Los postulados de Koch: revisión histórica y perspectiva actual

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Diseño y construcción de un convertidor multinivel en cascada basado en celdas monofásicas de corriente

91 p.En este trabajo se presenta el desarrollo de la topología de un convertidor multinivel en cascada basado en celdas monofásicas de corriente. El trabajo de esta memoria consta de simular esta topología de convertidor multinivel en cascada, con el fin de obtener la base del desarrollo posterior del convertidor, el diseño de las celdas de corriente, la construcción de las tarjetas electrónicas correspondientes al rectificador e inversor, así como su interconexión y el montaje sobre el set-up para conformar las celdas a fin de conectarlas en cascada y la realización de pruebas de estas celdas monofásicas de corriente y ver el desempeño global del convertidor. Este informe muestra los aspectos fundamentales en las etapas correspondientes del desarrollo del convertidor, así como la comparación de los resultados proporcionados por las simulaciones y por las pruebas experimentale

A survey of second homes: their number, character, owners and use

Second home ownership is increasing in importance in this country as underlying motivating forces are coupled to expanding opportunities for ownership, principally in ters of the availability of time, money and suitable property (Chapter 1). The study of this phenomenon is hampered by problems of definition and by difficulties of gathering information (Chapter 2), although much work has been undertaken abroad, particularly in France, Scandinavia and North America (Chapter 3.i). In Britain, knowledge is relatively limited in scope and is fragmentary in coverage (Chapter 3.ii), and the writer’s investigation into second homes in Weardale was made as a contribution from a region not previously studied but one where second homes have spread rapidly in recent years (Chapter 3.iii). Second homes in general are characterised by a wide variety of type (Chapter 4.1), and are often purchased or rented through private, rather than through commercial, channels (Chapter 4.ii). Their popularity may tend to increase property prices (Chapter 4.iii), while the common use of much old property often necessitates its extensive improvement and renovation (Chapter 4.iv). The owners of second homes are correspondingly diverse, although they tend to be above average in income and in education (Chapter 5.i). Their average use of the second home varies considerably as does the range of their activities while at the second home (Chapter 5.11), but less diversity is discernible In the location of the first home which is often within two hours driving time of the second home (Chapter 5.111).Increasing numbers of second homes in Britain cause effects at both national and local levels. Nationally, these involve the use of resources that could possibly be used for other purposes while, locally, there are complex economic, social and environmental implications which are, however, little understood at present (Chapter 6). As growth continues, controls seem to be necessary so that the Impact of second home construction on the landscape is minimised, and so that social and economic effects In second home localities are more beneficial than detrimental for the local Inhabitants (Chapter 7)

Análisis integral de la disolución de los metales preciosos con sistemas de lixiviación novedosos a base de aminas

En este trabajo de investigación se estudiaron, desde un enfoque electroquímico, los sistemas de lixiviación novedosos a base de aminas; la monoetanolamina (MEA) y la etilamina (EA), para mejorar el entendimiento del mecanismo de reacción de la disolución de los metales preciosos, i.e., el oro y la plata. Se presenta el efecto de la concentración de la MEA y la EA, en la velocidad de oxidación de los metales preciosos. El estudio es complementado por medio de técnicas electroquímicas tales como: Técnica del potencial de circuito abierto (OCP), voltametría lineal (VL) y cronoamperometrías. Los resultados demuestran que estas aminas tienen un gran potencial al disolver el Au y la Ag, debido a que se alcanzan densidades de corriente promedio de 0.008 y 0.013 A/cm2 empleando la MEA y 0.023 y 0.029 A/cm2 utilizando la EA, respectivamente. Además, los resultados dictaminan que tanto la MEA como la EA podrían disminuir el..

Revisión sistemática sobre la mejora de la velocidad en jugadores de fútbol sub-19

