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71.
Kaspar Delhey Anne Peters Arild Johnsen Bart Kempenaers 《Behavioral ecology and sociobiology》2007,61(6):853-862
Sex-allocation theory predicts that females paired to attractive males should bias the brood sex ratio towards male offspring,
as these would inherit the attractiveness of their father. We studied sex allocation based on male ornamentation in blue tits.
Brood sex ratios varied with male UV coloration in an age-dependent manner. For juvenile males, the proportion of sons increased
with increasing UV ornamentation, which is in agreement with previous findings from a Swedish population. However, the relationship
between UV ornamentation and brood sex ratio was reversed for adult males, with females paired to less UV-ornamented adult
males producing more sons. This pattern fits with the observation that, in our population, less UV-ornamented adult males
sire the majority of extra-pair young. To test the causality of the association between brood sex ratio and male coloration,
we experimentally manipulated crown colour largely within the natural range. We created two groups of males: one with higher
and one with lower UV reflectance, UV(+) and UV(−), respectively. Contrary to our expectations, there was no significant treatment
effect. However, in UV(−), but not UV(+) males, the proportion of sons was negatively correlated with male coloration before
manipulation. This suggests that the UV(−) treatment caused males that were more UV ornamented to decline more in attractiveness,
as shown in a similar experiment in Sweden. However, given that correlational patterns differ between these populations, similarities
in experimental results should not be taken as evidence for consistent patterns of adaptive sex allocation in this species. 相似文献
72.
Gail L. Patricelli Marc S. Dantzker Jack W. Bradbury 《Behavioral ecology and sociobiology》2007,61(7):1099-1110
Studies of animal acoustic communication have found that the frequency and temporal structure of acoustic signals can be shaped
by selection for efficient communication. The directionality of acoustic radiation may also be adapted for communication,
but we know relatively little about how directionality varies with signal function, sender morphology, and the environment
in which the sound is transmitted. We tested the hypothesis that the directionality of a vocalization is adapted to its function
in communication. This hypothesis predicts that vocalizations that are directed to multiple conspecifics (e.g., advertisements
and alarms) will be relatively omnidirectional because this will maximize the number of neighbors and mates that receive the
signal, and that vocalizations directed to particular individuals will be relatively directional because this will maximize
detection of the signal by the targeted receiver and minimize eavesdropping. To test these predictions, we measured the directionality
and amplitude of red-winged blackbird (Agelaius pheoniceus) vocalizations in the field by recording vocalizations simultaneously on eight calibrated microphones encircling the bird.
We found significant variation in directionality among vocalizations. Supporting our predictions, we found that the most omnidirectional
vocalizations were those used to alert conspecifics to danger, and the most directional vocalizations are those used during
courtship and solicitation of copulation, when the costs of eavesdropping are likely to be high. These results suggest that
the directionality of red-winged blackbird vocalizations is shaped by selection for effective communication. This study is
the first to provide statistical support for the hypothesis that directionality is related to the function of a signal in
communication. 相似文献
73.
Marc Hockings 《Environmental management》1998,22(3):337-345
/ An approach to evaluating the effectiveness of management of protected areas is proposed. This approach has been used in developing an evaluation strategy for the Fraser Island World Heritage Area in Australia. The main component of the strategy is built upon the desired outcomes specified in the management plan for the area and thus provides a basis for assessing the extent to which the plan's objectives are being achieved. A series of monitoring programs have been proposed to enable this assessment. Examples of monitoring programs developed as part of the evaluation strategy are presented. A second component of the strategy monitors the implementation of the management plan. A management information system has been developed to record and report on the extent to which the specific actions specified in the management plan have been implemented. The strategy is discussed in relation to seven objectives set for the evaluation program in its design phase.KEY WORDS: Planning; Evaluation; Monitoring; Management; Protected areas 相似文献
74.
