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581.
Kelley J. Kissner Patrick J. Weatherhead H. Lisle Gibbs 《Behavioral ecology and sociobiology》2005,59(2):207-214
To resolve conflicting field observations regarding the action of sexual selection, we used breeding experiments and paternity analysis of the 927 resulting offspring to assess how male size, condition, tail length, genetic similarity to the female, and variation in operational sex ratio (OSR) affected male reproductive success and the incidence of polyandry in northern watersnakes (Nerodia sipedon). Only size affected male mating success. Large males were more successful, but only when male size varied substantially and competition among males was intense (i.e., male-biased OSR). The conditional nature of the size advantage may explain why studies of free-living watersnakes have produced inconsistent results regarding the relationship between male size and mating success. Size differences between males did not affect the proportion of offspring each male sired within multiply sired litters. We found positive size-assortative mating, but only when the OSR was female biased, suggesting that smaller males had improved access to females when competition among males was reduced, but that competition with larger males still restricted mating opportunities of small males to less preferred, smaller females. Most litters (58%) were multiply sired and larger females were more likely to produce multiply sired litters, similar to free-living watersnakes. There was no association between the incidence of multiple paternity and OSR, however, suggesting that polyandry is not simply a function of opportunity, with females passively waiting for males to court them. 相似文献
582.
A diesel fuel contaminated aquifer in Menziken, Switzerland was treated for 4.5 years by injecting aerated groundwater, supplemented with KNO3 and NH4H2PO4 to stimulate indigenous populations of petroleum hydrocarbon (PHC) degrading microorganisms. After dissolved PHC concentrations had stabilized at a low level, engineered in situ bioremediation was terminated. The main objective of this study was to evaluate the efficacy of intrinsic in situ bioremediation as a follow-up measure to remove PHC remaining in the aquifer after terminating engineered in situ bioremediation. In the first 7 months of intrinsic in situ bioremediation, redox conditions in the source area became more reducing as indicated by lower concentrations of SO4(2-) and higher concentrations of Fe(II) and CH4. In the core of the source area, strongly reducing conditions prevailed during the remaining study period (3 years) and dissolved PHC concentrations were higher than during engineered in situ bioremediation. This suggests that biodegradation in the core zone was limited by the availability of oxidants. In lateral zones of the source area, however, gradually more oxidized conditions were reestablished again, suggesting that PHC availability increasingly limited biodegradation. The total DIC production rate in the aquifer decreased within 2 years to about 25% of that during engineered in situ bioremediation and remained at that level. Stable carbon isotope analysis confirmed that the produced DIC mainly originated from PHC mineralization. The total rate of DIC and CH4 production in the source area was more than 300 times larger than the rate of PHC elution. This indicates that biodegradation coupled to consumption of naturally occurring oxidants was an important process for removal of PHC which remained in the aquifer after terminating engineered measures. 相似文献
583.
Summary A demonstration of adaptive mate choice by females in resource-defence mating systems requires clear predictions as to how females should rank breeding situations (defined by the quality of both the resident male and the territory he defends) so as to maximize their fitness. Since male quality is only weakly correlated with territory quality in red-winged blackbirds (Agelaius phoeniceus), ranking breeding situations in this species will require a consideration of both those parameters independently of each other as long as both vary among males, are predictable before mating, and affect female fitness. Data from a two year study of an eastern Ontario population of this species suggested that two components of male parental quality, nest defence effort and provisioning of nestlings with food, both varied among males and were somewhat predictable. Two measures of nest defence effort were correlated with an index of epaulet size (a reliable predictor of captive dominance rank in this species) (Table 5), and provisioning appeared to be predictable on the basis of both courtship behavior and breeding experience. Our data also suggest that these two components of male parental quality do not covary. Since male provisioning tends to be restricted to the nestlings of the primary and secondary mates in this species, breeding situations must be ranked not only with respect to their manifold quality but also with respect to the mating status of individual females. 相似文献
584.
This paper addresses the failure of the social impact assessment process (SIA) used to analyze the effects of recent energy development near the Northern Cheyenne Reservation in Montana. Research conducted under the auspices of state and federal agencies to assess the impacts of coal development adjacent to the reservation has neglected to consider the potential negative consequences on the social interaction and organization of the Northern Cheyenne. The focus here is on one reservation, but the findings may be applicable to development near other reservations with similar demographic, social, and jurisdictional characteristics. Another important similarity includes the relationship between the reservations and persons and organizations outside them. An ideal model for analyzing reservations is described. 相似文献
585.
The equilibrium partitioning method (EqP-method) can be used to calculate soil quality standards (expressed in mg/kg) from aquatic quality standards (expressed in microg/l) using a partitioning coefficient. The validity of this application of the EqP-method was studied comparing aquatic with terrestrial toxicity data. The data set collected for deriving environmental quality standards in the Netherlands, was used for this study. For 10 organic substances (chlorpyrifos, atrazine, carbofuran, pentachlorophenol, chlordane, aldrin, trichlorobenzene, heptachlor, trichlorophenol and trichloroethene) and for 8 metals, sufficient data were available. The aquatic toxicity data were multiplied by the partitioning coefficient in order to obtain aquatic data expressed in mg/kg. For some compounds the terrestrial toxicity data were significantly higher than the aquatic data but for other compounds it was the other way around. These differences indicate that the EqP-method can give significant over-or underestimations, due to inaccurate partitioning coefficients or differences in species sensitivities. These over- or underestimations can have an impact on the setting of environmental quality standards which are based on the hazardous concentration 5% (HC5) values. The uncertainty in the calculation of HC5 values attributed to the use of the EqP-method, was quantified. The HC5 values derived using the EqP-method were in 5% of the cases more than 20 times higher than the corresponding HC5 values that were derived directly from soil toxicity tests. Despite of this uncertainty the use of the EqP-method can still be advocated for setting soil quality guidelines when only a very limited number of terrestrial toxicity data are available. 相似文献
586.
