Comparative Study of Inference Methods for Bayesian Nonnegative Matrix Factorisation

In this paper, we study the trade-offs of different inference approaches for Bayesian matrix factorisation methods, which are commonly used for predicting missing values, and for finding patterns in the data. In particular, we consider Bayesian nonnegative variants of matrix factorisation and tri-factorisation, and compare non-probabilistic inference, Gibbs sampling, variational Bayesian inference, and a maximum-a-posteriori approach. The variational approach is new for the Bayesian nonnegative models. We compare their convergence, and robustness to noise and sparsity of the data, on both synthetic and real-world datasets. Furthermore, we extend the models with the Bayesian automatic relevance determination prior, allowing the models to perform automatic model selection, and demonstrate its efficiency

Mineralization of sheep manure and its influence on lettuce production

Diversos resíduos orgânicos são utilizados na agricultura sem o adequado conhecimento da sua dinâmica de mineralização. Avaliou-se a mineralização de esterco de ovinos e sua influência na produção de alface. Utilizou-se o delineamento experimental de blocos ao acaso com três repetições. Foram utilizadas 25 t ha-1 como dose de esterco para cada um dos seguintes tratamentos: 1) esterco de ovinos que se alimentaram de feno de mandioca (PAM); 2) esterco de ovinos que se alimentaram de subproduto de ervilha (ERV); 3) esterco de ovinos que se alimentaram de feno de capim coast-cross (FCC); 4) esterco de ovinos que se alimentaram de subproduto de saccharina (SAC) e 5) solo sem aplicação de esterco (testemunha). Foi determinada semanalmente a respiração basal do solo, utilizada como indicador de mineralização da matéria orgânica. A massa fresca de alface foi avaliada como medida de produção. Os tratamentos ERV, FCC e SAC apresentaram ganhos de massa fresca na ordem de 68, 65 e 62% em relação à testemunha e de 43, 39 e 33% em relação ao PAM, respectivamente. A produção menor promovida pelo PAM, em relação às demais, pode ser explicada pela forma de mineralização da matéria orgânica que apresentou elevada respiração microbiana cinco dias após o transplantio, com acentuado declínio, nas medições subseqüentes, ao longo do ciclo da cultura. Os demais tratamentos apresentaram mineralização sincronizada com conseqüente aumento na produção de massa fresca. ____________________________________________________________________________________________________________ ABSTRACTSeveral organic wastes are used in agriculture with no precise knowledge about the mineralization dynamics of these materials. In this study the sheep manure mineralization and its influence on the lettuce production was evaluated. A randomized block design with three replications was used. Five treatments were studied using 25 t ha-1 as dose of manure: 1) sheep manure obtained from animals fed with cassava straw (PAM); 2) sheep manure obtained from animals fed with residue of pea crop (ERV); 3) sheep manure obtained from animals fed with Coast-Cross hay (FCC), 4) sheep manure obtained from animals fed with saccharin residue (SAC) and 5) soil without application of manure (control). Weekly the basal respiration was determined and used as an indicator of organic matter mineralization. Lettuce fresh mass was evaluated as a measure of production. Treatments ERV, FCC and SAC showed superior weight gains of 68, 65 and 62% compared to the control and 43, 39 and 33% compared to MAP, respectively. Lower production promoted by the MAP in relation to the other treatments can be explained by organic matter mineralization that showed a high microbial respiration five days after transplanting, with marked decline in subsequent measurements during the crop cycle. The other systems showed mineralization synchronized with the production increase of lettuce fresh mass

Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at √s=8 TeV

The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model

Health promotion in school environment in Brazil

ABSTRACT OBJECTIVE Evaluate the school environments to which ninth-year students are exposed in Brazil and in the five regions of the country according to health promotion guidelines. METHODS Cross-sectional study from 2012, with a representative sample of Brazil and its macroregions. We interviewed ninth-year schoolchildren and managers of public and private schools. We proposed a score of health promotion in the school environment (EPSAE) and estimated the distribution of school members according to this score. Crude and adjusted odds ratios (OR) were used, by ordinal regression, to determine the schoolchildren and schools with higher scores, according to the independent variables. RESULTS A student is more likely to attend a school with a higher EPSAE in the South (OR = 2.80; 95%CI 2.67–2.93) if the school is private (OR = 4.52; 95%CI 4.25–4.81) and located in a state capital, as well as if the student is 15 years of age or older, has a paid job, or has parents with higher education. CONCLUSIONS The inequalities among the country’s regions and schools are significant, demonstrating the need for resources and actions that promote greater equity

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

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter