| 1. |
- Adcox, K, et al.
(författare)
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PHENIX detector overview
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 2. |
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| 3. |
- Adler, SS, et al.
(författare)
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PHENIX on-line systems
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 560-592
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX On-Line system takes signals from the Front End Modules (FEM) on each detector subsystem for the purpose of generating events for physics analysis. Processing of event data begins when the Data Collection Modules (DCM) receive data via fiber-optic links from the FEMs. The DCMs format and zero suppress the data and generate data packets. These packets go to the Event Builders (EvB) that assemble the events in final form. The Level-1 trigger (LVL1) generates a decision for each beam crossing and eliminates uninteresting events. The FEMs carry out all detector processing of the data so that it is delivered to the DCMs using a standard format. The FEMs also provide buffering for LVL1 trigger processing and DCM data collection. This is carried out using an architecture that is pipelined and deadtimeless. All of this is controlled by the Master Timing System (MTS) that distributes the RHIC clocks. A Level-2 trigger (LVL2) gives additional discrimination. A description of the components and operation of the PHENIX On-Line system is given and the solution to a number of electronic infrastructure problems are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 4. |
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| 5. |
- Mathiasson, Lennart, et al.
(författare)
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Development of methods for the determination of vitamins A, E and beta-carotene in processed foods based on supercritical fluid extraction: a collaborative study.
- 2002
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Ingår i: Food Additives and Contaminants. - : Informa UK Limited. - 0265-203X. ; 19:7, s. 632-646
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Tidskriftsartikel (refereegranskat)abstract
- New methodologies based on supercritical fluid extraction (SFE) have been developed for the determination of fat-soluble vitamins in processed foods. The results obtained so far indicate that SFE is well suited to extraction of fat-soluble vitamins from food products, although validation work is required to establish accuracy and precision. The vitamins investigated were A, E and beta-carotene, and the processed foods were UHT milk, milk powder, minced meat, liver paste, infant formula, canned baby food and margarine. Extraction equipment employed analyte collection on either a solid-phase trap or in a solvent. After extraction, the samples were saponified and the vitamins determined using reversed-phase liquid chromatography with ultraviolet or fluorescence detection. Sample throughput was at least 12 samples day(-1), i.e. at least twice the number achievable with a conventional extraction methodology. The detection limits for the vitamins in different processed foods were well below 0.1 microg g(-1). Recoveries (in comparison with vitamin levels obtained using conventional solvent extraction) were close to 100% for experienced personal with access to modern automatic equipment. To reach this level, it was necessary to protect the vitamins with an antioxidant during the different steps of the analysis procedure, to add methanol or ethanol to the extraction cell to facilitate the analyte extraction from the food matrix, and when using a solid-phase trap, to employ a fractionated extraction-elution procedure to prevent breakthrough losses. The developed methods were tested in a validation exercise between five laboratories, which had taken part in the method development, and in an intercomparison between 10 laboratories including laboratories with less experience of vitamin determination. The within-laboratory RSD was generally
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| 6. |
- Turner, David R., 1951, et al.
(författare)
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The SWEDARP 1997/98 Expedition.
- 2004
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Ingår i: Deep Sea Research Part II. ; 51, s. 2543-2879
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Chierici, Melissa, 1968, et al.
