Rates of erosion and landscape change along the Blue Ridge escarpment, southern Appalachian Mountains, estimated from in situ cosmogenic 10Be

The Blue Ridge escarpment, located within the southern Appalachian Mountains of Virginia and North Carolina, forms a distinct, steep boundary between the lower-elevation Piedmont and higher-elevation Blue Ridge physiographic provinces. To understand better the rate at which this landform and the adjacent landscape are changing, we measured cosmogenic 10Be in quartz separated from sediment samples (n = 50) collected in thirty-two streams and from three exposed bedrock outcrops along four transects normal to the escarpment, allowing us to calculate erosion rates integrated over 104–105 years. These basin-averaged erosion rates (5.4–49 m My-1) are consistent with those measured elsewhere in the southern Appalachians and show a positive relationship between erosion rate and average basin slope. Erosion rates show no relationship with basin size or relative position of the Brevard fault zone, a fundamental structural element of the region. The cosmogenic isotopic data, when considered along with the distribution of average basin slopes in each physiographic province, suggest that the escarpment is eroding on average more rapidly than the Blue Ridge uplands, which are eroding more rapidly than the Piedmont lowlands. This difference in erosion rates by geomorphic setting suggests that the elevation difference between the uplands and lowlands adjacent to the escarpment is being reduced but at extremely slow rates

CULTIVAR AGROECOLOGÍA EN ESCUELAS PRIMARIAS DE MONTEVIDEO. PROGRAMA HUERTAS EN CENTROS EDUCATIVOS

El Programa Huertas en Centros Educativos (PHCE) es una experiencia que desarrollan conjuntamente la Intendencia de Montevideo, la Administración Nacional de Enseñanza Pública y la Universidad de la República, desde el año 2005. Se basa en la docencia, instalación y seguimiento de huertas agroecológicas en 49 escuelas primarias de Montevideo ubicadas en zonas de vulnerabilidad social. Trabajan en él, 35 orientadores de huerta que participan junto a unos 14.000 niños y 450 maestros en forma directa, vinculando la agroecología a las actividades curriculares de todos los grados. El objetivo general es promover un cambio cultural hacia una nueva forma de dignificar a la persona en relación con la naturaleza y fortalecer vínculos solidarios. Busca también desarrollar hábitos de trabajo y de alimentación saludable, prácticas agroecológicas y que las mismas se extiendan a los hogares. Resultados de evaluaciones continuas, señalan que el PHCE genera espacios agroecológicos en sus dimensiones técnico-productiva, socio-cultural y política. Contribuye al aprendizaje de las Ciencias de la Naturaleza, la formación en valores, el trabajo en equipo, propicia la atención a la diversidad, despertando el gusto y la revaloración del trabajo manual. Aporta al rescate de los aprendizajes y saberes de abuelos y padres, favoreciendo los vínculos familiares a partir de una tarea compartida. Para la Universidad, es un espacio de experiencia valiosa en los más de cincuenta estudiantes de Agronomía que se han desempeñado como docentes y/o pasantes. Además crea la oportunidad de articular acciones entre diversas ramas de la enseñanza y extender conceptos en agroecología a la comunidad

Validation tests of the CMS TIB/TID structures

Tracker Inner Barrel half-cylinders and Tracker Inner Disks of the CMS tracker have been integrated in three INFN sites. Integrated structures are submitted to an extensive set of tests whose main aim is to validate the functioning of the structures in CMS-like conditions. The tests have furthermore proven to be a great opportunity to study several aspects of the performance in detail. In this note the tests are described in some detail and an overview of the results is presented

feasibility study of a chp plant with steam turbine and biomass gasification for tissue paper production

