排序方式: 共有15条查询结果,搜索用时 18 毫秒
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After smoking, exposure to radon and its progeny is the second leading cause of lung cancer. The probability of inducing lung carcinomas by inhaled radon progeny depends on the deposited radiation dose, and is significantly affected by physiological and morphometric changes induced by smoking. Due to irritation of the airways, the inhalation of cigarette smoke leads to the hyperproduction of mucus. Two concurrent processes occur: on one hand, increased production of mucus protects the target cells against radiation damage; on the other hand, in the case of long-term smokers, a chronic lung obstruction develops, causing an increase in the radiation dose to the lungs. Depending on the duration and intensity of smoking, these processes contribute to the final radiation dose with different weights. The primary objective of this study was to investigate to what extent these smoke-induced changes can modify the resulting absorbed dose of inhaled radon progeny relative to healthy nonsmokers. Since the bronchial dose depends on the degree of lung tissue damage, we have used this dose as a tool for detecting the effects of smoking on the lung epithelium. In other words, the biological effect of radon served as a tracer of changes induced by smoking. 相似文献
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This paper analyses changes in the representation of alien taxa in ruderal vegetation of a model urban ecosystem. Two datasets of phytosociological relevés of ruderal communities from the area of Malacky (a city in southwestern Slovakia) were analysed. The relevés were recorded 50 years apart, the old relevés were recorded in the years 1954–1969 and the more recent relevés in the years 2014–2015. The average values of percentage number and percentage cover of archaeophytes and neophytes as groups in old and more recent datasets were compared. We also calculated the proportion of each taxon of archaeophytes and neophytes in ruderal vegetation in both periods. The results revealed a decrease in the average percentage number and percentage cover of archaeophytes in almost all classes of ruderal vegetation between the new and old dataset. On the contrary, an increase in representation of neophytes in all classes was recorded. Some rare taxa of archaeophytes were only recorded 50 years ago (e.g. Veronica opaca, Xanthium stumarium), while many taxa of neophytes (including some invasive taxa e.g. Ambrosia artemisiifolia, Stenactis annua) were only recorded in the years 2014–2015 in the ruderal vegetation of the urban ecosystem of Malacky. 相似文献
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Rendeková Alena Mičieta Karol Randáková Zuzana Ballová Dominika Eliašová Mariana Miškovic Ján 《Urban Ecosystems》2020,23(4):875-891
Urban Ecosystems - Tram and railway tracks represent specific urban habitats, which host a specific type of flora. This study aims to compile the information about species composition of flora of... 相似文献
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We investigate the determinants of decision rights transfer and its effects on the motivation of an agent. The study is based on a laboratory experiment conducted on 130 subjects playing an innovative principal–agent game. Interestingly, the results show that agents do not favour a delegation and a decision is considered rather burdensome. Although the experiment could not give support for the behavioural hypothesis of higher effort provided by participants who receive choice subsequently, the survey illuminates the interaction between delegation motives, effort motivators, goals and other perceptions of the agents. 相似文献
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Weronika Banaszak-Cibicka Lucyna Twerd Monika Fliszkiewicz Karol Giejdasz Aleksandra Langowska 《Urban Ecosystems》2018,21(4):599-613
Urbanisation is an expansive process and a majority of insects live in human-modified areas. At the same time, a decrease in pollinator species richness and abundance has recently been observed in Europe, which in turn may have serious ecological and economic consequences. This study investigates the abundance, species richness and functional traits of wild bees in urban city parks in comparison to natural areas. The aim of this research was to assess the potential conservation values of urban green areas for bees. The present study demonstrates that a large and diversified city park may be a favourable habitat for bees, comparable to the natural fauna both in terms of the number and abundance of bee species. However, the study also showed that there were differences in the occurrence of species with different functional traits in the city parks investigated and in the natural landscape. 相似文献
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