1,460 research outputs found

    Very long baseline interferometry

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    S-band stations with dual tracking capability have been used to gather double differential very long baseline interferometry data on Apollo 16 and Apollo 17. This was accomplished by simultaneously receiving both monochromatic radio signal emissions at each of two separated receiving stations, transmitting these data to a central processing facility, and calculating the differences between Doppler angular rates to determine the motion of the lunar roving vehicle

    Mathematical relationships of the MFOD ANTENNA axes

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    Equations for interrelating position data of different coordinate systems used in manned space flight network tracking equipmen

    A computational survey of candidate exonic splicing enhancer motifs in the model plant Arabidopsis thaliana

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    Algorithmic approaches to splice site prediction have relied mainly on the consensus patterns found at the boundaries between protein coding and non-coding regions. However exonic splicing enhancers have been shown to enhance the utilization of nearby splice sites. We have developed a new computational technique to identify significantly conserved motifs involved in splice site regulation. First, 84 putative exonic splicing enhancer hexamers are identified in Arabidopsis thaliana. Then a Gibbs sampling program called ELPH was used to locate conserved motifs represented by these hexamers in exonic regions near splice sites in confirmed genes. Oligomers containing 35 of these motifs have been shown experimentally to induce significant inclusion of A. thaliana exons. Second, integration of our regulatory motifs into two different splice site recognition programs significantly improved the ability of the software to correctly predict splice sites in a large database of confirmed genes. We have released GeneSplicerESE, the improved splice site recognition code, as open source software. Our results show that the use of the ESE motifs consistently improves splice site prediction accuracy.https://doi.org/10.1186/1471-2105-8-15

    Hawkeye: An interactive visual analytics tool for genome assemblies

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    Genome sequencing remains an inexact science, and genome sequences can contain significant errors if they are not carefully examined. Hawkeye is our new visual analytics tool for genome assemblies, designed to aid in identifying and correcting assembly errors. Users can analyze all levels of an assembly along with summary statistics and assembly metrics, and are guided by a ranking component towards likely mis-assemblies. Hawkeye is freely available and released as part of the open source AMOS project http://amos.sourceforge.net/hawkeye. © 2007 Schatz et al.; licensee BioMed Central Ltd

    Left ventricular assist device as bridge to heart transplantation - lessons learned with the MicroMed DeBakey axial blood flow pump

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    Objective: The MicroMed DeBakey left ventricular assist device (LVAD) axial blood flow pump was used as bridge to heart transplantation (HTx) in patients with terminal heart failure. The aim was to evaluate this novel mechanical circulatory support system in regard to overall outcome. Methods: Prospective study in 15 HTx candidates (mean age 40±7 years) with terminal heart failure and maximal medical treatment due to ischemic cardiomyopathy (CMP, n=5), dilated CMP (n=3), restrictive CMP (n=2), unclassified CMP (n=1), metabolic CMP (n=1), valvular CMP (n=1) and congenital CMP (n=2). All patients were implanted with a MicroMed DeBakey LVAD. A rescue procedure was necessary in eight critical patients, while seven underwent elective LVAD implantation. Procedures were performed via median sternotomy, in normotherm femoro-femoral CPB (mean duration 59±1 min). Oral Marcoumar© (INR 2.0-3.0) and Aspirin© (100 mg daily) were started as soon as possible. Patients were discharged into a specialized rehabilitation clinic from which it was possible to release them home after a few weeks. Results: Successful implantation and discharge from ICU (mean stay 10±7 days) was possible in 11 patients. Seven were transplanted (mean support 50.7 days) and one is awaiting HTx (support >310 days) in the comfort of his home (NYHA I). Survival was 100% among the transplanted patients. Of the seven elective implants, five, and of the eight rescue procedures three patients underwent successful HTx. Four patients died early, while three patients died late on pump support due to intracranial hemorrhage (n=2, 73 and 76 days) and chest infection (n=1, 124 days). All survivors were discharged from hospital, with significant decrease in NYHA class (mean 3.8-2.4 (n=11)). Treadmill testing showed increased exercise tolerance, from 35 to 71 W (n=4). Plasma BNP values (mean 950-162 ng/l (n=4)) and pulmonary resistance (mean 316-194.5 dyne s/cm5 (n=3)) decreased significantly during LVAD support. Conclusions: The MicroMed DeBakey LVAD is simple to implant; outpatient treatment is safe and efficient. Patients' condition and pulmonary resistances normalize within 6 weeks, making previously considered inoperable patients amenable for HTx. HTx can be performed in low-risk situation, allowing better donor-recipient matching and improving overall outcom

