401 research outputs found
Regional macroeconomic outcomes under alternative arrangements for the financing of urban infrastructure
Many studies, both of Australia and of comparable developed economies, have found that the economic benefits from investment in urban infrastructure are substantial. However the nature of this infrastructure is often such that it is under-provided by the private sector. In Australia, much of the responsibility for the provision of urban infrastructure rests with state and local government. However throughout the 1990âs many of Australiaâs state governments embarked on a period of fiscal restraint, seeking to improve financial positions weakened by exposure to failed state government enterprises in the early 1990âs. Perhaps because of the deferred consequences of reducing spending on infrastructure, a large proportion of this fiscal adjustment appears to have been borne by spending on public infrastructure. Today, policy attention at the state government level is again focussing on public infrastructure. However in spite of the now robust fiscal positions of Australiaâs state governments, there remains a reluctance on their part to finance public infrastructure through debt, and raising taxes is perceived as politically unpopular. Instead, governments are exploring alternative financing instruments, such as developer charges and public-private partnerships. This paper uses a dynamic multi-regional CGE model (MMRF) to evaluate the regional macro economic consequences of four alternative methods of financing an expansion in state government spending on public infrastructure. The four methods are developer charges, payroll tax, government debt, and residential rates. The paper confirms that the services provided by public infrastructure can have significant impacts on the regional macro economy. More importantly however, the paper demonstrates that the total gains from urban infrastructure are quite sensitive to the means chosen by government to finance infrastructure investment. In contrast to up-front financing methods (such as developer charges, payroll tax, and residential rates), the paper finds that the gains from urban infrastructure are greatest when the chosen financing method provides a closer match between the timing of the burden of financing the infrastructure and the timing of the benefits provided by the infrastructure. This can be achieved by instruments such as debt, public-private partnerships, and user charges. On this basis the paper finds that a greater reliance by regional government son debt financing might be warranted, and that the gains from infrastructure expenditure are least when that expenditure is financed by developer charges.
Studies on the role of the thymus and spleen in the immune system of the clawed toad (xenopus laevis, daudin)
1) A thymus-independent alioimmune system emerges early in the life of the clawed toad, independent of changes in the lymphoid system occurring at metamorphosis. Studies in Chapter 2 on first and second-set allograft rejection, both in larvae blocked from metamorphosing and in normally developing toads, show that there is no qualitative difference between the larval and adult allo-immune response. 2) In the intact adult, the spleen is shown to be a major site of cellular reactivity following allografting. Spleen transfer experiments between mutually tolerant partners demonstrate that this reactivity has an immunological basis. Preliminary studies in Chapter 3 implicate the spleen as a site of alioimmune memory.3) Work in Chapter 4 employs the sensitive ICA technique for investigating the role of thymus and spleen in humoral immunity. RFC kinetics in the spleen following administration of different doses of sheep erythrocytes reveal a dose response curve more similar to that described in mammals than in other amphibian species. Higher immunegen doses result in more rapid and more elevated RFC production. Morphological characterisation of rosettes failed to distinguish separate functional populations (i.e. "helper" and antibody producing) of lymphocytes in Xenopus. Early thymectomy abrogates responsiveness to injected SRBC as measured by cellular proliferation and RFC levels.4) Chapter 5 identifies a critical role of the thymus throughout much of larval life in the maturation of humoral immunity. Thymectomy up to stage 53 abrogates RFC production to SRBC, and antibody production is impaired by thymectomy as late as stage 57. Thymectomy later at stage 52 has no effect on allograft responses. The larval thymus controls development of both alioimmunity and humoral immunity but commands the maturation of the latter for a more prolonged period of development. Adult thymectomy has no effect on SRBC responsiveness up to 250 days post-surgery. 5) Chapter 6 provides new insight into the ultrastructure of developing thymus and emphasises the rudimentary nature of this organ at the time when thymectomy is routinely performed
New Zealand seaports
It is the purpose of this study to determine and explain changes in the relative status of New Zealand seaports during two significant periods in the country's economic development, in an attempt to identify and understand the complex physical and human factors affecting the development of ports.
