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241.
James Taylor 《Area》1997,29(2):160-171
Summary This paper discusses the relationship between advertising and 'race', using as its foundation the replication of a study conducted in the US which used content analysis to examine the representation of Black characters in television advertisements. The replication facilitates a comparison of the British and American cases, revealing significant differences in the frequency and perceived importance of such representations. It can also help draw out the specificities of the UK situation. The paper attempts to convey the complexity of the interplay between advertising and racialisation, and emphasises that while such quantitative, textual studies offer a useful basis for further research, they are limited by their failure to address the motivations of producers and how advertisements are read by different groups in different places.  相似文献   
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244.
Si87/Sr86 ratios have been determined for lavas and py lastic rocks from three basalt-andesite centers along the Lesser Antilles arc—Mt. Misery on the island of St. Kitts, Soufriere on the island of St. Vincent, and Carriacou, an island of The Grenadines. The average Si87/Sr86 content of these rocks is 0.7038 for Mt. Misery, 0.7041 for Soufriere, and 0.7053 for Carriacou. All the Sr87/Sr86 values from each center are the same within analytical uncertainty (±0.0002). The constancy of strontium isotopic data within each center supports the hypothesis that basalts and andesites for each specific center investigated are generated from the same source — in agreement with petrographic and major- and minor-element data. Strontium isotopic compositions and elemental concentrations, particularly of strontium and nickel, indicate that this source was mantle peridotite and that the relationship between the respective basalts and andesites is probably fractional crystallization.Publication authorized by the Director, U.S. Geological Survey.  相似文献   
245.
James  Hibbard  Daniel  Karig Asahiko  Taira 《Island Arc》1992,1(1):133-147
Abstract The Late Oligocene-Early Miocene Nabae Sub-belt of the Shimanto Accretionary Prism was created coevally (ca 25-15 Ma) with the opening of the Shikoku back-arc basin, located to the south of the southwest Japan convergent margin. The detailed geology of the sub-belt has been controversial and the interaction of the Shimanto accretionary prism and the opening of the Shikoku Basin has been ambiguous. New structural analysis of the sub-belt has led to a new perception of its structural framework and has significant bearing on the interpretation of the Neogene tectonics of southwest Japan. The sub-belt is divided into three units: the Nabae Complex; the Shijujiyama Formation; and the Maruyama Intrusive Suite. The Nabae Complex comprises coherent units and mélange, all of which show polyphase deformation. The first phase of deformation appears to have involved landward vergent thrusting of coherent units over the mélange terrane. The second phase of deformation involved continued landward vergent shortening. The Shijujiyama Formation, composed mainly of mafic volcanics and massive sandstone, is interpreted as a slope basin deposited upon the Nabae Complex during the second phase of deformation. The youngest deformational pulse involved regional flexing and accompanying pervasive faulting. During this event, mafic rocks of the Maruyama Intrusive Suite intruded the sub-belt. Fossil evidence in the Nabae Complex and radiometric dates on the intrusive rocks indicate that this tectonic scheme was imprinted upon the sub-belt between ~23 and ~14 Ma. The timing of accretion and deformation of the sub-belt coincides with the opening of the Shikoku Basin; hence, subduction and spreading operated simultaneously. Accretion of the Nabae Sub-belt was anomalous, involving landward vergent thrusting, magmatism in newly accreted strata and regional flexing. It is proposed that this complex and anomalous structural history is largely related to the subduction of the active Shikoku Basin spreading ridge and associated seamounts.  相似文献   
246.
The smart city encompasses a broad range of technological innovations which might be applied to any city for a wide variety of reasons. In this article, I make a distinction between local efforts to reshape the urban landscape, and a global smart city imaginary which those efforts draw upon and help sustain. While attention has been given to the malleability of the smart city concept at this global scale, there remains little effort to interrogate the way that the future is used to sanction specific solutions. Through a critical engagement with smart city marketing materials, industry documents, and consultancy reports, I explore how the future is recruited, rearranged, and represented as a rationalization for technological intervention in the present. This is performed amidst three recurring crises: massive demographic shifts and subsequent resource pressures, global climate change, and the conflicting demands of fiscal austerity that motivate the desire of so many cities to attract foreign direct investment and highly skilled workers. In revealing how crises are pre-empted, precautioned, and prepared for, I argue that the smart city imaginary normalizes a style and scale of response deemed appropriate under liberal capitalism.  相似文献   
247.
