Bryophyte diversity patterns in flooded and tierra firme forests in the Araracuara Region, Colombian Amazonia

We investigated patterns of bryophyte species richness and composition in two forest types of Colombian Amazonia, non-flooded tierra firme forest and floodplain forest of the Caquetá River. A total of 109 bryophyte species were recorded from 14 0.2 ha plots. Bryophyte life forms and habitats were analyzed, including the canopy and epiphylls. Bryophyte species did not show significant differences between landscapes but mosses and liverworts were different and with opposite responses balancing the overall richness. Independence test showed differences in both life form and habitat use distribution between the two forest types with more fan and mat bryophytes species in the floodplains, and more epiphytic liverworts in the tierra firme forest. Correspondence analysis showed differences in the bryophyte species assemblage between the two forest types where they may be responding to the higher humidity provided by the flooding. Despite of, the environmental differences detected, epiphyll species assemblages were not strongly affected. Apparently, epiphyll habitat is stressful enough to hide the environmental differences between the flooded and Tierra firme forests.Investigamos los patrones de riqueza de especies y composición florística de briofitos en dos tipos de bosque en la Amazonía Colombiana. Bosques no inundados de Tierra firme y bosques periódicamente inundados en los planos inundables del Rió Caquetá. Encontramos 109 especies de briofitos en 14 parcelas de 0.2 ha. Nosotros analizamos diferencias en la distribución de formas de vida y hábitat de los briofitos entre los dos tipos de bosque incluyendo especies del dosel y epifilas. El número de especies de briofitos no mostró diferencias significativas entre los dos tipos de bosque. Pero musgos y hepáticas si tuvieron diferencias con respuestas opuestas balanceando el número total de especies. Pruebas de independencia mostraron diferencias en la distribución de formas de vida y uso de hábitat entre los dos tipos de bosque con más especies de abanicos y esteras en los planos inundables, y más especies de hepáticas epifitas en el bosque de Tierra firme. El análisis de correspondencia mostró diferencias en la composición florística de briofitos entre ambos tipos de bosque, donde las comunidades de briofitos pueden estar respondiendo a un gradiente de humedad aportada por la inundación periódica de los planos inundables. La composición florística de los briofitos epifilos no mostró una separación tan clara entre los tipos de bosque como si fue detectada en los otros hábitat donde los briofitos fueron encontrados. Aparentemente, el hábitat epifilo es suficientemente estresante para ocultar el efecto de las diferentes condiciones ambientales de los bosques inundables y de Tierra firme

La autoría y el estilo del grupo

Se plantea un método de análisis del arte paleolítico basado en la caracterización de los aspectos referidos dal estilo de un autor y los pertenecientes al estilo del grupo en el que se inscribe. Este método pretende ahondar en la metodología de la identificación de autor y añadir a este análisis los criterios por los cuales es posible definir la variabilidad de un estilo compartido por un grupo. La manera de identificar al autor ha sido propuesta, y en parte desarrollada por Juan María Apellaniz, quien señala como criterios más decisivos de esta identificación los derivados de la manera de trazar y del modelado. Se retoma este análisis y se contribuye a su ampliación de dos maneras : una teórica, a partir de un modelo etnográfico, y otra práctica, basada en la experimentación, al tiempo que determinamos los criterios para la identificación del estilo grupal. Se plantea, por tanto, esta investigación en dos partes. Una primera, destinada al desarrollo de la metología del análisis, para lo cual se parte de un modelo etnográfico y de la experimentación replicativa, y una segunda, en la que se contrasta la validez de esta metología en la aplicación a dos conjuntos arqueológicos de época paleolítica

Actuar bajo la idea de la libertad: Kant y la tesis de la incorporación

Este artículo examina un supuesto fundamental de la filosofía moral kantiana, a saber: que sin libertad trascendental, entendida como la propiedad de la voluntad por la que se determina a actuar sin ser afectada por resortes sensibles, no se le pue- den imputar al presunto agente actos inmorales. Teóricamente se argumenta contra el sentido lógico del supuesto (se revela la consecuencia aporética de la concepción) y se muestra cuán superfluo es en la práctica. De todos modos, se le reconoce a Kant, contra una línea de argumentación nietzscheana bien conocida, el mérito de haber captado el compromiso humano insuperable con la idea de que somos seres discrecionales o libres trascendentalmente. Y, finalmente, se contemplan algunos ejemplos de la resonancia de ese mérito en autores contemporáneos (Nagel, Strawson, Dennett)

Migration, Bankers, and Social Capital. The Rise of a Basque “Industrial Cowboy” in the American West: John Etchart, 1900-1943

The present article contributes to the general topics of migration, banking and social capital. It analyzes the business career of John Etchart in the American West from 1900 to 1943; from being a wage-earning sheepherder to becoming one of the most prosperous stockmen in Montana. The biography-centered approach is patterned after the work of other scholars who have studied ranching businesses with emphasis on the dynamic individuals behind the companies. The biography of John Etchart offers a window into important issues for the study of Basque immigration and sheep industry in the West. Etchart’s story exemplifies the Basque immigrant’s climb up the agricultural ladder that involved the emergence of partnerships within the Basque community. Etchart is also tied to the creation and development of cooperative initiatives among woolgrowers beyond the Basque community. Finally, the Etchart history enhances understandings of the various business practices undertaken by livestock outfits in Montana in the 1920s and 1930s.I would like to thank the editors of RHI-IHR and two anonymous referees for their help and valuable comments. All errors are nevertheless mine. I acknowledge with pleasure financial support from the Research Group of the Basque University System IT1523-22 and both Grants PID2021-122846 NB-I00 funded by MCIN/AEI/10.13039/501100011033, ERDF A way of making Europe and PGC2018-094133-B-100 funded by MCIU/AEI/FEDER, UE

