3 research outputs found

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

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    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

    Enzymes of type II fatty acid synthesis and apicoplast differentiation and division in Eimeria tenella

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    Apicomplexan parasites, Eimeria tenella, Plasmodium spp. and Toxoplasma gondii, possess a homologous plastid-like organelle termed the apicoplast, derived from the endosymbiotic enslavement of a photosynthetic alga. However, currently no eimerian nuclear encoded apicoplast targeted proteins have been identified, unlike in Plasmodium spp. and T. gondii. In this study, we demonstrate that nuclear encoded enoyl reductase of E. tenella (EtENR) has a predicted N-terminal bipartite transit sequence, typical of apicoplast-targeted proteins. Using a combination of immunocytochemistry and EM we demonstrate that this fatty acid biosynthesis protein is located in the apicoplast of E. tenella. Using the EtENR as a tool to mark apicoplast development during the Eimeria lifecycle, we demonstrate that nuclear and apicoplast division appear to be independent events, both organelles dividing prior to daughter cell formation, with each daughter cell possessing one to four apicoplasts. We believe this is the first report of multiple apicoplasts present in the infectious stage of an apicomplexan parasite. Furthermore, the microgametes lacked an identifiable apicoplast consistent with maternal inheritance via the macrogamete. It was found that the size of the organelle and the abundance of EtENR varied with developmental stage of the E. tenella lifecycle. The high levels of EtENR protein observed during asexual development and macrogametogony is potentially associated with the increased synthesis of fatty acids required for the rapid formation of numerous merozoites and for the extracellular development and survival of the oocyst. Taken together the data demonstrate that the E. tenella apicoplast participates in type II fatty acid biosynthesis with increased expression of ENR during parasite growth. Apicoplast division results in the simultaneous formation of multiple fragments. The division mechanism is unknown, but is independent of nuclear division and occurs prior to daughter formation

    An extension to the internal/external frame of reference model to two verbal and numerical domains

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    Moeller J, Streblow L, Pohlmann B, Koeller O. An extension to the internal/external frame of reference model to two verbal and numerical domains. EUROPEAN JOURNAL OF PSYCHOLOGY OF EDUCATION. 2006;21(4):467-487.Beside interindividual social comparisons, intraindividual dimensional comparisons in which students compare their achievements in one subject with their achievements in other subjects have an impact on their academic self-concepts. The internal/external frame of reference (I/E) model by Marsh (1986) assumes that dimensional comparisons lead to negative paths from achievement in one subject (e.g., math) to self-concept in another subject (e.g., English). In the present study, the I/E model was extended to two verbal domains (German as the native language and English as a foreign language) and two numerical domains (mathematics and physics). Grades and domain-specific academic self-concepts of N= 1440 students from 63 classes were assessed In support of the extended I/E model, (a) math, physics, German, and English achievement were positively correlated, as were; (b) se flconcepts within the verbal and numerical domains, while; (c) self-concepts between the verbal and the numerical domains were almost uncorrelated; (d) positive paths were received from math, physics, German, and English achievement on the corresponding self-concepts; (e) negative paths were found from achievement in one domain to self-concept in the other; (f) positive paths were found from math (physics) achievement to physics (math) self-concept. Finally, (g), almost no effects were found within the verbal domain, i.e., from English (German) achievement to German (English) self-concept. Therefore, there is some support for the I/E model between domains; whereas effects from achievements on self-concepts within the domains were not negative
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