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141.
Vera A. Matrosova Ilya A. Volodin Elena V. Volodina Andrey F. Babitsky 《Behavioral ecology and sociobiology》2007,62(2):181-191
In most mammals, larger adult body size correlates with lower fundamental frequency and more closely spaced formants in vocalizations
relative to juveniles. In alarm whistles of two free-living rodents, the speckled ground squirrel Spermophilus suslicus and yellow ground squirrel S. fulvus, these cues to body size were absent despite prominent differences in body weight and skull and larynx sizes between juveniles
and adults. No significant correlations were found between the individual maximum fundamental frequency and body weight, both
within age classes and for pooled samples of all animals within species. Furthermore, the mean alarm whistle maximum fundamental
frequencies did not differ significantly between age classes (juvenile versus adult) in the speckled squirrel and were even
significantly lower in juvenile yellow squirrels. We discuss the hypothesis that the obfuscation of vocal differences between
juvenile and adult squirrels may represent a special adaptation of pup vocal behaviour—a form of “vocal mimicry,” resulting
in imitation of adult vocal pattern to avoid infanticide and age-dependent predation risk. 相似文献
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Vera Barbosa Phil Hobbs Robert Sneath Joanna Burgess Joanne Callan Richard Stuetz 《Water environment research》2006,78(8):842-851
The effects of hydrogen sulfide (H2S) diffusion into activated sludge (AS) on odor and volatile organic compound (VOC) concentrations in offgas were studied over an 8-week period. Most VOCs detected in the offgas of both aeration tanks were aromatic hydrocarbons. The VOC concentrations generally decreased when H2S was introduced to the AS compared with the control, indicating a negative effect of H2S on VOC removal. Two volatile organic sulfur compounds present in the test AS offgas showed an increase followed by a decrease during H2S peak loads. Six VOCs and odor concentration increased during the introduction of an H2S peak; however no correlation was observed between H2S and odor concentration. The increase in odor concentration resulted from the increase in the concentration of six aromatic VOCs, which had their removal slowed down during a 100-ppmv H2S peak. Activated sludge diffusion provides effective H2S removal with minimal affect on odor emissions. 相似文献
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The management of healthcare wastes is receiving greater attention because of the risks to both human health and the environment caused by inadequate waste management practices. In that context, the objective of this study was to analyse the healthcare waste management practices in hospitals of the Algarve region, Portugal, and in particular to assess the risk perceptions of, and actual risk to, healthcare staff. The study included three of the six hospitals in the region, covering 41% of the bed capacity. Data were collected via surveys, interviews, and on-site observations. The results indicate that waste separation is the main deficiency in healthcare waste practice, with correct separation being positively related to the degree of daily contact with the waste. Risk perceptions of healthcare staff show the highest levels for the environment (4.24) and waste workers (4.08), and the lowest for patients (3.29) and visitors (2.80), again being positively associated with the degree of daily contact. Risk perceptions of healthcare staff are related to the difficulties of the correct separation of wastes and the lack of knowledge concerning the importance of that separation. The risk of infection with needlesticks/sharps is higher during patient care than during waste handling, and the frequency of these injuries is related to the daily tasks of each healthcare group (doctors, nurses, and housekeepers). Furthermore, legislative definitions and classifications of healthcare wastes appear to have conditioned the management practices associated with, and the perceptions of risk concerning, healthcare wastes. 相似文献
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Patricia Palma Paula Alvarenga Vera L. Palma Rosa Maria Fernandes Amadeu M. V. M. Soares Isabel Rita Barbosa 《Environmental monitoring and assessment》2010,165(1-4):539-552
Multivariate statistical techniques were applied to evaluate spatial/temporal variations, and to interpret water quality data set obtained at Alqueva reservoir (south of Portugal). The water quality was monitored at nine different sites, along the water line, over a period of 18 months (from January 2006 to May 2007) using 26 water quality parameters. The cluster analysis allowed the formation of five different similarity groups between sampling sites, reflecting differences on the water quality at different locations of the Alqueva reservoir system. The PCA/FA identified six varifactors, which were responsible for 64% of total variance in water quality data set. The principal parameters, which explained the variability of quality water, were total phosphorus, oxidability, iron, parameters that at high concentrations indicate pollution from anthropogenic sources, and herbicides indicative of an intensive agricultural activity. The spatial analysis showed that the water quality was worse in the north of the reservoir. 相似文献
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