Valor taxonómico de la morfología de las semillas en las especies del género "Erica" presentes en el NO de España

Se estudia la morfología de las semillas en 1as 10 especies de1 género Erica que e forma espontánea se desarrollan en Galicia (N.O. de España). Para su observación, encaminada a comprobar el valor taxonómico de los caracteres morfológicos seminales, se han utiliado microscopio óptico y electrónico de barrido.El resultado de este estudio es el reconocimiento de diferencias dentro del género. e incluye además una clave para las especies estudiadas, basada en la morfología de las semillas.The seed morphology of 10 species of the genus Erica L. from Galicia (NW of Spain) gas studied, utilizing the optical microscope and scanning electron microscope, to determine the significance of seed coat features as taxonomic characters.The result of this study was the reconigtion of differences in seed morphology within the genus. A key to galician taxa of Erica based on seed morphology is included

Identification of the degradation mechanisms of organic solar cells:active layer and interfacial layers

Organic Solar Cells (OSCs) represent a photovoltaic technology with multiple interesting application properties. However, the establishment of this technology into the market is subject to the achievement of operational lifetimes appropriate to their application purposes. Thus, comprehensive understanding of the degradation mechanisms occurring in OSCs is mandatory in both selecting more intrinsically stable components and/or device architectures and implementing strategies that mitigate the encountered stability issues. Inverted devices can suffer from mechanical stress and delamination at the interface between the active layer, e.g. poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM), and the hole transport layer, e.g. poly(3,4-ethylenedioxythiophene):poly(p-styrene sulfonate) (PEDOT:PSS). This work proposes the incorporation of a thin adhesive interlayer, consisting of a diblock copolymer composed of a P3HT block and a thermally-triggerable, alkyl-protected PSS block. In this context, the synthesis of poly(neopentyl p-styrene sulfonate) (PNSS) with controlled molar mass and low dispersity (Ð ≤ 1.50) via Reversible Addition-Fragmentation chain Transfer (RAFT) polymerisation has been extensively studied. Subsequently, Atomic Force Microscopy (AFM) was explored to characterise the thermal deprotection of P3HT-b-PNSS thin layers to yield amphiphilic P3HT-b-PSS, indicating that surface deprotection prior to thermal treatment could occur. Finally, structural variation of the alkyl protecting group in PSS allowed reducing the thermal treatment duration from 3 hours (P3HT-b-PNSS) to 45 minutes for the poly(isobutyl p-styrene sulfonate) (PiBSS) analogous copolymer. Another critical issue regarding the stability of OSCs is the sunlight-driven chemical degradation of the active layer. In the study herein, the combination of experimental techniques and theoretical calculations has allowed identification of the structural weaknesses of poly[(4,4’- bis(2-ethylhexyl) dithieno [3,2-b:2’,3’-d]silole)-2,6-diyl-alt-(4,7-bis(2-thienyl)-2,1,3-benzothiadiazole)-5,5’-diyl], Si-PCPDTBT, upon photochemical treatment in air. Additionally, the study of the relative photodegradation rates in air of a series of polymers with systematically modified backbones and/or alkyl side chains has shown no direct correlation between chemical structure and stability. It is proposed instead that photostability is highly dependent on the crystalline character of the deposited films. Furthermore, it was verified that photostability of blends based on these polymers is dictated by the (de)stabilising effect that [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) has over each polymer. Finally, a multiscale analysis on the degradation of solar cells based on poly[4,4' bis(2- ethylhexyl) dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-[2,5 bis(3 tetradecylthiophen 2-yl)thiazole[5,4-d]thiazole)-1,8-diyl] and PCBM, indicated that by judicious selection of device layers, architectures, and encapsulation materials, operational lifetimes up to 3.3 years with no efficiency losses can be successfully achieved

Extreme Value Distributions

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The relevance of entrepreneurs personality characteristics for new ventures internacionalization

