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81.
Two drinking water production plants located in North Italy, collecting water from the River Po (Plants 1 and 2) were chosen for this study. Water samples were collected before and after the disinfection process and at two points along the piping system. Water samples were concentrated by the solid-phase extraction system and injected intraperitoneally into specimens of Cyprinus carpio. The concentration of water samples was 3 l/equiv. In order to assess the effects of the water samples on carp liver, total glutathione and glutathione-dependent enzymes, such as glutathione S-transferase, glutathione peroxidase, glutathione reductase and glyoxalase I, were measured following this treatment for 6 days at two experimental times (3 and 6 days). Both water plant-treated carp showed a general increase of the enzymatic activities of glutathione S-transferase, and glutathione reductase which might be employed as potential biomarkers of oxidative stress induced by disinfected river water. Plant 1-treated carp showed higher glyoxalase I and glutathione levels and lower glutathione peroxidase activity. A depleted level of total glutathione and of glyoxalase I for specimens of water plant 2 (for both experimental times), without correlation with the distances in the pipeline, suggests that river plant water can also lead to potentially adverse effects on selected biochemical parameters in C. carpio. 相似文献
82.
T. Lubjuhn Wolfgang Winkel Jörg Thomas Epplen Jörg Brün 《Behavioral ecology and sociobiology》2000,48(1):12-17
One of the most interesting aspects of the mating system of pied flycatchers is the regular occurrence of polygyny. Here we
present data on the reproductive success of polygynously paired pied flycatcher males compared to monogamous males based on
paternity analyses through DNA fingerprinting. Males paired with two females suffered a higher loss in reproductive output
per female compared to monogamous males due to (1) a greater proportion of unhatched eggs in their broods, (2) greater nestling
mortality and (3) a greater probability of being cuckolded. Nevertheless, the number of fledglings was significantly greater
for polygynous males. Based on the number of nestlings that returned for subsequent breeding seasons, however, the reproductive
success of monogamous and polygynous males did not differ significantly. These data raise the question as to why males attempt
polygyny.
Received: 16 August 1999 / Received in revised form: 15 March 2000 / Accepted: 18 March 2000 相似文献
83.
Strontium (Sr) and calcium (Ca) contents in the otoliths of yellow and silver European eels [Anguilla anguilla (L.)] collected from coastal waters of the Baltic Sea and a freshwater lake in Sweden were examined by wavelength dispersive
X-ray spectrometry with an electron microprobe. The mean Sr/Ca ratios from elver check to otolith edge were significantly
higher for the eels from coastal waters (5.39 ± 1.09‰) than for those from the lake (0.71 ± 0.89‰). The evidence indicates
that European eels in the Baltic Sea do not necessarily migrate into freshwater streams during the growth phase.
Received: 30 September 1999 / Accepted: 6 April 2000 相似文献
84.
Arm damage is a widely reported but superficially investigated aspect of the biology of the starfish Asterias rubens L. In the present study, the incidence of arm damage was surveyed in populations of A.
rubens at two sites in the Firth of Clyde, Scotland, and three sites in Gullmarsfjorden, Sweden. The mean (±SD) incidence across
all sites of individuals with basal arm damage (resulting from detachment at the basal autotomy plane) was 19.69 ± 8.86%,
the incidence of those with distal arm damage (resulting from amputation at more distal levels) was 7.74 ± 10.01%. The mean
incidence of arms with basal damage was 5.28 ± 4.12%, of those with distal damage 1.83 ± 2.45%. There was a significant negative
correlation between size and the incidence of basal damage at all but one site, but no significant correlation between size
and distal damage at any site. Mechanical tests on specimens of the aboral body wall from the basal region of the arm (which
included the autotomy plane) and from a more distal region revealed that with increasing body size there was a significant
increase in yield stress, ultimate stress and Young's modulus (stiffness) but no significant change in yield strain and ultimate
strain. There was no significant difference between the relationships for basal and distal specimens. It is hypothesised that
in larger individuals increased mechanical toughness replaces autotomy as an effective antipredator strategy. Using two methods
to induce autotomy, a significant positive correlation between size and the delay between the onset of stimulation and arm
detachment was found; this may represent a size-related decline in the efficiency of the autotomy mechanism through the relaxation
of selection pressure. Since size is an unreliable indicator of age in A.
rubens, the trends identified herein can be interpreted only tentatively as age-associated phenomena.
