3,707 research outputs found
Donât Demean âInvasivesâ: Conservation and Wrongful Species Discrimination
It is common for conservationists to refer to non-native species that have undesirable impacts on humans as âinvasiveâ. We argue that the classification of any species as âinvasiveâ constitutes wrongful discrimination. Moreover, we argue that its being wrong to categorize a species as invasive is perfectly compatible with it being morally permissible to kill animalsâassuming that conservationists âkill equallyâ. It simply is not compatible with the double standard that conservationists tend to employ in their decisions about who lives and who dies
HEDONIC PRICE ESTIMATION FOR COMMODITIES: AN APPLICATION TO COTTON
A model of hedonic prices Ăâ implicit prices of embodied quality attributes Ăâ was developed for cotton lint and the relative importance of various quality attributes were estimated with regression analysis from sample data on observed sales of cotton. Results indicated that producer prices were sensitive to variations in fiber length, micronaire, and trash content. Results also revealed differences in relative importance and sensitivity between years.Crop Production/Industries, Demand and Price Analysis,
Invisible Quarkonium Decays as a Sensitive Probe of Dark Matter
We examine in a model-independent manner the measurements that can be
performed at B-factories with sensitivity to dark matter. If a singlet scalar,
pseudo-scalar, or vector is present and mediates the Standard Model - dark
matter interaction, it can mediate invisible decays of quarkonium states such
as the , , and . Such scenarios have arisen in the
context of supersymmetry, extended Higgs sectors, solutions the supersymmetric
problem, and extra U(1) gauge groups from grand unified theories and
string theory. Existing B-factories running at the can produce
lower resonances by emitting an Initial State Radiation (ISR)
photon. Using a combination of ISR and radiative decays, the initial state of
an invisibly decaying quarkonium resonance can be tagged, giving sensitivity to
the spin and CP-nature of the particle that mediates standard model-dark matter
interactions. These measurements can discover or place strong constraints on
dark matter scenarios where the dark matter is approximately lighter than the
-quark. For the decay chains
(n=2,3) we analyze the dominant backgrounds and determine that with collected at the , the B-factories can limit
BR(\Upsilon(1S) \to invisible) \lsim 0.1%.Comment: 20 pages, 1 figure, accepted for publication in PR
Reference Revitalization and Roving Reference: Are the Reference Desk and Print Reference Sources Passé?
Print reference sources and references desks are still vital parts of reference service in some libraries, while in others innovative models such as roving reference and learning commons thrive. While undergraduate studentsâ preferences and usage has shifted from print to electronic, students still need to learn the application of metacognitive thinking skills in library research. Updating how reference is delivered to accommodate studentsâ emphasis on mobility and expectation of access to information has led to revitalizing reference collections, reconfiguring space as learning commons and roving reference as solutions at Taylor University and Palm Beach Atlantic University, while Whitworth University retains a more traditional configuration to meet student research needs
Progressive Mauve: Multiple alignment of genomes with gene flux and rearrangement
Multiple genome alignment remains a challenging problem. Effects of
recombination including rearrangement, segmental duplication, gain, and loss
can create a mosaic pattern of homology even among closely related organisms.
We describe a method to align two or more genomes that have undergone
large-scale recombination, particularly genomes that have undergone substantial
amounts of gene gain and loss (gene flux). The method utilizes a novel
alignment objective score, referred to as a sum-of-pairs breakpoint score. We
also apply a probabilistic alignment filtering method to remove erroneous
alignments of unrelated sequences, which are commonly observed in other genome
alignment methods. We describe new metrics for quantifying genome alignment
accuracy which measure the quality of rearrangement breakpoint predictions and
indel predictions. The progressive genome alignment algorithm demonstrates
markedly improved accuracy over previous approaches in situations where genomes
have undergone realistic amounts of genome rearrangement, gene gain, loss, and
duplication. We apply the progressive genome alignment algorithm to a set of 23
completely sequenced genomes from the genera Escherichia, Shigella, and
Salmonella. The 23 enterobacteria have an estimated 2.46Mbp of genomic content
conserved among all taxa and total unique content of 15.2Mbp. We document
substantial population-level variability among these organisms driven by
homologous recombination, gene gain, and gene loss. Free, open-source software
implementing the described genome alignment approach is available from
http://gel.ahabs.wisc.edu/mauve .Comment: Revision dated June 19, 200
Monopoles, strings and dark matter
We develop a scenario whereby monopoles in a hidden sector yield a decaying
dark matter candidate of interest for the PAMELA and FERMI excesses.
