Aprender a observar

En la etapa de Enseñanza Primaria, las actividades curriculares deben proporcionar al alumno los instrumentos básicos para el aprendizaje de nuevos conocimientos. El procedimiento de observación científica es uno de los instrumentos más valiosos para proporcionar información. A continuación exponemos nuestra experiencia en la enseñanza del procedimiento de observación a niños y niñas de 6 a 12 años. Presentamos una propuesta para programar este procedimiento, con una pauta concreta de trabajo y una secuencia de actividades para los tres ciclos de la Enseñanza Primaria

A dimensão dialógica e a prática educativa: reflexões a partir de Paulo Freire e Humberto Maturana

Ao observarmos o cotidiano nas escolas é possível constatar que nem sempre se reconhece e se valoriza a diferença e a singularidade que caracteriza cada sujeito envolvido, pois ocorrem situações de negação mútua entre alunos, entre alunos e professores e entre outras relações do espaço escolar que ferem a dignidade humana. Uma alternativa a essa realidade é a promoção de vivências dialógicas. Nesse sentido, objetivamos com este trabalho: Refletir sobre as contribuições teórico-conceituais desenvolvidas por Paulo Freire e por Humberto Maturana acerca da vivência do diálogo, suas possibilidades e impasses nas relações sociais e na relação educativa; e identificar, a partir de um estudo de caso realizado em uma escola da Rede Pública Estadual, as concepções dos educadores sobre a prática dialógica no cotidiano escolar. Para Freire, o diálogo é o encontro e a partilha de concepções de A com B e não de A sobre B ou vice versa, sendo que nesta relação é importante que ambos se disponham à escuta mútua reconhecendo a diversidade de concepções que estimula a curiosidade epistemológica. Para Maturana, a partir da Biologia, cada ser vivo se constitui como uma organização autopoiética, ou seja, tem a tarefa de produzir-se a si próprio, estabelecendo relações com o meio. Na existência humana, essas interações com o meio e entre os humanos se estabelecem num entrelaçamento de emoções e ações, que ele nomeia de conversação. A partir das reflexões pelos autores e o diálogo estabelecido com sujeitos da pesquisa destacamos: 1) As relações sociais se mantêm quando há aceitação do outro como legítimo outro na convivência, o que implica a aceitação de si próprio; 2) O diálogo cria um clima de aceitação para com a história e a diferença do outro, o que favorece relações de partilha de ideias e de releitura coletiva do mundo. Tanto Maturana e Freire, quanto os entrevistados valorizam o ...

La educación estatal en Argentina durante el peronismo : El caso de la provincia de Buenos Aires (1946-1955)

El objetivo de este trabajo es analizar el proceso de formulación y desarrollo de las políticas educativas durante el peronismo, teniendo en cuenta en qué medida intervinieron los actores estatales y no estatales. Nuestro ámbito de observación empírica, la provincia de Buenos Aires, nos permite dialogar con los trabajos efectuados desde un enfoque nacional. Nos interesa realizar un análisis histórico de la interacción entre estado y la sociedad, que tenga en cuenta no solo a los ejecutores sino a sus destinatarios. Se considera que los complejos procesos que rodearon la formulación de las políticas educativas durante esta etapa, se generaron en un contexto en que el gobierno provincial debió adecuar sus acciones a las presiones y demandadas no sólo de diversos actores externos, sino también de las facciones que integraban su trama política interna

La educación estatal en Argentina durante el peronismo : El caso de la provincia de Buenos Aires (1946-1955)

El objetivo de este trabajo es analizar el proceso de formulación y desarrollo de las políticas educativas durante el peronismo, teniendo en cuenta en qué medida intervinieron los actores estatales y no estatales. Nuestro ámbito de observación empírica, la provincia de Buenos Aires, nos permite dialogar con los trabajos efectuados desde un enfoque nacional. Nos interesa realizar un análisis histórico de la interacción entre estado y la sociedad, que tenga en cuenta no solo a los ejecutores sino a sus destinatarios. Se considera que los complejos procesos que rodearon la formulación de las políticas educativas durante esta etapa, se generaron en un contexto en que el gobierno provincial debió adecuar sus acciones a las presiones y demandadas no sólo de diversos actores externos, sino también de las facciones que integraban su trama política interna

La educación estatal en Argentina durante el peronismo : El caso de la provincia de Buenos Aires (1946-1955)

El objetivo de este trabajo es analizar el proceso de formulación y desarrollo de las políticas educativas durante el peronismo, teniendo en cuenta en qué medida intervinieron los actores estatales y no estatales. Nuestro ámbito de observación empírica, la provincia de Buenos Aires, nos permite dialogar con los trabajos efectuados desde un enfoque nacional. Nos interesa realizar un análisis histórico de la interacción entre estado y la sociedad, que tenga en cuenta no solo a los ejecutores sino a sus destinatarios. Se considera que los complejos procesos que rodearon la formulación de las políticas educativas durante esta etapa, se generaron en un contexto en que el gobierno provincial debió adecuar sus acciones a las presiones y demandadas no sólo de diversos actores externos, sino también de las facciones que integraban su trama política interna

