63 research outputs found
FLORA DA BAHIA: LEGUMINOSAE - CENOSTIGMA TUL., ERYTHROSTEMON KLOTZSCH E LIBIDIBIA (DC.) SCHLTDL. (CAESALPINIOIDEAE)
Leguminosae Juss. é a terceira famÃlia de angiospermas com maior diversidadeem número de espécies, sendo representada por 770 gêneros e cerca de 19.500 espéciesem seis subfamÃlias (LPWG, 2017). Possui distribuição global, ocorrendo nos principaisbiomas mundiais e apresenta grande diversidade morfológica, desde ervas efêmeras earbustos até árvores gigantes da floresta tropical e lianas lenhosas (LPWG, 2013)
Flora da Bahia: Violaceae e estudos taxonômicos no gênero Paypayrola Aubl.
Violaceae possui distribuição cosmopolita e inclui 23 gêneros e cerca de 800 espécies. No Brasil ocorrem 14 gêneros e cerca de 80 espécies, a maioria em Pombalia Vand. e Rinorea Aubl. (Souza e Lorenzi 2012; Paula-Souza, 2009).As Violaceae são ervas, árvores ou, menos frequentemente, lianas com folhas alternas espiraladas ou dÃsticas ou, menos frequentemente, opostas, simples, com estÃpulas conspÃcuas, persistentes ou caducas, raramente com pontuações translúcidas (Leonia Ruiz & Pav.), inflorescência em pseudoracemo, racemo, cimeira simples ou composta, fascÃculo ou flores solitárias, flores geralmente bissexuadas, actinomorfas a fortemente zigomorfas, diclamÃdeas, cálice pentâmero, dialissépalo, persistente na frutificação, imbricado, labelo (pétala abaxial) giboso a longamente calcarado nas flores zigomorfas, estames (3-)5, filetes livres ou unidos entre si, anteras rimosas, geralmente com conectivo provido de um apêndice membranáceo e apical (em algumas espécies os dois estames anteriores, são provido de apêndices nectarÃferos sobre os filetes), ovário súpero, (2-)3(-5)-carpelar, unilocular, placentação parietal, uni a pluriovulado, fruto cápsula, à s vezes membranácea e inflada (Anchietea e Hybanthopsis), raramente baga (Gloeospermum Triana & Planch. e Leonia) ou noz (Leonia) (Souza & Lorenzi 2012).A famÃlia tradicionalmente é dividida em três subfamÃlias (Hekking 1988): Leonioideae, com flores actinomorfas, prefloração irregularmente imbricada, representada apenas pelo gênero sul-americano Leonia; Violoideae, com flores actinomorfas ou zigomorfas, prefloração coclear distal ou quincuncial e Fusispermoideae, com flores actinomorfas, prefloração convoluta, representada pelo gênero Fusispermum Cuatrec. Paula-Souza (2009) realizou estudos filogenéticos na tribo Violeae e observou que Violoideae não é monofilética. Nesse mesmo trabalho também foi constatado o não monofiletismo de Hybanthus o que levou ao restabelecimento de Pombalia (Paula-Souza 2014), transferindo assim para este último gênero várias espécies listadas para a Bahia. No entanto, algumas espécies foram mantidas em Hybanthus mesmo apresentando caracterÃsticas que sustentariam sua transferência para Pombalia. Essa mesma autora aponta a necessidade de uma melhor diferenciação entre Pombalia e Hybanthus (Paula-Souza 2009).Apesar dos avanços no conhecimento da famÃlia, não existe um estudo taxonômico para o gênero Paypayrola, o que resulta em muitas confusões quanto a delimitação das espécies, sendo este o principal objetivo do presente trabalho
Inventário de Caesalpinia sensu lato (Leguminosae, Caesalpinioideae) no estado da Bahia
Leguminosae Juss. é a terceira famÃlia de angiospermas com maior diversidade em número de espécies, sendo representada por 770 gêneros e cerca de 20.000 espécies em seis subfamÃlias (Lewis et al., 2005; LPWG, 2017)
Measurement of production in pp collisions at =7  TeV with the ATLAS detector and limits on anomalous WWZ and WWγ couplings
This paper presents a measurement of the W^+W^- production cross section in pp collisions at sqrt{s}=7 TeV. The leptonic decay channels are analyzed using data corresponding to an integrated 4.6 fb-1 collected with the ATLAS detector at the Large Hadron Collider. The W^+W^- production cross section sigma(pp -> W^+W^-+X) is measured to be 51.9 +- 2.0 (stat) +- 3.9 (syst) +- 2.0 (lumi) pb, compatible with the Standard Model prediction of 44.7 +2.1 -1.9 pb. A measurement of the normalized fiducial cross section as a function of the leading lepton transverse momentum is also presented. The reconstructed transverse momentum distribution of the leading lepton is used to extract limits on anomalous WWZ and WWgamma couplings.Peer Reviewe
Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector
A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at TeV with the ATLAS experiment at the Large Hadron Collider. Four kinematic regions are explored using a dataset corresponding to an integrated luminosity of 4.7 fb(−1). No excess of events beyond expectations from Standard Model processes is observed, and limits are set on large extra dimensions and the pair production of dark matter particles.Peer Reviewe
