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1.
Sumana Siripattanakul Wanpen Wirojanagud John McEvoy Eakalak Khan 《Water, Air, & Soil Pollution: Focus》2008,8(3-4):257-266
Atrazine biodegradation by immobilized pure and mixed cultures was examined. A pure atrazine-degrading culture, Agrobacterium radiobacter J14a (J14a), and a mixed culture (MC), isolated from an atrazine-contaminated crop field, were immobilized using phosphorylated-polyvinyl
alcohol (PPVA). An existing cell immobilization procedure was modified to enhance PPVA matrix stability. The results showed
that the matrices remained mechanically and chemically stable after shaking with glass beads over 15 days under various salt
solutions and pH values. The immobilization process had a slight effect on cell viability. With the aid of scanning electron
microscopy, a suitable microstructure of PPVA matrices for cell entrapment was observed. There were two porous layers of spherical
gel matrices, the outside having an encapsulation property and the inside containing numerous pores for bacteria to occupy.
J14a and MC were immobilized at three cell-to-matrix ratios of 3.5, 6.7, and 20 mg dry cells/mL matrix. The atrazine biodegradation
tests were conducted in an aerobic batch system, which was inoculated with cells at 2,000 mg/L. The tests were also conducted
using free (non-immobilized) J14a and MC for comparative purpose. The cell-to-matrix ratio of 3.5 mg/mL provided the highest
atrazine removal efficiency of 40–50% in 120 h for both J14a and MC. The free cell systems, for both cultures, presented much
lower atrazine removal efficiencies compared to the immobilized cell systems at the same level of inoculation. 相似文献
2.
A biomonitoring survey using the moss species Hypnum cupressiforme Hedw. was conducted in the surroundings of two steel plants located in the North of Spain. Levels of V, Cr, Ni, Cu, Zn, As, Cd, Hg, Pb and N were determined. Very high concentrations in the areas of study were detected when compared to nearby unaffected regions. Similar trends were observed for all the elements in the differently orientated transects, showing an appreciable influence of the NW prevailing winds of the region in the dispersion of pollutants, as well as a clear decreasing gradient in the concentrations of metals in mosses within a distance of 1500 meters from the facilities. A differentiation between the elements emitted by the chimney as result of the industrial activity (V, Cr, Ni, Cu and As) and those with a high presence in steel slag deposits (Zn, Cd, Hg and Pb) was observed. The range of contamination was also established by means of the Contamination Factor, indicating a category 4 out of 6 categories, which shows the high levels reported in the areas of study. A different dynamic was registered for nitrogen regarding the rest of the heavy metals analysed except for Hg, probably due to the elevated volatility and mobility of both elements, as well as their high persistence in the atmosphere. 相似文献
3.
Darryn McEvoy Piotr Matczak Ilona Banaszak Adam Chorynski 《Mitigation and Adaptation Strategies for Global Change》2010,15(7):779-795
Whilst mitigation has dominated policy and research agendas in recent years there is an increasing recognition that communities
also need to be preparing for change that is unavoidable, partially a consequence of anthropogenic greenhouse gases already
emitted to the atmosphere. The perceived need for adaptation has also received additional impetus through the high public
profile now given to the impacts of current day weather variability, particularly the significant economic and social costs
associated with recent extreme events. However, being a relatively new focus for both research and policy communities; practical
evidence of the extent, feasibility, efficiency, and cost effectiveness of potential adaptation options remains largely lacking.
In response, this paper seeks to make a contribution to this embryonic but evolving knowledge base by considering the theoretical
underpinnings of adaptation and ultimately how this translates into practice ‘in the real world’. The analytical commentary,
based on a bottom-up approach involving iterative engagement with key stakeholders and experts, reflects on the identification
of measures that are either innovative or examples of good practice in reducing or transferring climate risks, as well as
considering those ‘enabling’ institutional structures and processes that act to support implementation on the ground. The
paper concludes by synthesising the key findings to date in order to highlight some of the opportunities for, and barriers
to, adaptation activity. 相似文献
4.
A sample of 135 female human service professionals completed the Maslach Burnout Inventory (MBI) and the Staff Burnout Scale for Health Professionals (SBS), along with measures of job satisfaction, role stress, self-esteem, alienation, and locus of control. Principal components factor analysis of this battery indicates considerable covariation of self-reported burnout with job dissatisfaction and perceived role stress, and moderate overlap with more general feelings of alienation and low self-esteem. Item factor analysis of the 22 MBI items resulted in two independent factors, one defined by the Emotional Exhaustion and Depersonalization items, the other by the Personal Accomplishment items. Item factoring of the SBS produced one large factor which was highly correlated with the MBI exhaustion-depersonalization factor. Implications of these findings for the construct validity of the MBI and SBS are discussed. 相似文献
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6.
Larvae of the sea bass Dicentrachus labrax were fed four Artemia sp. diets for 28 d. Three were nauplii enriched with emulsions of polyunsaturated fatty acids, and the fourth nauplii enriched with baker's yeast. At the end of the experimental period, the fatty acids of the bodies, heads and eyes of the larvae were analysed. A multivariate statistical method (discriminant analysis, DA) applied to the data revealed anatomical as well as dietary fatty acid pattern-discrimination. We propose here the use of discriminant analysis as a pattern-recognition method that will help to integrate the fatty acid information obtained in nutritional studies. 相似文献
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8.
