Definición de los procedimientos e indicadores de la cadena de custodia de la industria de pasta y papel vinculados a la normativa ISO 9000/14000

En el trabajo se ha reflejado la génesis del término „desarrollo sostenible‟ y la preocupación social y de los gobiernos hacia la sostenibilidad de los recursos, generando una política forestal a escala internacional, cuyo hito inicial desempeña la Cumbre de Rio y otros procesos, donde surge el término „sostenibilidad‟ - procesos gubernamentales que ponen su atención en los bosques,entre ellos el Proceso paneuropeo del que emanan los Criterios e indicadores de la gestión forestal sostenible, así como otros foros donde aparece la vinculación entre los productos y la sostenibilidad de los bosques de donde proceden. A partir de esos conceptos aparecen los sistemas de certificación, primero FSC, promovido por las ONG ambientalistas, y en respuesta a ello, el sistema PEFC de los propietarios forestales privados con las industrias forestales. En su introducción, el trabajo recoge como surge y evoluciona esta preocupación y como se sucede y desarrollan los sistemas de certificación en España, orientados tanto a la superficie forestal como a sus productos derivados. Tratando de ser una herramienta técnica, en estos últimos quince años, se han ido planteando metodologías y propuestas técnicas que puedan garantizar el origen sostenible del bosque de donde procede la materia prima. Aunque la persistencia de la masa forestal como término tiene importancia, no considera numerosos aspectos incluidos en el concepto “gestión forestal sostenible”. El trabajo manifiesta qué es y cómo se origina la Gestión Forestal Sostenible y muy ligado con ello, el origen de la certificación como herramienta, explicando cómo se incardina la certificación forestal española con las estructuras internacionales y se construyen nuevas estructuras a escala española y autonómica. Se expone el dominio y alcance técnico de la certificación, sus inicios y un análisis de la diversidad de sistemas y etiquetas existentes -como ha ido evolucionando a escala internacional y nacional, por sistemas, sectores y continentes, con especial atención en España, recopilando lo sucedido relevante para el sector forestal, industrias forestales y sistemas de certificación en los años de estudio de elaboración de la tesis. Se refleja la relevancia que adquiere la certificación forestal y de la cadena de custodia para la industria del papel, tanto por las regulaciones, normativas y legislación que involucran al producto derivado del bosque como por ser herramienta que enlaza el bosque sostenible con el consumidor. La aplicación de todas esas especificaciones técnicas que muestran la sostenibilidad del bosque y al trazabilidad en el proceso productivo comporta una carga administrativa de recopilación de información, de control para el seguimiento asociado con los registros necesarios, y de archivo de documentos, conforme a las exigencias que plantean los sistemas de certificación forestal. Por tanto, es importante definir un método y procedimientos genéricos para los correspondientes sistemas de gestión preexistentes en las empresas del sector de pasta y papel (de calidad/ de medio ambiente/integrados), para implantar un Sistema de Cadena de Custodia genérico (común a FSC y PEFC) en una instalación de celulosa y papel y un sistema de diligencia debida. Para ello, ha sido necesario analizar la línea de producción y establecer los puntos de su diagrama en los que se requiere el control de la trazabilidad, puntos en los que se procede al seguimiento y registro de la materia prima, materia semielaborada y producto, y de ahí proceder a redactar o retocar los procedimientos de gestión calidad/ medioambiental, en su caso, para incluir los campos de registro. Según determinen los procedimientos, se efectuará un seguimiento y registro de los, derivados que configuran una característica y se determinará una serie de indicadores del sistema de trazabilidad de la madera en la industria de celulosa y papel, es decir, un conjunto de parámetros cuantitativos y descriptivos, sujetos al seguimiento de forma periódica, que muestren el cambio y permitan observar la evaluación y control del Sistema de Cadena de Custodia. Además de asegurar la trazabilidad de la madera y fibra en la industria de pasta y papel y con ello la sostenibilidad del bosque del que procede, se avalará la legalidad de los aprovechamientos que proporcionan ese recurso maderable, cumpliendo así no sólo la legislación vigente sino también ambos sistemas de certificación FSC y PEFC. El sistema de cadena de custodia de la pasta y papel se caracteriza por los indicadores de seguimiento que permite el control de la trazabilidad. ABSTRACT This paper traces the origins of the term „Sustainable Development‟ and of both citizen and institutional concern for the sustainability of resources, leading to the enactment of a forestry policy at international level, of which the initial milestones are the Rio Summit and other processes in which the term „Sustainability‟ was born. Those forestfocused institutional initiatives include the pan-European process that led to the publication of Sustainable Forest Management Criteria and Indicators, and other forums that highlight the link between finished wood-based products and the sustainability of the forests from which that wood is sourced. Those concepts were the culture in which forest certification systems were engendered, first FSC, promoted by environmental NGOs, and subsequently PEFC, fostered in response to FSC by private forest owners and forest-based industries. In its Introduction, this paper looks at how such concern arose and has evolved and how certification systems came into existence in Spain and developed to encompass both forest lands and forest-based products. As part of a mission to provide an applicable technical tool, new methodologies and technical proposals have been put forward over the past fifteen years aimed at guaranteeing the sustainable origin of the forest from which raw material is sourced. Although the maintenance of forest stands as a term in its own right is important, it does not take many of the aspects included in the concept of “sustainable forest management” into account. This thesis describes what SFM is and how it was born, underlying the close link between SFM and the origin of certification as a tool, explaining how Spanish forest certification is embodied in international structures, while new structures are built here in Spain on both the national and regional scale. This work also details the domain and scope of forest certification from the technical standpoint, explains its beginnings, and assesses the various systems and labels that exist - how certification has evolved internationally and nationally across systems, sectors and continents, with special emphasis on Spain. It provides a compilation of events relevant to forestry, forest industries and forest certification systems that have taken place during the years this thesis has been in preparation. It reflects on the relevance that forest and chain of custody certification holds for the paper industry, in view not only of the regulations, policies and legislation that affect forest-based products but also of its role as a tool that bonds the sustainable forest with the consumer. Implementing the range of technical specifications to demonstrate forest sustainability and traceability throughout the production process entails the administrative burden of collecting information and providing controls to process the relevant records and documents to be kept on file in compliance with the requirements made by forest certification schemes. It is therefore important to define a generic method, together with its relevant procedures,that fits the management systems (quality / environmental / integrated)existing today in pulp and paper companies, in order to implement a generic Chain of Custody scheme (common to FSC and PEFC) in a pulp and paper mill, and a due diligence system. To achieve that, it has first been necessary to analyse the production line and establish points along the route where traceabilitycontrols need to be implemented and points where raw material, semi-finished goods and end products should be monitored and recorded. Subsequently, the procedures in quality / environmental management systems need to be drafted or amended as required to include fields that reflect those records. As required by the procedures, forest-based products that have a specific characteristic shall be monitored and recorded, and a number of indicators identified in the traceability system of wood for pulp & paper, i.e.createa set of quantitative and descriptive parameters subject to regular monitoringthat reveal changes and enable the Chain of Custody system to be assessed and controlled. In addition to ensuring the traceability of wood and fibre in the pulp and paper industry -and so the sustainability of the forest from which it is sourced -, the legality of the harvesting that produces that timber will also be enhanced, thus fulfilling not only the law but also both FSC and PEFC certification schemes. The chain of custody system for pulp and paper is characterised by monitoring indicators that enable traceability to be controlled.

