Coherent rho(0) production in ultraperipheral heavy-ion collisions

The STAR Collaboration reports the first observation of exclusive rho(0) photoproduction, AuAu-->AuAurho(0), and rho(0) production accompanied by mutual nuclear Coulomb excitation, AuAu-->Au*Au*rho(0), in ultraperipheral heavy-ion collisions. The rho(0) have low transverse momenta, consistent with coherent coupling to both nuclei. The cross sections at sqrt[s(NN)]=130 GeV agree with theoretical predictions treating rho(0) production and Coulomb excitation as independent processes.

Centrality dependence of high-p(T) hadron suppression in Au+Au collisions at sqrt[s(NN)]=130 GeV

Inclusive transverse momentum distributions of charged hadrons within 0.2<p(T)<6.0 GeV/c have been measured over a broad range of centrality for Au+Au collisions at sqrt[s(NN)]=130 GeV. Hadron yields are suppressed at high p(T) in central collisions relative to peripheral collisions and to a nucleon-nucleon reference scaled for collision geometry. Peripheral collisions are not suppressed relative to the nucleon-nucleon reference. The suppression varies continuously at intermediate centralities. The results indicate significant nuclear medium effects on high-p(T) hadron production in heavy-ion collisions at high energy.

Azimuthal anisotropy of K(0)(S) and Lambda+Lambda production at midrapidity from Au+Au collisions at sqrt[s(NN)]=130 GeV

We report STAR results on the azimuthal anisotropy parameter v(2) for strange particles K(0)(S), Lambda, and Lambda at midrapidity in Au+Au collisions at sqrt[s(NN)]=130 GeV at the Relativistic Heavy Ion Collider. The value of v(2) as a function of transverse momentum, p(t), of the produced particle and collision centrality is presented for both particles up to p(t) approximately 3.0 GeV/c. A strong p(t) dependence in v(2) is observed up to 2.0 GeV/c. The v(2) measurement is compared with hydrodynamic model calculations. The physics implications of the p(t) integrated v(2) magnitude as a function of particle mass are also discussed.

Midrapidity Lambda and Lambda(macro) production in Au+Au collisions at the square root of [s(NN)]=130 GeV

We report the first measurement of strange (Lambda) and antistrange (Lambda macro) baryon production from square root of [s(NN)]=130 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at midrapidity are presented as a function of centrality. The yield of Lambda and Lambda; hyperons is found to be approximately proportional to the number of negative hadrons. The production of Lambda; hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models alone.

Measurement of inclusive antiprotons from Au+Au collisions at square root of s(NN) = 130 GeV

We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at square root of s(NN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25<p( perpendicular)<0.95 GeV/c are found to fall less steeply for more central collisions. The extrapolated antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.

d Macro and (3)He macro production in square root of s(NN) = 130 GeV Au+Au collisions

The first measurements of light antinucleus production in Au+Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d macro and (3)He macro are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the (3)He macro freeze-out volume is smaller than the d macro freeze-out volume.

Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at square root of (sNN) = 130 GeV

The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons ( h(-)) in Au+Au interactions at square root of ([s(NN)]) = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dN(h(-))/d(eta)/(eta = 0) = 280+/-1(stat)+/-20(syst), an increase per participant of 38% relative to pp collisions at the same energy. The mean transverse momentum is 0.508+/-0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h(-) yield per participant is a strong function of p( perpendicular). The pseudorapidity distribution is almost constant within /eta/<1.

Pion Interferometry of square root of (s(NN)) =130 GeV Au + Au collisions at RHIC

Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)].

