374 research outputs found
Comparación química de suelos en distintas coberturas vegetales del PNC mediante métodos de clúster análisis
La vegetación y el suelo son indicadores importantes de la salud del páramo. La capa vegetal del páramo es importante para la protección del suelo y como hábitat para la fauna nativa (Hofstede et al., 2003). La evaluación de las características del suelo requiere medir sus propiedades físicas y químicas.
El Parque Nacional Cajas (PNC) es uno de los principales suministros de agua para la ciudad de Cuenca, puesto que sus suelos retienen grandes cantidades de líquido vital, especialmente el páramo de almohadillas; los suelos del pajonal resultan importantes en el secuestro de carbono atmosférico, mientras que los suelos de los bosques de Polylepis y bosques alto-andinos originan ecosistemas únicos evidenciado en un alto endemismo presente en el PNC; razón por lo cual el estudio de las características físico químicas del suelo resulta importante en la investigación de las interacciones sustrato-vegetal.
El análisis de conglomerados o clúster es una técnica de análisis exploratorio de datos que permite descubrir asociaciones y estructuras en los datos que no son evidentes a priori,ordenando objetos en grupos de asociación/similitud de forma que los objetos de un mismo grupo sean muy similares entre sí,y los objetos de clústeres diferentes sean distintos (Figueras, 2001).
El método KNN o k-Nearest Neighbors, basado en el reconocimiento de patrones de criterios de vecindad. Parte de la idea de que una nueva muestra será clasificada a la clase a la cual pertenezca la mayor cantidad de vecinos más cercanos del (reconocimiento de patrones patrón) del conjunto de entrenamiento más cercano a esta (Figueras, 2001).
El objetivo general de este estudio es investigar las relaciones entre las características químicas del suelo (Ca, Mg, Fe, K, Na, pH, conductividad, nitrógeno total, fósforo, y materia orgánica) y el tipo de coberturas vegetales presentes en el PNC (páramo de pajonal,páramo de almohadilla, bosque de Polylepis y bosque altoandino), mediante métodos de análisis clúster y clasificación KNN
Delayed trait development and the convergent evolution of shell kinesis in turtles
Developmental processes are foundational to clarifying the causes of convergent evolution. Here, we show how a key convergently evolving trait is slowly “acquired” in growing turtles. Adaptive morphological change tends to originate late in turtle ontogeny, owing to design constraints imposed by the shell. We investigated this trend by examining derived patterns of shell formation associated with the multiple (≥ 8) origins of shell closure (kinesis) in smallbodied turtles. Using box turtles as a model, we demonstrate that the flexible hinge joint required for shell kinesis differentiates gradually and via extensive repatterning of shell tissue. Disproportionate changes in shell shape and size substantiate that this transformation is a delayed ontogenetic response (3-5 years post-hatching) to structural alterations that arise in embryogenesis. These findings exemplify that the translation of genotype to phenotype may reach far beyond embryonic life stages. Thus, the temporal scope for developmental origins of adaptive morphological change might be broader than generally understood. We propose that delayed trait differentiation via tissue repatterning might facilitate phenotypic diversification and innovation that otherwise would not arise due to developmental constraints
GESTURAL DESIGN - HAND TRACKING FOR DIGITAL DRAWING
Computational design is increasingly interested in the active feedback between the user/designer and the digital space. Often, our initial instinct as designers comes from a gesture, a movement of the hands that gets translated into sketches and 3D models via the tools available to us. While the physical realm allows for muscle memory, tactile feedback, and creative output via movement, digital design often negates the body of the designer as it sequesters us into a screen-mouse-hand relationship. Moreover, current CAD software tools often reinforce this standardization, further limiting the potential of physical bodily gestures as a vehicle for architectural form-making. Seeking new opportunities for a gestural interface, this research explores how Machine Learning and parametric design tools can be used to translate active movements and gestural actions into rich and complex digital models without the need of specialized equipment. In this paper, we present an open-source and economically accessible methodology for designers to translate hand movements into the digital world, implementing the MediaPipe Hands tracking library. In developing this workflow, this research explores opportunities to create more direct, vital links between expressive gesture and architectural form, with an emphasis on creating platforms that are accessible not only to design experts, but also the broader public
Øysand research site: Geotechnical characterisation of deltaic sandy-silty soils
This paper describes the geology and geotechnical engineering properties of the fluvial and 18 deltaic gravelly-sandy-silty sediments at Øysand, Norway. Geophysical and geotechnical site 19 investigations carried out between 2016 and 2018 at the site are presented. Field testing included state-20 of-the-practice and state-of-the-art soil characterisation techniques such as total sounding, seismic 21 cone penetration testing, seismic flat dilatometer, multichannel analysis of surface waves, electrical 22 resistivity tomography, ground penetrating radar, piezometers, thermistors strings, slug tests, and 23 permeability tests using a newly developed CPT permeability probe from NGI. Several sampling 24 techniques were used at the site to assess sample quality. Laboratory testing consisted of index tests 25 and advanced triaxial tests with bender elements to estimate shear strength and stiffness. Data 26 interpretation, engineering soil properties and state variables derived from this analysis are presented, 27 along with comments on data quality. Engineering problems investigated at Øysand so far, are related 28 to: the impact of using different CPTU types, sample quality assessment by obtaining soils with state-29 of-the-practice and state-of-the-art techniques (such as gel push sampler and ground freezing), and 30 frost heave susceptibility
Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel
Producción CientíficaTransversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate “lumped” kinetics model to correctly fit the experimentally observed drug release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices.Este trabajo forma parte de los Proyectos de Investigación financiados por la Comisión Europea a través del Fondo Social Europeo (FSE) y de la Consejería de Educación mediante el Fondo Europeo de Desarrollo Regional (ERDF), el MINECO (Proyectos MAT2013-41723-R, MAT2013-42473-R, PRI−PIBAR-2011-1403 y MAT2012-38043), la Junta de Castilla y León (Proyectos VA155A12, VA152A12, and VA244U13), el CIBER-BBN y el Instituto de Salud Carlos III mediante el Centro de Medicina Regenerativa y Terapia Celular de Castilla y León
Publicitary speeches and the May’s Revolution. ‘El Dia’ newspaper, 1943-1958
El artículo aborda el estudio de los avisos publicados por comercios minoristas, por profesionales, por empresas privadas y del estado, por instituciones y por los organismos estatales en ocasión del aniversario del 25 de Mayo de 1810. Se hace a partir de un relevamiento de los ejemplares del diario El Día de la ciudad de La Plata correspondientes al mes de mayo de los años que van desde 1943 a 1958 inclusive. Se considera a la Revolución de Mayo como un lugar de memoria para explicar sus múltiples formas de representación dentro del amplio e interesado espectro de anunciantes.The article faces up the study of the warnings published by the retail stores, by proffesionals, by private companies and of the state, by institutions and by the statal organisms in the ocasion of the aniversary of the May 25th of 1810. It is done starting from a survey of the exemplars of the ‘El Dia’ diary of the city of ‘La Plata’, that squares to the month of May of the years that goes from 193 to 1958 including it. It is considered that the the May’s Revolution as a place of memory to explain its multiple ways of representation inside of the wide and interested spectre of advertisers.Dossier: La Revolución de MayoFacultad de Periodismo y Comunicación Socia
Towards a more accurate characterization of granular media 2.0: Involving AI in the process
publishedVersio
Rodent consumption by <i>Philodryas psammophidea</i> (Serpentes: Colubridae), from the Inter-andean Dry Valleys of Central Bolivia
In May 18, 2009 we found an adult female of Philodryas psammophidea (930 mm SVL), at a side of a crop field in the Tabacal valley (18º23’7.42” S – 64º38’7.88”W, 2015 m), Narciso Campero province southern Cochabamba, Bolivia. Ecologically, this valley belongs to the Inter-Andean Dry Forests of Bolivia. In the stomach of thesnake probably killed by a settler, therewas an adult female of Graomys domorum (Phyllotini; Sigmodontidae), a native rodent species widely distributed in the region.Asociación Herpetológica Argentina (AHA
Espectro de tamaños de gotas de distintas lluvias en Buenos Aires
Con el método de la formación de bolitas de engrudo mezclado con un colorante soluble en agua se muestreó siete lluvias distintas de las que se obtuvo en total 38 espectros. En los casos que los períodos de muestreó pudieron prolongarse el tiempo suficiente durante una misma lluvia, se constató con bastante nitidez la presencia de tres tipos de distribuciones de masa acumulada: i) un espectro cuasi monodisperso cuyo diámetro de gota máximo fue de 2 milímetros, espectro que se presentó comunmente hacia el final y ocasionalmente al principio de la precipitación, ii) una segunda distribución cuyo diámetro máximo, a veces excepcionalmente alto, (llegó hasta 5,8 milímetros), con el 50% de la masa de agua distribuido entre pocas gotas grandes y que se produjo en los momentos de precipitación más intensa, iii) una distribución predominante constituida por gotas de hasta 3 milímetros de diámetro.The method of the dough pellets with a soluble dye mixed in it, was used for the determination of raindrop size spectra in seven different rainfalls; 38 spectra were obtained. When the sampling period was long enough, it was possible to put in evidence three different types of distributions of the accumulated mass of water: i) a quasi monodisperse spectrum with two millimeters as the largest drop diameter. This type of spectrum was obtained near the end of the rainfall and occasionally at the beginning, ii) a second type was obtained when the rainfall was rather intense and characterized by an exceptional high figure of the largest diameters (5,8 millimeters in one occasion) and the 50% of accumulated, mass of water is distributed among a few large drops. iii) a prevailing spectrum formed by drops up to three millimeters of diameter.Asociación Argentina de Geofísicos y Geodesta
Some theoretical considerations about the “Extension Unversitaria” after an educative experience
El presente artículo forma parte de la auto-evaluación realizada por el equipo de Extensión Universitaria, que llevó a cabo un trabajo de integración de los diferentes niveles de la Educación, en una región de triple frontera. Esta se ubica en la intersección de los Ríos Uruguay y Quareim, y que forman la frontera entre las ciudades de Monte Caseros (Provincia de Corrientes-Argentina); Bella Unión (Uruguay) y Barra do Quaraí (Brasil). A pesar de los logros obtenidos, se reflexiona acerca de las dificultades que se han presentado utilizando el concepto de capital cultural, como una manera de contribuir a una crítica más general sobre la extensión universitaria.This article conforms a piece of the auto-evaluation made by the team of the “Extensión Universitaria”, that carried on an integration work of the different levels of the Education, in a region with three borders. It is located in the intersection of the Rivers Uruguay and Quareim, and conforms the borders between the cities of Monte Caseros (Corrientes- Argentina); Bella Unión (Uruguay) y Barra do Quaraí (Brasil). Despite the achievements, reflections came up about the difficulties that emerged using the concepts of “cultural capital”, as a way of contributing to a more general critic about the university extension (Extension Universitaria).Facultad de Periodismo y Comunicación Socia
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