Contributions towards understanding the heart beat and cardiac myocyte action potential of the fruit fly

Studying the heart during normal function and disease is crucial to our understanding of human health and to aspects of animal biology from energy consumption and metabolism to lifespan. The heart of the fruit fly, Drosophila melanogaster, has emerged as a model system for studying heart function and particularly the linkage between genes, function, and physiology. Yet many aspects of D. melanogaster adult heart physiology remain unclear. Many of the insights from study of the D. melanogaster adult heart are obtained using a semi-intact preparation with artificial haemolymph, in which the beating heart tube is exposed by removing a fly’s head and thorax, and ventral abdomen. We used both in vivo electrophysiology and videography to investigate the heart-beat and cardiac myocyte action potential (AP) of the beating heart in the semi- intact preparation. This allowed the quantification of the heart-beat and AP, showing that there is considerable variation of both even in wild type flies. We show that variation in the heart-beat’s rate is, in part, due to transitions between the different types of heart-beat that the adult heart can generate and, in part, an artefact of the dissection itself. We also identify and describe at least two different patterns of cardiac myocyte AP in wild type flies: a single and a double-action potential. Together, these reveal an unappreciated variability in the adult heart and cardiac myocyte AP that has not previously been recognised or quantified, with implications of the uncritical use of the semi-intact preparation. At the commencement of the work towards this thesis, the major ion channels supporting the cardiac myocyte AP were unknown, though some channel-types had been identified. Using the semi-intact preparation, we investigated the voltage-gated ion channels and resulting currents that produce the cardiac myocyte AP using a range of Ca2+ and Na+ voltage-gated ion channel mutants, including classical mutations and RNAi lines. Using both videography and electrophysiology, we identify the voltage-gated α1 subunits Ca2+ encoded by the cacophony (cac) gene. Our evidence comes from changes in the frequency of the heart-beat in RNAi lines coupled with pharmacological evidence from application of the α1 subunits voltage-gated Ca2+ channel blocker, verapamil.We also show that forskolin, which upregulates the protein kinase A pathway, moderately increases heart-beat’s frequency. Despite the effects of cacophony RNAi on the heart beat’s frequency, cardiac myocyte APs were unaffected. We discuss how these results can be reconciled. Finally, we investigated the communication between cardiac myocytes through gap junctions, which is essential for propagation of the cardiac myocyte AP throughout the heart. We used carbenoxolone, a known connexin gap junction blocker, to block D. melanogaster cardiac myocyte gap junctions. This block was concentration dependent with an EC50 of 0.071 mM. Using intracellular recordings, we show that carbenoxolone is capable of increasing cardiac myocyte input resistance, consistent with blocking gap junctions. We also identify subthreshold electrical events in cardiac myocytes that are consistent with gap-junctional inputs from neighbouring cells. This emphasises the key role of gap junctions in the adult D. melanogaster heart and provides some of the first evidence that carbenoxolone is a blocker of innexin gap junctions. Taken together, the work in this thesis provides key insights into both the molecular and physiological mechanisms underpinning the adult D. melanogaster heart-beat, and the tools used by researchers to study these mechanisms

Postnatal characterization of cells in the accessory olfactory bulb of wild type and reeler mice

Olfaction is the most relevant chemosensory sense of the rodents. General odors are primarily detected by the main olfactory system while most pheromonal signals are received by the accessory olfactory system. The first relay in the brain occurs in the olfactory bulb, which is subdivided in the main and accessory olfactory bulb (MOB/AOB). Given that the cell generation time is different between AOB and MOB, and the cell characterization of AOB remains limited, the goal of this work was first, the definition of the layering of AOB/MOB and second, the determination of cellular phenotypes in the AOB in a time window corresponding to the early postnatal development. Moreover, since reelin (Reln) deficiency has been related to olfactory learning deficits, we analyzed reeler mice. First, we compared the layering between AOB and MOB at early embryonic stages. Then, cell phenotypes were established using specific neuronal and glial markers as well as the Reln adaptor protein Dab1 to analyse differences in both genetic backgrounds. There was no apparent difference in the cell phenotypes among AOB and MOB or between wild type (wt) and reeler animals. However, a disruption in the granular cell layer of reeler with respect to wt mice was observed. In conclusion, the AOB in Reln-deficient mice showed similar neuronal and glial cell types being only affected the organization of granular neurons

