20 research outputs found
Criação em larga escala de Biomphalaria tenagophila
An efficient method for breeding Biomphalaria tenagophila (Taim lineage/RS) was developed over a 5-year-period (2005-2010). Special facilities were provided which consisted of four cement tanks (9.4 x 0.6 x 0.22 m), with their bottom covered with a layer of sterilized red earth and calcium carbonate. Standard measures were adopted, as follows: each tank should contain an average of 3000 specimens, and would be provided with a daily ration of 35,000 mg complemented with lettuce. A green-house effect heating system was developed which constituted of movable dark canvas covers, which allowed the temperature to be controlled between 20 - 24 ºC. This system was essential, especially during the coldest months of the year. Approximately 27,000 specimens with a diameter of 12 mm or more were produced during a 14-month-period. The mortality rates of the newly-hatched and adult snails were 77% and 37%, respectively. The follow-up of the development system related to 310 specimens of B. tenagophila demonstrated that 70-day-old snails reached an average of 17.0 ± 0.9 mm diameter. The mortality rates and the development performance of B. tenagophila snails can be considered as highly satisfactory, when compared with other results in literature related to works carried out with different species of the genus Biomphalaria, under controlled laboratory conditions.Foi desenvolvido um método eficiente de criação em larga escala de Biomphalaria tenagophila (linhagem Taim/RS) durante o perÃodo de 2005-2010. Foi concebida uma instalação que consiste de quatro tanques de alvenaria (9,4 x 0,6 x 0,22) com fundos recobertos por uma mistura constituÃda de terra vermelha esterilizada e carbonato de cálcio. Foi padronizado que cada tanque de criação conteria em média 3.000 exemplares e receberia diariamente 35.000 mg de ração e alface como complemento. O desenvolvimento de um sistema de aquecimento por efeito estufa constituÃdo de lonas escuras móveis permitiu controlar a temperatura entre 20 a 24 ºC, sistema essencial principalmente nos meses mais frios. Durante o perÃodo de 14 meses foram produzidos aproximadamente 27.000 exemplares com diâmetros superiores a 12 mm. As taxas de mortalidade dos caramujos recém-eclodidos e adultos foram de 77% e 37%, respectivamente. O acompanhamento do ritmo de crescimento de 310 B. tenagophila demonstrou que caramujos com 70 dias de idade alcançaram em média 17,0 ± 0,9 mm de diâmetro. As taxas de mortalidade e o desempenho de crescimento de caramujos do gênero B. tenagophila podem ser considerados altamente satisfatórios, comparando-se com os resultados da literatura realizados com espécies do gênero Biomphalaria em condições controladas de laboratório
Evolution from AGB to planetary nebula in the MSX survey
We investigate the evolution of oxygen- and carbon-rich AGB stars, post-AGB
objects, and planetary nebulae using data collected mainly from the MSX
catalogue. Magnitudes and colour indices are compared with those calculated
from a grid of synthetic spectra that describe the post-AGB evolution beginning
at the onset of the superwind. We find that carbon stars and OH/IR objects form
two distinct sequences in the (K-[8.3])x([8.3]-[14.7]) MSX colour diagram.
