816 resultados para physogastric queens


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract In species with social hierarchies, the death of dominant individuals typically upheaves the social hierarchy and provides an opportunity for subordinate individuals to become reproductives. Such a phenomenon occurs in the monogyne form of the fire ant, Solenopsis invicta, where colonies typically contain a single wingless reproductive queen, thousands of workers and hundreds of winged nonreproductive virgin queens. Upon the death of the mother queen, many virgin queens shed their wings and initiate reproductive development instead of departing on a mating flight. Workers progressively execute almost all of them over the following weeks. To identify the molecular changes that occur in virgin queens as they perceive the loss of their mother queen and begin to compete for reproductive dominance, we collected virgin queens before the loss of their mother queen, 6 h after orphaning and 24 h after orphaning. Their RNA was extracted and hybridized against microarrays to examine the expression levels of approximately 10 000 genes. We identified 297 genes that were consistently differentially expressed after orphaning. These include genes that are putatively involved in the signalling and onset of reproductive development, as well as genes underlying major physiological changes in the young queens.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Letter (rough copy) written to Colonel Hope, commander of the Queen’s Volunteers from J.P. Bradley offering his services (3 pages, handwritten). Bradley asks why he was not appointed to the new corps, Nov. 8, 1838.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study, the ovary morphology of newly emerged ant queens of Atta sexdens rubropilosa was studied in whole mount preparations by confocal microscopy. The ovaries are composed of approximately 40 ovarioles, showing non-synchronic oocyte maturation. The terminal filament with clusters of undifferentiated cells was found at the distal end of the ovarioles. Next to this region is the germarium, composed of several elongated cystocytes interconnected by cytoplasmic bridges. The nurse cells (23-28 cells) result from asymmetric mitosis. Cytoskeleton analysis showed F-actin concentrated at the muscle cells of the external tunica and in fusomes inside the ovarioles. Microtubules were concentrated around the nuclei of the nurse and follicular cells. In contrast, the oocytes and the external tunica showed faint staining for tubulin.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper presents a discussion about gender and body in the drag queens experience at Natal city (RN). From the different concepts that characterizes the identity processes on subjects who perform gender transformation (transvestites, transsexuals and female impersonators), the justification for studying the drag character is observed as a means to understand matters that are important when you take such a position. Therefore, there is a need for a linkage between the various concepts responsible for this definition, in addition to considering the historical and cultural process responsible for the creation of such categories, identities and stereotypes among these individuals. In this sense it will be possible to carry out a critical analysis on the different social loads present in each representation, and understand what is at stake in the attribution of classifications and terminologies that are applied to different expressions of metamorphosis. This ethnography considers the debate from a field research conducted at LGBT social establishments and other performance spaces of these people, verifying their dynamics in these places and investigating relationships between performers, personas and characters and also backstage scene in which they participate

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Trinta gatas, saudáveis, foram submetidas à ovariectomia pela técnica convencional e por videolaparoscopia. Amostras de sangue foram obtidas com o objetivo de verificar a intensidade da resposta inflamatória por meio da análise das concentrações de proteinas de fase aguda e contagem de leucócitos antes e até 144 horas após procedimento cirúrgico. As proteínas que apresentaram aumento significativo 24 horas após a cirurgia foram: ceruloplasmina, hemopexina, haptoglobina e α1-glicoproteína ácida, 69,8%, 103,5%, 117,3% e 199,0%, respectivamente, para ovariectomia convencional, e 22,3%, 46,1%, 79,8% e 74,6%, respectivamente, para ovariectomia por videolaparoscopia. A resposta inflamatória foi mais evidente nas gatas submetidas à ovariectomia convencional. Os resultados mostram aumento e diminuição na concentração de proteínas de fase aguda e na contagem de leucócitos, podendo ser utilizados na avaliação da resposta inflamatória induzida por procedimentos cirúrgicos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A neural network model for solving the N-Queens problem is presented in this paper. More specifically, a modified Hopfield network is developed and its internal parameters are computed using the valid-subspace technique. These parameters guarantee the convergence of the network to the equilibrium points. The network is shown to be completely stable and globally convergent to the solutions of the N-Queens problem. Simulation results are presented to validate the proposed approach.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Toxoplasma gondii isolates from Brazil are biologically and genetically different from European and North America isolates. Recently, four genotypes were considered the common clonal lineages in Brazil and were designated as types BrI, BrII, BrIII, and BrIV. The pathogenicity of two major Brazilian lineages was investigated after oral inoculation of queens in the middle third of their pregnancies with T. gondii cysts. Twelve pregnant queens without T. gondii antibodies were distributed in group A (infected with a type BrI isolate); group 2 (infected with type BrIII isolate), and group 3 (non-infected control). Infection with type BrI isolate caused toxoplasmosis manifestations and abortion from one litter. Toxoplasmosis manifestations besides premature stillbirth of one litter were observed in queens infected with type BrIII isolate. Indirect fluorescence antibody test showed T. gondii antibodies in all eight infected queens at 30 days after inoculation. In two 10-day-old kittens of the same litter (group 1), titers of 16 and 64 were detected. At the same time, titers of 16, 32, and 32 were detected in three kittens from the same litter (group 2). Experimental infection with tissue cysts from a type BrI and type BrIII isolates of T. gondii developed similar reproductive disturbance in primary infected pregnant queens.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present work is to perform morphological and histological studies of the ovaries of workers and mated queens of Pachycondyla striata ants, which belong to the subfamily Ponerinae. The ovaries, after being removed, were schematized. Next, historesin and electronic scanning microscopy techniques were applied, making it possible to note that the left ovary owns a greater number of ovarioles when compared to the right one (workers - 7 to the right and 8 to the left; queens - 6 to the right and 7 to the left) and that the ovarioles of workers present a rather wrinkled aspect due to the fact that they are not developed. The same situation does not occur in mated queens once they always present oocytes in distinct development phases in their ovarioles. Histologically it was observed that the ovarioles are of the meroistic polytrophic kind. Inside the ovarioles of workers, germinative cells were observed in their distal portion, but their lumen were empty. on the other hand, ovarioles of mated queens presented the germinative cells as well as oocytes in different degrees of development, although more than one developing oocyte was never observed in the interior of each ovariole. It was possible to note the presence of follicular epithelium, chorion and vitellin membrane in oocytes of mated queens, which change morphologically according the oocyte development stage.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper presents a study of the pericardial cells of Scaptotrigona postica an eusocial Brazilian stingless bee. Light and electron microscopy was used in a comparative study on workers and queens of different ages, exerting different functions in the colony. The pericardial cells are found only in the peticardial sinus, mainly in groups around the dorsal vessel. Each cell is enclosed by the basal membrane and its peripheral region is characterized by folds of the plasma membrane, which form canals and loops. The points where the plasma membrane folds is frequently closed by diaphragms, that along with the basal lamina form a barrier to substances from hemolymph. Along the membrane limiting the canals and loops, an intense endocytic activity through coated vesicles takes place indicating a selective absorption of hemolymph components. In older individuals, workers or queens, the cells exhibit larger quantities of cytoplasm inclusions, heterogeneous vacuoles containing the final products of intracellular digestion, and autophagic vacuoles with concentric membranous structures. The pericardial cells general morphology is in accordance with the role in processing metabolites captured from hemolymph and storage of indigested residues. (C) 2006 Elsevier Ltd. All rights reserved.