The objective was to compare and analyze the effectiveness of different training methodologies for speed improvement in U-19 soccer players. A systematic review literature study was carried out. Using the PRISMA statement, a bibliographic search was carried out through the PubMed database. Articles were included that were intervention studies written in Spanish or English, carried out in players aged 10 to 19 years that had at least one plyometric, strength, or sprint training method for speed improvement and that had an evaluation of sprinting. The results of the interventions showed benefits in speed improvement through the plyometric method (TE=0.66) in 20 m test, explosive strength (TE=0.64) in 5 m test, and sprint (TE=0.33) in 20 m test. It can be concluded that the explosive strength method obtains greater benefits in short distances (5-10 m) when low intensities are used and in 17-year-old players; the ideal training volume is 2 sessions per week. The sprint method at longer distances (20-30 m) in 14–15-year-olds, with a training volume of one or two sessions per week. Plyometrics achieves the same benefits over short and long distances (5-30 m) for ages 15-16 years with no noticeable difference in training volume.El objetivo fue comparar y analizar la efectividad de diferentes metodologías de entrenamiento para la mejora de la velocidad en futbolistas sub-19. Se llevó a cabo un estudio bibliográfico de revisión sistemática. Mediante la declaración PRISMA, se realizó una búsqueda bibliográfica a través de la base de datos PubMed. Se incluyeron artículos que fueran estudios de intervención escritos en castellano o en inglés, llevados a cabo en jugadores de 10 a 19 años, que tuvieran al menos un método de entrenamiento pliométrico, de fuerza o de sprint para la mejora de la velocidad y que tuvieran una evaluación del sprint. Los resultados de las intervenciones mostraron beneficios en la mejora de la velocidad a través del método pliométrico (TE=0,66) en test de 20 m, fuerza explosiva (TE=0,64) en test de 5 m y sprint (TE=0,33) en test de 20 m. Se puede llegar a la conclusión de que el método de fuerza explosiva obtiene mayores beneficios en las distancias cortas (5-10 m) cuando se emplean intensidades bajas y en jugadores de 17 años, el volumen de entrenamiento ideal es de 2 sesiones por semana. El método de sprint en distancias más largas (20-30 m) en edades de 14-15 años, con un volumen de entrenamiento de una o dos sesiones por semana. El pliométrico logra los mismos beneficios en distancias cortas y largas (5-30 m) para edades de 15-16 años y sin diferencias notables en el volumen de entrenamiento

Representaciones sociales y practicas emergentes de los clientes de casinos en Merida, Yucatan

En el marco de la dinamización económica del sector servicios, a partir de la última década los pobladores de Mérida, Yucatán, observaron la proliferación de establecimientos especializados en juegos de azar, con máquinas tragamonedas, juegos de apuestas y otros atractivos. La entidad se caracteriza por los salarios más bajos del país, sin embargo la aceptación social de los casinos, como opción de esparcimiento urbano, es elevada. Dichos establecimientos deben ofrecer satisfactores de otra índole que expliquen su poder de convocatoria. El estudio de las representaciones sociales sobre los casinos aporta información valiosa para entender las razones que motivan los usos y prácticas para acudir a ellos. Este trabajo estudia las representaciones sociales sobre los casinos de 20 personas que asisten a ellos. Utilizamos entrevistas semi-estructuradas y narraciones de experiencias personales. Exponemos los resultados en tres apartados: 1) Ir al casino, que describe las diferentes concepciones sobre dichos establecimientos y las estrategias de juego utilizadas. 2) Los demás qué opinan de mi juego, donde exponemos las opiniones de familiares y amigos sobre dicha práctica. 3) Nuevas prácticas y conductas sociales, en el que ambas se describen, discuten y analizan en el contexto de la dinámica urbana de Mérida

Parasitas do chupim molothrus bonariensis e do pássaro-preto-austral curaeus curaeus (Passeriformes: icteridae) no Chile

Comparative studies of parasites in sympatric bird species have been generally scarce. Parasitic infection/transmission can be spread in a number of ways that suggests possible direct and indirect, horizontal transmission between avian hosts. In order to determine whether two sympatric icterids from Central and Southern Chile share their parasite fauna (ecto-and endoparasites), we examined parasites of 27 Shiny Cowbirds, Molothrus bonariensis, and 28 Austral Blackbirds, Curaeus curaeus, including individuals captured in the wild and carcasses. We found that Shiny Cowbirds were infected with the chewing lice Brueelia bonariensis, Philopterus sp. 1, the feather mites Amerodectes molothrus, Proctophyllodes spp. (species 1 and 2), and the helminths Mediorhynchus papillosus, Plagiorhynchus sp., Dispharynx nasuta and Tetrameres paucispina, while Austral Blackbirds had the chewing lice Myrsidea sp., Philopterus sp. 2, the feather mites Proctophyllodes sp. 3, Amerodectes sp., and three helminths: Anonchotaenia sp., Capillaria sp. and M. papillosus. The flea Dasypsyllus (Neornipsyllus) cteniopus was found only on the Austral Blackbird. The only parasite species shared by both icterids was the acanthocephalan M. papillosus, possibly due to their feeding on the same intermediate insect hosts. With the exception of B. bonariensis and Philopterus sp. 1 found on the Shiny Cowbird, all species reported in this study represent new parasite-host associations and new records of parasite diversity in Chile.Estudos comparativos de parasitas em espécies de aves simpátricas são escassos. A infecção/transmissão de parasitas pode acontecer de diversas maneiras, incluindo possível transmissão direta, indireta ou horizontal entre as aves hospedeiras. Com o objetivo de determinar se dois icterídeos simpátricos do centro e sul do Chile compartilham a sua fauna parasitária (ecto- e endoparasitas), foram examinados os parasitas de 27 chupins Molothrus bonariensis e 28 pássaros-pretos-austral Curaeus curaeus, incluindo indivíduos capturados com rede de neblina e em carcaças. Nos chupins analisados, foram encontrados os piolhos de penas Brueelia bonariensis, Philopterus sp. 1, os ácaros Amerodectes molothrus, Proctophyllodes spp. (espécie 1 e 2), e os helmintos Mediorhynchus papillosus, Plagiorhynchus sp., Dispharynx nasuta e Tetrameres paucispina. Em contraste, os pássaros-pretos-austral estavam infectados com os piolhos Myrsidea sp., Philopterus sp. 2, os ácaros Proctophyllodes sp. 3, Amerodectes sp., e os helmintos Anonchotaenia sp., Capillaria sp. e M. papillosus. Adicionalmente, um espécime de pássaro-preto-austral estava parasitado pela pulga Dasypsyllus (Neornipsyllus) cteniopus. A única espécie de parasita que foi encontrada nas duas espécies de aves foi o acantocéfalo M. papillosus, possivelmente devido ao fato de que ambas as aves se alimentam dos insetos que são os hospedeiros intermediários deste parasita. Exceto os registros de B. bonariensis e Philopterus sp. 1 encontrados no chupim, todas as espécies reportadas neste estudo correspondem à novas associações de parasita/hospedeiro e novos registros para a diversidade parasitológica do Chile.Fil: Mena, Mabel. Universidad de Concepción; ChileFil: Valdebenito, José Osvaldo. University of Bath; Reino UnidoFil: Moreno, Lucila. Universidad de Concepción; ChileFil: Fuentes Castillo, Danny. Universidade de Sao Paulo; BrasilFil: Kinsella, John Mike. Helmwest Laboratory; Estados UnidosFil: Mironov, Sergey. Zoological Institute Of The Russian Academy Of Sciences; RusiaFil: Barrientos, Carlos. Universidad Santo Tomas, Santiago; ChileFil: Cicchino, Armando Conrado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Grupo de Entomología Edáfica Bonaerense Suboriental - GENEBSO; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: González Acuña, Daniel. Universidad de Concepción; Chil