Ventral striatal D(3) receptors and Parkinson's Disease

Antiparkinsonian drugs are thought to act largely through the D2 receptor family that includes the D(2) and D(3) receptors. D(2) and D(3) receptors exhibit both complementary and overlapping expression at the macro and cellular level. The D(3) receptor appears to be a primary target of the mesolimbic dopamine system, is highly enriched in expression within the "limbic" striato-pallidal-thalamic loop, and is recognized as being regulated by dopaminergic activity in distinctly different ways from the D(2) receptor. In Parkinson's Disease it has been determined that loss of dopaminergic innervation results in elevation of the D(2) receptor but reduced levels of the D(3) receptor. In many late-stage Parkinson's Disease patients there is a loss of antiparkinsonian response to L-dopa and other antiparkinsonian drugs that is often correlated with clinical signs for dementia. We have determined that the reduction of D(3) receptor, and not that of the D(2) receptor, is associated with the loss of response to L-dopa and other antiparkinsonian drugs. The reduction of D(3) receptor is also related to the presence of dementia. An elevation of D(3) receptors was evident in those Parkinson's Disease cases with continued good response to L-dopa. Thus, we believe that reduced D(3) receptor number is correlated with certain subgroups of Parkinson's Disease and may also be related to a further diminishment in the mesolimbic DA system.

Midrapidity antiproton-to-proton ratio from Au+Au collisions at sqrt [s(NN)]=130 GeV

We report results on the ratio of midrapidity antiproton-to-proton yields in Au+Au collisions at sqrt[s(NN)] = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of /y/<0.5 and 0.4<p(t)<1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65+/-0.01((stat))+/-0.07((syst)) for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-p pair production becomes important at midrapidity, a significant excess of baryons over antibaryons is still present.

Neuroimaging in bipolar disorder

OBJECTIVE

The authors reviewed neuroimaging studies of bipolar disorder in order to evaluate how this literature contributes to the current understanding of the neurophysiology of the illness.

METHOD

Papers were reviewed as identified, using the NIMH PubMed literature search systems that reported results of neuroimaging studies involving a minimum of five bipolar disorder patients compared with healthy comparison subjects.

RESULTS

Structural neuroimaging studies report mixed results for lateral and third ventriculomegaly. Recent studies suggest subcortical structural abnormalities in the striatum and amygdala, as well as the prefrontal cortex. Proton spectroscopic studies suggest that abnormalities in choline metabolism exist in bipolar disorder, particularly in the basal ganglia. Additionally, phosphorous MRS suggests that there may be abnormalities in frontal phospholipid metabolism in bipolar disorder. Functional studies have identified affective state-related changes in cerebral glucose metabolism and blood flow, particularly in the prefrontal cortex during depression, but no clear abnormalities specific to bipolar disorder have been consistently observed.

CONCLUSIONS

The current literature examining the neurophysiology of bipolar disorder using neuroimaging is limited. Nonetheless, abnormalities in specific frontal-subcortical brain circuits seem likely. Additional targeted studies are needed to capitalize on this burgeoning technology to advance our understanding of the neurophysiology of bipolar disorder.

A randomized, controlled trial of remacemide for motor fluctuations in Parkinson's disease

BACKGROUND

Preclinical studies suggest that glutamate antagonists help ameliorate motor fluctuations in patients with PD treated with levodopa.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study, the authors assessed the safety, tolerability, and efficacy of the glutamate receptor blocker remacemide hydrochloride in 279 patients with motor fluctuations treated with levodopa. The primary objective was to assess the short-term tolerability and safety of four dosage levels of remacemide during 7 weeks of treatment. Patients were also monitored with home diaries and the Unified PD Rating Scale (UPDRS) to collect preliminary data on treatment efficacy.

RESULTS

Remacemide was well tolerated up to a dosage of 300 mg/d on a twice daily schedule and 600 mg/d on a four times daily schedule. The most common dosage-related adverse events were dizziness and nausea, as observed in previous studies of remacemide. The percent "on" time and motor UPDRS scores showed trends toward improvement in the patients treated with 150 and 300 mg/d remacemide compared with placebo-treated patients, although these improvements were not significant.

