29,885 research outputs found
Peroxiredoxins are involved in two independent signalling pathways in the abiotic stress protection in Vitis vinifera
Peroxiredoxins (Prxs) play major roles in preventing oxidative damage and their function is consistent with the presence
of Prx isoforms in most, if not all, cellular compartments and their expression is dependent on environmental
conditions. The aim of this study was to identify and characterize genes encoding Prxs in Vitis vinifera. Quantitative
real time polymerase chain reaction (qRT PCR) was used to determine their response to irradiance, heat, and water
stress. We identified seven vvprx genes, two of which were especially responsive to water stress, followed by heat
stress, but no major changes were observed after high irradiance. The vvprxIIF targeted to mitochondria was the most
responsive to water stress and it might be involved in drought tolerance through H2O2 signalling. The vvprxII-2, a
putative PrxII, is targeted to the chloroplasts and was the most responsive to heat stress. It might be related with
abscisic acid-dependent thermotoleranc
Understanding thio-effects in simple phosphoryl systems : role of solvent effects and nucleophile charge.
Recent experimental work (J. Org. Chem., 2012, 77, 5829) demonstrated pronounced differences in measured thio-effects for the hydrolysis of (thio)phosphodichloridates by water and hydroxide nucleophiles. In the present work, we have performed detailed quantum chemical calculations of these reactions, with the aim of rationalizing the molecular bases for this discrimination. The calculations highlight the interplay between nucleophile charge and transition state solvation in SN2(P) mechanisms as the basis of these differences, rather than a change in mechanism
Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism
We probe the two-scale factor universality hypothesis by evaluating, firstly
explicitly and analytically at the one-loop order, the loop quantum corrections
to the amplitude ratios for O() scalar field theories with
rotation symmetry-breaking in three distinct and independent methods in which
the rotation symmetry-breaking mechanism is treated exactly. We show that the
rotation symmetry-breaking amplitude ratios turn out to be identical in the
three methods and equal to their respective rotation symmetry-breaking ones,
although the amplitudes themselves, in general, depend on the method employed
and on the rotation symmetry-breaking parameter. At the end, we show that all
these results can be generalized, through an inductive process based on a
general theorem emerging from the exact calculation, to any loop level and
physically interpreted based on symmetry ideas.Comment: 17 pages, 3 figure
Manejo e controle da Cochonilha Ortézia (Orthezia praelonga), em plantios irrigados de acerola, no Submédio São Francisco.
O cultivo da acerola é uma importante alternativa econômica para a Região Nordeste do Brasil. No Submédio São Francisco, há cerca de mil hectares cultivados e a expansão do cultivo deve-se, basicamente, ao apreciado sabor da fruta e ao alto teor de ácido ascórbico (vitamina C), que, em algumas variedades, alcança até 5.000 miligramas por 100 gramas de polpa.bitstream/CPATSA/37176/1/CTE83.pd
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