3,876 research outputs found
Efficiency tests in the Iberian stock markets
This paper investigates the efficiency of the two major stock indexes of the Iberian Peninsula, the Portuguese Stock Index (PSI-20) and the Spanish Stock Index (IBEX-35). We used daily data from January 1993 to September 2001 for the Portuguese stock index and daily data from October 1990 to September 2001 for the Spanish stock index. Serial correlations, unit root tests and variance ratio tests are used to test the efficiency of these two stock indexes. Although the complementary of these tests, we used all of them to get a higher robustness of the conclusions. We examined serial correlation coefficients for successive stock index changes to test whether they are statistically equal to zero to establish the random walk nature of stock indexes. The augmented Dickey-Fuller (ADF) test are used to test the null hypothesis that the series has a unit root and the variance ratio tests are used to examine the random walk hypothesis for the series of these two stock indexes. The results of the serial correlations, unit root tests and variance ratio tests provide ambiguous evidence for the random walk hypothesis. The empirical evidence from the unit root tests do not reject the efficient market hypothesis for the two stock indexes, while the results from the variance ratio tests and serial correlations do.stock indexes, market efficiency, unit roots
Células endoteliais progenitoras e células endoteliais circulantes na insuficiência cardíaca: um estudo transversal
The objective of the present thesis was to compare the levels of circulating
endothelial progenitor cells (EPCs), circulating endothelial cells (CECs), and
hematopoietic stem cells (HSCs) between patients with heart failure with reduced
ejection fraction (HFrEF) and a group of subjects with cardiovascular risk factors.
We also compared the levels of circulating EPCs, CECs, and HSCs between
subgroups regarding the presence of cardiovascular risk factors (e.g. diabetes
mellitus) and the etiology of heart failure (HF). To achieved this, whole peripheral
blood was drawn from patients previously diagnosed with HFrEF (n = 42) and
age-matched subjects presenting similar cardiovascular risk factors but without
established cardiovascular disease (n = 42). Then, a combination of markers was
used in peripheral blood samples in order to assess the number of circulating
EPCs, CECs, and HSCs via flow cytometry analysis. Patients with HFrEF had
significantly decreased levels of circulating EPCs (5.28 x 10-3 ± 6.83 x 10-4 % vs
7.76 x 10-3 ± 4.91 x 10-4 %, P ≤ 0.001) and CECs (5.11 x 10-3 ± 7.87 x 10-4 % vs
6.51 x 10-3 ± 5.21 x 10-4 %, P = 0.005) compared to subjects with cardiovascular
risk factors. However, levels of HSCs were not significantly different between the
two groups (P = 0.590). Additionally, CECs (6.69 x 10-3 ± 6.38 x 10-3 % vs 3.61 x
10-3 ± 2.71 x 10-3 %, P = 0.057) tended to circulate in higher number in patients
with ischemic HF compared to patients with non-ischemic HF. Patients with
HFrEF and diagnosed as overweight/obese had significantly higher levels of
circulating EPCs (6.10 x 10-3 ± 4.78 x 10-3 % vs 4.13 x 10-3 ± 3.55 x 10-3 %, P =
0.043) and CECs (6.27 x 10-3 ± 5.66 x 10-3 % vs 3.47 x 10-3 ± 3.54 x 10-3 %, P =
0.019) when compared to patients with HFrEF presenting a normal weight.