The origin and evolution of New Zealand seaports since the establishment of British settlement in 1840 has closely mirrored the nature and the direction of the economic growth of the country. Indeed, seaports as places âequipped. to facilitate the necessary relations between ships as agencies of sea transport and the landâ have been of supreme importance in the development of New Zealand, particularly in view of the country's remoteness from the main concentration of population and markets in the world, the overwhelming dependence on international trade and the necessity of sea transport within and between the North and the South Islands
Context-dependent use of visual cues in the shell selection behaviour of the hermit crab Pagurus bernhardus
Animals avoid predator attack in different ways; some carry defensive structures to reduce predation, with the classic example being hermit crabs and their use of a mollusc shell as a portable refugium. During shell selection, various shell characteristics are investigated by the crab to determine their suitability. Here we consider the role of visual cues. Previous research suggests that some hermit crabs are more likely to initially choose a conspicuous shell but also to move to backgrounds against which they are less conspicuous, suggesting a short-term/long-term trade-off. Across experiments in which we manipulated shell and background colour, we show initially that Pagurus bernhardus prefer black shells over white but this preference was lost in the absence of visual cues. We then show that the strength of preference was dependent on background colour. We repeated this last experiment with red and yellow shells against red or yellow backgrounds to investigate whether this preference extended to chromatic hues. A preference for darker (red) shells was expressed, but preference alteration with background was not observed. P. bernhardus therefore discriminate between shells in terms of shell and background colour, and discrimination may be rooted in a preference for darker shaded shells.PostprintPeer reviewe
A Real-Time Phase Vector Display for EEG Monitoring
A real-time, computer-based, phase vector display system has been developed which will output a vector whose phase is equal to the delay between a trigger and the peak of a function which is quasi-coherent with respect to the trigger. The system also contains a sliding averager which enables the operator to average successive trials before calculating the phase vector. Data collection, averaging and display generation are performed on a LINC-8 computer. Output displays appear on several X-Y CRT display units and on a kymograph camera/oscilloscope unit which is used to generate photographs of time-varying phase vectors or contourograms of time-varying averages of input functions
Constraints on the Emplacement and Uplift History of the Pine Mountain Thrust Sheet, Eastern Kentucky: Evidence from Coal Rank Trends
In this paper coal rank trends on both sides of the Pine Mountain thrust in eastern Kentucky are used to place constraints on thrust evolution. Vitrinite reflectance () measurements on a single Pennsylvanian coal horizon (Fire Clay coal) in eastern Kentucky increase from 0.5% in the north to about 1.0% toward the SE in front of the Pine Mountain thrust. The same horizon in the hangingwall of the thrust displays lower Rmax values (0.8-0.85%). The reflectance isograds are subparallel to the thrust within approximately 10 km of the trace of the fault. We attribute thermal maturation to (1) pre-orogenic maturation by burial to a depth of about 2 km followed by (2) maturation due to conductive relaxation in the footwall after thrusting. Isotherms would not have been offset unless the thrust velocity was \u3e\u3e 10km / Mα. Assuming no erosion, the emergent thrust would have been approximately 3 km thick. In order to explain the relatively low reflectance values observed in the footwall, rapid uplift (\u3e3 km/Ma) after thrust emplacement is required. Alternatively, if erosion kept pace with thrusting, the thrust sheet would have been substantially thinner (\u3c1 \u3ekm), and thermal equilibrium would be rapidly attained in the footwall. Localized frictional heating may have caused elevated reflectance values observed in sheared coals from outcrop scale faults
Migmatite-Like Textures in Anthracite: Further Evidence for Low-Grade Metamorphic Melting and Resolidification in High-Rank Coals
Previous studies demonstrated that melting, initiated by supercritical fluids in the 375â400 °C range, occurred as part of anthracite metamorphism in the Appalachian Basin. Based on the known behavior of vitrinite at high temperatures and, to a lesser extent, at high pressures, it was determined that the duration of the heating, melting, and resolidification event was about 1 h. In the current study, featureless vitrinite within banded maceral assemblages demonstrates the intimate association of melted and resolidified vitrinite with anthracite-rank macerals. By analogy with metamorphosed inorganic rocks, such associations represent diadysites and embrechites, i.e., cross-cutting and layered migmatites, respectively. Even though the temperature of formation of the anthracite structures is several hundred °C lower than that seen in metamorphosed inorganic rocks, anthracites are metamorphic rocks and the nomenclature for metamorphic rocks may be appropriate for coal
Feasibility of the Target Aerobic Movement Test in Children and Adolescents with Spina Bifida
The purpose of this study was to determine the feasibility of the Target Aerobic Movement Test (TAMT)â in a group of children and adolescents with spina bifida (n = 32). Thirty-two children (11 subjects-thoracic lesion, 21 subjects-lumbar lesion) volunteered for the study. Results indicated there were no significant differences in the proportion of subjects who passed Test 1 or Test 2 (p \u3e .05). Twenty-seven out of 28 eligible subjects (96%) on Test 1 and 25 of 27 eligible subjects (93%) on Test 2 met the criteria for successful completion of the TAMT. The TAMT appears to be a reliable and feasible test for measuring aerobic behavior in children and adolescents with spina bifida. Future research should focus on studying the feasibility of the TAMT with other populations with disabilities and to also determine if the test can become a more refined discriminator of aerobic behavior and aerobic capacity
Physical Activity and the Association With Self-Reported Impairments, Walking Limitations, Fear of Falling and Incidence of Falls in Persons With Late Effects of Polio.
The purpose of this study was to determine the association between physical activity and self-reported disability in ambulatory persons with mild to moderate late effects of polio (N=81, mean age 67 years). The outcome measures were: Physical Activity and Disability Survey (PADS), a pedometer, Self-reported Impairments in Persons with Late Effects of Polio Scale (SIPP), Walking Impact Scale (Walk-12), Falls Efficacy Scale - International (FES-I) and self-reported incidence of falls. The participants were physically active on average 158 minutes per day and walked 6212 steps daily. Significant associations were found between PADS and Walk-12 (r = -0.31, p < 0.001), and between the number of steps and SIPP, Walk-12 and FES-I (r = -0.22 to -0.32, p < 0.05). Walk-12 and age explained 14% of the variance in PADS and FES-I explained 9% of the variance in number of steps per day. Thus, physical activity was only weakly to moderately associated with self-reported disability
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