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Sample records for relations spin-down rates

  1. Tidal spin down rates of homogeneous triaxial viscoelastic bodies

    NASA Astrophysics Data System (ADS)

    Quillen, Alice C.; Kueter-Young, Andrea; Frouard, Julien; Ragozzine, Darin

    2016-12-01

    We use numerical simulations to measure the sensitivity of the tidal spin-down rate of a homogeneous triaxial ellipsoid to its axis ratios by comparing the drift rate in orbital semimajor axis to that of a spherical body with the same mass, volume and simulated rheology. We use a mass-spring model approximating a viscoelastic body spinning around its shortest body axis, with spin aligned with orbital spin axis, and in circular orbit about a point mass. The torque or drift rate can be estimated from that predicted for a sphere with equivalent volume if multiplied by 0.5 (1 + b^4/a^4)(b/a)^{-4/3} (c/a)^{-α _c} where b/a and c/a are the body axis ratios and index αc ≈ 1.05 is consistent with the random lattice mass-spring model simulations but αc = 4/3 suggested by scaling estimates. A homogeneous body with axis ratios 0.5 and 0.8, like Haumea, has orbital semimajor axis drift rate about twice as fast as a spherical body with the same mass, volume and material properties. A simulation approximating a mostly rocky body but with 20 per cent of its mass as ice concentrated at its ends has a drift rate 10 times faster than the equivalent homogeneous rocky sphere. However, this increase in drift rate is not enough to allow Haumea's satellite, Hi'iaka, to have tidally drifted away from Haumea to its current orbital semimajor axis.

  2. Measuring the Spin-Down Rate of a High-Velocity Pulsar

    NASA Astrophysics Data System (ADS)

    Tomsick, John

    2013-10-01

    The X-ray and radio morphology of IGR J11014-6103 strongly suggest that it is an energetic pulsar/PWN moving away from the center of the SNR MSH 11-61A at an extraordinarily large velocity of >2,400 km/s. Using XMM-Newton, we recently discovered 62.8 ms pulsations from IGR J11014-6103. Now, we need to measure the spin-down rate of PSR J1101-6101 in order to determine its spin-down power and spin-down age. The spin-down power is needed to understand the structure of its apparent bow-shock nebula and mysterious X-ray streak. The spin-down age is an upper limit on its true age, and will establish whether PSR J1101-6101 could have originated in MSH 11-61A, which would make it the pulsar with the largest known natal kick velocity.

  3. Understanding the spin-down rate changes of PSR B0919+06

    NASA Astrophysics Data System (ADS)

    Perera, B. B. P.; Stappers, B. W.; Weltevrede, P.; Lyne, A. G.; Bassa, C. G.

    2015-01-01

    We study the spin-down properties of PSR B0919+06 based on almost 30 years of radio observations. We confirm that the time derivative of the rotational frequency dot{ν} is modulated quasi-periodically and show that it exhibits a repeating double-peaked structure throughout the entire observation span. We model the dot{ν} variation of the pulsar assuming two spin-down rates with sudden switches between them in time. Our results show that the double-peak structure in dot{ν} has a repetition time of about 630 d until MJD 52000 (2001 April) and 550 d since then. During this cycle, the pulsar spin varies from the lower spin-down rate to the upper spin-down rate twice with different amounts of time spent in each state, resulting in a further quasi-stable secondary modulation of the two-state switching. This particular spin-down state switching is broadly consistent with free precession of the pulsar; however, strong evidence linked with this mechanism is not clearly established. We also confirm that the pulsar occasionally emits groups of pulses which appear early in pulse phase, so-called flares, and these events significantly contribute to the pulse-profile shape. We find the dot{ν} modulation and the pulse-shape variations are correlated throughout the observations. However, the flare state is not entirely responsible for this correlation. In addition to the flare state, we detect flare-like events from the pulsar in single-pulse observations. During these events, the shift in pulse phase is small compared to that of the main flare state and clearly visible only in single-pulse observations.

  4. Exploration of spin-down rate of neutron stars in high-mass X-ray binaries

    NASA Astrophysics Data System (ADS)

    Dai, Hai-Lang; Liu, Xi-Wei; Li, Xiang-Dong

    2016-04-01

    We use the evolutionary population synthesis method to investigate the statistical properties of the wind-fed neutron-star (NS) compact (Porb < 10 d) high-mass X-ray binaries (HMXBs) in our Galaxy, based on different spin-down models. Model 1 assumes that the surrounding material is treated as forming a quasi-static atmosphere. Model 2 assumes that the characteristic velocity of matter and the typical Alfvén velocity of material in the magnetospheric boundary layer are comparable to the sound speed in the external medium. We find that the spin-down rate in the supersonic propeller phase in either model 1 or model 2 is too low to produce the observed number of compact HMXBs. Model 3 assumes that the infalling material is ejected with the corotation velocity at the magnetospheric radius when the magnetospheric radius is larger than the corotation radius. Model 4 uses simple integration of the magnetic torque over the magnetosphere. Both models 3 and 4 have a larger spin down rate than that given by model 1 or 2. We also find that models 3 and 4 can predict a reasonable number of observed wind-fed NS compact HMXBs. By comparing our calculated results with the observed particular distributions of wind-fed NS compact HMXBs in a Ps versus Porb diagram, we find that the subsonic propeller phase may not exist at all. However, the spin-down rates in models 3 and 4 both seem reasonable to produce the observed distribution of wind-fed NS compact HMXBs in the Ps versus Porb diagram. We cannot find which spin-down rate seems more reasonable from our calculations.

  5. X-Ray Spectra of Young Pulsars and Their Wind Nebulae: Dependence on Spin-Down Energy Loss Rate

    NASA Technical Reports Server (NTRS)

    Gotthelf, E. V.

    2003-01-01

    An observational model is presented for the spectra of young rotation-powered pulsars and their nebulae based on a study of nine bright Crab-like pulsar systems observed with the Chandra X-ray observatory. A significant correlation is discovered between the X-ray spectra of these pulsars and that of their associated pulsar wind nebulae, both of which are observed to be a function of the spin-down energy loss rate, E. The 2-10 keV spectra of these objects are well characterized by an absorbed power-law model with photon indices, Gamma, in the range of 0.6 < Gamma (sub PSR) < 2.1 and 1.3 < Gamma(sub PWN) < 2.3, for the pulsars and their nebulae, respectively. A linear regression fit relating these two sets of indexes yields Gamma(sub PWN) = 0.91 +/- 0.18 + (0.66 +/- 0.11) Gamma (sub PSR), with a correlation coefficient of r = 0.97. The spectra of these pulsars are found to steepen as Gamma = Gamma(sub max) + alpha E (exp -1/2), with Gamma(sub max) providing an observational limit on the spectral slopes of young rotation-powered pulsars. These results reveal basic properties of young pulsar systems, allow new observational constraints on models of pulsar wind emission, and provide a means of predicting the energetics of pulsars lacking detected pulsations.

  6. Correlated spin-down rates and radio emission in PSR B1859+07

    NASA Astrophysics Data System (ADS)

    Perera, B. B. P.; Stappers, B. W.; Weltevrede, P.; Lyne, A. G.; Rankin, J. M.

    2016-01-01

    We study the spin-down changes of PSR B1859+07 over a period of more than 28 years of radio observation. We identify that the time derivative of the rotational frequency (ν) varies quasi-periodically with a period of ˜350 d, switching mainly between two spin-down states. The profile shape of the pulsar is correlated with the ν˙ variation, producing two slightly different profile shapes corresponding to high- and low-ν˙ states. In addition to these two normal emission states, we confirm the occasional flare-state of the pulsar, in which the emission appears early in spin phase compared to that of the common normal emission. The profile of the flare-state is significantly different from that of the two normal emission states. The correlation analysis further shows that the flare-state is not directly linked with the ν˙ changes. With a simple emission beam model, we estimate the emission altitude of the normal emission to be 240 km, and explain the origin of the flare-state as an emission height variation from the leading edge of the beam. We also argue that the emission of these states can be explained with a partially active beam model. In this scenario, the trailing portion of the radio beam is usually active and the normal emission is produced. The flare-state occurs when the leading edge of the beam becomes active while the trailing part is being blocked. This model estimates a fixed emission altitude of 360 km. However, the cause of the flare-state (i.e. the emission height variation, or the time-dependent activity across the radio beam) is not easily explained.

  7. SGR 1822-1606 (Swift 1822.3-1606): Spin-down rate and inferred dipole field strength

    NASA Astrophysics Data System (ADS)

    Gogus, Ersin; Strohmayer, Tod; Kouveliotou, Chryssa

    2011-07-01

    We have been monitoring the new source Swift 1822.3-1606 (Cummings et al. GCN 12159) with RXTE. We acquired a total exposure of 20.6 ks in 5 pointings, spanning a time baseline of 5 days. We clearly detect the 8.44 s pulsations reported earlier (Pagani et al. ATel #3489, Gogus et al ATel #3491, Rea et al Atel #3501). We employed an epoch folding technique to determine the spin ephemeris. Our preliminary analysis reveal the spin period, P = 8.4377158(9) s and the spin-down rate, Pdot = 2.2(5) x 10-11 s/s (Epoch: 55758.5 MJD).

  8. Discovery of a Spin-down State Change in the LMC Pulsar B0540-69

    NASA Astrophysics Data System (ADS)

    Marshall, F. E.; Guillemot, L.; Harding, A. K.; Martin, P.; Smith, D. A.

    2015-07-01

    We report the discovery of a large, sudden, and persistent increase in the spin-down rate of B0540-69, a young pulsar in the Large Magellanic Cloud, using observations from the Swift and RXTE satellites. The relative increase in the spin-down rate \\dot{ν } of 36% is unprecedented for B0540-69. No accompanying change in the spin rate is seen, and no change is seen in the pulsed X-ray emission from B0540-69 following the change in the spin-down rate. Such large relative changes in the spin-down rate are seen in the recently discovered class of “intermittent pulsars,” and we compare the properties of B0540-69 to such pulsars. We consider possible changes in the magnetosphere of the pulsar that could cause such a large change in the spin-down rate.

  9. A grid of MHD models for stellar mass loss and spin-down rates of solar analogs

    SciTech Connect

    Cohen, O.; Drake, J. J.

    2014-03-01

    Stellar winds are believed to be the dominant factor in the spin-down of stars over time. However, stellar winds of solar analogs are poorly constrained due to observational challenges. In this paper, we present a grid of magnetohydrodynamic models to study and quantify the values of stellar mass loss and angular momentum loss rates as a function of the stellar rotation period, magnetic dipole component, and coronal base density. We derive simple scaling laws for the loss rates as a function of these parameters, and constrain the possible mass loss rate of stars with thermally driven winds. Despite the success of our scaling law in matching the results of the model, we find a deviation between the 'solar dipole' case and a real case based on solar observations that overestimates the actual solar mass loss rate by a factor of three. This implies that the model for stellar fields might require a further investigation with additional complexity. Mass loss rates in general are largely controlled by the magnetic field strength, with the wind density varying in proportion to the confining magnetic pressure B {sup 2}. We also find that the mass loss rates obtained using our grid models drop much faster with the increase in rotation period than scaling laws derived using observed stellar activity. For main-sequence solar-like stars, our scaling law for angular momentum loss versus poloidal magnetic field strength retrieves the well-known Skumanich decline of angular velocity with time, Ω{sub *}∝t {sup –1/2}, if the large-scale poloidal magnetic field scales with rotation rate as B{sub p}∝Ω{sub ⋆}{sup 2}.

  10. Ion-acoustic shocks in magnetized quantum plasmas with relative density effects of spin-up and spin-down degenerate electrons

    NASA Astrophysics Data System (ADS)

    Hussain, S.; Mahmood, S.

    2017-10-01

    Ion-acoustic shock wave propagation in dense magnetized plasmas with relative density effects of spin-up and spin-down degenerate electrons is studied. The ions are classical, and their dissipative effects on plasma dynamics are included via kinematic viscosity. The electrons with spin-up and spin-down states are taken as separate species. The quantum tunneling effects of electrons are also considered in equations of motions of electrons. The Korteweg de Vries Burgers (KdVB) equation is derived, which admits the shock solution. The KdVB equation is solved numerically to study the transition from shock with oscillatory trails at its wave fronts to the monotonic shock structure with respect to variations in different plasma parameters. The parametric role of the spin density polarization ratio in the propagation characteristics of the shock wave structure is discussed.

  11. Magnetar Spin-Down.

    PubMed

    Harding; Contopoulos; Kazanas

    1999-11-10

    We examine the effects of a relativistic wind on the spin-down of a neutron star and apply our results to the study of soft gamma repeaters (SGRs), which are thought to be neutron stars with magnetic fields greater than 1014 G. We derive a spin-down formula that includes torques from both dipole radiation and episodic or continuous particle winds. We find that if SGR 1806-20 puts out a continuous particle wind of 1037 ergs s-1, then the pulsar age is consistent with that of the supernova remnant, but the derived surface dipole magnetic field is only 3x1013 G, in the range of normal radio pulsars. If instead the particle wind flows are episodic with small duty cycle, then the observed period derivatives imply magnetar-strength fields, while still allowing characteristic ages within a factor of 2 of the estimated supernova remnant age. Close monitoring of the periods of SGRs will allow us to establish or place limits on the wind duty cycle and thus the magnetic field and age of the neutron star.

  12. A Quarter-century of Observations of Comet 10P/Tempel 2 at Lowell Observatory: Continued Spin-down, Coma Morphology, Production Rates, and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Knight, Matthew M.; Schleicher, David G.; Farnham, Tony L.; Schwieterman, Edward W.; Christensen, Samantha R.

    2012-11-01

    We report on photometry and imaging of Comet 10P/Tempel 2 obtained at Lowell Observatory from 1983 through 2011. We measured a nucleus rotation period of 8.950 ± 0.002 hr from 16 nights of imaging acquired between 2010 September and 2011 January. This rotation period is longer than the period we previously measured in 1999, which was itself longer than the period measured in 1988, and demonstrates that Tempel 2 is continuing to spin down, presumably due to torques caused by asymmetric outgassing. A nearly linear jet was observed which varied little during a rotation cycle in both R and CN images acquired during the 1999 and 2010 apparitions. We measured the projected direction of this jet throughout the two apparitions and, under the assumption that the source region of the jet was near the comet's pole, determined a rotational pole direction of R.A./decl. = 151°/+59° from CN measurements and R.A./decl. = 173°/+57° from dust measurements (we estimate a circular uncertainty of 3° for CN and 4° for dust). Different combinations of effects likely bias both gas and dust solutions and we elected to average these solutions for a final pole direction of R.A./decl. = 162° ± 11°/+58° ± 1°. Photoelectric photometry was acquired on 3 nights in 1983, 2 nights in 1988, 19 nights in 1999/2000, and 10 nights in 2010/2011. The activity exhibited a steep "turn-on" ~3 months prior to perihelion (the exact timing of which varies) and a relatively smooth decline after perihelion. The activity during the 1999 and 2010 apparitions was similar; limited data in 1983 and 1988 (along with IUE data from the literature) were systematically higher and the difference cannot be explained entirely by the smaller perihelion distance. We measured a "typical" composition, in agreement with previous investigators. Monte Carlo numerical modeling with our pole solution best replicated the observed coma morphology for a source region located near a comet latitude of +80° and having a

  13. A QUARTER-CENTURY OF OBSERVATIONS OF COMET 10P/TEMPEL 2 AT LOWELL OBSERVATORY: CONTINUED SPIN-DOWN, COMA MORPHOLOGY, PRODUCTION RATES, AND NUMERICAL MODELING

    SciTech Connect

    Knight, Matthew M.; Schleicher, David G.; Schwieterman, Edward W.; Christensen, Samantha R.; Farnham, Tony L.

    2012-11-01

    We report on photometry and imaging of Comet 10P/Tempel 2 obtained at Lowell Observatory from 1983 through 2011. We measured a nucleus rotation period of 8.950 {+-} 0.002 hr from 16 nights of imaging acquired between 2010 September and 2011 January. This rotation period is longer than the period we previously measured in 1999, which was itself longer than the period measured in 1988, and demonstrates that Tempel 2 is continuing to spin down, presumably due to torques caused by asymmetric outgassing. A nearly linear jet was observed which varied little during a rotation cycle in both R and CN images acquired during the 1999 and 2010 apparitions. We measured the projected direction of this jet throughout the two apparitions and, under the assumption that the source region of the jet was near the comet's pole, determined a rotational pole direction of R.A./decl. = 151 Degree-Sign /+59 Degree-Sign from CN measurements and R.A./decl. = 173 Degree-Sign /+57 Degree-Sign from dust measurements (we estimate a circular uncertainty of 3 Degree-Sign for CN and 4 Degree-Sign for dust). Different combinations of effects likely bias both gas and dust solutions and we elected to average these solutions for a final pole direction of R.A./decl. = 162 Degree-Sign {+-} 11 Degree-Sign /+58 Degree-Sign {+-} 1 Degree-Sign . Photoelectric photometry was acquired on 3 nights in 1983, 2 nights in 1988, 19 nights in 1999/2000, and 10 nights in 2010/2011. The activity exhibited a steep 'turn-on' {approx}3 months prior to perihelion (the exact timing of which varies) and a relatively smooth decline after perihelion. The activity during the 1999 and 2010 apparitions was similar; limited data in 1983 and 1988 (along with IUE data from the literature) were systematically higher and the difference cannot be explained entirely by the smaller perihelion distance. We measured a 'typical' composition, in agreement with previous investigators. Monte Carlo numerical modeling with our pole solution best

  14. Switched magnetospheric regulation of pulsar spin-down.

    PubMed

    Lyne, Andrew; Hobbs, George; Kramer, Michael; Stairs, Ingrid; Stappers, Ben

    2010-07-23

    Pulsars are famed for their rotational clocklike stability and their highly repeatable pulse shapes. However, it has long been known that there are unexplained deviations (often termed timing noise) from the rate at which we predict these clocks should run. We show that timing behavior often results from two different spin-down rates. Pulsars switch abruptly between these states, often quasi-periodically, leading to the observed spin-down patterns. We show that for six pulsars the timing noise is correlated with changes in the pulse shape. Many pulsar phenomena, including mode changing, nulling, intermittency, pulse-shape variability, and timing noise, are therefore linked and are caused by changes in the pulsar's magnetosphere. We consider the possibility that high-precision monitoring of pulse profiles could lead to the formation of highly stable pulsar clocks.

  15. Spin-down dynamics of magnetized solar-type stars

    SciTech Connect

    Oglethorpe, R. L. F.; Garaud, P.

    2013-12-01

    It has long been known that solar-type stars undergo significant spin-down, via magnetic braking, during their main-sequence lifetimes. However, magnetic braking only operates on the surface layers; it is not yet completely understood how angular momentum is transported within the star and how rapidly the spin-down information is communicated to the deep interior. In this work, we use insight from recent progress in understanding internal solar dynamics to model the interior of other solar-type stars. We assume, following Gough and McIntyre, that the bulk of the radiation zone of these stars is held in uniform rotation by the presence of an embedded large-scale primordial field, confined below a stably stratified, magnetic-free tachocline by large-scale meridional flows downwelling from the convection zone. We derive simple equations to describe the response of this model interior to spin-down of the surface layers, which are identical to the two-zone model of MacGregor and Brenner, with a coupling timescale proportional to the local Eddington-Sweet timescale across the tachocline. This timescale depends both on the rotation rate of the star and on the thickness of the tachocline, and it can vary from a few hundred thousand years to a few Gyr, depending on stellar properties. Qualitative predictions of the model appear to be consistent with observations, although they depend sensitively on the assumed functional dependence of the tachocline thickness on the stellar rotation rate.

  16. Spin-down Dynamics of Magnetized Solar-type Stars

    NASA Astrophysics Data System (ADS)

    Oglethorpe, R. L. F.; Garaud, P.

    2013-12-01

    It has long been known that solar-type stars undergo significant spin-down, via magnetic braking, during their main-sequence lifetimes. However, magnetic braking only operates on the surface layers; it is not yet completely understood how angular momentum is transported within the star and how rapidly the spin-down information is communicated to the deep interior. In this work, we use insight from recent progress in understanding internal solar dynamics to model the interior of other solar-type stars. We assume, following Gough & McIntyre, that the bulk of the radiation zone of these stars is held in uniform rotation by the presence of an embedded large-scale primordial field, confined below a stably stratified, magnetic-free tachocline by large-scale meridional flows downwelling from the convection zone. We derive simple equations to describe the response of this model interior to spin-down of the surface layers, which are identical to the two-zone model of MacGregor & Brenner, with a coupling timescale proportional to the local Eddington-Sweet timescale across the tachocline. This timescale depends both on the rotation rate of the star and on the thickness of the tachocline, and it can vary from a few hundred thousand years to a few Gyr, depending on stellar properties. Qualitative predictions of the model appear to be consistent with observations, although they depend sensitively on the assumed functional dependence of the tachocline thickness on the stellar rotation rate.

  17. Spin-down in PQ GEM

    NASA Astrophysics Data System (ADS)

    Mason, K. O.

    1997-03-01

    X-ray and optical timings of the 833-s white dwarf spin period in the intermediate polar magnetic cataclysmic variable PQ Gem are assembled which span ~5.5 yr. The spin period is found to be increasing on a time-scale of 2.4x10^5 yr (P_solar =1.1x10^-10s s^-1). This is the largest spin period change yet found in an intermediate polar. Furthermore PQ Gem is only the second such star in which the rotation period of the white dwarf is confirmed to be lengthening. The spin ephemeris is used to compare phase-folded light curves obtained at different times in different wavelength bands. Previous observations have found a dip in the spin light curve which is most prominent at the lowest X-ray energies. This is shown to occur at a phase where models of the optical polarization light curve predict that the accretion region on the upper rotation hemisphere of the white dwarf is facing the observer. This, together with its short-term phase jitter, strongly suggests that the dip is caused by absorption in the magnetically controlled matter flow that is feeding a bright accretion arc at the footpoints of the magnetic field lines. The dip precedes the phase of maximum X-ray light by 30 deg-40 deg, implying that the accretion stream strikes the surface of the white dwarf at an angle. This is consistent with a geometry in which material accretes only along field lines which lead the magnetic pole in the rotation cycle of the white dwarf, independently supporting similar inferences drawn from optical polarization modelling. This may mean that matter is being threaded by the field lines outside the corotation radius, and would be consistent with the high rate of spin-down observed.

  18. Spinning-Down of Moving Magnetars in the Propeller Regime

    NASA Astrophysics Data System (ADS)

    Toropina, O. D.; Romanova, M. M.; Lovelace, R. V. E.

    2006-08-01

    We use axisymmmetric magnetohydrodynamic simulations to investigate the spinning-down of magnetars rotating in the propeller regime and moving supersonically through the interstellar medium. The star loses its angular momentum due to direct interaction of the rotating magnetosphere with the non-rotating interstellar medium. The simulations indicate that magnetars spin-down rapidly due to this interaction, much faster than for the case of a non-moving star. A magnetar with a surface magnetic field of 1013 - 1015 G is found to spin-down to a period P > 10^5-10^6 s in 10^4 - 10^5 yr. This may explain, why a number of soft gamma-repeaters is so small: because only a tiny fraction of all magnetars rotate sufficiently fast to be identified with the neutron stars. From many simulation runs we have derived an approximate scaling law for the angular momentum loss rate, dot{L} ∝ - ρ0.8μ0.6Ω_*1.5/v0.4, where ρ is the density of the interstellar medium, μ is the star's magnetic moment, Ω_* is its angular velocity, and v is velocity of motion.

  19. SPIN-UP/SPIN-DOWN MODELS FOR TYPE Ia SUPERNOVAE

    SciTech Connect

    Stefano, R. Di; Voss, R.

    2011-09-01

    In the single-degenerate scenario for Type Ia supernovae (SNe Ia), a white dwarf (WD) must gain a significant amount of matter from a companion star. Because the accreted mass carries angular momentum, the WD is likely to achieve fast spin periods, which can increase the critical mass, M{sub crit}, needed for explosion. When M{sub crit} is higher than the maximum mass achieved by the WD, the central regions of the WD must spin down before it can explode. This introduces super-Chandrasekhar single-degenerate explosions, and a delay between the completion of mass gain and the time of the explosion. Matter ejected from the binary during mass transfer therefore has a chance to become diffuse, and the explosion occurs in a medium with a density similar to that of typical regions of the interstellar medium. Also, either by the end of the WD's mass increase or else by the time of explosion, the donor may exhaust its stellar envelope and become a WD. This alters, generally diminishing, explosion signatures related to the donor star. Nevertheless, the spin-up/spin-down model is highly predictive. Prior to explosion, progenitors can be super-M{sub Ch} WDs in either wide binaries with WD companions or cataclysmic variables. These systems can be discovered and studied through wide-field surveys. Post-explosion, the spin-up/spin-down model predicts a population of fast-moving WDs, low-mass stars, and even brown dwarfs. In addition, the spin-up/spin-down model provides a paradigm which may be able to explain both the similarities and the diversity observed among SNe Ia.

  20. Spin-up/Spin-down Models for Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Voss, R.; Claeys, J. S. W.

    2011-09-01

    In the single-degenerate scenario for Type Ia supernovae (SNe Ia), a white dwarf (WD) must gain a significant amount of matter from a companion star. Because the accreted mass carries angular momentum, the WD is likely to achieve fast spin periods, which can increase the critical mass, M crit, needed for explosion. When M crit is higher than the maximum mass achieved by the WD, the central regions of the WD must spin down before it can explode. This introduces super-Chandrasekhar single-degenerate explosions, and a delay between the completion of mass gain and the time of the explosion. Matter ejected from the binary during mass transfer therefore has a chance to become diffuse, and the explosion occurs in a medium with a density similar to that of typical regions of the interstellar medium. Also, either by the end of the WD's mass increase or else by the time of explosion, the donor may exhaust its stellar envelope and become a WD. This alters, generally diminishing, explosion signatures related to the donor star. Nevertheless, the spin-up/spin-down model is highly predictive. Prior to explosion, progenitors can be super-M Ch WDs in either wide binaries with WD companions or cataclysmic variables. These systems can be discovered and studied through wide-field surveys. Post-explosion, the spin-up/spin-down model predicts a population of fast-moving WDs, low-mass stars, and even brown dwarfs. In addition, the spin-up/spin-down model provides a paradigm which may be able to explain both the similarities and the diversity observed among SNe Ia.

  1. Discovery of Pulsed Gamma Rays and a New Spin-Down State of the LMC Pulsar B0540-69

    NASA Astrophysics Data System (ADS)

    Marshall, Francis E.; Guillemot, Lucas; Kust Harding, Alice; Martin, Pierrick; Smith, David A.

    2016-01-01

    The young pulsar B0540-69 in the nearby Large Magellanic Cloud has the third largest spin-down luminosity of the ~2500 known pulsars. Multi-year observations with Fermi/LAT using the ephemerides from RXTE reveal that B0540-69 is the most luminous gamma-ray pulsar ever detected. Its pulsed luminosity above 100 MeV is 5.7x1036 erg/s, about 20 times brighter than the Crab Pulsar, the next brightest. The pulse profile in gamma rays is similar to that seen in X-rays and optical light; the giant radio pulses align with the shoulders of the high-energy profiles. The detection of B0540-69 in gamma rays offers a new look at particle acceleration and emission in the magnetospheres of very young pulsars. Unpulsed gamma-ray emission has also been detected from PSR J0537-6910, another young pulsar in the LMC. The two pulsars contribute most of the gamma-ray emission from the 30 Doradus nebula, indicating that cosmic rays contribute only a small part. Recent monitoring of B0540-69 with the Swift/XRT shows a large, sudden, and persistent increase in the spin-down rate of B0540-69. The relative increase in the spin-down rate of 36% is unprecedented for B0540-69. No accompanying change in the spin rate was seen, and no change was seen in the pulsed X-ray emission from B0540-69 following the change in the spin-down rate. Such large relative changes in the spin-down rate are seen in the recently discovered class of ``intermittent pulsars'', and we compare the properties of B0540-69 to such pulsars. We consider possible changes in the magnetosphere of the pulsar that could cause such a large change in the spin-down rate. These changes are likely to result in a new braking index for the pulsar. We report on continued monitoring with Swift/XRT to determine the new braking index and to detect a new state change, should it occur.

  2. DUAL SPIN-DOWN STATES OF THE PULSAR J1001-5507

    SciTech Connect

    Chukwude, A. E.; Buchner, S.

    2012-01-20

    Quasi-regular timing observations obtained, using the 26 m Hartebeesthoek Radio Astronomy Observatory radiotelescope near center frequencies of 1.668 and 2.272 GHz, between 1985 July and 2005 August have given a further insight into the long-term spin-down behavior of the pulsar J1001-5507 (B0959-54). Here, we show that the spin-down of the pulsar during {approx}20 years is dominated by dual spin-down modes characterized by two discrete and nearly stable spin-down rates ({nu}-dot{sub low}=-0.24871x10{sup -13} s{sup -2} and {nu}-dot{sub high}=-0.25195x10{sup -13} s{sup -2}). Our analysis demonstrates that the switching of the pulsar's spin-down rate from {nu}-dot{sub low} to {nu}-dot{sub high} modes occurred over about 800 days (between about MJD 48500 and MJD 49300) at a steady rate of {approx}-4.6 Multiplication-Sign 10{sup -24} s{sup -3}, after which the pulsar was found to be slowing down 1.3% faster. It is observed that the extreme pulse profile shapes at the two spin-down modes are notably different, while the interval of steady switching between the spin-down modes is coincident with evidence for some correlated pulse shape variations. We discuss these results in light of the current understanding of various mechanisms for radio pulsar spin-down modulation.

  3. On the Variable Spin-Down of SGR 1900+14

    NASA Technical Reports Server (NTRS)

    Thompson, Christopher; Duncan, Robert C.; Woods, Peter M.; Kouveliotou, Chryssa; vanParadijs, Jan; Finger, Mark H.

    1999-01-01

    We consider the physical implications of the rapid spindown of Soft Gamma Repeater 1900+14 reported in a companion paper by Woods et al. During an 80 day interval between June 1998 and the large outburst on August 27, 1998, the mean spin-down rate increased by a factor 2.3 resulting in a positive period offset of delta P/P = 1 X 10(exp -4)/ A radiation hydrodynamical outflow associated with the August 27 event could impart the required torque, but only if the dipole magnetic field is stronger than about 10(exp 14) G and the outflow lasts longer than the observed X-ray flare. A positive period increment is also a natural consequence of a gradual plastic deformation of the neutron star crust by an intense magnetic field. Finally, we discuss the relative stability of the long term spin-down rate of SGR 1900+14, and compare the relative spindown rates of the SGRs and the Anomalous X-ray Pulsars.

  4. Spin-Down and Active Nutation Controller /SDANC/ for the Galileo project

    NASA Technical Reports Server (NTRS)

    Lin, H. S.

    1980-01-01

    The Spin-Down and Active Nutation Controller stabilizes the Galileo spacecraft during spin-down from approximately 70 to 1 rpm. Angular motion of the spacecraft is sensed through a pair of accelerometers and a sun sensor which is needed only at low spin rates. Spin and nutation information is derived by a set of 'loosely coupled' spin and transverse rate estimators. Spin rate is reduced by two spin-down thrusters. The transverse angular rate is compared with a variable threshold; exceeding the threshold activates axial thrusters which impart appropriate transverse torque to reduce the nutation. The scheme was verified by extensive computer simulations and has been demonstrated over a wide range of initial conditions.

  5. Spin-down of a rotating air hockey disk

    NASA Astrophysics Data System (ADS)

    Weidman, Patrick; Julien, Keith

    2013-11-01

    We extend the work of Weidman (APS, DFD 2008) on the steady float height of a rotating disk to formulate and solve for the unsteady behavior of spin-down to rest. A similarity reduction of the Navier-Stokes equations reduces the problem to a coupled pair of partial differential equations in space and time. For a disk of fixed radius and density, the PDE's must be solved taking into account constraints imposed by the aerodynamic torque and aerodynamic lift. Thus the full solution for the unsteady azimuthal and axial dynamics of the disk can be obtained for given initial values of disk Reynolds number R = W h / ν and dimensionless disk rotation speed S =√{ 2} Ωh / W , where h is the float height, W is the fluid levitation velocity, Ω is the disk rotation rate, and ν is the kinematic viscosity of the fluid. Integrations reveal interesting families of solutions when plotted over steady solution curves in R- S parameter space and vindicate the quasi-steady spin-down theory reported in earlier work, valid only in a restricted region of parameter space.

  6. Realistic MHD Modelling of Cataclysmic Variable Spin-Down

    NASA Astrophysics Data System (ADS)

    Lascelles, Alex; Garraffo, Cecilia; Drake, Jeremy J.; Cohen, Ofer

    2017-01-01

    The orbital evolution of cataclysmic variables with periods above the "period gap" (>3 hrs) is governed by angular momentum loss via the magnetized wind of the unevolved secondary star. The usual prescription to study such systems takes into account only the magnetic field of the secondary and assumes its field is dipolar. It has been shown that introduction of the white dwarf and its magnetic field can significantly impact the wind’s structure, leading to a change in angular momentum loss rate and evolutionary timescale by an order of magnitude. Furthermore, the complexity of the magnetic field can drastically alter stellar spin-down rates. We explore the effects of orbital separation and magnetic field configuration on mass and angular momentum loss rates through 3-D magnetohydrodynamic simulations. We present the results of a study of cataclysmic variable orbital evolution including these new ingredients.

  7. Variable Spin-Down in the Soft Gamma Repeater SGR 1900+14 and Correlations with Burst Activity

    NASA Technical Reports Server (NTRS)

    Woods, Peter M.; Kouveliotou, Chryssa; vanParadijs, Jan; Finger, Mark H.; Thompson, Christopher; Duncan, Robert C.; Hurley, Kevin; Swank, Jean; Murakami, Toshio

    1999-01-01

    We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observation of the pulsed emission from SGR 1900+14 during September 1996, June-October 1998, and early 1999. Using these measurements and results reported elsewhere. we construct a period history of this source for 2.5 years. We find significant deviations from a steady spin-down trend during quiescence and the burst active interval. Burst And Transient Source Experiment (BATSE) observations of the burst emission are presented and correlations between the burst activity and spin-down rate of SGR 1900 + 14 are discussed. We find an 80 day interval during the summer of 1998 when the average spin-down rate is larger than the rate elsewhere by a factor of about 2.3. This enhanced spin-down may, be the result of a discontinuous spin-down event or "braking glitch" at the time of the giant flare on 27 August 1998. Furthermore find a large discrepancy between the pulsar period and average spin-down rate in X-rays as compared to radio observation for December 1998 and January 1999.

  8. Variable Spin-Down in the Soft Gamma Repeater SGR 1900+14 and Correlations with Burst Activity

    NASA Technical Reports Server (NTRS)

    Woods, Peter M.; Kouveliotou, Chryssa; VanParadijs, Jan; Finger, Mark H.; Thompson, Christopher; Duncan, Robert C.; Hurley, Kevin; Strohmayer, Tod; Swank, Jean; Murakami, Toshio

    1999-01-01

    We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observations of the pulsed emission from SGR 1900+ 14 during 1996 September, 1998 June-October, and early 1999. Using these measurements and results reported elsewhere, we construct a period history of this source for 2.5 yr. We find significant deviations from a steady spin-down trend during quiescence and the burst active interval. Burst and Transient Source Experiment observations of the burst emission are presented and correlations between the burst activity and spin-down rate of SGR 1900+14 are discussed. We find an 80 day interval during the summer of 1998 when the average spin-down rate is larger than the rate elsewhere by a factor approximately 2.3. This enhanced spin-down may be the result of a discontinuous spin-down event or "braking glitch" at the time of the giant flare on 1998 August 27. Furthermore, we find a large discrepancy between the pulsar period and average spin-down rate in X-rays as compared to radio observations for 1998 December and 1999 January.

  9. Variable Spin-Down in the Soft Gamma Repeater SGR 1900+14 and Correlations with Burst Activity

    NASA Technical Reports Server (NTRS)

    Woods, Peter M.; Kouveliotou, Chryssa; vanParadijs, Jan; Finger, Mark H.; Thompson, Christopher; Duncan, Robert C.; Hurley, Kevin; Swank, Jean; Murakami, Toshio

    1999-01-01

    We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observation of the pulsed emission from SGR 1900+14 during September 1996, June-October 1998, and early 1999. Using these measurements and results reported elsewhere. we construct a period history of this source for 2.5 years. We find significant deviations from a steady spin-down trend during quiescence and the burst active interval. Burst And Transient Source Experiment (BATSE) observations of the burst emission are presented and correlations between the burst activity and spin-down rate of SGR 1900 + 14 are discussed. We find an 80 day interval during the summer of 1998 when the average spin-down rate is larger than the rate elsewhere by a factor of about 2.3. This enhanced spin-down may, be the result of a discontinuous spin-down event or "braking glitch" at the time of the giant flare on 27 August 1998. Furthermore find a large discrepancy between the pulsar period and average spin-down rate in X-rays as compared to radio observation for December 1998 and January 1999.

  10. Variable Spin-Down in the Soft Gamma Repeater SGR 1900+14 and Correlations with Burst Activity

    NASA Technical Reports Server (NTRS)

    Woods, Peter M.; Kouveliotou, Chryssa; VanParadijs, Jan; Finger, Mark H.; Thompson, Christopher; Duncan, Robert C.; Hurley, Kevin; Strohmayer, Tod; Swank, Jean; Murakami, Toshio

    1999-01-01

    We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observations of the pulsed emission from SGR 1900+ 14 during 1996 September, 1998 June-October, and early 1999. Using these measurements and results reported elsewhere, we construct a period history of this source for 2.5 yr. We find significant deviations from a steady spin-down trend during quiescence and the burst active interval. Burst and Transient Source Experiment observations of the burst emission are presented and correlations between the burst activity and spin-down rate of SGR 1900+14 are discussed. We find an 80 day interval during the summer of 1998 when the average spin-down rate is larger than the rate elsewhere by a factor approximately 2.3. This enhanced spin-down may be the result of a discontinuous spin-down event or "braking glitch" at the time of the giant flare on 1998 August 27. Furthermore, we find a large discrepancy between the pulsar period and average spin-down rate in X-rays as compared to radio observations for 1998 December and 1999 January.

  11. Interfacial mass transfer to a cylinder endwall during spin-up/spin-down

    NASA Technical Reports Server (NTRS)

    Larrousse, Mark F.; Wilcox, William R.

    1990-01-01

    The local rate of mass transfer to the bottom endwall of a large aspect ratio cylinder was measured during spin-up/spin-down. The local mass transfer rate was a strong function radial position along the endwall. At the center during spin-up from rest, the maximum enhancement in mass transfer occurred after the Ekman time scale and before the viscous time scale. At the center during spin-down to rest, a stagnation vortex formed, causing the mass transfer rate to decay and then increase back to the original value of the order of the viscous time scale. Away from the center a much more complicated pattern was observed, but spin-up and spin-down were similar. Two peaks in mass transfer rate occurred for an Ekman number over 0.0074. Alternating spin-up and spin-down with a short period caused the center of the endwall to experience a nearly sinusoidal variation in mass transfer with the frequency equal to the forcing frequency. Near the edge the frequency was twice the forcing frequency.

  12. Studying stellar spin-down with Zeeman-Doppler magnetograms

    NASA Astrophysics Data System (ADS)

    See, V.; Jardine, M.; Vidotto, A. A.; Donati, J.-F.; Boro Saikia, S.; Fares, R.; Folsom, C. P.; Hébrard, É. M.; Jeffers, S. V.; Marsden, S. C.; Morin, J.; Petit, P.; Waite, I. A.; BCool Collaboration

    2017-04-01

    Magnetic activity and rotation are known to be intimately linked for low-mass stars. Understanding rotation evolution over the stellar lifetime is therefore an important goal within stellar astrophysics. In recent years, there has been increased focus on how the complexity of the stellar magnetic field affects the rate of angular-momentum loss from a star. This is a topic that Zeeman-Doppler imaging (ZDI), a technique that is capable of reconstructing the large-scale magnetic field topology of a star, can uniquely address. Using a potential field source surface model, we estimate the open flux, mass-loss rate and angular-momentum-loss rates for a sample of 66 stars that have been mapped with ZDI. We show that the open flux of a star is predominantly determined by the dipolar component of its magnetic field for our choice of source surface radius. We also show that, on the main sequence, the open flux, mass-loss and angular-momentum-loss rates increase with decreasing Rossby number. The exception to this rule is stars less massive than 0.3 M⊙. Previous work suggests that low-mass M dwarfs may possess either strong, ordered and dipolar fields or weak and complex fields. This range of field strengths results in a large spread of angular-momentum-loss rates for these stars and has important consequences for their spin-down behaviour. Additionally, our models do not predict a transition in the mass-loss rates at the so-called wind-dividing line noted from Lyα studies.

  13. On the Dramatic Spin-up/Spin-Down Torque Reversals in Accreting Pulsars

    NASA Technical Reports Server (NTRS)

    Nelson, Robert W.; Bildsten, Lars; Chakrabarty, Deepto; Finger, Mark H.; Koh, Danny T.; Prince, Thomas A.; Rubin, Bradley C.; Scott, D. Mathew; Vaughan, Brian A.; Wilson, Robert B.

    1997-01-01

    Dramatic torque reversals between spin-up and spin-down have been observed in half of the persistent X-ray pulsars monitored by the Burst and Transient Space Experiment (BATSE) all-sky monitor on the Compton Gamma Ray Observatory. Theoretical models developed to explain early pulsar timing data can explain spin-down torques via a disk-magnetosphere interaction if the star nearly corotates with the inner accretion disk. To produce the observed BATSE torque reversals, however, these equilibrium models require the disk to alternate between two mass accretion rates, with M+/- producing accretion torques of similar magnitude but always of opposite sign. Moreover, in at least one pulsar (GX 1+4) undergoing secular spin-down, the neutron star spins down faster during brief (approximately 20 day) hard X-ray flares-this is opposite the correlation expected from standard theory, assuming that BATSE pulsed flux increases with mass accretion rate. The 10 day to 10 yr intervals between torque reversals in these systems are much longer than any characteristic magnetic or viscous timescale near the inner disk boundary and are more suggestive of a global disk phenomenon. We discuss possible explanations of the observed torque behavior. Despite the preferred sense of rotation defined by the binary orbit, the BATSE observations are surprisingly consistent with an earlier suggestion for GX 1+4: the disks in these systems somehow alternate between episodes of prograde and retrograde rotation. We are unaware of any mechanism that could produce a stable retrograde disk in a binary undergoing Roche lobe overflow, but such flip-flop behavior does occur in numerical simulations of wind-fed systems. One possibility is that the disks in some of these binaries are fed by an X-ray-excited wind.

  14. Gravitational wave emission and spin-down of young pulsars

    SciTech Connect

    Alford, Mark G.; Schwenzer, Kai

    2014-01-20

    The rotation frequencies of young pulsars are systematically below their theoretical Kepler limit. r-modes have been suggested as a possible explanation for this observation. With the help of semi-analytic expressions that make it possible to assess the uncertainties of the r-mode scenario due to the impact of uncertainties in underlying microphysics, we perform a quantitative analysis of the spin-down and the emitted gravitational waves of young pulsars. We find that the frequency to which r-modes spin-down a young neutron star (NS) is surprisingly insensitive to both the microscopic details and the saturation amplitude. Comparing our result to astrophysical data, we show that for a range of sufficiently large saturation amplitudes r-modes provide a viable spin-down scenario and that all observed young pulsars are very likely already outside the r-mode instability region. Therefore, the most promising sources for gravitational wave detection are unobserved NSs associated with recent supernovae, and we find that advanced LIGO should be able to see several of them. Our analysis shows that despite the coupling of the spin-down and thermal evolution, a power-law spin-down with an effective braking index n {sub rm} ≤ 7 is realized. Because of this, the gravitational wave strain amplitude is completely independent of both the r-mode saturation amplitude and the microphysics and depends on the saturation mechanism only within some tens of percent. However, the gravitational wave frequency depends on the amplitude, and we provide the required expected timing parameter ranges to look for promising sources in future searches.

  15. Orbital Decay of a Binary System Consisting of Spin-Down Neutron Stars

    NASA Astrophysics Data System (ADS)

    Cheng, K. S.; Harko, T.; Yuan, Y. F.; Tang, P. S.

    2004-12-01

    {W}e consider the gravitational radiation from two time variable mass stars, orbiting around each other under the influence of gravity. The total rates of the variation of the energy, angular momentum, semimajor axis, eccentricity and orbital period are obtained. The results could be important for the understanding of general relativistic effects in the case of the variation of the gravitational mass due to spinning down of the compact stars, which sensitively depends on the equations of state. The cases of the binary systems PSR 1913+16 and PSR 1534+12 are analyzed in detail, and, for different equations of state of nuclear matter, the corrections to the orbital decay due to gravitational radiation and to the spinning down of the pulsars are calculated. The results show that a future significant improvement in the observational techniques could lead to the observation of the specific general relativistic effect of mass variation of pulsars due to spinning down, via the study of orbital decay, even in slowly rotating binary systems.

  16. The Long-term Post-outburst Spin Down and Flux Relaxation of Magnetar Swift J1822.3-1606

    NASA Astrophysics Data System (ADS)

    Scholz, P.; Kaspi, V. M.; Cumming, A.

    2014-05-01

    The magnetar Swift J1822.3-1606 entered an outburst phase in 2011 July. Previous X-ray studies of its post-outburst rotational evolution yielded inconsistent measurements of the spin-inferred magnetic field. Here we present the timing behavior and flux relaxation from over two years of Swift, RXTE, and Chandra observations following the outburst. We find that the ambiguity in previous timing solutions was due to enhanced spin down that resembles an exponential recovery following a glitch at the outburst onset. After fitting out the effects of the recovery, we measure a long-term spin-down rate of \\dot{\

  17. Beating the Spin-down Limit on Gravitational Wave Emission from the Vela Pulsar

    NASA Astrophysics Data System (ADS)

    Abadie, J.; Abbott, B. P.; Abbott, R.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Antonucci, F.; Arai, K.; Arain, M. A.; Araya, M. C.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballardin, G.; Ballmer, S.; Barker, D.; Barnum, S.; Barone, F.; Barr, B.; Barriga, P.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Basti, A.; Bauchrowitz, J.; Bauer, Th. S.; Behnke, B.; Bejger, M.; Beker, M. G.; Bell, A. S.; Belletoile, A.; Belopolski, I.; Benacquista, M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birindelli, S.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Boyle, M.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Breyer, J.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brummit, A.; Budzyński, R.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet-Castell, J.; Burmeister, O.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cain, J.; Calloni, E.; Camp, J. B.; Campagna, E.; Campsie, P.; Cannizzo, J.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chaibi, O.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chassande-Mottin, E.; Chelkowski, S.; Chen, Y.; Chincarini, A.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Chung, S.; Clara, F.; Clark, D.; Clark, J.; Clayton, J. H.; Cleva, F.; Coccia, E.; Colacino, C. N.; Colas, J.; Colla, A.; Colombini, M.; Conte, R.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Coulon, J.-P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Culter, R. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; D'Antonio, S.; Danzmann, K.; Das, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Davies, G.; Daw, E. J.; Day, R.; Dayanga, T.; De Rosa, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; del Prete, M.; Dent, T.; Dergachev, V.; DeRosa, R.; DeSalvo, R.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Emilio, M. Di Paolo; Di Virgilio, A.; Díaz, M.; Dietz, A.; Donovan, F.; Dooley, K. L.; Dorsher, S.; Douglas, E. S. D.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Engel, R.; Etzel, T.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Flaminio, R.; Flanigan, M.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Galimberti, M.; Gammaitoni, L.; Garcia, J.; Garofoli, J. A.; Garufi, F.; Gáspár, M. E.; Gemme, G.; Genin, E.; Gennai, A.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Greverie, C.; Grosso, R.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Hayler, T.; Heefner, J.; Heitmann, H.; Hello, P.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Hong, T.; Hooper, S.; Hosken, D. J.; Hough, J.; Howell, E. J.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Jaranowski, P.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kanner, J. B.; Katsavounidis, E.; Katzman, W.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Kelner, M.; Keppel, D. G.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, H.; Kim, N.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Korth, W. Z.; Kowalska, I.; Kozak, D.; Kringel, V.; Krishnamurthy, S.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, R.; Kwee, P.; Landry, M.; Lantz, B.; Lastzka, N.; Lazzarini, A.; Leaci, P.; Leong, J.; Leonor, I.; Leroy, N.; Letendre, N.; Li, J.; Li, T. G. F.; Liguori, N.; Lindquist, P. E.; Lockerbie, N. A.; Lodhia, D.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lu, P.; Luan, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; Macdonald, E.; Machenschalk, B.; MacInnis, M.; Mageswaran, M.; Mailand, K.; Majorana, E.; Maksimovic, I.; Man, N.; Mandel, I.; Mandic, V.; Mantovani, M.; Marandi, A.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Masserot, A.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McKechan, D. J. A.; Meadors, G.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Mercer, R. A.; Merill, L.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Michel, C.; Milano, L.; Miller, J.; Minenkov, Y.; Mino, Y.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Moesta, P.; Mohan, M.; Mohanty, S. D.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Morgado, N.; Morgia, A.; Mosca, S.; Moscatelli, V.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murray, P. G.; Nash, T.; Nawrodt, R.; Nelson, J.; Neri, I.; Newton, G.; Nishida, E.; Nishizawa, A.; Nocera, F.; Nolting, D.; Ochsner, E.; O'Dell, J.; Ogin, G. H.; Oldenburg, R. G.; O'Reilly, B.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Pagliaroli, G.; Palladino, L.; Palomba, C.; Pan, Y.; Pankow, C.; Paoletti, F.; Papa, M. A.; Parameswaran, A.; Pardi, S.; Parisi, M.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patel, P.; Pathak, D.; Pedraza, M.; Pekowsky, L.; Penn, S.; Peralta, C.; Perreca, A.; Persichetti, G.; Phelps, M.; Pichot, M.; Pickenpack, M.; Piergiovanni, F.; Pietka, M.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Podkaminer, J.; Poggiani, R.; Pöld, J.; Postiglione, F.; Prato, M.; Predoi, V.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Quetschke, V.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Ramet, C. R.; Rankins, B.; Rapagnani, P.; Raymond, V.; Re, V.; Redwine, K.; Reed, C. M.; Reed, T.; Regimbau, T.; Reid, S.; Reitze, D. H.; Ricci, F.; Riesen, R.; Riles, K.; Roberts, P.; Robertson, N. A.; Robinet, F.; Robinson, C.; Robinson, E. L.; Rocchi, A.; Roddy, S.; Rolland, L.; Rollins, J.; Romano, J. D.; Romano, R.; Romie, J. H.; Rosińska, D.; Röver, C.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sakata, S.; Sakosky, M.; Salemi, F.; Salit, M.; Sammut, L.; Sancho de la Jordana, L.; Sandberg, V.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Saraf, S.; Sassolas, B.; Sathyaprakash, B. S.; Sato, S.; Satterthwaite, M.; Saulson, P. R.; Savage, R.; Schilling, R.; Schlamminger, S.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sergeev, A.; Shaddock, D. A.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Shihan Weerathunga, T.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Smith, R.; Somiya, K.; Sorazu, B.; Soto, J.; Speirits, F. C.; Sperandio, L.; Stefszky, M.; Stein, A. J.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A. S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Szokoly, G. P.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Toncelli, A.; Tonelli, M.; Torre, O.; Torres, C.; Torrie, C. I.; Tournefier, E.; Travasso, F.; Traylor, G.; Trias, M.; Tseng, K.; Turner, L.; Ugolini, D.; Urbanek, K.; Vahlbruch, H.; Vaishnav, B.; Vajente, G.; Vallisneri, M.; van den Brand, J. F. J.; Van Den Broeck, C.; van der Putten, S.; van der Sluys, M. V.; van Veggel, A. A.; Vass, S.; Vasuth, M.; Vaulin, R.; Vavoulidis, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Veltkamp, C.; Verkindt, D.; Vetrano, F.; Viceré, A.; Villar, A. E.; Vinet, J.-Y.; Vocca, H.; Vorvick, C.; Vyachanin, S. P.; Waldman, S. J.; Wallace, L.; Wanner, A.; Ward, R. L.; Was, M.; Wei, P.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, H.; Yamamoto, K.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yu, P.; Yvert, M.; Zanolin, M.; Zhang, L.; Zhang, Z.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration; Buchner, S.; Hotan, A.; Palfreyman, J.

    2011-08-01

    We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector's second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star's spin axis and value of the wave polarization angle of, respectively, 1.9 × 10-24 and 2.2 × 10-24, with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of 2.1 × 10-24, with 95% degree of belief. These limits are below the indirect spin-down limit of 3.3 × 10-24 for the Vela pulsar, defined by the energy loss rate inferred from observed decrease in Vela's spin frequency, and correspond to a limit on the star ellipticity of ~10-3. Slightly less stringent results, but still well below the spin-down limit, are obtained assuming the star's spin axis inclination and the wave polarization angles are unknown.

  18. A Magnetar Wind Nebula: the Spin-down-Powered Wind is not Enough

    NASA Astrophysics Data System (ADS)

    Gill, Ramandeep; Granot, Jonathan; Baring, Matthew G.; Gelfand, Joseph; Younes, George A.; Kargaltsev, Oleg; Kust Harding, Alice; Kouveliotou, Chryssa; Huppenkothen, Daniela

    2016-04-01

    Magnetars are a small class of slowly-rotating (P~2-12 s) highly magnetized (surface dipole fields ~10^{14}-10^{15} G) that show a variety of bursting activity, powered by the decay of their super-strong magnetic field. While many rotation-powered pulsars are surrounded by a pulsar wind nebula (PWN) powered by their spin-down MHD wind (the prime example being the Crab nebula), only now has the first magnetar wind nebula (MWN) been discovered in X-rays, around Swift J1834.9-0846. We have analyzed this system in detail to see what can be learned from it. We find good evidence that unlike normal PWNe, this MWN cannot be powered by its spin-down MHD wind alone. A considerable contribution to the MWN energy should come from a different source, most likely sporadic outflows associated with the magnetar's bursting activity. This suggests that the MWN may serve as a calorimeter, and provide a new and robust estimate for the magnetar's long-term mean energy output rate in outflows. We also discuss other interesting aspects of this system.

  19. Sporadic mass loss, spin-down, and element redistribution in young disk galaxies

    NASA Astrophysics Data System (ADS)

    Charlton, Jane C.; Salpeter, Edwin E.

    1989-11-01

    Violent conditions in young spiral disks may be conducive to the high-velocity ejection of large 'blobs' of material powered by the concerted action of supernovae. Using explicit numerical Monte Carlo models, treating ejected 'bobs' as 'galactic cannonballs' traveling with little interaction through the corona, several important consequences for galactic evolution are found. Preferential escape from the galaxy or objects with high specific angular momenta lead to a significant spin-down of the disk. In addition, this process may contribute to the production of an exponential column density distribution, and a metallicity gradient. The models predict a reversal in the sign of the metallicity gradient at large radii because the metal-rich objects that return to such a low column density region suffer relatively little dilution.

  20. Torque Reversal and Spin-Down of the Accretion-Powered Pulsar 4U 1626-67

    NASA Technical Reports Server (NTRS)

    Chakrabarty, Deepto L.; Bildsten, L.; Grunsfeld, J. M.; Koh, D. T.; Prince, T. A.; Vaughan, B. A.; Finger, M. H.; Scott, D. M.; Wilson, R. B.

    1997-01-01

    Over 5 yr of hard X-ray (20-60 keV) monitoring of the 7.66 s accretion-powered pulsar 4U 1626-67 with the Compton Gamma Ray Observatory/BATSE large-area detectors has revealed that the neutron star is now steadily spinning down, in marked contrast to the steady spin-up and spin-down torques differ by only 15% with the neutron star spin changing on a timescale |v/v| approximately equals 5000 yr in both states. The current spin-down rate is itself decreasing on a timescale |v/v| approximately equals 26 yr. The long-term timing history shows small-amplitude variations on a 4000 day timescale, which are probably due to variations in the mass transfer rate. The pulsed 20-60 keV emission from 4U 1626-67 is well-fitted by a power-law spectrum with photon index gamma = 4.9 and a typical pulsed intensity of 1.5 x 10(exp -10) ergs cm (exp -2)s(exp -1). The low count rates with BATSE prohibited us from constraining the reported 42 minute binary orbit, but we can rule out long-period orbits in the range 2 days < or = P(orb) < or = 900 days. We compare the long-term torque behavior of 4U 1626-67 to other disk-fed accreting pulsars and discuss the implications of our results for the various theories of magnetic accretion torques. The abrupt change in the sign of the torque is difficult to reconcile with the extremely smooth spin-down now observed. The strength of the torque noise in 4U 1626-67, approximately 10(exp -22) Hz(exp 2)s(exp -2) Hz(exp -1), is the smallest ever measured for an accreting X-ray pulsar, and it is comparable to the timing noise seen in young radio pulsars. We close by pointing out that the core temperature and external torque (the two parameters potentially relevant to internal sources of timing noise) of an accreting neutron star are also comparable to those of young radio pulsars.

  1. Torque Reversal and Spin-Down of the Accretion-Powered Pulsar 4U 1626-67

    NASA Technical Reports Server (NTRS)

    Chakrabarty, Deepto L.; Bildsten, L.; Grunsfeld, J. M.; Koh, D. T.; Prince, T. A.; Vaughan, B. A.; Finger, M. H.; Scott, D. M.; Wilson, R. B.

