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61.
Depleted uranium particles in selected Kosovo samples   总被引:1,自引:0,他引:1  
Selected soil samples, collected in Kosovo locations where DU ammunition was expended during the 1999 Balkan conflict, have been investigated by secondary ion mass spectrometry (SIMS), X-ray fluorescence imaging using a micro-beam (micro-XRF) and scanning electron microscopy equipped with an energy dispersive X-ray fluorescence detector (SEM-EDXRF), with the objective to test the suitability of these techniques to identify the presence of small DU particles and measure their size distribution and the 235U/238U isotopic ratio (SIMS). Although the results do not permit any legitimate extrapolation to all the sites hit by the DU rounds used during the conflict, they indicated that there can be "spots ' where hundreds of thousands of particles may be present in a few milligrams of DU contaminated soil. The particle size distribution showed that most of the DU particles were <5 microm in diameter and more than 50% of the particles had a diameter <1.5 microm. Knowledge on DU particles is needed as a basis for the assessment of the potential environmental and health impacts of military use of DU, since it provides information on possible re-suspension and inhalation.  相似文献   
62.
Vogt RJ  Rusak JA  Patoine A  Leavitt PR 《Ecology》2011,92(5):1104-1114
Interannual variation of 45 annually resolved time series of environmental, limnological, and biotic parameters was quantified (1994-2009) in six lakes within 52,000 km2 to test the hypothesis that influx of energy (E; as irradiance, heat, wind) varies synchronously among sites and induces temporal coherence in lakes and their food webs, whereas influx of mass (m; as water, solutes, particles) reduces synchrony because local catchments uniquely modify hydrologic inputs. Overall, 82% of parameters exhibited significant (P < 0.05) synchrony (S) estimated as mean pair-wise correlation of Z-transformed time series. Influx of E as atmospheric heat and irradiance was both more highly synchronous and less temporally variable (months-to-decades) than influx of m as summer precipitation, snow, or river discharge. Similarly, S of limnological parameters varied from 0.08 to 0.85, with variables known to be regulated by E influx (ice melt, gas solubility) up to twofold more coherent than those regulated by m inputs (organic solutes). Pairs of variables linked by simple direct mechanisms exhibited similar S values (air temperature and ice melt, nutrients and algae), whereas the coherence of other parameters (water temperature, mixing) was intermediate to that of multiple regulatory agents. Overall, aggregate measures of plankton density varied more coherently among lakes than did constituent taxa. These findings suggest that environmental variability is transmitted to most levels of aquatic ecosystems, but that the precise effects depend on whether E or m fluxes predominate, the coherence of each forcing mechanism, and the strength of linkages between exogenous forcing and lake response.  相似文献   
63.
Biodiversity of sharks in the tropical Indo-Pacific is high, but species-specific information to assist sustainable resource exploitation is scarce. The null hypothesis of population genetic homogeneity was tested for scalloped hammerhead shark (Sphyrna lewini, n = 237) and the milk shark (Rhizoprionodon acutus, n = 207) from northern and eastern Australia, using nuclear (S. lewini, eight microsatellite loci; R. acutus, six loci) and mitochondrial gene markers (873 base pairs of NADH dehydrogenase subunit 4). We were unable to reject genetic homogeneity for S. lewini, which was as expected based on previous studies of this species. Less expected were similar results for R. acutus, which is more benthic and less vagile than S. lewini. These features are probably driving the genetic break found between Australian and central Indonesian R. acutus (F-statistics; mtDNA, 0.751–0.903, respectively; microsatellite loci, 0.038–0.047 respectively). Our results support the spatially homogeneous monitoring and management plan for shark species in Queensland, Australia.  相似文献   
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66.
