8,464 research outputs found
Controle do percevejo-castanho-da-raiz Scaptocoris carvalhoi, Becker 1967 (Hemiptera: cydnidae) com fungos entomopatogĂȘnicos.
A pesquisa teve como objetivo avaliar a eficiĂȘncia de isolados dos fungos Metarhizium anisopliae e Beauveria bassiana como agentes de mortalidade do percevejo-castanho Scaptocoris carvalhoi Becker, 1967. Os experimentos foram conduzidos na Embrapa AgropecuĂĄria Oeste, em Dourados, MS. Em condiçÔes de laboratĂłrio, suspensĂ”es de dez isolados de M. anisopliae e 11 de B. bassiana foram aplicadas topicamente no percevejo, inoculando-se 8 5 ”l da suspensĂŁo de 10 conĂdios/ml em cada inseto. Utilizou-se o delineamento inteiramente casualizado com cinco repetiçÔes. Cada parcela foi constituĂda por 15 insetos (dez adultos e cinco ninfas grandes). Em outro bioensaio foi avaliada a patogenicidade de M. anisopliae (Ma69) para ninfas e adultos, separadamente. Os nĂveis de mortalidade do percevejo foram maiores com M. anisopliae, variando de 73,3% a 94,7% contra 10,7% a 78,7% para B. bassiana. Quando ninfas e adultos foram avaliados separadamente nĂŁo houve diferença significativa com relação Ă mortalidade. Numa outra etapa, foi avaliada a virulĂȘncia de quatro isolados do fungo M. anisopliae (Ma7, Ma69, Ma283 e Ma342) em S. carvalhoi e determinadas a DL e o TL . A DL foi determinada 50 50 50 4 5 6 7 8 preparando concentraçÔes de 10 , 10 , 10 , 10 e 10 conĂdios/ml. Os menores valores da DL foram observados com os isolados 50 Ma69 e Ma7 e o maior com Ma283. Os valores de TL variaram de 50 0,32 a 5,84 dias, sem diferirem estatisticamente entre si. Em casa de vegetação foi avaliada a patogenicidade de um isolado de M. anisopliae (Ma69) em ninfas e adultos de S. carvalhoi, aplicando-se o fungo diretamente no solo dos vasos. Utilizou-se o delineamento inteiramente casualizado em 12 repetiçÔes, sendo a parcela constituĂda por 15 insetos. Para cada fase do inseto (adulto/ninfa) tratada com fungo houve uma testemunha, totalizando quatro tratamentos. Nos vasos contendo o fungo (Ma69), a percentagem de mortalidade de adultos + ninfas de S. carvalhoi foi de 57,3%, sendo estatisticamente superior Ă mortalidade verificada nos vasos nĂŁo tratados. Quando ninfas e adultos foram submetidos Ă presença do fungo, separadamente, o Ăndice de mortalidade foi significativamente maior para ninfas (80,8%) do que para adultos (32,2%). Os resultados obtidos evidenciam que o isolado Ma69 Ă© altamente patogĂȘnico para S. carvalhoi, tanto em laboratĂłrio quanto em casa de vegetação, constituindo uma alternativa promissora para sua utilização como inseticida microbiano.bitstream/item/38778/1/BP200524.pd
Chiral Fermions and Quadratic Divergences
In an approach towards naturalness without supersymmetry, renormalization
properties of nonsupersymmetric abelian quiver gauge theories are studied. In
the construction based on cyclic groups Z_p the gauge group is U(N)^p, the
fermions are all in bifundamentals and the construction allows scalars in
adjoints and bifundamentals. Only models without adjoint scalars, however,
exhibit both chiral fermions and the absence of one-loop quadratic divergences
in the scalar propagator.Comment: 11 page
Using emoji in response to customer reservation requests and service reviews
The use of paralinguistic cuesâincluding emojiâin computer-mediated communication has become prevalent in recent years. Brands and service providers have also been using these cues in their communication strategies. And yet, research examining how such emoji use influences customersâ perception and behavior is still scarce. In two experiments (combined ), we tested if using emoji to reply to a customer request (restaurant reservation, Study 1) or online review (hotel experience, Study 2) influenced perceptions of the brands. The emoji used by the brand was always congruent with the valence of the situation. Results from both studies revealed that the presence (vs. absence) of emoji influenced consumersâ perception of the brand/service at several levels. Specifically, the restaurant/hotel was perceived to have a more informal communication style, have a warmer service, and be more modern. In Study 1, we also observed that emoji use had a positive impact on competence perception and reservation intentions. Importantly, these effects of emoji use were not moderated by the valence of the situation. Taken together, our results showed that emoji can influence different perceptions about brands and services and determine how customers relate to brands.info:eu-repo/semantics/publishedVersio
No evidence for feedback: Unexceptional Low-ionization winds in Host galaxies of Low Luminosity Active Galactic Nuclei at Redshift z ~1
We study winds in 12 X-ray AGN host galaxies at z ~ 1. We find, using the
low-ionization Fe II 2586 absorption in the stacked spectra, that the
probability distribution function (PDF) of the centroid velocity shift in AGN
has a median, 16th and 84th percentiles of (-87, -251, +86) km/s respectively.
