Evolution and relationships of the conifer seed cone telemachus: Evidence from the triassic of antarctica

The seed cone Telemachus is known from several Triassic localities in Gondwana. New specimens from two localities in Antarctica provide additional information about the type species, Telemachus elongatus, based on details of morphology and anatomy revealed by using a modified transfer technique on the compressed plants. Seed cones of T. elongatus are up to 6.0 cm long and characterized by conspicuous, elongate bracts. A second Antarctic species, described here as Telemachus antarcticus, is segregated, based on a shorter bract and differences in cone size. Newly recognized features of the genus include the shape, size, and disposition of the ovules; vascularization of the ovuliferous complex; and scale and bract histology. As a result of this new information, it is now possible to compare Telemachus with the permineralized Middle Triassic conifer seed cone Parasciadopitys from the Central Transantarctic Mountains. The similarities between the two genera make it possible to relate organs in different preservational modes and to develop a more complete concept for this widely distributed Gondwana conifer. Placing the Telemachus plant within a phylogenetic context makes it possible to evaluate the relationship with other so-called transitional conifers, an informal group that has been interpreted as intermediate between Paleozoic and modern conifers.Fil: Escapa, Ignacio Hernán. University of Kansas; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Decombeix, Anne-Laure. University of Kansas; Estados UnidosFil: Taylor, Edith L.. University of Kansas; Estados UnidosFil: Taylor, Thomas N.. University of Kansas; Estados Unido

Tecnologías sociales y ciudadanía socio-técnica: notas para la construcción de la matriz material de un futuro viable

La tecnología es un tema negligenciado en las ciencias sociales, en general, y en los estudios sobre pobreza y marginalidad, en particular. Tradicionalmente cuando las ciencias sociales piensan la relación tecnología sociedad lo hacen a partir de presupuestos deterministas. Y cuando lo hacen, consideran a la tecnología en el marco de abordajes deterministas lineales: o consideran que la tecnología determina el cambio social (determinismo tecnológico), o consideran que la sociedad determina la tecnología (determinismo social). En la práctica estos abordajes teóricos construyen una separación tajante entre problemas sociales y problemas tecnológicos. Constituyen dos lenguajes diferentes que difícilmente se comunican. Tanto a nivel internacional como nacional, las producciones sobre la cuestión socio-técnica son relativamente escasas, y fragmentarias. Cuál es la perspectiva socio-técnica? Aquélla que intentando superar las limitaciones de los determinismos lineales considera que las sociedades son tecnológicamente construidas al mismo tiempo que las tecnologías son socialmente configuradas. Lamentablemente, hasta hoy estos estudios tampoco ocupan un espacio relevante en la formación curricular de científicos e intelectuales. ¿Tienen los ingenieros o sociólogos formación escolar o universitaria en alguna materia titulada “Tecnología y Sociedad”? ¿o “Sistemas sociales y sistemas tecnológicos”? ¿”Tecnología y civilización”? ¿”Tecnología y cultura”? Seguramente no si han cursado programas de formación en ciencias sociales. Pero probablemente tampoco si tienen estudios universitarios en ingeniería o ciencias exactas

Social Studies of Technology in Latin America

Presentación del Dossier En este artículo se describe la trayectoria de los estudios de ciencia y tecnología (CyT) en América Latina. Dicha trayectoria ha sido dividida en dos etapas: una que responde a la conformación de este campo y otra que se extiende desde los años 90 hasta la actualidad.Introduction to the Dossier In this article, the trajectory of science and technology (S&T) in Latin America is described. This trajectory has been divided into two stages. One corresponds to the creation of this field of study between the 1960s and the 1980s, during which the political focus on problems of development related to science and technology was most fruitful. Other lines of research were linked to internalist historical studies and, toward the end of the 1980s, to sociological and anthropological studies with a constructivist focus. The second stage begins in the 1990s and continues to the present. It covers, in large part, work on the economics of technological change and studies on policies and the implementation of technology, and, to a lesser extent, the sociology and history of technology. In addition to analyzing the focuses within these large areas of work on S&T, this article points out the absences and thematic gaps in this field of research

On kk-Gons and kk-Holes in Point Sets

We consider a variation of the classical Erd\H{o}s-Szekeres problems on the existence and number of convex $k$-gons and $k$-holes (empty $k$-gons) in a set of $n$ points in the plane. Allowing the $k$-gons to be non-convex, we show bounds and structural results on maximizing and minimizing their numbers. Most noteworthy, for any $k$ and sufficiently large $n$, we give a quadratic lower bound for the number of $k$-holes, and show that this number is maximized by sets in convex position

Collective action for innovation and small farmer market access: The Papa Andina experience