OH/IR objects are distributed in two groups: the bluest ones are crowded near
[14.7]-[21.3]=1 and [8.3]-[14.7]=2, and a second, redder group is spread over a
large area in the diagram, where post-AGB objects and planetary nebulae are
also found. High mass-loss rate OH/IR objects, post-AGB stars, and planetary
nebulae share the same region in the (K-[8.3])x([8.3]-[14.7]) and
[14.7]-[21.3]x([8.3]-[14.7]) colour-colour diagrams. This region in the diagram
is clearly separated from a bluer one where most OH/IR stars are found. We use
a grid of models of post-AGB evolution, which are compared with the data. The
gap in the colour-colour diagrams is interpreted as the result of the rapid
trajectory in the diagram of the stars that have just left the AGB.Comment: 11 pages, 5 postscript figures, LaTeX, uses Astronomy and
Astrophysics macro aa.cls, graphicx package, to be published in Astronomy and
Astrophysics, Also available at: http://www.astro.iag.usp.br/~macie
Search for Kaluza-Klein Graviton Emission in Collisions at TeV using the Missing Energy Signature
We report on a search for direct Kaluza-Klein graviton production in a data
sample of 84 of \ppb collisions at = 1.8 TeV, recorded
by the Collider Detector at Fermilab. We investigate the final state of large
missing transverse energy and one or two high energy jets. We compare the data
with the predictions from a -dimensional Kaluza-Klein scenario in which
gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for
=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71
TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure
Reduced Susceptibility of a Biomphalaria tenagophila Population to Schistosoma mansoni after Introducing the Resistant Taim/RS Strain of B. tenagophila into Herivelton Martins Stream
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Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Esquistossomose. Belo Horizonte, MG, BrazilUniversidade Federal de Juiz de Fora. Instituto de Ciencias Biologicas. Laboratorio de Parasitologia. Sao Pedro, MG, BrazilChacara Santa Ines. Bananal, SP, BrazilUniversidade Federal de Minas Gerais. Instituto de Ciencias Biologicas. Laboratório de Esquistossomose. Belo Horizonte, MG, BrazilSuperintendencia de Controle de Endemias. Sao Paulo, SP, Brazil,Fundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Helmintologia e Malacologia Medica. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Moluscário Dr. Lobato Paraense. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisa Rene Rachou. Laboratório de Esquistossomose. Belo Horizonte, MG, BrazilStudies performed in the last 30 years demonstrated that a strain of B. tenagophila from the Taim Biological Reserve is completely resistant to Schistosoma mansoni infection. This resistance to parasite infection is a dominant characteristic during crossbreeding with susceptible B. tenagophila strains. These experiments also identified a 350 bp molecular marker that is exclusive to the Taim strain and does not occur in other geographic strains of this snail species. The Taim strain (Taim/RS) of Biomphalaria tenagophila was bred on a large scale, physically marked and introduced into a stream in which previous malacological analyses had revealed the presence of only parasite-susceptible B. tenagophila. Samples of offspring captured 4, 11 and 14 months after the introduction of the Taim strain were examined, and the susceptibility of the snails to S. mansoni infection dropped from 38.6–26.5% to 2.1% during the 14 months after the introduction of the Taim snail strain. A significant correlation was also observed between the absence of infection and the identification of the Taim molecular marker. These results demonstrate that the genetic marker from the Taim strain was successfully introduced into the wild snail population. In addition, a significant relationship exists between the marker and resistance to infection
Criação em larga escala de Biomphalaria tenagophila
An efficient method for breeding Biomphalaria tenagophila (Taim lineage/RS) was developed over a 5-year-period (2005-2010). Special facilities were provided which consisted of four cement tanks (9.4 x 0.6 x 0.22 m), with their bottom covered with a layer of sterilized red earth and calcium carbonate. Standard measures were adopted, as follows: each tank should contain an average of 3000 specimens, and would be provided with a daily ration of 35,000 mg complemented with lettuce. A green-house effect heating system was developed which constituted of movable dark canvas covers, which allowed the temperature to be controlled between 20 - 24 ºC. This system was essential, especially during the coldest months of the year. Approximately 27,000 specimens with a diameter of 12 mm or more were produced during a 14-month-period. The mortality rates of the newly-hatched and adult snails were 77% and 37%, respectively. The follow-up of the development system related to 310 specimens of B. tenagophila demonstrated that 70-day-old snails reached an average of 17.0 ± 0.9 mm diameter. The