. Here the improvement in sensitivity, if one switches optimally over three cyclic data combinations of the eigenvector is about 55 % on an average over the LISA band-width. The corresponding SNR improvement is 60 %, if one maximises over the module.Comment: 16 pages, 10 figures, Submitted to Class. Quant. Gravit

Sensitivity and parameter-estimation precision for alternate LISA configurations

We describe a simple framework to assess the LISA scientific performance (more specifically, its sensitivity and expected parameter-estimation precision for prescribed gravitational-wave signals) under the assumption of failure of one or two inter-spacecraft laser measurements (links) and of one to four intra-spacecraft laser measurements. We apply the framework to the simple case of measuring the LISA sensitivity to monochromatic circular binaries, and the LISA parameter-estimation precision for the gravitational-wave polarization angle of these systems. Compared to the six-link baseline configuration, the five-link case is characterized by a small loss in signal-to-noise ratio (SNR) in the high-frequency section of the LISA band; the four-link case shows a reduction by a factor of sqrt(2) at low frequencies, and by up to ~2 at high frequencies. The uncertainty in the estimate of polarization, as computed in the Fisher-matrix formalism, also worsens when moving from six to five, and then to four links: this can be explained by the reduced SNR available in those configurations (except for observations shorter than three months, where five and six links do better than four even with the same SNR). In addition, we prove (for generic signals) that the SNR and Fisher matrix are invariant with respect to the choice of a basis of TDI observables; rather, they depend only on which inter-spacecraft and intra-spacecraft measurements are available.Comment: 17 pages, 4 EPS figures, IOP style, corrected CQG versio