Situating local experience of risk: Peripherality, marginality and place identity in the UK foot and mouth disease crisis     

Karen Bickerstaff  Peter Simmons  Nick Pidgeon 《Geoforum》2006,37(5):844-858

Research into exposure to, and experience of, environmental risk that has an explicitly spatial focus can be broadly differentiated into two strands. The first strand focuses on the responses of communities of exposure (or the threat of exposure) to some form of environmental hazard and to the policies put in place by institutional actors to manage the hazard. The second strand addresses social inequalities in exposure to environmental hazards and seeks to correlate uneven spatial distributions of risk across different social groups. It is argued that both strands are limited by their respective understandings of space - and that the way in which vulnerable communities experience environmental risk and its management will be shaped significantly by the complex interactions of different spatialisations or constructions of space. We explore this process by examining accounts of local experience of the UK’s 2001 foot and mouth disease crisis and its management in terms of the interplay of two different spatialisations: socio-cultural marginality and political-economic peripherality. We trace the relationship between these cultural and political-economic spatialisations through an analysis of the discursive mobilisation of contrasting place rhetorics. We conclude that focusing on these rhetorics can enhance our understanding of the spatial processes which are constitutive of place identity and in turn mediate the experience of environmental risk and its management.  相似文献   

Fluorescence spectra of Titan tholins: in-situ detection of astrobiologically interesting areas on Titan's surface     

Robert Hodyss  Gene McDonald  Mark A. Smith  J.L. Beauchamp 《Icarus》2004,171(2):525-530

We report the three-dimensional fluorescence spectra of Titan tholins in water and acetonitrile, and separate some of the fluorescent components of tholins using two-dimensional thin layer chromatography. In acetonitrile, tholins exhibit a broad fluorescence with a maximum at 471 nm, and an excitation maximum at 410 nm. The fluorescence spectrum of a water extraction displays a more complicated spectrum with multiple peaks. TLC results indicate the presence of at least three distinct fluorescent species. In addition, we obtained the two-dimensional fluorescence spectrum of tholins in water ice at 77 K, close to the surface temperature of Titan. The fluorescence of tholins in a 77 K ice matrix is red-shifted in comparison to a water solution, and undergoes a further red-shift when the water solution is heated prior to freezing. These results suggest that a simple fluorescence probe could be used on the surface of Titan to identify sites where tholins have been mixed with water, and possibly reveal information about the extent of heating the tholin-water mixture has undergone. This would be useful for a future mission with the goal of examining the organic chemistry of Titan.  相似文献   

Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica     

Clow GD  McKay CP  Simmons GM  Wharton RA 《Journal of climate》1988,1(7):715-728

In December 1985, an automated meteorological station was established at Lake Hoare in the dry valley region of Antarctica. Here, we report on the first year-round observations available for any site in Taylor Valley. This dataset augments the year-round data obtained at Lake Vanda (Wright Valley) by winter-over crews during the late 1960s and early 1970s. The mean annual solar flux at Lake Hoare was 92 W m-2 during 1986, the mean air temperature -17.3 degrees C, and the mean 3-m wind speed 3.3 m s-1. The local climate is controlled by the wind regime during the 4-month sunless winter and by seasonal and diurnal variations in the incident solar flux during the remainder of the year. Temperature increases of 20 degrees-30 degrees C are frequently observed during the winter due to strong f?hn winds descending from the Polar Plateau. A model incorporating nonsteady molecular diffusion into Kolmogorov-scale eddies in the interfacial layer and similarity-theory flux-profiles in the surface sublayer, is used to determine the rate of ice sublimation from the acquired meteorological data. Despite the frequent occurrence of strong winter f?hns, the bulk of the annual ablation occurs during the summer due to elevated temperatures and persistent moderate winds. The annual ablation from Lake Hoare is estimated to have been 35.0 +/- 6.3 cm for 1986.  相似文献   

Seismic velocities of Lewisian metamorphic rocks at pressures to 8 kbar: relationship to crustal layering in North Britain     

Jeremy Hall  Gene Simmons 《Geophysical Journal International》1979,58(2):337-347

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Delaware Bay and Chesapeake Bay populations of the horseshoe crabLimulus polyphemus are genetically distinct     

James C. Pierce  Gene Tan  Patrick M. Gaffney 《Estuaries and Coasts》2000,23(5):690-698

The Delaware Bay contains the world’s largest population of horseshoe crabs, which constitute an ecologically significant component of this estuarine ecosystem. The North Atlantic speciesLimulus polyphemus has an extensive geographical distribution, ranging from New England to the Gulf of Mexico. Recent assessments of the Delaware Bay population based on beach spawning and trawling data have suggested a considerable decrease in the number of adult animals since 1990. Considerable debate has centered on the accuracy of these estimates and their impact on marine fisheries management planning. Compounding this problem is the lack of information concerning the genetic structure of Atlantic horseshoe crab populations. This study assessed patterns of genetic variation within and between the horseshoe crab populations of Delaware Bay and Chesapeake Bay, using both Random Amplification of Polymorphic DNA (RAPD) and DNA sequence analysis of the mitochondrial cytochrome oxidase I gene (COI). We examined 41 animals from Delaware Bay and 14 animals from the eastern shore of Chesapeake Bay. To provide high quality, uncontaminated genomic DNA for RAPD analysis, DNA was isolated from hemocytes by direct cardiac puncture, purified by spin column chromatography, and quantified by agarose gel electrophoresis. RAPD fingerprints revealed a relative paucity of polymorphic fragments, with generally homogeneous banding patterns both within and between populations. DNA sequence analysis of 515 bases of the 5′ portion of the mitochondrial COI gene showed haplotype diversity in the Chesapeake Bay sample to be significantly higher than in the Delaware Bay sample, despite the larger size of the latter. Haplotype analysis indicates minimal contemporary gene flow between Delaware Bay and Chesapeake Bay crab populations, and further suggests that the Delaware Bay population is recovering from a recent population decline.  相似文献   

