Escala de Miedo al Covid-19 en Estudiantes Universitarios Chilenos: Propiedades psicométricas e invarianza de medida

Los últimos acontecimientos relacionados con el Covid-19 han sido muy estresantes en la vida de los universitarios chilenos. A partir de lo anterior, es imperativo contar con un instrumento sólido para medir el miedo al Covid. Esta investigación tiene como objetivo estimar las propiedades psicométricas de la Escala de Miedo al Covid-19 (FCV-19S) en una muestra de 562 estudiantes universitarios chilenos y confirmar su estructura factorial. Se realizó un análisis factorial confirmatorio y se estimaron los parámetros del modelo utilizando el método de mínimos cuadrados ponderados diagonalmente (DWLS). La evaluación de FCV-19S tuvo valores satisfactorios (ω = .94; α = .93). Los resultados mostraron que el modelo de dos factores correlacionados se ajusta mejor a los datos CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. Estos hallazgos sugieren que la FCV-19S tiene las propiedades psicométricas adecuadas para su aplicación en estudiantes universitarios chilenos.The latest events in the lives of university students in Chile have been very stressful quarantines, online classes, and fear of contagion. It is imperative to have a solid instrument to measure the fear of Covid. This research aims to estimate the psychometric properties of the ‘Fear of Covid-19 Scale (FCV-19S)’ in a sample of 562 Chilean university students and to confirm its factorial structure. Confirmatory factorial analyses were performed and model parameters were estimated using the diagonally weighted least squares (DWLS) method. The assessment of FCV-19S had satisfactory values (ω = .94; α = .93). The results showed that the two-correlated factor model best fit the data CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. These findings suggest that FCV-19S has the proper psychometric properties for its application to Chilean university students.Fil: Martínez Líbano, Jonathan. Universidad Andrés Bello; ChileFil: TorresVallejos, Javier. Universidad Andrés Bello; ChileFil: Simkin, Hugo Andrés. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oyanedel, Juan Carlos. Universidad Andrés Bello; ChileFil: Silva Fuentes, Alicia. Universidad de Las Américas.; EcuadorFil: Yeomans Cabrera, María Mercedes. Universidad de Las Américas.; Ecuado

Escala de Miedo al Covid-19 en Estudiantes Universitarios Chilenos: Propiedades psicométricas e invarianza de medida

The latest events in the lives of university students in Chile have been very stressful quarantines, online classes, and fear of contagion. It is imperative to have a solid instrument to measure the fear of Covid. This research aims to estimate the psychometric properties of the ‘Fear of Covid-19 Scale (FCV-19S)’ in a sample of 562 Chilean university students and to confirm its factorial structure. Confirmatory factorial analyses were performed and model parameters were estimated using the diagonally weighted least squares (DWLS) method. The assessment of FCV-19S had satisfactory values (ω = .94; α = .93). The results showed that the two-correlated factor model best fit the data CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. These findings suggest that FCV-19S has the proper psychometric properties for its application to Chilean university students.Los últimos acontecimientos relacionados con el Covid-19 han sido muy estresantes en la vida de los universitarios chilenos. A partir de lo anterior, es imperativo contar con un instrumento sólido para medir el miedo al Covid. Esta investigación tiene como objetivo estimar las propiedades psicométricas de la Escala de Miedo al Covid-19 (FCV-19S) en una muestra de 562 estudiantes universitarios chilenos y confirmar su estructura factorial. Se realizó un análisis factorial confirmatorio y se estimaron los parámetros del modelo utilizando el método de mínimos cuadrados ponderados diagonalmente (DWLS). La evaluación de FCV-19S tuvo valores satisfactorios (ω = .94; α = .93). Los resultados mostraron que el modelo de dos factores correlacionados se ajusta mejor a los datos CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. Estos hallazgos sugieren que la FCV-19S tiene las propiedades psicométricas adecuadas para su aplicación en estudiantes universitarios chilenos

Teaching Biochemistry Using New Strategies in the Universidad de Concepción (Symposium)

