A R-Script for Generating Multiple Sclerosis Lesion Pattern Discrimination Plots

Càlcul estadístic R; Geoestadística; Esclerosi múltipleCálculo estadístico R; Geoestadística; Esclerosis múltipleR statistical computing; Geostatistics; Multiple sclerosisOne significant characteristic of Multiple Sclerosis (MS), a chronic inflammatory demyelinating disease of the central nervous system, is the evolution of highly variable patterns of white matter lesions. Based on geostatistical metrics, the MS-Lesion Pattern Discrimination Plot reduces complex three- and four-dimensional configurations of MS-White Matter Lesions to a well-arranged and standardized two-dimensional plot that facilitates follow-up, cross-sectional and medication impact analysis. Here, we present a script that generates the MS-Lesion Pattern Discrimination Plot, using the widespread statistical computing environment R. Input data to the script are Nifti-1 or Analyze-7.5 files with individual MS-White Matter Lesion masks in Montreal Normal Brain geometry. The MS-Lesion Pattern Discrimination Plot, variogram plots and associated fitting statistics are output to the R console and exported to standard graphics and text files. Besides reviewing relevant geostatistical basics and commenting on implementation details for smooth customization and extension, the paper guides through generating MS-Lesion Pattern Discrimination Plots using publicly available synthetic MS-Lesion patterns. The paper is accompanied by the R script LDPgenerator.r, a small sample data set and associated graphics for comparison

With United Forces : How Design-Based Research can Link Theory and Practice in the Transdisciplinary Sphere of CLIL

This paper intends to exemplify how a design-based research (DBR) methodology can be used to put theory into practice by reporting on a first research cycle of a larger DBR project in the context of upper secondary CLIL history education in Austria. The project aims to identify design principles of teaching techniques and materials which both support the acquisition of subject-specific competences and language. To this end, this study draws on Dalton-Puffer's (2013) construct of Cognitive Discourse Functions (CDFs), comprising seven key categories of academic language functions which have also been shown to be closely linked to historical competences. In the course of this study, the researcher and a collaborating teacher systematically developed CDF-based history materials, which were then applied in the classroom and continuously evaluated, usinginterviews, observations, and written tasks for data collection.Results of the first research cycle suggest that students lack awareness of possible connections between content and language learning and struggle with expressing complex historical content. Both teacher and students responded positively to the intervention on a general level, but pointed out a number of potential refinements, such as a more continuous and balanced intertwining of content and language.Aquest article aspira a exemplificar com es pot utilitzar una metodologia d'investigació basada en el disseny d'una intervenció (DBR, sigles en anglès) per portar la teoria a la pràctica. A més a més, proporciona informació sobre el primer cicle d'investigació d'un projecte DBR de major abast, en un context educatiu d'història AICLE en el cicle superior de secundària a Àustria.L'objectiu del projecte és identificar els principis que inspiren les estratègies didàctiques i els materials d'ensenyament que fomenten l'adquisició de competències i llenguatge específics de la matèria. En aquest sentit, aquest estudi es basa en el concepte Funcions cognitivo-discursives (FCD), de Dalton-Puffer (2013), que comprèn set categories clau de funcions del llenguatge acadèmic, les quals, segons s'ha demostrat, estan estretament relacionades amb les competències històriques.En el curs d'aquest estudi, la persona investigadora i un docent col·laborador van desenvolupar sistemàticament materials de l'ensenyament de la història basats en el FCD que, posteriorment, es van pilotar i avaluar de forma continuada a l'aula, emprant entrevistes, observacions i tasques d'escriptura, utilitzades com a dades.Els resultats del primer cicle d'investigació suggereixen que els estudiants mostren una manca de consciència sobre les possibles connexions entre l'aprenentatge del contingut i el de la llengua, i tenen dificultats per expressar continguts històrics complexos. Tant el docent com els estudiants van respondre positivament a la intervenció en un nivell general, però van assenyalar una sèrie de possibles millores, tals com una interrelació més continuada i equilibrada de contingut i llengua.Este artículo aspira a ejemplificar cómo se puede utilizar una metodología de investigación basada en el diseño de una intervención (DBR, siglas en inglés) para llevar la teoría a la práctica. Además, proporciona información sobre el primer ciclo de investigación de un proyecto DBR de mayor alcance, en un contexto educativo de historia AICLE en el ciclo superior de secundaria en Austria.El objetivo del proyecto es identificar los principios que inspiran las estrategias didácticas y los materiales de enseñanza que fomentan la adquisición de competencias y lenguaje específicos de la asignatura. Para este fin, este estudio se basa en el constructo Funciones cognitivo-discursivas (FCD), de Dalton-Puffer (2013), que comprende siete categorías clave de funciones del lenguaje académico, las cuales, según se ha demostrado, están estrechamente relacionadas con las competencias históricas.En el curso de este estudio, la persona investigadora y un docente colaborador desarrollaron sistemáticamente materiales de enseñanza de la historia basados en el FCD, que luego se pilotaron y evaluaron de forma continuada en el aula, utilizando entrevistas, observaciones y tareas de escritura, utilizadas como datos.Los resultados del primer ciclo de investigación sugieren que los estudiantes muestran falta de conciencia sobre las posibles conexiones entre el aprendizaje del contenido y el de la lengua, y tienen dificultades para expresar contenidos históricos complejos. Tanto el docente como los estudiantes respondieron positivamente a la intervención en un nivel general, pero señalaron una serie de posibles mejoras tales como una interrelación más continuada y equilibrada de contenido y lenguaje

