898 resultados para Social workers.


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This study reviews published data on the behavior and natural history of Chartergellus and presents the first observations on social interactions in this genus of tropical swarm-founding wasps. Observations of Chartergellus golfitensis in Costa Rica and C. punctatior in Colombia showed that queens perform a post-oviposition egg-guarding vigil, and a bending display like that characteristic of epiponine social wasps that lack consistent morphological differences between workers and queens and have caste determination in the adult stage. Young, old, and queen (egg-laying) females of C. golfitensis showed small differences that indicate color changes with age, and structural differences that could be due to seasonal or colony-cycle changes in developmental conditions, but do not rule out the possibility of pre-adult caste determination, a phenomenon that needs to be carefully distinguished from pre-adult caste bias. Sexual dimorphism and the behavior of males at the nest in C. golfitensis is described, as well as the aggressive and avoidance behavior of females toward males. Nest structure in both species is as described previously for Chartergellus species, but some anomalies and their possible evolutionary significance are discussed. Cell initiation by an egg-laying queen, a behavior never seen by workers, and by a young female with slightly developed ovaries, may be vestiges of ancestral solitary reproductive traits where developed ovaries are associated with cell construction. © 2010 Dipartimento di Biologia Evoluzionistica dell'Università, Firenze, Italia.

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Includes bibliography

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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DNA methylation plays an important role in the epigenetic control of developmental and behavioral plasticity, with connections to the generation of striking phenotypic differences between castes (larger, reproductive queens and smaller, non-reproductive workers) in honeybees and ants. Here, we provide the first comparative investigation of caste- and life stage-associated DNA methylation in several species of bees and vespid wasps displaying different levels of social organization. Our results reveal moderate levels of DNA methylation in most bees and wasps, with no clear relationship to the level of sociality. Strikingly, primitively social Polistes dominula paper wasps show unusually high overall DNA methylation and caste-related differences in site-specific methylation. These results suggest DNA methylation may play a role in the regulation of behavioral and physiological differences in primitively social species with more flexible caste differences. © 2013 Springer-Verlag Berlin Heidelberg.

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Pós-graduação em Comunicação - FAAC

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This paper addresses how and why domestic workers in Jamaica are disenfranchised, with particular emphasis on the law’s inability to combat their exploitation in the labour force. My starting point is an online newspaper article entitled “Coping as a Domestic Helper”, which was based on a study investigating the living standard and coping strategies of minimum wage earners. In Jamaica domestic workers fall into three main categories - the residential worker, the non-residential weekly worker and the daily worker. Domestic workers are undervalued and their plight is especially grievous because they are characterized by a number of features that combine to have an exponentially negative effect on their social worth.