Perspectiva temporal y estilos de personalidad en estudiantes argentinos / Temporal perspective and personality styles in argentinean students

En la Psicología, el concepto de perspectiva temporal introducido por Lewin (1935) se define como la dirección preferencial de los pensamientos de un sujeto hacia el presente, pasado o futuro, dimensión más o menos estable de la personalidad, que influye sobre la motivación, el pensamiento y diversos aspectos de su conducta. Zimbardo define el concepto como un proceso no consciente mediante el cual el flujo de las experiencias personales y sociales se encuadran en categorías temporales que ayudan a dar orden, coherencia y significado a esas experiencias y lo operacionaliza, introduciendo también el concepto de perspectiva temporal balanceada (BTP). Se presentan los resultados de datos recogidos en una muestra de 329 estudiantes argentinos de nivel medio, terciario (nivel superior no universitario) y universitario, a partir de los que se exploró la posible relación entre perfiles de perspectiva temporal y estilos de personalidad y se evaluó el rol de la perspectiva temporal balanceada en la relación entre ambos constructos. Se aplicó el Inventario de Perspectiva Temporal (ZTPI - Zimbardo & Boyd, 1999), el Cuestionario de Perspectiva Temporal Futura Trascendental (PTFT - Boyd & Zimbardo, 1997) y la adaptación para Argentina del Inventario Millon de Estilos de Personalidad (Casullo & Castro Solano, 2000). Los análisis de correlaciones y de variancia arrojan evidencia empírica acerca de las relaciones significativas entre perfiles de perspectiva temporal y estilos de personalidad y se verifica, en particular, que hay un perfil de perspectiva temporal más adaptativo que el resto. Se interpretan los resultados como bidireccionales.

The time notion has a central place both in the philosophical reflection and in Psychology, indicating a systematical position with regard to the man's mode of existence in the world. In Psychology, the time perspective concept was introduced by Lewin (1935), and defined as the totality of the individual's views of his psychological future and psychological past existing at a given time, a more or less stable trait of the personality, which influences the motivation, thinking, and various aspects of their behaviour. Zimbardo is the author that more has been busy of the operationalization of this concept, which he defined as a non conscious process through which the flow of personal and social experiences is assigned to temporal categories that help give order, coherence and meaning to those experiences. The relative weight of the time frames introduce considerable differences in the decisions and behaviours and this preference for any of the dimensions can function as a static personality trait that can be non-adaptive. Hence, the authors introduce the concept of balanced time perspective (BTP) according to which the present, past and future are combined in a flexible manner, in response to the demands of the times and tasks in the life of the people, as well as to their dominant values. In this work we present the results of data collected in a sample of 329 students of secondary, tertiary and university levels, from which explored the possible relationship between profiles of temporal perspective and personality styles in Argentinean students and evaluate the role of balanced temporal perspective in that relationship. The ZTPI (Inventory of Temporal Perspective -Zimbardo & Boyd, 1999), the Questionnaire of Transcendental Future Time Perspective (PTFT -Boyd & Zimbardo, 1997), and the MIPS adaptation to Argentina (Casullo & Castro Solano, 2000) are applied. For the data analysis was used the following statistical: analysis of correlations, analysis of variance (ANOVA one way), tests of significance of the proportional differences and K-Means Cluster Analysis. We used the SPSS.20. Using cluster analysis, three profiles of time perspective and three personality styles are obtained. It is also estimated the deviation of balanced temporal perspective (DBTP) for each subject and three conglomerates were determinated. The correlations and variance analysis show empirical evidence about the meaningful relationships between profiles of temporal perspective and personality styles. It was verified, in particular, that there is a profile of temporal perspective more adaptive than the rest. In fact, 55% of the subjects who are identified with a profile of equilibrate-transcendent PT are within the group with open, active, strong and sociable personality stile, while 40% of subjects with conflicting PT are located in the style of conflicted personality. The inclusion of the future transcendental time scale, unified with the ZTPI allows us to see this perspective influences, in particular in the profiles of PT and its relationship with the personality styles. Some of these relationships and their difference with those found by the authors of both scales of PT are interpreted as a result of cultural differences. All the links found are confirmed on the basis of the determination of the balanced time perspective (BTP), which in our sample corresponds to the 28 per cent of the total number of subjects. There would be a two-way relationship, a mutual influence; on the one hand, certain personality traits would glances spreads to the temporal dimensions of the lived and living life and, on the other hand, the profile of temporal perspective that is being consolidated as personality trait refluxes on the rest of the traits, to contribute to the achievement of a identity with greater or lesser degree of adaptation and completeness.