Ryan PA 《Journal of the Air & Waste Management Association (1995)》2005,55(7):1014-1018
The U.S. Environmental Protection Agency (EPA) published the Regional Haze Rule (RHR) in 1999. The RHR default goal is to reduce haze linearly to natural background in 2064 from the baseline period of 2000-2004. The EPA default method for estimating natural and baseline visibility uses the Interagency Monitoring of Protected Visual Environments (IMPROVE) formula. The IMPROVE formula predicts the light extinction coefficient from aerosol chemical concentrations measured by the IMPROVE network. The IMPROVE light scattering coefficient formula using data from 1994-2002 underestimated the measured light scattering coefficient by 700 Mm(-1), on average, on days with precipitation. Also, precipitation occurred as often on the clearest as haziest days. This led to estimating the light extinction coefficient of precipitation, averaged over all days, as the light scattering coefficient on days with precipitation (700 Mm(-1)) multiplied by the percent of precipitation days in a year. This estimate added to the IMPROVE formula light extinction estimate gives a real world estimate of visibility for the 20% clearest, 20% haziest, and all days. For example, in 1993, the EPAs Report to Congress projected visibility in Class I areas would improve by 3 deciviews by 2010 across the haziest portions of the eastern United States because of the 1990 Clean Air Act Amendments. Omitted was the light extinction coefficient of precipitation. Adding in the estimated light extinction coefficient of precipitation, the estimated visibility improvement declines to <1 deciview. 相似文献
587.
Patrick Hohlfeld Thi-Tan Dang K. Nahoul Fernand Daffos François Forestier 《黑龙江环境通报》1994,14(10):907-912
Normal levels of cancer-associated antigen (CA) 19-9, neurone-specific enolase (NSE), cancer-associated antigen (CA) 125, and mucin-like carcinoma-associated antigen (MCA) during pregnancy were determined in 87 mothers and fetuses, using a solid-phase sandwich enzyme immunoassay. CA 19-9 concentrations were higher in the fetuses, whereas the other three tumour-associated antigen levels were higher in the mothers. Only fetal NSE and MCA levels were positively correlated with those in maternal serum. Contrary to adult samples, no difference was demonstrated between male and female fetal levels of CA 125. MCA was the only maternal marker that increased significantly with gestational age between 20 and 34 weeks' pregnancy. 相似文献
588.
Companies are increasingly interested in environmental performance indicators as a means of managing the degree to which environmental goals and objectives are implemented. Many companies have publicly endorsed goals associated with sustainable development, like the International Chamber of Commerce's (ICC) principles for sustainable development. There is a need for metrics that facilitate implementation of these principles at the facility level and for research metrics that measure management improvement. An existing environmental self-assessment management tool called ESAP by the Global Environmental Management Initiative has been modified to measure a facility's response to the ICC's 16 principles of sustainability. The new tool's focus was shifted to a practical, facility based and easily applied assessment of progress towards sustainable development as represented by the ICC's 16 principles of sustainability. The new tool was called the Green Management Assessment Tool or GMAT, pilot tested and used in a research setting. Such tools have value to companies that are interested in the strategic goals of sustainable development and struggle with shifting corporate goals and objectives to manufacturing operations at the facility level. 相似文献
589.
de Bonis L Peigné S Likius A Mackaye HT Vignaud P Brunet M 《Die Naturwissenschaften》2007,94(7):575-580
We report on the oldest fox (Canidae) ever found in Africa. It is dated to 7 Ma based on the degree of evolution of the whole
fauna. It belongs to a new species. Its overall size and some morphological characteristics distinguish the Chadian specimen
from all the other foxes. The presence of Vulpes and of the genus Eucyon in slightly younger African locality, as well as in southwestern Europe in the late Miocene, may indicate that canids migrated
in Europe from Africa through a trans-Mediterranean route. 相似文献
590.
Pheromones produce dramatic behavioral and physiological responses in a wide variety of species. Releaser pheromones elicit
rapid responses within seconds or minutes, while primer pheromones produce long-term changes which may take days to manifest.
Honeybee queen mandibular pheromone (QMP) elicits multiple distinct behavioral and physiological responses in worker bees,
as both a releaser and primer, and thus produces responses on vastly different time scales. In this study, we demonstrate
that releaser and primer responses to QMP can be uncoupled. First, treatment with the juvenile hormone analog methoprene leaves
a releaser response (attraction to QMP) intact, but modulates QMP’s primer effects on sucrose responsiveness. Secondly, two
components of QMP (9-ODA and 9-HDA) do not elicit a releaser response (attraction) but are as effective as QMP at modulating
a primer response, downregulation of foraging-related brain gene expression. These results suggest that different responses
to a single pheromone may be produced via distinct pathways. 相似文献