Development and Validation of Intracardiac Electrograms Software Tool for Analysis of Atrial Fibrillation Biomarkers

Atrial Fibrillation (AF) is the most common cardiac arrhythmia and is associated with a drastically increase of mortality risk. Mechanisms underlying the initiation and maintenance of AF are not understood yet and current treatments for AF are not completely efficient. Most effective one, around 50% of effectiveness, is the catheter ablation therapy but its long-term effects are reduced. Target ablation is thought to be a solution if AF focal sources were identified. Associated AF biomarkers to identify such zones are shortened action potential durations (APDs) and slow conduction velocities (CV). Identification of those biomarkers could be made through intracardiac electrogram (EGM) signals, however, they are very complex to interpret and there is still no validated method to perform it. The aim of this bachelor thesis is to develop and validate a software tool able to obtain APDs and CV from intracardiac EGM signals recorded directly from a swine heart. Electrical recording results are validated with optical mapping (OM) data recordings. The code was implemented with the purpose to work for nearby sinus rhythms, that is when it can be useful in clinical application to identify in patients with paroxystic AF the regions associated to the trigger of the AF. Simultaneous electrical and OM recordings of isolated swine heart are performed in a Langendorff system set-up. Software code processes electrical recordings by computing APDs with Botteron algorithm and computing phase maps. Once phase maps are obtained, trajectories are computed and thus CV. Electrical results are validated with OM data. Two catheters of different sizes are tested as well as results using 15 or 5 out of the 15 electrodes available in each catheter. APDs results were highly accurate, they were very similar to the OM data independently of whether catheter or number of electrodes was used. CV results were also similar to the OM data, varying inside the acceptable range proposed. Best results of CV were obtained with the small catheter and specifically for 5 electrode interpolation. Both APDs and CV results did not show statistically significative differences with the analysis of the T-student test. It can be concluded that the software code developed in this thesis demonstrates that is possible to compute both APD and CV values from intracardiac EGM signals with an acceptable accuracy. Optimal results for CV computation were obtained with the small catheter (2.5 cm radius) and using only 5 out of the 15 electrodes. This opens new insights into the use of EGM signals for the clinical estimation of proarrhythmic areas.Ingeniería Biomédic

A construcción dunha orientación renovadora para a educación en España

[Resumo] Os anos 1975 e 1976 foron claves na construcción dunha alternativa ós plane- amentos políticos da Ditadura en canto á educación se refire, xa que nese momento coin- ciden os intereses e demandas de diversos colectivos relacionados co ensino como os movementos de ensinantes, as mobilizacións cidadáns e de veciños e determinados sec- tores políticos comprometidos coa loita antifranquista.[Abstract] 1975 and 1976 were key years in the construction of an alternative to the poli- tical plans of the Dictatorship in terms of education. At that time the interests and demands of differnent communities related to education -such as the movements of educators- coin- cided with the mobilisation of citizens and residents as well as certain political sectors com- mitted to bringing down Franco’s dictatorship

A pedagoxía Freinet en España nos tempos da II República

[Resumo] Dar canta de como loran os comezos da pedagoxía Freinet en España é o obxectivo lunda- mental deste artículo. Nel seguimos os pasos dun pequeno grupo de mestres ilerdenses, que co tempo chegaron a lormar a Cooperativa española da Técnica Freinet, e as súas realizacións máis importantes destacando a publicación da revistas Colaboración, La imprenta en la escuela e a creación dunha esco- la Freinet en Barcelona.[Abstract] The purpose 01 this paper is to examine the origins 01 Freinet pedagogy in Spain. We retra- ce the steps 01 a group 01 schoolteachers lram Lérida, who, over time, created the Spanish Cooperative Group 01 the Freinet Technique, and highlight their most important achievements, notably the publication 01 the journals Colaboración, La imprenta en la escuela and the creation 01 a Freinet school in Barcelona

A Single Amino Acid Change Converts the Sugar Sensor SGLT3 into a Sugar Transporter

