Valuing Private and Public Greenspace Using Remotely Sensed Vegetation Indices

In a typical metropolitan area, greenspace varies substantially in its quality and extent. Remotely sensed vegetation index data is used to characterize the heterogeneity in private and public greenspace (riparian corridors) in metropolitan Tucson, Arizona. This data set enables the researcher to test if: (1) greenness is a significant determinant of house price variation in this desert city; and (2) whether there is an interaction between public and private greenspace. Private greenspace amenities can be endogenously improved by homeowners as a complement or substitute for the greenspace that is publicly provided, whereas public greenspace might be exogenous or endogenous depending on households ability to pressure the local government to protect or restore public greenspace. The results of a Hausman test indicate that endogeneity is a problem in the dataset and therefore an instrumental variable two stage least squares estimation is used. The results of this analysis indicate that homebuyers in the study area have preferences for both greener lots and greener riparian corridors and that private and public greenspace appear to be substitutes. Results are robust across multiple identification strategies designed to address potential endogeneity. The study results could have fundamental implications for the efficient use of limited water supplies in this semi-arid metropolitan area.Resource /Energy Economics and Policy,

How Do Homebuyers Value Different Types of Green Space?

It is important to understand tradeoffs in preferences for natural and constructed green space in semi-arid urban areas because these lands compete for scarce water resources. We perform a hedonic study using high resolution, remotely-sensed vegetation indices and house sales records. We find that homebuyers in the study area prefer greener lots, greener neighborhoods, and greener nearby riparian corridors, and they pay premiums for proximity to green space amenities. The findings have fundamental implications for the efficient allocation of limited water supplies between different types of green space and for native vegetation conservation in semi-arid metropolitan areas.hedonic model, locally weighted regression, spatial, open space, golf course, park, riparian, Consumer/Household Economics, Land Economics/Use,

Do Homebuyers Care about the 'Quality' of Natural Habitats?

We study if homebuyers in Tucson, Arizona care about the condition of natural habitats and if they have preferences between natural and manmade habitats. Using field work data we examine whether homebuyers willingness to pay is influenced by the biological condition of the neighboring riparian habitat and how homebuyers value alternative manmade green areas, specifically golf courses. We also explore the relationship between the field data and remote sensing vegetation indices. The results of a hedonic analysis of houses that sold within 0.2 miles of 51 stratified-random selected riparian survey sites in Tucson, Arizona reveals that homebuyers significantly value habitat quality and negatively value manmade park-like features. Homebuyers are willing to pay twenty percent more to live near a riparian corridor that is densely vegetated and contains more shrub and tree species, particularly species that are dependent on perennial water flow. These environmental premiums are significant, outweighing structural factors such as an additional garage or swimming pool. Likewise, proximity to a riparian habitat with low biological quality or to a golf course lowers property values.Land Economics/Use,

Shear Stress Measurements of Non-Spherical Particles in High Shear Rate Flows

The behavior of liquid-solid flows varies greatly depending on fluid viscosity; particle and liquid inertia; and collisions and near-collisions between particles. Shear stress measurements were made in a coaxial rheometer with a height to gap ratio (b/r0) of 11.7 and gap to outer radius ratio (h/b) of 0.166 that was specially designed to minimize the effects of secondary flows. Experiments were performed for a range of Reynolds numbers, solid fractions and ratio of particle to fluid densities. With neutrally buoyant particles, the dimensional shear stress exhibits a linear dependence on Reynolds number: the slope is monotonic but a non-linear function of the solid fraction. Though non-neutrally buoyant particles exhibit a similar linear dependence at higher Reynolds numbers, at lower values the shear stress exhibits a non-linear behavior in which the stress increases with decreasing Reynolds number due to particle settling

Elasticity of smectic liquid crystals with focal conic domains

We study the elastic properties of thermotropic smectic liquid crystals with focal conic domains (FCDs). After the application of the controlled preshear at different temperatures, we independently measured the shear modulus G' and the FCD size L. We find out that these quantities are related by the scaling relation G' ~ \gamma_{eff}/L where \gamma_{eff} is the effective surface tension of the FCDs. The experimentally obtained value of \gamma_{\rm eff} shows the same scaling as the effective surface tension of the layered systems \sqrt{KB} where K and B are the bending modulus and the layer compression modulus, respectively. The similarity of this scaling relation to that of the surfactant onion phase suggests an universal rheological behavior of the layered systems with defects.Comment: 14 pages, 7 figures, accepted for publication in JPC

Multivisceral intestinal transplantation: Surgical pathology

We report the diagnostic surgical pathology of two children who underwent multivisceral abdominal transplantation and survived for 1 month and 6 months. There is little relevant literature, and diagnostic criteria for the various clinical possibilities are not established; this is made more complicated by the simultaneous occurrence of more than one process. We based our interpretations on conventional histology, augmented with immunohistology, including HLA staining that distinguished graft from host cells in situ. In some instances functional analysis of T cells propagated from the same biopsies was available and was used to corroborate morphological interpretations. A wide spectrum of changes was encountered. Graft-versus-host disease, a prime concern before surgery, was not seen. Rejection was severe in 1 patient, not present in the other, and both had evidence of lymphoproliferative disease, which was related to Epstein-Barr virus. Bacterial translocation through the gut wall was also a feature in both children. This paper documents and illustrates the various diagnostic possibilities.. © 1989 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

Foundations of character: methodological aspects of a study of character development in three- to six-year-old children with a focus on sharing behaviours

This article focuses on methodological issues arising in a study of character development, using illustrations of ‘sharing behaviours.’ Based primarily in six early years settings in southeast England the research records naturalistic observations of peer interactions for 55 children aged three to six years. Applying grounded theory to the processes of observing, analysing and interpreting evidence required a cautious and collectively reflective approach. The methodology sought to moderate the influence of the researchers' prior knowledge of ‘grand theories’ of moral development and assumptions about relevance to the observation records. The study's originality lay in the exploration of moral development without reference to any particular grand theory as an explanatory framework; and in the reluctance to be drawn to potentially simplistic rationalisations of the children's intentions on the basis of their observed behaviours. Exploring young children's subjective experiences, this research provides insights into the intricacy of this process, steering away from ‘neat’ findings and attempting to reflect the sophistication of the children's skilful and sometimes surprising negotiations of moral dilemmas. Implications for practice relate to the complexities involved in attempts to unravel the developing moral characters of young children and the practice through which this may be nurtured

Critical behaviour of the Rouse model for gelling polymers

It is shown that the traditionally accepted "Rouse values" for the critical exponents at the gelation transition do not arise from the Rouse model for gelling polymers. The true critical behaviour of the Rouse model for gelling polymers is obtained from spectral properties of the connectivity matrix of the fractal clusters that are formed by the molecules. The required spectral properties are related to the return probability of a "blind ant"-random walk on the critical percolating cluster. The resulting scaling relations express the critical exponents of the shear-stress-relaxation function, and hence those of the shear viscosity and of the first normal stress coefficient, in terms of the spectral dimension $d_{s}$ of the critical percolating cluster and the exponents $\sigma$ and $\tau$ of the cluster-size distribution.Comment: 9 pages, slightly extended version, to appear in J. Phys.