Optimización de figuras y gráficos para su uso en divulgación científica a productores rurales

Tesis para obtener el grado de Maestría en Gestión de Contenidos, de la Universidad Austral, en diciembre de 2018La comprensión de figuras de datos, tanto a nivel científico como a nivel de divulgación científica, es un tema de creciente interés en el mundo, en particular a nivel educativo. La graphicacy, la habilidad de interpretar correctamente gráficos, es de particular interés en el caso de productores rurales, donde las agencias y otras deben explicar las mejoras y aportes técnicos en forma sencilla y comprensible. En esta tesis se investigó la complejidad de las figuras que se encuentran en las publicaciones técnicas de INTA dirigidas a productores y las preferencias de productores por tipo de figuras. Se analizó un corpus de revistas de divulgación científica de INTA para seleccionar figuras, las que fueron anonimizadas y rediseñadas para utilizarlas, tanto a las originales como a las modificadas, en una encuesta que se aplicó a 80 productores rurales del centro sureste de la provincia de Entre Ríos, Argentina. Los resultados mostraron que los productores prefieren y comprenden mejor, en forma significativa, las figuras modificadas, más simples, por sobre las originales. El análisis de las respuestas divididas en estratos mostró diferencias significativas por nivel educativo (universitario versus no universitario), no así en estratos de edad o de años en la actividad rural. Por otro lado, las personas encuestadas prefieren en forma significativa las figuras de barras por sobre las de líneas y las de barras verticales por sobre las de horizontales. No hubo diferencia en la preferencia de líneas juntas en el mismo gráfico o separadas en cuatro gráficos. En conclusión, los resultados señalan que la realización de esfuerzos para rediseñar y simplificar las figuras de los textos dirigidos a productores rurales mejora significativamente el nivel de comprensión de los datos proporcionados, en particular en las personas de menor nivel educativo.The comprehension of figures, both at the scientific level as well as to general public, is a subject of growing interest in the world, particularly at the educational level. Graphicacy, the ability to correctly interpret graphs, is of particular interest in the case of rural producers, where agencies like INTA (“Instituto Nacional de Tecnología Agropecuaria”) and others must explain improvements and technical contributions in a simple and understandable way. In this thesis the complexity of the figures found in INTA technical publications aimed at producers was investigated. Additionally, the preferences of producers by type of figures was assesed. A corpus of scientific dissemination magazines of INTA was analyzed to select figures, which were anonymized and redesigned to be used in a survey applied to 80 rural producers in the southeast center of the province of Entre Ríos, Argentina. The survey asked for preferences and comprehension of original and modifies figures. The results showed that the producers significantly preferred and better understand the modified, simpler figures, over the original ones. The analysis of the responses divided into strata showed significant differences by educational level (university versus non-university studies), but not in age or years in rural activity. On the other hand, the people surveyed preferred significantly the bars graphs over those of lines and those of vertical bars over those of horizontal bars. There was no difference in the preference of lines together in the same graph or separated into four graphs. In conclusion, the results indicate that the efforts made to redesign and simplify the figures of the texts addressed to rural producers significantly improves the level of understanding of the data provided, particularly among people of lower educational level.EEA Concepción del UruguayFil: Naveira, Carlos Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concepción del Uruguay; Argentin

TCR Translocations at the Normal-malignant T Cell Interface

Hematopoiesis is the process leading to production and maturation of peripheral blood cells. All blood cells are derived from hematopoietic stem cells (HSCs) which reside in hematopoietic organs. In mammals, the site of hematopoiesis changes during development, which is sequentially taking place in different organs starting with primitive erythrocytes in the yolk sac, the aorta-gonad mesonephros (AGM) region, the fetal lever, and finally the bone marrow (BM) during adulthood. Blood cells are short-lived, and with a daily demand for more than a billion new hematopoietic cells, a continuous replenishment of progenitor cells committed to specific hematopoietic lineages is required. HSCs are at the top of the hematopoietic hierarchy, and are the only source of progenitors. HSCs comprise 0.005-0.01% of the bone marrow, and their unique properties, i.e. the ability of self-renewal and multi-lineage differentiation potential in combination with a specific stem cell microenvironment/ niche, enable these cells to sustain the hematopoietic system. These cells differentiate into progenitor cells, either into common lymphoid progenitors (CLP) or common myeloid progenitors (CMP), which in due course differentiate into mature blood cells, providing cells to the myeloid or lymphoid system respectively 6. CLPs carry the potential to give rise to B cells, T cells (via the thymus) and NK cells, whereas CMPs have the potential to differentiate into erythrocytes, megakaryocytes, macrophages, and granulocytes. Dendritic cells can arise from both progenitor types. The process of hematopoietic lineage determination is tightly regulated by the BM microenvironment’s extrinsic factors, such as growth factors and cytokines mediated by cell-cell interactions, which sustain survival and proliferation of committed cells. Equally important in determining cell fate are the lineage- and cell-type-specific gene expression signatures (intrinsic factors). These signatures are based on the up and down regulation of transcription factors apparently regulated by the epigenetic-micro RNAs regulatory circuit. The strict regulation of both extrinsic and intrinsic signals is of utmost importance, as deregulation of the expression of these factors could result in hematopoietic malignancies such as leukemia or lymphoma. Such deregulation of gene expression is usually caused by irreversible molecular-cytogenetic changes introduced into the genomic DNA sequence. These changes can be caused by mutations, translocations and deletions concerning genes involved in cell cycle, differentiation, proliferation, and self-renewal processes. During the last decade it has become evident that, next to genetic aberrations, epigenetic alterations can also contribute to tumorigenesis, for example through gene silencing due to aberrant methylation.