Background: Sodium-glucose cotransporter proteins (SGLT) belong to the SLC5A family, characterized by the cotransport of Na + with solute. SGLT1 is responsible for intestinal glucose absorption. Until recently the only role described for SGLT proteins was to transport sugar with Na +. However, human SGLT3 (hSGLT3) does not transport sugar but causes depolarization of the plasma membrane when expressed in Xenopus oocytes. For this reason SGLT3 was suggested to be a sugar sensor rather than a transporter. Despite 70 % amino acid identity between hSGLT3 and hSGLT1, their sugar transport, apparent sugar affinities, and sugar specificity differ greatly. Residue 457 is important for the function of SGLT1 and mutation at this position in hSGLT1 causes glucose-galactose malabsorption. Moreover, the crystal structure of vibrio SGLT reveals that the residue corresponding to 457 interacts directly with the sugar molecule. We thus wondered if this residue could account for some of the functional differences between SGLT1 and SGLT3. Methodology/Principal Findings: We mutated the glutamate at position 457 in hSGLT3 to glutamine, the amino acid present in all SGLT1 proteins, and characterized the mutant. Surprisingly, we found that E457Q-hSGLT3 transported sugar, had the same stoichiometry as SGLT1, and that the sugar specificity and apparent affinities for most sugars were similar to hSGLT1. We also show that SGLT3 functions as a sugar sensor in a living organism. We expressed hSGLT3 and E457Q-hSGLT3 in C. elegans sensory neurons and found that animals sensed glucose in an hSGLT3-dependent manner

Physical versus economic depletion of a nonrenewable natural resource

The present paper explores the relationship between physical and economic depletion of a nonrenewable natural resource using a decomposition of mining costs akin to the one used in the literature on productivity and technical change. We argue that this decomposition can provide key insights on future availability of nonrenewable natural resources. Using data on slate mining in Galicia (Northern Spain), we provide quantitative evidence of the role played by physical depletion in economic exhaustion but also of the offsetting effects of technical change. Additionally, we provide a measure of the effects on economic depletion of input prices, output, fixed inputs and production scale. Input prices and fixed input misallocation contributes far more to economic depletion than physical depletion while technical change has a remarkable negative contribution to economic depletion. Policy implications are discussed, particularly, the importance of promoting technical change. Keywords: Non-renewable natural resources, Physical depletion, Economic depletion, Mining cost, Slate mining, Technical change, Total Cost Growth decompositio

A Gluten-Free Diet, Not an Appropriate Choice without a Medical Diagnosis

In the past, only people diagnosed with celiac disease, approximately 1% of the population, avoided gluten consumption through all their meals. However, popular media often now mistakenly present gluten-free foods as being a healthier choice, and more people have now concluded that gluten is a harmful part of the diet. A review of literature on gluten-free diets, gluten sensitivity, celiac disease, and attitudes toward gluten consumption was undertaken to examine the prevalence and consequences of adopting a gluten-free diet and to provide guidance to healthcare practitioners whose patients are now often adopting this diet without medical input. Aside from celiac disease, nonceliac gluten sensitivity (NCGS) occurs in those persons in which gluten ingestion leads to symptomatic manifestations in the absence of celiac disease or wheat allergy but who report a remission of certain symptoms after removing gluten from their diet. However, it was been shown that a large percentage of people who claim NCGS do not feel those manifestations under a double-blind challenge to gluten. Moreover, some parents, believing that ingesting gluten is detrimental for their health, adopt gluten-free diets for their children. A review of existing data shows that there are detrimental effects to going gluten free, including loss of the dietary fiber, deficiencies in dietary minerals and vitamins, and potential heavy metal exposure. Healthcare practitioners should query patients about their dietary choices, and in cases of questionable adoption of gluten-free diet, patients and parents are educated about the detriments of a gluten-free diet, and in cases where patients continue to insist on gluten-free foods, referrals to nutritional counseling are warranted in order to minimize potential harm

Nonvesicular Inhibitory Neurotransmission via Reversal of the GABA Transporter GAT-1