Breaking the Resolution limit in Photoacoustic Imaging using Positivity and Sparsity

In this tutorial, we aim to directly recreate some of our "aha" moments when exploring the impact of heat diffusion on the spatial resolution limit of photothermal imaging. Our objective is also to communicate how this physical limit can nevertheless be overcome and include some concrete technological applications. Describing diffusion as a random walk, one insight is that such a stochastic process involves not only a Gaussian spread of the mean values in space, with the variance proportional to the diffusion time, but also temporal and spatial fluctuations around these mean values. All these fluctuations strongly influence the image reconstruction immediately after the short heating pulse. The Gaussian spread of the mean values in space increases the entropy, while the fluctuations lead to a loss of information that blurs the reconstruction of the initial temperature distribution and can be described mathematically by a spatial convolution with a Gaussian thermal point-spread-function (PSF). The information loss turns out to be equal to the mean entropy increase and limits the spatial resolution proportional to the depth of the imaged subsurface structures. This principal resolution limit can only be overcome by including additional information such as sparsity or positivity. Prior information can be also included by using a deep neural network with a finite degrees of freedom and trained on a specific class of image examples for image reconstructio

A MS-lesion pattern discrimination plot based on geostatistics

Introduction A geostatistical approach to characterize MS-lesion patterns based on their geometrical properties is presented. Methods A dataset of 259 binary MS-lesion masks in MNI space was subjected to directional variography. A model function was fit to express the observed spatial variability in x, y, z directions by the geostatistical parameters Range and Sill. Results Parameters Range and Sill correlate with MS-lesion pattern surface complexity and total lesion volume. A scatter plot of ln(Range) versus ln(Sill), classified by pattern anisotropy, enables a consistent and clearly arranged presentation of MS-lesion patterns based on geometry: the so-called MS-Lesion Pattern Discrimination Plot. Conclusions The geostatistical approach and the graphical representation of results are considered efficient exploratory data analysis tools for cross-sectional, follow-up, and medication impact analysis

Geostatistical Analysis of White Matter Lesions in Multiple Sclerosis Identifies Gender Differences in Lesion Evolution

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system with presumed autoimmune origin. The development of lesions within the gray matter and white matter, which are highly variable with respect to number, total volume, morphology and spatial evolution and which only show a limited correlation with clinical disability, is a hallmark of the disease. Population-based studies indicate a distinct outcome depending on gender. Here, we studied gender-related differences in the evolution of white matter MS-lesions (MS-WML) in early MS by using geostatistical methods. Within a 3 years observation period, a female and a male MS patient group received disease modifying drugs and underwent standardized annual brain magnetic resonance imaging, accompanied by neurological examination. MS-WML were automatically extracted and the derived binary lesion masks were subject to geostatistical analysis, yielding quantitative spatial-statistics metrics on MS-WML pattern morphology and total lesion volume (TLV). Through the MS-lesion pattern discrimination plot, the following differences were disclosed: corresponding to gender and MS-WML pattern morphology at baseline, two female subgroups (F1, F2) and two male subgroups (M1, M2) are discerned that follow a distinct MS-WML pattern evolution in space and time. F1 and M1 start with medium-level MS-WML pattern smoothness and TLV, both behave longitudinally quasi-static. By contrast, F2 and M2 start with high-level MS-WML pattern smoothness and medium-level TLV. F2 and M2 longitudinal development is characterized by strongly diminishing MS-WML pattern smoothness and TLV, i.e., continued shrinking and break-up of MS-WML. As compared to the male subgroup M2, the female subgroup F2 shows continued, increased MS-WML pattern smoothness and TLV. Data from neurological examination suggest a correlation of MS-WML pattern morphology metrics and EDSS. Our results justify detailed studies on gender-related differences