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281.
282.
Alexander L. Bezzerides Kevin J. McGraw Robert S. Parker Jad Husseini 《Behavioral ecology and sociobiology》2007,61(9):1401-1408
Carotenoid- and melanin-based colors are valuable indicators of quality in many vertebrates, but their signaling role in invertebrates
remains relatively unexplored. The Asian ladybird beetle Harmonia axyridis is an ideal organism for studies of this nature because males and females exhibit highly variable red and black colors on
their elytra and are chemically defended with an alkaloid (harmonine). We used digital photography to quantify elytra coloration
and absorbance spectrophotometry and gas chromatography mass spectrometry analyses to quantify pigment and alkaloid concentrations,
respectively, in wild-caught male and female H. axyridis. We predicted that extensive or intense coloration would be an aposematic signal of high-alkaloid stores. We found that carotenoid
pigments largely controlled variation in red elytra coloration. There was no relationship between alkaloid content and either
elytra redness or carotenoid pigment concentration in either sex. However, we found a positive correlation between the extent
of elytra coloration and alkaloid content. Animals with proportionally more red (or less black) on the elytra were more alkaloid-rich;
this relationship was particularly strong in females. We also found that females with lighter black spots had greater amounts
of harmonine than those with darker spots. These results suggest that elytra color patterns have the potential to reveal information
about chemical defensiveness to mates or predators. Prior studies in this species show that nonmelanic forms are typically
less active and yet more sexually attractive than melanic forms, and both results may be explained by the fact that nonmelanics
are better chemically defended. 相似文献
283.
Many animals have color vision systems that are well suited to their local environments. Changes in color vision can occur over long periods (evolutionary time), or over relatively short periods such as during development. A select few animals, including stomatopod crustaceans, are able to adjust their systems of color vision directly in response to varying environmental stimuli. Recently, it has been shown that juveniles of some stomatopod species that inhabit a range of depths can spectrally tune their color vision to local light conditions through spectral changes in filters contained in specialized photoreceptors. The present study quantifies the potential for spectral tuning in adults of three species of Caribbean Neogonodactylus stomatopods that differ in their depth ranges to assess how ecology and evolutionary history influence the expression of phenotypically plastic color vision in adult stomatopods. After 12 weeks in either a full-spectrum “white” or a narrow-spectrum “blue” light treatment, each of the three species evidenced distinctive tuning abilities with respect to the light environment that could be related to its natural depth range. A molecular phylogeny generated using mitochondrial cytochrome oxidase C subunit 1 (CO-1) was used to determine whether tuning abilities were phylogenetically or ecologically constrained. Although the sister taxa Neogonodactylus wennerae and N. bredini both exhibited spectral tuning, their ecology (i.e. preferred depth range) strongly influenced the expression of the phenotypically plastic color vision trait. Our results indicate that adult stomatopods have evolved the ability to undergo habitat-specific spectral tuning, allowing rapid facultative physiological modification to suit ecological constraints. 相似文献
284.
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286.
Douglas W. Kuehl Brian C. Butterworth Alexander McBride Steven Kroner Donald Bahnick 《Chemosphere》1989,18(9-10):1997-2014
A survey of contamination of fish from major watersheds in the United States by 2,3,7,8-TCDD has been conducted by the U.S. EPA. Bottom feeding and predator fish were collected at 90 statistically selected and 305 regionally selected sites and analyzed by GC/MS. It was found that 19% of the statistically sampled sites and 31% of the regionally selected sites were contaminated at or above a minimum level of detection varying from 0.5 to 2.0 pg/g. Ten percent of all samples were contaminated at levels greater than 5.0 pg/g. It was also observed that a subset of samples collected at sites near discharge from pulp/paper manufacture (N=28) had a higher frequency of TCDD contamination above 5.0 pg/g (38%). This subset of samples also contained the sample of the greatest level of TCDD contamination (85 pg/g). 相似文献
287.
Dudek Daniel Golub Alexander Petsonk Annie Safonov George Saparov Mikhail 《Mitigation and Adaptation Strategies for Global Change》2002,7(2):155-172
Developing a transparent,accurate greenhouse gas (GHG) emissionsinventory is the first step toward buildingan effective GHG management system. Todate, GHG inventories have been conductedprimarily at national levels. Theinternationally accepted inventorymethodology developed by theIntergovernmental Panel on Climate Change(IPCC) is oriented to countrywideinventories. The electricity company RAOUESR is the largest single corporateemitter of GHG in the Russian Federation. The company is responsible for about 1/3 ofRussia's CO2 emissions; RAO's fossil fuelemissions are comparable to the fossil fuelemissions of the United Kingdom. The GHGinventory prepared by RAO is the first suchcorporate emissions inventory undertaken ina non-OECD country. In this article wepresent a detailed independent examinationof the methodology RAO applied for theinventory. We identify the most importantsources of uncertainty and we estimate theuncertainty. The main conclusion of theindependent review is that the methodologyutilized by RAO and the informationsupporting the methodology are reliable andpresent a reasonably accurate company-widepicture of RAO's CO2 emissions. The shareof other greenhouse gases is negligiblysmall and we did not focus on this fractionof RAO's GHG emissions. As a next step, RAOmay wish to conduct more precisefacility-by-facility inventories in orderto create a robust GHG emission managementsystem. 相似文献
288.
