44 research outputs found
Measurement of event-shape observables in Z→ℓ+ℓ− events in pp collisions at √ s=7 TeV with the ATLAS detector at the LHC
Event-shape observables measured using charged particles in inclusive
-boson events are presented, using the electron and muon decay modes of the
bosons. The measurements are based on an integrated luminosity of of proton--proton collisions recorded by the ATLAS detector at the
LHC at a centre-of-mass energy TeV. Charged-particle
distributions, excluding the lepton--antilepton pair from the -boson decay,
are measured in different ranges of transverse momentum of the boson.
Distributions include multiplicity, scalar sum of transverse momenta, beam
thrust, transverse thrust, spherocity, and -parameter, which are
in particular sensitive to properties of the underlying event at small values
of the -boson transverse momentum. The Sherpa event generator shows larger
deviations from the measured observables than Pythia8 and Herwig7. Typically,
all three Monte Carlo generators provide predictions that are in better
agreement with the data at high -boson transverse momenta than at low
-boson transverse momenta and for the observables that are less sensitive to
the number of charged particles in the event.Comment: 36 pages plus author list + cover page (54 pages total), 14 figures,
4 tables, submitted to EPJC, All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-0
Activation of excitatory amino acid receptors increases intracellular free [3H]arachidonate levels in cultured cerebellar neurons
[No abstract available
PHORBOL ESTERS ATTENUATE GLUTAMATE-STIMULATED INOSITOL PHOSPHOLIPID HYDROLYSIS IN NEURONAL CULTURES
The phorbol diesters 12-O-tetradecanoylphorbol-13-acetate (TPA) and phorbol-12,13-dibutyrate, but not 4-α-phorbol-didecanoate, inhibited the stimulation of inositol phospholipid hydrolysis by excitatory amino acids and carbamylcholine in primary cultures of cerebellar neurons. This inhibition was mimicked by the synthetic diacylglycerol 1,2-dioleoyl-rac-glycerol (DOG) and was selective for a specific glutamate-phosphoinositide receptor subtype (GP2 receptor) activated by glutamate and quisqualate. TPA was nearly inactive in inhibiting the stimulation of inositol phospholipid hydrolysis by N-methyl-D-aspartate, a selective agonist of the GP1 receptor. Phorbol diesters and DOG attenuated the stimulation of inositol phospholipid hydrolysis by glutamate and quisqualate also in cerebellar slices from 9-15-day-old rats; however, using this preparation, their action was weak and required high concentrations (>1 μM). The inhibition of signal transduction by phorbol diesters was not consequent to a reduced binding of glutamate to its membrane recognition sites. In fact, TPA induced only a small increase in the K(D) but not change in the B(max) of [3H]glutamate binding in cerebellar membranes. Phorbol diesters may act to inhibit specific GTP-binding proteins or particular forms of phosphoinositidase C associated with GP2 or muscarinic cholinergic receptors
Comparative effects of estrogens and prolactin on nigral and striatal GAD activity
The comparative effects of a 10 day estrogen treatment and estrogen independent hyperprolactinemia on nigral and striatal glutamic acid decarboxylase (GAD, EC 4.1.1.15) activity were investigated in male rats. Data obtained show that estrogen treatment decreases GAD activity in substantia nigra, while an increase was observed in conditions of hyperprolactinemia induced by modulation of strio-nigral GABAergic system by estrogens and prolactin is suggested. © 1982
Pyrrolidone-carboxylic acid magnesium salt (PCA-Mg2+) protects against seizures induced by excitatory amino acids
[No abstract available