14,369 research outputs found
Consumer Purchases of Biotech Sweet Corn: Results from a Market Experiment
In the increasingly consumer-driven food system, consumer preferences toward agricultural biotechnology have the potential to influence decisions about development and adoption of biotech crop varieties. Current knowledge about consumer attitudes toward biotech foods is largely based on a number of consumer surveys and a growing body of experimental auctions. This paper reports results of a market experiment designed to isolate the effect of the use of biotechnology on consumer choices between two otherwise identical products. Two related varieties of fresh-market sweet corn were grown, labeled, and sold side-by-side in nine participating grocery stores in the Philadelphia area. Sales data indicate a market share of biotech corn of about 45 percent, with store-specific shares varying between 10 and 80 percent. Over 700 surveys were collected in stores. Surprisingly, only 65 percent of respondents noticed that there were two types of corn for sale despite the labeling and merchandising, and 87 percent of the sample spent one minute or less choosing their corn. About half of the respondents had heard of biotechnology before, and 16 percent volunteered the biotechnology trait as an influence on their purchase decision. Approximately 40 percent of the sample purchased some of the biotech variety, with several respondents purchasing some of each.Institutional and Behavioral Economics,
INCOME, WEALTH, AND THE ECONOMIC WELL-BEING OF FARM HOUSEHOLDS
Agricultural policy is rooted in the 1930s notion that providing transfers of money to the farm sector translates into increased economic well-being of farm families. This report shows that changes in income for the farm sector or for any particular group of farm businesses do not necessarily reflect changes confronting farm households. Farm households draw income from various sources, including off-farm work, other businesses operated, and increasingly nonfarm investments. Likewise, focus on a single indicator of well-being, like income, overlooks other indicators such as the wealth held by the household and the level of consumption expenditures for health care, food, housing, and other items. Using an expanded definition of economic well-being, we show that farm households as a whole are relatively better off than the average U.S. household, but that about 6 percent remain economically disadvantaged relative to the rest of the population.Consumption, farm households, income, wealth, well-being, off-farm employment, Consumer/Household Economics,
Bogged Down Trying to Define Federal Wetlands
This article examines these cases as well as the history, policies, and rationales behind identifying and conserving wetlands. It proposes a unique analytical method for valuation of wetlands. Under the proposed analysis, government agencies and landowners would be required to prepare economic impact statements containing cost/benefit analyses measuring the effects of wetlands delineations upon land values. These analyses would provide the basis for determining the value of preserving wetlands ecosystems as well as the basis for determining fair compensation payable to landowners in the event they suffer land use or income loss as a result of wetlands delineations
Bc spectroscopy in a quantum-chromodynamic potential model
We have investigated spectroscopy with the use of a
quantum-chromodynamic potential model which was recently used by us for the
light-heavy quarkonia. We give our predictions for the energy levels and the
1 transition widths. We also find, rather surprisingly, that although
is not a light-heavy system, the heavy quark effective theory with the
inclusion of the and corrections is as successful
for as it is for and .Comment: 10 page ReVTeX pape
Discovering the True Chrysoperla carnea (Insecta: Neuroptera: Chrysopidae) Using Song Analysis, Morphology, and Ecology
What was once considered a single Holarctic species of green lacewing, Chrysoperla carnea (Stephens), has recently been shown to be a complex of many cryptic, sibling species, the carnea species group, whose members are reproductively isolated by their substrate-borne vibrational songs. Because species in the complex are diagnosed by their song phenotypes and not by morphology, the current systematic status of the type species has become a problem. Here, we attempt to determine which song species corresponds to Stephens' 1835 concept of C. carnea, originally based on a small series of specimens collected in or near London and currently housed in The Natural History Museum. With six European members of the complex from which to choose, we narrow the field to just three that have been collected in England: C. lucasina (Lacroix), Cc2 ‘slow-motorboat', and Cc4 ‘motorboat'. Ecophysiology eliminates C. lucasina, because that species remains green during adult winter diapause, while Cc2 and Cc4 share with Stephens' type a change to brownish or reddish color in winter. We then describe the songs, ecology, adult morphology, and