44 research outputs found

    Análises bioquímicas e isoenzímicas de variedades de capim elefante Pennisetum purpureum (Schum)

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    This study characterized seven Pennisetum purpureum varieties, namely v. Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 and Uruckwami, through biochemical analyses, including protein, glucose and fructose contents, and polyacrylamide gel electrophoresis using the esterase system, by sampling 30, 60, 90, 120 and 150 day-old leaves. The number of nodes per stem and the percentage of bud emergence were also recorded. Variety Taiwan A-144 presented the highest number of nodes per stem and percentage of emerging buds. Protein concentration decreased gradually after 60 days for all varieties, except for Anão. Variety Guaçu presented the highest level of glucose in 90 day-old plants, whereas Cameroon presented the highest levels at 120 and 150 days. The esterase band patterns changed with plant age for all varieties, showing a tendency to increase the number of bands with time. The best age for discriminating between esterase bands of P. purpureum varieties was at 120 days, when most variation could be observed.Foram analisadas sete variedades de P. purpureum, tais como: Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 e Uruckwami, através de testes bioquímicos determinando a concentração de proteínas, glicose e frutose, além de observar, através de gel de eletroforese, as bandas de esterase. Os extratos protéicos foram preparados amostrando-se folhas com 30, 60, 90, 120 e 150 dias. Os números de nós por colmo e a porcentagem de brotamento das gemas foram também avaliados. A variedade Taiwan A-144 apresentou o maior número de nós por colmo e porcentagem de brotamento das gemas. Com relação à concentração de proteínas, esta decresceu gradualmente após 60 dias para todas as variedades, com exceção da Anão. A maior concentração de glicose foi apresentada pela variedade Guaçu aos 90 dias e pela Cameroon aos 120 e 150 dias. Os padrões eletroforéticos da esterase se alteraram com a idade da planta para todas as variedades, mostrando tendência a aumentar o número de bandas com o tempo. A melhor idade para discriminar as variedades de capim elefante foi aos 120 dias, onde foi encontrada maior variação

    Virulence exaltation of Clostridium perfringens strains from bovines

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    Ten out of eighty-nine strains biochemically identified as Clostridium perfringens, isolated from bovine organs, were selected by their different results showed in toxigenicity test on mice. Those and the standard strains, ATCC types A, B, C, and D, had their virulence exalted through serial intramuscular inoculation into guinea pigs. Results showed that, for toxigenic strains (6), one or two passages were enough to cause exaltation, while for the atoxigenic (4), five or six inoculations were needed. Esterase electrophoresis of standard and isolated strains, with and without exaltation, was performed. Electrophoresis analysis permits the following conclusions: strains that do not show any clinical symptoms in mice, when exalted demonstrate decreased esterase activity; on the contrary, it is increased when correlated with animal symptoms

    A Kinematical Approach to Conformal Cosmology

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    We present an alternative cosmology based on conformal gravity, as originally introduced by H. Weyl and recently revisited by P. Mannheim and D. Kazanas. Unlike past similar attempts our approach is a purely kinematical application of the conformal symmetry to the Universe, through a critical reanalysis of fundamental astrophysical observations, such as the cosmological redshift and others. As a result of this novel approach we obtain a closed-form expression for the cosmic scale factor R(t) and a revised interpretation of the space-time coordinates usually employed in cosmology. New fundamental cosmological parameters are introduced and evaluated. This emerging new cosmology does not seem to possess any of the controversial features of the current standard model, such as the presence of dark matter, dark energy or of a cosmological constant, the existence of the horizon problem or of an inflationary phase. Comparing our results with current conformal cosmologies in the literature, we note that our kinematic cosmology is equivalent to conformal gravity with a cosmological constant at late (or early) cosmological times. The cosmic scale factor and the evolution of the Universe are described in terms of several dimensionless quantities, among which a new cosmological variable delta emerges as a natural cosmic time. The mathematical connections between all these quantities are described in details and a relationship is established with the original kinematic cosmology by L. Infeld and A. Schild. The mathematical foundations of our kinematical conformal cosmology will need to be checked against current astrophysical experimental data, before this new model can become a viable alternative to the standard theory.Comment: Improved version, with minor changes. 58 pages, including 7 figures and one table. Accepted for publication in General Relativity and Gravitation (GERG

