In vitro callogenesis from seedling leaves of mahogany (Swietenia macrophylla King).

8º IVCHB

ELEMENTOS MINERAIS EM MADEIRAS DE EUCALIPTOS E ACÁCIA NEGRA E SUA INFLUÊNCIA NA INDÚSTRIA DE CELULOSE KRAFT BRANQUEADA

No ramo de papel e celulose os efluentes são um dos principais problemas e o consumo de água é crítico. Os circuitos internos estão sendo fechados e as fontes de contaminação precisam ser conhecidas. Uma das fontes de contaminação destes efluentes são os minerais da madeira, matéria-prima neste tipo de indústria. Neste trabalho foi avaliada a quantidade de alumínio, cálcio, cobre, ferro, potássio, magnésio, manganês, sódio, níquel e silício em madeiras de cinco espécies florestais, plantadas na região de Guaíba, RS, compreendendo Acacia mearnsii, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus saligna. As amostras de madeira foram tratadas com digestão ácida e com carbonização em mufla, solubilizando em ácido para serem analisadas por ICP (Inductively Coupled Plasm). Foi observado que a quantidade de elementos é considerável e os principais elementos encontrados foram K, Ca, Na, Al, Mn, e Si. As espécies Eucalyptus grandis e Eucalyptus saligna mostraram melhor crescimento. Por outro lado, Eucalyptus globulus e Eucalyptus dunnii mostraram menor crescimento e maior teor de elementos. Pelo fato dessas espécies introduzirem maiores quantidades de elementos no processo de fabricação, devem conduzir a maiores problemas industriais. A Acacia mearnsii mostrou o menor nível para ferro, manganês e níquel, sendo uma boa opção para uso em branqueamento com oxigênio, ozônio e peróxido. O silício observado estava em baixa quantidade, o que leva a afirmar que há, na prática industrial, muita contaminação da madeira explorada com solo já que se encontram altos valores de sílica nos circuitos de licores. A entrada dos elementos minerais estudados em uma fábrica de celulose via madeira varia de 4 a 6 kg por tonelada de polpa não-branqueada produzida. Cuidados especiais devem ser tomados com as espécies com madeiras mais ricas em cinzas e elementos minerais e mais baixas eficiências nutricionais, como foi o caso de Eucalyptus dunnii e Eucalyptus globulus

Resposta de sementes de Podocarpus lambertii ao congelamento: um modelo para a criopreservação de sementes de araucária.

Resumo

Ingestive Behaviour of Steers in Native Pastures in Southern Brazil

The Campos biome, particularly its native pastures, is the main resource for livestock production in southern Brazil (Boldrini, 1997). It has a huge floristic diversity in which more than 400 grass and 150 legume species are found. These pastures are very heterogeneous with horizontal as well as vertical structure. Hodgson (1985) stressed the importance of sward structure upon diet selection, emphasizing the difficulties animals could have to access all pasture layers in temperate pastures. This experiment investigates how variation in herbage allowance along the growing season influences the ingestive behaviour of steers

Adição de antraquinona na polpação alcalina de Eucalyptus saligna.

The present work evaluated different alkaline pulping conditions for Eucalyptus saligna wood. The objective was to evaluate the influence of the anthraquinone (AQ) on the reduction of the total reduced sulfur (TRS) in the aerial emissions, by reducing the sulfidity. The experiment consisted of 8 cooking with active alkali varying from  19 to 21%, sulfidity from  0 to 20% and anthraquinone from 0 to 0.1%, aiming to obtain  kappa numbers in the range 15.5±1.5. The H factor was used to control the relation time/temperature along cooking. The addition of anthraquinone increased the delignification rate allowing sulfidity reduction. The kraft/AQ pulping with sulfidities of 5 and 10% presented satisfactory results, making it possible the replacement of conventional kraft cooking, giving a reduction in process sulfidity without harms in pulping. In spite of a slightly lower performance, the soda/AQ cooking has potential to be used where the smell is a critical problem in the industrial operation.O presente trabalho avaliou diferentes variações dos parâmetros de polpações alcalinas de cavacos de madeira de Eucalyptus saligna, tendo como objetivo estudar a influência da antraquinona (AQ), visando a diminuir os compostos reduzidos de enxofre nas emissões aéreas por meio da redução da sulfidez. Foram realizados oito cozimentos com álcali ativo variando de 19 a 21%, sulfidez de 0 a 20% e antraquinona de 0 a 0,1%, visando aos números kappa de 15,5 ± 1,5, em condições alcalinas controladas pelo fator H. De um modo geral, a adição de antraquinona melhorou a deslignificação, possibilitando a redução da sulfidez. As deslignificações kraft/antraquinona, com sulfidez de 5 e 10%, apresentaram resultados satisfatórios, podendo ser utilizadas em substituição ao kraft convencional, proporcionando redução da sulfidez do processo sem-prejuízos na polpação. A deslignificação soda/antraquinona, apesar de desempenho ligeiramente inferior, tem potencial para instalações industriais onde o problema de odor é crítico

In vitro germination of embryonic axes of Araucaria angustifolia (Bertol.) Kuntze var. angustifolia and var. caiova.

