Functional ultrastructure of the midgut of the fire ant Solenopsis saevissima Forel 1904 (Formicidae : Myrmicinae)

Solenopsis saevissima has a midgut composed of columnar, regenerative, and goblet cells. The midgut epithelium was covered by a basal lamina. Outside the basal lamina, layers of inner oblique, circular, and outer longitudinal muscles were present. Columnar cells showed a basal plasma membrane containing numerous folds, mitochondria, and the nucleus. Rough endoplasmic reticulum, Golgi bodies, membrane bounded vacuoles, and spherocrystals were found in this region. The apical plasma membrane was constituted by microvilli, which were above a region rich in mitochondria. Regenerative cells were found in groups lying by the basal lamina. Goblet cells were associated with an ion-transporting mechanism between the haemolymph and the midgut epithelium. These cells were lying by the midgut lumen and large microvilli were evident, but the cytoplasmic features were similar to the columnar cells.

Segmental specializations in the Malpighian tubules of the fire ant Solenopsis saevissima Forel 1904 (Myrmicinae): an electron microscopical study

The Malpighian tubules of workers of the fire ant Solenopsis saevissima (Myrmicinae) were analyzed by scanning and transmission electron microscopy in order to determine their functional organization and association with the hindgut epithelium. The ants showed six Malpighian tubules with three segments morphologically and structurally different. The proximal segment was long and its cells showed abundant smooth endoplasmic reticulum and lipid droplets, which suggest their role in lipid secretion. The mid segment was long and undulated and it was composed by the cells that showed the typical features of ion transporting epithelia. The distal segment, short and flattened, adheres to the rectum wall. The cells of this segment showed the basal lamina fused to that of the rectum, it is probable that this part of the tubule may play a role in ion and water uptake from the feces. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

A case study of the 9 August 1988 South Atlantic storm: Numerical simulations of the wave activity

During 9-11 August 1988, a cyclone developed over Uruguay in the lee of the Andes Mountains and moved over the South Atlantic Ocean, where it redeveloped into an intense storm. This storm was responsible for unusual wave activity along the Brazilian shoreline from 22° to 32°S. The Brazilian news media reported the loss of at least one life, waves of 3 m and higher, and the disappearance of a drainage pipe, which weighed 8000 kg, off the shores of Rio de Janeiro. In this paper, the evolution of this intense storm and the associated ocean wave response is studied through European Centre for Medium-Range Weather Forecasts analyses, a hydrostatic limited-area meteorological model, and a second-generation prognostic wave model. The atmospheric model results indicated the presence of a long-lived and large fetch with surface wind velocities higher than 12 m s -1 directed toward the coast. Some areas with velocities of 20 m s -1 were embedded in the fetch. The wave model forced by this wind field was able to simulate waves with a significant height of 8 m far from the coast and about 4 m in regions very close to the Brazilian coast in agreement with the occurrence reported at Rio de Janeiro. The swell propagation toward the coast of Rio de Janeiro was obstructed by a northeastward 10-m wind during the first 24-h period of the model's integration. During the second 24-h period, the fetch was still large and strong, but the obstacle was removed by a counterclockwise rotation of wind direction favoring the swell and windsea propagation toward the Rio de Janeiro coast.

Effect of lecithin and soy oil on the fermentative performance of Saccharomyces uvarum I Z 1904

The proposal of this work was to study the effects of lecithin and soy oil on the fermentative performance of Saccharomyces uvarum I Z 1904, a yeast used in the industrial production of ethanol. High Test Molasses (HTM) was chosen as the fermentation media because it is a substratum that is poor in nutrients, and because it permits one to distinguish the action of lipids from other nutritional factors. The study of the optimization of the concentration of lipids by surface response analysis showed that the lipids favor the performance of the yeast principally when applied separately. Maximum concentrations of the two sources of lipids in the media stimulated the budding rate but did not constitute a protection against cell death. Considering the action of lipids on the cellular parameters studied, the supplementation of the media with 3.0 g/l of soy oil permitted the obtention of maximum responses of cellular viability, budding rate and viability of the buds after 6 successive cycles. In relation to the fermentative parameters, the use of 1.5 g/l of soy oil provided high yields and an equilibrium between the mass of ethanol produced (EM) and the alcoholic yield (Y p/s) , whereas the cellular viability after 6 cycles did not differ statistically from that observed with 3g/l of oil.

Biologia de Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) em algodoeiro

Leaf discs obtained from the first or second non-cotyledonal leaf of cotton (Gossypium hirsutum L.) seedlings were used for the study of the biology of Polyphagotarsonemus latus on cotton IAC-20 cultivar. Seedlings were grown in pots and placed on a layer of cotton moistened with distilled water. The assays were carried out at 28.5 ± 0.3°C, relative humidity of 71.0 ± 2.6% and a 14 h photophase. The duration of immature phases was 4.1 ± 0.1 days for females and 4.1 ± 0.3 days for males, with a survival of 91.2%. After a pre-oviposition period of 1.1 ± 0.2 days, the females deposited 4.5 ± 0.9 eggs per day during 6.8 ± 1.3 days, i.e., 29.6 ± 7.3 eggs per female. The longevity was 10.0 ± 1.5 days for females and 8.8 ± 1.1 days for males. The intrinsic rate of increase (rm) was 0.323; finite rate of increase (λ) 1.38 individual per female per day; mean generation time (T) 9.54 days and net reproductive rate (Ro) 21.73.

Boletín estadístico de América Latina, agosto 1965 = Statistical bulletin for Latin America, August 1965

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Boletín estadístico de América Latina, agosto 1964 = Statistical bulletin for Latin America, August 1964

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Regulación y supervisión de la banca e instituciones financieras: estudios de caso de América Latina y el Caribe: conclusiones y recomendaciones, Santiago 3-5 diciembre 1990 y 22-23 agosto 1991 = Regulation and supervision of banks and financial institutions: case studies in Latin America and the Caribbean: conclusions and recommendations, Santiago, 3-5 December 1990 and 22-23 August 1991

Documentos presentados a dos seminarios realizados en la Sede de CEPAL en Santiago entre el 3 y 5 de diciembre de 1990 y el 22 y 23 de agosto de 1991

Sistemas de pensiones de América Latina, diagnóstico y alternativas de reforma. Estudios de caso de América Latina y el Caribe: conclusiones y recomendaciones, Santiago 3-5 diciembre 1990 y 22-23 agosto 1991 = Pension systems in Latin America: diagnosis and reform alternatives. Case studies in Latin America and the Caribbean: conclusions and recommendations, Santiago, 3-5 December 1990 and 22-23 August 1991

Documentos presentados a dos seminarios realizados en la Sede de CEPAL en Santiago entre el 3 y 5 de diciembre de 1990 y el 22 y 23 de agosto de 1991

Paquete para Análisis Demográfico por Microcomputador (PANDEM), versión 2.00 (agosto 1988): manual del usuario = Package for Demographic Analysis by Microcomputer (PANDEM), versión 2.00 (August 1988): user's manual

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Committee on South-South Cooperation: provisional agenda, 29 August 2012

Spanish version available

Committee on South-South Cooperation: annotated provisional agenda, 29 August 2012

Spanish version available

Summary Recors of the Fifty-Seventh Meeting Held at Bogota on Wednesday, 31 August,1955 at 3.30 p.m.

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Summary Record of the Fifty-Fifth Meeting Held at Bogotá on Tuesday, 30 August,1955 at 4.15 p.m. horas

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Provisional Summarry Record of the Fifthy-Fourth Meeting Held at Bogotá on Tuesday, 30 August 1955 at 10:20 a.m.

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