Investigación sobre tratamientos de aguas seguros en emergencias

Esta Tesis Doctoral tiene como principal objetivo el obtener una cadena de tratamientos seguros de aguas seriados que nos permita asegurar la calidad de las aguas para consumo humano en caso de emergencias, de tal forma que se minimicen los efectos de acciones hostiles, como sabotajes o actos terroristas, desastres naturales, etc y buscar soluciones adecuadas para garantizar en este caso la salud. Las plantas de tratamientos de aguas existentes comercialmente no aseguran dicha calidad y la documentación sobre el tema presenta vacíos de conocimiento, contradicciones entre resultados de investigaciones o insostenibilidad de conclusiones de las mismas. Estas carencias nos permiten determinar los aspectos a tratar durante la investigación. Por ello, este objetivo se concretó en tres acciones: Investigar sobre rendimientos de plantas convencionales en eliminación de microorganismos y productos tóxicos y peligrosos. Introducir mejoras que garanticen el rendimiento de las plantas convencionales. Investigar sobre la conveniencia de complementar las instalaciones existentes buscando seguridad y garantía sanitaria. Y se desarrollaron tres líneas de investigación: LI 1 “Inorgánicos”: Investigación sobre la eliminación de los metales boro, cobre y molibdeno mediante procesos de intercambio iónico y de coagulaciónfloculación- decantación. LI 2 “Compuestos Orgánicos Volátiles”: Investigación sobre la eliminación de los compuestos orgánicos 1,1 dicloroetano, 1,2 dicloroetano, clorobenceno, 1,3 dicloropropeno y hexacloro 1,3 butadieno mediante procesos de carbón activo granular y de oxidación avanzada. LI 3 “Plantas portátiles”: Investigación sobre plantas existentes portátiles para verificar su rendimiento teórico y proponer mejoras. Estas líneas de investigación se desarrollaron tanto en el nivel teórico como en el empírico, bien sea en laboratorio como en campo. A lo largo del documento se demuestra que las principales fuentes de contaminación, salvo la degradación de yacimientos naturales, proceden de la actividad humana (efluentes industriales y agrícolas, aguas residuales y actividades beligerantes) que provocan un amplio espectro de enfermedades por lo que dificultan tanto la definición de la fuente como la anticipada detección de la enfermedad. Las principales conclusiones que se obtuvieron están relacionadas con el rendimiento de eliminación de los parámetros tras la aplicación de los procesos y plantas de tratamiento de aguas anteriormente reseñadas. Sin embargo, el verdadero elemento designador de originalidad de esta Tesis Doctoral, tal como se ha reseñado arriba, radica en la definición de un sistema seriado de procesos de tratamiento de aguas que asegura la calidad en caso de emergencia. Éste se define en el siguiente orden: pretratamiento, oxidación, coagulación-floculación-decantación, filtración por arena, intercambio iónico, carbón activo granular, microfiltración, radiación UV, ósmosis inversa, radiación UV y cloración final. The main objective of this Thesis is to obtain a chain of stepwise safe water treatments that allow us to ensure the quality of water for human consumption in case of emergencies, so that the effects of hostile actions, such as sabotage or terrorism, natural disasters, etc. and seek appropriate solutions in this case to ensure health. The existing commercial water treatment plants do not ensure quality, and the documentation on the subject presents knowledge gaps or contradictions. These gaps allow us to determine the issues to be discussed during the investigation. Therefore, this objective was manifested in three actions: Researching yields in commercial plants and microorganisms, or toxic and dangerous products removal. Improvements to ensure the performance of conventional plants. Inquire about the advisability of implementing existing facilities for safety and health guarantee. And three lines of research are developed: LI 1 “Inorganic elements”: Research removing metals iron, copper and molybdenum by ion exchange processes and coagulation-flocculation-decantation. LI 2 “Volatile Organic Compounds”: Research removing organic compounds 1,1 dichloroethane, 1,2 dichloroethane, chlorobenzene, 1,3-dichloropropene and 1,3-butadiene hexachloro through processes of granular activated carbon and advanced oxidation. LI 3 “Compact Water Treatment Plants”: Research on existing packaged plants to verify theoretical performance and suggest improvements. These lines of research are developed both theoretically and empirically, both in the laboratory and in the field. Throughout the document, it is evident that the main sources of pollution, other than the degradation of natural deposits, come from human activity (industrial and agricultural effluents, sewage and belligerent activities) which cause a broad spectrum of diseases which hamper both the definition of the source and the early detection of the disease. The main conclusions drawn are related to both the removal efficiency parameters after application of processes and treatment plants outlined above water. However, the real designator of originality of this thesis, such as outlined above, lies in the definition of a serial system water treatment processes assuring quality in case of emergency. This is defined in the following order: pretreatment, oxidation, coagulation-flocculation-sedimentation, sand filtration, ion exchange, granular activated carbon, microfiltration, UV radiation, reverse osmosis, UV radiation and final chlorination.

Valorización energética de biomasas en el marco de la política energética española. Incentivos económico-financieros y políticos, aportación de valor añadido y prospectiva estratégica de desarrollo

El modelo económico actual basado en el consumo y en la búsqueda permanente de una mayor calidad de vida, unido a una población mundial en aumento, contribuye a incrementar la demanda de servicios energéticos para cubrir las necesidades de energía de las personas y las industrias. Desde finales del siglo XIX la energía se ha generado fundamentalmente a partir de combustibles fósiles (carbón, petróleo y gas), convertidos en el suministro energético predominante mundialmente. Las emisiones de gases de efecto invernadero que genera la prestación de servicios energéticos han contribuido considerablemente al aumento histórico de las concentraciones de esos gases en la atmósfera, hasta el punto de que el consumo de combustibles fósiles es responsable de la mayoría de las emisiones antropogénicas (IPCC, 2012). Existen diversas opciones para disminuir las emisiones de gases de efecto invernadero del sector energético y con ello contribuir a mitigar el cambio climático, entre otras sería viable aumentar la eficiencia energética y sustituir combustibles de origen fósil por combustibles de origen renovable, pudiendo garantizar un suministro de energía sostenible, competitivo y seguro. De todas las energías renovables susceptibles de formar parte de una cartera de opciones de mitigación, esta tesis se centra en la bioenergía generada a partir de la valorización energética de las biomasas agrícolas, forestales, ganaderas o de otro tipo, con fines eléctricos y térmicos. Con objeto de mostrar su capacidad para contribuir a mitigar el cambio climático y su potencial contribución al desarrollo socioeconómico, a la generación de energía distribuida y a reducir determinados efectos negativos sobre el medio ambiente, se ha analizado minuciosamente el sector español de la biomasa en su conjunto. Desde el recurso biomásico que existe en España, las formas de extraerlo y procesarlo, las tecnologías de valorización energética, sus usos energéticos principales y la capacidad de implementación del sector en España. Asimismo se ha examinado el contexto energético tanto internacional y europeo como nacional, y se han analizado pormenorizadamente los instrumentos de soporte que han contribuido de manera directa e indirecta al desarrollo del sector en España. Además, la tesis integra el análisis de los resultados obtenidos mediante dos metodologías diferentes con fines también distintos. Por un lado se han obtenido los resultados medioambientales y socioeconómicos de los análisis de ciclo de vida input-output generados a partir de las cinco tecnologías biomásicas más ampliamente utilizadas en España. Y por otro lado, en base a los objetivos energéticos y medioambientales establecidos, se han obtenido distintas proyecciones de la implementación del sector a medio plazo, en forma de escenarios energéticos con horizonte 2035, mediante el modelo TIMES-Spain. La tesis ofrece también una serie de conclusiones y recomendaciones que podrían resultar pertinentes para los agentes que constituyen la cadena de valor del propio sector e interesados, así como para la formulación de políticas y mecanismos de apoyo para los agentes decisores, tanto del ámbito de la Administración General del Estado como autonómico y regional, sobre las características y ventajas de determinadas formas de valorización, sobre los efectos sociales y medioambientales que induce su uso, y sobre la capacidad de sector para contribuir a determinadas políticas más allá de las puramente energéticas. En todo caso, esta tesis doctoral aspira a contribuir a la toma de decisiones idóneas tanto a los agentes del sector como a responsables públicos, con objeto de adoptar medidas orientadas a fomentar modificaciones del sistema energético que incrementen la proporción de energía renovable y, de esta forma, contribuir a mitigar la amenaza que supone el cambio climático no solo en la actualidad, sino especialmente en los próximos años para las generaciones venideras. ABSTRACT The current economic model based on both, consumption and the constant search for greater quality of life, coupled with a growing world population, contribute to increase the demand for energy services in order to meet the energy needs of people and industries. Since the late nineteenth century, energy has been basically generated from fossil fuels (coal, oil and gas), which converted fossil fuels into the predominant World energy supply source. Emissions of greenhouse gases generated by the provision of energy services have contributed significantly to the historical increase in the concentrations of these gases in the atmosphere, to the extent that the consumption of fossil fuels is responsible for most of the anthropogenic emissions (IPCC, 2012). There are several options to reduce emissions of greenhouse gases in the energy sector and, thereby, to contribute to mitigate climate change. Among others, would be feasible to increase energy efficiency and progressively replacing fossil fuels by renewable fuels, which are able to ensure a sustainable, competitive and secure energy supply. Of all the renewable energies likely to form part of a portfolio of mitigation options, this thesis focuses on bioenergy generated from agricultural, forestry, farming or other kind of biomass, with electrical and thermal purposes. In order to show their ability to contribute to mitigate climate change and its potential contribution to socio-economic development, distributed energy generation and to reduce certain negative effects on the environment, the Spanish biomass sector as a whole has been dissected. From the types of biomass resources that exist in Spain, ways of extracting and processing them, energy production technologies, its main energy uses and the implementation capacity of the sector in Spain. It has also examined the international, European and national energy context, and has thoroughly analyzed the support instruments that have contributed directly and indirectly to the development of the sector in Spain, so far. Furthermore, the thesis integrates the analysis of results obtained using two different methodologies also with different purposes. On the one hand, the environmental and socio-economic results of the analysis of input-output cycle life generated from the five biomass technologies most widely used in Spain, have been obtained. On the other hand, different projections of the implementation of the sector in the medium term, as energy scenarios with horizon 2035, have been obtained by the model TIMES-Spain, based on several energy and environmental objectives. The thesis also offers a series of conclusions and recommendations that could be relevant to the agents that constitute the value chain of the biomass sector itself and other stakeholders. As well as policy and support mechanisms for decision-makers, from both: The Central and Regional Governments, on the characteristics and advantages of certain forms of valorization, on the social and environmental effects that induce their use, and the ability of the biomass sector to contribute to certain policies beyond the purely energy ones. In any case, this thesis aims to contribute to decision making, suitable for both: Industry players and to public officials. In order to adopt measures to promote significant changes in the energy system that increase the proportion of renewable energy and, consequently, that contribute to mitigate the threat of climate change; not only today but in the coming years, especially for future generations.