ATLAS search for new phenomena in dijet mass and angular distributions using collisions at TeV
Mass and angular distributions of dijets produced in LHC proton-proton collisions at a centre-of-mass energy =7 TeV have been studied with the ATLAS detector using the full 2011 data set with an integrated luminosity of 4.8/fb. Dijet masses up to 4.0 TeV have been probed. No resonance-like features have been observed in the dijet mass spectrum, and all angular distributions are consistent with the predictions of QCD. Exclusion limits on six hypotheses of new phenomena have been set at 95% CL in terms of mass or energy scale, as appropriate. These hypotheses include excited quarks below 2.83 TeV, colour octet scalars below 1.86 TeV, heavy W bosons below 1.68 TeV, string resonances below 3.61 TeV, quantum black holes with six extra space-time dimensions for quantum gravity scales below 4.11 TeV, and quark contact interactions below a compositeness scale of 7.6 TeV in a destructive interference scenario.Peer Reviewe
Search for diphoton events with large missing transverse momentum in 7 TeV proton-proton collision data with the ATLAS detector
A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb^-1. No excess of events was observed above the Standard Model prediction and model-dependent 95% confidence level exclusion limits are set. In the context of a generalised model of gauge-mediated supersymmetry breaking with a bino-like lightest neutralino of mass above 50 GeV, gluinos (squarks) below 1.07 TeV (0.87 TeV) are excluded, while a breaking scale Lambda below 196 TeV is excluded for a minimal model of gauge-mediated supersymmetry breaking. For a specific model with one universal extra dimension, compactification scales 1/R < 1.40 TeV are excluded. These limits provide the most stringent tests of these models to date.Peer Reviewe
Measurement of the flavour composition of dijet events in collisions at TeV with the ATLAS detector
This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at sqrt{s}=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb^-1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y| < 2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions.Peer Reviewe
Measurement of the differential cross-section of meson production in pp collisions at = 7 TeV at ATLAS
The production cross-section of B+ mesons is measured as a function of transverse momentum pT and rapidity y in proton--proton collisions at center-of-mass energy sqrt(s) = 7 TeV, using 2.4 fb-1 of data recorded with the ATLAS detector at the Large Hadron Collider. The differential production cross-sections, determined in the range 9<pT<120 GeV and y<2.25, are compared to next-to-leading-order theoretical predictions.Peer Reviewe
Study of heavy-flavor quarks produced in association with top-quark pairs at   TeV using the ATLAS detector
Using a sample of dilepton top-quark pair () candidate events, a study is performed of the production of top-quark pairs together with heavy-flavor (HF) quarks, the sum of and +c+X, collectively referred to as  + HF. The data set used corresponds to an integrated luminosity of 4.7   of proton-proton collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The presence of additional HF (b or c) quarks in the sample is inferred by looking for events with at least three b-tagged jets, where two are attributed to the b quarks from the decays and the third to additional HF production. The dominant background to  + HF in this sample is +jet events in which a light-flavor jet is misidentified as a heavy-flavor jet. To determine the heavy- and light-flavor content of the additional b-tagged jets, a fit to the vertex mass distribution of b-tagged jets in the sample is performed. The result of the fit shows that 79 ± 14 (stat) ± 22 (syst) of the 105 selected extra b-tagged jets originate from HF quarks, 3 standard deviations away from the hypothesis of zero + HF production. The result for extra HF production is quoted as a ratio (RHF) of the cross section for  + HF production to the cross section for production with at least one additional jet. Both cross sections are measured in a fiducial kinematic region within the ATLAS acceptance. RHF is measured to be [6.2±1.1(stat)±1.8(syst)]% for jets with > 25  GeV and |η| < 2.5, in agreement with the expectations from Monte Carlo generators.Peer Reviewe
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