1,355 research outputs found
Un nuevo reto diagnóstico: síndrome de clippers
El síndrome inflamatorio linfocítico crónico con realce perivascular pontino respondedor a corticoides, o síndrome de CLIPPERS (Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids), es una patología del SNC de etiología desconocida. Se define principalmente a partir de aspectos clínicos (diplopía, ataxia disratria y alteraciones sensitivas en la región facial), radiológicos (lesiones puntiformes que se realzan con la administración en gadolinio en la resonancia magnética) e histopatológicos, con una buena respuesta a corticoides. Presenta un infiltrado inflamatorio de predominio linfocítico perivascular, localizado principalmente en puente y cerebelo. A pesar de esta clara descripción, puede confundirse con otras entidades. Esta situación hace necesarios un exhaustivo diagnóstico diferencial y el establecimiento de unos criterios diagnósticos claros, basados en aspectos clínicos, radiológicos e histológicos. Se trata, por lo tanto, de un nuevo reto diagnóstico donde una de los principales objetivos a futuro es encontrar un biomarcador específico para esta entidad.Grado en Medicin
Language, Twitter and Academic Conferences
Using Twitter during academic conferences is a way of engaging and connecting
an audience inherently multicultural by the nature of scientific collaboration.
English is expected to be the lingua franca bridging the communication and
integration between native speakers of different mother tongues. However,
little research has been done to support this assumption. In this paper we
analyzed how integrated language communities are by analyzing the scholars'
tweets used in 26 Computer Science conferences over a time span of five years.
We found that although English is the most popular language used to tweet
during conferences, a significant proportion of people also tweet in other
languages. In addition, people who tweet solely in English interact mostly
within the same group (English monolinguals), while people who speak other
languages tend to show a more diverse interaction with other lingua groups.
Finally, we also found that the people who interact with other Twitter users
show a more diverse language distribution, while people who do not interact
mostly post tweets in a single language. These results suggest a relation
between the number of languages a user speaks, which can affect the interaction
dynamics of online communities.Comment: 4 pages, 3 figures, 4 tables, submitted to ACM Hypertext and Social
Media 201
Bi-factor exploratory structural equation modeling done right: using the SLiDapp application
Background: Due to its fl exibility and statistical properties, bi-factor
Exploratory Structural Equation Modeling (bi-factor ESEM) has
become an often-recommended tool in psychometrics. Unfortunately,
most recent methods for approximating these structures, such as the
SLiD algorithm, are not available in the leading software for performing
ESEM (i.e., Mplus). To resolve this issue, we present a novel, user-friendly
Shiny application for integrating the SLiD algorithm in bi-factor ESEM
estimation in Mplus. Thus, a two-stage framework for conducting SLiDbased bi-factor ESEM in Mplus was developed. Method: This approach
was presented in a step-by-step guide for applied researchers, showing
the utility of the developed SLiDApp application. Using data from the
Open-Source Psychometrics Project (N = 2495), we conducted a bi-factor
ESEM exploration of the Generic Conspiracist Beliefs Scale. We studied
whether bi-factor modelling was appropriate and if both general and group
factors were related to each personality trait. Results: The application
of the SLiD algorithm provided unique information regarding this factor
structure and its ESEM structural parameters. Conclusions: The results
illustrated the usefulness and validity of SLiD-based bi-factor ESEM, and
how the proposed Shiny app could make it eaiser for applied researchers
to use these methodsThis work was supported by Grant FPU15/ 03246 from the
Ministry of Education, Culture and Sports (Spain), by the Cátedra
de Modelos y Aplicaciones Psicométricos (Instituto de Ingeniería
del Conocimiento and Autonomous University of Madrid) and
by Grant PSI2017-85022-P from Ministerio de Economia y
Competitividad (Spain) and Fondo Social Europe
Are fit indices really fit to estimate the number of factors with categorical variables?: some cautionary findings via Monte Carlo Simulation
This paper is not the copy of record and may not exactly replicate the authoritative document published in the APA journal. Please do not copy or cite without author's permission. The final article is available, upon publication, at: http://dx.doi.org/10.1037/met0000064An early step in the process of construct validation consists of establishing the fit of an unrestricted "exploratory" factorial model for a prespecified number of common factors. For this initial unrestricted model, researchers have often recommended and used fit indices to estimate the number of factors to retain. Despite the logical appeal of this approach, little is known about the actual accuracy of fit indices in the estimation of data dimensionality. The present study aimed to reduce this gap by systematically evaluating the performance of 4 commonly used fit indices-the comparative fit index (CFI), the Tucker-Lewis index (TLI), the root mean square error of approximation (RMSEA), and the standardized root mean square residual (SRMR)-in the estimation of the number of factors with categorical variables, and comparing it with what is arguably the current golden rule, Horn's (1965) parallel analysis. The results indicate that the CFI and TLI provide nearly identical estimations and are the most accurate fit indices, followed at a step below by the RMSEA, and then by the SRMR, which gives notably poor dimensionality estimates. Difficulties in establishing optimal cutoff values for the fit indices and the general superiority of parallel analysis, however, suggest that applied researchers are better served by complementing their theoretical considerations regarding dimensionality with the estimates provided by the latter metho
Searching for G: A New evaluation of SPM-LS dimensionality
There has been increased interest in assessing the quality and usefulness of short versions
of the Raven’s Progressive Matrices. A recent proposal, composed of the last twelve matrices of the
Standard Progressive Matrices (SPM-LS), has been depicted as a valid measure of g. Nonetheless, the
results provided in the initial validation questioned the assumption of essential unidimensionality
for SPM-LS scores. We tested this hypothesis through two di erent statistical techniques. Firstly, we
applied exploratory graph analysis to assess SPM-LS dimensionality. Secondly, exploratory bi-factor
modelling was employed to understand the extent that potential specific factors represent significant
sources of variance after a general factor has been considered. Results evidenced that if modelled
appropriately, SPM-LS scores are essentially unidimensional, and that constitute a reliable measure of
g. However, an additional specific factor was systematically identified for the last six items of the test.
