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391.
Morphometric variation was used to study population structure of the cutlassfish Trichiurus lepturus on the Kenyan coast. In all, 16 morphometric measurements taken from 193 individuals from six sites were subjected to multivariate statistical analysis in order to determine possible stock differentiation. Multivariate analysis of variance indicated significant differences in the means of a combination of the morphometric characters among the sites, and discriminant function analysis by groups showed the presence of phenotypically distinct populations on the south and north coasts of Kenya. A classification tree analysis of morphometric characters validated the distinct groups and indicated certain characters to be useful for classifying specimens to source sites. The likely presence of distinct north and south stocks of T. lepturus on the Kenyan coast observed in our study will require validation by other methods, but indicates the potential need for spatially explicit models for managing fish populations on a large spatial scale. 相似文献
392.
The scheme of recent fault tectonics and neotectonic stresses of the area adjacent to the Strel’tsovka Caldera in the southeastern
Transbaikal region has been compiled for the first time on the basis of structural and geomorphic study. The faults were ranked
by criteria of slip direction stability along separate segments and their expression in topography. Neotectonic stresses of
corresponding ranks were ascertained as well. The heterogeneity of neotectonic stress field is related to the mosaic development
of compression, extension, and the three-axial stress state. Comparison of morphogenetic features of recent and older faults
shows the different character of the deformation mechanism and orientation of tectonic displacements. It has been established
that the Strel’tsovka Caldera and its northwestern segment, in particular, developed as an echeloned system of pull-apart
grabens, but the caldera itself is situated in a recent rise, whereas the northwestern segment is located in a neotectonic
depression corresponding to the Dry Urulyungui Basin filled with volcanic and sedimentary rocks. Such a structure markedly
expands the outlook for discovery of hidden uranium mineralization in the studied area. The elaborated scheme of neotectonic
faults and stresses reflects the postore geodynamic setting and completes the reconstruction of geodynamic conditions pertaining
to the periods of preore preparation and ore-forming tectonomagmatic reactivation. 相似文献
393.
Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting 总被引:4,自引:4,他引:0
M. Lillenberg M.Sc. S. Yurchenko Ph.D. K. Kipper M.Sc. K. Herodes Ph.D. V. Pihl Ph.D. R. Lõhmus Ph.D. M. Ivask A. Kuu Ph.D. S. Kutti M.Sc. S. V. Litvin B.Sc. L. Nei 《International Journal of Environmental Science and Technology》2010,7(2):307-312
The concentrations of some widely used pharmaceuticals, namely fluoroquinolones (ciprofloxacin C17 H18FN3O3, norfloxacin C17 H18FN3O3 and ofloxacin C18 H20FN3O4 and sulfonamides (sulfadimethoxine C12 H14N4O4s and sulfamethoxazole C10 H11N3O3S were determined in urban sewage sludge utilized for making compost. The levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge — 426 μg/kg — was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 μg/kg of norfloxacin and 20 μg/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used pharmaceuticals. 相似文献
394.
José?F.?MolinaEmail author Stefano?Poli H?kon?Austrheim Johannes?Glodny Anatolij?Rusin 《Contributions to Mineralogy and Petrology》2004,147(4):484-504
Metasomatic amphibole-eclogite sequences grew in selvages of quartz veins from the Marun-Keu complex (Polar Urals, Russia) during high-pressure metamorphism. Relicts of a pre-metasomatic eclogite-facies assemblage are present in the wallrock layers as irregular patches. Wallrock interstitial quartz trails lying at a high angle to reaction fronts provide evidence for grain-scale pore channelisation which may be produced by intergranular-fluid compositional gradients parallel to the quartz trails. Disequilibrium at vein-wallrock scale is inferred from wallrock mineral heterogeneity and from variable initial Sr isotope ratios in mineral separates. Mass-balance calculations between relicts and wallrock assemblages reveal chemical imbalances caused by open system-behaviour with two way mass-transfer. The vein-wallrock system registers a prograde history from 408–434 °C (relicts) to 526–668 °C (vein precipitates). Vein and metasomatic assemblages formed during a single fluid-rock interaction process, implying high heating rates (100 °C/Ma), which could result from heat advection by large-scale fluid circulation.Editorial responsibility: W. Schreyer 相似文献
395.
Benedicto?SotoEmail authorView authors OrcID profile 《Theoretical and Applied Climatology》2018,131(1-2):101-110
With the surface air temperature (SAT) data at 37 stations on Central Yunnan Plateau (CYP) for 1961–2010 and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data, the temporal-spatial patterns of the SAT trends are detected using Sen’s Nonparametric Estimator of Slope approach and MK test, and the impact of urbanization on surface warming is analyzed by comparing the differences between the air temperature change trends of urban stations and their corresponding rural stations. Results indicated that annual mean air temperature showed a significant warming trend, which is equivalent to a rate of 0.17 °C/decade during the past 50 years. Seasonal mean air temperature presents a rising trend, and the trend was more significant in winter (0.31 °C/decade) than in other seasons. Annual/seasonal mean air temperature tends to increase in most areas, and higher warming trend appeared in urban areas, notably in Kunming city. The regional mean air temperature series was significantly impacted by urban warming, and the urbanization-induced warming contributed to approximately 32.3–62.9 % of the total regional warming during the past 50 years. Meantime, the urbanization-induced warming trend in winter and spring was more significant than that in summer and autumn. Since 1985, the urban heat island (UHI) intensity has gradually increased. And the urban temperatures always rise faster than rural temperatures on the CYP. 相似文献