    1997-01-01

    Over 5 yr of hard X-ray (20-60 keV) monitoring of the 7.66 s accretion-powered pulsar 4U 1626-67 with the Compton Gamma Ray Observatory/BATSE large-area detectors has revealed that the neutron star is now steadily spinning down, in marked contrast to the steady spin-up and spin-down torques differ by only 15% with the neutron star spin changing on a timescale |v/v| approximately equals 5000 yr in both states. The current spin-down rate is itself decreasing on a timescale |v/v| approximately equals 26 yr. The long-term timing history shows small-amplitude variations on a 4000 day timescale, which are probably due to variations in the mass transfer rate. The pulsed 20-60 keV emission from 4U 1626-67 is well-fitted by a power-law spectrum with photon index gamma = 4.9 and a typical pulsed intensity of 1.5 x 10(exp -10) ergs cm (exp -2)s(exp -1). The low count rates with BATSE prohibited us from constraining the reported 42 minute binary orbit, but we can rule out long-period orbits in the range 2 days < or = P(orb) < or = 900 days. We compare the long-term torque behavior of 4U 1626-67 to other disk-fed accreting pulsars and discuss the implications of our results for the various theories of magnetic accretion torques. The abrupt change in the sign of the torque is difficult to reconcile with the extremely smooth spin-down now observed. The strength of the torque noise in 4U 1626-67, approximately 10(exp -22) Hz(exp 2)s(exp -2) Hz(exp -1), is the smallest ever measured for an accreting X-ray pulsar, and it is comparable to the timing noise seen in young radio pulsars. We close by pointing out that the core temperature and external torque (the two parameters potentially relevant to internal sources of timing noise) of an accreting neutron star are also comparable to those of young radio pulsars.

  2. Comparing models of the periodic variations in spin-down and beamwidth for PSR B1828-11

    NASA Astrophysics Data System (ADS)

    Ashton, G.; Jones, D. I.; Prix, R.

    2016-05-01

    We build a framework using tools from Bayesian data analysis to evaluate models explaining the periodic variations in spin-down and beamwidth of PSR B1828-11. The available data consist of the time-averaged spin-down rate, which displays a distinctive double-peaked modulation, and measurements of the beamwidth. Two concepts exist in the literature that are capable of explaining these variations; we formulate predictive models from these and quantitatively compare them. The first concept is phenomenological and stipulates that the magnetosphere undergoes periodic switching between two metastable states as first suggested by Lyne et al. The second concept, precession, was first considered as a candidate for the modulation of B1828-11 by Stairs et al. We quantitatively compare models built from these concepts using a Bayesian odds ratio. Because the phenomenological switching model itself was informed by these data in the first place, it is difficult to specify appropriate parameter-space priors that can be trusted for an unbiased model comparison. Therefore, we first perform a parameter estimation using the spin-down data, and then use the resulting posterior distributions as priors for model comparison on the beamwidth data. We find that a precession model with a simple circular Gaussian beam geometry fails to appropriately describe the data, while allowing for a more general beam geometry provides a good fit to the data. The resulting odds between the precession model (with a general beam geometry) and the switching model are estimated as 102.7±0.5 in favour of the precession model.

  3. Open clusters as laboratories for stellar spin-down and magnetic activity decay

    NASA Astrophysics Data System (ADS)

    Douglas, Stephanie; Agueros, Marcel A.; Covey, Kevin R.

    2017-01-01

    The oldest open clusters within 250 pc of the Sun, the Hyades and Praesepe, are important benchmarks for calibrating stellar properties such as rotation and magnetic activity. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ~600 Myr. The repurposed Kepler mission, K2, has allowed us to measure rotation periods for dozens of Hyads and hundreds of Praesepe members, including the first periods measured for fully convective Hyads. These data have enabled new tests of models describing the evolution of stellar rotation; discrepancies with these models imply that we still do not fully understand how magnetic fields affect stellar spin-down. I will present rotation periods measured for 48 Hyads and 699 Praesepe members with K2, along with associated Halpha and X-ray fluxes. I will also show how we can compare the dependence of H-alpha and X-ray emission on rotation in order to test theories of magnetic field topology and stellar dynamos. These tests inform models of stellar wind-driven angular momentum loss and the age-rotation-activity relation.

  4. CONSTRAINING THE SPIN-DOWN TIMESCALE OF THE WHITE DWARF PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect

    Meng, Xiangcun; Podsiadlowski, Philipp

    2013-12-01

    Justham and Di Stefano et al. proposed that the white dwarf progenitor of a Type Ia supernova (SN Ia) may have to spin down before it can explode. As the white dwarf spin-down timescale is not well known theoretically, here we try to constrain it empirically (within the framework of this spin-down model) for progenitor systems that contain a giant donor and for which circumbinary material has been detected after the explosion: we obtain an upper limit of a few 10{sup 7}yr. Based on the study of Di Stefano and Kilic, this means that it is too early to rule out the existence of a surviving companion in SNR 0509–67.5.

  5. THE SPIN-DOWN OF SWIFT J1822.3-1606: A NEW GALACTIC MAGNETAR

    SciTech Connect

    Livingstone, M. A.; Scholz, P.; Kaspi, V. M.; Ng, C.-Y.; Gavriil, Fotis P.

    2011-12-20

    On 2011 July 14, a new magnetar candidate, Swift J1822.3-1606, was identified via a rate trigger on the Swift/Burst Alert Telescope. Here we present an initial analysis of the X-ray properties of the source, using data from the Rossi X-ray Timing Explorer, Swift, and the Chandra X-ray Observatory, spanning 2011 July 16-October 8. We measure a precise spin period of P = 8.43771968(6) s and a spin-down rate of P-dot =2.54(22) Multiplication-Sign 10{sup -13}, at MJD 55761.0, corresponding to an inferred surface dipole magnetic field of B = 4.7(2) Multiplication-Sign 10{sup 13} G, the second lowest thus far measured for a magnetar, though similar to those of 1E 2259+586 and several high-magnetic field radio pulsars. We show that the flux decay in the 1-10 keV band is best fit by a double exponential with timescales of 9 {+-} 1 and 55 {+-} 9 days. The pulsed count rate decay in the 2-10 keV band, by contrast, is better fit by a single exponential decay with timescale 15.9 {+-} 0.2 days. After increasing from {approx}35% for {approx}20 days after the onset of the outburst, the pulsed fraction in the 2-10 keV band remained constant at {approx}45%. We argue that these properties confirm this source to be a new member of the class of objects known as magnetars. We consider the distribution of magnetar periods and inferred dipole magnetic field strengths, showing that the former appears flat in the 2-12 s range, while the latter appears peaked in the 10{sup 14}-10{sup 15} G range.

  6. The Spin-down of Swift J1822.3-1606: A New Galactic Magnetar

    NASA Astrophysics Data System (ADS)

    Livingstone, M. A.; Scholz, P.; Kaspi, V. M.; Ng, C.-Y.; Gavriil, Fotis P.

    2011-12-01

    On 2011 July 14, a new magnetar candidate, Swift J1822.3-1606, was identified via a rate trigger on the Swift/Burst Alert Telescope. Here we present an initial analysis of the X-ray properties of the source, using data from the Rossi X-ray Timing Explorer, Swift, and the Chandra X-ray Observatory, spanning 2011 July 16-October 8. We measure a precise spin period of P = 8.43771968(6) s and a spin-down rate of \\dot{P}=2.54(22)\\times 10^{-13}, at MJD 55761.0, corresponding to an inferred surface dipole magnetic field of B = 4.7(2) × 1013 G, the second lowest thus far measured for a magnetar, though similar to those of 1E 2259+586 and several high-magnetic field radio pulsars. We show that the flux decay in the 1-10 keV band is best fit by a double exponential with timescales of 9 ± 1 and 55 ± 9 days. The pulsed count rate decay in the 2-10 keV band, by contrast, is better fit by a single exponential decay with timescale 15.9 ± 0.2 days. After increasing from ~35% for ~20 days after the onset of the outburst, the pulsed fraction in the 2-10 keV band remained constant at ~45%. We argue that these properties confirm this source to be a new member of the class of objects known as magnetars. We consider the distribution of magnetar periods and inferred dipole magnetic field strengths, showing that the former appears flat in the 2-12 s range, while the latter appears peaked in the 1014-1015 G range.

  7. GRAVITATIONAL-WAVE SPIN-DOWN AND STALLING LOWER LIMITS ON THE ELECTRICAL RESISTIVITY OF THE ACCRETED MOUNTAIN IN A MILLISECOND PULSAR

    SciTech Connect

    Vigelius, M.; Melatos, A.

    2010-07-01

    The electrical resistivity of the accreted mountain in a millisecond pulsar is limited by the observed spin-down rate of binary radio millisecond pulsars (BRMSPs) and the spins and X-ray fluxes of accreting millisecond pulsars (AMSPs). We find {eta}{>=}10{sup -28} s ({tau}{sub SD}/1 Gyr){sup -0.8} (where {tau}{sub SD} is the spin-down age) for BRMSPs and {eta}{>=}10{sup -25} s ( M-dot{sub a}/ M-dot{sub E}){sup 0.6} (where M-dot{sub a} and M-dot{sub E} are the actual and Eddington accretion rates) for AMSPs. These limits are inferred assuming that the mountain attains a steady state, where matter diffuses resistively across magnetic flux surfaces but is replenished at an equal rate by infalling material. The mountain then relaxes further resistively after accretion ceases. The BRMSP spin-down limit approaches the theoretical electron-impurity resistivity at temperatures {approx_gt}10{sup 5} K for an impurity concentration of {approx}0.1, while the AMSP stalling limit falls 2 orders of magnitude below the theoretical electron-phonon resistivity for temperatures above 10{sup 8} K. Hence, BRMSP observations are already challenging theoretical resistivity calculations in a useful way. Next-generation gravitational-wave interferometers will constrain {eta} at a level that will be competitive with electromagnetic observations.

  8. (S)Pinning down protein interactions by NMR

    PubMed Central

    Kunze, Micha Ben Achim; Erlendsson, Simon

    2017-01-01

    Abstract Protein molecules are highly diverse communication platforms and their interaction repertoire stretches from atoms over small molecules such as sugars and lipids to macromolecules. An important route to understanding molecular communication is to quantitatively describe their interactions. These types of analyses determine the amounts and proportions of individual constituents that participate in a reaction as well as their rates of reactions and their thermodynamics. Although many different methods are available, there is currently no single method able to quantitatively capture and describe all types of protein reactions, which can span orders of magnitudes in affinities, reaction rates, and lifetimes of states. As the more versatile technique, solution NMR spectroscopy offers a remarkable catalogue of methods that can be successfully applied to the quantitative as well as qualitative descriptions of protein interactions. In this review we provide an easy‐access approach to NMR for the non‐NMR specialist and describe how and when solution state NMR spectroscopy is the method of choice for addressing protein ligand interaction. We describe very briefly the theoretical background and illustrate simple protein–ligand interactions as well as typical strategies for measuring binding constants using NMR spectroscopy. Finally, this review provides examples of caveats of the method as well as the options to improve the outcome of an NMR analysis of a protein interaction reaction. PMID:28019676

  9. Quark Deconfinement in Neutron Star Cores: The Effects of Spin-down

    NASA Astrophysics Data System (ADS)

    Staff, Jan E.; Ouyed, Rachid; Jaikumar, Prashanth

    2006-07-01

    We study the role of spin-down in driving quark deconfinement in the high-density cores of isolated neutron stars. Assuming spin-down to be solely due to magnetic braking, we obtain typical timescales to quark deconfinement for neutron stars that are born with Keplerian frequencies. Employing different equations of state (EOSs), we determine the minimum and maximum neutron star masses that will allow for deconfinement via spin-down only. We find that the time to reach deconfinement is strongly dependent on the magnetic field and that this time is least for EOSs that support the largest minimum mass at zero spin, unless rotational effects on stellar structure are large. For a fiducial critical density of 5ρ0 for the transition to the quark phase (ρ0=2.5×1014 g cm-3 is the saturation density of nuclear matter), we find that neutron stars lighter than 1.5 Msolar cannot reach a deconfined phase. Depending on the EOS, neutron stars of more than 1.5 Msolar can enter a quark phase only if they are spinning faster than about 3 ms as observed now, whereas larger spin periods imply either that they are already quark stars or that they will never become them.

  10. Angular momentum loss and stellar spin-down in magnetic massive stars

    NASA Astrophysics Data System (ADS)

    ud-Doula, Asif; Owocki, Stanley P.; Townsend, Richard H. D.

    2009-04-01

    We examine the angular momentum loss and associated rotational spin-down for magnetic hot stars with a line-driven stellar wind and a rotation-aligned dipole magnetic field. Our analysis here is based on our previous 2-D numerical MHD simulation study that examines the interplay among wind, field, and rotation as a function of two dimensionless parameters, W(=Vrot/Vorb) and ‘wind magnetic confinement’, η∗ defined below. We compare and contrast the 2-D, time variable angular momentum loss of this dipole model of a hot-star wind with the classical 1-D steady-state analysis by Weber and Davis (WD), who used an idealized monopole field to model the angular momentum loss in the solar wind. Despite the differences, we find that the total angular momentum loss averaged over both solid angle and time follows closely the general WD scaling ~ ṀΩR2A. The key distinction is that for a dipole field Alfvèn radius RA is significantly smaller than for the monopole field WD used in their analyses. This leads to a slower stellar spin-down for the dipole field with typical spin-down times of order 1 Myr for several known magnetic massive stars.

  11. CONSTRAINING THE SPIN-DOWN OF THE NEARBY ISOLATED NEUTRON STAR RX J0806.4-4123, AND IMPLICATIONS FOR THE POPULATION OF NEARBY NEUTRON STARS

    SciTech Connect

    Kaplan, D. L.; Van Kerkwijk, M. H. E-mail: mhvk@astro.utoronto.c

    2009-11-01

    The nearby isolated neutron stars (INSs) are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine fundamental neutron-star properties by modeling their spectra, and because they appear to be a large fraction of the overall neutron-star population. Here, we describe a series of XMM -Newton observations of the nearby INS RX J0806.4-4123, taken as part of larger program of timing studies. From these, we limit the spin-down rate to nu-dot=(-4.3+-2.3)x10{sub -16}Hz s{sup -1}. This constrains the dipole magnetic field to be <3.7 x 10{sup 13} G at 2sigma, significantly less than the field of approx10{sup 14} G implied by simple models for the X-ray absorption found at 0.45 keV. We confirm that the spectrum is thermal and stable (to within a few percent), but find that the 0.45 keV absorption feature is broader and more complex than previously thought. Considering the population of INSs, we find that magnetic field decay from an initial field of approx<3 x 10{sup 14} G accounts most naturally for their timing and spectral properties, both qualitatively and in the context of the models for field decay of Pons and collaborators.

  12. Spin Down of Pulsations in the Cooling Tail of an X-ray Burst from 4U 1636-53

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.

    1999-01-01

    We report the discovery with the proportional counter array (PCA) onboard the Rossi X-ray Timing Explorer (RXTE) of a decrease in the frequency of X-ray brightness oscillations in the cooling tail of an X-ray burst from 4U 1636-53. This is the first direct evidence for a spin down of the pulsations seen during thermonuclear bursts. We find that the spin down episode is correlated with the appearance in this burst of an extended tail of emission with a decay timescale much longer than is seen in other bursts from 4U 1636-53 in the same set of observations. We present both time resolved energy and variability spectra during this burst and compare them with results from a second burst which shows neither a spin down episode nor an extended tail. A spectral evolution study of the "spin down" burst reveals a secondary signature of weak radius expansion, not seen in other bursts, and correlated with the spin down episode, which may indicate a secondary thermonuclear energy release. We interpret the spin down episode in the context of an angular momentum conserving shell, which is reexpanded and therefore spun down by an additional thermonuclear energy release which could also explain the extended X-ray tail.

  13. Can magnetar spin-down power extended emission in some short GRBs?

    NASA Astrophysics Data System (ADS)

    Gompertz, B. P.; O'Brien, P. T.; Wynn, G. A.; Rowlinson, A.

    2013-05-01

    Extended emission gamma-ray bursts are a subset of the `short' class of burst which exhibit an early time rebrightening of gamma emission in their light curves. This extended emission arises just after the initial emission spike, and can persist for up to hundreds of seconds after trigger. When their light curves are overlaid, our sample of 14 extended emission bursts show a remarkable uniformity in their evolution, strongly suggesting a common central engine powering the emission. One potential central engine capable of this is a highly magnetized, rapidly rotating neutron star, known as a magnetar. Magnetars can be formed by two compact objects coalescing, a scenario which is one of the leading progenitor models for short bursts in general. Assuming that a magnetar is formed, we gain a value for the magnetic field and late-time spin period for nine of the extended emission bursts by fitting the magnetic dipole spin-down model of Zhang and Mészáros. Assuming that the magnetic field is constant, and the observed energy release during extended emission is entirely due to the spin-down of this magnetar, we then derive the spin period at birth for the sample. We find that all birth spin periods are in good agreement with those predicted for a newly born magnetar.

  14. The long-term post-outburst spin down and flux relaxation of magnetar swift J1822.3–1606

    SciTech Connect

    Scholz, P.; Kaspi, V. M.; Cumming, A.

    2014-05-01

    The magnetar Swift J1822.3–1606 entered an outburst phase in 2011 July. Previous X-ray studies of its post-outburst rotational evolution yielded inconsistent measurements of the spin-inferred magnetic field. Here we present the timing behavior and flux relaxation from over two years of Swift, RXTE, and Chandra observations following the outburst. We find that the ambiguity in previous timing solutions was due to enhanced spin down that resembles an exponential recovery following a glitch at the outburst onset. After fitting out the effects of the recovery, we measure a long-term spin-down rate of ν-dot =(−3.0 ± 0.3)×10{sup −16} s{sup –2} which implies a dipolar magnetic field of 1.35 × 10{sup 13} G, lower than all previous estimates for this source. We also consider the post-outburst flux evolution, and fit it with both empirical and crustal cooling models. We discuss the flux relaxation in the context of both crustal cooling and magnetospheric relaxation models.

  15. Spin-down of Pulsars, and Their Electromagnetic and Gravitational Wave Radiations

    NASA Astrophysics Data System (ADS)

    Yue-zhu, Zhang; Yan-yan, Fu; Yi-huan, Wei; Cheng-min, Zhang; Shao-hua, Yu; Yuan-yue, Pan; Yuan-qi, Guo; De-hua, Wang

    2016-04-01

    Pulsars posses extremely strong magnetic fields, and their magnetic axis does not coincide with their rotation axis, this causes the pulsars to emit electromagnetic radiations. Pulsars rely on their rotational energy to compensate for the energy loss caused by the electromagnetic radiation, which leads to the gradually decelerated spin of pulsars. According to the theoretical deduction, we have calculated the initial period of the Crab Nebula pulsar, and derived the period evolution of the pulsar at any time in the future under the effect of the electromagnetic radiation. Considered the possible existence of quadrupole moment in the mass distribution of a pulsar, the gravitational wave radiation will also make the pulsar spin down, hence the variation of spin period of the Crab pulsar under the effect of gravitational wave radiation is further analyzed. Finally, combining the two kinds of radiation mechanisms, the evolution of spin period of the Crab pulsar under the joint action of these two kinds of radiation mechanisms is analyzed.

  16. Beating the Spin-Down Limit on Gravitational Wave Emission from the Crab Pulsar

    NASA Astrophysics Data System (ADS)

    Abbott, B.; Abbott, R.; Adhikari, R.; Ajith, P.; Allen, B.; Allen, G.; Amin, R.; Anderson, S. B.; Anderson, W. G.; Arain, M. A.; Araya, M.; Armandula, H.; Armor, P.; Aso, Y.; Aston, S.; Aufmuth, P.; Aulbert, C.; Babak, S.; Ballmer, S.; Bantilan, H.; Barish, B. C.; Barker, C.; Barker, D.; Barr, B.; Barriga, P.; Barton, M. A.; Bastarrika, M.; Bayer, K.; Betzwieser, J.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Biswas, R.; Black, E.; Blackburn, K.; Blackburn, L.; Blair, D.; Bland, B.; Bodiya, T. P.; Bogue, L.; Bork, R.; Boschi, V.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Brinkmann, M.; Brooks, A.; Brown, D. A.; Brunet, G.; Bullington, A.; Buonanno, A.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Camp, J. B.; Cannizzo, J.; Cannon, K.; Cao, J.; Cardenas, L.; Casebolt, T.; Castaldi, G.; Cepeda, C.; Chalkley, E.; Charlton, P.; Chatterji, S.; Chelkowski, S.; Chen, Y.; Christensen, N.; Clark, D.; Clark, J.; Cokelaer, T.; Conte, R.; Cook, D.; Corbitt, T.; Coyne, D.; Creighton, J. D. E.; Cumming, A.; Cunningham, L.; Cutler, R. M.; Dalrymple, J.; Danzmann, K.; Davies, G.; DeBra, D.; Degallaix, J.; Degree, M.; Dergachev, V.; Desai, S.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Dickson, J.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doomes, E. E.; Drever, R. W. P.; Duke, I.; Dumas, J.-C.; Dupuis, R. J.; Dwyer, J. G.; Echols, C.; Effler, A.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, T.; Fairhurst, S.; Fan, Y.; Fazi, D.; Fehrmann, H.; Fejer, M. M.; Finn, L. S.; Flasch, K.; Fotopoulos, N.; Freise, A.; Frey, R.; Fricke, T.; Fritschel, P.; Frolov, V. V.; Fyffe, M.; Garofoli, J.; Gholami, I.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Goda, K.; Goetz, E.; Goggin, L.; González, G.; Gossler, S.; Gouaty, R.; Grant, A.; Gras, S.; Gray, C.; Gray, M.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grimaldi, F.; Grosso, R.; Grote, H.; Grunewald, S.; Guenther, M.; Gustafson, E. K.; Gustafson, R.; Hage, B.; Hallam, J. M.; Hammer, D.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G.; Harstad, E.; Hayama, K.; Hayler, T.; Heefner, J.; Heng, I. S.; Hennessy, M.; Heptonstall, A.; Hewitson, M.; Hild, S.; Hirose, E.; Hoak, D.; Hosken, D.; Hough, J.; Huttner, S. H.; Ingram, D.; Ito, M.; Ivanov, A.; Johnson, B.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamat, S.; Kanner, J.; Kasprzyk, D.; Katsavounidis, E.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Khalili, F. Ya.; Khan, R.; Khazanov, E.; Kim, C.; King, P.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R. K.; Kozak, D.; Kozhevatov, I.; Krishnan, B.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M. M.; Lantz, B.; Lazzarini, A.; Lei, M.; Leindecker, N.; Leonhardt, V.; Leonor, I.; Libbrecht, K.; Lin, H.; Lindquist, P.; Lockerbie, N. A.; Lodhia, D.; Lormand, M.; Lu, P.; Lubinski, M.; Lucianetti, A.; Lück, H.; Machenschalk, B.; MacInnis, M.; Mageswaran, M.; Mailand, K.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A.; Markowitz, J.; Maros, E.; Martin, I.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R.; Mavalvala, N.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McHugh, M.; McIntyre, G.; McIvor, G.; McKechan, D.; McKenzie, K.; Meier, T.; Melissinos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C. J.; Meyers, D.; Miller, J.; Minelli, J.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Mohanty, S.; Moreno, G.; Mossavi, K.; MowLowry, C.; Mueller, G.; Mukherjee, S.; Mukhopadhyay, H.; Müller-Ebhardt, H.; Munch, J.; Murray, P.; Myers, E.; Myers, J.; Nash, T.; Nelson, J.; Newton, G.; Nishizawa, A.; Numata, K.; O'Dell, J.; Ogin, G.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pan, Y.; Pankow, C.; Papa, M. A.; Parameshwaraiah, V.; Patel, P.; Pedraza, M.; Penn, S.; Perreca, A.; Petrie, T.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Postiglione, F.; Principe, M.; Prix, R.; Quetschke, V.; Raab, F.; Rabeling, D. S.; Radkins, H.; Rainer, N.; Rakhmanov, M.; Ramsunder, M.; Rehbein, H.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Rivera, B.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, A.; Rogan, A. M.; Rollins, J.; Romano, J. D.; Romie, J.; Route, R.; Rowan, S.; Rüdiger, A.; Ruet, L.; Russell, P.; Ryan, K.; Sakata, S.; Samidi, M.; Sancho de la Jordana, L.; Sandberg, V.; Sannibale, V.; Saraf, S.; Sarin, P.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R.; Savov, P.; Schediwy, S. W.; Schilling, R.; Schnabel, R.; Schofield, R.; Schutz, B. F.; Schwinberg, P.; Scott, S. M.; Searle, A. C.; Sears, B.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Sinha, S.; Sintes, A. M.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Somiya, K.; Sorazu, B.; Stein, L. C.; Stochino, A.; Stone, R.; Strain, K. A.; Strom, D. M.; Stuver, A.; Summerscales, T. Z.; Sun, K.-X.; Sung, M.; Sutton, P. J.; Takahashi, H.; Tanner, D. B.; Taylor, R.; Taylor, R.; Thacker, J.; Thorne, K. A.; Thorne, K. S.; Thüring, A.; Tokmakov, K. V.; Torres, C.; Torrie, C.; Traylor, G.; Trias, M.; Tyler, W.; Ugolini, D.; Ulmen, J.; Urbanek, K.; Vahlbruch, H.; Van Den Broeck, C.; van der Sluys, M.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, J.; Veitch, P.; Villar, A.; Vorvick, C.; Vyachanin, S. P.; Waldman, S. J.; Wallace, L.; Ward, H.; Ward, R.; Weinert, M.; Weinstein, A.; Weiss, R.; Wen, S.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Wilmut, I.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Wu, W.; Yakushin, I.; Yamamoto, H.; Yan, Z.; Yoshida, S.; Zanolin, M.; Zhang, J.; Zhang, L.; Zhao, C.; Zotov, N.; Zucker, M.; Zweizig, J.; LIGO Scientific Collaboration; Santostasi, G.

    2008-08-01

    We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret our results in the context of two possible gravitational wave emission mechanisms.

  17. Neutrino cooling and spin-down of rapidly rotating compact stars

    SciTech Connect

    Jaikumar, Prashanth; Sandalski, Stou

    2010-11-15

    The gravitational-wave instability of r modes in rapidly rotating compact stars is believed to spin them down to angular frequencies {Omega}{approx}0.1{Omega}{sub Kepler} soon after their birth in a supernova. We point out that the r-mode perturbation also impacts the neutrino cooling and viscosity in hot compact stars via processes that restore weak equilibrium. We illustrate this fact with a simple model of spin-down due to gravitational-wave emission in compact stars composed entirely of three-flavor degenerate quark matter (a strange quark star). Nonequilibrium neutrino cooling of this oscillating fluid matter is quantified. Our results imply that a consistent treatment of the thermal and spin-frequency evolution of a young and hot compact star is a requisite in estimating the persistence of gravitational waves from such a source.

  18. Dissipation, energy transfer, and spin-down luminosity in 2.5D PIC simulations of the pulsar magnetosphere

    NASA Astrophysics Data System (ADS)

    Belyaev, Mikhail A.

    2015-05-01

    We perform 2.5D axisymmetric simulations of the pulsar magnetosphere (aligned dipole rotator) using the charge conservative, relativistic, electromagnetic particle in cell code PICSAR. Particle in cell codes are a powerful tool to use for studying the pulsar magnetosphere, because they can handle the force-free and vacuum limits and provide a self-consistent treatment of magnetic reconnection. In the limit of dense plasma throughout the magnetosphere, our solutions are everywhere in the force-free regime except for dissipative regions at the polar caps, in the current layers, and at the Y-point. These dissipative regions arise self-consistently, since we do not have any explicit dissipation in the code. A minimum of ≈15-20 per cent of the electromagnetic spin-down luminosity is transferred to the particles inside 5 light cylinder radii. However, the particles can carry as much as ≳ 50 per cent of the spin-down luminosity if there is insufficient plasma in the outer magnetosphere to screen the component of electric field parallel to the magnetic field. In reality, the component of the spin-down luminosity carried by the particles could be radiated as gamma-rays, but high-frequency synchrotron emission would need to be implemented as a sub-grid process in our simulations and is not present for the current suite of runs. The value of the spin-down luminosity in our simulations is within ≈10 per cent of the force-free value, and the structure of the electromagnetic fields in the magnetosphere is on the whole consistent with the force-free model.

  19. Separated spin-up and spin-down quantum hydrodynamics of degenerated electrons: Spin-electron acoustic wave appearance.

    PubMed

    Andreev, Pavel A

    2015-03-01

    The quantum hydrodynamic (QHD) model of charged spin-1/2 particles contains physical quantities defined for all particles of a species including particles with spin-up and with spin-down. Different populations of states with different spin directions are included in the spin density (the magnetization). In this paper I derive a QHD model, which separately describes spin-up electrons and spin-down electrons. Hence electrons with different projections of spins on the preferable direction are considered as two different species of particles. It is shown that the numbers of particles with different spin directions do not conserve. Hence the continuity equations contain sources of particles. These sources are caused by the interactions of the spins with the magnetic field. Terms of similar nature arise in the Euler equation. The z projection of the spin density is no longer an independent variable. It is proportional to the difference between the concentrations of the electrons with spin-up and the electrons with spin-down. The propagation of waves in the magnetized plasmas of degenerate electrons is considered. Two regimes for the ion dynamics, the motionless ions and the motion of the degenerate ions as the single species with no account of the spin dynamics, are considered. It is shown that this form of the QHD equations gives all solutions obtained from the traditional form of QHD equations with no distinction of spin-up and spin-down states. But it also reveals a soundlike solution called the spin-electron acoustic wave. Coincidence of most solutions is expected since this derivation was started with the same basic equation: the Pauli equation. Solutions arise due to the different Fermi pressures for the spin-up electrons and the spin-down electrons in the magnetic field. The results are applied to degenerate electron gas of paramagnetic and ferromagnetic metals in the external magnetic field. The dispersion of the spin-electron acoustic waves in the partially spin

  20. Spinning down newborn neutron stars: Nonlinear development of the r-mode instability

    SciTech Connect

    Bondarescu, Ruxandra; Teukolsky, Saul A.; Wasserman, Ira

    2009-05-15

    We model the nonlinear saturation of the r-mode instability via three-mode couplings and the effects of the instability on the spin evolution of young neutron stars. We include one mode triplet consisting of the r-mode and two near-resonant inertial modes that couple to it. We find that the spectrum of evolutions is more diverse than previously thought. We start our evolutions with a star of temperature {approx}10{sup 10} K and a spin frequency close to the Kepler break-up frequency. We assume that hyperon bulk viscosity dominates at high temperatures (T{approx}10{sup 9}-10{sup 10} K) and boundary layer viscosity dominates at lower temperatures ({approx}a fewx10{sup 8} K). To explore possible nonlinear behavior, we vary properties of the star such as the hyperon superfluid transition temperature, the strength of the boundary layer viscosity, and the fraction of the star that cools via direct URCA reactions. The evolution of the star is dynamic and initially dominated by fast neutrino cooling. Nonlinear effects become important when the r-mode amplitude grows above its first parametric instability threshold. The balance between neutrino cooling and viscous heating plays an important role in the evolution. Depending on the initial r-mode amplitude, and on the strength of the viscosity and of the cooling this balance can occur at different temperatures. If thermal equilibrium occurs on the r-mode stability curve, where gravitational driving equals viscous damping, the evolution may be adequately described by a one-mode model. Otherwise, nonlinear effects are important and lead to various more complicated scenarios. Once thermal balance occurs, the star spins down oscillating between thermal equilibrium states until the instability is no longer active. The average evolution of the mode amplitudes can be approximated by quasistationary states that are determined algebraically. For lower viscosity we observe runaway behavior in which the r-mode amplitude passes several

  1. Oblique propagation of longitudinal waves in magnetized spin-1/2 plasmas: Independent evolution of spin-up and spin-down electrons

    SciTech Connect

    Andreev, Pavel A. Kuz’menkov, L.S.

    2015-10-15

    We consider quantum plasmas of electrons and motionless ions. We describe separate evolution of spin-up and spin-down electrons. We present corresponding set of quantum hydrodynamic equations. We assume that plasmas are placed in an uniform external magnetic field. We account different occupation of spin-up and spin-down quantum states in equilibrium degenerate plasmas. This effect is included via equations of state for pressure of each species of electrons. We study oblique propagation of longitudinal waves. We show that instead of two well-known waves (the Langmuir wave and the Trivelpiece–Gould wave), plasmas reveal four wave solutions. New solutions exist due to both the separate consideration of spin-up and spin-down electrons and different occupation of spin-up and spin-down quantum states in equilibrium state of degenerate plasmas.

  2. ON THE SPIN-DOWN AND MAGNETIC FIELD OF THE X-RAY PULSAR 1E 1207.4-5209

    SciTech Connect

    Halpern, J. P.; Gotthelf, E. V. E-mail: eric@astro.columbia.edu

    2011-06-01

    We analyze all of the archival X-ray timing data from the years 2000-2008 on the weakly magnetized central compact object (CCO) pulsar 1E 1207.4-5209 in an attempt to measure its dipole magnetic field strength via spin-down. because most of these observations were not planned for the purpose of phase-coherent timing, the resulting ephemeris is not unique, but is restricted to two comparably good timing solutions that correspond to B{sub s} = 9.9 x 10{sup 10} G or 2.4 x 10{sup 11} G, respectively, assuming dipole spin-down. One of these should be the correct value and the other one an alias. There are no spinning-up solutions. The smaller value of B{sub s} is close to the surface field of 8 x 10{sup 10} G that is measured independently from the unique absorption lines in the X-ray spectrum of 1E 1207.4-5209, assuming that the lowest-energy line at 0.7 keV is the electron-cyclotron fundamental. We suggest that 1E 1207.4-5209 has the strongest magnetic field among CCOs, which would account for the unique presence of its cyclotron absorption spectrum, while other CCOs likely have even weaker fields for which the cyclotron fundamental falls below the observable soft X-ray band.

  3. X-Ray Measurement of the Spin-down of Calvera: A Radio- and Gamma-Ray-Quiet Pulsar

    NASA Astrophysics Data System (ADS)

    Halpern, J. P.; Bogdanov, S.; Gotthelf, E. V.

    2013-12-01

    We measure spin-down of the 59 ms X-ray pulsar Calvera by comparing the XMM-Newton discovery data from 2009 with new Chandra timing observations taken in 2013. Its period derivative is \\dot{P}=(3.19+/- \\,0.08)\\times 10^{-15}, which corresponds to spin-down luminosity \\dot{E}=6.1\\times 10^{35} erg s-1, characteristic age \\tau _c\\equiv P/2\\dot{P}=2.9\\times 10^5 yr, and surface dipole magnetic field strength Bs = 4.4 × 1011 G. These values rule out a mildly recycled pulsar, but Calvera could be an orphaned central compact object (anti-magnetar), with a magnetic field that was initially buried by supernova debris and is now reemerging and approaching normal strength. We also performed unsuccessful searches for high-energy γ-rays from Calvera in both imaging and timing of >100 MeV Fermi photons. Even though the distance to Calvera is uncertain by an order of magnitude, an upper limit of d < 2 kpc inferred from X-ray spectra implies a γ-ray luminosity limit of <3.3 × 1032 erg s-1, which is less than that of any pulsar of comparable \\dot{E}. Calvera shares some properties with PSR J1740+1000, a young radio pulsar that we show by virtue of its lack of proper motion was born outside of the Galactic disk. As an energetic, high-Galactic-latitude pulsar, Calvera is unique in being undetected in both radio and γ-rays to faint limits, which should place interesting constraints on models for particle acceleration and beam patterns in pulsar magnetospheres.

  4. Angular momentum redistribution by mixed modes in evolved low-mass stars. II. Spin-down of the core of red giants induced by mixed modes

    NASA Astrophysics Data System (ADS)

    Belkacem, K.; Marques, J. P.; Goupil, M. J.; Mosser, B.; Sonoi, T.; Ouazzani, R. M.; Dupret, M. A.; Mathis, S.; Grosjean, M.

    2015-07-01

    The detection of mixed modes in subgiants and red giants by the CoRoT and Kepler space-borne missions allows us to investigate the internal structure of evolved low-mass stars, from the end of the main sequence to the central helium-burning phase. In particular, the measurement of the mean core rotation rate as a function of the evolution places stringent constraints on the physical mechanisms responsible for the angular momentum redistribution in stars. It showed that the current stellar evolution codes including the modelling of rotation fail to reproduce the observations. An additional physical process that efficiently extracts angular momentum from the core is thus necessary. Our aim is to assess the ability of mixed modes to do this. To this end, we developed a formalism that provides a modelling of the wave fluxes in both the mean angular momentum and the mean energy equations in a companion paper. In this article, mode amplitudes are modelled based on recent asteroseismic observations, and a quantitative estimate of the angular momentum transfer is obtained. This is performed for a benchmark model of 1.3 M⊙ at three evolutionary stages, representative of the evolved pulsating stars observed by CoRoT and Kepler. We show that mixed modes extract angular momentum from the innermost regions of subgiants and red giants. However, this transport of angular momentum from the core is unlikely to counterbalance the effect of the core contraction in subgiants and early red giants. In contrast, for more evolved red giants, mixed modes are found efficient enough to balance and exceed the effect of the core contraction, in particular in the hydrogen-burning shell. Our results thus indicate that mixed modes are a promising candidate to explain the observed spin-down of the core of evolved red giants, but that an other mechanism is to be invoked for subgiants and early red giants.

  5. The spin-down rate of Swift J1822.3-1606 finally measured: confirmation as magnetar

    NASA Astrophysics Data System (ADS)

    Kuiper, L.; Hermsen, W.

    2011-09-01

    Data from monitoring observations of magnetar-candidate Swift J1822.3-1606 with RXTE PCA covering a time span of about 10 weeks (MJD 55758-55826) since its discovery on July 14, 2011 (ATEL #3488; GCN #12159) have been used to construct an accurate phase-coherent timing solution. Barycentered pulse arrival times (ToA's; see ATEL #3493 for the adopted source location) have been obtained by a cross-correlation method with a high-statistics pulse-profile template.

  6. Pulsar wind model for the spin-down behavior of intermittent pulsars

    SciTech Connect

    Li, L.; Tong, H.; Yan, W. M.; Yuan, J. P.; Wang, N.; Xu, R. X.

    2014-06-10

    Intermittent pulsars are part-time radio pulsars. They have higher slow down rates in the on state (radio-loud) than in the off state (radio-quiet). This gives evidence that particle wind may play an important role in pulsar spindown. The effect of particle acceleration is included in modeling the rotational energy loss rate of the neutron star. Applying the pulsar wind model to the three intermittent pulsars (PSR B1931+24, PSR J1841–0500, and PSR J1832+0029) allows their magnetic fields and inclination angles to be calculated simultaneously. The theoretical braking indices of intermittent pulsars are also given. In the pulsar wind model, the density of the particle wind can always be the Goldreich-Julian density. This may ensure that different on states of intermittent pulsars are stable. The duty cycle of particle wind can be determined from timing observations. It is consistent with the duty cycle of the on state. Inclination angle and braking index observations of intermittent pulsars may help to test different models of particle acceleration. At present, the inverse Compton scattering induced space charge limited flow with field saturation model can be ruled out.

  7. Magnetospheric accretion and spin-down of the prototypical classical T Tauri star AA Tau

    NASA Astrophysics Data System (ADS)

    Donati, J.-F.; Skelly, M. B.; Bouvier, J.; Gregory, S. G.; Grankin, K. N.; Jardine, M. M.; Hussain, G. A. J.; Ménard, F.; Dougados, C.; Unruh, Y.; Mohanty, S.; Aurière, M.; Morin, J.; Farès, R.; MAPP Collaboration

    2010-12-01

    From observations collected with the ESPaDOnS spectropolarimeter at the Canada-France-Hawaii Telescope (CFHT) and with the NARVAL spectropolarimeter at the Télescope Bernard Lyot (TBL), we report the detection of Zeeman signatures on the prototypical classical T Tauri star AA Tau, both in photospheric lines and accretion-powered emission lines. Using time series of unpolarized and circularly polarized spectra, we reconstruct at two epochs maps of the magnetic field, surface brightness and accretion-powered emission of AA Tau. We find that AA Tau hosts a 2-3 kG magnetic dipole tilted at ≃20° to the rotation axis, and of presumably dynamo origin. We also show that the magnetic poles of AA Tau host large cool spots at photospheric level and accretion regions at chromospheric level. The accretion rate at the surface of AA Tau at the time of our observations (estimated from the emission in the He I D3 line mainly) is strongly variable, ranging from -9.6 to -8.5 and equal to -9.2 in average (in logarithmic scale and in M⊙ yr-1); this is an order of magnitude smaller than the disc accretion rate at which the magnetic truncation radius (below which the disc is disrupted by the stellar magnetic field) matches the corotation radius (where the Keplerian period equals the stellar rotation period) - a necessary condition for accretion to occur. It suggests that AA Tau is largely in the propeller regime, with most of the accreting material in the inner disc regions being expelled outwards and only a small fraction accreted towards the surface of the star. The strong variability in the observed surface mass accretion rate and the systematic time-lag of optical occultations (by the warped accretion disc) with respect to magnetic and accretion-powered emission maxima also support this conclusion. Our results imply that AA Tau is being actively spun-down by the star/disc magnetic coupling and appears as an ideal laboratory for studying angular momentum losses of forming suns

  8. Are ultralong gamma-ray bursts powered by black holes spinning down?

    NASA Astrophysics Data System (ADS)

    Nathanail, Antonios; Contopoulos, Ioannis

    2015-10-01

    Gamma-ray bursts (GRBs) are violent explosions, coming from cosmological distances. They are detected in gamma-rays (also X-rays, UV, optical, radio) almost every day, and have typical durations of a few seconds to a few minutes. Some GRBs have been reported with extraordinary durations of 104 s, the so-called ultralong GRBs. It has been debated whether these form a new distinct class of events or whether they are similar to long GRBs. According to Blandford & Znajek, the spin energy of a rotating black hole can be extracted electromagnetically, should the hole be endowed with a magnetic field supported by electric currents in a surrounding disc. We argue that this can be the case for the central engines of GRBs and we show that the duration of the burst depends on the magnetic flux accumulated on the event horizon of the black hole. We thus estimate the surface magnetic field of a possible progenitor star, and we conclude that an ultralong GRB may originate from a progenitor star with a relatively low magnetic field.

  9. Connecting Related Rates and Differential Equations

    ERIC Educational Resources Information Center

    Brandt, Keith

    2012-01-01

    This article points out a simple connection between related rates and differential equations. The connection can be used for in-class examples or homework exercises, and it is accessible to students who are familiar with separation of variables.

  10. Connecting Related Rates and Differential Equations

    ERIC Educational Resources Information Center

    Brandt, Keith

    2012-01-01

    This article points out a simple connection between related rates and differential equations. The connection can be used for in-class examples or homework exercises, and it is accessible to students who are familiar with separation of variables.

  11. A Laboratory Exercise with Related Rates.

    ERIC Educational Resources Information Center

    Sworder, Steven C.

    A laboratory experiment, based on a simple electric circuit that can be used to demonstrate the existence of real-world "related rates" problems, is outlined and an equation for voltage across the capacitor terminals during discharge is derived. The necessary materials, setup methods, and experimental problems are described. A student laboratory…

  12. Relative flow rates of explosive powders

    SciTech Connect

    Willson, V.P.

    1988-05-31

    A study was performed to determine the relative flow rates of various explosive powders and evaluate their adaptability for use in automated dispensing systems. Results showed that PBX 9407, LX-15, RX-26-BH, and HNAB are potential candidates for use in these systems. It was also shown that powders with graphite and stearate additives generated the least amount of static and were the easiest to handle.

  13. Climatology tuned reflectivity-rain rate relations

    NASA Technical Reports Server (NTRS)

    Short, David A.; Rosenfeld, Daniel; Atlas, David

    1989-01-01

    The climatologically-tuned relationships between reflectivity, Z, and rain rate, R, are examined. A method is presented which selects the Z-R relation that assures that the values of R are weighted according to their climatological frequency of occurrence. The method is an extension of the approach suggested by Calheiros and Zawadski (1987). Also, consideration is given to the method of optimizing Z-R relations by matching hourly gage and radar-deduced rain amounts proposed by Smith et al. (1975). These two methods are described and applied to data from Germany and from the GARP Atlantic Tropical Experiment. The differences in the Z-R relations obtained using the two approaches are discussed.

  14. Climatology tuned reflectivity-rain rate relations

    NASA Technical Reports Server (NTRS)

    Short, David A.; Rosenfeld, Daniel; Atlas, David

    1989-01-01

    The climatologically-tuned relationships between reflectivity, Z, and rain rate, R, are examined. A method is presented which selects the Z-R relation that assures that the values of R are weighted according to their climatological frequency of occurrence. The method is an extension of the approach suggested by Calheiros and Zawadski (1987). Also, consideration is given to the method of optimizing Z-R relations by matching hourly gage and radar-deduced rain amounts proposed by Smith et al. (1975). These two methods are described and applied to data from Germany and from the GARP Atlantic Tropical Experiment. The differences in the Z-R relations obtained using the two approaches are discussed.

  15. X-ray measurement of the spin-down of CalverA: A radio- and gamma-ray-quiet pulsar

    SciTech Connect

    Halpern, J. P.; Bogdanov, S.; Gotthelf, E. V.

    2013-12-01

    We measure spin-down of the 59 ms X-ray pulsar Calvera by comparing the XMM-Newton discovery data from 2009 with new Chandra timing observations taken in 2013. Its period derivative is P-dot =(3.19± 0.08)×10{sup −15}, which corresponds to spin-down luminosity E-dot =6.1×10{sup 35} erg s{sup –1}, characteristic age τ{sub c}≡P/2 P-dot =2.9×10{sup 5} yr, and surface dipole magnetic field strength B{sub s} = 4.4 × 10{sup 11} G. These values rule out a mildly recycled pulsar, but Calvera could be an orphaned central compact object (anti-magnetar), with a magnetic field that was initially buried by supernova debris and is now reemerging and approaching normal strength. We also performed unsuccessful searches for high-energy γ-rays from Calvera in both imaging and timing of >100 MeV Fermi photons. Even though the distance to Calvera is uncertain by an order of magnitude, an upper limit of d < 2 kpc inferred from X-ray spectra implies a γ-ray luminosity limit of <3.3 × 10{sup 32} erg s{sup –1}, which is less than that of any pulsar of comparable E-dot . Calvera shares some properties with PSR J1740+1000, a young radio pulsar that we show by virtue of its lack of proper motion was born outside of the Galactic disk. As an energetic, high-Galactic-latitude pulsar, Calvera is unique in being undetected in both radio and γ-rays to faint limits, which should place interesting constraints on models for particle acceleration and beam patterns in pulsar magnetospheres.

  16. On relative supernova rates and nucleosynthesis roles

    NASA Technical Reports Server (NTRS)

    Arnett, W. David; Schramm, David N.; Truran, James W.

    1988-01-01

    It is shown that the Ni-56-Fe-56 observed in SN 1987A argues that core collapse supernovae may be responsible for more that 50 percent of the iron in the galaxy. Furthermore it is argued that the time averaged rate of thermonuclear driven Type I supernovae may be at least an order of magnitude lower than the average rate of core collapse supernovae. The present low rate of Type II supernovae (below their time averaged rate of approx. 1/10 yr) is either because the past rate was much higher because many core collapse supernovae are dim like SN 1987A. However, even in this latter case they are only an order of magnitude dimmer that normal Type II's due to the contribution of Ni-56 decay to the light curve.

  17. On relative supernova rates and nucleosynthesis roles

    NASA Technical Reports Server (NTRS)

    Arnett, W. David; Schramm, David N.; Truran, James W.

    1989-01-01

    It is shown that the Ni-56-Fe-56 observed in SN 1987A argues that core collapse supernovae may be responsible for more than 50 percent of the iron in the galaxy. Furthermore it is argued that the time averaged rate of thermonuclear driven Type I supernovae may be at least an order of magnitude lower than the average rate of core collapse supernovae. The present low rate of Type II supernovae (below their time averaged rate of approx. 1/10 yr) is either because the past rate was much higher because many core collapse supernovae are dim like SN 1987A. However, even in this latter case they are only an order of magnitude dimmer that normal Type II's due to the contribution of Ni-56 decay to the light curve.

  18. Rotational history of the sun: Spin-down of the interior by circulation currents and fluid instabilities

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Sofia, S.

    1980-01-01

    A number of astronomical observations show that solar-type stars begin the main-sequence stage with surface rotation rates which are much greater than that of the sun. The subsequent decrease in the surface rotation rate is due to the braking torque exerted by magnetically-coupled mass loss (the solar wind). The direct braking action of the solar wind should be confined to the convective envelope so the rotation of the radiative interior remains an open question. After reviewing the relevant astronomical data, we describe how angular momentum could be transported out of the radiative interior by fluid instabilities and estimate the time scales for such transport. This picture is used to construct an evolutionary model of the sun, which predicts the present rotation of the radiative interior. The results of such a model are interpreted in terms of the measured oblateness of the solar surface.

  19. "Molecular Clock" Analogs: A Relative Rates Exercise

    ERIC Educational Resources Information Center

    Wares, John P.

    2008-01-01

    Although molecular clock theory is a commonly discussed facet of evolutionary biology, undergraduates are rarely presented with the underlying information of how this theory is examined relative to empirical data. Here a simple contextual exercise is presented that not only provides insight into molecular clocks, but is also a useful exercise for…

  20. Feedback Functions, Optimization, and the Relation of Response Rate to Reinforcer Rate

    ERIC Educational Resources Information Center

    Soto, Paul L.; McDowell, Jack J.; Dallery, Jesse

    2006-01-01

    The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate…

  1. Rotation in solar-type stars. I - Evolutionary models for the spin-down of the sun

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Sofia, S.

    1981-01-01

    Models of rotating, 1 solar mass stars through the pre-main sequence and main sequence stages have been calculated. The calculations begin on the Hayashi track with rapid, rigid-body rotation, with angular momentum removed from the convective envelope to simulate the effect of the solar wind as the models evolve. Interior angular momentum redistribution by circulation flows and rotational instabilities is computed by a diffusion technique. It is found that at the present age of solar evolution, the models employed have internal rotation rates significantly larger than those allowed by measured solar oblateness, suggesting that the effects of circulation currents near the outer boundary of the radiative interior have been underestimated. An important result of this study is the implication that circulation currents produce deep mixing of such minor constituents as He-3 and C-13, perhaps also explaining the observed steady depletion of lithium during the main-sequence stage.

  2. A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster.

    PubMed

    Meibom, Søren; Barnes, Sydney A; Platais, Imants; Gilliland, Ronald L; Latham, David W; Mathieu, Robert D

    2015-01-29

    The ages of the most common stars--low-mass (cool) stars like the Sun, and smaller--are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The rotation rates of all cool stars decrease substantially with time as the stars steadily lose their angular momenta. If properly calibrated, rotation therefore can act as a reliable determinant of their ages based on the method of gyrochronology. To calibrate gyrochronology, the relationship between rotation period and age must be determined for cool stars of different masses, which is best accomplished with rotation period measurements for stars in clusters with well-known ages. Hitherto, such measurements have been possible only in clusters with ages of less than about one billion years, and gyrochronology ages for older stars have been inferred from model predictions. Here we report rotation period measurements for 30 cool stars in the 2.5-billion-year-old cluster NGC 6819. The periods reveal a well-defined relationship between rotation period and stellar mass at the cluster age, suggesting that ages with a precision of order 10 per cent can be derived for large numbers of cool Galactic field stars.

  3. The application of stepwise regression method in discussing the relation between interest rate and inflation rate

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohong; Chen, Yu; Jia, Haiwei

    2009-07-01

    The paper study the relation between Interest rate and Inflation rate, we use the Stepwise Regression Method to build the math model about the relation between Interest rate and Inflation rate. And the model has passed the significance test, and we use the model to discuss the influence on social economy through adjust Deposit rate, so we can provide a lot of theory proof for government to draw policy.

  4. Pulse Phase Dependence of Low Energy Emission Lines in an X-ray pulsar 4U 1626-67 during its spin-up and spin-down phase

    NASA Astrophysics Data System (ADS)

    Beri, Aru; Paul, Biswajit; Dewangan, Gulab Chand

    2016-07-01

    We will present the results obtained from the new observation of an ultra-compact X-ray binary pulsar 4U 1626-67, carried out with the XMM-Newton observatory. 4U 1626-67, a unique accretion powered pulsar underwent two torque reversals since its discovery in 1977. Pulse phase resolved spectroscopy of this source performed using the data from the XMM-Newton observatory during its spin-down phase revealed the dependence of the emission lines on the pulse phase. O VII emission line at 0.569 keV showed the maximum variation by factor of 4. These variations were interpreted due to warps in the accretion disk (Beri et al. 2015). Radiation pressure induced warping is also believed to be the cause for spin-down. In light of this possible explanation for spin-down torque reversal we expect different line variability during the spin-up phase. We will discuss the implications of the results obtained after performing pulse phase resolved spectroscopy using data from the EPIC-pn during the current spin-up phase. Detailed study of the prominent Neon and Oxygen line complexes with the high resolution Reflection Grating Spectrometer (RGS) on-board XMM-Newton will also be presented.

  5. Feedback Functions, Optimization, and the Relation of Response Rate to Reinforcer Rate

    PubMed Central

    Soto, Paul L; McDowell, Jack J; Dallery, Jesse

    2006-01-01

    The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate was arranged according to a quadratic equation with a maximum at a unique response rate. The experiment consisted of two phases, during which 6 Long Evans rats lever pressed for food. In the first phase of the experiment, the rats responded on six fixed-interval-plus-quadratic-feedback schedules, and in the second phase the rats responded on three variable-interval-plus-quadratic-feedback schedules. Responding in both phases was inconsistent with a one-to-one relation of response rate to reinforcer rate. Instead, different response rates were obtained at equivalent reinforcer rates. Responding did vary directly with the vertex of the feedback function in both phases, a finding consistent with optimization of reinforcer rate. The present results suggest that the feedback function relating reinforcer rate to response rate imposed by a reinforcement schedule can be an important determinant of behavior. Furthermore, the present experiment illustrates the benefit of arranging feedback functions to investigate assumptions about the variables that control schedule performance. PMID:16602376

  6. RELATIVE DISSOLUTION RATES OF RADIOACTIVE MATERIALS USED AT AWE.

    PubMed

    Miller, T J; Bingham, D; Cockerill, R; Waldren, S; Moth, N

    2016-09-01

    A simple in vitro dissolution test was used to provide a semi-quantitative comparison of the relative dissolution rates of samples of radioactive materials used at Atomic Weapons Establishment in a lung fluid surrogate (Ringer's solution). A wide range of dissolution rates were observed for aged legacy actinides, freshly produced actinide alloys and actinides from waste management operations. © Crown copyright 2015.

  7. Calculus students' ability to solve geometric related-rates problems

    NASA Astrophysics Data System (ADS)

    Martin, Tami

    2000-09-01

    This study assessed the ability of university students enrolled in an introductory calculus course to solve related-rates problems set in geometric contexts. Students completed a problem-solving test and a test of performance on the individual steps involved in solving such problems. Each step was characterised as primarily relying on procedural knowledge or conceptual understanding. Results indicated that overall performance on the geometric related-rates problems was poor. The poorest performance was on steps linked to conceptual understanding, specifically steps involving the translation of prose to geometric and symbolic representations. Overall performance was most strongly related to performance on the procedural steps.

  8. Inflow rate, a time-symmetric observable obeying fluctuation relations.

    PubMed

    Baiesi, Marco; Falasco, Gianmaria

    2015-10-01

    While entropy changes are the usual subject of fluctuation theorems, we seek fluctuation relations involving time-symmetric quantities, namely observables that do not change sign if the trajectories are observed backward in time. We find detailed and integral fluctuation relations for the (time-integrated) difference between entrance rate and escape rate in mesoscopic jump systems. Such inflow rate, which is even under time reversal, represents the discrete-state equivalent of the phase-space contraction rate. Indeed, it becomes minus the divergence of forces in the continuum limit to overdamped diffusion. This establishes a formal connection between reversible deterministic systems and irreversible stochastic ones, confirming that fluctuation theorems are largely independent of the details of the underling dynamics.

  9. Component duration and relative response rates in multiple schedules.

    NASA Technical Reports Server (NTRS)

    Todorov, J. C.

    1972-01-01

    Pigeons were trained on a multiple variable-interval 30-sec, variable interval 90-sec schedule with each component presented alternately for an equal duration. This duration of exposure was varied from 5 to 300 sec. The rate of response in the variable-interval 30-sec component relative to the rate of response in the variable-interval 90-sec component was studied. Results are plotted and discussed.

  10. Oxygen consumption of cycle ergometry is nonlinearly related to work rate and pedal rate.

    PubMed

    Londeree, B R; Moffitt-Gerstenberger, J; Padfield, J A; Lottmann, D

    1997-06-01

    The purpose of the study was to develop an equation to predict the oxygen cost of cycle ergometry. Forty subjects performed an incremental cycle ergometer test on three occasions at 50, 70, or 90 rpm in a counterbalanced order. Work rate was incremented every 5 or 6 min when steady rate values were achieved. To ensure accurate work rates, ergometer resistance was calibrated and flywheel revolutions were electronically measured. Oxygen consumption was measured with a computer interfaced system which provided results every minute. Oxygen consumption (mL.min-1) was the dependent variable, and independent variables were work rate (WR in kgm.min-1), pedal rate (rpm), weight (Kg), and gender (males, 0; females, 1). The following nonlinear equation was selected; VO2 = 0.42.WR1.2 + 0.00061.rpm3 + 6.35.Wt + 0.1136.RPM50.WR-0.10144.RPM90-WR-52-Gender, R2 = 0.9961, Sy.x = 106 mL.min-1, where RPM50: 50 rpm = 1, and RPM90: 90 rpm = 1, else = 0. It was concluded that the oxygen cost of cycle ergometry is nonlinearly related to work rate and pedal rate, linearly related to weight, and that females use less oxygen for a particular work rate.

