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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 31 (1984), S. 403-407 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume La composition des colonies deLeptothorax allardycei (Mann) est étudiée. L'importance numérique du couvain augmente linéairement avec le nombre d'ouvrières dans la colonie. Il n'y a pas de preuve d'un “reproductivity effect” chez cette espèce. Le rendement des colonies reste constant malgré l'augmentation de la population. Les conséquences pour la croissance de la colonie sont brièvement analysées.
    Notes: Summary The composition of colonies ofLeptothorax allardycei (Mann) is examined. The number of total brood increases linearly with the number of workers in the colony. There is no evidence of the reproductivity effect inL. allardycei. The relative efficiency of colonies remains constant with increases in colony size. The implications for colony size are briefly discussed.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 41 (1994), S. 401-410 
    ISSN: 1420-9098
    Keywords: Nest structure ; temperature ; brood movement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The structure and thermal environment produced by the nest cones of the western harvester ant,Pogonomyrmex occidentalis, are investigated. The nest cone is oriented so that the longest slope faces towards the southeast ad the nest entrance faces the southeast. The temperature of the soil was monitored at thirty-six locations within the nest in order to measure the daily temperature change as a function of depth, aspect and radial distance from the center of peak of the cone. The occupancy of the nest cone by workers and by brood was assessed by core samples taken at different times of day in different portions of the cone. The brood are only present during the midmorning sample and are present in greatest numbers on the eastern side of the cone. The adult workers are present in the cone in highest numbers during the midmorning, virtually absent from the cone during mid-afternoon and returning in smaller numbers at dusk, apparently spending the night near the surface on the eastern side of the mound. The eastern and southern portions of the cone are occupied most frequently while the western side of the cone is nearly vacant. The nest cone is an adaptation which magnifies the amplitude of daily temperature fluctation. By moving to appropriate areas of the nest cone, the ants can take advantage of the increased range of temperature.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 35 (1988), S. 198-205 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume On étudie le modèle spatial de l'escalade de l'agression chez la FourmiLeptothorax allardycei. 973 interactions agressives furent observées, puis classées en fonction du niveau d'agression et en rapport avec les types de couvain présent. L'agression est plus probable en présence du couvain qu'en l'absence de celui-ci, et une escalade de l'agression se montre encore plus probable en présence des œufs. Un schéma présente l'enchaînement des décisions impliquées dans le commencement de l'agression et dans son escalade consécutive.
    Notes: Summary The spatial pattern of escalated aggression is examined in the antLeptothorax allardycei. A total of 973 aggressive interactions were observed, categorized according to the level of aggression achieved and the type of nearby brood. Aggression is more likely to occur in the presence of brood, and escalated aggression is most likely to occur in the presence of the eggs. A model for the decision involved in the initiation of aggression and its subsequent escalation is presented.
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  • 4
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume La convergence évolutive deZacryptocerus varians et deCamponotus (Colobopsis) sp. est manifeste dans trois domaines: 1-une convergence de structures (ouvrières major dont la tête est structurée pour la défense; grands œufs); 2-une convergence de structure comportementale (taux élevé de trophallaxies orales; échanges de boulettes infra-buccales); 3-une convergence de répertoire comportemental (nombre d'items comportementaux en commun; distance comportementale). Les méthodes d'analyse de convergence du répertoire comportemental, qui utilisent des techniques dérivées de la taxonomie numérique, peuvent être particulièrement utiles pour obtenir des mesures quantitatives des effets relatifs de la phylogenèse et de l'écologie dans le comportement social des insectes. Par contraste avec la convergence comportementale des ouvrières minor, les ouvrières major ne présentent pas cette convergence. Les ouvrières major deColobopsis n'ont pas un comportement aussi spécialisé que les ouvrières major deZ. varians et sont relativement plus nombreuses, conformément à la théorie ergonomique habituelle. Nous nous sommes efforcés de rendre compte des convergences et divergences dans les aspects de la sociobiologie des deux espèces.
