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41.
This paper examines the attitudes and perceptions of local people about ecological resources, environmental hazards, and future land use of the Idaho National Engineering and Environmental Laboratory (INEEL). Such monitoring of attitudes is an important aspect of environmental assessment. We interviewed 262 people who attended the 42nd Annual Free Fishermen's Breakfast at St. Anthony, Idaho, on 23 March 1997. We tested the null hypotheses that there were no differences in perceptions about ecological resources, hazards and future land use of INEEL as a function of gender, age, education, and place of residence. Dumping trash in the ocean and cutting rainforests rated as the environmental problems of highest concern, and ozone, radon and high voltage lines rated the lowest; cleaning up Department of Energy sites rated intermediate. Respondents were most willing to expend government funds to make drinking water clean. Three significant differences were found: 1) women rated environmental problems as more severe than did men, and women were more willing to expend federal funds to solve these problems, 2) respondents under 30 years of age rated environmental problems as more severe than older people, and they were more willing to spend money to solve them, and, 3) respondents who had not finished high school were more concerned with environmental problems and were more willing to spend money to solve them than respondents with a high school education. Maintaining INEEL as a National Environmental Research Park (NERP) rated as the most preferred future land use, followed by continued reprocessing of nuclear materials and hunting. Using INEEL for housing and additional nuclear waste storage rated the lowest. Men rated grazing livestock and additional nuclear waste storage higher than did women. In general, respondents from 30 – 49 rated several economic uses (hunting, grazing livestock, growing crops) higher than did people in other age groups. Respondents with some college rated these economic uses higher than did respondents who had not graduated from high school. These results indicate that respondents living around INEEL believe that INEEL should continue with a reprocessing and NERP mission, but that other peripheral uses, such as hunting, hiking and grazing, should be allowed on some of the land. These views should aid in environmental assessment of the site, and in developing further management plans for INEEL.  相似文献   
42.
Modified SBA-15 mesoporous silica for heavy metal ions remediation   总被引:1,自引:0,他引:1  
N-Propylsalicylaldimino-functionalized SBA-15 mesoporous silica was prepared, characterized and used as an adsorbent for heavy metal ions. The organic-inorganic hybrid material was obtained using successive grafting procedures of SBA-15 silica with 3-aminopropyl-triethoxysilane and salicylaldehyde, respectively. For comparison an amorphous silica gel was functionalized using the same procedure. The structure and physicochemical properties of the materials were characterized by means of elemental analysis, X-ray diffraction (XRD), nitrogen adsorption-desorption, thermogravimetric analysis and FTIR spectroscopy. The organic functional groups were successfully grafted on the SBA-15 surfaces and the ordering of the support was not affected by the chemical modification. The behavior of the grafted solids for the adsorption of heavy metals ions from aqueous solutions was investigated. The hybrid materials showed high adsorption capacity and high selectivity for copper ions. Other ions, such as nickel, zinc, and cobalt were adsorbed by the modified SBA-15 material. The adsorbent can be regenerated by acid treatment without altering its properties.  相似文献   
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Arsenic concentrations of 73 soil samples collected in the semi-arid Zimapán Valley range from 4 to 14 700 mg As kg(-1). Soil arsenic concentrations decrease with distance from mines and tailings and slag heaps and exceed 400 mg kg(-1) only within 500 m of these arsenic sources. Soil arsenic concentrations correlate positively with Cu, Pb, and Zn concentrations, suggesting a strong association with ore minerals known to exist in the region. Some As was associated with Fe and Mn oxyhydroxides, this association is less for contaminated than for uncontaminated samples. Very little As was found in the mobile water-soluble or exchangeable fractions. The soils are not arsenic contaminated at depths greater than 100 cm below the surface. Although much of the arsenic in the soils is associated with relatively immobile solid phases, this represents a long-term source of arsenic to the environment.  相似文献   
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Batch biochemical leaching tests were carried out to investigate the mobility of arsenic from a contaminated soil collected from a French gold mining site. The specific objective of this research was to examine the effect of indigenous bacterial activity on arsenic mobilization under anaerobic conditions. In a first step, physical and chemical characterizations were performed to provide data concerning the liquid-solid partitioning and mobility of arsenic and other inorganic constituents. In a second step, batch bioleaching tests were conducted in shaker flasks to determine the effect of indigenous bacterial activity under different anaerobic conditions (i.e., addition of mineral nutrients and carbon sources) on arsenic mobilization. Results indicated that arsenic release during contact with deionized water was limited by its very low solubility in the interstitial solution and by the stability of the different arsenic compounds formed with the amorphous solid phases of the soil (mainly iron (oxy)hydroxides). However, an increased mobilization potential was observed over the long term under anaerobic conditions with indigenous bacterial activity enhanced by the addition of carbon sources.  相似文献   
47.