Lastly, when comparing subjects from the age-matched group, subjects with
dyslipidemia had significantly higher levels of CECs (7.74 x 10-3 ± 3.64 x 10-3 %
vs 5.34 x 10-3 ± 2.59 x 10-3 %, P = 0.042) compared to subjects without
dyslipidemia. In conclusion, the main result of this study is that the circulating
levels of EPCs and CECs were significantly decreased in patients with HFrEF in
comparison to subjects with cardiovascular risk factors. The current observations
regarding cardiovascular risk factors suggest that EPCs, CECs, and HSCs play
an important role in the detection and repair of vascular damage and endothelial
dysfunction.O presente trabalho teve como principal objetivo comparar os níveis de células
endoteliais progenitoras (CEPs), células endoteliais circulantes (CECs) e células
estaminais hematopoiéticas (CEHs) em circulação entre doentes com
insuficiência cardíaca com fração de ejeção reduzida (ICFEr) e um grupo de
adultos com fatores de risco cardiovasculares. Adicionalmente, os níveis das
CEPs, CECs e CEHs foram comparados entre subgrupos em função da
presença de fatores de risco (ex. diabetes) e da etiologia da insuficiência
cardíaca. Inicialmente foram recolhidas amostras de sangue periférico de
doentes com ICFEr (n = 42) e indivíduos da mesma faixa etária com fatores de
risco cardiovasculares, mas sem qualquer doença cardiovascular estabelecida
(n = 42). Em seguida, foi utilizada uma combinação de anticorpos nas amostras
de sangue periférico para quantificação do número de CEPs, CECs e CEHs por
citometria de fluxo. Doentes com ICFEr apresentaram níveis de CEPs (5.28 x
10-3 ± 6.83 x 10-4 % vs 7.76 x 10-3 ± 4.91 x 10-4 %, P ≤ 0.001) e CECs (5.11 x 10-
3 ± 7.87 x 10-4 % vs 6.51 x 10-3 ± 5.21 x 10-4 %, P = 0.005) significativamente
inferiores aos indivíduos com fatores de risco cardiovasculares. Contudo, não
foram encontradas diferenças significativas nos níveis de CEHs entre os dois
grupos (P = 0.590). Adicionalmente, observou-se que as CECs (6.69 x 10-3 ±
6.38 x 10-3 % vs 3.61 x 10-3 ± 2.71 x 10-3 %, P = 0.057) tendem a circular em
maior número em doentes com ICFEr com etiologia isquémica
comparativamente a doentes com ICFEr não isquémica. Doentes com ICFEr e
com sobrepeso/obesidade apresentaram níveis de CEPs (6.10 x 10-3 ± 4.78 x
10-3 % vs 4.13 x 10-3 ± 3.55 x 10-3 %, P = 0.043) e CECs (6.27 x 10-3 ± 5.66 x 10-
3 % vs 3.47 x 10-3 ± 3.54 x 10-3 %, P = 0.019) significativamente superiores
comparativamente a doentes com ICFEr e com peso normal. Por último, dentro
do grupo de indivíduos com fatores de risco cardiovasculares, indivíduos com
dislipidemia apresentaram níveis de CECs (7.74 x 10-3 ± 3.64 x 10-3 % vs 5.34 x
10-3 ± 2.59 x 10-3 %, P = 0.042) significativamente superiores em comparação a
indivíduos sem dislipidemia. Em conclusão, os principais resultados deste
estudo indicam que o número de CECs e CEPs em circulação encontra-se
significativamente reduzido em doentes com ICFEr comparativamente a
indivíduos com fatores de risco para doenças cardiovasculares. As observações
atuais em relação aos fatores de risco para doenças cardiovasculares sugerem
que CEPs, CECs e CEHs desempenham um papel fundamental na sinalização
e reparação do dano vascular e disfunção endotelial.Mestrado em Biomedicina Molecula
Web Services: Metodologias de Desenvolvimento
Os Web Services são uma tecnologia emergente, sobre a qual muito se tem especulado. No decorrer deste artigo efectua-se uma primeira contextualização, aproveitanto ao mesmo tempo para apresentar a arquitectura de funcionamento de um qualquer Web Service. De seguida, e aproveitando a implementação de um caso de estudo em quatro plataformas de desenvolvimento distintas, propomos metodologias de desenvolvimento para Web Services e respectivas aplicações cliente
Labour productivity, wages and the functional distribution of income in Portugal : a sectoral approach
The main purpose of this paper is to study the functional distribution of income in Portugal in the long run, considering the period between 1953 and 2017. The labour share in income or value added depends on two fundamental variables, the labour productivity and the average labour compensation. The trends of these variables are quantified, for the aggregate economy and for its main productive sectors. An interesting result emerges, namely the different dynamics across sectors, both for the (unadjusted) wage share (considering only the wages of employees) and for the adjusted labour share (considering also as labour compensation one fraction of mixed income). Moreover, a shift-share analysis is used, in order to distinguish the importance of each sector’s wage share evolution (“within” effect) and the changes in each sector’s weight (structural changes, or “between” effect). Finally, a first attempt to incorporate the effect of wage inequality on the functional distribution of income is made, subtracting the labour compensation of the highest paid workers (top 10%, 5% and 1%) in order to calculate the wage share of the (so-called) typical workers.info:eu-repo/semantics/publishedVersio