CONCLUSION

Remacemide is a safe and tolerable adjunct to dopaminergic therapy for patients with PD and motor fluctuations. Although this study had limited power to detect therapeutic effects, the observed improvement is consistent with studies of non-human primates with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian signs and symptoms. Additional studies are warranted to confirm these results over an extended period of observation, and to explore the potential neuroprotective effects of remacemide in slowing the progression of PD.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Neuroimaging in bipolar disorder

OBJECTIVE

The authors reviewed neuroimaging studies of bipolar disorder in order to evaluate how this literature contributes to the current understanding of the neurophysiology of the illness.

METHOD

Papers were reviewed as identified, using the NIMH PubMed literature search systems that reported results of neuroimaging studies involving a minimum of five bipolar disorder patients compared with healthy comparison subjects.

RESULTS

Structural neuroimaging studies report mixed results for lateral and third ventriculomegaly. Recent studies suggest subcortical structural abnormalities in the striatum and amygdala, as well as the prefrontal cortex. Proton spectroscopic studies suggest that abnormalities in choline metabolism exist in bipolar disorder, particularly in the basal ganglia. Additionally, phosphorous MRS suggests that there may be abnormalities in frontal phospholipid metabolism in bipolar disorder. Functional studies have identified affective state-related changes in cerebral glucose metabolism and blood flow, particularly in the prefrontal cortex during depression, but no clear abnormalities specific to bipolar disorder have been consistently observed.

CONCLUSIONS

The current literature examining the neurophysiology of bipolar disorder using neuroimaging is limited. Nonetheless, abnormalities in specific frontal-subcortical brain circuits seem likely. Additional targeted studies are needed to capitalize on this burgeoning technology to advance our understanding of the neurophysiology of bipolar disorder.

Lexical boundary error analysis in hypokinetic and ataxic dysarthria

This investigation is the second in a series to examine a potential source of reduced intelligibility in dysarthric speech, namely the mismatch between listeners' perceptual strategies and the acoustic information available in the dysarthric speech signal. Lexical boundary error (LBE) analysis was conducted on listener transcripts from phrases produced by speakers with hypokinetic dysarthria, ataxic dysarthria, and normal controls. By design, the hypokinetic and ataxic dysarthric tapes elicited similar intelligibility (words-correct) scores. However, they elicited different numbers and patterns of lexical boundary errors. The nature of the error pattern differences can be traced to the listeners' use of available syllabic strength information to segment the acoustic stream. Specifically, although both dysarthric speech samples elicited numerous lexical boundary errors, those for the hypokinetic speech generally conformed to predictions offered from studies of degraded normal speech. Those for the ataxic speech did not conform strongly to such predictions. It appears that the prosodic deficits of the ataxic speech (tendency toward syllabic isochrony, excessive loudness variation, and reduced vowel working space consequent to reductions in vowel strength) posed more of a problem for listeners than did the prosodic deficits of the hypokinetic speech (rapid rate, monotony, reduced vowel working space).

Tolerance of pupae and pharate adults of Callosobruchus subinnotatus Pic (Coleoptera: Bruchidae) to modified atmospheres: a function of metabolic rate

