112 research outputs found

    Maximum listening speeds for the blind

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    Proceedings of the 9th International Conference on Auditory Display (ICAD), Boston, MA, July 7-9, 2003.Blind people usually use voice output using a computer, however, there is little objective data about how fast or accurately they can obtain information in a fixed amount of time In this paper, we describe the highest and the most suitable listening rate for the blind based on our human factors experiments, aiming at producing a kind of indicator for use by developers. We experimented with the highest and the most suitable listening rates for blind users with objective and subjective test methods. The results showed that the advanced blind testers could listen to the spoken material at speeds 1.6 times faster than the highest rate of the tested TTS (Text-to- Speech) engine. This indicates that the currently available TTS engines should support faster rates. It also showed that the highest rate often changes depending on the difficulty of the sentences and words. These results would be valuable and useful indicators for developers to design applications for the blind and to improve the nonvisual user interfaces

    Polymorphic segmental duplications at 8p23.1 challenge the determination of individual defensin gene repertoires and the assembly of a contiguous human reference sequence

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    BACKGROUND: Defensins are important components of innate immunity to combat bacterial and viral infections, and can even elicit antitumor responses. Clusters of defensin (DEF) genes are located in a 2 Mb range of the human chromosome 8p23.1. This DEF locus, however, represents one of the regions in the euchromatic part of the final human genome sequence which contains segmental duplications, and recalcitrant gaps indicating high structural dynamics. RESULTS: We find that inter- and intraindividual genetic variations within this locus prevent a correct automatic assembly of the human reference genome (NCBI Build 34) which currently even contains misassemblies. Manual clone-by-clone alignment and gene annotation as well as repeat and SNP/haplotype analyses result in an alternative alignment significantly improving the DEF locus representation. Our assembly better reflects the experimentally verified variability of DEF gene and DEF cluster copy numbers. It contains an additional DEF cluster which we propose to reside between two already known clusters. Furthermore, manual annotation revealed a novel DEF gene and several pseudogenes expanding the hitherto known DEF repertoire. Analyses of BAC and working draft sequences of the chimpanzee indicates that its DEF region is also complex as in humans and DEF genes and a cluster are multiplied. Comparative analysis of human and chimpanzee DEF genes identified differences affecting the protein structure. Whether this might contribute to differences in disease susceptibility between man and ape remains to be solved. For the determination of individual DEF gene repertoires we provide a molecular approach based on DEF haplotypes. CONCLUSIONS: Complexity and variability seem to be essential genomic features of the human DEF locus at 8p23.1 and provides an ongoing challenge for the best possible representation in the human reference sequence. Dissection of paralogous sequence variations, duplicon SNPs ans multisite variations as well as haplotypes by sequencing based methods is the way for future studies of interindividual DEF locus variability and its disease association

    Postmortem and helminthological examination of seabirds killed by oil spilled at Ishikari, Hokkaido, Japan, in November 2004

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    Postmortems and helminthological examinations were performed on beached seabirds killed by oil spilled from a grounded freighter at Ishikari, Hokkaido, Japan in November 13, 2004. The carcasses were covered with crude oil, but they had adequate subcutaneous fat levels. Gross pathological findings consisting of gastric ulcers, pulmonary edema, enlarged spleens and blackish liquid contents in the digestive tracts suggested that they had a rapid progression to death caused by a loss of ascending force, hypothermia and dehydration. Although the visceral organs had degenerated, no direct evidence of mortality caused by ingesting oil was observed. However, extensive acute inflammatory reactions caused by large numbers of mature and immature nematodes (Contracaecum rudolphii) deeply penetrating the gastric walls was observed in two of the birds. Helminthological investigations were conducted on 21 birds from six species, namely: Phalacrocorax capillatus, Aythya marila, Cerorhinca monocerata, Synthliboramphus antiquus, Aethia cristatella, and Brachyramphus perdix. Thirteen helminth species were obtained and identified, including eight nematodes (Eucoleus contortus, Baruscapillaria mergi, B. rudolphii, Amidostomum acutum, C. rudolphii, Tetrameres fissispina, Cosmocephalus obvelatus and Stegophorus stercorarii), three trematodes (Aporchis sp., Hyptiasmus sp. and Renicola sp.), one cestode (Diorchis nyrocae) and one acanthocephalan species (Andracantha phalacrocoracis). Of these, B. rudolphii from S. antiquus, C. rudolphii and Renicola sp. from A. cristatella, and C. obvelatus and Renicola sp. from B. perdix were first host records. Additionally, B. rudolphii was the first geographical record of this species in Japan

