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101.
During the EU project BEEP a battery of biomarkers was applied in flounder (Platichthys flesus) and the blue mussel (Mytilus edulis) collected at three locations off the Lithuanian coast (Baltic Sea) in June and September 2001 and 2002. The elevated biomarker responses in specimens sampled in September 2001 were apparently related to the extensive dredging activities in the Klaipeda port area and subsequent dumping of contaminated sediments. High concentrations of organic pollutants (organochlorines and PBDEs) were also measured in the tissues of both indicator species. In addition, response levels of genotoxicity, cytotoxicity, immunotoxicity as well as concentrations of PAH metabolites in the bile of flounder showed elevations in 2002 after an oil spill in the Būtinge oil terminal in November 2001. In flounder, biomarker measurements 10 months after the spill indicated recovery processes but in mussels a high level of genotoxicity could still be observed 22 months later. The present study illustrates the usefulness of the multi-biomarker approach in the detection of biological effects of pollution in this region of the Baltic Sea.  相似文献   
102.
Field studies in the framework of the EU funded BEEP project (Biological Effects of Environmental Pollution in Marine Coastal Ecosystems, 2001-2004) aimed at validating and intercalibrating a battery of biomarkers of contaminant exposure and effects in selected indicator species in the Mediterranean, the North Atlantic and the Baltic Seas. Major strategic goals of the BEEP project were the development of a sensitive and cost-efficient biological effects monitoring approach, delivery of information and advice to end-user groups, and the implementation of a network of biomarker researchers around Europe. Based on the main results obtained in the Baltic Sea component of the BEEP the present paper summarises and assesses the applicability of biomarkers for different regions and species in this sea area. Moreover, a general strategy and some practical considerations for the monitoring of biological effects in the Baltic Sea are outlined.  相似文献   
103.
The relative performance of (i) percent live cover, (ii) colony density, (iii) generic richness, (iv) partial colony mortality, and (v) colony size of hard corals were evaluated to determine which variables best discriminated the coral communities near a small river in Okinawa, Japan. An analysis of their variance was undertaken across a combination of sites at three depths, at increasing distance from a river's influence (Zatsun River). The river provides a periodic and localized input of sediment and fresh water to the adjacent coral reef; the effects of which we assume attenuate at increasing distance from the river mouth. The mean frequency of partially dead coral colonies (i.e., the proportion of live coral colonies that were partially dead) presented the clearest and most reliable response to river affect, and the power to discriminate among sites improved steadily with increasing depth. Spatial examination of the prevalence of partial mortality, regardless of how long ago the infliction occurred, provides a clear window to long-term processes involving population and community change and indeed the reef building capacity of the communities.  相似文献   
104.
Higher-order moments, minima and maxima of turbulent temperature and water vapour mixing ratio probability density functions measured with an eddy-covariance system near the ground were related to each other and to vertical boundary-layer profiles of the same scalars obtained through airborne soundings. The dependence of kurtosis on squared skewness showed a kurtosis intercept below the Gaussian expectation, suggesting a compression of the probability density function by the presence of natural boundaries. This hypothesis was corroborated by comparing actual minima and maxima of turbulent fluctuations to estimates obtained from the first four sample moments by fitting a four-parameter beta distribution. The most sharply defined boundaries were found for the minima of temperature datasets during the day, indicating that negative temperature fluctuations at the sensor are limited by the availability of lower temperatures in the boundary layer. By comparison to vertical profiles, it could be verified that the turbulent minimum of temperature near the ground is close to the minimum of potential temperature in the boundary layer. The turbulent minimum of water vapour mixing ratio was found to be equal to the mixing ratio at a height above the minimum of the temperature profile. This height roughly agrees with the top of the non-local unstable domain according to bulk Richardson number profiles. We conclude that turbulence statistics measured near the surface cannot be solely explained by local effects, but contain information about the whole boundary layer including the entrainment zone.  相似文献   
105.
