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101.
J Murdoch 《Area》2004,36(1):50-58
This article argues that policy discourses need to be set within the heterogeneous resources that governments routinely use to govern across the state/non-state divide. It employs the governmentality perspective to show how a discursive coalition in the planning for housing sector uses such resources to embed a new rationality of 'planning for sustainability' in a host of differing local arenas. The article extends the governmentality approach by proposing that this 'embedding' process is geographically uneven as the discourse becomes enmeshed in differing economic and environmental circumstances. The analysis thus reveals a geography of governmentality by showing how local actions intrude upon the functioning of governmental networks.  相似文献   
102.
The open-air Acheulian site in Holon, Israel, was dated by the luminescence methods and by electron spin resonance (ESR). Situated in the coastal plain Quaternary Kurkar Group, the Holon site was first excavated in the late 1960s, when typical lower Paleolithic lithics and middle Pleistocene fauna were found. In order to date the site, new test pits were dug adjacent to the earlier excavations and the archaeological bed was exposed in a section comprising a series of paleosols and aeolianites. Alkali feldspars separated from the sediments were dated using the infrared stimulated luminescence and thermoluminescence signals, and quartz was dated using the optically stimulated luminescence signal. The age of the archaeological bed is constrained by two samples to 198,000 ± 22,000–201,000 ± 17,000 yr. The age of the base of the section is 240,000 ± 29,000 yr, and the age of the top is 81,000 ± 8000 yr. Two teeth from the archaeological bed, recovered from the original excavation collection, yielded an average ESR age of 204,000 ± 16,000 yr, calculated using the linear uptake model, which is in a very good agreement with the luminescence ages. These dates place Holon within the range of other late Acheulian and Acheulo-Yabrudian sites in this region such as Tabun E (younger chronology), Yabrud I (archaeological level 18), and Berekhat Ram.  相似文献   
103.
The aim of this study was to investigate the cycling of dissolved inorganic and organic nutrients using moored instrumented buoys (SmartBuoys) during the spring bloom in the North Sea. The instrumentation on the buoys enabled high frequency measurements of water-column integrated irradiance and in situ chlorophyll to be made, and also preserved water sample collection which were used for dissolved inorganic and organic nutrient analyses. The SmartBuoys were located in the year-round well-mixed plume zone associated with the River Thames and in the summer stratified central North Sea. These site locations allowed comparison of nutrient concentrations and cycling, and spring bloom development at two contrasting sites. The spring bloom was expected to be initiated at both stations due to increasing insolation and decreasing suspended load leading to higher water-column integrated irradiance. Due to differences in suspended load between the sites, the spring bloom started ∼2 months earlier in the central North Sea. The spring bloom in the Thames plume also resulted in higher maximum phytoplankton biomass due to the higher pre-bloom nutrient concentrations associated with riverine input. The use of SmartBuoys is also shown to allow the cycling of dissolved organic nutrients to be examined over the critical, and often undersampled, spring bloom period. Dissolved Organic Nitrogen (DON) clearly increased during the spring bloom in the central North Sea compared to winter concentrations. DON also increased in the Thames plume although showing greater winter variability related to higher riverine and sedimentary dissolved organic matter input at this shallow (∼18 m) coastal site. DON increase during the spring bloom was therefore related to primary production at both sites probably due to active release by phytoplankton. At both stations DON decreased to pre-bloom concentrations as the bloom declined suggesting the released DON was bioavailable and removed due to heterotrophic uptake and production. The preserved nutrient samples from the central North Sea site were also suitable for Dissolved Organic Phosphorus (DOP) analysis due to their low suspended load with similar trends and cycling to DON, albeit at lower concentrations. This suggested similar processes controlling both DON and DOP. The variable timing of short term events such as the spring bloom makes sampling away from coastal regions difficult without the use of autonomous technology. This study demonstrates for the first time the applicability of using preserved samples from automated buoys for the measurement of dissolved organic nutrients.  相似文献   
104.
