270 research outputs found
The chronic food deficit of early modern Portugal : curse or myth?
The chronic food deficit of early modern Portugal: curse or myth? Two historiographie currents have debated whether early modern Portugal was cursed by an excessive dependence on agricultural imports due to being unable to feed its population. In this short paper, the first long-run systematic quantitative study of this question, we show that the former view is a myth and therefore could not be a curse. Throughout the entire period, a certain amount of grain was in fact imported but cereal purchases abroad never represented more than a diminutive percentage of total food consumption. More importantly, the country carried out a diversified trade in foodstuffs which was seldom seriously out of balance. Portuguese agriculture showed itself consistently capable of specializing in different foodstuffs for export. It was thus not hopelessly inefficient and succeeded reasonably well in meeting the basic nutritional needs of the population.info:eu-repo/semantics/publishedVersio
The chronic food deficit of early modern Portugal : curse or myth?
Two historiographical currents have debated whether early modern Portugal was cursed by an excessive dependence on foreign food imports as a result of being unable to feed its population, or not. In this short paper, the first long-run systematic quantitative study of this question, we show that the former view is a myth and therefore could not be a curse. Throughout the entire period, a certain amount of grain was in fact imported but cereal purchases abroad never represented more than a diminutive percentage of total food consumption. More importantly, the country carried out a diversified trade in foodstuffs which was seldom seriously out of balance. Portuguese agriculture showed itself consistently capable of specializing in different foodstuffs for export. It was thus not hopelessly inefficient and succeeded reasonably well in meeting the basic nutritional needs of the population
Political ideology and overconfidence in decision-making
This dissertation aims to analyze the correlation between overconfidence and political ideologies. Because we live in the European Union that is facing social and economic disintegrations as well as new challenges, it’s more usual to see the arising of more extreme, radical political ideologies. In this paper it is studied, based on previous literature, how conservatives/right-wing parties might display higher amounts of overconfidence bias than liberals/left-wing parties. With the assistance of an online survey, overconfidence is tested not only in financial literacy but also in decision making. Subjective and Objective Knowledge are also analyzed independently so that it is possible to correlate both overconfidence and political ideologies. Regression Models are also used. It was confirmed that it’s not possible to correlate objective knowledge and political ideology, however it wasn’t possible to confirm that conservatives do display higher amounts of overconfidence than liberals. It was concluded that political ideology might not be a good estimator for overconfidence.Esta dissertação procura analisar a correlação entre ideologias polÃticas e o excesso de confiança. Porque atualmente vivemos na União Europeia que sofre com uma desintegração social e económica, e novos desafios, é frequente ver a ascensão de partidos e ideologias mais extremistas e radicais. Nesta dissertação é estudado como Conservadores/ Defensores de partidos de Extrema Direita cometem mais o erro de excesso de confiança do que os Liberais/Defensores de partidos de Extrema Esquerda, algo já defendido anteriormente noutros estudos cientÃficos. Com o auxÃlio de um questionário realizado online, o excesso de confiança é testado no conhecimento financeiro, assim como na tomada de decisão de cada indivÃduo. Conhecimento Subjetivo e Objetivo são também analisados independentemente, de forma a ser possÃvel correlacionar o excesso de confiança com as diferentes ideologias polÃticas. Modelos de Regressão Linear são também usados. Foi confirmado que não é possÃvel correlacionar conhecimento objetivo com ideologias polÃticas, no entanto, não foi possÃvel confirmar que pessoas mais conservadoras demonstram maiores nÃveis de excesso de confiança do que liberais. Foi concluÃdo que ideologias polÃticas não são o melhor estimador para prever o excesso de confiança de um individuo
The great escape? The contribution of the empire to Portugal’s economic growth, 1500-1800
Newly assembled macroeconomic statistics for early modern Portugal reveal one
of Europe’s most vigorous colonial traders and at the same time one of its least
successful growth records. Using an estimated model in the spirit of Allen (2009)
we conclude that intercontinental trade had a substantial and increasingly
positive impact on economic growth. In the heyday of colonial expansion,
eliminating the economic links to empire would have reduced Portugal’s per
capita income by roughly a fifth. While the empire helped the domestic economy
it was not sufficient to annul the tendency towards decline in relation to Europe’s
advanced core which set in from the 17th century onwards. We conclude that the
explanation for Portugal’s long-term backwardness must be sought primarily in
domestic condition
Alkaline treatments to render starch-based biodegradable polymers self-mineralizable
