986 resultados para Brazilian coastal zones


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The economic development of a region depends on the speed that people and goods can travel. The reduction of people and goods travel time can be achieved by planning smooth road layouts, which are obtained by crossing natural obstacles such as hills, by tunneling at great depths, and allowing the reduction of the road alignment length. The stress state in rock masses at such depths, either because of the overburden or due to the tectonic conditions of the rock mass induces high convergences of the tunnel walls. These high convergence values are incompatible with the supports structural performance installed in the excavation stabilization. In this article it is intended to evaluate and analyze some of the solutions already implemented in several similar geological and geotechnical situations, in order to establish a methodological principle for the design of the tunnels included in a highway section under construction in the region influenced by the Himalayas, in the state of Himachal Pradesh (India) and referenced by "four laning of Kiratpur to Ner Chowk section".

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A detailed knowledge of the 3-D arrangement and lateral facies relationships of the stacking patterns in coastal deposits is essential to approach many geological problems such as precise tracing of sea level changes, particularly during small scale fluctuations. These are useful data regarding the geodynamic evolution of basin margins and yield profit in oil exploration. Sediment supply, wave-and tidal processes, coastal morphology, and accommodation space generated by eustasy and tectonics govern the highly variable architecture of sedimentary bodies deposited in coastal settings. But these parameters change with time, and erosional surfaces may play a prominent role in areas located towards land. Besides, lateral shift of erosional or even depositional loci very often results in destruction of large parts of the sediment record. Several case studies illustrate some commonly found arrangements of facies and their distinguishing features. The final aim is to get the best results from the sedimentological analysis of coastal units.

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This paper describes a high-resolution stratigraphic correlation scheme for the early to middle Miocene Lagos-Portimão Formation of central Algarve, southern Portugal. The Lagos Portimão-Formation of central Algarve is a 60 m thick package of horizontally bedded siliciclastics and carbonates. The bryozoan and mollusc dominated biofacies is typical of a shallow marine, warm-temperate climatic environment. We define four stratigraphic marker beds based on biofacies, lithology, and gamma-ray signatures. Marker bed 1 is a reddish shell bed composed predominantly of bivalve shells in various stages of fragmentation. Marker bed 2 is a fossiliferous sandstone / sandy rudstone characterized by bryozoan masses. Marker bed 3 is also a fossiliferous sandstone with abundant larger foraminifers and foliate bryozoans. Marker bed 4 is composed of three distinct layers; two fossiliferous sandstones with an intercalated shell bed. The upper sandstone unit displays thickets of the bryozoan Celleporaria palmate associated with the coral Culizia parasitica. This stratigraphic framework allows to correlate isolated outcrops within the stratigraphic context of the Lagos-Portimão Formation and to establish high resolution chronostratigraphic Sr-isotopic dating.

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A retrospective survey of 473 cases of snake bite admitted to a Brazilian teaching hospital from 1984 to 1990 revealed 91 cases of bite without envenoming and/or caused by non-venomous snakes. In 17 of these cases the snake was identified, and one patient was bitten by a snake-like reptile (Amphisbaena mertensii). In 43 cases diagnosis was made on clinical grounds (fang marks in the absence of signs of envenoming). The other 30 cases were of patients who complained of being bitten but who did not show any sign of envenoming or fang mark. Most cases occurred in men (66;73%), in the 10-19 years age group (26;29%), in the lower limbs (51/74;69%), between 6 A. M. and 2 P.M. (49;61%) and in the month of April (16; 18%). One patient bitten by Philodryas olfersii developed severe local pain, swelling and redness at the site of the bite, with normal clotting time. The patient bitten by Drymarcon corais was misdiagnosed as being bitten by a snake of the genus Bothrops, was given the specific antivenom, and developed anaphylaxis. One patient bitten by Sibynomorphus mikanii presented prolonged clotting time, and was also given antivenom as a case of Bothrops bite. Correct identification of venomous snakes by physicians is necessary to provide correct treatment to victims of snake bite, avoiding unnecessary distress to the patient, and overprescription of antivenom, which may eventually cause severe untoward effects.

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PURPOSE: To determine how often and by what means an indentifiable pulmonary pathogen can be recognized in human immunodeficiency virus (HIV) infected patients with respiratory disorders in Brazil, which are the most frequently observed microorganisms and what impact specific therapy has on these agents. PATIENTS AND METHODS: Thirty-five HIV seroposiüve subjects with respiratory complaints were studied. All patients had a complete history, physical examination and blood counts. The pulmonary assessment included chest radiograms; sputum examination for bacterial and fungal pathogens; bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. Patients with treatable complications received standard antimicrobial therapy. RESULTS: One or more microorganisms were found in 24 subjects and another 3 individuals showed nonspecific interstitial pneumonitis. The sputum examination identified the pulmonary pathogens in 7 cases. The bronchoalveolar lavage and the histopathologic examination were diagnostic in 14% and 83%, respectively, of the 28 individuals that were submitted to bronchoscopy. The most frequently identified microorganism was P. carinii (55%), followed by M. tuberculosis (41%) and cytomegalovirus (8%). The clinical, laboratory and radiographic findings failed to distinguish the specific pulmonary pathogens. Twenty-three individuals with P. carinii pneumonitis and/or tuberculosis received specific therapy; among the evaluable patients the therapeutic response rates were 79% for PCP and 100% for TB. CONCLUSIONS: We have determined that tuberculosis, P. carinii and cytomegalovirus pneumonitis are the most common respiratory opportunistic diseases in Brazilian patients infected with HIV. The histologic evaluation was crucial in order to identify the pulmonary pathogens. Tuberculosis in AIDS individuals displayed clinical and radiographic findings atypical for reactivation disease. However, most of the features observed in HIV infected patients had been previously described in infection of the normal host. Furthermore, the AIDS subjects showed a good therapeutic response to anti-tuberculous drugs.