The seasonal cycle of submesoscale flows

The seasonal cycle of submesoscale flows in the upper ocean is investigated in an idealised model domain analogous to mid-latitude open ocean regions. Submesoscale processes become much stronger as the resolution is increased, though with limited evidence for convergence of the solutions. Frontogenetical processes increase horizontal buoyancy gradients when the mixed layer is shallow in summer, while overturning instabilities weaken the horizontal buoyancy gradients as the mixed layer deepens in winter. The horizontal wavenumber spectral slopes of surface temperature and velocity are steep in summer and then shallow in winter. This is consistent with stronger mixed layer instabilities developing as the mixed layer deepens and energising the submesoscale. The degree of geostrophic balance falls as the resolution is made finer, with evidence for stronger non-linear and high-frequency processes becoming more important as the mixed layer deepens. Ekman buoyancy fluxes can be much stronger than surface cooling and are locally dominant in setting the stratification and the potential vorticity at fronts, particularly in the early winter. Up to 30% of the mixed layer volume in winter has negative potential vorticity and symmetric instability is predicted inside mesoscale eddies as well as in the frontal regions outside of the vortices

The imprint of Southern Ocean overturning on seasonal water mass variability in Drake Passage

Seasonal changes in water mass properties are discussed in thermohaline coordinates from a seasonal climatology and repeat hydrographic sections. The SR1b CTD transects along Drake Passage are used as a case study. The amount of water within temperature and salinity classes and changes therein are used to estimate dia-thermal and dia-haline transformations. These transformations are considered in combination with climatologies of surface buoyancy flux to determine the relative contributions of surface buoyancy fluxes and subsurface mixing to changes in the distribution of water in thermohaline coordinates. The framework developed provides unique insights into the thermohaline circulation of the water masses that are present within Drake Passage, including the erosion of Antarctic Winter Water (AAWW) during the summer months and the interaction between the Circumpolar Deep Waters (CDW) and Antarctic Intermediate Water (AAIW). The results presented are consistent with summertime wind-driven inflation of the CDW layer and deflation of the AAIW layer, and with new AAIW produced in the winter as a mixture of CDW, remnant AAWW, and surface waters. This analysis therefore highlights the role of surface buoyancy fluxes in the Southern Ocean overturning

Observation of a large lee wave in the Drake Passage

Lee waves are thought to play a prominent role in Southern Ocean dynamics, facilitating a transfer of energy from the jets of the Antarctic Circumpolar Current to microscale, turbulent motions important in water mass transformations. Two EM-APEX profiling floats deployed in the Drake Passage during the Diapycnal and Isopycnal Mixing Experiment (DIMES) independently measured a 120 ± 20-m vertical amplitude lee wave over the Shackleton Fracture Zone. A model for steady EM-APEX motion is developed to calculate absolute vertical water velocity, augmenting the horizontal velocity measurements made by the floats. The wave exhibits fluctuations in all three velocity components of over 15 cm s−1 and an intrinsic frequency close to the local buoyancy frequency. The wave is observed to transport energy and horizontal momentum vertically at respective peak rates of 1.3 ± 0.2 W m−2 and 8 ± 1 N m−2. The rate of turbulent kinetic energy dissipation is estimated using both Thorpe scales and a method that isolates high-frequency vertical kinetic energy and is found to be enhanced within the wave to values of order 10−7 W kg−1. The observed vertical flux of energy is significantly larger than expected from idealized numerical simulations and also larger than observed depth-integrated dissipation rates. These results provide the first unambiguous observation of a lee wave in the Southern Ocean with simultaneous measurements of its energetics and dynamics

