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131.
132.
Heavy-metal uptake by crops from polluted river sediments covered by non-polluted topsoil 总被引:3,自引:0,他引:3
Cadmium uptake by maize from polluted river sediments covered with a clean top layer of variable thickness is discussed in
relation to root distribution. Two pathways for uptake are distinguished: roots penetrating the contaminated layer or contaminants
moving into the root zone. Relative Cd uptake proved to be roughly proportional to the fraction of total root length found
in the contaminated layer. A deeper water table induced a deeper root development and more Cd uptake for a given thickness
of clean topsoil. A model based on exponential decrease of root length density with depth is acceptable as first approximation
only. Little or no evidence was found for contaminants moving into the root zone during the ten years of the experiment. 相似文献
133.
134.
te Rijdt W. P. Hoorntje E. T. de Brouwer R. Oomen A. Amin A. van der Heijden J. F. Karper J. C. Westenbrink B. D. Silljé H. H. W. te Riele A. S. J. M. Wiesfeld A. C. P. van Gelder I. C. Willems T. P. van der Zwaag P. A. van Tintelen J. P. Hillege J. H. Tan H. L. van Veldhuisen D. J. Asselbergs F. W. de Boer R. A. Wilde A. A. M. van den Berg M. P. 《Netherlands heart journal》2022,30(2):84-95
Netherlands Heart Journal - The p.Arg14del (c.40_42delAGA) phospholamban (PLN) pathogenic variant is a founder mutation that causes dilated cardiomyopathy (DCM) and arrhythmogenic... 相似文献
135.
Eva‐Maria Brouwer Giang Ngo Shivam Yadav Roman Ladig Enrico Schleiff 《Molecular microbiology》2019,111(5):1302-1316
β‐barrel‐shaped outer membrane proteins (OMPs) ensure regulated exchange of molecules across the cell‐wall of Gram‐negative bacteria. They are synthesized in the cytoplasm and translocated across the plasma membrane via the SEC translocon. In the periplasm, several proteins participate in the transfer of OMPs to the outer membrane‐localized complex catalyzing their insertion. This process has been described in detail for proteobacteria and some molecular components are conserved in cyanobacteria. For example, Omp85 proteins that catalyze the insertion of OMPs into the outer membrane exist in cyanobacteria as well. In turn, SurA and Skp involved in OMP transfer from plasma membrane to Omp85 in E. coli are likely replaced by Tic22 in cyanobacteria. We describe that anaTic22 functions as periplasmic holdase for OMPs in Anabaena sp. PCC 7120 and provide evidence for the process of substrate delivery to anaOmp85. AnaTic22 binds to the plasma membrane with specificity for phosphatidylglycerol and monogalactosyldiacylglycerol. Substrate recognition induces membrane dissociation and interaction with the N‐terminal POTRA domain of Omp85. This leads to substrate release by the interaction with a proline‐rich domain and the first POTRA domain of Omp85. The order of events during OMP transfer from plasma membrane to Omp85 in cyanobacteria is discussed. 相似文献
136.
1. Variation in survival, a major determinant of fitness, may be caused by individual or environmental characteristics. Furthermore, interactions between individuals may influence survival through the negative feedback effects of density dependence. Compared to species in temperate regions, we have little knowledge about population processes and variation in fitness in tropical bird species. 2. To investigate whether variation in survival could be explained by population size or climatic variables we used capture-recapture models in conjunction with a long-term data set from an island population of the territorial, cooperatively breeding Seychelles warbler (Acrocephalus sechellensis). The lack of migration out of the study population means that our results are not confounded by dispersal. 3. Annual survival was high, both for adults (84%) and juveniles (61%), and did not differ between the sexes. Although there was significant variation in survival between years, this variation could not be explained by overall population size or weather variables. 4. For territorial species, resource competition will work mainly on a local scale. The size of a territory and number of individuals living in it will therefore be a more appropriate measure of density than overall population density. Consequently, both an index of territory quality per individual (food availability) and local density, measured as group size, were included as individual covariates in our analyses. 5. Local density had a negative effect on survival; birds living in larger groups had lower survival probabilities than those living in small groups. Food availability did not affect survival. 6. Our study shows that, in a territorial species, although density-dependent effects might not be detectable at the population level they can be detected at the individual territory level - the scale at which individuals compete. These results will help to provide a better understanding of the small-scale processes involved in the dynamics of a population in general, but in particular in tropical species living in relatively stable environments. 相似文献
137.