Evolución de los sistemas técnicos de reproducción musical

Con el fin de analizar la caracterización del proceso de evolución de los sistemas técnicos de reproducción musical se han planteado dos vías principales de análisis: en primer lugar, el estudio de las características técnicas de cuatro sistemas de reproducción que se han considerado representativos de dicho avance (sistemas basados en disco de vinilo, casete compacto, disco compacto y formato de codificación perceptual) y, en segundo lugar, el funcionamiento de dichos sistemas dentro del concepto que se ha denominado como cadena de transmisión de información de tipo musical. A través de la evaluación del grado de evolución de cada sistema y de su posterior comparación se procederá a realizar dicha caracterización. Para ello se tendrán en cuenta factores objetivos como, por ejemplo, la calidad de la señal de audio pero también cualitativos como, por ejemplo, la portabilidad que pueda proporcionar un tipo de sistema u otro. Por otra parte, se plantea un segundo objetivo que es actualizar la definición de reproductor, si así se desprende de los análisis, con la aparición de reproductores basados en codificación perceptual. ABSTRACT. In order to analyze the characterization of the process of evolution of technical systems of music playback considered two main ways of analysis: first, the study of the technical characteristics of four playback systems that have been considered representative of the advance (based on vinyl, compact cassette, compact disc and perceptual formats coding systems) and, second, the operation of these systems within the concept that has been called chain of information transmission of music. Through the evaluation of the degree of development of each system and its subsequent comparison will proceed to make such characterization. For this objective kept in mind factors such as the quality of the audio signal but also qualitative, for example, portability that can provide a particular device type will be considered. Moreover, a second objective is to update the definition of the player, if it is apparent from the analysis, with the appearance of players based on perceptual coding arises.

La casa crecedera. El crecimiento programado de la vivienda con innovación europea y economía de medios latinoamericana