/ Public contact is a vital component of any program to manage natural resources. A well-planned public contact program uses a variety of strategies to create a sympathetic and environmentally aware public and to meet specific management-related objectives. A methodology is proposed that can be applied to planning public contact at any level, from media design for a specific project to corporate strategies for communication. The methodology integrates management-driven, client-driven and resource-driven planning to provide the connections essential to effective communication.KEY WORDS: Planning; Public contact; Interpretation; Conservation; Management 相似文献
75.
Multixenobiotic defence mechanism (MXDM) has been recently described as a first line defence system in many aquatic organisms and it has raised attention for its potential as an early biomarker of exposure to environmental stress. In order to investigate the relevance of this biomarker in the freshwater zebra mussel Dreissena polymorpha, we examined its response to exposure and to cessation of exposure. For this purpose, depurated zebra mussels were transplanted to natural rivers or exposed to medium experimentally contaminated with fuel oil 2 in the laboratory. After the exposure period, mussels were submitted to depuration in clean water in the laboratory. The level of MXDM activity was assessed by the efflux method that allows a simple and fast measure of the rate of rhodamine B efflux. MXDM activity was induced following exposure and induction appears earlier after laboratory exposure (3 days) than after in the field exposure (3-14 days). The level of MXDM response could not be directly correlated to exposure dose in the laboratory and to isolated physicochemical parameters or AOX levels in the field. The behaviour of MXDM activity seems to reflect the occurrence of exposure to a global stress rather than to specific compounds. Our results highlighted the possibility to monitor MXDM response in the freshwater zebra mussel. In spite of the difficulty to interpret responses resulting from the lack of specificity of response, multixenobiotic defence mechanism displays qualities to represent a biomarker of general stress in freshwater ecosystems. 相似文献
76.
Elisabet Berggren Marc Debois Janet Duffield Annett Janusch 《Environmental science and pollution research international》1997,4(1):55-59
Council Regulation (EEC) No 2455/92 has been adopted by the Council of the European Communities, in 1992, to improve information exchange on certain dangerous chemicals with third countries, particularly developing countries. To implement the notification procedure in accordance with the Regulation, a database has been developed to manage and simplify the procedure. The software exists in three versions; one adapted for use by the Designated Authorities of the Member States, another for the European Chemicals Bureau (ECB) and the third one is an information version aimed at Designated National Authorities outside the European Union and Industry. The database “EDEXIM” is currently working in a PC environment and is being developed as an on-line system with a stand-alone client/server architecture. 相似文献
77.
L.L. Lamparski T.J. Nestrick N.N. Frawley R.A. Hummel C.W. Kocher N.H. Mahle J.W. McCoy D.L. Miller T.L. Peters J.L. Pillepich W.E. Smith S.W. Tobey 《Chemosphere》1986,15(9-12):1445-1452
During 1983 and 1984, The Dow Chemical Company conducted a study to determine the extent of dioxin contamination at its Midland, Michigan plant and the surrounding area. The primary objectives of this study were to identify, rank order, and when possible quantify potential sources of dioxins to the environment and also to determine the extent of contamination in areas affected by the Dow facility. Early in the study, it was estimated that approximately 0.6g/year of 2378-TCDD was being emitted in 2.5 × 1010L of wastewater effluent. Data will describe observed sources of TCDD (both current and historical), environmental levels, existing water treatment methods, control measures taken, and future improvements on the water system to reduce TCDD in the effluent. 相似文献
78.
