RESUMEN
The authors discuss limitations of two popular measurement procedures, the Likert scale and conventional pretest-posttest self-report design. Both techniques have limits and yet are often combined, leading to restricted fidelity for measuring change. The authors go on to discuss two innovations in measurement that provide researchers with greater assessment fidelity: Visual analog scales and the retrospective pretest design. Moreover, when used in combination, these innovations measurement techniques provide dramatic increases in the power to detect and quantify change.
Se discuten las limitaciones de dos procedimientos de medición extremadamente populares; la escala Likert y los diseños pre-post tradicionales. Ambos métodos tienen limitaciones; estos métodos son comúnmente combinados obteniendo como resultado una fidelidad limitada para la medición del cambio. Se discute sobre dos innovaciones en medición que proveen al investigador una mayor fidelidad: escalas visuales análogas y el diseño pre-test retrospectivo. Además, cuando se usan de manera combinada, estas innovaciones en medición proveen notables incrementos en el poder de detección y la cuantificación de cambios.
RESUMEN
La evaluación de las actitudes en el ámbito educativo ha sido utilizada como herramienta para prevenir la pérdida de asignaturas y la deserción académica. El objetivo del estudio es realizar el análisis psicométrico del instrumento Actitudes hacia las Matemáticas con el Modelo de Respuesta Graduada de Samejima (MRG). Se contó con una muestra total de 944 estudiantes de primeros semestres de diferentes carreras universitarias. Se realizó el análisis a partir de la TCT y se ajustó el modelo MRG. Se estimaron y analizaron los parámetros de los ítems y se encontró que la mayoría se ajustan al modelo. En conclusión, se encuentra que la escala cuenta con adecuadas propiedades psicométricas. Finalmente, se presentan las bondades del uso del MRG para la evaluación de actitudes.
The assessment of attitudes in education has been used as a tool for preventing the loss of subjects and the desertion. The aim of the study is to perform a psychometric analysis of the "Attitudes towards Mathematics" scale with Samejima´s graded response model (MRG). The sample was of 944 students from different university careers. To analyze the TCT and the MRG model was used. In conclusion, the scale has good psychometric quality. Finally, the benefits of using the MRG for assessing attitudes are presented.
RESUMEN
MRG proteins are conserved during evolution in fungi, flies, mammals and plants, and they can exhibit diversified functions. The animal MRGs were found to form various complexes to activate gene expression. Plant MRG1/2 and MRG702 were reported to be involved in the regulation of flowering time via binding to H3K36me3-marked flowering genes. Herein, we determined the crystal structure of MRG701 chromodomain (MRG701). MRG701 forms a novel dimerization fold both in crystal and in solution. Moreover, we found that the dimerization of MRG chromodomains is conserved in green plants. Our findings may provide new insights into the mechanism of MRGs in regulation of gene expression in green plants.
Asunto(s)
Secuencia de Aminoácidos , Arabidopsis , Genética , Metabolismo , Proteínas de Arabidopsis , Química , Genética , Metabolismo , Sitios de Unión , Proteínas Cromosómicas no Histona , Química , Genética , Metabolismo , Clonación Molecular , Cristalografía por Rayos X , Escherichia coli , Genética , Metabolismo , Expresión Génica , Histonas , Química , Genética , Metabolismo , Modelos Moleculares , Oryza , Genética , Metabolismo , Péptidos , Química , Genética , Metabolismo , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Isoformas de Proteínas , Química , Genética , Metabolismo , Multimerización de Proteína , Estructura Secundaria de Proteína , Proteínas Recombinantes , Química , Genética , Metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Viridiplantae , Genética , MetabolismoRESUMEN
Recently,a large family of G-protein coupled receptors (GPCRs) has been identified as mas-related genes (Mrgs),Which are specific expressed in small diameter sensory neurons in the trigeminal and dorsal root ganglia,suggesting a role in pain transmission.Mrgs receptors have been shown to modulate some physiological and pathological activities,such as pain and immunity.It is important to discover ligands of Mrgs for understanding and elucidating their potential physiological and pathophysiological roles.The studies on pharmacological spectrum of NPS make it an interesting target for pharmaceutical development.
RESUMEN
Objective:To search for gene related to hepatocellular carcinoma ( HCC), and study its, potential significance in liver oncogenesis. Methods:The difference in mRNA expression among HCC, nontumorous liver tissue, fetal liver tissue and normal liver tissue was investigated by differential display technique. Ten hepatic tissues of HCC versus surrounding noncancerous liver tissues were examined with MRG98.2 as a probe in Dot blot analysis. Expression of vascular endothelial growth factor (VEGF)mRNA in above mentioned samples was examined with reverse transcription- polymerase chain reaction(RT~ PCR). Results:Fifty five differentially expressed cDNA fragments were isolated from HCC samples, 24 of them were present in HCC and fetal liver tissues simultaneously. Dot blot analysis showed that differential display fragment MRG98.2 expressed in 7 cases of HCC samples (7/10)but only slightly in 2 of the surrounding noncancerous hepatic tissues (2/10). The expression of VEGFmRNA was upregulation in 6/7 of HCC samples expressed MRG98. 2. Gmclusian :The activation of some genes expressed in fetal period may have an important role in the genesis of HCC. MRG98.2 may be a gene related to HCC. Its expression in HCC correlates with VEGFmRNA. MRG98.2 expression is helpful in predicting a tendency toward invasion and metastasis of HCC.