Assessing mammal trapping standards in wild boar drop-net capture

Applying contemporary trapping standards when managing wildlife should no longer be an option, but a duty. Increasing wild boar populations originate a growing number of conflicts and hunting is the only cost-effective management option in most cases. However, new scenarios where hunting is unfeasible emerge and trapping necessities cope with lacking regulatory frameworks and technical guidelines. In this research, we evaluated drop nets, a capture method not considered by the international trapping standards, to capture Eurasian wild boar (Sus scrofa), a wildlife species not included in the list of mammal species under the scope of the Agreement on International Humane Trapping Standards (AIHTS). Less than 20% of the captured wild boars presented moderate or severe injuries attributable to the capture method, hence fulfilling the acceptance thresholds of the outdated AIHTS. Based on the new standards thresholds of acceptance, the humaneness of drop-nets in our study ranged 66-78%, under the 85% required. The capture success and selectivity were 100%, as ensured by operator-driven triggering, which should be considered the main strengths of this method, together with the minimization of animal suffering owing the short duration of the stressful situation. Additionally, in spite of the socially adverse environment, with people contrary to wild boar removal, no disturbances against the capture system or operations occurred. This is the first assessment of a drop-net capture method according to internationally accepted mammal trapping standards, with unconclusive results. However, there is a need for adapted procedures and thresholds of acceptance aimed at not-mechanical traps in general, and specifically at drop-nets. Compared to other live-capture methods, drop-nets minimize the duration of the stressful situation -at the expense of a strong adrenergic acute response-, maximize the probabilities of capturing entire sounders of prosocial species, which may be also considered as more humane, and has the ability to coordinate higher values of capture success, absolute selectivity and adaptability to difficult environments

Predicting human-wildlife interaction in urban environments through agent-based models

Altres ajuts: acords transformatius de la UABSynurbic species adapt to global urbanization by increasingly inhabiting urban environments, where social and ecological factors, such as anthropogenic food resources and habitat alterations, promote close human-wildlife interactions. Ineffective management of these interactions can result in conflicts, altered animal population dynamics, and increased public and private expenditures. This study presents the Barcelona wild boar (BCNWB)-prototype model, a spatially explicit, incremental agent-based simulation that captures interactions between citizens and wild boar (Sus scrofa) agents in fine-scale GIS-based scenarios in Barcelona. Developed using GAMA software, the model's results were analyzed with QGIS and R software. The model aims to simulate the dynamics of the social-ecological system underlying the urban ecosystem use by synurbic wild boars and their interactions with humans in the (peri)urban area of Barcelona, Spain. The BCNWB-prototype model demonstrated high accuracy in predicting the magnitude and location of wild boar movements (multiple-resolution-goodness-of-fit = 0.73) compared to reported wild boar presences in Barcelona. The model also forecasted 115 attack events and 1,442 direct feeding events during a one-year simulation period, as compared to the actual 150 attacks and 1,858 feeding events reported annually. The model's strong performance highlights its potential as a predictive tool for identifying priority areas for human-wild boar interactions and conflicts. Additionally, the model could be employed to assess the cost-effectiveness of management strategies and evaluate the spread, transmission risks, and public health implications of pathogens carried by wild boars