Review of: Christopher Yeomans, The Expansion of Autonomy

Christopher Yeomans's new book is devoted to explaining what kind of moral psychology and philosophy of action guide Hegel's effort to grant objectivity to Kant's concept of a self-determining will and even to demonstrate its actualization in particular forms of citizenship. The challenge is to illuminate how Hegel's concept of freedom abstractly understood as 'being at home with oneself in the other', or recognizing oneself in an other entails that our moral duty is to meet the obligations of a particular social role (the farmer, the craftsman, the industrial producer, the public servant, and so on), while recognizing that these social roles are both chosen by agents and socially defined

Mechanical Properties of Thin-Film Composite Membranes and Their Role in Osmotic Processes

My research goal was to understand the role of membrane mechanical properties (e.g. strength and stiffness) in the transport of water and salt through polymer-based thin-film composite (TFC) membranes used for osmotic processes (OP). OP are membrane processes in which the main driving force is a concentration difference of solute(s) in the solutions in contact with the two sides of a semipermeable membrane. OP applications may include removing water from products/contaminants, harvesting energy from salinity gradients, and lowering costs of seawater desalination. The study system for my research was a set of TFC reverse osmosis (RO) membranes designed for rejecting salts in desalination. These TFC RO membranes have thick supporting layers (~150 μm), which increases the diffusion pathway for salts within the membranes. This decreases the effective salinity gradient between the two surfaces of the membrane active layer, which ultimately decreases the process productivity (i.e., water flux). I aimed to provide guidelines for the improved design of TFC membranes for OP, considering the trade-off between membrane mechanical integrity and productivity. My research approach comprised measurements and analysis of the individual mechanical properties of the three polymeric layers (active, porous support, and backing) that comprise TFC RO membranes, and correlation of these mechanical properties with TFC membrane transport properties and performance in OP. Initially, I studied helically coiled and multiwall carbon nanotubes as additives to create nanocomposite porous supports with improved mechanical properties. The results support the idea that increasing the mechanical stiffness of TFC membrane nanocomposite supports is an effective strategy for enhancing water production in desalination operations. Secondly, I evaluated woven polyester mesh as a backing layer and analyzed the role of mesh opening size on burst strength and mass-transfer resistance of TFC membranes used for OP. The findings show that mass-transfer resistances in OP are an additive effect of the multiple layers that compose a membrane and can be reduced by using more open (yet functional) backing layers such as polyester woven mesh in place of standard nonwoven mesh. Thirdly, I aimed to correlate the reduction in stiffness of the active layer with the change in water permeance of five commercial TFC membranes after contact with five different C1-C4 monohydric alcohols. The motivation was to explain the improvements in water flux after alcohol contact, which is used to pre wet membranes before OP operation. Correlation of results suggests that the mixing of water with the alcohols facilitates penetration of the alcohols into the active layer, likely by disrupting inter-chain hydrogen bonds, thus increasing the active layer free volume for water permeation. Finally, I studied water and sodium chloride transport through TFC membranes that were subjected to known degrees of mechanical strain. I demonstrated the importance of knowing the stress-strain curve of the membrane and highlighted that stiffer membrane structures are desirable to avoid reaching a strain above the reported onset fracture strain of the selective layer. With this information, I introduced a deformability coefficient and a solution-diffusion model with defects to guide the design of membranes and modules for pressurized osmotic processes. In closing the dissertation, I provided recommendations and research opportunities that I envision would improve TFC membrane productivity in OP

Water consumption in Bogotá: a review comparison with other major cities of Latin America

En el desarrollo de este documento se identificara el consumo de agua de Bogotá, Sao Paulo y Ciudad de México, en donde se encontraran los sectores con mayor consumo de agua de cada una de estas ciudades; de igual manera se mostraran cuáles son las medidas, proyectos o leyes que se han dispuesto a tomar para que haya un consumo racional de este recurso. Por otro lado, se mostrara la utilización que estas ciudades les dan a sus aguas residuales luego de ser tratadas. Posteriormente se realizaran dos comparaciones una entre Bogotá y Sao Paulo, y la otra entre Bogotá y Ciudad de México, en donde se observaran las medidas que cada una de estas ciudades ha tomado para disminuir el consumo de agua potable per cápita.In the development of this document was identified water consumption Bogota, Sao Paulo and Mexico City, where they find the sectors with higher water consumption of each of these cities, the same way they show what measures, projects or laws that have been willing to take to be a rational use of this resource. On the other hand, we show that using these cities give their wastewater after being treated. Subsequently perform two comparisons one in Bogota and Sao Paulo, and the other between Bogota and Mexico City, where they observe the measures that each of these cities has taken to reduce water consumption per capita.Pregrad