Propriedades psicométricas do Questionário Revisado de Bullying/Vitimização de Olweus para Crianças em español

Bullying is an important risk factor for the mental health of children and adolescents, since victim’s present higher levels of emotional problems while those who carry it out show greater behavioural problems. Despite its relevance, few instruments exist for its measurement in school-age children. The present study sought to evaluate the psychometric properties of the Revised Olweus Bully/Victim Questionnaire in a Spanish-speaking sample, with the particularity of being the first analysis of Spanish-speaking children. A quantitative study was carried out, implementing AFE, AFC, and Spearman's correlations. An intentional sample of 670 Argentinian children, male (48 %) and female (52 %), from 10 to 12 years old (mean age= 10.80; SD = 0.72) answered this test, such as the Friendship Quality Scale and the Kovacs Depression Inventory. The results indicated a factorial structure of two dimensions called victimization and bullying that coincided with those postulated by the author of the questionnaire. Cronbach's and Omega's alphas were satisfactory. The evidence of concurrent validity with the perception of the quality of friendship and depression was confirmed. The results indicated that this questionnaire presented adequate psychometric properties in its adaptation to Argentinian Spanish.El bullying es un importante factor de riesgo para la salud mental de niños y adolescentes, ya que las víctimas presentan mayores niveles de problemas emocionales; mientras que los acosadores muestran mayores problemas de conducta. A pesar de su relevancia, existen pocos instrumentos para su medición en niños de edad escolar. El presente estudio buscó evaluar las propiedades psicométricas del Cuestionario Revisado de Bullying/Victimización de Olweus en una muestra de habla hispana, con la particularidad de ser el primer análisis de habla hispana en niños. Se realizó un estudio instrumental, implementando AFE, AFC y correlaciones de Pearson. Una muestra intencional de 670 niños argentinos, varones (48 %) y mujeres (52 %), de 10 a 12 años (edad media = 10.80; DE = .72) contestaron el cuestionario, la Escala de Calidad de la Amistad y el Inventario de Depresión de Kovacs. Los resultados indicaron una estructura factorial de dos dimensiones: victimización y bullying, que coincidieron con las postuladas por el autor del cuestionario. Los valores de los coeficientes alfas de Cronbach y de omega de McDonald fueron satisfactorios. Se confirmó la evidencia de validez concurrente con la percepción de la calidad de la amistad y la depresión. El cuestionario presentó adecuadas propiedades psicométricas en su adaptación al español argentino.  O bullying é um importante fator de risco para a saúde mental de crianças e adolescentes, uma vez que as vítimas apresentam maiores níveis de problemas emocionais enquanto aqueles que o praticam apresentam maiores problemas comportamentais. Apesar de sua relevância, existem poucos instrumentos para sua mensuração em crianças em idade escolar. O presente estudo procurou avaliar as propriedades psicométricas do Questionário Revisado de Bullying/ Vitimização de Olweus em uma amostra de língua espanhol, com a particularidade de ser a primeira análise em língua espanhola em crianças. Foi realizado um estudo instrumental, implementando AFE, AFC e correlações de Pearson. Uma amostra intencional de 670 crianças argentinas, meninos (48 %) e meninas (52 %), com idades de 10 a 12 anos (média de idade = 10,80; DP = 0,72) responderam ao questionário, a Escala de Qualidade da Amizade e o Inventário de Depressão de Kovacs. Os resultados indicaram uma estrutura fatorial de duas dimensões denominadas vitimização e bullying, que coincidiram com as postuladas pelo autor do questionário. Os valores dos coeficientes alfas de Cronbach e Omega de McDonald foram satisfatórios. Foi confirmada a evidência de validade concorrente com a qualidade percebida da amizade e a depressão. O questionário apresentou propriedades psicométricas adequadas em sua adaptação ao espanhol argentino

Measuring the Terminal Heights of Bolides to Understand the Atmospheric Flight of Large Asteroidal Fragments

The extent of penetration into the Earth's atmosphere of a meteoroid is defined by the point where its kinetic energy is no longer sufficient to produce luminosity. For most of the cases this is the point where the meteoroid disintegrates in the atmosphere due to ablation process and dynamic pressure during flight. However, some of these bodies have particular physical properties (bigger size, higher bulk strength, etc.) or favorable flight conditions (lower entry velocity or/and a convenient trajectory slope, etc.) that allow them to become a meteorite-dropper and reach the ground. In both cases, we define the end of the luminous path of the trajectory as the terminal height or end height. Thus, the end point shows the amount of deceleration till the final braking. We thus assume that the ability of a fireball to produce meteorites is directly related to its terminal height. Previous studies have discussed the likely relationship between fireball atmospheric flight properties and the terminal height. Most of these studies require the knowledge of a set of properties and physical variables which cannot be determined with sufficient accuracy from ground-based observations. The recently validated dimensionless methodology offers a new approach to this problem. All the unknowns can be reduced to only two parameters which are easily derived from observations. Despite the calculation of the analytic solution of the equations of motion is not trivial, some simplifications are admitted. Here, we describe the best performance range and the errors associated with these simplifications. We discuss how terminal heights depend on two or three variables that are easily retrieved from the recordings, provided at least three trajectory (h, v) points. Additionally, we review the importance of terminal heights, and the way they have been estimated in previous studies. Finally we discuss a new approach for calculating terminal heights.Peer reviewe

