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  • 1
    ISSN: 1420-9098
    Keywords: Lasioglossum malachurum ; sweat bee ; Dufour's gland volatiles ; ontogenetic patterns of odorous compounds ; pheromones ; mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ontogenetic patterns of volatile compounds identified in Dufour's gland extracts from queens and workers of the primitively eusocial sweat beeLasioglossum malachurum (K.) were compared. Only young unmated queens showed high proportions of isopentenyl esters, while macrocyclic lactones were dominant in old breeding queens, spring queens, and workers. In young queens the relative and absolute amounts of volatiles changed one day after mating. A discriminant analysis revealed significant differences in odor patterns of unmated and mated young queens. The fat body was the largest in young females, while eggs could be recorded only in breeding queens. Possible functions of different odor components in the investigated female groups are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 45 (1998), S. 473-476 
    ISSN: 1420-9098
    Keywords: Key words: Africanized honey bee, worker reproduction, vitellogenin, fertility, worker-derived drones, population dynamics.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: The remarkable spread of Africanized honey bees over large areas of South and North America has been attributed mainly to the high fertility of their queens and drones. However, workers of Africanized honey bees, within a few days under queenless conditions, are likewise capable of attaining an enhanced status of fertility. We demonstrate this at the physiological level by measuring their high rate of vitellogenin production with a molecular assay. The probable impact of the resulting production of large numbers of worker-derived drones on the population dynamics and spread of intruding Africanized honey bees has been neglected in previous discussions.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1420-908X
    Keywords: Key words: Rat — Mast cell degranulation — Heart — Ischemia — Reperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. In the present study, the possible role of mast cells in ischemia/reperfusion-induced myocardial injury was evaluated in the isolated 'mast cell depleted' rat heart. Hearts isolated from sensitized and non-sensitized rats were perfused according to Langendorff. After 30 min of normoxic perfusion, hearts were challenged with antigen, a procedure which is known to result in a massive mast cell degranulation in sensitized hearts. After another 20 min, both 'mast cell depleted' and control hearts were subjected to 30 min of ischemia followed by 30 min of reperfusion. The release of lactate dehydrogenase (LDH) was determined to quantitate the extent of irreversible injury of cardiomyocytes. Histamine release was measured to establish mast cell degranulation. Coronary flow (CF) and left ventricular developed pressure (LVDP) were monitored to study the consequences of the procedures on hemodynamic recovery. It was found that both CF and LVDP sign ificantly increased during the first min after antigen challenge. These changes were accompanied by an almost complete degranulation of cardiac mast cells. The increase in CF and LVDP values were rapidly followed by a decrease, reaching minimal values of 159 ± 4% and 85 ± 4% of those before administration of antigen, respectively, at 2–3 min after antigen challenge. No effect of antigen challenge on LDH release were found indicating that mast cell degranulation did not compromise myocyte integrity. During reperfusion following 30 min of ischemia both the increase in CF and LVDP in 'mast cell-depleted' hearts were not significantly different from those in control (non-sensitized) hearts. Similarly, at the end of the reperfusion-phase, CF and LVDP values in sensitized hearts were comparable to those in control hearts. Reperfusion results in increased LDH release, which at no point in time was significantly different between sensitized and non-sensitized hearts. In non-sensitized hearts histamine release during the reperfusion phase was not detectable. Therefore, the results indicate that in the isolated rat heart, mast cells are most likely not involved in acute ischemia/reperfusion-induced myocardial injury.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 24 (1977), S. 264-265 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 36 (1989), S. 1-14 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die ausgewogene Zusammensetzung des Larvenfutters wird allgemein als ein wichtiger Faktor in der Kastenbildung der Honigbiene angesehen. Ob dies für Stachellose Bienen in ähnlicher Weise gilt, war eine offene Frage. Wir analysierten die wasserlöslichen Hauptkomponenten im Larvenfutter von 7 Meliponinen-Arten. Die Ergebnisse wurden herangezogen, um die Hypothese zu überprüfen, daß eine ausgewogene Zusammensetzung des Larvenfutters der Selektion unterliegt. Dazu wurden chemosystematische Bäume berechnet und mit einem bereits publizierten, strukturell-morphologisch begründeten Stammbaum verglichen. Ein beträchtlicher Grad an Kongruenz zwischen den chemosystematischen Bäumen für die allgemeine Zusammensetzung des Larvenfutters und dem Stammbaum erlaubte es, die Zusammensetzung des Larvenfutters hoch-eusozialer Bienen in Bezug auf die funktionalen Aspekte der Larvenernährung zu diskutieren.