mortality rates and the development performance of B. tenagophila snails can be considered as highly satisfactory, when compared with other results in literature related to works carried out with different species of the genus Biomphalaria, under controlled laboratory conditions.Foi desenvolvido um método eficiente de criação em larga escala de Biomphalaria tenagophila (linhagem Taim/RS) durante o perÃodo de 2005-2010. Foi concebida uma instalação que consiste de quatro tanques de alvenaria (9,4 x 0,6 x 0,22) com fundos recobertos por uma mistura constituÃda de terra vermelha esterilizada e carbonato de cálcio. Foi padronizado que cada tanque de criação conteria em média 3.000 exemplares e receberia diariamente 35.000 mg de ração e alface como complemento. O desenvolvimento de um sistema de aquecimento por efeito estufa constituÃdo de lonas escuras móveis permitiu controlar a temperatura entre 20 a 24 ºC, sistema essencial principalmente nos meses mais frios. Durante o perÃodo de 14 meses foram produzidos aproximadamente 27.000 exemplares com diâmetros superiores a 12 mm. As taxas de mortalidade dos caramujos recém-eclodidos e adultos foram de 77% e 37%, respectivamente. O acompanhamento do ritmo de crescimento de 310 B. tenagophila demonstrou que caramujos com 70 dias de idade alcançaram em média 17,0 ± 0,9 mm de diâmetro. As taxas de mortalidade e o desempenho de crescimento de caramujos do gênero B. tenagophila podem ser considerados altamente satisfatórios, comparando-se com os resultados da literatura realizados com espécies do gênero Biomphalaria em condições controladas de laboratório
Biomphalaria tenagophila: dynamics of populations of resistant and susceptible strains to Schistosoma mansoni, with or without pressure of the parasite
Resistant (Taim, RS) and susceptible albino (Joinville, SC) Biomphalaria tenagophila populations were kept together, at different proportions, throughout a 18-month-period. Some of the snail groups were submitted to Schistosoma mansoni infection. The targets of this study were (a) to analyze the populational dynamics among resistant and susceptible individuals to S. mansoni; (b) to study the resistance phenotype in descendants of cross-breeding; (c) to observe whether the parasite could exert any kind of selection in those snail populations. Throughout the experiment it could be observed that the susceptible B. tenagophila strain (Joinville) underwent a selective pressure of the parasite that was negative, since the individuals showed a high mortality rate. Although B. tenagophila (Taim) population presented a higher mortality rate without pressure of the parasite, this event was compensated by a reproductive capacity. B. tenagophila Taim was more fecund than B. tenagophila Joinville and was able to transmit the resistance character to their descendants. F1 generation obtained by cross-breeding between resistant and susceptible lineages was completely resistant to S. mansoni infection, irrespective of the Taim proportion. Moreover, less than 5% of F2 progeny were susceptible to S. mansoni infection
Biomphalaria tenagophila : dynamics of populations of resistant and susceptible strains to Schistosoma mansoni , with or without pressure of the parasite
Resistant (Taim, RS) and susceptible albino (Joinville, SC)
Biomphalaria tenagophila populations were kept together, at different
proportions, throughout a 18-month-period. Some of the snail groups
were submitted to Schistosoma mansoni infection. The targets of this
study were (a) to analyze the populational dynamics among resistant and
susceptible individuals to S. mansoni ; (b) to study the resistance
phenotype in descendants of cross-breeding; (c) to observe whether the
parasite could exert any kind of selection in those snail populations.
Throughout the experiment it could be observed that the susceptible B.
tenagophila strain (Joinville) underwent a selective pressure of the
parasite that was negative, since the individuals showed a high
mortality rate. Although B. tenagophila (Taim) population presented a
higher mortality rate without pressure of the parasite, this event was
compensated by a reproductive capacity. B. tenagophila Taim was more
fecund than B. tenagophila Joinville and was able to transmit the
resistance character to their descendants. F1 generation obtained by
cross-breeding between resistant and susceptible lineages was
completely resistant to S. mansoni infection, irrespective of the Taim
proportion. Moreover, less than 5% of F2 progeny were susceptible to S.
mansoni infection
Susceptibility of <i>B. tenagophila</i> collected before and after the introduction of the resistant lineage to infection after exposure to the SJ strain of <i>S. mansoni</i>.
<p>PI: post-introduction.</p><p>*Significant differences between <i>B. tenagophila</i> collected before and after the introduction of the resistant lineage (<i>p</i><0.05). Pearson’s chi-square test which is suitable for comparisons between proportions, and Fisher’s exact test were used at frequencies lower than 5.</p