The new paradigms of higher education require new teaching strategies to meet the  learning  objectives  of  Biochemistry  courses.  In  our  department  there  have been some early educational innovations through the incorporation of topics of protein  structure  in  web  page,  which  then  evolved  into  interactive  java applications  based  on  the  use  of  CHIME,  and  is  currently  being  adapted  to Jmol.  Another  tool  used  is  the  PROTLAB  software,  which  is  a  simulator  of protein  purification  with  40  different  proteins.  Recently  have  added  new activities to motivate the study of Biochemistry, especially first years student: Art and  Biochemistry  where  the  students  express  some  of  the  biochemistry concepts  through  artistic  expression  and  are  graded  including  students.  For senior  student,  have  been  designed  activities  to  apply  the  basic  knowledge  of biochemistry  to  the  explanation  of  everyday  events  for  the  general  public, through the generation of a Wiki in a simple language. Debates activities have also  been  established  for  discussion  of  topics  related  to  biochemistry.  Also applications available in the web are used to reinforce some topics. All activities have  a  greater  acceptance  of  students,  although  the  effect  on  learning outcomes is ambiguou

Psychometric Properties of the Emotional Exhaustion Scale (ECE) in Chilean Higher Education Students

The main objective of this study was to estimate the psychometric properties of the Emotional Fatigue Scale (ECE) in a sample of 1308 Chilean university students and confirm the unifactorial structure of the scale. Exploratory and confirmatory factor analyses were carried out. The ECE assessment had an internal consistency of 0.893 (Cronbach’s Alpha). An exploratory factor analysis with Varimax rotation and a confirmatory analysis were performed, obtaining the factor that explains 52.3% of the variance. The results indicated that the ECE has adequate psychometric properties for use with higher education students in Chile. The ECE scale has good psychometric properties to be applied in the Chilean university context. Its usage may be very relevant to contribute to higher education institutions to emphasize students’ mental health and prevent possible severe pathologies in future professionals. It is suggested to use the ECE scale together with the EES-Int, which is the only interpretation table for this instrument

Structural-functional analysis of the oligomeric protein R-phycoerythrin

The structure of phycobiliproteins and their spatial organization in the phycobilisome provide the environment for high efficiency in light harvesting and conduction towards photosystem II. This article focuses on the analysis of R-phycoerythrin, a light harvesting hexameric phycobiliprotein that is part of the phycobilisomes. The interaction surfaces and the environment of the chromophores of R-phycoerythrin were studied in order to explain its structural stability and spectroscopic sensitivity, properties revealed by perturbation experiments. Three interaction surfaces are described (ab), (ab)3 and (ab)6. The analysis shows the importance of a subunits in the interaction between trimers, the homodimeric nature of the monomer (ab) and also the presence of anchor points in every interaction surface studied: a18Phe and b18Tyr for (ab), b76Asn for (ab)3 and a25Asn for (ab)6 . Side chains of arginine, lysine or glutamine residues are located in the proximity of the chromophores providing the correct stabilization of their carboxylates. Aspartic acids residues are associated through H-bonds to the N atom of the two central rings of the tetrapyrrolic chromophores. Changes in the spectroscopic properties are observed in perturbation experiments, confirming the spatial requirement for an efficient resonance energy transfer among chromophores and through the phycobilisom

Escala de Miedo al Covid-19 en Estudiantes Universitarios Chilenos: Propiedades psicométricas e invarianza de medida