  11. Do Dogs Know Related Rates Rather than Optimization?

    ERIC Educational Resources Information Center

    Perruchet, Pierre; Gallego, Jorge

    2006-01-01

    Although dogs seemingly follow the optimal path where they get to a ball thrown into the water, they certainly do not know the minimization function proposed in the calculus books. Trading the optimization problem for a related rates problem leads to a mathematically identical solution, which, it is argued here, is a more plausible model for the…

  12. Do Dogs Know Related Rates Rather than Optimization?

    ERIC Educational Resources Information Center

    Perruchet, Pierre; Gallego, Jorge

    2006-01-01

    Although dogs seemingly follow the optimal path where they get to a ball thrown into the water, they certainly do not know the minimization function proposed in the calculus books. Trading the optimization problem for a related rates problem leads to a mathematically identical solution, which, it is argued here, is a more plausible model for the…

  13. WHAT SETS THE INITIAL ROTATION RATES OF MASSIVE STARS?

    SciTech Connect

    Rosen, Anna L.; Krumholz, Mark R.; Ramirez-Ruiz, Enrico

    2012-04-01

    The physical mechanisms that set the initial rotation rates in massive stars are a crucial unknown in current star formation theory. Observations of young, massive stars provide evidence that they form in a similar fashion to their low-mass counterparts. The magnetic coupling between a star and its accretion disk may be sufficient to spin down low-mass pre-main-sequence (PMS) stars to well below breakup at the end stage of their formation when the accretion rate is low. However, we show that these magnetic torques are insufficient to spin down massive PMS stars due to their short formation times and high accretion rates. We develop a model for the angular momentum evolution of stars over a wide range in mass, considering both magnetic and gravitational torques. We find that magnetic torques are unable to spin down either low-mass or high-mass stars during the main accretion phase, and that massive stars cannot be spun down significantly by magnetic torques during the end stage of their formation either. Spin-down occurs only if massive stars' disk lifetimes are substantially longer or their magnetic fields are much stronger than current observations suggest.

  14. Investigation Of Obesity-Related Mortality Rates In Delaware

    PubMed Central

    Wentzien, Derald E.; Bautista, Riza C.; Gross, Catherine C.

    2017-01-01

    As Delaware’s adult obesity crisis continues to be a leading public health concern, we evaluated Delaware’s 1999–2014 vital records to examine the association between obesity and mortality. We used the Delaware population death records from the Centers for Disease Control and Prevention (CDC) WONDER database and the Delaware Health Statistics Center (DHSC). Together with the vital records, we incorporated Microsoft Excel, SAS (Statistical Analysis System) and GIS (geographic information system) tools to analyze obesity influences from county residence, economic status, education, gender, and race. Using the 15-year (1999–2014) time span with the CDC WONDER database, we observed a statistically significant 28.7% increase in the age-adjusted Delaware obesity-related mortality rates (where obesity was a contributory factor). Furthermore, obesity influenced death counts in all three Delaware counties (New Castle, Kent, and Sussex). Kent County experienced the largest increase (66.0%), followed by New Castle County (47.4%), and Sussex County (25.2%). The DHSC mortality rates for all leading causes of death from 2000 to 2011 indicated relatively stable mortality rates for Delaware. However, using CDC WONDER data, the Delaware mortality rate for obesity as a single underlying cause in 2011 was 56.9% higher than mortality rate in 2000. PMID:28690914

  15. Rate-related kinematic changes in younger and older adults.

    PubMed

    van Brenk, Frits; Terband, Hayo; van Lieshout, Pascal; Lowit, Anja; Maassen, Ben

    2013-01-01

    This study aimed to investigate the effects of speech rate changes on kinematic characteristics and stability of speech movements in younger and older speakers using electromagnetic midsagittal articulography. Eight young adults and 8 older adults engaged in a series of syllable repetition tasks of /pa/, /sa/ and /ta/ obtained at self-paced slow, habitual and fast speech rates, as well as in a series of metronome-guided speech rates, ranging from 2 to 4 syllables per second. The kinematic parameters duration, amplitude and peak velocity were obtained for opening and closing movements. Older speakers were able to increase speech rate to the same degree or higher compared to younger speakers in both pacing conditions. Kinematic data show that older adults increased duration and decreased peak velocity in closing movements of alveolar constrictions at slower rates more prominently than younger adults. The results on movement stability revealed no differences between age groups. The results suggest that an age-related difference in speed-accuracy trade-off can be ruled out. Differences in kinematic characteristics point towards the possibility that older adults aimed to facilitate a closed-loop control system to maintain movement stability at slower speech rates.

  16. Phonation related rate coding and recruitment in the genioglossus muscle

    PubMed Central

    Shumway, K.R.; Porfirio, D.J.; Bailey, E.F.

    2015-01-01

    Motor unit (MU) recruitment was assessed in two muscles with similar muscle fiber type compositions and that participate in skilled movements: the tongue muscle, genioglossus (GG) and the hand muscle, first dorsal interosseous (FDI). Our primary objectives were to determine in the framework of a voluntary movement whether muscle force is regulated in tongue as it is in limb i.e., via processes of rate coding and recruitment. Recruitment in the two muscles was assessed within each subject in the context of ramp force (FDI) and in the tongue (GG) during vowel production and specifically, in the context of ramp increases in loudness, and subsequently expressed relative to the maximal. The principle findings of the study are that the general rules of recruitment and rate coding hold true for both GG and FDI and second, that average firing rates, firing rates at recruitment and peak firing rates in GG are significantly higher than for FDI (P <0.001) despite tasks performed across comparable force ranges (∼2-40% of max). The higher firing rates observed in the tongue within the context of phonation may be a function of that muscle's dual role as (prime) mover and hydrostatic support element. PMID:25899868

  17. Relations between convergence rates in Schatten p-norms

    SciTech Connect

    Albini, Paolo; Toigo, Alessandro; Umanita, Veronica

    2008-01-15

    In quantum estimation theory and quantum tomography, the quantum state obtained by sampling converges to the ''true'' unknown density matrix under topologies that are different from the natural notion of distance in the space of quantum states, i.e., the trace class norm. In this paper, we address such problem, finding relations between the rates of convergence in the Schatten p-norms and in the trace class norm.

  18. Heart Rate Variability in Sleep-Related Migraine without Aura

    PubMed Central

    Vollono, Catello; Gnoni, Valentina; Testani, Elisa; Dittoni, Serena; Losurdo, Anna; Colicchio, Salvatore; Di Blasi, Chiara; Mazza, Salvatore; Farina, Benedetto; Della Marca, Giacomo

    2013-01-01

    Objectives: This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Methods: Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heart rate variability analysis. Results: A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. Conclusions: These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways. Citation: Vollono C; Gnoni V; Testani E; Dittoni S; Losurdo A; Colicchio S; Di Blasi C; Mazza S; Farina B; Della Marca G. Heart rate variability in sleep-related migraine without aura. J Clin Sleep Med 2013;9(7):707-714. PMID:23853566

  19. Engineering aspects of rate-related processes in food manufacturing.

    PubMed

    Adachi, Shuji

    2015-01-01

    Many rate-related phenomena occur in food manufacturing processes. This review addresses four of them, all of which are topics that the author has studied in order to design food manufacturing processes that are favorable from the standpoint of food engineering. They include chromatographic separation through continuous separation with a simulated moving adsorber, lipid oxidation kinetics in emulsions and microencapsulated systems, kinetic analysis and extraction in subcritical water, and water migration in pasta.

  20. Reproductive Rates in Australian Rodents Are Related to Phylogeny

    PubMed Central

    Geffen, Eli; Rowe, Kevin C.; Yom-Tov, Yoram

    2011-01-01

    Background The native rodents of Australia are commonly divided into two groups based on the time of their colonization of the Sahulian continent, which encompasses Australia, New Guinea, and the adjacent islands. The first group, the “old endemics,” is a diverse assemblage of 34 genera that are descended from a single colonization of the continent during the Pliocene. A second group, the “new endemics,” is composed of several native Rattus species that are descended from a single colonization during the Pleistocene. Finally, a third group is composed of three non-native species of Rattus and Mus introduced into Australia by humans over the last 200 years. Previous studies have claimed that the three groups differ in their reproductive rates and that this variation in rates is associated with the unique environmental conditions across Australia. We examined these hypotheses using phylogenetically controlled methods. Methodology and Results We examined the relationship between the reproductive rates of the Australian rodents and the environmental variations across the continent, as well as the epoch of their colonization of the continent. Our results revealed no significant correlation with environmental variables but a significant association between colonization age and all the reproductive parameters examined. Discussion Based on a larger phylogeny of the subfamily Murinae, we showed that significant differences in reproductive rates among colonization groups are shared with their closest relatives outside Sahul. Therefore, the lower reproductive rates in the old endemics are more likely to be the result of phylogenetic history and conservation of traits than an adaptation to the Australian environment. In the new endemics, we found a trend of increasing reproductive rates with diversification. We suggest that the differences in reproductive rates of the old endemic rodents and the native Rattus represent alternative adaptive strategies that have allowed

  1. Measuring task-related changes in heart rate variability.

    PubMed

    Moses, Ziev B; Luecken, Linda J; Eason, James C

    2007-01-01

    Small beat-to-beat differences in heart rate are the result of dynamic control of the cardiovascular system by the sympathetic and parasympathetic nervous systems. Heart rate variability (HRV) has been positively correlated with both mental and physical health. While many studies measure HRV under rest conditions, few have measured HRV during stressful situations. We describe an experimental protocol designed to measure baseline, task, and recovery values of HRV as a function of three different types of stressors. These stressors involve an attention task, a cold pressor test, and a videotaped speech presentation. We found a measurable change in heart rate in participants (n=10) during each task (all p's < 0.05). The relative increase or decrease from pre-task heart rate was predicted by task (one-way ANOVA, p= 0.0001). Spectral analysis of HRV during the attention task revealed consistently decreased measures of both high (68+/-7%, mean+/-S.E.) and low (62+/-13%) frequency HRV components as compared to baseline. HRV spectra for the cold pressor and speech tasks revealed no consistent patterns of increase or decrease from baseline measurements. We also found no correlation in reactivity measures between any of our tasks. These findings suggest that each of the tasks in our experimental design elicits a different type of stress response in an individual. Our experimental approach may prove useful to biobehavioral researchers searching for factors that determine individual differences in responses to stress in daily life.

  2. Component duration and relative response rates in multiple schedules1

    PubMed Central

    Todorov, João Claudio

    1972-01-01

    Pigeons were trained on a multiple variable-interval 30-sec, variable-interval 90-sec schedule with each component presented alternately for an equal (on the average) duration. This average duration of exposure to each component was varied from 5 to 300 sec. The main concern was with rate of response in the variable-interval 30-sec component relative to rate of response in the variable-interval 90-sec component. In all cases, rate of response was higher in the variable-interval 30 sec component, but the discrepancy in the rate produced by the two schedules tended to be greatest when the duration of component presentation was brief. The mean proportion of responses emitted during the variable-interval 30-sec component (responses in variable-interval 30-sec component divided by total responses) varied from about 0.60 to 0.71, where 0.75 would be expected on the basis of a matching rule, and 0.59 was that obtained by Lander and Irwin (1968). These results are in agreement with data reported by Shimp and Wheatley (1971) from a similar experiment. PMID:16811566

  3. SHAPING THE DUST MASS-STAR-FORMATION RATE RELATION

    SciTech Connect

    Hjorth, Jens; Gall, Christa; Michałowski, Michał J. E-mail: cgall@phys.au.dk

    2014-02-20

    There is a remarkably tight relation between the observationally inferred dust masses and star-formation rates (SFRs) of Sloan Digital Sky Survey galaxies, M {sub dust} ∝ SFR{sup 1.11}. Here we extend the M {sub dust}-SFR relation to the high end and show that it bends over at very large SFRs (i.e., dust masses are lower than predicted for a given SFR). We identify several distinct evolutionary processes in the diagram: (1) a star-bursting phase in which dust builds up rapidly at early times. The maximum attainable dust mass in this process is the cause of the bend-over of the relation. A high dust-formation efficiency, a bottom-light initial mass function, and negligible supernova shock dust destruction are required to produce sufficiently high dust masses. (2) A quiescent star-forming phase in which the subsequent parallel decline in dust mass and SFR gives rise to the M {sub dust}-SFR relation, through astration and dust destruction. The dust-to-gas ratio is approximately constant along the relation. We show that the power-law slope of the M {sub dust}-SFR relation is inversely proportional to the global Schmidt-Kennicutt law exponent (i.e., ∼0.9) in simple chemical evolution models. (3) A quenching phase which causes star formation to drop while the dust mass stays roughly constant or drops proportionally. Combined with merging, these processes, as well as the range in total baryonic mass, give rise to a complex population of the diagram which adds significant scatter to the original M {sub dust}-SFR relation. (4) At very high redshifts, a population of galaxies located significantly below the local relation is predicted.

  4. Heart rate variability related to effort at work.

    PubMed

    Uusitalo, Arja; Mets, Terhi; Martinmäki, Kaisu; Mauno, Saija; Kinnunen, Ulla; Rusko, Heikki

    2011-11-01

    Changes in autonomic nervous system function have been related to work stress induced increases in cardiovascular morbidity and mortality. Our purpose was to examine whether various heart rate variability (HRV) measures and new HRV-based relaxation measures are related to self-reported chronic work stress and daily emotions. The relaxation measures are based on neural network modelling of individual baseline heart rate and HRV information. Nineteen healthy hospital workers were studied during two work days during the same work period. Daytime, work time and night time heart rate, as well as physical activity were recorded. An effort-reward imbalance (ERI) questionnaire was used to assess chronic work stress. The emotions of stress, irritation and satisfaction were assessed six times during both days. Seventeen subjects had an ERI ratio over 1, indicating imbalance between effort and reward, that is, chronic work stress. Of the daily emotions, satisfaction was the predominant emotion. The daytime relaxation percentage was higher on Day 2 than on Day 1 (4 ± 6% vs. 2 ± 3%, p < 0.05) and the night time relaxation (43 ± 30%) was significantly higher than daytime or work time relaxation on the both Days. Chronic work stress correlated with the vagal activity index of HRV. However, effort at work had many HRV correlates: the higher the work effort the lower daytime HRV and relaxation time. Emotions at work were also correlated with work time (stress and satisfaction) and night time (irritation) HRV. These results indicate that daily emotions at work and chronic work stress, especially effort, is associated with cardiac autonomic function. Neural network modelling of individual heart rate and HRV information may provide additional information in stress research in field conditions.

  5. Heart rate variability in sleep-related migraine without aura.

    PubMed

    Vollono, Catello; Gnoni, Valentina; Testani, Elisa; Dittoni, Serena; Losurdo, Anna; Colicchio, Salvatore; Di Blasi, Chiara; Mazza, Salvatore; Farina, Benedetto; Della Marca, Giacomo

    2013-07-15

    This is an observational study aimed to investigate the activity of autonomic nervous system during sleep in patients with sleep-related migraine. Eight consecutive migraineurs without aura were enrolled (6 women and 2 men), aged 30 to 62 years (mean 48.1 ± 9.3 years). Inclusion criteria were: high frequency of attacks (> 5 per month) and occurrence of more than 75% of the attacks during sleep causing an awakening. Patients were compared with a control group of 55 healthy subjects (23 men and 32 women, mean age 54.2 ± 13.0 years), and with a further control group of 8 age- and gender-matched healthy controls. Patient and controls underwent polysomnography and heart rate variability analysis. A significant reduction of the LF/HF ratio during N2 and N3 sleep stages was observed in migraineurs compared with controls. No differences in sleep macrostructure were observed; cyclic alternating pattern (CAP) time and CAP rate were lower in migraineurs than in controls. These findings indicate a peculiar modification of the autonomic balance during sleep in sleep-related migraine. The reduction of LF/HF ratio in NREM sleep was observed in controls, but it was quantitatively much more evident in migraineurs. Changes in LF/HF could be consequent to an autonomic unbalance which could manifest selectively (or alternatively become more evident) during sleep. These findings, together with the reduction in CAP rate, could be an expression of reduced arousability during sleep in patients with sleep-related migraine. The simultaneous involvement of the autonomic, arousal, and pain systems might suggest involvement of the hypothalamic pathways.

  6. Factors related to heart rate variability among firefighters.

    PubMed

    Shin, Jae-Hong; Lee, Jung-Youb; Yang, Seon-Hee; Lee, Mi-Young; Chung, In-Sung

    2016-01-01

    The aim of this study was to investigate factors associated with heart rate variability in firefighters working in a metropolitan city in South Korea. Self-administered questionnaires including Korean Occupational Stress Scale (KOSS) as well as surveys collecting socio-demographic characteristics and work-related factors were given to 962 firefighters. After exclusion for missing data, 645 firefighters were included, and analysis of covaiance adjusted for the general risk factors and job characteristics were used to assess the relationship between heart rate variability and associated factors. SDNN and RMSSD and were decreased in the area of occupational climate of the group with high job stress (p = 0.027, p = 0.036). HF(ln) was decreased in the area of organizational system and occupational climate of the group with high stress that statistically significant level (p = 0.034, p = 0.043). Occupational climate and organizational system are associated with reduction of heart rate variability. Preventive medical care plans for cardiovascular disease of firefighters through the analysis and evaluation of job stress factors are needed.

  7. Do resident's leadership skills relate to ratings of technical skill?

    PubMed

    Gannon, Samantha J; Law, Katherine E; Ray, Rebecca D; Nathwani, Jay N; DiMarco, Shannon M; D'Angelo, Anne-Lise D; Pugh, Carla M

    2016-12-01

    This study sought to compare general surgery research residents' survey information regarding self-efficacy ratings to their observed performance during a simulated small bowel repair. Their observed performance ratings were based on their leadership skills in directing their assistant. Participants were given 15 min to perform a bowel repair using bovine intestines with standardized injuries. Operative assistants were assigned to help assist with the repair. Before the procedure, participants were asked to rate their expected skills decay, task difficulty, and confidence in addressing the small bowel injury. Interactions were coded to identify the number of instructions given by the participants to the assistant during the repair. Statistical analyses assessed the relationship between the number of directional instructions and participants' perceptions self-efficacy measures. Directional instructions were defined as any dialog by the participant who guided the assistant to perform an action. Thirty-six residents (58.3% female) participated in the study. Participants who rated lower levels of decay in their intraoperative decision-making and small bowel repair skills were noted to use their assistant more by giving more instructions. Similarly, a higher number of instructions correlated with lower perceived difficulty in selecting the correct suture, suture pattern, and completing the entire surgical task. General surgery research residents' intraoperative leadership skills showed significant correlations to their perceptions of skill decay and task difficulty during a bowel repair. Evaluating resident's directional instructions may provide an additional individualized intraoperative assessment metric. Further evaluation relating to operative performance outcomes is warranted. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Relations between radiotherapy resources and breast cancer patient survival rates.

    PubMed

    Mochimaru, Yuko; Ohno, Yuko; Numasaki, Hodaka; Theshima, Teruki; Shibuya, Hitoshi

    2010-01-01

    In Japan, the number of patients that have been treated with radiotherapy (RT), particularly those with breast cancer, has increased in the past decade, and is expected to double in the next decade. There is, however, a shortage of RT resources, particularly personnel, which represents a social problem. The shortage of RT resources might cause a difference in survival rate among treated patients. This study analyzed the characteristics of RT resources in RT facilities from Osaka based on the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) database with principle component analysis and cluster analysis. In addition, the relation between RT resources and treatment outcome of breast cancer patients was investigated by linking together Osaka Cancer Registry (OCR) and JASTRO data via a stratified key cord. By using the linked dataset it was shown that the prognosis of breast cancer patients was highly correlated with the scale of RT resources available at the RT facilities collaterally. From cluster analysis, four groups were identified based on RT facility information. The breast cancer survival rates for localized stage patients obtained in classified hospital groups showed a similar pattern, however, large differences (up to 20%) were seen in regional stage patients. Additional findings were: RT facilities with less than 1 radiation oncologist had the poorest outcome; RT was performed primarily at University hospitals; and differences in RT resources within the RT facilities had an effect on breast cancer patient prognosis in Osaka, Japan.

  9. Human heart rate variability relation is unchanged during motion sickness

    NASA Technical Reports Server (NTRS)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

  10. Human heart rate variability relation is unchanged during motion sickness

    NASA Technical Reports Server (NTRS)

    Mullen, T. J.; Berger, R. D.; Oman, C. M.; Cohen, R. J.

    1998-01-01

    In a study of 18 human subjects, we applied a new technique, estimation of the transfer function between instantaneous lung volume (ILV) and instantaneous heart rate (HR), to assess autonomic activity during motion sickness. Two control recordings of ILV and electrocardiogram (ECG) were made prior to the development of motion sickness. During the first, subjects were seated motionless, and during the second they were seated rotating sinusoidally about an earth vertical axis. Subjects then wore prism goggles that reverse the left-right visual field and performed manual tasks until they developed moderate motion sickness. Finally, ILV and ECG were recorded while subjects maintained a relatively constant level of sickness by intermittent eye closure during rotation with the goggles. Based on analyses of ILV to HR transfer functions from the three conditions, we were unable to demonstrate a change in autonomic control of heart rate due to rotation alone or due to motion sickness. These findings do not support the notion that moderate motion sickness is manifested as a generalized autonomic response.

  11. Determination of relative growth rates of natural quartz crystals

    PubMed

    Ihinger; Zink

    2000-04-20

    Although the theory describing crystal growth in the geological environment is well established, there are few quantitative studies that delimit the absolute time involved in the growth of natural crystals. The actual mechanisms responsible for the variation in size and shape of individual crystal faces are, in fact, not well understood. Here we describe a micro-infrared spectroscopic study of a single, gem-quality quartz crystal that allows us to measure the size, shape and relative growth rate of each of the crystal faces that are active throughout its growth history. We demonstrate that the abundances of hydrogen-bearing impurities can serve as 'speedometers' to monitor the growth rate of advancing crystal faces. Our technique can be applied to crystals from a variety of geological environments to determine their growth histories. Within the electronics industry, the technique might facilitate the production of defect-free synthetic crystals required for high-quality resonators and, ultimately, might allow determination of the absolute time involved in geological processes such as the crystallization of magmas, fluid flow in metamorphism and the sealing of open cracks in earthquake rupture zones.

  12. Hemodialysis catheter-related infection: rates, risk factors and pathogens.

    PubMed

    Sahli, Farida; Feidjel, Razika; Laalaoui, Rima

    2016-07-13

    The main complication of central venous catheter (CVC) in hemodialysis is infection. Identifying CVC related infection (CVC-RI) risk factors and causative micro-organisms is important for setting prevention policies. There were no data regarding CVC-RI in hemodialysis in Algeria. To determine rates of CVC-RI in hemodialysis in Setif university hospital, risk factors and causative microorganisms, we conducted a prospective study from November 2014 to May 2015 involving patients with CVC in hemodialysis. Micro-organisms isolated from semi quantitative culture of CVC and blood culture were identified and tested for antibiotic susceptibility using the automated MicroScan system (DADE Behring, Sacramento, CA, USA). Chi-square test was performed to compare demographic and clinical variables (age, sex, comorbidities, duration of CVC, insertion site) in the groups of patients with and without CVC-RI. P<0.05 was considered statistically significant. All analyses were performed using SPSS V17 for Windows statistical package (SPSS Inc., Chicago, IL, USA). 94 patients and 152 CVC procedures were analyzed. 34 CVC-RI were documented with an incidence of 16.6 per 1000 CVC-days. Incidence of CVC related bloodstream infection (CVC-RBI) was 10.8 per 1000 CVC-days. Independent risk factors associated with CVC-RI were diabetes (P=0.01) and duration of catheterization (P= 0.01). Causative micro-organisms were: Klebsiella pneumoniae 26.5%, coagulase-negative staphylococci 23.5% and Staphylococcus aureus 23.5%. Micro-organisms were multidrug-resistant (MDR). Mortality was statistically associated to inadequate antibiotic therapy. The duration of CVC should be reduced by creation of fistulas. More compliance to hygiene measure is needed for decreasing CVC-RI and resistance rate.

  13. Scaling Relations of Galactic Winds with Star Formation Rate

    NASA Astrophysics Data System (ADS)

    Tanner, Ryan; Cecil, Gerald; Heitsch, Fabian

    2017-01-01

    The galactic scale outflows generated by nuclear starbursts consist of a multiphase medium where each phase has a distinct velocity depending on the characteristics of the starburst. Using synthetic absorption lines generated from 3D hydrodynamical simulations we probe the outflow velocity of the hot, warm, and neutral gas entrained in a galactic wind. By varying the star formation rate (SFR) in our simulations, we find no correlation between the outflow velocity of the hot gas with the SFR, but we do find a correlation between the outflow velocity of both warm and neutral gas with the SFR. The scaling relation between outflow velocity and SFR only holds for low SFR until the scaling relation abruptly flattens at a SFR determined by the mass loading of the starburst. The outflow velocity of the hot gas only depends on the mass loading of the starburst and not the SFR. For low SFRs the difference between the velocity of cold gas, as measured by absorption lines of neutral or low ionized gas, may be 5-7 times lower than the velocity of the hot, highly ionized gas. The difference in velocity between the cold and hot gas for higher SFRs depends on the mass loading factor of the starburst. Thus the measured velocities of neutral or low ionized gas cannot be used to estimate the outflow velocity of the hot gas without determining the mass loading of the starburst.

  14. An Optimal Relation of Radar Reflectivity to Lightning Rate

    NASA Technical Reports Server (NTRS)

    Heckman, S.

    1999-01-01

    Thunderstorms separate charge. Most places they lift positive charge or lower negative, a few places they lift negative or lower positive. The electrical generator is stronger in some parts of the cloud than in others. Our long term goal is to map this generator. Cloud physicists tell us that uncharged ice and water particles become charged by collision, and that the charge transferred depends on size, temperature and humidity. There is still some disagreement about exactly how the charge transferred depends on size, temperature, and humidity. In principle, if we knew this ice physics, and also knew the distribution of particles everywhere in the storm, and the winds everywhere and the temperature and humidity everywhere, then we could compute everywhere the electrical power of the thunderstorm generator. In practice it is difficult to know all these things, particularly the distribution of particles, so it is difficult to use real thunderstorms to falsify cloud electrification theories. We here take one small step towards computing that map of electrical generator power, by relating radar reflectivity profiles of 2000 storms to lightning flash rates of those storms. This small step by itself doesn't falsify any existing electrification theories; it merely places weak constraints on the relation of electric generator power to cloud ice.

  15. Provider-Initiated Patient Satisfaction Reporting Yields Improved Physician Ratings Relative to Online Rating Websites.

    PubMed

    Ricciardi, Benjamin F; Waddell, Brad S; Nodzo, Scott R; Lange, Jeffrey; Nocon, Allina A; Amundsen, Spencer; Tarity, T David; McLawhorn, Alexander S

    2017-08-17

    Recently, providers have begun to publicly report the results of patient satisfaction surveys from their practices. However, these outcomes have never been compared with the findings of commercial online physician rating websites. The goals of the current study were to (1) compare overall patient satisfaction ratings for orthopedic surgeons derived from provider-based third-party surveys with existing commercial physician rating websites and (2) determine the association between patient ratings and provider characteristics. The authors identified 12 institutions that provided publicly available patient satisfaction outcomes derived from third-party surveys for their orthopedic surgeons as of August 2016. Orthopedic surgeons at these institutions were eligible for inclusion (N=340 surgeons). Provider characteristics were recorded from publicly available data. Four high-traffic commercial online physician rating websites were identified: Healthgrades.com, UCompareHealthCare.com, Vitals.com, and RateMDs.com. For each surgeon, overall ratings (on a scale of 1-5), total number of ratings, and percentage of negative ratings were compared between provider-initiated internal ratings and each commercial online website. Associations between baseline factors and overall physician ratings and negative ratings were assessed. Provider-initiated internal patient satisfaction ratings showed a greater number of overall patient ratings, higher overall patient satisfaction ratings, and a lower percentage of negative comments compared with commercial online physician rating websites. A greater number of years in practice had a weak association with lower internal ratings, and an academic practice setting and a location in the Northeast were protective factors for negative physician ratings. Compared with commercial online physician rating websites, provider-initiated patient satisfaction ratings of orthopedic surgeons appear to be more favorable, with greater numbers of responses

  16. Relative rates and features of musculoskeletal complications in adult sicklers.

    PubMed

    Bahebeck, Jean; Atangana, Réné; Techa, André; Monny-Lobe, Marcel; Sosso, Maurice; Hoffmeyer, Pierre

    2004-04-01

    The purpose of this study was to prospectively look for the relative rates and features of musculoskeletal complications in a sample of adult homozygous SS sicklers in Yaoundé. During a 3-year period, known homozygous SS sicklers aged sixteen years or more, with suspicion or evidence of locomotor system disease, including leg ulcer, were consecutively investigated through complete medical history, clinical examination, full blood count, C-reactive protein, standard radiographs of the area of complaint, and, when necessary, CT scan and pus analysis. Those patients with no definite diagnosis were excluded. The study group comprised 84 patients aged 16 to 51 years (mean age: 22 years), with a male/female ratio of 0.75. Four of them (4.5%) were older than 40 years. Thirty five (41.6%) presented a total of 50 lesions of aseptic osteonecrosis, which were located in the hips in 25 cases (50%), in the lumbar spine in 20 cases (40%), in the humeral head in four cases (10%) and in the talar body in one case. The hip necrosis was grade I in 6 cases, grade II in four, grade III in 11 and terminal in four. Multiple sites of necrosis were observed in six patients. Nineteen (22.6%) of the sicklers came on with 36 malleolar ulcers, more frequently in males (sex ratio: 5/1) and 28 (78%) located on the medial side. Fifteen sites of osteomyelitis were noted in 14 patients (17.8%) and septic arthritis in six (7%). Less frequent complications were impingement syndrome, gout osteoarthropathy, stress fracture, subtalar fusion, knee osteoarthritis, tendonitis of the anterior tibialis, and recurrent dislocation of the patella. All patients were managed conventionally, except for advanced aseptic necrosis in which the indication for arthroplasty was delayed till the terminal stage. As suggested by another recent report from Senegal, efforts should be made to improve the life expectancy of sicklers in Sub-Saharan African countries, by acting on education, social and medical care

  17. Afterhyperpolarization-firing rate relation of turtle spinal neurons.

    PubMed

    Stauffer, E K; Stuart, D G; McDonagh, J C; Hornby, T G; Reinking, R M

    2005-02-01

    This study addressed the afterhyperploarization-firing rate relationship of unanesthetized turtle spinal motoneurons and interneurons. The afterhyperploarization of their solitary action potential at rheobase was compared to that during the cells' minimum and maximum firing rates. Like previous mammalian findings, afterhyperpolarization duration and area at rheobase were 32 and 19% less for high- versus low-threshold motoneurons. Contrariwise, maximum firing rate was two times less for the high-threshold group. Other new findings were that for high- versus low-threshold interneurons, afterhyperpolarization duration and area were 25 and 95% less, and maximum firing rate 21% higher for the high-threshold group. For combined motoneurons versus interneurons, there were no differences in afterhyperpolarization duration and area at rheobase, whereas maximum firing rate was 265% higher for the interneurons. For high-threshold motoneurons alone, there were significant associations between minimum firing rate and afterhyperpolarization duration and area measured at rheobase. In summary, this study showed that (1) the afterhyperploarization values of both turtle spinal motoneurons and interneurons at rheobase provided little indication of their corresponding values at the cells' minimum and maximum firing states, and (2) the evolution of afterhyperploarization from rheobase to maximum firing state differed both qualitatively and quantitatively for motoneurons versus interneurons.

  18. Colorectal Cancer in Jordan: Survival Rate and Its Related Factors

    PubMed Central

    Arqoub, Kamal H.; Tarawneh, Mohammad R.; Al-zaghal, Marwan J.; Subih, Hadil S.

    2017-01-01

    Objectives. To estimate the survival rate of colorectal cancer (CRC) and determine its predictors among Jordanian patients who were diagnosed in the period of 2005–2010. Methods. This study was based on Jordan cancer registry. All CRC cases that were registered in cancer registry during 2005–2010 were analyzed using the survival analysis. The last date for follow-up was 1st Oct 2016. Results. A total of 3005 patients with CRC were registered during 2005–2010. The overall 5-year and 10-year survival rates for patients with CRC were 58.2% and 51.8%, respectively. The 5-year survival rate decreased significantly from 60.4% for the age <50 years to 49.3% for the age ≥70 years (p < 0.005). The 5-year survival rate was 72.1% for the localized stage, 53.8% for the regional stage, and 22.6% for the distant metastasis. In the multivariate analysis, the only factors that were significantly associated with survival were age, grade, stage, and location of tumor. Conclusions. The overall 5-year and ten-year survival rates for CRC were 58.2% and 51.8%, respectively. Increased age, poor differentiation, advanced cancer stage, and right-sided cancers were associated with lower survival rates. Screening strategies are needed for early detection of colon adenomas and colorectal cancer in Jordan. PMID:28458690

  19. Unemployment Rate, Smoking in China: Are They Related?

    PubMed Central

    Wang, Qing; Shen, Jay J.; Cochran, Chris

    2016-01-01

    Background: Studies on the relationship between unemployment rate and smoking have yielded mixed results. The issue in China has not been studied. This study aims to examine the influence of unemployment rate on smoking in China. Methods: Logit model and two-stage least squares (2SLS) estimation were used to estimate the effects. Estimations were done for 4585 individual over 45 using data from China Health and Retirement Longitudinal Study conducted in Zhejiang and Gansu provinces in 2008 and 2012. Results: A percent increase in the unemployment rate resulted in the increase in the likelihood of smoking by a combined 9.1 percent for those who smoked including a 2.9% increase for those who smoked 1–10 cigarettes per day; a 2.8% increase for those who smoked 11–20 cigarettes per day; and a 3.4% increase for those who smoked 20 cigarettes or more per day. The effects were stronger for those who were employed. Non-drinkers were more likely to engage in smoking with increased unemployment rate. 2SLS estimation revealed the same association. Conclusions: The unemployment rate was positively associated with smoking behavior. Smoking control and intervention strategies should focus on both the individual′s characteristics and the physical environment in which unemployment rate tend to rise. PMID:26761019

  20. Unemployment Rate, Smoking in China: Are They Related?

    PubMed

    Wang, Qing; Shen, Jay J; Cochran, Chris

    2016-01-08

    Studies on the relationship between unemployment rate and smoking have yielded mixed results. The issue in China has not been studied. This study aims to examine the influence of unemployment rate on smoking in China. Logit model and two-stage least squares (2SLS) estimation were used to estimate the effects. Estimations were done for 4585 individual over 45 using data from China Health and Retirement Longitudinal Study conducted in Zhejiang and Gansu provinces in 2008 and 2012. A percent increase in the unemployment rate resulted in the increase in the likelihood of smoking by a combined 9.1 percent for those who smoked including a 2.9% increase for those who smoked 1-10 cigarettes per day; a 2.8% increase for those who smoked 11-20 cigarettes per day; and a 3.4% increase for those who smoked 20 cigarettes or more per day. The effects were stronger for those who were employed. Non-drinkers were more likely to engage in smoking with increased unemployment rate. 2SLS estimation revealed the same association. The unemployment rate was positively associated with smoking behavior. Smoking control and intervention strategies should focus on both the individual's characteristics and the physical environment in which unemployment rate tend to rise.

  1. Emergent relation between surface vapor conductance and relative humidity profiles yields evaporation rates from weather data.

    PubMed

    Salvucci, Guido D; Gentine, Pierre

    2013-04-16

    The ability to predict terrestrial evapotranspiration (E) is limited by the complexity of rate-limiting pathways as water moves through the soil, vegetation (roots, xylem, stomata), canopy air space, and the atmospheric boundary layer. The impossibility of specifying the numerous parameters required to model this process in full spatial detail has necessitated spatially upscaled models that depend on effective parameters such as the surface vapor conductance (C(surf)). C(surf) accounts for the biophysical and hydrological effects on diffusion through the soil and vegetation substrate. This approach, however, requires either site-specific calibration of C(surf) to measured E, or further parameterization based on metrics such as leaf area, senescence state, stomatal conductance, soil texture, soil moisture, and water table depth. Here, we show that this key, rate-limiting, parameter can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and E. The relation is that the vertical variance of the relative humidity profile is less than would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. It is found to hold over a wide range of climate conditions (arid-humid) and limiting factors (soil moisture, leaf area, energy). With this relation, estimates of E and C(surf) can be obtained globally from widely available meteorological measurements, many of which have been archived since the early 1900s. In conjunction with precipitation and stream flow, long-term E estimates provide insights and empirical constraints on projected accelerations of the hydrologic cycle.

  2. Age-Related Differences in Speech Rate Perception Do Not Necessarily Entail Age-Related Differences in Speech Rate Use

    ERIC Educational Resources Information Center

    Heffner, Christopher C.; Newman, Rochelle S.; Dilley, Laura C.; Idsardi, William J.

    2015-01-01

    Purpose: A new literature has suggested that speech rate can influence the parsing of words quite strongly in speech. The purpose of this study was to investigate differences between younger adults and older adults in the use of context speech rate in word segmentation, given that older adults perceive timing information differently from younger…

  3. Age-Related Differences in Speech Rate Perception Do Not Necessarily Entail Age-Related Differences in Speech Rate Use

    ERIC Educational Resources Information Center

    Heffner, Christopher C.; Newman, Rochelle S.; Dilley, Laura C.; Idsardi, William J.

    2015-01-01

    Purpose: A new literature has suggested that speech rate can influence the parsing of words quite strongly in speech. The purpose of this study was to investigate differences between younger adults and older adults in the use of context speech rate in word segmentation, given that older adults perceive timing information differently from younger…

  4. Bouts of responding: the relation between bout rate and the rate of variable-interval reinforcement.

    PubMed Central

    Shull, Richard L; Grimes, Julie A; Bennett, J Adam

    2004-01-01

    By nose poking a lighted key, rats obtained food pellets on either a variable-interval schedule of reinforcement or a schedule that required an average of four additional responses after the end of tile variable-interval component (a tandem variable-interval variable-ratio 4 schedule). With both schedule types, the mean variable interval was varied between blocks of sessions from 16 min to 0.25 min. Total rate of key poking increased similarly as a function of the reinforcer rate for the two schedule types, but response rate was higher with than without the four-response requirement. Analysis of log survivor plots of interresponse times showed that key poking occurred in bouts. The rate of initiating bouts increased as a function of reinforcer rate but was either unaffected or was decreased by adding the four-response requirement. Within-bout response rate was insensitive to reinforcer rate and only inconsistently affected by the four-response requirement. For both kinds of schedule, the ratio of bout time to between-bout pause time was approximately a power function of reinforcer rate, with exponents above and below 1.0. PMID:15113134

  5. Divergence of conserved non-coding sequences: rate estimates and relative rate tests.

    PubMed

    Wagner, Günter P; Fried, Claudia; Prohaska, Sonja J; Stadler, Peter F

    2004-11-01

    In many eukaryotic genomes only a small fraction of the DNA codes for proteins, but the non-protein coding DNA harbors important genetic elements directing the development and the physiology of the organisms, like promoters, enhancers, insulators, and micro-RNA genes. The molecular evolution of these genetic elements is difficult to study because their functional significance is hard to deduce from sequence information alone. Here we propose an approach to the study of the rate of evolution of functional non-coding sequences at a macro-evolutionary scale. We identify functionally important non-coding sequences as Conserved Non-Coding Nucleotide (CNCN) sequences from the comparison of two outgroup species. The CNCN sequences so identified are then compared to their homologous sequences in a pair of ingroup species, and we monitor the degree of modification these sequences suffered in the two ingroup lineages. We propose a method to test for rate differences in the modification of CNCN sequences among the two ingroup lineages, as well as a method to estimate their rate of modification. We apply this method to the full sequences of the HoxA clusters from six gnathostome species: a shark, Heterodontus francisci; a basal ray finned fish, Polypterus senegalus; the amphibian, Xenopus tropicalis; as well as three mammalian species, human, rat and mouse. The results show that the evolutionary rate of CNCN sequences is not distinguishable among the three mammalian lineages, while the Xenopus lineage has a significantly increased rate of evolution. Furthermore the estimates of the rate parameters suggest that in the stem lineage of mammals the rate of CNCN sequence evolution was more than twice the rate observed within the placental amniotes clade, suggesting a high rate of evolution of cis-regulatory elements during the origin of amniotes and mammals. We conclude that the proposed methods can be used for testing hypotheses about the rate and pattern of evolution of putative

  6. Relational Responding Modulates and Reverses Affective Ratings in Evaluative Conditioning

    ERIC Educational Resources Information Center

    Molet, Mikael; Macquet, Benjamin; Charley, Gregory

    2013-01-01

    Three experiments explored relational responding in evaluative conditioning. In Experiment 1, the participants were trained with a computer task to make relational responses by putting CSs of different sizes in boxes in order of size. Subsequently they were instructed that these different sized CSs represented different intensities of hypothetical…

  7. Relational Responding Modulates and Reverses Affective Ratings in Evaluative Conditioning

    ERIC Educational Resources Information Center

    Molet, Mikael; Macquet, Benjamin; Charley, Gregory

    2013-01-01

    Three experiments explored relational responding in evaluative conditioning. In Experiment 1, the participants were trained with a computer task to make relational responses by putting CSs of different sizes in boxes in order of size. Subsequently they were instructed that these different sized CSs represented different intensities of hypothetical…

  8. CREME96 and Related Error Rate Prediction Methods

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.

    2012-01-01

    Predicting the rate of occurrence of single event effects (SEEs) in space requires knowledge of the radiation environment and the response of electronic devices to that environment. Several analytical models have been developed over the past 36 years to predict SEE rates. The first error rate calculations were performed by Binder, Smith and Holman. Bradford and Pickel and Blandford, in their CRIER (Cosmic-Ray-Induced-Error-Rate) analysis code introduced the basic Rectangular ParallelePiped (RPP) method for error rate calculations. For the radiation environment at the part, both made use of the Cosmic Ray LET (Linear Energy Transfer) spectra calculated by Heinrich for various absorber Depths. A more detailed model for the space radiation environment within spacecraft was developed by Adams and co-workers. This model, together with a reformulation of the RPP method published by Pickel and Blandford, was used to create the CR ME (Cosmic Ray Effects on Micro-Electronics) code. About the same time Shapiro wrote the CRUP (Cosmic Ray Upset Program) based on the RPP method published by Bradford. It was the first code to specifically take into account charge collection from outside the depletion region due to deformation of the electric field caused by the incident cosmic ray. Other early rate prediction methods and codes include the Single Event Figure of Merit, NOVICE, the Space Radiation code and the effective flux method of Binder which is the basis of the SEFA (Scott Effective Flux Approximation) model. By the early 1990s it was becoming clear that CREME and the other early models needed Revision. This revision, CREME96, was completed and released as a WWW-based tool, one of the first of its kind. The revisions in CREME96 included improved environmental models and improved models for calculating single event effects. The need for a revision of CREME also stimulated the development of the CHIME (CRRES/SPACERAD Heavy Ion Model of the Environment) and MACREE (Modeling and

  9. Protostellar spin-down: a planetary lift?

    NASA Astrophysics Data System (ADS)

    Bouvier, J.; Cébron, D.

    2015-11-01

    When they first appear in the HR diagram, young stars rotate at a mere 10 per cent of their break-up velocity. They must have lost most of the angular momentum initially contained in the parental cloud, the so-called angular momentum problem. We investigate here a new mechanism by which large amounts of angular momentum might be shed from young stellar systems, thus yielding slowly rotating young stars. Assuming that planets promptly form in circumstellar discs and rapidly migrate close to the central star, we investigate how the tidal and magnetic interactions between the protostar, its close-in planet(s), and the inner circumstellar disc can efficiently remove angular momentum from the central object. We find that neither the tidal torque nor the variety of magnetic torques acting between the star and the embedded planet are able to counteract the spin-up torques due to accretion and contraction. Indeed, the former are orders of magnitude weaker than the latter beyond the corotation radius and are thus unable to prevent the young star from spinning up. We conclude that star-planet interaction in the early phases of stellar evolution does not appear as a viable alternative to magnetic star-disc coupling to understand the origin of the low angular momentum content of young stars.

  10. Relation of heart rate recovery to heart rate variability in persons with paraplegia.

    PubMed

    Jae, Sae Young; Heffernan, Kevin S; Lee, Miyoung; Fernhall, Bo

    2011-04-01

    Heart rate recovery (HRR) after treadmill exercise testing is an index of cardiac autonomic activity in non-disabled persons, but it is unknown if this is also the case in individuals with spinal cord injury (SCI). We investigated the relationship between HRR after maximal arm exercise testing and resting autonomic activity in persons with paraplegia. A total of 17 (male n = 9, female n = 8) active individuals with paraplegia (injury below T6) were included in the study. Frequency domain analyses of resting heart rate variability were obtained and participants completed a maximal arm exercise test. HRR was calculated as the difference between peak heart rate during the test and heart rate 1 min (HRR1) and 2 (HRR2) min after cessation of exercise. HRR 1 and HRR 2 were statistically significantly correlated with high-frequency (HF) power (r = 0.46, p < 0.05 and r = 0.47, p < 0.05) and the LF/HF ratio (r = -0.49, p < 0.05 and r = -0.50, p < 0.05). After adjusting for age, peak heart rate and peak oxygen uptake, HRR 2 was still significantly associated with HF power (r = 0.50, p < 0.05) and the LF/HF ratio (r = -0.58, p < 0.05). These findings indicate that HRR after maximal arm exercise testing is associated with resting cardiac autonomic activity in persons with paraplegia. This would suggest that HRR after maximal arm exercise testing can be used as an index of autonomic function in this population.

  11. Relating reconnection rate, exhaust structure and effective resistivity

    NASA Astrophysics Data System (ADS)

    Singh, Nagendra

    2014-03-01

    The magnetic reconnection structure consists of a central diffusion region (CDR) and a cone or wedge shaped reconnection exhaust containing accelerated plasma flows and electromagnetic fluctuations. We predict here the relationship among the exhaust half-cone angle (θe), the half width (w) of the CDR, the outflow velocity Vo, and the effective resistivity (ηeff), which includes the effects of all the nonideal terms in the generalized Ohm's law. The effective resistivity is defined as the ratio of reconnection electric field Erec to the current density Jy at the X point and it essentially represents the loss of momentum from the current-carrying plasma particles due to scattering by waves, their inertia or outflux from the CDR. The relation is checked against relevant results previously reported from laboratory experiments, space observations, and simulations, showing excellent agreement. The relation can be used for estimating the ad-hoc effective resistivity often used in magnetohydrodynamic modeling of reconnection.

  12. Relating reconnection rate, exhaust structure and effective resistivity

    SciTech Connect

    Singh, Nagendra

    2014-03-15

    The magnetic reconnection structure consists of a central diffusion region (CDR) and a cone or wedge shaped reconnection exhaust containing accelerated plasma flows and electromagnetic fluctuations. We predict here the relationship among the exhaust half-cone angle (θ{sub e}), the half width (w) of the CDR, the outflow velocity V{sub o}, and the effective resistivity (η{sub eff}), which includes the effects of all the nonideal terms in the generalized Ohm's law. The effective resistivity is defined as the ratio of reconnection electric field E{sub rec} to the current density J{sub y} at the X point and it essentially represents the loss of momentum from the current-carrying plasma particles due to scattering by waves, their inertia or outflux from the CDR. The relation is checked against relevant results previously reported from laboratory experiments, space observations, and simulations, showing excellent agreement. The relation can be used for estimating the ad-hoc effective resistivity often used in magnetohydrodynamic modeling of reconnection.

  13. Modeling relative frost weathering rates at geomorphic scales

    NASA Astrophysics Data System (ADS)

    Rempel, Alan W.; Marshall, Jill A.; Roering, Joshua J.

    2016-11-01

    amplitudes, with a broad maximum centered on a mean annual temperature near the threshold required for crack growth. Warmer mean annual temperatures lead to less damage because of the reduction in time during which it is cold enough for cracking, whereas colder mean annual temperatures are accompanied by reduced water supply due to the temperature dependence of permeability. All of the controlling parameters in our model are tied explicitly to physical properties that can in principle be measured independently, which suggests promise for informing geomorphic interpretations of the role of frost weathering in evolving landforms and determining erosion rates.

  14. Comparison of the sputter rates of oxide films relative to the sputter rate of SiO{sub 2}

    SciTech Connect

    Baer, D. R.; Engelhard, M. H.; Lea, A. S.; Nachimuthu, P.; Droubay, T. C.; Kim, J.; Lee, B.; Mathews, C.; Opila, R. L.; Saraf, L. V.; Stickle, W. F.; Wallace, R. M.; Wright, B. S.

    2010-09-15

    There is a growing interest in knowing the sputter rates for a wide variety of oxides because of their increasing technological importance in many different applications. To support the needs of users of the Environmental Molecular Sciences Laboratory, a national scientific user facility, as well as our research programs, the authors made a series of measurements of the sputter rates from oxide films that have been grown by oxygen plasma-assisted molecular beam epitaxy, pulsed laser deposition, atomic layer deposition, electrochemical oxidation, or sputter deposition. The sputter rates for these oxide films were determined in comparison with those from thermally grown SiO{sub 2}, a common reference material for sputter rate determination. The film thicknesses and densities for most of these oxide films were measured using x-ray reflectivity. These oxide films were mounted in an x-ray photoelectron or Auger electron spectrometer for sputter rate measurements using argon ion sputtering. Although the primary objective of this work was to determine relative sputter rates at a fixed angle, the measurements also examined (i) the angle dependence of the relative sputter rates, (ii) the energy dependence of the relative sputter rates, and (iii) the extent of ion beam induced reduction for some oxides. Oxide films examined include SiO{sub 2}, Al{sub 2}O{sub 3}, CeO{sub 2}, Cr{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, HfO{sub 2}, In-Sn oxide, Ta{sub 2}O{sub 5}, TiO{sub 2} (anatase, rutile, and amorphous), and ZnO. The authors found that the sputter rates for the oxides can vary up to a factor of 2 (usually lower) from that observed for SiO{sub 2}. The ratios of sputter rates relative to those of SiO{sub 2} appear to be relatively independent of ion beam energy in the range of 1-4 kV and for incident angles <50 deg. As expected, the extent of ion beam induced reduction of the oxides varies with the sputter angle.

  15. Comparison of the Sputter Rates of Oxide Films Relative to the Sputter Rate of SiO2

    SciTech Connect

    Baer, Donald R.; Engelhard, Mark H.; Lea, Alan S.; Nachimuthu, Ponnusamy; Droubay, Timothy C.; Kim, J.; Lee, B.; Mathews, C.; Opila, R. L.; Saraf, Laxmikant V.; Stickle, William F.; Wallace, Robert; Wright, B. S.

    2010-09-02

    Because of the increasing technological importance of oxide films for a variety of applications, there is a growing interest in knowing the sputter rates for a wide variety of oxides. To support needs of users of the Environmental Molecular Sciences Laboratory (EMSL) User facility as well as our research programs, we have made a series of measurements of the sputter rates for oxide films that have been grown by oxygen plasma assisted molecular beam epitaxy (OPA-MBE), pulsed laser deposition (PLD), Atomic Layer Deposition (ALD), electrochemical oxidation, or sputter deposition. The sputter rates for these oxide films were determined in comparison to the sputter rates for thermally grown SiO2, a common sputter rate reference material. The film thicknesses and densities of these films were usually measured using x-ray reflectivity (XRR). These samples were mounted in an x-ray photoelectron spectroscopy (XPS) system or an Auger electron spectrometer for sputtering measurements using argon ion sputtering. Although the primary objective was to determine relative sputter rates at a fixed angle, the measurements were also used to determine: i) the angle dependence of the relative sputter rates; ii) the energy dependence of the relative sputter rates; and iii) the extent of ion beam reduction for the various oxides. Materials examined include: SiO2 (reference films), Al2O3, CeO2, Cr2O3, Fe2O3, HfO2, ITO (In-Sn-oxide) Ta2O5, TiO2 (anatase and rutile) and ZnO. We find that the sputter rates for the oxides can vary up to a factor of two (usually slower) from that observed for SiO2. The ratios of sputter rates to SiO2 appear to be relatively independent of ion beam energy for the range of 1kV to 4 kV and for incident angles of less than 50º. As expected, the ion beam reduction of the oxides varies with the sputter angle. These studies demonstrate that we can usually obtain sputter rate reproducibility better than 5% for similar oxide films.

  16. Relative Cooling Rates of Meteoritic Fe-Ni Metal Determined from Kamacite-Taenite Interface Compositions

    NASA Astrophysics Data System (ADS)

    Goldstein, J. I.; Yang, J.; Scott, E. R. D.

    2013-09-01

    The validity of the kamacite/taenite interface method to obtain relative metallorgaphic cooling rates was reinvestigated. Strong support is found for the 50 fold variation in cooling rate across the IVA chemical group.

  17. Variation in cesarean section rates is not related to maternal and neonatal outcomes.

    PubMed

    Pallasmaa, Nanneli; Alanen, Anna; Ekblad, Ulla; Vahlberg, Tero; Koivisto, Mari; Raudaskoski, Tytti; Ulander, Veli-Matti; Uotila, Jukka

    2013-10-01

    The aim of this study was to compare the rate of cesarean sections in 12 delivery units in Finland, and to assess possible associations between cesarean section rates and maternal and neonatal complications. Prospective multicenter cohort study. The 12 largest delivery units in Finland. Total obstetric population between 1 January 2005 and 30 June 2005 (n = 19 764). Prospectively collected data on 2496 cesarean sections and data derived from the Finnish Birth Register on all deliveries in these units were compared. Cesarean section rates and maternal complication rates were adjusted for known risk factors. Cesarean section rate, maternal complications related to cesarean section, and neonatal asphyxia. The cesarean section rates varied significantly between the hospitals (12.9-25.1%, p < 0.0001), as did the maternal complication rates related to cesarean section (13.0-36.5%, p < 0.0001). There was no relation between maternal complications and the cesarean section rate. The differences remained after adjusting for risk factors. Neonatal asphyxia rates varied between 0.14 and 2.8% (p < 0.0001) and were not related to the cesarean section rates. The rates of cesarean section, maternal complications and neonatal asphyxia vary markedly between different delivery units. Good maternal and neonatal outcomes can be achieved with cesarean section rates <15%. © 2013 Nordic Federation of Societies of Obstetrics and Gynecology.

  18. Trends in rates of acetaminophen-related adverse events in the United States.

    PubMed

    Major, Jacqueline M; Zhou, Esther H; Wong, Hui-Lee; Trinidad, James P; Pham, Tracy M; Mehta, Hina; Ding, Yulan; Staffa, Judy A; Iyasu, Solomon; Wang, Cunlin; Willy, Mary E

    2016-05-01

    The goal of this study is to summarize trends in rates of adverse events attributable to acetaminophen use, including hepatotoxicity and mortality. A comprehensive analysis of data from three national surveillance systems estimated rates of acetaminophen-related events identified in different settings, including calls to poison centers (2008-2012), emergency department visits (2004-2012), and inpatient hospitalizations (1998-2011). Rates of acetaminophen-related events were calculated per setting, census population, and distributed drug units. Rates of poison center calls with acetaminophen-related exposures decreased from 49.5/1000 calls in 2009 to 43.5/1000 calls in 2012. Rates of emergency department visits for unintentional acetaminophen-related adverse events decreased from 58.0/1000 emergency department visits for adverse drug events in 2009 to 50.2/1000 emergency department visits in 2012. Rates of hospital inpatient discharges with acetaminophen-related poisoning decreased from 119.8/100 000 hospitalizations in 2009 to 108.6/100 000 hospitalizations in 2011. After 2009, population rates of acetaminophen-related events per 1 million census population decreased for poison center calls and hospitalizations, while emergency department visit rates remained stable. However, when accounting for drug sales, the rate of acetaminophen-related events (per 1 million distributed drug units) increased after 2009. Prior to 2009, the rates of acetaminophen-related hospitalizations had been slowly increasing (p-trend = 0.001). Acetaminophen-related adverse events continue to be a public health burden. Future studies with additional time points are necessary to confirm trends and determine whether recent risk mitigation efforts had a beneficial impact on acetaminophen-related adverse events. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public

  19. Autonomic responses to heat pain: Heart rate, skin conductance, and their relation to verbal ratings and stimulus intensity.

    PubMed

    Loggia, Marco L; Juneau, Mylène; Bushnell, M Catherine

    2011-03-01

    In human pain experiments, as well as in clinical settings, subjects are often asked to assess pain using scales (eg, numeric rating scales). Although most subjects have little difficulty in using these tools, some lack the necessary basic cognitive or motor skills (eg, paralyzed patients). Thus, the identification of appropriate nonverbal measures of pain has significant clinical relevance. In this study, we assessed heart rate (HR), skin conductance (SC), and verbal ratings in 39 healthy male subjects during the application of twelve 6-s heat stimuli of different intensities on the subjects' left forearm. Both HR and SC increased with more intense painful stimulation. However, HR but not SC, significantly correlated with pain ratings at the group level, suggesting that HR may be a better predictor of between-subject differences in pain than is SC. Conversely, changes in SC better predicted variations in ratings within a given individual, suggesting that it is more sensitive to relative changes in perception. The differences in findings derived from between- and within-subject analyses may result from greater within-subject variability in HR. We conclude that at least for male subjects, HR provides a better predictor of pain perception than SC, but that data should be averaged over several stimulus presentations to achieve consistent results. Nevertheless, variability among studies, and the indication that gender of both the subject and experimenter could influence autonomic results, lead us to advise caution in using autonomic or any other surrogate measures to infer pain in individuals who cannot adequately report their perception. Skin conductance is more sensitive to detect within-subject perceptual changes, but heart rate appears to better predict pain ratings at the group level.

