1,170 research outputs found
A supergeometric approach to Poisson reduction
This work introduces a unified approach to the reduction of Poisson manifolds
using their description by graded symplectic manifolds. This yields a
generalization of the classical Poisson reduction by distributions
(Marsden-Ratiu reduction). Further it allows one to construct actions of strict
Lie 2-groups and to describe the corresponding reductions.Comment: 40 pages. Final version accepted for publicatio
Inter-relation of sylvatic and domestic transmission of Trypanosoma cruzi in areas with and without domestic vectorial transmission in Minas Gerais, Brazil
During the period 1980-1986, we captured triatomine bugs and mammalian
reservoir hosts from sylvatic and domestic situations in different
municipalities of the State of Minas Gerais. Trypanosoma cruzi was
isolated from captured bugs, mammals and patients. After cultivation in
LIT medium, the electrophoretic enzyme profiles were determined. We
obtained a total of 32 parasite isolates from regions with active
domestic transmission, and 24 isolates from areas under control. For
the first areas the results suggest introduction of T. cruzi from
sylvatic habitats, through incursion of infected opossums and/or
sylvatic T. sordida, which appears to have given rise to at least one
acute human infection. Of particular interest is the finding of
sylvatic opossums and a T. sordida nymph infected with ZB, that could
indicate return of parasites from chronic human infections to sylvatic
transmission cycles. For the areas under control we also interpret the
results as interaction between sylvatic and domestic cycles of
transmission, here through the invasion of houses by bugs carrying the
Z1 zymodeme from the sylvatic environment. The Multivariate
Correspondence Analysis gives a spatial description between the
different parasite isolates and confirms the existence of a bridge in
the opposite direction in the region with active vectorial transmission
including the exporting of Z2 through the peridomestic environment into
the sylvatic cycle. For the other areas this bridge corresponds
especially to Panstrongylus megistus, importing Z1 into the domestic
environment
Hidrogenionic potential (pH) of the attractant, trap density and control threshold for Ceratitis capitata (Diptera: tephritidae) on Hamlin oranges in São Paulo central region, Brazil
This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant
(protein bait) Milhocina® and borax (sodium borate) in the feld, on the capture of fruit flies in McPhail
traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove
in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata,
comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C.
capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four
densities were similar, indicating that the population can be estimated with one trap per hectare in areas
with high populations. It was found positive relationships between captures of C. capitata and the number
of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures
and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin
orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.Esta pesquisa teve como objetivos: avaliar o efeito do pH inicial, 4.5; 6.5 e 8.5, do atrativo
proteico Milhocina® e bórax (tetraborato de sódio) na captura de moscas-das-frutas em armadilhas McPhail;
estudar densidades de armadilhas, 1; 2; 4 e 8 por hectare, para estimar níveis de controle em laranja cv.
Hamlin, na região central de São Paulo. A espécie predominante, com 99% das moscas-das-frutas capturadas,
foi Ceratitis capitata, sendo 80% de fêmeas. As maiores capturas de C. capitata ocorreram nas armadilhas
com Milhocina® e bórax em pH 8.5. As capturas, nas 4 densidades, foram semelhantes, indicando que a
população pode ser estimada com uma armadilha por hectare em áreas de altas populações. Houve relações
positivas entre capturas de C. capitata e o número de frutos danificados, 2 e 3 semanas após a captura. Assim,
foram obtidas equações que relacionam a captura e o dano, possibilitando estimar níveis de controle desse
inseto. As perdas médias causadas por C. capitata em laranja cv. Hamlin chegaram a 2,5 toneladas de frutos
por hectare ou 7,5% da produção.info:eu-repo/semantics/publishedVersio
Mass-luminosity relation for FGK main sequence stars: metallicity and age contributions
The stellar mass-luminosity relation (MLR) is one of the most famous
empirical "laws", discovered in the beginning of the 20th century. MLR is still
used to estimate stellar masses for nearby stars, particularly for those that
are not binary systems, hence the mass cannot be derived directly from the
observations. It's well known that the MLR has a statistical dispersion which
cannot be explained exclusively due to the observational errors in luminosity
(or mass). It is an intrinsic dispersion caused by the differences in age and
chemical composition from star to star. In this work we discuss the impact of
age and metallicity on the MLR. Using the recent data on mass, luminosity,
metallicity, and age for 26 FGK stars (all members of binary systems, with
observational mass-errors <= 3%), including the Sun, we derive the MLR taking
into account, separately, mass-luminosity, mass-luminosity-metallicity, and
mass-luminosity-metallicity-age. Our results show that the inclusion of age and
metallicity in the MLR, for FGK stars, improves the individual mass estimation
by 5% to 15%.Comment: 7 pages, 4 figures, 1 table, accepted in Astrophysics and Space
Scienc
Analysis of the workforce Skills for the factories of the future