Melissa M. Lunden Kenneth L. Revzan Marc L. Fischer Tracy L. Thatcher David Littlejohn Susanne V. Hering Nancy J. Brown 《Atmospheric environment (Oxford, England : 1994)》2003,37(39-40):5633
Recent studies associate particulate air pollution with adverse health effects; however, the exposure to indoor particles of outdoor origin is not well characterized, particularly for individual chemical species. We conducted a field study in an unoccupied, single-story residence in Clovis, California to provide data and analyses to address issues important for assessing exposure. We used real-time particle monitors both outdoors and indoors to quantify nitrate, sulfate, and carbon particulate matter of particle size 2.5 μm or less in diameter (PM-2.5). The results show that measured indoor ammonium nitrate concentrations were significantly lower than would be expected based solely on penetration and deposition losses. The additional reduction can be attributed to the transformation indoors of ammonium nitrate into ammonia and nitric acid gases, which are subsequently lost by deposition and sorption to indoor surfaces. A mass balance model that accounts for the kinetics of ammonium nitrate evaporation was able to reproduce measured indoor ammonium nitrate and nitric acid concentrations, resulting in a fitted value of the deposition velocity for nitric acid of 0.56 cm s−1. The results indicate that indoor exposure to outdoor ammonium nitrate in Central Valley of California are small, and suggest that exposure assessments based on total particle mass measured outdoors may obscure the actual causal relationships for indoor exposure to particles of outdoor origin. 相似文献
79.
Effect of pH on phosphine production and the fate of phosphorus during anaerobic process with granular sludge 总被引:6,自引:0,他引:6
The effect of pH on phosphine formation during anaerobic cultivation of granular sludge was investigated. The sludge was taken from full-scale anaerobic reactors treating brewery wastewater. Acetate and phosphate were used as the carbon source and phosphorus source respectively. After 10 days cultivation in the dark, results showed that acidic conditions were more favorable for free phosphine production. At pH 5, the optimum concentration 86.42 ng PH3 m-3 of free phosphine was obtained. The level at pH 7 was reduced to 18.53 ng PH3 m-3, about 1/5 of the maximum. The maximum concentration of matrix-bound phosphine of 3.30 ng PH3 kg-1 wet sludge was achieved at pH 6. More than 83% of the total phosphine was matrix-bound phosphine, which accounted for 0.003-0.009 per thousand of the phosphate removal, while free phosphine comprised 0.00002-0.001 per thousand of the phosphate removal. Most of the phosphorus removal from solution was turned into chemical precipitation or was adsorbed by sludge. The mechanism of the phosphate reduction-step in the formation of phosphine production is still unknown. The promotion of phosphine formation by low pH is compatible with an acidic bio-corrosion mechanism of metal particles in the sludge or of metal phosphides which form phosphine at low pH. 相似文献
80.
Aline Chiabai Joseph V. Spadaro Marc B. Neumann 《Mitigation and Adaptation Strategies for Global Change》2018,23(7):1159-1176
The study aims to explore the main drivers influencing the economic appraisal of heat warning systems by integrating epidemiological modelling and benefit-cost analysis. To shed insights on heat wave mortality valuation, we consider three valuation schemes: (i) a traditional one, where the value of a statistical life (VSL) is applied to both displaced and premature mortality; (ii) an intermediate one, with VSL applied for premature mortality and value of a life year (VOLY) for displaced mortality; and (iii) a conservative one, where both premature and displaced mortality are quantified in terms of loss of life expectancy, and then valued using the VOLY approach. When applying these three schemes to Madrid (Spain), we obtain a benefit-cost ratio varying from 12 to 3700. We find that the choice of the valuation scheme has the largest influence, whereas other parameters such as attributable risk, displaced mortality ratio, or the comprehensiveness and effectiveness of the heat warning system are less influential. The results raise the question of which is the most appropriate approach to value mortality in the context of heat waves, given that the lower bound estimate for the benefit-cost ratio (option iii using VOLY) is up to two orders of magnitude lower than the value based on the traditional VSL approach (option i). The choice of the valuation methodology has significant implications for public health authorities at the local and regional scale, which becomes highly relevant for locations where the application of the VOLY approach could lead to benefit-cost ratios significantly lower than 1. We propose that specific metrics for premature and displaced VOLYs should be developed for the context of heat waves. Until such values are available, we suggest testing the economic viability of heat warning systems under the three proposed valuation schemes (i–iii) and using values for VOLY commonly applied in air pollution as the health end points are similar. Lastly, periodical reassessment of heat alert plans should be performed by public health authorities to monitor their long-term viability and cost-effectiveness. 相似文献