Intramolecular surfaces for vicinal proton–proton coupling constants 3JHH

Equations for the intramolecular surfaces of the 3JHH coupling constants in ethane, ethylene, and acetylene are formulated, and the corresponding coefficients are estimated from calculations at the DFT/B3LYP level. The chosen variables are changes in bond lengths, in the torsion angle φ between the coupled protons Ha and Hb, in bond angles, and in dihedral angles. The 3JHH surface of ethane is formulated as an extended Karplus equation with the coefficients of a truncated Fourier series on the torsion angle φ expanded as second-order Taylor series in the chosen variables taking into account the invariance of 3JHH under reflections and rotations of nuclear coordinates. Partial vibrational contributions from linear and square terms corresponding to changes in the geometry of the Ha − Ca − Cb − Hb fragment are important while those from cross terms are small with a few exceptions. The 3JHH surface of ethane is useful to predict contributions to 3JHH from changes in local geometry of derivatives but vibrational contributions are predicted less satisfactorily. The predicted values at the B3LYP/BS2 level of the 3JHH couplings (vibrational contributions at 300 K) from equilibrium geometries are 9.79 (−0.17) for acetylene, and 17.08 (1.93) and 10.73(0.93) for the trans and cis couplings of ethylene.

Willingness Towards Continuous Assessment

Among the factors that affect the convergence towards the European Higher Education Area, university teaching staff's motivation is fundamental, and consequently, it is crucial to empirically know what this motivation depends on. In this context, one of the most relevant changes in the teacher-student relationship is assessment. In fact, the transition from a static assessment -focused on only one temporal point (final exam)- to a dynamic assessment, will require changes in thought and action, both on the part of teachers and students. In this line, the objective of this paper is to analyze the determinants of teaching staff's predisposition to the continuous assessment method. Specifically, we consider the following explanatory dimensions: teaching method used (which measures their degree of involvement with the ongoing adaptation process), type of subject (core, compulsory and optional), and teacher's personal characteristics (professional status and gender). The empirical application carried out at the University of Alicante uses Logit Models with Random Coefficients to capture heterogeneity, and shows that "cooperative learning" is a clear-cut determinant of "continuous assessment" as well as "continuous assessment plus final examination". Also, a conspicuous result, which in turn becomes a thought-provoking finding, is that professional status is highly relevant as a teacher's engagement is closely related to prospects of stability. Consequently, the most relevant implications from the results revolve around the way academic institutions can propose and implement inducement for their teaching staff.

Fostering Teaching Staff's Engagement in Continuous Assessment

Among the factors that affect the convergence towards the European Higher Education Area, university teaching staff's motivation is fundamental, and consequently, it is crucial to empirically know what this motivation depends on. In this context, one of the most relevant changes in the teacher-student relationship is assessment. In fact, the transition from a static assessment -focused on only one temporal point (final exam)- to a dynamic assessment, will require changes in thought and action, both on the part of teachers and students. In this line, the objective of this paper is to analyze the determinants of teaching staff's predisposition to the continuous assessment method. Specifically, we consider the following explanatory dimensions: teaching method used (which measures their degree of involvement with the ongoing adaptation process), type of subject (core, compulsory and optional), and teacher's personal characteristics (professional status and gender). The empirical application carried out at the University of Alicante uses Logit Models with Random Coefficients to capture heterogeneity, and shows that "cooperative learning" is a clear-cut determinant of "continuous assessment" as well as "continuous assessment plus final examination". Also, a conspicuous result, which in turn becomes a thought-provoking finding, is that professional status is highly relevant as a teacher's engagement is closely related to prospects of stability. Consequently, the most relevant implications from the results revolve around the way academic institutions can propose and implement inducement for their teaching staff.

