Validity and reliability of using MVP 4 Function Walk4Life digital pedometers to assess physical activity levels among preschool-aged Head Start children

The Surgeon General recommends preschoolers 3-5 years old accumulate 60 minutes of moderate-to-vigorous physical activity (MVPA) per day. However, there is limited data measuring physical activity (PA) and MVPA amongst this population. The purpose of this cross-sectional study is to determine the validity, reliability, and feasibility of using MVP 4 Function Walk4Life digital pedometers (MVP-4) in measuring MVPA among preschoolers using the newly modified direct observational technique, System for Observing Fitness Instruction Time-Preschool Version (SOFIT-P) as the gold standard. An ethnically diverse population of 3-5 year old underserved children were recruited from two Harris County Department of Education (HCDE) Head Start centers. For 2 days at baseline and 2 days at post-test, 75 children enrolled wore MVP-4 pedometers for approximately 6-hours per observation day and were observed using SOFIT-P during predominantly active times. Statistical analyses used Pearson "r" correlation coefficients to determine mean minutes of PA and MVPA, convergent and criterion validity, and reliability. Significance was set at p = <0.05. Feasibility was determined through process evaluation information collected during this study via observations from data collectors and teacher input. Results show mean minutes of PA and MVPA ranged between 30-42 and 11-14 minutes, respectively. Convergent validity comparing BMI percentiles with MVP-4 PA outcomes show no significance at pre-test; however, each measurement at post-test showed significance for MVPA (p = 0.0247, p = 0.0056), respectively. Criterion validity comparing percent MVPA time between SOFIT-P and MVP-4 pedometers was determined; however, results deemed insufficient due to inconsistency in observation times while using the newly developed SOFIT-P. Reliability measures show no significance at pre-test, yet show significant results for all PA outcomes at post-test (p = 0.001, p = 0.001, p = 0.0010, p = 0.003), respectively. Finally, MVP-4 pedometers lacked feasibility due to logistical barriers in design. Researchers feel the significant results at post-test are secondary to increased familiarity and more accurate placement of pedometers across time. Researchers suggest manufacturers of MVP-4 pedometers further modify the instrument for ease of use with this population, following which future studies ought to determine validity using objective measures or all-day direct observation techniques.^

Proyecto Wiki : La escritura colaborativa digital en adultos que estudian inglés como lengua extranjera

El presente trabajo intenta presentar las posibilidades que ofrece la herramienta virtual wiki a la hora de favorecer la visión de toda escritura como proceso, fomentar el trabajo colaborativo y contribuir a la alfabetización digital en adultos que están adquiriendo el inglés como lengua extranjera. Durante el receso invernal forzoso debido a la Gripe A de julio de 2009 en nuestro país, se decidió crear un espacio wiki para trabajar con los alumnos de Adultos 4B que asisten a la Escuela de Lenguas de la Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina. El material a trabajar se desprende de una de las lecturas obligatorias incluidas en el programa de dicho curso (selección de cuentos graduados de I, Robot, de Isaac Asimov). El espacio wiki permitirá a los alumnos y a la docente abordar la adquisición de contenidos de manera semipresencial, compensando así las clases perdidas por el receso forzoso. Mediante el uso de esta herramienta virtual con alumnos adultos se busca alentar la producción escrita en lengua inglesa por parte de los mismos, así como también iniciarlos en la creación y decodificación de discursos digitales y ayudarlos a desarrollar estrategias comunicativas eficaces en la Sociedad de la Información

Proyecto Wiki : La escritura colaborativa digital en adultos que estudian inglés como lengua extranjera

El presente trabajo intenta presentar las posibilidades que ofrece la herramienta virtual wiki a la hora de favorecer la visión de toda escritura como proceso, fomentar el trabajo colaborativo y contribuir a la alfabetización digital en adultos que están adquiriendo el inglés como lengua extranjera. Durante el receso invernal forzoso debido a la Gripe A de julio de 2009 en nuestro país, se decidió crear un espacio wiki para trabajar con los alumnos de Adultos 4B que asisten a la Escuela de Lenguas de la Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina. El material a trabajar se desprende de una de las lecturas obligatorias incluidas en el programa de dicho curso (selección de cuentos graduados de I, Robot, de Isaac Asimov). El espacio wiki permitirá a los alumnos y a la docente abordar la adquisición de contenidos de manera semipresencial, compensando así las clases perdidas por el receso forzoso. Mediante el uso de esta herramienta virtual con alumnos adultos se busca alentar la producción escrita en lengua inglesa por parte de los mismos, así como también iniciarlos en la creación y decodificación de discursos digitales y ayudarlos a desarrollar estrategias comunicativas eficaces en la Sociedad de la Información

Proyecto Wiki : La escritura colaborativa digital en adultos que estudian inglés como lengua extranjera

El presente trabajo intenta presentar las posibilidades que ofrece la herramienta virtual wiki a la hora de favorecer la visión de toda escritura como proceso, fomentar el trabajo colaborativo y contribuir a la alfabetización digital en adultos que están adquiriendo el inglés como lengua extranjera. Durante el receso invernal forzoso debido a la Gripe A de julio de 2009 en nuestro país, se decidió crear un espacio wiki para trabajar con los alumnos de Adultos 4B que asisten a la Escuela de Lenguas de la Universidad Nacional de La Plata (UNLP), Buenos Aires, Argentina. El material a trabajar se desprende de una de las lecturas obligatorias incluidas en el programa de dicho curso (selección de cuentos graduados de I, Robot, de Isaac Asimov). El espacio wiki permitirá a los alumnos y a la docente abordar la adquisición de contenidos de manera semipresencial, compensando así las clases perdidas por el receso forzoso. Mediante el uso de esta herramienta virtual con alumnos adultos se busca alentar la producción escrita en lengua inglesa por parte de los mismos, así como también iniciarlos en la creación y decodificación de discursos digitales y ayudarlos a desarrollar estrategias comunicativas eficaces en la Sociedad de la Información