A compressional study of (Na,Ca)(Ti3+,Mg)Si2O6-clinopyroxenes was carried out at high pressures between 10−4 and 10.2 GPa using in situ single-crystal X-ray diffraction, Raman spectroscopy and optical absorption spectroscopy. Compressional discontinuities accompanied by structural changes, in particular, the appearance of two distinct Ti3+–Ti3+ distances within the octahedral chains at 4.37 GPa, provide evidence for the occurrence of a phase transition in NaTi3+Si2O6. Equation-of-state parameters are K 0 = 115.9(7) GPa with K′ = −0.9(3) and K 0 = 102.7(8) GPa with K′ = 4.08(5) for the low- and high-pressure range, respectively. The transition involves a C2/c–P [`1] \overline{1} symmetry change, which can be confirmed by the occurrence of new modes in Raman spectra. Since no significant discontinuity in the evolution of the unit-cell volume with pressure has been observed, the transition appears to be second-order in character. The influence of the coupled substitution Na+Ti3+↔Ca2+Mg2+ on the static compression behavior and the structural stability has been investigated using a sample of the intermediate composition (Na0.54Ca0.46)(Mg0.46Ti0.54)Si2O6. No evidence for a deviation from continuous compression behavior has been found, neither in lattice parameter nor in structural data and the fit of a third-order Birch–Murnaghan equation-of-state to the pressure–volume data yields a bulk modulus of K 0 = 109.1(5) GPa and K′ = 5.02(13). Raman and polarized absorption spectra have been compared to NaTiSi2O6 and reveal major similarities. The main driving force for the phase transition in NaTi3+Si2O6 is the localization of the Ti3+ d-electron and the accompanying distortion, which is suppressed in the (Na,Ca)(Ti3+,Mg)Si2O6-clinopyroxene.  相似文献   
106.
Microprobe analysis, single crystal X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray absorption spectroscopy were applied on Fe-rich osumilite from the volcanic massif of Mt. Arci, Sardinia, Italy. Osumilite belongs to the space group P6/mcc with unit cell parameters a = 10.1550(6), c = 14.306(1) Å and chemical formula (K0.729)C (Na0.029)B (Si10.498 Al1.502)T1 (Al2.706 Fe 0.294 2+ )T2 (Mg0.735 Mn0.091 Fe 1.184 2+ )AO30. Structure refinement converged at R = 0.0201. Unit cell parameter a is related to octahedral edge length as well as to Fe2+ content, unlike the c parameter which does not seem to be affected by chemical composition. The determination of the amount of each element on the mineral surface, obtained through X-ray photoelectron spectroscopy high-resolution spectra in the region of the Si2p, Al2p, Mg1s and Fe2p core levels, suggests that Fe presents Fe2+ oxidation state and octahedral coordination. Two peaks at 103.1 and 100.6 eV can be related to Si4+ and Si1+ components, respectively, both in tetrahedral coordination. The binding energy of Al2p, at 74.5 eV, indicates that Al is mostly present in the distorted T2 site, whereas the Mg peak at 1,305.2 eV suggests that this cation is located at the octahedral site. X-ray absorption at the Fe L2,3-edges confirms that iron is present in the mineral structure, prevalently in the divalent state and at the A octahedral site.  相似文献   
107.
108.
ABSTRACT

Growth in water use and threatened shortages of water have become increasingly important in the modern world system. Natural resources are exploited extensively by capitalist interests in industrially advanced nations, while the lower strata of the world system, the underdeveloped societies, are left with limited access to natural resources for their productive processes, particularly water resources. We contribute to socio-hydrological research by examining underlying socio-structural factors that play a part in the process of deteriorating conditions of global water resources. Drawing on a world-systems perspective, this study examines how socio-structural forces – world-system position, per capita beef consumption, per capita energy consumption, and urbanization – affect per capita water footprint, which includes an accounting of “virtual water” consumption. We find that per capita beef consumption and per capita energy consumption have significant positive direct effects, and the world-system position has a significant indirect and total effect on per capita water footprint.  相似文献   
109.
A grid-based technique for mapping potential evapotranspiration is described. An attempt is made to extrapolate the constituent parameters of Penman's equation (1962) over a grid, so that the equation can be evaluated for every grid square. Data for a part of Southwest England are used to demonstrate the technique. Aspect and slope, which determine evaporation to a considerable degree, have been included using a formula derived by Okanoue.  相似文献   
110.
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