CYTOPHOTOMETRIC EVALUATION OF CORPORA ALLATA DNA DURING THE DEVELOPMENT OF LARVAE OF WORKERS AND QUEENS (APIS-MELLIFERA L, HYMENOPTERA, APIDAE)

Cytophotometric observation of corpora allata from workers and queens of A. mellifera showed significant variations in DNA content from the 2nd to the 4th instar of both castes, but the differences between castes are present only in the 2nd instar.The corpora allata are characterized by the presence of diploid, as well as polyploid cells, distributed in classes that are well established since the earliest developmental stages. However the frequency of cell nuclei in the higher classes of ploidy increases with development. This occurrence is responsible for the increase of the average DNA content in older larvae.

A specialized midgut region in stingless bees (Hymenoptera: Apidae: Meliponinae)

Ultrastructure of the anterior end of the midgut of three Neotropical stingless bees, including an obligate necrophagous species Trigona hypogea, suggests that this midgut region has no role in nutrient absorption because its lumen is reduced by a thick cuticle that lines the outer epithelium of the cardiac valve. A possible involvement of this midgut region in the production of the peritrophic membrane compounds is discussed.

CORPORA-ALLATA IN FEMALES OF NEOPONERA-VILLOSA ANTS (HYMENOPTERA FORMICIDAE) - RELATIONS WITH OVARIAN DEVELOPMENT

In female ants of the species Neoponera villosa the corpora allata are paired structures located dorsolaterally to the esophagus (Camargo-Mathias and Caetano, 1991). In the present study the glandular volume of the corpora allata was estimated and the activity of the glands was compared with the ovarian development. In the workers there was a relation between activity of these glands and ovaries in stages 0 to IV. In workers, with ovaries at stage V (maximum development) there was a smaller activity of the corpora allata. Another increasing activity was found in workers with ovaries at stage VII.In the queens, mainly those which were mated, whose ovaries were always fully developed, the volume of the corpora allata was smaller than those of the workers.

Built to Bite: Feeding Kinematics, Bite Forces, and Head Shape of a Specialized Durophagous Lizard, Dracaena Guianensis (Teiidae)

Most lizards feed on a variety of food items that may differ dramatically in their physical and behavioral characteristics. Several lizard families are known to feed upon hard-shelled prey (durophagy). Yet, specializations toward true molluscivory have been documented for only a few species. As snails are hard and brittle food items, it has been suggested that a specialized cranial morphology, high bite forces, and an adapted feeding strategy are important for such lizards. Here we compare head and skull morphology, bite forces, and feeding kinematics of a snail-crushing teiid lizard (Dracaena guianensis) with those in a closely related omnivorous species (Tupinambis merianae). Our data show that juvenile D. guianensis differ from T. merianae in having bigger heads and greater bite forces. Adults, however, do not differ in bite force. A comparison of feeding kinematics in adult Dracaena and Tupinambis revealed that Dracaena typically use more transport cycles, yet are more agile in manipulating snails. During transport, the tongue plays an important role in manipulating and expelling shell fragments before swallowing. Although Dracaena is slow, these animals are very effective in crushing and processing hard-shelled prey. J. Exp. Zool. 317A:371381, 2012. (c) 2012 Wiley Periodicals, Inc.

Histological, histochemical and morphometric study of female corpora allata of Pachycondyla striata ants (Hymenoptera: Ponerinae)

In this study we utilized both histological/histochemical tests and morphometric/statistical tests to observe developmental differences in the corpora allata in Pachycondyla striata workers and queens ants. The general structure of corpora allata was similar between workers and queens. The differences found among the volumes was not statistically significant when the probability value was set at 5%. Although the queen corpora allata volume has been observed smaller than those of the worker and the right gland volume has been smaller than those of the left one. Differences also were observed histologically, the worker corpora allata cells showed homogeneous cytoplasm and sparse nuclear chromatin in well defined nuclei. It was the reverse in the queens, in which the corpora allata cells showed some secretory cytoplasmic vesicles and nuclei with a different morphology, i. e., from extremely large with sparse chromatin to small with condensed chromatin. Employing histochemical tests verified that the corpora allata in both castes contained large amounts of RNA and protein in the cytoplasm of their cells and an absence of polysaccharides. Differences in the lipid amounts in worker's glands were found, whereas, in the queens' corpora allata lipids always occur.

A specialized genetic algorithm to solve the short term transmission network expansion planning

In this paper, the short term transmission network expansion planning (STTNEP) is solved through a specialized genetic algorithm (SGA). A complete AC model of the transmission network is used, which permits the formulation of an integrated power system transmission network expansion planning problem (real and reactive power planning). The characteristics of the proposed SGA to solve the STTNEP problem are detailed and an interior point method is employed to solve nonlinear programming problems during the solution steps of the SGA. Results of tests carried out with two electrical energy systems show the capabilities of the SGA and also the viability of using the AC model to solve the STTNEP problem. © 2009 IEEE.

Specialized genetic algorithm for transmission network expansion planning considering reliability

This paper presents a methodology to solve the transmission network expansion planning problem (TNEP) considering reliability and uncertainty in the demand. The proposed methodology provides an optimal expansion plan that allows the power system to operate adequately with an acceptable level of reliability and in an enviroment with uncertainness. The reliability criterion limits the expected value of the reliability index (LOLE - Loss Of Load Expectation) of the expanded system. The reliability is evaluated for the transmission system using an analytical technique based in enumeration. The mathematical model is solved, in a efficient way, using a specialized genetic algorithm of Chu-Beasley modified. Detailed results from an illustrative example are presented and discussed. © 2009 IEEE.

Specialized fungal parasites and opportunistic fungi in gardens of attine ants

Ants in the tribe Attini (Hymenoptera: Formicidae) comprise about 230 described species that share the same characteristic: all coevolved in an ancient mutualism with basidiomycetous fungi cultivated for food. In this paper we focused on fungi other than the mutualistic cultivar and their roles in the attine ant symbiosis. Specialized fungal parasites in the genus Escovopsis negatively impact the fungus gardens. Many fungal parasites may have small impacts on the ants' fungal colony when the colony is balanced, but then may opportunistically shift to having large impacts if the ants' colony becomes unbalanced. Copyright © 2012 Fernando C. Pagnocca et al.

Specialized Seed Dispersal in Epiphytic Cacti and Convergence with Mistletoes

Mistletoes represent the best example of specialization in seed dispersal, with a reduced assemblage of dispersal agents. Specific dispersal requirements mediated by the specificity of seed deposition site have apparently led to the evolution of such close relationships between mistletoes and certain frugivores. Here, we provide evidences for another case of specialization involving epiphytic cacti in the genus Rhipsalis, and small Neotropical passerines Euphonia spp., which also act as the main seed dispersers of mistletoes in the family Viscaceae. With field observations, literature search, and observations on captive birds, we demonstrated that Rhipsalis have specific establishment requirements, and euphonias are the most effective dispersers of Rhipsalis seeds in both quantitative and qualitative aspects, potentially depositing seeds onto branches of host plants. We interpret the similar dispersal systems of Rhipsalis and Viscaceae mistletoes, which involve the same dispersal agents, similar fruit morphologies, and fruit chemistry as convergent adaptive strategies that enable seeds of both groups to reach adequate microsites for establishment in host branches. © 2013 by The Association for Tropical Biology and Conservation.

Report of the videoconference of specialized agencies and other organizations of the United Nations system on preparations for the gender parity observatory for Latin America and the Caribbean

Includes bibliography

Tradução juramentada de contratos sociais: questões lexicais, terminológicas e fraseológicas

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