    Re-Assembly of the Genome of Francisella tularensis Subsp. holarctica OSU18

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    Francisella tularensis is a highly infectious human intracellular pathogen that is the causative agent of tularemia. It occurs in several major subtypes, including the live vaccine strain holarctica (type B). F. tularensis is classified as category A biodefense agent in part because a relatively small number of organisms can cause severe illness. Three complete genomes of subspecies holarctica have been sequenced and deposited in public archives, of which OSU18 was the first and the only strain for which a scientific publication has appeared [1]. We re-assembled the OSU18 strain using both de novo and comparative assembly techniques, and found that the published sequence has two large inversion mis-assemblies. We generated a corrected assembly of the entire genome along with detailed information on the placement of individual reads within the assembly. This assembly will provide a more accurate basis for future comparative studies of this pathogen

    pavarotti encodes a kinesin-like protein required to organize the central spindle and contractile ring for cytokinesis

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    Mutations in the Drosophila gene pavarotti result in the formation of abnormally large cells in the embryonic nervous system. In mitotic cycle 16, cells of pav mutant embryos undergo normal anaphase but then develop an abnormal telophase spindle and fail to undertake cytokinesis. We show that the septin Peanut, actin, and the actin-associated protein Anillin, do not become correctly localized in pav mutants. pav encodes a kinesin-like protein, PAV–KLP, related to the mammalian MKLP-1. In cellularized embryos, the protein is localized to centrosomes early in mitosis, and to the midbody region of the spindle in late anaphase and telophase. We show that Polo kinase associates with PAV–KLP with which it shows an overlapping pattern of subcellular localization during the mitotic cycle and this distribution is disrupted in pavmutants. We suggest that PAV–KLP is required both to establish the structure of the telophase spindle to provide a framework for the assembly of the contractile ring, and to mobilize mitotic regulator proteins

    pavarotti encodes a kinesin-like protein required to organize the central spindle and contractile ring for cytokinesis

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    Mutations in the Drosophila gene pavarotti result in the formation of abnormally large cells in the embryonic nervous system. In mitotic cycle 16, cells of pav mutant embryos undergo normal anaphase but then develop an abnormal telophase spindle and fail to undertake cytokinesis. We show that the septin Peanut, actin, and the actin-associated protein Anillin, do not become correctly localized in pav mutants. pav encodes a kinesin-like protein, PAV–KLP, related to the mammalian MKLP-1. In cellularized embryos, the protein is localized to centrosomes early in mitosis, and to the midbody region of the spindle in late anaphase and telophase. We show that Polo kinase associates with PAV–KLP with which it shows an overlapping pattern of subcellular localization during the mitotic cycle and this distribution is disrupted in pavmutants. We suggest that PAV–KLP is required both to establish the structure of the telophase spindle to provide a framework for the assembly of the contractile ring, and to mobilize mitotic regulator proteins

    Equation of state in the fugacity format for the two-dimensional Coulomb gas

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    We derive the exact general form of the equation of state, in the fugacity format, for the two-dimensional Coulomb gas. Our results are valid in the conducting phase of the Coulomb gas, for temperatures above the Kosterlitz-Thouless transition. The derivation of the equation of state is based on the knowledge of the general form of the short-distance expansion of the correlation functions of the Coulomb gas. We explicitly compute the expansion up to order O(ζ6)O(\zeta^6) in the activity ζ\zeta. Our results are in very good agreement with Monte Carlo simulations at very low density
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