El concepto de casa crecedera, tal y como lo conocemos en la actualidad, se acuñó por primera vez en 1932 en el concurso Das Wachsende Haus organizado por Martin Wagner y Hans Poelzig dentro del marco de la Exposición Internacional Sonne, Luft und Haus für alle, promovida por la Oficina de Turismo de la ciudad de Berlín. En dicho concurso, se definía este tipo de vivienda como aquella célula básica o vivienda semilla que, dependiendo de las necesidades y posibilidades de los habitantes, podía crecer mediante otras estancias, conformando una vivienda completa en sí misma en cada fase de crecimiento. Numerosos arquitectos de primer orden, tales como Walter Gropius, Bruno Taut, Erich Mendelsohn o Hans Scharoun, participaron en este concurso, abriendo una nueva vía de exploración dentro de la vivienda flexible, la del crecimiento programado. A partir de ese momento, en Europa, y subsecuentemente en EEUU y otras regiones desarrolladas, se iniciaron numerosas investigaciones teóricas y prácticas en torno al fenómeno del crecimiento en la vivienda desde un enfoque vinculado a la innovación, tanto espacial como técnica. Por otro lado, aunque dentro del marco de la arquitectura popular de otros países, ya se ensayaban viviendas crecederas desde el siglo XVIII debido a que, por su tamaño, eran más asequibles dentro del mercado. Desde los años treinta, numerosos países en vías de desarrollo tuvieron que lidiar con migraciones masivas del campo a la ciudad, por lo que se construyeron grandes conjuntos habitacionales que, en numerosos casos, estaban conformados por viviendas crecederas. En todos ellos, la aproximación al crecimiento de la vivienda se daba desde una perspectiva diferente a la de los países desarrollados. Se primaba la economía de medios, el uso de sistemas constructivos de bajo costo y, en muchos casos, se fomentaba incluso la autoconstrucción guiada, frente a las construcciones prefabricadas ensambladas por técnicos especializados que se proponían, por ejemplo, en los casos europeos. Para realizar esta investigación, se recopiló información de estas y otras viviendas. A continuación, se identificaron distintas maneras de producir el crecimiento, atendiendo a su posición relativa respecto de la vivienda semilla, a las que se denominó mecanismos de ampliación, utilizados indistintamente sin tener en cuenta la ubicación geográfica de cada casa. La cuestión de porqué se prefiere un mecanismo en lugar de otro en un caso determinado, desencadenó el principal objetivo de esta Tesis: la elaboración de un sistema de análisis y diagnóstico de la vivienda crecedera que, de acuerdo a determinados parámetros, permitiera indicar cuál es la ampliación o sucesión de ampliaciones óptimas para una familia concreta, en una ubicación establecida. Se partió de la idea de que el crecimiento de la vivienda está estrechamente ligado a la evolución de la unidad de convivencia que reside en ella, de manera que la casa se transformó en un hábitat dinámico. Además se atendió a la complejidad y variabilidad del fenómeno, sujeto a numerosos factores socio-económicos difícilmente previsibles en el tiempo, pero fácilmente monitorizables según unos patrones determinados vinculados a la normatividad, el número de habitantes, el ahorro medio, etc. Como consecuencia, para el diseño del sistema de optimización de la vivienda crecedera, se utilizaron patrones evolutivos. Dichos patrones, alejados ya del concepto espacial y morfológico usualmente utilizado en arquitectura por figuras como C. Alexander o J. Habraken, pasaron a entenderse como una secuencia de eventos en el tiempo (espaciales, sociales, económicos, legales, etc.), que describen el proceso de transformación y que son peculiares de cada vivienda. De esta manera, el tiempo adquirió una especial importancia al convertirse en otro material más del proyecto arquitectónico. Fue en la construcción de los patrones donde se identificaron los mencionados mecanismos de ampliación, entendidos también como sistemas de compactación de la ciudad a través de la ocupación tridimensional del espacio. Al estudiar la densidad, mediante los conceptos de holgura y hacinamiento, se aceptó la congestión de las ciudades como un valor positivo. De esta forma, las posibles transformaciones realizadas por los habitantes (previstas desde un inicio) sobre el escenario del habitar (vivienda semilla), se convirtieron también en herramientas de proyecto urbano que responden a condicionantes del lugar y de los habitantes con distintas intensidades de crecimiento, ocupación y densidad. Igualmente, en el proceso de diseño del sistema de optimización, se detectaron las estrategias para la adaptabilidad y transformación de la casa crecedera, es decir, aquella serie de acciones encaminadas a la alteración de la vivienda para facilitar su ampliación, y que engloban desde sistemas constructivos en espera, que facilitan las costuras entre crecimiento y vivienda semilla, hasta sistemas espaciales que permiten que la casa altere su uso transformándose en un hábitat productivo o en un artefacto de renta. Así como los mecanismos de ampliación están asociados a la morfología, se descubrió que su uso es independiente de la localización, y que las estrategias de adaptabilidad de la vivienda se encuentran ligadas a sistemas constructivos o procesos de gestión vinculados a una región concreta. De esta manera, la combinación de los mecanismos con las estrategias caracterizan el proceso de evolución de la vivienda, vinculándola a unos determinados condicionantes sociales, geográficos y por tanto, constructivos. Finalmente, a través de la adecuada combinación de mecanismos de ampliación y estrategias de adaptabilidad en el proyecto de la vivienda con crecimiento programado es posible optimizar su desarrollo en términos económicos, constructivos, sociales y espaciales. Como resultado, esto ayudaría no sólo a mejorar la vida de los habitantes de la vivienda semilla en términos cualitativos y cuantitativos, sino también a compactar las ciudades mediante sistemas incluyentes, ya que las casas crecederas proporcionan una mayor complejidad de usos y diversidad de relaciones sociales. ABSTRACT The growing house concept -as we currently know it- was used for the first time back in 1932 in the competition Das Wachsende Haus organized by Martin Wagner and Hans Poelzig during the International Exhibition Sonne, Luft und Haus für alle, promoted by Berlin's Tourist Office. In that competition this type of housing was defined as a basic cell or a seed house unit, and depending on the needs and capabilities of the residents it could grow by adding rooms and defining itself as a complete house unit during each growing stage. Many world-top class architects such as Walter Gropius, Bruno Taut, Erich Mendelsohn or Hans Scharoun, were part of this competition exploring a new path in the flexible housing field, the scheduled grownth. From that moment and on, in Europe -and subsequently in the USA and other developed areas- many theorical and pragmatical researchs were directed towards the growing house phenomena, coming from an initial approach related to innovation, spacial and technical innovation. Furthermore -inside the traditional architecture frame in other countries, growing houses were already tested in the XVIII century- mainly due to the size were more affordable in the Real State Market. Since the 30's decade many developing countries had to deal with massive migration movements from the countryside to cities, building large housing developments were -in many cases- formed by growing housing units. In all of these developing countries the growing house approach was drawn from a different perspective than in the developed countries. An economy of means was prioritized, the utilization of low cost construction systems and -in many cases- a guided self-construction was prioritized versus the prefabricated constructions set by specialized technics that were proposed -for instance- in the European cases. To proceed with this research, information from these -and other- housing units was gathered. From then and on different ways to perform the growing actions were identified, according to its relative position from the seed house unit, these ways were named as addition or enlargement mechanisms indifferently utilized without adknowledging the geographic location for each house. The question of why one addition mechanism is preferred over another in any given case became the main target of this Thesis; the ellaboration of an analysis and diagnosis system for the growing house -according to certain parameters- would allow to point out which is the addition or addition process more efficient for a certain family in a particular location. As a starting point the grownth of the housing unit is directly linked to the evolution of the family unit that lives on it, so the house becomes a dynamic habitat. The complexity and the variability of the phenomena was taken into consideration related to a great number of socio-economic factors hardly able to be foreseen ahead on time but easy to be monitored according to certain patterns linked to regulation, population, average savings, etc As a consequence, to design the optimization system for the growing house, evolutionary patterns were utilized. Those patterns far away from the spatial and morphologic concept normally utilized in Architecture by characters like C. Alexander or J. Habraken, started to be understood like a sequence of events on time (spatial events, social events, economic events, legal events, etc) that describes the transformation process and that are particular for each housing unit. Therefore time became something important as another ingredient in the Architectural Project. The before mentioned addition or enlargement mechanisms were identified while building the patterns; these mechanisms were also understood as city's system of compactation through the tridimendional ocupation of space. Studying density, thorough the concepts of comfort and overcrowding, traffic congestion in the city was accepted as a positive value. This way, the possible transformations made by the residents (planned from the begining) about the residencial scenary (seed house), also became tools of the urban project that are a response to site's distinctive features and to the residents with different grownth intensities, activities and density Likewise, during the process of designing the optimization system, strategies for adaptations and transformation of the growing house were detected, in other words, the serial chain of actions directed to modify the house easing its enlargement or addition, and that comprehends from constructive systems on hold -that smooths the costures between grownth and housing seed- to spatial systems that allows that the house modify its utilization, becoming a productive habitat or a rental asset. Because the enlargement mechanisms are linked to the morphology, it was discovered that the use it's not related to the location, and that the adaptation strategies of the houses are linked to constructive systems or management processes linked to a particular area. This way the combination of mechanisms and strategies characterizes the process of housing evolution, linking it to certain social and geographic peculiarities and therefore constructives. At last, through the certain combination of enlargement mechanisms and adaptability strategies in the housing with scheduled grownth project is possible to optimize its development in economic, constructive, social and spatial terms. As a result, this would help not only to improve the life of the seed house residents in qualitative and quantitative terms but also to compact the cities through inclusive systems, given that the growing houses provide a larger complexity of uses and social relations.

