2,443 research outputs found
Radar cross calibration investigation TAMU radar polarimeter calibration measurements
A short pulse, 20 MHz bandwidth, three frequency radar polarimeter system (RPS) operates at center frequencies of 10.003 GHz, 4.75 GHz, and 1.6 GHz and utilizes dual polarized transmit and receive antennas for each frequency. The basic lay-out of the RPS is different from other truck mounted systems in that it uses a pulse compression IF section common to all three RF heads. Separate transmit and receive antennas are used to improve the cross-polarization isolation at each particular frequency. The receive is a digitally controlled gain modulated subsystem and is interfaced directly with a microprocesser computer for control and data manipulation. Antenna focusing distance, focusing each antenna pair, rf head stability, and polarization characteristics of RPS antennas are discussed. Platform and data acquisition procedures are described
Evaluation of measurement accuracies of the Higgs boson branching fractions in the International Linear Collider
Precise measurement of Higgs boson couplings is an important task for
International Linear Collider (ILC) experiments and will facilitate the
understanding of the particle mass generation mechanism.
In this study, the measurement accuracies of the Higgs boson branching
fractions to the and quarks and gluons, , were evaluated with the full International Large
Detector model (\texttt{ILD\_00}) for the Higgs mass of 120 GeV at the
center-of-mass (CM) energies of 250 and 350 GeV using neutrino, hadronic and
leptonic channels and assuming an integrated luminosity of ,
and an electron (positron) beam polarization of -80% (+30%).
We obtained the following measurement accuracies of the Higgs cross section
times branching fraction () for decay
of the Higgs into , , and ; as 1.0%, 6.9%, and 8.5% at
a CM energy of 250 GeV and 1.0%, 6.2%, and 7.3% at 350 GeV, respectively.
After the measurement accuracy of the cross section ()
was corrected using the results of studies at 250 GeV and their extrapolation
to 350 GeV, the derived measurement accuracies of the branching fractions
() to , , and gg were 2.7%, 7.3%, and 8.9% at
a CM energy of 250 GeV and 3.6%, 7.2%, and 8.1% at 350 GeV, respectively.Comment: 15 pages, 6 figure
There is detectable variation in the lipidomic profile between stable and progressive patients with idiopathic pulmonary fibrosis (IPF)
Background
Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by fibrosis and progressive loss of lung function. The pathophysiological pathways involved in IPF are not well understood. Abnormal lipid metabolism has been described in various other chronic lung diseases including asthma and chronic obstructive pulmonary disease (COPD). However, its potential role in IPF pathogenesis remains unclear.
Methods
In this study, we used ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) to characterize lipid changes in plasma derived from IPF patients with stable and progressive disease. We further applied a data-independent acquisition (DIA) technique called SONAR, to improve the specificity of lipid identification.
Results
Statistical modelling showed variable discrimination between the stable and progressive subjects, revealing differences in the detection of triglycerides (TG) and phosphatidylcholines (PC) between progressors and stable IPF groups, which was further confirmed by mass spectrometry imaging (MSI) in IPF tissue.
Conclusion
This is the first study to characterise lipid metabolism between stable and progressive IPF, with results suggesting disparities in the circulating lipidome with disease progression
Automated radiofrequency-based US measurement of common carotid intima-media thickness in RA patients treated with synthetic vs synthetic and biologic DMARDs
Objective. To compare the carotid intima-media thickness (IMT) assessed with automated radiofrequency-based US in RA patients treated with synthetic vs synthetic and biologic DMARDs and controls. Methods. Ninety-four RA patients and 94 sex-and age-matched controls were prospectively recruited at seven centres. Cardiovascular (CV) risk factors and co-morbidities, RA characteristics and therapy were recorded. Common carotid artery (CCA)-IMT was assessed in RA patients and controls with automated radiofrequency-based US by the same investigator at each centre. Results. Forty-five (47.9%) RA patients had been treated with synthetic DMARDs and 49 (52.1%) with synthetic and biologic DMARDs. There were no significant differences between the RA patients and controls in demographics, CV co-morbidities and CV disease. There were significantly more smokers among RA patients treated with synthetic and biologic DMARDs (P = 0.036). Disease duration and duration of CS and synthetic DMARD therapy was significantly longer in RA patients treated with synthetic and biologic DMARDs (P<0.0005). The mean CCA-IMT was significantly greater in RA patients treated only with synthetic DMARDs than in controls [591.4 (98.6) vs 562.1 (85.8); P = 0.035] and in RA patients treated with synthetic and biologic DMARDs [591.4 (98.6) vs 558.8 (95.3); P = 0.040). There was no significant difference between the mean CCA-IMT in RA patients treated with synthetic and biologic DMARDs and controls (P = 0.997). Conclusion. Our results suggest that radiofrequency-based measurement of CCA-IMT can discriminate between RA patients treated with synthetic DMARDs vs RA patients treated with synthetic and biologic DMARDs
Brazil and the development of international scientific biosafety testing guidelines for transgenic crops.
