Cuestiones de escala en el ámbito de la “Huella Hídrica”.

La aplicación de la “Huella Hídrica” a la realidad española debe hacerse desde la consciencia de que hasta hace relativamente poco, el pensamiento científico dominante era el reduccionismo, cuyo enfoque considera que basta un conocimiento detallado de cada uno de los componentes de un sistema y de sus leyes fundamentales, para entenderlo globalmente. Y es que, el interés por este indicador surge de la importancia que cobran conceptos como “escasez” y “contaminación” del agua, como consecuencia directa e indirecta de la actividad humana sobre los sistemas hídricos, tanto en España como en los países de América Latina; con el fin de mejorar la gestión –desde la oferta y la demanda- de los recursos hídricos del planeta y reducir las desigualdades territoriales. De este modo, en el presente estudio se realiza una estimación de la “Huella Hídrica” de España y América Latina, así como de a la Red de Parques Nacionales Españoles, tanto a nivel económico como ambiental, describiendo los recursos hídricos utilizados, necesarios para satisfacer la demanda de bienes y servicios consumidos, en los prolegómenos del siglo XXI.

Calibration of assessment instruments – classification in mathematics at the Universidad Jorge Tadeo Lozano

Item Response Theory, IRT, is a valuable methodology for analyzing the quality of the instruments utilized in assessment of academic achievement. This article presents an implementation of the mentioned theory, particularly of the Rasch model, in order to calibrate items and the instrument used in the classification test for the Basic Mathematics subject at Universidad Jorge Tadeo Lozano. 509 responses chains of students, obtained in the june 2011 application, were analyzed with a set of 45 items, through eight case studies that are showing progressive steps of calibration. Criteria of validity of items and of whole instrument were defined and utilized, to select groups of responses chains and items that were finally used in the determination of parameters which then allowed the classification of assessed students by the test.

Validación de dos herramientas para la evaluación de cambios en las actitudes de alumnos en situaciones frecuentes en cuidado paliativo

Objective: To determine the psychometric properties of two scales designed to examine attitudes regarding palliative care: Comfort Scale in Palliative Care (CSPC, Pereira et al.) and Tanatophobia Scale (TS, Merrill et al.)Method: Seventy-seven students who completed an online course on psychosocial aspects of palliative care offered by the Latin American Association of Palliative Care participated in the study. They also completed the scales before and after the course. Construct validity and reliability of the CSPC and the TS were assessed using a Principal Components Analysis, internal reliability coefficient and test-retest reliability. Further, comparative statistics between the pre-course and post-course results were obtained in order to determine changes in attitudes.Results: The Principal Components Analysis showed satisfactory fit to the data. 3 components were extracted: two for the CSPC and one for the TS, which explained 55.37% of the variance. Internal consistency coefficients were satisfactory in all cases and Cronbach´s Alphas were satisfactory for all the scales, particularly for the CSPC. Test-retest reliability in t1 and t2 was found to be non significant, indicating that measures were not related in time. Regarding pre-course/post-course comparisons, significant changes in comfort assisting patients (p = 0.004) and comfort assisting families (p = 0.001) following the course were identified, but changes in thanatophobia were non significant (p > 0.05).Conclusions: both scales are valid and reliable. Attitudes regarding the practice of palliative care and how they change, particularly regarding psychosocial issues, can be accurately measured using the examined scales.