Razonamiento espacial y rendimiento académico / Spatial reasoning and academic achievement

Se presentan los resultados de una investigación cuyos objetivos fueron evaluar los siguientes puntos: (a) el nivel de razonamiento espacial en alumnos del Ciclo Básico Común (CBC) de la Facultad de Arquitectura, Diseño y Urbanismo de la Universidad de Buenos Aires (UBA), (b) la relación entre razonamiento espacial y rendimiento académico, (c) la relación entre razonamiento espacial y educación media de origen, (d) el progreso en razonamiento espacial al finalizar el CBC y (e) las posibles diferencias en razonamiento espacial y en rendimiento académico según sexo. La muestra estuvo compuesta por 596 alumnos que cursaban la materia Dibujo. Se usó un diseño cuasi-experimental de clases intactas, con pre y post-test. Resultaron diferencias significativas en el nivel de razonamiento espacial entre el comienzo y el final del CBC, consideradas como un efecto de la enseñanza. Los varones superaron a las mujeres en capacidad de razonamiento espacial. Las mujeres registraron una menor tasa de deserción, mayor incremento en los puntajes de razonamiento espacial post-test y en el rendimiento final, que se interpretan en relación con el rol del esfuerzo. El rendimiento de la primera parte del año, en combinación con el nivel de razonamiento espacial en el momento del ingreso, permitió predecir el 60% del resultado final. Se verifican diferencias en razonamiento espacial y en los índices de deserción en relación con la variable Carrera.

The paper reports an enquiry aimed at: (1) assessing the spatial reasoning level reached by students admitted to the university entrance course at the Architecture, Design and Urban Planning School of the University of Buenos Aires, (2) examining the relation between spatial reasoning and academic achievement, (3) exploring the relation between spatial reasoning and secondary schooling, (4) evaluating spatial reasoning progress at the end of the course, and (5) ascertaining possible gender - related differences in spatial reasoning and academic achievement. Current literature is reviewed, focusing on the concept of spatial reasoning, the skills involved, gender - related differences and academic achievement, with special reference to technology studies. Two prevailing trends are identified: the factorial approach and cognitive. Explanations of male spatial skills advantage stress biological or environmental aspects or a combination of both. Students' poor spatial reasoning performance at the start of university highlights the need to develop spatial competence at the lower levels of schooling, particularly in secondary school, within an integral education approach. This would en- compass all the essential dimensions of the human being, rather than concentrate on disembodied rationality. Research points to mental visualisation and graphic communication abilities as necessary components of drawing and design. Training in object manipulation, block building and the sketching of observed objects has been found to enhance performance in activities specifically related to the contents taught, although transfer to test situations would seem harder to accomplish. Spatial skills training should, therefore, become part of university curriculum, especially in the case of technology courses. The sample was made up of 596 students enrolled in the Drawing Course. A quasi-experimental pre-test post-test intact group design was used and the results were linked to gender-related attribution patterns. Students' initially low spatial reasoning level would point to secondary schooling shortcomings. Significant differences in spatial reasoning level have been observed between the beginning and the end of the course, which might be ascribed to instructional intervention, consistently with research findings on the effects of training on spatial reasoning ability. Results for the whole sample reveal that male subjects scored higher on spatial reasoning ability, but no significant gender-related differences have been detected in the case of subjects with a technologically oriented secondary education. This might be associated with gender-based differences concerning the role of specific training. Drop-out rates were lower among women, who, together with higher post-test score increases and final achievement scores would point to the part played by effort in compensating for skills deficits. Female subjects would appear to make better use of the instruction received. Spatial reasoning has been found to be a good predictor of achievement, with initial spatial reasoning level combined with first semester achievement predicting 60% of the final achievement scores. Academic achievement levels were lower than spatial reasoning ones, especially in the first test. The gap narrowed in the second, which suggests that students learned to use their ability to better advantage during the course. It is concluded that the spatial reasoning capacity of students newly admitted to university may be characterised as limited, which might pose a major hurdle to the completion of technology entrance courses. Secondary schooling should be redefined in terms of the relationship between spatial skills and the capacity to assign representational content to conceptual knowledge, which is required for the latter to become fully possessed and transferable. Far from being restricted to the sphere of technical performance, the need to integrate the conceived and the perceived is rooted in the very nature of human knowledge. A relation has been identified between differences in spatial reasoning and drop-out rates, on the one hand, and degree course choice, on the other.

