| 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. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 3. |
- Ng, M Y M, et al.
(författare)
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Meta-analysis of 32 genome-wide linkage studies of schizophrenia
- 2009
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 14:8, s. 774-785
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Tidskriftsartikel (refereegranskat)abstract
- A genome scan meta-analysis (GSMA) was carried out on 32 independent genome-wide linkage scan analyses that included 3255 pedigrees with 7413 genotyped cases affected with schizophrenia (SCZ) or related disorders. The primary GSMA divided the autosomes into 120 bins, rank-ordered the bins within each study according to the most positive linkage result in each bin, summed these ranks (weighted for study size) for each bin across studies and determined the empirical probability of a given summed rank (P(SR)) by simulation. Suggestive evidence for linkage was observed in two single bins, on chromosomes 5q (142-168 Mb) and 2q (103-134 Mb). Genome-wide evidence for linkage was detected on chromosome 2q (119-152 Mb) when bin boundaries were shifted to the middle of the previous bins. The primary analysis met empirical criteria for 'aggregate' genome-wide significance, indicating that some or all of 10 bins are likely to contain loci linked to SCZ, including regions of chromosomes 1, 2q, 3q, 4q, 5q, 8p and 10q. In a secondary analysis of 22 studies of European-ancestry samples, suggestive evidence for linkage was observed on chromosome 8p (16-33 Mb). Although the newer genome-wide association methodology has greater power to detect weak associations to single common DNA sequence variants, linkage analysis can detect diverse genetic effects that segregate in families, including multiple rare variants within one locus or several weakly associated loci in the same region. Therefore, the regions supported by this meta-analysis deserve close attention in future studies.
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| 4. |
- Carlsson, Ella, et al.
(författare)
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Mass composition of the escaping plasma at Mars
- 2006
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Ingår i: Icarus. - : Elsevier BV. - 0019-1035 .- 1090-2643. ; 182:2, s. 320-328
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Tidskriftsartikel (refereegranskat)abstract
- Data from the Ion Mass Analyzer (IMA) sensor of the ASPERA-3 instrument suite on Mars Express have been analyzed to determine the mass composition of the escaping ion species at Mars. We have examined 77 different ion-beam events and we present the results in terms of flux ratios between the following ion species: CO2+/O+ and O-2(+)/O+. The following ratios averaged over all events and energies were identified: CO2+/O+ = 0.2 and O-2(+)/O+ = 0.9. The values measured are significantly higher, by a factor of 10 for O-2(+)/O+, than a contemporary modeled ratio for the maximum fluxes which the martian ionosphere can supply. The most abundant ion species was found to be O+, followed by O-2(+) and CO2+. We estimate the loss of CO2+ to be 4.0 x 10(24) s(-1) (0.29 kg s(-1)) by using the previous measurements of Phobos-2 in our calculations. The dependence of the ion ratios in relation to their energy ranges we studied, 0.3-3.0 keV, indicated that no clear correlation was found.
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| 5. |
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| 6. |
- Berry, C C, et al.
(författare)
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Human fibroblast and human bone marrow cell response to lithographically nanopatterned adhesive domains on protein rejecting substrates.
- 2007
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Ingår i: IEEE Transactions on Nanobioscience. - 1536-1241. ; 6:3, s. 201-9
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Tidskriftsartikel (refereegranskat)abstract
- The separate influence of topographical and chemical cues on cell attachment and spreading are well documented; however, that of duel-cue substrates is less so. In this study graft copolymers that sterically stabilize biological surfaces were employed alongside nanotopographical features fabricated by colloidal lithography. This resulted in the production of a range of substrates whereby the effect of chemistry and or topography on both on human fibroblast and bone marrow cell adhesion and spreading could be observed. The current studies indicate an enhancement of cell response as a consequence of modifications in material topography, whereas the current selected chemical cues inhibited cell function. Critically, in combination, topography modulated the effects of chemical environment.
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| 7. |
- Carroll, M. A., et al.
(författare)
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Reactive nitrogen oxide fluxes to a mixed hardwood forest
- 2008
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Ingår i: International Geosphere-Biosphere Programme, Congress in May 2008.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Measurements of NOx (nitric oxide and nitrogen dioxide) mixing ratios and fluxes (20 May – 1 September) and NOy mixing ratios and fluxes (9 August – 1 September) were made at a northern mixed hardwood forest located at the University of Michigan Biological Station in northern Michigan, USA (45.5 deg N, 84.7 deg W, elevation 238 m) in 2005. During the 15-week period of NOx measurements, the site received flow from two dominant flow regimes: the north-northwest (ozone 20 – 40 ppbv) and the south-southwest (ozone 40 – 100 ppbv) approximately 26% and 27% of the time, respectively. Typical ambient NOx and NOy levels ranged from 0.5 – 2.4 ppbv and 0.5 to 3 ppbv, respectively. NO and NOy fluxes were found to be strongly diurnal with mid-day maximum downward fluxes of 0.5 – 2 and 1 – 2 μmole per square meter per hour, respectively, and nighttime fluxes at or near zero. In contrast, NO2 fluxes were small and upward during the morning, small and downward during the afternoon, and at or near zero at night. NOx fluxes were found to be essentially zero throughout the day and night. If all of the NOy deposition in this study were in the form of nitric acid, it would increase the available nutrient nitrate input to the forest by 8% over measured wet nitrate deposition.
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| 8. |
- Hogg, A., et al.
(författare)
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Multi-year measurements of stomatal and non-stomatal fluxes
- 2007
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Ingår i: American Geophysical Union, Meeting in San Francisco, 10–14 December 2007.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Measurements of ozone, sensible heat, and latent heat fluxes, as well as relative humidity, temperature, pressure, wind speed, leaf area index, ambient ozone, and plant physiological parameters were made at a northern mixed hardwood forest located at the University of Michigan Biological Station (UMBS) in northern Michigan during the growing seasons 2002 through 2005. The ozone measurements were used to calculate total ozone flux and partitioning between stomatal and non-stomatal sinks. Total ozone flux varied diurnally with downward flux reaching -100 μmol m-2 h-1 at midday, at or near zero at night. Mean daytime canopy conductance varied over the four years: 0.39 mol m-2 s-1 (2002), 0.41 mol m-2 s-1 (2003), 0.52 mol m-2 s-1 (2004), and 0.43 mol m-2 s-1 (2005). Stomatal conductance showed expected patterns of behavior with respect to photosynthetic photon flux density (PPFD) and vapor pressure deficit (VPD). Estimated peak growing season stomatal ozone burden (flux) was 2.9 x105 nmol m-2 in 2002, 5.6 x105 nmol m-2 in 2003, 6.6 x105 nmol m-2 in 2004, and 4.1 x105 nmol m-2 in 2005. Non-stomatal conductance for ozone increased monotonically with increasing PPFD, and increased with temperature before falling off again at high temperature. Daytime non-stomatal ozone sinks were large and varied with time and environmental drivers. Daytime non-stomatal ozone conductance accounted for as much as 61% (2002), 31% (2003), 36% (2004), or 57% (2005) of canopy conductance, with the non-stomatal partition representing 4.2x105 nmol m-2 (2002), 2.0x105 nmol m-2 (2003), 3.5x105 nmol m-2 (2004), 3.5x105 nmol m-2 (2005) of the flux. Non-stomatal ozone conductance was strongly diurnal and a significant proportion of total canopy conductance.
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