Effects of interconnected suspension systems on the dynamics of sport motorcycles

The effects of interconnected front and rear suspension systems on the in-plane dynamics of sport motorcycle is investigated. The interconnected suspension mathematical description is presented and included in a high-fidelity motorcycle model. The suspension behaviour under road step bump inputs is studied for different values of stiffness and damping interconnection coefficients. Optimal values of interconnection coefficients are proposed for the current motorcycle model. Finally, the oscillating dynanlics of the motorcycle at straight rurrning conditions is studied through its normal modes

Improved linkage analysis of Quantitative Trait Loci using bulk segregants unveils a novel determinant of high ethanol tolerance in yeast

Background: Bulk segregant analysis (BSA) coupled to high throughput sequencing is a powerful method to map genomic regions related with phenotypes of interest. It relies on crossing two parents, one inferior and one superior for a trait of interest. Segregants displaying the trait of the superior parent are pooled, the DNA extracted and sequenced. Genomic regions linked to the trait of interest are identified by searching the pool for overrepresented alleles that normally originate from the superior parent. BSA data analysis is non-trivial due to sequencing, alignment and screening errors. Results: To increase the power of the BSA technology and obtain a better distinction between spuriously and truly linked regions, we developed EXPLoRA (EXtraction of over-rePresented aLleles in BSA), an algorithm for BSA data analysis that explicitly models the dependency between neighboring marker sites by exploiting the properties of linkage disequilibrium through a Hidden Markov Model (HMM). Reanalyzing a BSA dataset for high ethanol tolerance in yeast allowed reliably identifying QTLs linked to this phenotype that could not be identified with statistical significance in the original study. Experimental validation of one of the least pronounced linked regions, by identifying its causative gene VPS70, confirmed the potential of our method. Conclusions: EXPLoRA has a performance at least as good as the state-of-the-art and it is robust even at low signal to noise ratio's i.e. when the true linkage signal is diluted by sampling, screening errors or when few segregants are available

Optical Particle Detection in Liquid Suspensions with a Hybrid Integrated Microsystem

AbstractA compact, robust and portable system for optical particle detection in liquid suspensions, achieved through the hybrid integration of commercial components, such as VCSELs and microlenses, in a silicon micromachined structure is presented. We demonstrate the feasibility of fabricating a device providing up to 4 collimated laser beams, with the ability of detecting and distinguishing microparticles of several diameters, even in mixed suspensions. This optical microsystem represents an alternative design for microflow cytometers based on optical fibres, and is aligned with the current tendency set by the Point-of-care devices

Physically based alternative to the PE criterion for meteoroids

Meteoroids impacting the Earth atmosphere are commonly classified using the PE criterion. This criterion was introduced to support the identification of the fireball type by empirically linking its orbital origin and composition characteristics. Additionally, it is used as an indicator of the meteoroid tensile strength and its ability to penetrate the atmosphere. However, the level of classification accuracy of the PE criterion depends on the ability to constrain the value of the input data, retrieved from the fireball observation, required to derive the PE value. To overcome these uncertainties and achieve a greater classification detail, we propose a new formulation using scaling laws and dimensionless variables that groups all the input variables into two parameters that are directly obtained from the fireball observations. These two parameters, alpha and beta, represent the drag and the mass-loss rates along the luminous part of the trajectory, respectively, and are linked to the shape, strength, ablation efficiency, mineralogical nature of the projectile, and duration of the fireball. Thus, the new formulation relies on a physical basis. This work shows the mathematical equivalence between the PE criterion and the logarithm of 2 alpha beta under the same PE criterion assumptions. We demonstrate that log(2 alpha beta) offers a more general formulation that does not require any preliminary constraint on the meteor flight scenario and discuss the suitability of the new formulation for expanding the classification beyond fully disintegrating fireballs to larger impactors including meteorite-dropping fireballs. The reliability of the new formulation is validated using the Prairie Network meteor observations.Peer reviewe