The implications of such findings for future work on the SPM-LS are discusse
La tutoría en educación infantil en la escuela rural
La tutoría en la escuela rural es de vital importancia, ya que con ello se asesora a los niños en su proceso de enseñanza-aprendizaje. A partir de unos instrumentos y técnicas varias el maestro tutor es capaz de llevar a cabo la acción tutorial. Normalmente el maestro que más tiempo pasa con los alumnos en el aula es el encargado de realizar la tutoría con los alumnos y con las familias, puesto que es quién mejor conoce las características de cada uno de los alumnos. Para que un maestro pueda actuar como tutor de aula precisa de una formación no sólo académica, sino también psicopedagógica, para poder actuar con cualquier alumno, atendiendo a las características personales y sociales de cada niño, además de actuar también con los alumnos que precisen de apoyo educativo o tengan necesidades educativas especiales; todo ello sujeto a la atención a la diversidad. Además de la formación correspondiente, el tutor debe poseer una serie de cualidades y características que le ayudarán a realizar una acción tutorial mucho más adecuada a la etapa educativa que va a tutorizar. Es importante la colaboración de las familias en las actividades de la escuela. Si pedimos su participación, se podrá realizar todo tipo de actividades y tareas, además los niños al ver a sus familias como miembros activos de la escuela, se sentirán más a gusto en ella. Los maestros deben contar con esta colaboración y deben aceptarla para una mayor conexión familia-escuela. La acción tutorial con las familias va fundamentada en la recogida de información del niño, pero también en la explicación de las dificultades o necesidades educativas que al alumno le puedan surgir en un momento determinado
Validation of suspected somatic Single Nucleotide Variations in the brain of Alzheimer disease patients
Next-generation sequencing techniques and genome-wide association study analyses have provided a huge amount of data, thereby enabling the identification of DNA variations and mutations related to disease pathogenesis. New techniques and software tools have been developed to improve the accuracy and reliability of this identification. Most of these tools have been designed to discover and validate single nucleotide variants (SNVs). However, in addition to germ-line mutations, human tissues bear genomic mosaicism, which implies that somatic events are present only in low percentages of cells within a given tissue, thereby hindering the validation of these variations using standard genetic tools. Here we propose a new method to validate some of these somatic mutations. We combine a recently developed software with a method that cuts DNA by using restriction enzymes at the sites of the variation. The non-cleaved molecules, which bear the SNV, can then be amplified and sequenced using Sanger's technique. This procedure, which allows the detection of alternative alleles present in as few as 10% of cells, could be of value for the identification and validation of low frequency somatic events in a variety of tissues and diseases
Salicylic acid and Bacillus subtilis as control of early blight (Alternaria solani) in tomato plants (Solanum lycopersicum)
Alternaria solani is the causal agent of early blight disease in tomatoes (Solanum lycopersicum) and every year is responsible for significant economic losses suffered worldwide by the producers of this crop. Since salicylic acid and Bacillus subtilis are resistance-inducing agents in plants, they were evaluated in order to know their effect on the infection caused by early blight in the tomato crop. Plants of 75 days old were transplanted in furrows 8 m wide by 43.2 m long, the exogenous application of treatments were made, growth variables (plant height and stem diameter), yield (total fruits) and damage in tomato plants were evaluated. The results show significant statistical differences between treatments compared with the control (P≤0.000). B. subtilis applied to the root and salicylic acid applied to the foliage, reduced the severity of A. solani in tomato plants, and caused a significant increment in the crop growth and yield. The use of resistance inducers can represent an alternative of sustainable production and efficient control against pathogens, aimed at reducing the use of agrochemicals and production costs.Alternaria solani is the causal agent of early blight disease in tomatoes (Solanum lycopersicum) and every year is responsible for significant economic losses suffered worldwide by the producers of this crop. Since salicylic acid and Bacillus subtilis are resistance-inducing agents in plants, they were evaluated in order to know their effect on the infection caused by early blight in the tomato crop. Plants of 75 days old were transplanted in furrows 8 m wide by 43.2 m long, the exogenous application of treatments were made, growth variables (plant height and stem diameter), yield (total fruits) and damage in tomato plants were evaluated. The results show significant statistical differences between treatments compared with the control (P≤0.000). B. subtilis applied to the root and salicylic acid applied to the foliage, reduced the severity of A. solani in tomato plants, and caused a significant increment in the crop growth and yield. The use of resistance inducers can represent an alternative of sustainable production and efficient control against pathogens, aimed at reducing the use of agrochemicals and production costs
