Inglês (US)

The composition and potential hosts of mycophagous Drosophilidae from a section of the Brazilian Amazon forest in the Caxiuanã National forest were investigated. Sampling was performed in three different periods at long the wet season (January (beginning) and July (end) 2013 and May (middle) 2014). The samples were collected from existing trails by actively searching for fungal fruiting bodies where Drosophilidae were present. We present composition and richness analysis over two years of sampling sampling Drosophilidae and Fungi. We evaluate sampling completeness using asymptotic species richness estimators. Out of 159 fruiting body samples and 64 fungal species, 5,124 drosophilids belonging to 55 species and 5 genera were collected. The mycophagous Drosophilidae richness values estimated by Jackknife 1 and Bootstrap were 69 and 61, respectively. The estimated fly richness correlated positively with fungal richness and abundance. Among the Drosophilidae species identified in this study, approximately 5% represent new occurrences for Brazil and 56% represent new species. Four genera belonging to the Zygothrica genus group are found in the Amazon region, and these genera represent 80% of the fungus-associated fauna known to date for the tropics. In conclusion, our results show that the fungal richness and abundance were the factors that determined the high diversity of mycophagous Drosophilidae

Inglês (US)

The composition and potential hosts of mycophagous Drosophilidae from a section of the Brazilian Amazon forest in the Caxiuanã National forest were investigated. Sampling was performed in three different periods at long the wet season (January (beginning) and July (end) 2013 and May (middle) 2014). The samples were collected from existing trails by actively searching for fungal fruiting bodies where Drosophilidae were present. We present composition and richness analysis over two years of sampling sampling Drosophilidae and Fungi. We evaluate sampling completeness using asymptotic species richness estimators. Out of 159 fruiting body samples and 64 fungal species, 5,124 drosophilids belonging to 55 species and 5 genera were collected. The mycophagous Drosophilidae richness values estimated by Jackknife 1 and Bootstrap were 69 and 61, respectively. The estimated fly richness correlated positively with fungal richness and abundance. Among the Drosophilidae species identified in this study, approximately 5% represent new occurrences for Brazil and 56% represent new species. Four genera belonging to the Zygothrica genus group are found in the Amazon region, and these genera represent 80% of the fungus-associated fauna known to date for the tropics. In conclusion, our results show that the fungal richness and abundance were the factors that determined the high diversity of mycophagous Drosophilidae

Cultura política de la democracia en Perú y en las Américas, 2014 : gobernabilidad democrática a través de 10 años del Barómetro de las Américas

El presente estudio es parte de un programa de investigaciones que el Proyecto de Opinión Pública de América Latina (LAPOP) viene llevando a cabo desde hace más de dos décadas. LAPOP es un consorcio de instituciones académicas y de investigación en las Américas, con sede central en Vanderbilt University, en Estados Unidos. En el proyecto LAPOP participan más de 30 instituciones de toda la región, cuyos esfuerzos tienen el propósito de producir estudios científicos, objetivos e independientes de opinión pública. Dichas investigaciones se enfocan principalmente en la medición de actitudes y comportamientos políticos relacionados con la democracia y la calidad de vida

Checklist of the dipterofauna (Insecta) from Roraima, Brazil, with special reference to the Brazilian Ecological Station of Maracá

Roraima is a Brazilian state located in the northern portion of the Amazon basin, with few studies regarding its biodiversity. The Ecological Station of Maracá (Brazil, state of Roraima) harbors the third largest Brazilian pluvial island and is composed of a transitional landscape of savanna and Amazon rainforest components. Despite its ecological importance and strategic localization, few studies covered the dipterofauna of this locality. An updated checklist addressing 41 families of true flies (Diptera) occurring in Roraima is presented based on the literature and the specimens collected during a field expedition that occurred in 2015. This checklist brings several improvements such as new records of 165 taxa to the state of Roraima, 29 taxa to Brazil, and 259 morphotypes, mostly likely representing undescribed species

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Compressed representation of a partially defined integer function over multiple arguments

In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic