Modeling and Numerical Methods for the Study of Nonlinear Electromagnetic Problems

The main objective of the PhD thesis is the study of mathematical problems that arise in low frequency electromagnetics, mainly oriented to the numerical simulation of industrial processes. Specifically, we focus on both eddy currents and transient magnetic problems. In Part I, we first perform the mathematical and numerical analysis of a 3D harmonic formulation with sources given in terms of the current through or the potential drop on surfaces located at the domain boundary, and then we describe a finite element method for the numerical simulation of magnetization processes in ferromagnetic pieces presenting hysteresis. In Part II we deal with problems related to electrical machines. Firstly, we perform the mathematical analysis of a basic transient magnetic formulation, next next we study an optimal control problem on a synchronous machine, and we finally present a novel method for accelerating the steady-state computation in induction motors with squirrel-cage rotor

Spore morphology and sporoderm ultrastructure in Adiantopsis Fée (Pteridaceae-Pteridophyta) from Argentina

The aim of this study is to analyse, describe and compare the spores of the two Adiantopsis species that grow in Argentina, A. chlorophylla (Sw.) Fée and A. radiata (L.) Fée. The study used herbarium material observed with light microscopy (LM), scanning electron microscopes (SEM) and transmission electron microscopes (TEM). The spores of both species are trilete with an echinate surface. The exospore is smooth, two-layered in section; both layers with different thickness and contrast. Depending on the plane of sectioning, channels are seen running through the exospore and in the apertural region. The perispore strongly contrasted when seen with TEM, is two-layered and bears ornamentation. The two layers have different thickness and structure. The inner layer P1 is the thickest layer and has three strata, which form the sculptural elements. The outer layer P2 covers all the surfaces of P1. Two levels of ornamentation are clearly distinguished: a basal level composed of fused ridges, and an upper level composed of echinae. The spores of A. chlorophylla are triangular-globose in polar view, with convex sides, 25 - 50 μm in equatorial diameter and have more ornamental processes per surface unit than the spores of A. radiata. The spores of A. radiata are triangular in polar view and 30 - 40 μm in equatorial diameter. Size and ornamentation help to establish differences at species level, and together with the exomorphological characteristics of the sporophyte, contribute to the systematics of this genus.Facultad de Ciencias Naturales y Muse

Spore morphology and sporoderm ultrastructure in Adiantopsis Fée (Pteridaceae-Pteridophyta) from Argentina

The aim of this study is to analyse, describe and compare the spores of the two Adiantopsis species that grow in Argentina, A. chlorophylla (Sw.) Fée and A. radiata (L.) Fée. The study used herbarium material observed with light microscopy (LM), scanning electron microscopes (SEM) and transmission electron microscopes (TEM). The spores of both species are trilete with an echinate surface. The exospore is smooth, two-layered in section; both layers with different thickness and contrast. Depending on the plane of sectioning, channels are seen running through the exospore and in the apertural region. The perispore strongly contrasted when seen with TEM, is two-layered and bears ornamentation. The two layers have different thickness and structure. The inner layer P1 is the thickest layer and has three strata, which form the sculptural elements. The outer layer P2 covers all the surfaces of P1. Two levels of ornamentation are clearly distinguished: a basal level composed of fused ridges, and an upper level composed of echinae. The spores of A. chlorophylla are triangular-globose in polar view, with convex sides, 25 - 50 μm in equatorial diameter and have more ornamental processes per surface unit than the spores of A. radiata. The spores of A. radiata are triangular in polar view and 30 - 40 μm in equatorial diameter. Size and ornamentation help to establish differences at species level, and together with the exomorphological characteristics of the sporophyte, contribute to the systematics of this genus.Facultad de Ciencias Naturales y Muse

Ethnographic "experimental collaborations" as practitioner methodology

In this paper we discuss emergent cross-cutting themes across a series of educational intervention projects in which practitioners-in-training adopted and adapted in their proposals and work design the logic of ethnographic experimental collaboration (XCOL) and participatory action research (PAR) (Clark, 2010; Estalella & Sánchez-Criado, 2018) perspectives. We were involved in three interventions developed in Madrid (Spain) across formal and informal learning contexts as part of the internship/practicum of future educational psychologists. Our work was designed in response to the identified needs and demands of the internship sites. Yet, as educational interventions, they were explicitly conceptualized and implemented in ways that depart substantially from the common expectations of process-product educational intervention and dominant ways, at least in Spain, of constructing educational accountability (cf. Berliner, 1989; Gage & Needels, 1989). We unpack four themes relevant across the three projects, which emerged from our joint discussions of the three interventions: (a) how "outcomes/results" are reconstructed in XCOL/PAR educational interventions, (b) the transformations in our emergent professional identities, (c) the place of different materialities and expressive media in the work we planned (d) how space-time constraints were construed in our unfolding projects

La implantación de los Grados, una oportunidad para internacionalizar la enseñanza jurídica

The Bologna Process aims at enhancing international mobility among students and professors by improving the similarities among legal curriculums and, with it, making the recognition of credits obtained in other universities easier. This standpoint opens the door to many ways to internationalize the legal teaching, aiming this paper at highlighting some of them; beyond the possibility of spending one semester or one course in a foreign university -already planned in most legal curriculums-, this paper outlines the fact that the current openness to other legal systems, imposed by the internationalization of societies and economies, must be taken into account in the design of the legal curriculum as well, and in particular by adapting the teaching methodology, with a special attention to the comparative law method besides other pedagogical tools.El proceso de Bolonia aspira a fomentar la movilidad de estudiantes y profesores, facilitando la lectura de los planes de estudio de las distintas universidades y, con ello, el reconocimiento de los créditos cursados en otros países. Ello abre las puertas a numerosas fórmulas de internacionalización de la enseñanza jurídica que aquí se pondrán de manifiesto; más allá de la inclusión en el currículum de la posibilidad de pasar un semestre o un curso en una universidad extranjera, este trabajo persigue destacar que la apertura a otros ordenamientos jurídicos ha de proyectarse también sobre el diseño del currículum y, en particular, sobre la metodología de la enseñanza en el país donde el estudiante cursa principalmente sus estudios, a través del empleo regular del análisis de Derecho comparado y otros métodos pedagógicos

Morfología y ultraestructura de las esporas de las Equisetaceae (Equisetopsida) del Noroeste de Argentina

La familia Equisetaceae se haya representada en el Noroeste de Argentina por el género Equisetum Michx. ex DC con dos especies, E. bogotense Kunth y E. giganteum L. El estudio se realizó en base a material de herbario y fresco. Las observaciones se realizaron con microscopios óptico y electrónicos de barrido y transmisión. Las esporas son esferoidales, miden 35-64 µm de diámetro ecuatorial, su citoplasma posee clorofila. En ambas especies, las esporas presentan una estructura abertural circular y a ambos lados de la misma poseen un par de eláteres acintados de extremos espatulados, no resistentes al tratamiento de acetólisis. La esporodermis consta de dos paredes, perisporio, delgado, ornamentado, con dos estratos, de 930 nm-1,2 µm de espesor, y exosporio, de 1,4- 3,1 µm de espesor, compacto, con dos estratos y superficie levemente ondulada o plegada. Entre ambas paredes se ha observado una capa intermedia de naturaleza laxa, y diferente espesor en esporas con distintos estadios de maduración. Las esporas son similares, en ambas especies, en cuanto a la forma y ultraestructura de la esporodermis; se observan diferencias en el tamaño de las mismas.Spore morphology and wall ultrastructure in Equisetaceae spores (Equisetopsida) from north-western Argentina. The family Equisetaceae is represented in the study area by the genus Equisetum with two species, E. bogotense and E. giganteum. The study was based on herbarium and fresh specimens and the spores were studied under light microscope, scanning and transmission electron microscopes. The spores are spheroid, 35-64 µm in equatorial diameter, the cytoplasm has chlorophyll. In both species studied, the spores have a circular and small unique type of aperture which at both sides of the aperture, in the outer side have two thread-like elaters, spathulate. These structures are non-resistant to the acetolysis treatment. The sporoderm is composed of two walls, perispore, 930 nm-1,2 µm thick, ornamented, with two layers in section. The exospore is two layered, compact, 1,4-3,1 µm thick, slightly wave-like. Between both walls was observed an intermediate layer composed of a laxe structure, in spores in different stages of maturation. In both species, the spores are similar in the shape and sporoderm ultrastructure while differences were found in spore sizes.Facultad de Ciencias Naturales y Muse

Morfología y ultraestructura de las esporas de NephrolepIs cordifolIa (DavallIaceae) del Noroeste de Argentina

La familia Davalliaceae se encuentra representada en el Noroeste argentino por el género Nephrolepis, con una única especie N. cordifolia. El estudio se realizó en base a material de herbario y fresco. La observación se realizó con microscopios óptico y electrónicos de barrido y transmisión. Las esporas son monoletes, de forma elipsoidal, superficie rugada, miden en promedio 20 µm de diámetro polar y 35 µm de diámetro ecuatorial mayor. La esporodermis está constituida por dos paredes: exosporio y perisporio. El exosporio, 1,3-2,6 µm de espesor, presenta procesos verrucosos, y consta de 2 capas. El perisporio, 920 nm-2,75 µm de espesor, con procesos verrucosos y tuberculados, con dos capas. Las esporas de las Davalliaceae muestran cierta similitud con las esporas de Microgramma, Pecluma y Polypodium (Polypodiaceae), en cuanto al tipo de esporas aunque se diferencian de las mismas por el tamaño, y por la estructura de la esporodermis. La ornamentación en las Polypodiaceae está dada por el exosporio, mientras que en Nephrolepis es el perisporio quien la determina.Spore morphology and wall ultrastructure in Nephrolepis cordifolia (Davalliaceae) from North-West Argentina. The family Davalliaceae is represented in the study area by the genus Nephrolepis, with only one species N. cordifolia. The study was based on herbarium and fresh material and the spores were studied under light microscope, scanning electron microscope and transmission electron microscope. The spores are monolete, the shape in polar view is ellipsoidal, and have a rugate surface, 20 µm in polar diameter (mean), 35 µm in mayor equatorial diameter (mean). Mature spores have a sporoderm composed of exospores and perispore. The exospore is two-layered, 1,3 to 2,6 µm thick, verrucate. The perispore is two layered, 920 nm to 2,75 µm thick, with verrucae and tubercles. The spores of Davalliaceae show some similarities with the spores of Microgramma, Pecluma y Polypodium (Polypodiaceae), referred to spore type, but differ from the last ones in size and sporoderm structure. The ornamentation of the spores of the Polypodiaceae is determined by the exospore, while in Nephrolepis the ornamentation is determined by the perispore.Fil: Piñeiro, Maria Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Palinología; ArgentinaFil: Morbelli, Marta Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Palinología; Argentin