The PDF of the velocity dispersion in AGN has a median, 84th and 16th
percentile of (139, 253, 52) km/s respectively. The centroid velocity and the
velocity dispersions are obtained from a two component (ISM+wind) absorption
line model. The equivalent width PDF of the outflow in AGN has median, 84th and
16th percentiles of (0.4, 0.8, 0.1) Angstrom. There is a strong ISM component
in Fe II 2586 absorption with (1.2, 1.5, 0.8) Angstrom, implying presence of
substantial amount cold gas in the host galaxies. For comparison, star-forming
and X-ray undetected galaxies at a similar redshift, matched roughly in stellar
mass and galaxy inclination, have a centroid velocity PDF with percentiles of
(-74, -258, +90) km/s, and a velocity dispersion PDF percentiles of (150, 259,
57) km/s. Thus, winds in the AGN are similar to star-formation-driven winds,
and are too weak to escape and expel substantial cool gas from galaxies. Our
sample doubles the previous sample of AGN studied at z ~ 0.5 and extends the
analysis to z ~ 1. A joint reanalysis of the z ~ 0.5 AGN sample and our sample
yields consistent results to the measurements above.Comment: 24 pages, 11 figures, accepted in Ap
Finite dimensional quantizations of the (q,p) plane : new space and momentum inequalities
We present a N-dimensional quantization a la Berezin-Klauder or frame
quantization of the complex plane based on overcomplete families of states
(coherent states) generated by the N first harmonic oscillator eigenstates. The
spectra of position and momentum operators are finite and eigenvalues are
equal, up to a factor, to the zeros of Hermite polynomials. From numerical and
theoretical studies of the large behavior of the product of non null smallest positive and largest eigenvalues, we infer
the inequality (resp. ) involving, in suitable
units, the minimal () and maximal () sizes of
regions of space (resp. momentum) which are accessible to exploration within
this finite-dimensional quantum framework. Interesting issues on the
measurement process and connections with the finite Chern-Simons matrix model
for the Quantum Hall effect are discussed
The effect of thresholding on temporal avalanche statistics
We discuss intermittent time series consisting of discrete bursts or
avalanches separated by waiting or silent times. The short time correlations
can be understood to follow from the properties of individual avalanches, while
longer time correlations often present in such signals reflect correlations
between triggerings of different avalanches. As one possible source of the
latter kind of correlations in experimental time series, we consider the effect
of a finite detection threshold, due to e.g. experimental noise that needs to
be removed. To this end, we study a simple toy model of an avalanche, a random
walk returning to the origin or a Brownian bridge, in the presence and absence
of superimposed delta-correlated noise. We discuss the properties after
thresholding of artificial timeseries obtained by mixing toy avalanches and
waiting times from a Poisson process. Most of the resulting scalings for
individual avalanches and the composite timeseries can be understood via random
walk theory, except for the waiting time distributions when strong additional
noise is added. Then, to compare with a more complicated case we study the
Manna sandpile model of self-organized criticality, where some further
complications appear.Comment: 15 pages, 12 figures, submitted to J. Stat. Mech., special issue of
the UPoN2008 conferenc
Mixture of Kernels and Iterated Semidirect Product of Diffeomorphisms Groups
In the framework of large deformation diffeomorphic metric mapping (LDDMM),
we develop a multi-scale theory for the diffeomorphism group based on previous
works. The purpose of the paper is (1) to develop in details a variational
approach for multi-scale analysis of diffeomorphisms, (2) to generalise to
several scales the semidirect product representation and (3) to illustrate the
resulting diffeomorphic decomposition on synthetic and real images. We also
show that the approaches presented in other papers and the mixture of kernels
are equivalent.Comment: 21 pages, revised version without section on evaluatio
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