Electrophoresis and spectrometric analyses of adaptation-related proteins in thermally stressed Chromobacterium violaceum

Chromobacterium violaceum is a Gram-negative proteobacteria found in water and soil; it is widely distributed in tropical and subtropical regions, such as the Amazon rainforest. We examined protein expression changes that occur in C. violaceum at different growth temperatures using electrophoresis and mass spectrometry. The total number of spots detected was 1985; the number ranged from 99 to 380 in each assay. The proteins that were identified spectrometrically were categorized as chaperones, proteins expressed exclusively under heat stress, enzymes involved in the respiratory and fermentation cycles, ribosomal proteins, and proteins related to transport and secretion. Controlling inverted repeat of chaperone expression and inverted repeat DNA binding sequences, as well as regions recognized by sigma factor 32, elements involved in the genetic regulation of the bacterial stress response, were identified in the promoter regions of several of the genes coding proteins, involved in the C. violaceum stress response. We found that 30°C is the optimal growth temperature for C. violaceum, whereas 25, 35, and 40°C are stressful temperatures that trigger the expression of chaperones, superoxide dismutase, a probable small heat shock protein, a probable phasing, ferrichrome-iron receptor protein, elongation factor P, and an ornithine carbamoyltransferase catabolite. This information improves our comprehension of the mechanisms involved in stress adaptation by C. violaceum. © FUNPEC-RP

Ingestão e digestibilidade aparente em ovinos alimentados com silagens de capim-elefante inoculadas com Streptococcus bovis

Foram avaliadas a ingestão e a digestibilidade aparente de silagens de capim, utilizando-se 20 ovinos adultos, sem raça definida, castrados, distribuídos em delineamento inteiramente ao acaso, com quatro tratamentos: silagem de capim-elefante; silagem de capim-elefante inoculada com 10(6)UFC/g de()estirpes de Enterococcus faecium; silagem de capim-elefante inoculada com 10(6)UFC/g de estirpes de Streptococcus bovis JB1; e silagem de capim-elefante inoculada com 10(6)UFC/g de()estirpes de S. bovis HC5, e cinco repetições por tratamento. O período de avaliação foi de 21 dias, sendo 15 para adaptação e seis para as coletas. Observou-se diferença (P<0,05) entre o consumo de matéria seca, sendo a silagem-controle a que apresentou os valores mais baixos - 1,43%PV ou 42,79g/kg PV0,75/dia -, enquanto a silagem inoculada com S. bovis HC5 apresentou o melhor consumo de matéria seca, 2,3% PV ou 56,10g/kg PV0,75/dia. Menores valores de digestibilidade da matéria seca ocorreram na silagem-controle, 42,8% da MS, seguida pela silagem de capim-elefante inoculada com E. faecium e S. bovis JB1. Para a digestibilidade aparente da fibra em detergente neutro, houve efeito dos inoculantes (P<0,05) com valores acima de cinco pontos percentuais em relação à silagem inoculada, 54,7%

PROFESSOR E PROFESSOR DE MATEMÁTICA: DAS INFORMAÇÕES QUE SE TEM ACERCA DA FORMAÇÃO QUE SE ESPERA

O presente artigo faz um levantamento da bibliografia disponível acerca da formação de professores em cursos de licenciatura, iniciando com um tratamento hermenêutico ao termo "formação", passando pela atual situação dos docentes no estado de São Paulo. Caracteriza a constituição das instituições formadoras e levanta aspectos convergentes em relação ao tratamento do tema na literatura. Finalmente são feitas considerações específicas sobre a formação dos professores em cursos de Licenciatura em Matemática.<br>This paper makes a review of the literature on teacher training, begining with hermeneutical remarks on the word "formation". It discusses the actual context of teaching in the State of São Paulo, focusing the constitution of training programmes in universities, and bring some convergent features about this theme available in the literature. Finally, this work focuses the training of Mathematics teachers

Ecological and reproductive aspects of Neoechinorhynchus pimelodi Brasil-Sato & Pavanelli (Eoacanthocephala, Neoechinorhynchidae) of Pimelodus maculatus Lacépède (Siluroidei, Pimelodidae) of the São Francisco River, Brazil

Ecological and reproductive aspects of Neoechinorhynchus pimelodi Brasil-Sato & Pavanelli, 1998, in Pimelodus maculatus Lacépède, 1803 collected in the São Francisco river during periods of drought (July 1995 and 1996) and floodings (January 1996 and 1997) of this river basin are provided. In tropical regions where the amount of rainfall alters the hydrological regimen of limnological systems water temperature has not had an important role in infections of N. pimelodi in P. maculatus. Prevalence was somewhat higher during drought periods. Intensity of infection varied slightly between collecting periods. Mature male and female acanthocephalans were present in all periods. Females were predominant. Mature females were present in higher numbers during flooding periods with a corresponding decrease in juvenile acanthocephalans. Recruitment and constant losses of N. pimelodi seem to be controlled by transmission mechanisms independently of density. Mechanisms may consist of infected prey availability (potential intermediate hosts) and changes of preferred alimentary items in the diets of juvenile and mature P. maculatus