1. |
- Anghinolfi, F., et al.
(författare)
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Hadron beam test of a scintillating fibre tracker system for elastic scattering and luminosity measurement in ATLAS
- 2007
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- A scintillating fibre tracker is proposed to measure elastic proton scattering at very small angles in the ATLAS experiment at CERN. The tracker will be located in so-called Roman Pot units at a distance of 240 m on each side of the ATLAS interaction point. An initial validation of the design choices was achieved in a beam test at DESY in a relatively low energy electron beam and using slow off-the-shelf electronics. Here we report on the results from a second beam test experiment carried out at CERN, where new detector prototypes were tested in a high energy hadron beam, using the first version of the custom designed front-end electronics. With a spatial resolution of 25 mu m an adequate tracking performance was obtained, under conditions which are similar to the situation at the LHC. In addition, the alignment method using so-called overlap detectors was studied and shown to have the expected precision.
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2. |
- Mapelli, A., et al.
(författare)
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Development of a detector (ALFA) to measure the absolute LHC luminosity at ATLAS
- 2008
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Ingår i: Astroparticle, Particle and Space Physics, Detectors and Medical Physics Applications - Proceedings of the 10th Conference. - 9812819088 - 9789812819086 ; , s. 984-988
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Konferensbidrag (refereegranskat)abstract
- The ATLAS collaboration plans to determine the absolute luminosity of the CERN LHC at Interaction Point 1 by measuring the trajectory of protons elastically scattered at very small angles (μrad). A scintillating fibre tracker system called ALFA (Absolute Luminosity For ATLAS) is proposed for this measurement. Detector modules will be placed above and below the LHC beam axis in roman pot units at a distance of 240 m on cach side of the ATLAS interaction point. They allow the detectors to approach the beam axis to millimeter distance. Overlap detectors also based on the scintillating fibre technology, will measure the precise relative position of the two detector modules, Results obtained during beam tests at DESY and at CERN validate the detectors design and demonstrate the achievable resolution. We also report about radiation hardness studies of the scintillating fibres to estimate the lifetime of the ALFA system at different operating conditions of the LHC.
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3. |
- Böser, S, et al.
(författare)
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SPATS : An acoustic array at the South Pole
- 2007
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Ingår i: Journal of Physics, Conference Series. - : Institute of Physics. - 1742-6588 .- 1742-6596. ; 60, s. 292-295
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The detection of extraterrestrial EHE neutrinos requires detection volumes at least one order of magnitude larger than currently constructed km3 optical neutrino detectors. In ice, it is anticipated that the absorption length for acoustic waves reaches up to to several kilometers. This makes ice an attractive host environment for a next generation acoustic neutrino detector. To measure the acoustic properties of ice at South Pole, a test setup has been developed, ready to be deployed in the 2006/07 summer season.
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4. |
- Böser, S, et al.
(författare)
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Status of the South Pole Acoustic Test Setup
- 2007
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 81:1, s. 012010-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Due to the low flux of ultra-high energetic neutrinos induced in interactions of cosmic rays with the cosmic microwave background, very large instrumented volumes and new registration techniques are necessary for their detection. The south polar ice offers the unique opportunity to implement existing Cherenkov techniques as well as registration of radio and acoustic waves from the neutrino interaction. A simulation of a ~ 120 km3 hybrid optical/radio/acoustic detector showed that event rates of ~ 10 per year can be achieved. In this simulation the ultrasonic parameters of antarctic ice regarding absorption, scattering and environmental noise pose the key uncertainty. To evaluate the acoustic properties in-situ, the South Pole Acoustic Test Setup (SPATS) has been created. An array of custom-made ultrasonic sensors and transmitters will be deployed on three strings in the upper 400 m of the holes of the IceCube experiment. The status of the experiment and a first evaluation of its performance are presented here.
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5. |
- Böser, S, et al.