Mercury determination in urine samples by gold nanostructured screen-printed carbon electrodes after vortex-assisted ionic liquid dispersive liquid–liquid microextraction

A novel approach is presented to determine mercury in urine samples, employing vortex-assisted ionic liquid dispersive liquid–liquid microextraction and microvolume back-extraction to prepare samples, and screen-printed electrodes modified with gold nanoparticles for voltammetric analysis. Mercury was extracted directly from non-digested urine samples in a water-immiscible ionic liquid, being back-extracted into an acidic aqueous solution. Subsequently, it was determined using gold nanoparticle-modified screen-printed electrodes. Under optimized microextraction conditions, standard addition calibration was applied to urine samples containing 5, 10 and 15 μg L−1 of mercury. Standard addition calibration curves using standards between 0 and 20 μg L−1 gave a high level of linearity with correlation coefficients ranging from 0.990 to 0.999 (N = 5). The limit of detection was empirical and statistically evaluated, obtaining values that ranged from 0.5 to 1.5 μg L−1, and from 1.1 to 1.3 μg L−1, respectively, which are significantly lower than the threshold level established by the World Health Organization for normal mercury content in urine (i.e., 10–20 μg L−1). A certified reference material (REC-8848/Level II) was analyzed to assess method accuracy finding 87% and 3 μg L−1 as the recovery (trueness) and standard deviation values, respectively. Finally, the method was used to analyze spiked urine samples, obtaining good agreement between spiked and found concentrations (recovery ranged from 97 to 100%).

O cancioneiro de Airas Engeitado, trovador

As cantigas da lírica galego-portuguesa são obras de um conjunto diversificado de autores e constituem-se como um rico património literário e cultural da Idade Média, produzido entre os séculos XII e XIV. Ao longo dos tempos, o seu interesse tem conduzido ao estudo de aspetos da transmissão dos textos, da biografia dos trovadores e das influências recebidas de territórios além peninsulares, bem como tem levado à concretização de diversas edições críticas. A presente tese tem como objetivo a edição crítica das cantigas de um dos trovadores da lírica galego-portuguesa, Airas Engeitado. Este autor foi editado pela última vez em 1932, por José Joaquim Nunes, juntamente com as cantigas de amor que Carolina Michaëlis considerou excluídas do cancioneiro da Ajuda. Esta edição não foi, até à data e que seja do nosso conhecimento, revista por nenhum editor. A edição de Nunes, sobre a qual o próprio Nunes manifestou dúvidas, apresenta os textos de Engeitado bastante deturpados, pelo que se procede aqui a uma nova edição crítica, com critérios de edição mais exigentes que os de Nunes na edição referida e normas de transcrição diferentes. Procede-se também ao enquadramento e explicação de uma lírica de autor com caraterísticas que podemos considerar singulares, no contexto da lírica galego-portuguesa. As quatro cantigas de amor que considero da autoria de Airas Engeitado chegaram até nós pelo Cancioneiro da Biblioteca Nacional (B), pelo Cancioneiro da Biblioteca Vaticana (V) e foram mencionadas na Tavola Colocciana, índice de B. Além do estabelecimento crítico das cantigas de Airas Engeitado, fazem-se diversos apontamentos sobre questões paleográficas, notas que abordam as divergências existentes entre as minhas leituras dos testemunhos e as leituras do editor anterior, bem como notas que remetem para peculiaridades lexicais, sintáticas ou dos esquemas de versificação das cantigas. Em breve capítulo, resume-se o pouco que se sabe sobre a biografia de Airas Engeitado e faz-se o enquadramento das cantigas editadas na tradição manuscrita. Questão de extrema relevância é a da dupla atribuição da cantiga A gran direito lazerei, que equaciono e discuto também no capítulo sobre a tradição manuscrita. É nesta reflexão que fundamento a minha decisão de incluir a cantiga na presente edição, apesar de ela ter sido, até à data, unanimemente atribuída a Afonso Eanes do Coton.

