| 11. |
- Dawson, K. S., et al.
(författare)
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An Intensive Hubble Space Telescope Survey for z>1 Type Ia Supernovae by Targeting Galaxy Clusters
- 2009
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 138, s. 1271-1283
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Tidskriftsartikel (refereegranskat)abstract
- We present a new survey strategy to discover and study high-redshift Type Ia supernovae (SNe Ia) using the Hubble Space Telescope (HST). By targeting massive galaxy clusters at 0.9 < z < 1.5, we obtain a twofold improvement in the efficiency of finding SNe compared to an HST field survey and a factor of 3 improvement in the total yield of SN detections in relatively dust-free red-sequence galaxies. In total, sixteen SNe were discovered at z>0.95, nine of which were in galaxy clusters. This strategy provides an SN sample that can be used to decouple the effects of host-galaxy extinction and intrinsic color in high-redshift SNe, thereby reducing one of the largest systematic uncertainties in SN cosmology. Based on observations made with the NASA/ESA Hubble Space Telescope and obtained from the data archive at the Space Telescope Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555. The observations are associated with program 10496.
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| 12. |
- Katayama, S, et al.
(författare)
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Antisense transcription in the mammalian transcriptome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1564-1566
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Tidskriftsartikel (refereegranskat)abstract
- Antisense transcription (transcription from the opposite strand to a protein-coding or sense strand) has been ascribed roles in gene regulation involving degradation of the corresponding sense transcripts (RNA interference), as well as gene silencing at the chromatin level. Global transcriptome analysis provides evidence that a large proportion of the genome can produce transcripts from both strands, and that antisense transcripts commonly link neighboring “genes” in complex loci into chains of linked transcriptional units. Expression profiling reveals frequent concordant regulation of sense/antisense pairs. We present experimental evidence that perturbation of an antisense RNA can alter the expression of sense messenger RNAs, suggesting that antisense transcription contributes to control of transcriptional outputs in mammals.
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| 13. |
- Barbary, K., et al.
(författare)
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Discovery of an Unusual Optical Transient with the Hubble Space Telescope
- 2009
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 690, s. 1358-1362
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Tidskriftsartikel (refereegranskat)abstract
- We present observations of SCP 06F6, an unusual optical transient discovered during the Hubble Space Telescope Cluster Supernova Survey. The transient brightened over a period of ~100 days, reached a peak magnitude of ~ 21.0 in both i 775 and z 850, and then declined over a similar timescale. There is no host galaxy or progenitor star detected at the location of the transient to a 3σ upper limit of i 775 >= 26.4 and z 850 >= 26.1, giving a corresponding lower limit on the flux increase of a factor of ~ 120. Multiple spectra show five broad absorption bands between 4100 Å and 6500 Å, and a mostly featureless continuum longward of 6500 Å. The shape of the light curve is inconsistent with microlensing. The transient's spectrum, in addition to being inconsistent with all known supernova types, does not match any spectrum in the Sloan Digital Sky Survey database. We suggest that the transient may be one of a new class. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute (STScI). STScI is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under the NASA contract NAS 5-26555. The observations are associated with program GO-10496. Based in part on observations obtained at the European Southern Observatory under ESO program 077.A-0110. Based in part on observations collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA.
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| 14. |
- Huang, X., et al.
(författare)
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HUBBLE SPACE TELESCOPE DISCOVERY OF A z=3.9 MULTIPLY IMAGED GALAXY BEHIND THE COMPLEX CLUSTER LENS WARPS J1415.1+36 AT z=1.026
- 2009
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Ingår i: ASTROPHYS J LETT. ; 707:1, s. l12-L16
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of a multiply lensed Ly alpha emitter at z = 3.90 behind the massive cluster WARPS J1415.1+3612 at z = 1.026. Images taken by the Hubble Space Telescope using the Advanced Camera for Surveys reveal a complex lensing system that produces a prominent, highly magnified arc and a triplet of smaller arcs grouped tightly around a spectroscopically confirmed cluster member. Spectroscopic observations using the Faint Object Camera and Spectrograph on Subaru confirm strong Lya emission in the source galaxy and provide the redshifts for more than 21 cluster members with a velocity dispersion of 807 +/- 185 km s(-1). Assuming a singular isothermal sphere profile, the mass within the Einstein ring (7.13 +/- 0.'' 38) corresponds to a central velocity dispersion of 686(-19)(+15) km s(-1) for the cluster, consistent with the value estimated from cluster member redshifts. Our mass profile estimate from combining strong lensing and dynamical analyses is in good agreement with both X-ray and weak lensing results.
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| 15. |
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| 16. |
- Concina, B., et al.
(författare)
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Delayed ionisation of C-76
- 2006
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Ingår i: INTERNATIONAL JOURNAL OF MASS SPECTROMETRY. - : Elsevier BV. - 1387-3806. ; 252:2, s. 96-99
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Tidskriftsartikel (refereegranskat)
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| 17. |
- Rubin, D., et al.
