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Matthias Achternbosch Klaus-Rainer Br?utigam Nicola Hartlieb Christel Kupsch Ulf Richers Peter Stemmermann 《Waste management & research》2005,23(4):328-337
The results of model calculations carried out to identify and quantify the input pathways of trace elements into cement and concrete and to estimate the extent to which trace element concentrations in cement may change due to waste utilization are presented. As expected, primary raw materials represented the most important input pathway for trace elements into cement, but the contribution from wastes was not negligible. The use of waste led to a slight increase of the concentrations of cadmium, antimony and zinc in cement. For cobalt, lead and vanadium, this increase was less distinct and for all other trace elements considered, the effect of the use of wastes on trace element concentrations in cement could not be demonstrated clearly. The trace element content of concrete was governed by the aggregates for most elements considered. However, for arsenic, cadmium, lead and zinc, both cement and the additive coal fly ash contributed noticeably to the total trace element concentration in the concrete. 相似文献
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László Z. Garamszegi Thorsten J. S. Balsby Ben D. Bell Marta Borowiec Bruce E. Byers Tudor Draganoiu Marcel Eens Wolfgang Forstmeier Paolo Galeotti Diego Gil Leen Gorissen Poul Hansen Helene M. Lampe Stefan Leitner Jan Lontkowski Laurent Nagle Erwin Nemeth Rianne Pinxten Jean-Marc Rossi Nicola Saino Aurélie Tanvez Russell Titus János Török Els Van Duyse Anders P. Møller 《Behavioral ecology and sociobiology》2005,57(4):305-317
Repertoire size, the number of unique song or syllable types in the repertoire, is a widely used measure of song complexity in birds, but it is difficult to calculate this exactly in species with large repertoires. A new method of repertoire size estimation applies species richness estimation procedures from community ecology, but such capture-recapture approaches have not been much tested. Here, we establish standardized sampling schemes and estimation procedures using capture-recapture models for syllable repertoires from 18 bird species, and suggest how these may be used to tackle problems of repertoire estimation. Different models, with different assumptions regarding the heterogeneity of the use of syllable types, performed best for different species with different song organizations. For most species, models assuming heterogeneous probability of occurrence of syllables (so-called detection probability) were selected due to the presence of both rare and frequent syllables. Capture-recapture estimates of syllable repertoire size from our small sample did not differ significantly from previous estimates using larger samples of count data. However, the enumeration of syllables in 15 songs yielded significantly lower estimates than previous reports. Hence, heterogeneity in detection probability of syllables should be addressed when estimating repertoire size. This is neglected using simple enumeration procedures, but is taken into account when repertoire size is estimated by appropriate capture-recapture models adjusted for species-specific song organization characteristics. We suggest that such approaches, in combination with standardized sampling, should be applied in species with potentially large repertoire size. On the other hand, in species with small repertoire size and homogenous syllable usage, enumerations may be satisfactory. Although researchers often use repertoire size as a measure of song complexity, listeners to songs are unlikely to count entire repertoires and they may rely on other cues, such as syllable detection probability.Communicated by A. Cockburn 相似文献
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Human digit ratios depend on birth order and sex of older siblings and predict maternal fecundity 总被引:1,自引:0,他引:1
In men, the length ratio of the second to fourth finger (2D:4D) is smaller, while the length of the fourth finger relative
to body height (4D:H) is larger than in women. Inter- and intrasexual variations in 2D:4D and 4D:H may depend on variation
in fetal androgen and oestrogen environment. As maternal physiology varies with parity and is differentially affected by gestation
of either sex, offspring 2D:4D and 4D:H may change according to sex and number of older siblings and may predict subsequent
maternal performance. We analysed 2D:4D and 4D:H in Caucasian university students. 2D:4D was smaller and 4D:H was larger in
males than in females, but no sexual dimorphism existed in 2D:H. In males, length ratios did not vary with birth order. 2D:4D
became more masculine with increasing proportion of males among older siblings, and 2D:4D and 4D:H became more feminine as
the number of older sisters increased. In females, length ratios did not vary with the number of older sisters or brothers.
2D:4D was also not related to birth order, but 4D:H became more masculine with birth order. In females, residual maternal
fecundity (number of maternal offspring after the participant) decreased as 4D:H became more masculine. These findings are
partly consistent with those from previous studies and suggest that maternal fecundity co-varies with length ratios and thus
possibly fetal hormone environment of older offspring. 2D:4D and 4D:H may therefore represent powerful tools to investigate
the relationships between fetal environment, offspring phenotype and maternal life history at mechanistic and evolutionary
levels. 相似文献