Diversidade microbiana na produção de etanol utilizando técnicas tradicionais e biologia molecular.

Mestrado (Ciências Genômicas e Biotecnologia) - Universidade Católica de Brasília, Brasília, DF. Orientadora CNPAE: Betania Ferraz Quirino

Factors controlling spatio-temporal variation in carbon dioxide efflux from surface litter, roots, and soil organic matter at four rain forest sites in the eastern Amazon

[1] This study explored biotic and abiotic causes for spatio-temporal variation in soil respiration from surface litter, roots, and soil organic matter over one year at four rain forest sites with different vegetation structures and soil types in the eastern Amazon, Brazil. Estimated mean annual soil respiration varied between 13-17 t C ha(-1) yr(-1), which was partitioned into 0-2 t C ha(-1) yr(-1) from litter, 6-9 t C ha(-1) yr(-1) from roots, and 5-6 t C ha(-1) yr(-1) from soil organic matter. Litter contribution showed no clear seasonal change, though experimental precipitation exclusion over a one-hectare area was associated with a ten-fold reduction in litter respiration relative to unmodified sites. The estimated mean contribution of soil organic matter respiration fell from 49% during the wet season to 32% in the dry season, while root respiration contribution increased from 42% in the wet season to 61% during the dry season. Spatial variation in respiration from soil, litter, roots, and soil organic matter was not explained by volumetric soil moisture or temperature. Instead, spatial heterogeneity in litter and root mass accounted for 44% of observed spatial variation in soil respiration (p < 0.001). In particular, variation in litter respiration per unit mass and root mass accounted for much of the observed variation in respiration from litter and roots, respectively, and hence total soil respiration. This information about patterns of, and underlying controls on, respiration from different soil components should assist attempts to accurately model soil carbon dioxide fluxes over space and time

Ecophysiological responses of the winegrape Chenin Blanc under different irrigation management in the São Francisco river valley.

The So Francisco Valley has been considered a new growing region for wine grapeproduction. In this region, the wines have a typical taste and are the unique ones producedunder tropical conditions. Because the irrigation management is one of the most importantfactors related to grape and wine quality, a study was carried out by the Embrapa Semirido,in the VINIBRASIL Farm vineyards, at Lagoa Grande, State of Pernambuco, Brazil inwhich the grapevine ¡§Chenin Blanc¡¨, grafted onto the IAC 572 rootstock, and spaced by 1,0m x 3,0 m, was submitted to different irrigation managements: T1) 75% Kc; T2) 50% Kc; T3)50 % Kc until 80 days after pruning and then 75% Kc until harvest and; T4) about 30% Kc(Farm management). Irrigation water was applied by dripping and the treatments initiated 45days after pruning. The effects of treatments were observed based on the ecophysiologicalperformance of the grapevine through measurements of leaf water potential (£Zl) obtainedwith a pressure chamber and gas exchange variables (stomatal conductance, gs;transpiration rate, E; photosynthesis, A), with a portable infrared gas analyzer (IRGA ¡V Licor6200) during flowering and maturation (August to September, 2006). The results showed thatgrapevines submitted to the T1 treatment presented the highest £Zl, gs, E and A values duringthe hottest hours of day followed by T3 and T2. The T4 treatment presented the lowestvalues on these variables but higher intrinsic water use efficiency (WUE) calculated as A/gs.At harvest, this treatment showed lower bunch number per plant and yield but higher oBrixand higher pH. The results suggest that the monitoring of the ecophysiological performanceof winegrapes during the growth cycle, might be a good tool to establish an appropriatedirrigation management toward grape and wine quality

Full Counting Statistics of Non-Commuting Variables: the Case of Spin Counts

We discuss the Full Counting Statistics of non-commuting variables with the measurement of successive spin counts in non-collinear directions taken as an example. We show that owing to an irreducible detector back-action, the FCS in this case may be sensitive to the dynamics of the detectors, and may differ from the predictions obtained with using a naive version of the Projection Postulate. We present here a general model of detector dynamics and path-integral approach to the evaluation of FCS. We concentrate further on a simple "diffusive" model of the detector dynamics where the FCS can be evaluated with transfer-matrix method. The resulting probability distribution of spin counts is characterized by anomalously large higher cumulants and substantially deviates from Gaussian Statistics.Comment: 11 pages, 3 figure

Avaliação do teor de ácido pirúvico em genótipos de cebola no Nordeste do Brasil.

O objetivo desse trabalho foi de quantificar o ácido pirúvico (pungência) de genótipos de cebola produzida em diferentes locais. Foram realizados dois experimentos simultâneos, em Mossoró-RN e Juazeiro-BA no período de maio a setembro de 2004. O delineamento utilizado foi em blocos casualizados, com 3 repetições, em esquema fatorial 18 x 2, sendo composto de 18 genótipos de cebola e 2 locais de avaliação. Os genótipos cultivados em Mossoró obtiveram as maiores pungência em relação aos cultivados em Juazeiro. Para os valores de pungência em Mossoró, observou-se que o Granex 429 pode ser considerado como uma cebola doce por apresentar teores de ácido pirúvico entre 3,0 e 5,0 ?mol/mL, e os demais genótipos que apresentaram valores superiores a 5,0 são considerados como pungentes. Em Juazeiro o CNPH 6047, Granex 429 e Régia foram considerados como cebola doce e os demais como pungentes.Suplemento. Edição dos resumos expandidos do 45. Congresso Brasileiro de Olericultura; 15. Congresso Brasileiro de Floricultura e Plantas Ornamentais; 2. Congresso Brasileiro de Cultura de Tecidos de Plantas, Fortaleza, ago. 2005. 1 CD-ROM

Simulação da movimentação de agrotóxicos no solo com o uso de geotecnologias, como instrumento para avaliação do potencial de risco de contaminação de águas subterrâneas na Amazônia Oriental.

Pesticides use represents a great environmental risk with high economic cost. The objective of this study is to investigate groundwater contamination risk in a small watershed in northeastern Pará State, Brazil, coupling remote sensing, GIS techniques, and simulations. We have confirmed a high risk exposure to contamination by Dimethoate in 67.76 ha, which represents 1.67% of the total watershed area. According to these analyses, Dimethoate has the potential to reach 12.96 m depth in the soil. The groundwater in the study area has a high risk of exposure to contamination by this pesticide, as the water table depth ranges from 1.5 to 13.0 meters. The shallow water table together with soil and geological characteristics increases the potential risk of contamination of groundwater

Phase Transition in Liquid Drop Fragmentation

A liquid droplet is fragmented by a sudden pressurized-gas blow, and the resulting droplets, adhered to the window of a flatbed scanner, are counted and sized by computerized means. The use of a scanner plus image recognition software enables us to automatically count and size up to tens of thousands of tiny droplets with a smallest detectable volume of approximately 0.02 nl. Upon varying the gas pressure, a critical value is found where the size-distribution becomes a pure power-law, a fact that is indicative of a phase transition. Away from this transition, the resulting size distributions are well described by Fisher's model at coexistence. It is found that the sign of the surface correction term changes sign, and the apparent power-law exponent tau has a steep minimum, at criticality, as previously reported in Nuclear Multifragmentation studies [1,2]. We argue that the observed transition is not percolative, and introduce the concept of dominance in order to characterize it. The dominance probability is found to go to zero sharply at the transition. Simple arguments suggest that the correlation length exponent is nu=1/2. The sizes of the largest and average fragments, on the other hand, do not go to zero but behave in a way that appears to be consistent with recent predictions of Ashurst and Holian [3,4].Comment: 10 pages, 11 figures. LaTeX (revtex4) with psfig/epsfi