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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 31 (1984), S. 254-263 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Dass Einsetzen fremder Bienenköniginnen (Apis mellifera) in Beobachtungskolonien mit individuell markierten Arbeiterinnen ergab drei voneinander verschiedene, gleichzeitig auftretende Wirkungen. 1) Vollkommene Passivität; 2) nicht aggressives; und 3) aggressives Knäueverhalten. Knäueln dauerte 9,2 Std. (N=12) und wurde von etwa 15–20% der Populationen in den Kolonien ausgeführt. Die Beteiligung am Knäueln war altersabhängig, 91,2% der Arbeiterinnen mit Knäuelverhalten waren 12 Tage alt oder älter. Lediglich ein kleiner Anteil (0,5–2%) der Arbeiterinnen in den Kolonien verhielten sich aggresiv, während die restlichen nicht-aggressives Knäuelverhalten zeigten. Aggressive Arbeiterinnen verbrachten signifikant mehr zeit beim Knäulen als nicht-aggressive Arbeiterinnen, jedoch war kein Unterschied im Alter der zwei Untergruppen sichtbar. Fremde Königinnen wurden nicht unmittelbar nach dem Einsetzen getötet und wurden während der Dauer des Knäuelverhaltens nicht fortwährend angegriffen. Knäuelnde Arbeiterrinen begannen sich allmählich an einige fremde Königinnen 3–5 Std. nach dem Einsetzen zu gewöhnen. Die Stärke der Arbeiter-Aggressivität sank ständig, während die Aktivität der Königen zunahm. Des Beobachtungen des Königinnenverhaltens während dem Knäulen stützen nicht die “Stress Pheromon Hypothese” (Yadava undSmith, 1971).
    Notes: Summary Introductions of foreign queen honey bees (Apis mellifera) to observation colonies containing individually marked workers resulted in three distinct, simultaneously occurring responses: 1) complete passivity; 2) nonaggressive balling behavior; and 3) aggressive balling behavior. Balling persisted for 9.2 h (N=12) and involved approximately 15–20% of the colonies' populations. Participation in a ball was age-dependent, with 91.2% of the balling workers 12 days old or older. Only a small fraction (0.5–2%) of the colonies' workers behaved aggressively, while the remainder displayed nonaggressive balling behavior. Aggressive workers spent significantly more time in a ball than did nonaggressive workers, but there was no difference in age between the two subgroups. Foreign queens were not killed immediately upon introduction and were not continuously attacked throughout the balling period. Balling workers gradually became conditioned to some foreign queens beginning 3–5 h after introduction; the incidence of worker aggression steaily decreased while queen activity increased. Observations of queen behavior during balling do not support the “stress pheromone hypothesis” (Yadava andSmith, 1971).
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    BJOG 100 (1993), S. 0 
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective To study the fibrinolytic pathways and their relationship with the contact system in women using combined oral contraceptives (COCs).Design Serial plasma samples were collected from 18 women before treatment with COCs containing 30 μg oestrogen during treatment cycles 3 and 6, and 2 weeks after stopping treatment. Fibrinolysis was measured before and after dextran sulphate mediated contact activation using fibrin plates.Results Fibrinolysis increased significantly during cycles 3 and 6 (from 77% to 100% and 113%, respectively, P〈0.01) and showed a further increase after dextran sulphate activation (from 134% to 158% and 167%, respectively, P〈0.01). Tissue-plasminogen activator, urokinase-plasminogen activator and plasminogen activator inhibitor did not change significantly. There were significant elevations of Factor XII (from 0.92 μ/ml to 1.43 u/ml, P〈0.01) and prekallikrein (0.94 u/ml to 1.10 u/ml, P〈0.05) in cycle 3, which both remained high at cycle 6 (P〈0.01) and decreased after stopping the COC. Alpha-2-macroglobulin and C1-esterase inhibitor showed no significant change, but alpha-1-antitrypsin increased from 0.85 u/ml to 1.11 u/ml by cycle 3 (P〈0.01), and returned to near normal levels after stopping the COC.Conclusions The increase in fibrinolysis may be due to increased levels of Factor XII and prekallikrein without a corresponding increase in their natural inhibitors (C1-esterase inhibitor and alpha-2-macroglobulin). A parallel increase in the intrinsic pathway of coagulation may be limited by elevated alpha-1-antitrypsin at the level of activated Factor XI. The increase in fibrinolysis caused by oral contraceptives may balance any potential thrombotic risk due to increased fibrinogen or vitamin K dependent coagulation factors.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Psychology 50 (1999), S. 651-682 
    ISSN: 0066-4308
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Psychology
    Notes: Abstract The discipline of neuroethology integrates perspectives from neuroscience, ethology, and evolutionary biology to investigate the mechanisms underlying the behavior of animals performing ecologically relevant tasks. One goal is to determine if common organizational principles are shared between nervous systems in diverse taxa. This chapter selectively reviews the evidence that particular brain regions subserve behaviors that require spatial learning in nature. Recent evidence suggests that the insect brain regions known as the mushroom bodies may function similarly to the avian and mammalian hippocampus. Volume changes in these brain regions during the life of an individual may reflect both developmental and phylogenetic trends. These patterns may reveal important structure-function relationships in the nervous system.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Entomology 37 (1992), S. 637-665 
    ISSN: 0066-4170
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 183 (1998), S. 143-152 
    ISSN: 1432-1351
