Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

AAV Exploits Subcellular Stress Associated with Inflammation, Endoplasmic Reticulum Expansion, and Misfolded Proteins in Models of Cystic Fibrosis

Barriers to infection act at multiple levels to prevent viruses, bacteria, and parasites from commandeering host cells for their own purposes. An intriguing hypothesis is that if a cell experiences stress, such as that elicited by inflammation, endoplasmic reticulum (ER) expansion, or misfolded proteins, then subcellular barriers will be less effective at preventing viral infection. Here we have used models of cystic fibrosis (CF) to test whether subcellular stress increases susceptibility to adeno-associated virus (AAV) infection. In human airway epithelium cultured at an air/liquid interface, physiological conditions of subcellular stress and ER expansion were mimicked using supernatant from mucopurulent material derived from CF lungs. Using this inflammatory stimulus to recapitulate stress found in diseased airways, we demonstrated that AAV infection was significantly enhanced. Since over 90% of CF cases are associated with a misfolded variant of Cystic Fibrosis Transmembrane Conductance Regulator (ΔF508-CFTR), we then explored whether the presence of misfolded proteins could independently increase susceptibility to AAV infection. In these models, AAV was an order of magnitude more efficient at transducing cells expressing ΔF508-CFTR than in cells expressing wild-type CFTR. Rescue of misfolded ΔF508-CFTR under low temperature conditions restored viral transduction efficiency to that demonstrated in controls, suggesting effects related to protein misfolding were responsible for increasing susceptibility to infection. By testing other CFTR mutants, G551D, D572N, and 1410X, we have shown this phenomenon is common to other misfolded proteins and not related to loss of CFTR activity. The presence of misfolded proteins did not affect cell surface attachment of virus or influence expression levels from promoter transgene cassettes in plasmid transfection studies, indicating exploitation occurs at the level of virion trafficking or processing. Thus, we surmised that factors enlisted to process misfolded proteins such as ΔF508-CFTR in the secretory pathway also act to restrict viral infection. In line with this hypothesis, we found that AAV trafficked to the microtubule organizing center and localized near Golgi/ER transport proteins. Moreover, AAV infection efficiency could be modulated with siRNA-mediated knockdown of proteins involved in processing ΔF508-CFTR or sorting retrograde cargo from the Golgi and ER (calnexin, KDEL-R, β-COP, and PSMB3). In summary, our data support a model where AAV exploits a compromised secretory system and, importantly, underscore the gravity with which a stressed subcellular environment, under internal or external insults, can impact infection efficiency

The Emergence of Emotions

Emotion is conscious experience. It is the affective aspect of consciousness. Emotion arises from sensory stimulation and is typically accompanied by physiological and behavioral changes in the body. Hence an emotion is a complex reaction pattern consisting of three components: a physiological component, a behavioral component, and an experiential (conscious) component. The reactions making up an emotion determine what the emotion will be recognized as. Three processes are involved in generating an emotion: (1) identification of the emotional significance of a sensory stimulus, (2) production of an affective state (emotion), and (3) regulation of the affective state. Two opposing systems in the brain (the reward and punishment systems) establish an affective value or valence (stimulus-reinforcement association) for sensory stimulation. This is process (1), the first step in the generation of an emotion. Development of stimulus-reinforcement associations (affective valence) serves as the basis for emotion expression (process 2), conditioned emotion learning acquisition and expression, memory consolidation, reinforcement-expectations, decision-making, coping responses, and social behavior. The amygdala is critical for the representation of stimulus-reinforcement associations (both reward and punishment-based) for these functions. Three distinct and separate architectural and functional areas of the prefrontal cortex (dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex) are involved in the regulation of emotion (process 3). The regulation of emotion by the prefrontal cortex consists of a positive feedback interaction between the prefrontal cortex and the inferior parietal cortex resulting in the nonlinear emergence of emotion. This positive feedback and nonlinear emergence represents a type of working memory (focal attention) by which perception is reorganized and rerepresented, becoming explicit, functional, and conscious. The explicit emotion states arising may be involved in the production of voluntary new or novel intentional (adaptive) behavior, especially social behavior

Measurement of the cross-section for b-jets produced in association with a Z boson at root s=7 TeV with the ATLAS detector ATLAS Collaboration

A measurement is presented of the inclusive cross-section for b-jet production in association with a Z boson in pp collisions at a centre-of-mass energy of root s = 7 TeV. The analysis uses the data sample collected by the ATLAS experiment in 2010, corresponding to an integrated luminosity of approximately 36 pb(-1). The event selection requires a Z boson decaying into high P-T electrons or muons, and at least one b-jet, identified by its displaced vertex, with transverse momentum p(T) > 25 GeV and rapidity vertical bar y vertical bar < 2.1. After subtraction of background processes, the yield is extracted from the vertex mass distribution of the candidate b-jets. The ratio of this cross-section to the inclusive Z cross-section (the average number of b-jets per Z event) is also measured. Both results are found to be in good agreement with perturbative QCD predictions at next-to-leading order