Mestrado em Ciências EmpresariaisO Empreendedorismo Internacional (EI) tem origem na área do negócio internacional e do empreendedorismo. Baseada em três abordagens teóricas, visão baseada no conhecimento, teoria dos escalões superiores e perspectiva cognitiva, esta investigação pretende contribuir para uma melhor compreensão do processo de internacionalização e do papel desempenhado pelas características do empreendedor. Este estudo analisa a influência das características empreendedoras e de personalidade, bem como, as característica da empresa e a sua influência na internacionalização. Esta investigação apresenta os seguintes objectivos: i) desenvolver um quadro conceptual estruturado para o processo de internacionalização; ii) identificar características empreendedoras do indivíduo e da empresa relevantes para a internacionalização; e iii) distinguir entre novas empresas domésticas e internacionais (DNVs e INVs) relativamente ao mindset empreendedor. As hipóteses foram testadas através de dados recolhidos por questionário e dados secundários obtidos a partir da base de dados eInforma D&B, para DNVs e INVs Portuguesas criadas entre 2004 e 2013. Os resultados forneceram suporte empírico para as relações entre características de personalidade do empreendedor e características empreendedoras. Adicionalmente, foi encontrada uma relação entre a orientação e intenção empreendedoras do indivíduo. Foi encontrado suporte empírico para as relações entre características empreendedoras individuais e a orientação empreendedora e internacional da empresa. Para além disso, a orientação internacional manifestou uma relação positiva relativamente ao tipo de empresa e à percentagem de exportação. Esta investigação forneceu uma abordagem a diferentes níveis destacando o papel do empreendedor cuja personalidade e características empreendedoras são determinantes para a identidade da empresa e para a internacionalização.International Entrepreneurship (IE) has its origins from international business and entrepreneurship research. Contemplating three main frameworks, knowledge-based view, upper echelons theory and cognitive perspective, this research aims to contribute to a better understanding of the internationalization process and the role of the entrepreneur’s characteristics. The study analyzes the influence of the entrepreneur’s personality and entrepreneurial characteristics as well as the firm characteristics and the influence of the latter on internationalization. The following objectives were defined: i) develop a well-structured framework for the internationalization process; ii) identify entrepreneurial characteristics at the individual and firm level relevant to internationalization; and iii) distinguish INVs from DNVs regarding the entrepreneurial mindset. Hypotheses were tested through a survey data combined with secondary data provided by eInforma D&B database for Portuguese INVs and DNVs founded between 2004 and 2013. The results provided empirical support for the relationships between several entrepreneur’s personality characteristics and entrepreneurial characteristics. Additionally, an association was found between individual entrepreneurial orientation and individual entrepreneurial intent. There was also empirical support for relationships between individual entrepreneurial characteristics and the firm’s entrepreneurial and international orientation. Furthermore, international orientation was positively related to the type of venture and the firm’s export percentage. The present research provided a different level approach highlighting the role of the entrepreneur whose personality and entrepreneurial characteristics are determinant to the firm’s identity and its internationalization

Depressive symptoms and alcohol use among adolescents

Alcohol is the most consumed substance by young people, sometimes it’s associated with depressive symptoms. Objective: Assess the factors associated with alcohol use among 13-year-old teenagers, like depressive symptoms. Methods: Data of a population-based cohort of urban teenagers included cross-sectional information of 919 boys and 1016 girls collected by self-reported questionnaire. Depressive symptoms were evaluated using Beck Depressive Inventory II (BDI). The Mann-Whitney test was used to compare medians. Odds ratio (OR) and multiple linear regression (β) were performed to estimate the magnitude of associations with 95% confidence intervals (95%CI). The final model was adjusted for parents’ education, sports, smoking, have friends who drink and parents’ history of depression. Results: Overall 515(50.0%) girls and 425(44.9%) boys have experimented alcoholic beverages and, 48(4.7%) girls and 62(6.6%) boys have drunk(one drink at least once time per month) at 13-year-old. For both genders, after adjustment, being experimenter was significantly associated with parents’ education, tobacco use and friends who drink. In girls, characteristics that was significantly associated to be drinker were tobacco use OR=6.9(3.1-15.2) and friends who drink OR=6.4(2.7-15.2). In boys, to be drinker was associated with tobacco use OR=5.9(2.7-13.0), friends who drink OR=7.3(3.5-15.4) and cohabiting with people who drink OR=5.1(1.4-17.6). Adolescents who have drunk presented a high score in BDI [median(25p-75p)] in girls[6.01(2.00-10.00)vs.6.38(3.00-11.99),p=0.002)] and in boys[3.00(1.01-6.01)vs.3.99(1.01-6.99),p=0.039]. After adjustment, the association was not significant in girls(β=0.583,95%CI[-0.483;1.648]) in boys(β=0.623,95%CI[-0.170;1.417]). Conclusions: Among 13-year-old adolescents parents’ education, smoking and friends who drink were associated with drinking behaviour. After adjustment, depressive symptoms did not show a significant association with alcohol use