  20. Modeling Relative Position Relative Velocity and Range Rate for Formation Flying

    DTIC Science & Technology

    2002-01-01

    The epoch is near the autumnal equinox and the orbit plane is nearly parallel to the sun-earth vector. This explains why the effect is mostly in the...improve if fl is changed or an epoch not so close to equinox is used. A projected circular case was run at 600 km altitude. Unexpectedly, the relative

  1. Judges' perception of candidates' organization and communication, in relation to oral certification examination ratings.

    PubMed

    Houston, James E; Myford, Carol M

    2009-11-01

    To determine (1) whether judges differed in the levels of severity they exercised when rating candidates' performance in an oral certification exam, (2) to what extent candidates' clinical competence ratings were related to their organization/communication ratings, and (3) to what extent clinical competence ratings could predict organization/communication ratings. Six hundred eighty-four physicians participated in a medical specialty board's 2002 oral examination. Ninety-nine senior members of the medical specialty served as judges, rating candidates' performances. Candidates' clinical competence ratings were analyzed using multifaceted Rasch measurement to investigate judge severity. A Pearson correlation was calculated to examine the relationship between ratings of clinical competence and organization/communication. Logistic regression was used to determine to what extent clinical competence ratings predicted organization/communication ratings. There were about three statistically distinct strata of judge severity; judges were not interchangeable. There was a moderately strong relationship between the two sets of candidate ratings. Higher clinical competence ratings were associated with an organization/communication rating of acceptable, whereas lower clinical competence ratings were associated with an organization/communication rating of unacceptable. The judges' clinical competence ratings correctly predicted 61.9% of the acceptable and 88.3% of the unacceptable organization/communication ratings. Overall, the clinical competence ratings correctly predicted 80% of the organization/communication ratings. The close association between the two sets of ratings was possibly due to a "halo" effect. Several explanations for this relationship were explored, and the authors considered the implications for their understanding of how judges carry out this complex rating task.

  2. The relation between auditory-nerve temporal responses and perceptual rate integration in cochlear implants.

    PubMed

    Hughes, Michelle L; Baudhuin, Jacquelyn L; Goehring, Jenny L

    2014-10-01

    The purpose of this study was to examine auditory-nerve temporal response properties and their relation to psychophysical threshold for electrical pulse trains of varying rates ("rate integration"). The primary hypothesis was that better rate integration (steeper slope) would be correlated with smaller decrements in ECAP amplitude as a function of stimulation rate (shallower slope of the amplitude-rate function), reflecting a larger percentage of the neural population contributing more synchronously to each pulse in the train. Data were obtained for 26 ears in 23 cochlear-implant recipients. Electrically evoked compound action potential (ECAP) amplitudes were measured in response to each of 21 pulses in a pulse train for the following rates: 900, 1200, 1800, 2400, and 3500 pps. Psychophysical thresholds were obtained using a 3-interval, forced-choice adaptive procedure for 300-ms pulse trains of the same rates as used for the ECAP measures, which formed the rate-integration function. For each electrode, the slope of the psychophysical rate-integration function was compared to the following ECAP measures: (1) slope of the function comparing average normalized ECAP amplitude across pulses versus stimulation rate ("adaptation"), (2) the rate that produced the maximum alternation depth across the pulse train, and (3) rate at which the alternating pattern ceased (stochastic rate). Results showed no significant relations between the slope of the rate-integration function and any of the ECAP measures when data were collapsed across subjects. However, group data showed that both threshold and average ECAP amplitude decreased with increased stimulus rate, and within-subject analyses showed significant positive correlations between psychophysical thresholds and mean ECAP response amplitudes across the pulse train. These data suggest that ECAP temporal response patterns are complex and further study is required to better understand the relative contributions of adaptation

  3. The relation between auditory-nerve temporal responses and perceptual rate integration in cochlear implants

    PubMed Central

    Hughes, Michelle L.; Baudhuin, Jacquelyn L.; Goehring, Jenny L.

    2014-01-01

    The purpose of this study was to examine auditory-nerve temporal response properties and their relation to psychophysical threshold for electrical pulse trains of varying rates (“rate integration”). The primary hypothesis was that better rate integration (steeper slope) would be correlated with smaller decrements in ECAP amplitude as a function of stimulation rate (shallower slope of the amplitude-rate function), reflecting a larger percentage of the neural population contributing more synchronously to each pulse in the train. Data were obtained for 26 ears in 23 cochlear-implant recipients. Electrically evoked compound action potential (ECAP) amplitudes were measured in response to each of 21 pulses in a pulse train for the following rates: 900, 1200, 1800, 2400, and 3500 pps. Psychophysical thresholds were obtained using a 3-interval, forced-choice adaptive procedure for 300-ms pulse trains of the same rates as used for the ECAP measures, which formed the rate-integration function. For each electrode, the slope of the psychophysical rate-integration function was compared to the following ECAP measures: (1) slope of the function comparing average normalized ECAP amplitude across pulses versus stimulation rate (“adaptation”), (2) the rate that produced the maximum alternation depth across the pulse train, and (3) rate at which the alternating pattern ceased (stochastic rate). Results showed no significant relations between the slope of the rate-integration function and any of the ECAP measures when data were collapsed across subjects. However, group data showed that both threshold and average ECAP amplitude decreased with increased stimulus rate, and within-subject analyses showed significant positive correlations between psychophysical thresholds and mean ECAP response amplitudes across the pulse train. These data suggest that ECAP temporal response patterns are complex and further study is required to better understand the relative contributions of

  4. Lightning rates relative to tornadic storm evolution on 22 May 1981

    NASA Technical Reports Server (NTRS)

    Macgorman, Donald R.; Burgess, Donald W.; Mazur, Vladislav; Rust, W. David; Taylor, William L.

    1989-01-01

    Lightning and Doppler radar data for two tornadic storms in Oklahoma on May 22, 1981 are used to analyze ground flash rates relative to the time of tornadoes. It is found that the ground flash rates had no obvious relationship with the tornado times, although the stroke rate in both storms was greatest after the tornadic stage ended. The variations in the cyclone shear and the intracloud flash rates within 10 km of the mesocyclone region are examined. The results suggest that most tornadic storms have an increase in total flash rates near the time of the tornado and that this increase is often dominated by intracloud flashes.

  5. Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery.

    PubMed

    Esco, Michael R; Williford, Henry N; Olson, Michele S

    2011-08-01

    The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., VO2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean VO2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg(-1)·min(-1) and 24.7 ± 2.2 kg·m(-2), respectively. Although VO2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and VO2max.

  6. Relative rate studies of the reactions of chlorine atoms with simple alkanes and the chlorinated methanes

    SciTech Connect

    Wingen, L.; Lee, J.J.; Neavyn, R.

    1995-12-01

    The reactions of chlorine atoms with organics are of interest because atomic chlorine is a potential tropospheric oxidant. Relative rate constants for the reaction of pairs of simple alkanes (ethane/propane, ethane/n-butane, and isobutane/n-butane) and the chlorinated methanes (chloromethane, dichloromethane, and chloroform relative to methane) were measured, using the photolysis of Cl{sub 2} as the source of chlorine atoms and following the loss of the organics by GC-FID. The ratios of the relative rate constants were in excellent agreement with the literature except for ethane/n-butane, where our results are approximately 20% lower than recently published values, and for chloroform/methane, where our value is approximately 50% higher than the values recommended by JPL and JPCRD. Our results will be compard to previously published relative rate studies as well as to the results of absolute rate constant studies, and the differences will be discussed.

  7. Suicide Rate Differences by Sex, Age, and Urbanicity, and Related Regional Factors in Korea

    PubMed Central

    Cheong, Kyu-Seok; Choi, Min-Hyeok; Cho, Byung-Mann; Yoon, Tae-Ho; Kim, Chang-Hun; Kim, Yu-Mi

    2012-01-01

    Objectives Identify the characteristics related to the suicide rates in rural and urban areas of Korea and discover the factors that influence the suicide rate of the rural and urban areas. Methods Using the data on causes of death from 2006 to 2008, the suicide rates were calculated and compared after age-standardization based on gender, age group and urbanicity. And, in order to understand the factors that influence suicide rate, total 10 local characteristics in four domains - public service, social integration, residential environment, and economic status - were selected for multiple regression analysis. Results The suicide rates were higher in men than women, in rural areas than urban, and in older people than the younger. Generally, although there were variations according to age group and urbanicity, suicide rates were significantly related to residential environment and regional economic status but not related to regional welfare spending and social integration. In addition, the population over the age of 65 years, only regional economic status has significantly influence on their suicide rates. Conclusions The influence of characteristics of regions on suicide rate is various by age-group, gender, and urbanicity. Therefore, in order to lower suicide rate and reduce the gap between regions, various approaches must be adopted by taking into account the socioeconomic characteristics of the regions. PMID:22509447

  8. Increased Fall-Related Mortality Rates in New Mexico, 1999–2005

    PubMed Central

    Wendelboe, Aaron M.; Landen, Michael G.

    2011-01-01

    Objective In 2000, fall injuries affected 30% of U.S. residents aged ≥65 years and cost $19 billion. In 2005, New Mexico (NM) had the highest fall-related mortality rate in the United States. We described factors associated with these elevated fall-related mortality rates. Methods To better understand the epidemiology of fatal falls in NM, we used state and national (Web-based Injury Statistics Query and Reporting System) vital records data for 1999–2005 to identify unintentional falls that were the underlying cause of death. We calculated age-adjusted mortality rates, rate ratios (RRs), and 95% confidence intervals (CIs) by sex, ethnicity, race, and year. Results For 1999–2005 combined, NM's fall-related mortality rate (11.7 per 100,000 population) was 2.1 times higher than the U.S. rate (5.6 per 100,000 population). Elevated RRs persisted when stratified by sex (male RR=2.0, female RR=2.2), ethnicity (Hispanic RR=2.5, non-Hispanic RR=2.1), race (white RR=2.0, black RR=1.7, American Indian RR=2.3, and Asian American/Pacific Islander RR=3.1), and age (≥50 years RR=2.0, <50 years RR=1.2). Fall-related mortality rates began to increase exponentially at age 50 years, which was 15 years younger than the national trend. NM non-Hispanic individuals had the highest demographic-specific fall-related mortality rate (11.8 per 100,000 population, 95% CI 11.0, 12.5). NM's 69.5% increase in fall-related mortality rate was approximately twice the U.S. increase (31.9%); the increase among non-Hispanic people (86.2%) was twice that among Hispanic people (43.5%). Conclusions NM's fall-related mortality rate was twice the U.S. rate; exhibited a greater increase than the U.S. rate; and persisted across sex, ethnicity, and race. Fall-related mortality disproportionately affects a relatively younger population in NM. Characterizing fall etiology will assist in the development of effective prevention measures. PMID:22043102

  9. A cloud model-radiative model combination for determining microwave TB-rain rate relations

    NASA Technical Reports Server (NTRS)

    Szejwach, Gerard; Adler, Robert F.; Jobard, Esabelle; Mack, Robert A.

    1986-01-01

    The development of a cloud model-radiative transfer model combination for computing average brightness temperature, T(B), is discussed. The cloud model and radiative transfer model used in this study are described. The relations between rain rate, cloud and rain water, cloud and precipitation ice, and upwelling radiance are investigated. The effects of the rain rate relations on T(B) under different climatological conditions are examined. The model-derived T(B) results are compared to the 92 and 183 GHz aircraft observations of Hakkarinen and Adler (1984, 1986) and the radar-estimated rain rate of Hakkarinen and Adler (1986); good correlation between the data is detected.

  10. Dose- and Rate-Dependent Effects of Cocaine on Striatal Firing Related to Licking

    PubMed Central

    Tang, Chengke; Mittler, Taliah; Duke, Dawn C.; Zhu, Yun; Pawlak, Anthony P.; West, Mark O.

    2011-01-01

    To examine the role of striatal mechanisms in cocaine-induced stereotyped licking, we investigated the acute effects of cocaine on striatal neurons in awake, freely moving rats before and after cocaine administration (0, 5, 10, or 20 mg/kg). Stereotyped licking was induced only by the high dose. Relative to control (saline), cocaine reduced lick duration and concurrently increased interlick interval, particularly at the high dose, but it did not affect licking rhythm. Firing rates of striatal neurons phasically related to licking movements were compared between matched licks before and after injection, minimizing any influence of sensorimotor variables on changes in firing. Both increases and decreases in average firing rate of striatal neurons were observed after cocaine injection, and these changes exhibited a dose-dependent pattern that strongly depended on predrug firing rate. At the middle and high doses relative to the saline group, the average firing rates of slow firing neurons were increased by cocaine, resulting from a general elevation of movement-related firing rates. In contrast, fast firing neurons showed decreased average firing rates only in the high-dose group, with reduced firing rates across the entire range for these neurons. Our findings suggest that at the high dose, increased phasic activity of slow firing striatal neurons and simultaneously reduced phasic activity of fast firing striatal neurons may contribute, respectively, to the continual initiation of stereotypic movements and the absence of longer movements. PMID:17991811

  11. The pattern of mammalian evolution and the relative rate of molecular evolution

    SciTech Connect

    Easteal, S. )

    1990-01-01

    The rates of nucleotide substitution at four genes in four orders of eutherian mammals are compared in relative rate tests using marsupial orthologs for reference. There is no evidence of systematic variation in evolutionary rate among the orders. The sequences are used to reconstruct the phylogeny of the orders using maximum likelihood, parsimony and compatibility methods. A branching order of rodent then ungulate then primate and lagomorph is overwhelmingly indicated. The nodes of the nucleotide based cladograms are widely separated in relation to the total lengths of the branches. The assumption of a star phylogeny that underlies Kimura's test for molecular evolutionary rate variation is shown to be invalid for eutherian mammals. Excess variance in nucleotide or amino acid differences between mammalian orders, above that predicted by neutral theory is explained better by variation in divergence time than by variation in evolutionary rate.

  12. Seasonal variations of indoor microbial exposures and their relation to temperature, relative humidity, and air exchange rate.

    PubMed

    Frankel, Mika; Bekö, Gabriel; Timm, Michael; Gustavsen, Sine; Hansen, Erik Wind; Madsen, Anne Mette

    2012-12-01

    Indoor microbial exposure has been related to adverse pulmonary health effects. Exposure assessment is not standardized, and various factors may affect the measured exposure. The aim of this study was to investigate the seasonal variation of selected microbial exposures and their associations with temperature, relative humidity, and air exchange rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m(3)) and were lowest in winter (median, 26 CFU/m(3)). Indoor bacteria peaked in spring (median, 2,165 CFU/m(3)) and were lowest in summer (median, 240 CFU/m(3)). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the mass of inhalable dust and number of particles. Temperature and air exchange rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and air exchange rates were significantly associated with several indoor microbial exposures, they could not fully explain the observed seasonal variations when tested in a mixed statistical model. In conclusion, the season significantly affects indoor microbial exposures, which are influenced by temperature, relative humidity, and air exchange rates.

  13. Seasonal Variations of Indoor Microbial Exposures and Their Relation to Temperature, Relative Humidity, and Air Exchange Rate

    PubMed Central

    Bekö, Gabriel; Timm, Michael; Gustavsen, Sine; Hansen, Erik Wind

    2012-01-01

    Indoor microbial exposure has been related to adverse pulmonary health effects. Exposure assessment is not standardized, and various factors may affect the measured exposure. The aim of this study was to investigate the seasonal variation of selected microbial exposures and their associations with temperature, relative humidity, and air exchange rates in Danish homes. Airborne inhalable dust was sampled in five Danish homes throughout the four seasons of 1 year (indoors, n = 127; outdoors, n = 37). Measurements included culturable fungi and bacteria, endotoxin, N-acetyl-beta-d-glucosaminidase, total inflammatory potential, particles (0.75 to 15 μm), temperature, relative humidity, and air exchange rates. Significant seasonal variation was found for all indoor microbial exposures, excluding endotoxin. Indoor fungi peaked in summer (median, 235 CFU/m3) and were lowest in winter (median, 26 CFU/m3). Indoor bacteria peaked in spring (median, 2,165 CFU/m3) and were lowest in summer (median, 240 CFU/m3). Concentrations of fungi were predominately higher outdoors than indoors, whereas bacteria, endotoxin, and inhalable dust concentrations were highest indoors. Bacteria and endotoxin correlated with the mass of inhalable dust and number of particles. Temperature and air exchange rates were positively associated with fungi and N-acetyl-beta-d-glucosaminidase and negatively with bacteria and the total inflammatory potential. Although temperature, relative humidity, and air exchange rates were significantly associated with several indoor microbial exposures, they could not fully explain the observed seasonal variations when tested in a mixed statistical model. In conclusion, the season significantly affects indoor microbial exposures, which are influenced by temperature, relative humidity, and air exchange rates. PMID:23001651

  14. Age-related changes in auditory and visual interactions in temporal rate perception

    PubMed Central

    Brooks, Cassandra J.; Anderson, Andrew J.; Roach, Neil W.; McGraw, Paul V.; McKendrick, Allison M.

    2015-01-01

    We investigated how aging affects the integration of temporal rate for auditory flutter (amplitude modulation) presented with visual flicker. Since older adults were poorer at detecting auditory amplitude modulation, modulation depth was individually adjusted so that temporal rate was equally discriminable for 10 Hz flutter and flicker, thereby balancing the reliability of rate information available to each sensory modality. With age-related sensory differences normalized in this way, rate asynchrony skewed both auditory and visual rate judgments to the same extent in younger and older adults. Therefore, reliability-based weighting of temporal rate is preserved in older adults. Concurrent presentation of synchronous 10 Hz flicker and flutter improved temporal rate discrimination consistent with statistically optimal integration in younger but not older adults. In a control experiment, younger adults were presented with the same physical auditory stimulus as older adults. This time, rate asynchrony skewed perceived rate with greater auditory weighting rather than balanced integration. Taken together, our results indicate that integration of discrepant auditory and visual rates is not altered due to the healthy aging process once sensory deficits are accounted for, but that aging does abolish the minor improvement in discrimination performance seen in younger observers when concordant rates are integrated. PMID:26624937

  15. Age-related changes in auditory and visual interactions in temporal rate perception.

    PubMed

    Brooks, Cassandra J; Anderson, Andrew J; Roach, Neil W; McGraw, Paul V; McKendrick, Allison M

    2015-01-01

    We investigated how aging affects the integration of temporal rate for auditory flutter (amplitude modulation) presented with visual flicker. Since older adults were poorer at detecting auditory amplitude modulation, modulation depth was individually adjusted so that temporal rate was equally discriminable for 10 Hz flutter and flicker, thereby balancing the reliability of rate information available to each sensory modality. With age-related sensory differences normalized in this way, rate asynchrony skewed both auditory and visual rate judgments to the same extent in younger and older adults. Therefore, reliability-based weighting of temporal rate is preserved in older adults. Concurrent presentation of synchronous 10 Hz flicker and flutter improved temporal rate discrimination consistent with statistically optimal integration in younger but not older adults. In a control experiment, younger adults were presented with the same physical auditory stimulus as older adults. This time, rate asynchrony skewed perceived rate with greater auditory weighting rather than balanced integration. Taken together, our results indicate that integration of discrepant auditory and visual rates is not altered due to the healthy aging process once sensory deficits are accounted for, but that aging does abolish the minor improvement in discrimination performance seen in younger observers when concordant rates are integrated.

  16. Mental workload measurement: Event-related potentials and ratings of workload and fatigue

    NASA Technical Reports Server (NTRS)

    Biferno, M. A.

    1985-01-01

    Event-related potentials were elicited when a digitized word representing a pilot's call-sign was presented. This auditory probe was presented during 27 workload conditions in a 3x3x3 design where the following variables were manipulated: short-term load, tracking task difficulty, and time-on-task. Ratings of workload and fatigue were obtained between each trial of a 2.5-hour test. The data of each subject were analyzed individually to determine whether significant correlations existed between subjective ratings and ERP component measures. Results indicated that a significant number of subjects had positive correlations between: (1) ratings of workload and P300 amplitude, (2) ratings of workload and N400 amplitude, and (3) ratings of fatigue and P300 amplitude. These data are the first to show correlations between ratings of workload or fatigue and ERP components thereby reinforcing their validity as measures of mental workload and fatigue.

  17. The effects of coloured light filter overlays on reading rates in age-related macular degeneration.

    PubMed

    Eperjesi, Frank; Fowler, Colin W; Evans, Bruce J W

    2004-12-01

    To determine the effect of coloured light filter overlays on reading rates for people with age-related macular degeneration (AMD). Using a prospective clinical trial design, we examined the null hypothesis that coloured light filter overlays do not improve reading rates in AMD when compared to a clear filter. Reading rates for 12 subjects with non-exudative AMD, associated with a relative scotoma and central fixation (mean age 81 years, SD 5.07 years) were determined using the Rate of Reading Test (printed, nonsense, lower case sans serif, stationary text) with 10 different, coloured light filter overlays (Intuitive Overlays); figures in brackets are percentage transmission values); rose (78%), pink (78%), purple (67%), aqua (81%), blue (74%), lime-green (86%), mint-green (85%), yellow (93%), orange (83%) and grey (71%). A clear overlay (Roscolene # 00) (360 cdm-2) with 100% transmittance was used as a control. Anova indicated that there was no statistically significant difference in reading rates with the coloured light filter overlays compared to the clear filter. Furthermore, chi-squared analysis indicated that the rose, purple and blue filters had a significantly poorer overall ranking in terms of reading rates compared to the other coloured and clear light filters. Coloured light filter overlays are unlikely to provide a clinically significant improvement in reading rates for people with non-exudative AMD associated with a relative scotoma and central fixation.

  18. Specific cerebellar regions are related to force amplitude and rate of force development.

    PubMed

    Spraker, M B; Corcos, D M; Kurani, A S; Prodoehl, J; Swinnen, S P; Vaillancourt, D E

    2012-01-16

    The human cerebellum has been implicated in the control of a wide variety of motor control parameters, such as force amplitude, movement extent, and movement velocity. These parameters often covary in both movement and isometric force production tasks, so it is difficult to resolve whether specific regions of the cerebellum relate to specific parameters. In order to address this issue, the current study used two experiments and SUIT normalization to determine whether BOLD activation in the cerebellum scales with the amplitude or rate of change of isometric force production or both. In the first experiment, subjects produced isometric pinch-grip force over a range of force amplitudes without any constraints on the rate of force development. In the second experiment, subjects varied the rate of force production, but the target force amplitude remained constant. The data demonstrate that BOLD activation in separate sub-areas of cerebellar regions lobule VI and Crus I/II scales with both force amplitude and force rate. In addition, BOLD activation in cerebellar lobule V and vermis VI was specific to force amplitude, whereas BOLD activation in lobule VIIb was specific to force rate. Overall, cerebellar activity related to force amplitude was located superior and medial, whereas activity related to force rate was inferior and lateral. These findings suggest that specific circuitry in the cerebellum may be dedicated to specific motor control parameters such as force amplitude and force rate.

  19. Abnormalities in Automatic Processing of Illness-Related Stimuli in Self-Rated Alexithymia

    PubMed Central

    Brandt, Laura; Pintzinger, Nina M.; Tran, Ulrich S.

    2015-01-01

    Aim To investigate abnormalities in automatic information processing related to self- and observer-rated alexithymia, especially with regard to somatization, controlling for confounding variables such as depression and affect. Sample 89 healthy subjects (60% female), aged 19–71 years (M = 32.1). 58 subjects were additionally rated by an observer. Measures Alexithymia (self-rating: TAS-20, observer rating: OAS); automatic information processing (priming task including verbal [illness-related, negative, positive, neutral] and facial [negative, positive, neutral] stimuli); somatoform symptoms (SOMS-7T); confounders: depression (BDI), affect (PANAS). Results Higher self-reported alexithymia scores were associated with lower reaction times for negative (r = .19, p < .10) and positive (r = .26, p < .05) verbal primes when the target was illness-related. Self-reported alexithymia was correlated with number (r = .42, p < .01) and intensity of current somatoform symptoms (r = .36, p < .01), but unrelated to observer-rated alexithymia (r = .11, p = .42). Discussion Results indicate a faster allocation of attentional resources away from task-irrelevant information towards illness-related stimuli in alexithymia. Considering the close relationship between alexithymia and somatization, these findings are compatible with the theoretical view that alexithymics focus strongly on bodily sensations of emotional arousal. A single observer rating (OAS) does not seem to be an adequate alexithymia-measure in community samples. PMID:26090893

  20. Relative rates for plasma homo- and copolymerizations of olefins in a homologous series of fluorinated ethylenes

    NASA Technical Reports Server (NTRS)

    Golub, M. A.; Wydeven, T.

    1997-01-01

    It is well known that the rate of plasma polymerization, or deposition rate, of a given monomer depends on various plasma process parameters, e.g., monomer flow rate, pressure, power, frequency (DC, rf or microwave), location of the substrate in the reactor, reactor geometry or configuration, and temperature. In contrast, little work has been done to relate deposition rates to monomer structures for a homologous series of monomers where the rates are obtained under identical plasma process parameters. For the particular series of fluorinated ethylenes (C2HxF4-x; x = 0-4), deposition rates were reported for ethylene (ET), vinyl fluoride, vinylidene fluoride and tetrafluoroethylene (TFE), but for plasma polymerizations carried out under different discharge conditions, e.g., pressure, current density, and electrode temperature. Apparently, relative deposition rates were reported for only two members of that series (ET, x = 4, and TFE, x = 0) for which the plasma polymerizations were conducted under identical conditions. We now present relative deposition rates for both homopolymerizations and copolymerizations of the entire series of fluorinated ethylenes (x = 0-4). Our interest in such rates stems from prior work on the plasma copolymerization of ET and TFE in which it was found that the deposition rates for the plasma copolymers, when plotted versus mol % TFE in the ET/TFE feed stock, followed a concave-downward curve situated above the straight line joining the deposition rates for the plasma homopolymers. This type of plot (observed also for an argon-ET/TFE plasma copolymerization) indicated a positive interaction between ET and TFE such that each monomer apparently "sensitized" the plasma copolymerization of the other. Since the shape of that plot is not altered if mol % TFE is replaced by F/C, the fluorine-to-carbon ratio, this paper aims (1) to show how the relative deposition rates for plasma copolymers drawn from all pairs of monomers in the C2HxF4-x series

  1. Relative rates for plasma homo- and copolymerizations of olefins in a homologous series of fluorinated ethylenes

    NASA Technical Reports Server (NTRS)

    Golub, M. A.; Wydeven, T.

    1997-01-01

    It is well known that the rate of plasma polymerization, or deposition rate, of a given monomer depends on various plasma process parameters, e.g., monomer flow rate, pressure, power, frequency (DC, rf or microwave), location of the substrate in the reactor, reactor geometry or configuration, and temperature. In contrast, little work has been done to relate deposition rates to monomer structures for a homologous series of monomers where the rates are obtained under identical plasma process parameters. For the particular series of fluorinated ethylenes (C2HxF4-x; x = 0-4), deposition rates were reported for ethylene (ET), vinyl fluoride, vinylidene fluoride and tetrafluoroethylene (TFE), but for plasma polymerizations carried out under different discharge conditions, e.g., pressure, current density, and electrode temperature. Apparently, relative deposition rates were reported for only two members of that series (ET, x = 4, and TFE, x = 0) for which the plasma polymerizations were conducted under identical conditions. We now present relative deposition rates for both homopolymerizations and copolymerizations of the entire series of fluorinated ethylenes (x = 0-4). Our interest in such rates stems from prior work on the plasma copolymerization of ET and TFE in which it was found that the deposition rates for the plasma copolymers, when plotted versus mol % TFE in the ET/TFE feed stock, followed a concave-downward curve situated above the straight line joining the deposition rates for the plasma homopolymers. This type of plot (observed also for an argon-ET/TFE plasma copolymerization) indicated a positive interaction between ET and TFE such that each monomer apparently "sensitized" the plasma copolymerization of the other. Since the shape of that plot is not altered if mol % TFE is replaced by F/C, the fluorine-to-carbon ratio, this paper aims (1) to show how the relative deposition rates for plasma copolymers drawn from all pairs of monomers in the C2HxF4-x series

  2. Work-related ill health in doctors working in Great Britain: incidence rates and trends.

    PubMed

    Zhou, Anli Yue; Carder, Melanie; Gittins, Matthew; Agius, Raymond

    2017-09-21

    BackgroundDoctors have a higher prevalence of mental ill health compared with other professional occupations but incidence rates are poorly studied.AimsTo determine incidence rates and trends of work-related ill health (WRIH) and work-related mental ill health (WRMIH) in doctors compared with other professions in Great Britain.MethodIncidence rates were calculated using an occupational physician reporting scheme from 2005-2010. Multilevel regression was use to study incidence rates from 2001 to 2014.ResultsAnnual incidence rates for WRIH and WRIMH in doctors were 515 and 431 per 100 000 people employed, respectively. Higher incidence rates for WRIH and WRMIH were observed for ambulance staff and nurses, respectively. Doctors demonstrated an annual average incidence rates increase for WRIH and WRMIH, especially in women, whereas the other occupations demonstrated a decreasing or static trend. The difference in trends between the occupations was statistically significant.ConclusionsWRIH and WRMIH incidence rate are increasing in doctors, especially in women, warranting further research. © The Royal College of Psychiatrists 2017.

  3. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    NASA Technical Reports Server (NTRS)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in

  4. Gender- and age-related differences in heart rate dynamics: are women more complex than men?

    NASA Technical Reports Server (NTRS)

    Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

    1994-01-01

    OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in

  5. Reconstruction of high frame rate image sequences in biomechanical related areas.

    PubMed

    Costa, Monica; Soares, Salviano; Barroso, Joao

    2010-01-01

    Regular video cameras shoot normally at 25/30 frames per second (fps). Actually there are available in the market equipments that allow us to acquire video at 1.000.000 fps. When we observe a video sequence it becomes noticeable that great part of the information remains unchanged regardless of the bit rate or frame rate used. One origin of discontinuity in video signals is directly related to movement. Several areas use high frame rate images to analyze and comprehend certain events or effects, biomechanical engineering is one of them. Biomechanics engineering studies the mechanics of a living body, especially the forces exerted by muscles and gravity on the skeletal structure. Some examples are athlete assessment, were images are capture and then the acquired parameters are analyzed. This article describes a new methodology to decrease the space needed to store high frame rate image sequences in the specific case of biomechanical related areas.

  6. Are smoking and passive smoking related with heart rate variability in male adolescents?

    PubMed Central

    Gondim, Renata Melo; Farah, Breno Quintella; Santos, Carolina da Franca Bandeira Ferreira; Ritti-Dias, Raphael Mendes

    2015-01-01

    Objective To analyze the relation between smoking and passive smoking with heart rate variability parameters in male adolescents. Methods The sample consisted of 1,152 males, aged 14 and 19 years. Data related to smoking and passive smoking were collected using a questionnaire. RR intervals were obtained by a heart rate monitor, on supine position, for 10 minutes. After collecting the RR intervals, time (standard deviation of all RR intervals, root mean square of the squared differences between adjacent normal RR intervals and the percentage of adjacent intervals over 50ms) and frequency domains (low and high frequency and sympathovagal balance) parameters of heart rate variability were obtained. Results No significant differences between smoker and nonsmoker adolescents were observed in heart rate variability parameters (p>0.05). Similarly, heart rate variability parameters did not show significant difference between exposed and not exposed to passive smoking (p>0.05). Conclusion Cigarette smoking and passive smoking are not related to heart rate variability in adolescence. PMID:25993065

  7. Flow rate-pressure drop relation for deformable shallow microfluidic channels

    NASA Astrophysics Data System (ADS)

    Christov, Ivan C.; Cognet, Vincent; Stone, Howard A.

    2013-11-01

    Laminar flow in devices fabricated from PDMS causes deformation of the passage geometry, which affects the flow rate-pressure drop relation. Having an accurate flow rate-pressure drop relation for deformable microchannels is of importance given that the flow rate for a given pressure drop can be as much as 500% of the flow rate predicted by Poiseuille's law for a rigid channel. proposed a successful model of the latter phenomenon by heuristically coupling linear elasticity with the lubrication approximation for Stokes flow. However, their model contains a fitting parameter that must be found for each channel shape by performing an experiment. We present a perturbative derivation of the flow rate-pressure drop relation in a shallow deformable microchannel using Kirchoff-Love theory of isotropic quasi-static plate bending and Stokes' equations under a ``double lubrication'' approximation (i.e., the ratio of the channel's height to its width and of the channel's width to its length are both assumed small). Our result contains no free parameters and confirms Gervais et al.'s observation that the flow rate is a quartic polynomial of the pressure drop. ICC was supported by NSF Grant DMS-1104047 and the U.S. DOE through the LANL/LDRD Program; HAS was supported by NSF Grant CBET-1132835.

  8. The solar cycle variation of the rates of CMEs and related activity

    NASA Technical Reports Server (NTRS)

    Webb, David F.

    1991-01-01

    Coronal mass ejections (CMEs) are an important aspect of the physics of the corona and heliosphere. This paper presents results of a study of occurrence frequencies of CMEs and related activity tracers over more than a complete solar activity cycle. To properly estimate occurrence rates, observed CME rates must be corrected for instrument duty cycles, detection efficiencies away from the skyplane, mass detection thresholds, and geometrical considerations. These corrections are evaluated using CME data from 1976-1989 obtained with the Skylab, SMM and SOLWIND coronagraphs and the Helios-2 photometers. The major results are: (1) the occurrence rate of CMEs tends to track the activity cycle in both amplitude and phase; (2) the corrected rates from different instruments are reasonably consistent; and (3) over the long term, no one class of solar activity tracer is better correlated with CME rate than any other (with the possible exception of type II bursts).

  9. Average Rate of Heat-Related Hospitalizations in 23 States, 2001-2010

    EPA Pesticide Factsheets

    This map shows the 2001??2010 average rate of hospitalizations classified as ??heat-related?? by medical professionals in 23 states that participate in CDC??s hospitalization tracking program. Rates are based on hospital discharge records for May 1 to September 30 of every year. Rates have been age-adjusted to account for differences in the population distribution over time and between states??for example, if one state has a higher proportion of older adults than another. For more information: www.epa.gov/climatechange/science/indicators

  10. Relative Rates for Plasma Homo- and Copolymerizations of Olefins in a Homologous Series of Fluorinated Ethylenes

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Wydeven, Theodore; Kliss, Mark (Technical Monitor)

    1996-01-01

    The relative rates of plasma (co)polymerizations of ethylene, vinyl fluoride, vinylidene fluoride, trifluoroethylene and tetrafluoroethylene (VF(sub x); x = 0-4, respectively) were determined in an rf, capacitively coupled, tubular reactor with external electrodes using identical plasma parameters. The averages of deposition rates obtained by both microgravimetry and ellipsometry were plotted versus the F/C ratios of the monomers or monomer blends. The deposition rates for VF(sub x)(x = 1-3) and 20 monomer blends were all located above a straight line joining the rates for VF(sub 0) and VF(sub 4), following a concave-downward plot of deposition rate versus F/C ratio similar to that reported previously for VF(sub 0)/VF(sub 4) blends. The deposition rates for VF(sub m)/VF(sub n) blends (m = 3 or 4; n = 0-2) were all greater than expected for non-interacting monomers; those for VF(sub 0)/VF(sub 2) and VF(sub 1)/VF(sub 2) blends were all lower than expected; while those for VF(sub 0)/VF(sub 1) and VF(sub 3)/VF(sub 4) blends fen on a straightline plot versus F/C ratio, indicative of apparent non-interaction between monomers. The mechanisms for plasma (co)polymerizations of VF(sub x) monomers responsible for the wide range of relative deposition rates remain to be elucidated.

  11. Relative Rates for Plasma Homo- and Copolymerizations of Olefins in a Homologous Series of Fluorinated Ethylenes

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Wydeven, Theodore; Kliss, Mark (Technical Monitor)

    1996-01-01

    The relative rates of plasma (co)polymerizations of ethylene, vinyl fluoride, vinylidene fluoride, trifluoroethylene and tetrafluoroethylene (VF(sub x); x = 0-4, respectively) were determined in an rf, capacitively coupled, tubular reactor with external electrodes using identical plasma parameters. The averages of deposition rates obtained by both microgravimetry and ellipsometry were plotted versus the F/C ratios of the monomers or monomer blends. The deposition rates for VF(sub x)(x = 1-3) and 20 monomer blends were all located above a straight line joining the rates for VF(sub 0) and VF(sub 4), following a concave-downward plot of deposition rate versus F/C ratio similar to that reported previously for VF(sub 0)/VF(sub 4) blends. The deposition rates for VF(sub m)/VF(sub n) blends (m = 3 or 4; n = 0-2) were all greater than expected for non-interacting monomers; those for VF(sub 0)/VF(sub 2) and VF(sub 1)/VF(sub 2) blends were all lower than expected; while those for VF(sub 0)/VF(sub 1) and VF(sub 3)/VF(sub 4) blends fen on a straightline plot versus F/C ratio, indicative of apparent non-interaction between monomers. The mechanisms for plasma (co)polymerizations of VF(sub x) monomers responsible for the wide range of relative deposition rates remain to be elucidated.

  12. New test of general relativity - Measurement of de Sitter geodetic precession rate for lunar perigee

    NASA Technical Reports Server (NTRS)

    Bertotti, Bruno; Ciufolini, Ignazio; Bender, Peter L.

    1987-01-01

    According to general relativity, the calculated rate of motion of lunar perigee should include a contribution of 19.2 msec/yr from geodetic precession. It is shown that existing analyses of lunar-laser-ranging data confirm the general-relativistic rate for geodetic precession with respect to the planetary dynamical frame. In addition, the comparison of earth-rotation results from lunar laser ranging and from VLBI shows that the relative drift of the planetary dynamical frame and the extragalactic VLBI reference frame is small. The estimated accuracy is about 10 percent.

  13. New test of general relativity - Measurement of de Sitter geodetic precession rate for lunar perigee

    NASA Technical Reports Server (NTRS)

    Bertotti, Bruno; Ciufolini, Ignazio; Bender, Peter L.

    1987-01-01

    According to general relativity, the calculated rate of motion of lunar perigee should include a contribution of 19.2 msec/yr from geodetic precession. It is shown that existing analyses of lunar-laser-ranging data confirm the general-relativistic rate for geodetic precession with respect to the planetary dynamical frame. In addition, the comparison of earth-rotation results from lunar laser ranging and from VLBI shows that the relative drift of the planetary dynamical frame and the extragalactic VLBI reference frame is small. The estimated accuracy is about 10 percent.

  14. Creativity and mental illness: prevalence rates in writers and their first-degree relatives.

    PubMed

    Andreasen, N C

    1987-10-01

    Rates of mental illness were examined in 30 creative writers, 30 matched control subjects, and the first-degree relatives of both groups. The writers had a substantially higher rate of mental illness, predominantly affective disorder, with a tendency toward the bipolar subtype. There was also a higher prevalence of affective disorder and creativity in the writers' first-degree relatives, suggesting that these traits run together in families and could be genetically mediated. Both writers and control subjects had IQs in the superior range; the writers excelled only on the WAIS vocabulary subtest, confirming previous observations that intelligence and creativity are independent mental abilities.

  15. Oral health-related quality of life in youth receiving cleft-related surgery: self-report and proxy ratings.

    PubMed

    Broder, Hillary L; Wilson-Genderson, Maureen; Sischo, Lacey

    2017-04-01

    This paper evaluated the impact of cleft-related surgery on the oral health-related quality of life (OHRQoL) of youth with cleft over time. Data were derived from a 5-year, multi-center, prospective, longitudinal study of 1196 youth with cleft lip and/or palate and their caregivers. Eligible youth were between 7.5 and 18.5 years old, spoke English or Spanish, and were non-syndromic. During each observational period, which included baseline, and 1- and 2-year post-baseline follow-up visits, youths and their caregivers completed the Child Oral Health Impact Profile, a validated measure of OHRQoL. Multilevel mixed-effects models were used to analyze the effects of receipt of craniofacial surgery on OHRQoL over time. During the course of this study a total of 516 patients (43 %) received at least one surgery. Youth in the surgery recommendation group had lower self- (β = -2.18, p < 0.05) and proxy-rated (β = -2.92, p < 0.02) OHRQoL when compared to non-surgical self- and proxy-rated OHRQoL at baseline. Both surgical and non-surgical youth (β = 3.73, p < 0.001) and caregiver (β = 1.91, p < 0.05) ratings of OHRQoL improved over time. There was significant incremental improvement (time × surgery interaction) in self-reported OHRQoL for youth postsurgery (β = 1.04, p < 0.05), but this postsurgery increment was not seen in the caregiver proxy ratings. Surgical intervention impacts OHRQoL among youth with cleft. Youth who were surgical candidates had lower baseline self- and caregiver-rated OHRQoL when compared to non-surgical youth. Youth who underwent cleft-related surgery had significant incremental improvements in self-rated but not caregiver (proxy)-rated OHRQoL after surgery.

  16. A parametric study of the behavior of the angular momentum vector during spin rate changes of rigid body spacecraft

    NASA Technical Reports Server (NTRS)

    Longuski, J. M.

    1982-01-01

    During a spin-up or spin-down maneuver of a spinning spacecraft, it is usual to have not only a constant body-fixed torque about the desired spin axis, but also small undesired constant torques about the transverse axes. This causes the orientation of the angular momentum vector to change in inertial space. Since an analytic solution is available for the angular momentum vector as a function of time, this behavior can be studied for large variations of the dynamic parameters, such as the initial spin rate, the inertial properties and the torques. As an example, the spin-up and spin-down maneuvers of the Galileo spacecraft was studied and as a result, very simple heuristic solutions were discovered which provide very good approximations to the parametric behavior of the angular momentum vector orientation.

  17. Self-rated health as a comprehensive indicator of lifestyle-related health status.

    PubMed

    Yamada, Chizumi; Moriyama, Kengo; Takahashi, Eiko

    2012-11-01

    To evaluate the usefulness of self-rated health (SRH) as a comprehensive indicator of lifestyle-related health status by examining the relationships between SRH and: (1) history of cancer and cardiovascular disease; (2) treatment of hypertension, diabetes, and dyslipidemia; (3) abnormalities in clinical parameters including blood pressure, fasting glucose, and lipids; and (4) lifestyle habits. 3744 health-check examinees at Tokai University Hachioji Hospital seen between April 2009 and March 2010 were enrolled. SRH was graded as "good," "relatively good," "relatively poor," or "poor." For statistical comparison, the differences among "healthy" (=good), "relatively healthy" (=relatively good), and "unhealthy" (=relatively poor plus poor) groups were examined. Mantel-Haenszel odds ratios were calculated to remove the confounding effect of age, using the healthy group as the reference. The Mantel-extension method was used as a trend test. 1049 subjects rated their health as good, 2194 as relatively good, 428 as relatively poor, and 73 as poor. The prevalence of all diseases showed significant odds ratios and trends as SRH deteriorated. Obesity, blood pressure, glucose metabolism, and lipids deteriorated significantly as SRH became poorer, and a trend was observed in all parameters. Weight change, exercise, smoking, and rest showed significant odds ratios and trends as SRH deteriorated. SRH appears useful as a comprehensive indicator of lifestyle-related health status.

  18. A mixed-phase relative rates technique for measuring aerosol reaction kinetics

    NASA Astrophysics Data System (ADS)

    Hearn, John D.; Smith, Geoffrey D.

    2006-09-01

    A mixed-phase relative rates approach for measuring rates of reaction in aerosols is presented. Using this method the rate of reaction of methyl oleate (MO) particles, normalized to the gas-particle collision rate, was measured to be γMO = 1.12 (+/-0.36) × 10-3 with 2-methyl-2-butene as the gas-phase reference. This value compares favorably with our previously published value of 1.23 × 10-3 measured using an absolute technique. Reaction of bis(2-ethylhexyl) sebacate (BES) particles with Cl and OH radicals was also studied using acetone and hexanal, respectively, as the gas-phase references. The rates of reaction of BES, normalized to the gas-particle collision rate, were measured to be γBES = 1.8 (-0.3+0.8) and γBES = 2.0 (-0.1+0.6) with Cl and OH, respectively. These fast rates of reaction (γBES > 1) imply that secondary reactions, perhaps involving radical chain mechanisms, could impact the rate at which organic particles are oxidized in the atmosphere.

  19. [The effect of assertiveness training on communication related factors and personnel turnover rate among hospital nurses].

    PubMed

    Kang, Myung Ja; Lee, Haejung

    2006-08-01

    The purpose of this study was to investigate the effects of assertiveness training on nurses' assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate. A non-equivalent control group pretest-posttest design was used in this study. Nurses were assigned into the experimental or control groups, each consisting of 39 nurses. Data was collected between January to March 2004. An 'Assertiveness Training Program' for Nurses developed by Park was used for the study. To emphasize assertiveness practice, 5 practice sessions utilizing ABCDE principles were added to Park's program. To examine the effects of the program, differences between the two groups in assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate were analyzed using ANCOVA. The assertiveness training was effective in improving the nurses' assertiveness behaviors, but was not effective in improving interpersonal relations, reducing the subjects' communication conflicts, changing the conflict management style or reducing their personnel turnover rate. There have been many studies about factors affecting nurses' personnel turnover rates, but few have been done about methods of intervention to reduce the personnel turnover rate. Thus, this study provides a significant contribution in attempting such an intervention from nursing management perspectives.

  20. Age influences the relation between subjective valence ratings and emotional word use during autobiographical memory retrieval.

    PubMed

    Ford, Jaclyn H; DiGirolamo, Marissa A; Kensinger, Elizabeth A

    2016-09-01

    Recent research reveals an age-related increase in positive autobiographical memory retrieval using a number of positivity measures, including valence ratings and positive word use. It is currently unclear whether the positivity shift in each of these measures co-occurs, or if age uniquely influences multiple components of autobiographical memory retrieval. The current study examined the correspondence between valence ratings and emotional word use in young and older adults' autobiographical memories. Positive word use in narratives was associated with valence ratings only in young adults' narratives. Older adults' narratives contained a consistent level of positive word use regardless of valence rating, suggesting that positive words and concepts may be chronically accessible to older adults during memory retrieval, regardless of subjective valence. Although a relation between negative word use in narratives and negative valence ratings was apparent in both young and older adults, it was stronger in older adults' narratives. These findings confirm that older adults do vary their word use in accordance with subjective valence, but they do so in a way that is different from young adults. The results also point to a potential dissociation between age-related changes in subjective valence and in positive word use.

  1. Relative rates of AIDS among racial/ethnic groups by exposure categories.

    PubMed Central

    Haverkos, H. W.; Turner, J. F.; Moolchan, E. T.; Cadet, J. L.

    1999-01-01

    The relative rates of acquired immunodeficiency syndrome (AIDS) were calculated among racial/ethnic populations using Centers for Disease Control and Prevention HIV (human immunodeficiency virus)/Surveillance reports assuming that racial/ethnic distributions reflect that of the US Census Data from 1990. For comparison, a rate of 1 was assigned to whites in each calculation. The overall relative rates were whites--1, African Americans--4.7, Hispanics--3, Asian/Pacific Islanders--0.4, and Native Americans--0.5. Acquired immunodeficiency syndrome surveillance data show higher rates of AIDS for African Americans and Hispanics compared with whites, Asians/Pacific Islanders, and Native Americans. The relative rates for African Americans and Hispanics compared with whites were highest for injecting drug users, heterosexual contact, and pediatric patients. These results led us to explore possible explanations for increased AIDS reporting in African Americans and Hispanics. We then explored available national datasets regarding those variables. The analyses indicate that variables such as access and receptivity to HIV prevention and treatment efforts, race/ethnicity, sexual behaviors, sexually transmitted diseases, socioeconomic status, and substance abuse interact in a complex fashion to influence HIV transmission and progression to AIDS in affected communities. PMID:10063784

  2. The Effect of Changes in Relative Humidity on the Hydration Rate of Pachuca Obsidian

    SciTech Connect

    Anovitz, Lawrence {Larry} M; Riciputi, Lee R; Cole, David R; Gruszkiewicz, Miroslaw {Mirek} S; Elam, J. Michael

    2006-01-01

    The effect of relative humidity on the hydration rate of obsidian and other glasses has been debated since the early work of (I. Friedman, R. Smith, Am. Antiquity 25 (1960) 476). While more recent work has been in general agreement that a relative humidity dependence does exist, hydration profiles as a function of relative humidity have not been obtained. In this paper we present the results of a study in which samples of Pachuca obsidian were hydrated for approximately 5 days at 150 C at relative humidities ranging from 21% to 100%, and the resultant profiles were measured by secondary ion mass spectrometry (SIMS). The results suggest that the hydration rate is, indeed, a function of relative humidity, but for the relative humidity levels commonly observed in most soils the effects on hydration dating are expected to be relatively small. In addition, analysis of the surface values as sorption isotherms and comparisons with nitrogen sorption isotherms suggests that water is relatively strongly bound to the obsidian surface. By assuming a situation in which the 'surface' refers to active centers within the glass we have shown that an adsorption model provides a useful approach to modeling the diffusive process.

  3. 13 CFR 120.1060 - Confidentiality of Reports, Risk Ratings and related Confidential Information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Confidentiality of Reports, Risk Ratings and related Confidential Information. 120.1060 Section 120.1060 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Supervision §...

  4. Is the Physical Availability of Alcohol and Illicit Drugs Related to Neighborhood Rates of Child Maltreatment?

    ERIC Educational Resources Information Center

    Freisthler, Bridget; Needell, Barbara; Gruenewald, Paul J.

    2005-01-01

    Objective: This study examines how the availability of alcohol and illicit drugs (as measured by alcohol outlet density and police incidents of drug sales and possessions) is related to neighborhood rates of child abuse and neglect, controlling for other neighborhood demographic characteristics. Method: Data from substantiated reports of child…

  5. Relation of Course, Instructor, and Student Characteristics to Dimensions of Student Ratings of Teaching Effectiveness

    ERIC Educational Resources Information Center

    Heckert, Teresa M.; Latier, Amanda; Ringwald, Amy; Silvey, Brenna

    2006-01-01

    This research investigated the relation of course, instructor, and student characteristics to student ratings of teaching effectiveness, both overall and within the dimensions of pedagogical skill, rapport with students, difficulty appropriateness, and course value/learning. Interest in the course content, expected grades, satisfaction with the…

  6. An estimator for the relative entropy rate of path measures for stochastic differential equations

    NASA Astrophysics Data System (ADS)

    Opper, Manfred

    2017-02-01

    We address the problem of estimating the relative entropy rate (RER) for two stochastic processes described by stochastic differential equations. For the case where the drift of one process is known analytically, but one has only observations from the second process, we use a variational bound on the RER to construct an estimator.

  7. Absolute and Relative Reliability of Percentage of Syllables Stuttered and Severity Rating Scales

    ERIC Educational Resources Information Center

    Karimi, Hamid; O'Brian, Sue; Onslow, Mark; Jones, Mark

    2014-01-01

    Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…

  8. The Influence of Selected Academic, Demographic, and Instructional Program Related Factors on Elementary Student Retention Rates

    ERIC Educational Resources Information Center

    Scott, Marshall, III

    2011-01-01

    The purpose of this study was to examine the influence of selected academic, demographic, and instructional program related factors on the retention rates of elementary school students. More specifically, this study was concerned with the relationship and predictability of the reading and mathematics variables scores, gender, ethnicity, program…

  9. Is the Physical Availability of Alcohol and Illicit Drugs Related to Neighborhood Rates of Child Maltreatment?

    ERIC Educational Resources Information Center

    Freisthler, Bridget; Needell, Barbara; Gruenewald, Paul J.

    2005-01-01

    Objective: This study examines how the availability of alcohol and illicit drugs (as measured by alcohol outlet density and police incidents of drug sales and possessions) is related to neighborhood rates of child abuse and neglect, controlling for other neighborhood demographic characteristics. Method: Data from substantiated reports of child…

  10. Understanding and Producing the Reduced Relative Construction: Evidence from Ratings, Editing and Corpora

    ERIC Educational Resources Information Center

    Hare, Mary; Tanenhaus, Michael K.; McRae, Ken

    2007-01-01

    Two rating studies demonstrate that English speakers willingly produce reduced relatives with internal cause verbs (e.g., "Whisky fermented in oak barrels can have a woody taste"), and judge their acceptability based on factors known to influence ambiguity resolution, rather than on the internal/external cause distinction. Regression analyses…

  11. Citation Rate of Highly-Cited Papers in 100 Kinesiology-Related Journals

    ERIC Educational Resources Information Center

    Knudson, Duane

    2015-01-01

    This study extended previous research on several citation-based bibliometric variables for highly cited articles in a large (N = 100) number of journals related to Kinesiology. Total citations and citation rate of the 30 most highly cited articles in each journal were identified by searchers of "Google Scholar (GS)". Other major…

  12. Alcohol-Related Vehicular Death Rates for College Students in the Commonwealth of Virginia

    ERIC Educational Resources Information Center

    Turner, James; Bauerle, Jennifer; Keller, Adrienne

    2011-01-01

    Objective: Determine rate of college student alcohol-related vehicular traffic fatalities in Virginia during 2007. Participants: Undergraduates at colleges and universities in Virginia. Methods: Institutions with membership in the American College Health Association were invited to participate in a survey. Data collected from institutional reports…

  13. Absolute and Relative Reliability of Percentage of Syllables Stuttered and Severity Rating Scales

    ERIC Educational Resources Information Center

    Karimi, Hamid; O'Brian, Sue; Onslow, Mark; Jones, Mark

    2014-01-01

    Purpose: Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide…

  14. Citation Rate of Highly-Cited Papers in 100 Kinesiology-Related Journals

    ERIC Educational Resources Information Center

    Knudson, Duane

    2015-01-01

    This study extended previous research on several citation-based bibliometric variables for highly cited articles in a large (N = 100) number of journals related to Kinesiology. Total citations and citation rate of the 30 most highly cited articles in each journal were identified by searchers of "Google Scholar (GS)". Other major…

  15. Alcohol-Related Vehicular Death Rates for College Students in the Commonwealth of Virginia

    ERIC Educational Resources Information Center

    Turner, James; Bauerle, Jennifer; Keller, Adrienne

    2011-01-01

    Objective: Determine rate of college student alcohol-related vehicular traffic fatalities in Virginia during 2007. Participants: Undergraduates at colleges and universities in Virginia. Methods: Institutions with membership in the American College Health Association were invited to participate in a survey. Data collected from institutional reports…

  16. Understanding and Producing the Reduced Relative Construction: Evidence from Ratings, Editing and Corpora

    ERIC Educational Resources Information Center

    Hare, Mary; Tanenhaus, Michael K.; McRae, Ken

    2007-01-01

    Two rating studies demonstrate that English speakers willingly produce reduced relatives with internal cause verbs (e.g., "Whisky fermented in oak barrels can have a woody taste"), and judge their acceptability based on factors known to influence ambiguity resolution, rather than on the internal/external cause distinction. Regression analyses…

  17. Community Colleges and Labor Market Conditions: How Does Enrollment Demand Change Relative to Local Unemployment Rates?

    ERIC Educational Resources Information Center

    Hillman, Nicholas W.; Orians, Erica Lee

    2013-01-01

    This study uses fixed-effects panel data techniques to estimate the elasticity of community college enrollment demand relative to local unemployment rates. The findings suggest that community college enrollment demand is counter-cyclical to changes in the labor market, as enrollments rise during periods of weak economic conditions. Using national…

  18. Response-Time Variability Is Related to Parent Ratings of Inattention, Hyperactivity, and Executive Function

    ERIC Educational Resources Information Center

    Gomez-Guerrero, Lorena; Martin, Cristina Dominguez; Mairena, Maria Angeles; Di Martino, Adriana; Wang, Jing; Mendelsohn, Alan L.; Dreyer, Benard P.; Isquith, Peter K.; Gioia, Gerard; Petkova, Eva; Castellanos, F. Xavier

    2011-01-01

    Objective: Individuals with ADHD are often characterized as inconsistent across many contexts. ADHD is also associated with deficits in executive function. We examined the relationships between response time (RT) variability on five brief computer tasks to parents' ratings of ADHD-related features and executive function in a group of children with…

  19. Community Colleges and Labor Market Conditions: How Does Enrollment Demand Change Relative to Local Unemployment Rates?

    ERIC Educational Resources Information Center

    Hillman, Nicholas W.; Orians, Erica Lee

    2013-01-01

    This study uses fixed-effects panel data techniques to estimate the elasticity of community college enrollment demand relative to local unemployment rates. The findings suggest that community college enrollment demand is counter-cyclical to changes in the labor market, as enrollments rise during periods of weak economic conditions. Using national…

  20. Application of Content Validity Methods to the Development of a Job-Related Performance Rating Criterion.

    ERIC Educational Resources Information Center

    Distefano, M. K., Jr.; And Others

    1983-01-01

    Demonstrated the use of quantitative content validity procedures in the development of a job-related behavioral rating scale criterion for entry-level psychiatric aides. Found that 78 of 83 items were significantly job-relevant using the computation procedures of both Lawshe and Aiken. (JAC)

  1. Background seismicity rate at subduction zones linked to slab-bending-related hydration

    NASA Astrophysics Data System (ADS)

    Nishikawa, Tomoaki; Ide, Satoshi

    2015-09-01

    Tectonic properties strongly control variations in seismicity among subduction zones. In particular, fluid distribution in subduction zones influences earthquake occurrence, and it varies among subduction zones due to variations in fluid sources such as hydrated oceanic plates. However, the relationship between variations in fluid distribution and variations in seismicity among subduction zones is unclear. Here we divide Earth's subduction zones into 111 regions and estimate background seismicity rates using the epidemic type aftershock sequence model. We demonstrate that background seismicity rate correlates to the amount of bending of the incoming oceanic plate, which in turn is related to the hydration of oceanic plates via slab-bending-related faults. Regions with large bending may have high-seismicity rates because a strongly hydrated oceanic plate causes high pore fluid pressure and reduces the strength of the plate interface. We suggest that variations in fluid distribution can also cause variations in seismicity in subduction zones.