Sur les tests lisses d'ajustement dans le context des series chronologiques

La plupart des modèles en statistique classique repose sur une hypothèse sur la distribution des données ou sur une distribution sous-jacente aux données. La validité de cette hypothèse permet de faire de l’inférence, de construire des intervalles de confiance ou encore de tester la fiabilité du modèle. La problématique des tests d’ajustement vise à s’assurer de la conformité ou de la cohérence de l’hypothèse avec les données disponibles. Dans la présente thèse, nous proposons des tests d’ajustement à la loi normale dans le cadre des séries chronologiques univariées et vectorielles. Nous nous sommes limités à une classe de séries chronologiques linéaires, à savoir les modèles autorégressifs à moyenne mobile (ARMA ou VARMA dans le cas vectoriel). Dans un premier temps, au cas univarié, nous proposons une généralisation du travail de Ducharme et Lafaye de Micheaux (2004) dans le cas où la moyenne est inconnue et estimée. Nous avons estimé les paramètres par une méthode rarement utilisée dans la littérature et pourtant asymptotiquement efficace. En effet, nous avons rigoureusement montré que l’estimateur proposé par Brockwell et Davis (1991, section 10.8) converge presque sûrement vers la vraie valeur inconnue du paramètre. De plus, nous fournissons une preuve rigoureuse de l’inversibilité de la matrice des variances et des covariances de la statistique de test à partir de certaines propriétés d’algèbre linéaire. Le résultat s’applique aussi au cas où la moyenne est supposée connue et égale à zéro. Enfin, nous proposons une méthode de sélection de la dimension de la famille d’alternatives de type AIC, et nous étudions les propriétés asymptotiques de cette méthode. L’outil proposé ici est basé sur une famille spécifique de polynômes orthogonaux, à savoir les polynômes de Legendre. Dans un second temps, dans le cas vectoriel, nous proposons un test d’ajustement pour les modèles autorégressifs à moyenne mobile avec une paramétrisation structurée. La paramétrisation structurée permet de réduire le nombre élevé de paramètres dans ces modèles ou encore de tenir compte de certaines contraintes particulières. Ce projet inclut le cas standard d’absence de paramétrisation. Le test que nous proposons s’applique à une famille quelconque de fonctions orthogonales. Nous illustrons cela dans le cas particulier des polynômes de Legendre et d’Hermite. Dans le cas particulier des polynômes d’Hermite, nous montrons que le test obtenu est invariant aux transformations affines et qu’il est en fait une généralisation de nombreux tests existants dans la littérature. Ce projet peut être vu comme une généralisation du premier dans trois directions, notamment le passage de l’univarié au multivarié ; le choix d’une famille quelconque de fonctions orthogonales ; et enfin la possibilité de spécifier des relations ou des contraintes dans la formulation VARMA. Nous avons procédé dans chacun des projets à une étude de simulation afin d’évaluer le niveau et la puissance des tests proposés ainsi que de les comparer aux tests existants. De plus des applications aux données réelles sont fournies. Nous avons appliqué les tests à la prévision de la température moyenne annuelle du globe terrestre (univarié), ainsi qu’aux données relatives au marché du travail canadien (bivarié). Ces travaux ont été exposés à plusieurs congrès (voir par exemple Tagne, Duchesne et Lafaye de Micheaux (2013a, 2013b, 2014) pour plus de détails). Un article basé sur le premier projet est également soumis dans une revue avec comité de lecture (Voir Duchesne, Lafaye de Micheaux et Tagne (2016)).

Perspectives in Resource Management and Climate Change Adaptation in the Southern and Eastern Mediterranean. MEDPRO Policy Paper No. 6, March 2013

This policy paper focuses on the sustainable management of some key natural resources in southern and eastern Mediterranean countries (SEMCs) under climate change and anthropogenic pressures. In a business-as-usual and even more so in a failed cooperation scenario, water resources, ecosystems and biodiversity in the region are under stress, with negative consequences for agriculture, food security, tourism and development. However, proper adaptation strategies are shown to be effective in reconciling resource conservation with GDP, trade and population growth. These need be implemented in different ways: technological, institutional, behavioural; and at different levels: regional, national and international. There is ample room for fruitful cooperation between the EU and SEMCs in this area, which can take the form of EU direct financial and technical support when resources in SEMCs are scarce, and of multilateral and bilateral cooperation programmes to improve resource efficiency. The EU could also take on the role of coordinating these different bilateral actions and, at the same time, support SEMCs to establish a structured programme focused on the communication and dissemination of emerging best practices.

