8,100 research outputs found
A deep redshift survey of field galaxies. Comments on the reality of the Butcher-Oemler effect
A spectroscopic survey of over 400 field galaxies has been completed in three fields for which we have deep UBVI photographic photometry. The galaxies typically range from B=20 to 22 and possess redshifts z from 0.1 to 0.5 that are often quite spiky in distribution. Little, if any, luminosity evolution is observed up to redshifts z approx 0.5. By such redshifts, however, an unexpectedly large fraction of luminous galaxies has very blue intrinsic colors that suggest extensive star formation; in contrast, the reddest galaxies still have colors that match those of present-day ellipticals
AN ECONOMIC ANALYSIS OF INTERNATIONAL FEED AND MALTING BARLEY MARKETS: AN ECONOMETRIC SPATIAL OLIGOPOLISTIC APPROACH
A "hybrid" spatial price equilibrium model is developed to evaluate changes in production, consumption, and trade of feed and malting barley under alternative domestic and agricultural trade policy regimes. The analysis includes the economic welfare impacts of changes in various farm subsidy programs on the United States, Canada, Australia, and European Union (EU-15) which are the four major barley exporting countries in the world. The actions of competitive U.S. grain traders under the Export Enhancement Program cause feed barley exports to be segmented into two distinct markets. A spatial equilibrium is established in which the Canadian Wheat Board and Australian marketing boards behave as oligopolists in export markets under arbitrage conditions induced by U.S. and EU-15 grain traders.Malting, Feed, Farm Subsidy, Trade Policy, Export Market, Welfare, International Relations/Trade,
CREATING, PROTECTING, AND USING CROP BIOTECHNOLOGIES WORLDWIDE IN AN ERA OF INTELLECTUAL PROPERTY
Proponents tout the positive incentive-to-innovate effects of intellectual property rights (IPRs), while others maintain that the expanding subject matter and geographical extent of IPRs are stifling crop research, especially research and development (R&D) dealing with developing-country crop concerns. Much of this debate relies on anecdotes and misleading or incomplete evidence on the extent and nature of the IPRs pertaining to crop technologies, including the jurisdictional extent of the property rights and their practice. In this paper we review the evidence on the scope of agricultural R&D worldwide, provide new data on the structure of crop-related IPRs, and summarize trends on the uptake of proprietary bioengineered crops.plant patents, utility patents, plant breeders' rights, crop varieties, public and private agricultural R&D, biotechnology, Research and Development/Tech Change/Emerging Technologies,
Modulational instability of two-component Bose-Einstein condensates in an optical lattice
We study modulational instability of two-component Bose-Einstein condensates
in an optical lattice, which is modelled as a coupled discrete nonlinear Schr
\"{o}dinger equation. The excitation spectrum and the modulational instability
condition of the total system are presented analytically. In the
long-wavelength limit, our results agree with the homogeneous two-component
Bose-Einstein condensates case. The discreteness effects result in the
appearance of the modulational instability for the condensates in miscible
region. The numerical calculations confirm our analytical results and show that
the interspecies coupling can transfer the instability from one component to
another.Comment: 4 pages, 3 figures (to be published in Phys. Rev. A
The Evolving Landscape of IP Rights for Plant Varieties in the United States, 1930-2008
The United States was the first country in the world to explicitly offer intellectual property protection for plant varieties. Beginning in 1930, asexually reproduced plants were afforded plant patent protection, in 1970 sexually propagated plants could be awarded plant variety protection certificates, and beginning in 1985, courts confirmed that varieties of all types of plants were eligible for utility patents. From 1930 to 2008, a total of 34,340 varietal rights applications were lodged. The number of rights being sought continues to grow, with 42 percent of all the varietal rights claimed since 2000. Contrary to popular perception, most of these rights are for horticultural crops (69 percent), with ornamentals accounting for the lion’s share of the horticulture-related rights (73 percent, or 50 percent of all plant rights). Food and feed crops constitute only 24 percent of the rights sought, although just two crops (corn and soybean) made up 84 percent of the 3,719 varietal rights claimed via utility patents. The structure of these rights has changed dramatically over the years. During the 1930s when the only rights on offer were plant patents, 72 percent of the rights sought were for ornamental crops and individual innovators played a substantial role (50 percent of the rights). By 2004-2008, the annual applications for plant patents had increased in number but fallen to a 60 percent share of the total rights claimed. During this recent period, utility patents were as popular as plant variety protection certificates, and ornamentals made up a large but much reduced share of the total (52 percent). Individual innovators accounted for only 12 percent of the rights, whereas the corporate sector sought the dominant share of varietal rights (82 percent in 2004-2008). These intellectual property markets are complex, with corporations, universities and other agencies seeking different types of rights for different crops.plant patents, plant variety protection, utility patents, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Resource /Energy Economics and Policy, Q16, Q18, O32, O34,
