10,079 research outputs found
A holey fiber based Brillouin laser
We demonstrate for the first time a Brillouin laser based on a Holey Fiber (HF). Using a simple Fabry-Perot resonator scheme containing a 75m long highly nonlinear HF with an effective area of 2.85µm2 we obtain a threshold of 125mW and a slope efficiency of ~70%
Economic profile of Florida's marine life industry
The marine life industry in Florida is defined as the harvest of live marine specimens (fish and
invertebrate species including plants, live rock and sand, and small “critters”) for commercial use,
primarily aquariums. This paper summarizes data collected on the industry since 1990, including
total landings, revenues, and trends over time. Regional analysis shows where the primary collecting
areas are located in Florida. Seasonal analysis shows when the majority of landings occur within the
year. Statistics on the number of participants by type (i.e., collector versus wholesaler) provide
insight into the size of the industry. Trends are evaluated in terms of changes across the 9-year
period from 1990 to 1998. In general, the number of licensed collectors has increased substantially,
landings of fish and animal invertebrates peaked in 1994, angelfish dominated the fish landings, live
rock dominated the invertebrate landings, and the average landings per trip have remained relatively
constant. (67pp.
1999 US tropical fish wholesaler survey: results and implications
A survey of marine life wholesalers was initiated in 1999 as a first step towards understanding the
nature of Florida’s marine life industry, the demand for Florida products, and the need for changes in
the way the industry is regulated. Florida firms deal primarily in marine species and collect much of
their own product. Wholesalers outside of Florida handle more freshwater species and purchase most
of their inventory, the majority from overseas suppliers. Dealers predict that the average firm size
will continue to grow as the industry consolidates. Niche markets for eco-friendly product will gain
momentum. In Florida, marketing strategies should point to the high quality of Florida species with
emphasis on the growing popularity of invertebrates. Wholesalers should look to provide buyers of
Florida product with more consistent quantities throughout the year. Resource managers will be
challenged to find ways to protect over-harvested species without interfering with the collection of
abundant species while considering the effect of new regulations. (42pp.
The Stellar and Gaseous Contents of the Orion Dwarf Galaxy
We present new KPNO 0.9-m optical and VLA HI spectral line observations of
the Orion dwarf galaxy. This nearby (D ~ 5.4 Mpc), intermediate-mass (M_dyn =
1.1x10^10 Solar masses) dwarf displays a wealth of structure in its neutral
ISM, including three prominent "hole/depression" features in the inner HI disk.
We explore the rich gas kinematics, where solid-body rotation dominates and the
rotation curve is flat out to the observed edge of the HI disk (~6.8 kpc). The
Orion dwarf contains a substantial fraction of dark matter throughout its disk:
comparing the 4.7x10^8 Solar masses of detected neutral gas with estimates of
the stellar mass from optical and near-infrared imaging (3.7x10^8 Solar masses)
implies a mass-to-light ratio of ~13. New H alpha observations show only
modest-strength current star formation (~0.04 Solar masses per year); this star
formation rate is consistent with our 1.4 GHz radio continuum non-detection.Comment: Astronomical Journal, in press. Full-resolution version available
from http://www.macalester.edu/~jcannon/pubs.htm
POLICY IMPLICATIONS OF RESTRICTED ACCESS STRATEGIES FOR MULTISPECIES FISHERIES
The commercial fishery that primarily targets king mackerel, stone crab, snappers, groupers and spiny lobster in Monroe and Collier counties is one of the most important commercial fisheries in Florida. These species currently face problems of overfishing and/or over capitalization. A dual-based restricted profit function is used to estimate the economic and technical interactions that exist in this multi-species fishery, primarily using own-price and cross-price elasticities of supply. It is found that the production technology does not exhibit input-output separability and nonjointness-in-inputs over all species groups. This result suggests that these key species may be more efficiently managed as a group, rather than with the use of existing single species regulations. Spiny lobster and stone crab, the dominant value species in the fishery, are shown to have very elastic substitution relationships with king mackerel.Resource /Energy Economics and Policy,
