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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 81 (1959), S. 2214-2219 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 34 (1987), S. 136-141 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Resume Afin de déterminer le rôle de l'expérience sociale précoce sur l'ontogenèse de la reconnaissance des cocons par une espèce esclave de fourmi, des expériences de laboratoire ont été réalisées surFormica cunicularia, une espèce communément esclave deFormica sanguinea. Dans un test de choix, des ouvrières adultes deF. cunicularia provenant d'une colonie pure soignèrent uniquement des cocons homospécifiques, tandis qu'elles détruisirent les cocons hétérospécifiques, non familiers (F. sanguinea etF. lugubris). Après quoi, 3 groupes de colonies artificielles ont été constitués avec de jeunes ouvrières deF. cunicularia de même âge, retirées expérimentalement de leurs cocons. Après une période d'entraînement de quinze jours avec des cocons homospécifiques (groupe C), des cocons deF. sanguinea (groupe T), on en l'absence de tout cocon (groupe I), ces ouvrières furent soumises à un test de choix entre des cocons deF. cunicularia et deF. sanguinea. Le choix des ouvrières des groupes C et T fut toujours en faveur des cocons auxquels elles avaient été familiarisées au cours de la période d'entraînement. En outre, la privation des cocons rompit la discrimination des cocons et l'aptitude aux soins des fourmis du groupe I. Sur la base de ces données et de celles que nous avons obtenues récemment sur la reconnaissance des partenaires du nid chez la même espèce, nous pouvons soutenir que l'expérience sociale suivant immédiatement l'éclosion chez l'ouvrière deF. cunicularia peut expliquer son esclavage dans la nature et, par conséquent, l'altruisme interspécifique de cet hôte à l'égard de son parasite.
    Notes: Summary In order to determine the role of early social experience on the ontogeny of cocoon recognition by a slave-ant species, laboratory experiments were carried out inFormica cunicularia, a common slave ofFormica sanguinea. In a choice-test, adultF. cunicularia workers coming from a pure colony tended only the homospecific cocoons, whereas destroyed the heterospecific unfamiliar ones (F. sanguinea andF. lugubris). Subsequently, 3 groups of artificial colonies were set up with callowF. cunicularia workers of the same age experimentally removed from their cocoons. After a 15-day training period with homospecific cocoons (group C),F. sanguinea cocoons (group T), or in absence of any cocoons (group I), these workers were given a choice-test betweenF. cunicularia andF. sanguinea cocoons. The choice of the workers belonging to groups C and T was always directed towards the cocoons with which workers had become familiar during the training period. Moreover, early deprivation of cocoons disrupted the cocoon discrimination and care ability of ants belonging to group I. On the basis of these data and those recently obtained by us on nestmate recognition in the same species, we can assume that social experience immediately following eclosion ofF. cunicularia workers can fully explain their enslavement in nature and, therefore, the interspecific altruism of this host species towards the parasite.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 45 (1998), S. 85-96 
    ISSN: 1420-9098
    Keywords: Key words: Chemical communication, Dufour's gland, recruitment, trail following, Messor capitatus.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: Some aspects of the chemical communication system employed by the harvesting ant Messor capitatus during foraging were investigated in the laboratory. After locating a conspicuous food item the scouts return home dragging their gaster on the ground. Once inside the nest they run among nestmates and perform an excited motor display. Soon after, groups of workers rush out and move towards the food. Bioassays of different gland extracts showed that nestmates are activated and induced to leave the nest by substances from Dufour's gland. This gland was also found to be the source of the orientation-recruitment trails by which foragers reach newly discovered food sources. The bioassays showed that poison gland extracts are also active in inducing trail following. However, this response was accompanied by typical aggressive reactions by tested ants, suggesting that the poison gland is involved in alarm communication and recruitment towards a source of danger rather than in foraging activities. Some features of the Dufour's gland trail (such as its durability and lack of colony-specificity) are discussed with regard to the ecological requirements of this species.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 43 (1996), S. 391-400 
    ISSN: 1420-9098
    Keywords: Ants ; brood care ; chemical mimicry ; host choice ; phylogenetic distance ; evolution of slavery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In a laboratory choice-test, free-living ant workers ofFormica cunicularia andF. rufibarbis (subgenusServiformica), both potentially slave species of the obligatory slave-makerPolyergus rufescens, cared for cocoons of this parasite and for homocolonial cocoons at comparable rates. Both potential hosts did not differ in their capacity to rear the parasite brood. This fact is discussed in relation to host selection and specificity inP. rufescens. No such attraction and/or tolerance was found towards cocoons of the facultative slave-makerFormica sanguinea, which also enslaves both host species. Workers ofF. lugubris, a species which is never enslaved, destroyed cocoons from both slave-making species. The attractiveness of the brood ofP. rufescens for both potentially slave species could be due to an interspecific brood pheromone in addition to brood mimicry. An alternative hypothesis is a close phylogenetic distance between this slave-maker andServiformica species. The capacity to gain acceptance by adult slave workers might be one of the crucial evolutionary steps separating obligatory from facultative slave-making ants.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1420-9098
