182,104 research outputs found
Modified Kinematic Technique for Measuring Pathological Hyperextension and Hypermobility of the Interphalangeal Joints
No full textDynamic finger joint motion is difficult to measure using optical motion analysis techniques due to the limited surface area allowed for adequate marker placement. This paper describes an extension of a previously validated kinematic measurement technique using a reduced surface marker set and outlines the required calculations based on a specific surface marker placement to calculate flexion/extension and hyperextension of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. The modified technique has been assessed for accuracy using a series of static reference frames (absolute residual error = ±3.7°, cross correlation between new method and reference frames; r = 0.99). The method was then applied to a small group of participants with rheumatoid arthritis (seven females, one male; mean age = 62.8 years ± 12.04) and illustrated congruent strategies of movement for a participant and a large range of finger joint movement over the sample (5.8–71.1°, smallest to largest active range of motion). This method used alongside the previous paper [1] provides a comprehensive, validated method for calculating 3-D wrist, hand, fingers, and thumb kinematics to date and provides a valuable measurement tool for clinical research
Metcalf (Thomas R.) : Idéologies of the Raj
No full textPouchepadass Jacques. Metcalf (Thomas R.) : Idéologies of the Raj. In: Revue française d'histoire d'outre-mer, tome 83, n°311, 2e trimestre 1996. pp. 154-156
Neutrino masses, dark energy and the gravitational lensing of pre-galactic H i
No full textWe study the constraints which the next generation of radio telescopes could place on the mass and number of neutrino species by studying the gravitational lensing of high-redshift 21-cm emission in combination with wide-angle surveys of galaxy lensing. We use simple characterizations of reionization history and of proposed telescope designs to forecast the constraints and detectability threshold for neutrinos. It is found that the degeneracy between neutrino parameters and dark energy parameters is significantly reduced by incorporating 21-cm lensing. The combination of galaxy and 21-cm lensing could constrain the sum of the neutrino masses to within ∼0.04 eV and the number of species to within ∼0.1. This is an improvement of a factor of 2.6 in mass and 1.4 in number over a galaxy lensing survey alone. This includes marginalizing over an 11-parameter cosmological model with a two-parameter model for the dark energy equation of state. If the dark energy equation of state is held fixed at w ≡ p/ρ = -1, the constraints improve to ∼0.025 eV and 0.04. These forecasted errors depend critically on the fraction of sky that can be surveyed in redshifted 21-cm emission (25 per cent is assumed here) and the redshift of reionization (z = 7 is assumed here). It is also found that neutrinos with masses too small to be detected in the data could none the less cause a significant bias in the measured dark energy equation of state. © 2009 The Author. Journal compilation. © 2009 RAS
A review of clinical upper limb assessments under the framework of the WHO ICF
No full textThis paper is intended to provide a practical overview for clinicians and researchers involved in assessing upper limb function. It considers 25 upper limb assessments used in musculoskeletal care and presents a simple, straightforward comparative review of each. The World Health Organization International Classification on Functioning, Disability and Health (WHO ICF) is used to provide a relative summary of purpose between each assessment. Measurement properties of each assessment are provided, considering the type of data generated, availability of reliability estimates and normative data for the assessmen
Erratum: The elliptical power law profile lens (Astronomy and Astrophysics (2015) 580 (A79) DOI: 10.1051/0004-6361/201526773)
No full textThe authors would like to point out two errors in the article as it was originally published. Due to a typographical error, Eq. (17) erroneously expresses the shear of the elliptical power law profile lens in the elliptic coordinates R and ' instead of the physical polar coordinates r and ø. The correct expression is (r; ø) = -ei2ø κ (r) + (1 - t) ei ø α (r; ø) r ; (17) i.e. the same formula with the substitutions R → r and α → ø. This result correctly recovers the singular isothermal ellipsoid result γ = -κ (z/z∗) = -ei2ø when t = 1. The preceding Eq. (16) is correct. Furthermore, Fig. 2 incorrectly contains and refers to the pseudo-caustics for power law profile lenses with slope t > 1. Since the main result of the original paper shows that the elliptical lenses have the same (elliptical) radial profile as the circular ones, the degenerate critical line at the origin R = 0 is mapped to R = 1 when t > 1, just as in the circular case. Hence only the isothermal case t = 1 has a pseudo-caustic at finite radius. The dashed lines in the plot are due to a numerical error. A corrected version of Fig. 2 is shown below. (Figure Presented)
Metcalf (Thomas R.) : Idéologies of the Raj
No full textPouchepadass Jacques. Metcalf (Thomas R.) : Idéologies of the Raj. In: Revue française d'histoire d'outre-mer, tome 83, n°311, 2e trimestre 1996. pp. 154-156
hardRain: an R package for quick, automated rainfall detection in ecoacoustic datasets using a threshold-based approach - Case Study dataset
No full texthardRain: an R package for quick, automated rainfall detection in ecoacoustic datasets using a threshold-based approach - CaseStudy datase
Forecasting the detection of Lyman-alpha forest weak lensing from the dark energy spectroscopic instrument and other future surveys
No full textThe apparent angular positions of quasars are deflected on the sky by the gravitational field sourced by foreground matter. This weak lensing effect is measurable through the distortions it introduces in the lensed quasar spectra. Discrepancies in the statistics of the Lyman- α forest spectral absorption features can be used to reconstruct the foreground lensing potential. We extend the study of this method of Lyman- α forest weak gravitational lensing to lower angular forest spectrum source densities than previous work. We evaluate the performance of the Lyman- α lensing estimator of Metcalf et al. (2020) on mock data based on the angular forest source density ( 50 per square degree) and volume (about 700,000 spectra total) of the DESI survey. We simulate the foreground galaxy distribution and lensing potentials with redshift evolution approximated by N-body simulation and simulate Gaussian-random Lyman- α forests to produce mock data for the entire DESI footprint. By correlating the foreground galaxy distribution with the potential reconstructed by the estimator, we find that a weak lensing detection with signal to noise of ∼4 will be possible with the full DESI data. We show that spectral surveys with low density and high volume are promising candidates for forest weak lensing in addition to the high resolution data that have been considered in previous work. We present forecasts for future spectral surveys and show that with larger datasets a detection with signal to noise >10 will be possible
Gravitational lensing of pregalactic 21 cm radiation
No full textLow-frequency radio observations of neutral hydrogen during and before the epoch of cosmic reionization will provide hundreds of quasi-independent source planes, each of precisely known redshift, if a resolution of ∼ 1 arcminutes or better can be attained. These planes can be used to reconstruct the projected mass distribution of foreground material. A wide-area survey of 21 cm lensing would provide very sensitive constraints on cosmological parameters, in particular on dark energy. These are up to 20 times tighter than the constraints obtainable from comparably sized, very deep surveys of galaxy lensing although the best constraints come from combining data of the two types. Any radio telescope capable of mapping the 21 cm brightness temperature with good frequency resolution (∼ 0,05 MHz) over a band of width ≳ 10 MHz should be able to make mass maps of high quality. If the reionization epoch is at z ≲ 9 very large amounts of cosmological information will be accessible. The planned Square Kilometer Array (SKA) should be capable of mapping the mass with a resolution of a few arcminutes depending on the reionization history of the Universe and how successfully foreground sources can be subtracted. The Low-Frequency Array (LOFAR) will be able to measure an accurate matter power spectrum if the same conditions are met
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