Photons produced in pp interactions at 450 GeV/c were detected by reconstructing the e+e− pairs of photon conversions in a 1 mm thick lead sheet placed in front of the MWPCs of the OMEGA spectrometer ...at CERN. A soft photon signal 4.1±0.8 times the inner bremsstrahlung prediction was observed in the forward rapidity region (yc.m.s.⩾1.2), thus extending the domain of the anomalous soft photon effect seen already in K+p, π+p and π−p interactions.
In the rTg4510 mouse model, expression of the mutant human tau variant P301L leads to development of neurofibrillary tangles (NFTs), neuronal death, and memory impairment, reminiscent of the ...pathology observed in human tauopathies. In the present study, we examined the effects of mutant tau expression on the electrophysiology and morphology of individual neurons using whole-cell patch-clamp recordings and biocytin filling of pyramidal cells in cortical slices prepared from rTg4510 (TG) and wild-type (WT) littermate mice. Among the TG cells, 42% contained a clear Thioflavin-S positive inclusion in the soma and were categorized as NFT positive (NFT+), while 58% had no discernable inclusion and were categorized as NFT negative (NFT−). The resting membrane potential (
V
r) was significantly depolarized (+
8 mV) in TG cells, and as a consequence, evoked repetitive action potential (AP) firing rates were also significantly increased. Further, single APs were significantly shorter in duration in TG cells and the depolarizing voltage deflection or “sag” evoked by hyperpolarization was significantly greater in amplitude. In addition to these functional electrophysiological changes, TG cells exhibited significant morphological alterations, including loss or significant atrophy of the apical tuft, reduced dendritic complexity and length, and reduced spine density. Importantly, NFT− and NFT+ TG cells were indistinguishable with regard to both morphological and electrophysiological properties. Our observations show that expression of mutated tau results in significant structural and functional changes in neurons, but that these changes occur independent of mature NFT formation.
The reaction pp -> pf (eta eta) ps has been studied at 450 GeV/c. For the first time a partial wave analysis of the centrally produced eta eta system has been performed. Signals for the f0(1500), ...f0(1710) and f2(2150) are observed and the decay branching fractions of these states are determined.
The reactions
pp→
p
f
(
X
0)
p
s
, where
X
0 is observed decaying to
π
0
π
0
π
0
π
0 ,
π
+
π
−
π
+
π
− and
π
+
π
−
π
0
π
0 , have been studied at 450 GeV/
c. There is evidence for an
a
2(1320)
π ...decay mode of the
η
2(1645) and
η
2(1870) in the
π
+
π
−
π
0
π
0 and
π
+
π
−
π
+
π
− final states. The
f
2(1950) is consistent with being a single resonance with a dominant
f
2(1270)
ππ decay mode. The
f
0(1370) is found to decay dominantly to
ρρ while the
f
0(1500) is found to decay to
ρρ and
σσ.
In this Letter we present additional experimental characteristics of anomalous soft photon radiation observed in π−p interactions at 280 GeV/c in the CERN experiment WA91, together with a ...re-calculated ratio of the observed direct soft photon signal to the expected level of the hadronic inner bremsstrahlung, which is found to be 5.3±1.0. The other presented characteristics, energy dependence and angular distributions of direct soft photons, show the similarity of the observed signal to the expected hadronic bremsstrahlung behaviour.
A partial wave analysis of the centrally produced
π
+
π
− channel has been performed in
pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. ...Evidence is found for the
f
0(980),
f
0(1300),
f
0(1500) and
f
j
(1710) with
J = 0 in the
S-wave. The ϱ(770) is observed dominantly in the
P
0
−-wave and the
f
2(1270) is observed dominantly in the
D
0
−-wave. In addition, there is evidence for a broad enhancement in the
D-wave below 1 GeV.
The reaction
pp→
p
f
(
ηη)
p
s
has been studied at 450 GeV/c. For the first time a partial wave analysis of the centrally produced
ηη system has been performed. Signals for the
f
0(1500),
f
0(1710) ...and
f
2(2150) are observed and the decay branching fractions of these states are determined.
Photons produced in
π
−p interactions at 280 GeV/
c were detected by reconstructing the e
+e
− pairs produced via the materialisation of the photons in a 1 mm thick lead sheet placed in front of the ...MWPC's of the OMEGA spectrometer at CERN. A soft photon signal 7.8 ± 1.5 times the Q.E.D. inner bremsstrahlung prediction was observed confirming the results of a previous experiment.
A coupled channel analysis of the centrally produced
K
+
K
−and
π
+
π
−final states has been performed in
pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ...ratios to
ππ and
K
K
of the
f
0(980),
f
0(1370),
f
0(1500) and
f
0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the
π
+
π
−and
K
+
K
−channels has been performed.
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