larval morphology of Cc2 and Cc4, making statistical comparisons between the two species. Results strongly reinforce the conclusion that Cc2 and Cc4 deserve separate species status. In particular, adult morphology displays several subtle but useful differences between the species, including the shape of the basal dilation of the metatarsal claw and the genital ‘lip' and ‘chin' of the male abdomen, color and coarseness of the sternal setae at the tip of the abdomen and on the genital lip, and pigment distribution on the stipes of the maxilla. Furthermore, behavioral choice experiments involving playback of conspecific versus heterospecific songs to individuals of Cc2 and Cc4 demonstrate strong reproductive isolation between the two species. Comparison of the adult morphology of song-determined specimens to that of preserved specimens in the original type series and in other collections in The Natural History Museum, London, indicate that the ‘true' Chrysoperla carnea (Stephens) is Cc4. Cc2 cannot be confidently associated with any previously described species and is therefore assigned a new name, Chrysoperla pallida sp. nov., and formally describe
Cosmic No Hair for Braneworlds with a Bulk Dilaton Field
Braneworld cosmology supported by a bulk scalar field with an exponential
potential is developed. A general class of separable backgrounds for both
single and two-brane systems is derived, where the bulk metric components are
given by products of world-volume and bulk coordinates and the world-volumes
represent any anisotropic and inhomogeneous solution to an effective
four-dimensional Brans-Dicke theory of gravity. We deduce a cosmic no hair
theorem for all ever expanding, spatially homogeneous Bianchi world-volumes and
find that the spatially flat and isotropic inflationary scaling solution
represents a late-time attractor when the bulk potential is sufficiently flat.
The dependence of this result on the separable nature of the bulk metric is
investigated by applying the techniques of Hamilton-Jacobi theory to
five-dimensional Einstein gravity. We employ the spatial gradient expansion
method to determine the asymptotic form of the bulk metric up to third-order in
spatial gradients. It is found that the condition for the separable form of the
metric to represent the attractor of the system is precisely the same as that
for the four-dimensional world-volume to isotropize. We also derive the
fourth-order contribution to the Hamilton-Jacobi generating functional.
Finally, we conclude by placing our results within the context of the
holographic approach to braneworld cosmology.Comment: 13 pages, uses RevTeX
Statistically Motivated Second Order Pooling
Second-order pooling, a.k.a.~bilinear pooling, has proven effective for deep
learning based visual recognition. However, the resulting second-order networks
yield a final representation that is orders of magnitude larger than that of
standard, first-order ones, making them memory-intensive and cumbersome to
deploy. Here, we introduce a general, parametric compression strategy that can
produce more compact representations than existing compression techniques, yet
outperform both compressed and uncompressed second-order models. Our approach
is motivated by a statistical analysis of the network's activations, relying on
operations that lead to a Gaussian-distributed final representation, as
inherently used by first-order deep networks. As evidenced by our experiments,
this lets us outperform the state-of-the-art first-order and second-order
models on several benchmark recognition datasets.Comment: Accepted to ECCV 2018. Camera ready version. 14 page, 5 figures, 3
table
Backlund Transformations, D-Branes, and Fluxes in Minimal Type 0 Strings
We study the Type 0A string theory in the (2,4k) superconformal minimal model
backgrounds, focusing on the fully non-perturbative string equations which
define the partition function of the model. The equations admit a parameter,
Gamma, which in the spacetime interpretation controls the number of background
D-branes, or R-R flux units, depending upon which weak coupling regime is
taken. We study the properties of the string equations (often focusing on the
(2,4) model in particular) and their physical solutions. The solutions are the
potential for an associated Schrodinger problem whose wavefunction is that of
an extended D-brane probe. We perform a numerical study of the spectrum of this
system for varying Gamma and establish that when Gamma is a positive integer
the equations' solutions have special properties consistent with the spacetime
interpretation. We also show that a natural solution-generating transformation
(that changes Gamma by an integer) is the Backlund transformation of the KdV
hierarchy specialized to (scale invariant) solitons at zero velocity. Our
results suggest that the localized D-branes of the minimal string theories are
directly related to the solitons of the KdV hierarchy. Further, we observe an
interesting transition when Gamma=-1.Comment: 17 pages, 3 figure
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