    Keywords: Ants ; slavery ; colony foundation ; Polyergus rufescens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The socially parasitic mode of founding new colonies by queens of the European amazon antPolyergus rufescens was analysed in the laboratory. Newly-mated females of this obligatory slave-maker were individually introduced into queenright and queenless artificially established colonies of bothFormica cunicularia (the slave present in the natal dulotic nest) andF. rufibarbis (another potentialServiformica host). Particular attention was devoted to the behavioural patterns displayed by these young queens during the usurpation phases. Our observations, supported also by video-taping, show that the slave-making female, before laying her eggs, must penetrate the host colony, kill the resident queen, become accepted by the adult workers and appropriate the host brood. The parasite was almost always adopted in the colonies ofF. cunicularia, whereas in the presence ofF. rufibarbis it was generally killed in a short time. The failure in the attempt of usurping the colonies ofF. rufibarbis is discussed in relation to the host specificity typical of this slave-maker. Finally, egg-laying byPolyergus successful usurpers, the subsequent eclosion of the brood, and its complete social integration in the newly-established mixed colonies were also recorded.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1420-9098
    Keywords: Ants ; obligatory slave-marker ; Polyergus rufescens ; slave raids ; intraspecific dulosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Four intraspecific slave raids involving 3 colonies of the European amazon antPolyergus rufescens Latr. occurred during hot and sunny afternoons in July 1992 near Parma, Italy. Generally, no fighting between the resident ants and the invaders was recorded, and pillage of the brood lasted just a few minutes. The brood captured during 3 raids was collected and transported ot the laboratory where slavemaker callow workers eclosed and were accepted by both the raiders and hosts present in artificial mixed colonies. This is the first case of functional intraspecific slavery recorded in the field for the obligatory dulotic formicine antP. rufescens.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 47 (2000), S. 7-10 
    ISSN: 1420-9098
    Keywords: Key words: Ants, Polyergus rufescens, colony usurpation, Dufour's gland, appeasement allomone.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary: In the European slave-making ant Polyergus rufescens, the occurrence of chemical strategies during the initial phase of dependent colony foundation or usurpation was investigated. To test this idea, we analysed the effect of the secretion of different glands (Dufour's, poison, pygidial, rectal, and mandibular) on the behaviour of workers of its common host species, Formica cunicularia (subgenus Serviformica). Workers of another species, Formica rufibarbis (Serviformica), were daubed with these extracts, and introduced into colony fragments of F. cunicularia. The results of a set of laboratory aggression test showed that the secretion of the mandibular, pygidial, rectal, and poison glands do not alter the characteristic aggressive reactions generally performed by resident workers against alien ants. By contrast, the Dufour's gland seems to play a crucial role in the appeasement of residents of the target host colony. In fact, its secretion drastically lowers the degree of overt attacks shown by F. cunicularia workers against the intruders. This chemical strategy probably allows an easier invasion and usurpation of host colonies by newly mated females of P. rufescens.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 882-885 
    ISSN: 1420-9071
    Keywords: Flavonoids ; DNA polymerase ; RNA polymerase ; inhibitory effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Flavonoids, (−)-epigallocatechin (1), myricetin (2) and quercetin (3), were investigated for inhibitory effects onE. coli DNA polymerase I and T7 bacteriophage RNA polymerase. In both DNA and RNA synthesis,1 and3 inhibited enzyme reactions by non-competitive and mixed type inhibition respecitively, with regard to template DNAs. Myricetin (2) inhibited DNA and RNA polymerase reactions by mixed type and competitive type inhibition, respectively, with template DNAs. It was suggested that2 interacts with covalently closed/circular DNA.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0509
    Keywords: Key words: Liver—Biliary—Calculi—Magnetic resonance imaging.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a case of intrahepatic biliary calculi. A localized dilated intrahepatic duct of the left lateral segment of the liver was filled with material that showed marked hyperintensity on T1- and T2-weighted magnetic resonance (MR) images. These MR findings are unusual for intrahepatic stones. Pathologically, the stones were muddy bilirubin calculi, the chemical and physical characteristics of which are surmised to have been the cause of the unusual MR findings.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-0509
    Keywords: Key words: Spleen—Hematopoiesis—Magnetic resonance imaging.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a case with focal mass–like lesion of the spleen in polycythemia vera. Magnetic resonance imaging of the lesion showed homogeneous hyperintensity on T2-weighted images, with progressive enhancement on dynamic magnetic resonance images after bolus injection of gadolinium. The magnetic resonance features of focal splenic extramedullary hematopoiesis have not been previously reported.
    Type of Medium: Electronic Resource
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