Eficiência das auxinas (AIB e ANA) no enraizamento de miniestacas de clones de Eucalyptus cloeziana F. Muell

Este trabalho teve como objetivo avaliar a eficiência das auxinas AIB (ácido indolbutírico) e ANA (ácido naftalenoacético) no enraizamento adventício de miniestacas de clones de Eucalyptus cloeziana. Foram utilizadas miniestacas provenientes de sete clones de Eucalyptus cloeziana, estabelecidos em minijardim clonal, sendo avaliados os efeitos de AIB (0, 1.500, 3.000 e 6.000 mg L-1) na forma líquida e em pó e ANA (0, 3.000 e 6.000 mg L-1) na forma líquida. Os resultados apontaram ser a miniestaquia técnica viável na propagação vegetativa dos clones de Eucalyptus cloeziana estudados, apresentando, de modo geral, alto índice de enraizamento das miniestacas. Os clones com maior potencial de enraizamento adventício responderam mais positivamente às menores dosagens de AIB, enquanto nos clones com capacidade de enraizamento reduzida houve tendência de as maiores dosagens de AIB serem mais eficientes no enraizamento, independentemente da forma de aplicação do fitorregulador (líquido ou pó). O ANA, de modo geral, não influenciou significativamente o enraizamento das miniestacas da maioria dos clones estudados.

Efeito dos reguladores de crescimento AIB e ANA no enraizamento de miniestacas de clones de Eucalyptus grandis x Eucalyptus urophylla

Este estudo teve como objetivo avaliar a eficiência dos reguladores de crescimento AIB e ANA no enraizamento de miniestacas de quatro clones de Eucalyptus grandis x E. urophylla. As miniestacas foram coletadas no minijardim clonal conduzido em sistema de hidroponia em canaletas. O delineamento experimental utilizado foi em blocos ao acaso, em arranjo fatorial 2 x 5 x 4, constituído de dois reguladores de crescimento (AIB e ANA), cinco doses de AIB e ANA e quatro clones, em quatro repetições e parcelas compostas de 16 plantas/repetição. Foram feitas avaliações em casa de vegetação, casa de sombra e pleno sol, quanto ao porcentual de sobrevivência, altura, diâmetro de colo e massa seca da parte aérea e radicular das miniestacas enraizadas. Conclui-se que a utilização do AIB nas doses entre 500 e 2.000 mg L-1 mostrou-se mais eficiente do que o ANA nos quatro clones estudados.

Efeitos do meio de cultura e da relação BAP/ANA na multiplicação in vitro de clones de Eucalyptus grandis x E. urophylla em biorreator de imersão temporária

Foram realizados três experimentos individuais com o objetivo de testar diferentes meios de cultura e combinações entre os fitorreguladores BAP e ANA na multiplicação de clones de Eucalyptus grandis x E. urophylla, utilizando o biorreator de imersão temporária RITA®. O meio de cultura MS e a frequência de imersão a cada 2 h promoveram maior massa fresca e número de brotos por explantes. No entanto, houve diferença quanto ao crescimento das culturas entre os dois clones avaliados. A combinação 1,0 µM de BAP com 0,5 µM de ANA foi a que resultou maiores médias em relação à massa fresca e ao número de brotos. As culturas apresentaram alto percentual de hiper-hidricidade, sendo essa desordem fator limitante nas condições deste estudo para o cultivo de Eucalyptus em biorreatores.

Extraction of genomic DNA from Melipona quadrifasciata (Hymenoptera: Apidae, Meliponinae)

The objective of the present study was to test three different procedures for DNA extraction of Melipona quadrifasciata based on existing methods for DNA extraction of Apis, plants and fungi. These methods differ in the concentrations of specific substances in the extraction buffer. The results demonstrate that the method used for Apis is not adequate for DNA extraction from M. quadrifasciata. On the other hand, with minor modifications this method and the methods for plants and fungi were adequate for DNA extraction of this stingless bee, both for adults and larvae