Ocean mixing beneath Pine Island Glacier ice shelf, West Antarctica

Ice shelves around Antarctica are vulnerable to an increase in ocean-driven melting, with the melt rate depending on ocean temperature and the strength of flow inside the ice-shelf cavities. We present measurements of velocity, temperature, salinity, turbulent kinetic energy dissipation rate, and thermal variance dissipation rate beneath Pine Island Glacier ice shelf, West Antarctica. These measurements were obtained by CTD, ADCP, and turbulence sensors mounted on an Autonomous Underwater Vehicle (AUV). The highest turbulent kinetic energy dissipation rate is found near the grounding line. The thermal variance dissipation rate increases closer to the ice-shelf base, with a maximum value found ∼0.5 m away from the ice. The measurements of turbulent kinetic energy dissipation rate near the ice are used to estimate basal melting of the ice shelf. The dissipation-rate-based melt rate estimates is sensitive to the stability correction parameter in the linear approximation of universal function of the Monin-Obukhov similarity theory for stratified boundary layers. We argue that our estimates of basal melting from dissipation rates are within a range of previous estimates of basal melting

Spatial variations in silicate-to-nitrate ratios in Southern Ocean surface waters are controlled in the short term by physics rather than biology

The nutrient composition (high in nitrate but low in silicate) of Subantarctic Mode Water (SAMW) forces diatom scarcity across much of the global surface ocean. This is because diatoms cannot grow without silicate. After formation and downwelling at the Southern Ocean's northern edge, SAMW re-emerges into the surface layers of the mid- and low-latitude oceans, providing a major nutrient source to primary producers in those regions. The distinctive nutrient composition of SAMW originates in the surface waters of the Southern Ocean, from which SAMW is formed. These waters are observed to transition from being rich in both silicate and nitrate in high-latitude areas of the Southern Ocean to being nitrate-rich but silicate-depleted at SAMW formation sites further north. Here we investigate the key controls of this change in nutrient composition with an idealised model, consisting of a chain of boxes linked by a residual (Ekman- and eddy-induced) overturning circulation. Biological processes are modelled on the basis of seasonal plankton bloom dynamics, and physical processes are modelled using a synthesis of outputs from the data-assimilative Southern Ocean State Estimate. Thus, as surface water flows northward across the Southern Ocean toward sites of SAMW formation, it is exposed in the model (as in reality) to seasonal cycles of both biology and physics. Our results challenge previous characterisations of the abrupt northward reduction in silicate-to-nitrate ratios in Southern Ocean surface waters as being predominantly driven by biological processes. Instead, our model indicates that, over shorter timescales (years to decades), physical processes connecting the deep and surface waters of the Southern Ocean (i.e. upwelling and entrainment) exert the primary control on the spatial distribution of surface nutrient ratios

Circulation, retention, and mixing of waters within the Weddell-Scotia Confluence, Southern Ocean:The role of stratified Taylor columns

The waters of the Weddell-Scotia Confluence (WSC) lie above the rugged topography of the South Scotia Ridge in the Southern Ocean. Meridional exchanges across the WSC transfer water and tracers between the Antarctic Circumpolar Current (ACC) to the north and the subpolar Weddell Gyre to the south. Here, we examine the role of topographic interactions in mediating these exchanges, and in modifying the waters transferred. A case study is presented using data from a free-drifting, intermediate-depth float, which circulated anticyclonically over Discovery Bank on the South Scotia Ridge for close to 4 years. Dimensional analysis indicates that the local conditions are conducive to the formation of Taylor columns. Contemporaneous ship-derived transient tracer data enable estimation of the rate of isopycnal mixing associated with this column, with values of O(1000 m2/s) obtained. Although necessarily coarse, this is of the same order as the rate of isopycnal mixing induced by transient mesoscale eddies within the ACC. A picture emerges of the Taylor column acting as a slow, steady blender, retaining the waters in the vicinity of the WSC for lengthy periods during which they can be subject to significant modification. A full regional float data set, bathymetric data, and a Southern Ocean state estimate are used to identify other potential sites for Taylor column formation. We find that they are likely to be sufficiently widespread to exert a significant influence on water mass modification and meridional fluxes across the southern edge of the ACC in this sector of the Southern Ocean