Industry 4.0 is promoting the digitisation of manufacturing sector towards smart and more efficient factories, seen worldwide as the fourth industrial revolution. However, its complete adoption strongly depends on the skills that existing workforce and future professionals can have in the different dimensions of this multidisciplinary vision, contributing to increase the digital maturity level of companies from the industrial sector. Additionally, new job profiles are emerging to face the implementation of these innovative approaches, which implies the need for the re-qualification and up-skilling of existing workforce, particularly focusing the digital skills. In this context, this paper analyses the gap and impact in the non-technical and technical skills required for the successful transition into digitisation, particularly across six manufacturing areas covering the collaborative robotics (cobots), additive manufacturing, mechatronics and machine automation, data analytics, cybersecurity and humanmachine interface.This work is part of the FIT4FoF project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 820701.info:eu-repo/semantics/publishedVersio
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
Poder de mercado no segmento de distribuição de Gasolina C: uma análise a partir da nova organização industrial empírica
Este artigo tem como objetivo avaliar o grau de poder de mercado no setor de distribuiçãode gasolina C, nas regiões brasileiras, no período de 2002 a 2008. Para tal,baseou-se na Teoria da Nova Organização Industrial Empírica (NOIE), especificamente,no modelo proposto por Bresnahan (1982) e Lau (1982). Uma versão dinâmica domodelo também foi estimada. Os resultados indicaram que, exceto para a região Norte,para o modelo estático, as empresas distribuidoras de gasolina C não agem comotomadoras de preços (Λ = 0). No outro extremo, a hipótese de conluio perfeito (Λ = 1) entre elas foi rejeitada. Verificou-se que, em várias regiões, os parâmetrosrevelaram-se suficientemente baixos, sugerindo que as empresas distribuidoras apresentamelevada competição entre si.This study aims to assess the degree of market power in the distribution sector gasolineC, in Brazilian regions, from 2002 to 2008. To this end, based on the Theory of the NewEmpirical Industrial Organization (NOIE), specifically, the model proposed by Bresnahan(1982) and Lau (1982). A dynamic version of the model was also estimated. The resultsindicated that, except for the northern region to the static model, the distributors ofgasoline C does not act as price takers. At the other extreme, the hypothesis of perfectcollusion between them was rejected. It was found that, in many regions, parametersproved to be sufficiently low, suggesting that the distributors have high competitionwith each other
Electrogenerated hydrophilic carbon nanomaterials with tailored electrocatalytic activity
This work investigates the influence of the type of buffer electrolyte used in the generation of Electrochemical Hydrophilic Carbon (EHC) on their physical-chemical properties and electrocatalytic activity. The EHC nanomaterials were prepared in three different biological buffers, phosphate, glycine and citrate buffers (EHC@phosphate, EHC@glycine, EHC@citrate) and their surface properties were fully characterized by AFM, XPS and Raman. The EHC nanomaterials drop cast onto a glassy carbon electrode were electrochemically characterized in [Fe(CN)6]3-/4- and [Ru(NH3)6]3+/2+ redox probes solutions, and their electrocatalytic activity was investigated towards hydrogen peroxide and oxygen reduction reactions (ORR) in a phosphate buffer solution. It was found that the nature of buffer electrolyte strongly influences the surface chemical state of the EHC materials, disorder degree in the hexagonal sp2 carbon network and oxygen functional groups, affecting both the EHC electrocatalytic activity towards the ORR and H2O2 reduction reaction. The most catalytic material for the ORR was EHC@citrate, whereas EHC@glycine showed the highest oxygen conversion (n ≅ 2.7 to 3). Moreover, it was shown that the content of oxygen singly bonded to carbon correlates strongly with the number of electrons transferred.
A very singular behaviour in the electrochemical reduction of hydrogen peroxide was observed on EHC@glycine, qualitatively interpreted as an autocatalytic reaction. In contrast, a blocking-like effect was depicted on EHC@phosphate. These results must have an important impact in the development of materials with peroxidase-like activity and in the design of O2 sensors with non-sensitivity to H2O2.publishe
Photosynthesis, yield and raw material quality of sugarcane injured by multiple pests
Understanding sugarcane (Saccharum spp.) response to multiple pest injury, sugarcane borer (Diatraea saccharalis) and spittlebug (Mahanarva fimbriolata), is essential to make better management decisions. Moreover, the consequences of both pests on the sugarcane raw material quality have not yet been studied. A field experiment was performed in São Paulo State, Brazil, where sugarcane plants were exposed to pests individually or in combination. Plots consisted of a 2-m long row of caged sugarcane plants. Photosynthesis was measured once every 3 months (seasonal measurement). Yield and sugar production were assessed. The measured photosynthesis rate was negatively affected by both borer and spittlebug infestations. Photosynthesis reduction was similar on plants infested by both pests as well as by spittlebug individual infestation. Plants under spittlebug infestation resulted in yield losses and represented 17.6% (individual infestation) and 15.5% (multiple infestations). The sucrose content and the sucrose yield per area were reduced when plants were infested by multiple pests or spittlebug
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
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