La paradoja de Mies : las simetrías invisibles a través del Pabellón de Barcelona

El vínculo de Mies van der Rohe con la simetría es un invariante que se intuye en toda su obra más allá de su pretendida invisibilidad. Partiendo del proyecto moderno como proceso paradójico, que Mies lo expresa en sus conocidos aforismos, como el célebre “menos es más”, la tesis pretende ser una aproximación a este concepto clave de la arquitectura a través de una de sus obras más importantes: el Pabellón Alemán para la Exposición Universal de 1.929 en Barcelona. Ejemplo de planta asimétrica según Bruno Zevi y un “auténtico caballo de Troya cargado de simetrías” como lo definió Robin Evans. El Pabellón representó para la modernidad, la culminación de una década que cambió radicalmente la visión de la arquitectura hasta ese momento, gracias al carácter inclusivo de lo paradójico y las innumerables conexiones que hubo entre distintas disciplinas, tan antagónicas, como el arte y la ciencia. De esta última, se propone una definición ampliada de la simetría como principio de equivalencia entre elementos desde la invariancia. En esta definición se incorpora el sentido recogido por Lederman como “expresión de igualdad”, así como el planteado por Hermann Weyl en su libro Simetría como “invariancia de una configuración bajo un grupo de automorfismos” (libro que Mies tenía en su biblioteca privada). Precisamente para Weyl, el espacio vacío tiene un alto grado de simetría. “Cada punto es igual que los otros, y en ninguno hay diferencias intrínsecas entre las diversas direcciones." A partir de este nuevo significado, la obra de Mies adquiere otro sentido encaminado a la materialización de ese espacio, que él pretendía que “reflejase” el espíritu de la época y cuya génesis se postula en el Teorema de Noether que establece que “por cada simetría continua de las leyes físicas ha de existir una ley de conservación”. Estas simetrías continúas son las simetrías invisibles del espacio vacío que se desvelan “aparentemente” como oposición a las estructuras de orden de las simetrías de la materia, de lo lleno, pero que participan de la misma lógica aporética miesiana, de considerarlo otro material, y que se definen como: (i)limitado, (in)grávido, (in)acabado e (in)material. Finalmente, una paradoja más: El “espacio universal” que buscó Mies, no lo encontró en América sino en este pabellón. Como bien lo han intuido arquitectos contemporáneos como Kazuyo Sejima + Ryue Nishizawa (SANAA) legítimos herederos del maestro alemán. ABSTRACT The relationship between Mies van der Rohe with the symmetry is an invariant which is intuited in his entire work beyond his intentional invisibility. Based on the modern project as a paradoxical process, which Mies expresses in his aphorisms know as the famous “less is more”, the thesis is intended to approach this key concept in architecture through one of his most important works: The German Pavilion for the World Expo in 1929 in Barcelona, an example of asymmetric floor according to Bruno Zevi and a “real Trojan horse loaded with symmetries”. As defined by Robin Evans. For modernity, this Pavilion represented the culmination of a decade which radically changed the vision of architecture so far, thanks to the inclusive character of the paradoxical and the innumerable connections that there were amongst the different disciplines, as antagonistic as Art and Science. Of the latter, an expanded definition of symmetry is proposed as the principle of equivalence between elements from the invariance. Incorporated into this definition is the sense defined by Leterman as “expression of equality,” like the one proposed by Hermann Weyl in his book Symmetry as “configuration invariance under a group of automorphisms” (a book which Mies had in his private library). Precisely for Weyl, the empty space has a high degree of symmetry. “Each point is equal to the other, and in none are there intrinsic differences among the diverse directions.” Based on this new meaning, Mies’ work acquires another meaning approaching the materialization of that space, which he intended to “reflect” the spirit of the time and whose genesis is postulated in the Noether’s theorem which establishes that “for every continuous symmetry of physical laws, there must be a law of conservation.” These continuous symmetries are the invisible empty space symmetries which reveal themselves “apparently” as opposition to the structures of matter symmetries, of those which are full, but which participate in the same Mies aporetic logic, if deemed other material, and which is defined as (un)limited, weight(less), (un)finished and (im)material. Finally, one more paradox: the “universal space” which Mies search for, he did not find it in America, but at this pavilion, just as the contemporary architects like Kazuyo Sejima + Ryue Nishizawa (SANAA) rightfully intuited, as legitimate heirs of the German master.