"The Andean highlands are home to some of the poorest rural households in South America. Native potato varieties and local knowledge for their cultivation and use are unique resources possessed by farmers in these areas. As the forces of globalization and market integration penetrate the Andes, they present both challenges and opportunities for farmers there. This paper reports on how the Papa Andina Regional Initiative is promoting the use of collective action to reduce poverty in the Andes, by developing market niches and adding value to potatoes, particularly the native potatoes grown by poor farmers. Since 1998, Papa Andina has worked with partners in Bolivia, Ecuador and Peru to stimulate pro-poor innovation within market chains for potato-based products. Market chain actors (including small-scale potato producers, traders, and processors), researchers, and other service providers have engaged in innovation processes via two principal tools for facilitating collective action: the Participatory Market Chain Approach (PMCA) and Stakeholder Platforms. The PMCA fosters commercial, technological, and institutional innovation through a structured process that builds interest, trust, and collaboration among participants. Stakeholder Platforms provide a space for potato producers, other market chain actors, and service providers to come together to identify their common interests, share knowledge, and develop joint activities. The PMCA and Stakeholder Platforms have empowered Andean potato farmers by expanding their knowledge of markets, market agents, and business opportunities. Social networks built up among producers, market agents, and service providers have stimulated commercial innovation, which in turn has stimulated technical and institutional innovation. These innovations have allowed small farmers to market their potatoes on more favorable terms and other market chain actors to increase their incomes. This paper describes experiences with collective action in Bolivia, Ecuador, and Peru, via the PMCA and Stakeholder Platforms. Based on these experiences, a number of lessons are formulated for using collective action to stimulate innovation, market access, and poverty reduction in other settings." authors' abstractCollective action, Small farmers, Potato, Participatory methods, Innovation, stakeholders, Markets,

Repensando los bienes comunes: análisis socio-técnico sobre la construcción y regulación de los bienes comunes

El presente artículo analiza los bienes comunes desde una perspectiva socio-técnica. Puntualmente, invita a repensarlos en función de algunos cambios tecnológicos recientes. A partir de esta perspectiva es posible observar cómo los bienes comunes son parte de un proceso continuo de luchas, negociaciones y redefiniciones políticas entre diferentes grupos de actores. Analiza como estas luchas políticas son parte de un proceso de co-construcción entre el diseño tecnológico y las nuevas formas de regulación.This article discusses the commons ("common goods") from a socio-technical view. Specifically, it invites us to rethink them in the light of some recent technological changes. From this perspective it is possible to see how the commons are part of a continuous process of struggles, negotiations and political re-definitions among different groups of players. Analyze how these political struggles are part of a process of co-construction between the design of technologies and new forms of regulation

Public production of medicines: challenges for a strategic policy on health

La producción pública de medicamentos constituye la solución a un problema de disponibilidad de medicamentos y de su accesibilidad por parte de amplios sectores de la población. Se trata de un sector estratégico que requiere la necesidad de implementar y articular políticas públicas, que integren las áreas de ciencia y tecnología con las de investigación y desarrollo en salud. En este este artículo se analizan algunas de las capacidades tecno-productivas y socio-institucionales de la producción pública de medicamentos en Argentina y se señalan sus fortalezas y debilidades para constituirse como un sector estratégico en el área de salud. Este tipo de análisis permite una mejor comprensión de las posibilidades locales de desarrollo productivo para resolver problemas sociales. Por otro lado brinda elementos para orientar la gestión de políticas y tecnologías vinculadas con el desarrollo estratégico de un país.The public production of medicines could be the solution to a problem of availability of medicines and their accessibility by large sectors of the population. It is a strategic sector that needs the implementation and articulation of public policies that integrate the areas of science and technology with those of production and development in health. In this article, we analyze some of the techno-productive and socio-institutional capacities of the public production of medicines in Argentina. We also show their strengths and weaknesses to become a strategic sector in the health area. This type of analysis allows a better understanding of the local possibilities of productive development to solve social problems. On the other hand, it provides elements to guide the administration of policies and technologies linked to the strategic development of a country.Universidad Nacional de La Plata (UNLP) - Cátedra Libre Ciencia, Política y Socieda

Public production of medicines: challenges for a strategic policy on health

La producción pública de medicamentos constituye la solución a un problema de disponibilidad de medicamentos y de su accesibilidad por parte de amplios sectores de la población. Se trata de un sector estratégico que requiere la necesidad de implementar y articular políticas públicas, que integren las áreas de ciencia y tecnología con las de investigación y desarrollo en salud. En este este artículo se analizan algunas de las capacidades tecno-productivas y socio-institucionales de la producción pública de medicamentos en Argentina y se señalan sus fortalezas y debilidades para constituirse como un sector estratégico en el área de salud. Este tipo de análisis permite una mejor comprensión de las posibilidades locales de desarrollo productivo para resolver problemas sociales. Por otro lado brinda elementos para orientar la gestión de políticas y tecnologías vinculadas con el desarrollo estratégico de un país.The public production of medicines could be the solution to a problem of availability of medicines and their accessibility by large sectors of the population. It is a strategic sector that needs the implementation and articulation of public policies that integrate the areas of science and technology with those of production and development in health. In this article, we analyze some of the techno-productive and socio-institutional capacities of the public production of medicines in Argentina. We also show their strengths and weaknesses to become a strategic sector in the health area. This type of analysis allows a better understanding of the local possibilities of productive development to solve social problems. On the other hand, it provides elements to guide the administration of policies and technologies linked to the strategic development of a country.Universidad Nacional de La Plata (UNLP) - Cátedra Libre Ciencia, Política y Socieda

Palladium-catalyzed Transformations of Salvinorin A, a Neoclerodane Diterpene from Salvia divinorum

Transformations that selectively modify the furan ring present in a variety of naturals products would be useful in the synthesis of biological probes but remain largely underexplored. The neoclerodane diterpene salvinorin A, isolated from Salvia divinorum, is an example of a furan-containing natural product. Following selective bromination of salvinorin A, Suzuki-Miyaura and Sonogashira couplings were accomplished in moderate to good yields without hydrolyzing the labile C-2 acetate or altering the stereochemistry of the epimerizable centers