Patricia Marqués-Gallego Hans den Dulk Jaap Brouwer Ganna V. Kalayda 《Journal of inorganic biochemistry》2009,103(12):1602-1608
A new anticancer-active platinum(II) compound [Pt(A9pyp)(dmso)(cbdca)], containing the E-1-(9-anthryl)-3-(2-pyridyl)-2-propenone ligand (abbreviated as A9pyp) has been synthesized by the replacement of the anionic chloride ligands in cis-[Pt(A9pyp)(dmso)Cl2] by the dianionic chelating cyclobutanedicarboxylate ligand (abbreviated as cbdca). The in vitro relevance of the leaving group of these new platinum(II) compounds has been investigated. Measurements of the time-dependent intracellular accumulation of both compounds in human ovarian carcinoma cell lines show that the leaving group affects their cellular uptake. In addition, the leaving group also influences DNA platination, and, therefore, has an effect on the biological activity against a pair of human ovarian carcinoma cell lines, i.e. sensitive and resistant to cisplatin. 相似文献
138.
Patricia Marqués-Gallego Ulrich Jaehde Jaap Brouwer 《Journal of inorganic biochemistry》2009,103(5):791-796
The anticancer properties of two new fluorescent platinum(II) compounds, cis-[Pt(A9opy)Cl2] and cis-[Pt(A9pyp)(dmso)Cl2] are described. These compounds are highly active against several human tumor cell lines, including human ovarian carcinoma sensitive and cisplatin-resistant cell lines (A2780 and A2780R). To study the cellular processing of these new compounds, a series of in vitro studies have been performed, including the investigation of intracellular platinum accumulation and DNA-platination experiments in A2780 and A2780R cells. Compared to cisplatin, both compounds are accumulated highly in both sensitive and resistant cell lines, and more platinum has been found to bind to the nuclear DNA. Interestingly, cis-[Pt(A9opy)Cl2] shows high accumulation and DNA adduct formation in the resistant cell line A2780R, as compared to the sensitive counterpart A2780 cell line. This suggests that cis-[Pt(A9opy)Cl2] is able to overcome some of the well-known resistance mechanisms in this cell line, such as decreased cellular uptake and increased DNA repair. 相似文献
139.
Martijn Van De Pol Lyanne Brouwer Bruno J. Ens Kees Oosterbeek Joost M. Tinbergen 《Evolution; international journal of organic evolution》2010,64(3):836-851
Fluctuating and disruptive selection are important mechanisms for maintaining intrapopulation trait variation. Nonetheless, few field studies quantify selection pressures over long periods and identify what causes them to fluctuate. Diet specialists in oystercatchers differ in short‐term payoffs (intake), but their long‐term payoffs are hypothesized to be condition dependent. We test whether phenotypic selection on diet specialization fluctuates between years due to the frequency of specialists, competitor density, prey abundance, and environmental conditions. Short‐term payoffs proved to be poor predictors of long‐term fitness payoffs of specialization. Sex‐differences in diet specialization were maintained by opposing directional fecundity and viability selection between the sexes. Contrasting other studies, selection on individual diet specialization was neither negative frequency‐ or density‐dependent nor dependent on prey abundance. Notwithstanding, viability selection fluctuated strongly (stabilizing?disruptive) over the 26‐year study period: slightly favoring generalists in most years, but strongly disfavoring generalists in rare harsh winters, suggesting generalists cannot cope with extreme conditions. Although selection fluctuated, mean selection on specialists was weak, which can explain how individual specialization can persist over long periods. Because rare events can dramatically affect long‐term selective landscapes, more care should be taken to match the timescale of evolutionary studies to the temporal variability of critical environmental conditions. 相似文献
140.
Constructing a fish metabolic network model 总被引:1,自引:0,他引:1
We report the construction of a genome-wide fish metabolic network model, MetaFishNet, and its application to analyzing high
throughput gene expression data. This model is a stepping stone to broader applications of fish systems biology, for example
by guiding study design through comparison with human metabolism and the integration of multiple data types. MetaFishNet resources,
including a pathway enrichment analysis tool, are accessible at . 相似文献