    Notes: Summary The convergence ofZacryptocerus varians andCamponotus (Colobopsis) sp. is manifest in three ways: i) Structural convergence (shield-headed major workers, large eggs), ii) Qualitative behavioral convergence (high rate of oral trophallaxis, traffic in infrabuccal pellets, iii) Repertoire convergence (number of behavioral categories in common, behavioral distance). Methods of analyzing repertoire convergence using techniques borrowed from numerical taxonomy may be especially useful in obtaining quantitative measurements of the relative effects of phylogeny and ecology in social insect behavior. In constrast to the behavioral convergence of the minor workers, the major workers do not show this convergence. The major workers ofColobopsis are not as behaviorally specialized as the major workers ofZ. varians and in accordance with current ergonomic theory are relatively more numerous. An effort is made to account for the areas of convergence and divergence in features of their sociobiology.
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  • 5
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
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  • 6
    ISSN: 1432-2072
    Keywords: NBQX ; GYKI 52466 ; MK 801 ; DRL responding ; Delayed matching ; AMPA antagonists ; Glutamate receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of NBQX (1.56–7.5 mg/kg, IP), a competitive antagonist at the AMPA type of glutamate receptor, were studied in two operant behavioural paradigms, differential reinforcement of low response rates (DRL), and delayed matching to position (DMTP), which have been shown to be sensitive to the antagonists of the NMDA type of glutamate receptor. Additionally, the non-competitive AMPA antagonist, GYKI 52466 (7.5–15 mg/kg, IP), was studied in the DRL procedure. As a positive control, the non-competitive NMDA antagonist, MK 801 (0.0125–0.1 mg/kg, IP) was studied in both procedures. During performance of the DRL schedule, MK 801 increased response rates in a dose dependent manner, and decreased the number of reinforcers obtained. The increase in response rates could be attributed to both a shift in the median inter-response time (IRT) to shorter intervals, and to a marked, dose dependent increase in the occurrence of bursts of responses (responses occurring within 3 s of a previous response). In contrast, NBQX and GYKI 52466 both decreased response rates in a dose dependent fashion, and did not shift the distribution of the IRTs, or increase the occurrence of burst responding. In the DMTP procedure, accuracy of matching decreased with increasing delay (up to 30 s, between presentation of sample and opportunity to respond). NBQX disrupted responding at a dose of 7.5 mg/kg, but lower doses were ineffective in influencing accuracy of performance of the discrimination. In contrast, MK 801 (0.1 and 0.2 mg/kg) reduced accuracy of matching at all delays, while tending to increase the speed of responding. These data demonstrate differences in the effects of AMPA and NMDA antagonists on performance of well trained operant behaviour.
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  • 7
    ISSN: 1432-2161
    Keywords: Key words Malignant fibrous histiocytoma ; Carcinogenesis ; Osteolysis ; Latency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Tumors developing in association with metallic implants are being reported with increasing frequency in the orthopedic literature. The authors report the tenth case of malignant fibrous histiocytoma associated with a total hip replacement. The diagnosis was made during an evaluation for rapid radiographic osteolysis surrounding the femoral component detected less than 1 year after revision of a hemiarthroplasty to a total hip replacement. The short latency period and aggressiveness of this tumor mimicking rapid osteolysis prompted a review of the literature, etiology and significance of implant-associated malignant fibrous histiocytoma.
