1,065 research outputs found
New data on the stratigraphy and chronology of the prehistoric site of Prazo (Freixo de Numão)
The Prazo archaeological site is located near Freixo de Numáo (Vila Nova de Foz Cóa, north-eastern Portugal). The site, discovered in the early '80s, initially revealed a significant historical record, having been a Roman villa whose occupation continued through part of the Middle Ages. In 1996, fieldwork there uncovered Neolithic layers. They were excavated from 1997 to 2001, revealing also the existence of a pre-Neolithic occupation. This paper presents the geoarchaeology and chronology of the prehistoric succession of Prazo, which is arranged as follows: an upper Pleistocene complex formed of slope waste sediments, featuring upper Palaeolithic finds and structures; an early to mid Holocene succession, also composed from slope waste deposits, containing Epipalaeolithic/Mesolithic and Early Neolithic archaeological assemblages and features; and an upper Holocene complex, corresponding to occupations in the Roman and Middle Ages. The available data - deriving from the geoarchaeological survey at the site and from an extensive range of radiocarbon dates - are presented as part of a preliminary discussion of the environmental evolution and the settlement strategies at the site
Optimization of Dengue Epidemics: a test case with different discretization schemes
The incidence of Dengue epidemiologic disease has grown in recent decades. In
this paper an application of optimal control in Dengue epidemics is presented.
The mathematical model includes the dynamic of Dengue mosquito, the affected
persons, the people's motivation to combat the mosquito and the inherent social
cost of the disease, such as cost with ill individuals, educations and sanitary
campaigns. The dynamic model presents a set of nonlinear ordinary differential
equations. The problem was discretized through Euler and Runge Kutta schemes,
and solved using nonlinear optimization packages. The computational results as
well as the main conclusions are shown.Comment: Presented at the invited session "Numerical Optimization" of the 7th
International Conference of Numerical Analysis and Applied Mathematics
(ICNAAM 2009), Rethymno, Crete, Greece, 18-22 September 2009; RepositoriUM,
id: http://hdl.handle.net/1822/1083
Luminescence properties of MOCVD grown Al0.2Ga0.8N layers implanted with Tb
AlxGa1-xN (x = 0.20) layers grown on (0001) sapphire substrates by metal organic chemical vapour deposition were implanted with terbium (Tb) ions at 150 keV with a fluence of 7 × 1014 Tb cm−2 at different temperatures. After thermal annealing, all layers evidenced the Tb-related 5D4-7FJ intra-4f8 transitions, demonstrating an enhancement of their intensity with increasing implantation temperature. A detailed spectroscopic analysis of the optical properties of these layers was conducted using luminescence techniques. An atypical behaviour for the relative intensity of both the broad visible band and the intraionic lines was found as a function of temperature and its origin is discussed based on potential fluctuation phenomena and energy transfer processes. The 5D4-7FJ intra-4f8 transitions exhibit thermal population with increasing temperature between ∼100 K and ∼200–230 K, with a subsequent decrease up to RT due to further competitive non-radiative recombination paths. The values calculated for the population energies of each sample are in good agreement with the ones obtained for the activation energies of the de-excitation of the yellow broad band also present in the spectra, suggesting a correlation between the host defect de-excitation processes and the population of the ion emitting levels.publishe
Toxicidade induzida pela terapêutica intermitente com Rifampicina: Análise de um caso clínico
SUMMARYWe repport the case of a patient who developed a severe drug-induced hypersensitivity sistemic reaction to Rifampicin, that included a flulike syndrome, severe hemolytic anaemia, renal failure, shock and toxic epidermal necrolysis.Besides the clinical evolution we consider the difficulties in clinical diagnosis and the role of the in vitro laboratory assays
Giant Cell Arteritis Presenting as Simultaneous Bilateral Critical Upper Limb Ischemia - Clinical Case
Introdução: A arterite de células gigantes (ACG), de etiologia desconhecida, é a vasculite sistémica mais comum nos adultos e pode ter uma ampla variedade de apresentações clínicas.
Atinge mais frequentemente os ramos extracranianos da artéria carótida mas, em 10-15% dos
casos, pode ocorrer o envolvimento das artérias subclávia, axilar e braquial.
Caso clínico: Tratava-se de uma doente do sexo feminino, de 80 anos, com antecedentes de
HTA e doença cerebrovascular. Foi observada no serviço de urgência por arrefecimento e dor em
repouso nos membros superiores, com evidências de cianose digital distal bilateral. As queixas
tinham tido início 2 meses antes e agravamento progressivo desde então.
Realizou um angio-TC que mostrou a existência de oclusão de ambas as artérias axilares/braquiais proximais e imagens sugestivas de vasculite ao nível de ambas as artérias
subclávias, aorta e artérias femorais comuns. Foi medicada com corticoterapia; contudo,
por não apresentar melhoria significativa após 5 dias, optou-se por realizar um bypass
carotídeo-umeral bilateral. Após a cirurgia, ocorreu resolução completa das queixas e a
doente apresentava pulso radial palpável bilateralmente. Seis meses após a cirurgia, a doente
encontrava-se assintomática e os bypasses permeáveis.
Conclusão: O presente trabalho pretende expor o caso de uma doente com o diagnóstico inaugural e ACG,que se apresentou com isquemia crítica bilateral e simultânea. Este quadro clínico
exigiu a realização de um procedimento de revascularização raro
Detection of graves using the micro-resistivity method
This paper describes a case history of the application of resistivity methods on the detection of a tomb tentatively
associated with Damião de Goes, a prominent Portuguese humanist who lived in the XVI century. The survey
carried out inside Varzea Church comprised dipole-dipole, gradient and pole-pole arrays. The results obtained
from the 2D inversion of dipole-dipole data and 3D inversion of the gradient array have shown high resistivity
anomalies that were assigned to the walls of the tomb. The low resistivity anomalies observed in between were
interpreted as due to the presence of water enriched by ions from the decomposition of human bodies. This result
is corroborated by the imaging obtained using the 3D probability tomography of the gradient and pole-pole data.
Excavation works, carried out in accordance with the results of the geoelectrical investigation, successfully found
a 2.7×0.8×1.7 m tomb, where several human bones have been collected. A 3D resistivity model incorporating the
main features of the tomb was built after the excavation. The pole-pole model responses calculated from this model
reproduce the main features observed in the data
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