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11.
DUNCAN WILSON 《Bioethics》2013,27(4):215-223
This article details the relationship between history and bioethics. I argue that historians' reluctance to engage with bioethics rests on a misreading of the field as solely reducible to applied ethics, and overlooks previous enthusiasm for historical perspectives. I claim that seeing bioethics as its practitioners see it – as an interdisciplinary meeting ground – should encourage historians to collaborate in greater numbers. I conclude by outlining how bioethics might benefit from new histories of the field, and how historians can lend a fresh perspective to bioethical debates. 相似文献
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DUNCAN M. PORTER
fls GINA MURRELL JOHN PARKER 《Botanical journal of the Linnean Society. Linnean Society of London》2009,159(1):12-18
This paper reports 24 newly discovered specimens of 21 species made by Charles Darwin in Argentina, Australia, Brazil, Chile, Ecuador and Uruguay while on the 1831–1836 voyage of HMS Beagle. They have been found in Cambridge University Herbarium and the herbaria of the Missouri Botanical Garden, Natural History Museum, London, New York Botanical Garden and the Royal Botanic Gardens, Kew, since the earlier publications of Porter. Included are type specimens of Calceolaria darwinii (isotype; = C. uniflora), Cuscuta gymnocarpa (holotype and isotypes), C. sandwichiana var. mimosae (isolectotypes = C. gymnocarpa), Ephedra frustillata (lectotype and isolectotypes), Ourisia breviflora (isolectotype), Polypodium paleaceum (syntype?; = Ctenitis sloanei) and Urera gaudichaudiana (holotype; = Laportea aestuans). © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 12–18. 相似文献
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1. In addition to exhibiting preferences for particular plant species, vertebrate herbivores select particular individuals of these species whilst leaving others undamaged. This pattern of diet selection may reflect differences in the chemical composition (and hence nutritional quality) between individual plants, and/or variability in the physical constraints on intake rate, such as plant structure.
2. An experiment was conducted to test the effects of environmental manipulations on the morphology and chemical composition of Sitka Spruce saplings, and to evaluate the consequences for herbivory by Red Deer. Fertilizing the trees increased tree height, branch span and leader length, twig width and needle width, and decreased the concentrations of total phenolics, condensed tannins, fibre and lignin but monoterpene content was not altered. Shading also reduced phenolic and tannin concentrations.
3. When the fertilized and shaded trees were offered to deer in feeding trials, the probability of a tree being visited by a deer and the biomass removed were influenced by tree morphological variables, as were the bite rate and intake rate of the deer. More biomass was removed from larger trees.
4. Once the effects of tree morphology had been taken into account, there was no effect of the fertilizer and shade treatments on deer browsing behaviour that could be attributed to changes in chemical composition of the trees. The relationship between intake rate and bite size at each tree varied between individual deer, but the functional response relationship between intake rate and bite size was not influenced by the treatments applied to the trees.
5. Tree morphology may have a larger influence on deer feeding behaviour than tree chemical composition. 相似文献
2. An experiment was conducted to test the effects of environmental manipulations on the morphology and chemical composition of Sitka Spruce saplings, and to evaluate the consequences for herbivory by Red Deer. Fertilizing the trees increased tree height, branch span and leader length, twig width and needle width, and decreased the concentrations of total phenolics, condensed tannins, fibre and lignin but monoterpene content was not altered. Shading also reduced phenolic and tannin concentrations.
3. When the fertilized and shaded trees were offered to deer in feeding trials, the probability of a tree being visited by a deer and the biomass removed were influenced by tree morphological variables, as were the bite rate and intake rate of the deer. More biomass was removed from larger trees.
4. Once the effects of tree morphology had been taken into account, there was no effect of the fertilizer and shade treatments on deer browsing behaviour that could be attributed to changes in chemical composition of the trees. The relationship between intake rate and bite size at each tree varied between individual deer, but the functional response relationship between intake rate and bite size was not influenced by the treatments applied to the trees.
5. Tree morphology may have a larger influence on deer feeding behaviour than tree chemical composition. 相似文献
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1. When dissolved oxygen levels decline in aquatic systems, prey may be unable to maintain behaviours protecting them from predators. We examined how oxygen availability affected anti‐predator responses in the freshwater clam, Corbicula fluminea. 2. When attacked, bivalves protect their soft tissues by closing their protective valves. This reduces vulnerability to small predators, but ventilation and oxygen uptake are suspended. We found that after a simulated attack, clams under low oxygen conditions reopened their valves sooner than clams under high oxygen conditions, suggesting that hypoxia increases vulnerability to predation. 3. Bivalves may also evade predators through burial into the substratum. Deeper burial confers greater refuge from predators, but increases the costs of ventilation. In a second experiment, we studied how burial depth of C. fluminea is affected by oxygen availability. Additionally, we examined whether clams changed burial depth following a simulated attack by a small predator, and whether this response was affected by oxygen availability. Our results offered partial support for the hypothesis that burial depth is reduced under hypoxic conditions, but the simulated attack did not affect burial depth in any oxygen treatments. 相似文献
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B. D. HARRISON D. J. ROBINSON W. P. MOWAT G. H. DUNCAN 《The Annals of applied biology》1983,102(2):331-338
All isolates of tobacco rattle virus (TRV) found in naturally infected narcissus leaves produced nucleoprotein particles, mostly in large concentrations but, because of antigenic diversity, less than half of the isolates were identified by immunosorbent electron microscopy (ISEM) and still fewer by enzyme-linked immunosorbent assay. All were identified by a nucleic acid hybridisation test in which DNA complementary to RNA-1 of strain PRN of TRV was allowed to react with nucleic acid extracted from leaf tissue. Spraing-affected tubers in some potato stocks yielded only NM isolates of TRV. These isolates do not produce virus particles and they were therefore not detected by ISEM. The infectivity of nucleic acid extracts from recently harvested tubers with spraing symptoms was much greater than that of extracts prepared from tubers after 8 months' storage. In other potato stocks, some spraing-affected tubers contained NM isolates and the rest contained particle-producing isolates (M isolates) of TRV. The infectivity of sap and of nucleic acid, extracted 7 months after harvest from tubers infected with M isolates, was much greater than that of nucleic acid extracted from comparable tubers infected with NM isolates. TRV was detected by nucleic acid hybridisation in extracts of almost all tubers containing either M or NM isolates, even when the tubers were not tested until 7–8 months after harvest. The probable sequence of events occurring after tubers are infected with TRV is outlined, and it is suggested that the virus will rarely become established in fields as a result of planting infected tubers. 相似文献
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Abstract: We designed a reliable and inexpensive universal trap timer that records the time from the moment a single-live-capture trap is triggered by an animal to when the observer checks the trap. Combined with trapping information, the diel activity pattern of a given species or demographic group can then be described or compared between imposed treatments. The universal trap timer is adaptable to operate reliably with most single-capture trap designs, requires no permanent modification of traps, and is easy to construct. 相似文献