468 research outputs found
Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury
Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) is an important pest for Brazilian sugarcane. In the present study, we detected two distinct spots in hemolymph from septic injured larvae (HDs1 and HDs2), which are separated by 2DE gel electrophoresis. Both spots were subjected to in-gel tryptic digestion and MALDI-TOF/TOF analysis, which revealed the sequence VFGTLGSDDSGLFGK present in both HDs1 and HDs2. This sequence had homology and 80% identity with specific Lepidoptera antimicrobial peptides called gloverins. Analyses using the ImageMaster 2D software showed pI 8.94 of the HDs1 spot, which is similar to that described to Hyalophora gloveri gloverin (pI 8.5). Moreover, the 14-kDa molecular mass of the spot HDs1 is compatible to that of gloverins isolated from the hemolymph of Trichoplusia ni, Helicoverpa armigera and H. gloveri. Antimicrobial assays with partially purified fractions containing the HDs1 and HDs2 polypeptides demonstrated activity against Escherichia coli. This is the first report of antimicrobial polypeptides in D. saccharalis, and the identification of these peptides may help in the generation of new strategies to control this pest
A geometric approach to time evolution operators of Lie quantum systems
Lie systems in Quantum Mechanics are studied from a geometric point of view.
In particular, we develop methods to obtain time evolution operators of
time-dependent Schrodinger equations of Lie type and we show how these methods
explain certain ad hoc methods used in previous papers in order to obtain exact
solutions. Finally, several instances of time-dependent quadratic Hamiltonian
are solved.Comment: Accepted for publication in the International Journal of Theoretical
Physic
Markov Properties of Electrical Discharge Current Fluctuations in Plasma
Using the Markovian method, we study the stochastic nature of electrical
discharge current fluctuations in the Helium plasma. Sinusoidal trends are
extracted from the data set by the Fourier-Detrended Fluctuation analysis and
consequently cleaned data is retrieved. We determine the Markov time scale of
the detrended data set by using likelihood analysis. We also estimate the
Kramers-Moyal's coefficients of the discharge current fluctuations and derive
the corresponding Fokker-Planck equation. In addition, the obtained Langevin
equation enables us to reconstruct discharge time series with similar
statistical properties compared with the observed in the experiment. We also
provide an exact decomposition of temporal correlation function by using
Kramers-Moyal's coefficients. We show that for the stationary time series, the
two point temporal correlation function has an exponential decaying behavior
with a characteristic correlation time scale. Our results confirm that, there
is no definite relation between correlation and Markov time scales. However
both of them behave as monotonic increasing function of discharge current
intensity. Finally to complete our analysis, the multifractal behavior of
reconstructed time series using its Keramers-Moyal's coefficients and original
data set are investigated. Extended self similarity analysis demonstrates that
fluctuations in our experimental setup deviates from Kolmogorov (K41) theory
for fully developed turbulence regime.Comment: 25 pages, 9 figures and 4 tables. V3: Added comments, references,
figures and major correction
Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
This paper reports a measurement of D*+/- meson production in jets from
proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the
CERN Large Hadron Collider. The measurement is based on a data sample recorded
with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets
with transverse momentum between 25 and 70 GeV in the pseudorapidity range
|eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay
chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate
is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for
D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z <
1. Monte Carlo predictions fail to describe the data at small values of z, and
this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table,
matches published version in Physical Review
Influencia de la irrigación en el atizonamiento de las hojas de ñame (Dioscorea cayennensis) por Curvularia eragrostidis en el N.E. de Brasil
El atizonmiento de las hojas(quema), causado por Curvularia eragrostidis, es una de las principales enfermedades del ñame (Dioscorea cayennensis) en elnoreste brasilero. Por esto se analizó el progreso y patrón espacial de la enfermedad en cuatro áreas con plantaciones comerciales de ñame, dos irrigadas (A y B ) y dos no irrigadas (Cy D), localizadas en ell municipio deAlianca, Estado de Pernambuco, Brasil.En las áreas irrigadas, la cantidad inicial y la máxima severidad de la enfermedad, fueron superiores a las verificadas en las áreas no irrigadas. Utilizando el modelo de Gompertz, no se verificaron diferencias significativas entre las tasas de progreso de la enfermedad, siendo idénticas en las áreas A, B, C y ligeramente inferior en el área D. Los valores de área bajo la curva de progreso de la enfermedad fueron superiores en las áreas irrigadas, aunque con pequeña diferencia a lo constatado en el área D. En las áreas B, C y D, las plantas enfermas presentaron un patrón aleatorio, dentro y entre las lineas de plantación y el área A presentó un patrón agregado, especialmente entre las lineas.Considerando estos resultados, es posible concluir que la irrigación no tuvo influencia significativa en la severidad de la mancha necrótica de las hojas deñame ni en la agregación de plantas enfermas dentro de las áreas de plantación
A method for the complete analysis of NORM building materials by γ-ray spectrometry using HPGe detectors
