89 resultados para AFT


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The purpose of this experiment was to characterize the species of Eimeria affecting lambs and their infection pattern. Faecal samples were collected from each animal at 14-day intervals, beginning when lambs were 2 weeks old and ending when they were 32 weeks old. The oocysts were counted and identified as E. intricata, E. parva, E. pallida, E. crandallis, E. bakuensis, E. weybridgensis, E. ahsata and E. ovinoidalis. The highest oocyst counts were observed when the lambs were 4-8 weeks old.

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Two experiments were carried out to evaluate a larval development assay for the detection of anthelmintic resistance in O. circumcincta. In Experiment I, the dose responses to levamisole (LEV), thiabendazole (TBZ) and ivermectin (IVM) of 8 isolates of O. circumcincta were measured 34 days after infection (DAI). Four of these isolates were shown to be resistant to 1 or more anthelmintics. With 2 exceptions, all isolates considered to be resistant had higher LD50 values than the susceptible isolates for that anthelmintic. One exception was isolate RM8, which was considered to be resistant to all 3 anthelmintics based on faecal egg count reduction tests in goats, but the LD50 value for LEV did not differ from that for the susceptible isolates. The other exception was an isolate considered to be susceptible to TBZ which had a relatively high LD50 value. In an unrelated trial that was prompted by this finding, this isolate was confirmed to be benzimidazole-resistant. Isolate RM8 and an isolate susceptible to all 3 anthelmintics (SK2) were used in the second experiment, which was conducted to monitor changes in the LD50 values of LEV, TBZ and IVM over time following a single infection of 35 000 infective larvae in young sheep. Faecal samples were collected weekly from 24 to 115 DAI. With all 3 anthelmintics, the LD50 values increased with time to a peak around 50-60 DAI, and then declined to levels similar to those observed soon after patency. This trend was consistent for both isolates. The highest mean LD50 values for isolates SK2 for IVM and TBZ and RM8 for IVM and RM8, respectively, were 1.7 and 1.8 times, and 2.2 and 2.9 times higher than the initial mean LD50 values. There was a clear distinction in LD50 values between isolates at each sampling day for both IVM and TBZ. However, as a consequence of the changes in LD50 values with time, the peak LD50 values of IVM for isolate SK2 were higher than the minimum LD50 values of isolate RM8. As there was no apparent difference in LEV efficacy between these 2 isolates, the data were pooled. The highest mean LD50 value was 2.3 times higher than the initial LD50 value. (C) 1997 Australian Society for Parasitology.

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Includes Bibliography

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Includes bibliography.

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Pós-graduação em Medicina Veterinária - FMVZ

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

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Pós-graduação em Saúde Coletiva - FMB

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This study aimed to investigate the relation between physical activity levels (PAL) of hypertensive patients, seeing different do- mains, and, to compare anthropometric variables and blood pressure (BP). The survey was conducted with 192 patients, mean age 63 ± 11 years. The anthropometric variables were body weight, body mass index (BMI) and waist circumference (WC). PAL was estimated using Baecke ́s questionnaire and categorized in four domains (OPA = occupational; leisure time = LTPA; locomotion = LPA and Total PA). Student t test unpaired was applied for comparisons between active and insufficiently active. Differences between active and sedentary in relation to anthropometry and resting blood pressure were observed for the LTPA, LPA and Total PA and significant negative correlations were observed between LPA and Total PA with systolic BP (p<0,05). Conclusion: the LPA and LTPA were associated with resting BP in hypertensive. No differences in BMI and WC among physically active and insuffi- ciently active were found.

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We investigated the color vision pattern in Cebus apella monkeys by means of electroretinogram measurements (ERG) and genetic analysis. Based on ERG we could discriminate among three types of dichromatic males. Among females, this classification is more complex and requires additional genetic analysis. We found five among 10 possible different phenotypes, two trichromats and three dichromats. We also found that Cebus present a new allele with spectral peak near 552 nm, with the amino acid combination SFT at positions 180, 277 and 285 of the opsin gene, in addition to the previously described SYT, AFT and AFA alleles. (C) 2009 Elsevier Ltd. All rights reserved.