  2. Relational interventions in psychotherapy: development of a therapy process rating scale.

    PubMed

    Ulberg, Randi; Ness, Elisabeth; Dahl, Hanne-Sofie Johnsen; Høglend, Per Andreas; Critchfield, Kenneth; Blayvas, Phelix; Amlo, Svein

    2016-09-06

    In psychodynamic psychotherapy, one of the therapists' techniques is to intervene on and encourage exploration of the patients' relationships with other people. The impact of these interventions and the response from the patient are probably dependent on certain characteristics of the context in which the interventions are given and the interventions themselves. To identify and analyze in-session effects of therapists' techniques, process scales are used. The aim of the present study was to develop a simple, not resource consuming rating tool for in-session process to be used when therapists' interventions focus on the patients' relationships outside therapy. The present study describes the development and use of a therapy process rating scale, the Relational Work Scale (RWS). The scale was constructed to identify, categorize and explore therapist interventions that focus on the patient's relationships to family, friends, and colleges Relational Interventions and explore the impact on the in-session process. RWS was developed with sub scales rating timing, content, and valence of the relational interventions, as well as response from the patient. For the inter-rater reliability analyzes, transcribed segments (10 min) from 20 different patients were scored with RWS by two independent raters. Two clinical vignettes of relational work are included in the paper as examples of how to rate transcripts from therapy sessions with RWS. The inter-rater agreement on the RWS items was good to excellent. Relational Work Scale might be a potentially useful tool to identify relational interventions as well as explore the interaction of timing, category, and valence of relational work in psychotherapies. The therapist's interventions on the patient's relationships with people outside therapy and the following patient-therapist interaction might be explored. First Experimental Study of Transference-interpretations (FEST307/95) REGISTRATION NUMBER: ClinicalTrials.gov Identifier

  3. Empirical Study of Relations between Stock Returns and Exchange Rate Fluctuations in China

    NASA Astrophysics Data System (ADS)

    Chen, Jian-Bao; Wang, Deng-Ling; Cheng, Ting-Ting

    The existing theories tell us that there exist interaction relations between stock prices and exchange rates. However, empirical research results don’t always support these theories. This paper uses quantile regression techniques to check whether the above theories hold in Chinese markets. We first eliminate the impact of the calendar effect and the time trends on stock market returns and exchange rate fluctuations using Gallant, Rossi, and Tachen’s method (1992) by combination with stepwise regression method, and then do quantile regression analysis according to the adjusted data. The empirical results are summarized as follows: the influences of exchange rate fluctuations to stock returns are negative at most quantiles of stock returns; the opposite influences are not significant at most quantiles of exchange rate fluctuations. Some explanations according to these results are given.

  4. Star Formation Rate and Gas Relations in the Arp 299 Merger from the VIXENS Survey

    NASA Astrophysics Data System (ADS)

    Heiderman, Amanda L.; Evans, N. J.; Gebhardt, K.; Blanc, G. A.; Davis, T.; Papovich, C. J.; van den Bosch, R.; Iono, D.; Yun, M.; VIXENS Team

    2014-01-01

    We investigate the relationship between star formation and gas content in late interaction phase merger Arp 299 from the VIRUS-P Investigation of the eXtreme ENvironments of Starbursts (VIXENS) integral field unit survey. By comparing H-alpha, Pa-alpha and 24um data to CO(1-0), CO(2-1), HCN(1-0), HCO+(1-0), and HI maps, we explore the relation between the star formation rate and gas surface densities on spatially resolved ~kpc scales. We find discrepancies from known extragalactic spatially resolved relations in nearby spiral galaxies and disk-averaged relations in high-z mergers.

  5. Response rate viewed as engagement bouts: effects of relative reinforcement and schedule type.

    PubMed Central

    Shull, R L; Gaynor, S T; Grimes, J A

    2001-01-01

    The rate of a reinforced response is conceptualized as a composite of engagement bouts (visits) and responding during visits. Part I of this paper describes a method for estimating the rate of visit initiations and the average number of responses per visit from log survivor plots: the proportion) of interresponse times (IRTs) longer than some elapsed time (log scale) plotted as a function of elapsed time. In Part 2 the method is applied to IRT distributions from rats that obtained food pellets by nose poking a lighted key under various multiple schedules of reinforcement. As expected, total response rate increased as a function of (a) increasing the rate of reinforcement (i.e., variable-interval [VI] 4 min vs. VI 1 mi), (b) increasing the amount of the reinforcer (one food pellet vs. four pellets), (c) increasing the percentage of reinforcers that were contingent on nose poking (25% vs. 100%), and (d) requiring additional responses after the end of the VI schedule (i.e., adding a tandem variable-ratio [VR] 9 requirement). The first three of these variables (relative reinforcement) increased the visit-initiation rate. The tandem VR, in contrast, increased the number of responses per visit. Thus, variables that have similar effects on total response rate can be differentiated based on their effects on the componemts of response rate. PMID:11453618

  6. Relations between the development of patterns of sleeping heart rate and body temperature in infants.

    PubMed

    Petersen, S A; Pratt, C; Wailoo, M P

    2001-09-01

    Overnight patterns of rectal temperature and heart rate were recorded from 119 normal infants at weekly intervals from 7 to about 16 weeks of age. All data were collected in the infants' own homes. As previously reported, different infants developed an adult-like night time rectal temperature pattern abruptly at different ages. When heart rate data were collated by age, there was an apparently gradual fall in sleeping heart rate from 7 to about 14 weeks of age. This was, however, an artefact of data collation. Individual infants showed abrupt falls in heart rate at the time that the adult-like body temperature pattern appeared, but this occurred at different ages in different babies, so when data were collated cross sectionally, an apparently gradual fall resulted. The relation between the developmental changes in sleeping heart rate and rectal temperature was different in boys and girls, with girls showing a more abrupt and greater change in heart rate at the time of development of the adult-like body temperature pattern. Infants whose parents smoked had significantly lower heart rates once the adult-like body temperature pattern had appeared.

  7. Diversification rates are more strongly related to microhabitat than climate in squamate reptiles (lizards and snakes).

    PubMed

    Bars-Closel, Melissa; Kohlsdorf, Tiana; Moen, Daniel S; Wiens, John J

    2017-09-01

    Patterns of species richness among clades can be directly explained by the ages of clades or their rates of diversification. The factors that most strongly influence diversification rates remain highly uncertain, since most studies typically consider only a single predictor variable. Here, we explore the relative impacts of macroclimate (i.e., occurring in tropical vs. temperate regions) and microhabitat use (i.e., terrestrial, fossorial, arboreal, aquatic) on diversification rates of squamate reptile clades (lizards and snakes). We obtained data on microhabitat, macroclimatic distribution, and phylogeny for >4000 species. We estimated diversification rates of squamate clades (mostly families) from a time-calibrated tree, and used phylogenetic methods to test relationships between diversification rates and microhabitat and macroclimate. Across 72 squamate clades, the best-fitting model included microhabitat but not climatic distribution. Microhabitat explained ∼37% of the variation in diversification rates among clades, with a generally positive impact of arboreal microhabitat use on diversification, and negative impacts of fossorial and aquatic microhabitat use. Overall, our results show that the impacts of microhabitat on diversification rates can be more important than those of climate, despite much greater emphasis on climate in previous studies. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  8. The Relation between the Area-Average Rain Rate and the Rain Cell Size Distribution Parameters.

    NASA Astrophysics Data System (ADS)

    Sauvageot, Henri; Mesnard, Frédéric; Tenório, Ricardo S.

    1999-01-01

    A review of the literature on the rain cell diameter distribution (RCDD) is first presented. It shows that RCDD, for a given rain-rate threshold , is accurately described by an exponential distribution with an exponential parameter weakly variable from one place to another and almost independent of . Then it is demonstrated that integrating the RCDD enables the writing of interesting and simple relations between the moments of the RCDD and useful area-averaged rain field parameters, notably the average cell diameter and F(), the fractional area occupied by the rain cells having a rain rate above . From F(), an equation relating the area-average rain rate R to the second moment of the RCDD is obtained. Now, an explicit knowledge of the RCDD is not necessary to obtain R. RCDD can be replaced by the distribution of the chords of the rain cells. Indeed, the moments of the rain cell chord distribution are analytically related to the moments of the RCDD. Thus, an equation showing that R is a function of the only area-averaged chord length is written. Based on this relation, a very simple method for the measurement of precipitation from the random intersect of the rain cell population by a scanning remote sensor is proposed. In this method, R is inferred from the simple estimation of the area-averaged chord length observed, for example, with a radar sampling, in a binary way, a rain cell distribution thresholded at a mean rain rate . The interest of this method is a reduced requirement for the measuring time and for the range of R to be sensed. Besides, it is suggested that this method can be implemented for area-average rain-rate estimates from a spaceborne microwave sensor. Some tests and simulations using ground-based radar data are presented in order to support the validity of the proposed relation.

  9. STAR FORMATION RATES IN MOLECULAR CLOUDS AND THE NATURE OF THE EXTRAGALACTIC SCALING RELATIONS

    SciTech Connect

    Lada, Charles J.; Forbrich, Jan; Lombardi, Marco; Alves, Joao F. E-mail: jforbrich@cfa.harvard.edu E-mail: joao.alves@univie.ac.at

    2012-02-01

    In this paper, we investigate scaling relations between star formation rates and molecular gas masses for both local Galactic clouds and a sample of external galaxies. We specifically consider relations between the star formation rates and measurements of dense, as well as total, molecular gas masses. We argue that there is a fundamental empirical scaling relation that directly connects the local star formation process with that operating globally within galaxies. Specifically, the total star formation rate in a molecular cloud or galaxy is linearly proportional to the mass of dense gas within the cloud or galaxy. This simple relation, first documented in previous studies, holds over a span of mass covering nearly nine orders of magnitude and indicates that the rate of star formation is directly controlled by the amount of dense molecular gas that can be assembled within a star formation complex. We further show that the star formation rates and total molecular masses, characterizing both local clouds and galaxies, are correlated over similarly large scales of mass and can be described by a family of linear star formation scaling laws, parameterized by f{sub DG}, the fraction of dense gas contained within the clouds or galaxies. That is, the underlying star formation scaling law is always linear for clouds and galaxies with the same dense gas fraction. These considerations provide a single unified framework for understanding the relation between the standard (nonlinear) extragalactic Schmidt-Kennicutt scaling law, that is typically derived from CO observations of the gas, and the linear star formation scaling law derived from HCN observations of the dense gas.

  10. Co/Ni ratios at taenite/kamacite interfaces and relative cooling rates in iron meteorites

    NASA Astrophysics Data System (ADS)

    Wasson, John T.; Hoppe, Peter

    2012-05-01

    We report a pilot study of a new technique to use the distribution of Co between kamacite and taenite to infer relative cooling rates of iron meteorites; data of Widge and Goldstein (1977) showed that the distribution is temperature dependent. A plot of the logarithm of the double ratio [(Co/Ni)kamacite/(Co/Ni)taenite] (abbreviated Rαγ) against inverse temperature yields a linear equation showing that the ratio ranges from ˜2.5 at 1080 K to ˜30 at 710 K. Thus, a measurement of Rαγ in the kamacite and taenite near the interface offers information about relative cooling rates; the higher Rαγ, the lower the cooling rate. A major advantage of this technique is that it is mainly affected by the final (low-temperature) cooling rate, just before the sample cooled to the blocking temperature where diffusion became insignificant. To test this method we used the NanoSIMS ion probe to measure Rαγ in two IVA and two IIIAB irons; members of each pair differ by large factors in elemental composition and in published metallographic cooling rates (Yang and Goldstein, 2006; Yang et al., 2008). Despite differing by a factor of 25 in estimated metallographic cooling rate, the two IVA irons showed similar Rαγ values of ˜22. If experimental uncertainties are considered this implies that, at low temperatures, their cooling rates differ by less than a factor of 5 with 95% confidence, i.e., significantly less than the range in metallographic cooling rates. In contrast, the IIIAB irons have different ratios; Rαγ in Haig is 29 whereas that in Cumpas, with a reported cooling rate 4.5 times lower, is 22, the opposite of that expected from the published cooling rates. A reevaluation of the Yang-Goldstein IIIAB data set shows that Haig has anomalous metallographic properties. We suggest that both the high Rαγ in Haig and the systematically low taenite central Ni contents are the result of impact-produced fractures in the taenite that allowed equilibration with kamacite down to

  11. Relative deprivation in income and self-rated health in the United States.

    PubMed

    Subramanyam, Malavika; Kawachi, Ichiro; Berkman, Lisa; Subramanian, S V

    2009-08-01

    Absolute income is robustly associated with health status. Few studies have, however, examined if relative income is independently associated with health. We examined if, over and above the effects of absolute income, individual relative deprivation in income as well as position in the income hierarchy is associated with individual poor health in the U.S. Using three rounds of the Current Population Surveys (CPS), we analyzed the association between self-rated health (1=fair/poor, 0=otherwise) and the Yitzhaki index of relative deprivation in income and percentile position in the income hierarchy across 17 reference groups. Over and above the effects of absolute income, the odds ratio for reporting poor health among individuals in the highest quintile of relative deprivation compared to the lowest quintile ranged between 2.18 and 3.30, depending on the reference groups used. A 10 percentile increase in income position within reference groups was associated with an odds ratio of poor health of 0.89. Relative deprivation appeared to explain between 33 and 94% of the association between individual income and self-rated health. Relative deprivation in income is independently associated with poor health over and above the well established effects of absolute income on health. Relative deprivation may partly explain the association between income inequality and worse population health status.

  12. Enhanced Atlantic sea-level rise relative to the Pacific under high carbon emission rates

    NASA Astrophysics Data System (ADS)

    Krasting, J. P.; Dunne, J. P.; Stouffer, R. J.; Hallberg, R. W.

    2016-03-01

    Thermal expansion of the ocean in response to warming is an important component of historical sea-level rise. Observational studies show that the Atlantic and Southern oceans are warming faster than the Pacific Ocean. Here we present simulations using a numerical atmospheric-ocean general circulation model with an interactive carbon cycle to evaluate the impact of carbon emission rates, ranging from 2 to 25 GtC yr-1, on basin-scale ocean heat uptake and sea level. For simulations with emission rates greater than 5 GtC yr-1, sea-level rise is larger in the Atlantic than Pacific Ocean on centennial timescales. This basin-scale asymmetry is related to the shorter flushing timescales and weakening of the overturning circulation in the Atlantic. These factors lead to warmer Atlantic interior waters and greater thermal expansion. In contrast, low emission rates of 2 and 3 GtC yr-1 will cause relatively larger sea-level rise in the Pacific on millennial timescales. For a given level of cumulative emissions, sea-level rise is largest at low emission rates. We conclude that Atlantic coastal areas may be particularly vulnerable to near-future sea-level rise from present-day high greenhouse gas emission rates.

  13. Addition by Subtraction: The Relation Between Dropout Rates and School-Level Academic Achievement

    PubMed Central

    GLENNIE, ELIZABETH; BONNEAU, KARA; VANDELLEN, MICHELLE; DODGE, KENNETH A.

    2013-01-01

    Background/Context Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding is that high-stakes testing policies that mandate grade repetition and high school exit exams may be the tipping point for students who are already struggling academically. These extra demands may, in fact, push students out of school. Purpose/Objective/Focus This article examines two hypotheses regarding the relation between school-level accountability and dropout rates. The first posits that improvements in school performance lead to improved success for everyone. If school-level accountability systems improve a school for all students, then the proportion of students performing at grade level increases, and the dropout rate decreases. The second hypothesis posits that schools facing pressure to improve their overall accountability score may pursue this increase at the cost of other student outcomes, including dropout rate. Research Design Our approach focuses on the dynamic relation between school-level academic achievement and dropout rates over time—that is, between one year’s achievement and the subsequent year’s dropout rate, and vice versa. This article employs longitudinal data of records on all students in North Carolina public schools over an 8-year period. Analyses employ fixed-effects models clustering schools and districts within years and controls each year for school size, percentage of students who were free/reduced-price lunch eligible, percentage of students who are ethnic minorities, and locale. Findings/Results This study finds partial evidence that improvements in school-level academic performance will lead to improvements (i.e., decreases) in school-level dropout rates. Schools with improved

  14. Addition by Subtraction: The Relation Between Dropout Rates and School-Level Academic Achievement.

    PubMed

    Glennie, Elizabeth; Bonneau, Kara; Vandellen, Michelle; Dodge, Kenneth A

    2012-01-01

    Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding is that high-stakes testing policies that mandate grade repetition and high school exit exams may be the tipping point for students who are already struggling academically. These extra demands may, in fact, push students out of school. This article examines two hypotheses regarding the relation between school-level accountability and dropout rates. The first posits that improvements in school performance lead to improved success for everyone. If school-level accountability systems improve a school for all students, then the proportion of students performing at grade level increases, and the dropout rate decreases. The second hypothesis posits that schools facing pressure to improve their overall accountability score may pursue this increase at the cost of other student outcomes, including dropout rate. Our approach focuses on the dynamic relation between school-level academic achievement and dropout rates over time-that is, between one year's achievement and the subsequent year's dropout rate, and vice versa. This article employs longitudinal data of records on all students in North Carolina public schools over an 8-year period. Analyses employ fixed-effects models clustering schools and districts within years and controls each year for school size, percentage of students who were free/reduced-price lunch eligible, percentage of students who are ethnic minorities, and locale. This study finds partial evidence that improvements in school-level academic performance will lead to improvements (i.e., decreases) in school-level dropout rates. Schools with improved performance saw decreased dropout rates following these successes. However, we find

  15. Perioperative closure-related complication rates and cost analysis of barbed suture for closure in TKA.

    PubMed

    Gililland, Jeremy M; Anderson, Lucas A; Sun, Grant; Erickson, Jill A; Peters, Christopher L

    2012-01-01

    The use of barbed suture for surgical closure has been associated with lower operative times, equivalent wound complication rate, and comparable cosmesis scores in the plastic surgery literature. Similar studies would help determine whether this technology is associated with low complication rates and reduced operating times for orthopaedic closures. We compared a running barbed suture with an interrupted standard suture technique for layered closure in primary TKA to determine if the barbed suture would be associated with (1) shorter estimated closure times; (2) lower cost; and (3) similar closure-related perioperative complication rates. We retrospectively compared two-layered closure techniques in primary TKA with either barbed or knotted sutures. The barbed group consisted of 104 primary TKAs closed with running barbed suture. The standard group consisted of 87 primary TKAs closed with interrupted suture. Cost analysis was based on cost of suture and operating room time. Clinical records were assessed for closure-related complications within the 6-week perioperative period. Average estimated closure time was 2.3 minutes shorter with the use of barbed suture. The total closure cost was similar between the groups. The closure-related perioperative complication rates were similar between the groups. Barbed suture is associated with a slightly shorter estimated closure time, although this small difference is of questionable clinical importance. With similar overall cost and no difference in perioperative complications in primary TKA, this closure methodology has led to more widespread use at our institution.

  16. Temporal discounting rates and their relation to exercise behavior in older adults.

    PubMed

    Tate, Linda M; Tsai, Pao-Feng; Landes, Reid D; Rettiganti, Mallikarjuna; Lefler, Leanne L

    2015-12-01

    As our nation's population ages, the rates of chronic illness and disability are expected to increase significantly. Despite the knowledge that exercise may prevent chronic disease and promote health among older adults, many still are inactive. Factors related to exercise behaviors have been explored in recent years. However, temporal discounting is a motivational concept that has not been explored in regard to exercise in older adults. Temporal discounting is a decision making process by which an individual chooses a smaller more immediate reward over a larger delayed reward. The aim of this study was to determine if temporal discounting rates vary between exercising and non-exercising older adults. This study used cross-sectional survey of 137 older adults living in the community. Older adults were recruited from 11 rural Arkansas churches. The Kirby delay-discounting Monetary Choice Questionnaire was used to collect discounting rates and then bivariate analysis was performed to compare temporal discounting rate between the exercisers and non-exercisers. Finally, multivariate analysis was used to compare discounting rate controlling for other covariates. The results indicated that exercising older adults display lower temporal discounting rates than non-exercising older adults. After controlling for education, exercisers still have lower temporal discounting rates than non-exercisers (p<0.001). These findings are important as several chronic health conditions relate to lack of exercise especially in older adults. This research suggests that if we can find appropriate incentives for discounting individuals, some type of immediate reward, then potentially we can design programs to engage and retain older adults in exercise. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. [Variability in the rate of episiotomies and its relation to severe perineal tears and neonatal morbility].

    PubMed

    Hernández-Martínez, Antonio; Pascual-Pedreño, Ana Isabel; Baño Garnés, Ana Belén; Melero-Jiménez, María del Rocio; Molina Alarcón, Milagros

    2014-01-01

    To determine the variability in the use of episiotomy among midwives and its relation to third and fourth-degree tears, and the impact on neonatal morbidity. A study was conducted on historical groups from a total of 2,366 eutocic births with a single live fetus greater than or equal to 37 weeks gestation and 18 midwives over a three year period (2009, 2010 and 2011) in "Mancha-Centro" Hospital (Alcázar de San Juan).The outcomes variables for this analysis were the incidence of episiotomy, perineal lacerations, and neonatal morbidity. The variability in the use of episiotomy ranged from 19.5% to 50.1% among the 18 midwives in the study, with an average rate of 34.9% (824). Grouped at intervals, 22.1% (524) had a rate of ≤25%, 26.1% (621) between 26-35%, 38% (898) between 36-44%, and 13.7% (323) a rate of ≥45%, with homogeneity between the groups for all the confounding factors. There was no statistical association between higher rates of episotomy and pH of umbilical artery<7.10, Apgar score after 5 min<7, and the level of neonatal resuscitation type iii and iv. There was also no relationship between the rate of episiotomy with perineal integrity and third and fourth-degree tears. The variability in the rate of episiotomy is high, and it is not related to the increased presence of third and fourth-degree tears or increased neonatal morbidity. Episiotomy rates should not be greater than 25%, in order to prevent perineal trauma or loss of fetal well-being. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  18. Implementation of strain rate sensitive material properties into impact related problems

    SciTech Connect

    Laubscher, R.F.; Merwe, P. van der

    1995-12-31

    Strain rate sensitivity is discussed in general. A general strain rate sensitive constitutive model is then derived with a yield criterion for an isotropic hardening material incorporating a modified version of the Cowper Symonds equation. Experimental data for 10 different metals ranging from carbon steels to titanium alloys are fitted to this constitutive model. It is shown that with this relatively simple model a good agreement can be achieved between the constitutive model and the experimental data for most metals. The manner in which this constitutive model may be used in design is discussed along with its incorporation into numerical methods such as finite elements.

  19. Evolution of cultural traits occurs at similar relative rates in different world regions

    PubMed Central

    Currie, Thomas E.; Mace, Ruth

    2014-01-01

    A fundamental issue in understanding human diversity is whether or not there are regular patterns and processes involved in cultural change. Theoretical and mathematical models of cultural evolution have been developed and are increasingly being used and assessed in empirical analyses. Here, we test the hypothesis that the rates of change of features of human socio-cultural organization are governed by general rules. One prediction of this hypothesis is that different cultural traits will tend to evolve at similar relative rates in different world regions, despite the unique historical backgrounds of groups inhabiting these regions. We used phylogenetic comparative methods and systematic cross-cultural data to assess how different socio-cultural traits changed in (i) island southeast Asia and the Pacific, and (ii) sub-Saharan Africa. The relative rates of change in these two regions are significantly correlated. Furthermore, cultural traits that are more directly related to external environmental conditions evolve more slowly than traits related to social structures. This is consistent with the idea that a form of purifying selection is acting with greater strength on these more environmentally linked traits. These results suggest that despite contingent historical events and the role of humans as active agents in the historical process, culture does indeed evolve in ways that can be predicted from general principles PMID:25297866

  20. Vulnerability of Louisiana's coastal wetlands to present-day rates of relative sea-level rise

    PubMed Central

    Jankowski, Krista L.; Törnqvist, Torbjörn E; Fernandes, Anjali M

    2017-01-01

    Coastal Louisiana has lost about 5,000 km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world's highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion and shallow subsidence rates. Comparison of vertical accretion rates with RSLR rates at the land surface (present-day RSLR rates are 12±8 mm per year) shows that 65% of wetlands in the Mississippi Delta (SE Louisiana) may keep pace with RSLR, whereas 58% of the sites in the Chenier Plain (SW Louisiana) do not, rendering much of this area highly vulnerable to RLSR. At least 60% of the total subsidence rate occurs within the uppermost 5–10 m, which may account for the higher vulnerability of coastal Louisiana wetlands compared to their counterparts elsewhere. PMID:28290444

  1. Sex differences in work-related injury rates among electric utility workers.

    PubMed

    Kelsh, M A; Sahl, J D

    1996-05-15

    Few epidemiologic studies have evaluated sex differences in work-related injury rates. In this study, the authors examined injury trends by type of injury, severity of injury, and how the injury occurred among a cohort of 9,582 female and 26,898 male electric utility workers employed during 1980-1992 by the Southern California Edison Company. Sex-specific unadjusted injury rates were higher throughout the period for male workers. However, after adjustment for occupation, job experience, and age, elevated rate ratios indicate that female workers have higher injury rates. Mantel-Haenszel summary rate ratios and 95% confidence intervals were 1.49 (1.43-1.54) for all types of injuries, 1.27 (1.16-1.39) for head and neck injuries, 1.48 (1.38-1.58) for upper extremity injuries, 1.11 (1.01-1.21) for back injuries, and 2.11 (1.97-2.25) for lower extremity injuries. The rate ratios were slightly higher for more severe injuries, which suggests that potential reporting bias was not a likely explanation for these findings. The authors conclude that differences between male and female workers in training, physical capacity, task assignments, and other factors could explain these injury trends.

  2. Phonation-related rate coding and recruitment in the genioglossus muscle.

    PubMed

    Shumway, K R; Porfirio, D J; Bailey, E F

    2015-07-01

    Motor unit recruitment was assessed in two muscles with similar muscle fiber-type compositions and that participate in skilled movements: the tongue muscle, genioglossus (GG), and the hand muscle, first dorsal interosseous (FDI). Our primary objectives were to determine in the framework of a voluntary movement whether muscle force is regulated in tongue as it is in limb, i.e., via processes of rate coding and recruitment. Recruitment in the two muscles was assessed within each subject in the context of ramp force (FDI) and in the tongue (GG) during vowel production and specifically, in the context of ramp increases in loudness, and subsequently expressed relative to the maximal. The principle findings of the study are that the general rules of recruitment and rate coding hold true for both GG and FDI, and second, that average firing rates, firing rates at recruitment and peak firing rates in GG are significantly higher than for FDI (P < 0.001) despite tasks performed across comparable force ranges (~2-40 % of max). The higher firing rates observed in the tongue within the context of phonation may be a function of that muscle's dual role as (prime) mover and hydrostatic support element.

  3. Rate coefficients of hydroxyl radical reactions with pesticide molecules and related compounds: A review

    NASA Astrophysics Data System (ADS)

    Wojnárovits, László; Takács, Erzsébet

    2014-03-01

    Rate coefficients published in the literature on hydroxyl radical reactions with pesticides and related compounds are discussed together with the experimental methods and the basic reaction mechanisms. Recommendations are made for the most probable values. Most of the molecules whose rate coefficients are discussed have aromatic ring: their rate coefficients are in the range of 2×109-1×1010 mol-1 dm3 s-1. The rate coefficients show some variation with the electron withdrawing-donating nature of the substituent on the ring. The rate coefficients for triazine pesticides (simazine, atrazine, prometon) are all around 2.5×109 mol-1 dm3 s-1. The values do not show variation with the substituent on the s-triazine ring. The rate coefficients for the non-aromatic molecules which have C=C double bonds or several C-H bonds may also be above 1×109 mol-1 dm3 s-1. However, the values for molecules without C=C double bonds or several C-H bonds are in the 1×107-1×109 mol-1 dm3 s-1 range.

  4. Vulnerability of Louisiana's coastal wetlands to present-day rates of relative sea-level rise

    NASA Astrophysics Data System (ADS)

    Jankowski, Krista L.; Törnqvist, Torbjörn E.; Fernandes, Anjali M.

    2017-03-01

    Coastal Louisiana has lost about 5,000 km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world's highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion and shallow subsidence rates. Comparison of vertical accretion rates with RSLR rates at the land surface (present-day RSLR rates are 12+/-8 mm per year) shows that 65% of wetlands in the Mississippi Delta (SE Louisiana) may keep pace with RSLR, whereas 58% of the sites in the Chenier Plain (SW Louisiana) do not, rendering much of this area highly vulnerable to RLSR. At least 60% of the total subsidence rate occurs within the uppermost 5-10 m, which may account for the higher vulnerability of coastal Louisiana wetlands compared to their counterparts elsewhere.

  5. Vulnerability of Louisiana's coastal wetlands to present-day rates of relative sea-level rise.

    PubMed

    Jankowski, Krista L; Törnqvist, Torbjörn E; Fernandes, Anjali M

    2017-03-14

    Coastal Louisiana has lost about 5,000 km(2) of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world's highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion and shallow subsidence rates. Comparison of vertical accretion rates with RSLR rates at the land surface (present-day RSLR rates are 12±8 mm per year) shows that 65% of wetlands in the Mississippi Delta (SE Louisiana) may keep pace with RSLR, whereas 58% of the sites in the Chenier Plain (SW Louisiana) do not, rendering much of this area highly vulnerable to RLSR. At least 60% of the total subsidence rate occurs within the uppermost 5-10 m, which may account for the higher vulnerability of coastal Louisiana wetlands compared to their counterparts elsewhere.

  6. The influence of fatigue-induced increase in relative work rate on temperature regulation during exercise.

    PubMed

    Kacin, Alan; Golja, Petra; Tipton, Michael J; Eiken, Ola; Mekjavic, Igor B

    2008-05-01

    Heat-loss responses during steady-load exercise are affected by an increase in relative work rate induced by muscle ischaemia or hypoxaemia. The present study investigated whether progressive increases in perception of exertion and relative oxygen uptake %VO2peak which occur during prolonged steady-load exercise as a result of progressively increased peripheral fatigue, might also affect the regulation of heat loss responses and hence the exercise-induced increase in mean body temperature. Ten male subjects first performed a ramp-test to exhaustion on a cycle ergometer to evaluate their initial peak oxygen uptake (Control VO2peak). On a separate day, 120 min of cycling at constant power output corresponding to 60% of Control VO2peak was performed in thermoneutral environment (Ta = 23 degrees C, RH = 50%, wind speed = 5 m s(-1)). This was immediately followed by another maximal performance test (Fatigue VO2peak). During prolonged exercise, median (range) rating of perceived exertion for whole-body (RPEwb) increased (P < 0.01) from initial 3.5 (1-5) to 5.5 (5-9) at the end of exercise. Fatigue VO2peak and peak power output were 9 (5) and 10 (5)% lower (P < 0.01) when compared to control values. At the onset of exercise, heat production, mechanical efficiency, heat loss and mean body temperature increased towards asymptotic values, thereafter remained constant throughout the 120 min exercise, despite the concomitant progressive increase in relative work rate, as reflected in increased RPEwb and relative oxygen uptake. It is thus concluded that the increase in relative work rate induced predominantly by peripheral muscle fatigue affects neither the level of increase in mean body temperature nor the regulation of heat loss responses during prolonged steady-load exercise.

  7. Injecting drug users in Scotland, 2006: Listing, number, demography, and opiate-related death-rates

    PubMed Central

    King, Ruth; Bird, Sheila M.; Overstall, Antony; Hay, Gordon; Hutchinson, Sharon J.

    2013-01-01

    Using Bayesian capture–recapture analysis, we estimated the number of current injecting drug users (IDUs) in Scotland in 2006 from the cross-counts of 5670 IDUs listed on four data-sources: social enquiry reports (901 IDUs listed), hospital records (953), drug treatment agencies (3504), and recent Hepatitis C virus (HCV) diagnoses (827 listed as IDU-risk). Further, we accessed exact numbers of opiate-related drugs-related deaths (DRDs) in 2006 and 2007 to improve estimation of Scotland's DRD rates per 100 current IDUs. Using all four data-sources, and model-averaging of standard hierarchical log-linear models to allow for pairwise interactions between data-sources and/or demographic classifications, Scotland had an estimated 31700 IDUs in 2006 (95% credible interval: 24900–38700); but 25000 IDUs (95% CI: 20700–35000) by excluding recent HCV diagnoses whose IDU-risk can refer to past injecting. Only in the younger age-group (15–34 years) were Scotland's opiate-related DRD rates significantly lower for females than males. Older males’ opiate-related DRD rate was 1.9 (1.24–2.40) per 100 current IDUs without or 1.3 (0.94–1.64) with inclusion of recent HCV diagnoses. If, indeed, Scotland had only 25000 current IDUs in 2006, with only 8200 of them aged 35+ years, the opiate-related DRD rate is higher among this older age group than has been appreciated hitherto. There is counter-balancing good news for the public health: the hitherto sharp increase in older current IDUs had stalled by 2006. PMID:23730265

  8. Linear rate-equilibrium relations arising from ion channel-bilayer energetic coupling

    PubMed Central

    Greisen, Per; Lum, Kevin; Ashrafuzzaman, Md.; Greathouse, Denise V.; Andersen, Olaf S.; Lundbæk, Jens A.

    2011-01-01

    Linear rate-equilibrium (RE) relations, also known as linear free energy relations, are widely observed in chemical reactions, including protein folding, enzymatic catalysis, and channel gating. Despite the widespread occurrence of linear RE relations, the principles underlying the linear relation between changes in activation and equilibrium energy in macromolecular reactions remain enigmatic. When examining amphiphile regulation of gramicidin channel gating in lipid bilayers, we noted that the gating process could be described by a linear RE relation with a simple geometric interpretation. This description is possible because the gating process provides a well-understood reaction, in which structural changes in a bilayer-embedded model protein can be studied at the single-molecule level. It is thus possible to obtain quantitative information about the energetics of the reaction transition state and its position on a spatial coordinate. It turns out that the linear RE relation for the gramicidin monomer-dimer reaction can be understood, and the quantitative relation between changes in activation energy and equilibrium energy can be interpreted, by considering the effects of amphiphiles on the changes in bilayer elastic energy associated with channel gating. We are not aware that a similar simple mechanistic explanation of a linear RE relation has been provided for a chemical reaction in a macromolecule. RE relations generally should be useful for examining how amphiphile-induced changes in bilayer properties modulate membrane protein folding and function, and for distinguishing between direct (e.g., due to binding) and indirect (bilayer-mediated) effects. PMID:21768343

  9. Growth rates are related to production efficiencies in juveniles of the sea urchin Lytechinus variegatus.

    PubMed

    Heflin, L E; Gibbs, V K; Jones, W T; Makowsky, R; Lawrence, A L; Watts, S A

    2013-09-01

    Growth rates of newly-metamorphosed urchins from a single spawning event (three males and three females) were highly variable, despite being held en masse under identical environmental and nutritional conditions. As individuals reached ~5 mm diameter (0.07-0.10 g wet weight), they were placed in growth trials (23 dietary treatments containing various nutrient profiles). Elapsed time from the first individual entering the growth trials to the last individual entering was 121 days (N = 170 individuals). During the five-week growth trials, urchins were held individually and proffered a limiting ration to evaluate growth rate and production efficiency. Growth rates among individuals within each dietary treatment remained highly variable. Across all dietary treatments, individuals with an initially high growth rate (entering the study first) continued to grow at a faster rate than those with an initially low growth rate (entering the study at a later date), regardless of feed intake. Wet weight gain (ranging from 0.13 -3.19 g, P < 0.0001, R(2) = 0.5801) and dry matter production efficiency (ranging from 25.2-180.5%, P = 0.0003, R(2) = 0.6162) were negatively correlated with stocking date, regardless of dietary treatment. Although canalization of growth rate during en masse early post-metamorphic growth is possible, we hypothesize that intrinsic differences in growth rates are, in part, the result of differences (possibly genetic) in production efficiencies of individual Lytechinus variegatus. That is, some sea urchins are more efficient in converting feed to biomass. We further hypothesize that this variation may have evolved as an adaptive response to selective pressure related to food availability.

  10. Are mortality rates for different operations related?: implications for measuring the quality of noncardiac surgery.

    PubMed

    Dimick, Justin B; Staiger, Douglas O; Birkmeyer, John D

    2006-08-01

    Except in cardiac surgery, measuring quality with procedure-specific mortality rates is unreliable because of small sample sizes at individual hospitals. Statistical power can be improved by combining mortality data from multiple operations. We sought to determine whether this approach would still be useful in understanding performance with individual procedures. We studied 11 high-risk operations performed in the national Medicare population (1996-1999). For each operation, we calculated 1) the risk-adjusted mortality rate for the procedure and 2) the mortality rate with up to 10 other operations combined ("other" mortality). To test for an association between these mortality rates, we calculated the correlation coefficient adjusting for random variation. We then collapsed hospitals into quintiles of other mortality and calculated procedure-specific mortality rates within each of these quintiles. Mortality with specific operations was modestly correlated with other mortality: coefficients ranged from 0.14 for pneumonectomy to 0.35 for esophagectomy. Despite small to moderate correlations, other mortality was a good predictor of procedure-specific mortality for 10 of the 11 operations. Pancreatic resection had the strongest relationship, with procedure-specific mortality rates at hospitals in the worst quintile of other mortality 3-fold higher than those in the best quintile (15.2% vs. 6.3%, P < 0.001). Pneumonectomy had the weakest relationship with no significant relationship between other mortality and procedure-specific mortality. Hospitals with low mortality rates for 1 operation tend to have lower mortality rates for other operations. These relationships suggest that different operations share important structures and processes of care related to performance. Future efforts aimed at predicting procedure-specific performance should consider incorporating data from other operations at that hospital.

  11. Growth rates are related to production efficiencies in juveniles of the sea urchin Lytechinus variegatus

    PubMed Central

    Heflin, L.E.; Gibbs, V.K.; Jones, W.T.; Makowsky, R.; Lawrence, A.L.; Watts, S.A.

    2014-01-01

    Growth rates of newly-metamorphosed urchins from a single spawning event (three males and three females) were highly variable, despite being held en masse under identical environmental and nutritional conditions. As individuals reached ~5 mm diameter (0.07–0.10 g wet weight), they were placed in growth trials (23 dietary treatments containing various nutrient profiles). Elapsed time from the first individual entering the growth trials to the last individual entering was 121 days (N = 170 individuals). During the five-week growth trials, urchins were held individually and proffered a limiting ration to evaluate growth rate and production efficiency. Growth rates among individuals within each dietary treatment remained highly variable. Across all dietary treatments, individuals with an initially high growth rate (entering the study first) continued to grow at a faster rate than those with an initially low growth rate (entering the study at a later date), regardless of feed intake. Wet weight gain (ranging from 0.13 −3.19 g, P < 0.0001, R2 = 0.5801) and dry matter production efficiency (ranging from 25.2–180.5%, P = 0.0003, R2 = 0.6162) were negatively correlated with stocking date, regardless of dietary treatment. Although canalization of growth rate during en masse early post-metamorphic growth is possible, we hypothesize that intrinsic differences in growth rates are, in part, the result of differences (possibly genetic) in production efficiencies of individual Lytechinus variegatus. That is, some sea urchins are more efficient in converting feed to biomass. We further hypothesize that this variation may have evolved as an adaptive response to selective pressure related to food availability. PMID:25435593

  12. Relation of eye dominance with performance and subjective ratings in golf putting.

    PubMed

    Sugiyama, Yoshio; Lee, Mi-Sook

    2005-06-01

    Previous research has discussed the interaction of hand preference, eye dominance, and sport performance. In this study, the relation of eye dominance with performance and subjective ratings in golf putting was investigated. 47 right-handed Japanese students from a college of physical education putted 10 balls to a drawn circle 3 m away, each under right-handed and left-handed stance conditions. Putting performance was measured by the number of successful putts. After putting in each condition, they rated subjective visibility and feelings of hitting. Analyses indicated that right-eyed subjects had significantly better performance using the right-handed stance than the left-handed stance, whereas left-eyed subjects showed the opposite. Most subjective ratings were more positive with right-handed stance for both right-eyed and left-eyed subjects. These findings suggest that eye dominance could have some influence on putting performance of Japanese novice golfers.

  13. Stigma, Attitudes, and Help-Seeking Intentions for Psychological Problems in Relation to Regional Suicide Rates.

    PubMed

    Reynders, Alexandre; Kerkhof, Ad J F M; Molenberghs, Geert; Van Audenhove, Chantal

    2016-02-01

    In this ecological study, we investigated whether help-seeking related to stigma, intentions, and attitudes toward suicide are associated with the suicide rates of 20 regions within the Netherlands and Belgium. Significant associations were found between regional suicide rates and the intention to seek informal help (β = -1.47, p = .001), self-stigma (β = 1.33, p = .038), and shame (β = .71, p = .030). The association between self-stigma and suicide rate was mediated by intentions to seek informal help. These results suggest that to promote suicide prevention at the level of the regional population, stigma, shame, and intentions to seek help should be targeted in the public domain. © 2015 The American Association of Suicidology.

  14. The impact of varicella vaccination on varicella-related hospitalization rates: global data review

    PubMed Central

    Hirose, Maki; Gilio, Alfredo Elias; Ferronato, Angela Esposito; Ragazzi, Selma Lopes Betta

    2016-01-01

    Abstract Objective: To describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. Data source: We identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination) in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or) "hospitalization". Publications in English published between January 1995 and May 2015 were included. Data synthesis: 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4%–99.2% reduction in hospitalization rates in children younger than four years, 6–14 years after the onset of universal vaccination (1995), with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1–4 years) in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1–4 years) in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1–4 years) in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1–4 years) in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years) in four years, coverage of 77.2% and Italy 69.7%–73.8% decrease (general population), coverage of 60%–95%. Conclusions: The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between data. PMID

  15. The impact of varicella vaccination on varicella-related hospitalization rates: global data review.

    PubMed

    Hirose, Maki; Gilio, Alfredo Elias; Ferronato, Angela Esposito; Ragazzi, Selma Lopes Betta

    2016-09-01

    to describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. we identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination) in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or) "hospitalization". Publications in English published between January 1995 and May 2015 were included. 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4% -99.2% reduction in hospitalization rates in children younger than four years after 6-14 years after the onset of universal vaccination (1995), with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1-4 years) in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1-4 years) in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1-4 years) in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1-4 years) in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years) in four years, coverage of 77.2% and Italy 69.7% -73.8% decrease (general population), coverage of 60%-95%. The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between data. Copyright © 2016 Sociedade de Pediatria de São Paulo. Publicado por

  16. Relative patterns and rates of evolution in heron nuclear and mitochondrial DNA.

    PubMed

    Sheldon, F H; Jones, C E; McCracken, K G

    2000-03-01

    Mitochondrial cytochrome b sequence data from 15 species of herons (Aves: Ardeidae), representing 13 genera, were compared with DNA hybridization data of single-copy nuclear DNA (scnDNA) from the same species in a taxonomic congruence assessment of heron phylogeny. The two data sets produced a partially resolved, completely congruent estimate of phylogeny with the following basic structure: (Tigrisoma, Cochlearius, (((Zebrilus, (Ixobrychus, Botaurus)), (((Ardea, Casmerodius), Bubulcus), ((Egretta thula, Egretta caerulea, Egretta tricolor), Syrigma), Butorides, Nycticorax, Nyctanassa)))). Because congruence indicated similar phylogenetic information in the two data sets, we used the relatively unsaturated DNA hybridization distances as surrogates of time to examine graphically the patterns and rates of change in cytochrome b distances. Cytochrome b distances were computed either from whole sequences or from partitioned sequences consisting of transitions, transversions, specific codon site positions, or specific protein-coding regions. These graphical comparisons indicated that unpartitioned cytochrome b has evolved at 5-10 times the rate of scnDNA. Third-position transversions appeared to offer the most useful sequence partition for phylogenetic analysis because of their relatively fast rate of substitution (two times that of scnDNA) and negligible saturation. We also examined lineage-based rates of evolution by comparing branch length patterns between the nuclear and cytochrome b trees. The degree of correlation in corresponding branch lengths between cytochrome b and DNA hybridization trees depended on DNA sequence partitioning. When cytochrome b sequences were not partitioned, branch lengths in the cytochrome b and DNA hybridization trees were not correlated. However, when cytochrome b sequences were reduced to third-position transversions (i.e., unsaturated, relatively fast changing data), branch lengths were correlated. This finding suggests that lineage

  17. Star Formation Rate and Gas Relations in the Arp 299 Merger from the VIXENS Survey

    NASA Astrophysics Data System (ADS)

    Heiderman, Amanda; Evans, Neal J.; Gebhardt, Karl; Blanc, Guillermo; Davis, Timothy; Papovich, Casey; van den Bosch, Remco; Iono, Daisuke; Yun, Min S.

    2015-08-01

    We highlight first results from the VIRUS-P Investigation of the eXtreme ENvironments of Starbursts (VIXENS) integral field unit survey. We investigate the relationship between star formation and gas content in late interaction phase merger Arp 299 from VIXENS. By comparing Hα, Paα, and 24μm images to CO(2→1), CO(3→2), HCN(1→0), HCO+(1→0), and HI maps, we explore the relation between the star formation rate and gas surface densities on spatially resolved ~kpc scales. We find that the SFR-gas relations for Arp 299 are discrepant from known extragalactic spatially resolved relations in nearby spiral galaxies and disk-averaged relations in high-z mergers.

  18. A Novel Method for Extracting Respiration Rate and Relative Tidal Volume from Infrared Thermography

    PubMed Central

    Lewis, Gregory F.; Gatto, Rodolfo G.; Porges, Stephen W.

    2010-01-01

    In psychophysiological research, measurement of respiration has been dependent on transducers having direct contact with the participant. The current study provides empirical data demonstrating that a noncontact technology, infrared video thermography, can accurately estimate breathing rate and relative tidal volume across a range of breathing patterns. Video tracking algorithms were applied to frame-by-frame thermal images of the face to extract time series of nostril temperature and to generate breath-by-breath measures of respiration rate and relative tidal volume. The thermal indices of respiration were contrasted with criterion measures collected with inductance plethysmography. The strong correlations observed between the technologies demonstrate the potential use of facial video thermography as a noncontact technology to monitor respiration. PMID:21214587

  19. Heart rate-left ventricular ejection time relations - Variations during postural change and cardiovascular challenges

    NASA Technical Reports Server (NTRS)

    Lance, V. Q.; Spodick, D. H.

    1976-01-01

    Experiments were conducted on healthy human subjects to determine HR-LVET (Heart Rate-Left Ventricular Ejection Time) regression relations in different postures, including tilt, and during isometric exercise. The subjects were tested in the resting state in supine and sitting positions, during isometric handgrip in supine and sitting positions and during 70 deg headup tilt. The recordings included a bipolar electrocardiogram and a right external carotid pulse curve. Comparison of the HR-LVET relation for the conditions under analysis revealed differences among the respective regression equations, which can be explained by the well-established differences in stroke volume and ejection rate among these states. These differences appear to account for the fact that under conditions in which stroke volume variations should be the major determinant, slopes will be similar but intercepts will vary. Since substantial differences among intercepts are observed, caution should be exercised whenever the intercept factor is used to predict LVET for HR.

  20. Heart rate-left ventricular ejection time relations - Variations during postural change and cardiovascular challenges

    NASA Technical Reports Server (NTRS)

    Lance, V. Q.; Spodick, D. H.

    1976-01-01

    Experiments were conducted on healthy human subjects to determine HR-LVET (Heart Rate-Left Ventricular Ejection Time) regression relations in different postures, including tilt, and during isometric exercise. The subjects were tested in the resting state in supine and sitting positions, during isometric handgrip in supine and sitting positions and during 70 deg headup tilt. The recordings included a bipolar electrocardiogram and a right external carotid pulse curve. Comparison of the HR-LVET relation for the conditions under analysis revealed differences among the respective regression equations, which can be explained by the well-established differences in stroke volume and ejection rate among these states. These differences appear to account for the fact that under conditions in which stroke volume variations should be the major determinant, slopes will be similar but intercepts will vary. Since substantial differences among intercepts are observed, caution should be exercised whenever the intercept factor is used to predict LVET for HR.

  1. THE OBSERVED RELATION BETWEEN STELLAR MASS, DUST EXTINCTION, AND STAR FORMATION RATE IN LOCAL GALAXIES

    SciTech Connect

    Zahid, H. J.; Kewley, L. J.; Kudritzki, R. P.; Yates, R. M.

    2013-02-15

    In this study, we investigate the relation between stellar mass, dust extinction, and star formation rate (SFR) using {approx}150,000 star-forming galaxies from SDSS DR7. We show that the relation between dust extinction and SFR changes with stellar mass. For galaxies at the same stellar mass, dust extinction is anti-correlated with the SFR at stellar masses <10{sup 10} M {sub Sun }. There is a sharp transition in the relation at a stellar mass of 10{sup 10} M {sub Sun }. At larger stellar masses, dust extinction is positively correlated with the SFR for galaxies at the same stellar mass. The observed relation between stellar mass, dust extinction, and SFR presented in this study helps to confirm similar trends observed in the relation between stellar mass, metallicity, and SFR. The relation reported in this study provides important new constraints on the physical processes governing the chemical evolution of galaxies. The correlation between SFR and dust extinction for galaxies with stellar masses >10{sup 10} M {sub Sun} is shown to extend to the population of quiescent galaxies suggesting that the physical processes responsible for the observed relation between stellar mass, dust extinction, and SFR may be related to the processes leading to the shutdown of star formation in galaxies.

  2. Determination of relative rate constants for in vitro RNA processing reactions by internal competition.

    PubMed

    Lin, Hsuan-Chun; Yandek, Lindsay E; Gjermeni, Ino; Harris, Michael E

    2014-12-15

    Studies of RNA recognition and catalysis typically involve measurement of rate constants for reactions of individual RNA sequence variants by fitting changes in substrate or product concentration to exponential or linear functions. A complementary approach is determination of relative rate constants by internal competition, which involves quantifying the time-dependent changes in substrate or product ratios in reactions containing multiple substrates. Here, we review approaches for determining relative rate constants by analysis of both substrate and product ratios and illustrate their application using the in vitro processing of precursor transfer RNA (tRNA) by ribonuclease P as a model system. The presence of inactive substrate populations is a common complicating factor in analysis of reactions involving RNA substrates, and approaches for quantitative correction of observed rate constants for these effects are illustrated. These results, together with recent applications in the literature, indicate that internal competition offers an alternate method for analyzing RNA processing kinetics using standard molecular biology methods that directly quantifies substrate specificity and may be extended to a range of applications. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. The Relation between Recombination Rate and Patterns of Molecular Evolution and Variation in Drosophila melanogaster

    PubMed Central

    Campos, José L.; Halligan, Daniel L.; Haddrill, Penelope R.; Charlesworth, Brian

    2014-01-01

    Genetic recombination associated with sexual reproduction increases the efficiency of natural selection by reducing the strength of Hill–Robertson interference. Such interference can be caused either by selective sweeps of positively selected alleles or by background selection (BGS) against deleterious mutations. Its consequences can be studied by comparing patterns of molecular evolution and variation in genomic regions with different rates of crossing over. We carried out a comprehensive study of the benefits of recombination in Drosophila melanogaster, both by contrasting five independent genomic regions that lack crossing over with the rest of the genome and by comparing regions with different rates of crossing over, using data on DNA sequence polymorphisms from an African population that is geographically close to the putatively ancestral population for the species, and on sequence divergence from a related species. We observed reductions in sequence diversity in noncrossover (NC) regions that are inconsistent with the effects of hard selective sweeps in the absence of recombination. Overall, the observed patterns suggest that the recombination rate experienced by a gene is positively related to an increase in the efficiency of both positive and purifying selection. The results are consistent with a BGS model with interference among selected sites in NC regions, and joint effects of BGS, selective sweeps, and a past population expansion on variability in regions of the genome that experience crossing over. In such crossover regions, the X chromosome exhibits a higher rate of adaptive protein sequence evolution than the autosomes, implying a Faster-X effect. PMID:24489114

  4. Temperature and rainfall are related to fertility rate after spring artificial insemination in small ruminants

    NASA Astrophysics Data System (ADS)

    Abecia, J. A.; Arrébola, F.; Macías, A.; Laviña, A.; González-Casquet, O.; Benítez, F.; Palacios, C.

    2016-10-01

    A total number of 1092 artificial inseminations (AIs) performed from March to May were documented over four consecutive years on 10 Payoya goat farms (36° N) and 19,392 AIs on 102 Rasa Aragonesa sheep farms (41° N) over 10 years. Mean, maximum, and minimum ambient temperatures, mean relative humidity, mean solar radiation, and total rainfall on each insemination day were recorded. Overall, fertility rates were 58 % in goats and 45 % in sheep. The fertility rates of the highest and lowest deciles of each of the meteorological variables indicated that temperature and rainfall had a significant effect on fertility in goats. Specifically, inseminations that were performed when mean (68 %), maximum (68 %), and minimum (66 %) temperatures were in the highest decile, and rainfall was in the lowest decile (59 %), had a significantly ( P < 0.0001) higher proportion of does that became pregnant than did the ewes in the lowest decile (56, 54, 58, and 49 %, respectively). In sheep, the fertility rates of the highest decile of mean (62 %), maximum (62 %), and minimum (52 %) temperature, RH (52 %), THI (53 %), and rainfall (45 %) were significantly higher ( P < 0.0001) than were the fertility rates among ewes in the lowest decile (46, 45, 45, 45, 46, and 43 %, respectively). In conclusion, weather was related to fertility in small ruminants after AI in spring. It remains to be determined whether scheduling the dates of insemination based on forecasted temperatures can improve the success of AI in goats and sheep.

  5. Hungry for an intervention? Adolescents' ratings of acceptability of eating-related intervention strategies.

    PubMed

    Stok, F Marijn; de Ridder, Denise T D; de Vet, Emely; Nureeva, Liliya; Luszczynska, Aleksandra; Wardle, Jane; Gaspar, Tania; de Wit, John B F

    2016-01-05

    Effective interventions promoting healthier eating behavior among adolescents are urgently needed. One factor that has been shown to impact effectiveness is whether the target population accepts the intervention. While previous research has assessed adults' acceptance of eating-related interventions, research on the opinion of adolescents is lacking. The current study addressed this gap in the literature. Two thousand seven hundred sixty four adolescents (aged 10-17 years) from four European countries answered questions about individual characteristics (socio-demographics, anthropometrics, and average daily intake of healthy and unhealthy foods) and the acceptability of ten eating-related intervention strategies. These strategies varied in type (either promoting healthy eating or discouraging unhealthy eating), level of intrusiveness, setting (home, school, broader out-of-home environment), and change agent (parents, teacher, policy makers). Based on adolescents' acceptability ratings, strategies could be clustered into two categories, those promoting healthy eating and those discouraging unhealthy eating, with acceptability rated significantly higher for the former. Acceptability of intervention strategies was rated moderate on average, but higher among girls, younger, overweight and immigrant adolescents, and those reporting healthier eating. Polish and Portuguese adolescents were overall more accepting of strategies than UK and Dutch adolescents. Adolescents preferred intervention strategies that promote healthy eating over strategies that discourage unhealthy eating. Level of intrusiveness affected acceptability ratings for the latter type of strategies only. Various individual and behavioral characteristics were associated with acceptability. These findings provide practical guidance for the selection of acceptable intervention strategies to improve adolescents' eating behavior.

  6. [Cluster analysis on the blood pressure control rate and related factors of hypertensive outpatients in China].

    PubMed

    Sun, Li; Wang, Jiwei; Yu, Jinming

    2015-01-01

    To explore the blood pressure (BP) control rate and related factors in different parts of China. This cross-sectional survey was performed between March and May 2011 in 132 tertiary or secondary hospitals from 31 cities across China. Five consecutive hypertensive patients consulted to individual physician in these hospitals were included and a total of 4 110 patients aged ≥ 18 years were included, and 3 682 patients finished the follow-up protocol. All objects underwent questionnaire survey and physical examination. Cities were divided into 3 categories. Among included hypertensive outpatients, the prevalence of coronary heart disease was the highest (37.4%, 1 368/3 662) comorbidity. The most commonly used antihypertensive medication was calcium channel blocker (51.3%, 1 861/3 628). Blood control rate was the highest in city category II(37.0%) and the lowest in city category I (9.1%). Accordingly, body mass index (BMI, (25.7 ± 0.6) kg/m(2)) and waist circumference ( (90.6 ± 3.1 ) cm) were the largest and the prevalence of coronary heart disease (60.8%) and stroke (19.0%) were the highest in hypertensive outpatients from city categoryI. Blood pressure control rate varies among various cities in China. High BMI and co-morbidities of coronary heart disease and stroke are related to poor blood pressure control rate.

  7. Uncertainties in corrosion rate measurements of fasteners exposed to treated wood at 100% relative humidity

    Treesearch

    Samuel L. Zelinka

    2007-01-01

    This paper evaluates the effect that uncertainties in measurements of time, weight, and surface area have on the determination of the corrosion rate of metal fasteners in contact with wood. Three different types of nails were driven into alkaline copper quaternary (ACQ)-treated wood and exposed to 26.7°C (80°C) at 100 % relative humidity environment for up to 1 year....