Corsac fox (Vulpes corsac) and red fox (Vulpes vulpes) diets often consist of small quantities of vegetation, including fruit and seeds that may represent important sources of energy and nutrition. However, details of the species consumed are few, but may provide insight into the role of foxes as seed dispersers. We analyzed scats of corsac (n = 408) and red foxes (n = 533) collected in an arid region of Mongolia from June 2006 to June 2007. We found 13 seed species in corsac scats, the most common being Allium polyrhizum, Asparagus gobicus, and Tribulus terrestris, and 12 species in red fox scats, the most common being Amygdalus pedunculata, Corispermum mongolicum, and T. terrestris. The proportion of scats with seeds varied significantly by season for both foxes. Seeds occurred most frequently during the breeding period, which corresponded with winter, and least frequently during the dispersal period in autumn for both species. We detected no differences in the proportion of scats with seeds between species seasonally. Our results suggest that fruit represents an important component of diet, especially during winter when availability of other prey items is low, and that both foxes may facilitate seed dispersal of some plant species.  相似文献   
105.
Dissolved and total organic and inorganic carbon in some British rivers   总被引:2,自引:0,他引:2  
Rivers transport both organic and inorganic carbon from their sources to the sea. Results of ~800 organic and inorganic analyses from various British rivers of contrasting size and land use are presented here: (1) the headwater River Tern, a rural river of 852 km2 catchment; (2) the Ouseburn, a small urban 55 km2 catchment; (3) the River Tyne, a larger river system of ~3000 km2 catchment; (4) a spatial survey from 205 sample sites on ~60 rivers from SW England. We found that, with the exception of peat-rich headwaters, DIC concentration is always greater than DOC. DIC is primarily in the form HCO3 , with DIC concentrations highest in highly urbanised catchments, typically greater than those observed in catchments with carbonate bedrock, demonstrating a significant and previously unrecognised anthropogenic inorganic carbon input to urban rivers.  相似文献   
106.
Reconstructing climate change quantitatively over millennial timescales is crucial for understanding the processes that affect the climate system. One of the best methods for producing high resolution, low error, quantitative summer air temperature reconstructions is through chironomid analyses. We analysed over 50 lakes from NW and W Iceland covering a range of environmental gradients in order to test whether the distribution of the Icelandic chironomid fauna was driven by summer temperature, or whether other environmental factors were more dominant. A range of analyses showed the main environmental controls on chironomid communities to be substrate (identified through loss-on-ignition and carbon content) and mean July air temperature, although other factors such as lake depth and lake area were also important. The nature of the Icelandic landscape, with numerous volcanic centres (many of which are covered by ice caps) that produce large quantities of ash, means that relative lake carbon content and summer air temperature do not co-vary, as they often do in other chironomid datasets within the Arctic as well as more temperate environments. As the chironomid–environment relationships are thus different in Iceland compared to other chironomid training sets, we suggest that using an Icelandic model is most appropriate for reconstructing past environmental change from fossil Icelandic datasets. Analogue matching of Icelandic fossil chironomid datasets with the Icelandic training set and another European chironomid training set support this assertion. Analyses of a range of chironomid-inferred temperature transfer functions suggest the best to be a two component WA-PLS model with r 2 jack = 0.66 and RMSEP = 1.095°C. Using this model, chironomid-inferred temperature reconstructions of early Holocene Icelandic sequences show the magnitude of temperature change compared to contemporary temperatures to be similar to other NW European chironomid sequences, suggesting that the predictive power of the model is good.  相似文献   
107.
