242 research outputs found

    Thermal requirements of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) lines in Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs.

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    This study aimed to evaluate the impact of temperature on the development of two lines of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), to determine the thermal requirements of this parasitoid wasp on Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs. The experiment was carried out with two lines (“Ubajara” and “Guaraciaba”, Ceará State) of T. pretiosum collected naturally parasitizing eggs of N. elegantalis in tomato (Solanum lycopersicum) fruits. In this experiment, 40 eggs of the host N. elegantalis and 4 females of the parasitoids were used, with exposure to parasitism for 24 hours at 25 ± 1 °C, relative humidity of 70 ± 10 %, and 12-h photophase. At the end of this period, females were removed and the tubes were transferred to incubators (RH = 70 ± 10 %; 12-h photophase), exposed to 15, 20, 25, 30, or 35 °C, until emergence of the following generation of the parasitoids. The percentage of emergence, sex ratio, the number of parasitoids that emerged per egg, and cycle duration were assessed. The experiments were set up in a completely randomized experimental design with 5 treatments (temperatures) and 12 replicates. ANOVA was conducted and the means were compared by Tukey test (P < 0.05). The base temperatures were 10.77 °C and 10.86 °C and the number of generations per year were 33.29 and 35.63 for “Ubajara” and “Guaraciaba”, respectively. The study showed that temperature changed the biological parameters, and cycle duration of the “Ubajara” and “Guaraciaba” lines decreased as temperature increased

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

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    We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

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    Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

    Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

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    Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

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    The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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    Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

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    The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

    Requerimientos térmicos de las líneas de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) en huevos de Neoleucinodes elegantalis (Lepidoptera: Crambidae)

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    This study aimed to evaluate the impact of temperature on the development of two lines of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), to determine the thermal requirements of this parasitoid wasp on Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs. The experiment was carried out with two lines (“Ubajara” and “Guaraciaba”, Ceará State) of T. pretiosum collected naturally parasitizing eggs of N. elegantalis in tomato (Solanum lycopersicum) fruits. In this experiment, 40 eggs of the host N. elegantalis and 4 females of the parasitoids were used, with exposure to parasitism for 24 hours at 25 ± 1 °C, relative humidity of 70 ± 10 %, and 12-h photophase. At the end of this period, females were removed and the tubes were transferred to incubators (RH = 70 ± 10 %; 12-h photophase), exposed to 15, 20, 25, 30, or 35 °C, until emergence of the following generation of the parasitoids. The percentage of emergence, sex ratio, the number of parasitoids that emerged per egg, and cycle duration were assessed. The experiments were set up in a completely randomized experimental design with 5 treatments (temperatures) and 12 replicates. ANOVA was conducted and the means were compared by Tukey test (P &lt; 0.05). The base temperatures were 10.77 °C and 10.86 °C and the number of generations per year were 33.29 and 35.63 for “Ubajara” and “Guaraciaba”, respectively. The study showed that temperature changed the biological parameters, and cycle duration of the “Ubajara” and “Guaraciaba” lines decreased as temperature increased.El objetivo de este estudio fue evaluar el impacto de la temperatura en el desarrollo de dos líneas de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), para determinar los requisitos térmicos de este parasitoide en huevos de Neoleucinodes elegantalis (Lepidoptera: Crambidae). El experimento se llevó a cabo con dos líneas (“Ubajara” y “Guaraciaba”, Ceará) de T. pretiosum a partir de huevos parasitarios de N. elegantalis en frutos de tomate (Solanum lycopersicum). En este experimento, se usaron 40 huevos del huésped N. elegantalis y 4 hembras de los parasitoides, con exposición al parasitismo durante 24 horas (a 25 ± 1 °C, 70 ± 10 % de HR y fotofase de 12 h). Al final de este período, se retiraron las hembras y los tubos se transfirieron a incubadoras (HR = 70 ± 10 % y fotofase de 12 h, a 15, 20, 25, 30 o 35 °C, hasta la aparición de la generación siguiente de parasitoides. Los parámetros evaluados fueron el porcentaje de emergencia, la proporción de sexos, el número de parasitoides que surgieron por huevo y la duración del ciclo. Los experimentos se establecieron en un diseño experimental completamente al azar con cinco tratamientos (temperaturas) y 12 repeticiones. Se realizó ANOVA y se compararon las medias mediante la prueba de Tukey. La temperatura base fue de 10,77 y 10,86 °C y el número de generaciones por año fue de 33,29 y 35,63 para “Ubajara” y “Guaraciaba”, respectivamente. La temperatura cambió los parámetros biológicos, y la duración del ciclo de las líneas “Ubajara” y “Guaraciaba” disminuyó a medida que aumentaba la temperatura

    New occurrence and potential distribution of Anastrepha zacharyi (Diptera: Tephritidae) in the Eastern Amazon

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    The species Anastrepha zacharyi Norrbom has recently been recorded in the Amazon, however the species is subsampling in the biome. In this research, we report a new occurrence of A. zacharyi in the state of Pará and, through climate suitability modelling, present new possible distribution areas of the species in the Brazilian eastern Amazon
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