Relação das Perceções de Justiça Organizacional na Avaliação de Desempenho

A avaliação de desempenho é utilizada pelas organizações para aprovisionar os programas de desenvolvimento, distribuição de recompensas e, também, para fornecer uma perceção de justiça aos trabalhadores em relação às suas tarefas, aos postos de trabalho, à organização, às chefias e aos departamentos. É um processo contínuo através do qual a comunicação é afetivamente feita entre as chefias e os funcionários de uma organização. O objetivo deste trabalho é explorar o sistema de avaliação de desempenho no âmbito da justiça organizacional, e, mais especificamente, dos três tipos de justiça, designadamente, a justiça distributiva, a justiça procedimental e a justiça interacional. Assim, pretende-se conhecer a perceção dos militares em relação à distribuição de resultados na avaliação de desempenho, à forma como se processa a avaliação de desempenho e à dinâmica das relações na avaliação de desempenho. A amostra deste estudo foram 231 militares, das categorias de Oficiais e Sargentos, de várias especialidades, da Força Aérea Portuguesa. Os dados foram recolhidos através de um questionário disponibilizado a todos os militares dos Quadros Permanentes da Força Aérea. Pelos resultados obtidos, observou-se que há perceção de justiça organizacional no sistema de avaliação do mérito nos militares da Força Aérea, com coeficientes positivos em todas as dimensões de justiça. Destaca-se a justiça interpessoal, seguida da distributiva, procedimental, e informacional. Verifica-se ainda que as perceções de justiça procedimental e informacional estão muito próximas.

Assortative matching of exporters and importers

This paper uses the opening of the US textile/apparel market for China at the end of the Multifibre Arrangement in 2005 as a natural experiment to provide evidence for positive assortative matching of Mexican exporting firms and US importing firms by their capability. We identify three findings for liberalized products by comparing them to other textile/apparel products: (1) US importers switched their Mexican partners to those making greater preshock exports, whereas Mexican exporters switched their US partners to those making fewer preshock imports; (2) for firms who switched partners, trade volume of the old partners and the new partners are positively correlated; (3) small Mexican exporters stop exporting. We develop a model combining Becker-type matching of final producers and suppliers with the standard Melitz-type model to show that these findings are consistent with positive assortative matching but not with negative assortative matching or purely random matching. The model indicates that the findings are evidence for a new mechanism of gain from trade.

