| 1. |
- 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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| 2. |
- Ross, Owen A., et al.
(författare)
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Genomic investigation of alpha-synuclein multiplication and parkinsonism
- 2008
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 63:6, s. 743-750
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Copy number variation is a common polymorphic phenomenon within the human genome. Although the majority of these events are non-deleterious they can also be highly pathogenic. Herein we characterize five families with parkinsonism that have been identified to harbor multiplication of the chromosomal 4q21 locus containing the a-synuclein gene (SNCA). Methods: A methodological approach using fluorescent in situ hybridization and Affymetrix (Santa Clara, CA) 250K SNP microarrays was used to characterize the multiplication in each family and to identify the genes encoded within the region. The telomeric and centromeric breakpoints of each family were further narrowed using semiquantitative polymerase chain reaction with microsatellite markers and then screened for transposable repeat elements. Results: The severity of clinical presentation is correlated with SNCA dosage and does not appear to be overtly affected by the presence of other genes in the multiplicated region. With the exception of the Lister kindred, in each family the multiplication event appears de novo. The type and position of Alu/LINE repeats are also different at each breakpoint. Microsatellite analysis demonstrates two genomic mechanisms are responsible for chromosome 4q21 multiplications, including both SNCA duplication and recombination. Interpretation: SNCA dosage is responsible for parkinsonism, autonomic dysfunction, and dementia observed within each family. We hypothesize dysregulated expression of wild-type (alpha-synuclein results in parkinsonism and may explain the recent association of common SNCA variants in sporadic Parkinson's disease. SNCA genomic duplication results from intraallelic (segmental duplication) or interallelic recombination with unequal crossing over, whereas both mechanisms appear to be required for genomic SNCA triplication.
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| 3. |
- Chatyrko (Tjatyrko), Vitalij A, et al.
(författare)
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Addition and product theorems for ind
- 2008
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Ingår i: Topology and its Applications. - : Elsevier Science B.V., Amsterdam.. - 0166-8641 .- 1879-3207. ; 155:17-18, s. 2202-2210
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we improve two theorems for the small inductive dimension ind in the regular T-1-spaces: an addition theorem from [M.G Charalambous, V.A. Chatyrko. Some estimates of the inductive dimensions of the union of two sets, Topology Appl. 146/147 (2005) 227-238] and a product theorem from [V.A. Chatyrko. K.L. Kozlov. On (transfinite) small inductive dimension of products. Comment. Math. Univ. Carolin. 41 (3) (2000) 597-603].
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| 4. |
- Chatyrko, Vitalij A, et al.
(författare)
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Transfinite large inductive dimensions modulo absolute Borel classes
- 2009
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Ingår i: JOURNAL OF THE MATHEMATICAL SOCIETY OF JAPAN. - : Mathematical Society of Japan (Project Euclid). - 0025-5645. ; 61:2, s. 327-344
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Tidskriftsartikel (refereegranskat)abstract
- The following inequalities between transfinite large inductive dimensions modulo absolutely additive (resp. multiplicative) Borel classes A(alpha) (resp. M(alpha)) hold in separable metrizable spaces: (i) A(0)-trInd >= M(0)-trInd >= max{A(1)-trInd, M(1)-trInd}, and (ii) min{A(alpha)-trInd, M(alpha)-trInd} >= max{A(beta)-trInd, M(beta)-trInd}, where 1 <= alpha < beta < omega(1). We show that for any two functions a and m from the set of ordinals Omega = {alpha : alpha < omega(1)} to the set {-1} boolean OR Omega boolean OR {infinity} such that (i) a(0) >= m(0) >= max{a(1), m(1)}, and (ii) min{a(alpha), m(alpha)} >= max{a(beta), m(beta)}, whenever 1 <= alpha < beta < omega(1), there is a separable metrizable space X such that A(alpha)-trInd X = a(alpha) and M(alpha)-trInd X = m(alpha) for each 0 <= alpha < omega(1).
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