Abstract In remote areas, such as India, Africa and Southeast Asia, typically not connected to the natural gas distribution network, tissue paper production is currently carried out using a Yankee cylinder and two hot air hoods heated with saturated steam produced in conventional boilers. In this way the drying air is heated at medium temperature, around 160-180 °C, with consequent low levels of dried paper production. In this context, the present study intends to evaluate the technical and economic feasibility of using a wood biomass fixed bed downdraft gasification plant for the production of syngas to be used as fuel in gas hoods, in order to reach high drying temperatures (around 500 °C), comparable with those of the current modern hoods powered with natural gas. Using previously developed calculation codes, an evaluation of energy performance of the paper drying system and of the gasification plant has been performed. The present study also evaluates the possibility of applying a CHP plant, powered by biomass, for the production of steam and electric, this last obtained adopting a steam turbine, thus covering all the electrical and thermal needs of the paper mill. Results show that, for a paper mill with a production of about 80 t/day of paper, two gasification reactors with a thermal output of about 1.95 MWt, and a consumption of dry biomass of 0.86 t/h, are required. For the steam system, the net electric power needed to meet the needs of the paper mill is about 3100 kW with a consumption of 4.72 t/h of moist biomass and a net efficiency of 23.9 %

Three-dimensional stochastic model of actin–myosin binding in the sarcomere lattice

The effect of molecule tethering in three-dimensional (3-D) space on bimolecular binding kinetics is rarely addressed and only occasionally incorporated into models of cell motility. The simplest system that can quantitatively determine this effect is the 3-D sarcomere lattice of the striated muscle, where tethered myosin in thick filaments can only bind to a relatively small number of available sites on the actin filament, positioned within a limited range of thermal movement of the myosin head. Here we implement spatially explicit actomyosin interactions into the multiscale Monte Carlo platform MUSICO, specifically defining how geometrical constraints on tethered myosins can modulate state transition rates in the actomyosin cycle. The simulations provide the distribution of myosin bound to sites on actin, ensure conservation of the number of interacting myosins and actin monomers, and most importantly, the departure in behavior of tethered myosin molecules from unconstrained myosin interactions with actin. In addition, MUSICO determines the number of cross-bridges in each actomyosin cycle state, the force and number of attached cross-bridges per myosin filament, the range of cross-bridge forces and accounts for energy consumption. At the macroscopic scale, MUSICO simulations show large differences in predicted force-velocity curves and in the response during early force recovery phase after a step change in length comparing to the two simplest mass action kinetic models. The origin of these differences is rooted in the different fluxes of myosin binding and corresponding instantaneous cross-bridge distributions and quantitatively reflects a major flaw of the mathematical description in all mass action kinetic models. Consequently, this new approach shows that accurate recapitulation of experimental data requires significantly different binding rates, number of actomyosin states, and cross-bridge elasticity than typically used in mass action kinetic models to correctly describe the biochemical reactions of tethered molecules and their interaction energetics

Las hipermediaciones y los modos de lectura juvenil de los textos escolares

Este trabajo se propone explorar los usos y apropiaciones de las TIC (Tecnologías de la información y la comunicación) por parte de estudiantes de Nivel Medio de la ciudad de Puerto Madryn, durante el período de pandemia, con el objetivo de analizar el modo en que impactan en sus lecturas de los textos escolares, especialmente, los literarios

¿Desde dónde enseñar literatura?

Este trabajo se propone reflexionar sobre cuatro ideas de gran influencia en la práctica áulica de la enseñanza de la Literatura: metodologías en construcción para la enseñanza de la Literatura; la lectura de textos literarios como práctica sociocultural; los lectores (modelos y reales, buenos y malos); los problemas de comprensión lectora

Las masculinidades también se oponen al patriarcado

El artículo consiste en una propuesta de trabajo ESI para ciclo orientado de secundaria y/o estudiantes de EPJA (Educación para jóvenes y adultos). Los cuentos Vidas privadas, de Angélica Gorodischer; El marica, de Abelardo Castillo, y Entre Mercurio y Venus, de Marha Mercader, constituyen el corpus para, a través del análisis, cuestionar (deconstruir) las convenciones constitutivas del modelo binario heterosexual, una de las causas de la homofobia y transfobia en nuestra sociedad