(författare)
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Looking Beyond Lambda with the Union Supernova Compilation
- 2009
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 695, s. 391-403
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Tidskriftsartikel (refereegranskat)abstract
- The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data—provides a powerful tool for constraining cosmological models. Here we examine particular classes of scalar field, modified gravity, and phenomenological models to assess whether they are consistent with observations even when their behavior deviates from the cosmological constant Λ. Some models have tension with the data, while others survive only by approaching the cosmological constant, and a couple are statistically favored over Λ cold dark matter. Dark energy described by two equation-of-state parameters has considerable phase space to avoid Λ and next-generation data will be required to constrain such physics, with the level of complementarity between probes varying with cosmology.
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| 18. |
- Baron, P., et al.
(författare)
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AMATERASU: Model for atmospheric TeraHertz Radiation analysis and simulation
- 2008
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Ingår i: Journal of the National Institute of Information and Communications Technology. - 1349-3205. ; 55:1, s. 109-121
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Tidskriftsartikel (refereegranskat)abstract
- We describe the current status of the Advanced Model for Atmospheric TeraHertz Radiation Analysis and Simulation (AMATERASU) that is being developed in the framework of the NICT THz project. This code aims to be used for studying the insterest of the THz frequency region for atmospheric remote sensing, communication systems and estimate the impact of the THz thermal atmospheric emission in the Earth energy budget. This paper presents the first stage of the model development that concerns a non scattering and a horizontal homogeneous atmosphere, e.g., the geophysical parameters are only altitude dependent. A scattering module is being developed but it is presented in an other paper in this issue. The model is based on the Microwave Observation and Lines Estimation and REtrieval code (MOLIERE). The absorption coefficient module has been modified in order to extend the frequency coverage from the submillimeter wavelength to the near InfraRed region. A new radiative transfer module has been implemented that can handle the different types of optical paths and any location for the receiver. AMATERASU includes the original MOLIERE instrument simulator and retrieval codes. The validation methodology is discussed and some examples of the current applications are given. The next steps of the development are presented in the conclusion including the modeling of the horizontal inhomogeneties in the atmopshere.
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| 19. |
- Darkeh, M. H. S. E., et al.
(författare)
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The minimum number of target lesions that need to be measured to be representative of the total number of target lesions (according to RECIST)
- 2009
-
Ingår i: British Journal of Radiology. - : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 82:980, s. 681-6
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Tidskriftsartikel (refereegranskat)abstract
- Response evaluation criteria in solid tumours (RECIST) were introduced as a means to classify tumour response with no definition of the minimum number of lesions. This study was conducted in order to evaluate discrepancies between full assessments based on either all target lesions or fewer lesions. RECIST evaluation was performed on separate occasions based on between one and seven of the target lesions, with simultaneous assessment of non-target lesions. 99 patients were included. 38 patients demonstrated progressive disease, in 61% of whom it was a result of the appearance of new lesions or unequivocal progress in non-target lesions. 32 patients showed stable disease, with 8 having results that differed when 1-3 target lesions were measured. 22 cases were considered as having partial regression, with only 1 case differing when performing 1-3 target lesion assessments. Seven cases demonstrated complete response. The number of discordant cases increased gradually from measuring three lesions to one target lesion. The average number of available target lesions among those with discrepancies was 7.1, which was significantly higher than those demonstrating concordance (4.1 lesions; p<0.05). In conclusion, measuring fewer than four target lesions might cause discrepancies when more than five target lesions are present.
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| 20. |
- Dunham, Christine M., et al.
(författare)
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Structures of tRNAs with an expanded anticodon loop in the decoding center of the 30S ribosomal subunit
- 2007
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Ingår i: RNA. - : Cold Spring Harbor Laboratory. - 1355-8382 .- 1469-9001. ; 13:6, s. 817-823
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Tidskriftsartikel (refereegranskat)abstract
- During translation, some +1 frameshift mRNA sites are decoded by frameshift suppressor tRNAs that contain an extra base in their anticodon loops. Similarly engineered tRNAs have been used to insert nonnatural amino acids into proteins. Here, we report crystal structures of two anticodon stem–loops (ASLs) from tRNAs known to facilitate +1 frameshifting bound to the 30S ribosomal subunit with their cognate mRNAs. ASLCCCG and ASLACCC (5'–3' nomenclature) form unpredicted anticodon–codon interactions where the anticodon base 34 at the wobble position contacts either the fourth codon base or the third and fourth codon bases. In addition, we report the structure of ASLACGA bound to the 30S ribosomal subunit with its cognate mRNA. The tRNA containing this ASL was previously shown to be unable to facilitate +1 frameshifting in competition with normal tRNAs (Hohsaka et al. 2001), and interestingly, it displays a normal anticodon–codon interaction. These structures show that the expanded anticodon loop of +1 frameshift promoting tRNAs are flexible enough to adopt conformations that allow three bases of the anticodon to span four bases of the mRNA. Therefore it appears that normal triplet pairing is not an absolute constraint of the decoding center.
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