Evidence for a structural motif in toxins and interleukin-2 that may be responsible for binding to endothelial cells and initiating vascular leak syndrome

The dose-limiting toxicity of interleukin-2 (IL-2) and immunotoxin (IT) therapy in humans is vascular leak syndrome (VLS). VLS has a complex etiology involving damage to vascular endothelial cells (ECs), extravasation of fluids and proteins, interstitial edema, and organ failure. IL-2 and ITs prepared with the catalytic A chain of the plant toxin, ricin (RTA), and other toxins, damage human ECs in vitro and in vivo. Damage to ECs may initiate VLS; if this damage could be avoided without losing the efficacy of ITs or IL-2, larger doses could be administered. In this paper, we provide evidence that a three amino acid sequence motif, (x)D(y), in toxins and IL-2 damages ECs. Thus, when peptides from RTA or IL-2 containing this sequence motif are coupled to mouse IgG, they bind to and damage ECs both in vitro and, in the case of RTA, in vivo. In contrast, the same peptides with a deleted or mutated sequence do not. Furthermore, the peptide from RTA attached to mouse IgG can block the binding of intact RTA to ECs in vitro and vice versa. In addition, RTA, a fragment of Pseudomonas exotoxin A (PE38-lys), and fibronectin also block the binding of the mouse IgG-RTA peptide to ECs, suggesting that an (x)D(y) motif is exposed on all three molecules. Our results suggest that deletions or mutations in this sequence or the use of nondamaging blocking peptides may increase the therapeutic index of both IL-2, as well as ITs prepared with a variety of plant or bacterial toxins.

From ab initio quantum mechanics to molecular neurobiology: A cation–π binding site in the nicotinic receptor

The nicotinic acetylcholine receptor is the prototype ligand-gated ion channel. A number of aromatic amino acids have been identified as contributing to the agonist binding site, suggesting that cation–π interactions may be involved in binding the quaternary ammonium group of the agonist, acetylcholine. Here we show a compelling correlation between: (i) ab initio quantum mechanical predictions of cation–π binding abilities and (ii) EC50 values for acetylcholine at the receptor for a series of tryptophan derivatives that were incorporated into the receptor by using the in vivo nonsense-suppression method for unnatural amino acid incorporation. Such a correlation is seen at one, and only one, of the aromatic residues—tryptophan-149 of the α subunit. This finding indicates that, on binding, the cationic, quaternary ammonium group of acetylcholine makes van der Waals contact with the indole side chain of α tryptophan-149, providing the most precise structural information to date on this receptor. Consistent with this model, a tethered quaternary ammonium group emanating from position α149 produces a constitutively active receptor.

A streptavidin mutant with altered ligand-binding specificity

The biotin-binding site of streptavidin was modified to alter its ligand-binding specificity. In natural streptavidin, the side chains of N23 and S27 make two of the three hydrogen bonds with the ureido oxygen of biotin. These two residues were mutated to severely weaken biotin binding while attempting to maintain the affinity for two biotin analogs, 2-iminobiotin and diaminobiotin. Redesigning of the biotin-binding site used the difference in local electrostatic charge distribution between biotin and these biotin analogs. Free energy calculations predicted that the introduction of a negative charge at the position of S27 plus the mutation N23A should disrupt two of the three hydrogen bonds between natural streptavidin and the ureido oxygen of biotin. In contrast, the imino hydrogen of 2-iminobiotin should form a hydrogen bond with the side chain of an acidic amino acid at position 27. This should reduce the biotin-binding affinity by approximately eight orders of magnitude, while leaving the affinities for these biotin analogs virtually unaffected. In good agreement with these predictions, a streptavidin mutant with the N23A and S27D substitutions binds 2-iminobiotin with an affinity (Ka) of 1 × 106 M−1, two orders of magnitude higher than that for biotin (1 × 104 M−1). In contrast, the binding affinity of this streptavidin mutant for diaminobiotin (2.7 × 104 M−1) was lower than predicted (2.9 × 105 M−1), suggesting the position of the diaminobiotin in the biotin-binding site was not accurately determined by modeling.

Nuclear Ferritin Protects DNA From UV Damage in Corneal Epithelial Cells

Previously, we identified the heavy chain of ferritin as a developmentally regulated nuclear protein of embryonic chicken corneal epithelial cells. The nuclear ferritin is assembled into a supramolecular form indistinguishable from the cytoplasmic form of ferritin found in other cell types and thus most likely has iron-sequestering capabilities. Free iron, via the Fenton reaction, is known to exacerbate UV-induced and other oxidative damage to cellular components, including DNA. Since corneal epithelial cells are constantly exposed to UV light, we hypothesized that the nuclear ferritin might protect the DNA of these cells from free radical damage. To test this possibility, primary cultures of cells from corneal epithelium and stroma, and from skin epithelium and stroma, were UV irradiated, and DNA strand breaks were detected by an in situ 3′-end labeling method. Corneal epithelial cells without nuclear ferritin were also examined. We observed that the corneal epithelial cells with nuclear ferritin had significantly less DNA breakage than other cell types examined. Furthermore, increasing the iron concentration of the culture medium exacerbated the generation of UV-induced DNA strand breaks in corneal and skin fibroblasts, but not in the corneal epithelial cells. Most convincingly, corneal epithelial cells in which the expression of nuclear ferritin was inhibited became much more susceptible to UV-induced DNA damage. Therefore, it seems that corneal epithelial cells have evolved a novel, nuclear ferritin-based mechanism for protecting their DNA against UV damage.