    Harmonization and standardization of nucleus pulposus cell extraction and culture methods

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    Background In vitro studies using nucleus pulposus (NP) cells are commonly used to investigate disc cell biology and pathogenesis, or to aid in the development of new therapies. However, lab-to-lab variability jeopardizes the much-needed progress in the field. Here, an international group of spine scientists collaborated to standardize extraction and expansion techniques for NP cells to reduce variability, improve comparability between labs and improve utilization of funding and resources. Methods The most commonly applied methods for NP cell extraction, expansion, and re-differentiation were identified using a questionnaire to research groups worldwide. NP cell extraction methods from rat, rabbit, pig, dog, cow, and human NP tissue were experimentally assessed. Expansion and re-differentiation media and techniques were also investigated. Results Recommended protocols are provided for extraction, expansion, and re-differentiation of NP cells from common species utilized for NP cell culture. Conclusions This international, multilab and multispecies study identified cell extraction methods for greater cell yield and fewer gene expression changes by applying species-specific pronase usage, 60–100 U/ml collagenase for shorter durations. Recommendations for NP cell expansion, passage number, and many factors driving successful cell culture in different species are also addressed to support harmonization, rigor, and cross-lab comparisons on NP cells worldwide

    Biochemical and isoenzyme analyses of elephant grass, Pennisetum purpureum (Schum) varieties Análises bioquímicas e isoenzímicas de variedades de capim elefante Pennisetum purpureum (Schum)

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    This study characterized seven Pennisetum purpureum varieties, namely v. Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 and Uruckwami, through biochemical analyses, including protein, glucose and fructose contents, and polyacrylamide gel electrophoresis using the esterase system, by sampling 30, 60, 90, 120 and 150 day-old leaves. The number of nodes per stem and the percentage of bud emergence were also recorded. Variety Taiwan A-144 presented the highest number of nodes per stem and percentage of emerging buds. Protein concentration decreased gradually after 60 days for all varieties, except for Anão. Variety Guaçu presented the highest level of glucose in 90 day-old plants, whereas Cameroon presented the highest levels at 120 and 150 days. The esterase band patterns changed with plant age for all varieties, showing a tendency to increase the number of bands with time. The best age for discriminating between esterase bands of P. purpureum varieties was at 120 days, when most variation could be observed.Foram analisadas sete variedades de P. purpureum, tais como: Anão, Bajra, Cameroon, Guaçu, Roxo, Taiwan A-144 e Uruckwami, através de testes bioquímicos determinando a concentração de proteínas, glicose e frutose, além de observar, através de gel de eletroforese, as bandas de esterase. Os extratos protéicos foram preparados amostrando-se folhas com 30, 60, 90, 120 e 150 dias. Os números de nós por colmo e a porcentagem de brotamento das gemas foram também avaliados. A variedade Taiwan A-144 apresentou o maior número de nós por colmo e porcentagem de brotamento das gemas. Com relação à concentração de proteínas, esta decresceu gradualmente após 60 dias para todas as variedades, com exceção da Anão. A maior concentração de glicose foi apresentada pela variedade Guaçu aos 90 dias e pela Cameroon aos 120 e 150 dias. Os padrões eletroforéticos da esterase se alteraram com a idade da planta para todas as variedades, mostrando tendência a aumentar o número de bandas com o tempo. A melhor idade para discriminar as variedades de capim elefante foi aos 120 dias, onde foi encontrada maior variação

    Esterase electrophoresis of Clostridium perfringens bovine strains

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    Eighty-nine of 144 isolates of Clostridium perfringens obtained from 187 samples of 71 bovine in several Brazilian states were submitted to esterase electrophoresis for typing. Mobilites electrophoresis, as parameter, were settled down by isolates from ATCC pattern of types A, B, C, and D. Of the 89 isolates, 43 (48.3%) were characterized as electrophoretic type A, 20 (22.5%) as D, 18 (20.2%) as C, and 3 (3.4%) as B. Five (5.6%) isolates did not identity with any type. Similarly, esterase electrophoresis enabled the typing of 94.4 % of the isolates, demonstrating to be an appropriate method for animal sample analyses
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