(författare)
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The South Pole Acoustic Test Setup : calibrations and lake test
- 2007
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 81, s. 012016-
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. In order to detect the small neutrino fluxes expected at ultra-high energies, large volumes of materials have to be instrumented with inexpensive but sensitive acoustic sensors. The South Pole Acoustic Test Setup (SPATS) will be installed in the Antarctic ice during the polar season 2006/2007 after which the collected data will be used to reveal the acoustic properties of the South Polar ice cap. The developed piezoceramic based ultrasound sensors and transmitters that are part of this system have been extensively studied during calibration measurements in water, using a commercial hydrophone as reference. Also, a SPATS system test was accomplished in Lake Torneträsk, Abisko (Sweden). This allowed verification of the DAQ system, transmitter range and sensor performance. Here the results of the calibrations and the Abisko lake measurements are reported.
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6. |
- Tinker, N. A., et al.
(författare)
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New DArT markers for oat provide enhanced map coverage and global germplasm characterization
- 2009
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 10:39
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genomic discovery in oat and its application to oat improvement have been hindered by a lack of genetic markers common to different genetic maps, and by the difficulty of conducting whole-genome analysis using high-throughput markers. This study was intended to develop, characterize, and apply a large set of oat genetic markers based on Diversity Array Technology (DArT). Results: Approximately 19,000 genomic clones were isolated from complexity-reduced genomic representations of pooled DNA samples from 60 oat varieties of global origin. These were screened on three discovery arrays, with more than 2000 polymorphic markers being identified for use in this study, and approximately 2700 potentially polymorphic markers being identified for use in future studies. DNA sequence was obtained for 2573 clones and assembled into a non-redundant set of 1770 contigs and singletons. Of these, 705 showed highly significant (Expectation < 10E-10) BLAST similarity to gene sequences in public databases. Based on marker scores in 80 recombinant inbred lines, 1010 new DArT markers were used to saturate and improve the 'Kanota' x 'Ogle' genetic map. DArT markers provided map coverage approximately equivalent to existing markers. After binning markers from similar clones, as well as those with 99% scoring similarity, a set of 1295 non-redundant markers was used to analyze genetic diversity in 182 accessions of cultivated oat of worldwide origin. Results of this analysis confirmed that major clusters of oat diversity are related to spring vs. winter type, and to the presence of major breeding programs within geographical regions. Secondary clusters revealed groups that were often related to known pedigree structure. Conclusion: These markers will provide a solid basis for future efforts in genomic discovery, comparative mapping, and the generation of an oat consensus map. They will also provide new opportunities for directed breeding of superior oat varieties, and guidance in the maintenance of oat genetic diversity.
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8. |
- Danila, DC, et al.
(författare)
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Circulating Tumor Cell Number and Prognosis in Progressive Castration-Resistant Prostate Cancer
- 2007
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Ingår i: Clinical Cancer Research. - 1078-0432. ; 13:23, s. 7053-7058
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The development of tumor-specific markers to select targeted therapies and to assess clinical outcome remains a significant area of unmet need. We evaluated the association of baseline circulating tumor cell (CTC) number with clinical characteristics and survival in patients with castrate metastatic disease considered for different hormonal and cytotoxic therapies. EXPERIMENTAL DESIGN: CTC were isolated by immunomagnetic capture from 7.5-mL samples of blood from 120 patients with progressive clinical castrate metastatic disease. We estimated the probability of survival over time by the Kaplan-Meier method. The concordance probability estimate was used to gauge the discriminatory strength of the informative prognostic factors. RESULTS: Sixty-nine (57%) patients had five or more CTC whereas 30 (25%) had two cells or less. Higher CTC numbers were observed in patients with bone metastases relative to those with soft tissue disease and in patients who had received prior cytotoxic chemotherapy relative to those who had not. CTC counts were modestly correlated to measurements of tumor burden such as prostate-specific antigen and bone scan index, reflecting the percentage of boney skeleton involved with tumor. Baseline CTC number was strongly associated with survival, without a threshold effect, which increased further when baseline prostate-specific antigen and albumin were included. CONCLUSIONS: Baseline CTC was predictive of survival, with no threshold effect. The shedding of cells into the circulation represents an intrinsic property of the tumor, distinct from extent of disease, and provides unique information relative to prognosis.
