| 1. |
- Abdesselam, A., et al.
(författare)
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Engineering for the ATLAS SemiConductor Tracker (SCT) end-cap
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS SemiConductor Tracker (SCT) is a silicon-strip tracking detector which forms part of the ATLAS inner detector. The SCT is designed to track charged particles produced in proton-proton collisions at the Large Hadron Collider (LHC) at CERN at an energy of 14 TeV. The tracker is made up of a central barrel and two identical end-caps. The barrel contains 2112 silicon modules, while each end-cap contains 988 modules. The overall tracking performance depends not only on the intrinsic measurement precision of the modules but also on the characteristics of the whole assembly, in particular, the stability and the total material budget. This paper describes the engineering design and construction of the SCT end-caps, which are required to support mechanically the silicon modules, supply services to them and provide a suitable environment within the inner detector. Critical engineering choices are highlighted and innovative solutions are presented - these will be of interest to other builders of large-scale tracking detectors. The SCT end-caps will be fully connected at the start of 2008. Further commissioning will continue, to be ready for proton-proton collision data in 2008.
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| 2. |
- Abdesselam, A., et al.
(författare)
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The ATLAS semiconductor tracker end-cap module
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 575:3, s. 353-389
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Tidskriftsartikel (refereegranskat)abstract
- The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker. (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip 3.3 mu s buffer. The highest anticipated dose after 10 years operation is 1.4x10(14) cm(-2) in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area similar to 70 cm(2), each having 2 x 768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X-0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e(-) equivalent noise charge (ENC) rising to only 1800e(-) ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide flex read-out circuit and the ABCD3TA read-out ASICs. Finally, the accuracy of module assembly must not compromise the 16 mu m (r phi) resolution perpendicular to the strip directions or 580 mu m radial resolution coming from the 40 mrad front-back stereo angle. A total of 2210 modules were built to the tight tolerances and specifications required for the SCT. This was 234 more than the 1976 required and represents a yield of 93%. The component flow was at times tight, but the module production rate of 40-50 per week was maintained despite this. The distributed production was not found to be a major logistical problem and it allowed additional flexibility to take advantage of where the effort was available, including any spare capacity, for building the end-cap modules. The collaboration that produced the ATLAS SCT end-cap modules kept in close contact at all times so that the effects of shortages or stoppages at different sites could be rapidly resolved.
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| 3. |
- Szatmari, Peter, et al.
(författare)
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Mapping autism risk loci using genetic linkage and chromosomal rearrangements.
- 2007
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 39:3, s. 319-328
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Tidskriftsartikel (refereegranskat)abstract
- Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,168 families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.
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| 4. |
- Bonduelle, M, et al.
(författare)
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A multi-centre cohort study of the physical health of 5-year-old children conceived after intracytoplasmic sperm injection, in vitro fertilization and natural conception
- 2005
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Ingår i: Hum Reprod. ; 20:2, s. 413-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Over a million children have been born from assisted conception worldwide. Newer techniques being introduced appear less and less 'natural', such as intracytoplasmic sperm injection (ICSI), but there is little information on these children beyond the neonatal period. METHODS: 540 ICSI conceived 5-year-old children from five European countries were comprehensively assessed, along with 538 matched naturally conceived children and 437 children conceived with standard IVF. RESULTS: Of the 540 ICSI children examined, 63 (4.2%) had experienced a major congenital malformation. Compared with naturally conceived children, the odds of a major malformation were 2.77 (95% CI 1.41-5.46) for ICSI children and 1.80 (95% CI 0.85-3.81) for IVF children; these estimates were little affected by adjustment for socio-demographic factors. The higher rate observed in the ICSI group was due partially to an excess of malformations in the (boys') urogenital system. In addition, ICSI and IVF children were more likely than naturally conceived children to have had a significant childhood illness, to have had a surgical operation, to require medical therapy and to be admitted to hospital. A detailed physical examination revealed no further substantial differences between the groups, however. CONCLUSIONS: Singleton ICSI and IVF 5-year-olds are more likely to need health care resources than naturally conceived children. Assessment of singleton ICSI and IVF children at 5 years of age was generally reassuring, however, we found that ICSI children presented with more major congenital malformations and both ICSI and IVF children were more likely to need health care resources than naturally conceived children. Ongoing monitoring of these children is therefore required.
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| 5. |
- Collier, Andrew, et al.
(författare)
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Evidence of standing waves during a Pi2 pulsation event observed on Cluster
- 2006
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 24:10, s. 2719-2733
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Tidskriftsartikel (refereegranskat)abstract
- Observations of Pi2 pulsations at middle and low latitudes have been explained in terms of cavity mode resonances, whereas transients associated with field-aligned currents appear to be responsible for the high latitude Pi2 signature. Data from Cluster are used to study a Pi2 event observed at 18:09 UTC on 21 January 2003, when three of the satellites were within the plasmasphere (L=4.7,4.5 and 4.6) while the fourth was on the plasmapause or in the plasmatrough (L=6.6). Simultaneous pulsations at ground observatories and the injection of particles at geosynchronous orbit corroborate the occurrence of a substorm. Evidence of a cavity mode resonance is established by considering the phase relationship between the orthogonal electric and magnetic field components associated with radial and field-aligned standing waves. The relative phase between satellites located on either side of the geomagnetic equator indicates that the field-aligned oscillation is an odd harmonic. Finite azimuthal Poynting flux suggests that the cavity is effectively open ended and the azimuthal wave number is estimated as m similar to 13.5.
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| 6. |
- Stark, Jennifer R., et al.
(författare)
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Prospective study of Trichomonas vaginalis infection and prostate cancer incidence and mortality : Physicians' Health Study
- 2009
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Ingår i: Journal of the National Cancer Institute. - Cary, USA : Oxford University Press. - 0027-8874 .- 1460-2105. ; 101:20, s. 1406-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: A recent nested case-control study found that the presence of antibodies against Trichomonas vaginalis, a common nonviral sexually transmitted infection, was positively associated with subsequent incidence of prostate cancer. We confirmed these findings in an independent population and related serostatus for antibodies against T vaginalis to prostate cancer incidence and mortality.Methods: We conducted a case-control study nested within the Physicians' Health Study that included 673 case subjects with prostate cancer and 673 individually matched control subjects who had available plasma samples. Plasma from blood samples collected at baseline was assayed for antibodies against T vaginalis with an enzyme-linked immunosorbent assay. We used conditional logistic regression to estimate the odds ratios (ORs) of incident prostate cancer, extraprostatic prostate cancer, and cancer that would ultimately progress to bony metastases or prostate cancer-specific death.Results: Although not statistically significant, the magnitude of the association between T vaginalis-seropositive status and overall prostate cancer risk (OR = 1.23, 95% confidence interval [CI] = 0.94 to 1.61) was similar to that reported previously. Furthermore, a seropositive status was associated with statistically significantly increased risks of extraprostatic prostate cancer (OR = 2.17, 95% CI = 1.08 to 4.37) and of cancer that would ultimately progress to bony metastases or prostate cancer-specific death (OR = 2.69, 95% CI = 1.37 to 5.28).Conclusions: This large prospective case-control study obtained further support for an association between a seropositive status for antibodies against T vaginalis and the risk of prostate cancer, with statistically significant associations identified for the risk of extraprostatic prostate cancer and for clinically relevant, potentially lethal prostate cancer.
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