529 research outputs found
THE EFFECT OF FEEDGRAIN PROGRAM PARTICIPATION ON CHEMICAL USE
Economic incentives created by the commodity programs are hypothesized to cause program participants to apply agrichemicals at greater rates than nonparticipants. Corn producers who participate in the USDA feedgrain program are shown to apply nitrogen, herbicides, and insecticides at statistically greater rates than those who do not participate.Crop Production/Industries,
15 Years: 15 Points of Progress, Transformational Leadership, 1997-2010 [Western Kentucky University]
This report, 15 Years: 15 Points of Progress, documents the most significant changes at WKU since our transformation began in late Fall, 1997. Our success is measurable. Our achievements are significant. Most importantly, our transformation is a lasting one
AGRICULTURE IN AN ECOSYSTEMS FRAMEWORK
By broadening the definition of an ecosystem to include economic activities, can we better characterize the interactions and relationships among agricultural activities and important indicators of ecological system health? This paper addresses research approaches for assessing the role of agriculture in an ecosystems context. Environmental regulation and resource management policies have heightened the interest in understanding interactions among agricultural activities and the natural resource base, including the impacts of agriculture on environmental quality and the impacts on agriculture of ecosystem restoration efforts. What are the most meaningful indicators of environmental quality? Which agricultural practices and policies should be considered, along with which nonagricultural resource uses? Finally, does the evolving thinking about ecosystems permit us to link agricultural practices and policies more directly and meaningfully to conceptions of sustainability, of both natural and socioeconomic systems? This paper presents a brief synopsis of ecosystem management, drawing from several recent governmental initiatives. It then provides an overview of the economics of ecosystem management from the perspective of the role of agriculture; discusses two specific cases, the Pacific Northwest and South Florida; and concludes with a discussion of promising economic approaches, data needs, and caveats to those engaged in policy analysis involving ecosystem restoration.Environmental Economics and Policy,
Multivariate Estimations of Equilibrium Climate Sensitivity from Short Transient Warming Simulations
One of the most used metrics to gauge the effects of climate change is the
equilibrium climate sensitivity, defined as the long-term (equilibrium)
temperature increase resulting from instantaneous doubling of atmospheric
CO. Since global climate models cannot be fully equilibrated in practice,
extrapolation techniques are used to estimate the equilibrium state from
transient warming simulations. Because of the abundance of climate feedbacks -
spanning a wide range of temporal scales - it is hard to extract long-term
behaviour from short-time series; predominantly used techniques are only
capable of detecting the single most dominant eigenmode, thus hampering their
ability to give accurate long-term estimates. Here, we present an extension to
those methods by incorporating data from multiple observables in a
multi-component linear regression model. This way, not only the dominant but
also the next-dominant eigenmodes of the climate system are captured, leading
to better long-term estimates from short, non-equilibrated time series.Comment: Main Text (10 pages, 4 figures) plus Supporting Information (36
pages, 18 figures, 1 table
Projections of the Transient State-Dependency of Climate Feedbacks
When the climate system is forced, e.g. by emission of greenhouse gases, it
responds on multiple time scales. As temperatures rise, feedback processes
might intensify or weaken. Current methods to analyze feedback strength,
however, do not take such state dependency into account; they only consider
changes in (global mean) temperature and assume all feedbacks are linearly
related to that. This makes (transient) changes in feedback strengths almost
intangible and generally leads to underestimation of future warming. Here, we
present a multivariate (and spatially explicit) framework that facilitates
dissection of climate feedbacks over time scales. Using this framework,
information on the composition of projected (transient) future climates and
feedback strengths can be obtained. Moreover, it can be used to make
projections for many emission scenarios through linear response theory. The new
framework is illustrated using the Community Earth System Model version 2
(CESM2).Comment: main text: 11 pages, 4 figures, 1 table Supporting Information: 14
pages, 17 figures, 1 table, 8 movie
Compactness for Holomorphic Supercurves
We study the compactness problem for moduli spaces of holomorphic supercurves
which, being motivated by supergeometry, are perturbed such as to allow for
transversality. We give an explicit construction of limiting objects for
sequences of holomorphic supercurves and prove that, in important cases, every
such sequence has a convergent subsequence provided that a suitable extension
of the classical energy is uniformly bounded. This is a version of Gromov
compactness. Finally, we introduce a topology on the moduli spaces enlarged by
the limiting objects which makes these spaces compact and metrisable.Comment: 38 page
Large Scale Matrix Degradation by Stromal Cells Independent of Invadopodia
Invadopodia are actin-rich structures at the base of many neoplastic cells that sequester matrix metalloproteases that act to degrade the surrounding stroma to facilitate the invasive process. Conventional invadopodia are dependent upon Src kinase and the large GTPase dynamin 2 (Dyn 2). Whether invadopodia are the only mechanism by which cells degrade matrix is unclear. We have observed that cells of mesenchymal origin degrade matrix in an unique way different from tumor cells. The HYPOTHESIS of this study is that fibroblasts, and other cells of mesenchymal origin, degrade matrix by a mechanism distinct from that of epithelial-based tumor cells. The CONCLUSION is that stromal cells degrade matrix by a novel mechanism distinct from traditional invadopodia
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