55 resultados para Green, Charles, 1785-1870.
Resumo:
Among many managers Charles Handy might well be described as a ‘world class’ management thinker. He is certainly the first British management author to have achieved international guru status. The author of widely-commended management best-sellers and MBA set texts, known through broadcasting and management videos, he has presented himself more recently as a self-styled ‘social philosopher’. But just how philosophical is he? Does he offer genuinely new ideas? And what explains his vast appeal? Ashly Pinnington considers three works from Handy’s social philosopher period. He argues that they are conservative and focused on the interests of managers and business owners rather than employees or society as a whole. Like a mediaeval friar seeking converts, Handy uses mythic structures and exempla to invest his claims and propositions with plausibility and authority. Drawing on research into management gurus as a phenomenon, Ashly Pinnington concludes that when we read authors like Handy we should attend not merely to the ‘philosophy’ but also to the way narrative techniques are used in conveying ideological and moral messages.
Resumo:
The prevalence of neoplasia in birds is generally low; however, in some species of companion and aviary birds, the incidence is high and neoplasia is a common cause of death. Surgical excision or limb amputation has been performed as the therapeutic plan. Chemotherapy in the treatment of avian neoplasia is largely empirical and poorly documented. For example, cisplatin has been used intralesionally in macaws (Ara species) with limited clinical success. Eight sulphur-crested cockatoos (Cacatua galerita), under general isoflurane anesthesia, were infused intravenously with cisplatin at 6.4 or 1.0 mg/kg over 1 hour and hydrated with lactated Ringer's solution for 1 hour before and 2 hours after cisplatin infusion. Birds were euthanatized 96 hours after infusion, except for 2 birds given the low cisplatin dose, which were euthanatized on day 35 after dosing. All birds tolerated the study procedure while under anesthesia. Blood pressure, heart rate, and respiratory rate did not change significantly. In the low-dose group, the mean cloacal temperature decreased significantly during the infusion period (P < .001) and then rose progressively to preinfusion values by 24 hours. Also in this group, the mean body weight tended to increase during the infusion period before significantly decreasing (P < .05) by 5% at 96 hours after dosing. At 24 hours after dosing, all birds were bright and eating. However, intermittent regurgitation and fecal changes (moist, dark green feces and yellow urates) occurred in 3 of 8 birds, especially those given the high dose. By 72 hours after dosing, droppings in the low-dose group were normal in appearance. One bird in the high-dose group died by 94 hours after dosing. Myelosuppression was not observed in any bird and at necropsy, no evidence of cisplatin toxicity was found except in 1 bird given the high cisplatin dose. On histology, this bird showed nephrotoxicity, and its serum uric acid levels and mean estimated white blood cell count increased significantly by 24 hours after dosing. This paper reports for the first time the effect of systemic cisplatin administration in birds and provides veterinarians data for formulating efficacious and safe protocols for platinum-containing compounds when treating neoplasia in parrots and other companion birds.
Resumo:
This study describes the developmental changes in pulmonary surfactant (PS) lipids throughout incubation in the sea turtle, Chelonia mydas. Total phospholipid (PL), disaturated phospholipid (DSP) and cholesterol (Chol) harvested from lung washings increased with advancing incubation, where secretion was maximal at pipping, coincident with the onset of pulmonary ventilation. The DSP/PL ratio increased, whereas the Chol/PL and the Chol/DSP ratio declined throughout development. The phospholipids, therefore, are independently regulated from Chol and their development matches that of mammals. To explore whether hypoxia could elicit an effect on the development of the PS system, embryos were exposed to a chronic dose of 17% O-2 for the final similar to 40% of incubation. Hypoxia did not affect incubation time, absolute, nor relative abundance of the surfactant lipids, demonstrating that the development of the system is robust and that embryonic development continues unabated under mild hypoxia. Hypoxia-incubated hatchlings had lighter wet lung weights than those from normoxia, inferring that mild hypoxia facilitates lung clearance in this species. (C) 2001 Elsevier Science B.V. All rights reserved.
Resumo:
Four temperature data-loggers were placed in each of five green sea turtle nests on Heron Island in the 1998-99 nesting season. Temperatures in all nests increased as incubation progressed due to general sand heating and increased metabolic heat production of the developing embryos. Even at the top of nests no daily diurnal fluctuation in temperature was evident. The temperature of eggs in the middle of the nest increased above those in the nest periphery during the last third of incubation. However, this metabolic nest heating would have little effect on hatchling sex ratio because it occurred after the sex-determining period. Small differences in temperature between regions of a nest persisted throughout incubation and may be important in ensuring the production of at least some individuals of the opposite sex in nests that have temperatures close to either the all-male or all-female determining temperatures. Location and degree of shading of nests had little effect on mean nest temperature, but deeper nests were generally cooler and therefore were predicted to produce a higher proportion of males than were shallower nests. Nest temperature profile data indicated that the 1998-99 nesting season on Heron Island would have produced a strongly female-biased sex ratio amongst hatchlings.