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INTRODUÇÃO: A contaminação por chumbo afeta todos os sistemas do corpo humano, principalmente o sistema nervoso. OBJETIVO: Investigar se há correlação entre o nível de plumbemia e o desempenho em testes do processamento auditivo. MÉTODO: Estudo retrospectivo. 73 crianças, com idade entre 7 a 15 anos, residentes em uma área onde houve emissão de partículas de chumbo acima do permitido, com nível de plumbemia maior ou igual a 10 microgramas/dL, exames audiológicos (audiometria e timpanometria) dentro dos padrões de normalidade. Para avaliar o processamento auditivo foram utilizados o Teste de Fusão Auditiva-Revisado (AFT-R), subteste 1, e o Teste Dicótico de Dígitos (etapa de integração binaural). Foi utilizado o teste de Spearman para verificar a correlação entre os dados. RESULTADOS: O nível de plumbemia variou de 10 a 30,2microgamas/dL, sendo a média correspondente a 15,8 microgramas/dL (desvio-padrão de 4,8). Dessas crianças, 60,3% apresentaram desempenho ruim no teste AFT-R, ou seja, resultados superiores a 60ms. Quanto ao Teste Dicótico de Dígitos, 46,2% das crianças apresentaram desempenho ruim para a orelha direita e 67,3% apresentaram desempenho ruim na orelha esquerda. Conforme o resultado do teste de correlação de Spearman, não houve significância estatística entre o nível de chumbo e os resultados dos testes do processamento auditivo. CONCLUSÃO: Não houve correlação entre o nível de plumbemia e o desempenho nas habilidades do processamento auditivo, entretanto crianças contaminadas pelo chumbo apresentaram desempenho inferior nas habilidades do processamento auditivo.

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The Calabrian-Peloritani arc represents key site to unravel evolution of surface processes on top of subducting lithosphere. During the Pleistocene, in fact the arc uplifted at rate of the order of about 1mm/yr, forming high-standing low-relief upland (figure 2). Our study is focused on the relationship between tectonic and land evolution in the Sila Massif, Messina strait and Peloritani Mts. Landforms reflect a competition between tectonic, climatic, and surficial processes. Many landscape evolution models that explore feedbacks between these competing processes, given steady forcing, predict a state of erosional equilibrium, where the rates of river incision and hillslope erosion balance rock uplift. It has been suggested that this may be the final constructive stage of orogenic systems. Assumptions of steady erosion and incision are used in the interpretation of exhumation and uplift rates from different geologic data, and in the formulation of fluvial incision and hillslope evolution models. In the Sila massif we carried out cosmogenic isotopes analysis on 24 samples of modern fluvial sediments to constrain long-term (~103 yr) erosion rate averaged on the catchment area. 35 longitudinal rivers profiles have been analyzed to study the tectonic signal on the landscape evolution. The rivers analyzed exhibit a wide variety of profile forms, diverging from equilibrium state form. Generally the river profiles show at least 2 and often 3 distinct concave-up knickpoint-bounded segments, characterized by different value of concavity and steepness indices. River profiles suggest three main stages of incision. The values of ks and θ in the lower segments evidence a decrease in river incision, due probably to increasing uplift rate. The cosmogenic erosion rates pointed out that old landscape upland is eroding slowly at ~0.1 mm/yr. In the contrary, the flanks of the massif is eroding faster with value from 0.4 to 0.5 mm/yr due to river incision and hillslope processes. Cosmogenic erosion rates mach linearly with steepness indices and with average hillslope gradient. In the Messina area the long term erosion rate from low-T thermochronometry are of the same order than millennium scale cosmogenic erosion rate (1-2 mm/yr). In this part of the chain the fast erosion is active since several million years, probably controlled by extensional tectonic regime. In the Peloritani Mts apatite fission-track and (U-Th)/He thermochronometry are applied to constraint the thermal history of the basement rock. Apatite fission-track ages range between 29.0±5.5 and 5.5±0.9 Ma while apatite (U-Th)/He ages vary from 19.4 to 1.0 Ma. Most of the AFT ages are younger than the overlying terrigenous sequence that in turn postdates the main orogenic phase. Through the coupling of the thermal modelling with the stratigraphic record, a Middle Miocene thermal event due to tectonic burial is unravel. This event affected a inner-intermediate portion of the Peloritani belt confined by young AFT data (<15 Ma) distribution. We interpret this thermal event as due to an out-of–sequence thrusting occurring in the inner portion of the belt. Young (U-Th)/He ages (c. 5 Ma) record a final exhumation stage with increasing rates of denudation since the Pliocene times due to postorogenic extensional tectonics and regional uplift. In the final chapter we change the spatial scale to insert digital topography analysis and field data within a geodynamic model that can explain surface evidence produced by subduction process.

