3,387 research outputs found
The Implicit Value of Irrigation Through Parcel Level Hedonic Price Modeling
This paper relies on data associated 2,100 agricultural land sale transactions across two major Nebraska Watersheds (the Republican and Central Platte) over the 2000 to 2008 time period. The sales were spatially referenced (digitized into a GIS) in order to quantify and geo-spatially predict and map the implicit values of irrigation through the use of hedonic price modeling. Marginal implicit prices vary substantially across subwatersheds (natural resource districts), and the contribution of irrigation to sale prices is directly related to the extent to dependency of production agriculture on irrigation. This information is now currently being used to evaluate the economic efficiency of recent irrigation retirement programs and to help ensure that current and future retirement programs are cost-effective through targeting that retires irrigation land with the greatest hydrologic impact on water resources for the lowest cost.Farm Management, Production Economics, Resource /Energy Economics and Policy,
IMPLICIT PRICES OF WETLAND EASEMENTS
Farmland prices were regressed against sale size, gross production values, surrounding land uses and wetlands, and perpetual wetland easements administered by United States Fish and Wildlife Service. Each additional wet wetland acre reduced average cropland values by 234 which corresponds to 57% of local cropland values.Resource /Energy Economics and Policy,
THE FEASIBILITY OF WETLAND RESTORATION TO REDUCE FLOODING IN THE RED RIVER VALLEY: A CASE STUDY OF THE MAPLE RIVER WATERSHED, NORTH DAKOTA
The economic feasibility of alternative wetland restoration activities to store water and reduce flood damage was evaluated in the Maple River Watershed, North Dakota, a sub-watershed of the Red River of the North Watershed. The evaluation was based on recent hydrologic modeling and wetland restoration studies, the National Wetland Inventory, local land rental values, and site-specific historical flood damage. With benefit-cost ratios ranging from 0.08 to 0.13, neither simple wetland restoration based on plugging existing drains, nor restoration with outlet control devices, nor complete restoration intended to provide a full range of wetland-based environmental services were economically feasible over a 20-year future period. Peak flood stages and flood damage would need to be reduced by between 4 and 12 percent in order for wetland restoration options to break even. The inclusion of additional wetland benefits did not make wetland restoration economically feasible. It is, therefore, not recommended that public funds be used for extensive wetland restoration projects throughout the Maple River Watershed or the Red River Valley in order to reduce flood damage.Economic feasibility, wetland restoration, flooding, Red River Valley, Land Economics/Use,
THE INFLUENCE OF THE THREAT OF FLOODING ON HOUSING VALUES IN FARGO, NORTH DAKOTA AND MOORHEAD, MINNESOTA
The hedonic valuation method (HVM) was used to quantify the impact of the threat of flooding on housing values in Fargo, North Dakota and Moorhead, Minnesota (Fargo-Moorhead). Prices of 3,783 Fargo-Moorhead homes sold between 1995 and 1998 were regressed against structural housing characteristics, neighborhood and environmental indicators, and three flood risk variables. Being located in the 100-year floodplain lowered the sale price of an average home by 10,241 less than similar homes located outside the floodplain and before the 1997 flood event. The aftermath of publicity of the 1997 flood was specifically responsible for average 100-year floodplain homes being reduced by an additional 3,100 more than similar homes not in the floodplain. It was concluded that homebuyers in Fargo-Moorhead place a value on flooding risk, that more disclosure is needed regarding the location of the 500-year floodplain, and that substantial housing value related benefits are likely to be generated by various flood mitigation projects in the area that result in a re-designation and reduction of the 100-year floodplain.Hedonic valuation method, flooding, floodplain, Fargo, Moorhead, Red River of the North, housing values, Community/Rural/Urban Development,
On the relationship between sigma models and spin chains
We consider the two-dimensional non-linear sigma model with
topological term using a lattice regularization introduced by Shankar and Read
[Nucl.Phys. B336 (1990), 457], that is suitable for studying the strong
coupling regime. When this lattice model is quantized, the coefficient
of the topological term is quantized as , with integer or
half-integer. We study in detail the relationship between the low energy
behaviour of this theory and the one-dimensional spin- Heisenberg model. We
generalize the analysis to sigma models with other symmetries.Comment: To appear in Int. J. MOd. Phys.
