Efeitos dos excessos de alumínio, cloro e manganês em dois cultivares de soja (Glycine max (L.) Merrill)

Two soybean cultivars, Santa Rosa and FV-1, were grown in nutrient solution in the presence of high concentrations of Al (24 ppm), CI (1750 ppm) and Mn (25 ppm). Observations, measurements and chemical analyses allowed for the following conclusions to be drawn: (1) symptoms of toxicity are in agreement with those described in the literatura; (2) the detrimental effect obeyed the decreasing order - Mn Al CI; (3) dry matter production by the variety UFV - 1 was relatively more affected by the treatments; (4) leaf analyses do not provide a reliable indication of the sensitivity of the two varieties to the high levels of the three elements in the substrate; (5) Ca/Al ratio in the roots keeps a good relationship with the relative tolerance of the two cultivas to excess Al in the medium.Dois cultivares de soja, Santa Rosa e UFV-1, foram cultivados em solução nutritiva na presença de excesso de alumínio, cloro e manganês. Além de provocar o aparecimento de sintomas foliares (cloro e manganês) ou radiculares (alumínio), os elementos em excesso causaram diminuições no crescimento e impediram a produção de vagens. A análise mineral das folhas mostrou a influência dos tratamentos na composição do tecido

Search for the Standard Model Higgs boson decaying into bb¯ produced in association with top quarks decaying hadronically in pp collisions at √s = 8 TeV with the ATLAS detector

A search for Higgs boson production in association with a pair of top quarks (tt¯ H) is performed, where the Higgs boson decays to bb¯, and both top quarks decay hadronically. The data used correspond to an integrated luminosity of 20.3 fb−1 of pp collisions at √s = 8 TeV collected with the ATLAS detector at the Large Hadron Collider. The search selects events with at least six energetic jets and uses a boosted decision tree algorithm to discriminate between signal and Standard Model background. The dominant multijet background is estimated using a dedicated data-driven technique. For a Higgs boson mass of 125 GeV, an upper limit of 6.4 (5.4) times the Standard Model cross section is observed (expected) at 95% confidence level. The best-fit value for the signal strength is μ = 1.6 ± 2.6 times the Standard Model expectation for mH = 125 GeV. Combining all tt¯ H searches carried out by ATLAS at √s = 8 and 7 TeV, an observed (expected) upper limit of 3.1 (1.4) times the Standard Model expectation is obtained at 95% confidence level, with a signal strength μ = 1.7 ± 0.8