Received: 4 September 1999 / Accepted: 17 February 2000 相似文献
85.
Three marine diatoms Lauderia annulata Cleve, Odontella sinensis (Greville) Grunow and Thalassiosira rotula Meunier were exposed to ultraviolet (UV) radiation of different wavebands under controlled laboratory conditions (0.035 vol%
CO2, 18 °C). Several changes in the patterns of pigments in these organisms were seen depending on the waveband of UV radiation
and species examined. UV-B and UV-B plus UV-A radiation led to a reduction in the overall pigment content of all three diatoms.
The uptake of 15N-ammonium was less affected by 5-h UV-A (WG 320) but significantly reduced after UV-B and UV-B plus UV-A exposure. The pattern
of free amino acid pools varied depending on the applied UV wavebands and the tested diatom. The main protein-bound amino
acids of T. rotula decreased after 5-h UV irradiance except leucine. Contents of adenosine 5′-mono-, di-, and triphosphate (AMP, ADP and ATP)
were affected differently by UV radiation; ATP values increased at the end of UV-B and UV-B plus UV-A exposure. These results
have been discussed with reference to the impact of the different UV sources and the influence on the nitrogen metabolism
in connection to pigments and supply with energy.
Received: 13 May 1997 / Accepted: 11 October 1997 相似文献
86.
Peter Weindler Frank Böhme Varis Liepa Wolfgang Wiltschko 《Behavioral ecology and sociobiology》1998,42(4):289-294
To assess the role of celestial rotation during daytime in the development of the magnetic compass course, pied flycatchers
(Ficedula hypoleuca Pallas, Muscicapidae) were handraised in Latvia under various celestial and magnetic conditions. Tests were performed during
autumn migration in the local geomagnetic field (50 000 nT, 73° inclination) in the absence of celestial cues. A group of
birds that had never seen the sky showed a bimodal preference for the migratory southwest-northeast axis, whereas a second
group that had been exposed to the natural sky from sunrise to sunset in the local geomagnetic field showed a unimodal preference
for the seasonally appropriate southwesterly direction. A third group that had also been exposed to the daytime sky, but in
the absence of magnetic compass information, also oriented bimodally along a southwest-northeast axis. These findings demonstrate
that observing celestial rotation during daytime enables birds to choose the right end of the migratory axis for autumn migration
at the Latvian test location. This transformation of axial behavior into appropriate migratory orientation, however, requires
the birds to have simultaneous access to information on both celestial rotation and the geomagnetic field.
Received: 19 September 1997 / Accepted after revision: 22 November 1997 相似文献
87.
K. Håkan Olsén J. Torbjörn Järvi Ian Mayer Erik Petersson Frederieke Kroon 《Chemoecology》1998,8(1):9-17
Summary. In the present experiment the behaviour and endocrine status of males of the brown trout, Salmo trutta L., (Salmoniformes: Salmonidae) were studied when males were kept in a stream tank with a nest digging female. Groups of
mature adult males and precocious intact or anosmic male parr were placed with the nesting female so that the group resembled
a natural spawning situation with big anadromous fish acting as dominant males and precocious parr acting as “sneakers”. A
control experiment was also run with only males without a female present. In intact parr there were significant positive correlations
between the per cent of the total observation time spent with a female, milt volume, and plasma concentration of 17α, 20β-dihydroxy-4-pregnen-3-one.
Anosmic parr had significantly lower volumes of strippable milt and gonadal steroid hormone levels compared with intact parr.
However, no differences were found in the control experiment. Significantly fewer anosmic parr attended and courted the nesting
female and those anosmic fish that attended the female had significantly lower plasma levels of gonadal hormones. Intact parr
also displayed a greater number of agonistic acts against other parr without any difference in fighting ability. No differences
in aggression occured in the control experiment. In adult males together with a female, post-experimental gonadal steroid
hormone levels were higher than pre-experimental levels. Positive correlations between aggression and androgen hormone levels
were observed in adult males. No differences in plasma hormone levels were observed between adult males and intact precocious
males. The results show that olfactory occlusion results in low steroid hormone levels and milt volumes in precocious males
placed in a spawning situation. The courting behaviour was also affected by anosmia. Odours from the nesting female may have
caused the enhanced plasma hormone levels and stimulated the males to attend the female.