OBJECTIVE: This study addresses the biomechanical response of isolated kidneys to traumatic insult. METHODS: Kidneys were subjected to blunt impact by using a freely swinging right cylindrical pendulum. Force-deformation characteristics were derived for 65 impacted adult pig kidneys. Renal injuries were classified by autopsy, and an injury risk analysis was performed. In addition a finite element model that simulated the experiments was implemented. RESULTS/CONCLUSIONS: The kidneys showed a viscoelastic response. An energy-based injury threshold was identified, with a strain energy density of 21 kJ/m(3) corresponding to a 50-percent risk of renal injury level AIS3 or higher. Finally, the impact tests were simulated using a finite element model of the kidney to investigate relevant injury mechanisms. The model predicted the renal capsule and underlying parenchyma to first fail at an impact energy level of 4.0 J, consistent with experimental results.  相似文献   
67.
Calcium ions and pigment migration in fly photoreceptors   总被引:4,自引:0,他引:4  
  相似文献   
68.
PROBLEM: On July 1, 1998, in an effort to ameliorate the problem of high teenage driver crash rates, California implemented a graduated driver licensing system (GDLS). METHOD: Data on injury crashes of 16- and 17-year-old drivers from a pre-GDLS year were compared with data from two post-GDLS years. Per-capita crash rate ratios were adjusted for changes in crash rates of 25- to 34-year-old drivers, who were unaffected by the GDLS. Prevented numbers and 95% confidence intervals were estimated. RESULTS: Fatal or severe injury crash rates were significantly lower during each of the two post-GDLS years (adjusted rate ratios (RR)=0.72 and 0.83, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Significant rate reductions were observed for all crash types, particularly for struck object (RR=0.71 and 0.80, for 2000 vs. 1997 and 2001 vs. 1997, respectively) and non-collision (RR=0.63 and 0.72, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Minor injury crash rates were also lower during post-GDLS years (RR=0.87 and 0.90, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Percent reductions were notably larger during the hours of the late night driving restriction (midnight-5 a.m.) (RR=0.79 and 0.87, for 2000 vs. 1997 and 2001 vs. 1997, respectively). SUMMARY: The implementation of the California GDLS was followed by large reductions in the rate of injury-producing motor-vehicle crashes. IMPACT ON INDUSTRY: This evaluation supports previous evidence that GDLS is an effective countermeasure to adolescent motor-vehicle crashes and their associated injuries. States with a traditional licensing system may prevent adolescent driver crashes by adopting a GDLS. Future studies should examine factors that influence teenager compliance with GDLS provisions and identify approaches to improving compliance.  相似文献   
69.
Matthaei  J. H.  Heller  G.  Voigt  H-P  Kleinkauf  H.  Küntzel  H.  Vogt  M.  Matthaei  H. 《Die Naturwissenschaften》1965,52(24):653-655
The Science of Nature -  相似文献   
70.
This paper examines Indigenous water rights in rural and remote Australia and how water justice seems to be elusive in many of these spaces. The purpose of this literature review is to link water justice theory and practices to the way different water cultures are valued in Australia while simultaneously critiquing the water justice movement. This paper situates the notion of water justice as a specific kind of environmental justice to cater for the unique qualities that define this resource. In doing so, this paper draws on Schlosberg’s (2004) conception of environmental justice with its trivalent approach that describes the following three ‘circles of concern’: recognition of difference, plurality of participation, and finally equitable distribution of resources and costs and benefits. This framework provides that if the first two ‘circles of concern’ are not in existence in a natural resource management process, then inequitable distribution of that resource is a likely outcome. This paper presents two areas where water injustices exist in the context of Indigenous rural and remote Australia. The first relates to how Indigenous rights to water have been inadequately recognized and the second presents empirical data on water supply and sanitation in rural and remote Indigenous communities that demonstrates ongoing dilemmas around securing this basic human right. The undervaluing of cultural differences relating to water is argued to be antecedent to the injustice manifest in poor water supply and sanitation provision for Indigenous rural contexts. This paper does not attempt to survey the body of ethnographic work on society-water relations in rural and remote Indigenous Australian contexts but reviews the gaps in current mainstream acknowledgement of Indigenous water cultures. In exploring water justice in rural and remote Indigenous Australia, this paper offers a novel approach to a dilemma more frequently analysed solely as a health development issue.  相似文献   
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