7,116 research outputs found
Time evolution towards q-Gaussian stationary states through unified Ito-Stratonovich stochastic equation
We consider a class of single-particle one-dimensional stochastic equations
which include external field, additive and multiplicative noises. We use a
parameter which enables the unification of the traditional
It\^o and Stratonovich approaches, now recovered respectively as the
and particular cases to derive the associated Fokker-Planck
equation (FPE). These FPE is a {\it linear} one, and its stationary state is
given by a -Gaussian distribution with , where characterizes the
strength of the confining external field, and is the (normalized)
amplitude of the multiplicative noise. We also calculate the standard kurtosis
and the -generalized kurtosis (i.e., the standard
kurtosis but using the escort distribution instead of the direct one). Through
these two quantities we numerically follow the time evolution of the
distributions. Finally, we exhibit how these quantities can be used as
convenient calibrations for determining the index from numerical data
obtained through experiments, observations or numerical computations.Comment: 9 pages, 2 figure
Fungitoxicidade de grupos quÃmicos sobre Myrothecium roridum in vitro e sobre a mancha-de-mirotécio em algodoeiro.
O objetivo deste trabalho foi avaliar a fungitoxicidade de produtos pertencentes aos grupos dos benzimidazóis, triazóis, estrobilurinas, isoftalonitrilas e ditiocarbamatos sobre a germinação conidial e o crescimento micelial in vitro de isolados de Myrothecium roridum e, in vivo, sobre a severidade da mancha-de-mirotécio em plantas de algodoeiro. Nos testes in vitro os fungicidas foram solubilizados em meio BDA, utilizando-se as concentrações de 0,1, 1, 10 e 100 mg L-1 de ingrediente ativo. A fungitoxidade dos produtos foi avaliada por meio da ED50 (dose necessária para inibir 50% da germinação conidial ou crescimento micelial). Em casa de vegetação, estimou-se a severidade da mancha-de-mirotécio pela porcentagem de área foliar lesionada nas plantas de algodoeiro tratadas antes (preventivo) e depois (curativo) da inoculação do patógeno. Os fungicidas tiofanato metÃlico, carbendazim, metconazol, tiofanato metÃlico + clorotalonil, piraclostrobina + epoxiconazol, piraclostrobina + metiram, triflostrobina + propiconazol e tebuconazol inibiram com alta eficácia (ED50<1 mg L-1), ou com eficácia (ED50 entre 1 e 10 mg L-1), a germinação conidial e o crescimento micelial in vitro de M. roridum. Os fungicidas piraclostrobina + epoxiconazol, tebuconazol, metconazol e azoxistrobina + ciproconazol são os mais eficazes em testes in vivo. O tratamento preventivo é mais eficaz que o curativo
Using MODIS to detect cropping frequency variation in mechanized agriculture in Amazonia.
Policy makers concerned with managing rapidly developing agriculture on the Amazon frontier currently have no Basin-wide spatial and temporal information on exactly when and how soubean and other mechanized annual cropping have developed in the region. To address this, we present a reliminary evaluation of the use of moderate resolution Imaging Spectroradiometer (MODIS) 250 m vegetation index (VI) time-series data to detect croppping frequency in two municipalities, Vilhena, Rondônia, and Santarém, Pará
Using MODIS to detect cropping frequency variation in mechanized agriculture in Amazonia.
Policy makers concerned with managing rapidly developing agriculture on the Amazon frontier currently have no Basin-wide spatial and temporal information on exactly when and how soubean and other mechanized annual cropping have developed in the region. To address this, we present a reliminary evaluation of the use of moderate resolution Imaging Spectroradiometer (MODIS) 250 m vegetation index (VI) time-series data to detect croppping frequency in two municipalities, Vilhena, Rondônia, and Santarém, Pará
Anharmonic transitions in nearly dry L-cysteine I
Two special dynamical transitions of universal character have been recently
observed in macromolecules at K and K.
Despite their relevance, a complete understanding of the nature of these
transitions and their consequences for the bio-activity of the macromolecule is
still lacking. Our results and analysis concerning the temperature dependence
of structural, vibrational and thermodynamical properties of the orthorhombic
polymorph of the amino acid L-cysteine (at a hydration level of 3.5%) indicated
that the two referred temperatures define the triggering of very simple and
specific events that govern all the biochemical interactions of the
biomolecule: activation of rigid rotors (), phonon-phonon interactions
with phonons of water dimer (), and water rotational barriers
surpassing ().Comment: 4 pages, 4 figures, submitted to Physical Review Letter
Signature for heavy Majorana neutrinos in hadronic collisions
The production and decay of new possible heavy Majorana neutrinos are
analyzed in hadronic collisions. New bounds on the mixing of these particles
with standard neutrinos are estimated according to a fundamental representation
suggested by grand unified models. A clear signature for these Majorana
neutrinos is given by same-sign dileptons plus a charged weak vector boson in
the final state. We discuss the experimental possibilities for the future Large
Hadron Collider (LHC) at CERN.Comment: Latex2e(epsfig), 12 pages, 8 figures, to appear Physical Review
Pair production of the heavy leptons in future high energy linear e^{+}e^{-} colliders
The littlest Higgs model with T-parity predicts the existence of the T-odd
particles, which can only be produced in pair. We consider pair production of
the T-odd leptons in future high energy linear collider ().
Our numerical results show that, as long as the T-odd leptons are not too
heavy, they can be copiously produced and their possible signals might be
detected via the processes in future
experiments.Comment: Discussions added, typos and references correcte
Resistência genética de algodoeiro à mancha de ramulária.
bitstream/CNPA/18275/1/COMTEC273.PD
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