New Cooperative Development Issues
This article briefly reviews the increased interest in new cooperative development, factors for successful cooperative development, and strategies to improve the performance of new and emerging cooperatives. The article highlights issues identified by a panel of cooperative leaders, USDA specialists and academic expertsCooperatives, New Cooperatives, Developing Cooperatives, Agribusiness, P13, L22, L43,
Na(V)1.5 sodium channel window currents contribute to spontaneous firing in olfactory sensory neurons
Olfactory sensory neurons (OSNs) fire spontaneously as well as in response to odor; both forms of firing are physiologically important. We studied voltage-gated Na+ channels in OSNs to assess their role in spontaneous activity. Whole cell patch-clamp recordings from OSNs demonstrated both tetrodotoxin-sensitive and tetrodotoxin-resistant components of Na+ current. RT-PCR showed mRNAs for five of the nine different Na+ channel α-subunits in olfactory tissue; only one was tetrodotoxin resistant, the so-called cardiac subtype NaV1.5. Immunohistochemical analysis indicated that NaV1.5 is present in the apical knob of OSN dendrites but not in the axon. The NaV1.5 channels in OSNs exhibited two important features: 1) a half-inactivation potential near −100 mV, well below the resting potential, and 2) a window current centered near the resting potential. The negative half-inactivation potential renders most NaV1.5 channels in OSNs inactivated at the resting potential, while the window current indicates that the minor fraction of noninactivated NaV1.5 channels have a small probability of opening spontaneously at the resting potential. When the tetrodotoxin-sensitive Na+ channels were blocked by nanomolar tetrodotoxin at the resting potential, spontaneous firing was suppressed as expected. Furthermore, selectively blocking NaV1.5 channels with Zn2+ in the absence of tetrodotoxin also suppressed spontaneous firing, indicating that NaV1.5 channels are required for spontaneous activity despite resting inactivation. We propose that window currents produced by noninactivated NaV1.5 channels are one source of the generator potentials that trigger spontaneous firing, while the upstroke and propagation of action potentials in OSNs are borne by the tetrodotoxin-sensitive Na+ channel subtypes.This work was aided by support from Boston University, the Rocky Mountain Taste and Smell Center Core for Cellular Visualization and Analysis [National Institute on Deafness and Other Communication Disorders (NIDCD) P30 DC-04657; D. Restrepo, principal investigator], and NIDCD Grants DC-04863 to V. Dionne and DC-006070 to D. Restrepo and T. E. Finger. (Boston University; P30 DC-04657 - Rocky Mountain Taste and Smell Center Core for Cellular Visualization and Analysis [National Institute on Deafness and Other Communication Disorders (NIDCD)]; DC-04863 - Rocky Mountain Taste and Smell Center Core for Cellular Visualization and Analysis [National Institute on Deafness and Other Communication Disorders (NIDCD)]; DC-006070 - Rocky Mountain Taste and Smell Center Core for Cellular Visualization and Analysis [National Institute on Deafness and Other Communication Disorders (NIDCD)])https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4122723/Accepted manuscrip
Searching for Weak or Complex Magnetic Fields in Polarized Spectra of Rigel
Seventy-eight high-resolution Stokes V, Q and U spectra of the B8Iae
supergiant Rigel were obtained with the ESPaDOnS spectropolarimeter at CFHT and
its clone NARVAL at TBL in the context of the Magnetism in Massive Stars
(MiMeS) Large Program, in order to scrutinize this core-collapse supernova
progenitor for evidence of weak and/or complex magnetic fields. In this paper
we describe the reduction and analysis of the data, the constraints obtained on
any photospheric magnetic field, and the variability of photospheric and wind
lines.Comment: IAUS272 - Active OB Stars: Structure, Evolution, Mass Loss and
Critical Limit
Control of the cation occupancies of MnZn ferrite synthesized via reverse micelles
Variations in cation occupancy in mixed metal ferrite systems can affect their electronic and magnetic properties. It is known that different synthesis parameters can lead to various cation distributions and the ability to tune these distributions is of great interest. This study uses the extended x-ray-absorption fine structure–IR relationship to investigate the effect of various Fe2+/Fe3+ ratios in initial synthesis conditions on cation distribution for manganesezincferrite (MZFO). Differences in the precipitated material before firing could lead to differences in the final material if fired under similar conditions. This work uses several different ratios of Fe3+/Fe2+, which will affect the initial cell potential for the reaction, to synthesize nano MZFO. All samples were fired for 5h at 500°C under flowing nitrogen. Transmission electron microscopy micrographs reveal highly crystalline uniform nanoparticles of 16±2nm. The x-ray diffraction revealed single phase crystalline MZFO with an average crystallite size of around 14nm. The saturation magnetization ranged from 43to68emu∕g as measured by vibrating-sample magnetometry. The Fourier transform infrared (FTIR) analysis was used to determine the cation occupancies while changing the initial Fe3+/Fe2+ ratios from 10∕90 to90∕10. The FTIRspectra revealed a shift in the first absorption region in the far IR from 566.98to549.62cm−1 corresponding to the octahedral occupancies. This shift corresponds to a change in the percentage of octahedral sites occupied by manganese from roughly 25% to 12%. This change in manganese occupancy is also observed in the iron occupancies, which in turn help to explain the variation in saturation magnetization
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