Microcosm experiments have been carried out with whole natural meiobenthic communities to look at the effects of TBT sediment contamination on the community structure of the dominant nematode component of the meiobenthos. TBT has a high affinity for aquatic sediments, yet this is the first study of the effects of this contaminant in sediment on natural benthic communities. Three communities were studied from contrasting locations in south-west England: the intertidal of the Lynher estuary (muddy sediment) and the Exe estuary (sandy sediment) and the subtidal (50m depth) at Rame Head off Plymouth (muddy sand). Fresh sediment with natural meiobenthic communities was incubated for 2 months with TBT-contaminated sediment (three dose levels) in bottles. Nematodes were identified and enumerated and subjected to multivariate data analysis. The sandy Exe estuary fauna was significantly affected by TBT-contaminated sediment at all three doses (0.3, 0.6 and 0.9 microg g(-1) dry wt (as Sn) sediment), whereas the offshore fauna from Rame Head was significantly affected only at the highest dose. The muddy Lynher estuary meiofauna was affected (somewhat peculiarly) at the medium dose level only. Meiobenthic nematodes may not be as sensitive to TBT-contaminated sediment as other infaunal benthos but exhibited responses to levels of contamination still persisting in some UK estuaries and harbours. Comparing the effects of TBT with those of copper and zinc in the same laboratory experiments, our observations suggest that the relative impact of TBT on meiobenthic community structure is not as great as these contaminants in marine sediments. Although there are very few observations of TBT toxicity in sediment, it appears that TBT is toxic at much lower concentrations in seawater (ppb) than it is in sediment (ppm). 相似文献
9.
Impact and adaptation opportunities for European agriculture in response to climatic change and variability 总被引:2,自引:0,他引:2
Marco Moriondo Marco Bindi Zbigniew W. Kundzewicz M. Szwed A. Chorynski P. Matczak M. Radziejewski D. McEvoy Anita Wreford 《Mitigation and Adaptation Strategies for Global Change》2010,15(7):657-679
Climate change, involving changes in mean climate and climatic variability, is expected to severely affect agriculture and
there is a need to assess its impact in order to define the appropriate adaptation strategies to cope with. In this paper,
we projected a scenario of European agriculture in a +2°C (above pre-industrial levels) world in order to assess the potential
effect of climatic change and variability and to test the effectiveness of different adaptation options. For this purpose,
the outputs of HadCM3 General Circulation Model (GCM) were empirically downscaled for current climate (1975–2005) and a future
period (2030–2060), to feed a process-based crop simulation model, in order to quantify the impact of a changing climate on
agriculture emphasising the impact due to changes in the frequency of extreme events (heat waves and drought). The same climatic
dataset was used to compare the effectiveness of different adaptations to a warmer climate strategies including advanced or
delayed sowing time, shorter or longer cycle cultivar and irrigation. The results indicated that both changes in mean climate
and climate variability affected crop growth resulting in different crop fitting capacity to cope with climate change. This
capacity mainly depended on the crop type and the geographical area across Europe. A +2°C scenario had a higher impact on
crops cultivated over the Mediterranean basin than on those cultivated in central and northern Europe as a consequence of
drier and hotter conditions. In contrast, crops cultivated in Northern Europe generally exhibited higher than current yields,
as a consequence of wetter conditions, and temperatures closer to the optimum growing conditions. Simple, no-cost adaptation
options such as advancement of sowing dates or the use of longer cycle varieties may be implemented to tackle the expected
yield loss in southern Europe as well as to exploit possible advantages in northern regions. 相似文献
10.
Jo McEvoy Geoffrey M. While David L. Sinn Erik Wapstra 《Behavioral ecology and sociobiology》2013,67(1):79-90
Competition between males is a key component of the agonistic intrasexual interactions that influence resource acquisition, social system dynamics, and ultimately reproductive success. Sexual selection theory predicts that traits that enhance success in intrasexual competition (particularly male–male competition) should be favored. In vertebrates, this often includes body size and aggression, with larger and/or more aggressive males outcompeting smaller or less aggressive conspecifics. The majority of studies consider aggression as a flexible trait which responds to local social or environmental conditions. However, aggression frequently shows considerable within-individual consistency (i.e., individuals have identifiable aggressive behavioral types). Little is known about how such consistency in aggression may influence competition outcomes. We integrated a detailed field study with a laboratory experiment to examine how a male’s aggressive phenotype and his size influence competitive interactions in Egernia whitii, a social lizard species which exhibits strong competition over resources (limited permanent shelter sites and basking sites). Individual aggression and size did not predict competition outcome in the laboratory nor did they predict home range size, overlap, or reproductive success in the field. However, winners of laboratory trial contests maintained consistent aggressive phenotypes while consistency in aggression was lost in losers. We suggest that aggression may be important in other functional contexts, such as parental care, and that alternative traits, such as fighting experience, may be important in determining competition outcome in this species. 相似文献