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71.
David B. McDonald 《Behavioral ecology and sociobiology》2009,63(7):1029-1034
I use 10 years of data from a long-term study of lek-mating long-tailed manakins to relate the social network among males
to their spatial and genetic structure. Previously, I showed that the network connectivity of young males predicts their future
success. Here, I ask whether kinship might shape the organization of this “young-boy network”. Not surprisingly, males that
were more socially distant (linked by longer network paths) were affiliated with perch zones (lek arenas) that were further
apart. Relatedness (r) among males within the network decreased as social distance increased, as might be expected under kin selection. Nevertheless,
any role for indirect inclusive fitness benefits is refuted by the slightly negative mean relatedness among males at all social
distances within the network (overall mean r = −0.06). That is, relatedness ranged from slightly negative (−0.04) to more negative (−0.2). In contrast, relatedness in
dyads for which at least one of the males was outside the social network (involving at least one blood-sampled male not documented
to have interacted with other banded males) was slightly above the random expectation (mean r = 0.05). The slight variations around r = 0 among males of different categories likely reflect dispersal dynamics, rather than any influence of kinship on social
organization. Relatedness did not covary with the age difference between males. These results, together with previous results
for lack of relatedness between alpha and beta male partners, refute any role for kin selection in the evolution of cooperative
display in this lek-mating system.
This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau,
and R. James). 相似文献
72.
Virender K. Sharma Xin Yu Thomas J. McDonald Chetan Jinadatha Dionysios D. Dionysiou Mingbao Feng 《Frontiers of Environmental Science & Engineering》2019,13(3):37
73.
As a result of 210Po's previously identified association with sulphur-rich proteins, metallothioneins could have a significant effect on the
behaviour and fate of 210Po in molluscs. Starved control and cadmium-exposed mussels, Mytilus edulis, were fed 210Po-labelled algae (Isochrysis galbana) for 5 d and then allowed to depurate in clean sea water. Cadmium-exposed M. edulis accumulated less 210Po in the digestive gland and the remainder of the tissue than control mussels, although this was due to a decrease in tissue
weight. More than 40% of 210Po was identified as being associated with high molecular weight and heat-treated cytosol proteins in M. edulis. Mussels in a starved state are known to recycle as much as 90% of their amino acids. It is proposed that 210Po associated with these and other proteins is recycled, explaining why no significant loss of 210Po was observed from the remainder of the tissue in either control or Cd-exposed mussels. Cadmium-induced metallothioneins
had no effect on the distribution of 210Po in M. edulis; <5% associated with the cytosolic fraction was considered to principally contain metallothioneins. It is suggested that
210Po's apparent relationship with metallothioneins is coincidental rather than connected with its role in the regulation of
metals.
Received: 30 March 1998 / Accepted: 3 August 1998 相似文献
74.
In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas. 相似文献
75.
A. D. Tucker H. I. McCallum C. J. Limpus K. R. McDonald 《Behavioral ecology and sociobiology》1998,44(2):85-90
We compared natal dispersals of freshwater crocodiles (Crocodylus johnstoni) against the prediction of male dispersal bias for a polygynous mating system. The crocodiles inhabited a linear series of
pools and we calculated the net distances from natal pools to recapture locations some 12–18 years later, at maturity. Philopatry
was assessed in terms of adult social distances. A female social distance was 0.46 pools and a male social distance was 1.0
pool. By these criteria, both sexes showed low levels of philopatry (7–12%). However, individuals of both sexes dispersed
from the natal site long before they were sexually mature. Divergence in dispersal patterns by sex occurred after the maturity
threshold, as males dispersed two to three times farther than females. Intrasexual competition by males is resolved by a size-based
hierarchy. The displacement of small males from local mating access is a probable cause of the longer dispersals undertaken
by males. Competition, rather than inbreeding avoidance, is driving dispersal in this population of freshwater crocodiles.
Received: 8 May 1998 / Accepted after revision: 26 June 1998 相似文献
76.
