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101.
\"This paper discusses the use of suppression to protect data in the Special Migration Statistics, a dataset produced from the 1991 [British] Census, and argues that this procedure prevents accurate analysis of the data. A computer program is described that uses a series of methods to ?recover' data which were suppressed, and to estimate those parts of the data which cannot be recovered.... The program has been used to recover and estimate data successfully, and results include sample tables of migrants between types of districts by ethnicity.\" 相似文献
102.
Rees P 《Geography review》1994,7(3):25-30
\"This article examines the geography of age across the counties of England and Wales and the regions of Scotland [and in Northern Ireland].\" Sections are included on national and subnational age structures and on spatial patterns for childhood ages, working ages, and retired ages. 相似文献
103.
New Zealand fisheries management has been the focus of a great deal of research, largely because of the early, and very successful, introduction of a neoliberal property regime in the country's commercial fisheries. Less attention has been paid to the other management activities of New Zealand's Ministry of Fisheries. This paper outlines the fisheries management issues arising over the last decade in the region to the north of Auckland and the practices of the Ministry as it worked to address them. 相似文献
104.
105.
M. H. Rees 《Planetary and Space Science》1975,23(12):1589-1596
The mechanisms of energy dissipation in the atmosphere for magnetospheric substorm energy sources are examined quantitatively, and the height-integrated energy budget is determined for average auroral conditions. Under steady-state conditions (1) at least 60% of the energy deposited by typical auroral particle bombardment heats the neutral atmosphere; about 11% maintains the enhanced level of ionization. Only about 4% is radiated in the visible, near i.r., and near u.v. spectral regions, which are detectable by ground-based and airborne observations, and 6% is known to be radiated in the medium and far u.v. spectrum. Another 3% of the energy is expended in maintaining enhanced electron and ion temperatures, bremsstrahlung radiation, and long-wave radio emissions. This leaves about 16% of the energy unaccounted for; it is argued that the bulk of this energy must reside in extreme u.v. radiation originating from highly excited atomic, molecular, and ionic states. Both laboratory and field evidence support this suggestion. (2) Orthogonal electric fields dissipate substantial energy in the atmosphere; the amount is governed by the ionospheric conductivity profile. In fact, the energy dissipated by electric fields can exceed the energy deposited by particle bombardment. About one-half of this energy goes into heating the neutral gas. (3) Plasma heat conduction is a small energy source that may have a large spatial extent. Its principal effect is heating of the electron gas, which, in turn, raises the electron temperature. Only 3% of the energy goes into radiation of OI(λ6300), the spectroscopic signature of SAR-ARCS. 相似文献
106.
Judith A. Rees 《Geoforum》1981,12(3):211-225
Conventional economic appraisals of the water industry have concentrated on economic efficiency defined almost entirely in allocative terms, the key issues being the efficiency with which available water resources are allocated between users and with which factors of production are invested in new facilities. Since marginal cost pricing has been viewed as the mechanism theoretically capable of bringing about optimality in resource allocation, assessments of water industry practices have all too often been reduced to reiteration of the extent to which current pricing practices diverge from the theoretical optima. This paper, based on empirical work on water suppliers in both Britain and Australia, questions the relevance of this conventional approach.First, it is argued that the concentration on allocative efficiency has diverted attention from the equally crucial issue of whether the industry is efficient in managerial, technical and product terms. Since technological efficiency must exist in an industry before a Pareto optimal allocation of resources can occur, the presupposition, in papers which argue that the introduction of optimal pricing rules will ensure allocative efficiency, must be that the industry is already producing an appropriate product using least cost production methods. No such presupposition can be made in an industry where the profit motive and competitive forces do not operate.Second, it is argued that optimal pricing policies can only produce optimal resource allocations if consumers act in a prescribedly rational way to the prices set. Although it is well known that ‘second-best’ pricing rules may be needed to counter inefficient conditions prevailing in other sectors of the economy, the effect of market imperfec- tions on the way consumers react to prices has been less well analysed. Using results from a study of firms' reactions to trade effluent charges, it is shown that the structure of companies and the way they operate their revenue and capital budgets may severely limit the effectiveness of the price mechanism in ensuring allocative efficiency.Finally, the paper considers the ‘equity’ with which the costs of water services are distributed between consumers. Once again it is argued that the issue has been neglected since the distribution of income is irrelevant to the achievement of allocative optimality in Paretian terms. Evidence is presented that contradicts the popular myth that, although current pricing arrangements may be less than efficient, they are at least ‘broadly fair’. It is shown that, in practice, price discrimination against low income consumers is widespread, and this can hardly be regarded as equitable, whatever definition of equity is used. 相似文献
107.