Processing gender agreement errors in pleasant and unpleasant words: An ERP study at the sentence level

In this study we examine the extent to which aspects such as the emotionality coded in words may interfere with the processing of gender agreement errors in a sentence grammaticality judgement task. We follow the methodological pattern of our previous experiments, using consistently the same kind of structure and task (gender agreement) and only emotional (pleasant vs unpleasant) words, in an attempt to clarify whether neural correlates and performance show similar patterns in positive and negative words. We found an emotional effect in the N400 time window for unpleasant adjectives as well as the classic grammaticality effects in the left anterior negativity (LAN) and the P600 components. Overall, our results confirm those of our previous studies in that the LAN and the P600 grammaticality effects are not influenced by the emotional valence of moderately arousing pleasant and unpleasant words, showing that during sentence reading morphosyntactic error detection seems to be encapsulatedThe present study was supported by the Spanish Ministry of Economy and Competitiveness and the Fondo Europeo de Desarrollo Regional (MINECO/FEDER; Grant Nos. PSI2015-65116-P) and a research grant from the Autonomous Government of Galicia (Consellería de Educación, Xunta de Galicia, grant code GRC 2015/006)S

A general estimator for the right endpoint with an application to supercentenarian women's record

We extend the setting of the right endpoint estimator introduced in Fraga Alves and Neves (Statist. Sinica 24:1811{1835, 2014) to the broader class of light-tailed distributions with finite endpoint, belonging to some domain of attraction induced by the extreme value theorem. This stretch enables a general estimator for the finite endpoint, which does not require estimation of the (supposedly non-positive) extreme value index. A new testing procedure for selecting max-domains of attraction also arises in connection with the asymptotic properties of the general endpoint estimator. The simulation study conveys that the general endpoint estimator is a valuable complement to the most usual endpoint estimators, particularly when the true extreme value index stays above -1/2, embracing the most common cases in practical applications. An illustration is provided via an extreme value analysis of supercentenarian women data

The role of emotionality in the acquisition of new concrete and abstract words

A processing advantage for emotional words relative to neutral words has been widely demonstrated in the monolingual domain (e.g., Kuperman et al., 2014). It is also well-known that, in bilingual speakers who have a certain degree of proficiency in their second language, the effects of the affective content of words on cognition are not restricted to the native language (e.g., Ferré et al., 2010). The aim of the present study was to test whether this facilitatory effect can also be obtained during the very early stages of word acquisition. In the context of a novel word learning paradigm, participants were trained on a set of Basque words by associating them to their Spanish translations. Words’ concreteness and affective valence were orthogonally manipulated. Immediately after the learning phase and 1 week later, participants were tested in a Basque go-no go lexical decision task as well as in a translation task in which they had to provide the Spanish translation of the Basque words. A similar pattern of results was found across tasks and sessions, revealing main effects of concreteness and emotional content as well as an interaction between both factors. Thus, the emotional content facilitated the acquisition of abstract, but not concrete words, in the new language, with a more reliable effect for negative words than for positive ones. The results are discussed in light of the embodied theoretical view of semantic representation proposed by Kousta et al. (2011)This research was funded by the Spanish Ministry of Economy and Competitiveness (PSI2012-37623 and PSI2012-32834). Besides, it was funded by FCT (Foundation for Science and Technology) through the state budget, with reference IF/00784/2013/CP1158/CT0013S

Reducción de microcontaminantes orgánicos persistentes en medios acuosos : fotodegradación directa y degradación fotocatalizada de propranolol en agua de mar

