Estudio comparativo del tiempo, valoración y tipo de uso de plazas y parques entre estudiantes de cuarto básico de los Colegios British High School de las Condes y la Escuela España de la Comuna De Cerro Navia

Tesis (Profesor de Educación Física, Licenciado en Educación)El propósito de esta investigación es dar a conocer la realidad actual sobre el uso y tiempo que los niños dedican para recrearse al aire libre en espacios como parques y plazas. Es fundamental saber la importancia del uso de los espacios recreacionales para el desarrollo integral de los niños, la recomendación mundial de tiempo de recreación es de una hora diaria como mínimo

Using orthoimages generated from oblique terrestrial photography to estimate and monitor vegetation cover

Percent vegetation cover is important variable used in understanding ecosystem processes, vegetation health and productivity. Downward looking images captured using a handheld camera have been demonstrated as a viable option for rapidly capturing in situ information to assess vegetation cover. This technique, however, is prone to perspective distortions biasing cover estimates towards taller vegetation elements. In this paper we present a new approach to generate imagery for use in vegetation cover estimation utilising multiple overlapping photographs and structure from motion algorithms to produce a 3D point cloud representation of the target plot. This point cloud is then converted into an orthoimage consisting of four bands-red, green, blue and vegetation height-which is free from perspective distortions. The approach is trialled in two Eucalypt forests in South Eastern Australia to produce an estimate of change in cover of all vegetation elements following a prescribed burn. Orthoimages are generated with 2.5 mm resolution and classified using object-based image analysis and random forests into broad vegetation and fuel classes. Utilising this approach an overall classification accuracy of 81% is achieved with the resulting estimates of cover agreeing with visual point based interpretation to within 6% across all classes

A method for validating the structural completeness of understory vegetation models captured with 3D remote sensing

Characteristics describing below canopy vegetation are important for a range of forest ecosystem applications including wildlife habitat, fuel hazard and fire behaviour modelling, understanding forest recovery after disturbance and competition dynamics. Such applications all rely on accurate measures of vegetation structure. Inherent in this is the assumption or ability to demonstrate measurement accuracy. 3D point clouds are being increasingly used to describe vegetated environments, however limited research has been conducted to validate the information content of terrestrial point clouds of understory vegetation. This paper describes the design and use of a field frame to co-register point intercept measurements with point cloud data to act as a validation source. Validation results show high correlation of point matching in forests with understory vegetation elements with large mass and/or surface area, typically consisting of broad leaves, twigs and bark 0.02 m diameter or greater in size (SfM, MCC 0.51-0.66; TLS, MCC 0.37-0.47). In contrast, complex environments with understory vegetation elements with low mass and low surface area showed lower correlations between validation measurements and point clouds (SfM, MCC 0.40 and 0.42; TLS, MCC 0.25 and 0.16). The results of this study demonstrate that the validation frame provides a suitable method for comparing the relative performance of different point cloud generation processes

Prevotella denticola Lipopolysaccharide from a Cystic Fibrosis Isolate Possesses a Unique Chemical Structure

Prevotella spp. is a strict anaerobe frequently detected in the airways of cystic fibrosis patients. Little is known about the role of Prevotella in the pathophysiology of cystic fibrosis. We report the first complete structural elucidation of the lipopolysaccharide from a cystic fibrosis clinical isolate of Prevotella. The unique structure is highly phosphorylated and has no heptose residues