108.
D. Rees R. W. Smith F. Signernes K. Henriksen U. Brandstrom M. Harris G. Maskall 《Annales Geophysicae》1998,16(11):1461-1474
Two Doppler imaging systems (DIS) or wide-field imaging Fabry-Perot interferometers (FPI), have recently been commissioned, one at the Auroral Station, Adventdalen, Longyearbyen, Svalbard, and the second at the IRF, Kiruna, Sweden. These instruments can provide wide-field (600 * 800 km) images of neutral wind flows in the upper thermosphere, by measuring the Doppler shift of the atomic oxygen forbidden near 630 nm, which is emitted from an altitude of approximately 240 km. From the instrument in Svalbard, at mid-winter, it is possible to observe the dayside polar cusp and the polar cap throughout the entire day, whereas from Kiruna, the night-time auroral oval is observable during the hours of darkness. Measurements of thermospheric dynamics from the DIS can be used in conjunction with observations of ionospheric plasma flows and thermal plasma densities by the EISCAT-Svalbard radar (ESR) and by EISCAT, along with other complementary observations by co-located instruments such as the auroral large-scale imaging system (ALIS). Such combined data sets will allow a wide range of scientific studies to be performed concerning the dynamical response of the thermosphere and ionosphere, and the important energetic and momentum exchange processes resulting from their complex interactions. These processes are particularly important in the immediate vicinity of the polar cusp and within the auroral oval. Early results from Svalbard in late 1995 will be discussed. The DIS in Kiruna observed two interesting geomagnetic disturbances in early 1997, the minor geomagnetic storm of 10, 11 January, and the disturbed period from 7–10 February. During these events, the thermospheric wind response showed some interesting departures from the average behaviour, which we attribute to the result of strong and variable Lorenz forcing (ion drag) and Joule and particle heating during these geomagnetic disturbances. 相似文献
109.
M.J. WhitehouseA. Atkinson A.P. Rees 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(7):725-732
In this study we examined the hypothesis that, under conditions of replete macronutrients and iron in the Southern Ocean, phytoplankton abundance and specific N uptake rates are influenced strongly by the processes of grazing and NH4 regeneration. NH4 and NO3 uptake rates by marine phytoplankton were measured to the northeast and northwest of the island of South Georgia during January-February 1998. Mean specific uptake rate for NO3 (vNO3) was 0.0026 h−1 (range 0.0013-0.0065 h−1) and for NH4 (vNH4) was 0.0097 h−1 (0.0014-0.0376 h−1). vNH4 was related positively with NH4 availability, which ranged from 0.1 to 1.5 mmol m−3 within the upper mixed layer. Ambient NH4 concentrations and vNH4 were both positively related to local krill biomass values, computed from mean values along acoustic transect segments within 2 km of the uptake measurement stations. These biomass values ranged from ∼1 g krill fresh mass m−2 in the northwest to >4 kg krill wet mass m−2 in the northeast. In contrast to the variability found with NH4 concentrations and uptake rates, vNO3 was more uniform across the sampling sites. Under these conditions, increasing NH4 concentration appeared to represent an additional N resource. However, high vNH4 tended to be found for stations with lower phytoplankton standing stocks, across a total range of 0.24-20 mg chlorophyll a m−3. These patterns suggest a coupling between phytoplankton biomass, vNH4 and krill in this region of variable but high krill biomass. Locally high concentrations of krill in parts of the study area appeared to have two opposing effects. On the one hand they could graze down phytoplankton stocks, but on the other hand, their NH4 excretion supported enhanced uptake rates by the remaining, ungrazed cells. 相似文献
110.