[EN] A methodology including software tools for analysing NORM building materials and residues by low-level gamma-ray spectrometry has been developed. It comprises deconvolution of gamma-ray spectra using the software GALEA with focus on the natural radionuclides and Monte Carlo simulations for efficiency and true coincidence summing corrections. The methodology has been tested on a range of building materials and validated against reference materials
Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data
We present an update of a search for supersymmetry in final states containing
jets, missing transverse momentum, and one isolated electron or muon, using
1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the
ATLAS experiment at the LHC in the first half of 2011. The analysis is carried
out in four distinct signal regions with either three or four jets and
variations on the (missing) transverse momentum cuts, resulting in optimized
limits for various supersymmetry models. No excess above the standard model
background expectation is observed. Limits are set on the visible cross-section
of new physics within the kinematic requirements of the search. The results are
interpreted as limits on the parameters of the minimal supergravity framework,
limits on cross-sections of simplified models with specific squark and gluino
decay modes, and limits on parameters of a model with bilinear R-parity
violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables,
final version to appear in Physical Review
Measurement of charm production at central rapidity in proton-proton collisions at TeV
The -differential production cross sections of the prompt (B
feed-down subtracted) charmed mesons D, D, and D in the rapidity
range , and for transverse momentum GeV/, were
measured in proton-proton collisions at TeV with the ALICE
detector at the Large Hadron Collider. The analysis exploited the hadronic
decays DK, DK, DD, and their charge conjugates, and was performed on a
nb event sample collected in 2011 with a
minimum-bias trigger. The total charm production cross section at TeV and at 7 TeV was evaluated by extrapolating to the full phase space
the -differential production cross sections at TeV
and our previous measurements at TeV. The results were compared
to existing measurements and to perturbative-QCD calculations. The fraction of
cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/307
Analysis of milk using a portable potentiometric electronic tongue based on five polymeric membrane sensors
A portable potentiometric electronic tongue (PE-tongue) was developed and applied to evaluate the quality of milk with different fat content (skimmed, semi-skimmed, and whole) and with different nutritional content (classic, calcium-enriched, lactose-free, folic acid-enriched, and enriched in sterols of vegetal origin). The system consisted of a simplified array of five sensors based on PVC membranes, coupled to a data logger. The five sensors were selected from a larger set of 20 sensors by applying the genetic algorithm (GA) to the responses to compounds usually found in milk including salts (KCl, CaCl2, and NaCl), sugars (lactose, glucose, and galactose), and organic acids (citric acid and lactic acid). Principal component analysis (PCA) and support vector machine (SVM) results indicated that the PE-tongue consisting of a five-electrode array could successfully discriminate and classify milk samples according to their nutritional content. The PE-tongue provided similar discrimination capability to that of a more complex system formed by a 20-sensor array. SVM regression models were used to predict the physicochemical parameters classically used in milk quality control (acidity, density, %proteins, %lactose, and %fat). The prediction results were excellent and similar to those obtained with a much more complex array consisting of 20 sensors. Moreover, the SVM method confirmed that spoilage of unsealed milk could be correctly identified with the simplified system and the increase in acidity could be accurately predicted. The results obtained demonstrate the possibility of using the simplified PE-tongue to predict milk quality and provide information on the chemical composition of milk using a simple and portable system.We appreciate the financial support of MINECO-FEDER Plan Nacional (RTI 2018-097990-B-100) and Junta de Castilla y Leon - FEDER (VA275P18) and “Infraestructuras Red de Castilla y León (INFRARED)” UVA01info:eu-repo/semantics/publishedVersio
Influencia de la distancia de plantación y selección de genotipos de mani (Arachis hypogaea L.) resistentes a Cercosporidium personatum (Berk & Curt.)Deigh. y Puccinia arachidis Speg.
La mancha negra y la roya, causadas respectivamente por los hongos Cercosporidium personatum y Puccinia arachidis, constituyen las principales enfermedades del maní en el N.E. brasilero. Buscando contribuir al manejo integrado de esas enfermedades, 15 genotipos de maní fueron analizados con respecto a los niveles de resistencia bajo condiciones naturales de infección.El diseño se efectuó en bloques completos al azar, con 5 repeticiones. La evaluación fue efectuada a los 85 días después de la siembra, midiendose la incidencia y la severidad de las enfermedades en 45 folíolos por parcela.Los genotipos BR-1, L2IAC2, CNPA Senegal y CNPA 125 AM, se destacaron de los demas al evidenciar los menores niveles de severidad de la mancha negra, mientras en la incidencia de la roya se destacó CNPA Senegal y CNPA Havana. El efecto de los tipos de espacimientos de siembra fueron de 0,3, 0,5 y 0,7 m entre líneas con 5, 10 y 15 plantas/m lineal. Los niveles de severidad de las enfermedades fueron analizados utilizándose el cultivar IAC Tupa. La evaluación fue efectuada 90 días después de fa siembra, en 45 folíolos de la línea central de cada parcela. Los reslIltados no evidenciaron un efecto significativo de los tipos de espacimientos en la severidad de la mancha negra y de la roya
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