    Hyper-expansion of large DNA segments in the genome of kuruma shrimp, Marsupenaeus japonicus

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    <p>Abstract</p> <p>Background</p> <p>Higher crustaceans (class Malacostraca) represent the most species-rich and morphologically diverse group of non-insect arthropods and many of its members are commercially important. Although the crustacean DNA sequence information is growing exponentially, little is known about the genome organization of Malacostraca. Here, we constructed a bacterial artificial chromosome (BAC) library and performed BAC-end sequencing to provide genomic information for kuruma shrimp (<it>Marsupenaeus japonicus</it>), one of the most widely cultured species among crustaceans, and found the presence of a redundant sequence in the BAC library. We examined the BAC clone that includes the redundant sequence to further analyze its length, copy number and location in the kuruma shrimp genome.</p> <p>Results</p> <p>Mj024A04 BAC clone, which includes one redundant sequence, contained 27 putative genes and seemed to display a normal genomic DNA structure. Notably, of the putative genes, 3 genes encode homologous proteins to the inhibitor of apoptosis protein and 7 genes encode homologous proteins to white spot syndrome virus, a virulent pathogen known to affect crustaceans. Colony hybridization and PCR analysis of 381 BAC clones showed that almost half of the BAC clones maintain DNA segments whose sequences are homologous to the representative BAC clone Mj024A04. The Mj024A04 partial sequence was detected multiple times in the kuruma shrimp nuclear genome with a calculated copy number of at least 100. Microsatellites based BAC genotyping clearly showed that Mj024A04 homologous sequences were cloned from at least 48 different chromosomal loci. The absence of micro-syntenic relationships with the available genomic sequences of <it>Daphnia </it>and <it>Drosophila </it>suggests the uniqueness of these fragments in kuruma shrimp from current arthropod genome sequences.</p> <p>Conclusions</p> <p>Our results demonstrate that hyper-expansion of large DNA segments took place in the kuruma shrimp genome. Although we analyzed only a part of the duplicated DNA segments, our result suggested that it is difficult to analyze the shrimp genome following normal analytical methodology. Hence, it is necessary to avoid repetitive sequence (such as segmental duplications) when studying the other unique structures in the shrimp genome.</p

    Radiation Hybrid Maps of Medaka Chromosomes LG 12, 17, and 22

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    The Medaka is an excellent genetic system for studies of vertebrate development and disease and environmental and evolutionary biology studies. To facilitate the mapping of markers or the cloning of affected genes in Medaka mutants identified by forward-genetic screens, we have established a panel of whole-genome radiation hybrids (RHs) and RH maps for three Medaka chromosomes. RH mapping is useful, since markers to be mapped need not be polymorphic and one can establish the order of markers that are difficult to resolve by genetic mapping owing to low genetic recombination rates. RHs were generated by fusing the irradiated donor, OLF-136 Medaka cell line, with the host B78 mouse melanoma cells. Of 290 initial RH clones, we selected 93 on the basis of high retention of fragments of the Medaka genome to establish a panel that allows genotyping in the 96-well format. RH maps for linkage groups 12, 17, and 22 were generated using 159 markers. The average retention for the three chromosomes was 19% and the average break point frequency was ∼33 kb/cR. We estimate the potential resolution of the RH panel to be ∼186 kb, which is high enough for integrating RH data with bacterial artificial chromosome clones. Thus, this first RH panel will be a useful tool for mapping mutated genes in Medaka

    Mutant analyses reveal different functions of fgfr1 in medaka and zebrafish despite conserved ligand–receptor relationships

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    AbstractMedaka (Oryzias latipes) is a small freshwater teleost that provides an excellent developmental genetic model complementary to zebrafish. Our recent mutagenesis screening using medaka identified headfish (hdf) which is characterized by the absence of trunk and tail structures with nearly normal head including the midbrain–hindbrain boundary (MHB). Positional-candidate cloning revealed that the hdf mutation causes a functionally null form of Fgfr1. The fgfr1hdf is thus the first fgf receptor mutant in fish. Although FGF signaling has been implicated in mesoderm induction, mesoderm is induced normally in the fgfr1hdf mutant, but subsequently, mutant embryos fail to maintain the mesoderm, leading to defects in mesoderm derivatives, especially in trunk and tail. Furthermore, we found that morpholino knockdown of medaka fgf8 resulted in a phenotype identical to the fgfr1hdf mutant, suggesting that like its mouse counterpart, Fgf8 is a major ligand for Fgfr1 in medaka early embryogenesis. Intriguingly, Fgf8 and Fgfr1 in zebrafish are also suggested to form a major ligand–receptor pair, but their function is much diverged, as the zebrafish fgfr1 morphant and zebrafish fgf8 mutant acerebellar (ace) only fail to develop the MHB, but develop nearly unaffected trunk and tail. These results provide evidence that teleost fish have evolved divergent functions of Fgf8–Fgfr1 while maintaining the ligand–receptor relationships. Comparative analysis using different fish is thus invaluable for shedding light on evolutionary diversification of gene function