Breast cyst fluids increase the proliferation of breast cell lines in correlation with their hormone and growth factor concentration.

OBJECTIVE AND DESIGN: Gross cystic disease (GCD) of the breast is reported to occur in 7% of women in the developed world and, although not premalignant, is thought to be associated with an increased risk of breast cancer. Hormone and growth factor concentration levels were measured in breast cyst fluid (BCF) to correlate them with their mitogenic activity in tumour (MCF-7) or nontransformed (MCF-10A) cells. RESULTS: Oestradiol (E2), oestrone (E1), E2-sulfate (E2-S), E1-sulfate (E1-S) and epidermal growth factor (EGF) concentrations were, as expected, significantly higher in type I than in type II cysts, while transforming growth factor-beta 2 (TGF-beta2) showed higher levels in type II cysts. Fifty per cent of the BCF samples stimulated [3H]-thymidine incorporation into MCF-7 cells while 34.5% inhibited this parameter. In MCF-10A cells, most BCF samples were stimulatory (85%). E2, E1 and EGF concentrations in BCF samples correlated significantly and positively with cell proliferation in MCF-7 cells, whereas a significant negative correlation was found for TGF-beta2. In MCF-10A cells, only E2-S and E1-S exhibited significant positive correlation, whereas a significant negative correlation was found for TGF-beta2. Progesterone (Pg), E2 and EGF incubated under the same conditions had a stimulatory effect on [3H]-thymidine incorporation into MCF-7 cells, whereas TGF-beta2 inhibited this parameter. Pg, E2, E1 and EGF significantly stimulated this parameter in MCF-10A cells. CONCLUSIONS: The stimulatory action of BCF on cell proliferation in a model of human breast epithelial cells could partly explain the increased incidence of breast cancer in cyst-bearing women.

Human breast cell lines exhibit functional alpha2-adrenoceptors.