Atmospheric flow over forested and non-forested complex terrain
Tese de doutoramento. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 200
A educação inclusiva em África. O caso de Cabo Verde
"Publicación de carácter científico, surgida del proyecto de investigación internacional coordinada por la Universidad de Jaén (España) y el Centro Universitario del Sur (Guadalajara, Mexico)
Proposta de uma demonstração de impacto socioeconómico para uma instituição do sector não lucrativo
As organizações com cariz social têm características únicas e os procedimentos contabilísticos e as Demonstrações Financeiras produzidas não reflectem essa singularidade. Deste modo, o principal objectivo do presente estudo prende-se com a apresentação de uma proposta de Demonstração de Impacto Socioeconómico aplicada à Santa Casa da Misericórdia de Alfândega da Fé, partindo de uma metodologia utilizada para uma entidade do 3.º Sector e promovida por Mook e Quarter (2006). Apesar de evidenciar o mesmo resultado líquido do período, a Demonstração de Impacto Socioeconómico, contrariamente à Demonstração de Resultados convencional, reflecte o valor que os seus voluntários adicionaram à Santa Casa da Misericórdia de Alfândega da Fé no exercício de 2010, ilustra o impacto desta sobre os seus principais intervenientes, sobre a economia social, sobre o sector privado e sobre o sector público
Projeto empresa - APOA - Apoio à publicação de obras académicas
Para ter sucesso na implementação de um serviço ou produto, o empreendedor deve definir e apresentar a sua ideia de negócio de forma clara e rigorosa, para ultrapassar as barreiras que poderá encontrar no mercado em que vai entrar. Portanto, é importante escolher uma ferramenta que possa auxiliar o empreendedor em todo o seu processo de criação de propostas de valor.N/
Trazodone Addition to Paroxetine and Mirtazapine in a Patient with Treatment-Resistant Depression: The Pros and Cons of Combining Three Antidepressants
Dual antidepressant combination for treatment-resistant depression is a strategy well supported by literature and accepted in clinical practice. Rather, the usefulness of the combination of more than two antidepressants is controversial. This may be related to the possibility of higher side-effect burden and to doubts about its pharmacological effectiveness and therapeutic advantage compared to other standard treatment options. We report a relapse of moderate-to-severe depressive symptoms with insomnia that successfully remitted after the addition of trazodone to a dual combination of paroxetine and mirtazapine (in standard effective doses) in a patient with treatment-resistant depression. We also review the literature and discuss the utility of triple antidepressant combination in treatment-resistant depression. This clinical case highlights the utility of combining trazodone as a third antidepressant for the relapse of depressive symptoms after the failure of a dual antidepressant combination. Trazodone may be advantageous in patients presenting recurrence of moderate-to-severe depressive symptoms that include sleep problems and/or insomnia and may be particularly useful when benzodiazepines are not recommended. Although its use may be controversial and associated with higher risk of side-effects, more investigation is needed to determine the efficacy and safety for triple antidepressant combinations as reliable strategies for treatment-resistant depression in clinical practice
Two new species of deep water south Brazilian turriforms (Neogastropoda, Conoidea, Turridae and Cochlespiridae)
Two deep water new species of turriforms are described from south Brazilian coast. One of them is the turrid Polystira tupan sp. nov., one of the largest species of the genus (~80 mm), with proper sculpture, shallow anal notch, collected off Santa Catarina, 350 m. The other is a cochlespirid that has been confused with Cochlespira elegans, a north Atlantic species; as it has different sculpture, shape, peripheric spines, etc., a new species, Cochlespira notomaris sp. nov., is introduced, occurring so far from off Santa Catarina to Rio Grande do Sul, 200‑1,000 m. For comparative purposes, the holotype of C. elegans is also illustrated
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