排序方式: 共有103条查询结果,搜索用时 15 毫秒
41.
Cyclodiene pesticides: aldrin, isodrin, dieldrin and endrin were dechlorinated by methanogenic granular sludge in spiked batch tests. Initial pesticides concentration was 7 or 9 mgl(-1). Two monodechlorinated analogues were formed during the conversions of aldrin and isodrin. Dieldrin was transformed into two monodechlorinated products as well as into aldrin and two monodechlorinated derivatives of aldrin. In respect of endrin three monodechlorinated and three didechlorinated products were found. The dechlorination of endrin was the most rapid, and was almost complete within 28 days. The dechlorinations of aldrin, isodrin and dieldrin were much slower: over a period of 3 months only 59%, 70% and 88% was transformed, respectively. The amounts of released chloride corresponded 0.54 +/- 0.23, 1.05 +/- 0.25, 1.10 +/- 0.12 of theoretical value for suggested reactions, for aldrin, isodrin and dieldrin respectively. For endrin it was much higher. These transformations did not occur in control samples containing autoclaved granules or in control blank samples without sludge. However, in aldrin spiked blanks, a conversion into a six-chlorinated analogue was found. 相似文献
42.
Joanna Rutkowska Tomasz Wilk Mariusz Cichoń 《Behavioral ecology and sociobiology》2007,61(8):1211-1217
There is accumulating evidence that maternal hormones may play a role in offspring sex adjustment, but little is known about
the costs of such hormone-mediated mechanisms. Recent studies have reported sex-specific effects of hormones on offspring
viability. Specifically, we previously found that elevating the plasma androgen level in mothers results in a male-biased
offspring primary sex ratio, but it affects the viability of sons negatively and daughters positively in zebra finches (Taeniopygia guttata; Rutkowska and Cichoń, Anim Behav, 71:1283–1288, 2006). In this study, we studied further fitness consequences of exposure
to elevated yolk androgen levels in zebra finches. We measured growth rate and cellular immune response of nestlings that
hatched from eggs laid by females injected with testosterone during egg laying and nestlings of unaffected control females.
We found that sons of testosterone-treated females grew slower in comparison to sons of control females. The significant interaction
between experimental group and offspring sex indicates that sons of testosterone-treated mothers suffered impaired immune
responsiveness while daughters seemed to benefit from elevated androgen level in terms of enhanced immune responsiveness.
We found no effects of androgens on offspring performance at adulthood—neither fecundity of females nor attractiveness of
males was affected. We conclude that the benefits of biasing sex ratio towards males by increasing androgen level in the yolk
may be limited due to negative effects on male offspring performance early in life. 相似文献
43.
44.
45.
Leon Gradoń Tomasz Sosnowskic Zygmunt Podolec 《International journal of occupational safety and ergonomics》2013,19(1):31-42
Aerosols of a physiological salt solution and aqueous solutions of salbutamol, sodium cromoglicate, and dornase aifa were generated in a pneumatic nebulizer and analyzed in a system with controlled humidity of air as a carrier gas. Mass distribution of aerosol particles and yield of generation for pulse nebulization were measured. Pulsation of generation was realized with an attachment maintained by a computer program. Opening times of the valve were in the range 50-800 ms. The results indicate the possibility of improving aerosol particle delivery to the lung using a pulse generation system. 相似文献
46.
Tomasz R. Sosnowski Magdalena Skoczek Hanna Droździel 《International journal of occupational safety and ergonomics》2013,19(4):391-409
The rate of oxygen transport from atmospheric air into water and perfluorocarbon compound (PFC) was investigated. Static and dynamic systems with and without the presence of the lung surfactant monolayer were considered. For the case of water used as an oxygen absorbent, the monolayer activity allowed a simulation of the gas uptake into the lung hypophase. In the second case, a two-phase liquid system with water as a hypophase and PFC as the blood substitute simulated oxygen transport in the alveolus-blood system. Original experimental measurement devices gave the opportunity of determining the gas transport rate with the possibilities of indicating the role of the lung surfactant in the process and evaluating the influence of environmental conditions on the transport phenomena. Results of that work suggest a possible enhancing role of the lung surfactant in the oxygen transfer rate. 相似文献
47.
Ciesielski T Pastukhov MV Fodor P Bertenyi Z Namieśnik J Szefer P 《Environmental pollution (Barking, Essex : 1987)》2006,139(2):372-384
Concentrations of Al, Ba, Cd, Cu, Fe, Mn, Mo, Si, Sr, Zn, Ca, K, Mg, Na and P in the livers of Baikal seal, plankton, zoobenthos, and fish, constituting the food sources for the seals, were determined by ICP-MS and ICP-AES. The accumulation of elements in the liver of seals, affected by internal and external (environmental) factors, was assessed by multidimensional (ANOVA, FA) and correlation analyses. FA has enabled identification of abiotic and biotic factors responsible for the accumulation of elements in the livers of Baikal seals. Significant influence of sex and development stage of the seals analysed on hepatic concentrations of some elements was found. The observed differences in element concentrations between pups, males and females could be attributable to the reproductive cycle of this species. ANOVA showed differences in concentrations of Fe, Zn, Cu and Cd in seals from the three separate basins of the lake. BMFs suggest biomagnification of Fe and Zn in the fish-seal trophic link. 相似文献
48.
Virtual Conservation: How the European Union is Turning a Blind Eye to Its Vanishing Primeval Forests 总被引:3,自引:0,他引:3
Tomasz Wesoowski 《Conservation biology》2005,19(5):1349-1358
49.
Zbytniewski Radoslaw Kosobucki Przemyslaw Kowalkowski Tomasz Buszewski Boguslaw 《Environmental science and pollution research international》2002,9(1):68-74
Sewage sludge is a serious problem facing modern wastewater treatment plants. One of the methods to safely utilize the sludge is through composting and the agricultural use of the final product.In this study the compost samples from municipal sewage sludge are compared to the natural, rich in organic matter samples. Based on physicochemical properties of the material, the maturity indices are obtained to evaluate the quality of organic matter and estimate the similarities between the samples.The study shows that one-dimensional analysis like that based on maturity indices does not provide satisfactory answers concerning the nature of such complex materials. The data set of the analysis naturally possesses a multidimensional character so that the employment of advanced chemometric techniques like cluster analysis show a number of features which were hidden within the ‘data flood’.The major conclusion of this work is that the compost from sewage sludge is similar to peat in the significance of the properties of the organic matter. Moreover, the organic matter of agricultural soil, which is most stable and has been naturally matured over a long period of time, differs substantially from the other samples. 相似文献
50.
A study of the influence of muscle type and muscle force level on individual frequency bands of the EMG power spectrum. 总被引:1,自引:0,他引:1
Pawe? Bartuzi Danuta Roman-Liu Tomasz Tokarski 《International journal of occupational safety and ergonomics》2007,13(3):241-254
The aim of this study was to analyse the electromyographic (EMG) power spectrum indicating differences in the frequency bands of the spectrum resulting from differences in muscle type and force level for the extensor digitorum (ED), palmaris longus (PL) and biceps brachii (BB) muscles. The study was performed on 12 young men as 2 tests different in terms of the type of exerted force (30, 15 and 5% MVC, maximum voluntary contraction). The parameters of the EMG power spectrum were obtained as a result of a division of the EMG power spectrum into ranges determined by border frequencies. The results suggest that (a) frequency bands contained in the 30-80 Hz range and over the frequency of 300 Hz depend on muscle force, and (b) the power spectrum in the frequency range of up to 40 Hz and 60-300 Hz indicates muscle type. 相似文献