Resumo. Brasil Biotec

Auditory stimulation and cardiac autonomic regulation

Previous studies have already demonstrated that auditory stimulation with music influences the cardiovascular system. In this study, we described the relationship between musical auditory stimulation and heart rate variability. Searches were performed with the Medline, SciELO, Lilacs and Cochrane databases using the following keywords: "auditory stimulation", "autonomic nervous system", "music" and "heart rate variability". The selected studies indicated that there is a strong correlation between noise intensity and vagal-sympathetic balance. Additionally, it was reported that music therapy improved heart rate variability in anthracycline-treated breast cancer patients. It was hypothesized that dopamine release in the striatal system induced by pleasurable songs is involved in cardiac autonomic regulation. Musical auditory stimulation influences heart rate variability through a neural mechanism that is not well understood. Further studies are necessary to develop new therapies to treat cardiovascular disorders

Two-loop Yang-Mills diagrams from superstring amplitudes

Starting from the superstring amplitude describing interactions among D-branes with a constant world-volume field strength, we present a detailed analysis of how the open string degeneration limits reproduce the corresponding field theory Feynman diagrams. A key ingredient in the string construction is represented by the twisted (Prym) super differentials, as their periods encode the information about the background field. We provide an efficient method to calculate perturbatively the determinant of the twisted period matrix in terms of sets of super-moduli appropriate to the degeneration limits. Using this result we show that there is a precise one-to-one correspondence between the degeneration of different factors in the superstring amplitudes and one-particle irreducible Feynman diagrams capturing the gauge theory effective action at the two-loop level.Comment: 42 pages plus appendices, 10 figure

Interaction Between Cortical Auditory Processing and Vagal Regulation of Heart Rate in Language Tasks: A Randomized, Prospective, Observational, Analytical and Cross-Sectional Study

Cortical auditory evoked potentials (CAEP) throughout a language task is beneficial during psychophysiological evaluation to advance identification of language disorders. So as to better comprehend human communication and to provide additional elements for neuropsychological examinations we aimed to (1) examine the influence of language tasks on cortical auditory processing and vagal control of heart rate and (2) to verify a possible association between the parasympathetic cardiac regulation and cortical auditory processing in language tasks. This study was completed with 49 women. The subjects were separated into two groups: (1) phonological language tasks (N = 21) and (2) semantic (N = 21) language tasks. Heart rate variability (HRV) and CAEP were evaluated before and after the tests. HRV reduced (small effect size) and P3 wave latency increased after the phonological task. Identical variables were significantly correlated after the phonological task and linear regression indicated significant interaction between pNN50 (percentage of adjacent RR intervals with a difference of duration greater than 50 milliseconds) and P3 latency (16.9%). In conclusion, phonological language tasks slightly reduced parasympathetic control of HR and increased cognitive effort. The association between HRV and CAEP are anticipated to be involved in this mechanism

A relationship between brainstem auditory evoked potential and vagal control of heart rate in adult women

Numerous studies have investigated the connection between autonomic control of heart rate (HR) and auditory stimulus. Yet, the literature lacks evidence of a close association between auditory brainstem processing and HR autonomic control. We aimed to evaluate and verify the relationship between auditory brainstem response (ABR) and HR variability (HRV) in healthy women. Forty‑six healthy female subjects, between the ages of 18 and 30 years old participated in the study. They were subjected to an audiometry examination, followed by rest for 10 minutes for HR recording. Next, ABR evaluation was completed discretely in both ears, with I, III and V wave components. Linear regression revealed that the root‑mean square of differences between adjacent normal RR intervals (RMSSD) and the triangular interpolation of RR interval (TINN) exhibited a significant association with Wave I in the right ear. These variables contributed to 28.2% (R²) of Wave I. In conclusion, there was a significant interaction between the autonomic control of HR and auditory processing in the right ear, suggesting that vagal tone interacts with the cochlear nerve