Spatial analysis of the tuberculosis treatment dropout, Buenos Aires, Argentina

OBJECTIVE Identify spatial distribution patterns of the proportion of nonadherence to tuberculosis treatment and its associated factors.METHODS We conducted an ecological study based on secondary and primary data from municipalities of the metropolitan area of Buenos Aires, Argentina. An exploratory analysis of the characteristics of the area and the distributions of the cases included in the sample (proportion of nonadherence) was also carried out along with a multifactor analysis by linear regression. The variables related to the characteristics of the population, residences and families were analyzed.RESULTS Areas with higher proportion of the population without social security benefits (p = 0.007) and of households with unsatisfied basic needs had a higher risk of nonadherence (p = 0.032). In addition, the proportion of nonadherence was higher in areas with the highest proportion of households with no public transportation within 300 meters (p = 0.070).CONCLUSIONS We found a risk area for the nonadherence to treatment characterized by a population living in poverty, with precarious jobs and difficult access to public transportation.

Winter survival of immature instars of Mansonia indubitans Dyar & Shannon and Mansonia titillans Walker (Diptera: Culicidae), in Buenos Aires, Argentina

We conducted a whole year research on the ecology of Mansonia indubitans and Ma. titillans in Macáes Pond, Costanera Sur Reserve, Buenos Aires, Argentina. The usage of different floating plants by immature instars and their overwintering was analized. The percentage of usage of the available floating macrophytes (Pistia, Limnobium, and Salvinia) by the larvae and pupae was studied. Also, we defined positivity (P+) as the percentage of plants with immature instars for each plant genus on a monthly basis. Ma. immature instars were captured throughout the year and Pistia was the resource most commonly exploited by the mosquitoes. The percentage of fourth-instar larvae and pupae on Pistia roots with respect to total immature instars captured was assessed on a monthly and seasonal basis. The proportion of fourth-instar larvae and pupae from both species of Mansonia on water lettuce roots, showed significant differences between months and seasons. Our results suggest that the populations of Ma. indubitans and Ma. titillans in Macáes Pond, survive during winter mainly as fourth-instar larvae.

What is BRT? Rolling out the Metrobús in Buenos Aires, Argentina

This issue of the FAL bulletin describes the Metrobús line which recently started operating in Buenos Aires and provides a preliminary analysis of its performance.

Control of Aedes aegypti with temephos in a Buenos Aires cemetery, Argentina

The efficacy of a larvicide, temephos, for controlling Ae. aegypti was evaluated in a cemetery in Buenos Aires, Argentina. Breeding sites decreased from 18.4% in the first study period (Nov 1998 to May 1999, without temephos) to 2.2% in the second period (Nov 1999 to May 2000, two applications), and to 0.05% in the third one (Nov 2000 to May 2001, five applications). Ovitraps with eggs decreased from 17% in the first period to 5.8% in the second period, and to 2.9% in the third one. Results suggest that, in Buenos Aires, Ae. aegypti populations are highly susceptible to temephos. It is recommended to limit the use of temephos to prevent potential epidemics rather than for routine control.

Inventories and concentration profiles of 137Cs in undisturbed soils in the northeast of Buenos Aires Province, Argentina

Inventories and vertical distribution of (137)Cs were determined in La Plata region undisturbed soils, Argentina. A mean inventory value of 891 ± 220 Bq/m(2) was established, which is compatible with the values expected from atmospheric weapon tests fallout. The study was complemented with pH, organic carbon fraction, texture and mineralogical soil analyses. Putting together Southern Hemisphere (137)Cs inventory data, it is possible to correlate these data with the mean annual precipitations. The large differences in (137)Cs concentration profiles were attributed to soil properties, especially the clay content and the pH values. A convection-dispersion model with irreversible retention was used to fit the activity concentration profiles. The obtained effective diffusion coefficient and effective convection velocity parameters values were in the range from 0.2 cm(2)/y to 0.4 cm(2)/y and from 0.23 cm/y to 0.43 cm/y, respectively. These data are in agreement with values reported in literature. In general, with the growth of clay content in the soil, there was an increase in the transfer rate from free to bound state. Finally, the highest transfer rate from free to bound state was obtained for soil pH value equal to 8.

Hydatidosis cases in one of Mar del Plata City hospitals, Buenos Aires, Argentina

Hydatidosis is a zoonosis of worldwide distribution produced mainly by the metacestode Echinococcus granulosus. In Argentina, its distribution reaches endemic levels. The aims of this investigation were to contribute to the knowledge of hydatidosis in the southeast of Buenos Aires province, study its evolution at the Interzonal General Hospital for Acute Diseases between 1992 and 2002 and discuss its importance. Clinical records of operated and/or diagnosed patients were reviewed with regard to this disease. One hundred and twenty cases were analyzed. Among the patients, 56.7% were women. The average age was 42.2+16.8 years. 68.3% lived in urban areas. In 75% of the cases, ultrasonography was used. Hepatic location was most frequently seen. 89.2% received surgical treatment. Albendazole was used for 19 patients. The mean length of hospital stay was 16 days. We conclude that this zoonosis is a disease that generates high costs in medical care and for this reason more epidemiological studies should be carried out and public health authorities should implement control and prevention strategies in the region.