Gas-phase photolytic production of hydroxyl radicals in an ultraviolet purifier for air and surfaces
David R. Crosley Melanie Doyle-Eisele Jacob D. McDonald 《Journal of the Air & Waste Management Association (1995)》2017,67(2):231-240
We have measured the concentration of hydroxyl radicals (OH) produced in the gas phase by a commercially available purifier for air and surfaces, using the time rate of decay of n-heptane added to an environmental chamber. The hydroxyl generator, an Odorox® BOSS? model, produces the OH through 185-nm photolysis of ambient water vapor. The steady-state concentration of OH produced in the 120 m3 chamber is, with 2σ error bars, (3.25 ± 0.80) × 106 cm?3. The properties of the hydroxyl generator, in particular the output of the ultraviolet lamps and the air throughput, together with an estimation of the water concentration, were used to predict the amount of OH produced by the device, with no fitted parameters. To relate this calculation to a steady-state concentration, we must estimate the OH loss rate within the chamber owing to reaction with the n-heptane and the 7 ppb of background hydrocarbons that are present. The result is a predicted steady-state concentration in excellent agreement with the measured value. This shows we understand well the processes occurring in the gas phase during operation of this hydroxyl radical purifier.Implications: Hydroxyl radical air purifiers are used for cleaning both gaseous contaminants, such as volatile organic compounds (VOCs) or hazardous gases, and biological pathogens, both airborne and on surfaces. This is the first chemical kinetic study of such a purifier that creates gas-phase OH by ultraviolet light photolysis of H2O. It shows that the amount of hydroxyls produced agrees well with nonparameterized calculations using the purifier lamp output and device airflow. These results can be used for designing appropriate remediation strategies. 相似文献
77.
78.
Singing performance,frequency matching and courtship success of long-tailed manakins (Chiroxiphia linearis) 总被引:2,自引:0,他引:2
We examined the relationship between song performance and courtship success in the lek-mating long-tailed manakin (Chiroxiphia linearis) of Costa Rica. Teams of male manakins form cooperative partnerships consisting of a dominant alpha male and a beta male partner with a variable number of subordinate affiliates. Each alpha and beta partnership performs a joint song virtually in unison, which attracts females to their lek arena. We quantified four aspects of song performance, including synchrony, degree of consistency in the alpha male's singing, degree of consistency in the beta male's singing, and degree of sound frequency matching between partners. When all four variables were included in a discriminant function analysis, average frequency matching alone was useful in discriminating between teams with high rates of visitation by females and those with low visitation rates. Only frequency matching was correlated with the rate at which females visited display lek arenas. We propose that the degree of frequency matching provides an unambiguous ideal against which dual-male courtship performance can be assessed. This aspect of song performance may provide information useful to females in assesing a potential mate's ability to form a cooperative long-term partnership. 相似文献
79.
John W. Kern Trent L. McDonald Steven. C. Amstrup George M. Durner Wallace P. Erickson 《Environmental and Ecological Statistics》2003,10(4):405-418
Kernel density estimators are often used to estimate the utilization distributions (UDs) of animals. Kernel UD estimates have a strong theoretical basis and perform well, but are usually reported without estimates of error or uncertainty. It is intuitively and theoretically appealing to estimate the sampling error in kernel UD estimates using bootstrapping. However, standard equations for kernel density estimates are complicated and computationally expensive. Bootstrapping requires computing hundreds or thousands of probability densities and is impractical when the number of observations, or the area of interest is large. We used the fast Fourier transform (FFT) and discrete convolution theorem to create a bootstrapping algorithm fast enough to run on commonly available desktop or laptop computers. Application of the FFT method to a large (n>20,000) set of radio telemetry data would provide a 99.6% reduction in computation time (i.e., 1.6 as opposed to 444 hours) for 1000 bootstrap UD estimates. Bootstrap error contours were computed using data from a radio-collared polar bear (Ursus maritimus) in the Beaufort Sea north of Alaska. 相似文献
80.
Vives I Batlle J Wilson RC Watts SJ Jones SR McDonald P Vives-Lynch S 《Journal of environmental radioactivity》2008,99(11):1711-1730
A generic approach has been developed to simulate dynamically the uptake and turnover of radionuclides by marine biota. The approach incorporates a three-compartment biokinetic model based on first order linear kinetics, with interchange rates between the organism and its surrounding environment. Model rate constants are deduced as a function of known parameters: biological half-lives of elimination, concentration factors and a sample point of the retention curve, allowing for the representation of multi-component release. The new methodology has been tested and validated in respect of non-dynamic assessment models developed for regulatory purposes. The approach has also been successfully tested against research dynamic models developed to represent the uptake of technetium and radioiodine by lobsters and winkles. Assessments conducted on two realistic test scenarios demonstrated the importance of simulating time-dependency for ecosystems in which environmental levels of radionuclides are not in equilibrium. 相似文献