Support for the involvement of TPH2 gene in affective disorders.
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Biomedical subjects
Publications and source records attributed to M Harvey.
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Before issuing a new or revised authorization to discharge liquid radioactive waste to a river, past and current practice has been to assess the impact of each discharge on a site-by-site basis. This paper reports an assessment of the combined impact of all the (year 1999) authorized discharges in the upper River Thames (UK) catchment. A modification of the PC-CREAM model, using parameters specific to the upper River Thames, was used to estimate "potential doses" to the population, using the authorized discharge activity for each of the discharges as the main driving variable. The main purpose of this study was to investigate the difference in doses between single and multiple discharges in the Thames. A partial validation of the model against measurements was also carried out as a secondary investigation. The source term of the upper Thames consisted of 90 authorized discharges for 86 sites, made up of three nuclear licensed sites, 36 industrial discharges, 25 research organizations, 20 hospitals and two miscellaneous organizations. Of the authorized discharges, nuclear sites constituted 67% of the total activity in authorizations to discharge; hospitals 16%, research organizations 13%, and industry only 3%. Three radionuclides made up 96% of the total authorized discharge activity: tritium-74%; Tc-15%, and C-7%. No other single radionuclide constituted more than 1.5% of the total activity. All of the discharges from non-nuclear sites were via a sewage works so that, in total, only 39 discrete discharges to the river were included in the model. For the purposes of the assessments, it was assumed that all discharges were at the authorized limits (rather than using actual discharge). Even with this maximizing assumption, all the calculated potential doses from the combined source terms were significantly less than the radiation dose limit of 1 mSv y for a member of the public. The highest estimated potential doses were investigated further to identify the major pathways. Ingestion of fish was the main pathway in several river stretches and in the highest case constituted 97% of the dose. In a few stretches, external irradiation from the riverbank or ingestion of drinking water were the main pathways, but the potential contribution was a very small percentage (<1%) of the dose limit for members of the public. An investigation of the reasons for the relatively high potential doses resulting from fish showed that the radionuclide with the largest contribution was P. Three factors had a major effect on potential dose estimations in these circumstances: the fish consumption rate, the P concentration factor and the use of P in some cases to represent radionuclides authorized for discharge as "any other radionuclide, except alpha emitters." Using the precautionary principle, all authorized activity in the latter designation was modeled as the radionuclide which would produce the highest dose to humans.
The invariant differential cross section for inclusive neutral-pion production in p+p collisions at sqrt[s]=200 GeV has been measured at midrapidity (|eta|<0.35) over the range 1<p(T) less, similar 14 GeV/c by the PHENIX experiment at the Relativistic Heavy Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.
The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at sqrt[s(NN)]=200 GeV for identified and inclusive charged particle production at central rapidities (|eta|<0.35) with respect to the reaction plane defined at high rapidities (|eta|=3-4 ). We observe that the v(2) of mesons falls below that of (anti)baryons for p(T)>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.
We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at sqrt[s(NN)]=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5<p(T)<4.5 GeV/c) a significant fraction of all produced particles are protons and antiprotons. They show a centrality-scaling behavior different from that of pions. The pmacr;/pi and p/pi ratios are enhanced compared to peripheral Au+Au, p+p, and e(+)e(-) collisions. This enhancement is limited to p(T)<5 GeV/c as deduced from the ratio of charged hadrons to pi(0) measured in the range 1.5<p(T)<9 GeV/c.
Transverse momentum spectra of neutral pions in the range 1<p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in Au+Au collisions at sqrt[s(NN)]=200 GeV. The pi(0) multiplicity in central reactions is significantly below the yields measured at the same sqrt[s(NN)] in peripheral Au+Au and p+p reactions scaled by the number of nucleon-nucleon collisions. For the most central bin, the suppression factor is approximately 2.5 at p(T)=2 GeV/c and increases to approximately 4-5 at p(T) approximately 4 GeV/c. At larger p(T), the suppression remains constant within errors. The deficit is already apparent in semiperipheral reactions and increases smoothly with centrality.
High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.
