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91.
Consort intrusion behavior has been proposed to largely function as a means of preventing or suppressing the reproductive activity of subordinate males. In the Japanese macaques of Arashiyama B troop this behavior was found to be ineffective in influencing female mate choice and affecting differential reproduction. Mainly directed towards the female of the pair intrusion resembled sexual solicitation and appeared to be an extension of consort behavior. Although the intruder male was almost always dominant over the other male, intrusion failed to provide priority of access to the estrous female as she most frequently chose to remain with her current partner. Copulations which were intruded upon were as likely to end in ejaculation as those which were undisturbed. Only a small proportion of intruder male-female pairs mated. Pairs that did mate were likely to have been in consort before or during the period in which intrusion occurred. No significant correlation was found between male rank order and number of possible females impregnated. Individual young, middle to lower ranking males were estimated to have been reproductively the most successful.  相似文献   
92.
The undecapeptide substance P (SP) contained in primary afferent nerves is thought to mediate that part of the neurogenic inflammatory response consisting of vasodilation and plasma extravasation. This response is diminished in rats pretreated as neonates with the neurotoxin capsaicin. It is not known whether primary afferent nerves influence cellular responses of the immune response to antigenic stimulation. Using 6- to 12-wk-old Sprague-Dawley rats pretreated as neonates with capsaicin, we examined the regional lymph node response to a s.c. antigenic stimulus of sheep red blood cells. The number of cells secreting antigen-specific antibody in these animals was reduced by more than 80% using direct and indirect plaque assay methods. The reduced antibody response in capsaicin-pretreated animals was reversed by a s.c. infusion of SP given over a 4-hr period at the injection site immediately after antigen stimulation. This response had a threshold at approximately 1.0 X 10(-5) M SP. SP1-7 (1.0 X 10(-5) M) was without effect but an infusion of SP5-11 (1.0 X 10(-5) M) reversed the effects of capsaicin treatment indicating a carboxyl-terminal effect of SP. The results suggest that the reduced response of capsaicin-treated animals to an antigenic stimulus is due to an effect of capsaicin on the SP-containing primary afferent nerves rather than a toxic effect of capsaicin on the immune system.  相似文献   
93.
In swine, the nasal turbinate epithelium is both a site of swine herpesvirus 1 (pseudorabies virus, PRV) replication and a tissue affected by toxin fromPasteurella multocida serogroup D. We examined the effects of exposure to PRV and exposure to toxin in mice, swine, and nasal turbinate cell cultures. Increased mortality in mice was observed when nonlethal doses of PRV (1000 or 100 plaque-forming units, PFU) were administered along with nonlethal doses (60–200 ng/kg) of toxin. In swine, clinical disease and death in adult pigs was observed after an intradermal injection of toxin (20 ng/kg) and intranasal exposure to 1000 PFU/kg of PRV. Nasal turbinate cell cultures incubated with toxin and PRV had increased protein synthesis, DNA synthesis, and increased recovery of virus particles. These findings indicate that a toxin fromP. multocida serogroup D enhances swine herpesvirus 1 replication and lethality in cell cultures and animal models.  相似文献   
94.
Summary Fifty four microcosmic communities were assembled over 4 months from a 28-species source pool of phytoplankton using nine different invasion patterns each replicated six times. Three communities from each set of replicates then were invaded with a cladoceran that feeds on phytoplankton. All communities were then treated identically for an additional 4 months. In all nine invasion categories species richness was greater in predated communities. Predation opened communities to invasion by increasing the representation of infrequently sampled species at the expense of more common species. Invasion rate was four times more influential than predation and over eleven times more important than either invasion order or the timing pattern of interspecific arrivals in determining species richness in this system of communitites.  相似文献   
95.
A conserved zinc finger domain in higher plants   总被引:3,自引:0,他引:3  
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96.
97.
Helicopters can be used to collect water samples from many lakes over a wide geographic area within a relatively short time period. Here we report the results from an experiment in which sequential water samples from a lake were collected first from a nonmotorized boat and then immediately afterward from a helicopter. No significant differences were found between the means of the measurement of 20 chemical parameters for the two methods of collection. When compared to obtaining samples from a boat, collection of samples from a helicopter platform had no effect on the content of the water samples.  相似文献   
98.
A total of 17 facultatively lithoautotrophic strains of Nitrobacter were investigated. They all were found to be related on the species level by DNA hybridizations. The G+C content of DNA ranged between 58.9 and 59.9 mol %. The isolates originated from divers environments. The cells were 0.5–0.8×1.2–2.0 m in size and motile by one polar to subpolar flagellum. Cell-division normally occurred by budding. Polar caps of intracytoplasmic membranes as well as carboxysomes were present. The cells tended to excrete extracellular polymers forming aggregates or biofilms. Heterotrophic growth was slower than mixotrophic but often faster than litoautotrophic growth. In the presence of nitrite and organic substances the organisms often showed diphasic growth. First nitrite and then the organic material was oxidized. In the absence of oxygen growth was possible by dissimilatory nitrate reduction. Nitrite, nitric and nitrous oxide as well as ammonia were formed. Depending on growth conditions the generation times varied from 12 to 140 h. The new Nitrobacter spec. may be one of the most abundant nitrite-oxidizing bacteria in soils, fresh waters and natural as well as artificial stones. For this organism the name Nitrobacter vulgaris is proposed.The type strain is filed with the culture collection of the Institut für Allgemeine Botanik, Universität Hamburg, FRG.  相似文献   
99.
An apparatus was developed which permits the automated deliveryof volatile chemical stimuli for use in neurophysiology experiments.A computer-controlled olfactometer, incorporating electronicmass flow controllers (EMFCs) and Teflon-lined solenoid valves,generated and delivered clean or odorized air. Neural and respiratorysignals from the animal were amplified and stored, along withtrial information (e.g. odorant concentration) on a chart recorderand video cassette recorder, both of which were controlled bythe computer. This apparatus was used to measure responses totoluene from the rat ethmoid nerve, a part of the ophthalmicdivision of the trigeminal nerve. Multi-unit responses to thiscompound were first observed at 2000 p.p.m. The magnitude ofthe response increased linearly with logarithmic increases inconcentration up to vapour saturation. Changes in respirationin response to toluene also were observed, although neural responsesoften were seen in the absence of respiratory changes.  相似文献   
100.
This article applied distributed artificial intelligence to the real-time planning and control of flexible manufacturing systems (FMS) consisting of asynchronous manufacturing cells. A knowledge-based approach is used to determine the course of action, resource sharing, and processor assignments. Within each cell there is an embedded automatic planning system that executes dynamic scheduling and supervises manufacturing operations. Because of the decentralized control, real-time task assignments are carried out by a negotiation process among cell hosts. The negotiation process is modeled by augmented Petri nets —the combination of production rules and Petri nets—and is excuted by a distributed, rule-based algorithm.  相似文献   
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