Christine M. Bunck Richard M. Prouty Alexander J. Krynitsky 《Environmental monitoring and assessment》1987,8(1):59-75
Starlings were collected from 129 sites throughout the contiguous United States in the fall of 1982 and analyzed for organochlorine compounds as part of a nationwide monitoring program. Residues of 14 organochlorine compounds were found. Only DDE, polychlorobiphenyls (PCB), dieldrin, and heptachlor epoxide occurred in more than 50% of the 10-starling pools. Geographical variation in the occurrence of seven organochlorine compounds was noted. Mean DDE levels were higher in the southwestern United States. Mean PCB levels were higher in the eastern United States. The occurrence frequency of most organochlorines in 1982 was similar to that which was reported in the previous nationwide study in 1979. A slight increase in occurrence was noted for trans-nonachlor. Mean DDE level in 1982 was similar to that of 1979. Mean PCB level in 1982 was lower than the 1979 mean, but this change may not reflect a decrease in environmental PCB levels. 相似文献
289.
Alexander P. Economopoulos 《Environmental monitoring and assessment》1996,43(1):49-64
The formulation of rational wastewater control strategies is becoming increasingly important in many countries where, exploding urbanization, industrialization and/or tourism, often combined with improved standards of living and better awareness of the environmental problems, are resulting in enlarged pollution problems, but also in the availability of expanding financial resources for environmental protection. However, more often than one tends to believe, lack of planning, or planning with limited understanding of the principles involved, has resulted in solutions that are both expensive and incapable of addressing the key problems.As rigorous planning is extremely resource intensive, and for this reason impractical for most study areas, the development of a much simplified analysis procedure, capable of generating rational, near-optimum, strategies and detailed action programs, is required, if proper environmental management is to be widely practiced.In an effort to achieve the above objectives, a systems analysis approach is selected as the most suitable at rationalizing the allocation of available resources and at producing detailed action programs that promote implementation. In the context of this approach, new, easy to use models have been developed, while others, have been selected, adapted and streamlined in their use. The entire problem analysis and strategy synthesis procedures have thus been simplified and defined to a degree appropriate for widespread use, and the resultant procedure is actively promoted by WHO and UNEP. 相似文献
290.
Thomassen Y Nieboer E Romanova N Nikanov A Hetland S VanSpronsen EP Odland JØ Chashchin V 《Journal of environmental monitoring : JEM》2004,6(12):985-991
The exposure characterisation described in this paper for 135 copper refinery workers (45 females, 90 males) focuses on the concentrations of copper, nickel and other trace elements in the inhalable aerosol fractions, as well as in the water-soluble and water-insoluble subfractions. Some information is also provided on the thoracic and respirable aerosol fractions. Further, results are presented for volatile hydrides of arsenic and selenium released in the copper purification steps of the electrorefining process. For the pyrometallurgical operations, a comparison of the geometric means for the inhalable aerosol fraction indicated that water-soluble copper levels were on average 19-fold higher compared to nickel (p < 0.001) and a significant association was evident between them (r = 0.87, p < 0.001); for the insoluble subfraction, the copper : nickel ratio was 12.5 (p < 0.001) and the inter-element correlation had r = 0.98 and p < 0.001. Although for the electrorefinery workers the relative inhalable concentrations of copper and nickel were not significantly different (p > 0.05), the corresponding inter-element associations were: slope of 7.7, r= 0.54, p < or =0.001 for the water-soluble subfraction and slope of 1.3, r = 0.71 and p < or =0.001 for the water-insoluble subfraction. On average, a good proportion of the inhalable copper and nickel were found in the thoracic (40%) and respirable (20%) aerosol fractions. Cobalt air concentrations were generally low with geometric means and 95% confidence intervals of 3.1 (2.4-4.2)microg m(-3) (pyrometallurgical workers) and 0.3 (0.4-0.5) microg m(-3)(electrorefinery workers). Similarly, the maximum concentrations of cadmium and lead were low, respectively 4 and 25 microg m(-3). Of the hydrides, tellurium and antimony could not be detected, but for the arsenic (arsine) and selenium hydrides measurable exposure occurred for almost all electrorefinery workers, although the levels were generally low at 0.2 microg m(-3). 相似文献