520 resultados para Reactivation
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Around the southern margins of the São Francisco Craton, there is a zone of tectonic interference between the Brasília belt to the west and the younger Ribeira belt to the east. U-Pb monazite and 40Ar/39Ar cooling age determinations carried out in the area reveal the cooling histories of these belts and the timing of tectonic overprint, unraveling the final stages of Brasiliano Orogeny in SE Brazil. The U-Pb monazite data from migmatized paragneisses and late-stage pegmatites in the Socorro-Guaxupé Nappe System of the southern Brasília belt show that migmatization peaked between ca. 613±1 and 607±3 Ma. 40Ar/39Ar biotite and muscovite ages of paragneisses and schists in this area indicate that the northern high-grade core of the Nappe System (Guaxupé Domain) was uplifted and cooled through the 350°C isotherm between 599±1 and 587±1 Ma. In contrast, samples from the southern high-grade core of the Nappe System, the Socorro Domain, south of the Jacutinga shear zone, yields a broader and younger spectrum of 40Ar/39Ar biotite ages between 571±1 and 562±1 Ma, attributed to a later uplift and cooling of the crust. The cooling ages can be assigned to local resetting of the 40Ar/39Ar system during transpressive tectonic overprint due to reactivation as a result of collision of the Ribeira belt. A younger group of 40Ar/39Ar mica ages (537±1 to 521±1Ma) in schists of the Socorro Domain, are associated with transpressional structures of the Ribeira belt. Rock samples from the Jacutinga and Três Corações shear zones, yield 40Ar/39Ar biotite-muscovite ages around 520 Ma. These are typical cooling ages of the Ribeira belt, and are interpreted to mark the western limit of the Ribeira belt transpressional regime within the Brasília belt. The youngest biotite-muscovite cooling ages in schists of the Socorro Domain, between 510±2 and 491±1 Ma, mark the final cooling and exhumation of that part of the Brasília belt.
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Evaporative cooling operates using water and air as working fluids. It consists in water evaporation, through the passage of an airflow, thus decreasing the air temperature. This system has a great potential to provide thermal comfort in places where air humidity is low, being, however, less efficient where air humidity is high. A way to solve this problem is to use dehumidifiers to pre-conditioning the process air. This paper presents a system that can be used in humid climates coupling desiccant dehumidification equipment to evaporative coolers. The paper shows, initially, the main characteristics of the evaporative cooling and of the adsorption dehumidification systems. Later on the coupled systems, in which occurs a dehumidification by adsorption in a counter flow rotary heat exchanger following the evaporate cooling of the air in evaporative coolers, are analyzed. The thermodynamic equations of state are also presented. Following, this paper analyzes some operation parameters such as: reactivation temperature, R/P relationship (reactivation air flow/ process air flow) and the thermodynamic conditions of the entering air flow. The paper shows the conditions for the best operation point, with regard to thermal comfort conditions and to the energy used in the process. In addition this paper presents an application of the system in different climate characteristics of several tropical and equatorial cities. Copyright © 2005 by ABCM.
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Objective: To investigate the prevalence of infection, disease and eventual institutional outbreak of tuberculosis in a psychiatric hospital using the PPD test, as well as testing for mycobacteria in material collected from the respiratory tree and using molecular tracking technique based on insertion sequence 6110 (IS6110). Methods: Between February and August of 2002, PPD tests were given to 74 inpatients and 31 staff members at a psychiatric hospital in the city of Rio Verde, located in the state of Goiás, Brazil. In addition, respiratory tree material collected from the inpatients was submitted to testing for Mycobacterium tuberculosis. Results: Among the patients analyzed, mycobacteria were isolated from five (6.8%): four identified as M. tuberculosis and one as M. chelonae. The M. tuberculosis isolates were sensitive to isoniazid and rifampicin, and, when submitted to the restriction fragment length polymorphism/IS6110 technique, presented unique genetic profiles, totally distinct from one another, suggesting that all of the tuberculosis cases were due to endogenous reactivation. It was not possible to characterize this group of cases as an institutional outbreak. Performing the two-step tuberculin test in the patients, the infection rates were 23% and 31%, compared with 42% among staff members, who were submitted to the one-step test. Conclusion: The results indicate a high incidence of tuberculosis infection among inpatients and hospital staff, as well as a high occurrence of the disease among inpatients.