[Abstracts] Pharmaceuticals and Personal Care Products (PPCPs) ultimately end up in aquatic environments, including the seas, where they behave as persistent, due to their continuous input, and bioaccumulate, with known negative consequences for marine ecosystems. However, there is a lack of studies concerning their degradation mechanisms in different conditions and environments. As the whole surface of seawater receives direct sunlight, it can promote photochemical reactions in these organic molecules leading to photoproducts which differ from the parent compound, and that may have different effects on the ecosystems. The aim of this project was to carry out a first approach to environmental physical organic chemistry, studying the way a pharmaceutical commonly detected in surface waters, the β-blocker propranolol, interacts with visible and ultraviolet radiation under different conditions, including the presence of the photocatalyst TiO2 P25, in distilled water and seawater. Propranolol hydrochloride solutions (30 mg∙L-1) were placed in glass vessels and irradiated with a medium or low pressure Hg vapour lamp during 2-3.5 hours. TiO2 Degussa P25 was added to the solution in photocatalytic experiments. The obtained results showed an increasing efficiency when samples containing propranolol were treated with UV radiation rather than with Vis radiation. When these solutions were irradiated with Vis light, seawater matrix was found to increase the first order photodegradation rate constants. Such dependence was not observed upon direct UV photolysis. For photocatalytic experiments, a correlation was established between the pH of the solution and the rate of degradation, becoming faster at higher pH values. An initial inhibition in the HPLC-DAD area vs. time kinetic profile of propranolol was also observed, due to a combination of both the acidity of the medium and the change in adsorption characteristics of the catalyst when it is being irradiated. The saline media was found to decrease the photocatalytic rate constant. Three photoproducts (mono-, di- and trihydroxypropranolol) were assigned by using high-resolution mass spectrometry, and a mechanism for their formation was proposed.[Resumen] Los compuestos farmacéuticos y cosméticos (en inglés PPCPs: Pharmaceuticals and Personal Care Products) son liberados a ambientes acuáticos, llegando finalmente al mar, donde, debido a su continua introducción se comportan como persistentes, y se bioacumulan, con sobradamente conocidas consecuencias negativas para los ecosistemas marinos. Pese a ello, existe una carencia de estudios relativos a sus mecanismos de degradación en diferentes condiciones y ambientes. La superficie del agua de mar recibe directamente la radiación solar, de modo que ésta puede provocar cambios fotoquímicos en los citados compuestos, dando lugar a fotoproductos de distintas características, y que pueden provocar sobre los ecosistemas efectos diferentes de los de la sustancia de partida. Este proyecto representa una primera aproximación al área de la Química Física Orgánica Ambiental a través del estudio de la interacción de un fármaco frecuentemente detectado en aguas superficiales, el β-bloqueante propranolol, con la luz visible y la ultravioleta bajo diferentes condiciones, incluyendo la presencia del fotocatalizador TiO2 P25, en agua destilada y agua de mar. Para ello, se introdujeron disoluciones de propranolol (30 mg∙L-1) en su forma hidrocloruro en fotorreactores de vidrio y fueron irradiadas con lámparas de vapor de Hg de media o baja presión durante un periodo de 2 a 3 horas y media. En el caso de los experimentos de fotocatálisis, se añadió TiO2 Degussa P25 a la disolución. Los resultados mostraron una eficiencia de degradación más alta para las muestras de propranolol que fueron irradiadas con radiación UV en vez de visible. Cuando las disoluciones se irradiaron con esta última, se observó un incremento en las constantes cinéticas de orden uno en aquellas de matriz marina. Dicha dependencia no se observó para los experimentos de fotólisis directa con luz UV. Para los experimentos de fotocatálisis, se estableció una correlación entre el pH de la disolución y la velocidad de la degradación, siendo ésta mayor a los valores de pH más altos. También se observó una inhibición inicial en la traza cinética, área obtenida por HPLC-DAD frente al tiempo, del propranolol, atribuida a una combinación de efectos asociados al pH y al cambio inducido por la irradiación en las características de adsorción del catalizador. En este caso, el medio salino disminuyó las velocidades de reacción. El empleo de la técnica de espectrometría de masas permitió la identificación de tres fotoproductos (mono-, di- y tri-hidroxipropanol), y la proposición de un mecanismo para su formación.Traballo fin de mestrado (UDC.CIE). Química ambiental y fundamental. Curso 2011/201