Motivational profiles and their relationships with basic psychological needs, academic performance, study strategies, self-esteem, and vitality in dental students in Chile

Purpose To determine dental students’ motivational profiles through a person-centred approach and to analyse the associations with the satisfaction of their basic psychological needs, study strategies, academic performance, self-esteem, and vitality. Methods A total of 924 students from the University of San Sebastian (Chile) participated in this cross-sectional cor¬relational study in spring 2016. Data were collected through 5 self-reported instruments, in addition to students’ academic performance. The Cronbach alpha, descriptive statistics, and correla¬tion scores were computed. A k-means cluster analysis with intrinsic and controlled motivation was conducted to identify different mo-tivational profiles. Subsequently, multivariate analysis of covariance controlling for the effects of gender and year of study was carried out to assess differences among the retained motivational profiles and learning variables. Results All instruments showed acceptable Cronbach alpha scores. A 4-cluster solution was retained for the motivational profile over a 3- or 5-cluster solution. Students’ motiva-tional profiles were characterized by different degrees of intrinsic and controlled motivation. The high intrinsic motivation groups showed higher perceptions of their basic psychological, a greater propensity for a deep rather than surface study strategy, better academic performance, and higher scores for self-esteem and vitality than the low intrinsic motivation groups, regardless of the degree of controlled motivation. Conclusion Students with a high intrinsic motivation profile, regardless of their controlled motivation scores, reported better learning characteristics. Therefore, special attention should be paid to students’ motivational profiles, as the quality of motivation might serve as a basis for interventions to support their academic success and well-being

Mosaic isochromosome xq and microduplication 17p13.3p13.2 in a patient with Turner syndrome and congenital cataract

La combinación del síndrome de Turner con otros trastornos genéticos, como la catarata congénita, ha sido reportada. Sin embargo, su asociación con una forma de catarata nuclear congénita con herencia autosómica dominante y penetrancia incompleta no ha sido reportada previamente en la literatura. Tampoco existen reportes de su presentación junto con rearreglos en el cromosoma 17. A continuación, presentamos el excepcional caso de una paciente con una constelación de anomalías mayores y menores, diagnosticada con síndrome de Turner en mosaico por isocromosoma Xq, asociado a una microduplicación 17p13.3p13.2, quien además presenta catarata nuclear congénita bilateral de herencia autosómica dominante con penetrancia incompleta. Se realiza una revisión acerca del origen y la causa de estas alteraciones genéticas y una aproximación a la hipótesis de la patogénesis de la asociación de dos de estos trastornos genéticos en una misma paciente.The combination of Turner syndrome with other genetic disorders such as congenital cataract has been reported, but its association with a congenital form with autosomal dominant inheritance and incomplete penetrance has not been previously reported in the literature. There are no reports on its presentations with rearrangements on chromosome 17. We report the exceptional case of a 20 months old girl with a constellation of major and minor anomalies, diagnosed with mosaic Turner syndrome by isochromosome Xq associated with a microduplication 17p13.3p13.2, who also had bilateral congenital nuclear cataract autosomal dominant with incomplete penetrance. We reviewed in the literature the origin and cause of these genetic alterations and we provided an approach to the hypothesis of the pathogenesis of the association of two of these genetic disorders in the same patient

Classical and semiclassical calculations of state-selective cross sections for electron capture and excitation in Be4++ H(2s) collisions

A computational study of Be4++H(2s) collisions has been carried out. Two computational models have been employed: the classical trajectory Monte Carlo (CTMC) method and the numerical solution of the time-dependent Schrödinger equation (GTDSE). The integral n and nl partial cross sections for H excitation and electron capture, obtained with both methods, are compared at two energies: 20 and 100 keV/u. It is shown that the CTMC, with an improved hydrogenic initial distribution, provides excitation cross sections in good agreement with the numerical calculation for excitation to H(n) with n>3. The agreement between the corresponding nl partial cross sections from both methods is less satisfactory at 100 keV/u, where there is a transition from the low-energy mechanism that involves an increase of the populations with l, and the high-energy mechanism, where the dipole-allowed transitions are dominant. The electron capture cross sections calculated with the CTMC method do not depend on the initial distribution and show a reasonable agreement with the GTDSE ones, which supports the use of the CTMC method to calculate electron capture cross sections into highly excited levels and total cross sections. The mechanism of the electron capture process is discussed and CTMC calculations of the ionization process are also presente