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An integrated array of analytical methods -including clay mineralogy, vitrinite reflectance, Raman spectroscopy on carbonaceous material, and apatite fission-track analysis- was employed to constrain the thermal and thermochronological evolution of selected portions of the Pontides of northern Turkey. (1) A multimethod investigation was applied for the first time to characterise the thermal history of the Karakaya Complex, a Permo-Triassic subduction-accretion complex cropping out throughout the Sakarya Zone. The results indicate two different thermal regimes: the Lower Karakaya Complex (Nilüfer Unit) -mostly made of metabasite and marble- suffered peak temperatures of 300-500°C (greenschist facies); the Upper Karakaya Complex (Hodul and the Orhanlar Units) –mostly made of greywacke and arkose- yielded heterogeneous peak temperatures (125-376°C), possibly the result of different degree of involvement of the units in the complex dynamic processes of the accretionary wedge. Contrary to common belief, the results of this study indicate that the entire Karakaya Complex suffered metamorphic conditions. Moreover, a good degree of correlation among the results of these methods demonstrate that Raman spectroscopy on carbonaceous material can be applied successfully to temperature ranges of 200-330°C, thus extending the application of this method from higher grade metamorphic contexts to lower grade metamorphic conditions. (2) Apatite fission-track analysis was applied to the Sakarya and the İstanbul Zones in order to constrain the exhumation history and timing of amalgamation of these two exotic terranes. AFT ages from the İstanbul and Sakarya terranes recorded three distinct episodes of exhumation related to the complex tectonic evolution of the Pontides. (i) Paleocene - early Eocene ages (62.3-50.3 Ma) reflect the closure of the İzmir-Ankara ocean and the ensuing collision between the Sakarya terrane and the Anatolide-Tauride Block. (ii) Late Eocene - earliest Oligocene (43.5-32.3 Ma) ages reflect renewed tectonic activity along the İzmir-Ankara. (iii) Late Oligocene- Early Miocene ages reflect the onset and development of the northern Aegean extension. The consistency of AFT ages, both north and south of the tectonic contact between the İstanbul and Sakarya terranes, suggest that such terranes were amalgamated in pre-Cenozoic times. (3) Fission-track analysis was also applied to rock samples from the Marmara region, in an attempt to constrain the inception and development of the North Anatolian Fault system in the region. The results agree with those from the central Pontides. The youngest AFT ages (Late Oligocene - early Miocene) were recorded in the western portion of the Marmara Sea region and reflect the onset and development of northern Aegean extension. Fission-track data from the eastern Marmara Sea region indicate rapid Early Eocene exhumation induced by the development of the İzmir-Ankara orogenic wedge. Thermochronological data along the trace of the Ganos Fault –a segment of the North Anatolian Fault system- indicate the presence of a tectonic discontinuity active by Late Oligocene time, i.e. well before the arrival of the North Anatolian Fault system in the area. The integration of thermochronologic data with preexisting structural data point to the existence of a system of major E-W-trending structural discontinuities active at least from the Late Oligocene. In the Early Pliocene, inception of the present-day North Anatolian Fault system in the Marmara region occurred by reactivation of these older tectonic structures.