Young runoff fractions control streamwater age and solute concentration dynamics          下载免费PDF全文

Paolo Benettin  Scott W. Bailey  Andrea Rinaldo  Gene E. Likens  Kevin J. McGuire  Gianluca Botter 《水文研究》2017,31(16):2982-2986

We introduce a new representation of coupled solute and water age dynamics at the catchment scale, which shows how the contributions of young runoff waters can be directly referenced to observed water quality patterns. The methodology stems from recent trends in hydrologic transport that acknowledge the dynamic nature of streamflow age and explores the use of water age fractions as an alternative to the mean age. The approach uses a travel time‐based transport model to compute the fractions of streamflow that are younger than some thresholds (e.g., younger than a few weeks) and compares them to observed solute concentration patterns. The method is here validated with data from the Hubbard Brook Experimental Forest during spring 2008, where we show that the presence of water younger than roughly 2 weeks, tracked using a hydrologic transport model and deuterium measurements, mimics the variation in dissolved silicon concentrations. Our approach suggests that an age–discharge relationship can be coupled to classic concentration–discharge relationship, to identify the links between transport timescales and solute concentration. Our results highlight that the younger streamflow components can be crucial for determining water quality variations and for characterizing the dominant hydrologic transport dynamics.  相似文献   

Lunar Ice: Adsorbed Water on Subsurface Polar Dust     

F.H CocksP.A Klenk  S.A WatkinsW.N Simmons  J.C CocksE.E Cocks  J.C Sussingham 《Icarus》2002,160(2):386-397

Differential scanning calorimetry indicates that adsorbed water and goethite, a product of hydrated ilmenite, are thermally stable over geologic time in the lunar polar regions. Adsorbed water can undergo burial as a result of several mechanisms, thereby achieving protection from sputtering or Lyman α radiation losses. Adsorbed, subsurface water layers on lunar dust, and any hydrated minerals present, could account for a majority of the hydrogen at the north lunar pole as well as account for a portion of that found at the south pole, particularly in small (<10 km) craters. Lunar ice, if it forms by condensation of water vapor in polar cold traps, will initially be in the form of amorphous solid water, and its rate of crystallization will depend on trap temperature and the composition of the surfaces upon which it has condensed. Between 95 and 110 K, diurnal temperature fluctuations cause surface ice deposits to migrate through the lunar regolith. Via such migration, stable and immobile layers of adsorbed water will be formed. In this temperature range, which can be expected at the margins of large craters and in smaller craters, any water resource would be a mixture of relatively unstable bulk ice and stable adsorbed water on subsurface dust and fines.  相似文献   

Jurassic planktonic foraminifera from the United Kingdom     

Melissa J. Oxford  F. JohnGregory  Malcolm B. Hart  rew S. Henderson  Michael D. Simmons  & Matthew P. Watkinson 《地学学报》2002,14(3):205-209

Unequivocal planktonic foraminifera have been discovered in Oxfordian strata from Dorset and Scotland. These assemblages are, in part, coeval with previously reported occurrences of planktonic taxa in the Oxfordian of Normandy and Seine Maritime (France). Three species are now reported from the United Kingdom for the first time: Globuligerina oxfordiana ( Grigelis, 1958 ), Haeuslerina helvetojurassica ( Haeusler, 1881 ) and Compactogerina sp. cf. C. stellapolaris ( Grigelis, 1977 ). There appears to be a close relationship between the distribution of these planktonic taxa in the UK and a marked sea-level highstand.  相似文献   

Simulating MODFLOW‐Based Reactive Transport Under Radially Symmetric Flow Conditions     

Ilka Wallis  Henning Prommer  Vincent Post  Alexander Vandenbohede  Craig T. Simmons 《Ground water》2013,51(3):398-413

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Particle-size effects on dissolved arsenic adsorption to an Australian laterite   总被引：1，自引：0，他引：1  

Raul Mollehuara Canales  Huade Guan  Erick Bestland  John Hutson  Craig T. Simmons 《Environmental Earth Sciences》2013,68(8):2301-2312

In this study, arsenic adsorption to an Australian laterite has been examined for a particle-size range between 38 μm and 25 mm. The results show that particle size influences both kinetic and equilibrium characteristics of arsenic adsorption. The equilibrium adsorption capacity increases from around 100 mg kg^?1 for laterite particles coarser than 4 mm, to around 160 mg kg^?1 for laterite particles between 75 μm and 4 mm, and to over 200 mg kg^?1 for laterite particles finer than 75 μm. The kinetic adsorption data can be fitted with the pseudo-second-order reaction model, in particular for finer particles where the film diffusion and/or surface reaction are important processes. The model-fitted rate constant remains steady for laterite particles coarser than 2 mm, increases moderately with particle size in the range between 75 μm and 2 mm, and increases dramatically for laterite particles finer than 75 μm. These arsenic adsorption behaviours can be explained by the relative importance of two particle-size-dependent processes: quick external-surface adsorption (more important for fine particles) and slow intraparticle adsorption (more important for coarse particles). Most of the external-surface adsorption completes in the first hour of the experiment. To apply the studied laterite for dissolved arsenic removal, it is recommended that fine particles, in particular finer than 75 μm, should be used if the contact time is the limitation, and that coarse particles, in particular 2–4 mm, should be used if sufficient contact time is available.  相似文献