833 research outputs found
A new method for quantification of hepatobiliary scintigraphy using 99mTc-mebrofenin. A comparative study
A method based upon the application of mathematical techniques of deconvolution on the classical compartmental model for the quantitative study of liver function from hepatobiliary scintigraphy using 99mTc-mebrofenin data is proposed. The theory in which the method is based upon is presented and a comparison with a published methodology of obtaining the hepatic extraction after scintigraphic sudies has been performed using the results on 36 rats studies obtained with the two methods. A highly significant correlation between the two techniques was verified. The characteristics of the two methodologies, the proposed one based upon a theoretical approach and the other one on an empirical approximation are discussed. Comments are made on the interest and limitations of the presented technique that may be an useful tool for the evaluation of hepatic insufficiency
Ecophysiological potential of the Dão terroir for the production of Touriga Nacional red grapes
Proceedings - IX International Terroir Congress, 2012Aiming to evaluate the potential of the portuguese Dão winegrowing region for the production of Touriga Nacional
(TN) red grapes, climatic, ecophysiological and viticultural data from two different climatic years (2004, wet year and
2005, dry year) are presented and discussed. The data was collected in the control non-irrigated plants of an irrigation
experiment installed at the Dão Research Station, Nelas, Portugal. The vineyard is established in a typical granitic soil
and trained on a vertical shoot positioning. According to the Géoviticulture Multicriteria Climatic Classification
System, the Dão region is classified as temperate/temperate warm for the heliothermal index, with cool nights (night
cold index) and moderately dry (dryness index). In 2004 the predawn leaf water potential presented always values
higher than -0.2 MPa from flowering to harvest but in 2005 moderate to severe water stress was observed during the
ripening period (-0.4 MPa at veraison to -0.6 MPa at harvest). Leaf stomatal conductance and photosynthetic rate
displayed a decreasing pattern from flowering to harvest in both years but attained much lower values in the 2005
ripening period as compared to that of 2004. The yield was similar in both years but 2005 showed lower sugar content,
similar titratable acidity and a higher anthocyanin berry skin content. Our data shows that the Dão terroir presents a
high inter-annual climate variability which has important repercussions on TN responses being the most unfavorable
climatic years those were the high temperatures are coincident with water stress during the first half of the ripening
period. In those years irrigation should be applied in order to obtain better quality grapes
A new MILP based approach for unit commitment in power production planning
This paper presents a complete, quadratic programming formulation of the standard thermal unit commitment problem in power generation planning, together with a novel iterative optimisation algorithm
for its solution. The algorithm, based on a mixed-integer formulation of the problem, considers piecewise
linear approximations of the quadratic fuel cost function that are dynamically updated in an iterative
way, converging to the optimum; this avoids the requirement of resorting to quadratic programming,
making the solution process much quicker.
From extensive computational tests on a broad set of benchmark instances of this problem, the algorithm was found to be flexible and capable of easily incorporating different problem constraints. Indeed,
it is able to tackle ramp constraints, which although very important in practice were rarely considered in
previous publications.
Most importantly, optimal solutions were obtained for several well-known benchmark instances,
including instances of practical relevance, that are not yet known to have been solved to optimality. Computational experiments and their results showed that the method proposed is both simple and extremely
effective
Clinical relevance of incidental colonic uptake 18F-FDG PET/CT. Correlation with colonoscopy and histopathology
Gerador de relatórios Purus.
Arquitetura do Purus. Arquivo de definição de dados (DataSource). Arquivo de definição de relatório. Recursos. Agrupamento. Funções do grupo. Parametrização de definição de relatório. Inclusão de caracteres ASCII. Formatação de dados. Relatórios no formato CSV. Execução do Purus. Reportmanager.bitstream/CNPTIA/9889/1/comuntec30.pdfAcesso em: 30 maio 2008
Courtship Sounds Advertise Species Identity and Male Quality in Sympatric Pomatoschistus spp. Gobies
Acoustic signals can encode crucial information about species identity and individual quality. We recorded and compared male courtship drum sounds of the sand goby Pomatoschistus minutus and the painted goby P. pictus and examined if they can function in species recognition within sympatric populations. We also examined which acoustic features are related to male quality and the factors that affect female courtship in the sand goby, to determine whether vocalisations potentially play a role in mate assessment. Drums produced by the painted goby showed significantly higher dominant frequencies, higher sound pulse repetition rates and longer intervals between sounds than those of the sand goby. In the sand goby, male quality was predicted by visual and acoustic courtship signals. Regression analyses showed that sound amplitude was a good predictor of male length, whereas the duration of nest behaviour and active calling rate (i.e. excluding silent periods) were good predictors of male condition factor and fat reserves respectively. In addition, the level of female courtship was predicted by male nest behaviour. The results suggest that the frequency and temporal patterns of sounds can encode species identity, whereas sound amplitude and calling activity reflects male size and fat reserves. Visual courtship duration (nest-related behaviour) also seems relevant to mate choice, since it reflects male condition and is related to female courtship. Our work suggests that acoustic communication can contribute to mate choice in the sand goby group, and invites further study
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