Three developmental stages (pupae, early pharate and late pharate adults) of Callosobruchus subinnotatus (Pic.) were investigated for their tolerance or susceptibility to four modified atmospheres. Two of these atmospheres were hypercarbic and two were hypoxic. The hypercarbic atmospheres were found to cause mortality earlier than hypoxic atmospheres. Late pharate adults died earlier than pupae or early pharate adults. Late pharate adults that survived the exposure took a longer time to eclose than the pupae or early pharate adult.Using high resolution microrespirometric techniques, it was possible to record the oxygen consumption rate and CO(2) output of different developmental stages in air. The metabolic rate was determined manometrically as the oxygen uptake rate at an ambient temperature of 25 degrees C. The oxygen uptake rate differed significantly between groups of 20 individuals of different stages (p<0.01; t-test). The lowest rate of oxygen uptake (510.6+/-52.2 &mgr;l g(-1) h(-1)) was recorded in pupae. Higher oxygen uptake rates were found in early pharate adults (668.4+/-45.6 &mgr;l g(-1) h(-1)) and late pharate adults (1171.2+/-45.0 &mgr;l g(-1) h(-1)), and adult beetles (1310.4+/-53.4 &mgr;l g(-1) h(-1)). The patterns of CO(2) release were similar to those of oxygen uptake. CO(2) release was highest in eclosed adults and late pharate adults followed by early pharate adults, and lowest in pupae. The mode of CO(2) release ranged from continuous CO(2) release in pupae to discontinuous CO(2) release in late pharate and eclosed adults. Thus, high metabolic rates, and perhaps, in conjunction with discontinuous CO(2) of late pharate adults are responsible for their higher susceptibility to modified atmospheres than pupae and early pharate adults.

The relationship between dorsolateral prefrontal neuronal N-acetylaspartate and evoked release of striatal dopamine in schizophrenia

Schizophrenia has been linked to abnormal dopamine function, recently to excessive amphetamine-induced release of striatal dopamine, and also to pathology of prefrontal cortical neurons. It has been hypothesized that prefrontal pathology is a primary condition that leads to dopamine dysregulation. We evaluated in vivo the relationship between neuronal integrity in dorsolateral prefrontal cortex, assessed as N-acetylaspartate (NAA) relative concentrations measured with proton magnetic resonance spectroscopic imaging, and amphetamine-induced release of striatal dopamine, assessed with 11C-raclopride Positron Emission Tomography (PET) in patients with schizophrenia and in healthy subjects. In the patients, NAA measures in dorsolateral prefrontal cortex selectively predicted striatal displacement of 11C-raclopride after amphetamine infusions (rho = -0.76, p < .02). In contrast, NAA measures in other cortical regions and in healthy subjects did not show any correlation. These results support the hypothesis that in schizophrenia neuronal pathology of dorsolateral prefrontal cortex is directly related to abnormal subcortical dopamine function.

The relation between dopamine D2 receptor density and personality: preliminary evidence from the NEO personality inventory-revised

OBJECTIVE

To examine the relation between dopamine (DA) D2 receptor-specific binding and personality, we assessed the relation between DA D2 binding and the NEO Personality Inventory-Revised (NEO PI-R).

BACKGROUND

Previous studies have demonstrated a relation between DA D2 receptor-specific binding and a personality trait involving personal detachment as defined by the Karolinska Scales of Personality: A subsequent study using a different measure of personal detachment failed to replicate this finding, suggesting that metric properties of the personality scale may be important. To further examine this issue, we assessed the relation between DA D2 binding and a third personality measure, the NEO PI-R.

METHODS

Eighteen adult subjects completed the NEO PI-R and participated in an 11C-raclopride positron emission tomography study to quantify striatal DA D2 receptor binding.

RESULTS

We did not find a significant relation between binding and detachment-like traits on the NEO PI-R; however, we found a significant relation between DA D2 receptor binding and the NEO PI-R personality facet of Depression (r = 0.75, p <0.0001).

CONCLUSIONS

The results fail to replicate the findings of previous studies reporting an association between DA D2 receptor density and personal detachment, suggesting that the relation is relatively specific to the trait defined by the Karolinska Scales of Personality. The relation between a nonclinical personality trait of depression and DA D2 binding, if replicated, may help to elucidate the role of dopamine in depression.

[Effects of chronic stress on physical or psychological health - an analysis of family caregivers of dementia patients]

The effects of chronical strains on physical or psychological health are subject of this paper. Stress-related symptoms of family caregivers of dementia patients have been proven in various studies. For this group of people an analysis of the health risk factors is regarded as to be especially important. Diary investigations allow to identify the individual assessment (by the caring person) of factors related to the care situation and to recognize the health and quality of sleep have been used as indicators regarding the state of health. In this study strong differences in the individual view of stress factors and their effects on psychological an physical state of the caring person are shown.