  8. Nephrostomy tube related pyelonephritis in patients with cancer: epidemiology, infection rate and risk factors.

    PubMed

    Bahu, Ramez; Chaftari, Anne-Marie; Hachem, Ray Y; Ahrar, Kamran; Shomali, William; El Zakhem, Aline; Jiang, Ying; AlShuaibi, Munirah; Raad, Issam I

    2013-01-01

    Nephrostomy tube placement is often necessary to avert acute renal failure in patients with cancer with obstructive uropathy or in patients with ureteral leak. However, there have been limited published studies on the rate and risk of nephrostomy tube related pyelonephritis in patients with cancer. Therefore, in this study we determined rates of nephrostomy tube related pyelonephritis and predisposing risk factors in patients with cancer. We retrospectively reviewed patients who underwent nephrostomy tube placement between September 1, 2009 and September 16, 2010 at MD Anderson Cancer Center. Patients were followed for 90 days. The primary outcome assessed was the development of nephrostomy tube related pyelonephritis and the secondary outcome was the development of asymptomatic bacteriuria. We also determined risk factors associated with pyelonephritis. Of the 200 patients analyzed 38 (19%) had pyelonephritis and 15 (7.5%) had asymptomatic bacteriuria. Of the nephrostomy tube related infections 34 cases (89%) were with the primary nephrostomy tube. Subsequently 4 of the patients who underwent nephrostomy tube exchange had an episode of pyelonephritis. Pyelonephritis developed within the first month in 19 (10%) patients. Prior urinary tract infection and neutropenia were found to be significant risk factors for pyelonephritis (p = 0.047 and 0.03, respectively). The placement of nephrostomy tubes in patients with cancer is associated with a significant rate of pyelonephritis. Neutropenia and history of urinary tract infection were significant risk factors for pyelonephritis. This finding warrants further investigation into preventive strategies to reduce the infection rate. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  9. Dynamics of choice: relative rate and amount affect local preference at three different time scales.

    PubMed

    Aparicio, Carlos F; Baum, William M

    2009-05-01

    To examine extended control over local choice, the present study investigated preference in transition as food-rate ratio provided by two levers changed across seven components within daily sessions, and food-amount ratio changed across phases. Phase 1 arranged a food-amount ratio of 4:1 (i.e., the left lever delivered four pellets and the right lever one pellet); Phase 2 reversed the food-amount ratio to 1:4, and in Phase 3 the food-amount ratio was 3:2. At a relatively extended time scale, preference was described well by a linear relation between log response ratio and log rate ratio (the generalized matching law). A small amount of carryover occurred from one rate ratio to the next but disappeared after four food deliveries. Estimates of sensitivity to food-amount ratio were around 1.0 and were independent of rate ratio. Analysis across food deliveries within rate-ratio components showed that the effect of a small amount was diminished by the presence of a large amount-that is, when a larger amount was present in the situation (three or four pellets), the value of a small amount (one or two pellets) became paltry. More local analysis of visits to the levers between food deliveries showed that postfood visits following a large amount were disproportionately longer than following a small amount. Continuing food deliveries from the same source tended to make visits less dependent on relative amount, but a discontinuation (i.e., food from the other lever) reinstated dependence on relative amount. Analysis at a still smaller time scale revealed preference pulses following food deliveries that confirmed the tendency toward dependence on absolute amount with continuing deliveries, and toward dependence on relative amount following discontinuations. A mathematical model based on a linear-operator equation accounts for many of the results. The larger and longer preference following a switch to a larger amount is consistent with the idea that local preference depends on

  10. DYNAMICS OF CHOICE: RELATIVE RATE AND AMOUNT AFFECT LOCAL PREFERENCE AT THREE DIFFERENT TIME SCALES

    PubMed Central

    Aparicio, Carlos F; Baum, William M

    2009-01-01

    To examine extended control over local choice, the present study investigated preference in transition as food-rate ratio provided by two levers changed across seven components within daily sessions, and food-amount ratio changed across phases. Phase 1 arranged a food-amount ratio of 4∶1 (i.e., the left lever delivered four pellets and the right lever one pellet); Phase 2 reversed the food-amount ratio to 1∶4, and in Phase 3 the food-amount ratio was 3∶2. At a relatively extended time scale, preference was described well by a linear relation between log response ratio and log rate ratio (the generalized matching law). A small amount of carryover occurred from one rate ratio to the next but disappeared after four food deliveries. Estimates of sensitivity to food-amount ratio were around 1.0 and were independent of rate ratio. Analysis across food deliveries within rate-ratio components showed that the effect of a small amount was diminished by the presence of a large amount—that is, when a larger amount was present in the situation (three or four pellets), the value of a small amount (one or two pellets) became paltry. More local analysis of visits to the levers between food deliveries showed that postfood visits following a large amount were disproportionately longer than following a small amount. Continuing food deliveries from the same source tended to make visits less dependent on relative amount, but a discontinuation (i.e., food from the other lever) reinstated dependence on relative amount. Analysis at a still smaller time scale revealed preference pulses following food deliveries that confirmed the tendency toward dependence on absolute amount with continuing deliveries, and toward dependence on relative amount following discontinuations. A mathematical model based on a linear-operator equation accounts for many of the results. The larger and longer preference following a switch to a larger amount is consistent with the idea that local preference

  11. Investigation of Organic Compound Reactivity in Liquid and Frozen Aqueous Systems Using Relative Rate Experiments

    NASA Astrophysics Data System (ADS)

    Kurek, L.; Grannas, A. M.

    2012-12-01

    Previous studies have shown that snow and ice are highly reactive media where photochemical reactions occur. These reactions can have important consequences for the environment, including the production of organic compounds, halogens and nitrogen oxides that impact surface boundary layer chemistry. Laboratory-based studies have shown that the nature of the sample and the physical location of solutes play a large role in determining the reactivity of a particular compound. During the freezing of aqueous solutions, most solute molecules become excluded from the ice crystal lattice, increasing their apparent concentrations as they accumulate in liquid-like layers, micropockets, and microveins within the ice (freeze-concentration effect). In an effort to better understand how the physicochemical properties of solutes may impact reactivity in frozen solutions, we have examined the relative reaction rates of various organic compounds with hydroxyl radical in both liquid and frozen conditions. Solutions containing two target organic compounds and hydrogen peroxide were made in liquid and frozen phases, and then irradiated using a Q-Panel 340 lamp to simulate natural sunlight. Relative rates of reaction were then obtained for the two compounds in both liquid and ice conditions. In most cases the reactions proceeded more quickly in liquid samples, and the relative rates of reaction were different in liquid and frozen conditions. We will discuss the potential role of a compound's physicochemical properties and the influence of the physical nature of the sample with respect to observed reactivity differences.

  12. Relative deformation rates of collocated VLBI stations and comparisons with global solutions

    NASA Astrophysics Data System (ADS)

    Yang, Zhi-gen; Berube, M.; Searle, A.

    2005-07-01

    Based on the 3-dimensional velocity vectors of VLBI stations in the international terrestrial reference frame ITRF2000 and the earth's plate movement model NNR-NUVEL-1A and taking as constraints the observed rates of change of VLBI baseline lengths, we have estimated and discussed the local/regional crustal relative deformation between the stations in 6 collocated VLBI sites world-wide, and made comparisons with the VLBI global solution glb2003 and the result of VTRF2003. Our results indicate that between the collocated VLBI stations Kashima and Kashima34 of Japan and between the NRAO20 and NRAO85_3 stations of Unites States there probably exists a relative vertical deformation of ˜4mm/yr, that a ˜2 mm/yr difference between the vertical deformation rates of the Westford and Haystack stations is basically confirmed, and that there exists a relative vertical deformation rate of 1˜ mm/yr between the Kokee and Kauai stations. Our method seems to be effective for detecting local/regional crustal vertical deformation between collocated VLBI stations and for improving the ITRF solution.

  13. Conscientiousness mediates the relation between perceived parental socialisation and self-rated health.

    PubMed

    Takahashi, Yusuke; Roberts, Brent W; Hoshino, Takahiro

    2012-01-01

    The pathways between parenting behaviours, personality and physical health have all been separately studied. Prior research has paid little attention to the indirect effects of personality in the path between parenting behaviours and better health. The purpose of this study was to explore the mediational effects of conscientiousness on the relationships between parental socialisation of responsibility and self-rated health, and to examine potential age differences in this mediational pathway. In total, 736 female and 749 male members across Japan participated in this study. They were divided into three groups by age category: younger-, middle-aged and older-aged. Conscientiousness and health were concurrently rated, while parental socialisation of responsibility was retrospectively assessed. Our analyses revealed that parental socialisation of responsibility is positively associated with conscientiousness and self-rated health, that conscientiousness is positively associated with self-rated health, and that conscientiousness fully mediated the effect of parental socialisation of responsibility on self-rated health. The mediational links were consistent across younger, middle-aged and older-aged cohorts. Our findings suggest that greater parental socialisation of responsibility relates to higher conscientiousness, and consequently healthier adults. These findings imply that parental behaviours could be a plausible target for intervention to foster the development of conscientiousness and better health.

  14. Relative reinforcer rates and magnitudes do not control concurrent choice independently.

    PubMed

    Elliffe, Douglas; Davison, Michael; Landon, Jason

    2008-09-01

    One assumption of the matching approach to choice is that different independent variables control choice independently of each other. We tested this assumption for reinforcer rate and magnitude in an extensive parametric experiment. Five pigeons responded for food reinforcement on switching-key concurrent variable-interval variable-interval schedules. Across conditions, the ratios of reinforcer rates and of reinforcer magnitudes on the two alternatives were both manipulated. Control by each independent variable, as measured by generalized-matching sensitivity, changed significantly with the ratio of the other independent variable. Analyses taking the model-comparison approach, which weighs improvement in goodness-of-fit against increasing number of free parameters, were inconclusive. These analyses compared a model assuming constant sensitivity to magnitude across all reinforcer-rate ratios with two alternative models. One of those alternatives allowed sensitivity to magnitude to vary freely across reinforcer-rate ratios, and was less efficient than the common-sensitivity model for all pigeons, according to the Schwarz-Bayes information criterion. The second alternative model constrained sensitivity to magnitude to be equal for pairs of reinforcer-rate ratios that deviated from unity by proportionately equal amounts but in opposite directions. This model was more efficient than the common-magnitude-sensitivity model for 2 of the pigeons, but not for the other 3. An analysis of variance, carried out independently of the generalized-matching analysis, also showed a significant interaction between the effects of reinforcer rate and reinforcer magnitude on choice. On balance, these results suggest that the assumption of independence inherent in the matching approach cannot be maintained. Relative reinforcer rates and magnitudes do not control choice independently.

  15. Glycolysis Is Dynamic and Relates Closely to Respiration Rate in Stored Sugarbeet Roots

    PubMed Central

    Megguer, Clarice A.; Fugate, Karen K.; Lafta, Abbas M.; Ferrareze, Jocleita P.; Deckard, Edward L.; Campbell, Larry G.; Lulai, Edward C.; Finger, Fernando L.

    2017-01-01

    Although respiration is the principal cause of the loss of sucrose in postharvest sugarbeet (Beta vulgaris L.), the internal mechanisms that control root respiration rate are unknown. Available evidence, however, indicates that respiration rate is likely to be controlled by the availability of respiratory substrates, and glycolysis has a central role in generating these substrates. To determine glycolytic changes that occur in sugarbeet roots after harvest and to elucidate relationships between glycolysis and respiration, sugarbeet roots were stored for up to 60 days, during which activities of glycolytic enzymes and concentrations of glycolytic substrates, intermediates, cofactors, and products were determined. Respiration rate was also determined, and relationships between respiration rate and glycolytic enzymes and metabolites were evaluated. Glycolysis was highly variable during storage, with 10 of 14 glycolytic activities and 14 of 17 glycolytic metabolites significantly altered during storage. Changes in glycolytic enzyme activities and metabolites occurred throughout the 60 day storage period, but were greatest in the first 4 days after harvest. Positive relationships between changes in glycolytic enzyme activities and root respiration rate were abundant, with 10 of 14 enzyme activities elevated when root respiration was elevated and 9 glycolytic activities static during periods of unchanging respiration rate. Major roles for pyruvate kinase and phosphofructokinase in the regulation of postharvest sugarbeet root glycolysis were indicated based on changes in enzymatic activities and concentrations of their substrates and products. Additionally, a strong positive relationship between respiration rate and pyruvate kinase activity was found indicating that downstream TCA cycle enzymes were unlikely to regulate or restrict root respiration in a major way. Overall, these results establish that glycolysis is not static during sugarbeet root storage and that changes

  16. Health-related quality of life, lung function and dyspnea rating in COPD patients.

    PubMed

    Justine, M; Tahirah, F; Mohan, V

    2013-01-01

    COPD is a progressive and irreversible disease, thus assessing the impact of the disease on health-related quality of life (HRQOL) is important in the management of COPD. The aim of this study was to examine the relationship between HRQOL, lung function and dyspnea rating in patients with stable COPD. One hundred COPD patients (mean age = 64.76 +/- 11.43 years) were recruited for this cross-sectional study. Lung function test was measured using a FlowScreen portable spirometry. Dyspnea rating was measured using the baseline dyspnea index (BDI). HRQOL was assessed using the SF-36v2 which summarized two components; physical health component summary (PHCS) and mental health component summary (MHCS). The mean value of lung function (Forced expiratory volume in 1 second, FEV1% predicted) was 58.19 +/- 30.24 and dyspnea rating was 6.85 +/- 2.68. The lung function was significantly correlated with MHCS (r=.294, p < 0.05) but not with the PHCS (p > 0.05). The dyspnea rating was significantly correlated with both PHCS (r=.730, p < 0.05) and MHCS (r = .324, p < 0.05). Regression analysis indicated that dyspnea rating emerged as the most significant predictor for PHCS and MHCS accounting for 54% and 12% of the variances respectively. The findings show that dyspnea rating is an important factor in predicting HRQOL of patients with COPD. This indicates that dyspnea rating influences HRQOL to a greater extent than the physiological measurement of lung function. Therefore, focusing on such predictors at an early stage may provide meaningful benefits in the management of COPD.

  17. Age-standardized mortality rates related to viral hepatitis in Brazil.

    PubMed

    Perazzo, Hugo; Pacheco, Antonio G; Luz, Paula M; Castro, Rodolfo; Hyde, Chris; Fittipaldi, Juliana; Rigolon, Caroline; Cardoso, Sandra W; Grinsztejn, Beatriz; Veloso, Valdiléa G

    2017-07-31

    Liver-related mortality has been increasing worldwide. We aimed to estimate the age-standardized mortality rates from viral hepatitis in Brazil. The Brazilian National Death Registry was analyzed from 2008 to 2014. Viral hepatitis deaths were defined by the following ICD-10 codes in the death certificate: hepatitis A [B15.0; B15.9]; hepatitis B [B16.2; B16.9; B18.1]; hepatitis C [B17.1; B18.2]; hepatitis Delta [B16.0; B16.1; B18.0; B17.0] and other viral hepatitis [B17.2; B17.8; B18.8; B18.9; B19.0; B19.9]. Crude mortality rates were calculated by the ratio between total number of deaths and estimated population. Mortality rates were age-standardized by the direct method using the WHO standard population. Thirty four thousand ,nine hundred seventy eight deaths had viral hepatitis mentioned in their death certificate [65% male, aged 58 years, 73% associated with hepatitis C]. Age-standardized mortality rate (95% CI) due to viral hepatitis was 2.695 (2.667-2.724) deaths per 100,000 inhabitants: South region had the higher rates [3.997 (3.911-4.085)]. Mortality rates associated with hepatitis A and Delta were 0.032 (0.029-0.035) and 0.028 (0.025-0.031), respectively. Hepatitis C mortality rates were 4-fold higher than those associated with hepatitis B [1.964 (1.940-1.989) vs 0.500 (0.488-0.512)]. South region had the higher rates for hepatitis C [3.163 (3.087-3.241)] and North had the higher rates for hepatitis A [0.066 (0.049-0.087)], B [0.986 (0.918-1.058)] and Delta [0.220 (0.190-0.253)]. Viral hepatitis remains a major public health issue in Brazil. Mortality rates were not homogeneous across the country, suggesting that health policies should be customized according to geographical location.

  18. The Association between Work-Related Rumination and Heart Rate Variability: A Field Study

    PubMed Central

    Cropley, Mark; Plans, David; Morelli, Davide; Sütterlin, Stefan; Inceoglu, Ilke; Thomas, Geoff; Chu, Chris

    2017-01-01

    The objective of this study was to examine the association between perseverative cognition in the form of work-related rumination, and heart rate variability (HRV). We tested the hypothesis that high ruminators would show lower vagally mediated HRV relative to low ruminators during their leisure time. Individuals were classified as being low (n = 17) or high ruminators (n = 19), using the affective scale on the work-related rumination measure. HRV was assessed using a wrist sensor band (Microsoft Band 2). HRV was sampled between 8 pm and 10 pm over three workday evenings (Monday to Wednesday) while individuals carried out their normal evening routines. Compared to the low ruminators, high affective ruminators demonstrated lower HRV in the form of root mean square successive differences (RMSSDs), relative to the low ruminators, indicating lower parasympathetic activity. There was no significant difference in heart rate, or activity levels between the two groups during the recording periods. The current findings of this study may have implications for the design and delivery of interventions to help individuals unwind post work and to manage stress more effectively. Limitations and implications for future research are discussed. PMID:28197087

  19. The Association between Work-Related Rumination and Heart Rate Variability: A Field Study.

    PubMed

    Cropley, Mark; Plans, David; Morelli, Davide; Sütterlin, Stefan; Inceoglu, Ilke; Thomas, Geoff; Chu, Chris

    2017-01-01

    The objective of this study was to examine the association between perseverative cognition in the form of work-related rumination, and heart rate variability (HRV). We tested the hypothesis that high ruminators would show lower vagally mediated HRV relative to low ruminators during their leisure time. Individuals were classified as being low (n = 17) or high ruminators (n = 19), using the affective scale on the work-related rumination measure. HRV was assessed using a wrist sensor band (Microsoft Band 2). HRV was sampled between 8 pm and 10 pm over three workday evenings (Monday to Wednesday) while individuals carried out their normal evening routines. Compared to the low ruminators, high affective ruminators demonstrated lower HRV in the form of root mean square successive differences (RMSSDs), relative to the low ruminators, indicating lower parasympathetic activity. There was no significant difference in heart rate, or activity levels between the two groups during the recording periods. The current findings of this study may have implications for the design and delivery of interventions to help individuals unwind post work and to manage stress more effectively. Limitations and implications for future research are discussed.

  20. Is bigger really better? Relative and absolute body size influence individual growth rate under competition.

    PubMed

    Van Buskirk, Josh; Cereghetti, Eva; Hess, Julia S

    2017-06-01

    Models suggest that the mechanism of competition can influence the growth advantage associated with being large (in absolute body size or relative to other individuals in the population). Large size is advantageous under interference, but disadvantageous under exploitative competition. We addressed this prediction in a laboratory experiment on Rana temporaria tadpoles competing for limited food. There were 166 target individuals spanning a 10-fold range in body mass reared for 3 days with three other individuals that were either the same size, half as large, or twice as large as the target. Relative growth rate (proportion per day) declined with size, and absolute growth rate (mass per day) reached a peak at intermediate size and declined thereafter. Tadpoles grew slowly if they were large relative to their competitors, although relative body size was less important than absolute size. As a result, size variation declined in groups that were initially composed of individuals of variable size. Thus, bigger was not better under exploitative competition. Our results help connect individual-level behavior with individual growth and the size distribution of the population.

  1. The relationships between relative growth rate, meristematic potential and compensatory growth of semiarid-land shrubs.

    PubMed

    Wandera, J L; Richards, J H; Mueller, R J

    1992-06-01

    Inherent relative growth rate has been suggested as a major determinant of plant species' capacity to regrow and compensate for tissues lost to herbivores. We investigated: 1) the relationship between compensatory growth capacity and relative growth rate (RGR) in six semiarid-land shrubs following removal in winter or spring of 90% of the previous year's growth, 2) the influence of loss of buds on production of new growth and 3) the relationship between meristematic potential and the capacity to produce new growth in four of the six semiarid-land shrub species. Four-year-old plants growing under field conditions were used in the study. The species with the highest inherent growth rate, sagebrush [Artemisia tridentata ssp. vaseyana (Rydb.) Beetle], died following the severe clipping treatments. The other five species exactly compensated for lost tissues. Inherent growth rates and compensatory growth capacity of the shrubs were not correlated. Loss of 90% of the buds on the previous year's growth did not limit production of new growth. Instead, shrubs that lost buds produced more new growth biomass than the controls. The shrub species had significantly different meristematic potential. Curlleaf mountain mahogany (Cercocarpus ledifolius Nutt.) and serviceberry (Amelanchier alnifolia Nutt.) had the greatest and least number of buds and long shoots per plant, respectively. The number of long shoots produced following bud removal was positively correlated with new growth biomass, while the percentage of long shoots produced at the basal position on twigs was negatively correlated with new growth biomass. Our results suggest that inherent growth rate is not likely to influence production of new growth following browsing when resources for growth are not limiting. In contrast, the ability of a shrub to initiate long shoot growth is likely to influence production of new growth even when resources for growth are abundant.

  2. p53 mutations associated with aging-related rise in cancer incidence rates.

    PubMed

    Richardson, Richard B

    2013-08-01

    TP53's role as guardian of the genome diminishes with age, as the probability of mutation increases. Previous studies have shown an association between p53 gene mutations and cancer. However, the role of somatic TP53 mutations in the steep rise in cancer rates with aging has not been investigated at a population level. This relationship was quantified using the International Agency for Research on Cancer (IARC) TP53 and GLOBOCAN cancer databases. The power function exponent of the cancer rate was calculated for 5-y age-standardized incidence or mortality rates for up to 25 cancer sites occurring in adults of median age 42 to 72 y. Linear regression analysis of the mean percentage of a cancer's TP53 mutations and the corresponding cancer exponent was conducted for four populations: worldwide, Japan, Western Europe, and the United States. Significant associations (P ≤ 0.05) were found for incidence rates but not mortality rates. Regardless of the population studied, positive associations were found for all cancer sites, with more significant associations for solid tumors, excluding the outlier prostate cancer or sex-related tumors. Worldwide and Japanese populations yielded P values as low as 0.002 and 0.005, respectively. For the United States, a significant association was apparent only when analysis utilized the Surveillance, Epidemiology, and End Results (SEER) database. This study found that TP53 mutations accounts for approximately one-quarter and one-third of the aging-related rise in the worldwide and Japanese incidence of all cancers, respectively. These significant associations between TP53 mutations and the rapid rise in cancer incidence with aging, considered with previously published literature, support a causal role for TP53 according to the Bradford-Hill criteria. However, questions remain concerning the contribution of TP53 mutations to neoplastic development and the role of factors such as genetic instability, obesity, and gene deficiencies other

  3. An Investigation Relating Longitudinal Pilot-Induced Oscillation Tendency Rating to Describing Function Predictions for Rate-Limited Actuators

    DTIC Science & Technology

    2004-03-01

    is not. A PIO could mean any oscillation that occurs during manual , piloted control. But some of these situations could be the result of pilot...Pilot-Induced Oscillations (PIO) Due to Actuator Rate Limiting Using the Open-Loop Onset Point (OLOP) Criterio . MS Thesis, AFIT/GAE/ENY/01M-02

  4. Exploring Systematic Effects in the Relation Between Stellar Mass, Gas Phase Metallicity, and Star Formation Rate

    NASA Astrophysics Data System (ADS)

    Telford, O. Grace; Dalcanton, Julianne J.; Skillman, Evan D.; Conroy, Charlie

    2016-08-01

    There is evidence that the well-established mass-metallicity relation in galaxies is correlated with a third parameter: star formation rate (SFR). The strength of this correlation may be used to disentangle the relative importance of different physical processes (e.g., infall of pristine gas, metal-enriched outflows) in governing chemical evolution. However, all three parameters are susceptible to biases that might affect the observed strength of the relation between them. We analyze possible sources of systematic error, including sample bias, application of signal-to-noise ratio cuts on emission lines, choice of metallicity calibration, uncertainty in stellar mass determination, aperture effects, and dust. We present the first analysis of the relation between stellar mass, gas phase metallicity, and SFR using strong line abundance diagnostics from Dopita et al. for ˜130,000 star-forming galaxies in the Sloan Digital Sky Survey and provide a detailed comparison of these diagnostics in an appendix. Using these new abundance diagnostics yields a 30%-55% weaker anti-correlation between metallicity and SFR at fixed stellar mass than that reported by Mannucci et al. We find that, for all abundance diagnostics, the anti-correlation with SFR is stronger for the relatively few galaxies whose current SFRs are elevated above their past average SFRs. This is also true for the new abundance diagnostic of Dopita et al., which gives anti-correlation between Z and SFR only in the high specific star formation rate (sSFR) regime, in contrast to the recent results of Kashino et al. The poorly constrained strength of the relation between stellar mass, metallicity, and SFR must be carefully accounted for in theoretical studies of chemical evolution.

  5. The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome.

    PubMed

    Xian, Hong; Liu, Weijian; Marshall, Cynthia; Chandiramani, Pooja; Bainter, Emily; Martin, Wade H

    2016-09-01

    Arm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise, but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity. Thus, the purpose of this investigation was to characterize the relationship of peak arm exercise heart rate responses to abnormal stress test findings, coronary revascularization, and mortality in patients unable to perform leg exercise. From 1997 until 2002, arm cycle ergometer stress tests were performed in 443 consecutive veterans age 64.1 yr (11.0 yr) (mean (SD)), of whom 253 also underwent myocardial perfusion imaging (MPI). Patients were categorized by frequency distributions of quartiles of percentage age-predicted peak heart rate (APPHR), heart rate reserve (HRR), and peak heart rate-systolic blood pressure product (PRPP). Exercise-induced ST-segment depression, abnormal MPI findings, coronary revascularization, and 12.0-yr (1.3 yr) Kaplan-Meier all-cause and cardiovascular mortality plots were then characterized by quartiles of APPHR, HRR, and PRPP. A reduced frequency of abnormal arm exercise ECG results was associated only with the lowest quartile of APPHR (≤69%) and HRR (≤43%), whereas higher frequency of abnormal MPI findings exhibited an inverse relationship trend with lower APPHR (P = 0.10) and HRR (P = 0.12). There was a strong inverse association of APPHR, HRR, and PRPP with all-cause (all P ≤ 0.01) and cardiovascular (P < 0.05) mortality. The frequency of coronary revascularization was unrelated to APPHR or HRR. Arm exercise ECG stress test sensitivity is only reduced at ≤69% APPHR or ≤43% HRR, whereas arm exercise MPI sensitivity and referral for coronary revascularization after arm exercise stress testing are not adversely affected by even a severely blunted peak heart rate. However, both all-cause mortality and cardiovascular mortality are strongly and inversely related to APPHR and HRR.

  6. Recurrence rate of basal cell carcinoma with positive histopathological margins and related risk factors*

    PubMed Central

    Lara, Fernanda; Santamaría, Jesus Rodriguez; Garbers, Luiz Eduardo Fabricio de Melo

    2017-01-01

    BACKGROUND The best way to approach surgically removed basal cell carcinoma with positive histopathological margins is a controversial issue. Some authors believe that the more appropriate treatment is an immediate reoperation while others prefer a periodic follow up. The rates of recurrence are variable in literature, between 10% and 67%. OBJECTIVE To define the recurrence rate of basal cell carcinoma with positive margins after surgery. Secondarily, identify morphological aspects that can suggest a more frequent tumoral recurrence. METHODS This was a retrospective and observational study made by analysis of medical records of 487 patients between January 2003 and December 2009 in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). From 402 basal cell carcinomas surgically treated, 41 fulfilled inclusion criteria and were evaluated for five years or more. Recurrence rate of these tumors was analyzed in all patients and clinical characteristics such as sex, age, tumor size, tumor site, ulceration, and histological type were evaluated in order to find if they were related to more common tumoral recurrence. RESULTS The rate of positive margins after surgery was 12.18%. There were five cases of tumoral recurrence in the observation group and three cases in the re-excision group. Tumor size, site, histological type, ulceration and type of positive margin did not differ statistically between groups. It was not possible to consider if these factors were important in recurrence rates. STUDY LIMITATIONS Ideally, a prospective study with a larger sample would be more accurate. CONCLUSION The treatment of choice in basal cell carcinoma with positive margins must be individualized to reduce recurrence rates. PMID:28225958

  7. Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits.

    PubMed

    Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U

    2016-01-01

    One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants' personality traits as described in the 'Big Five Inventory' (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits.

  8. Genome Size Evolution in Relation to Leaf Strategy and Metabolic Rates Revisited

    PubMed Central

    Beaulieu, Jeremy M.; Leitch, Ilia J.; Knight, Charles A.

    2007-01-01

    Background and Aims It has been proposed that having too much DNA may carry physiological consequences for plants. The strong correlation between DNA content, cell size and cell division rate could lead to predictable morphological variation in plants, including a negative relationship with leaf mass per unit area (LMA). In addition, the possible increased demand for resources in species with high DNA content may have downstream effects on maximal metabolic efficiency, including decreased metabolic rates. Methods Tests were made for genome size-dependent variation in LMA and metabolic rates (mass-based photosynthetic rate and dark respiration rate) using our own measurements and data from a plant functional trait database (Glopnet). These associations were tested using two metrics of genome size: bulk DNA amount (2C DNA) and monoploid genome size (1Cx DNA). The data were analysed using an evolutionary framework that included a regression analysis and independent contrasts using a phylogenetic tree with estimates of molecular diversification times. A contribution index for the LMA data set was also calculated to determine which divergences have the greatest influence on the relationship between genome size and LMA. Key Results and Conclusions A significant negative association was found between bulk DNA amount and LMA in angiosperms. This was primarily a result of influential divergences that may represent early shifts in growth form. However, divergences in bulk DNA amount were positively associated with divergences in LMA, suggesting that the relationship may be indirect and mediated through other traits directly related to genome size. There was a significant negative association between genome size and metabolic rates that was driven by a basal divergence between angiosperms and gymnosperms; no significant independent contrast results were found. Therefore, it is concluded that genome size-dependent constraints acting on metabolic efficiency may not exist within

  9. Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits

    PubMed Central

    Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U.

    2016-01-01

    One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants’ personality traits as described in the ‘Big Five Inventory’ (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits

  10. Recurrence rate of basal cell carcinoma with positive histopathological margins and related risk factors.

    PubMed

    Lara, Fernanda; Santamaría, Jesus Rodriguez; Garbers, Luiz Eduardo Fabricio de Melo

    2017-01-01

    The best way to approach surgically removed basal cell carcinoma with positive histopathological margins is a controversial issue. Some authors believe that the more appropriate treatment is an immediate reoperation while others prefer a periodic follow up. The rates of recurrence are variable in literature, between 10% and 67%. To define the recurrence rate of basal cell carcinoma with positive margins after surgery. Secondarily, identify morphological aspects that can suggest a more frequent tumoral recurrence. This was a retrospective and observational study made by analysis of medical records of 487 patients between January 2003 and December 2009 in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). From 402 basal cell carcinomas surgically treated, 41 fulfilled inclusion criteria and were evaluated for five years or more. Recurrence rate of these tumors was analyzed in all patients and clinical characteristics such as sex, age, tumor size, tumor site, ulceration, and histological type were evaluated in order to find if they were related to more common tumoral recurrence. The rate of positive margins after surgery was 12.18%. There were five cases of tumoral recurrence in the observation group and three cases in the re-excision group. Tumor size, site, histological type, ulceration and type of positive margin did not differ statistically between groups. It was not possible to consider if these factors were important in recurrence rates. Ideally, a prospective study with a larger sample would be more accurate. The treatment of choice in basal cell carcinoma with positive margins must be individualized to reduce recurrence rates.

  11. Pulmonary Artery Wedge Pressure Relative to Exercise Work Rate in Older Men and Women.

    PubMed

    Esfandiari, Sam; Wright, Stephen P; Goodman, Jack M; Sasson, Zion; Mak, Susanna

    2017-07-01

    An augmented pulmonary artery wedge pressure (PAWP) response may explain exercise intolerance in some humans. However, routine use of exercise hemodynamic testing is limited by a lack of data from normal older men and women. Our objective was to evaluate the exercise PAWP response and the potential for sexual dimorphism in healthy, nondyspneic older adults. Thirty-six healthy volunteers (18 men [54 ± 7 yr] and 18 women [58 ± 6 yr]) were studied at rest (control) and during two stages of semi-upright cycle ergometry, at heart rates of 100 bpm (light exercise) and 120 bpm (moderate exercise). Right heart catheterization was performed to measure pulmonary pressures. The PAWP response to exercise was assessed in context of exercise work rate and body size. At control, PAWP was similar between men and women. Work rates were significantly smaller in women at comparable HR (P < 0.001). PAWP increased similarly at light exercise, with no further increase at moderate exercise. When indexed to work rate alone or work rate adjusted to body weight and height, the PAWP response at light and moderate exercise was significantly elevated in women compared with men (P < 0.05 condition-sex interaction). The change in PAWP relative to the increase in cardiac output did not exceed 2 mm Hg·L·min in any volunteer at moderate exercise. The similar rise in the PAWP response to submaximal exercise occurs despite lower work rate in healthy older women compared with men, even when adjusted for smaller body size. It is important to consider sex in the development of normal reference ranges for exercise hemodynamic testing.

  12. Calculation of relative glomerular filtration rate and correlation with delayed technetium-99m DMSA imaging

    SciTech Connect

    Taylor, A. Jr.; Kipper, M.; Witztum, K.

    1986-01-01

    The relative renal uptake of Tc-99m DMSA was compared with the relative glomerular filtration rate (GFR) in ten patients with serum creatinines ranging from 0.3 to 2.5 mg/dl. Relative GFR was based on the renal uptake of Tc-99m DTPA determined by two methods: 1) integrating the counts from 1 to 3 minutes postinjection and correcting for background. 2) Totalizing the individual renal counts in a single 15-second frame from 2:45 minutes to 3:00 minutes postinjection and correcting for background. The two methods of determining relative DTPA uptake showed excellent correlation, r = 0.98. Relative DMSA uptake determined at 24 hours post-injection using computer-assisted regions of interest showed excellent correlation with the relative GFR determined by either the integral or single-frame method, r = 0.98. The addition of background subtraction for the DMSA images at 24 hours did not improve the correlation.

  13. A retrospective study on related factors affecting the survival rate of dental implants

    PubMed Central

    Kang, Jeong-Kyung; Lee, Ki; Lee, Yong-Sang; Park, Pil-Kyoo

    2011-01-01

    PURPOSE The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age 65 ± 10.58 years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P<.05). No significant differences were found in relation to the following factors: gender, diameter and bone quality (P>.05). CONCLUSION Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival. PMID:22259704

  14. Proliferation Rates of Bovine Primary Muscle Cells Relate to Liveweight and Carcase Weight in Cattle

    PubMed Central

    Coles, Chantal A.; Wadeson, Jenny; Leyton, Carolina P.; Siddell, Jason P.; Greenwood, Paul L.; White, Jason D.; McDonagh, Matthew B.

    2015-01-01

    Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM) of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5–20 hours in culture) in vitro (P < 0.05). The proliferation rates of myoblasts during early stages of culture in vitro were also found to be positively related to the liveweight and carcase weight of cattle (P < 0.05). Gene expression of MYF5 was also found to be significantly down-regulated in WagyuX compared with Angus cattle (P < 0.05). These findings suggest that early events during myogenesis are important for determining liveweight and caracase weights in cattle. PMID:25875203

  15. Proliferation rates of bovine primary muscle cells relate to liveweight and carcase weight in cattle.

    PubMed

    Coles, Chantal A; Wadeson, Jenny; Leyton, Carolina P; Siddell, Jason P; Greenwood, Paul L; White, Jason D; McDonagh, Matthew B

    2015-01-01

    Muscling in cattle is largely influenced by genetic background, ultimately affecting beef yield and is of major interest to the beef industry. This investigation aimed to determine whether primary skeletal muscle cells isolated from different breeds of cattle with a varying genetic potential for muscling differ in their myogenic proliferative capacity. Primary skeletal muscle cells were isolated and cultured from the Longissimus muscle (LM) of 6 month old Angus, Hereford and Wagyu X Angus cattle. Cells were assessed for rate of proliferation and gene expression of PAX7, MYOD, MYF5, and MYOG. Proliferation rates were found to differ between breeds of cattle whereby myoblasts from Angus cattle were found to proliferate at a greater rate than those of Hereford and Wagyu X Angus during early stages of growth (5-20 hours in culture) in vitro (P < 0.05). The proliferation rates of myoblasts during early stages of culture in vitro were also found to be positively related to the liveweight and carcase weight of cattle (P < 0.05). Gene expression of MYF5 was also found to be significantly down-regulated in WagyuX compared with Angus cattle (P < 0.05). These findings suggest that early events during myogenesis are important for determining liveweight and caracase weights in cattle.

  16. Low fluence rate photodynamic therapy combined with intravitreal bevacizumab for neovascular age-related macular degeneration.

    PubMed

    Costagliola, Ciro; Romano, Mario R; Rinaldi, Michele; dell'Omo, Roberto; Chiosi, Flavia; Menzione, Massimo; Semeraro, Francesco

    2010-02-01

    To report the efficacy and safety of intravitreal bevacizumab (IVB) alone versus IVB plus low-fluence photodynamic therapy (PDT) in age-related macular degeneration (AMD) patients and to verify the occurrence of a synergistic effect of the combined approach on visual acuity, size and morphology of lesion, as well as on the treatment rate. Prospective comparative interventional study on 85 patients with treatment-naive classic, or predominantly classic, subfoveal choroidal neovascularisation secondary to AMD. Patients were randomly assigned to group 1 (IVB injections) and group 2 (IVB plus low fluence PDT). In group 2, the PDT with verteporfin was delivered with a low fluence rate (300 mW/cm2 for 83 s, 25 J/cm2). The follow-up was scheduled at 1, 3, 6, 9 and 12 months. The eye without recurrence received a mean of 2.8 (group 1) versus 1.4 (group 2) IVB injections, whereas the eyes with recurrence received a mean of 3.2 (group 1) versus 2.2 (group 2) IVB injections. The difference in reinjection rate between the two groups was statistically significant (p=0.03, ANOVA test). Visual acuity improvement was not statistically significant between the two groups (p=0.31). The combination of IVB with low fluence PDT for the treatment of classic or predominantly classic neovascular AMD works in a synergistic fashion with a significant reduction in IVB reinjections rate.

  17. A Needs Assessment of Health Issues Related to Maternal Mortality Rates in Afghanistan: A Pilot Study.

    PubMed

    Naim, Ali; Feldman, Robert; Sawyer, Robin

    2015-01-01

    Maternal death rates in Afghanistan were among the highest in the world during the reign of the Taliban. Although these figures have improved, current rates are still alarming. The aim of this pilot study was to develop a needs assessment of the major health issues related to the high maternal mortality rates in Afghanistan. In-depth interviews were conducted with managerial midwives, clinical midwives, and mothers. Results of the interviews indicate that the improvement in the maternal mortality rate may be attributed to the increase in the involvement of midwives in the birthing process. However, barriers to decreasing maternal mortality still exist. These include transportation, access to care, and sociocultural factors such as the influence of the husband and mother-in-law in preventing access to midwives. Therefore, any programs to decrease maternal mortality need to address infrastructure issues (making health care more accessible) and sociocultural factors (including husbands and mother-in-laws in maternal health education). However, it should be noted that these findings are based on a small pilot study to help develop a larger scale need assessment.

  18. The rate of handedness conversion and related factors in left-handed children.

    PubMed

    Meng, Ling-fu

    2007-03-01

    The rate of handedness conversion was 2.7% to 11.8% in prior studies based on the total population including innately right-handed people. However, the conversion rate of innately left-handed people has not been reported. The purpose of this study was to investigate the percentage of handedness conversion in children who are innately left-handed. The data in the present study showed that 59.3% (121/211) of left-handed children had been forced to convert to right-handedness. Current handedness was also reported by 114 of the 121 informants, and the rates of right-, left-, and mixed-handedness were 56.1% (64/114), 26.3% (30/114), and 17.5% (20/114) respectively. More than half had successfully changed from left to right. Some variables, especially the educational level of the parents and the child's grade level, were related to this conversion intention. The children whose parents had less education were more likely to be forced to change handedness. Additionally, the rate of handedness conversion in younger children was lower than in older children. However, even for the children whose parents had higher education, or for the children who were younger, there was a high percentage (45.7% and 41.8% respectively) who had changed their handedness. Therefore, preventing the possible side effects for children who have undergone hand conversion should be emphasised in the future.

  19. Self- versus parent-ratings of industriousness, affect, and life satisfaction in relation to academic outcomes.

    PubMed

    Fogarty, Gerard J; Davies, Janet E; MacCann, Carolyn; Roberts, Richard D

    2014-06-01

    Parents consult with schools on how to help their children succeed, but schools rarely consult with parents, even though most parents have considerable expertise concerning their children's thoughts, feelings, and abilities. This study compares the prediction of academic achievement from self- and parent-ratings of feelings towards school (both positive and negative), life satisfaction, and the conscientiousness facet of industriousness for 357 adolescents. The student sample consisted of 383 participants (194 boys) mostly aged between 12 and 14. The parent sample consisted of 374 participants, 83% of whom were mothers. Self-report and other-report scales measuring the above-mentioned constructs were administered to students and parents. Hierarchical regression analysis was used to test hypotheses concerning the incremental validity of parent-ratings. Self-ratings explained 28.6% of the variance in grade point average (GPA) with parent-ratings explaining an additional 12.1%. The incremental effect was strongest for industriousness. These results suggest that parent-reports are often more accurate than adolescent self-reports, but that both methods of assessment make unique contributions to the explanation of variance in school grades. Parental understanding constitutes a relatively untapped reservoir of knowledge available to teachers, school counsellors and administrators, education policy makers, and beyond. It makes sense to ask parents about their children when assessing those individual differences that contribute to better educational outcomes. © 2013 The British Psychological Society.

  20. Predicting organic hydrogen atom transfer rate constants using the Marcus cross relation

    PubMed Central

    Warren, Jeffrey J.; Mayer, James M.

    2010-01-01

    Chemical reactions that involve net hydrogen atom transfer (HAT) are ubiquitous in chemistry and biology, from the action of antioxidants to industrial and metalloenzyme catalysis. This report develops and validates a procedure to predict rate constants for HAT reactions of oxyl radicals (RO•) in various media. Our procedure uses the Marcus cross relation (CR) and includes adjustments for solvent hydrogen-bonding effects on both the kinetics and thermodynamics of the reactions. Kinetic solvent effects (KSEs) are included by using Ingold’s model, and thermodynamic solvent effects are accounted for by using an empirical model developed by Abraham. These adjustments are shown to be critical to the success of our combined model, referred to as the CR/KSE model. As an initial test of the CR/KSE model we measured self-exchange and cross rate constants in different solvents for reactions of the 2,4,6-tri-tert-butylphenoxyl radical and the hydroxylamine 2,2′-6,6′-tetramethyl-piperidin-1-ol. Excellent agreement is observed between the calculated and directly determined cross rate constants. We then extend the model to over 30 known HAT reactions of oxyl radicals with OH or CH bonds, including biologically relevant reactions of ascorbate, peroxyl radicals, and α-tocopherol. The CR/KSE model shows remarkable predictive power, predicting rate constants to within a factor of 5 for almost all of the surveyed HAT reactions. PMID:20215463

  1. Relations between rate of negative reinforcement and the persistence of task completion.

    PubMed

    Romani, Patrick W; Ringdahl, Joel E; Wacker, David P; Lustig, Nicole H; Vinquist, Kelly M; Northup, John; Kane, Alexandra M; Carrion, Deva P

    2016-03-01

    Research has shown that differential reinforcement of alternative behavior (DRA) can be an effective intervention to address problem behavior maintained by negative reinforcement emitted by young children. However, few studies have evaluated the variables that are related to long-term maintenance (i.e., persistence) of treatment effects. Research on behavioral persistence predicts that the rate of reinforcement provided for a target behavior is correlated with its persistence when challenged. There were 2 purposes of the current investigation. First, we evaluated the effects of the rate of negative reinforcement on the persistence of task completion. Second, we applied the findings regarding rate of reinforcement to a treatment context for 3 participants who engaged in destructive behavior that was reinforced by escape from demands. Results were evaluated within a multielement design and indicated that the rate of negative reinforcement had a moderate influence on the persistence of task completion. These results contribute to the existing literature by extending analyses of persistence to treatment contexts. © 2015 Society for the Experimental Analysis of Behavior.

  2. Relative size of the hyperstriatum ventrale is the best predictor of feeding innovation rate in birds.

    PubMed

    Timmermans, S; Lefebvre, L; Boire, D; Basu, P

    2000-10-01

    Within the avian telencephalon, the dorsal ventricular ridge (DVR) contains higher order and multimodal integration areas. Using multiple regressions on 17 avian taxa, we show that an operational estimate of behavioral flexibility, the frequency of feeding innovation reports in ornithology journals, is most closely predicted by relative size of one of these DVR areas, the hyperstriatum ventrale. Neither phylogeny, juvenile development mode, nor species sampled account for the relationship. Similar results are found when the hyperstriatum ventrale is lumped with a second DVR structure, the neostriatum. In simple correlations, size of the wulst and the striatopallidal complex is associated with feeding innovation rate, but the two structures are eliminated from the multiple regressions. Our results parallel those on primates showing a correlation between innovation rate and neocortex size and support the idea that the mammalian neocortex and the neostriatum-hyperstriatum ventrale complex in birds have similar integrative roles.

  3. Proxy ratings of patient quality of life--factors related to patient-proxy agreement.

    PubMed

    von Essen, Louise

    2004-01-01

    It is generally agreed that patients are the best raters of their quality of life (QL). Where it is not possible to obtain information from the patient the use of proxies can be an alternative. The proxy can be a significant other or a healthcare provider. The use of a proxy offers a solution to non-response. The accuracy of proxy reports is most typically determined by examining the extent to which patient and proxy ratings agree. A literature overview shows that agreement depends on several factors. Methodological limitations may have an impact on agreement. Agreement also varies according to the QL domains under study; the highest agreement is usually found for concrete domains. In addition, patient and proxy characteristics are related to agreement. When designing QL studies the threat of selection bias due to exclusion of patients has to be balanced against the threat of information bias due to proxy ratings.

  4. Heart rate variability in idiopathic dilated cardiomyopathy: relation to disease severity and prognosis.

    PubMed Central

    Yi, G.; Goldman, J. H.; Keeling, P. J.; Reardon, M.; McKenna, W. J.; Malik, M.

    1997-01-01

    OBJECTIVE: To assess the clinical importance of heart rate variability (HRV) in patients with idiopathic dilated cardiomyopathy (DCM). PATIENTS AND METHODS: Time domain analysis of 24 hour HRV was performed in 64 patients with DCM, 19 of their relatives with left ventricular enlargement (possible early DCM), and 33 healthy control subjects. RESULTS: Measures of HRV were reduced in patients with DCM compared with controls (P < 0.05). HRV parameters were similar in relatives and controls. Measures of HRV were lower in DCM patients in whom progressive heart failure developed (n = 28) than in those who remained clinically stable (n = 36) during a follow up of 24 (20) months (P = 0.0001). Reduced HRV was associated with NYHA functional class, left ventricular end diastolic dimension, reduced left ventricular ejection fraction, and peak exercise oxygen consumption (P < 0.05) in all patients. DCM patients with standard deviation of normal to normal RR intervals calculated over the 24 hour period (SDNN) < 50 ms had a significantly lower survival rate free of progressive heart failure than those with SDNN > 50 ms (P = 0.0002, at 12 months; P = 0.0001, during overall follow up). Stepwise multiple regression analysis showed that SDNN < 50 ms identified, independently of other clinical variables, patients who were at increased risk of developing progressive heart failure (P = 0.0004). CONCLUSIONS: HRV is reduced in patients with DCM and related to disease severity. HRV is clinically useful as an early non-invasive marker of DCM deterioration. PMID:9068391

  5. Free energy of cluster formation and a new scaling relation for the nucleation rate

    SciTech Connect

    Tanaka, Kyoko K.; Tanaka, Hidekazu; Diemand, Jürg; Angélil, Raymond

    2014-05-21

    Recent very large molecular dynamics simulations of homogeneous nucleation with (1 − 8) × 10{sup 9} Lennard-Jones atoms [J. Diemand, R. Angélil, K. K. Tanaka, and H. Tanaka, J. Chem. Phys. 139, 074309 (2013)] allow us to accurately determine the formation free energy of clusters over a wide range of cluster sizes. This is now possible because such large simulations allow for very precise measurements of the cluster size distribution in the steady state nucleation regime. The peaks of the free energy curves give critical cluster sizes, which agree well with independent estimates based on the nucleation theorem. Using these results, we derive an analytical formula and a new scaling relation for nucleation rates: ln J{sup ′}/η is scaled by ln S/η, where the supersaturation ratio is S, η is the dimensionless surface energy, and J{sup ′} is a dimensionless nucleation rate. This relation can be derived using the free energy of cluster formation at equilibrium which corresponds to the surface energy required to form the vapor-liquid interface. At low temperatures (below the triple point), we find that the surface energy divided by that of the classical nucleation theory does not depend on temperature, which leads to the scaling relation and implies a constant, positive Tolman length equal to half of the mean inter-particle separation in the liquid phase.

  6. Implication of base heart rate in autonomic nervous function, blood pressure and health-related QOL.

    PubMed

    Okano, Yasuko; Hirawa, Nobuhito; Matsushita, Kei; Tamura, Kouichi; Kihara, Minoru; Toya, Yoshiyuki; Tochikubo, Osamu; Umemura, Satoshi

    2005-01-01

    Increased resting heart rate (HR) and increased sympathetic nervous activity are independent risk factors for cardiovascular disease. Recently, base heart rate (HRo: minimum stable HR during sleep) has been reported to relate to cardiac stroke volume and age. However, little is known about the relevance of HRo. The aim of our study was to evaluate how HRo is associated with HR variability (HRV), blood pressure and health-related quality of life (HRQOL) in healthy subjects. A total of 139 volunteers participated in this study that measured 24-hr HR, HRV, and blood pressure. HRo was estimated from the trendgram and the histogram of HR during the nighttime (sleep) period, and calculated as the 1% lowest value of its integral. HRQOL was assessed by Medical Outcome Study Short-Forum 36-Item Health Survey. Sympathetic nervous activity (ratio of low frequency to high frequency component: LF/HF) and parasympathetic nervous activity (high frequency component: HF) were calculated by ECG monitoring. HRo was positively correlated with 24-hr LF/HF and nighttime LF/HF. HRo was negatively correlated with 24-hr HF and nighttime HF. Moreover, HRo was positively correlated with the scores of social functioning and role-physical. Using multivariate analysis, HRo is related to LF/HF, body mass index, and the score of social functioning (HRQOL). HRo may be a useful indicator for assessing sympathetic nervous activity and HRQOL in normotensive healthy subjects.

  7. Dependence of the Firearm-Related Homicide Rate on Gun Availability: A Mathematical Analysis

    PubMed Central

    Wodarz, Dominik; Komarova, Natalia L.

    2013-01-01

    In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data. PMID:23923062

  8. Interspecific correlates of plasticity in relative growth rate following a decrease in nitrogen availability.

    PubMed

    Useche, Antonio; Shipley, Bill

    2010-02-01

    Nitrogen availability varies greatly over short time scales. This requires that a well-adapted plant modify its phenotype by an appropriate amount and at a certain speed in order to maximize growth and fitness. To determine how plastic ontogenetic changes in each trait interact and whether or not these changes are likely to maximize growth, ontogenetic changes in relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA) and root weight ratio (RWR), before and after a decrease in nitrogen supply, were studied in 14 herbaceous species. Forty-four plants of each species were grown in hydroponic culture under controlled conditions in a control treatment where the supply of nitrogen remained constant at 1 mm, and in a stress treatment where the nitrogen supply was abruptly decreased from 1 to 0.01 mm during the growth period. In the treatment series, and in comparison with the control, NAR and RGR decreased, RWR increased, and SLA did not change except for the timing of ontogenetic change. Species having greater increases in the maximum rate of change in RWR also had smaller reductions in RGR; plasticity in RWR is therefore adaptive. In contrast, species which showed a greater decrease in NAR showed stronger reductions in RGR; plasticity in NAR is therefore not adaptive. Plasticity in RGR was not related to plasticity in SLA. There were no significant relationships among the plasticities in NAR, RWR or SLA. Potentially fast-growing species experienced larger reductions in RGR following the nitrogen reduction. These results suggest that competitive responses to interspecific competition for nitrogen might be positively correlated with the plasticity in the maximum rate of change in RWR in response to a reduction in nitrogen supply.

  9. Rating child passenger safety laws relative to best practice recommendations for occupant protection.

    PubMed

    Klinich, Kathleen D; Benedetti, Marco; Manary, Miriam A; Flannagan, Carol A

    2017-05-19

    State laws regarding child passenger protection vary substantially. The objective of this study was to develop a scoring system to rate child passenger safety laws relative to best practice recommendations for each age of child. State child passenger safety and seat belt laws were retrieved from the LexisNexis database for the years 2002-2015. Text of the laws was reviewed and compared to current best practice recommendations for child occupant protection for each age of child. A 0-4 scale was developed to rate the strength of the state law relative to current best practice recommendations. A rating of 3 corresponds to a law that requires a restraint that is sufficient to meet best practice, and a rating of 4 is given to a law that specifies several options that would meet best practice. Scores of 0, 1, or 2 are given to laws requiring less than best practice to different degrees. The same scale is used for each age of child despite different restraint recommendations for each age. Legislation that receives a score of 3 requires rear-facing child restraints for children under age 2, forward-facing harnessed child restraints for children aged 2 to 4, booster seats for children 5 to 10, and primary enforcement of seat belt use in all positions for children aged 11-13. Legislation requiring use of a "child restraint system according to instructions" would receive a score of 1 for children under age 2 and a 2 for children aged 2-4 because it would allow premature use of a booster for children weighing more than 13.6 kg (30 lb). The scoring system developed in this study can be used in mathematical models to predict how child passenger safety legislation affects child restraint practices.

  10. Dependence of the firearm-related homicide rate on gun availability: a mathematical analysis.

    PubMed

    Wodarz, Dominik; Komarova, Natalia L

    2013-01-01

    In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data.

  11. Temperature and rainfall are related to fertility rate after spring artificial insemination in small ruminants.

    PubMed

    Abecia, J A; Arrébola, F; Macías, A; Laviña, A; González-Casquet, O; Benítez, F; Palacios, C

    2016-10-01

    A total number of 1092 artificial inseminations (AIs) performed from March to May were documented over four consecutive years on 10 Payoya goat farms (36° N) and 19,392 AIs on 102 Rasa Aragonesa sheep farms (41° N) over 10 years. Mean, maximum, and minimum ambient temperatures, mean relative humidity, mean solar radiation, and total rainfall on each insemination day were recorded. Overall, fertility rates were 58 % in goats and 45 % in sheep. The fertility rates of the highest and lowest deciles of each of the meteorological variables indicated that temperature and rainfall had a significant effect on fertility in goats. Specifically, inseminations that were performed when mean (68 %), maximum (68 %), and minimum (66 %) temperatures were in the highest decile, and rainfall was in the lowest decile (59 %), had a significantly (P < 0.0001) higher proportion of does that became pregnant than did the ewes in the lowest decile (56, 54, 58, and 49 %, respectively). In sheep, the fertility rates of the highest decile of mean (62 %), maximum (62 %), and minimum (52 %) temperature, RH (52 %), THI (53 %), and rainfall (45 %) were significantly higher (P < 0.0001) than were the fertility rates among ewes in the lowest decile (46, 45, 45, 45, 46, and 43 %, respectively). In conclusion, weather was related to fertility in small ruminants after AI in spring. It remains to be determined whether scheduling the dates of insemination based on forecasted temperatures can improve the success of AI in goats and sheep.

  12. Heart Rate Variability and Sleep-Related Breathing Disorders in the General Population.

    PubMed

    Aeschbacher, Stefanie; Bossard, Matthias; Schoen, Tobias; Schmidlin, Delia; Muff, Christoph; Maseli, Anna; Leuppi, Jörg D; Miedinger, David; Probst-Hensch, Nicole M; Schmidt-Trucksäss, Arno; Risch, Martin; Risch, Lorenz; Conen, David

    2016-09-15

    Obstructive sleep apnea seems to have an important influence on the autonomic nervous system. In this study, we assessed the relations of sleep apnea-related parameters with 24-hour heart rate variability (HRV) in a large population of young and healthy adults. Participants aged 25 to 41 years with a body mass index <35 kg/m(2) and without known obstructive sleep apnea were included in a prospective population-based cohort study. HRV was assessed using 24-hour electrocardiographic monitoring. The SD of all normal RR intervals (SDNN) was used as the main HRV variable. Apnea-Hypopnea Index (AHI) and oxygen desaturation index (ODI) were obtained from nighttime pulse oximetry with nasal airflow measurements. We defined sleep-related breathing disorders as an AHI ≥5 or an ODI ≥5. Multivariable regression models were constructed to assess the relation of HRV with either AHI or ODI. Median age of the 1,255 participants was 37 years, 47% were men, and 9.6% had an AHI ≥5. Linear inverse associations of SDNN across AHI and ODI groups were found (p for trend = 0.006 and 0.0004, respectively). The β coefficients (95% CI) for the relation between SDNN and elevated AHI were -0.20 (-0.40 to -0.11), p = 0.04 and -0.29 (-0.47 to -0.11), p = 0.002 for elevated ODI. After adjustment for 24-hour heart rate, the same β coefficients (95% CI) were -0.06 (-0.22 to 0.11), p = 0.51 and -0.14 (-0.30 to 0.01), p = 0.07, respectively. In conclusion, even early stages of sleep-related breathing disorders are inversely associated with HRV in young and healthy adults, suggesting that they are tightly linked with autonomic dysfunction. However, HRV and 24-hour heart rate seem to have common information. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Age-related changes in the rate of muscle activation and rapid force characteristics.