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9. |
- Heller, T., et al.
(författare)
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Plasma concentrations of mycophenolic acid acyl glucuronide are not associated with diarrhea in renal transplant recipients
- 2007
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Ingår i: American Journal of Transplantation. - : Elsevier BV. - 1600-6135 .- 1600-6143. ; 7:7, s. 1822-1831
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine whether plasma concentrations of the acyl (AcMPAG) and phenolic (MPAG) glucuronide metabolites of mycophenolic acid (MPA) were related to diarrhoea in renal transplant patients on mycophenolate mofetil (MMF) with cyclosporine (CsA) or tacrolimus (TCL). Blood samples (0, 30, 120 min) were taken at days 3, 10, week 4, months 3, 6 and 12 for determination of MPA, MPAG and AcMPAG. MPA-AUC was estimated using validated algorithms. Two hour AUCs were calculated for MPAG and AcMPAG. Immunosuppressive therapy consisted of CsA/MMF (n= 110) and of TCL/MMF (n= 180). In 70/290 (24%) patients 86 episodes of diarrhoea were recorded during 12 months. Significantly more patients on TCL (31.1%) suffered from diarrhea compared to CsA (12.7%). MMF dose, MPA-AUC and the 2 h AUCs of MPAG and AcMPAG did not differ between patients with and without diarrhoea. Plasma AcMPAG and MPAG concentrations were substantially higher in patients on CsA compared with TCL, while MPA-AUC was lower in the former group. These data support the concept that CsA inhibits the biliary excretion of MPAG and AcMPAG, thereby potentially reducing the risk of intestinal injury through enterohepatic recycling of MPA and its metabolites.
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10. |
- Kølendorf, K., et al.
(författare)
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Insulin detemir lowers the risk of hypoglycaemia and provides more consistent plasma glucose levels compared with NPH insulin in Type 1 diabetes
- 2006
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Ingår i: Diabetic Medicine. - : Wiley-Blackwell Publishing Inc.. - 0742-3071 .- 1464-5491. ; 23:7, s. 729-735
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Hypoglycaemia remains a major barrier preventing optimal glycaemic control in Type 1 diabetes due to the limitations of conventional insulin preparations. We investigated whether basal-bolus therapy with insulin detemir (detemir), a new soluble basal insulin analogue, was more effective in reducing the risk of hypoglycaemia compared with NPH insulin (NPH).METHODS: In this multinational, open-label, cross-over trial, 130 individuals with Type 1 diabetes received detemir and NPH twice daily in a randomized order in combination with premeal insulin aspart (IAsp) during two 16-week treatment periods. Risk of hypoglycaemia was based on self-measured plasma glucose (SMPG) and self-reported episodes during the last 10 weeks of each period.RESULTS: Risk of nocturnal and overall hypoglycaemia was, respectively, 50% and 18% lower with detemir than with NPH (P < 0.001). A total of 19 severe hypoglycaemic episodes occurred during treatment with detemir compared with 33 with NPH (NS). HbA(1c) decreased by 0.3% point with both treatments and was comparable at 7.6% (+/- sem 0.06%, 95% confidence interval -0.106, 0.108) after 16 weeks with similar doses of basal insulin. Within-person variation in mean plasma glucose was lower with detemir than with NPH (sd 3.00 vs. 3.33, P < 0.001), as was prebreakfast SMPG (P < 0.0001).CONCLUSIONS: Detemir was associated with a significantly lower risk of hypoglycaemia compared with NPH at similar HbA1c when used in combination with mealtime IAsp. The more consistent plasma glucose levels observed with detemir may allow people to aim for tighter glycaemic control without an increased risk of hypoglycaemia.
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