2,538 research outputs found
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,
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 structureāIR 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 500Ā°C under flowing nitrogen. Transmission electron microscopy micrographs reveal highly crystalline uniform nanoparticles of 16Ā±2nm. The x-ray diffraction revealed single phase crystalline MZFO with an average crystallite size of around 14nm. The saturation magnetization ranged from 43to68emuāg 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 10ā90 to90ā10. The FTIRspectra revealed a shift in the first absorption region in the far IR from 566.98to549.62cmā1 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
Thymic Involution in Viable Motheaten (meĻ ) Mice is Associated with a Loss of Intrathymic Precursor Activity
Mice homozygous for the viable motheaten (meĻ
) allele manifest abnormalities in
thymocytopoiesis, are severely immunodeficient, and develop autoimmune disorders
early in life. Premature thymic involution occurs in meĻ
/meĻ
mice, and their bone marrow
prothymocytes are unable to repopulate the thymus of adoptive recipients following
intravenous (i.v.) transfer. However, analysis of thymocytopoiesis following intrathymic
(i.t.) adoptive transfer of bone marrow from meĻ
/meĻ
mice demonstrates the presence of
normal numbers of prothymocytes. To investigate intrathymic development in meĻ
/meĻ
mice, we determined intrathymic precursor cell number and activity. Dual labeling
analyses showed that an involuted meĻ
/meĻ
thymus is relatively enriched (fivefold) in
CD4ā CD8ā thymocytes (intrathymic precursor phenotype) compared with wild-type
(+/+) thymus. However, thymocytes from meĻ
/meĻ
mice were deficient in precursor
activity when adoptively transferred i.t. into irradiated recipients. Thymocytes
recovered from the involuted thymus of aged or steroid-treated normal mice also
displayed reduced precursor activity. However, the phenotypic profile of thymocyte
subsets from steroid-treated mice was enriched in single positive cells (mature
phenotype) and was distinctly different from the subset distribution of thymocytes in
meĻ
/meĻ
and aged mice. These results suggest that intrathymic precursor activity in
meĻ
/meĻ
mice is decreased, and may be reflective of decreased prothymocyte seeding to
the thymus in vivo, In addition, the results suggest that the thymic involution in meĻ
/meĻ
mice is not due solely to effects of corticosteroids
Thymic involution in viable motheaten (me(v)) mice is associated with a loss of intrathymic precursor activity
Mice homozygous for the viable motheaten (me(v)) allele manifest abnormalities in thymocytopoiesis, are severely immunodeficient, and develop autoimmune disorders early in life. Premature thymic involution occurs in me(v)/me(v) mice, and their bone marrow prothymocytes are unable to repopulate the thymus of adoptive recipients following intravenous (i.v.) transfer. However, analysis of thymocytopoiesis following intrathymic (i.t.) adoptive transfer of bone marrow from me(v)/me(v) mice demonstrates the presence of normal numbers of prothymocytes. To investigate intrathymic development in me(v)/me(v) mice, we determined intrathymic precursor cell number and activity. Dual labeling analyses showed that an involuted me(v)/me(v) thymus is relatively enriched (fivefold) in CD4-CD8- thymocytes (intrathymic precursor phenotype) compared with wild-type (+/+) thymus. However, thymocytes from me(v)/me(v) mice were deficient in precursor activity when adoptively transferred i.t. into irradiated recipients. Thymocytes recovered from the involuted thymus of aged or steroid-treated normal mice also displayed reduced precursor activity. However, the phenotypic profile of thymocyte subsets from steroid-treated mice was enriched in single positive cells (mature phenotype) and was distinctly different from the subset distribution of thymocytes in me(v)/me(v) and aged mice. These results suggest that intrathymic precursor activity in me(v)/me(v) mice is decreased, and may be reflective of decreased prothymocyte seeding to the thymus in vivo. In addition, the results suggest that the thymic involution in me(v)/me(v) mice is not due solely to effects of corticosteroids
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
One parameter control of the size of iron oxide nanoparticles synthesized in reverse micelles
Iron oxide nanoparticles were synthesized via reverse micelle methods. The initial iron concentration was varied, while maintaining all other parameters constant, in order to investigate the effect of the iron concentration on the resultant iron oxide nanoparticle size. Increasing the iron concentration from 0.125M to 0.5M yielded an increase in average nanoparticle diameter from 4.71 to 7.95 nm, as measured by transmission electron microscopy. Three other concentrations between 0.125M and 0.5M showed corresponding size variations, all with statistical significance. Magnetic characterization by vibrating sample magnetometry and powder x-ray diffraction was performed to verify proper phase and material. Further insight into the reverse micelle method was acquired along with the ability to tune the nanoparticle size
Cation occupancy determination in manganese zinc ferrites using Fourier transform infrared spectroscopy
The magnetic and electric properties of ferrites are influenced by the cation distribution within the crystalline spinel lattice. Methods such as extended x-ray-absorption fine structure(EXAFS) have been used to determine cation occupancies within the crystalline structure of materials such as manganesezincferrite (MZFO); however, it is not practical to be used for daily analysis. Fourier transform infrared (FTIR)spectroscopy is another technique which has the potential to determine cation occupancy while offering speed and convenience. In the literature it has been demonstrated that in ferrite systems FTIR data can be correlated to cation percentages when comparing tetrahedral (Td) and octahedral (Oh) sites. FTIRspectra were collected on a series of MZFO nanoparticles in the range from 200 to 600cmā1 and two absorbance peaks were observed. The first absorption region shifted with changing sample composition as calculated from transmission EXAFS experiments and elemental analysis. The data was normalized to the maximum of the peak of interest and the shifts were correlated to cation occupancy
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