    Keywords: Key wordsApis mellifera ; Division of labor ; Juvenile hormone ; Behavioral development ; Primer pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Previous studies suggest that older honey bee workers possess an inhibitory signal that regulates behavioral development in younger bees. To study how this inhibitor is transmitted, bees were reared for 7 days in double-screen cages, single-screen cages, or unrestricted in a typical colony (control bees). Double-screen cages prevented physical contact with colony members while single-screen cages allowed only antennation and food exchange. Bees reared in double-screen cages showed accelerated endocrine and behavioral development; they had significantly higher rates of juvenile hormone biosynthesis and juvenile hormone titers than did control bees and also were more likely to become precocious foragers. Relative to the other two groups, bees reared in single-screen cages showed intermediate juvenile hormone biosynthesis rates and titers, and intermediate rates of behavioral development. These results indicate that physical contact is required for total inhibition. We also began to test the hypothesis that worker mandibular glands are the sources of an inhibitory signal. Old bees with mandibular glands removed were significantly less inhibitory towards young bees than were sham-operated and unoperated bees. These results suggest that an inhibitor is produced by the worker mandibular glands.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 184 (1999), S. 471-479 
    ISSN: 1432-1351
    Keywords: Key wordsApis mellifera ; Behavioral development ; Dopamine ; Octopamine ; Serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Brain levels of dopamine, serotonin, and octopamine were measured in relation to both age-related division of labor and inter-individual differences in task specialization independent of age in honey bee colonies. The only differences among similarly aged bees performing different tasks were significantly lower levels of dopamine in food storers than comb builders and significantly lower levels of octopamine in soldiers than foragers, but soldiers also were slightly younger than foragers. Differences associated with age-related division of labor were stronger. Older bees, notably foragers, had significantly higher levels of all three amines than did younger bees working in the hive. Using social manipulations to unlink chronological age and behavioral status, octopamine was found to exhibit the most robust association between behavior and amine level, independent of age. Octopamine levels were significantly lower in normal-age nurses versus precocious foragers and overage nurses versus normal-age foragers, but not different in reverted nurses versus reversion colony foragers. Dopamine levels were significantly lower in normal-age nurses versus precocious foragers, but higher in reverted nurses versus reversion colony foragers. Serotonin levels did not differ in any of these comparisons. These correlative results suggest that octopamine is involved in the regulation of age-related division of labor in honey bees.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 186 (2000), S. 261-268 
    ISSN: 1432-1351
    Keywords: Key words Dominance ; Reproduction ; Biogenic amines ; Bumble bees ; Social insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To begin to explore the role of biogenic amines in reproductive division of labor in social insects, brain levels of dopamine, serotonin, and octopamine were measured in bumble bee (Bombus terrestris) workers and queens that differ in behavioral and reproductive state. Levels of all three amines were similar for mated and virgin queens. Young workers that developed with or without a queen had similar amine levels, but in queenright colonies differences in biogenic amine levels were associated with differences in behavior and reproductive physiology. Dominant workers had significantly higher octopamine levels compared with workers of lower dominance status but of similar size, age, and ovary state. High dopamine levels were associated with the last stages of oocyte development irrespective of worker social status and behavior. These results suggest that biogenic amines are involved in behavioral and physiological aspects of regulation of reproduction in bumble bees.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-1351
    Keywords: Key wordsApis mellifera ; Behavioural development ; Division of labor ; Dopamine ; Serotonin ; Octopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Levels of the biogenic amines dopamine, serotonin, and octopamine were measured in different brain regions of adult worker honey bees as a function of age-related division of labor, using social manipulations to unlink age and behavioral state. In the antennal lobes, foragers had higher levels of all three amines than nurses, regardless of age. Differences were larger for octopamine than serotonin or dopamine. In the mushroom bodies, older bees had higher levels of all three amines than younger bees, regardless of behavioral state. These correlative results suggest that increases in octopamine in the antennal lobes may be particularly important in the control of age-related division of labor in honey bees.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1435-9456
    Keywords: Key words Proboscis extension reflex ; Associative learning ; Social insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied the association between honey bee (Apis mellifera) division of labor and performance on an olfactory reversal-learning test. Manipulations of colony age structure and flight experience were used to test whether differences in performance are associated with age, current behavioral state, or flight experience. Nurse bees showed significantly faster rates of extinction to a learned odor than did foragers. This difference was associated primarily with differences in behavioral state, rather than age; it was seen when comparing nurses and foragers from typical colonies and normal-age nurses and precocious foragers from single-cohort colonies. Differences in extinction rate were not related to differences in flight experience; there was no difference between foragers and foraging-age bees denied flight experience. These results suggest that changes in learning and memory occur in association with division of labor. We speculate on the possible functional significance of the difference in extinction rate between nurses and foragers.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 45 (1989), S. 765-767 
    ISSN: 1420-9071
    Keywords: Social behavior ; honeybee ; division of labor ; behavior genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Recent studies have demonstrated a genotypic component to the division of labor among worker honeybees. However, these studies used artificially-selected strains of bees or colonies derived from queens that were instrumentally inseminated with the semen from very few males. We present evidence for genotypic variability among groups of workers performing tasks in colonies with naturally-mated queens. These results demonstrate that genetic structure is a level of social organization in honeybees.
    Type of Medium: Electronic Resource
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