    Notes: Summary Nutritional balance of larval food supposedly plays an important role in honey bee caste formation. Whether this is similar in stingless bees was an open question. We analysed the major water-soluble constituents in the larval food of 7 species of meliponids. The data were used to evaluate the hypothesis that a balanced composition of larval food is shaped by selection. Chemosystematic trees were calculated and compared to a published phylogenetic tree based on morphological characters. A considerable degree of congruence between the chemosystematic trees for the general composition of larval food and the phylogenetic tree allowed us to discuss the composition of larval food in highly eusocial bees in relation to functional aspects of larval nutrition.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1420-908X
    Keywords: Key words: Mast cell — Histamine — Fatty acids — Rat — Diet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: In the present study we determined the extent to which the degranulation process in mast cells was related to the fatty acid composition of membrane phospholipids.¶Material: Peritoneal mast cells were isolated from Wistar rats (3 groups of 18 animals each), fed for 6 weeks diets which differed in their fatty acid compositions: (i) genuine salmon oil, abundant in (n-3) fatty acids, (ii) sunflowerseed oil, rich in (n-6) fatty acids, particularly linoleic acid, and (iii) hydrogenated coconut oil, rich in saturated fatty acids.¶Methods: Mast cells (106/ml) were stimulated with various concentrations of the mast cell-degranulating agent, compound 48/80 (0.1–10 〈mu〉g/ml). The extent of mast cell degranulation was quantified by determination of histamine in the supernatants using HPLC techniques.¶Results: No differences in compound 48/80-induced histamine release between the three dietary groups for any of the concentrations of compound 48/80 tested were found. Analysis of variance followed by Tukey's method for multiple comparisons was used to evaluate the effect of changes in the dietary fat type.¶Conclusion: These findings strongly suggest that in contrast to the formation of eicosanoids, the process of mast cell degranulation by a receptor-independent pathway is not controlled by the fatty acid composition of membrane phospholipids.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1420-9098
    Keywords: Caste polymorphism ; morphometry ; allometry ; discriminant analysis ; stingless bees
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Morphometric data obtained from natural andin vitro-rared queens, workers, and drones of the stingless bee.Scaptotrigona postica were subjected to allometric and multivariate tests to study sex- and caste-related growth patterns. As imaginai phenotype variation appears to be restricted in members of a normal colony, the inclusion ofin vitro-reared individuals permitted an analysis of a considerably wider size range for each morph, and proved important for the calculation of reliable regression statistics in the allometric analyses. Our results show that essentially no individuals with a mixture or transition of sex or caste traits are produced, and, consequently, that for most morphometric characters, queens, workers, and drones lie on different regression lines. Hence, workers cannot be considered as masculinized females, as has been suggested in studies based exclusively on multivariate analyses. Instead, the various morphs may result from a stepwise programming and reprogramming of a few growth rule parameters during critical stages of preimaginal development, and complex hypothetical shifts in the balance of maleness and femaleness genes need not be assumed. A multivariate discriminant analysis, on the other hand, proved to be an efficient tool for the selection of diagnostic size characters.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 51 (1995), S. 945-952 
    ISSN: 1420-9071
    Keywords: Juvenile hormone synthesis ; honey bee drones ; pupal stages ; imaginal development ; Apis mellifera carnica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Juvenile hormone synthesis was measured by the corpora allata radiochemical assay in vitro. No hormone was produced during pupal stages, but soon after adult eclosion the corpora allata were reactived. The rate of juvenile hormone III synthesis increased until day 10 after emergence. Possible functions of juvenile hormone in adult drones are discussed.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 174 (1974), S. 285-296 
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Nur in den ersten Tagen nach dem Schlüpfen stimmen die TiterÄnderungen der Haemolymph-Proteine bei den Imagines aller Kasten der Honigbiene weitgehend überein. Später überwiegen kastenspezifische Besonderheiten. Die Ontogenese der Titer-Schwankungen aller Protein-Fraktionen der Haemolymphe wird für Königinnen, Arbeiterinnen und Drohnen dargestellt. Bei adulten Königinnen und ebenso bei eierlegenden Arbeiterinnen dominieren die Dotterproteine. Bei normalen Arbeiterinnen erscheint Dottermaterial nur vorübergehend während der Ammen-Phase im Spektrum, das im übrigen die stärksten Veränderungen aufweist. Abgrenzbare Perioden in der Entwicklung der Haemolymph-Spektren stimmen mit bekannten altersabhängigen Verhaltensmustern gut überein. Ihre soziale Regulation wird diskutiert.
    Notes: Summary It is only during the first days after hatching that similarities are found in the titer variations of haemolymph proteins in imagines of all castes of the honeybee. Later on caste-specific features occur. The ontogenesis of titer variations of all protein fractions is described for queens, workers, and drones. In the case of adult queens and egg-laying workers as well vitellogenin is predominant. In normal workers vitellogenic material is only present during the nurse phase. Generally the haemolymph protein pattern of worker bees shows the largest titer changes. Defined periods in the development of haemolymph protein patterns coincide with known age-dependent successions of behavioral activities. Their social regulation is discussed.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Type of Medium: Electronic Resource
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