A chromosome 4p haplotype segregating with Parkinson's disease and postural tremor

We investigated a large family with levodopa-responsive, Lewy body parkinsonism in which the disease segregates as an apparent autosomal dominant trait. After performing a genome screen, we identified a chromosome 4p haplotype that segregates with the disease. However, this haplotype also occurs in individuals in the pedigree who do not have clinical Lewy body parkinsonism but rather suffer from postural tremor, consistent with essential tremor. These data demonstrate a new locus for Lewy body parkinsonism and suggest that in some circumstances postural tremor can be an alternative phenotype of the samepathogenic mutation as Lewy body parkinsonism.

Dopamine D2 receptor density and personal detachment in healthy subjects

OBJECTIVE

The purpose of this study was to examine the relationship between the personality trait involving personal detachment and dopamine D2 receptor specific binding in healthy subjects.

METHOD

Eighteen adult subjects completed the Karolinska Scales of Personality and the Tridimensional Personality Questionnaire and participated in a study that used [11C]raclopride positron emission tomography (PET) to quantify striatal D2 receptor binding.

RESULTS

A significant relationship was found between D2 receptor specific binding and detachment scores on the Karolinska Scales of Personality but not between D2 receptor specific binding and attachment scores on the Tridimensional Personality Questionnaire. In an exploratory analysis, the authors found a significant relationship between binding and the sentimentality cluster on the Tridimensional Personality Questionnaire but on no other personality clusters scores on the Tridimensional Personality Questionnaire or Karolinska Scales of Personality.

CONCLUSIONS

These findings replicate those of a recent report that personal detachment scores on the Karolinska Scales of Personality are related to dopamine D2 receptor density and extends this finding by suggesting that the relationship is relatively specific to the trait defined by the Karolinska Scales of Personality and does not generalize to other forms of detachment.

Syllabic strength and lexical boundary decisions in the perception of hypokinetic dysarthric speech

This investigation evaluated a possible source of reduced intelligibility in hypokinetic dysarthric speech, namely the mismatch between listeners' perceptual strategies and the acoustic information available in the dysarthric speech signal. A paradigm of error analysis was adopted in which listener transcriptions of phrases were coded for the presence and type of word boundary errors. Seventy listeners heard 60 phrases produced by speakers with hypokinetic dysarthria. The six-syllable phrases alternated strong and weak syllables and ranged in length from three to five words. Lexical boundary violations were defined as erroneous insertions or deletions of lexical boundaries that occurred either before strong or before weak syllables. A total of 1596 lexical boundary errors in the listeners' transcriptions was identified unanimously by three independent judges. The pattern of errors generally conformed with the predictions of the Metrical Segmentation Strategy hypothesis [Cutler and Norris, J. Exp. Psychol. 14, 113-121 (1988)] which posits that listeners attend to strong syllables to identify word onsets. However, the strength of adherence to this pattern varied across speakers. Comparison of acoustic evidence of syllabic strength to lexical boundary error patterns revealed a source of intelligibility deficit associated with this particular type of dysarthric speech pattern.

SGD: Saccharomyces Genome Database

The Saccharomyces Genome Database (SGD) provides Internet access to the complete Saccharomyces cerevisiae genomic sequence, its genes and their products, the phenotypes of its mutants, and the literature supporting these data. The amount of information and the number of features provided by SGD have increased greatly following the release of the S.cerevisiae genomic sequence, which is currently the only complete sequence of a eukaryotic genome. SGD aids researchers by providing not only basic information, but also tools such as sequence similarity searching that lead to detailed information about features of the genome and relationships between genes. SGD presents information using a variety of user-friendly, dynamically created graphical displays illustrating physical, genetic and sequence feature maps. SGD can be accessed via the World Wide Web at http://genome-www.stanford.edu/Saccharomyces/