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11.
C Edworthy NC James B Erasmus JOG Kemp H Kaiser WM Potts 《African Journal of Marine Science》2018,40(1):67-74
The physiology of fishes in the early stages of development remains poorly assessed despite the importance of identifying energy bottlenecks in organisms faced with changing environmental conditions. This study describes the metabolic activity of dusky kob Argyrosomus japonicus throughout its early development, from hatchling to settlement stage. Standard, routine and active metabolic rates (SMR, RMR and AMR, respectively) were assessed to determine the species’ metabolic scope and identify how metabolism changes with growth and development. Distinct metabolic changes occurred in association with developmental changes during the early life stages, with flexion-stage larvae showing significantly reduced metabolic scope (approx. 0.30 µmol O2 ind.–1 h–1), representing an energy bottleneck. Based on these findings, it is likely that larvae of A. japonicus are most susceptible to environmental perturbations during flexion. The variability of metabolic rates during the diel cycle was also assessed and revealed that the early-stage larvae showed no preference for daylight, although settlement-stage juveniles were more active during daylight hours (RMR = 12.78 µmol O2 ind.–1 h–1) than at night (RMR = 5.87 µmol O2 ind.–1 h–1). These results suggest that metabolic measurements of the SMR of A. japonicus larvae can be taken at any time of the diel cycle until the settlement phase, when readings should take place at night. 相似文献
12.
In the Granite Falls-Montevideo area, Minnesota, granulite faciesmineral assemblages were collected from three major lithologicunits—hornblende-pyroxene gneiss, garnet-biotite gneiss,and granitic gneiss. Mineral assemblages most commonly observedare: plagioclase-hornblende-orthopyroxene-clinopyroxene-magnetite-ilmenite-(biotite-quartz);quartz-plagioclase-biotite-garnet-orthopyroxene-(orthoclase);quartz-plagioclase-biotite-garnet-(orthoclase); quartz-plagioclase-microcline-(garnet-hematite);and quartz-plagio-clase-microcline-biotite-(garnet-hematite-rutile).Partial analyses of isomorphous phases from the hornblende-pyroxenegneiss and the garnet-biotite gneiss were determined with anelectron microprobe. Negligible compositional variation within single grains andof a particular mineral within a given specimen, regular distributionof Fe and Mg between coexisting hornblende, ortho-pyroxene,and clinopyroxene, obedience of the mineral assemblages to theGibbs Phase Rule, and lack of empirically determined incompatiblephases indicate a close approach to chemical equilibrium duringmetamorphism. Plots of coexisting biotite, garnet, and orthopyroxeneon an appropriate phase diagram result in some crossing tielines which cannot be adequately explained by temperature orpressure differences, but suggest that H2O and/or O2 were notperfectly mobile components during metamorphism. This is alsoindicated by interlayering of hornblende assemblages with pyroxeneassemblages and by different iron oxide phases in essentiallythe same mineral assemblage. Textural and chemical relationships of retrograde metamorphicassemblages suggest that some retrograde reactions are a resultof cooling following the granulite-facies metamorphism, butthat others may have resulted from recrystallization duringa stage of thermal metamorphism that is reflected in the potassium-argonand rubidium-strontium biotite ages of the metamorphic rocks. 相似文献
13.
Researchers usually examine therapeutic landscapes, spaces that have or are felt to have healing properties, in positive terms. We reconsider the therapeutic landscape notion by applying it to J. D. Salinger's The Catcher in the Rye . The main character, Holden Caulfield, is sickened by his transition between childhood and adulthood, and he relies on therapeutic landscapes as an imaginary escape. Yet his therapeutic landscapes are oversimplified and unrealistic. Through examples from Holden's experiences, we explore therapeutic landscapes as ambivalent, nuanced spaces. We argue that therapeutic landscapes should be considered beyond exceptional cases, in everyday experience. 相似文献
14.
The Sun Belt has become a part of the American vocabulary without a careful examination of its validity as a region. This analysis, using a variety of techniques and variables taken from the topics of federal involvement, economic well-being, and population change, concludes that the Sun Belt does not emerge as a distinct and homogeneous region. The Snow Belt would be better expressed as the Core (the old Manufacturing Belt). 相似文献