    PubMed

    Thompson, Brennan J; Ryan, Eric D; Herda, Trent J; Costa, Pablo B; Herda, Ashley A; Cramer, Joel T

    2014-04-01

    Declines in muscle size and strength are commonly reported as a consequence of aging; however, few studies have investigated the influence of aging on the rate of muscle activation and rapid force characteristics across the lifespan. This study aims to investigate the effects of aging on the rate of muscle activation and rapid force characteristics of the plantar flexors. Plantar flexion peak force (PF), absolute (peak, 50, and 100-200 ms), and relative (10 %, 30 %, and 50 %) rate of force development (RFD), the rapid to maximal force ratio (RFD/PF), and the rate of electromyography rise (RER) were examined during an isometric maximal voluntary contraction (MVC) in young (age = 22 ± 2 years), middle-aged (43 ± 2 years), and old (69 ± 5 years) men. The old men exhibited lower PF (30.7 % and 27.6 % lower, respectively) and absolute (24.4-55.1 %) and relative (16.4-28.9 %) RFD values compared to the young and middle-aged men (P ≤ 0.03). RER values were similar between the young and old men (P ≥ 0.30); however, RER values were greater for the middle-aged men when compared to the young and old men for the soleus (P < 0.01) and the old men for the medial gastrocnemius (P ≤ 0.02). Likewise, RFD/PF ratios were similar between young and old men (P ≥ 0.26); however, these ratios were greater for the middle-aged men at early (P ≤ 0.03), but not later (P ≥ 0.10), time intervals. The lower PF and absolute and relative RFD values for the old men may contribute to the increased functional limitations often observed in older adults. Interestingly, higher rates of muscle activation and greater early RFD/PF ratios in middle-aged men may be a reflection of physiological alterations in the neuromuscular system occurring in the fifth decade.

  14. Short-Term Heart Rate Recovery is Related to Aerobic Fitness in Elite Intermittent Sport Athletes.

    PubMed

    Watson, Andrew M; Brickson, Stacey L; Prawda, Evan R; Sanfilippo, Jenifer L

    2017-04-01

    Watson, AM, Brickson, SL, Prawda, ER, and Sanfilippo, JL. Short-term heart rate recovery is related to aerobic fitness in elite intermittent sport athletes. J Strength Cond Res 31(4): 1055-1061, 2017-Although heart rate recovery (HRR) has been suggested as a measure of fitness, minimal data exist among athletes. The purpose of this study was to determine if HRR is related to aerobic fitness in elite athletes and whether this relationship is influenced by sex or body composition. Eighty-four collegiate athletes (45 male athletes) underwent body fat percentage (BF%) determination by dual-energy x-ray absorptiometry and maximal treadmill testing followed by 5 minutes of recovery. V[Combining Dot Above]O2max and heart rate (HRmax) were determined, and HRR was calculated as a percentage of HRmax at 10 seconds, 30 seconds, and 1, 2, 3, 4, and 5 minutes after test completion. After stratifying by sex, participants were grouped as high fit or low fit based on V[Combining Dot Above]O2max median split. Heart rate recovery was compared between sexes and fitness level at each time point. Multivariable regression analysis was used to identify independent predictors of HRR using V[Combining Dot Above]O2max, BF%, and sex as covariates. Heart rate recovery did not differ significantly between sexes and was faster among high-fit participants at 10 and 30 seconds, but at no other time. V[Combining Dot Above]O2max was significantly correlated with HRR at 10 and 30 seconds (r = -0.34, p < 0.001 and r = -0.28, p = 0.008) only. After controlling for BF% and sex, V[Combining Dot Above]O2max remained significantly associated with HRR at 10 seconds (p = 0.007) but not at 30 seconds (p = 0.067) or any time thereafter. Aerobic capacity is related to faster HRR during the first 30 seconds only, suggesting that only very short term HRR should be used as a measure of aerobic fitness in intermittent sport athletes.

  15. Negative Trends in Transport-related Mortality Rates in Broiler Chickens.

    PubMed

    Vecerek, Vladimir; Voslarova, Eva; Conte, Francesca; Vecerkova, Lenka; Bedanova, Iveta

    2016-12-01

    The high incidence of deaths during transport for slaughter is associated with poor welfare and represents a considerable loss to the poultry industry. In the period from 2009 to 2014, all shipments of broiler chickens to poultry processing plants were monitored in the Czech Republic and the numbers of chickens transported and those dying as a result of their transport were recorded and analysed. Overall transport-related mortality of broiler chickens transported for slaughter in the Czech Republic was 0.37%. It ranged from 0.31% to 0.72%, the increase approximately corresponding to the increasing transport distance. Statistically highly significant (p<0.001) differences were found when comparing transport-related mortality rates in individual seasons of the year. The greatest mortality (0.55%) was associated with transports carried out in winter months whereas the lowest death losses (0.30%) were found in chickens transported for slaughter in summer months. Our study revealed greater transport-related mortality rates in broiler chickens transported for slaughter in the Czech Republic than expected when considering earlier studies. The most pronounced increases were found in transports for shorter distances and in winter months. However, an increase was found at all transport distances monitored except for distances exceeding 300 km and all seasons except for summer. Furthermore, a general increasing tendency in chicken losses during the monitored period was found. The particularly alarming finding is that the mortality of broiler chickens being transported to processing plants has been showing a long-term increasing tendency over the last two decades. Further research should focus on the identification of specific factors leading to such high and growing mortality rates and developing practical guidelines to improve the welfare of the birds in transit accordingly.

  16. Negative Trends in Transport-related Mortality Rates in Broiler Chickens

    PubMed Central

    Vecerek, Vladimir; Voslarova, Eva; Conte, Francesca; Vecerkova, Lenka; Bedanova, Iveta

    2016-01-01

    The high incidence of deaths during transport for slaughter is associated with poor welfare and represents a considerable loss to the poultry industry. In the period from 2009 to 2014, all shipments of broiler chickens to poultry processing plants were monitored in the Czech Republic and the numbers of chickens transported and those dying as a result of their transport were recorded and analysed. Overall transport-related mortality of broiler chickens transported for slaughter in the Czech Republic was 0.37%. It ranged from 0.31% to 0.72%, the increase approximately corresponding to the increasing transport distance. Statistically highly significant (p<0.001) differences were found when comparing transport-related mortality rates in individual seasons of the year. The greatest mortality (0.55%) was associated with transports carried out in winter months whereas the lowest death losses (0.30%) were found in chickens transported for slaughter in summer months. Our study revealed greater transport-related mortality rates in broiler chickens transported for slaughter in the Czech Republic than expected when considering earlier studies. The most pronounced increases were found in transports for shorter distances and in winter months. However, an increase was found at all transport distances monitored except for distances exceeding 300 km and all seasons except for summer. Furthermore, a general increasing tendency in chicken losses during the monitored period was found. The particularly alarming finding is that the mortality of broiler chickens being transported to processing plants has been showing a long-term increasing tendency over the last two decades. Further research should focus on the identification of specific factors leading to such high and growing mortality rates and developing practical guidelines to improve the welfare of the birds in transit accordingly. PMID:26954219

  17. Relation of heart rate recovery after exercise testing to coronary artery calcification.

    PubMed

    Jae, Sae Young; Kurl, Sudhir; Laukkanen, Jari A; Yoon, Eun Sun; Choi, Yoon-Ho; Fernhall, Bo; Franklin, Barry A

    2017-08-01

    We examined whether slow heart rate recovery (HRR) after exercise testing as an estimate of impaired autonomic function is related to coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. We evaluated 2088 men who participated in a health-screening program that included measures of CAC and peak or symptom-limited cardiopulmonary exercise testing. HRR was calculated as the difference between peak heart rate (HR) during exercise testing and the HR at 2 min of recovery after peak exercise. We measured CAC using multidetector computed tomography to calculate the Agatston coronary artery calcium score. Advanced CAC was defined as a mean CAC >75th percentile for each age group. HRR was negatively correlated with CAC (r = -.14, p < .01). After adjusting for conventional risk factors, participants in the lowest quartile of HRR (<38 bpm) were 1.59 times (95% CI: 1.17-2.18; p < .05) more likely to have advanced CAC than their counterparts in the highest quartile of HRR (>52 bpm). Each 1 bpm decrease in HRR was associated with 1% increase in advanced CAC after adjusting for potential confounders. An attenuated HRR after exercise testing is associated with advanced CAC, independent of coronary risk factors and other related hemodynamic response. KEY MESSAGES Slow heart rate recovery (HRR) after maximal exercise testing, indicating decreased autonomic function, is associated with an increased risk of cardiovascular event and mortality. Slow HRR has been linked with the occurrence of malignant ventricular arrhythmias, but it remains unclear whether slow HRR is associated with an increased risk of coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. An attenuated HRR after exercise testing was associated with advanced CAC, independent of coronary risk factors and other potential hemodynamic confounder, supporting the hypothesis that slow HRR is related to the burden of atherosclerotic coronary artery

  18. The management and outcome of documented intraoperative heart rate-related electrocardiographic changes.

    PubMed

    Hobai, Ion A; Gauran, Cosmin; Chitilian, Hovig V; Ehrenfeld, Jesse M; Levinson, John; Sandberg, Warren S

    2011-10-01

    The authors analyzed surgical cases in which electrocardiographic (ECG) signs of cardiac ischemia were noted to be precipitated by increases in heart rate (ie, heart rate-related ECG changes [REC]). The authors aimed to find REC incidence, specificity for coronary artery disease (CAD), and the outcome associated with different management strategies. A retrospective review. A university hospital, tertiary care. Patients undergoing surgery under anesthesia. A chart review. The authors searched 158,252 anesthesia electronic records for comments noting REC (ie, ST-segment or T-wave changes). After excluding cases with potentially confounding conditions (eg, hypotension, hyperkalemia, and so on), 26 cases were analyzed. REC commonly was precipitated by anesthesia-related events (ie, intubation, extubation, and treatment of bradycardia). In 24 cases, REC was managed by prompt heart rate reduction using β-blocker agents, opioids, and/or cardioversion in the addition to the removal of stimulus. Only 1 case had a copy of the ECG printed. Two cases were aborted, 1 was shortened and 23 proceeded without change. Postoperative troponin T levels were checked, and cardiology consultation was obtained in selected cases and led to further cardiac evaluation in 6 cases. Postoperative myocardial infarction developed in only 1 patient in whom the ECG changes were allowed to persist throughout the case. This incidence of reported REC was much lower than the previously reported incidence of ischemia-related ECG changes, suggesting that the largest proportion of events go unnoticed. In many patients, subsequent cardiology workup did not confirm the existence of clinically significant CAD. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. A radiobiological model for the relative biological effectiveness of high-dose-rate 252Cf brachytherapy.

    PubMed

    Rivard, Mark J; Melhus, Christopher S; Zinkin, Heather D; Stapleford, Liza J; Evans, Krista E; Wazer, David E; Odlozilíková, Anna

    2005-09-01

    While there is significant clinical experience using both low- and high-dose-rate 252Cf brachytherapy, there are minimal data regarding values for the neutron relative biological effectiveness (RBE) with both modalities. The aim of this research was to derive a radiobiological model for 252Cf neutron RBE and to compare these results with neutron RBE values used clinically in Russia. The linear-quadratic (LQ) model was used as the basis to characterize cell survival after irradiation, with identical cell killing rates (S(N) = S(gamma)) between 252Cf neutrons and photons used for derivation of RBE. Using this equality, a relationship among neutron dose and LQ radiobiological parameter (i.e., alpha(N), beta(N), alpha(gamma), beta(gamma)) was obtained without the need to specify the photon dose. These results were used to derive the 252Cf neutron RBE, which was then compared with Russian neutron RBE values. The 252Cf neutron RBE was determined after incorporating the LQ radiobiological parameters obtained from cell survival studies with fast neutrons and teletherapy photons. For single-fraction high-dose-rate neutron doses of 0.5, 1.0, 1.5 and 2.0 Gy, the total biologically equivalent doses were 1.8, 3.4, 4.7 and 6.0 RBE Gy with 252Cf neutron RBE values of 3.2, 2.9, 2.7 and 2.5, respectively. Using clinical data for late-responding reactions from 252Cf, Russian investigators created an empirical model that predicted high-dose-rate 252Cf neutron RBE values ranging from 3.6 to 2.9 for similar doses and fractionation schemes and observed that 252Cf neutron RBE increases with the number of treatment fractions. Using these relationships, our results were in general concordance with high-dose-rate 252Cf RBE values obtained from Russian clinical experience.

  20. Relation of Total and Cardiovascular Death Rates to Climate System, Temperature, Barometric Pressure, and Respiratory Infection.

    PubMed

    Schwartz, Bryan G; Qualls, Clifford; Kloner, Robert A; Laskey, Warren K

    2015-10-15

    A distinct seasonal pattern in total and cardiovascular death rates has been reported. The factors contributing to this pattern have not been fully explored. Seven locations (average total population 71,354,000) were selected where data were available including relatively warm, cold, and moderate temperatures. Over the period 2004 to 2009, there were 2,526,123 all-cause deaths, 838,264 circulatory deaths, 255,273 coronary heart disease deaths, and 135,801 ST-elevation myocardial infarction (STEMI) deaths. We used time series and multivariate regression modeling to explore the association between death rates and climatic factors (temperature, dew point, precipitation, barometric pressure), influenza levels, air pollution levels, hours of daylight, and day of week. Average seasonal patterns for all-cause and cardiovascular deaths were very similar across the 7 locations despite differences in climate. After adjusting for multiple covariates and potential confounders, there was a 0.49% increase in all-cause death rate for every 1°C decrease. In general, all-cause, circulatory, coronary heart disease and STEMI death rates increased linearly with decreasing temperatures. The temperature effect varied by location, including temperature's linear slope, cubic fit, positional shift on the temperature axis, and the presence of circulatory death increases in locally hot temperatures. The variable effect of temperature by location suggests that people acclimatize to local temperature cycles. All-cause and circulatory death rates also demonstrated sizable associations with influenza levels, dew point temperature, and barometric pressure. A greater understanding of how climate, temperature, and barometric pressure influence cardiovascular responses would enhance our understanding of circulatory and STEMI deaths.

  1. Growth Rate and Relocation Movements of Common Nighthawk (Chordeiles minor) Nestlings in Relation to Age

    USGS Publications Warehouse

    Kramer, Gunnar R.; Chalfoun, Anna D.

    2012-01-01

    Relocation by dependent young is a survival strategy that occurs among a wide range of taxa. The Common Nighthawk (Chordeiles minor) lays its eggs on bare substrate and, once hatched, nestlings may relocate to new sites daily. We located and monitored eight Common Nighthawk nests in Grand Teton National Park, Wyoming, quantified inter-use-site distances in relation to nestling age, and calculated a nestling growth rate curve. Common Nighthawk nestlings grow in a nearly linear fashion. Nestlings moved up to 48 m in a single day and larger, older nestlings tended to move greater distances between daily use-sites.

  2. An Examination of Sunspot Number Rates of Growth and Decay in Relation to the Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    On the basis of annual sunspot number averages, sunspot number rates of growth and decay are examined relative to both minimum and maximum amplitudes and the time of their occurrences using cycles 12 through present, the most reliably determined sunspot cycles. Indeed, strong correlations are found for predicting the minimum and maximum amplitudes and the time of their occurrences years in advance. As applied to predicting sunspot minimum for cycle 24, the next cycle, its minimum appears likely to occur in 2006, especially if it is a robust cycle similar in nature to cycles 17-23.

  3. Differential relations between heart rate and skin conductance, and public speaking anxiety.

    PubMed

    Croft, Rodney J; Gonsalvez, Craig J; Gander, Joanne; Lechem, Lisa; Barry, Robert J

    2004-09-01

    The present pilot study tested whether the lack of consistent findings of relations between autonomic nervous system (ANS) activity and non-clinical levels of public speaking anxiety (PSA) can be explained by methodology. An ambulatory protocol was utilised to test whether the interaction of belief structure with each of an undergraduate student speaker's heart rate and skin conductance level predicted state speech anxiety better than their linear summation. Results suggest that in a non-clinical population, the interaction of ANS activity and belief structure is an important determinant of PSA, and may account for variable findings in the literature.

  4. Heart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorder

    PubMed Central

    Ehlers, Anke; Suendermann, Oliver; Boellinghaus, Inga; Vossbeck-Elsebusch, Anna; Gamer, Matthias; Briddon, Emma; Martin, Melanie Walwyn; Glucksman, Edward

    2010-01-01

    Physiological responses to trauma reminders are one of the core symptoms of posttraumatic stress disorder (PTSD). Nevertheless, screening measures for PTSD largely rely on symptom self-reports. It has been suggested that psychophysiological assessments may be useful in identifying trauma survivors with PTSD (Orr and Roth, 2000). This study investigated whether heart rate (HR) responses to standardized trauma-related pictures distinguish between trauma survivors with and without acute PTSD. Survivors of motor vehicle accidents or physical assaults (N = 162) watched standardized trauma-related, generally threatening and neutral pictures at 1 month post-trauma while their ECG was recorded. At 1 and 6 months, structured clinical interviews assessed PTSD diagnoses. Participants completed self-report measures of PTSD severity and depression, peritraumatic responses, coping behaviors and appraisals. Trauma survivors with acute PTSD showed greater HR responses to trauma-related pictures than those without PTSD, as indicated by a less pronounced mean deceleration, greater peak responses, and a greater proportion showing HR acceleration of greater than 1 beat per minute. There were no group differences in HR responses to generally threatening or neutral pictures. HR responses to trauma-related pictures contributed to the prediction of PTSD diagnosis over and above what could be predicted from self-reports of PTSD and depression. HR responses to trauma-related pictures were related to fear and data-driven processing during the trauma, safety behaviors, suppression of trauma memories, and overgeneralized appraisals of danger. The results suggest that HR responses to standardized trauma-related pictures may help identify a subgroup of patients with acute PTSD who show generalized fear responses to trauma reminders. The early generalization of triggers of reexperiencing symptoms observed in this study is consistent with associative learning and cognitive models of PTSD. PMID

  5. Heart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorder.

    PubMed

    Ehlers, Anke; Suendermann, Oliver; Boellinghaus, Inga; Vossbeck-Elsebusch, Anna; Gamer, Matthias; Briddon, Emma; Martin, Melanie Walwyn; Glucksman, Edward

    2010-10-01

    Physiological responses to trauma reminders are one of the core symptoms of posttraumatic stress disorder (PTSD). Nevertheless, screening measures for PTSD largely rely on symptom self-reports. It has been suggested that psychophysiological assessments may be useful in identifying trauma survivors with PTSD (Orr and Roth, 2000). This study investigated whether heart rate (HR) responses to standardized trauma-related pictures distinguish between trauma survivors with and without acute PTSD. Survivors of motor vehicle accidents or physical assaults (N=162) watched standardized trauma-related, generally threatening and neutral pictures at 1 month post-trauma while their ECG was recorded. At 1 and 6 months, structured clinical interviews assessed PTSD diagnoses. Participants completed self-report measures of PTSD severity and depression, peritraumatic responses, coping behaviors and appraisals. Trauma survivors with acute PTSD showed greater HR responses to trauma-related pictures than those without PTSD, as indicated by a less pronounced mean deceleration, greater peak responses, and a greater proportion showing HR acceleration of greater than 1 beat per minute. There were no group differences in HR responses to generally threatening or neutral pictures. HR responses to trauma-related pictures contributed to the prediction of PTSD diagnosis over and above what could be predicted from self-reports of PTSD and depression. HR responses to trauma-related pictures were related to fear and data-driven processing during the trauma, safety behaviors, suppression of trauma memories, and overgeneralized appraisals of danger. The results suggest that HR responses to standardized trauma-related pictures may help identify a subgroup of patients with acute PTSD who show generalized fear responses to trauma reminders. The early generalization of triggers of reexperiencing symptoms observed in this study is consistent with associative learning and cognitive models of PTSD. 2010

  6. Dynamical relations for left ventricular ejection - Flow rate, momentum, force and impulse

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Selzer, R. H.; Gordon, D. G.; Ledbetter, D. C.; Crawford, D. W.

    1984-01-01

    An investigation was carried out to quantitatively evaluate left ventricular volume flow rate, momentum, force and impulse derived from application of conservation principles for mass and momentum of blood within the ventricle during the ejection phase. An automated digital image processing system was developed and applied to left ventricular angiograms which are computer processed and analyzed frame by frame to determine the dynamical relations by numerical methods. The initial experience with force and impulse has indicated that neither quantity seemed to be a sensitive indicator of coronary artery disease as evaluated by qualitative angiography for the particular patient group studied. Utilization of the dynamical relations in evaluating human left ventricular performance requires improved means of measurement and interpretation of clinical studies.

  7. Dynamical relations for left ventricular ejection - Flow rate, momentum, force and impulse

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Selzer, R. H.; Gordon, D. G.; Ledbetter, D. C.; Crawford, D. W.

    1984-01-01

    An investigation was carried out to quantitatively evaluate left ventricular volume flow rate, momentum, force and impulse derived from application of conservation principles for mass and momentum of blood within the ventricle during the ejection phase. An automated digital image processing system was developed and applied to left ventricular angiograms which are computer processed and analyzed frame by frame to determine the dynamical relations by numerical methods. The initial experience with force and impulse has indicated that neither quantity seemed to be a sensitive indicator of coronary artery disease as evaluated by qualitative angiography for the particular patient group studied. Utilization of the dynamical relations in evaluating human left ventricular performance requires improved means of measurement and interpretation of clinical studies.

  8. Season of Birth Is Related to Child Retention Rates, Achievement, and Rate of Diagnosis of Specific LD

    ERIC Educational Resources Information Center

    Martin, Roy P.; Foels, Patricia; Clanton, Greg; Moon, Kathryn

    2004-01-01

    A sizable literature has demonstrated that the achievement of children in early elementary school is related to their season of birth: Those born in summer typically perform less well than those born in the fall. A small literature indicates that more children diagnosed with specific learning disabilities (SLD) are born in the summer. We have…

  9. The relation between gravity rate of change and vertical displacement in previously glaciated areas

    NASA Astrophysics Data System (ADS)

    Olsson, Per-Anders; Milne, Glenn; Scherneck, Hans-Georg; Ågren, Jonas

    2015-01-01

    The rate of change of surface gravity, g˙, and vertical deformation rate of the solid surface, u˙, are two observables of glacial isostatic adjustment (GIA). They contribute with different information on the same phenomenon. Their relation contains information of the underlying physics and a trustworthy relation allows to combine these observations to strengthen the overall observational accuracy of the phenomenon. In this paper we investigate the predicted relation between g˙ and u˙ in previously glaciated areas. We use the normal mode approach for one dimensional earth models and solutions of the sea level equation with time-dependent coastline geometry. Numerical predictions of g˙ and u˙ are computed for Laurentia, Fennoscandia and the British Isles respectively, using six different earth models. Within each region a linear trend is then fitted using the relation g˙ = Cu˙ +g˙0. The estimated C and g˙0 differ more between the regions than between different earth models within each region. For Fennoscandia C ≈ -0.163 μGal/mm and for Laurentia C ≈ -0.152 μGal/mm. Maximum residuals between the linear trend and spatially varying model predictions of g˙ are 0.04 μGal/yr in Fennoscandia and 0.17 μGal/yr in Laurentia. For the British Isles the results are harder to interpret, mainly since this region is located on the zero uplift isoline of Fennoscandia. In addition, we show temporal variation of the relation since the last glacial maximum till present-day. The temporal and spatial variation of the relation between g˙ and u˙ can be explained by (i) the elastic respectively viscous proportion of the total signal and (ii) the spectral composition of the regional signal. Additional local effects, such as the Newtonian attraction and elastic deformation from local sea level changes, are examined in a case study for six stations in the Nordic absolute gravity network. The influence of these local effects on the relation between g˙ and u˙ is negligible

  10. The influence of weather conditions on the relative incident rate of fishing vessels.

    PubMed

    Wu, Yue; Pelot, Ronald P; Hilliard, Casey

    2009-07-01

    There is a long history of studying the relationship between weather and maritime activities. This article analyzes the link between relative incident rate (RIR) and general weather factors within certain gridded areas and time periods. The study area, which encompasses a broad extent of Atlantic Canadian waters, includes fishing incidents recorded by the Canadian Coast Guard from 1997 to 1999. Methodologies used for traffic track generation in a geographical information system and aggregation of all relevant weather data needed for the statistical analyses are presented. Ultimately, a regression tree was built to illustrate the relationship between incident rate and the following six weather factors: wave height; sea surface temperature; air temperature; ice concentration; fog presence; and precipitation. Results from the regression tree reveal that the RIR defined as (incident number per area-day)/(traffic amount per area-day) across grid cells with incidents, increases as the weather conditions deteriorate in a general way, and the concentration of ice has the biggest influence on the magnitude of incident rates for a given level of traffic exposure. The results from this analysis may assist administrators of maritime traffic, especially those associated with fishing activities, through a better understanding of the influence on RIR of certain weather conditions within given areas in specific time periods.

  11. Seasonal predator removal relative to hatch rate of duck nests in waterfowl production areas

    USGS Publications Warehouse

    Sargeant, A.B.; Sovada, M.A.; Shaffer, T.L.

    1995-01-01

    These authors report that hatch rates of duck nests were related to removal of predators from waterfowl production areas. Cost effectiveness of such efforts is questioned. The prairie pothole region (PPR) is the primary breeding ground of several species of North American ducks (Bellrose 1980). Much habitat of breeding ducks in the PPR has been destroyed or degraded by intensive agriculture (e.g., Kiel et al. 1972, Bellrose 1980, Sugden and Beyersbergen 1984, Boyd 1985), resulting in high predation rates on duck nests (Sargeant and Raveling 1992). Because of predation, hatch rate (HR) of duck nests in Waterfowl Production Areas (WPA's) in the PPR is often less than the 15-20% suggested for stability of populations of the 5 most common species of dabbling ducks (e.g., Cowardin et al. 1985, Greenwood 1986, Klett et al. 1988, Greenwood et al. 1990). Managers seek ways to reduce depredations of duck clutches in WPA's, but little information is available concerning effects of predator removal. We evaluated seasonal (spring and early summer) removal of predators from WPA's in Minnesota and North Dakota. Our objectives were to compare HR in uplands of WPA's with and without predators removed and to determine functional aspects of conducting predator removal.

  12. The Relative Rate of LGRB Formation as a Function of Metallicity

    NASA Astrophysics Data System (ADS)

    Graham, J. F.; Fruchter, A. S.

    2017-01-01

    There is now strong evidence that long-duration gamma-ray bursts (LGRBs) are preferentially formed in low-metallicity environments. However, the magnitude of this effect and its functional dependence on metallicity have not been well characterized. In our previous paper, we compared the metallicity distribution of LGRB host galaxies to that of star-forming galaxies in the local universe. Here we build upon this work by in effect dividing one distribution by the other, and thus directly determine the relative rate of LGRB formation as a function of metallicity in the low-redshift universe. We find a dramatic cutoff in LGRB formation above a metallicity of {log}({{O}}/{{H}})+12≈ 8.3 in the KK04 scale, with LGRBs forming between 10 and 50 times more frequently per unit star formation below this cutoff than above. Furthermore, our data suggest that the rate of LGRB formation per unit star formation continues to fall above this break. We estimate that the LGRB formation rate per unit star formation may drop by as much as a factor of 100 between one-third solar and solar metallicity.

  13. Future projections of child oral-related hospital admission rates in Western Australia.

    PubMed

    Alsharif, Alla; Kruger, Estie; Tennant, Marc

    2016-01-11

    This study aimed to project the hospital admission rates of Western Australian children for oral conditions, with a particular focus on dental caries, embedded and impacted teeth, and pulp and periapical conditions through to the year 2026. Two methods were used to generate projection data through to the year 2026, using the Western Australian Hospital Morbidity Dataset for the period 1999-2000 to 2008-2009. The projected admission rate increase in those children aged 14 years and younger from 2000 to 2026 was 43%. The admission rates are expected to more than double over time (7317 cases in 2026 compared to only 3008 cases in 2000) for those children living in metropolitan areas. Dental caries, embedded and impacted teeth, and pulp and periapical conditions will remain the top (mostly) preventable causes of admission throughout this time. Anticipating the future burden of oral-related hospital admissions in children, in terms of expected numbers of cases, is vital for optimising the resource allocation for early diagnosis, prevention and treatment. A concerted effort will be required by policymakers and oral healthcare communities to effect substantial change for the future.

  14. Enclosure fire hazard analysis using relative energy release criteria. [burning rate and combustion control

    NASA Technical Reports Server (NTRS)

    Coulbert, C. D.

    1978-01-01

    A method for predicting the probable course of fire development in an enclosure is presented. This fire modeling approach uses a graphic plot of five fire development constraints, the relative energy release criteria (RERC), to bound the heat release rates in an enclosure as a function of time. The five RERC are flame spread rate, fuel surface area, ventilation, enclosure volume, and total fuel load. They may be calculated versus time based on the specified or empirical conditions describing the specific enclosure, the fuel type and load, and the ventilation. The calculation of these five criteria, using the common basis of energy release rates versus time, provides a unifying framework for the utilization of available experimental data from all phases of fire development. The plot of these criteria reveals the probable fire development envelope and indicates which fire constraint will be controlling during a criteria time period. Examples of RERC application to fire characterization and control and to hazard analysis are presented along with recommendations for the further development of the concept.

  15. Mechanical properties and constitutive relations for molybdenum under high-rate deformation

    SciTech Connect

    Chen, S.R.; Maudlin, P.J.; Gray, G.T. III

    1998-01-01

    Molybdenum and its alloys have received increased interest in recent years for ballistic applications. The stress-strain behavior of several molybdenums possessing various compositions, manufacturing sources, and the degree of pre-straining, were investigated as a function of temperature from 77 to 1,273 K, and strain rate from 10{sup {minus}3} s{sup {minus}1} to 8,000 s{sup {minus}1}. The yield stress was found to be sensitive to the test temperature and strain rate, however, the strain hardening remained rate-insensitive. The constitutive response of a powder-metallurgy molybdenum was also investigated; similar mechanical properties compared to conventionally wrought processed molybdenums were achieved. Constitutive relations based upon the Johnson-Cook, the Zerilli-Armstrong and the Mechanical Threshold Stress (MTS) models were evaluated and fit for the various Mo-based materials. The capabilities and limitations of each model for large-strain applications were examined. The differences between the three models are demonstrated using model comparisons to Taylor cylinder validation experiments.

  16. Relative rate and product studies of the OH-acetone reaction.

    PubMed

    Raff, Jonathan D; Stevens, Philip S; Hites, Ronald A

    2005-06-02

    The rate constants for the reaction of acetone (kH) and d6-acetone (kD) with OH radicals have been measured at atmospheric pressure over a range of temperatures by a relative rate method by using on-line mass spectrometry. The following Arrhenius expressions have been determined for these reactions (in units of cm(3) molecule(-1) s(-1)): k(H)(T) = (9.8 x 10(-13)) exp[-(484 +/- 44)/T] between 253 and 373 K, and kD(T) = (4.0 x 10(-13)) exp[-(755 +/- 89)/T] between 293 and 373 K. This is the first study to investigate the temperature dependence of kH and kD by using a relative rate method and confirms previous rate constants determined by absolute methods. Agreement of our rate constants with those determined in the absence of water suggests that the presence of water vapor has a minimal effect on the kinetics of this reaction under the conditions of our study. The observed kinetic isotope effect (kH/kD = 5.6 +/- 0.4 at 293 K) is evidence that H-atom abstraction occurs in the mechanism. The acetic acid yields of the reaction of OH with acetone and d6-acetone were also investigated by on-line mass spectrometry. Acetic acid yields show a negative temperature dependence that decreases from 0.12 at 273 K to 0.05 at 353 K. The yields of d3-acetic acid decrease from 0.20 at 283 K to 0.13 at 323 K. Kinetic modeling of our data suggests that 50-70% of the observed acetic acid in our system may be due to secondary reactions involving acetonoxy and HOx radical reactions. However, secondary chemistry cannot easily explain the observed formation of d3-acetic acid in the deuterated system, where about 90% of the observed d3-acetic acid is likely due to an OH-addition mechanism.

  17. Rates of and factors associated with delivery-related perinatal death among term infants in Scotland.

    PubMed

    Pasupathy, Dharmintra; Wood, Angela M; Pell, Jill P; Fleming, Michael; Smith, Gordon C S

    2009-08-12

    Rates of obstetric intervention in labor, including cesarean delivery, have increased significantly in most developed countries. It is, however, unclear if this has been paralleled by decreased rates of perinatal and neonatal death associated with complications of labor at term. To determine whether rates of perinatal death at term, either during labor or in the neonatal period, have changed in Scotland during the last 20 years and whether this was associated with a reduction in deaths ascribed to intrapartum anoxia. A population-based, retrospective cohort study of linked data from a registry of births (Scottish Morbidity Record 02) and a registry of perinatal deaths (Scottish Stillbirth and Infant Death Survey) between 1988 and 2007. Participants included all births of a singleton infant in a cephalic presentation at term (N = 1,012,266), excluding those with perinatal death due to congenital anomaly or antepartum stillbirth. Delivery-related perinatal death, defined as intrapartum stillbirth or neonatal death unrelated to congenital abnormality. These events were also subdivided into those events ascribed to intrapartum anoxia and all other causes. The risk of death was modeled using logistic regression and analyses were adjusted for maternal age, height, parity, socioeconomic deprivation status, gestational age, birth weight percentile, fetal sex, onset of labor, and the annual number of births per hospital. During the study period, the risk of delivery-related perinatal death decreased from 8.8 to 5.5 per 10,000 births (unadjusted change, -38%; 95% confidence interval [CI], -51% to -21%). When analyzed by the cause of death, there was a significant decrease in the risk of death ascribed to intrapartum anoxia (5.7 to 3.0 per 10,000 births; unadjusted change, -48%; 95% CI, -62% to -29%), but no significant change in the risk of death ascribed to other causes. When deaths ascribed to intrapartum anoxia were analyzed by the time of death in relation to delivery

  18. Incidence rates of sickness absence related to mental disorders: a systematic literature review

    PubMed Central

    2014-01-01

    Background Over the past decade, growing attention has been given to the mental health of workers. One way to examine the mental health of workers is to look at the incidence rates of mental illness-related sickness absence. There is a scarcity of literature in which the incidence rates of mental illness-related sickness absence among different countries have been considered together. The purpose of this systematic literature review is to address the question: Are there similarities and differences in the incidence rates of mental disorder-related sickness absence among and within OECD identified Social Democratic, Liberal and Latin American country categories? In this paper, we seek to identify differences and similarities in the literature rather than to explain them. With this review, we lay the groundwork for and point to areas for future research as well as to raise questions regarding reasons for the differences and similarities. Methods A systematic literature search of the following databases were performed: Medline Current, Medline In-process, PsycINFO, Econlit and Web of Science. The search period covered 2002–2013. The systematic literature search focused on working adults between 18–65 years old who had not retired and who had mental and/or substance abuse disorders. Intervention studies were excluded. The search focused on medically certified sickness absences. Results A total of 3,818 unique citations were identified. Of these, 10 studies met the inclusion/exclusion criteria; six were from Social Democratic countries. Their quality ranged from good to excellent. There was variation in the incidence rates reported by the studies from the Social Democratic, Liberal and Latin American countries in this review. Conclusions The results of this systematic review suggest that this is an emerging area of inquiry that needs to continue to grow. Priority areas to support growth include cross jurisdictional collaboration and development of a typology

  19. Defensive Traits in Young Pine Trees Cluster into Two Divergent Syndromes Related to Early Growth Rate.

    PubMed

    Moreira, Xoaquín; Sampedro, Luis; Zas, Rafael; Pearse, Ian S

    2016-01-01

    The combination of defensive traits leads to the evolution of 'plant defense syndromes' which should provide better protection against herbivores than individual traits on their own. Defense syndromes can be generally driven by plant phylogeny and/or biotic and abiotic factors. However, we lack a solid understanding of (i) the relative importance of shared evolution vs. convergence due to similar ecological conditions and (ii) the role of induced defense strategies in shaping defense syndromes. We investigate the relative roles of evolutionary and ecological factors shaping the deployment of pine defense syndromes including multiple constitutive and induced chemical defense traits. We performed a greenhouse experiment with seedlings of eighteen species of Pinaceae family, and measured plant growth rate, constitutive chemical defenses and their inducibility. Plant growth rate, but not phylogenetic relatedness, determined the deployment of two divergent syndromes. Slow-growing pine species living in harsh environments where tissue replacement is costly allocated more to constitutive defenses (energetically more costly to produce than induced). In contrast, fast-growing species living in resource-rich habitats had greater inducibility of their defenses, consistent with the theory of constitutive-induced defense trade-offs. This study contributes to a better understanding of evolutionary and ecological factors driving the deployment of defense syndromes.

  20. Genetic variants related to gap junctions and hormone secretion influence conception rates in cows

    PubMed Central

    Sugimoto, Mayumi; Sasaki, Shinji; Gotoh, Yusaku; Nakamura, Yuuki; Aoyagi, Yoshito; Kawahara, Takayoshi; Sugimoto, Yoshikazu

    2013-01-01

    The recent decline in fertility is a serious problem in the dairy industry. To overcome this problem, we performed a genome-wide association study using 384 Holsteins and identified four loci associated with conception rates. Two of them contained gap junction-related genes: PKP2 and CTTNBP2NL. Further analysis confirmed that PKP2 increased connexin 43, a gap junction protein, whereas CTTNBP2NL dephosphorylated connexin 43. Knockdown of PKP2 or overexpression of CTTNBP2NL inhibited embryo implantation in mice. The other two loci contained neuroendocrine-related genes: SETD6 and CACNB2. Additional experiments indicated that SETD6 is involved in the transcriptional regulation of gonadotropin-releasing hormone, whereas CACNB2 controlled the secretion of follicle-stimulating hormone in cattle. The total allele substitution effect of these genes on conception rate was 3.5%. Our findings reveal important roles for gap junction communication and the neuroendocrine system in conception and suggest unique selection methods to improve reproductive performance in the livestock industry. PMID:24218568

  1. Do cognitive interventions alter the rate of age-related cognitive change?

    PubMed Central

    Salthouse, Timothy A.

    2015-01-01

    There has recently been a great deal of interest in cognitive interventions, particularly when applied in older adults with the goal of slowing or reversing age-related cognitive decline. Although seldom directly investigated, one of the fundamental questions concerning interventions is whether the intervention alters the rate of cognitive change, or affects the level of certain cognitive measures with no effect on the trajectory of change. This question was investigated with a very simple intervention consisting of the performance of three versions (treatment) or one version (control) of the relevant cognitive tests at an initial occasion. Participants were retested at intervals ranging from less than 1 to 12 years, which allowed rates of change to be examined in the control and treatment groups. Although the intervention can be considered modest, participants in the treatment group had about .25 standard deviations less negative cognitive change over an interval of approximately three years than those in the control group, which is comparable to effect sizes reported with more intensive interventions. However, there were no interactions of the intervention with length of the interval between occasions, and thus there was no evidence that the intervention affected the course of age-related cognitive decline. PMID:26478640

  2. Selective Heart Rate Reduction Improves Metabolic Syndrome-related Left Ventricular Diastolic Dysfunction.

    PubMed

    Merabet, Nassiba; Fang, Yuehua; Nicol, Lionel; Monteil, Christelle; Rémy-Jouet, Isabelle; Henry, Jean-Paul; Wecker, Didier; Le Bouter-Banon, Sabrina; Roussel, Jerome; Richard, Vincent; Thuillez, Christian; Mulder, Paul

    2015-10-01

    Enhanced heart rate observed in metabolic syndrome (MS) contributes to the deterioration of left ventricular (LV) function via impaired LV filling and relaxation, increased myocardial O2 consumption, and reduced coronary perfusion. However, whether heart rate reduction (HRR) opposes LV dysfunction observed in MS is unknown. We assessed in Zucker fa/fa rats, a rat model of MS, the cardiovascular effects of HRR induced by the If current inhibitor S38844 (3 mg · kg(-1) · d(-1)). Delayed short-term (4 days) and long-term (90 days) HRR induced by S38844 reduced LV end-diastolic pressure and LV end-diastolic pressure-volume relation, increased myocardial tissue perfusion, decreased myocardial oxidized glutathione levels, and preserved cardiac output, without modifying LV end-systolic pressure and LV end-systolic pressure-volume relation, although only long-term S38844 opposed LV collagen accumulation. Long-term S38844 improved flow-induced endothelium-dependent dilatation of mesenteric arteries, while metabolic parameters, such as plasma glucose levels, and Hb1c, were never modified. In rats with MS, HRR induced by the If inhibitor S38844 improved LV diastolic function and endothelium-dependent vascular dilatation, independent from modifications in metabolic status. Moreover, this improvement in cardiac function involves not only immediate effects such as improved myocardial perfusion and reduced oxidative stress but also long-term effects such as modifications in the myocardial structure.

  3. Defensive Traits in Young Pine Trees Cluster into Two Divergent Syndromes Related to Early Growth Rate

    PubMed Central

    Moreira, Xoaquín; Sampedro, Luis; Zas, Rafael; Pearse, Ian S.

    2016-01-01

    The combination of defensive traits leads to the evolution of ‘plant defense syndromes’ which should provide better protection against herbivores than individual traits on their own. Defense syndromes can be generally driven by plant phylogeny and/or biotic and abiotic factors. However, we lack a solid understanding of (i) the relative importance of shared evolution vs. convergence due to similar ecological conditions and (ii) the role of induced defense strategies in shaping defense syndromes. We investigate the relative roles of evolutionary and ecological factors shaping the deployment of pine defense syndromes including multiple constitutive and induced chemical defense traits. We performed a greenhouse experiment with seedlings of eighteen species of Pinaceae family, and measured plant growth rate, constitutive chemical defenses and their inducibility. Plant growth rate, but not phylogenetic relatedness, determined the deployment of two divergent syndromes. Slow-growing pine species living in harsh environments where tissue replacement is costly allocated more to constitutive defenses (energetically more costly to produce than induced). In contrast, fast-growing species living in resource-rich habitats had greater inducibility of their defenses, consistent with the theory of constitutive-induced defense trade-offs. This study contributes to a better understanding of evolutionary and ecological factors driving the deployment of defense syndromes. PMID:27028433

  4. The Dense-gas Mass versus Star Formation Rate Relation: A Misleading Linearity?

    NASA Astrophysics Data System (ADS)

    Parmentier, G.

    2017-07-01

    We model the star formation relation of molecular clumps in dependence of their dense-gas mass when their volume density profile is that of an isothermal sphere (i.e., {ρ }{clump}(r)\\propto {r}-2). Dense gas is defined as gas whose volume density is higher than a threshold {ρ }{th}=700 {M}⊙ {{pc}}-3 (i.e., HCN(1-0)-mapped gas). We divide the clump into two regions: a dense inner region (where {ρ }{clump}(r)≥slant {ρ }{th}), and low-density outskirts (where {ρ }{clump}(r)< {ρ }{th}). We find that the total star formation rate of clumps scales linearly with the mass of their dense inner region, even when more than half of the clump star formation activity takes place in the low-density outskirts. We therefore emphasize that a linear star formation relation does not necessarily imply that star formation takes place exclusively in the gas whose mass is given by the star formation relation. The linearity of the star formation relation is strengthened when we account for the mass of dense fragments (e.g., cores, fibers) seeding star formation in the low-density outskirts, and which our adopted clump density profile {ρ }{clump}(r) does not resolve. We also find that the star formation relation is significantly tighter when considering the dense gas than when considering all the clump gas, as observed for molecular clouds of the Galactic plane. When the clumps have no low-density outskirts (i.e., they consist of dense gas only), the star formation relation becomes superlinear and progressively wider.

  5. On the reversal of star formation rate-density relation at z = 1: Insights from simulations

    SciTech Connect

    Tonnesen, Stephanie; Cen, Renyue E-mail: cen@astro.princeton.edu

    2014-06-20

    Recent surveys have found a reversal of the star formation rate (SFR)-density relation at z = 1 from that at z = 0, while the sign of the slope of the color-density relation remains unchanged. We use adaptive mesh refinement cosmological hydrodynamic simulations of a 21 × 24 × 20 h {sup –3} Mpc{sup 3} region to examine the SFR-density and color-density relations of galaxies at z = 0 and z = 1. The local environmental density is defined by the dark matter mass in spheres of radius 1 h {sup –1} Mpc, and we probe two decades of environmental densities. Our simulations produce a large increase of SFR with density at z = 1, as in the Elbaz et al. observations. We also find a significant evolution to z = 0, where the SFR-density relation is much flatter. The simulated color-density relation is consistent from z = 1 to z = 0, in agreement with observations. We find that the increase in SFR with local density at z = 1 is due to a growing population of star-forming galaxies in higher-density environments. At z = 0 and z = 1 both the SFR and cold gas mass are correlated with the galaxy halo mass, and therefore the correlation between median halo mass and local density is an important cause of the SFR-density relation at both redshifts. However, at z = 0 the local density on 1 h {sup –1} Mpc scales affects galaxy SFRs as much as halo mass. Finally, we find indications that while at z = 0 high-density environments depress galaxy SFRs, at z = 1 high-density environments tend to increase SFRs.

  6. Erythrocyte storage increases rates of NO- and Nitrite scavenging: Implications for transfusion related toxicity

    PubMed Central

    Stapley, Ryan; Owusu, Benjamin Y.; Brandon, Angela; Cusick, Marianne; Rodriguez, Cilina; Marques, Marisa B.; Kerby, Jeffrey D.; Barnum, Scott R.; Weinberg, Jordan A.; Lancaster, Jack R.; Patel, Rakesh P.

    2013-01-01

    Synopsis Storage of erythrocytes in blood banks is associated with biochemical and morphological changes to the RBC. It has been suggested that these changes have a potential negative clinical effects characterized by inflammation and microcirculatory dysfunction which add to other transfusion related toxicities. However, mechanisms linking RBC storage and toxicity remain unclear. In this study we tested the hypothesis that storage of leukodepleted RBC result in cells that inhibit nitric oxide (NO)-signaling more so than younger cells. Using competition kinetic analyses and protocols that minimized contributions from hemolysis or microparticles, our data indicate that NO-consumption rates increased ~40-fold and NO-dependent vasodilation was inhibited 2-4 fold with 42d old vs. 0d RBC. These results are likely due to the formation of smaller RBC with increased surface area: volume as a consequence of membrane loss during storage. The potential for older RBC to affect NO-formation via deoxygenated RBC mediated nitrite reduction was also tested. RBC storage did not affect deoxygenated RBC-dependent stimulation of nitrite-induced vasodilation. However, stored RBC did increase the rates of nitrite oxidation to nitrate in vitro. Significant loss of whole blood nitrite was also observed in stable trauma patients after transfusion with 1 RBC unit, with the decrease in nitrite occurring after transfusion with RBC stored for >25d, but not with younger RBC. Collectively, these data suggest that increased rates of reactions between intact RBC and NO and nitrite may contribute to mechanisms that lead to storage lesion-related transfusion risk PMID:22720637

  7. Erythrocyte storage increases rates of NO and nitrite scavenging: implications for transfusion-related toxicity.

    PubMed

    Stapley, Ryan; Owusu, Benjamin Y; Brandon, Angela; Cusick, Marianne; Rodriguez, Cilina; Marques, Marisa B; Kerby, Jeffrey D; Barnum, Scott R; Weinberg, Jordan A; Lancaster, Jack R; Patel, Rakesh P

    2012-09-15

    Storage of erythrocytes in blood banks is associated with biochemical and morphological changes to RBCs (red blood cells). It has been suggested that these changes have potential negative clinical effects characterized by inflammation and microcirculatory dysfunction which add to other transfusion-related toxicities. However, the mechanisms linking RBC storage and toxicity remain unclear. In the present study we tested the hypothesis that storage of leucodepleted RBCs results in cells that inhibit NO (nitric oxide) signalling more so than younger cells. Using competition kinetic analyses and protocols that minimized contributions from haemolysis or microparticles, our data indicate that the consumption rates of NO increased ~40-fold and NO-dependent vasodilation was inhibited 2-4-fold comparing 42-day-old with 0-day-old RBCs. These results are probably due to the formation of smaller RBCs with increased surface area: volume as a consequence of membrane loss during storage. The potential for older RBCs to affect NO formation via deoxygenated RBC-mediated nitrite reduction was also tested. RBC storage did not affect deoxygenated RBC-dependent stimulation of nitrite-induced vasodilation. However, stored RBCs did increase the rates of nitrite oxidation to nitrate in vitro. Significant loss of whole-blood nitrite was also observed in stable trauma patients after transfusion with 1 RBC unit, with the decrease in nitrite occurring after transfusion with RBCs stored for >25 days, but not with younger RBCs. Collectively, these data suggest that increased rates of reactions between intact RBCs and NO and nitrite may contribute to mechanisms that lead to storage-lesion-related transfusion risk.

  8. Simultaneous monitoring of maternal and fetal heart rate variability during labor in relation with fetal gender.

    PubMed

    Gonçalves, Hernâni; Fernandes, Diana; Pinto, Paula; Ayres-de-Campos, Diogo; Bernardes, João

    2017-08-21

    Male gender is considered a risk factor for several adverse perinatal outcomes. Fetal gender effect on fetal heart rate (FHR) has been subject of several studies with contradictory results. The importance of maternal heart rate (MHR) monitoring during labor has also been investigated, but less is known about the effect of fetal gender on MHR. The aim of this study is to simultaneously assess maternal and FHR variability during labor in relation with fetal gender. Simultaneous MHR and FHR recordings were obtained from 44 singleton term pregnancies during the last 2 hr of labor (H1, H2 ). Heart rate tracings were analyzed using linear (time- and frequency-domain) and nonlinear indices. Both linear and nonlinear components were considered in assessing FHR and MHR interaction, including cross-sample entropy (cross-SampEn). Mothers carrying male fetuses (n = 22) had significantly higher values for linear indices related with MHR average and variability and sympatho-vagal balance, while the opposite occurred in the high-frequency component and most nonlinear indices. Significant differences in FHR were only observed in H1 with higher entropy values in female fetuses. Assessing the differences between FHR and MHR, statistically significant differences were obtained in most nonlinear indices between genders. A significantly higher cross-SampEn was observed in mothers carrying female fetuses (n = 22), denoting lower synchrony or similarity between MHR and FHR. The variability of MHR and the synchrony/similarity between MHR and FHR vary with respect to fetal gender during labor. These findings suggest that fetal gender needs to be taken into account when simultaneously monitoring MHR and FHR. © 2017 Wiley Periodicals, Inc.

  9. Age-Related Differences of Organism-Specific Peritonitis Rates: A Single-Center Experience.

    PubMed

    Kotera, Nagaaki; Tanaka, Mototsugu; Aoe, Mari; Chikamori, Masatomo; Honda, Tomoko; Ikenouchi, Ayako; Miura, Rika; Sugahara, Mai; Furuse, Satoshi; Saito, Katsunori; Mise, Naobumi

    2016-12-01

    Peritonitis remains an important cause of morbidity and mortality in peritoneal dialysis (PD) patients, but its incidence and the distribution of causative organisms vary widely between institutions and age groups. This study was performed to investigate the recent status and risk factors of PD-related peritonitis and to clarify differences between age groups. We retrospectively reviewed the medical records of 119 PD patients treated at our department between January 2002 and January 2013. We calculated both overall and organism-specific peritonitis rates and also analyzed risk factors. Sixty-three episodes of peritonitis occurred during 261.5 patient-years for an incident rate of 0.24 episodes/patient-year. Multivariate analysis showed that older age (≥65 years) and hypoalbuminemia (<3.0 g/dL) were associated with an increased risk of peritonitis (P = 0.035 and P = 0.029, respectively). In elderly patients (≥65 years old), the rate of peritonitis due to Gram-positive and Gram-negative bacteria was 0.17 and 0.08 episodes/patient-year, respectively, and Gram-positive peritonitis was markedly more frequent than in younger patients (<65 years old). In particular, there was a high frequency of Staphylococcus aureus peritonitis in elderly patients (0.09 episodes/patient-year) and it had a poor outcome. At our department, the risk of peritonitis was increased in older patients and patients with hypoalbuminemia. The distribution of causative organisms was markedly different between age groups and analysis of organism-specific peritonitis rates helped to identify current problems with our PD program.

  10. Exploring the Role of Galaxy Morphology in the Mass-Metallicity-Star Formation Rate Relation

    NASA Astrophysics Data System (ADS)

    Pahl, Anthony; Rafelski, Marc; Scarlata, Claudia; Pacifici, Camilla; Henry, Alaina L.; Gardner, Jonathan P.; Elmegreen, Debra M.

    2017-01-01

    The Mass-Metallicity-Star Formation Rate (M-Z-SFR) fundamental relation reveals the underlying physics behind galaxy evolution: the mechanics of gas inflow, outflow, and the formation of stars are intimately connected. At higher redshift, we observe galaxies which are believed to be more actively accreting from the cosmic web, and as a result bright star-forming clumps are expected to form due to the increased gravitational instability of the galactic medium. We investigate these “clumpy” galaxies in context of their location on the M-Z-SFR plane to search for evidence of metal-poor gas inflows as predicted by theoretical models, and to help us understand how galaxies form and change at a higher redshift (1.3 < z < 2.2). We use the CANDELS survey to examine the morphological structure of star forming regions utilizing the high resolution of space-based HST imaging. We create stamps in their rest-frame UV light to investigate recent star formation and visually classify the morphology of the galaxies. We also utilize stellar population fits of the photometric data to determine properties such as mass and star formation rate. From the grism data of the 3D-HST survey, we select 1861 galaxies based on the strong detection of the [OIII_5007] line, and determine metallicity through the line-diagnostic R_23 using [OIII_5007], [OII_3727] and H_beta. We improve these results through the stacking of spectra to remove a sample bias of requiring strong detections on weak emission lines. Using mass, star formation rate, and metallicity we compare the location of clumpy galaxies on the fundamental plane to investigate possible diminished metallicity and heightened star formation rate compared to the remainder of the sample. This will enable us to better understand the theoretical underpinnings of gas accretion and galaxy evolution at high redshift.

  11. Relating Spontaneously Reported Extrapyramidal Adverse Events to Movement Disorder Rating Scales.

    PubMed

    Widschwendter, Christian G; Karayal, Onur N; Kolluri, Sheela; Vanderburg, Douglas; Kemmler, Georg; Fleischhacker, W Wolfgang

    2015-06-26

    While antipsychotic-induced extrapyramidal symptoms (EPS) and akathisia remain important concerns in the treatment of patients with schizophrenia, the relationship between movement disorder rating scales and spontaneously reported EPS-related adverse events (EPS-AEs) remains unexplored. Data from four randomized, placebo- and haloperidol-controlled ziprasidone trials were analyzed to examine the relationship between spontaneously reported EPS-AEs with the Simpson Angus Scale (SAS) and Barnes Akathisia Rating Scale (BARS). Categorical summaries were created for each treatment group to show the frequencies of subjects with EPS-AEs in each of the SAS and BARS categories at weeks 1, 3, and 6, and agreement between ratings was quantified by means of weighted kappa (κ). In general, we found greater frequencies of EPS-AEs with increasing severity of the SAS and BARS scores. The EPS-AEs reported with a "none" SAS score ranged from 0 to 22.2%, with a "mild" SAS score from 3.3 to 29.0%, and with a "moderate" SAS score from 0 to 100%. No subjects in any treatment group reported "severe" SAS scores or corresponding EPS-AEs. Agreement between SAS scores and EPS-AEs was poor for ziprasidone and placebo (κ < 0.2) and only slightly better for haloperidol. The EPS-AEs reported with "non questionable" BARS scores ranged from 1.9 to 9.8%, with "mild moderate" BARS scores from 12.8 to 54.6%, and with "marked severe" scores from 0 to 100%. Agreement was modest for ziprasidone and placebo (κ < 0.4) and moderate for haloperidol (κ < 0.6). These findings may reflect either underreporting of AEs by investigators and subjects or erroneous rating scale evaluations. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  12. Subjective rating of weak tactile stimuli is parametrically encoded in event-related potentials.

    PubMed

    Auksztulewicz, Ryszard; Blankenburg, Felix

    2013-07-17

    Neural signatures of somatosensory awareness have often been studied by examining EEG responses to hardly detectable stimuli. Previous reports consistently showed that event-related potentials (ERPs) measured over early somatosensory cortex diverge for detected and missed perithreshold stimuli at 80-100 ms after stimulus onset. So far, however, all previous studies have operationalized somatosensory awareness as binary stimulus detection. Here, we investigated whether ERP components attributed to neuronal activity in early somatosensory cortices would parametrically reflect subjective ratings of stimulus awareness. EEG (64 channel) was recorded in human participants (N = 20), with perithreshold electrical stimulation applied to the left median nerve. Participants indicated perceptibility on a continuous visual rating scale, and stimulation intensity was readjusted in each block to a perithreshold level. The aim of the analysis was to investigate which brain areas reflect the subsequent perceptual awareness ratings parametrically, and how early such parametric effects occur. Parametric ERP effects were found as early as 86 ms after stimulus onset. This parametric modulation of ERP amplitude was source localized to secondary somatosensory cortex, and attributed to feedforward processing between primary and secondary somatosensory cortex by means of dynamic causal modeling (DCM). Furthermore, later in the analysis window, the subjective rating of stimuli correlated with the amplitude of the N140 component and with a broadly distributed P300 component. By DCM modeling, these late effects were explained in terms of recurrent processing within the network of somatosensory and premotor cortices. Our results indicate that early neural activity in the somatosensory cortex can reflect the subjective quality of tactile perception.

