575 research outputs found
Desenvolvimento larval de Simulium (Chirostilbia) pertinax (Diptera: Simuliidae) em criadouro artificial
This study aimed to observe the influence of different concentrations of nutrients over the period of development of Simulium (Chirostilbia) pertinax larvae. Were collected Simulium pertinax engorged females and then subjected to oviposition under stress. The eggs were removed and transported to an artificial breeding site, in which two alimentary supplements were compared, viz. algae and yeast in different concentrations. Few variations of abiotic factors were observed during the study, and they were within the standards of the S. (C.) pertinax species. Regarding the rate of pupae formation, a higher concentration of 5 ml of algae + 10 ml of yeast was observed, with significant differences in concentrations of 10 ml of algae and 10 ml of algae and 5 ml of yeast. In tests with 5ml of algae, 10 ml of yeast, and 5 ml of yeast, the end of larval development was not obtained in all replications. The small variation of abiotic factors is consistent with results of other authors, and the values observed in this experiment can be regarded as appropriate when compared to the standards required by this species. Use of seaweed, with or without other elements, for breeding in the laboratoryhas been made by several authors, as well as use of yeast. When S. (C.) pertinax were fed only with culture of algae, larval survival was up to 43 days, and, on the other hand, when fed with yeast broth they did not reach the complete larval development.Key words: Simulium (Chirostilbia) pertinax, larvae development period, larval feeding.Este estudo teve por objetivo observar a influência de diferentes concentrações de nutrientes sobre o período de desenvolvimento larvário de Simulium (Chirostilbia) pertinax. Foram coletadas fêmeas de S. (C.) pertinax ingurgitadas e submetidas à oviposição por “stress”. Os ovos foram retirados e transportados a um criadouro artificial, no qual foram comparados dois suplementos alimentares: alga e levedura, em diferentes concentrações. Poucas variações dos fatores abióticos foram observadas durante o estudo, encontrando-se dentro dos padrões para a espécie S. (C.) pertinax. Em relação à taxa de formação de pupas, foi observada uma maior taxa na concentração de 5 ml de alga + 10 ml de levedura, com diferença significativa em relação às concentrações de 10 ml de alga + 5 ml de levedura. Nos testes com 5 ml de alga, 10 ml de levedura e 5 ml de levedura, não foi obtido o término do desenvolvimento larvário em todas as repetições. A pouca variação dos fatores abióticos é compatível com resultados de outros autores; assim, os valores observados neste experimento podem ser considerados adequados, quando comparados aos padrões exigidos por esta espécie. A utilização de alga, associada ou não a outros elementos, para criação em laboratório, tem sido feita por diversos autores, assim como a utilização de levedura. Em criação de S. (C.) pertinax alimentada com cultura exclusiva de algas, ocorreu sobrevida larvária máxima de 43 dias, e, quando alimentada com caldo de levedura, não obtivemos o desenvolvimento larvário completo.Palavras-chave: Simulium (Chirostilbia) pertinax, período larvário, alimentação larval
Abundances of the elements in the solar system
A review of the abundances and condensation temperatures of the elements and
their nuclides in the solar nebula and in chondritic meteorites. Abundances of
the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New
Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New
York: Springer-Verlag, p. 560-63
Protons in near earth orbit
The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured
by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at
an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is
parameterized by a power law. Below the geomagnetic cutoff a substantial second
spectrum was observed concentrated at equatorial latitudes with a flux ~ 70
m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated
trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure
The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Molecular Gas Reservoirs in High-redshift Galaxies
We study the molecular gas properties of high-z galaxies observed in the ALMA Spectroscopic Survey (ASPECS) that targets an ˜1 arcmin2 region in the Hubble Ultra Deep Field (UDF), a blind survey of CO emission (tracing molecular gas) in the 3 and 1 mm bands. Of a total of 1302 galaxies in the field, 56 have spectroscopic redshifts and correspondingly well-defined physical properties. Among these, 11 have infrared luminosities {L}{IR}\gt {10}11 {L}⊙ , i.e., a detection in CO emission was expected. Out of these, 7 are detected at various significance in CO, and 4 are undetected in CO emission. In the CO-detected sources, we find CO excitation conditions that are lower than those typically found in starburst/sub-mm galaxy/QSO environments. We use the CO luminosities (including limits for non-detections) to derive molecular gas masses. We discuss our findings in the context of previous molecular gas observations at high redshift (star formation law, gas depletion times, gas fractions): the CO-detected galaxies in the UDF tend to reside on the low-{L}{IR} envelope of the scatter in the {L}{IR}{--}{L}{CO}\prime relation, but exceptions exist. For the CO-detected sources, we find an average depletion time of ˜1 Gyr, with significant scatter. The average molecular-to-stellar mass ratio ({M}{{H}2}/M *) is consistent with earlier measurements of main-sequence galaxies at these redshifts, and again shows large variations among sources. In some cases, we also measure dust continuum emission. On average, the dust-based estimates of the molecular gas are a factor ˜2-5× smaller than those based on CO. When we account for detections as well as non-detections, we find large diversity in the molecular gas properties of the high-redshift galaxies covered by ASPECS
A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics
experiment that will study cosmic rays in the to range and will be installed on the International Space Station
(ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the
space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected
cosmic ray triggers. Part of the \emph{Mir} space station was within the
AMS-01 field of view during the four day \emph{Mir} docking phase of this
flight. We have reconstructed an image of this part of the \emph{Mir} space
station using secondary and emissions from primary cosmic rays
interacting with \emph{Mir}. This is the first time this reconstruction was
performed in AMS-01, and it is important for understanding potential
backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor
stylistic and grammer change
Miniestaquia de Eucalyptus benthamii: efeito do genótipo, AIB, zinco, boro e coletas de brotações
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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