A specific transition state for S-peptide combining with folded S-protein and then refolding

We measured the folding and unfolding kinetics of mutants for a simple protein folding reaction to characterize the structure of the transition state. Fluorescently labeled S-peptide analogues combine with S-protein to form ribonuclease S analogues: initially, S-peptide is disordered whereas S-protein is folded. The fluorescent probe provides a convenient spectroscopic probe for the reaction. The association rate constant, kon, and the dissociation rate constant, koff, were both determined for two sets of mutants. The dissociation rate constant is measured by adding an excess of unlabeled S-peptide analogue to a labeled complex (RNaseS*). This strategy allows kon and koff to be measured under identical conditions so that microscopic reversibility applies and the transition state is the same for unfolding and refolding. The first set of mutants tests the role of the α-helix in the transition state. Solvent-exposed residues Ala-6 and Gln-11 in the α-helix of native RNaseS were replaced by the helix destabilizing residues glycine or proline. A plot of log kon vs. log Kd for this series of mutants is linear over a very wide range, with a slope of −0.3, indicating that almost all of the molecules fold via a transition state involving the helix. A second set of mutants tests the role of side chains in the transition state. Three side chains were investigated: Phe-8, His-12, and Met-13, which are known to be important for binding S-peptide to S-protein and which also contribute strongly to the stability of RNaseS*. Only the side chain of Phe-8 contributes significantly, however, to the stability of the transition state. The results provide a remarkably clear description of a folding transition state.

Human interleukin-10-related T cell-derived inducible factor: Molecular cloning and functional characterization as an hepatocyte-stimulating factor

IL-10-related T cell-derived inducible factor (IL-TIF or IL-21) is a new cytokine structurally related to IL-10 and originally identified in the mouse as a gene induced by IL-9 in T cells and mast cells. Here, we report the cloning of the human IL-TIF cDNA, which shares 79% amino acid identity with mouse IL-TIF and 25% identity with human IL-10. Recombinant human IL-TIF was found to activate signal transducer and activator of transcription factors-1 and -3 in several hepatoma cell lines. IL-TIF stimulation of HepG2 human hepatoma cells up-regulated the production of acute phase reactants such as serum amyloid A, α1-antichymotrypsin, and haptoglobin. Although IL-10 and IL-TIF have distinct activities, antibodies directed against the β chain of the IL-10 receptor blocked the induction of acute phase reactants by IL-TIF, indicating that this chain is a common component of the IL-10 and IL-TIF receptors. Similar acute phase reactant induction was observed in mouse liver upon IL-TIF injection, and IL-TIF expression was found to be rapidly increased after lipopolysaccharide (LPS) injection, suggesting that this cytokine contributes to the inflammatory response in vivo.

Polarity and permeation profiles in lipid membranes

The isotropic 14N-hyperfine coupling constant, a\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{o}^{N}}}\end{equation*}\end{document}, of nitroxide spin labels is dependent on the local environmental polarity. The dependence of a\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{_{o}^{N}}}\end{equation*}\end{document} in fluid phospholipid bilayer membranes on the C-atom position, n, of the nitroxide in the sn-2 chain of a spin-labeled diacyl glycerophospholipid therefore determines the transmembrane polarity profile. The polarity variation in phospholipid membranes, with and without equimolar cholesterol, is characterized by a sigmoidal, trough-like profile of the form {1 + exp [(n − no)/λ]}−1, where n = no is the point of maximum gradient, or polarity midpoint, beyond which the free energy of permeation decreases linearly with n, on a characteristic length-scale, λ. Integration over this profile yields a corresponding expression for the permeability barrier to polar solutes. For fluid membranes without cholesterol, no ≈ 8 and λ ≈ 0.5–1 CH2 units, and the permeability barrier introduces an additional diffusive resistance that is equivalent to increasing the effective membrane thickness by 35–80%, depending on the lipid. For membranes containing equimolar cholesterol, no ≈ 9–10, and the total change in polarity is greater than for membranes without cholesterol, increasing the permeability barrier by a factor of 2, whereas the decay length remains similar. The permeation of oxygen into fluid lipid membranes (determined by spin-label relaxation enhancements) displays a profile similar to that of the transmembrane polarity but of opposite sense. For fluid membranes without cholesterol no ≈ 8 and λ ≈ 1 CH2 units, also for oxygen. The permeation profile for polar paramagnetic ion complexes is closer to a single exponential decay, i.e., no lies outside the acyl-chain region of the membrane. These results are relevant not only to the permeation of water and polar solutes into membranes and their permeabilities, but also to depth determinations of site-specifically spin-labeled protein residues by using paramagnetic relaxation agents.

Photochemical energy conversion in a helical oligoproline assembly.

A general method is described for constructing a helical oligoproline assembly having a spatially ordered array of functional sites protruding from a proline-II helix. Three different redox-active carboxylic acids were coupled to the side chain of cis-4-amino-L-proline. These redox modules were incorporated through solid-phase peptide synthesis into a 13-residue helical oligoproline assembly bearing in linear array a phenothiazine electron donor, a tris(bipyridine)ruthenium(II) chromophore, and an anthraquinone electron acceptor. Upon transient 460-nm irradiation in acetonitrile, this peptide triad formed with 53% efficiency an excited state containing a phenothiazine radical cation and an anthraquinone radical anion. This light-induced redox-separated state had a lifetime of 175 ns and stored 1.65 eV of energy.

Unexpected beta2-microglobulin sequence diversity in individual rainbow trout.

For mammals beta2-microglobulin (beta2m), the light chain of major histocompatibility complex (MHC) class I molecules, is invariant (or highly conserved) and is encoded by a single gene unlinked to the MHC. We find that beta2m of a salmonid fish, the rainbow trout (Oncorhynchus mykiss), does not conform to the mammalian paradigm. Ten of 12 randomly selected beta2m cDNA clones from an individual fish have different nucleotide sequences. A complex restriction fragment length polymorphism pattern is observed with rainbow trout, suggesting multiple beta2m genes in the genome, in excess of the two genes expected from the ancestral salmonid tetraploidy. Additional duplication and diversification of the beta2m genes might have occurred subsequently. Variation in the beta2m cDNA sequences is mainly at sites that do not perturb the structure of the mature beta2m protein, showing that the observed diversity of the trout beta2m genes is not primarily a result of pathogen selection.