We measured monthly soil surface elevation change and determined its relationship to groundwater changes at a mangrove forest site along Shark River, Everglades National Park, Florida. We combined the use of an original design, surface elevation table with new rod-surface elevation tables to separately track changes in the mid zone (0–4 m), the shallow root zone (0–0.35 m), and the full sediment profile (0–6 m) in response to site hydrology (daily river stage and daily groundwater piezometric pressure). We calculated expansion and contraction for each of the four constituent soil zones (surface [accretion and erosion; above 0 m], shallow zone [0–0.35 m], middle zone [0.35–4 m], and bottom zone [4–6]) that comprise the entire soil column. Changes in groundwater pressure correlated strongly, with changes in soil elevation for the entire profile (Adjusted R2 = 0.90); this relationship was not proportional to the depth of the soil profile sampled. The change in thickness of the bottom soil zone accounted for the majority (R2 = 0.63) of the entire soil profile expansion and contraction. The influence of hydrology on specific soil zones and absolute elevation change must be considered when evaluating the effect of disturbances, sea level rise, and water management decisions on coastal wetland systems.  相似文献   
248.
Coal fires in natural outcrops, in abandoned and active coal mines, and in coal and coal-refuse piles are responsible for the uncontrolled emissions of gases, including CO, CO2, H2S, hydrocarbons, and volatile aromatics. Typically, measurements of gases at a mine vent are made over a short time interval, perhaps no more than 10 min, including the time for replicate measurements. Such timing provides little information on longer-term variations in emissions, although comparisons of seasonal measurements suggest such changes do occur. To address this problem, we placed temperature and CO data loggers in coal fire vents to collect time series measurements for a period of up to three weeks. For one experiment, 11 days of data at one-minute intervals indicated that the CO emissions were generally in the 400–550 ppmv range. However near daily depressions in CO concentrations occurred and in some cases fell below 50 ppmv; followed by an increase to ~ 700–800 ppmv; in turn followed by a return to the ambient conditions. Data for a separate 21-day collection period in a different vent of the same fire exhibited similar trends, albeit at a higher CO concentration. The drop in CO concentration may be associated with a meteorologically-driven inhalation cycle of the fire, whereby air diluted the combustion generated CO. We propose this was followed by an increase in the intensity of the fire due to increased O2 from the inhaled air, producing increased CO concentrations, before settling back to the ambient conditions.  相似文献   
249.
A combination of field studies and mathematical modeling was used to examine the role of subtidal benthic algae in the eutrophication processes in two shallow estuarine systems. Field measurements indicated uptake by benthic algae retained ammonium and phosphate in the sediments when light at the sediment surface exceeded ≈150 μE m2 s?1. The measurements were used to calibrate a newly developed model of benthic algal activity. The benthic algal model was coupled with a hydrodynamic model, a eutrophication model, and a sediment diagenesis model. In the simulated ecosystem, benthic algae had a major influence in the intra-annual cycling of nitrogen and phosphorus. When nutrients were abundant in the water column (late winter and spring) they were transferred to the sediments through algal activity. Diagenesis released these nutrients to the water column in summer when nutrients were scarce. As a result of the nutrient transfer, annual primary production in the water column, in the presence of benthic algae, exceeded production in the absence of the algae.  相似文献   
250.
Barite (BaSO4) deposits generally arise from mixing of soluble barium-containing fluids with sulfate-rich fluids. While the role of biological processes in modulating barium solubility has been shown, no studies have shown that the biological oxidation of sulfide to sulfate leads to barite deposition. Here we present an example of microbially mediated barite deposition in a continental setting. A spring in the Anadarko Basin of southwestern Oklahoma produces water containing abundant barium and sulfide. As emergent water travels down a stream to a nearby creek, sulfate concentration increases from 0.06 mM to 2.2 mM while Ba2+ concentration drops from 0.4 mM to less than 7 μM. Stable isotope analysis, microbial activity studies, and in situ experiments provide evidence that as sulfide-rich water flows down the stream, anaerobic, anoxygenic, phototrophic bacteria play a dominant role in oxidizing sulfide to sulfate. Sulfate then precipitates with Ba2+ producing barite as travertine, cements, crusts, and accumulations on microbial mats. Our studies suggest that phototrophic sulfide oxidation and concomitant sulfur cycling could prove to be important processes regulating the cycling of barium in continental sulfur-containing systems.  相似文献   
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