Search

El presente trabajo brinda un enfoque científico-metodológico y social en la enseñanza de la asignatura Biodiversidad, que se imparte en el Plan de estudio E, por la modalidad de curso diurno y encuentro en las Carreras de Educación, Biología y Ciencias Agrarias, en la Universidad de Cienfuegos. Primero, se hizo una revisión documental de la impartición de esta asignatura. Se observó que no se profundiza en aspectos relacionados con la diversidad genética, la diversidad ecológica (los ecosistemas acuáticos y terrestres) y la diversidad de organismos, tampoco en los orígenes moleculares y en la formación de la vida sobre la tierra, entre otros contenidos de interés actual. Por lo que la inserción en el currículo electivo de nuevos contenidos (1-10), adaptados metológicamente al programa analítico y al diseñando de habilidades instructivas y educativas con un enfoque social desde la ciencia tendrán efectos notables en lograr en los futuros profesionales una visión integral de la biodiversidad. Ello modificará su conducta ética y social y de responsabilidad y respecto al medioambiente y generará acciones concretas en la comunidad y de respecto a la conservación de la diversidad de las especies. Palabras clave: Ecosistemas, Diversidad genética, Diversidad ecológica, Diversidad de organismos, Orígenes moleculares. ABSTRACT The present work provides a scientific-methodological and social approach to the Biodiversity subject teaching, which is taught in Study Plan E, through full-time and encounter courses in the Biology and Agrarian Sciences Education Degree at the University of Cienfuegos. First, a documentary review of the teaching of this subject was carried out, observing that it does not delve into aspects that have to do with genetic diversity, ecological diversity (aquatic and terrestrial ecosystems), and the diversity of organisms, nor in the origins molecular and formation of life on earth, among other contents of current interest. Therefore, the insertion into the elective curriculum of new content (1-9), methodologically adapted to the analytical program, and designing instructive and educational skills with a social approach from science will surely have notable effects on achieving future professionals, a comprehensive vision of biodiversity, modifying its ethical and socially responsible behavior, concerning the environment, generating concrete actions in the community, regarding the conservation of the diversity of species. Keywords: Ecosystems, Genetic diversity, Ecological diversity, Organism diversity, Molecular origins.

The development of scientific concepts is usually described as a pathway from the realm of concrete life to the abstract principles of science, in a higher level of generalisation. In this paper, we argue that the appropriation of scientific concepts occurs in the return to concrete in a higher level of conceptual development, which means a transition from the given concrete to a thoughtful and recreated concrete. In the first part of the paper we ground this point of view based on the intellectual routes of Lev Vigotski and on the Philosophy of Language of Michail Bakhtin. From Vigotski, we discuss the dialectic method of research, the concept of semiotic mediation and its implications to conceptual development, the relationship between everyday and scientific concepts and the role of concrete and abstract realms in conceptual development. From Bakhtin, we understand conceptual development as sense making in the dialogue between voices in different spheres of social life. In the second part of this paper we present empirical evidence to support this thesis. This will be done by analysing the meanings evoked by rural teacher students to the concept of energy in narratives produced by them at the end of a module of study on this subject. We seek to examine how the subjects of this experience populate with new meanings, dialectically and dialogically, the concept of energy. The main result of this study is the presence of a hybridisation of scientific and everyday life discourses in the efforts of subjects to confer relevant meanings (in both personal and social aspects) to the abstract statements of science. We conclude with some implications of this thesis to science education research and practice.