Digital surface model, hillshade and Lambertian reflectance model of the rock glaciers Oelgrube and Aeusseres Hochebenkar (Oetztal Alps, Tyrol, Austria)

With full-waveform (FWF) lidar systems becoming increasingly available from different commercial manufacturers, the possibility for extracting physical parameters of the scanned surfaces in an area-wide sense, as addendum to their geometric representation, has risen as well. The mentioned FWF systems digitize the temporal profiles of the transmitted laser pulse and of its backscattered echoes, allowing for a reliable determination of the target distance to the instrument and of physical target quantities by means of radiometric calibration, one of such quantities being the diffuse Lambertian reflectance. The delineation of glaciers is a time-consuming task, commonly performed manually by experts and involving field trips as well as image interpretation of orthophotos, digital terrain models and shaded reliefs. In this study, the diffuse Lambertian reflectance was compared to the glacier outlines mapped by experts. We start the presentation with the workflow for analysis of FWF data, their direct georeferencing and the calculation of the diffuse Lambertian reflectance by radiometric calibration; this workflow is illustrated for a large FWF lidar campaign in the Ötztal Alps (Tyrol, Austria), operated with an Optech ALTM 3100 system. The geometric performance of the presented procedure was evaluated by means of a relative and an absolute accuracy assessment using strip differences and orthophotos, resp. The diffuse Lambertian reflectance was evaluated at two rock glaciers within the mentioned lidar campaign. This feature showed good performance for the delineation of the rock glacier boundaries, especially at their lower parts.

Digital elevation model (DEM) of the ice sheet in western Dronning Maud Land, Antarctica

In this paper, a new digital elevation model (DEM) is derived for the ice sheet in western Dronning Maud Land, Antarctica. It is based on differential interferometric synthetic aperture radar (SAR) from the European Remote Sensing 1/2 (ERS-1/2) satellites, in combination with ICESat's Geoscience Laser Altimeter System (GLAS). A DEM mosaic is compiled out of 116 scenes from the ERS-1 ice phase in 1994 and the ERS-1/2 tandem mission between 1996 and 1997 with the GLAS data acquired in 2003 that served as ground control. Using three different SAR processors, uncertainties in phase stability and baseline model, resulting in height errors of up to 20 m, are exemplified. Atmospheric influences at the same order of magnitude are demonstrated, and corresponding scenes are excluded. For validation of the DEM mosaic, covering an area of about 130,000 km**2 on a 50-m grid, independent ICESat heights (2004-2007), ground-based kinematic GPS (2005), and airborne laser scanner data (ALS, 2007) are used. Excluding small areas with low phase coherence, the DEM differs in mean and standard deviation by 0.5 +/- 10.1, 1.1 +/- 6.4, and 3.1 +/- 4.0 m from ICESat, GPS, and ALS, respectively. The excluded data points may deviate by more than 50 m. In order to suppress the spatially variable noise below a 5-m threshold, 18% of the DEM area is selectively averaged to a final product at varying horizontal spatial resolution. Apart from mountainous areas, the new DEM outperforms other currently available DEMs and may serve as a benchmark for future elevation models such as from the TanDEM-X mission to spatially monitor ice sheet elevation.

Digital terrain model (DTM) of the central Fram Strait

Based on data from R/V Polarstern multibeam sonar surveys between 1984 and 1997 a high resolution bathymetry has been generated for the central Fram Strait. The area ensonified covers approx. 36,500 sqkm between 78°N-80°N and 0°E-7.5°E. Basic outcome of the investigation is a Digital Terrain Model (DTM) with 100 m grid spacing which was utilized for contouring and generation of a new series of bathymetric charts (AWI BCFS).

Northeast Greenland - Digital Bathymetric Compilation, with links to DBM in ArcGIS format

A new digital bathymetric model (DBM) for the Northeast Greenland (NEG) continental shelf (74°N - 81°N) is presented. The DBM has a grid cell size of 250 m × 250 m and incorporates bathymetric data from 30 multibeam cruises, more than 20 single-beam cruises and first reflector depths from industrial seismic lines. The new DBM substantially improves the bathymetry compared to older models. The DBM not only allows a better delineation of previously known seafloor morphology but, in addition, reveals the presence of previously unmapped morphological features including glacially derived troughs, fjords, grounding-zone wedges, and lateral moraines. These submarine landforms are used to infer the past extent and ice-flow dynamics of the Greenland Ice Sheet during the last full-glacial period of the Quaternary and subsequent ice retreat across the continental shelf. The DBM reveals cross-shelf bathymetric troughs that may enable the inflow of warm Atlantic water masses across the shelf, driving enhanced basal melting of the marine-terminating outlet glaciers draining the ice sheet to the coast in Northeast Greenland. Knolls, sinks, and hummocky seafloor on the middle shelf are also suggested to be related to salt diapirism. North-south-orientated elongate depressions are identified that probably relate to ice-marginal processes in combination with erosion caused by the East Greenland Current. A single guyot-like peak has been discovered and is interpreted to have been produced during a volcanic event approximately 55 Ma ago.