Los últimos acontecimientos relacionados con el Covid-19 han sido muy estresantes en la vida de los universitarios chilenos. A partir de lo anterior, es imperativo contar con un instrumento sólido para medir el miedo al Covid. Esta investigación tiene como objetivo estimar las propiedades psicométricas de la Escala de Miedo al Covid-19 (FCV-19S) en una muestra de 562 estudiantes universitarios chilenos y confirmar su estructura factorial. Se realizó un análisis factorial confirmatorio y se estimaron los parámetros del modelo utilizando el método de mínimos cuadrados ponderados diagonalmente (DWLS). La evaluación de FCV-19S tuvo valores satisfactorios (ω = .94; α = .93). Los resultados mostraron que el modelo de dos factores correlacionados se ajusta mejor a los datos CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. Estos hallazgos sugieren que la FCV-19S tiene las propiedades psicométricas adecuadas para su aplicación en estudiantes universitarios chilenos.The latest events in the lives of university students in Chile have been very stressful quarantines, online classes, and fear of contagion. It is imperative to have a solid instrument to measure the fear of Covid. This research aims to estimate the psychometric properties of the ‘Fear of Covid-19 Scale (FCV-19S)’ in a sample of 562 Chilean university students and to confirm its factorial structure. Confirmatory factorial analyses were performed and model parameters were estimated using the diagonally weighted least squares (DWLS) method. The assessment of FCV-19S had satisfactory values (ω = .94; α = .93). The results showed that the two-correlated factor model best fit the data CFI = .993, TLI = .989, RMSEA = .053, SRMR = .049. These findings suggest that FCV-19S has the proper psychometric properties for its application to Chilean university students.Fil: Martínez Líbano, Jonathan. Universidad Andrés Bello; ChileFil: TorresVallejos, Javier. Universidad Andrés Bello; ChileFil: Simkin, Hugo Andrés. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Oyanedel, Juan Carlos. Universidad Andrés Bello; ChileFil: Silva Fuentes, Alicia. Universidad de Las Américas.; EcuadorFil: Yeomans Cabrera, María Mercedes. Universidad de Las Américas.; Ecuado

Impact of white wine macromolecules on fractionation performance of ultrafiltration membranes

Aim: The aim of this study was to investigate the performance of ultrafiltration (UF) membranes to achieve a selective separation of macromolecules from Sauvignon blanc wine into stable and unstable fractions and to characterize the main compounds separated. Methods and results: The macromolecules from two Sauvignon blanc wines (Curicó Valley and Casablanca Valley, Chile) were separated by a cascade of UF membranes into three nominal fractions (10-30, 30-100 and 100-300 kDa). These fractions were characterized by native and SDS electrophoresis and membrane performance was evaluated by protein rejection and transmission. Separation by UF allowed the concentration of thermally unstable proteins in the 10-30 kDa retentate fraction, increasing heat induced haze by 8.9 fold, while heat stable glycoproteins were concentrated into the 100-300 kDa retentate fraction, reducing heat induced haze by 5.3 fold compared to unfiltered wine. The retention of high macromolecular species by the UF membrane with a 100 kDa molecular weight cut-off contributed to increased protein aggregation in the filtered wines. Conclusion: The concentration and purification of anti-hazing compounds by membrane filtration seem to be a new technology to improve the protein stability of white wines. Significance and impact of the study: Specific wine proteins are responsible for wine instability, resulting in haze formation in white wines. On the other hand, glycoproteins prevent protein aggregation and precipitation, thereby improving wine stability. Fractionation of wine macromolecules by UF membranes may help us to improve our knowledge about the contribution of specific proteins and glycoproteins to the haze stability of white wines

Crystal Structure of Escherichia coli Agmatinase: Catalytic Mechanism and Residues Relevant for Substrate Specificity

Agmatine is the product of the decarboxylation of L-arginine by the enzyme arginine decarboxylase. This amine has been attributed to neurotransmitter functions, anticonvulsant, anti-neurotoxic, and antidepressant in mammals and is a potential therapeutic agent for diseases such as Alzheimer’s, Parkinson’s, and cancer. Agmatinase enzyme hydrolyze agmatine into urea and putrescine, which belong to one of the pathways producing polyamines, essential for cell proliferation. Agmatinase from Escherichia coli (EcAGM) has been widely studied and kinetically characterized, described as highly specific for agmatine. In this study, we analyze the amino acids involved in the high specificity of EcAGM, performing a series of mutations in two loops critical to the active-site entrance. Two structures in different space groups were solved by X-ray crystallography, one at low resolution (3.2 Å), including a guanidine group; and other at high resolution (1.8 Å) which presents urea and agmatine in the active site. These structures made it possible to understand the interface interactions between subunits that allow the hexameric state and postulate a catalytic mechanism according to the Mn2+ and urea/guanidine binding site. Molecular dynamics simulations evaluated the conformational dynamics of EcAGM and residues participating in non-binding interactions. Simulations showed the high dynamics of loops of the active site entrance and evidenced the relevance of Trp68, located in the adjacent subunit, to stabilize the amino group of agmatine by cation-pi interaction. These results allow to have a structural view of the best-kinetic characterized agmatinase in literature up to now