Sur les tests lisses d'ajustement dans le context des series chronologiques

La plupart des modèles en statistique classique repose sur une hypothèse sur la distribution des données ou sur une distribution sous-jacente aux données. La validité de cette hypothèse permet de faire de l’inférence, de construire des intervalles de confiance ou encore de tester la fiabilité du modèle. La problématique des tests d’ajustement vise à s’assurer de la conformité ou de la cohérence de l’hypothèse avec les données disponibles. Dans la présente thèse, nous proposons des tests d’ajustement à la loi normale dans le cadre des séries chronologiques univariées et vectorielles. Nous nous sommes limités à une classe de séries chronologiques linéaires, à savoir les modèles autorégressifs à moyenne mobile (ARMA ou VARMA dans le cas vectoriel). Dans un premier temps, au cas univarié, nous proposons une généralisation du travail de Ducharme et Lafaye de Micheaux (2004) dans le cas où la moyenne est inconnue et estimée. Nous avons estimé les paramètres par une méthode rarement utilisée dans la littérature et pourtant asymptotiquement efficace. En effet, nous avons rigoureusement montré que l’estimateur proposé par Brockwell et Davis (1991, section 10.8) converge presque sûrement vers la vraie valeur inconnue du paramètre. De plus, nous fournissons une preuve rigoureuse de l’inversibilité de la matrice des variances et des covariances de la statistique de test à partir de certaines propriétés d’algèbre linéaire. Le résultat s’applique aussi au cas où la moyenne est supposée connue et égale à zéro. Enfin, nous proposons une méthode de sélection de la dimension de la famille d’alternatives de type AIC, et nous étudions les propriétés asymptotiques de cette méthode. L’outil proposé ici est basé sur une famille spécifique de polynômes orthogonaux, à savoir les polynômes de Legendre. Dans un second temps, dans le cas vectoriel, nous proposons un test d’ajustement pour les modèles autorégressifs à moyenne mobile avec une paramétrisation structurée. La paramétrisation structurée permet de réduire le nombre élevé de paramètres dans ces modèles ou encore de tenir compte de certaines contraintes particulières. Ce projet inclut le cas standard d’absence de paramétrisation. Le test que nous proposons s’applique à une famille quelconque de fonctions orthogonales. Nous illustrons cela dans le cas particulier des polynômes de Legendre et d’Hermite. Dans le cas particulier des polynômes d’Hermite, nous montrons que le test obtenu est invariant aux transformations affines et qu’il est en fait une généralisation de nombreux tests existants dans la littérature. Ce projet peut être vu comme une généralisation du premier dans trois directions, notamment le passage de l’univarié au multivarié ; le choix d’une famille quelconque de fonctions orthogonales ; et enfin la possibilité de spécifier des relations ou des contraintes dans la formulation VARMA. Nous avons procédé dans chacun des projets à une étude de simulation afin d’évaluer le niveau et la puissance des tests proposés ainsi que de les comparer aux tests existants. De plus des applications aux données réelles sont fournies. Nous avons appliqué les tests à la prévision de la température moyenne annuelle du globe terrestre (univarié), ainsi qu’aux données relatives au marché du travail canadien (bivarié). Ces travaux ont été exposés à plusieurs congrès (voir par exemple Tagne, Duchesne et Lafaye de Micheaux (2013a, 2013b, 2014) pour plus de détails). Un article basé sur le premier projet est également soumis dans une revue avec comité de lecture (Voir Duchesne, Lafaye de Micheaux et Tagne (2016)).

Concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs) in liver samples of different marine mammals (1984-2009)

Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.

(Table T1) Ice rafted debris characteristics of ODP Site 177-1092

We have carried out a multiphase analysis of samples from ODP Site 177-1092, Meteor Rise, subantarctic South Atlantic. Samples were analyzed for ice-rafted debris (IRD [see Table T1]) and stable isotopes from benthic foraminifera [see Murphy et al., 2002, doi:10.1016/S0031-0182(01)00495-3]. Both analyses were performed on the same samples. Additional work was performed to identify the paleomagnetic stratigraphy. The analyzed samples range in age from about 2.6(?) Ma to 4.6 Ma, a time span that saw considerable global warmth, but witnessed overall global refrigeration and the transition to truly bipolar glaciations. IRD arrived frequently during the Early and early Late Pliocene, but only as 'background rafting' (occasional grains per sample). The first identifiable IRD above background rafting is associated with marine isotope stage (MIS) KM4 (~3.18 Ma). Successive IRD peaks become larger, the same pattern as noted at nearby Site 114-704. A very large peak near the top of the record, approximately 2.8 Ma, is considered to represent a hiatus. Peaks below 51.3 meters composite depth (mcd) coincide with positive excursions of the oxygen isotopic record, and with negative excursions of the carbon isotopic curve, a pattern also noted at Site 114-704. However, the reasonably large IRD peak at 51 mcd (tentatively identified with MIS G11) coincides with a positive excursion on the carbon isotopic curve and negative excursion on the oxygen isotopic curve. This relationship suggests a northern hemisphere interglacial, rising sea level, destabilization of the Antarctic margin, and delivery of Antarctic icebergs to the Southern Ocean. Such a mechanism has recently been suggested by Kanfoush et al. (2000, doi:10.1126/science.288.5472.1815) for latest Pleistocene stadial/interstadial oscillations. Here we suggest that such a mechanism may have been in place on glacial/interglacial time scales as early as the Late Pliocene.