The freshwater cyanobacterium Cylindrospermopsis raciborskii is known to produce toxic effects in several countries. Acute and chronic exposures to C. raciborskii in Australia have been linked to liver damage (hepatotoxicity) with concomitant effects on the kidneys, adrenal glands, small intestine, lungs, thymus, and heart. The alkaloid cylindrospermopsin, which produces these toxic effects, is thought to be a potent inhibitor of protein synthesis. C. raciborskii strains producing cylindrospermopsin or analogue alkaloids have also been reported in Florida, USA, and Thailand. Brazilian isolates of C. raciborskii are also toxic but act by a different mechanism, causing acute death in mice with neurotoxic symptoms similar to those induced by the saxitoxins. In this article we compare the toxicity in the mouse of a C. raciborskii French strain with C. raciborskii strains from various other sources (Australia, Brazil, Mexico, and Hungary). We tested the toxicity of cell extracts by a mouse bioassay. Acute, fatal neurotoxicity was produced by the Brazilian strain, which was confirmed by liquid chromatography with fluorescence detection of the cell extracts, which revealed the presence of saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin, along with two unidentified compounds. Acute hepatotoxicity with severe liver, kidney, and thymus damage was observed with the Australian cylindrospermopsin-producing strain. The Mexican and Hungarian strains were not found to be toxic to mice in our experimental conditions. No animals died after exposure to the extracts of the French C. raciborskii strain. Histological examination of the liver revealed moderate, multifocal necrosis characterized by small areas of hepatocellular necrosis, combined with disorganization of the parenchyma and congestion of the inner sinusoid. These symptoms and lesions resembled those induced by cylindrospermopsin, but the chemical analysis performed by liquid chromatography coupled with either a diode array detector or a mass spectrometer demonstrated that this toxin was not present in our culture extract.
Although UK general practice is highly computerized, comprehensive use of these computers is often limited to registration data and the issue of repeat prescriptions. The recording of diagnostic data is patchy. This study examines whether patients with, or at risk of, osteoporosis can be readily identified from general practice computer records. It reports the findings of a pilot study designed to show the variability of recording the diagnosis of osteoporosis and osteopenia, as well as how useful surrogate markers might be to identify these patients. The study also illustrates the difficulties that even skilled practitioners in a primary care research network experience in extracting clinical data from practice information systems. Computer searches were carried out across six practices in a general practice research network in the south-east of England. Two of these practices had previously undertaken research projects in osteoporosis and were consequently expected to have excellent data quality in osteoporosis. These two practices had a combined list size of 27,500 and the remaining practices had a combined practice population of 43,000 patients. The data were found to be variable with over 10-fold differences between practices in the recorded prevalence of osteoporosis diagnosis as well as its surrogate markers-such as fragility fractures, long-term steroid prescription, etc. There was no difference in data quality between the two practices that had conducted osteoporosis research and the rest of the group, other than in the areas of diagnostic recording and prescribing for osteoporosis and recording of fractures. Issues were raised by the practices that struggled to identify patients at risk of osteoporosis about the limitations of Read classification in this disease area. Practices need further assistance if the patients at risk are to be identified. Without urgent action, it will be difficult for practices to identify the patients who are likely to benefit from Standard 6-'Falls' of the National Service Framework for Older People. These findings also have broader implications as UK general practice moves towards the implementation of a quality-based contract.
OBJECTIVE: Estimation of stroke volume variation (e.g. systolic blood pressure and systolic area variability) and central extracellular compartment volume (e.g. initial volume of distribution of glucose, IVDG) may be useful in guiding fluid therapy in mechanically ventilated patients. The reliability of systolic blood pressure (SBP) variability has been well validated, but little is known about systolic area (SA) variability or IVDG. Our aim was to investigate SBP and SA variability and IVDG as predictors of preload responsive hypovolaemia in post-cardiac surgery patients. METHODS: Thirty-four mechanically ventilated patients undergoing preload enhancement post elective cardiac surgery were studied. The maximum-minimum difference and power spectral measurement of SBP and SA variability were derived from the arterial waveform trace and examined before and after rapid volume infusion. IVDG was determined prior to volume infusion from three-minute incremental glucose estimation and (with SBP and SA variability) correlated with subjects classified as hypotensive and preload responsive. RESULTS: Neither IVDG or SA and SBP variability were found to correlate with subjects identified as hypotensive and preload responsive. However, the power spectral measures of SBP and SA variability were significantly reduced (p = 0.007 and p = 0.026, respectively) following preload enhancement in fluid responsive subjects. CONCLUSIONS: Our results indicate that neither IVDG, nor SBP and SA variability are predictive of preload responsive hypotension in post-cardiac surgery patients. Spectral analysis of SBP and SA may be more sensitive at assessing preload responsiveness in this patient group than traditional maximum-minimum measures.
