204 research outputs found
A new methodology for the quantitative visualization of coherent flow structures in alluvial channels using multibeam echo-sounding (MBES)
In order to investigate the interactions between turbulence and suspended sediment transport in natural aqueous environments, we ideally require a technique that allows simultaneous measurement of fluid velocity and sediment concentration for the whole flow field. Here, we report on development of a methodology using the water column acoustic backscatter signal from a multibeam echo sounder to simultaneously quantify flow velocities and sediment concentrations. The application of this new technique is illustrated with reference to flow over the leeside of an alluvial sand dune, which allows, for the first time in a field study, quantitative visualization of large-scale, whole flow field, turbulent coherent flow structures associated with the dune leeside that are responsible for suspending bed sediment. This methodology holds great potential for use in a wide range of aqueous geophysical flows
NON-LINEAR ANALYSIS OF CENTRE OF PRESSURE PATTERNS IN THE GOLF SWING – POINCARE PLOTS
Little research exists in the golf swing examining shot to shot differences in the short or long term. The aim of this study was to use Poincare plots to examine if short and long term patterns exist among golfers. Five golfers performed 50 golf swings hitting a ball into a net while standing on two AMTI force plates. Centre of Pressure in the direction of the swing (CPy) was calculated for each swing. Poincare plots with CPy Range at swing N on the x-axis and CPy Range at swing N + 1 on the y-axis were constructed for each golfer. Plots were individual specific with short and long term variability highlighting interesting differences between golfers. Interesting shot to shot patterning existed, especially for one
golfer. The use of Poincare plots in future work can provide useful information to the golfer and coach
Hypervelocity impact study: The effect of impact angle on crater morphology
The Space Power Institute (SPI) of Auburn University has conducted preliminary tests on the effects of impact angle on crater morphology for hypervelocity impacts. Copper target plates were set at angles of 30 deg and 60 deg from the particle flight path. For the 30 deg impact, the craters looked almost identical to earlier normal incidence impacts. The only difference found was in the apparent distribution of particle residue within the crater, and further research is needed to verify this. The 60 deg impacts showed marked differences in crater symmetry, crater lip shape, and particle residue distribution. Further research on angle effects is planned, because the particle velocities for these shots were relatively slow (7 km/s or less)
Selection of housekeeping genes for gene expression studies in human reticulocytes using real-time PCR
BACKGROUND: Control genes, which are often referred to as housekeeping genes, are frequently used to normalise mRNA levels between different samples. However, the expression level of these genes may vary among tissues or cells and may change under certain circumstances. Thus, the selection of housekeeping genes is critical for gene expression studies. To address this issue, 7 candidate housekeeping genes including several commonly used ones were investigated in isolated human reticulocytes. For this, a simple ΔCt approach was employed by comparing relative expression of 'pairs of genes' within each sample. On this basis, stability of the candidate housekeeping genes was ranked according to repeatability of the gene expression differences among 31 samples. RESULTS: Initial screening of the expression pattern demonstrated that 1 of the 7 genes was expressed at very low levels in reticulocytes and was excluded from further analysis. The range of expression stability of the other 6 genes was (from most stable to least stable): GAPDH (glyceraldehyde 3-phosphate dehydrogenase), SDHA (succinate dehydrogenase), HPRT1 (hypoxanthine phosphoribosyl transferase 1), HBS1L (HBS1-like protein) and AHSP (alpha haemoglobin stabilising protein), followed by B2M (beta-2-microglobulin). CONCLUSION: Using this simple approach, GAPDH was found to be the most suitable housekeeping gene for expression studies in reticulocytes while the commonly used B2M should be avoided
Hypervelocity Impact Testing of Space Station Freedom Solar Cells
Solar array coupons designed for the Space Station Freedom electrical power system were subjected to hypervelocity impacts using the HYPER facility in the Space Power Institute at Auburn University and the Meteoroid/Orbital Debris Simulation Facility in the Materials and Processes Laboratory at the NASA Marshall Space Flight Center. At Auburn, the solar cells and array blanket materials received several hundred impacts from particles in the micron to 100 micron range with velocities typically ranging from 4.5 to 10.5 km/s. This fluence of particles greatly exceeds what the actual components will experience in low earth orbit. These impacts damaged less than one percent of total area of the solar cells and most of the damage was limited to the cover glass. There was no measurable loss of electrical performance. Impacts on the array blanket materials produced even less damage and the blanket materials proved to be an effective shield for the back surface of the solar cells. Using the light gas gun at MSFC, one cell of a four cell coupon was impacted by a 1/4 inch spherical aluminum projectile with a velocity of about 7 km/s. The impact created a neat hole about 3/8 inch in diameter. The cell and coupon were still functional after impact
Hypervelocity impact induced arcing and Kapton pyrolization in a plasma environment
Tests were performed on the Space Station Freedom (SSF) solar array flat conductor circuit (FCC) to determine if hypervelocity impacts could induce pyrolization of Kapton and/or cross-conductor arcing. A sample piece of FCC was placed in a plasma environment and biased to +200 V relative to the plasma potential. The FCC was then impacted with particles in the 100 micron size range with hypervelocities of about 7 km/s. These tests were unable to induce Kapton pyrolization, cross-conductor arcing, or any other plasma interaction
Real-world Comparative Effectiveness of Tocilizumab Monotherapy vs. Tumor Necrosis Factor Inhibitors with Methotrexate in Patients with Rheumatoid Arthritis
INTRODUCTION: Controlled clinical studies have shown that the efficacy of tocilizumab (TCZ) monotherapy is superior to that of tumor necrosis factor inhibitor (TNFi) monotherapy and comparable to that of TCZ plus methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). This study compared the real-world effectiveness of TCZ monotherapy vs. TNFis plus MTX in US patients with RA.