Previous work has demonstrated that plant uptake of radiocaesium (RCs) is related to the activity concentration of RCs in soil solution, which is linked to the soil/soil solution distribution coefficient, K(D). The solid-liquid distribution of RCs is generally studied in soil suspensions in the laboratory and there are few reported measurements for in situ soil solutions. From a data set of 53 different soils (contaminated with either 134CsCl or 137CsCl) used in pot trials to investigate grass uptake of RCs, we analysed the variation of in situ K(D) with measured soil properties. The soils differed widely in % clay (0.5-58%), organic matter content (1.9-96%) and pH (2.4-7.0, CaCl2). The K(D) varied between 29 and 375,000 L kg-' (median 1460 L kg(-1)). Stepwise multiple regression analysis showed a significant correlation between the log K(D) and pH (p < 0.001), log %clay (p < 0.01) and log exchangeable K (p < 0.001) (overall R2 = 0.70). The in situ K(D) values were further compared to K(D)S predicted using an existing model, which assumes that RCs sorption occurs on specific sites and regular ion-exchange sites on the soil solid phase. Sorption of RCs on specific sites was quantified from the radiocaesium interception potential (RIP) measured for each soil and the soil solution concentrations of K+ and NH4+. The in situ log K(D) correlated well with the predicted K(D) (R2 = 0.85 before plant growth, R2 = 0.83 after plant growth). However, the observations were fivefold to eightfold higher than the predictions, particularly for the mineral soils. We attribute the under-prediction to the long contact times (minimum 4 weeks) between the RCs tracers and our experimental soils relative to the short (24 h) contact times used in RIP measurements. We conclude that our data confirmed the model but that ageing of RCs in soil is a factor that needs to be considered to better predict in situ KD values.  相似文献   
48.
Effective ecosystem‐based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components’ vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions.  相似文献   
49.
Marfan syndrome (MFS) is an autosomal dominant disorder with a prevalence of 2–3 per 10 000 individuals. Symptoms range from skeletal overgrowth, cutaneous striae to ectopia lentis and aortic dilatation leading to dissection. Prenatal diagnosis was until recently mainly performed in familial cases by linkage analysis. However, mutation detection has become available with thorough screening methods. The phenotypic variability observed in MFS makes reproductive options difficult, as molecular diagnosis cannot predict clinical severity of the disease. Data are presented on 15 prenatal and/or preimplantation genetic diagnoses (PGD) in nine families, originating from Belgium, the Netherlands, Spain and France. In four families data from linkage analysis were used, whereas in five other families the causative FBN1 mutation was characterised. Four PGD cycles in two couples led to one ongoing pregnancy. In addition, two amniocenteses and nine chorionic villus (CV) samplings were performed. In five pregnancies an affected fetus was diagnosed. In one of them, the couple chose to continue the pregnancy and an affected child was born, whereas the other four couples decided to terminate the pregnancy. It is expected that the greater availability of mutation testing of the FBN1 gene will increase requests for prenatal diagnosis. PGD appears to be an acceptable alternative for couples facing ethical reproductive dilemmas. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
50.
We compared membrane thickness of fully developed eggs with those of non-developed eggs in different endangered falcon taxa. To our knowledge, membrane thickness variation during development has never been examined before in falcons or any other wild bird. Yet, the egg membrane constitutes an important protective barrier for the developing embryo. Because eggshell thinning is a general process that occurs during bird development, caused by calcium uptake by the embryo, eggs are expected to be less protected and vulnerable to breakage near the end of development. Thus, egg membranes could play an important protective role in the later stages of development by getting relatively thicker. We used linear mixed models to explore the variation in membrane thickness (n = 378 eggs) in relation to developmental stage, taxon, female age, mass and identity (73 females), egg-laying sequence (105 clutches) and the study zone. Our results are consistent with the prediction that egg membranes are thicker in fully developed eggs than in non-developed eggs, suggesting that the increase in membrane thickness during development may compensate for eggshell thinning. In addition, our data shown that thicker membranes are associated with larger, heavier and relatively wider eggs, as well as with eggs that had thinner eggshells. Egg-laying sequence, female age and the study zone did not explain the observed variation of membrane thickness in the falcon taxa studied. As we provide quantitative data on membrane thickness variation during development in falcons not subjected to contamination or food limitation (i.e. bred under captive conditions), our data may be used as a reference for studies on eggs from natural populations. Considering the large variation in membrane thickness and the multiple factors affecting on it and its importance in the protection of the embryo, we encourage other researchers to include measurements on membranes in studies exploring eggshell thickness variation.  相似文献   
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