Searching hit potential antimicrobials in natural compounds space against biofilm formation

Biofilms are communities of microorganisms that can colonize biotic and abiotic surfaces and thus play a significant role in the persistence of bacterial infection and resistance to antimicrobial. About 65% and 80% of microbial and chronic infections are associated with biofilm formation, respectively. The increase in infections by multi-resistant bacteria instigates the need for the discovery of novel natural-based drugs that act as inhibitory molecules. The inhibition of diguanylate cyclases (DGCs), the enzyme implicated in the synthesis of the second messenger, cyclic diguanylate (c-di-GMP), involved in the biofilm formation, represents a potential approach for preventing the biofilm development. It has been extensively studied using PleD protein as a model of DGC for in silico studies as virtual screening and as a model for in vitro studies in biofilms formation. This study aimed to search for natural products capable of inhibiting the Caulobacter crescentus enzyme PleD. For this purpose, 224,205 molecules from the natural products ZINC15 database, have been evaluated through molecular docking and molecular dynamic simulation. Our results suggest trans-Aconitic acid (TAA) as a possible starting point for hit-to-lead methodologies to obtain new inhibitors of the PleD protein and hence blocking the biofilm formation

SINTESIS, CARACTERIZACION Y EVALUACION DE NUEVOS TIPOS DE SORBENTES DE IONES DE METALES PESADOS

La sorción es uno de los métodos aplicados en el campo de la separación de sustancias. Es de destacar que hasta aproximada­mente !a década de los años ochenta las aplicaciones de separación y concentración con quimisorbentes estaban basadas principal­mente en procedimientos cromatográficos dentro del campo de !a Química Analítica. En la actualidad, las fronteras de esta temática han crecido suficientemente como para ·hacer que el término "quimisorbente" resulte insuficiente para caracterizar todas las varian­tes desarrolladas con nuevos enfoques. Desde principios de los años noventa aparecen organizados diversos trabajos bajo la deno­minación de Química de Reactivos Soportados, campo en que no solamente se tratan de llevar a cabo separaciones de sustancias, sino que se manejan las potencialidades de estos reactivos en la síntesis y transformaciones de especies químicas. Las aplicaciones están diseminadas en ámbitos muy amplios: purificación de fluidos, recuperación de sustancias valiosas, catálisis heterogénea, fotoquímica y fotofísica, lucha contra la corrosión, entre otros ejemplos

Saturation mutagenesis reveals manifold determinants of exon definition.

To illuminate the extent and roles of exonic sequences in the splicing of human RNA transcripts, we conducted saturation mutagenesis of a 51-nt internal exon in a three-exon minigene. All possible single and tandem dinucleotide substitutions were surveyed. Using high-throughput genetics, 5560 minigene molecules were assayed for splicing in human HEK293 cells. Up to 70% of mutations produced substantial (greater than twofold) phenotypes of either increased or decreased splicing. Of all predicted secondary structural elements, only a single 15-nt stem-loop showed a strong correlation with splicing, acting negatively. The in vitro formation of exon-protein complexes between the mutant molecules and proteins associated with spliceosome formation (U2AF35, U2AF65, U1A, and U1-70K) correlated with splicing efficiencies, suggesting exon definition as the step affected by most mutations. The measured relative binding affinities of dozens of human RNA binding protein domains as reported in the CISBP-RNA database were found to correlate either positively or negatively with splicing efficiency, more than could fit on the 51-nt test exon simultaneously. The large number of these functional protein binding correlations point to a dynamic and heterogeneous population of pre-mRNA molecules, each responding to a particular collection of binding proteins