Micro‐X‐ray fluorescence scanning spectroscopy of marine and lake sedimentary sequences can provide detailed palaeoenvironmental records through element intensity proxy data. However, problems with the effects of interstitial pore water on the micro‐X‐ray fluorescence intensities have been pointed out. This is because the X‐ray fluorescence intensities are measured directly at the surfaces of split wet sediment core samples. This study developed a new method for correcting X‐ray fluorescence data to compensate for the effects of pore water using a scanning X‐ray analytical microscope. This involved simultaneous use of micro‐X‐ray fluorescence scanning spectroscopy and an X‐ray transmission detector. To evaluate the interstitial pore water content from the X‐ray transmission intensities, a fine‐grained sediment core retrieved from Lake Baikal (VER99‐G12) was used to prepare resin‐embedded samples with smooth surfaces and uniform thickness. Simple linear regression between the linear absorption coefficients of the samples and their porosity, based on the Lambert–Beer law, enabled calculation of the interstitial pore spaces and their resin content with high reproducibility. The X‐ray fluorescence intensities of resin‐embedded samples were reduced compared with those of dry sediment samples because of: (i) the X‐ray fluorescence absorption of resin within sediment; and (ii) the sediment dilution effects by resin. An improved micro‐X‐ray fluorescence correction equation based on X‐ray fluorescence emission theory considers the instrument's sensitivity to each element, which provides a reasonable explanation of these two effects. The resin‐corrected X‐ray fluorescence intensity was then successfully converted to elemental concentrations using simple linear regression between the data from micro‐X‐ray fluorescence scanning spectroscopy and from the conventional analyzer. In particular, the calculated concentration of SiO2 over the depth of the core, reflecting diatom/biogenic silica concentration, was significantly changed by the calibrations, from a progressively decreasing trend to an increasing trend towards the top of the core.  相似文献   
108.
In 2007, an Individual Fishing Quota (IFQ) program was introduced to the valuable red snapper (Lutjanus campechanus) fishery in the US Gulf of Mexico. This study assessed the current perceived scale and causes of red snapper discarding in the Gulf in recent years within the commercial reef fish fishery, according to commercial fishermen. Data were collected through interviews, which took place with fishermen in April and May 2010, and which were unexpectedly halted due to the Deepwater Horizon oil spill that occurred in late April 2010. Results suggest that for those fishermen fully participating in the IFQ program, snapper discarding has decreased since program implementation. For those not fully involved in the program (e.g., due to participation costs), discarding has likely since increased.  相似文献   
109.
This data note describes the Biscuit Brook and Neversink Reservoir watershed long-term monitoring data that includes: 1) stream discharge, (1983–2020 for Biscuit Brook and 1937–2020 for the Neversink Reservoir watershed), 2) stream water chemistry, 1983–2020, at 4 stations, 3) fish survey data from 16 locations in the watershed 1990–2019, 4) soil chemistry data from 2 headwater sub-watersheds, 1993–2012 and 5) periodic stream water chemistry sampling data from 364 locations throughout the watershed, 1983–2020. The Neversink Reservoir watershed in the Catskill Mountains of New York, USA drains an area of 172.5 km2. The watershed feeds one of six reservoirs in New York City's West of Hudson water supply, which accounts for about 90% of the city's water supply. Biscuit Brook is a 9.63 km2 tributary sub-watershed within the Neversink Reservoir watershed.  相似文献   
110.
Climate change mitigation via a reduction in the anthropogenic emissions of carbon dioxide (CO2) is the principle requirement for reducing global warming, its impacts, and the degree of adaptation required. We present a simple conceptual model of anthropogenic CO2 emissions to highlight the trade off between delay in commencing mitigation, and the strength of mitigation then required to meet specific atmospheric CO2 stabilization targets. We calculate the effects of alternative emission profiles on atmospheric CO2 and global temperature change over a millennial timescale using a simple coupled carbon cycle-climate model. For example, if it takes 50 years to transform the energy sector and the maximum rate at which emissions can be reduced is ?2.5% $\text{year}^{-1}$ , delaying action until 2020 would lead to stabilization at 540 ppm. A further 20 year delay would result in a stabilization level of 730 ppm, and a delay until 2060 would mean stabilising at over 1,000 ppm. If stabilization targets are met through delayed action, combined with strong rates of mitigation, the emissions profiles result in transient peaks of atmospheric CO2 (and potentially temperature) that exceed the stabilization targets. Stabilization at 450 ppm requires maximum mitigation rates of ?3% to ?5% $\text{year}^{-1}$ , and when delay exceeds 2020, transient peaks in excess of 550 ppm occur. Consequently tipping points for certain Earth system components may be transgressed. Avoiding dangerous climate change is more easily achievable if global mitigation action commences as soon as possible. Starting mitigation earlier is also more effective than acting more aggressively once mitigation has begun.  相似文献   
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