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261.
The influence of Cracow's urban pollution on small forest ecosystems was studied during 1998-2000. Seven sites located at different distances from the Cracow conurbation and from busy road were selected. Two sites were situated 26 and 31 km from Cracow town along an eastern transect, the other five-3, 8, 14, 26 and 35 km respectively, from Cracow-along a southern transect. At the beginning of September, five litter traps were set at each site. The quantity of litter fall, along with percentage composition of each species, were estimated for an area of 1 m(2). The concentration of Cd, Pb, Cu, Zn and Fe in the litter fall and the input of these metals to the forest floor were determined. The input of cadmium ranged from 84 microg m(-2) at Kornatka in 1998 to 382 microg m(-2) at Bonarka in 2000. The input of lead was about 10 times higher than cadmium and varied from 406 microg m(-2) at Weglówka in 1998 to 3717 microg m(-2) at Bonarka in 2000. Input of Cu, Zn and Fe to the forest floor showed the similar tendency. During 1998-2000, the highest heavy metal concentrations in the litter fall and their impact on the forest floor were always found at sites close to the Cracow conurbation and, in the eastern transect, close to a steel works. Input of metals to the forest floor tended to decrease with increasing distance from the centre of Cracow.  相似文献   
262.
Ecology of kin and nonkin larval interactions in Tribolium beetles   总被引:1,自引:0,他引:1  
Summary The larvae of flour beetles Tribolium castaneum and T. confusum were reared in two kinds of groups: full siblings and unrelated individuats. These kin and nonkin groups were reared in open cultures, in which emigration was permitted (both species) and in closed cultures, in which emigration was prohibited (only T. confusum). We measured larval development time and survivorship, weight of pupae, and time of larval emigration from open cultures. The effects of age structure were investigated by establishing open cultures of larvae of uniform age (larvae hatched from eggs laid within 72 h) and cultures of larvae of variable age (eggs laid within 240 h). In closed cultures of siblings, T. confusum larvae pupated on an average 2.2 days earlier than larvae reared in nonsibling groups. In T. castaneum, more small and medium size and fewer large size larvae emigrated from groups of siblings compared to groups of nonsiblings. Males that emigrated and pupated remained with their sibs for a shorter time than did similar males raised with unrelated larvae. In T. castaneum, age structure variation reduced the sibs tendency to migrate, but did not influence interactions among unrelated larvae. The genetical effects of kinship and the ecological effects of age structure were shown to affect the interactions of Tribolium larvae reared in groups. Reducing the similarity between individuals, either genetically or demographically (using mixed broods or mixed age cohorts), changed the pattern of larval interactions. Upon occasion, the effects of kin interactions may well be the mechanical consequences of the coexistence of similar individuals rather than the effects of altruistic behavior.  相似文献   
263.
This paper presents the verification of two partial indices proposed for the evaluation of continuous and impulse noise pollution in quarries. These indices, together with the sound power of machines index and the noise hazard index at the workstation, are components of the global index of assessment of noise hazard in the working environment of a quarry. This paper shows the results of acoustic tests carried out in an andesite quarry. Noise generated by machines and from performed blasting works was investigated. On the basis of acoustic measurements carried out in real conditions, the sound power levels of machines and the phenomenon of explosion were determined and, based on the results, three-dimensional models of acoustic noise propagation in the quarry were developed. To assess the degree of noise pollution in the area of the quarry, the continuous and impulse noise indices were used.  相似文献   
264.
Cadmium effects on the ovary structure and oocytes were tested in earthworms Dendrobaena veneta exposed to 10 and 50 mg Cd kg(-1) in soil after 10 and 20 days of the experiment. In both experimental doses cadmium caused damage to the structure of the ovary but the effects were different in each group. At 10 mg Cd kg(-1) concentration in soil, young stages of oocytes and trophocytes were most sensitive to cadmium deleterious effects whereas somatic cells in the ovarian stroma were only slightly affected. Cadmium. at a concentration of 50 mg Cd kg(-1) in soil caused most damage in the somatic cells leading to the occurrence of unnaturally swollen elements and desmosomes destruction. At both experimental concentrations cadmium induced degenerative changes in cell nuclei and an increase in number of cell organelles (RER and Golgi complex elements) in the cytoplasm of oocytes and trophocytes. These also proved to be more active. No ultrastructural changes were manifested in oogonia. In both experimental groups degenerative changes occurred as early as after 10 days of Cd exposure.  相似文献   
265.
The general properties of piezoelectric sorption detectors utilised in the detection of air pollution have been characterised. Examples of detection, with the aid of these detectors, of the organophosphorus compounds, sulphur dioxide, ammonia, hydrocarbons and their derivatives and other air pollutants have been given. Based on information given in this paper, general conclusions including advantages, and difficulties of using piezoelectric detectors in practice have been described.  相似文献   
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Although shell colour polymorphism of the land snail Cepaea nemoralis is a well-known phenomenon, proximate and ultimate factors driving its evolution remain uncertain. Polymorphic species show variation in behavioural responses to selective forces. Therefore, we estimated effects of various environmental factors (temperature, humidity, food availability, (micro)habitat structure and predatory pressure) on behavioural response (frequency of locomotion, climbing and hiding) of C. nemoralis morphs, in experimental and natural conditions. In the experimental part of study, the frequency of locomotion was negatively affected by temperature and the presence of food and positively influenced by the presence of light. Morphs significantly differed in behavioural responses to environmental variability. Pink mid-banded and yellow five-banded morphs climbed less often and hide in shelter more often than yellow and pink unbanded individuals when temperature was low and food was absent. Snails fed most often at moderate temperature compared to low and high temperatures. Field investigations partially confirmed differences among morphs in frequency of climbing, but not in terms of probability of hiding in sheltered sites. In natural colonies, temperature and (micro)habitat structure significantly affected frequency of climbing as well as hiding in shelter. Snails more often hid in sheltered sites where thrushes preyed on Cepaea. Tendency of unbanded morphs to climb trees may have evolved under avian predatory pressure as thrushes forage on a ground. Tendency of banded morphs to hide in sheltered sites may reflect prey preferences for cryptic background. The results implicate that differential behaviour of C. nemoralis morphs compensate for their morphological and physiological limitations of adaptation to habitat.  相似文献   
270.
We analyzed occupational exposure to potentially infectious body fluids among health care workers (HCWs). Nurses were the most common exposed category of HCWs. In 73.6% cases needle sticks had been the reason of exposure. Recapping a needle was the cause of exposure in 6.9% accidents. Among 189 registered HCWs, 66 (34.9%) performed invasive procedures without any personal protective equipment. Prophylaxis with antiretroviral drugs was necessary in 43 (22.8%) cases. As many as 60.3% of exposure incidents to potentially infectious material result from non-compliance with the relevant recommendations. Continuous education and training is critically needed to prevent occupational exposure to blood-borne infections among health care workers.  相似文献   
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