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Severe freezing injury was produced in the hind foot of 26 mongrel dogs. All dogs were given daily whirlpool treatment and protective bandaging for 14 days following injury. In addition, certain dogs received a vasodilator, fasciotomy, or both vasodilator and fasciotomy following injury. Deep foot temperatures, foot volumes, tissue pressures, and 14 day tissue loss-salvage scores were compared. Significant differences between fasciotomy and nonfasciotomy dogs were seen in foot temperature, volume, and tissue pressure immediately following fasciotomy. Though there was no significant difference in 14 day tissue loss, there was clinically apparent prolongation of integrity of the local vascular system for 2 to 5 days following fasciotomy, and total foot salvage in several dogs receiving fasciotomy.  相似文献   
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The persistence under controlled chemical and physical conditions and the ability to respond to defined environmental changes was follow d in extremely simple (homogenous or 2-phase) ecosystems with continuous or semicontinuous flow. In the homogenous case the Aufwuchs was removed. Primary productivity and community respiration were computed by means of continuous recording of dissolved oxygen. Under constant environmental conditions the systems usually exhibited slow oscillations of the ecosystem parameters around an equilibrium state. The temporal variations of functional criteria such as elimination rate of easily degradable organic substances or daily oxygen amplitude were slight in comparison to the significant random oscillations in individual numbers of the predominating species of phytoplankton and zooplankton. One of the mechanisms responsible for this functional stability may be the inverse relationship between biomass and activity per unit biomass as observed also in the laboratory models. If the sewage pond microecosystems after a shut down in the inflow were operated without any exchange of nutrients and gases they nevertheless maintained a very high level both of autotrophic and heterotrophic metabolism. Step forcing of nutrient (sewage) concentration, dilution rate or day length produced a new equilibrium state within 1 or 2 days, if the functional criteria mentioned above were taken as output signals. Also in the case of pulse forcing such a rapid adaptation was to be observed. This may contribute to the fact, that the turnover rate of the population was in the same range as the renewal rate of the water. The results are discussed with respect to short and long term effects of abatement of pollution from flowing and standing waters.  相似文献   
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The Natural History of Good and Evil Morality is a result of evolution by natural selection. It facilitates the stability of groups which gives advantage to the involved individuals and is thus, at least in some basic form – as moral‐analogous behavior –, also developed in nonhuman primates and other mammalian species. Of crucial importance is reciprocal altruism that, however, for long periods of time applied only to – and was favored by natural selection in – comparatively small groups. Its extension therefore meets fundamental difficulties, and we have to consider limitations to morality. From the perspective of evolutionary theory (evolutionary ethics) humans by nature are neither good nor evil. Under certain cultural constraints they can develop enormous destructive potentials, but also experience stimuli for cooperative and helping behavior.  相似文献   
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The oriental fruit fly, Bactrocera dorsalis (Hendel), is a key pest that causes reduction of the crop yield within the international fruit market. Fruit flies have been suppressed by two Area-Wide Integrated Pest Management programs in Thailand using Sterile Insect Technique (AW-IPM-SIT) since the late 1980s and the early 2000s. The projects’ planning and evaluation usually rely on information from pest status, distribution, and fruit infestation. However, the collected data sometimes does not provide enough detail to answer management queries and public concerns, such as the long term sterilization efficacy of the released fruit fly, skepticism about insect migration or gene flow across the buffer zone, and the re-colonisation possibility of the fruit fly population within the core area. Established microsatellite DNA markers were used to generate population genetic data for the analysis of the fruit fly sampling from several control areas, and non-target areas, as well as the mass-rearing facility. The results suggested limited gene flow (m < 0.100) across the buffer zones between the flies in the control areas and flies captured outside. In addition, no genetic admixture was revealed from the mass-reared colony flies from the flies within the control area, which supports the effectiveness of SIT. The control pests were suppressed to low density and showed weak bottleneck footprints although they still acquired a high degree of genetic variation. Potential pest resurgence from fragmented micro-habitats in mixed fruit orchards rather than pest incursion across the buffer zone has been proposed. Therefore, a suitable pest control effort, such as the SIT program, should concentrate on the hidden refuges within the target area.  相似文献   
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Recent research focuses on animal personalities, that is individual differences in behaviour that are consistent across contexts and over time. From an adaptive perspective, such limited behavioural plasticity is surprising, since a more flexible structure of behaviour should provide a selective advantage. Here, we argue that consistency can be advantageous because it makes individuals predictable. Predictability, however, can only be advantageous if at least some individuals in the population respond to individual differences. Consequently, the evolution of consistency and responsiveness are mutually dependent. We present a general analysis of this coevolutionary feedback for scenarios that can be represented as matrix games with two pure strategies (e.g. hawk-dove game, snowdrift game). We first show that responsive strategies are favoured whenever some individual differences are present in the population (e.g. due to mutation and drift). We then show that the presence of responsive individuals can trigger a coevolutionary process between responsiveness and consistency that gives rise to populations in which responsive individuals coexist with unresponsive individuals who show high levels of adaptive consistency in their behaviour. Next to providing an adaptive explanation for consistency, our results also link two key features associated with personalities, individual differences in responsiveness and behavioural consistency.  相似文献   
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Summary Filamentous bacteria were isolated from bulking activated sludge and identified as Herpetosiphon spec. The Gram-negative filaments are more than 500 m long and they show gliding motility. The bacteria grown in artificial media (J- or EC-medium), in shaken cultures yield about 3 g cells per liter. Optimum growth was observed at 25°C and pH 7.2. The colonies are either uncoloured or bright red depending on the cultivation medium. The isolated bacteria exhibit lytic activity towards cells of Escherichia coli and Klebsiella pneumoniae. The G+C ratio of the five strains from different bulking sludge samples was found to be between 48.7 moles% and 49.0 moles%.  相似文献   
28.
Vocal production in songbirds requires the control of the respiratory system, the syrinx as sound source and the vocal tract as acoustic filter. Vocal tract movements consist of beak, tongue and hyoid movements, which change the volume of the oropharyngeal–esophageal cavity (OEC), glottal movements and tracheal length changes. The respective contributions of each movement to filter properties are not completely understood, but the effects of this filtering are thought to be very important for acoustic communication in birds. One of the most striking movements of the upper vocal tract during vocal behavior in songbirds involves the OEC. This study measured the acoustic effect of OEC adjustments in zebra finches by comparing resonance acoustics between an utterance with OEC expansion (calls) and a similar utterance without OEC expansion (respiratory sounds induced by a bilateral syringeal denervation). X-ray cineradiography confirmed the presence of an OEC motor pattern during song and call production, and a custom-built Hall-effect collar system confirmed that OEC expansion movements were not present during respiratory sounds. The spectral emphasis during zebra finch call production ranging between 2.5 and 5 kHz was not present during respiratory sounds, indicating strongly that it can be attributed to the OEC expansion.  相似文献   
29.
Rust fungi on Aizoaceae in southern Africa have been examined and reported based on 27 specimens collected during a biodiversity study and previously collected herbarium specimens. Eight species including five new species have been recognized, and they are described in detail and illustrated. Together with two additional species in literature, ten species of rust fungi are now recognized on Aizoaceae in southern Africa. Part 223 in the series “Studies in Heterobasidiomycetes” from the Botanical Institute, University of Tübingen.  相似文献   
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