Long-acting paliperidone in Ekbom's syndrome in Lewy body dementia: A case report

Ekbom Syndrome (ES) is characterised by fixed, delusional beliefs that one's body is infested by parasites or other vermin in absence of supporting clinical evidence. Antipsychotic (AP) treatment, including long-acting injectable (LAI) AP in subjects with poor compliance, is prescribed to manage behavioural and psychotic symptomatology

La comunicación educativa desde mirada del docente virtual

La inclusión de las Tecnologías de Comunicación y la Web 2.0 en el campo educativo requiere de una reflexión profunda que resulta esencial para poder obtener óptimos resultados; pues implica, no únicamente la integración per se de las tecnologías como distribuidoras de información, sino un  replanteamiento pedagógico eficiente cuyo diseño estimule al aprendiz a convertirse en un autodidacta generador y constructor social de conocimientos. Aplicar tecnología educativa supone capacitación e investigación, no solo en el área de especialidad de cada docente, sino en los campos de la didáctica, el uso eficiente de la tecnología, el diseño gráfico y la comunicación. Podremos hablar de comunidades de aprendizaje y generación social del conocimiento, cuando verdaderamente los mensajes distribuidos por medio de la tecnología, generen interacción y comunicación entre aprendices, profesores y contenidos; y produzcan en el estudiante y en el profesor –concebidos todos como una comunidad - aprendizajes significativos que puedan proyectar para resolver problemas cercanos a su realidad de forma colaborativa, que los ayuden a mejorar su medio ambiente, que los estimulen a crecer como seres humanos

La imagen del sujeto y el pensamiento en las Primeras invenciones de Felisberto Hernández

Una de las singularidades de la escritura de Felisberto Hernández es su construcción original de un relato laxo, lábil, en cuanto a la estructura y organización narrativa que le da soporte. Resulta fácil identificar en sus cuentos cierta forma errática, digresiva, sin final concluyente, obra de un narrador entregado a las asociaciones más que al eje cognoscitivo, epistémico, de una historia (el arquetipo de esta descripción se encontraría rápidamente en el volumen Nadie encendía las lámparas,..

Love And Tragedy in Four Stories of War of The Twentieth Century: Erich Maria Remarque, Ernest Hemingway. Tristan and Iseult Revisited?

The influence of the Western imaginary of tragic love, from Tristan and Iseult to our days, appears in the different declinations of the myth, from love-passion or amour fou to the popular accents of melodrama, with its repetitive logic of the obstacles. A use of the fatality inscribed in the archetypal amorous plot seems to potentiate, in an unexpected way, the capacity of denunciation of certain celebrated novels of the twentieth century on the subject of the war. Such connotations could shed light on the importance of the confrontational dimension between individual and society contained in the original legend

Chapter Strategic Planning Document of Port Authority System, a new city-ports agreement: the case of Northern Tyrrhenian Sea AdSP

Legislative Decrees 169/16 and 232/17 have modified Law 84/94. The changes introduces the Port System Regulatory Plan, composed of the PRPs of the individual ports and the Strategic System Planning Document. Among the contents of the DPSS, for which institutional agreements between AdSP and territorial bodies are envisaged, there is the identification of the so-called "Areas of port-city interaction". The objective of this research is to propose a methodology for identifying the areas of influence of the port on the city, measuring the degree of interaction through a system with indicators

Chapter Evaluation and monitoring of the Livorno’s Fossi System

The ditches and canals of Livorno, also called Fossi, are the most characterized elements the city, not only from a historical point of view, but also and above all from an urban landscape characterization point of view. Due to the overlapping of skills not yet resolved, fragmented information and data exist regarding the real extent of the pleasure craft, the status of the canals, the provision of services and general safety. The hypothesis is to succeed, through a multi-criteria assessment of scenarios, to support and quantify the displacement of vessels that negatively affect accessibility and the landscape of Livorno's Fossi system elsewhere

