University of Victoria

About: University of Victoria is a education organization based out in Victoria, British Columbia, Canada. It is known for research contribution in the topics: Population & Galaxy. The organization has 14994 authors who have published 41051 publications receiving 1447972 citations. The organization is also known as: Victoria College.

First Cosmic Shear Results from the Canada-France-Hawaii Telescope Wide Synoptic Legacy Survey

Abstract: We present the first measurements of the weak gravitational lensing signal induced by the large-scale mass distribution in the universe from data obtained as part of the ongoing Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data used in this analysis are from the Wide Synoptic Survey, which aims to image � 170 deg 2 in five filters. We have analyzed an effective area of � 22 deg 2 (31 pointings) of i 0 data spread over two of the three survey fields. These data are of excellent quality, and the results bode well for the remainder of the survey: we do not detect a significant ‘‘B’’ mode, suggesting that residual systematics are negligible at the current level of accuracy. Assuming a cold dark matter model and marginalizing over the Hubble parameter h 2½ 0:6; 0:8� , the source redshift distribution, and systematics, we constrain � 8, the amplitude of the matter power spectrum. At a fiducial matter density m ¼ 0:3 we find � 8 ¼ 0:85 � 0:06. This estimate is in excellent agreement with previous studies. A combination of our results with those from the Deep component of the CFHTLS enables us to place a constraint on a constant equation of state for the dark energy, based on cosmic shear data alone. We find that w0 < � 0:8 at 68% confidence. Subject headingg cosmology: observations — dark matter — gravitational lensing Online material: color figures

Increased cut-off wavelength for a subwavelength hole in a real metal

Abstract: A waveguide mode of a subwavelength rectangular hole in a real metal is analyzed. Due to coupling between surface plasmons on the long edges of the hole, the cut-off wavelength increases as the hole-width is reduced. The cut-off wavelength is found to be much larger than Rayleigh's criterion for perfect metals - 2.3 times as large for a 15 nm wide hole. The analytical results are verified by finite-difference calculations. The finite difference calculations also show the influence of including material loss.

A unified phylogeny-based nomenclature for histone variants

Abstract: Histone variants are non-allelic protein isoforms that play key roles in diversifying chromatin structure. The known number of such variants has greatly increased in recent years, but the lack of naming conventions for them has led to a variety of naming styles, multiple synonyms and misleading homographs that obscure variant relationships and complicate database searches. We propose here a unified nomenclature for variants of all five classes of histones that uses consistent but flexible naming conventions to produce names that are informative and readily searchable. The nomenclature builds on historical usage and incorporates phylogenetic relationships, which are strong predictors of structure and function. A key feature is the consistent use of punctuation to represent phylogenetic divergence, making explicit the relationships among variant subtypes that have previously been implicit or unclear. We recommend that by default new histone variants be named with organism-specific paralog-number suffixes that lack phylogenetic implication, while letter suffixes be reserved for structurally distinct clades of variants. For clarity and searchability, we encourage the use of descriptors that are separate from the phylogeny-based variant name to indicate developmental and other properties of variants that may be independent of structure.

Development and Application of a Salmonid EST Database and cDNA Microarray: Data Mining and Interspecific Hybridization Characteristics

Abstract: Gene and genome duplications are thought to be primary mechanisms of increasing the number of coding sequences subject to selection, leading to new proteins, morphogenic variations, and phenotypes (Ohno 1970; Holland et al. 1994; Sidow 1996). Members of the teleost family Salmonidae, including salmon, trout, char, grayling, and whitefish, all diverged from a common ancestor that is believed to have undergone a tetraploidization event 25 to 100 million years ago, after the teleost radiation (Allendorf and Thorgaard 1984). This relatively recent putative genome duplication in the salmonid lineage is supported by karyological and genome size data. Members of the family Clupeidae (e.g., herring, alewife), thought to maintain the ancestral diploid status, have 48 to 52 mostly acrocentric chromosomes per 2N cell and genome sizes of 0.8 to 1.4 pg/N, whereas salmonids have 52 to 102 chromosomes per 2N cell (over half metacentric or submetacentric) and genome sizes of 1.9 to 3.8 pg/N (Ohno et al. 1968; Phillips and Rab 2001; Gregory 2002). Because extant salmonids exhibit quadrivalents in meiosis (primarily in males; Ohno et al. 1965; Allendorf and Thorgaard 1984) and disomic and tetrasomic inheritance at different loci (Allendorf and Danzmann 1997), they appear to be in the process of re-establishing diploidy. Remarkably, ∼50% of examined salmonid loci persist as functional duplicates (Bailey et al. 1978). Research on salmonid genomes will shed light on poorly understood evolutionary phenomena such as genome duplication and duplicate gene silencing. In addition to their scientific importance as recent tetraploids, salmonids also serve as prominent models for studies involving environmental toxicology (Katchamart et al. 2002), carcinogenesis (Bailey et al. 1996), comparative immunology (Shum et al. 2001), and the molecular genetics and physiology of the stress response (Basu et al. 2002), olfaction (Zhang et al. 2001), vision (Faillace et al. 2002), osmoregulation (Tipsmarck et al. 2002), growth (Devlin et al. 2001), and gametogenesis (Madigou et al. 2002). Furthermore, Atlantic salmon (AS; Salmo salar) are of particular importance to the global aquaculture industry. GRASP (Genomics Research on Atlantic Salmon Project), an initiative funded by Genome Canada, is intended to improve understanding of physiological and evolutionary processes influencing the survival and phenotype of salmonids and other fish in natural and aquaculture environments. GRASP has developed genomics resources to help achieve these goals. There is a rich literature in salmonid genetics, physiology, and ecology to support these genomics research tools. A previously reported S. salar EST project surveyed 1152 ESTs from six cDNA libraries, with 510BLAST-identified sequences representing 178 salmon genes (Davey et al. 2001). There are currently (August 2003) ∼60,000 S. salar nucleotide sequences in GenBank, of which >51,000 were submitted by GRASP. In addition to forming an EST database containing >80,000 sequences from five salmonid species, GRASP has built a microarray from 3557 unique salmonid cDNAs. Initial cross-species testing of this microarray has shown it to be effective in hybridizations with salmon, trout, and whitefish targets.