On the abundance discrepancy problem in HII regions

The origin of the abundance discrepancy is one of the key problems in the physics of photoionized nebula. In this work, we analize and discuss data for a sample of Galactic and extragalactic HII regions where this abundance discrepancy has been determined. We find that the abundance discrepancy factor (ADF) is fairly constant and of the order of 2 in all the available sample of HII regions. This is a rather different behaviour than that observed in planetary nebulae, where the ADF shows a much wider range of values. We do not find correlations between the ADF and the O/H, O++/H+ ratios, the ionization degree, Te(High), Te(Low)/ Te(High), FWHM, and the effective temperature of the main ionizing stars within the observational uncertainties. These results indicate that whatever mechanism is producing the abundance discrepancy in HII regions it does not substantially depend on those nebular parameters. On the contrary, the ADF seems to be slightly dependent on the excitation energy, a fact that is consistent with the predictions of the classical temperature fluctuations paradigm. Finally, we obtain that Te values obtained from OII recombination lines in HII regions are in agreement with those obtained from collisionally excited line ratios, a behaviour that is again different from that observed in planetary nebulae. These similar temperature determinations are in contradiction with the predictions of the model based on the presence of chemically inhomogeneous clumps but are consistent with the temperature fluctuations paradigm. We conclude that all the indications suggest that the physical mechanism responsible of the abundance discrepancy in HII regions and planetary nebulae are different.Comment: 14 pages, 8 figures, 9 tables. Accepted for publication in the Ap

Estudio de mercado para la leche fresca en la ciudad de Talca

135 p.Esta investigación esta dirigida principalmente a instituciones, pequenos/medianos productores de leche y en general, a todos aquellos agentes relacionados con el sector lechero, esto, debido a que el trabajo realizado analiza el comportamiento del consumidor ante el consumo de leche fresca. El objetivo general del estudio radica en determinar si existe un nicho de mercado en el ciudad de Talca, para un producto de origen regional con certificación de calidad como la leche fresca. Para lograr este objetivo fue necesario realizar diversas acciones, desde la búsqueda de bibliografía referente al tema, hasta la aplicación de un cuestionario estructurado a una muestra total de 381 personas, segmentadas por estratos socioeconómicos. Finalmente, se puede inferir de los resultados obtenidos que en general, las decisiones de compra varían según el estrato al que pertenezca cada consumidor. Las características de nicho de mercado, variaran de acuerdo al estrato al que pertenece el consumidor. Es así, como en el estrato alto la distribución del producto, deberá realizarse por intermedio del supermercado, sin embargo, es para los estratos medio y bajo, dicha intermediación puede realizarse a través de los distribuidores informales. En cuanto a la percepción que tienen los consumidores acerca de un producto de origen artesanal, esta no variara significativamente de un estrato a otro, sin embargo, la evaluación con respecto a un producto con cobertura nacional es definitivamente menor. El nicho que se considera como atrayente para realizar un proceso de penetración, con un producto como la leche fresca seria el constituido por el estrato medio

Substance Use among Adolescents Involved in Bullying: A Cross-Sectional Multilevel Study.

Being involved in bullying as a victim or perpetrator could have deleterious health consequences. Even though there is some evidence that bullies and victims of bullying have a higher risk for drug use, less is known about bystanders. The aim of this research was to study the association between bullying experience (as victims, bullies, or bystanders) and substance use. We gathered complete information from a nationally representative sample of 36,687 students (51.4% female) attending 756 schools in Chile. We used a self-reported questionnaire which was developed based on similar instruments used elsewhere. This questionnaire was piloted and presented to an expert panel for approval. We used multilevel multivariate logistic regression analyses, controlling for several variables at the individual (e.g., school membership, parental monitoring) and school levels (e.g., school type, school denomination). This study shows that bullies and bully-victims have a high risk for cigarette, alcohol, and cannabis use than bystanders. This is one of the few studies exploring the association between witnessing bullying and substance use. These findings add new insights to the study of the co-occurrence of bullying and substance use. Other factors, such as higher academic performance, stronger school membership, and better parental monitoring reduced the risk of any substance use, while the experience of domestic violence and the perception of social disorganization in the neighborhood, increased the risk. These findings may help the design of preventive interventions