Component NRM directions for sediment core HLY0503-06JPC

The Arctic oceans have been fertile ground for the recording of apparent excursions of the geomagnetic field, implying that the high latitude field had unusual characteristics at least over the last 1-2 Myrs. Alternating field demagnetization of the natural remanent magnetization (NRM) of Core HLY0503-6JPC from the Mendeleev Ridge (Arctic Ocean) implies the presence of primary magnetizations with negative inclination apparently recording excursions in sediments deposited during the Brunhes Chron. Thermal demagnetization, on the other hand, indicates the presence of multiple (often anti-parallel) magnetization components with negative inclination components having blocking temperatures predominantly, but not entirely, below ~ 350 °C. Thermo-magnetic tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate that the negative inclination components are carried by titanomaghemite, presumably formed by seafloor oxidation of titanomagnetite. The titanomaghemite apparently carries a chemical remanent magnetization (CRM) that is partially self-reversed relative to the detrital remanent magnetization (DRM) carried by the host titanomagnetite. The partial self-reversal could have been accomplished by ionic ordering during oxidation, thereby changing the balance of the magnetic moments in the ferrimagnetic sublattices.

Fe isotopic composition in continental iron cycle (Table 1)

The effect of continental weathering on the iron isotope compositions of natural materials is investigated. Unweathered igneous rocks, pelagic clay, and dust fall within the range delta56Fe=0 +/- 0.3 per mil. Rivers with large suspended loads also have delta56Fe values near zero. Dilute streams have delta56Fe values that trend towards lower delta56Fe (~-1) suggesting that dissolved riverine iron is isotopically light relative to igneous rocks. Bulk soil and soil leaches display systematically different delta56Fe profiles, indicating that isotopically distinct Fe pools are generated during pedogenesis. Nannofossil ooze, which contains Fe scavenged from the ocean water column, has delta56Fe c. 0, but is consistent with seawater dissolved Fe having negative delta56Fe. It is inferred that continental weathering under modern oxidizing Earth surface conditions preferentially releases dissolved Fe with negative delta56Fe, which is transported in rivers to the ocean. A preliminary analysis of the marine Fe budget suggests that riverine Fe has a substantial role in determining the delta56Fe of both the modern and ancient oceans, but other inputs, particularly that from diagenesis of marine sediments, may also be important. Since the chemical pathways of Fe processing during weathering are dependent on oxidation state and biological activity, Fe isotopes may prove useful for detecting changes in these parameters in the geologic past.

Kvinnligt och manligt på sociala medier : En kvantitativ studie om medieanvändning och negativa känslor

In the present study the use and experience of using social media was examined in men and women in order to evaluate a possible relationship to gender. Particular emphasis was placed upon negative emotions. A questionnaire was constructed and submitted via Facebook by an online survey. There were 61 women and 50 men who completed the questionnaire. It was found that women and men used social media similarly with regard to frequency and the kind of social media they approached. Both genders used social media on a daily basis and both had profiles on the most popular social network sites as Facebook, Instagram, YouTube and Snapchat. The main purpose for using social media was to maintain already established friend relationships and to take part of other peoples content. A majority of the women but not the men used blogs, whereas a majority of the men but not the women used Twitter more frequently. The study also indicated a sex difference concerning the contents they took part of in the social media. More women took part of content that was related to a female stereotypic image whereas more men took part of content that was related to a male stereotypic image. There was no gender difference concerning contents such as fashion, entertainment, humour, news or politics. In the women there was a significant relationship between the use of social media and negative emotions. However, in the men, such a relationship was not found. The results indicate that more women tend to experience negative emotions when active on social media. More women experienced life as meaningless and boring, as well as stress after consuming contents in social media. They also did compare their life with others on social media leaving them with negative feelings. Such relationships could not be found in the men. In conclusion the present study indicated that for many aspects the use of social media is similar in women and men. However there seems to be a difference with regard to the experience of negative emotions in relation to the use of social media in women but not in men.