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Cytomegalovirus (CMV) disease is a major cause of morbidity and mortality in solid organ transplantation. Disseminated toxoplasmosis after liver transplantation is a rare but fatal event. Serologic screening of the donor and the recipient is essential to prophylactic management, early diagnosis and therapeutic strategies to minimize the consequences of these infections. The aim of the present study was to determine the seroprevalence of CMV and Toxoplasma gondii (TG) in a Brazilian liver transplant waiting list (LTWL). Serological data were collected from 44 candidates on the LTWL between May 2003 and November 2004. Serological investigation of antibodies IgM and IgG against CMV (anti-CMV) and TG (anti-T. gondii) was performed using fluorometry commercial kits. IgG anti-CMV was positive in 37 patients (94.9%) out of 39 available results. There were not IgM anti-CMV positive results. Out of 36 analyzed patients, 22 (61.1%) presented positive IgG anti-T. gondii and none had positive IgM anti-T. gondii. The high CMV seroprevalence among our LTWL reinforces the need for appropriate protocols to avoid related complications, like reactivation and superinfection by CMV. Environmental and drug prophylactic strategies against primary infection and reactivation, as well as early diagnosis and treatment of toxoplasmosis complications, are essential for the good outcome of transplant patients.
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Triatomines are of great concern in public health because they are vectors of Chagas' disease. This study presents an analysis of the species Triatoma melanosoma. The cytogenetic characteristics of triatomines include holocentric chromosomes, post-reductional meiosis in the sex chromosomes and nucleolar fragmentation in the meiotic cycle. The methodology utilized consisted of the techniques of lacto-acetic orcein staining and silver ion impregnation. The organs analyzed were adult testicles. The results enabled to classify the chromosomes by number and size, being three large, eight medium and one small heterochromosome. The three largest chromosomes and the heterochromosomes showed heteropyknotic chromatin in meiosis. The heterochromosomes in 8.05% of the cells in metaphase I behaved as pseudobivalents, contrasting with 91.95% of the cells with individualized sex chromosomes, confirming the achiasmatic nature of these chromosomes. However, the pseudobivalents occurred prominently in metaphase II (78.38%), this fact probably is related to the post-reductional nature of the sex chromosomes. The nucleolus in T. melanosoma persisted until the diplotene phase after which it began to fragment. Nucleolar corpuscles were observed in metaphases I and II and during anaphases I and II, these characteristics being related to the phenomenon of nucleolar persistence. In the initial spermatids, peripheral silver ion impregnation occurred, which could be analogous to the pre-nucleolar corpuscles observed after fragmentation. Thus, this study extends our knowledge of the characteristics of triatomines, in particular, heteropyknotic degree, kinetic activity, formation of sex chromosome achiasmatic pseudobivalency, confirmation of the fragmentation phenomenon, and post-meiotic nucleolar reactivation. ©FUNPEC-RP.
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Includes bibliography
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Structures transverse/sub-transverse to the shoreline have been identified and characterized on the precambrian basement outcrop on the continent adjacent to the northern Santos Basin. These structures were analyzed from images of digital elevation model SRTM 90m by extracting NW-SE lineaments that intersect the NE-SW foliation. The lineaments were selected, classified into 48 segments that extend toward offshore, and correlated with basin structures. In the basin 25 2D seismic sections, 12 well logs and data from potential methods were interpreted, identifying the key stratigraphic levels and the major structures. Structural maps of each horizon were generated. Six transfer faults (FTs) were recognized and named FT-1 to FT-6, whose extensions correspond to continental lineaments named FC1 to FC6. The FTs are related to the basin deformation and evolution. In seismic sections, these faults have lateral slip in flower structures, displacement inversions from normal at the top to reverse at the base, abrupt changes in thickness or even disappearance of the seismic reflectors. The structural map of the Basement and Top of the Rift shows control of some depocenters by faults and displacements in some areas. The maps of potential methods indicate that there are pronounced anomaly shifts in some areas, associated with FTs. Some seismic sections indicate reactivation of FTs when they intersect horizons from the basement until the most recent layers. The 3D integration of data facilitated the observation of the FT extensions in the continent discontinuity.