The monopoles are not completely hidden due to a very small kinetic mixing and
a hidden photon mass. The latter also causes the monopoles and anti-monopoles
to be connected by strings. The resulting long-lived objects eventually decay
to hidden photons which tend to escape galactic cores before decaying. The mass
scales are those of the hidden photon ( MeV), the monopole
( TeV) and the mixing scale (close to the Planck scale). A gauge
coupling in the hidden sector is the only other parameter. This coupling must
be strong and this results in light point-like monopoles and light thin
strings.Comment: 21 pages, various improvements and additional reference
Ranking capital investment alternatives: a computer simulation
A computer simulation model is used to compare the relative effectiveness of ten capital budgeting ranking techniques. The model consists of a cash flow simulator that generates mutually exclusive and independent projects. The projects are then ranked according to a pre-selected criteria, and accepted for investment until the available funds are exhausted. This continues for several periods, and at the horizon date the net value of the firm and the rate of return realized on initial funds supplied the firm are used to compare ranking criteria
Applications of SLR
Satellite Laser Ranging (SLR) has a rich history of development which began in the 1960s with 10 meter-level first generation systems. These systems evolved with order of magnitude improvements to the systems that now produce several millimeter single shot range precisions. What began, in part, as an interesting application of the new laser technology has become an essential component of modern, precision space geodesy, which in turn enables contributions to a variety of science areas. Modern space geodesy is the beneficiary of technological developments which have enabled precision geodetic measurements. Aside from SLR and its closely related technique, Lunar Laser Ranging (LLR), Very Long Baseline Interferometry (VLBI) has made prominent science contributions also. In recent years, the Global Positioning System (GPS) has demonstrated a rapidly growing popularity as the result of demonstrated low cost with high precision instrumentation. Other modern techniques such as DORIS have demonstrated the ability to make significant science contributions; furthermore, PRARE can be expected to contribute in its own right. An appropriate question is 'why should several techniques be financially supported'? While there are several answers, I offer the opinion that, in consideration of the broad science areas that are the benefactors of space geodesy, no single technique can meet all the requirements and/or expectations of the science areas in which space geodesy contributes or has the potential for contributing. The more well-known science areas include plate tectonics, earthquake processes, Earth rotation/orientation, gravity (static and temporal), ocean circulation, land, and ice topography, to name a few applications. It is unfortunate that the modern space geodesy techniques are often viewed as competitive, but this view is usually encouraged by funding competition, especially in an era of growing needs but diminishing budgets. The techniques are, for the most part, complementary and the ability to reduce the data to geodetic parameters from several techniques promotes confidence in the geophysical interpretations. In the following sections, the current SLR applications are reviewed in the context of the other techniques. The strengths and limitations of SLR are reviewed and speculation about the future prospects are offered
Synergism of SLR and GPS
The launch of GPS-35 (RPN 5) with a laser retroreflector has provided an opportunity to compare SLR-determined orbits of a GPS satellite with those determined by GPS receivers operated with the transmitted radio signals on the L(sub 1) and L(sub 2) frequencies. Operational considerations of the SLR and hardware design have influenced the amount and quality of SLR data collected on this satellite. As of February 1, 1994, all of the collected SLR data have been collected from northern hemisphere stations. Adequate southern hemisphere coverage is required to fully compare the results obtained from L(sub 1)/L(sub 2) and from SLR
INFLUENCE OF THIRD BODY LONG PERIODS PERTURBATIONS ON THE SECULAR RATES DUE TO EARTH OBLATENESS
Equations for long period and secular perturbations due to the Moon, Sun and the Earth potential field are applied to equations expressing the influence of both the Moon and Sun long period and secular perturbations on the secular rates due to the Earth potential field. Usual Keplerian elements are used. No singularities are present in the equations neither in the final integrated variables
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