We report on measurements of the cross section and provide first data on spin correlation parameters A(TT') and A(TL') in inclusive scattering of longitudinally polarized electrons from nuclear-polarized hydrogen. Polarized electrons were injected into an electron storage ring operated at a beam energy of 720 MeV. Polarized hydrogen was produced by an atomic beam source and injected into an open-ended cylindrical cell, located in the electron storage ring. The four-momentum transfer squared ranged from Q2 = 0.2 GeV(2)/c(2) at the elastic scattering peak to Q2 = 0.11 GeV(2)/c(2) at the Delta(1232) resonance. The data provide a stringent test of pion electroproduction models.
The spin-momentum correlation parameter A(V)(ed) was measured for the 2H-->(e-->,e'p)n reaction for missing momenta up to 350 MeV/c at Q2 = 0.21 (GeV/c)(2) for quasielastic scattering of polarized electrons from vector-polarized deuterium. The data give detailed information about the deuteron spin structure and are in good agreement with the results of microscopic calculations based on realistic nucleon-nucleon potentials and including various spin-dependent reaction mechanism effects. The experiment reveals in a most direct manner the effects of the D state in the deuteron ground-state wave function and shows the importance of isobar configurations for this reaction.
Many everyday tasks require that we use our hands co-operatively. For tasks where both hands are required to perform the same action, a common motor program can be used. But, where each hand must perform a different action, some degree of independent control of each hand is required. In this paper we examine the co-ordination of bimanual movement kinematics in a female patient recovering from brain injury involving anterior regions of the parietal lobe of the right hemisphere, which has resulted in a dense hemianaesthesia of her left arm. A particular focus of this paper is the co-ordination of bimanual movements for reaches executed without visual feedback. Specifically we present new data, which quantify the synchronisation of patient D.B.'s hands by comparing their relative time lag at the start and the end of her bimanual reaches. The results are discussed with particular reference to the role played by limb proprioception in the planning and control of prehension movements.
Hemispatial neglect affects the ability to explore space on the side opposite a brain lesion. This deficit is also mirrored in abnormal saccadic eye movement patterns. The present study investigated if the recovery of neglect is also reflected in saccadic eye movements. Patient AF, who displayed strong hemispatial neglect 1 month post-right thalamic stroke, had largely recovered 3 months later when tested on visual exploration tasks of the Behavioural Inattention Test. At this stage, AF was tested on a visual search task while his eye movements (direction, latencies and amplitudes of first saccades) and manual reaction times were recorded. The experimental conditions differed with respect to stimulus number and distracter type and increased in difficulty. AF correctly generated saccades into the neglected field when the target was presented alone. In contrast, a considerable left/right difference was present for all multiple-stimulus search displays. Although recovered from neglect in standardized assessment, AF showed a strong rightward bias resulting in highly asymmetric response times and eye movement behaviour. We conclude that eye movement patterns are far more susceptible to remaining spatial impairments and can thus provide a sensitive means to assess the extent of neglect recovery.
Some patients with hemispatial neglect show deficits in horizontal size perception. Most previous studies investigating this effect required the relative comparison of two horizontal stimuli. We examined whether the effect would also be present for single stimuli which would reflect an impairment in the computation of absolute horizontal length. Ten neglect patients, five with and five without hemianopia, and two control groups were asked to verbally judge the length of horizontal lines varying in length (3, 3.5, 4 inches) and spatial location (extreme left to extreme right). Three of the ten neglect patients judged a single object on the left as significantly smaller than a single object on the right, thus demonstrating a size processing deficit. This deficit was unrelated to hemianopia.
Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.
The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.
Twelve patients with hemispatial neglect and two control groups were tested to examine the effects of the Müller-Lyer and Judd illusions on bisection behaviour. The studies were designed to investigate whether neglect patients were indeed unaware of the left sides of the illusory figures. In Experiment 1, participants were asked to describe the illusory figures prior to bisection, whereas in Experiment 2, they compared two illusions whose fins, in the critical condition, differed on the left and then performed the bisection. It was found that the illusions worked equally well in all three groups. Interestingly, apart from one exception, almost all neglect patients explicitly reported the left-sided fins in Experiment 1. Only five patients failed to do so but only on an average of 16% of trials. In Experiment 2, six patients made errors in the comparison task but four of these patients did not neglect any left-sided fins in Experiment 1 (with the exception of three overall trials for LC and EdR). This finding seems a good indication that the two tasks differ in their requirements. The comparison task may be perceived as harder as it requires discrimination rather than detection and thus lead to more neglect type errors than the bisection task. In one neglect patient, the illusions consistently failed to work. This patient presented with an occipito-temporal and basal ganglia lesion and the mechanisms responsible for the processing of simple visual features might have possibly been impaired in her case.