Received 15 May 1997; accepted 29 June 1997. 相似文献
88.
Schimmack W Gerstmann U Schultz W Sommer M Tschöpp V Zimmermann G 《Journal of environmental radioactivity》2007,94(1):16-30
Differences between the root uptake of fallout radionuclides by different cultivars ('inter-cultivar' variability) growing on the same field may be influenced not only by genetic differences of the cultivars, but also by the spatial variability of the soil-to-grain transfer within the cultivation area of each cultivar. This 'intra-cultivar' variability was investigated in 2001 and 2002 for 137Cs and 90Sr using three winter wheat cultivars with four replicates for each cultivar at three different sites in Bavaria, Germany. The intra-cultivar variability proved to be in the same range as the inter-cultivar variability which was determined earlier at the same sites for both radionuclides. An ANOVA of the 137Cs data set revealed that the variability of the 137Cs soil-to-grain transfer was caused by the soil and climate (year) at the field sites and the interaction of cultivar and field. A significant contribution of the factor 'cultivar' alone to the variability could not be detected. This may be due to the complex environmental conditions to which plants are exposed in field experiments. To find wheat cultivars with minimal uptake of fallout radionuclides it may be better to examine the molecular mechanisms of their root uptake in order to identify targets for breeding "safer" plants. 相似文献
89.
Bioaerosol sampling by a personal rotating cup sampler CIP 10-M 总被引:1,自引:0,他引:1
Görner P Fabriès JF Duquenne P Witschger O Wrobel R 《Journal of environmental monitoring : JEM》2006,8(1):43-48
High concentrations of bioaerosols containing bacterial, fungal and biotoxinic matter are encountered in many workplaces, e.g. solid waste treatment plants, waste water treatment plants and sewage networks. A personal bioaerosol sampler, the CIP 10-M (M-microbiologic), has been developed to measure worker exposure to airborne biological agents. This sampler is battery operated; it is light and easy to wear and offers full work shift autonomy. It can sample much higher concentrations than biological impactors and limits the mechanical stress on the microorganisms. Biological particles are collected in 2 ml of liquid medium inside a rotating cup fitted with radial vanes to maintain an air flow rate of 10 l min(-1) at a rotational speed of approximately 7,000 rpm. The rotating cup is made of sterilisable material. The sampled particles follow a helicoidal trajectory as they are pushed to the surface of the liquid by centrifugal force, which creates a thin vertical liquid layer. Sterile water or another collecting liquid can be used. Three particle size selectors allow health-related aerosol fractions to be sampled according to international conventions. The sampled microbiological particles can be easily recovered for counting, incubation or further biochemical analysis, e.g., for airborne endotoxins. Its physical sampling efficiency was laboratory tested and field trials were carried out in industrial waste management conditions. The results indicate satisfactory collection efficiency, whilst experimental application has demonstrated the usefulness of the CIP 10-M personal sampler for individual bioaerosol exposure monitoring. 相似文献
90.
The Kyoto Protocol’s Clean Development Mechanism (CDM) is often cited as an exemplar of new, hybrid forms of global environmental governance operating at the public–private interface. Practically, enacting this arrangement involves a wide range of non-state actors. This broad involvement is here assumed to mark a shift towards more polycentric and networked modes of governance in which agents collaborate as ‘stakeholders’ in the process of consensual rule-setting and implementation. Using post-political critique, the depoliticising effects of the stakeholder framework on civil society actors are interrogated, using formal and informal participation opportunities to raise concerns regarding specific CDM projects. The analysis suggests that the CDM’s collaborative narrative of stakeholding structurally fails to stimulate public (re)engagement and is, instead, a prime example of simulative governance that struggles to achieve the simultaneity of two incompatibilities: the participatory revolution and the post-political turn. 相似文献