945 resultados para V-shaped structure


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Geological and geophysical studies (resistivity, self potential and VLF) were undertaken in the Tararaca and Santa Rita farms, respectively close to the Santo Antônio and Santa Cruz villages, eastern Rio Grande do Norte State, NE Brazil. Their aim was to characterize water acummulation structures in crystalline rocks. Based on geological and geophysical data, two models were characterized, the fracture-stream and the eluvio-alluvial through, in part already described in the literature. In the Tararaca Farm, a water well was located in a NW-trending streamlet; surrounding outcrops display fractures with the same orientation. Apparent resistivity sections, accross the stream channel, confirm fracturing at depth. The VLF profiles systematically display an alignment of equivalent current density anomalies, coinciding with the stream. Based on such data, the classical fracture-stream model seems to be well characterized at this place. In the Santa Rita Farm, a NE-trending stream display a metric-thick eluvioregolith-alluvial cover. The outcropping bedrock do not present fractures paralell to the stream direction, although the latter coincides with the trend of the gneiss foliation, which dips to the south. Geophysical data confirm the absence of a fracture zone at this place, but delineate the borders of a through-shaped structure filled with sediments (alluvium and regolith). The southern border of this structure dips steeper compared to the northern one. This water acummulation structure corresponds to an alternative model as regards to the classical fracture-stream, being named as the eluvio-alluvial trough. Its local controls are the drainage and relief, coupled with the bedrock weathering preferentially following foliation planes, generating the asymmetry of the through

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Pseudacteon wasmanni is a South American decapitating fly that parasitizes workers of Solenopsis fire ants. We used light microscopy (historesin serial-sectioning stained with Haematoxylin/Eosin) and scanning electron microscopy to show and analyze internal and whole external views of the female reproductive system. All specimens analyzed (n = 9) by light microscopy showed post-vitellogenic oocytes inside the ovaries. The lack of typical follicles (oocyte-nurse cell complexes) in all specimens suggests that oogenesis occurs during the pupal stage. The total number of eggs found ranged from 31 to 280 (X = 142 +/- 73, SD). The egg has a slugform or torpedo shape (about 130 by 20 mum) with a pointed apex at the posterior pole as defined by the fly; the micropyle appears to be in a depression or invagination at the anterior pole. An acute hypodermic-like ovipositor is evaginated from the hard sclerotized external genitalia during egg laying. The existence of a muscular bulb associated with the end of the common oviduct suggests that the egg is injected into the ant's body by a strong contraction of the bulb which probably is stimulated by bending of several ventral sensilla. During contraction, the abdomen extends out along a large fold between the sixth and seventh tergites in such a way that the sclerotized genitalia is rotated ventrally into a slightly anterior orientation in preparation for oviposition. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

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The excretory duct in the silk gland of the sugarcane borer Diatraea saccharalis consists of two morphologically distinct regions, recognized by scanning and transmission electron microscopy. The thin posterior region, adjacent to the glandular region, presents a regular surface. Secretory vesicles containing either electron-dense or fibrillar cuticular-like materials are observed in their apical cytoplasm; the same cuticular materials were detected as extracellular deposits among the microvilli. The short anterior region, near the common duct, exhibits surface protrusions; there are no secretory vesicles in their apical cytoplasm. These results show that only the duct cells at the posterior region are involved in the secretion of the cuticular intima elements. Desmosome-like structures were visualized linking together adjacent microvillar membranes only in the cells of anterior duct region, with unknown function. The transition between the duct and the glandular region is abrupt; the cells of the glandular and posterior duct regions present large amounts of microtubules. Nerve fibers can be observed between the duct cells in their two regions, suggesting that control of silk secretion may occur in the excretory duct via neurotransmitter liberation. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

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The frequency of dental abnormalities, such as delayed dental development, microdontia, hypoplasia, agenesis, V-shaped root and shortened root was evaluated in 76 acute lymphoblastic leukemia (ALL) pediatric patients who had been off chemotherapy for 6 months. These children had been subjected to one of the three Brazilian Protocols or the BFM86 Protocol. The patients were divided into three groups: Group I (GI; high risk) treated with one of the three Brazilian Protocols who received high-dose chemotherapy, intensive maintenance and cranial radiotherapy; Group II (GII; low risk) who were also treated with one of the three Brazilian Protocols using low-intensive chemotherapy with no radiotherapy; and Group III (GIII) based on the BFM86 Protocol.Of 76 children, 13 showed no dental abnormalities (8 were at the age of tooth formation). The remaining 63 children (82.9%) showed at least one dental anomaly.The abnormalities were probably caused by the type, intensity, frequency of the treatment and age of the patients at ALL diagnosis and this might have important consequences for the children's dental development. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

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A new species of hylid frog, from the genus Scinax, is described from Ilha de Porcos Pequena at the southern coast of São Paulo State, southeastern Brazil. The new species belongs to the Scinax perpusillus species group and is diagnosed by the following set of characters: moderate-size (males 16.2-18.8 turn SVL, female 18.8-20.6 mm SVL); canthus rostralis distinct and well defined; V-shaped depression between nostrils; eyes protruding and prominent, glandular skin surface of legs. This new species is found only on Ilha de Porcos Pequena, an island of approximately 24 ha and, therefore, is threatened because of restricted range size and susceptibility to habitat modification.

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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.

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This report presents the case of a nine-month-old bitch with incomplete occlusion of the skin and mucosa between the anus and dorsal commissure of the vulva. This anomaly, known as anovulvar cleft, was associated with a vaginal prolapse-hyperplasia. Anovulvar cleft is a rare condition in bitches and is caused by incomplete closure of the dorsal urogenital folds. Anovulvar cleft can lead to clitoritis, abrasion, dryness and devitalisation of the smooth exposed mucosa. Surgery can correct the condition. In the present study, surgical resection of the hyperplasic vaginal tissue associated with perineoplasty using an inverted V-shaped incision showed excellent results. An ovariohysterectomy was also performed to prevent recurrence of the vaginal prolapse-hyperplasia. © 2007 British Small Animal Veterinary Association.

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The dual path of insertion concept for removable partial denture (RPD) design may be used in esthetically demanding situations. When compared to conventional RPDs, the main advantage of this design is the minimal use of clasps. This clinical report describes the treatment of a patient with an anterior maxillary edentulous area using a dual path RPD. The diagnostic cast was surveyed to ensure the adequacy of the undercuts on the mesial surfaces of the anterior abutments, where rigid minor connectors were placed. Inverted V-shaped canine cingulum rest seats were prepared to provide resistance to tooth movement during function. The dual path RPD concept allows excellent esthetic results, minimizes tooth preparation, and reduces the tendency toward plaque accumulation in a Kennedy class IV partially edentulous arch. © 2008 by The American College of Prosthodontists.

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Includes bibliography

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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

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

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)