Ácido salicílico y Bacillus subtilis como control del tizón temprano (Alternaria solani) en plantas de tomate (Solanum lycopersicum)
Alternaria solani is the causal agent of early blight disease in tomatoes (Solanum
lycopersicum) and every year is responsible for significant economic losses suffered
worldwide by the producers of this crop. Since salicylic acid and Bacillus subtilis are
resistance-inducing agents in plants, they were evaluated in order to know their effect
on the infection caused by early blight in the tomato crop. Plants of 75 days old were
transplanted in furrows 8 m wide by 43.2 m long, the exogenous application of treatments
were made, growth variables (plant height and stem diameter), yield (total fruits)
and damage in tomato plants were evaluated. The results show significant statistical
differences between treatments compared with the control (P≤0.000). B. subtilis applied
to the root and salicylic acid applied to the foliage, reduced the severity of A. solani in
tomato plants, and caused a significant increment in the crop growth and yield. The
use of resistance inducers can represent an alternative of sustainable production and
efficient control against pathogens, aimed at reducing the use of agrochemicals and
production costs.Alternaria solani es el agente causal de la enfermedad del tizón temprano en el tomate
(Solanum lycopersicum) y cada año es responsable de pérdidas económicas significativas
sufridas por los productores de este cultivo a nivel mundial. Debido a que el ácido
salicílico y Bacillus subtilis, son agentes inductores de resistencia en las plantas, estos
fueron evaluados con la finalidad de conocer su efecto en la infección causada por el
tizón temprano en el cultivo de tomate. Plantas de 75 días de edad se trasplantaron en
surcos de 8 m de ancho por 43,2 m de largo, se realizó la aplicación exógena de los tratamientos,
se evaluaron variables de crecimiento (altura de la planta y diámetro del tallo),
rendimiento (frutos totales) y daño en plantas de tomate. Los resultados muestran que
existen diferencias estadísticas significativas entre los tratamientos comparados con
el testigo (P≤0,000). B. subtilis aplicado a la raíz y ácido salicílico aplicado al follaje,
redujo la severidad de A. solani en plantas de tomate, al mismo tiempo que causó un
incremento significativo en el crecimiento y rendimiento del cultivo. La utilización de
inductores de resistencia puede representar una alternativa de producción sustentable
y eficiente para el control de patógenos, a fin de reducir el uso de agroquímicos y los
costos de producción.
Palabras clave
inductores de resistencia • Alternaria solani • producción sustentableFil: Espinosa-Vázquez, Miguel Ángel.
Universidad de Ciencias y Artes de Chiapas (México). Facultad de Ingeniería. Maestría
en Ciencias en Desarrollo Sustentable y Gestión de RiesgosFil: Espinoza-Medinilla, Eduardo Estanislao.
Universidad de Ciencias y Artes de Chiapas (México). Facultad de Ingeniería. Maestría
en Ciencias en Desarrollo Sustentable y Gestión de RiesgosFil: Orantes-García, Carolina.
Universidad de Ciencias y Artes de Chiapas. Instituto de Ciencias BiológicasFil: Garrido-Ramírez, Eduardo.
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (México)Fil: Rioja-Paradela, Tamara Mila.
Universidad de Ciencias y Artes de Chiapas (México). Facultad de Ingeniería. Maestría
en Ciencias en Desarrollo Sustentable y Gestión de Riesgo
Preparation and Characterization of Aminoglycoside-Loaded Chitosan/Tripolyphosphate/Alginate Microspheres against E. coli
Although aminoglycosides are one of the common classes of antibiotics that have been widely used for treating infections caused by pathogenic bacteria, the evolution of bacterial resistance mechanisms and their inherent toxicity have diminished their applicability. Biocompatible carrier systems can help sustain and control the delivery of antibacterial compounds while reducing the chances of antibacterial resistance or accumulation in unwanted tissues. In this study, novel chitosan gel beads were synthesized by a double ionic co-crosslinking mechanism. Tripolyphosphate and alginate, a polysaccharide obtained from marine brown algae, were employed as ionic cross-linkers to prepare the chitosan-based networks of gel beads. The in vitro release of streptomycin and kanamycin A was bimodal; an initial burst release was observed followed by a diffusion mediated sustained release, based on a Fickian diffusion mechanism. Finally, in terms of antibacterial properties, the particles resulted in growth inhibition of Gram-negative (E. coli) bacteria
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