Corporate governance and the long-run performance of firms issuing seasoned equity: An Australian study
Corporate governance has been propelled to the forefront of contemporary business thinking by a string of high profile corporate collapses and dramatic regulatory responses in the United States, Australia and in other countries as well. A particularly extensive body of research has emerged surrounding the relationship between corporate governance and firm performance. We combine the governance literature with evidence on the long-term underperformance of firms issuing seasoned equity to examine the benefits of corporate governance in a setting where it is more likely to matter. That is, we address the question, Does good corporate governance mitigate post-issue underperformance? For a broad sample of Australian seasoned equity offerings and employing a comprehensive, self-constructed governance database, we first demonstrate that issuing firms substantially underperform a variety of benchmarks over the long term, confirming similar findings in the existing literature. We then find evidence that better-governed firms do not experience the same degree of post-issue underperformance. Our findings, which are robust to a variety of estimation methods and econometric specifications, are consistent with the windows of opportunity hypothesis and with equity raisings being an important channel through which better corporate governance can improve future performance
The M81 Group Dwarf Irregular Galaxy DDO 165. I. High Velocity Neutral Gas in a Post-Starburst System
We present new multi-configuration VLA HI spectral line observations of the
M81 group dIrr post-starburst galaxy DDO 165. The HI morphology is complex,
with multiple column density peaks surrounding a large region of very low HI
surface density that is offset from the center of the stellar distribution. The
bulk of the neutral gas is associated with the southern section of the galaxy;
a secondary peak in the north contains ~15% of the total HI mass. These
components appear to be kinematically distinct, suggesting that either tidal
processes or large-scale blowout have recently shaped the ISM of DDO 165. Using
spatially-resolved position-velocity maps, we find multiple localized
high-velocity gas features. Cross-correlating with radius-velocity analyses, we
identify eight shell/hole structures in the ISM with a range of sizes (~400-900
pc) and expansion velocities (~7-11 km/s). These structures are compared with
narrow- and broad-band imaging from KPNO and HST. Using the latter data, recent
works have shown that DDO 165's previous "burst" phase was extended temporally
(>1 Gyr). We thus interpret the high-velocity gas features, HI holes, and
kinematically distinct components of the galaxy in the context of the immediate
effects of "feedback" from recent star formation. In addition to creating HI
holes and shells, extended star formation events are capable of creating
localized high velocity motion of the surrounding interstellar material. A
companion paper connects the energetics from the HI and HST data.Comment: The Astrophysical Journal, in press. Full-resolution version
available on request from the first autho
Wave propagation in stereo-lithographical (STL) bone replicas at oblique incidence
Comparisons between predictions of a Biot-Allard model allowing for angle-dependent elasticity and
angle-and-porosity dependent tortuosity and transmission data obtained at normal incidence on
water-saturated replica bones are extended to oblique incidence. The model includes two parameters
which are adjusted for best fit at normal incidence. Using the same parameter values, it is found that predictions
of the variation of transmitted waveforms with angle through two types of bone replica are in
reasonable agreement with data despite the fact that scattering is not included in the theory
Competition in the market for takeover advisers
We investigate factors that motivate bidders to engage advisers, we model adviser selection and we test whether value-adding advisers gain market share. Our sample includes 801 attempted takeovers over 1989-1998 in Australia. Our results indicate advisers are likely to be engaged if the takeover deal is large, hostile, and includes non-cash compensation. We find deal completion is not as closely correlated with adviser rankings as does Rau (2000) but we confirm his finding that adviser ranked high on market value of deals advised do not have a comparative advantage in adding value to firms. However, we document some (limited) evidence that value- adding advisers achieve an increase in subsequent deal flow. Our results are consistent with specialization among takeover advisers
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