The uropathogenic Escherichia coli strain 536 carries at least five genetic elements on its chromosome that meet all criteria characteristic of pathogenicity islands (PAIs). One main feature of these distinct DNA regions is their instability. We applied the so-called island-probing approach and individually labeled all five PAIs of E. coli 536 with the counterselectable marker sacB to evaluate the frequency of PAI-negative colonies under the influence of different environmental conditions. Furthermore, we investigated the boundaries of these PAIs. According to our experiments, PAI II 536 and PAI III 536 were the most unstable islands followed by PAI I 536 and PAI V 536 , whereas PAI IV 536 was stable. In addition, we found that deletion of PAI II 536 and PAI III 536 was induced by several environmental stimuli. Whereas excision of PAI I 536 , PAI II 536 , and PAI V 536 was based on site-specific recombination between short direct repeat sequences at their boundaries, PAI III 536 was deleted either by site-specific recombination or by homologous recombination between two IS100-specific sequences. In all cases, deletion is thought to lead to the formation of nonreplicative circular intermediates. Such extrachromosomal derivatives of PAI II 536 and PAI III 536 were detected by a specific PCR assay. Our data indicate that the genome content of uropathogenic E. coli can be modulated by deletion of PAIs.

Age differences in social cognition between adolescents and young adults were investigated. Two large groups of adolescents and young adults were given tasks of theory of mind and emotion recognition. In addition, to control for possibly related basic cognitive development, working memory, speed of processing, and verbal ability were assessed. A strong age effect was revealed across both measures of social cognition. Adolescents performed with a lower accuracy than adults. Further analyses indicated that those age differences remained significant even after controlling for basic cognitive abilities. Exploratory analyses indicated no influence of pubertal phase on social cognition. Results suggest ongoing development of social cognition across adolescence, independent of individual differences in more basic cognitive abilities.

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. We examine behavioral gender differences and gender pairing effects in a laboratory experiment with face-to-face alternating-offers wage bargaining. Our results suggest that male players are able to obtain better bargaining outcomes than female players. Male employees get higher wages than female employees. Male employers pay lower wages to female employees than female employers pay to male employees. Moreover, we find gender differences in the first offers of the bargaining game. Terms of use: Documents in EconStor mayJEL-Code: C720, C910, J160.

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Social dilemmas are characterized by conflicts between immediate self-interest and long-term collective goals. Although such conflicts lie at the heart of various challenging social interactions, we know little about how cooperation in these situations develops. To extend work on social dilemmas to child and adolescent samples, we developed an ageappropriate computer task (the Pizzagame) with the structural features of a public goods game (PGG). We administered the Pizzagame to a sample of 191 children 9 to 16 years of age. Subjects were led to believe they were playing the game over the Internet with three sets of two same-aged, same-sex coplayers. In fact, the co-players were computer-generated and programmed to expose children to three consecutive conditions: (1) a cooperative strategy, (2) a selfish strategy, and (3) divergent cooperative-selfish strategies. Supporting the validity of the Pizzagame, our results revealed that children and adolescents displayed conditional cooperation, such that their contributions rose with the increasing cooperativeness of their co-players. Age and gender did not influence children and adolescents' cooperative behavior within each condition.However, older children adapted their behavior more flexibly between conditions to parallel the strategies of their coplayers. These results support the utility of the Pizzagame as a feasible, reliable, and valid instrument for assessing and quantifying child and adolescent cooperative behavior. Moreover, these findings extend previous work showing that age influences cooperative behavior in the PGG.