Smoking status as a potential confounder in the study of brain structure in schizophrenia

Several but not all MRI studies have reported volume reductions in the hippocampus and dorsolateral prefrontal cortex (DLPFC) in patients with schizophrenia. Given the high prevalence of smoking among schizophrenia patients and the fact that smoking has also been associated with alterations in brain morphology, this study evaluated whether a proportion of the known gray matter reductions in key brain regions may be attributed to smoking rather than to schizophrenia alone.We examined structural MRI data of 112 schizophrenia patients (53 smokers and 59 non-smokers) and 77 healthy non-smoker controls collected by the MCIC study of schizophrenia. An automated atlas based probabilistic method was used to generate volumetric measures of the hippocampus and DLPFC. The two patient groups were matched with respect to demographic and clinical variables.Smoker schizophrenia patients showed significantly lower hippocampal and DLPFC volumes than non-smoker schizophrenia patients. Gray matter volume reductions associated with smoking status ranged between 2.2% and 2.8%. Furthermore, we found significant volume differences between smoker patients and healthy controls in the hippocampus and DLPFC, but not between non-smoker patients and healthy controls.Our data suggest that a proportion of the volume reduction seen in the hippocampus and DLPFC in schizophrenia is associated with smoking rather than with the diagnosis of schizophrenia. These results may have important implications for brain imaging studies comparing schizophrenia patients and other groups with a lower smoking prevalence

Search for the supersymmetric partner of the top quark in pp\u304 collisions at 1as=1.8 TeV

We report on a search for the supersymmetric partner of the top quark (top squark) produced in tt\u304 events using 110 pb-1 of pp\u304 collisions at 1as = 1.8 TeV recorded with the Collider Detector at Fermilab. In the case of a light top squark, the decay of the top quark into a top squark plus the lightest supersymmetric particle (LSP) could have a significant branching ratio. The observed events are consistent with standard model tt\u304 production and decay. Hence, we set limits on the branching ratio of the top quark decaying into a top squark plus LSP, excluding branching ratios above 45% for a LSP mass up to 40 GeV/c2

Measurement of the \u3b3 + D*\ub1 cross section in p\u304p collisions at 1as = 1.8 TeV

We have measured the cross section of gamma + D-*+/- production in <(p)over bar p> collisions at root s = 1.8 TeV using the Collider Detector at Fermilab. In this kinematic region, the Compton scattering process (g(c) --> gamma(c)) is expected to dominate and thus provide a direct link to the charm quark density in the proton. From the 45 +/- 18 gamma + D-*+/- candidates in a 16.4 pb(-1) data sample, we have determined the production cross section to be 0.38 +/- 0.15(stat) +/- 0.11(syst) nb for the rapidity range y(D-*+/-) < 1.2 and y(gamma) < 0.9, and for the transverse momentum range p(T)(D-*+/-) > 6 GeV/c and 16 < p(T)(gamma) < 40 GeV/c. The measured cross section is compared to a theoretical prediction

Central pseudorapidity gaps in events with a leading antiproton at the Fermilab tevatron pp collider

The results from a similar measurement performed in a subsample of pp events containing a leading (high longitudinal momentum) antiproton. As such, large pseudorapidity gaps are presumed to be due to Pomeron exchanges and are the signature for diffraction. The process with a leading beam particle in the final state, which is kinematically associated with an adjacent pseudorapidity gap, is known as single diffraction dissociation (SD), while that with a central gap as double diffraction dissociation (DD)

Search for associated production of Y and vector boson in pp\u304 Collisions at 1as = 1.8 TeV

Associated production of \u3c5 and vector boson in pp\u304 collisions at 1as = 1.8 TeV were investigated. The CDF detector was used in the analysis. The analysis showed that \u3c5(1S) mesons in association with W\ub1 or Z0 bosons were not observed by the CDF detector

Search for long-lived charged massive particles in p p\u304 collisions at 1as = 1.8 TeV

A study was performed to search for long-lived charged massive particles in 90 pb-1 of data at CDF. No excess over background was observed. Cross section limits were observed using reference models for the two cases of strongly and weakly produced particles. In the strongly interacting case, these limits extend the excluded mass region to about 200 GeV/c2