This article examines how a primary teacher establishes links between students' initial contributions on the theme ‘water’ and the elements that will make up the teaching approach of this subject in the science classroom. For this purpose, we examine discursive interactions in the first lessons of a teaching sequence, looking for links between events that are being elicited and developed by the teacher with intense participation of the students. We shall also examine the teaching strategies conducted by the teacher, emphasizing the presence of visual resources in text production activities, understanding them as literacy practices in the context of science lessons. To examine the effectiveness of these strategies and mediational resources, we shall analyze some exemplars of the students' productions (texts and drawings). We will use as criteria of analysis: speech marks of the opening activity and of the preliminary discussions in the texts produced by the pupils; evidence of changes in the pupils’ initial repertoires about the theme; evidence of connections between the “water in our lives” and “water as a science subject”. The context of the research is a third year grade classroom in a public elementary school in Contagem / MG - Brazil.

This paper will examine how the conflict between the scientific point of view and the students’ everyday point of view can be perceived and overcome by the students with the mediation of a teacher. For this purpose we analyze a science class episode, which was recorded when a teaching sequence on heat and temperature was carried out with students aged 14-15 in a Brazilian secondary school. We used the framework proposed by Mortimer and Scott (2002, 2003) to make visible discursive moves that allows the students to become aware of the conflict between two models they use, in different circumstances, to interpret thermal phenomena: the kinetic particle model and a model of heat and cold exchange. Our analysis demonstrates how the teacher’s interventions guided the students to examine their own ideas through a slow and laborious meaning making process. We were able to identify changes in the teacher’s purposes and type of interventions as the students further developed their ideas. These changes are associated to alternations in the communicative approaches, first dialogic and then mainly authoritative. As in Mortimer and Machado (2000), our data indicate that the process of becoming aware of and overcoming conflicts, in the classroom, depends not only on the choice of suitable teaching strategies, but above all, on the discourse teacher and students build around the experiment.

Se realizó el estudio laparoscópico, histológico y su correlación con el comportamiento de los niveles séricos de alanina aminotransferasa en 160 pacientes seropositivos al virus hepatitis C, que asistieron a la consulta externa del Departamento de Gastroenterología del Hospital “Calixto García” en los años 1996-1998. Al examen laparoscópico se observó que 37,5 % de los casos presentaron hígado normal y también 37,7 % esteatosis hepática, con hepatitis aguda o crónica el resto de los pacientes estudiados (12,5 % en cada caso). En la comparación de los estudios histológicos y los valores séricos se constató que en los pacientes que mostraron hígado normal al estudio morfológico, los valores de alanina aminotransferasa estuvieron igualmente repartidos entre valores normales y oscilantes, en tanto que los casos con hepatitis crónica (mínima, leve y moderada) presentaron mayoritariamente valores oscilantes de esta enzima y en los casos diagnosticados como hepatitis aguda o crónica severa la alanina aminotransferasa alcanzó valores elevados mantenidos en la mayoría de los casos. La combinación del estudio histológico y la determinación de los niveles séricos de alanina aminotransferasa resultó la forma mas efectiva en la valoración clínica de los pacientes estudiadosA laparoscopic and histological study was conducted and its correlation with the behavior of serum levels of alanine aminotransferase was determined in 160 HCV seropositive patients that were seen at the Outopatient Department of Gastroenterology of “Calixto García” Hospital from 1996 to 1998. On the laparoscopic examination, it was observed that 37.5 % of the cases presented normal liver and that 37.7 % had hepatic steatosis. The rest of the studied patients had acute or chronic hepatitis (12.5 % in each case). On comparing the histological studies and the serum values, it was found that among those patients that presented normal liver in the morphological study, the values of alanine aminotransferase were equally distributed into normal and oscillating values; however, most of the cases with chronic hepatitis (minimum, mild and moderate) showed oscillating values of this enzime, and in the cases diagnosed as acute or chronic severe hepatitis, the alanine aminotransferase reached elevated values mantained in most of the cases.The combination of the histological study and the determination of serum values of alanine aminotransferase proved to be the most effective way in the clinical assessment of the studied patients