Adrenergic compounds (epinephrine and norepinephrine) are the most important hormones released during stress. Several different receptors are associated with their action in different tissues. However, alpha(2)-adrenoceptors have not yet been described in either normal or tumour human breast tissue. The aim of this work was to describe and characterize these receptors in several tumour and non-tumour human cell lines. The expression of alpha(2)-adrenoceptors was analyzed at the RNA (RT-PCR) and protein ([(3)H]-rauwolscine binding and immunocytochemistry) levels in different human breast cell lines, and the biological activity assessed by [(3)H]-thymidine incorporation. The cancer IBH-6, IBH-7 and MCF-7 and the non-tumour HBL-100 cells line, expressed both alpha(2B)- and alpha(2C)-adrenoceptor-subtypes. A single subtype was expressed in malignant HS-578T (alpha(2A)) and MDA-MB-231 and non-tumour MCF-10A cells (alpha(2B)). All cell lines exhibited significant binding for the specific antagonist [(3)H]-rauwolscine. The alpha-, alpha(2)-, and the alpha(1)-compounds with known affinity for alpha(2)-adrenoceptors, including epinephrine, norepinephrine, yohimbine, clonidine, rauwolscine and prazosin, competed significantly with binding in MCF-7 cells. In addition, IBH-6, IBH-7 and MCF-7 cells showed significant staining with specific antibodies against alpha(2B)- and alpha(2C)-adrenoceptor-subtypes, when tested by immunocytochemistry. In all cell lines, the specific agonist clonidine or oxymetazoline stimulated [(3)H]-thymidine incorporation. EC(50) values were in the range of 20-50 fM for IBH-6, IBH-7, and HS-578T; 0.14 pM for MCF-7; 2-82 pM for HBL-100 and MCF-10A cells, and a biphasic behaviour with a maximum value at 38.0 pM, was observed for MDA-MB-231 cells. The specific alpha(2)-adrenergic antagonist rauwolscine always reversed this stimulation at 0.1 nM. In conclusion, this study describes for the first time, the presence of alpha(2)-adrenoceptors in human epithelial breast cell lines. Moreover, activation of these receptors was associated with an enhancement of cell proliferation.

Future time perspective and motivational categories in Argentinean adolescents.

This study is based on a sample of 332 Argentinean teenagers in their last year of secondary school. In the context of the relational theory of motivation, an attempt is made to determine the motivational categories best predicting Future Time Perspective (FTP) extension. The influence of the sex, locus of control, social class, and school ethos variables on FTP extension is also explored. A scale measuring locus of control and the Motivational Induction Method (MIM) have been employed to obtain the data. Through stepwise multiple regression, a predictive set is determined, made up of life-meaning values, self-fulfillment, academic achievement motivation, locus of control, sensual values, and social contact. Significant differences are found in FTP extension and locus of control in relation to school ethos. The Mann-Whitney and Kruskal-Wallis tests are used as statistical proof. A one-way ANOVA is run to examine the relationship between locus of control and school ethos levels. The possibility of a motivational profile common to Argentinean teenagers is considered and the pedagogical consequences of the findings are discussed.

Three novel hormone-responsive cell lines derived from primary human breast carcinomas: functional characterization.

Human breast cancer primary cultures are useful tools for the study of several aspects of cancer biology, including the effects of chemotherapy and acute gene expression in response to different hormonal/chemotherapy treatments. The present study reports the conditions for primary culture of breast cancer samples from untreated patients and the most effective collagenization method to dissociate human samples consisting in an overnight incubation with 1 mg/ml types II or IV collagenase and further incubation in DMEM:F12 (1:1) medium supplemented with glutamine, bovine insulin, penicillin-streptomycin, HEPES, estradiol, cortisol (F), tri-iodothyronine (T(3)), transferrine (TR), and 10% fetal calf serum (FCS). These conditions proved to be appropriate for both primary culture and the development of stable cell lines. Of the seven cell lines obtained, three fast growing and estrogen receptor (ER)+/progesterone receptor (PgR)+/EGF receptor (EGFR)+ have been characterized. The cells are able to grow both in soft agar and in nude mice, and express cytokeratins, all parameters characteristic of malignant epithelial cell lines. The cells also exhibit an increased proliferation rate in the presence of estradiol, progesterone, and EGF, suggesting the presence of the corresponding receptors. The mRNA expression of type alpha- and beta-ER as well as EGFR, was confirmed by RT-PCR. In conclusion, the novel cell lines described, arose from primary tumors and are sensitive to estradiol, progesterone, and EGF. This not only expands the repertoire of breast cancer cells available as potentially useful tools for examining most parameters in breast cancer "in vitro", but also provides unique new models to explore the complex regulation by steroids as well as growth factors in such cells.