The similarity degree of chemical, ionizing radiation, and combined treatments of chemical plus ionizing radiation in their capacity to induce reciprocal translocations was analyzed by means of multivariate analysis techniques on mice germ cells. The effect of three different doses of gamma rays, four doses of X-rays, and different doses of adriamycin, mitomycin C, thio-tepa and bleomycin, as well as the combined treatments of two doses of gamma rays with adriamycin, mitomycin c and thio-tepa, were studied. Our objectives were: 1) to determine the degree of similarity between the effects of chemicals and ionizing radiations in relation to the induction of reciprocal translocations in germ cells; and 2) to test the conclusions reached by previous authors using only single treatments. Data were arranged in a basic data matrix, analyzed by cluster analysis and ordination methods. The results showed that: 1) as single and combined treatments were grouped together, there was not a specific pattern of chromosomal aberration induced for physical and chemical agents; 2) the association degree between single treatments was similar to that obtained by previous authors, although in this analysis combined treatments were added; and 3) some combined treatments using 9 Gy and drugs appear in different groups, although we expected that all the combined treatments of drugs with 9 Gy were grouped together. As a working hypothesis, we propose that the variability observed when the different treatments were compared could be dose dependent.

Por medio de técnicas de análisis multivariado se determinó el grado de similitud de distintos agentes químicos y radiaciones ionizantes en la inducción de translocaciones recíprocas en células germinales de ratón. Se comparó el efecto de tres diferentes dosis de rayos gamma, cuatro dosis de rayos X y distintas dosis de adriamicina, mitomicina C, thio-tepa y bleomicina, así como también los tratamientos combinados con dos dosis de rayos gamma con adriamicina, mitomicina C y tio-tepa, y cuatro de rayos X. Los objetivos del presente trabajo fueron: 1) determinar el grado de similitud entre los tipos de translocaciones recíprocas inducidas por los agentes químicos y las radiaciones ionizantes; y 2) comparar estos resultados con los obtenidos previamente por otros autores al comparar los tratamientos individuales. Para la comparación de los diferentes tratamientos se elaboró una matriz de datos analizada por medio de técnicas de agrupamiento y de ordenación. Los resultados revelaron que: 1) los tratamientos simples y combinados se agruparon juntos, indicando la falta de un patrón específico de aberraciones inducido; 2) el grado de asociación entre los tratamientos simples no se vio modificado, a pesar de la incorporación de los tratamientos combinados; y 3) algunos tratamientos combinados con 9 Gy y las diferentes drogas se asociaron con otros tratamientos, en lugar de asociarse juntos como era de esperarse teniendo en cuenta los resultados obtenidos por otros autores. Como hipótesis de trabajo, proponemos que la variabilidad observada en los diferentes tratamientos podría ser dependiente de la dosis empleada.

National scientific systems often require the use of techniques provided by Bibliometrics in order to measure the production in science and technology. A set of indicators built for that purpose make easier the mathematical and statistical analysis of bibliographic data included in science-and-tech publications. Free communications and lectures presented to congresses and scientific meetings may be one of the raw materials for them. SAG has annually organized in Argentina the national meeting of Genetics for more than 40 years, but for the present analysis, only data found in books of abstracts from 1984 to 2009 have been reviewed. The number of full conferences, symposia, and communications in posters were recorded and tabulated. We also provide here a classification of invited lecturers according to country of origin, and of the free communications according to sessions where they were presented, comparing the production among quinquennial periods. Sustained production along this period of time - and even important growing of several sections of the congress - are some of the results observed after the analysis. We also find remarkable the allocation of some room for the discussions on teaching in this type of meeting, because they are the very first contact of young students with their future profession. We conclude that SAG honors its commitment to promote the generation and spreading of scientific knowledge through its Genetic Congresses, the continuity and growth of which clearly indicating that there is a need for their existence.

Una de las áreas de la Bibliometría que recibe más demanda del sistema científico nacional es la medición de su propia producción. Un conjunto de indicadores construidos para tal fin permite realizar análisis estadísticos y matemáticos de los datos bibliográficos incluidos en las publicaciones de ciencia y tecnología. Las comunicaciones y presentaciones en congresos y reuniones científicas constituyen uno de los insumos para llevar a cabo esta tarea. En sus 41 años de trayectoria la SAG ha organizado anualmente Congresos en distintas partes del país, pero para la realización de este trabajo sólo se consideraron publicaciones conteniendo resúmenes de los congresos de la SAG desde 1984 hasta 2009. Se obtuvieron y procesaron datos desagregados en tablas relativas a la cantidad de conferencias, simposios-mesas redondas y paneles, o comunicaciones libres, éstas últimas, agrupadas por sección. Las conferencias y los simposios-mesas redondas, se agruparon por quinquenio, y por país de origen del presentador. Algunos de los resultados que se desprenden de este estudio son: que se observa una producción sostenida en el tiempo, que incluso muchas secciones están en crecimiento, y que debe destacarse el haber dado un espacio a la docencia (aunque con escasa participación), porque ella es importante como primer contacto de los estudiantes en su camino de formación como profesionales e investigadores. Hoy debemos reconocer que la SAG es una sociedad que cumple con sus propósitos de promover, divulgar y generar conocimiento nuevo a través de sus congresos, cuya continuidad y creciente participación, muestra claramente la necesidad de su existencia.