    Polycystic Kidney Disease in the Medaka (Oryzias latipes) pc Mutant Caused by a Mutation in the Gli-Similar3 (glis3) Gene

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    Polycystic kidney disease (PKD) is a common hereditary disease in humans. Recent studies have shown an increasing number of ciliary genes that are involved in the pathogenesis of PKD. In this study, the Gli-similar3 (glis3) gene was identified as the causal gene of the medaka pc mutant, a model of PKD. In the pc mutant, a transposon was found to be inserted into the fourth intron of the pc/glis3 gene, causing aberrant splicing of the pc/glis3 mRNA and thus a putatively truncated protein with a defective zinc finger domain. pc/glis3 mRNA is expressed in the epithelial cells of the renal tubules and ducts of the pronephros and mesonephros, and also in the pancreas. Antisense oligonucleotide-mediated knockdown of pc/glis3 resulted in cyst formation in the pronephric tubules of medaka fry. Although three other glis family members, glis1a, glis1b and glis2, were found in the medaka genome, none were expressed in the embryonic or larval kidney. In the pc mutant, the urine flow rate in the pronephros was significantly reduced, which was considered to be a direct cause of renal cyst formation. The cilia on the surface of the renal tubular epithelium were significantly shorter in the pc mutant than in wild-type, suggesting that shortened cilia resulted in a decrease in driving force and, in turn, a reduction in urine flow rate. Most importantly, EGFP-tagged pc/glis3 protein localized in primary cilia as well as in the nucleus when expressed in mouse renal epithelial cells, indicating a strong connection between pc/glis3 and ciliary function. Unlike human patients with GLIS3 mutations, the medaka pc mutant shows none of the symptoms of a pancreatic phenotype, such as impaired insulin expression and/or diabetes, suggesting that the pc mutant may be suitable for use as a kidney-specific model for human GLIS3 patients

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    In Silico Screening of Bacteriocin Gene Clusters within a Set of Marine <i>Bacillota</i> Genomes

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    Due to their potential application as an alternative to antibiotics, bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by bacteria, have received much attention in recent years. To identify bacteriocins within marine bacteria, most of the studies employed a culture-based method, which is more time-consuming than the in silico approach. For that, the aim of this study was to identify potential bacteriocin gene clusters and their potential producers in 51 marine Bacillota (formerly Firmicutes) genomes, using BAGEL4, a bacteriocin genome mining tool. As a result, we found out that a majority of selected Bacillota (60.78%) are potential bacteriocin producers, and we identified 77 bacteriocin gene clusters, most of which belong to class I bacteriocins known as RiPPs (ribosomally synthesized and post-translationally modified peptides). The identified putative bacteriocin gene clusters are an attractive target for further in vitro research, such as the production of bacteriocins using a heterologous expression system

    Multi-Omics Approaches and Radiation on Lipid Metabolism in Toothed Whales

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    Lipid synthesis pathways of toothed whales have evolved since their movement from the terrestrial to marine environment. The synthesis and function of these endogenous lipids and affecting factors are still little understood. In this review, we focused on different omics approaches and techniques to investigate lipid metabolism and radiation impacts on lipids in toothed whales. The selected literature was screened, and capacities, possibilities, and future approaches for identifying unusual lipid synthesis pathways by omics were evaluated. Omics approaches were categorized into the four major disciplines: lipidomics, transcriptomics, genomics, and proteomics. Genomics and transcriptomics can together identify genes related to unique lipid synthesis. As lipids interact with proteins in the animal body, lipidomics, and proteomics can correlate by creating lipid-binding proteome maps to elucidate metabolism pathways. In lipidomics studies, recent mass spectroscopic methods can address lipid profiles; however, the determination of structures of lipids are challenging. As an environmental stress, the acoustic radiation has a significant effect on the alteration of lipid profiles. Radiation studies in different omics approaches revealed the necessity of multi-omics applications. This review concluded that a combination of many of the omics areas may elucidate the metabolism of lipids and possible hazards on lipids in toothed whales by radiation
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