Água corrente acelera a germinação de sementes de carandá (Copernicia alba).

bitstream/item/129717/1/CT110.pd

Variation of elastic scattering across a quantum well

The Drude scattering times of electrons in two subbands of a parabolic quantum well have been studied at constant electron sheet density and different positions of the electron distribution along the growth direction. The scattering times obtained by magnetotransport measurements decrease as the electrons are displaced towards the well edges, although the lowest-subband density increases. By comparing the measurements with calculations of the scattering times of a two-subband system, new information on the location of the relevant scatterers and the anisotropy of intersubband scattering is obtained. It is found that the scattering time of electrons in the lower subband depends sensitively on the position of the scatterers, which also explains the measured dependence of the scattering on the carrier density. The measurements indicate segregation of scatterers from the substrate side towards the quantum well during growth.Comment: 4 pages, 4 figure

Models for synthetic biology

Synthetic biological engineering is emerging from biology as a distinct discipline based on quantification. The technologies propelling synthetic biology are not new, nor is the concept of designing novel biological molecules. What is new is the emphasis on system behavior

Metabolic engineering strategies for butanol production in Escherichia coli

The global market of butanol is increasing due to its growing applications as solvent, flavoring agent and chemical precursor of several other compounds. Recently, the superior properties of n-butanol as a biofuel over ethanol have stimulated even more interest. (Bio)butanol is natively produced together with ethanol and acetone by Clostridium species through Acetone-Butanol-Ethanol fermentation, at non-competitive, low titers compared to petrochemical production. Different butanol production pathways have been expressed in Escherichia coli, a more accessible host compared to Clostridium species, to improve butanol titers and rates.. The bioproduction of butanol is here reviewed from a historical and theoretical perspective. All tested rational metabolic engineering strategies in E. coli to increase butanol titers are reviewed: manipulation of central carbon metabolism; elimination of competing pathways; cofactor balancing; development of new pathways; expression of homologous enzymes; consumption of different substrates and molecular biology strategies. The progress in the field of metabolic modeling and pathway generation algorithms and their potential application to butanol production are also summarized here. The main goals are to gather all the strategies, evaluate the respective progress obtained, identify and exploit the outstanding challenges. This article is protected by copyright. All rights reserved.Ministério da Ciência, Tecnologia e Ensino Superior, Grant/Award Number: ERA‐IB‐2/0002/2014; Fundação para a Ciência e a Tecnologia, Grant/Award Numbers: ERA‐IB‐2/0002/2014, LISBOA¬01¬0145¬FEDER¬007660, PD/BD/52366/2013; European Commission, Grant/Award Number: H2020‐LEIT‐BIO‐2015‐1 686070–1info:eu-repo/semantics/publishedVersio

Estoques de carbono do estrato arbóreo de cerrados no Pantanal da Nhecolândia.

O objetivo deste trabalho foi estimar a biomassa aérea e o estoque de carbono do estrato arbóreo em duas áreas (um cerrado e um cerradão), localizadas no Pantanal da Nhecolândia, realizadas a partir de fórmula proposta por Brown et al. (1989) para florestas tropicais.bitstream/CPAP-2009-09/56774/1/COT68.pdfFormato eletrônico

Penetration depth study of the type-I superconductor PdTe2

Superconductivity in the topological non-trivial Dirac semimetal PdTe$_2$ was recently shown to be type-I. We here report measurements of the relative magnetic penetration depth, $\Delta \lambda$, on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation $\Delta \lambda (T)$ follows an exponential function for $T/T_c < 0.4$, consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a $\lambda (0)$-value of $\sim 500$~nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in $\Delta \lambda (T)$, which possibly relates to a locally lower $T_c$ due to defects in the single crystalline sample. single crystalline sample.Comment: 13 pages, including 5 figure

Quintais agroflorestais como estratégia de reprodução socioeconômica, cultural e ambiental no recanto dos evangélicos - Corumbá, MS.

O texto aborda a estratégia de sobrevivência que os moradores do Recanto dos Evangélicos, da Comunidade de Antonio Maria Coelho, Borda Oeste do Pantanal, Corumbá, MS encontram para conservar sua cultura de pequenos sitiantes e, ao mesmo tempo, conservar os recursos naturais existentes na região. Os dados foram coletados através de entrevistas semi-estruturadas aplicadas aos moradores do Recanto dos Evangélicos, além de observações realizadas em caminhadas tranversais no local. O aproveitamento coletivo da grande quantidade de espécies frutíferas e arbóreas já existentes nos quintais e a sua intensificação de forma ordenada em quintais agroflorestais racionais pode aumentar a segurança alimentar dos moradores e contribuir para a conservação ambiental da comunidade