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This paper presents a review on the geotectonic framework of the Southeastern Brazil and neighborhoods, and its importance in the regional geologic evolution, which was exposed as a main conference at the XI Symposium of Southeast Geology (São Pedro, SP, 2009). Although the geologic history dates back to the Archean, and Paleo to Mesoproterozoic processes related to the evolution of the Columbia and Rodinia supercontinents occurred, it was in the Neoproterozoic that the most important structural features developed due to collisional tectonics. The collisions began in the Brasiliano I (900-700 Ma), but mainly developed during the Brasiliano II (670-530 Ma) and ended in the Brasiliano III (580-490 Ma), resulting the orogenic systems of Mantiqueira and Tocantins. The final consolidation resulted in Gondwana, around 460 My in the part which correspond to the South America Platform. The structural features represent an important heritage that controlled much the Phanerozic geologic and tectonic processes: the formation of the Paraná Basin in the Ordovician-Jurassic, the South Atlantian reactivation (active magmatism and Paraná LIP, rifting, morphogenesis and the Atlantic opening), and the Neogene-Quaternary intraplate discrete neotectonism.
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The feline infectious respiratory disease is the most common diagnosed infection in the veterinary clinic routine, being the Feline Herpesvirus1 the most important causal agent. Once infected, the cat will become a lifetime latent carrier, experiencing episodes of viral reactivation and spontaneous spread especially when there is a stress factor involved. This virus acts in the upper respiratory system and is also associated with eye diseases. The diagnosis is made by viral isolation and treatment protocol is based on a topic antiviral therapy, even though many of them are epiteliotoxic and may progress with intense discomfort in felines.The purpose of this paper is to describe the main ocular manifestations and syndromes seen in cats suffering from feline herpesvirus. Conjunctivitis, epithelial and stromal keratitis, corneal ulceration and indolent ulcers are the main ocular manifestations associated with viral infection, whereas symblepharon, keratoconjunctivitis sicca, proliferative keratitis and corneal sequestration are the main eye syndromes that can be observed in infected animals.
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The area between São Paulo and Porto Alegre in southeastern Brazil plays a key area to understand and quantify the evolution of the South Atlantic passive continental margin (SAPCM) in Brazil. In this contribution, we present new thermochronological data attained by fission-track and (U-Th-Sm)/He analysis on apatites and zircons from metamorphic, sedimentary and intrusive rocks. The zircon fission-track ages range between 108.4 (15.0) and 539.9 (68.4). Ma, the zircon (U-Th-Sm)/He ages between 72.9 (5.8) and 525.1(2.4). Ma, whereas the apatite fission-track ages range between 40.0 (5.3) and 134.7 (8.0). Ma, and the apatite (U-Th-Sm)/He ages between 32.1 (1.5) and 93.0 (2.5). Ma. The spatial distribution of these ages shows three distinct blocks with a different evolution cut by old fracture zones. While the central block exhibits an old stable block, the Northern and especially the Southern block underwent complex post-rift exhumation. The sample of the Northern block shows two distinct cooling phases in the Upper Cretaceous and the Paleogene to Neogene. After sedimentation of the Permian sandstones the samples of the Central block were never heated up over 100. °C with a following moderate to fast cooling phase in Cretaceous to Eocene time and a fast cooling between Oligocene to Miocene. The five thermal models obtained in the Southern block indicate a complex evolution with three cooling phases. The exhumation events of the three blocks correspond with the Paraná-Etendekka event, the alkaline intrusions due to the Trinidad hotspot, and the evolution of the continental rift basins in SE Brazil and are, therefore, most likely to be the major force for the post-rift evolution of the passive continental margin in SE Brazil, which therefore corresponds to the three main phases of the Andean orogeny. © 2013 Elsevier B.V.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Geologia Regional - IGCE