Centromere domain organization and histone modifications

Centromere function requires the proper coordination of several subfunctions, such as kinetochore assembly, sister chromatid cohesion, binding of kinetochore microtubules, orientation of sister kinetochores to opposite spindle poles, and their movement towards the spindle poles. Centromere structure appears to be organized in different, separable domains in order to accomplish these functions. Despite the conserved nature of centromere functions, the molecular genetic definition of the DNA sequences that form a centromere in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, in the fruit fly Drosophila melanogaster, and in humans has revealed little conservation at the level of centromere DNA sequences. Also at the protein level few centromere proteins are conserved in all of these four organisms and many are unique to the different organisms. The recent analysis of the centromere structure in the yeast S. pombe by electron microscopy and detailed immunofluorescence microscopy of Drosophila centromeres have brought to light striking similarities at the overall structural level between these centromeres and the human centromere. The structural organization of the centromere is generally multilayered with a heterochromatin domain and a central core/inner plate region, which harbors the outer plate structures of the kinetochore. It is becoming increasingly clear that the key factors for assembly and function of the centromere structure are the specialized histones and modified histones which are present in the centromeric heterochromatin and in the chromatin of the central core. Thus, despite the differences in the DNA sequences and the proteins that define a centromere, there is an overall structural similarity between centromeres in evolutionarily diverse eukaryotes.

Modifications of the sympathetic skin response in workers chronically exposed to lead

The long-term effects of low-level lead intoxication are not known. The sympathetic skin response (SSR) was evaluated in a group of 60 former workers of a primary lead smelter, located in Santo Amaro, BA, Brazil. The individuals participating in the study were submitted to a clinical-epidemiological evaluation including questions related to potential risk factors for intoxication, complaints related to peripheral nervous system (PNS) involvement, neurological clinical examination, and also to electromyography and nerve conduction studies and SSR evaluation. The sample consisted of 57 men and 3 women aged 34 to 69 years (mean ± SD: 46.8 ± 6.9). The neurophysiologic evaluation showed the presence of lumbosacral radiculopathy in one of the individuals (1.7%), axonal sensorimotor polyneuropathy in 2 (3.3%), and carpal tunnel syndrome in 6 (10%). SSR was abnormal or absent in 12 cases, representing 20% of the sample. More than half of the subjects (53.3%) reported a history of acute abdominal pain requiring hospitalization during the period of work at the plant. A history of acute palsy of radial and peroneal nerves was reported by about 16.7 and 8.3% of the individuals, respectively. Mean SSR amplitude did not differ significantly between patients presenting or not the various characteristics in the current neurological situation, except for diaphoresis. The results suggest that chronic lead intoxication induces PNS damage, particularly affecting unmyelinated small fibers. Further systematic study is needed to more precisely define the role of lead in inducing PNS injury.

Modifications in the chemical compounds and sensorial attributes of Engraulis anchoita fillet during marinating process

Marinated fish are fish products preserved by the combined action of salt and organic acids. The objective of this work was to analyze the variations in the chemical compounds of anchovy fillets that give them sensorial characteristics during the marinating process of Engraulis anchoita. The protein content decreased slightly and the TVB-N level decreased significantly in both the brining and marinating stages. In the marinating stage an increase in the total free aminoacids was observed. The NBV level in the brining and marinating solutions increased during these stages due to the solubilization of the non-protein nitrogenous compounds and the degradation of some protein compounds.The decrease of the contents of protein and TVB-N, and the increase of the acidity and the free aminoacids content during the marinating process give the marinated fillets the characteristic texture and aroma.

Physicochemical properties, modifications and applications of starches from different botanical sources

Present trends towards technologies and processes that increase the use of residues make starchy vegetal biomass an important alternative material in various applications due to starch’s versatility, low cost and ease of use when its physicochemical properties are altered. Starch is increasingly used in many industrial applications and as a renewable energy resource. Starch can be modified to enhance its positive attributes and eliminate deficiencies in its native characteristics. In this article, the state of knowledge on conventional and unconventional starches and their properties, characteristics, modifications and applications are reviewed.