Competitive interactions between species of freshwater snails. I. Laboratory studies: Ib. Comparative studies of the dispersal and the vagility capabilities of Biomphalaria glabrata and Biomphalaria straminea

Experiments reported in the current paper, carried out under semi-field conditions created in the laboratory, have shown that b. straminea has competitive superiority when compared with B. glabrata. The former species has shown higher capabilities of both dispersal and vagility. In addition, B. straminea was able to compete sucessfully with B. glabrata.

Studies on Trypanosoma rangeli Tejera 1920. VII - Its effect on the survival of infected triatomine bugs

The pathological effects of Trypanosoma rangeli on Rhodnius prolixus and R. robustus, and the relation of mortality to infection, were studied under laboratory conditions. Frequent observations revealed that when the first instar nymphs of R. prolixus and R. robustus were infected with T. rangeli, survival of the bugs during the stages of development to the adult stage decreased. This decrease was statistically significant when compared with uninfected control-bugs, indicating that T. rangeli is pathogenic for both species of triatomine. In R. prolixus the most affected nymphal stages were the first, second and fifth instars, where a higher mortality was also observed. In R. robustus a progressive increase of the mortality from the first to fifth instars, was observed. The pathogenicity of T. rangeli as measured by overall mortality was the same in R. prolixus and R. robustus. The possible pathogenic mechanism of T. rangeli in triatomine-bugs and its epidemiological implications, are discussed.

Sport and multiculturalism: an European perspective

Opening conference of the academic course 2005/06 of the Olympic Studies Centre (CEO-UAB), given by Dr. Ian P. Henry, director of the Institute for Sport and Leisure Policy at Loughborough University (United Kingdom). The paper is structured around addressing three themes: how concepts of multiculturalism or interculturalism, nationality and citizenship can be linked to sports policy; how we can conceptualise (and therefore evaluate) the benefits which might be claimed to accrue from sporting projects in terms of multicultural or integration policy; and finally the issue of gender, multiculturalism and sports policy.

Jocs olímpics i educació: l'esport i l'escola de Barcelona'92

Aquest text és la transcripció de la intervenció de la Sra. M. Antònia Cardona, professora de Pedagogia de la Universitat Autònoma de Barcelona, en el Curs Universitari sobre Olimpisme que va organitzar el Centre d’Estudis Olímpics (CEO-UAB), el mes de febrer de 1991. En ell es tracta el tema de l'educació en els Jocs olímpics a l'escola.

Joves esportistes: la passió per l’esport

Aquest text és la ponència que va presentar l'autora com a conferenciant convidada al Segon Congrés Mundial de Ciències de l'Esport que es va celebrar a Barcelona l'octubre del 1991. També forma part de la col·lecció de documents de treball del Centre d'Estudis Olímpics.

Young athletes: passion for sport

The following text corresponds with the lecture that the author presented as "invited lecturer" at the Second World Conference on Sport Sciences held in Barcelona on October, 1991. It is also part of the working papers collection from the Olympic Studies Centre.

Barcelona'92: los Juegos de la comunicación

Este artículo es una síntesis de algunas partes del libro del autor de &i&Juegos Olímpicos y Comunicación&/i&, publicado por FUNDESCO. La investigación correspondiente se pudo realizar en el Centre d'Estudis Olímpics de la Universitat Autònoma de Barcelona con el apoyo de la C.I.C.Y.T. (Centro de Investigación Científica y Tecnológica), en el Plan Nacional de Investigación (Área del Deporte). Esta versión fue preparada para la revista &i&Telos&/i& de Fundesco, en enero de 1992.

Studies on Trypanosoma rangeli Tejera, 1920: IX. Course of infection in different stages of Rhodnius prolixus

Frequent individual observations od different stages of Rhodnius prolixus exposed to Trypanosoma rangeli, revealed a higher susceptibility to infection in the bugs exposed during the two first instars. The mortality rate in infected bugs was significantly higher than in controls, indicating that the parasite was responsible for the majority of deaths. An analysis of the mortality distribution, per instar, is presented. Statistical analysis of deaths among the different infected instars, showed that T. rangeli produces its pathological effect in any stage of R. prolixus independently of its susceptibility to the parasite. The survival to adult decreased in all the infected instar bugs. A significant longer time to reach the adult stage was observed in the infected bugs when compared with controls, excepting for specimens exposed in the third instar. The epidemiological significance of the present results is discussed.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 2 - Attempts to upgrade the reliability and the efficacy of xenodiagnosis in chronic Chagas' disease

In order to upgrade the reliability of xenodiagnosis, attention has been directed towards population dynamics of the parasite, with particular interest for the following factors: 1. Parasite density which by itself is not a research objective, but by giving an accurate portrayal of parasite development and multiplication, has been incorporated in screening of bugs for xenodiagnosis. 2. On the assumption that food availability might increase parasite density, bugs from xenodiagnosis have been refed at biweekly intervals on chicken blood. 3. Infectivity rates and positives harbouring large parasite yields were based on gut infections, in which the parasite population comprised of all developmental forms was more abundant and easier to detect than in fecal infections, thus minimizing the probability of recording false negatives. 4. Since parasite density, low in the first 15 days of infection, increases rapidly in the following 30 days, the interval of 45 days has been adopted for routine examination of bugs from xenodiagnosis. By following the enumerated measures, all aiming to reduce false negative cases, we are getting closer to a reliable xenodiagnostic procedure. Upgrading the efficacy of xenodiagnosis is also dependent on the xenodiagnostic agent. Of 9 investigated vector species, Panstrongylus megistus deserves top priority as a xenodiagnostic agent. Its extraordinary capability to support fast development and vigorous multiplication of the few parasites, ingested from the host with chronic Chagas' disease, has been revealed by the strikingly close infectivity rates of 91.2% vs. 96.4% among bugs engorged from the same host in the chronic and acute phase of the disease respectively (Table V), the latter comporting an estimated number of 12.3 x 10[raised to the power of 3] parasites in the circulation at the time of xenodiagnosis, as reported previously by the authors (1982).

Evaluation of the rabbit as a model for chagas' disease: I. Parasitological studies

In order to investigate the value of the rabbit as an experimental model for Chagas' disease, 72 animals have been inoculated by intraperitoneal and conjunctival route with bloodstream forms, vector-derived metacyclic trypomastigotes and tissue culture trypomastigotes of Trypanosoma cruzi strains Y, CL and Ernane. In 95.6% of the animals trypomastigotes had been detected at the early stages of infection by fresh blood examination. The course of parasitemia at the acute phase was strongly influenced by the parasite strain and route of inoculation. At the chronic phase parasites had been recovered by xenodiagnosis and/or hemoculture in 40% of the examined animals. The xenodiagnosis studies have shown selective interactions between the T. cruzi strains and the four species of vectors used, inducing significant variability in the results. The data herein present are consistent with the parasitological requirements established for a suitable model for chronic Chagas' disease.