48 research outputs found

    A New Low Reynolds Number Facility for Active Flow Control Applications

    Get PDF
    Recent interest in gaining understanding of the dynamics and behavior of the leading-edge vortex structure observed in biological flight systems has prompted the construction of a new low Reynolds number facility. This facility, a recirculating oil tunnel, gives several distinct advantages over similar facilities, utilizing water or air as the working fluid, for this kind of study. Additionally, as understanding is gained, active flow control strategies leading to the stabilization of the leading-edge vortex structure will be investigated, and this facility is specially equipped to enable this study. The tunnel has been designed and installed at the California Institute of Technology Graduate Aeronautical Laboratories. Design features of the facility will be discussed, along with some preliminary measurements conducted on a NACA 0012 wing

    Applying item-response theory to the development of a screening adaptation of the Goldman-Fristoe Test of Articulation-2

    Get PDF
    PURPOSE: Item Response Theory (IRT) is a psychometric approach to measurement that uses latent trait abilities (e.g., speech sound production skills) to model performance on individual items that vary by difficulty and discrimination. An IRT analysis was applied to preschooler’s productions of the words on the Goldman-Fristoe Test of Articulation-2 (GFTA-2) to identify candidates for a screening measure of speech sound production skills. METHOD: The phoneme accuracies from 154 preschoolers, with speech skills on the GFTA-2 ranging from the 1st to above the 90th percentile, were analyzed with a two-parameter logistic model. RESULTS: A total of 108 of the 232 phonemes from stimuli in the sounds-in-words subtest fit the IRT model. These phonemes, and subgroups of the most difficult of these phonemes, correlated significantly with the children’s overall percentile scores on the GFTA-2. Regression equations calculated for the five and ten most difficult phonemes predicted overall percentile score at levels commensurate with other screening measures. CONCLUSIONS: These results suggest that speech production accuracy can be screened effectively with a small number of sounds. They motivate further research towards the development of a screening measure of children’s speech sound production skills whose stimuli consist of a limited number of difficult phonemes

    Practice in Child Phonological Disorders: Tackling some Common Clinical Problems

    Get PDF
    Goal of presentation is to identify areas of child phonology that clinicans have difficulty with

    In Silico Metabolic Model and Protein Expression of Haemophilus influenzae Strain Rd KW20 in Rich Medium

    Full text link
    The intermediary metabolism of Haemophilus influenzae strain Rd KW20 was studied by a combination of protein expression analysis using a recently developed direct proteomics approach, mutational analysis, and mathematical modeling. Special emphasis was placed on carbon utilization, sugar fermentation, TCA cycle, and electron transport of H. influenzae cells grown microaerobically and anaerobically in a rich medium. The data indicate that several H. influenzae metabolic proteins similar to Escherichia coli proteins, known to be regulated by low concentrations of oxygen, were well expressed in both growth conditions in H. influenzae. An in silico model of the H. influenzae metabolic network was used to study the effects of selective deletion of certain enzymatic steps. This allowed us to define proteins predicted to be essential or non-essential for cell growth and to address numerous unresolved questions about intermediary metabolism of H. influenzae. Comparison of data from in vivo protein expression with the protein list associated with a genome-scale metabolic model showed significant coverage of the known metabolic proteome. This study demonstrates the significance of an integrated approach to the characterization of H. influenzae metabolism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63406/1/153623104773547471.pd

    Novel Blood Pressure Locus and Gene Discovery Using Genome-Wide Association Study and Expression Data Sets From Blood and the Kidney.

    Get PDF
    Elevated blood pressure is a major risk factor for cardiovascular disease and has a substantial genetic contribution. Genetic variation influencing blood pressure has the potential to identify new pharmacological targets for the treatment of hypertension. To discover additional novel blood pressure loci, we used 1000 Genomes Project-based imputation in 150 134 European ancestry individuals and sought significant evidence for independent replication in a further 228 245 individuals. We report 6 new signals of association in or near HSPB7, TNXB, LRP12, LOC283335, SEPT9, and AKT2, and provide new replication evidence for a further 2 signals in EBF2 and NFKBIA Combining large whole-blood gene expression resources totaling 12 607 individuals, we investigated all novel and previously reported signals and identified 48 genes with evidence for involvement in blood pressure regulation that are significant in multiple resources. Three novel kidney-specific signals were also detected. These robustly implicated genes may provide new leads for therapeutic innovation

    A Meta-analysis of Gene Expression Signatures of Blood Pressure and Hypertension

    Get PDF
    Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p<0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension

    Finishing the euchromatic sequence of the human genome

    Get PDF
    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

    Orbiting GPS Receiver Modified to Track New L2C Signal

    No full text
    The L2C signal is a great step forward for civil applications of GPS, enabling high-accuracy dual-frequency measurements. Engineers from the Jet Propulsion Laboratory and ITT teamed to reprogram FPGA firmware and add tracking software on an orbiting receiver to track the new GPS L2C signal from SAC-C. SAC-C is an Argentinean science satellite and was launched in November 2000 with a BlackJack GPS receiver. This is a dual-frequency digital receiver with 48 tracking channels and four antennas. On SAC-C, it provides precise orbits, atmospheric occultation data, tests of GPS surface reflections, and serves as an orbiting test bed for new GPS development such as the L2C tracking reported here
    corecore