Exact Zeros of the Partition Function for a Continuum System with Double Gaussian Peaks
We calculate the exact zeros of the partition function for a continuum system
where the probability distribution for the order parameter is given by two
asymmetric Gaussian peaks. When the positions of the two peaks coincide, the
two separate loci of zeros which used to give first-order transition touch each
other, with density of zeros vanishing at the contact point on the positive
real axis. Instead of the second-order transition of Ehrenfast classification
as one might naively expect, one finds a critical behavior in this limit.Comment: 13 pages, 6 figures, revtex, minor changes in fig.2, to be published
in Physical Review
THE IMPACT OF THE EXPORT ENHANCEMENT PROGRAM ON INTERNATIONAL FEED BARLEY MARKETS
A "hybrid" spatial price equilibrium model is developed to evaluate differences in trade flows and equilibrium prices for feed and malting barley exports from the U.S., Canada, Australia, and European Union, caused by the U.S. Export Enhancement Program (EEP). The analysis incorporates the relationships among several policy instruments.Demand and Price Analysis, International Relations/Trade,
The economics of generating and maintaining plant variety rights in China:
Notwithstanding the ambiguous research and productivity promoting effects of plant variety protections (PVPs), even in developed countries, many developing countries have adopted PVPs in the past few years to comply with their Trade-Related Aspects of Intellectual Property Rights (TRIPS) obligations. Seeking and maintaining PVPs reserves options to an expected revenue stream from the future sale of protected varieties, the value of which varies for a host of reasons. In this paper we empirically examine the pattern of plant variety protection applications in China since its PVP laws were first introduced in 1997. We place those PVP rights in the context of China's present and likely future seed markets to identify the economic incentives and institutional aspects that influence decisions to develop and apply for varietal rights.intellectual property, patents, Ownership, Plant propagation, plant breeding, Trade policies, Plant introduction, Crop performance, China,
AN OPTION PERSPECTIVE ON GENERATING AND MAINTAINING PLANT VARIETY RIGHTS IN CHINA
Notwithstanding the ambiguous research and productivity promoting effects of plant variety protections (PVPs), even in developed countries, many developing countries have adopted PVPs in the past few years, in part to comply with their Trade-Related Aspects of Intellectual Property Rights (TRIPS) obligations. Seeking and maintaining PVPs reserves options to an expected revenue stream from the future sale of protected varieties, the value of which varies for a host of reasons. In this paper we empirically examine the pattern of plant variety protection applications in China since its PVP laws were first introduced in 1997. We place those PVP rights in the context of China's present and likely future seed markets to identify the economic incentives and institutional influences on decisions to develop and apply for varietal rights.intellectual property rights, crop improvement, option value, seed markets, Resource /Energy Economics and Policy,
A Search for X-Ray Bright Distant Clusters of Galaxies
We present the results of a search for X--ray luminous distant clusters of
galaxies. We found extended X--ray emission characteristic of a cluster towards
two of our candidate clusters of galaxies. They both have a luminosity in the
ROSAT bandpass of and a redshift of ;
thus making them two of the most distant X--ray clusters ever observed.
Furthermore, we show that both clusters are optically rich and have a known
radio source associated with them. We compare our result with other recent
searches for distant X--ray luminous clusters and present a lower limit of
for the number density of such high redshift
clusters. This limit is consistent with the expected abundance of such clusters
in a standard (b=2) Cold Dark Matter Universe. Finally, our clusters provide
important high redshift targets for further study into the origin and evolution
of massive clusters of galaxies. Accepted for publication in the 10th September
1994 issue of ApJ.Comment: 20 pages Latex file + 1 postscript figure file appende
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