Prescription of anxiolytics, sedatives, hypnotics and antidepressants in outpatient, universal care during the COVID-19 pandemic in Portugal: a nationwide, interrupted time-series approach

Background: The COVID-19 pandemic has had a significant impact on the population's mental health. However, its impact on the consumption of anxiolytics, sedatives, hypnotics and antidepressants remains to be evaluated. Hence, this article aims to assess the prescription trends of these drugs in Portugal, from January 2018 to March 2021, while critically examining whether the COVID-19 pandemic had an impact on these prescription trends or not. Methods: A nationwide interrupted time-series analysis of the prescription data of anxiolytics, sedatives, hypnotics and antidepressants in outpatient setting of the public health sector was conducted. The data encompassed the defined daily dose per month, age range and sex and were analysed following a segmented regression approach. Results: The pandemic preceded an immediate reduction in the prescription of anxiolytics, sedatives and hypnotics for children and adolescents. However, an increasing trend throughout the pandemic has been noted in the prescription of these drugs, especially among adults aged 65 years or above. A drop in antidepressant prescription was observed as an immediate effect of the pandemic among male and female adolescents and elderly women. From March 2020 to March 2021, a decreasing prescription trend has been noted among men. Conclusions: When analysing specific genders and age ranges, differences can be noted, in terms of both immediate impact and prescribing trends throughout 1 year of the COVID-19 pandemic. The impact of the pandemic on mental health and its association with the consumption trends of psychoactive drugs, and with the access to mental health treatments, should be further assessed

The Impact of the COVID-19 Pandemic on Antibiotic Prescribing Trends in Outpatient Care: A Nationwide, Quasi-Experimental Approach

Coronavirus disease 2019 (COVID-19) has spread globally and is currently having a damaging impact on nearly all countries in the world. The implementation of stringent measures to stop COVID-19 dissemination had an influence on healthcare services and associated procedures, possibly causing antibiotic consumption fluctuations. This paper aims to evaluate the immediate and long-term impact of the COVID-19 pandemic on antibiotic prescribing trends in outpatient care of the Portuguese public health sector, including in primary healthcare centers and hospitals, as well as on specific antibiotic groups known to be closely associated with increased resistance. Segmented regression analysis with interrupted time series data was used to analyze whether the COVID-19 pandemic had an impact in antibiotic prescribing tendencies at a national level. The outcomes from this quasi-experimental approach demonstrate that, at the beginning of the pandemic, a significant, immediate decrease in the overall antibiotic prescribing trends was noticed in the context of outpatient care in Portugal, followed by a statistically non-significant fall over the long term. The data also showed a significant reduction in the prescription of particular antibiotic classes (antibiotics from the Watch group, 3rd-generation cephalosporins, fluoroquinolones, and clarithromycin) upon COVID-19 emergence. These findings revealed an important disruption in antibiotics prescribing caused by the current public health emergency

Validation of a simple sample preparation method for multielement analysis of bovine serum

Here we propose a single acid digestion (SAD) sample preparation method for ICP-MS analysis of animal serum samples to determine trace element contents. The method was evaluated in comparison with a commonly used procedure involving dilution of samples in an alkaline solution (AKD). In the SAD procedure, aliquots (1 mL) of bovine serum samples were treated at low temperature with a mixture of concentrated nitric acid and hydrogen peroxide. Trace elements (As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, U, and Zn) were directly determined by ICP-MS analysis of diluted solutions of samples. Both methods were sufficiently sensitive to enable quantification of most trace elements, with the exception of the AKD method for Cd, Hg and Pb. The quality of the data was verified by using certified reference material. Good results were obtained for the SAD procedure and all elements, but recoveries were unacceptable with the AKD procedure for Se (recovery: 57%), Cd (154%) and Fe (139%). Strong associations (R2 >0.90, P = 0.000) between the data obtained by both methods were demonstrated for the elements considered. The proposed SAD sample preparation method produced satisfactory results for determining most toxic and essential trace elements targeted in monitoring studies.S