The present research aims to develop a new route for surface functionalization of biodegradable polymers. The method is based on a wet chemistry modification, resulting in etching and/or hydrolysis in order to increase the amount of polar groups, such as hydroxyl (--OH) and carboxylic (--COOH) groups on the surface of the polymer. The polymer used as substrate was a corn starch-ethylene vinyl alcohol biodegradable blend (SEVA-C). For that purpose it was used in two different types of activation: (a) calcium hydroxide solution [Ca(OH)(2)] and (b) sodium hydroxide solution (NaOH). These treatments lead to the formation carboxylic acid-rich SEVA-C surfaces. Then, the samples were soaked in simulated body fluid (SBF) for different time periods of time until 7 days. After 1 day in SBF, the surface of SEVA-C was fully covered with spherulite particles. As the soaking time increased, the particles increased and coalesced, leading to the formation of a dense and uniform layer. Furthermore, thin-film X-ray diffraction confirms that the layer formed on the surface of the polymer was an apatite-like layer. These results suggest that this rather simple treatment is a good method for surface functionalization and subsequent mineral nucleation and growth on biodegradable polymeric surfaces to be used for bone-related applications
Sleep and quality of life in college students:comparison between sexe
College students are undergoing major academic and psychosocial pressures and show preference for evening activities. Due to the increasing enrollment in higher education and the propensity for sleep problems could jeopardize the health, academic performance and quality of life, the goal was to analyze the relationship between perceptions of quality of sleep (QS) and the perception of quality of life (QoL) among college students, comparing sexes.info:eu-repo/semantics/publishedVersio
Study of the influence of Beta-radiation on the properties and mineralization of different starch-based biomaterials
In this work, the effects of beta-radiation are assessed, for the first time, on starch-based biodegradable polymers, with the aim of using it as an alternative sterilization process to the previously studied sterilization methods. Different doses of radiation were used in order to investigate the possibility of using this sterilization technique as a treatment to tailor the surface and bulk properties (namely mechanical) of these polymers. The as-treated substrates were characterized by water-uptake measurements and contact angle (theta) measurements. The mechanical properties of the materials were characterized by tensile tests by means of ultimate tensile strength (UTS) and strain at break (epsilon). The fracture of the surfaces was observed by scanning electron microscopy (SEM). Dynamic mechanical analysis (DMA) was also used to characterize the viscolelastic behavior of the irradiated materials. The main effect of sterilization with beta-radiation over the starch-based polymers seems to be a surface modification by an increase of the hydrophilicity. Nevertheless, because beta-radiation did not significantly affect the mechanical properties, it can be regarded as an effective way of modifying the surface for applications were more hydrophilic surfaces are desirable
Preparation of bioactive coatings on the surface of bioinert polymers through an innovative auto-catalytic electroless route
The aim of this research was to develop a new methodology to obtain bioactive coatings
on bioinert and biodegradable polymers that are not intrinsically bioactive. In this study, three types
of materials were used as substrates: (i) high molecular weight polyethylene (HMWPE) and two
different types of starch based blends (ii) starch/ethylene vinyl alcohol blends, SEVA-C, and (iii)
starch/cellulose acetate blends, SCA. These materials were obtained by injection moulding and by
extrusion with blowing agents in order to obtain compact/porous 3D architectures. Three types of
baths were developed in order to produce the newly proposed auto-catalytic Ca-P coatings: (i)
alkaline, (ii) acid, and (iii) oxidant bath. The obtained results indicated that it was possible to coat
the materials surfaces with calcium phosphate (Ca-P) layer with only 60 min of immersion in the
different types of auto-catalytic solutions. These innovative auto-catalytic electroless route allows
for the production of an adherent bioactive film on the polymeric surfaces. Furthermore, it was
possible observe by SEM/EDS the clear bioactive nature of the Ca-P coatings after different
immersion periods, in a simulated body fluid (SBF)
Relação entre a sintomatologia psicopatológica, adesão ao tratamento e qualidade de vida na infecção pelo HIV e Aids = Relationship among psychopathological symptoms, treatment adherence and quality of life in HIV/AIDS Infection
O presente estudo observou a existência de relações significativas entre sintomatologia psicopatológica (BSI), adesão ao tratamento (CEAT-VIH) e qualidade de vida (WHOQOL-Bref) em 125 pessoas HIV-positivo/AIDS em tratamento antirretroviral, atendidos em um hospital do Porto (Portugal). A sintomatologia psicopatológica correlacionou-se negativamente com adesão ao tratamento e qualidade de vida, e a adesão ao tratamento associou-se positivamente com a qualidade de vida. O modelo preditor de adesão ao tratamento, mediante análise de regressão múltipla, incluiu a ausência de sintomatologia psicopatológica, o comportamento de retirada dos medicamentos na farmácia hospitalar e a presença de efeitos colaterais do tratamento (R² =0,30). Ademais, observou-se um efeito mediador de sintomatologia psicopatológica entre a adesão ao tratamento e a qualidade de vida das pessoas com HIV/AIDS.The study shows evidence of statistical association among psychopathological symptoms (BSI), treatment adherence (CEAT-VIH) and quality of life (WHOQOL-Bref) in 125 HIV-positive/AIDS patients followed at Porto Hospital (Portugal). The psychopathological symptoms present a negative correlation with treatment adherence and quality of life. On the other hand, adherence was positively correlated with quality of life. The model of adherence to the antiretroviral treatment using multiple regression analysis includes absence of psychopathological symptoms, an adherence behavior (i.e. to get the medication at the hospital's pharmacy) and the experience of side effects because of medication (R² = 0.30). Besides, psychopathological symptoms have a mediation effect between adherence and quality of life in people with HIV/AIDS
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