Some Aspects of the Development of Lobatostoma jungwirthi Kritscher, 1974 (Aspidogastrea) in Snails and Cichlid Fishes from Buenos Aires, Argentina

The molluscs Heleobia castellanosae and Ampullaria canaliculata and cichlid fishes were collected from an artificial pond at Tres de Febrero Park (Buenos Aires city), between June 1994 and May 1995. One hundred and eighty of 2,467 H. castellanosae examined were infected with pre-adults of Lobatostoma jungwirthi, 112 of them in concurrent infections with digeneans. L. jungwirthi was significantly more prevalent in larger snails, especially those infected with larval digeneans, but the prevalence of infection did not fluctuate significantly throughout the year. A. canaliculata and cichlids smaller than 10 cm were not infected, but larger Cichlasoma facetum harboured adults of L. jungwirthi in their intestines. Experimental infections of C. facetum and Gymnogeophagus meridionalis with pre-adult aspidogastreans obtained from H. castellanosae were successful. The development of L. jungwirthi in the snail host involves five arbitrary growth phases. Its life-cycle is heteroxenous, similar to that described for L. manteri, with H. castellanosae as the intermediate host and cichlid fishes as the definitive host in this pond.

Triatoma infestans in Greater Buenos Aires, Argentina

The Health Administration Agencies of many municipalities in Greater Buenos Aires (GBA) receive frequent reports on triatomines in houses. The aim of this work was to identify and describe the dispersal foci of Triatoma infestans in an urban neighborhood of GBA, and contribute to the knowledge of the epidemiological situation in the region. In June 1998, potentially infested places were entomologically evaluated. T. infestans was only detected in a hen building for egg production, which housed approximately 6,000 birds. A total of 2,930 insects were collected. Density was about 9 triatomines/m². The proportions of fifth instar nymphs and adults were significantly higher than those of the other stages (p<0.001). The number of triatomines collected largely exceeded the highest domestic infestation found in one house from rural endemic areas of Argentina. Though triatomines were negative for Trypanosoma cruzi, they could acquire the parasite by coming in contact with infected people living in GBA. Besides, the numerous and widely distributed places housing hens and chickens, would favor the settlement of the vector. Together, both facts may constitute a risk of parasitic vectorial transmission. It is recommended to intensify systematic activities of vector search and case detection in GBA.

Suitability of containers from different sources as breeding sites of Aedes aegypti (L.) in a cemetery of Buenos Aires City, Argentina

Cemeteries are ideal urban areas to study the importance of different types of containers as breeding sites of Aedes aegypti (L.). In the present study, the suitability of plastic, glass, ceramic and metal containers was evaluated in four patches within a cemetery of Buenos Aires City, Argentina. Between October 1998 and May 2000, we found 215 breeding sites of Ae. aegypti out of 13,022 water-filled containers examined. In two patches containing microenvironments sheltered from the sun, the use of the different types of containers was proportional to the offer (correlation coefficient = 0.99, P < 0.05 in both cases). In the remaining patches, plastic and metal containers were the most and less frequent breeding sites, respectively (P < 0.001 in both cases). The number of immatures per breeding site (median = 4.5) did not show significant differences among the four types of containers examined (H3, 215 = 1.216, P = 0.749). Differences found in patches from a same cemetery suggest that different microenvironmental conditions affect the suitability of each type of container for Ae. aegypti breeding. Plastic containers appeared as key breeding sites that should be removed to reduce the Ae. aegypti population in the study area.

Mortality in immatures of the floodwater mosquito Ochlerotatus albifasciatus (Diptera: Culicidae) and effects of parasitism by Strelkovimermis spiculatus (Nematoda: Mermithidae) in Buenos Aires Province, Argentina

Life tables were constructed for six cohorts of immature stages of the floodwater mosquito Ochlerotatus albifasciatus (Macquart) in a park in Buenos Aires, highlighting the mortality attributable to the parasitic nematode, Strelkovimermis spiculatus Poinar & Camino. Two cohorts were selected to compare parasite incidence in all mosquito stages when low and high parasitism occurred. Development time of Oc. albifasciatus from first instar to adult was 7.7-10 days in the spring, 6 days in the summer, and 10.9-21.9 days in the fall. Survival was estimated as 0-1.4% in the spring, 2% in the summer and 0.2-4.4% in the fall. The highest "K" value (Killing power) occurred during a fall cohort when prevalence of the parasite was 86.9%, and the lowest in a spring cohort. Parasitism occurred during all seasons, but S. spiculatus persisted to adult only in the summer and fall, when adult mosquitoes developed from parasitized third and fourth instars larvae. The abundance of S. spiculatus differed between old and young larvae only when parasite prevalence was the highest. Although pupae and adults of Oc. albifasciatus were parasitized, no pupal mortality attributable to parasitism was recorded. The proportion of parasitized adults ranged from 14.2% and 5.7% in the two cohorts compared. Pupal wet weight and adult wing lengths did not differ between parasitized and unparasitized individuals.