(författare)
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Variability in pH, fCO(2), oxygen and flux of CO2 in the surface water along a transect in the Atlantic sector of the Southern Ocean
- 2004
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Ingår i: Deep-Sea Research Part Ii-Topical Studies in Oceanography. - : Elsevier BV. - 0967-0645. ; 51:22-24, s. 2773-2787
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Tidskriftsartikel (refereegranskat)abstract
- Underway sampling and measurements of pH, fCO(2), oxygen and Chlorophyll a (Chl a) were performed in the surface waters from Cape Town (South Africa) to Queen Maud Land (Antarctica) in the Atlantic sector of the Southern Ocean during the austral summer 1997/1998. From direct measurements of these parameters and from calculated fCO(2) the oceanic carbon dioxide system was studied and related to hydrological and biological parameters. fCO(2) was in general undersaturated relative to the atmosphere and showed a large variability with values ranging from 313 to 377 muatm with a mean value of 346 +/- 13 muatm. The undersaturation was more pronounced in areas associated with fronts where high Chl a and high pH in situ values were observed. Using shipboard wind speed data, estimates of the CO2 flux were made along the transect and during three mesoscale surveys on the northward return transect in the area of the Spring Ice Edge (SIE), the Winter Ice Edge (WIE) and in the Antarctic Polar Front (APF). The undersaturation observed during the transect caused the ocean to act as a sink for CO2 with a mean sea-air flux for the entire transect of -3+/-5 mmol m(-2) d(-1) with a large variability between -20 mmol m(-2) d(-1) (oceanic uptake) to 1.3 mmol m(-2) d(-1) (oceanic source). The lowest fCO(2) values (largest oceanic uptake Of COD were found at the southern boundary of the APF at 53degreesS, which coincided with a supersaturation in oxygen and high pH values. Oxygen concentrations were measured from 50degreesS to 63degreesS and varied between 324 and 359 mumol kg(-1) with a mean value of 347 +/- 9 mumol kg(-1). In general only small deviations from equilibrium oxygen saturation were observed (mean value = 99+/-2%). However, in the SIE oxygen was clearly undersaturated, probably an effect of upwelling of oxygen poor deep water which had not yet been compensated for by biological production. Three weeks later, the ice edge had retreated in the SIE region and the Chl a concentration had increased three-fold, suggesting the start of a phytoplankton bloom. This was also seen in the oxygen concentration which had increased and showed supersaturation. This coincided with an increased oceanic uptake of CO2 in the SIE during the mesoscale survey. (C) 2004 Elsevier Ltd. All rights reserved.
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| 8. |
- Squitieri, Ferdinando, et al.
(författare)
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Homozygosity for CAG mutation in Huntington disease is associated with a more severe clinical course.
- 2003
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 126:Pt 4, s. 946-55
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Tidskriftsartikel (refereegranskat)abstract
- Huntington disease is caused by a dominantly transmitted CAG repeat expansion mutation that is believed to confer a toxic gain of function on the mutant protein. Huntington disease patients with two mutant alleles are very rare. In other poly(CAG) diseases such as the dominant ataxias, inheritance of two mutant alleles causes a phenotype more severe than in heterozygotes. In this multicentre study, we sought differences in the disease features between eight homozygotes and 75 heterozygotes for the Huntington disease mutation. We identified subjects homozygous for the Huntington disease mutation by DNA testing and compared their clinical features (age at onset, symptom presentation, disease severity and disease progression) with those of a group of heterozygotes, who were assessed longitudinally. The age at onset of symptoms in the homozygote cases was within the range expected for heterozygotes with the same CAG repeat lengths, whereas homozygotes had a more severe clinical course. The observation of a more rapid decline in motor, cognitive and behavioural symptoms in homozygotes was consistent with the extent of neurodegeneration as available at imaging in three patients, and at the post-mortem neuropathological report in one case. Our analysis suggests that although homozygosity for the Huntington disease mutation does not lower the age at onset of symptoms, it affects the phenotype and the rate of disease progression. These data, once confirmed in a larger series of patients, point to the possibility that the mechanisms underlying age at onset and disease progression in Huntington disease may differ.
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| 9. |
- Turner, David R., 1951, et al.
(författare)
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The SWEDARP 1997/98 marine expedition: overview
- 2004
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Ingår i: Deep-Sea Research Part Ii-Topical Studies in Oceanography. - : Elsevier BV. ; 51, s. 2745-2756.
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Tidskriftsartikel (refereegranskat)abstract
- The SWEDARP 1997/98 expedition aboard the S.A. Agulhas focused on three study areas along the 6degreesE meridian: 60degreesS, the location of the spring ice edge; 56degreesS, the location of the winter ice edge; and 50.5degreesS, the Antarctic Polar Front. This intensive study was preceded by a north-south transect through the area measuring surface water properties while under way. An extensive measurement programme included hydrography, tracers, nutrients, organic carbon, trace metals, bacteria, and primary and secondary producers (including production and grazing rates). Analysis of the results from the three study areas does not identify a single factor limiting primary production: water column stability and the optical regime, and probably iron supply contributed to the control of primary production. The study area acted as a sink for atmospheric CO2 at the time of measurement, while analysis of water column carbon inventories indicated a net CO2 source integrated over the spring season. (C) 2004 Elsevier Ltd. All rights reserved.
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