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  • 8
    ISSN: 1432-2072
    Keywords: Delayed matching to position ; Competitive NMDA antagonist ; Non-competitive NMDA antagonist ; Short term memory ; MK 801 ; CPP ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of the competitive NMDA antagonist CPP and the non-competitive NMDA antagonist MK 801 (dizolcipine) on short term working memory in the rat were investigated. The behavioural paradigm used was discrete trial, operant delayed matching to position, as originally described by Dunnett (1985), with delays of 0, 5, 15 and 30 s. These delays generated an orderly “forgetting” curve in control rats, with matching accuracy decreasing from approximately 100% at 0-s delay to approximately 75% at 30-s delay. Intraperitoneal (IP) administration of CPP (10 mg/kg) produced a markeddelay dependent impairment in performance, suggesting a specific effect on short term working memory. This effect was accompanied by a minor decrease in the speed of responding, and a slight increase in the number of missed trials. Lower doses of CPP had no significant effects on either matching accuracy or sedation. In contrast, IP administration of MK 801 (0.1 and 0.2 mg/kg) caused a markeddelay independent impairment in the accuracy of delayed matching performance, suggesting a non-specific disruption of performance. A lower dose (0.05 mg/kg) of MK 801 had no significant effect on matching accuracy. The two lower doses of MK 801 increased the number of nose pokes made during the delays and tended to increase the speed of responding, suggesting a stimulant-like action. The highest dose of MK 801 had the opposite effects and also decreased the number of trials completed. The results with CPP therefore support the hypothesized role of NMDA receptors in learning and memory, and the contrasting effects of these two NMDA antagonists support previous suggestions of different behavioural effects resulting from administration of competitive and non-competitive NMDA antagonists.
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  • 9
    ISSN: 1432-2072
    Keywords: d-Amphetamine ; Attention ; Discrimination ; Dopamine-Noradrenaline interaction ; Dorsal noradrenergic bundle ; alpha-Flupenthixol ; Nucleus accumbens ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A series of experiments examined the effects of lesions of the dorsal noradrenergic bundle (DNAB), induced by 6-hydroxydopamine (6-OHDA), on the behavioural response to systemic and intra-accumbens amphetamine, using a rat analogue of Leonard's 5-choice serial reaction time task for humans. Although the 6-OHDA DNAB lesion produced a profound depletion of cortical noradrenaline (NA) (to around 5% of control levels) it did not impair any aspect of performance on this task. Both systemic and intra-accumbens amphetamine increased behavioural measures of impulsivity of responding, but neither impaired discriminative accuracy in the sham-operated control rats. However, the DNAB lesioned rats did show a discriminative impairment following both low doses of systemic amphetamine, and intra-accumbens amphetamine. The latter effect was antagonised by systemic administration of the specific dopaminergic (DA) antagonist alpha-flupenthixol. The DNAB lesion did not alter the effect of amphetamine on any other behavioural measure, including speed and impulsivity of responding. These results suggest that although DA and NA participate in qualitatively different behavioural processes, the effects of DNAB lesions on attentional processes depend on the level of DA activity within the nucleus accumbens.
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  • 10
    ISSN: 1432-0762
    Keywords: Key words Inbreeding ; Ants ; Population structure ; Sampling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper we have two goals. First, we examine the effects of sample size on the statistical power to detect a given amount of inbreeding in social insect populations. The statistical power to detect a given level of inbreeding is largely a function of the number of colonies sampled. We explore two sampling schemes, one in which a single individual per colony is sampled for different sample sizes and a second sampling scheme in which constant sampling effort is maintained (the product of the number of colonies and the number of workers per colony is constant). We find that adding additional workers to a sample from a colony makes it easier to detect inbreeding in samples from given number of colonies; however, adding more colonies rather than more workers per colony always gives greater power to detect inbreeding. Because even relatively large amounts of sib-mating generate relatively small inbreeding coefficients, detection of even substantial deviations from random mating will require very large samples. Second, we look at the amount of inbreeding in a large population of the western harvest ant, Pogonomyrmex occidentalis. We find deviations from Hardy-Weinberg equilibrium equivalent to approximately 27% sib-mating in our population ( f = 0.09). Review of past studies on the population structure of other Pogonomyrmex species suggests that inbreeding may be a regular feature of the mating system of these ants. Although P. occidentalisis a swarm-mating species, there are a number of features of its population biology which suggest that the effective population size may be small. These include topographical variation that potentially breaks the population into demes, variation in the reproductive output of colonies, and variation in the size of reproductives produced by colonies.
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