Monitoring and assessing old-growth forest stands by plot sampling

Forest inventories are evolving towards multipurpose resource surveys, broadening their scope by including additional topics such as biodiversity issues. Surprisingly, few quantitative surveys have been devoted to old-growth forests, even if they constitute the most acknowledged forest biodiversity icons. In this framework, the use of probabilistic sampling may provide an effective as well as rigorous support for monitoring and assessing old-growth forests. To this purpose, the present paper proposes a two-phase sampling scheme. In the first phase, a coarse survey of few floristic and stand structural attributes is carried out by means of small plots systematically placed on the study area. Subsequently, in the second phase, a fine assessment of a large number of ecological attributes is performed on a subset of enlarged plots selected among the first-phase ones by means of simple random sampling without replacement. The proposed sampling scheme is implemented for monitoring and assessing the old forests of Cilento National Park (southern Italy). Results and comments are provided as an exemplicative case study.L'articolo è disponibile sul sito dell'editore www.tandf.co.uk/journals

PROYECTOS PROFESIONALES Y VALORES EN ESTUDIANTES UNIVERSITARIOS.

La  investigación tiene como objetivo determinar los vínculos existentes entre el desarrollo de los proyectos profesionales y los valores declarados asociados al desempeño profesional en estudiantes que cursan el segundo y cuarto año de Ingeniería Industrial del Instituto Superior Politécnico “José Antonio Echeverría” Caracterizamos el desarrollo de los proyectos profesionales, atendiendo a su contenido, estrategias para su consecución, temporalidad y previsión de obstáculos e identificamos los valores asociados al futuro desempeño profesional para establecer la relación entre proyectos profesionales y los valores declarados y comparar los resultados entre los años académicos. La muestra la constituyen 60 sujetos, 30 de primer año y 30 de cuarto año. Se trata de una investigación de carácter descriptivo, basada en una metodología mixta. Los resultados muestran que el contenido de los proyectos profesionales se orienta a la realización de sí mismo, la realización profesional y el trabajo afín, teniendo en la base de estas aspiraciones una orientación hacia lo personal. Las estrategias para su consecución son, en su generalidad, parcialmente estructuradas y se conciben en una temporalidad a mediano plazo fundamentalmente. En la previsión de obstáculos prevalecen los obstáculos externos. Los valores más relevantes declarados, asociados al desempeño profesional son: profesionalidad, laboriosidad, honestidad, y como cualidad, la perseverancia; los cuales se encuentran expresados en el contenido de los proyectos futuros orientados al desempeño profesional de los estudiantes. Solo se observan diferencias significativas entre los años académicos, en lo relativo a la realización profesional, a favor de cuarto año. Palabras claves: Proyectos profesionales y valores.     Abstract:  The current study aimed to explore the relationship between “Jose Antonio Echevarría” Technologic University students’ declared professional values, and their professional goals. In order to determine the content of the student’s professional goals we examined: a) the students’ strategies to achieve their goals and their projected timeline, b) foreseen obstacles for the achievement of their goals, and c) the content of their professional goals. Additionally, we aimed to determine relevant professional values for the aforementioned students, and to explore the likelihood of the students’ values and professional goals varying or developing over time. The study had a descriptive quality, and used a mixed methodology. Our sample was composed by sixty “José Antonio Echevarría” Polytechnic students (n=60), thirty of which were in their second academic year (n=30), and thirty on their fourth academic year (n=30). Second and fourth year students’ professional goals and values were qualitatively and quantitatively compared, in order to answer our research questions. Main results were as follows: a) the students’ professional goals are oriented towards self-realization, professional development, and engaging in professional activities aligned with their desired career, b) the majority of the students’ strategies for attaining their goals are partially structured and evidence a medium  term temporality projection, c) the students’ foreseen main obstacles relate to external factors and d) relevant professional values include: professionalism, honesty, perseverance and industriousness. Only one significant difference was observed between second and fourth year students, with fourth year students evidencing a higher degree of perceived significance for their professional development.  Key words: Professional projects and values