Under the umbrella of the International Organisation of Biological Control (IOBC), an international working group of public sector scientists entitled on Transgenic Organisms in Integrated Pest Management and Biological Control has been organized. The group will develop scientific principles and detailed scientific guidelines for biosafety testing of transgenic crops. The key elements of this project are: (1) An international initiative including expert scientists from leading research institutions in developed and developing countries; (2) coordination of the development and implementation of the guidelines as a dynamic process, which will include scientific and technical capacity building and communication among scientists and between scientists and policy makers; (3) rapid serial publication of sections of the guidelines as they are completed; and (4) rapid and timely revision of previously published sections. The guidelines will be constructed on a case-by-case basis and will have no regulatory legitimacy themselves
On Unbounded Composition Operators in -Spaces
Fundamental properties of unbounded composition operators in -spaces are
studied. Characterizations of normal and quasinormal composition operators are
provided. Formally normal composition operators are shown to be normal.
Composition operators generating Stieltjes moment sequences are completely
characterized. The unbounded counterparts of the celebrated Lambert's
characterizations of subnormality of bounded composition operators are shown to
be false. Various illustrative examples are supplied
Reliability testing of tendon disease using two different scanning methods in patients with rheumatoid arthritis
Objective. To assess the intra- and interobserver reliability of musculoskeletal ultrasonography (US) in detecting inflammatory and destructive tendon abnormalities in patients with RA using two different scanning methods.Methods. Thirteen observers examined nine patients with RA and one healthy individual in two rounds independently and blindly of each other. Each round consisted of two consecutive examinations, an anatomy-based examination and a free examination according to personal preferences. The following tendons were evaluated: wrist extensor compartments 2, 4 and 6, finger flexor tendons 3 and 4 at MCP level, tibialis posterior tendon and both peronei tendons. Overall, positive and negative agreements and \u3ba-values for greyscale (GS) tenosynovitis, peritendinous power Doppler (PPD) signal, intratendinous power Doppler (IPD) signal and GS tendon damage were calculated.Results. Intraobserver \u3ba-value ranges were 0.53-0.55 (P < 0.0005) for GS tenosynovitis, 0.61-0.64 (P < 0.0005) for PPD signal, 0.65-0.66 (P < 0.0005) for IPD signal and 0.44-0.53 (P < 0.0005) for GS tendon damage. For interobserver reliability, substantial overall agreement ranged from 80 to 89% for GS tenosynovitis, 97 to 100% for PPD signal, 97 to 100% for IPD signal and 97 to 100% for GS tendon damage. Results were independent of scanning technique.Conclusion. Intraobserver reliability for tenosynovitis and tendon damage varied from moderate for GS to good for PD. Overall interobserver reliability for tenosynovitis and tendon damage was excellent both for GS and PD. This qualitative scoring system may serve as the first step to a semi-quantitative score for tendon pathology. \ua9 The Author 2012. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved
How does a cadaver model work for testing ultrasound diagnostic capability for rheumatic-like tendon damage?
To establish whether a cadaver model can serve as an effective surrogate for the detection of tendon damage characteristic of rheumatoid arthritis (RA). In addition, we evaluated intraobserver and interobserver agreement in the grading of RA-like tendon tears shown by US, as well as the concordance between the US findings and the surgically induced lesions in the cadaver model. RA-like tendon damage was surgically induced in the tibialis anterior tendon (TAT) and tibialis posterior tendon (TPT) of ten ankle/foot fresh-frozen cadaveric specimens. Of the 20 tendons examined, six were randomly assigned a surgically induced partial tear; six a complete tear; and eight left undamaged. Three rheumatologists, experts in musculoskeletal US, assessed from 1 to 5 the quality of US imaging of the cadaveric models on a Likert scale. Tendons were then categorized as having either no damage, (0); partial tear, (1); or complete tear (2). All 20 tendons were blindly and independently evaluated twice, over two rounds, by each of the three observers. Overall, technical performance was satisfactory for all items in the two rounds (all values over 2.9 in a Likert scale 1-5). Intraobserver and interobserver agreement for US grading of tendon damage was good (mean κ values 0.62 and 0.71, respectively), with greater reliability found in the TAT than the TPT. Concordance between US findings and experimental tendon lesions was acceptable (70-100 %), again greater for the TAT than for the TPT. A cadaver model with surgically created tendon damage can be useful in evaluating US metric properties of RA tendon lesions
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