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In this work, we present results from teleseismic P-wave receiver functions (PRFs) obtained in Portugal, Western Iberia. A dense seismic station deployment conducted between 2010 and 2012, in the scope of the WILAS project and covering the entire country, allowed the most spatially extensive probing on the bulk crustal seismic properties of Portugal up to date. The application of the H-κ stacking algorithm to the PRFs enabled us to estimate the crustal thickness (H) and the average crustal ratio of the P- and S-waves velocities V p/V s (κ) for the region. Observations of Moho conversions indicate that this interface is relatively smooth with the crustal thickness ranging between 24 and 34 km, with an average of 30 km. The highest V p/V s values are found on the Mesozoic-Cenozoic crust beneath the western and southern coastal domain of Portugal, whereas the lowest values correspond to Palaeozoic crust underlying the remaining part of the subject area. An average V p/V s is found to be 1.72, ranging 1.63-1.86 across the study area, indicating a predominantly felsic composition. Overall, we systematically observe a decrease of V p/V s with increasing crustal thickness. Taken as a whole, our results indicate a clear distinction between the geological zones of the Variscan Iberian Massif in Portugal, the overall shape of the anomalies conditioned by the shape of the Ibero-Armorican Arc, and associated Late Paleozoic suture zones, and the Meso-Cenozoic basin associated with Atlantic rifting stages. Thickened crust (30-34 km) across the studied region may be inherited from continental collision during the Paleozoic Variscan orogeny. An anomalous crustal thinning to around 28 km is observed beneath the central part of the Central Iberian Zone and the eastern part of South Portuguese Zone.

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The frequency of viral markers for hepatitis B (HBV) and C (HCV), human immunodeficiency virus-1 (HIV-1) and human T-lymphotropic virus-1 (HTLV-1) was evaluated in 32 Brazilian ß-thalassemia multitransfused patients. Additionaly the serum concentrations of ferritin and alanine aspartate transaminase (ALAT) were determined. The results show a high prevalence of markers of infection by HBV (25.0%) and HCV (46.8%) and a low prevalence of markers for HIV-1 and HTLV-1. No correlations were demonstrated between the presence of the hepatitis markers and the number of units transfused or the serum concentrations of ferritin and ALAT.

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Neutralizing antibodies to EEE (6.7%), WEE (1.2%), ILH (26.6%), MAG (28.2%) and TCM (15.7%) viruses were found in sera of 432 equines of the Brazilian Pantanal, area where undiagnosed horse deaths are frequently observed. A 4-fold rise in CF titer to EEE virus was detected in acute and convalescent sera of an encephalitis horse sacrified in 1992. Antibodies to EEE, ILH, MAG and TCM viruses were detected in horses less than 2 years old indicating recent circulation of these viruses in the Pantanal. The evidence of recent equine encephalitis associated with rising CF titer to EEE warrants a more intensive study with attempts to isolate virus from horses with clinical manifestations of encephalitis.

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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia Ecológica

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At least eighteen species of triatominae have been found in the Brazilian Amazon, nine of them naturally infected with Trypanosoma cruzi or "cruzi-like" trypanosomes and associated with numerous wild reservoirs. Despite the small number of human cases of Chagas' disease described to date in the Brazilian Amazon the risk that the disease will become endemic in this area is increasing for the following reasons: a) uncontrolled deforestation and colonization altering the ecological balance between reservoir hosts and wild vectors; b) the adaptation of reservoir hosts of T.cruzi and wild vectors to peripheral and intradomiciliary areas, as the sole feeding alternative; c) migration of infected human population from endemic areas, accompanied by domestic reservoir hosts (dogs and cats) or accidentally carrying in their baggage vectors already adapted to the domestic habitat. In short, risks that Chagas' disease will become endemic to the Amazon appear to be linked to the transposition of the wild cycle to the domestic cycle in that area or to transfer of the domestic cycle from endemic areas to the Amazon.

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B. tenagophila snails from Ouro Branco, MG, showed positivity for S. mansoni, with infection rates of 5%, 10%, (SJ strain), and 1% (LE strain) using a pool of miracidia. The mollusks were found to be susceptive from the 3rd generation reared in laboratory onwards. The B. tenagophila (OB, MG) when individually exposed to 10 miracidia, showed infection rate of 2% for LE strain. B. glabrata snails from Gagé, MG, showed a positivity rate of 58% for S. mansoni (LE strain), under experimental conditions. The B. tenagophila from Cabo Frio, RJ and B. glabrata from Belo Horizonte, MG used as a control for SJ strain showed infection rates of 47% - 85% and 36% respectivily. For the LE strain, B. glabrata (BH, MG) used as control showed infection rate of 40% - 75%.