Se realizó un estudio de la seroprevalencia (anti-VHC), a un grupo de pacientes (2 599), que fueron atendidos por el servicio de consulta externa, e ingresos (salas), en el Hospital Universitario “General Calixto García ” durante los años 1996-1998. Se empleó la tecnología SUMA (sistema ultramicroanalítico) para la determinación de la seropositividad. La seropositividad total encontrada para este período fue de 11,15 %. Se observaron diferencias significativas en los casos seropositivos por años, así como de los pacientes atendidos por consulta externa (62,4 %), y aquellos atendidos por salas (37,6 %). Dentro de las salas que componen el servicio de ingreso, se observó que las de nefrología (40,3 %) y medicina (34,9 %), presentaron los porcentajes más elevados de casos seropositivos. Cuando se analizó su asociación con la infección por los virus de la hepatitis B y VIH, se observó que no existen diferencias significativas con respecto al sexo, notándose mayor asociación en la seroprevalencia entre los virus de la hepatitis B y VHC (37 casos: 12,7 %). Entre los rangos de edades analizados fue el de 41-70 años donde se reportó el mayor número de casos seropositivos y resultó significativamente mayor en el sexo masculino.A seroprevalence study (Anti-HCV) was conducted among a group of patients (2 599) that were seen at the outpatient and inpatient care services at “General Calixto García” Teaching Hospital from 1996 to 1998. The UMAS technology was used to determine the seropositivity. The total seropositivity found for that period was 11.15 %. Significant differences were observed in the seropositive cases by year as well as in the outpatients (62.4 %) and inpatients (37.6 %). The Nephrology Ward (40.3 %) and the Medicine Ward (34.9 %) showed the highest percentages of seropositive cases. When their association with the HBV and HIV infections was analyzed, there were no marked differences as regards sex. A greater association was observed in the seroprevalence between the HBV and the HCV (37 cases: 12.7 %). The highest number of seropositive cases was found in the patients aged 41-70. A significant prevalence of males was observed.

Se realizó un estudio sobre la influencia de la edad y el sexo, así como de las principales vías de trasmisión del virus de la hepatitis C en 160 pacientes seropositivos que asistieron al servicio de gastroenterología del Hospital “Calixto García” durante 1996-1998. Se les hizo una encuesta que recogía, además de los datos personales, antecedentes de intervenciones quirúrgicas, inyecciones, hemoterapia, trasplantes, tatuajes y otras intervenciones que constituyen riesgo para la transmisión del virus. Entre los rangos de edades analizados fue de 41 a 70 años donde se reportó el mayor número de casos seropositivos y resultó significativamente mayor en el sexo masculino. La principal vía de transmisión resultó la polihemoterapia (42,5 %).A study on the influence of age and sex as well as on the main routes of transmission of the hepatitis C virus was carried out among 160 seropositive patients that attended the Gastroenterology Service of “Calixto García” Hospital from 1996 to 1998. Personal data, history of previous operations, injections, hemotherapy, transplantations, tatoos and other interventions that may be a risk for the transmission of the virus, were collected in a survey. Among the analyzed age ranges, that from 4l to 70 showed the highest number of seropositive cases, and there was a marked prevalence of males. Polyhemotherapy proved to be the main route of transmission (45.2 %).

Este ensayo propone una reflexión sobre algunas conclusiones que surgen de un análisis respecto de las acciones públicasemprendidas por los migrantes latinoamericanos en Estados Unidos y migrantes bolivianos en Argentina, durante el primersemestre de 2006, en protesta contra las políticas y acciones antiinmigratorias en esos países.Desde una posición ético-política comprometida con los movimientos sociales y una perspectiva que se enfoca en el análisis delas redes de interacción social que surgen en el contexto de las migraciones -en particular, en estas dos coyunturas de conflicto ymovilización social planteadas- entendiendo a las relaciones comunicativas como un medio de búsqueda de intercomprensión yconsenso para la coordinación de acciones democráticas.En este marco, se ponen en contexto las problemáticas que envuelven a las comunidades migrantes en cuestión y sesistematizan las relaciones sociales y comunicativas establecidas por estos actores en los casos estudiados.En síntesis, se destaca la capacidad de los migrantes para la producción de relaciones sociales, políticas y culturales, generandoinstancias de diálogo intercultural y promoviendo la acción comunicativa para la resolución de desafíos sociales colectivos.