Data from five protein-coding loci related to dairy production were used to study the genetic diversity and population structure of Argentine and Bolivian Creole cattle breeds. Genomic DNA was extracted from blood samples of six Creole cattle breeds: Argentine (n = 230), Patagonian (n = 25); "Saavedreño" (n = 140), "Chaqueño Boliviano" (n = 30), "Yacumeño" (n = 27), and "Chusco" (n = 11). kappa-casein, beta-lactoglobulin, growth hormone and prolactin were measured by PCR-RFLP, while alphaS1-casein was typed by PCR-ASO. The results are discussed, focusing on: historical origin, recent differentiation and selection events, Zebu gene introgression, and population structure. This work shows that: (i) For the studied genes, the observed gene frequency profiles of Argentine and Bolivian Creole cattle breeds were close to the data reported for Iberian breeds and for other South-American Creole cattle breeds which are historically related; (ii) although Zebu gene introgression has been reported at the studied loci, these breeds seem to be far from the Zebu gene frequency profiles; and (iii) the Argentine and Bolivian Creole cattle showed significant levels of subdivision, but each population has maintained its degree of genetic variability.

Tripulantes de vôos internacionais estão expostos a radiações ionizantes originadas da colisão de partículas cósmicas com átomos da atmosfera. O grau de exposição varia de acordo com a altitude, latitude e a atividade solar. A análise citogenética mostrou um aumento significante no número de cromossomos dicêntricos (14,5 ± 0,76 por 1000 células) em membros ativos da tripulação, assim como em tripulantes aposentados (7,5 ± 0,59 por 1000 células), em relação a controles (0,5 ± 0,05 por 1000 células). Em tripulantes em atividade a freqüência de cromossomos em anel também aumentou (2,0 ± 0,31 por 1000 células), mas isso não ocorreu em tripulantes aposentados. Estas observações sugerem um alto grau de exposição do pessoal de bordo a radiações ionizantes. Conseqüentemente, o acompanhamento citogenético de tripulantes de aviões cronicamente expostos a baixas doses de radiação é um campo aberto para futuras investigações.

Air crew members of international flights are exposed to ionizing radiations originated from the collision of cosmic particles with atoms of the atmosphere. The degree of exposure varies according to the altitude, latitude, and solar activity. The cytogenetical analysis showed a significant increase of dicentric chromosomes (14.5 ± 0.76 per 1,000 cells) in active air crew members as well as in retired air crew members (7.5 ± 0.59 per 1,000 cells) in relation to controls (0.5 ± 0.05 per 1,000 cells). In active members the frequency of ring chromosomes was also increased (2.0 ± 0.31 per 1,000 cells) but not found in retired crew members. These observations suggest a high degree of exposure to ionizing radiations of air crew personnel. Consequently, the cytogenetic follow-up of air crews chronically exposed to low radiation doses is an open field for further investigations.

O grau de similaridade entre agentes químicos e físicos quanto a sua capacidade de induzir translocações recíprocas foi analisado por meio de técnicas de análise multivariada. Analisou-se o efeito de três diferentes doses de raios gama, quatro doses de raios-X e diferentes doses de adriamicina, mitomicina C, tio-tepa e bleomicina. Os dados foram arranjados em uma matriz básica por 2 métodos: análise de cluster e ordenação. Dois grupos principais foram encontrados, um incluindo doses de 9 e 10 Gy e o outro incluindo as outras doses de radiação ionizante e as substâncias químicas. Vários subgrupos foram encontrados dentro do segundo grupo. Usando dados de presença/ausência, não se encontrou um padrão específico de indução de danos cromossômicos para os agentes físicos e químicos. O aumento na freqüência de translocação recíproca observado com 9 e 10 Gy deveu-se a um aumento no tipo de configurações multivalentes. Esta variabilidade pode ser dependente da dose. Igualmente, a similaridade observada no segundo grupo entre as substâncias químicas e as doses menores de radiação ionizante também pode ser dependente da dose.

The degree of similarity between chemical and physical agents in their capacity to induce reciprocal translocations was analyzed by means of multivariate analysis techniques. The effect of three different doses of gamma rays, four doses of X-rays and different doses of adriamycin, mitomycin C, thio-tepa and bleomycin was analyzed. Data were arranged in a basic matrix by two methods: cluster analysis and ordination. Two main groups were found, one including doses of 9 and 10 Gy and the other including the remaining lower doses of ionizing radiation and the other chemicals. Various subgroups were found within the second group. Accordingly, using presence/absence data there was not a specific pattern of chromosomal damage induction for physical and chemical agents. The increase in the frequencies of reciprocal translocation observed with 9 and 10 Gy was due to an increase in the kind of multivalent configurations. This variability could be dose dependent. Likewise, the similarity observed in the second group between the chemicals and the lower doses of ionizing radiation could also be dose dependent.