THE IMPACT OF POPULATION GROWTH ON RESIDENTIAL PROPERTY TAXES

A multivariate model of the effect of population on local fiscal behavior, assessed value of property and average single family home values is estimated using cross-sectional data from Oregon. Regression results suggest that property tax levies are unit elastic with respect to population, that the total assessed value of property increases less than proportionally with population, and that the average value of a single family home increases with population. These results imply a positive relationship between population and both property tax rates and the tax bill of the average single family homeowner. Ceteris paribus, increases in average residential property taxes are associated with increases in population.Public Economics,

Response of Bird Populations to Long-term Changes in Local Vegetation and Regional Forest Cover

We analyzed data from a woodland site for a 59-year period to determine whether changes in bird populations are related to changes in the diversity and relative abundance of woody plant species even when vegetation structure, degree of forest fragmentation in the surrounding landscape, and regional changes in bird populations are taken into account. Principal component analyses generated vegetation factors encompassing variables such as total basal area, shrub density, basal area of common tree species, and measures of tree and shrub species diversity. We also calculated a forest edge/ forest area index based on GIS analysis of the landscape within 2 km of the study site. Poisson regression models revealed relationships between these covariates and population changes for 19 bird species and for seven groups of species characterized by similar migration strategies or habitat requirements. All groups of habitat specialists showed a positive relationship with the first vegetation factor, which indicates that they declined as total basal area and dominance of oaks and maples increased and as tree and shrub diversity decreased. This suggests that floristic diversity may be important for determining habitat quality. Bird species associated with the shrub layer and with hemlock stands showed positive relationships with the second vegetation factor, suggesting that the recent decline in eastern hemlocks (Tsuga canadensis) because of hemlock woolly adelgid (Adelges tsugae) had an adverse impact on these species. Forest migrants, shrub-layer specialists, long-distance migrants and permanent residents showed negative relationships with the forest edge/forest interior index, indicating that conservation efforts to protect bird communities should take the wider landscape into account. The strongest relationship for most species and species groups was with the first vegetation factor, which suggests that species composition and diversity of trees and shrubs may be especially important in determining abundance of many forest bird species

Information seeking in the Humanities: physicality and digitality

This paper presents a brief overview of a research project that is examining the information seeking practices of humanities scholars. The results of this project are being used to develop digital resources to better support these work activities. Initial findings from a recent set of interviews is offered, revealing the importance of physical artefacts in the humanities scholars’ research processes and the limitations of digital resources. Finally, further work that is soon to be undertaken is summarised, and it is hoped that after participation in this workshop these ideas will be refined

Space station full-scale docking/berthing mechanisms development

One of the most critical operational functions for the space station is the orbital docking between the station and the STS orbiter. The program to design, fabricate, and test docking/berthing mechanisms for the space station is described. The design reflects space station overall requirements and consists of two mating docking mechanism halves. One half is designed for use on the shuttle orbiter and incorporates capture and energy attenuation systems using computer controlled electromechanical actuators and/or attenuators. The mating half incorporates a flexible feature to allow two degrees of freedom at the module-to-module interface of the space station pressurized habitat volumes. The design concepts developed for the prototype units may be used for the first space station flight hardware

Impactite and pseudotachylite from Roter Kamm Crater, Namibia

Pseudotachylite is known to occur in a variety of geologic settings including thrust belts (e.g., the Alps and the Himalayas) and impact craters such as Roter Kamm, Namibia. Controversy exists, however, as to whether pseudotachylite can be produced by shock brecciation as well as by tectonic frictional melting. Also open to debate is the question of whether pseudotachylites form by frictional fusion or by cataclasis. It was speculated that the pseudotachylite at Roter Kamm was formed by extensional settling and adjustment of basement blocks during 'late modification stage' of impact. The occurrence of pseudotachylite in association with rocks resembling quenched glass bombs and melt breccias in a relatively young crater of known impact origin offers a rare opportunity to compare features of these materials. Petrographic, x-ray diffraction, and electron microprobe analyses of the impactites and pseudotachylites are being employed to determine the modes of deformation and to assess the role of frictional melting and comminution of adjacent target rocks

The continuous strength method for the design of circular hollow sections

Circular hollow sections (CHS) are widely used in a range of structural engineering applications. Their design is covered by all major design codes, which currently use elastic, perfectly-plastic material models and cross-section classification to determine cross-secti\on compressive and flexural resistances. Experimental data for stocky sections show that this can result in overly conservative estimates of cross-section capacity. The continuous strength method (CSM) has been developed to reflect better the observed behaviour of structural sections of different metallic materials. The method is deformation based and allows for the rational exploitation of strain hardening. In this paper, the CSM is extended to cover the design of non-slender and slender structural steel, stainless steel and aluminium CHS, underpinned by and validated against 342 stub column and bending test results. Comparisons with the test results show that, overall, the CSM on average offers more accurate and less scattered predictions of axial and flexural capacities than existing design methods

WFPC2 LRF Imaging of Emission Line Nebulae in 3CR Radio Galaxies

We present HST/WFPC2 Linear Ramp Filter images of high surface brightness emission lines (either [OII], [OIII], or H-alpha+[NII]) in 80 3CR radio sources. We overlay the emission line images on high resolution VLA radio images (eight of which are new reductions of archival data) in order to examine the spatial relationship between the optical and radio emission. We confirm that the radio and optical emission line structures are consistent with weak alignment at low redshift (z < 0.6) except in the Compact Steep Spectrum (CSS) radio galaxies where both the radio source and the emission line nebulae are on galactic scales and strong alignment is seen at all redshifts. There are weak trends for the aligned emission line nebulae to be more luminous, and for the emission line nebula size to increase with redshift and/or radio power. The combination of these results suggests that there is a limited but real capacity for the radio source to influence the properties of the emission line nebulae at these low redshifts (z < 0.6). Our results are consistent with previous suggestions that both mechanical and radiant energy are responsible for generating alignment between the radio source and emission line gas.Comment: 80 pages, 54 figures. Accepted for publication in ApJ

Phonological working memory impacts on information searching: An investigation of dyslexia

A key aspect of searching is the ability of users to absorb information from documents read in order to resolve their ask. One group of users who have problems with reading are dyslexic users, who due to underlying cognitive impairments in phonological processing and working memory, tend to read more slowly and make reading errors. The purpose of this study is to examine the impact of the dyslexia cognitive profile on information searching. Searches were logged for 8 dyslexic and 8 non-dyslexic university students, in order to examine the differences in searching behavior between the two groups. A set of literacy and phonological working memory tasks were also completed, in order to investigate the relationship between these cognitive variables and searching behavior. Results show that there is a significant difference between the two groups on the number of documents being judged irrelevant, and that this cannot be explained by a topic effect. Instead, the number of documents judged irrelevant is significantly correlated with a measure of working memory. This key result provides the research community the first real insight into impact of impaired short term memory on information searching

On the design of timber bolted connections subjected to fire

Paper 121Current research at the University of Canterbury is investigating the application of Johansen’s yield equations to the prediction of the failure strength of bolted connections in fire conditions. A series of single bolted connections using steel side plates have been heated at constant temperature for several hours, then loaded to failure. The failure loads have been used to determine the embedment strength of the joints at various temperatures over a range of temperatures from ambient to 300°C. These temperature-dependent embedment strengths have also been used in the Johansen’s equations for wood-steel-wood and wood-wood-wood connections and compared with the results for single bolted connections tested over a range of constant temperatures. Comparisons have also been made with the results of several similar connections tested in fire conditions and show considerable promise for predicting failure of such joints