ResumenEl problema del terrorismo y la lucha contra el mismo pasarona ser un tópico frecuente en los titulares de los medios decomunicación a partir de los ataques del 11 de septiembre de2001 en Estados Unidos. Los actos bélicos que sedesencadenaron a partir de aquel acontecimiento –la invasión aAfganistán e Irak y los ataques en Madrid y Londres- no hanhecho más que instalar definitivamente el tema en la opiniónpública y la agenda mediática.La prensa gráfica -superada en estos casos por la inmediatezde la televisión, Internet y la radio- debe recurrir a sucapacidad de profundizar sobre los hechos y proveer al lectordel análisis, la jerarquización de la noticia y un punto de vistaeditorial sobre el acontecimiento.Por su papel en la formación de opinión y porque el géneroeditorial es por excelencia un referente de la posiciónideológica del medio frente a una problemática social, analizarlos artículos editoriales de los diarios Clarín y La Nación puedeconstituir un aporte al conocimiento de cómo los dos mediosargentinos de mayor tirada diaria y alcance nacionalrepresentan el problema del terrorismo.

Prezados leitores, Conforme anunciado pela Professora Silvania Sousa do Nascimento em mensagem aos colaboradores da Revista, passo a assumir, a partir deste número, a função de Editor da Ensaio Pesquisa em Educação em Ciências.

Multiparameter flow cytometry (MFC) has become the preferred method for the lineage assignment and maturational analysis of malignant cells in acute leukemias. Multiparametric immunophenotyping analysis allows the detection of aberrant antigen expression and the analysis of heterogeneity and clonality of malignant cells in leukemias. Our objectives were to analyze the membrane antigen expression and to evaluate if the aberrant phenotypes occurrence in blasts cells of patients with acute leukemia is useful in monitoring the response to the treatment. We have retrospectively analyzed the MFC data of 364 samples sent to our laboratory in a 7 years period. For this purpose we have used a large panel of monoclonal antibodies against lymphoid, myeloid and precursors antigens. From the 364 analyzed samples, 60.2% showed a phenotype compatible with acute myeloid leukemia (AML), 28.8% with B lymphoblastic leukemia (B-LLA), 6.6% with T lymphoblastic leukemia (T-LLA) and 4.4% with rare leukemias. Aberrant phenotypes were found in 86% of the samples. The aberrant phenotypes identified were:1) lineage infidelity AML (54%), B-ALL (40%), T-ALL (29%); 2) absence of antigen expression: AML (21%), B-ALL (35%), T-ALL (70%); 3) altered antigen expression: AML (67%), B-ALL (66%),T-ALL (84%); 4) asynchronous expression: AML (26%), B-ALL (37%) and 5) ectopic phenotype: T-ALL (96%). Multiparameter flow cytometry of acute leukemias allowed identification of aberrant phenotypes in the majority of our patients, that are helpful for monitoring treatment response.

The coexistence of acute myeloid leukemia and chronic lymphocytic leukemia in the same patient is rare. The majority of the cases correspond to patients that developed acute leukemia during the evolutionary course of a chronic lymphatic leukemia following treatment with chemotherapy drugs. We report a case of acute myelomonocytic leukemia concurrent with untreated B-cell chronic lymphocytic leukemia in which the use of flow cytometry analysis with a large panel of monoclonal antibodies, allowed the demonstration of different pathological populations and determine immunophenotyping patterns. Published cases of simultaneous chronic lymphocytic leukemia and acute leukemia are reviewed. The use of multiparametric flow cytometry to differentiate the populations demonstrates the utility of this technology in the diagnosis of these hematological malignancies.