SummaryGABA transporters play an important but poorly understood role in neuronal inhibition. They can reverse, but this is widely thought to occur only under pathological conditions. Here we use a heterologous expression system to show that the reversal potential of GAT-1 under physiologically relevant conditions is near the normal resting potential of neurons and that reversal can occur rapidly enough to release GABA during simulated action potentials. We then use paired recordings from cultured hippocampal neurons and show that GABAergic transmission is not prevented by four methods widely used to block vesicular release. This nonvesicular neurotransmission was potently blocked by GAT-1 antagonists and was enhanced by agents that increase cytosolic [GABA] or [Na+] (which would increase GAT-1 reversal). We conclude that GAT-1 regulates tonic inhibition by clamping ambient [GABA] at a level high enough to activate high-affinity GABAA receptors and that transporter-mediated GABA release can contribute to phasic inhibition

Intención de emprendimiento: ventajas e inconvenientes percibidos

ABSTRAC: Purpose - Based on the Theory of Planned Behaviour, the purpose of this paper is to analyse the influence of the advantages and disadvantages of entrepreneurship surrounding the entrepreneurial intention on a university context. Design/methodology/approach - To test the hypothesis it is used a quantitative research. With a structural equations approach, it is explored the psychological mechanisms that could affect to the entrepreneurial intentions of university students. Findings - The results obtained show that the advantages related to entrepreneurship, in particular personal rewards, influence positively on the entrepreneurial attitude. However, the disadvantages, in particular economic aspects, have a negative effect. Additionally, the authors test that the gender and the academic training have a moderate effect on the variables which influence on the entrepreneurial intention. Originality/value - This paper contributes to the literature on entrepreneurship in two important aspects. First, it goes into detail about the influence that perceived advantages and disadvantages of starting a new business has on entrepreneurial intentions. Second, the authors examine relevant and special collective, university students that try to decide their professional future and, hence, it is a critical period to decide the startup of a new business.RESUMEN: Propósito - Con la Teoría de Comportamiento Planificado como marco de referencia este trabajo analiza la influencia de las ventajas e inconvenientes asociados al emprendimiento sobre la intención emprendedora en un contexto universitario. Diseño/metodología - Para la contrastación empírica de las hipótesis planteadas se realiza una investigación de naturaleza cuantitativa mediante la cual se exploran los mecanismos psicológicos que podrían guiar las intenciones de emprendimiento de los estudiantes universitarios. Resultados - Los resultados obtenidos ponen de manifiesto que las ventajas asociadas al emprendimiento, en especial las recompensas personales, influyen positivamente en la actitud emprendedora, mientras que los inconvenientes asociados al emprendimiento, y en particular los aspectos económicos, ejercen un efecto negativo. Asimismo, se constata que el sexo y los estudios cursados tienen un efecto moderador en las variables que afectan a la intención emprendedora. Originalidad/Valor - El presente trabajo aporta dos contribuciones fundamentales a la literatura sobre emprendimiento. Por un lado, profundiza en la comprensión de la influencia que tienen en la decisión de emprender las percepciones de los individuos respecto a las ventajas e inconvenientes de crear un negocio propio. Por otro lado, se examina un colectivo de especial relevancia en el ámbito del emprendimiento, como son los estudiantes universitarios, que se encuentran en situación de encaminar su futuro profesional y, por tanto, en un momento crítico para la decisión de crear una empresa propia

The Popular School Cooperative Movement (MCEP) and the magazine Collaboration (1976-1985): education and pedagogical renewal in post-Franco Spain

El Movimiento Cooperativo de Escuela Popular (MCEP), uno de los movimientos de renovación pedagógica existentes en España, nacido en los momentos finales del franquismo, acumula una intensa historia desde su inspiración en la Pedagogía Freinet. Entre sus iniciativas más significadas hay que referirse a la revista Colaboración (1976-1985), ya que en ella encontramos claves, pági-nas y notas que podrán ayudar a entender, en el plano educativo, el período de la llamada Transi-ción Política. En su análisis centraremos nuestra atenciónThe Movimiento Cooperativo de Escuela Popular (MCEP), one of the pedagogical renewal move-ments existing in Spain, born in the final moment’s political regime of Franco, accumulates an intense history, from its inspiration in the Pedagogy Freinet. Among its most significant initiatives, reference should be made to the journal Colaboración (1976-1985), since in it we find clues, pages and notes that can help us understand, on the educational level, the period of the so-called Political Transition. In your analysis we will focus our attentionS