METHODS: TCZ-naive patients from the Corrona RA registry with prior exposure to \u3e /= 1 TNFi who initiated TCZ monotherapy or TNFi + MTX were included. Outcomes included mean change in Clinical Disease Activity Index (CDAI), achievement of low disease activity (LDA; CDAI \u3c /= 10), achievement of modified American College of Rheumatology (mACR) 20/50 responses, and mean change in modified Health Assessment Questionnaire (mHAQ) at 6 months. Patients initiating TNFi + MTX were grouped by MTX dose ( \u3c /= 10 mg; \u3e 10 to \u3c /= 15 mg; \u3e 15 to \u3c /= 20 mg; \u3e 20 mg); outcomes in each group were compared with TCZ monotherapy using trimmed populations (excluding patients outside the propensity score distribution overlap).
RESULTS: Patients in all groups experienced improvement in CDAI at 6 months (mean change, - 6.9 to - 9.7), with no significant differences between the TCZ monotherapy and TNFi + MTX groups. Achievement of LDA and mACR responses at 6 months were comparable between the TCZ monotherapy and TNFi + MTX groups; overall, 26.8-38.0% of patients achieved LDA, 24.3-37.6% achieved mACR20 response and 13.2-20.8% achieved mACR50 response. The mean change in mHAQ at 6 months was - 0.1 in all groups.
CONCLUSIONS: In this real-world population of US patients with RA who had prior TNFi exposure, there was no evidence of a difference in the effectiveness of TCZ monotherapy compared with that of TNFi + MTX, regardless of MTX dose, at 6 months for improving RA disease activity.
FUNDING: Corrona, LLC. Plain language summary available for this article
Radio galaxy evolution: what you can learn from a Brief Encounter
We describe the pitfalls encountered in deducing from classical double radio
source observables (luminosity, spectral index, redshift and linear size) the
essential nature of how these objects evolve. We discuss the key role played by
hotspots in governing the energy distribution of the lobes they feed, and
subsequent spectral evolution. We present images obtained using the new 74 MHz
receivers on the VLA and discuss constraints which these enforce on models of
the backflow and ages in classical doubles.Comment: invited talk at `Lifecycles of Radio Galaxies' workshop; eds John
Biretta et a
Impact of rituximab on patient-reported outcomes in patients with rheumatoid arthritis from the US Corrona Registry
To evaluate the impact of rituximab on patient-reported outcomes (PROs) in a US-based observational cohort of patients with rheumatoid arthritis (RA). Patients with active RA, prior exposure to \u3e /=1 tumor necrosis factor inhibitor (TNFi) and who newly initiated rituximab were identified. Changes in PROs were assessed 1 year after rituximab initiation. PRO measures included Clinical Disease Activity Index (CDAI); patient global disease activity, pain and fatigue (visual analog score; 0-100); morning stiffness (hours); modified Health Assessment Questionnaire (mHAQ; 0-3); and EuroQoL EQ-5D. Of the 667 patients who newly initiated rituximab, baseline PRO and clinical measures indicated that patients were substantially impacted by their RA disease and quality of life; 54% of patients had high disease activity. One year after rituximab initiation, 49.0, 47.1, 49.8, and 23.2% of patients reported clinically meaningful improvements in patient global, pain, fatigue, and mHAQ, respectively. Morning stiffness and EuroQol EQ-5D domains improved in 48 and 19-32% of patients, respectively. These real-world registry data demonstrated that patients with long-standing, refractory RA experienced improvements in PROs 1 year after initiating rituximab
- …