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Gabriel E Machovsky-Capuska David Priddel Philip HW Leong Peter Jones Nicholas Carlile Lesley Shannon 《新西兰海洋与淡水研究杂志》2016,50(3):418-432
It is widely believed that predators maximise their energy intake while foraging and consume prey that are nutritionally similar. We combined GPS data loggers, miniaturised cameras, dietary sampling and nutritional geometry to examine the nutritional variability in the prey and selected diet, and foraging performance, of the masked booby (Sula dactylatra tasmani), a wild carnivore and marine top predator. Data loggers also revealed no significant differences between sexes in the foraging performance of chick-rearing adults. Females provided more food to their chicks than the males and, regardless of the nutritional variability of prey consumed, both sexes showed similar amounts of protein and lipid in their diets. Miniaturised cameras combined with nutritional analysis of prey provided, for the first time, fine-scale detail of the amounts of macronutrients consumed in each plunge dive and the overall foraging trip. Our methodology could be considered for future studies that aim to contribute to the general understanding of the behavioural and physiological mechanisms and ecological and evolutionary significance of animal foraging (e.g. energy expenditure budgets and prey selection for self- and offspring-feeding that could lead to sex-specific foraging strategies). 相似文献
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Wheat as food, wheat as industrial substance; comparative geographies of transformation and mobility 总被引：1，自引：0，他引：1
Wheat is the world’s second largest crop, supplies 19% of human calories, and is the largest volume crop traded internationally. Its uniquely malleable physical properties make it a valued industrial substance, albeit often an invisible one, as well as a food. This combination of transformation, invisibility and mobility demands new ways of thinking about wheat geographies. In this paper we document and analyse several ‘moments’ in the life of Australian wheat; at the supermarket, in the lives of coeliac sufferers, in laboratories, industrial factories and on the farm. We illustrate diverse patterns of interaction with wheat. The major plane of differentiation is between wheat as food and wheat as industrial substance. The explicit connection of food to the human body tends to fix the identity of wheat, whether as healthy staple of the nation, or harmful poison to coeliacs who must negotiate its presence using the regulatory regime of food labelling. This is no small task given the ubiquity of wheat; our survey of 10,235 supermarket items found it in 29.5% of labelled food items. In contrast, when wheat is physically and chemically disassembled to become an industrial substance, its presence and identity become mutable, hidden and often invisible. 相似文献
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Mauro Dall’Amico Lesley J. Gray Karen H. Rosenlof Adam A. Scaife Keith P. Shine Peter A. Stott 《Climate Dynamics》2010,34(2-3):381-398
In most climate simulations used by the Intergovernmental Panel on Climate Change 2007 fourth assessment report, stratospheric processes are only poorly represented. For example, climatological or simple specifications of time-varying ozone concentrations are imposed and the quasi-biennial oscillation (QBO) of equatorial stratospheric zonal wind is absent. Here we investigate the impact of an improved stratospheric representation using two sets of perturbed simulations with the Hadley Centre coupled ocean atmosphere model HadGEM1 with natural and anthropogenic forcings for the 1979–2003 period. In the first set of simulations, the usual zonal mean ozone climatology with superimposed trends is replaced with a time series of observed zonal mean ozone distributions that includes interannual variability associated with the solar cycle, QBO and volcanic eruptions. In addition to this, the second set of perturbed simulations includes a scheme in which the stratospheric zonal wind in the tropics is relaxed to appropriate zonal mean values obtained from the ERA-40 re-analysis, thus forcing a QBO. Both of these changes are applied strictly to the stratosphere only. The improved ozone field results in an improved simulation of the stepwise temperature transitions observed in the lower stratosphere in the aftermath of the two major recent volcanic eruptions. The contribution of the solar cycle signal in the ozone field to this improved representation of the stepwise cooling is discussed. The improved ozone field and also the QBO result in an improved simulation of observed trends, both globally and at tropical latitudes. The Eulerian upwelling in the lower stratosphere in the equatorial region is enhanced by the improved ozone field and is affected by the QBO relaxation, yet neither induces a significant change in the upwelling trend. 相似文献
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The surface binding site characteristics and Ni sorptive capacities of synthesized hydrous Mn oxyhydroxides experimentally conditioned to represent three hydrological conditions—MnOXW, freshly precipitated; MnOXD, dried at 37°C for 8 d; and MnOXC, cyclically hydrated and dehydrated (at 37°C) over a 24-h cycle for 7 d—were examined through particle size analysis, surface acid-base titrations and subsequent modelling of the pKa spectrum, and batch Ni sorption experiments at two pH values (2 and 5). Mineralogical bulk analyses by XRD indicate that all three treatments resulted in amorphous Mn oxyhydroxides; i.e., no substantial bulk crystalline phases were produced through drying. However, drying and repeated wetting and drying resulted in a non-reversible decrease in particle size. In contrast, total proton binding capacities determined by acid-base titrations were reversibly altered with drying and cyclically re-wetting and drying from 82 ± 5 μmol/m2 for the MnOXW to 21 ± 1 μmol/m2 for the MnOXD and 37 ± 5 μmol/m2 for the MnOXC. Total proton binding sites measured decreased by ≈75% with drying from the MnOXW and then increased to ≈50% of the MnOXW value in the MnOXC. Thus, despite a trend of higher surface area for the MnOXD, a lower total number of sites was observed, suggesting a coordinational change in the hydroxyl sites. Surface site characterization identified that changes also occurred in the types and densities of surface sites for each hydrologically conditioned Mn oxyhydroxide treatment (pH titration range of 2-10). Drying decreased the total number of sites as well as shifted the remaining sites to more acidic pKa values. Experimentally determined apparent pHzpc values decreased with drying, from 6.82 ± 0.06 for the MnOXW to 3.2 ± 0.3 for the MnOXD and increased again with rewetting to 5.05 ± 0.05 for the MnOXC. Higher Ni sorption was observed at pH 5 for all three Mn oxyhydroxide treatments compared to pH 2. However, changes in relative sorptive capacities among the three treatments were observed for pH 2 that are not explainable simply as a function of total binding site density or apparent pHzpc values. These results are the first to our knowledge, to quantitatively link the changes induced by hydrologic variability for surface acid base characteristics and metal sorption patterns. Further, these results likely extend to other amorphous minerals, such as Fe oxyhydroxides, which are commonly important geochemical solids for metal scavenging in natural environments. 相似文献
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A most distinctive feature of the settlement pattern of the Brasov area is the extreme dispersal of mixed farming encountered
in the western extreme of the county to the north and south of Zarnesti: the Bran and Poiana Marului areas. Here a system
of peasant subsistence farming developed in a political borderland between the Habsburg and Ottoman Empires. Despite feudal
pressures, the peasantry took all available opportunities to extend their independence including elaborate transhumance systems.
And after seeing transfrontier commerce as a source of plunder, in the tradition of Balkan highway robbery within relatively
unregulated spaces, the peasantry has profited through employment in factories, particularly during the communist period.
However, the current recession in manufacturing is throwing the rural population back on limited land resources. Although
farming assumes an important subsistence role which contributes to stability, the long-term survival of these communities
will depend on new sources of income. Rural tourism has considerable potential and a promising start has been made in Bran.
There are, however, constraints on the further development of the business and great attention will have to be given to the
conservation of the environment in both the Bucegi Mountains and the Piatra Craiului where national park status is proposed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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