Resumo:
Eggs from the Heron Island, Great Barrier Reef, nesting population of green turtles (Chelonia mydas) were incubated at all-male-determining (26 degreesC) and all-female-determining (30 degreesC) temperatures. Oxygen consumption and embryonic growth were monitored throughout incubation, and hatchling masses and body dimensions were measured from both temperatures. Eggs hatched after 79 and 53 days incubation at 26 degreesC and 30 degreesC respectively. Oxygen consumption at both temperatures increased to a peak several days before hatching, a pattern typical of turtle embryos, and the rate of oxygen was higher at 30 degreesC than 26 degreesC. The total amount of energy consumed during incubation, and hatchling dimensions, were similar at both temperatures, but hatchlings from 26 degreesC had larger mass, larger yolk-free mass and smaller residual yolks than hatchlings from 30 degreesC. Because of the difference in mass of hatchlings, hatchlings from 30 degreesC had a higher production cost.
Resumo:
Retention of green leaf area in grain sorghum under post-anthesis drought, known as stay-green, is associated with greater biomass production, lodging resistance and yield. The stay-green phenomenon can be examined at a cell, leaf, or whole plant level. At a cell level, the retention of chloroplast proteins such as LHCP2, OEC33 and Rubisco until late in senescence has been reported in sorghum containing the KS19 source of stay-green, indicating that photosynthesis may be maintained for longer during senescence in these genotypes. At a leaf level, longevity of photosynthetic apparatus is intimately related to nitrogen (N) status. At a whole plant level, stay-green can be viewed as a consequence of the balance between N demand by the grain and N supply during grain filling. To examine some of these concepts, nine hybrids varying in the B35 and KS19 sources of stay-green were grown under a postanthesis water deficit. Genotypic variation in delayed onset and reduced rate of leaf senescence were explained by differences in specific leaf nitrogen (SLN) and N uptake during grain filling. Matching N supply from age-related senescence and N uptake during grain tilling with grain N demand found that the shortfall in N supply for grain filling was greater in the senescent than stay-green hybrids, resulting in more accelerated leaf senescence in the former. We hypothesise that increased N uptake by stay-green hybrids is a result of greater biomass accumulation during grain filling in response to increased sink demand (higher grain numbers) which, in turn, is the result of increased radiation use efficiency and transpiration efficiency due to higher SLN. Delayed leaf senescence resulting from higher SLN should, in turn, allow snore carbon and nitrogen to be allocated to the roots of stay-green hybrids during grain filling, thereby maintaining a greater capacity to extract N from the soil compared with senescent hybrids.
Resumo:
The numerical implementation of the complex image approach for the Green's function of a mixed-potential integralequation formulation is examined and is found to be limited to low values of k(0) rho (in this context k(0) rho = 2 pirho/ lambda(0), where rho is the distance between the source and the field points of the Green's function and lambda(0) is the free space wavelength). This is a clear limitation for problems of large dimension or high frequency where this limit is easily exceeded. This paper examines the various strategies and proposes a hybrid method whereby most of the above problems can be avoided. An efficient integral method that is valid for large k(0) rho is combined with the complex image method in order to take advantage of the relative merits of both schemes. It is found that a wide overlapping region exists between the two techniques allowing a very efficient and consistent approach for accurately calculating the Green's functions. In this paper, the method developed for the computation of the Green's function is used for planar structures containing both lossless and lossy media.
Resumo:
The Green-striped burrowing frog. Cyclorana alboguttata survives extended drought periods by burrowing underground and aestivating. These frogs remain immobile within cocoons of shed skin and Mucus during aestivation and emerge from their burrows upon heavy rains to feed and reproduce. Extended periods of immobilisation in mammals typically result in muscle atrophy and a decrease in muscle performance. We examined the effect of aestivation and hence prolonged immobilisation, on skeletal Muscle mass. in vitro muscle performance, and locomotor performance in C. alboguttata. Frogs were aestivated in soil for 3 months and were compared with control animals that remained active, were fed, and had a continual supply of water. Compared to the controls, the wet mass of the gastrocnemius. sartorius, gracilus major. semimembranosus. peroneus, extensor cruris, tibialis posticus and tibialis anticus longus of aestivators remained unchanged indicating no muscle atrophy. The in-vitro performance characteristics of the gastroenemius muscle were maintained and burst swimming speed Was Unaffected, requiring no recovery from the extended period of immobilisation associated with aestivation. This preservation of muscle size, contractile condition and locomotor performance through aestivation enables C. alboguttata to compress their life history into unpredictable windows of opportunity, whenever heavy rains occur.