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11.
This study proposes a working hypothesis that Mediterranean hippopotamuses, and perhaps European ones as well, reduced their size, sometimes even drastically, from the ‘Mid‐Pleistocene Revolution’ (MPR, c.1.2–0.5 Ma) to the Late Pleistocene. In contrast to the Early Pleistocene, during this time period glacial/interglacial cycling was dominated by a 100‐ka periodicity, with more extended glacial phases (up to 85 ka) alternating with shorter interglacial phases (up to 15 ka). These changes seem to have somehow affected the size of hippopotamuses. While relatively larger hippopotamuses have been found in warmer and somewhat more humid intervals, data seem to indicate that they might not have grown as large under less favourable conditions, namely during colder and comparatively drier times. This is a possible response to climate‐driven fluctuations in food availability, but Pleistocene habitat fragmentation may also have had an influence. Environmental break‐up during the late Quaternary led to the isolation of megafauna populations, which underwent modifications similar to those observed in insular mammals. Although the amount of remains available is still limited, it is nonetheless a fact that hippopotamuses changed their body size through time, normally becoming smaller. If the conclusions are confirmed as data continue to accumulate, hippopotamuses might cast doubt on the generality of Bergmann's rule.  相似文献   
12.
The identification of the mineral species controlling the solubility of Al in acidic waters rich in sulfate has presented researchers with several challenges. One of the particular challenges is that the mineral species may be amorphous by X-ray diffraction. The difficulty in discerning between adsorbed or structural sulfate is a further complication. Numerous studies have employed theoretical calculations to determine the Al mineral species forming in acid sulfate soil environments. The vast majority of these studies indicate the formation of a mineral species matching the stoichiometry of jurbanite, Al(OH)SO4·5H2O. Much debate, however, exists as to the reality of jurbanite forming in natural environments, particularly in view of its apparent rare occurrence. In this work the use of Al, S and O K-edge XANES spectroscopy, in combination with elemental composition analyses of groundwater precipitates and a theoretical analysis of soluble Al concentrations ranging from pH 3.5 to 7, were employed to determine the mineral species controlling the solubility of Al draining from acid sulfate soils into Blacks Drain in north-eastern New South Wales, Australia. The results indicate that a mixture of amorphous Al hydroxide (Al(OH)3) and basaluminite (Al4(SO4)(OH)10·5H2O) was forming. The use of XANES spectroscopy is particularly useful as it provides insight into the nature of the bond between sulfate and Al, and confirms the presence of basaluminite. This counters the possibility that an Al hydroxide species, with appreciable amounts of adsorbed sulfate, is forming within these groundwaters.Below approximately pH 4.5, prior to precipitation of this amorphous Al(OH)3/basaluminite mixture, our studies indicate that the Al3+ activity of these acidic sulfate-rich waters is limited by the availability of dissolved Al from exchangeable and amorphous/poorly crystalline mineral species within adjacent soils. Further evidence suggests the Al3+ activity below pH 4.5 is then further controlled by dilution with either rainwater or pH 6-8 buffered estuarine water, and not a notional Al(OH)SO4 mineral species.  相似文献   
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Mountain farming provides high-quality food products due to the peculiar characteristics of the raw materials combined with traditional processing conditions. However, these products and their intrinsic characteristics are not clearly recognized by consumers on the market. Nowadays, Protected Designation of Origin(PDO), Protected Geographical Indication(PGI) and Traditional Specialities Guaranteed(TSG) certifications include products originating in mountain areas, even if a large part of mountain foodstuff is not protected by these certifications and foods not made in mountain areas are often labeled as ―mountain food products‖. For this reason, the European Union has set a specific Regulation in 2012 to recognize and protect mountain food and to make the consumers safer about the origin information. The objective of this paper is twofold: firstly, it presents the recent aspects related to European legislation of mountain food product; secondly, it aims at reviewing the main features of nutritional quality and technology of dairy and meat products, as the most widespread mountain food products, and the main protocols used to evaluate the authenticity of these food products. The promotion of mountain food product through a specific label and the use of tracing methods, which are able to verify the authenticity of the origin of these products, may play a pivotal role in increasing the consumer‘s loyalty towards these products and could be a way to boost a sustainable development of these economically marginal rural areas. However, the analytical protocols developed so far(stable isotopes, macro and microelements, radionuclides, spectroscopic, molecular techniques, volatile substances profile, terpenes) are in many cases still at the experimental level due to the extreme variability of the mountain origin of the products to be tested.  相似文献   
15.
We have determined the dry weight of suspended particulate matter in seawater in a section through the western Atlantic Ocean from 75°N to 52°S. The concentrations, operationally defined as that weight retained on 0.6-μm and 0.4-μm pore size Nuclepore filters, contained in 1 kg of seawater, range from 5 to 300 μg/kg and show readily explainable regional features. High concentrations are found in surface waters and in association with radpidly moving bottom waters in the Denmark Straits overflow and in Antarctic bottom waters to 15°S. Low concentrations, <12 μg/kg, characterize the mid-water regions of the sub-tropical gyres. High concentrations are seen in sinking Labrador Sea water and in a plume extending at least a kilometer off the bottom at 35°N–40°N where the cruise track intersects the North Atlantic gyre. It is doubtful whether this important phenomenon could be observed by any means other than through particulate observations, either optical or gravimetric, and this provides a unique insight into the scale of vertical turbulent processes.  相似文献   
16.
Electromagnetic sounding of geothermal zones   总被引:1,自引:0,他引:1  
Electromagnetic (EM) data provide a substantial contribution to the geophysical mapping and monitoring of geothermal reservoirs. This paper presents an up-to-date picture of the achievements of EM methods for geothermal exploration as they have emerged over the last few years. It has been proved that EM sounding of geothermal zones and distant monitoring macro-parameters of the reservoirs, fluid-filled faults and other elements of the geothermal system are possible provided that modern 3-D inversion is used along with techniques that reduce the effects of industrial and geological noise. In addition, geological and petrophysical data also need to be included in the analysis.  相似文献   
17.
Schwertmannite stability in acidified coastal environments   总被引:1,自引:0,他引:1  
A combination of analytical and field measurements has been used to probe the speciation and cycling of iron in coastal lowland acid sulfate soils. Iron K-edge EXAFS spectroscopy demonstrated that schwertmannite dominated (43-77%) secondary iron mineralization throughout the oxidized and acidified soil profile, while pyrite and illite were the major iron-bearing minerals in the reduced potential acid sulfate soil layers. Analyses of contemporary precipitates from shallow acid sulfate soil groundwaters indicated that 2-line ferrihydrite, in addition to schwertmannite, is presently controlling secondary Fe(III) mineralization. Although aqueous pH values and concentrations of Fe(II) were seasonally high, no evidence was obtained for the Fe(II)-catalyzed crystallization of either mineral to goethite. The results of this study indicate that: (a) schwertmannite is likely to persist in coastal lowland acid sulfate soils on a much longer time-scale than predicted by laboratory experiments; (b) this mineral is less reactive in these types of soils due to surface-site coverage by components such as silicate and possibly, to a lesser extent, natural organic matter and phosphate and; (c) active water table management to promote oxic/anoxic cycles around the Fe(II)-Fe(III) redox couple, or reflooding of these soils, will be ineffective in promoting the Fe(II)-catalyzed transformation of either schwertmannite or 2-line ferrihydrite to crystalline iron oxyhydroxides.  相似文献   
18.
Geothermal data are published using different IT services, formats and content representations, and can refer to both regional and global scale information. Geothermal stakeholders search for information with different aims. E-Infrastructures are collaborative platforms that address this diversity of aims and data representations. In this paper, we present a prototype for a European Geothermal Information Platform that uses INSPIRE recommendations and an e-Infrastructure (D4Science) to collect, aggregate and share data sets from different European data contributors, thus enabling stakeholders to retrieve and process a large amount of data. Our system merges segmented and national realities into one common framework. We demonstrate our approach by describing a platform that collects data from Italian, French, Hungarian, Swiss and Icelandic geothermal data providers.  相似文献   
19.
Numerical modeling of coastal circulation encompassing the nearshore requires forcing by tide, surface gravity waves, and possibly other factors. In the nearshore, the wave-induced longshore current and setup are dominant hydrodynamic processes, and lateral boundary conditions representing tide and oceanic forcing typically do not include surface-wave contributions. Without proper boundary conditions, significant gradients in current and water level can occur that contaminate the solution in the internal domain. A standard strategy is to place the boundaries far from the site of interest, but this strategy greatly increases computational demands, and it may not be appropriate for long-term simulations. This paper describes a wave-adjusted boundary condition that accounts for wave-induced water level and current acting in combination with tidal forcing. The wave-adjusted boundary condition is demonstrated for an idealized case of a parallel-contour beach and for an engineering application at Ocean City, MD.  相似文献   
20.
The palynological record from the Colle Curti and Cesi continental deposits has been examined in order to identify the main palaeofloristic and vegetational changes between 0.99 and 0.6–0.7 Ma. These data show a progressive increase in aridity, as well as a progressive decrease in temperature, which are associated with the transition in dominance from the 41 to 100 ka cyclicity in the Milankovitch orbital record during the Middle Pleistocene. The disappearance of Tsuga, recorded during the lower part of the Brunhes Chron, also has been related to a shift in global aridity. During the successive open vegetational phases (glacials), Chenopodiaceae and Artemisia progressively increase, whereas Cyperaceae decrease. Forest phases (interglacials) are successively dominated by Tsuga, Abies with Picea and, finally, Pinus; but all lack significant expansion of broad‐leaved deciduous taxa. Palynological and sedimentological data, in addition to taphonomic interpretations, demonstrate the occurrence of several hiatuses in the lower parts of the interglacials. These hiatuses are considered to represent the palaeoenvironmental response to climatic changes affecting local sedimentological and geomorphological conditions. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
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