The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Efeito do Manejo do Solo na Emergencia de Plantas Daninhas Anuais.

Por meio de amostragens mensais, no periodo de outubro a abril, foi registrada a dinamica de emergencia de 10 plantas daninhas, sob dois manejos: destruicao com revolvimento do solo por enxada rotativa tracionada por microtrator, ou sem revolvimento do solo, com herbicida de contato. Os resultados mostraram que o manejo de populacoes por meio de cultivo estimulou a emergencia das especies Bidens pilosa (picao-preto), Amaranthus viridis (caruru), Sonchus oleraceus (serralha), Rhynchelitrum roseum (capim-favorito), Portulaca oleracea (beldroega), Eleusine indica (capim-pe-de-galinha), Acanthospermum hispidum (carrapicho-de-carneiro), Galinsoga parviflora (picao-branco) e Eragrostis pilosa (capim-barba-de-alemão). A dinamica de emergencia de Brachiaria plantaginea (capim-marmelada) nao foi alterada pelo tipo de manejo. Quando a sementeira de outubro foi destruida sem re-volvimento do solo, este primeiro fluxo de emergencia representou cerca de 85 a 95% do total emergido no periodo de outubro a abril para o capim-marmelada, picao-preto, caruru e serralha. Para as especies capim-favorito, picao-branco, beldroega e carrapicho-de-carneiro a primeira emergencia de outubro significou cerca de 80, 70, 65 e 50% do total, respectivamente.Made available in DSpace on 2011-04-09T12:18:19Z (GMT). No. of bitstreams: 1 pab09fev91.pdf: 327890 bytes, checksum: 923939a61002c0c4ccc6d2a378d56e50 (MD5) Previous issue date: 2001-09-13199

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases

Efeito hormótico de gliphosate no desenvolvimento inicial de cana-de-açúcar Hormetic effect of glyphosate on the initial development of sugarcane

Efeito hormótico é definido como o efeito estimulante de pequenas doses de substâncias, as quais em doses maiores são inibitórias. Esta pesquisa objetivou verificar, em casa-de-vegetação, o efeito de subdoses do herbicida gliphosate no desenvolvimento inicial de cana-de-açúcar. Plantas de cana-de-açúcar foram obtidas de gemas isoladas plantadas em vasos plásticos de 2,5 L. Aos 50 dias após o plantio, gliphosate foi aplicado nas doses de 0; 1,8; 3,6; 7,2; 18; 36; 72; 180; 360 e 720 g e.a. ha-1. Aos 0 e 25 dias após a aplicação (DAA) foram avaliados altura da planta, número de perfilhos, número de folhas verdes, número de folhas secas e estimativa do conteúdo de clorofila (índice SPAD). Aos 25 DAA também foram determinadas a massa fresca e seca da parte aérea e raízes das plantas. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. A dose de 1,8 g e.a. ha-1 de gliphosate estimulou as características de crescimento no desenvolvimento inicial da cana-de-açúcar. Esse efeito hormótico poderá ser utilizado como manejo da cultura para obter melhor exploração do ambiente de produção.<br>Hormesis is defined as the stimulating effect of small doses of substances, which in larger doses are inhibitory. This research aimed at evaluating the effect of low doses of the herbicide glyphosate on the initial development of sugarcane in greenhouse. Sugarcane plants were obtained from isolated buds planted in plastic pots of 2.5 L. At 50 days after planting, glyphosate was sprayed at 0, 1.8, 3.6, 7.2, 18, 36, 72, 180, 360 and 720 g AE ha-1. At 0 and 25 days after application (daa), plant height, tiller number, number of green leaves, number of dead leaves and estimated chlorophyll contents (index SPAD) were evaluated. At 25 evaluated daa, fresh and dry mass of above-ground plant and roots were also determined. The experiment was installed in a completely randomized design with four replications. The glyphosate dose of 1.8 g AE ha-1 stimulated growth traits at the initial development of sugarcane. This hormetic effect could be used to manage the crop to exploit better the production environment