Antidepressant-like effect of ursolic acid isolated from Rosmarinus officinalis L. in mice: evidence for the involvement of the dopaminergic system.

Ursolic acid, a constituent from Rosmarinus officinalis, is a triterpenoid compound which has been extensively known for its anticancer and antioxidant properties. In the present study, we investigated the antidepressant-like effect of ursolic acid isolated from this plant in two predictive tests of antidepressant property, the tail suspension test (TST) and the forced swimming test (FST) in mice. Furthermore, the involvement of dopaminergic system in its antidepressant-like effect was investigated in the TST. Ursolic acid reduced the immobility time in the TST (0.01 and 0.1mg/kg, p.o.) and in the FST (10mg/kg, p.o.), similar to fluoxetine (10mg/kg, p.o.), imipramine (1mg/kg, p.o.) and bupropion (10mg/kg, p.o.). The effect of ursolic acid (0.1mg/kg, p.o.) in the TST was prevented by the pretreatment of mice with SCH23390 (0.05mg/kg, s.c., a dopamine D(1) receptor antagonist) and sulpiride (50mg/kg, i.p., a dopamine D(2) receptor antagonist). The administration of a sub-effective dose of ursolic acid (0.001mg/kg, p.o.) in combination with sub-effective doses of SKF38393 (0.1mg/kg, s.c., a dopamine D(1) receptor agonist), apomorphine (0.5µg/kg, i.p., a preferential dopamine D(2) receptor agonist) or bupropion (1mg/kg, i.p., a dual dopamine/noradrenaline reuptake inhibitor) reduced the immobility time in the TST as compared with either drug alone. Ursolic acid and dopaminergic agents alone or in combination did not cause significant alterations in the locomotor and exploratory activities. These results indicate that the antidepressant-like effect of ursolic acid in the TST is likely mediated by an interaction with the dopaminergic system, through the activation of dopamine D(1) and D(2) receptors.

A state observer for the Virgo inverted pendulum.

We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently.

In-vacuum Faraday isolation remote tuning.

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.

First results on angular distributions of thermal dileptons in nuclear collisions.

The NA60 experiment at the CERN Super Proton Synchrotron has studied dimuon production in 158A GeV In-In collisions. The strong excess of pairs above the known sources found in the complete mass region 0.2

Evidence for radial flow of thermal dileptons in high-energy nuclear collisions.

The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158A GeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.

J/psi production in Indium-Indium collisions at 158 GeV/nucleon.

The NA60 experiment studies muon pair production at the CERN Super Proton Synchrotron. In this Letter we report on a precision measurement of J/psi in In-In collisions. We have studied the J/psi centrality distribution, and we have compared it with the one expected if absorption in cold nuclear matter were the only active suppression mechanism. For collisions involving more than approximately 80 participant nucleons, we find that an extra suppression is present. This result is in qualitative agreement with previous Pb-Pb measurements by the NA50 experiment, but no theoretical explanation is presently able to coherently describe both results.

First measurement of the rho spectral function in high-energy nuclear collisions.

We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360,000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+pi- -->rho -->mu+mu- annihilation. The associated space-time averaged spectral function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masses directly to the chiral condensate.