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J R Aboal J A Fernández A Carballeira 《Environmental pollution (Barking, Essex : 1987)》2001,115(2):313-316
With the aim of optimizing protocols for sampling moss, pine and oak for biomonitoring of atmospheric contamination and also for inclusion in an Environmental Specimen Bank, 50 sampling units of each species were collected from the study area for individual analysis. Levels of Ca, Cu, Fe, Hg, Ni, and Zn in the plants were determined and the distributions of the concentrations studied. In moss samples, the concentrations of Cu, Ni and Zn, considered to be trace pollutants in this species, showed highly variable long-normal distributions; in pine and oak samples only Ni concentrations were log-normally distributed. In addition to analytical error, the two main source of error found to be associated with making a collective sample were: (1) not carrying out measurements on individual sampling units; and (2) the number of sampling units collected and the corresponding sources of variation (microspatial, age and interindividual). We recommend that a minimum of 30 sampling units are collected when contamination is suspected. 相似文献
945.
Jose Oliva Paula Payá Miguel Ángel Cámara Alberto Barba 《Journal of environmental science and health. Part. B》2013,48(7):775-781
The effects of six clarification agents [egg albumin, blood albumin, bentonite + gelatine, charcoal, polyvinylpolypyrrolidine (PVPP) and silica gel] on the removal of residues of three fungicides (famoxadone, fluquinconazole and trifloxystrobin) applied directly to a racked red wine, elaborated from Monastrell variety grapes from the D.O. Region of Jumilla (Murcia, Spain) were studied. The clarified wines were filtered with 0.45 μ m nylon filters to determine the influence of this winemaking process in the disappearance of fungicide residues. Analytical determination of fluquinconazole and trifloxystrobin was performed by gas chromatography with electron captor detector (ECD), while that of famoxadone using an HPLC equipped with a diode array detector (DAD). Generally, trifloxystrobin is the fungicide that is the lowest persistent one in wines, except in the egg albumin study whereas, the most persistent one is fluquinconazole. The elimination depends on the nature of the active ingredient, though the water stability in the presence of light within it has more influence than the solubility and polarity of the product itself. The most effective clarifying agents were the charcoal and PVPP. The silica gel and bentonite plus gelatine were not enough to reduce considerably the residual contents in the wine clarified with them. In general terms, filtration is not an effective step in the elimination of wine residues. The greatest removal after filtration is obtained in wines clarified with egg albumine and bentonite plus gelatine, and the lowest in those clarified with PVPP. 相似文献
946.
Edouard Lavergne Isabelle Calvès Anne Leila Meistertzheim Grégory Charrier Uwe Zajonz Jean Laroche 《Marine Biology》2014,161(5):1113-1126
Temporarily open/closed estuaries (TOCEs) are major ecosystems of the Indian Ocean coastal zones. Their functioning is tightly linked to climatic events such as monsoons and storms, and their mouth can close up for prolonged and variable periods of time, thus limiting their connectivity with the marine environment. Two types of genetic markers (i.e., mitochondrial cytochrome c oxidase I (COI) gene and microsatellites) were used to assess the genetic structure of 288 individuals of Terapon jarbua, a widely distributed fish species in the wider Gulf of Aden. Firstly, the hypothesis of panmixia was tested. Then, alternative hypotheses were investigated to explain the population genetic structure of T. jarbua: could it be shaped by (1) regional biogeographic barriers (i.e., Socotra Island vs. mainland Yemen) and/or (2) the particular functioning of TOCEs in relation to the species life cycle and particular physical ocean parameters? On one hand, the polymorphism of the COI inferred (1) a high haplotype diversity and a reduced nucleotide diversity over the whole data set and (2) a “star-like” shape of the haplotype network, thus suggesting a population expansion after local extinctions during the Pleistocene glaciations. On a second hand, the genotyping of eight microsatellites showed a significant genetic differentiation between T. jarbua populations in the wider Gulf of Aden (F ST = 0.035, p < 0.01), and thus, the panmixia hypothesis was rejected. Analyses of molecular variance results did not show any significant structure between Socotra Island and mainland Yemen and thus did not support the role of biogeographic barriers in structuring T. jarbua populations. Significant multi-locus deficits in heterozygotes at particular locations displaying high levels of F IS were recorded. It was suggested that a possible Wahlund effect took place in those TOCEs which could gather several cohorts of larvae stemming from different marine subpopulations over the sampled area. The present study emphasized the uniqueness of each TOCE as a potential reservoir of biodiversity and the urgent need for a better conservation program of those estuaries in the region, in order to avoid habitat fragmentation and permanent closure of those nursery areas by human activities. 相似文献
947.
José de Anchieta C. C. Nunes Cláudio L. S. Sampaio Francisco Barros 《Marine Biology》2013,160(9):2383-2394
Wave exposure and habitat complexity have been used to explain variations in the distribution patterns and behavior of many reef fishes. This study analyzed the influence of both factors on density and foraging activity, and the influence of group size on foraging in three species of the genus Halichoeres (Labridae) on tropical rocky shores. It was shown that initial phases (IP) and terminal phases (TP) Halichoeres, were influenced by wave exposure, although foraging in Halichoeres brasiliensis TP was not influenced by wave exposure. The IP in all three species were positively associated with rugosity and algal cover while the TP was positively associated with depth. Habitat complexity also influences foraging in these species. Group size influenced foraging activity, except in H. brasiliensis TP. We also found variations in microhabitat patches used for foraging between species and differences in the stomach contents between species and phases, showing that functional roles change in response to ontogenetic shifts. 相似文献
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950.
Small terrestrial non-eusuchian mesoeucrocodylians are common components of Cretaceous assemblages of Gondwanan provinces
with notosuchians and araripesuchids as flagship taxa in South America, Africa and Madagascar, well into the Late Cretaceous.
On the other hand, these are exceedingly rare in Laurasian landmasses during the Late Cretaceous. Small terrestrial mesoeucrocodylians
from Europe were often referred to the genus Theriosuchus, a taxon with stratigraphic range extending from the Late Jurassic to the late Early Cretaceous. Theriosuchus is abundantly reported from various European localities, although Asiatic and possibly North American members are also known.
It has often been closely associated with the first modern crocodilians, members of the Eusuchia, because of the presence
of procoelous vertebrae, a widespread key character diagnosing the Eusuchia. Nevertheless, the relationships of Theriosuchus have not been explored in detail although one species, Theriosuchus pusillus, has been extensively described and referred in numerous works. Here, we describe a new basal mesoeucrocodylian, Theriosuchus sympiestodon sp. nov. from the Maastrichtian of the Haţeg Basin, Romania, suggesting a large temporal gap (about 58 myr) in the fossil
record of the genus. Inclusion of the new taxon, along with Theriosuchus guimarotae, in a phylogenetic analysis confirms its referral to the genus Theriosuchus, within a monophyletic atoposaurid clade. Although phylogenetic resolution within this clade is still poor, the new taxon
appears, on morphological grounds, to be most closely related to T. pusillus. The relationships of Atoposauridae within Mesoeucrocodylia and especially to Neosuchia are discussed in light of the results
of the present contribution as well as from recent work. Our results raise the possibility that Atoposauridae might not be
regarded as a derived neosuchian clade anymore, although further investigation of the neosuchian interrelationships is needed.
Reports of isolated teeth referable to a closely related taxon from the Upper Cretaceous of Romania and France, together with
the presence of Doratodon and Ischyrochampsa, indicate a previously unsuspected diverse assemblage of non-eusuchian mesoeucrocodylians in the Late Cretaceous European
archipelago. 相似文献