  13. The influence of herbivory and weather on the vital rates of two closely related cactus species.

    PubMed

    Sauby, Kristen E; Kilmer, John; Christman, Mary C; Holt, Robert D; Marsico, Travis D

    2017-09-01

    Herbivory has long been recognized as a significant driver of plant population dynamics, yet its effects along environmental gradients are unclear. Understanding how weather modulates plant-insect interactions can be particularly important for predicting the consequences of exotic insect invasions, and an explicit consideration of weather may help explain why the impact can vary greatly across space and time. We surveyed two native prickly pear cactus species (genus Opuntia) in the Florida panhandle, USA, and their specialist insect herbivores (the invasive South American cactus moth, Cactoblastis cactorum, and three native insect species) for five years across six sites. We used generalized linear mixed models to assess the impact of herbivory and weather on plant relative growth rate (RGR) and sexual reproduction, and we used Fisher's exact test to estimate the impact of herbivory on survival. Weather variables (precipitation and temperature) were consistently significant predictors of vital rate variation for both cactus species, in contrast to the limited and varied impacts of insect herbivory. Weather only significantly influenced the impact of herbivory on Opuntia humifusa fruit production. The relationships of RGR and fruit production with precipitation suggest that precipitation serves as a cue in determining the trade-off in the allocation of resources to growth or fruit production. The presence of the native bug explained vital rate variation for both cactus species, whereas the invasive moth explained variation only for O. stricta. Despite the inconsistent effect of herbivory across vital rates and cactus species, almost half of O. stricta plants declined in size, and the invasive insect negatively affected RGR and fruit production. Given that fruit production was strongly size-dependent, this suggests that O. stricta populations at the locations surveyed are transitioning to a size distribution of predominantly smaller sizes and with reduced sexual

  14. Medication-related problem type and appearance rate in ambulatory hemodialysis patients

    PubMed Central

    Manley, Harold J; Drayer, Debra K; Muther, Richard S

    2003-01-01

    Background Hemodialysis (HD) patients are at risk for medication-related problems (MRP). The MRP number, type, and appearance rate over time in ambulatory HD patients has not been investigated. Methods Randomly selected HD patients were enrolled to receive monthly pharmaceutical care visits. At each visit, MRP were identified through review of the patient chart, electronic medical record, patient interview, and communications with other healthcare disciplines. All MRP were categorized by type and medication class. MRP appearance rate was determined as the number of MRP identified per month/number of months in study. The number of MRP per patient-drug exposures were determined using: {[(number of patients) × (mean number of medications)]/(number of months of study)} /number of MRP identified. Results were expressed as mean ± standard deviation or percentages. Results Patients were 62.6 ± 15.9 years old, had 6.4 ± 2.0 comorbid conditions, were taking 12.5 ± 4.2 medications, and 15.7 ± 7.2 doses per day at baseline. Medication-dosing problems (33.5%), adverse drug reactions (20.7%), and an indication that was not currently being treated (13.5%) were the most common MRP. 5,373 medication orders were reviewed and a MRP was identified every 15.2 medication exposures. Overall MRP appearance rate was 0.68 ± 0.46 per patient per month. Conclusion MRP continue to occur at a high rate in ambulatory HD patients. Healthcare providers taking care of HD patients should be aware of this problem and efforts to avoid or resolve MRP should be undertaken at all HD clinics. PMID:14690549

  15. Turnover rate of cerebrospinal fluid in female sheep: changes related to different light-dark cycles.

    PubMed

    Thiéry, Jean-Claude; Lomet, Didier; Bougoin, Sylvain; Malpaux, Benoit

    2009-08-04

    Sheep are seasonal breeders. The key factor governing seasonal changes in the reproductive activity of the ewe is increased negative feedback of estradiol at the level of the hypothalamus under long-day conditions. It has previously been demonstrated that when gonadotropin secretions are inhibited during long days, there is a higher concentration of estradiol in the cerebrospinal fluid (CSF) than during short days. This suggests an involvement of the CSF and choroid plexus in the neuroendocrine regulatory loop, but the mechanisms underlying this phenomenon remain unknown. One possible explanation of this difference in hormonal content is an effect of concentration or dilution caused by variations in CSF secretion rate. The aim of this study was thus to investigate changes in the CSF turnover rate related to light-dark cycles. The turnover rate of the CSF was estimated by measuring the time taken for the recovery of intraventricular pressure (IVP) after removal of a moderate volume (0.5 to 2 ml) of CSF (slope in mmHg/min). The turnover rate was estimated three times in the same group of sheep: during a natural period of decreasing day-length corresponding to the initial period when gonadotropin activity is stimulated (SG1), during a long-day inhibitory period (IG), and finally during a short-day stimulatory period (SG2). The time taken and the speed of recovery of initial IVP differed between groups: 8 min 30 sec, 0.63 +/- 0.07 mmHg/min(SG1), 11 min 1 sec, 0.38 +/- 0.06 mmHg/min (IG) and 9 min 0 sec, 0.72 +/- 0.15 mmHg/min (SG2). Time changes of IVP differed between groups (ANOVA, p < 0.005, SG1 different from IG, p < 0.05). The turnover rate in SG2: 183.16 +/- 23.82 mul/min was not significantly different from SG1: 169. 23 +/- 51.58 mul/min (Mann-Whitney test, p = 0.41), but was significantly different from IG: 71.33 +/- 16.59 mul/min (p = 0.016). This study shows that the turnover rate of CSF in ewes changes according to the light-dark cycle; it is increased

  16. Controlling the relative rates of adlayer formation and removal during etching in inductively coupled plasmas

    NASA Astrophysics Data System (ADS)

    Fuller, Nicholas Colvin Masi

    Laser desorption (LD) of the adlayer coupled with laser induced fluorescence (LIF) and plasma induced emission (PIE) of desorbed adsorbates is used to investigate the relative rates of chlorination and sputtering during the etching of Si in inductively coupled Cl2-Ar plasmas. Such an analysis is a two-fold process: surface analysis and plasma characterization. Surface analysis of Si etching using LD-LIF and LD-PIE techniques combined with etch rate measurements have revealed that the coverage of SiCl2 and etch rate increases and coverage of Si decreases abruptly for a chlorine fraction of 75% and ion energy of 80 eV. The precise Cl2 fraction for which these abrupt changes occur increases with an increase in ion energy. These changes may be caused by local chemisorption-induced reconstruction of Si <100>. Furthermore, the chlorination and sputtering rates are increased by ˜ an order of magnitude as the plasma is changed from Ar-dominant to Cl-dominant. Characterization of the plasma included determination of the dominant ion in Cl2 plasmas using LIF and a Langmuir probe and measurement of the absolute densities of Cl2, Cl, Cl+, and At + in Cl2-Ar discharges using optical emission actinometry. These studies reveal that Cl+ is the dominant positive ion in the H-mode and the dissociation of Cl2 to Cl increases with an increase in Ar fraction due to an increase in electron temperature. Furthermore, for powers exceeding 600 W, the neutral to ion flux ratio is strongly dependent on Cl2 fraction and is attributed mostly to the decrease in Cl density. Such dependence of the flux ratio on Cl2 fraction is significant in controlling chlorination and sputtering rates not only for Si etching, but for etching other key technological materials. ICP O2 discharges were also studied for low-kappa polymeric etch applications. These studies reveal that the electron temperature is weakly dependent on rf power and O2 dissociation is low (˜2%) at the maximum rf power density of 5.7 Wcm

  17. Relative growth rate variation of evergreen and deciduous savanna tree species is driven by different traits

    PubMed Central

    Tomlinson, Kyle W.; Poorter, Lourens; Bongers, Frans; Borghetti, Fabian; Jacobs, Loes; van Langevelde, Frank

    2014-01-01

    Background and Aims Plant relative growth rate (RGR) depends on biomass allocation to leaves (leaf mass fraction, LMF), efficient construction of leaf surface area (specific leaf area, SLA) and biomass growth per unit leaf area (net assimilation rate, NAR). Functional groups of species may differ in any of these traits, potentially resulting in (1) differences in mean RGR of groups, and (2) differences in the traits driving RGR variation within each group. We tested these predictions by comparing deciduous and evergreen savanna trees. Methods RGR, changes to biomass allocation and leaf morphology, and root non-structural carbohydrate reserves were evaluated for juveniles of 51 savanna species (34 deciduous, 17 evergreen) grown in a common garden experiment. It was anticipated that drivers of RGR would differ between leaf habit groups because deciduous species have to allocate carbohydrates to storage in roots to be able to flush leaves again, which directly compromises their LMF, whereas evergreen species are not subject to this constraint. Key Results Evergreen species had greater LMF and RGR than deciduous species. Among deciduous species LMF explained 27 % of RGR variation (SLA 34 % and NAR 29 %), whereas among evergreen species LMF explained between 2 and 17 % of RGR variation (SLA 32–35 % and NAR 38–62 %). RGR and LMF were (negatively) related to carbohydrate storage only among deciduous species. Conclusions Trade-offs between investment in carbohydrate reserves and growth occurred only among deciduous species, leading to differences in relative contribution made by the underlying components of RGR between the leaf habit groups. The results suggest that differences in drivers of RGR occur among savanna species because these have different selected strategies for coping with fire disturbance in savannas. It is expected that variation in the drivers of RGR will be found in other functional types that respond differently to particular disturbances. PMID

  18. On the Mass-Metallicity-Star Formation Rate Relation for Galaxies at z˜2

    NASA Astrophysics Data System (ADS)

    Salim, Samir; Lee, Janice C.; Davé, Romeel; Dickinson, Mark

    2015-07-01

    Recent studies have shown that the local mass-metallicity (M*-Z) relation depends on the specific star formation rate (sSFR). Whether such a dependence exists at higher redshifts, and whether the resulting M*-Z-SFR relation is redshift invariant, is debated. We re-examine these issues by applying the non-parametric techniques of Salim et al. to ˜130 z˜ 2.3 galaxies with N2 and O3 measurements from Keck Baryonic Structure Survey (KBSS). We find that the KBSS M*-Z relation depends on sSFR at intermediate masses where such dependence exists locally. KBSS and SDSS galaxies of the same mass and sSFR (“local analogs”) are similarly offset in the BPT diagram relative to the bulk of local star-forming galaxies, and thus we posit that metallicities can be compared self-consistently at different redshifts as long as the masses and sSFRs of the galaxies are similar. We find that the M*-Z-SFR relation of z˜ 2 galaxies is consistent with the local one at {log}{M}*\\lt 10, but is offset up to -0.25 dex at higher masses, so it is altogether not redshift invariant. This high-mass offset could arise from a bias that [O iii]-based, high-redshift spectroscopic surveys have against high-metallicity galaxies, but additional evidence disfavors this possibility. We identify three causes for the reported discrepancy between N2 and O3N2 metallicities at z˜ 2: (1) a smaller offset that is also present for SDSS galaxies, which we remove with new N2 calibration, (2) a genuine offset due to differing ISM condition, which is also present in local analogs, and (3) an additional offset due to unrecognized active galactic nucleus contamination.

  19. Rates and relative risk of hospital admission among women in violent intimate partner relationships.

    PubMed Central

    Kernic, M A; Wolf, M E; Holt, V L

    2000-01-01

    OBJECTIVES: This study assessed the history of hospitalization among women involved in violent intimate relationships. METHODS: In this 1-year retrospective cohort study, female residents of King County, Washington, who were aged 18 to 44 years and who had filed for a protection order were compared with nonabused women in the same age group. Outcome measures included overall and diagnosis-specific hospital admission rates and relative risk of hospitalization associated with abuse. RESULTS: Women known to be exposed to a violent intimate relationship were significantly more likely to be hospitalized with any diagnosis (age-specific relative risks [RRs] ranging from 1.2 to 2.1), psychiatric diagnoses (RR = 3.6, 95% confidence interval [CI] = 2.8, 4.6), injury and poisoning diagnoses (RR = 1.8, 95% CI = 1.2, 2.8), digestive system diseases (RR = 1.9, 95% CI = 1.3, 2.9), and diagnoses of assault (RR = 4.9, 95% CI = 1.1, 22.1) or attempted suicide (RR = 3.7, 95% CI = 1.6, 9.2) in the year before filing a protection order. CONCLUSIONS: This study showed an increased relative risk of both overall and diagnosis-specific hospitalizations among abused women. Intimate partner violence has a significant impact on women's health and use of health care. PMID:10983199

  20. Relative rate constants for the reactions of atomic oxygen with HO2 anad OH radicals

    NASA Technical Reports Server (NTRS)

    Keyser, L. F.

    1983-01-01

    Relative rate constants for the reactions O + HO2 - OH + O2 (1) and O + OH - H + O2 (2) were obtained by using the discharge-flow resonance fluorescence technique at 2 torr total pressure and 299 K. HO2 radicals were generated by reacting atomic hydrogen with an excess of O2. Quasi-steady-state concentrations of OH and HO2 were established in the presence of excess atomic oxygen. Observed concentration ratios, namely the ratio of the OH concentration to the HO2 concentration, resulted in a value of 1.7 + or 0.2 for k1/k2. The error limits are twice the standard deviation obtained from the data analysis. Overall experimental error is estimated to be + or - 25 percent. This result confirms earlier direct measurements of k1 and k2 which required knowledge of absolute radical or atomic oxygen concentrations.

  1. Relative rates of nitric oxide and nitrous oxide production by nitrifiers, denitrifiers, and nitrate respirers

    NASA Technical Reports Server (NTRS)

    Anderson, I. C.; Levine, J. S.

    1986-01-01

    An account is given of the atmospheric chemical and photochemical effects of biogenic nitric and nitrous oxide emissions. The magnitude of the biogenic emission of NO is noted to remain uncertain. Possible soil sources of NO and N2O encompass nitrification by autotropic and heterotropic nitrifiers, denitrification by nitrifiers and denitrifiers, nitrate respiration by fermenters, and chemodenitrification. Oxygen availability is the primary determinant of these organisms' relative rates of activity. The characteristics of this major influence are presently investigated in light of the effect of oxygen partial pressure on NO and N2O production by a wide variety of common soil-nitrifying, denitrifying, and nitrate-respiring bacteria under laboratory conditions. The results obtained indicate that aerobic soils are primary sources only when there is sufficient moisture to furnish anaerobic microsites for denitrification.

  2. Vertex evoked potentials in a rating-scale detection task: Relation to signal probability

    NASA Technical Reports Server (NTRS)

    Squires, K. C.; Squires, N. K.; Hillyard, S. A.

    1974-01-01

    Vertex evoked potentials were recorded from human subjects performing in an auditory detection task with rating scale responses. Three values of a priori probability of signal presentation were tested. The amplitudes of the N1 and P3 components of the vertex potential associated with correct detections of the signal were found to be systematically related to the strictness of the response criterion and independent of variations in a priori signal probability. No similar evoked potential components were found associated with signal absent judgements (misses and correct rejections) regardless of the confidence level of the judgement or signal probability. These results strongly support the contention that the form of the vertex evoked response is closely correlated with the subject's psychophysical decision regarding the presence or absence of a threshold level signal.

  3. Relative rates of nitric oxide and nitrous oxide production by nitrifiers, denitrifiers, and nitrate respirers

    NASA Technical Reports Server (NTRS)

    Anderson, I. C.; Levine, J. S.

    1986-01-01

    An account is given of the atmospheric chemical and photochemical effects of biogenic nitric and nitrous oxide emissions. The magnitude of the biogenic emission of NO is noted to remain uncertain. Possible soil sources of NO and N2O encompass nitrification by autotropic and heterotropic nitrifiers, denitrification by nitrifiers and denitrifiers, nitrate respiration by fermenters, and chemodenitrification. Oxygen availability is the primary determinant of these organisms' relative rates of activity. The characteristics of this major influence are presently investigated in light of the effect of oxygen partial pressure on NO and N2O production by a wide variety of common soil-nitrifying, denitrifying, and nitrate-respiring bacteria under laboratory conditions. The results obtained indicate that aerobic soils are primary sources only when there is sufficient moisture to furnish anaerobic microsites for denitrification.

  4. Possible relations between general population suicide rates and societal crime: a cross-national study.

    PubMed

    Shah, Ajit; Bhandarkar, Ritesh

    2008-10-01

    Crime may be associated with a less structured society, less social integration, and feelings of less security and greater distress among citizens, which characteristics may lead to mental illness and subsequent suicide. Therefore, a cross-national analysis examining the association of general population suicide rates with percent of males and females in the population victimised by different categories of crime was undertaken using cross-national data from the World Health Organization and United Nations for 42 countries. Spearman correlations were generally weak and not statistically significant. Those values were at variance with the study's hypothesis and may be explained by several factors, including methodological issues. Individual-level case-control or cohort studies of suicides and attempted suicides in the general population may permit exploration of the relation of general population suicides with experience and percent by nations of being victimised by crime.

  5. Breastfeeding rates and factors related to cessation in a military population.

    PubMed

    Bales, Karrn; Washburn, John; Bales, James

    2012-12-01

    Evidence continues to accumulate showing the benefits of breastfeeding to infants, mothers, and society as a whole. However, breastfeeding success rates nationwide have consistently fallen short of recommendations set forth by the American Academy of Pediatrics. There are several potential barriers to successful breastfeeding, and many of these could be magnified in the demanding careers of military members and their families. We surveyed 254 women at a regional military medical facility, both active duty members and dependents of active duty members, regarding their ability to successfully breastfeed their infants. We found that American Academy of Pediatrics target goals in this population as a whole were indeed nearly met at this facility, but also found that active duty members and those who encountered military-related difficulty fell well short of these goals. These findings suggest potential barriers to breastfeeding success that warrant further study from the U.S. Department of Defense.

  6. Rate of increase of collaboration in chemical physics and related fields

    NASA Astrophysics Data System (ADS)

    Memory, Jasper D.; Lane, Heather M.

    2002-10-01

    As an extension of earlier work on this subject, the rate of increase of collaboration in chemical physics and related fields is estimated by determining the mean number of authors per article in leading journals as a function of time. Those means for the first one hundred articles of the year were determined for the period 1960-2000 in five-year intervals for the Journal of Chemical Physics, the Journal of the American Chemical Society, and the Journal of the American Institute of Chemical Engineers. The results were analyzed by linear regression, and gave increases, in authors per decade, of 0.3, 0.5, and 0.2, with r values of 0.96, 0.97, and 0.94, respectively (p < 0.0001 in each case). Implications for the hypothesis of "critical mass" of research groups are noted.

  7. Relative rate constants for the reactions of atomic oxygen with HO2 anad OH radicals

    NASA Technical Reports Server (NTRS)

    Keyser, L. F.

    1983-01-01

    Relative rate constants for the reactions O + HO2 - OH + O2 (1) and O + OH - H + O2 (2) were obtained by using the discharge-flow resonance fluorescence technique at 2 torr total pressure and 299 K. HO2 radicals were generated by reacting atomic hydrogen with an excess of O2. Quasi-steady-state concentrations of OH and HO2 were established in the presence of excess atomic oxygen. Observed concentration ratios, namely the ratio of the OH concentration to the HO2 concentration, resulted in a value of 1.7 + or 0.2 for k1/k2. The error limits are twice the standard deviation obtained from the data analysis. Overall experimental error is estimated to be + or - 25 percent. This result confirms earlier direct measurements of k1 and k2 which required knowledge of absolute radical or atomic oxygen concentrations.

  8. Tide-related biological rhythm in the oxygen consumption rate of ghost shrimp (Neotrypaea uncinata).

    PubMed

    Leiva, Félix P; Niklitschek, Edwin J; Paschke, Kurt; Gebauer, Paulina; Urbina, Mauricio A

    2016-07-01

    The effects of tidal height (high and low), acclimation to laboratory conditions (days in captivity) and oxygen level (hypoxia and normoxia) were evaluated in the oxygen consumption rate (OCR) of the ghost shrimp Neotrypaea uncinata We evaluated the hypothesis that N. uncinata reduces its OCR during low tide and increases it during high tide, regardless of oxygen level or acclimation. Additionally, the existence of an endogenous rhythm in OCR was explored, and we examined whether it synchronized with tidal, diurnal or semidiurnal cycles. Unexpectedly, high OCRs were observed at low tide, during normoxia, in non-acclimated animals. Results from a second, longer experiment under normoxic conditions suggested the presence of a tide-related metabolic rhythm, a response pattern not yet demonstrated for a burrowing decapod. Although rhythms persisted for only 2 days after capture, their period of 12.8 h closely matched the semidiurnal tidal cycle that ghost shrimp confront inside their burrows.

  9. Relating Complexity and Error Rates of Ontology Concepts. More Complex NCIt Concepts Have More Errors.

    PubMed

    Min, Hua; Zheng, Ling; Perl, Yehoshua; Halper, Michael; De Coronado, Sherri; Ochs, Christopher

    2017-05-18

    Ontologies are knowledge structures that lend support to many health-information systems. A study is carried out to assess the quality of ontological concepts based on a measure of their complexity. The results show a relation between complexity of concepts and error rates of concepts. A measure of lateral complexity defined as the number of exhibited role types is used to distinguish between more complex and simpler concepts. Using a framework called an area taxonomy, a kind of abstraction network that summarizes the structural organization of an ontology, concepts are divided into two groups along these lines. Various concepts from each group are then subjected to a two-phase QA analysis to uncover and verify errors and inconsistencies in their modeling. A hierarchy of the National Cancer Institute thesaurus (NCIt) is used as our test-bed. A hypothesis pertaining to the expected error rates of the complex and simple concepts is tested. Our study was done on the NCIt's Biological Process hierarchy. Various errors, including missing roles, incorrect role targets, and incorrectly assigned roles, were discovered and verified in the two phases of our QA analysis. The overall findings confirmed our hypothesis by showing a statistically significant difference between the amounts of errors exhibited by more laterally complex concepts vis-à-vis simpler concepts. QA is an essential part of any ontology's maintenance regimen. In this paper, we reported on the results of a QA study targeting two groups of ontology concepts distinguished by their level of complexity, defined in terms of the number of exhibited role types. The study was carried out on a major component of an important ontology, the NCIt. The findings suggest that more complex concepts tend to have a higher error rate than simpler concepts. These findings can be utilized to guide ongoing efforts in ontology QA.

  10. Application of the relative wavelet energy to heart rate independent detection of atrial fibrillation.

    PubMed

    García, Manuel; Ródenas, Juan; Alcaraz, Raúl; Rieta, José J

    2016-07-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a growing healthcare burden worldwide. It is often asymptomatic and may appear as episodes of very short duration; hence, the development of methods for its automatic detection is a challenging requirement to achieve early diagnosis and treatment strategies. The present work introduces a novel method exploiting the relative wavelet energy (RWE) to automatically detect AF episodes of a wide variety in length. The proposed method analyzes the atrial activity of the surface electrocardiogram (ECG), i.e., the TQ interval, thus being independent on the ventricular activity. To improve its performance under noisy recordings, signal averaging techniques were applied. The method's performance has been tested with synthesized recordings under different AF variable conditions, such as the heart rate, its variability, the atrial activity amplitude or the presence of noise. Next, the method was tested with real ECG recordings. Results proved that the RWE provided a robust automatic detection of AF under wide ranges of heart rates, atrial activity amplitudes as well as noisy recordings. Moreover, the method's detection delay proved to be shorter than most of previous works. A trade-off between detection delay and noise robustness was reached by averaging 15 TQ intervals. Under these conditions, AF was detected in less than 7 beats, with an accuracy higher than 90%, which is comparable to previous works. Unlike most of previous works, which were mainly based on quantifying the irregular ventricular response during AF, the proposed metric presents two major advantages. First, it can perform successfully even under heart rates with no variability. Second, it consists of a single metric, thus turning its clinical interpretation and real-time implementation easier than previous methods requiring combined indices under complex classifiers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Calibrating the Decline Rate - Peak Luminosity Relation for Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Rust, Bert W.; Pruzhinskaya, Maria V.; Thijsse, Barend J.

    2015-08-01

    The correlation between peak luminosity and rate of decline in luminosity for Type I supernovae was first studied by B. W. Rust [Ph.D. thesis, Univ. of Illinois (1974) ORNL-4953] and Yu. P. Pskovskii [Sov. Astron., 21 (1977) 675] in the 1970s. Their work was little-noted until Phillips rediscovered the correlation in 1993 [ApJ, 413 (1993) L105] and attempted to derive a calibration relation using a difference quotient approximation Δm15(B) to the decline rate after peak luminosity Mmax(B). Numerical differentiation of data containing measuring errors is a notoriously unstable calculation, but Δm15(B) remains the parameter of choice for most calibration methods developed since 1993. To succeed, it should be computed from good functional fits to the lightcurves, but most workers never exhibit their fits. In the few instances where they have, the fits are not very good. Some of the 9 supernovae in the Phillips study required extinction corrections in their estimates of the Mmax(B), and so were not appropriate for establishing a calibration relation. Although the relative uncertainties in his Δm15(B) estimates were comparable to those in his Mmax(B) estimates, he nevertheless used simple linear regression of the latter on the former, rather than major-axis regression (total least squares) which would have been more appropriate.Here we determine some new calibration relations using a sample of nearby "pure" supernovae suggested by M. V. Pruzhinskaya [Astron. Lett., 37 (2011) 663]. Their parent galaxies are all in the NED collection, with good distance estimates obtained by several different methods. We fit each lightcurve with an optimal regression spline obtained by B. J. Thijsse's spline2 [Comp. in Sci. & Eng., 10 (2008) 49]. The fits, which explain more that 99% of the variance in each case, are better than anything heretofore obtained by stretching "template" lightcurves or fitting combinations of standard lightcurves. We use the fits to compute estimates of

  12. Longevity, growth rate and related traits among strains of Tribolium castaneum.

    PubMed

    Soliman, M H; Lints, F A

    1975-01-01

    Longevity of eight laboratory strains of the flour beetle Tribolium castaneum, with various geographic backgrounds, was studied under constant laboratory conditions of 33 degrees C and 70% relative humidity in standard medium (95% whole wheat flour and 5% dried yeast) during a period of 227 days starting from the egg stage. The eggs were collected from the same parents, first a few days after emergence and afterwards at intervals of 13, 9, 10 and 11 days. Mean survival time (MST) was found to be strain-specified. It ranges from 128.6 days for KJ (Kyoto, Japan) to 174.2 days for ES (Edinburgh, Scotland). MST was highly correlated with the percentage of adults alive after 227 days, which did not change the ranking order of strain longevity. Parental age had no effect on longevity. The mean adult longevity of the strains was correlated with the available data on adult weight, growth rate, viability and productivity. There was no relationship between adult weight and longevity. LIfe span was found to depend on growth rate (measured as 13-day larval weight), percent viability (from 13-day larvae to adulthood) and productivity. Developmental time was also found to influence adult life span within certain limits (two extreme strains deviated). The data suggest that ageing and death in T. castaneum is under genetic control and support the idea that ageing, allied to development, is genetically controlled.

  13. Varying relative degradation rates of oil in different forms and environments revealed by ramped pyrolysis.

    PubMed

    Pendergraft, Matthew A; Rosenheim, Brad E

    2014-09-16

    Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon ((13)C) and radiocarbon ((14)C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil.

  14. A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise.

    PubMed

    Anselmino, Matteo; Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2017-01-01

    Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model. The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task-MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR-SHR-simulations, and 100 bpm for the higher resting HR-HHR-simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)-the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations-was calculated at each exercise grade (VCI4, VCI6 and VCI8). Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56). The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase.

  15. HIV in the Leather Community: Rates and Risk-Related Behaviors

    PubMed Central

    Moskowitz, David A.; Seal, David W.; Rintamaki, Lance; Rieger, Gerulf

    2014-01-01

    There exist many subcultures of men who have sex with men (MSM), all with differing values and health behaviors. The Leathermen comprise one such subculture, which is characterized by a heightened valuation of hypersexuality and adherence to sexual control dynamics (i.e., submission and dominance). No previous research has specifically examined this community for differences in sexual health (e.g., HIV rates) and sexual health behaviors (e.g., condom use). We conducted a large survey of men (N = 1,554) at one leather and non-leather event, collecting data from 655 Submissives, Dominants, Switches, and non-orienting Leathermen. Leathermen were 61% more likely to be HIV-positive than non-Leathermen. Decreased condom use found in HIV-positive Leathermen (relative to HIV-positive non-Leathermen) was a potential factor contributing to heightened HIV rates. Universal low condom use in Submissives engaging in receptive, and Dominants engaging in insertive, anal intercourse was an additional trend that potentially contributed to increased numbers of HIV-positive Leathermen. Our recommendation is for heightened awareness of the risks associated with sex among Leathermen, especially unprotected anal intercourse with sero-uncertain Submissives. PMID:19904599

  16. Does seed mass drive the differences in relative growth rate between growth forms?

    PubMed

    Houghton, Jennie; Thompson, Ken; Rees, Mark

    2013-07-07

    The idea that herbaceous plants have higher relative growth rates (RGRs) compared with woody plants is fundamental to many of the most influential theories in plant ecology. This difference in growth rate is thought to reflect systematic variation in physiology, allocation and leaf construction. Previous studies documenting this effect have, however, ignored differences in seed mass. As woody species often have larger seeds and RGR is negatively correlated with seed mass, it is entirely possible the lower RGRs observed in woody species is a consequence of having larger seeds rather than different growth strategies. Using a synthesis of the published literature, we explored the relationship between RGR and growth form, accounting for the effects of seed mass and study-specific effects (e.g. duration of study and pot volume), using a mixed-effects model. The model showed that herbaceous species do indeed have higher RGRs than woody species, and that the difference was independent of seed mass, thus at all seed masses, herbaceous species on average grow faster than woody ones.

  17. Water relations and leaf growth rate of three Agropyron genotypes under water stress.

    PubMed

    García, María G; Busso, Carlos A; Polci, Pablo; García Girou, Norberto L; Echenique, Viviana

    2002-12-01

    The effects of water stress on leaf water relations and growth are reported for three perennial tussock grass genotypes under glasshouse conditions. Studies were performed in genotypes El Palmar INTA and Selección Anguil of Agropyron scabrifolium (Döell) Parodi, and El Vizcachero of A. elongatum (Host) Beauv. Agropyron scabrifolium El Palmar INTA is native to a region with warm-temperate and humid climate without a dry season, and an average annual precipitation of 900 mm. Agropyron scabrifolium Selección Anguil comes from a region with a sub-humid, dry to semiarid climate and a mean annual precipitation of 600 mm. Agropyron elongatum is a widespread forage in semiarid Argentina with well-known water stress resistance. A mild water stress treatment was imposed slowly; plants reached a minimum pre-dawn leaf water potential of about -1.83 MPa by day 21 after watering was withheld. In all genotypes, water stress led to a reduction of leaf growth. There was a tendency for a greater epicuticular wax accumulation on water-stressed plants of A. scabrifolium Selección Anguil and A. elongatum than on those of A. scabrifolium El Palmar INTA. This may have contributed to obtain greater turgor pressures and relative water contents in the first two than in the later genotype. In turn, this may have contributed to determine smaller leaf growth rate reductions in A. scabrifolium Selección Anguil and A. elongatum than in A. scabrifolium El Palmar INTA under water stress. This study demonstrated variation in water stress resistance between genotypes in A. scabrifolium, and between A. scabrifolium Selección Anguil and A. elongatum versus A. scabrifolium El Palmar INTA, which was related to their differential responses in water relations.

  18. Low heart rate variability and cancer-related fatigue in breast cancer survivors.

    PubMed

    Crosswell, Alexandra D; Lockwood, Kimberly G; Ganz, Patricia A; Bower, Julienne E

    2014-07-01

    Cancer-related fatigue is a common and often long lasting symptom for many breast cancer survivors. Fatigued survivors show evidence of elevated inflammation, but the physiological mechanisms driving inflammatory activity have not been determined. Alterations in the autonomic nervous system, and particularly parasympathetic nervous system activity, are a plausible, yet understudied contributor to cancer-related fatigue. The goal of this study was to replicate one previous study showing an association between lower parasympathetic activity and higher fatigue in breast cancer survivors (Fagundes et al., 2011), and to examine whether inflammation mediates this association. Study participants were drawn from two samples and included 84 women originally diagnosed with early stage breast cancer prior to age 50. Participants completed questionnaires, provided blood samples for determination of interleukin (IL)-6 and C-reactive protein (CRP), and underwent electrocardiography (ECG) assessment for evaluation of resting heart rate variability (HRV), a measure of parasympathetic activity. Results showed that lower HRV was associated with higher fatigue (p<.05), as predicted. In bivariate analyses, HRV was also correlated with circulating concentrations of IL-6 and CRP. However, path analyses did not support inflammation as a mediator of the association between HRV and fatigue; instead, associations among these variables appeared to be driven by age and BMI. These findings identify HRV as a potential contributor to cancer-related fatigue, but suggest that inflammation does not mediate this association in younger, healthy breast cancer survivors who are several years post-treatment. The autonomic nervous system merits additional attention in research on the etiology of cancer-related fatigue. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Mechanical properties and constitutive relations for tantalum and tantalum alloys under high-rate deformation

    SciTech Connect

    Chen, S.R.; Gray, G.T. III; Bingert, S.R.

    1996-05-01

    Tantalum and its alloys have received increased interest as a model bcc metal and for defense-related applications. The stress-strain behavior of several tantalums, possessing varied compositions and manufacturing histories, and tantalum alloyed with tungsten, was investigated as a function of temperature from {minus}196 C to 1,000 C, and strain rate from 10{sup {minus}3} s{sup {minus}1} to 8,000 s{sup {minus}1}. The yield stress for all the Ta-materials was found to be sensitive to the test temperature, the impurity and solute contents; however, the strain hardening remained very similar for various ``pure`` tantalums but increased with alloying. Powder-metallurgy (P/M) tantalum with various levels of oxygen content produced via different processing paths was also investigated. Similar mechanical properties compared to conventionally processed tantalums were achieved in the P/M Ta. This data suggests that the frequently observed inhomogeneities in the mechanical behavior of tantalum inherited from conventional processes can be overcome. Constitutive relations based upon the Johnson-Cook, the Zerilli-Armstrong, and the Mechanical Threshold Stress models were evaluated for all the Ta-based materials. Parameters were also fit for these models to a tantalum-bar material. Flow stresses of a Ta bar stock subjected to a large-strain deformation of {var_epsilon} = 1.85 via multiple upset forging were obtained. The capabilities and limitations of each model for large-strain applications are examined. The deformation mechanisms controlling high-rate plasticity in tantalum are revisited.

  20. Adolescent body mass index and erythrocyte sedimentation rate in relation to colorectal cancer risk

    PubMed Central

    Kantor, Elizabeth D.; Udumyan, Ruzan; Signorello, Lisa B.; Giovannucci, Edward L.; Montgomery, Scott; Fall, Katja

    2015-01-01

    Objective Adult obesity and inflammation have been associated with risk of colorectal cancer (CRC); however, less is known about how adolescent body mass index (BMI) and inflammation, as measured by erythrocyte sedimentation rate (ESR), relate to CRC risk. We sought to evaluate these associations in a cohort of 239,658 Swedish men who underwent compulsory military enlistment examinations in late adolescence (ages 16–20 years). Design At the time of the conscription assessment (1969–1976), height and weight were measured and erythrocyte sedimentation rate was assayed. By linkage to the national cancer registry, these conscripts were followed for CRC through January 1, 2010. Over an average of 35 years of follow-up, 885 cases of CRC occurred, including 501 colon cancers and 384 rectal cancers. Cox regression was used to estimate adjusted hazard ratios (HRs) and corresponding 95% confidence intervals (95% CIs). Results Compared with normal weight (BMI: 18.5-<25kg/m2) in late adolescence, upper overweight (BMI: 27.5-<30 kg/m2) was associated with a 2.08-fold higher risk of CRC (95% CI: 1.40, 3.07) and obesity (BMI: 30+ kg/m2) was associated with a 2.38-fold higher risk of CRC (95% CI: 1.51, 3.76) (p-trend:<0.001). Male adolescents with ESR(15+ mm/hr) had a 63% higher risk of CRC (HR: 1.63; 95% CI: 1.08, 2.45) than those with low ESR (<10 mm/hr) (p-trend:0.006). Associations did not significantly differ by anatomic site. Conclusion Late-adolescent BMI and inflammation, as measured by ESR, may be independently associated with future CRC risk. Further research is needed to better understand how early-life exposures relate to CRC. PMID:25986947

  1. Intolerance of uncertainty and startle potentiation in relation to different threat reinforcement rates.

    PubMed

    Chin, Brian; Nelson, Brady D; Jackson, Felicia; Hajcak, Greg

    2016-01-01

    Fear conditioning research on threat predictability has primarily examined the impact of temporal (i.e., timing) predictability on the startle reflex. However, there are other key features of threat that can vary in predictability. For example, the reinforcement rate (i.e., frequency) of threat is a crucial factor underlying fear learning. The present study examined the impact of threat reinforcement rate on the startle reflex and self-reported anxiety during a fear conditioning paradigm. Forty-five participants completed a fear learning task in which the conditioned stimulus was reinforced with an electric shock to the forearm on 50% of trials in one block and 75% of trials in a second block, in counter-balanced order. The present study also examined whether intolerance of uncertainty (IU), the tendency to perceive or experience uncertainty as stressful or unpleasant, was associated with the startle reflex during conditions of low (50%) vs. high (75%) reinforcement. Results indicated that, across all participants, startle was greater during the 75% relative to the 50% reinforcement condition. IU was positively correlated with startle potentiation (i.e., increased startle response to the CS+ relative to the CS-) during the 50%, but not the 75%, reinforcement condition. Thus, despite receiving fewer electric shocks during the 50% reinforcement condition, individuals with high IU uniquely demonstrated greater defense system activation when impending threat was more uncertain. The association between IU and startle was independent of state anxiety. The present study adds to a growing literature on threat predictability and aversive responding, and suggests IU is associated with abnormal responding in the context of uncertain threat.

  2. 77 FR 73456 - Update to the TR-12 Fuel Related Rate Adjustment Policy (SDDC Fuel Surcharge Policy)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... Department of the Army Update to the TR-12 Fuel Related Rate Adjustment Policy (SDDC Fuel Surcharge Policy...: Reference: TR-12 Fuel Related Rate Adjustment Policy. Background: The following FRA policy applies to... increases in diesel fuel prices. Miscellaneous: A copy of the TR-12 FRA Policy can be accessed via the...

  3. Carcass composition, bone mechanical properties, and meat quality traits in relation to growth rate in rabbits.

    PubMed

    Gondret, F; Larzul, C; Combes, S; de Rochambeau, H

    2005-07-01

    The objective of this study was to characterize correlated responses in carcass composition, bone mechanical properties, and meat quality indicators to divergent selection for growth rate. Rabbits from low (LOW) or high (HIGH) lines divergently selected over five generations on 63-d BW and a control group (CONT) were used. Rabbits were slaughtered at an average BW of 2,306 +/- 65 g, corresponding to 63, 58, or 52 d of age in LOW (n = 41), CONT (n = 43), and HIGH (n = 44) groups, respectively. Postweaning ADG and G:F increased (P < 0.001) in the order LOW < CONT < HIGH groups. The lengths of the tibia and femur in rabbit legs decreased (P < 0.001) with increasing growth rate. Tibia and femur bone intrinsic stiffness, as assessed by a three-point flexure test, followed the order (P < 0.001) of HIGH < CONT < LOW groups. At the same BW, HIGH rabbits and CONT rabbits showed many similarities for dressing percent, carcass composition, and color and chemical composition of muscles or meat parts. In contrast, carcass yield and the relative proportion of hind part were 3% greater (P < 0.01) in LOW rabbits than in CONT and HIGH rabbits. The meat-to-bone ratio in the hind leg was 11% greater (P < 0.001) in the LOW group compared with the CONT and HIGH groups. Yellow color index and moisture content in LM, a fast-twitch glycolytic muscle, were lower (P < 0.05) in LOW rabbits than in HIGH rabbits, but ultimate pH, WHC, and cooking loss did not differ between the two growth-selected lines. Ultimate pH in semitendinosus, a mixed slow- and fast-twitch oxidoglycolytic muscle, was less (P < 0.001) in HIGH rabbits than in CONT and LOW rabbits. However, lactate dehydrogenase and isocitrate dehydrogenase activities in this muscle (n = 21 per group), assessed at the time of slaughter as markers of glycolytic and oxidative capacities, respectively, did not differ among groups. Growth rate did not modify mean cross-sectional area and type frequency of myofibers in semitendinosus muscle

  4. Characterization of tropical precipitation using drop size distribution and rain rate-radar reflectivity relation

    NASA Astrophysics Data System (ADS)

    Das, Saurabh; Maitra, Animesh

    2017-03-01

    Characterization of precipitation is important for proper interpretation of rain information from remotely sensed data. Rain attenuation and radar reflectivity (Z) depend directly on the drop size distribution (DSD). The relation between radar reflectivity/rain attenuation and rain rate (R) varies widely depending upon the origin, topography, and drop evolution mechanism and needs further understanding of the precipitation characteristics. The present work utilizes 2 years of concurrent measurements of DSD using a ground-based disdrometer at five diverse climatic conditions in Indian subcontinent and explores the possibility of rain classification based on microphysical characteristics of precipitation. It is observed that both gamma and lognormal distributions are performing almost similar for Indian region with a marginally better performance by one model than other depending upon the locations. It has also been found that shape-slope relationship of gamma distribution can be a good indicator of rain type. The Z-R relation, Z = ARb, is found to vary widely for different precipitation systems, with convective rain that has higher values of A than the stratiform rain for two locations, whereas the reverse is observed for the rest of the three locations. Further, the results indicate that the majority of rainfall (>50%) in Indian region is due to the convective rain although the occurrence time of convective rain is low (<10%).

  5. Relative in vitro growth rates of duckweeds (Lemnaceae) - the most rapidly growing higher plants.

    PubMed

    Ziegler, P; Adelmann, K; Zimmer, S; Schmidt, C; Appenroth, K-J

    2015-01-01

    Relative growth rates (RGR), doubling times (DT) and relative weekly yields (RY) of 39 clones (ecotypes) from 13 species representing all five genera of duckweeds were determined under standardised cultivation conditions. RGR ranged overall from 0.153 to 0.519 day(-1) , DT from 1.34 to 4.54 days and RY from 2.9 to 37.8 week(-1) . The RGR and RY data can be compared directly to other published findings to only a limited extent on account of missing clonal designations for and limited accessibility to previously investigated clones, as well as the use of different data denominators. However, they are consistent with the published results of other comparative duckweed studies of similar scope in showing that RGR does not vary primarily at the level of the genus or species, but rather reflects the adaptation of individual clones to specific local conditions. The RGR data support the widely held assumption that duckweeds can grow faster than other higher plants and that they can thus surpass land-based agricultural crops in productivity. Duckweeds are highly promising for the production of biomass for nutrition and energy, but extensive clonal comparison will be required to identify the most suitable isolates for this purpose.

  6. Articulatory-to-Acoustic Relations in Response to Speaking Rate and Loudness Manipulations

    PubMed Central

    Mefferd, Antje S.; Green, Jordan R.

    2011-01-01

    Purpose In this investigation, the authors determined the strength of association between tongue kinematic and speech acoustics changes in response to speaking rate and loudness manipulations. Performance changes in the kinematic and acoustic domains were measured using two aspects of speech production presumably affecting speech clarity: phonetic specification and variability. Method Tongue movements for the vowels /ia/ were recorded in 10 healthy adults during habitual, fast, slow, and loud speech using three-dimensional electromagnetic articulography. To determine articulatory-to-acoustic relations for phonetic specification, the authors correlated changes in lingual displacement with changes in acoustic vowel distance. To determine articulatory-to-acoustic relations for phonetic variability, the authors correlated changes in lingual movement variability with changes in formant movement variability. Results A significant positive linear association was found for kinematic and acoustic specification but not for kinematic and acoustic variability. Several significant speaking task effects were also observed. Conclusion Lingual displacement is a good predictor of acoustic vowel distance in healthy talkers. The weak association between kinematic and acoustic variability raises questions regarding the effects of articulatory variability on speech clarity and intelligibility, particularly in individuals with motor speech disorders. PMID:20699341

  7. We should be using nonlinear indices when relating heart-rate dynamics to cognition and mood

    PubMed Central

    Young, Hayley; Benton, David

    2015-01-01

    Both heart rate (HR) and brain functioning involve the integrated output of a multitude of regulatory mechanisms, that are not quantified adequately by linear approximations such as means and standard deviations. It was therefore considered whether non-linear measures of HR complexity are more strongly associated with cognition and mood. Whilst resting, the inter-beat (R-R) time series of twenty-one males and twenty-four females were measured for five minutes. The data were summarised using time, frequency and nonlinear complexity measures. Attention, memory, reaction times, mood and cortisol levels were assessed. Nonlinear HR indices captured additional information, enabling a greater percentage of the variance in behaviour to be explained. On occasions non-linear indices were related to aspects for behaviour, for example focused attention and cortisol production, when time or frequency indices were not. These effects were sexually dimorphic with HR complexity being more strongly associated with the behaviour of females. It was concluded that nonlinear rather than linear methods of summarizing the HR times series offers a novel way of relating brain functioning and behaviour. It should be considered whether non-linear measures of HR complexity can be used as a biomarker of the integrated functioning of the brain. PMID:26565560

  8. Large-scale variation in boreal and temperate forest carbon turnover rate related to climate

    NASA Astrophysics Data System (ADS)

    Thurner, Martin; Beer, Christian; Carvalhais, Nuno; Forkel, Matthias; Santoro, Maurizio; Tum, Markus; Schmullius, Christiane

    2016-05-01

    Vegetation carbon turnover processes in forest ecosystems and their dominant drivers are far from being understood at a broader scale. Many of these turnover processes act on long timescales and include a lateral dimension and thus can hardly be investigated by plot-level studies alone. Making use of remote sensing-based products of net primary production (NPP) and biomass, here we show that spatial gradients of carbon turnover rate (k) in Northern Hemisphere boreal and temperate forests are explained by different climate-related processes depending on the ecosystem. k is related to frost damage effects and the trade-off between growth and frost adaptation in boreal forests, while drought stress and climate effects on insects and pathogens can explain an elevated k in temperate forests. By identifying relevant processes underlying broadscale patterns in k, we provide the basis for a detailed exploration of these mechanisms in field studies, and ultimately the improvement of their representations in global vegetation models (GVMs).

  9. Offenders, Judges, and Officers Rate the Relative Severity of Alternative Sanctions Compared to Prison

    ERIC Educational Resources Information Center

    Moore, Nathan T.; May, David C.; Wood, Peter B.

    2008-01-01

    Recent work suggests that offenders rate several alternatives as more severe than imprisonment. We build on this literature by comparing punishment exchange rates generated by criminal court judges with rates generated by offenders and their supervising officers. Findings reveal that none of the three groups rates prison as the most severe…

  10. Association of Diabetes Related Complications with Heart Rate Variability among a Diabetic Population in the UAE

    PubMed Central

    Khandoker, Ahsan H.; Al-Angari, Haitham M.; Khalaf, Kinda; Lee, Sungmun; Almahmeed, Wael; Al Safar, Habiba S.

    2017-01-01

    Microvascular, macrovascular and neurological complications are the key causes of morbidity and mortality among type II diabetes mellitus (T2DM) patients. The aim of this study was to investigate the alterations of cardiac autonomic function of diabetic patients in relation to three types of diabetes-related complications. ECG recordings were collected and analyzed from 169 T2DM patients in supine position who were diagnosed with nephropathy (n = 55), peripheral neuropathy (n = 64) and retinopathy (n = 106) at two hospitals in the UAE. Comparison between combinations of patients with complications and a control diabetic group (CONT) with no complication (n = 34) was performed using time, frequency and multi-lag entropy measures of heart rate variability (HRV). The results show that these measures decreased significantly (p<0.05) depending on the presence and type of diabetic complications. Entropy, (median, 1st- 3rd interquartile range) for the group combining all complications (1.74,1.37–2.09) was significantly lower than the corresponding values for the CONT group (1.77, 1.39–2.24) with lag-1 for sequential beat-to-beat changes. Odds ratios (OR) from the entropy analysis further demonstrated a significantly higher association with the combination of retinopathy and peripheral neuropathy versus CONT (OR: 1.42 at lag 8) and an even OR for the combination of retinopathy and nephropathy (OR: 2.46 at lag 8) compared to the other groups with complications. Also, the OR of low frequency power to high frequency power ratio (LF/HF) showed a higher association with these diabetic-related complications compared to CONT, especially for the patient group combining all complications (OR: 4.92). This study confirms that the type of microvascular or peripheral neuropathy complication present in T2DM patients have different effects on heart rate entropy, implying disorders of multi-organ connectivity are directly associated with autonomic nervous system dysfunction. Clinical

  11. Association of Diabetes Related Complications with Heart Rate Variability among a Diabetic Population in the UAE.

    PubMed

    Khandoker, Ahsan H; Al-Angari, Haitham M; Khalaf, Kinda; Lee, Sungmun; Almahmeed, Wael; Al Safar, Habiba S; Jelinek, Herbert F

    2017-01-01

    Microvascular, macrovascular and neurological complications are the key causes of morbidity and mortality among type II diabetes mellitus (T2DM) patients. The aim of this study was to investigate the alterations of cardiac autonomic function of diabetic patients in relation to three types of diabetes-related complications. ECG recordings were collected and analyzed from 169 T2DM patients in supine position who were diagnosed with nephropathy (n = 55), peripheral neuropathy (n = 64) and retinopathy (n = 106) at two hospitals in the UAE. Comparison between combinations of patients with complications and a control diabetic group (CONT) with no complication (n = 34) was performed using time, frequency and multi-lag entropy measures of heart rate variability (HRV). The results show that these measures decreased significantly (p<0.05) depending on the presence and type of diabetic complications. Entropy, (median, 1st- 3rd interquartile range) for the group combining all complications (1.74,1.37-2.09) was significantly lower than the corresponding values for the CONT group (1.77, 1.39-2.24) with lag-1 for sequential beat-to-beat changes. Odds ratios (OR) from the entropy analysis further demonstrated a significantly higher association with the combination of retinopathy and peripheral neuropathy versus CONT (OR: 1.42 at lag 8) and an even OR for the combination of retinopathy and nephropathy (OR: 2.46 at lag 8) compared to the other groups with complications. Also, the OR of low frequency power to high frequency power ratio (LF/HF) showed a higher association with these diabetic-related complications compared to CONT, especially for the patient group combining all complications (OR: 4.92). This study confirms that the type of microvascular or peripheral neuropathy complication present in T2DM patients have different effects on heart rate entropy, implying disorders of multi-organ connectivity are directly associated with autonomic nervous system dysfunction. Clinical

  12. Relationship between relative cerebral blood flow, relative cerebral blood volume, and relative cerebral metabolic rate of oxygen in the preterm neonatal brain.

    PubMed

    Nourhashemi, Mina; Kongolo, Guy; Mahmoudzadeh, Mahdi; Goudjil, Sabrina; Wallois, Fabrice

    2017-04-01

    The mechanisms responsible for coupling between relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative cerebral metabolic rate of oxygen ([Formula: see text]), an important function of the microcirculation in preterm infants, remain unclear. Identification of a causal relationship between rCBF-rCBV and [Formula: see text] in preterms may, therefore, help to elucidate the principles of cortical hemodynamics during development. We simultaneously recorded rCBF and rCBV and estimated [Formula: see text] by two independent acquisition systems: diffuse correlation spectroscopy and near-infrared spectroscopy, respectively, in 10 preterms aged between 28 and 35 weeks of gestational age. Transfer entropy was calculated in order to determine the directionality between rCBF-rCBV and [Formula: see text]. The surrogate method was applied to determine statistical significance. The results show that rCBV and [Formula: see text] have a predominant driving influence on rCBF at the resting state in the preterm neonatal brain. Statistical analysis robustly detected the correct directionality of rCBV on rCBF and [Formula: see text] on rCBF. This study helps to clarify the early organization of the rCBV-rCBF and [Formula: see text] inter-relationship in the immature cortex.

  13. On the Rate of Relaxation for the Landau Kinetic Equation and Related Models

    NASA Astrophysics Data System (ADS)

    Bobylev, Alexander; Gamba, Irene M.; Zhang, Chenglong

    2017-08-01

    We study the rate of relaxation to equilibrium for Landau kinetic equation and some related models by considering the relatively simple case of radial solutions of the linear Landau-type equations. The well-known difficulty is that the evolution operator has no spectral gap, i.e. its spectrum is not separated from zero. Hence we do not expect purely exponential relaxation for large values of time t>0. One of the main goals of our work is to numerically identify the large time asymptotics for the relaxation to equilibrium. We recall the work of Strain and Guo (Arch Rat Mech Anal 187:287-339 2008, Commun Partial Differ Equ 31:17-429 2006), who rigorously show that the expected law of relaxation is \\exp (-ct^{2/3}) with some c > 0. In this manuscript, we find an heuristic way, performed by asymptotic methods, that finds this "law of two thirds", and then study this question numerically. More specifically, the linear Landau equation is approximated by a set of ODEs based on expansions in generalized Laguerre polynomials. We analyze the corresponding quadratic form and the solution of these ODEs in detail. It is shown that the solution has two different asymptotic stages for large values of time t and maximal order of polynomials N: the first one focus on intermediate asymptotics which agrees with the "law of two thirds" for moderately large values of time t and then the second one on absolute, purely exponential asymptotics for very large t, as expected for linear ODEs. We believe that appearance of intermediate asymptotics in finite dimensional approximations must be a generic behavior for different classes of equations in functional spaces (some PDEs, Boltzmann equations for soft potentials, etc.) and that our methods can be applied to related problems.

  14. Temperature, traffic-related air pollution, and heart rate variability in a panel of healthy adults.

    PubMed

    Wu, Shaowei; Deng, Furong; Liu, Youcheng; Shima, Masayuki; Niu, Jie; Huang, Qinsheng; Guo, Xinbiao

    2013-01-01

    Both ambient temperature and air pollution have been associated with alterations in cardiac autonomic function, but the responsive patterns associated with temperature exposure and the interactive effects of temperature and air pollution remain largely unclear. We investigated the associations between personal temperature exposure and cardiac autonomic function as reflected by heart rate variability (HRV) in a panel of 14 healthy taxi drivers in the context of traffic-related air pollution. We collected real-time data on study subjects' in-car exposures to temperature and traffic-related air pollutants including particulate matter with an aerodynamic diameter ≤2.5 μm (PM(2.5)) and carbon monoxide (CO) and HRV indices during work time (8:30-21:00) on 48 sampling days in the warm season (May-September) and cold season (October-March). We applied mixed-effects models and loess models adjusting for potential confounders to examine the associations between temperature and HRV indices. We found nonlinear relationships between temperature and HRV indices in both the warm and cold seasons. Linear regression stratified by temperature levels showed that increasing temperature levels were associated with declines in standard deviation of normal-to-normal intervals over different temperature strata and increases in low-frequency power and low-frequency:high-frequency ratio in higher temperature range (>25 °C). PM(2.5) and CO modified these associations to various extents. Temperature was associated with alterations in cardiac autonomic function in healthy adults in the context of traffic-related air pollution. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. The radio continuum-star formation rate relation in WSRT sings galaxies

    SciTech Connect

    Heesen, Volker; Brinks, Elias; Leroy, Adam K.; Heald, George; Braun, Robert; Bigiel, Frank; Beck, Rainer E-mail: v.heesen@soton.ac.uk E-mail: heald@astron.nl E-mail: bigiel@uni-heidelberg.de

    2014-05-01

    We present a study of the spatially resolved radio continuum-star formation rate (RC-SFR) relation using state-of-the-art star formation tracers in a sample of 17 THINGS galaxies. We use SFR surface density (Σ{sub SFR}) maps created by a linear combination of GALEX far-UV (FUV) and Spitzer 24 μm maps. We use RC maps at λλ22 and 18 cm from the WSRT SINGS survey and Hα emission maps to correct for thermal RC emission. We compare azimuthally averaged radial profiles of the RC and FUV/mid-IR (MIR) based Σ{sub SFR} maps and study pixel-by-pixel correlations at fixed linear scales of 1.2 and 0.7 kpc. The ratio of the integrated SFRs from the RC emission to that of the FUV/MIR-based SF tracers is R{sub int}=0.78±0.38, consistent with the relation by Condon. We find a tight correlation between the radial profiles of the radio and FUV/MIR-based Σ{sub SFR} for the entire extent of the disk. The ratio R of the azimuthally averaged radio to FUV/MIR-based Σ{sub SFR} agrees with the integrated ratio and has only quasi-random fluctuations with galactocentric radius that are relatively small (25%). Pixel-by-pixel plots show a tight correlation in log-log diagrams of radio to FUV/MIR-based Σ{sub SFR}, with a typical standard deviation of a factor of two. Averaged over our sample we find (Σ{sub SFR}){sub RC}∝(Σ{sub SFR}){sub hyb}{sup 0.63±0.25}, implying that data points with high Σ{sub SFR} are relatively radio dim, whereas the reverse is true for low Σ{sub SFR}. We interpret this as a result of spectral aging of cosmic-ray electrons (CREs), which are diffusing away from the star formation sites where they are injected into the interstellar medium. This is supported by our finding that the radio spectral index is a second parameter in pixel-by-pixel plots: those data points dominated by young CREs are relatively radio dim, while those dominated by old CREs are slightly more RC bright than what would be expected from a linear extrapolation. We studied the ratio R of

  16. Breast Cancer-Related Arm Lymphedema: Incidence Rates, Diagnostic Techniques, Optimal Management and Risk Reduction Strategies

    SciTech Connect

    Shah, Chirag; Vicini, Frank A.

    2011-11-15

    As more women survive breast cancer, long-term toxicities affecting their quality of life, such as lymphedema (LE) of the arm, gain importance. Although numerous studies have attempted to determine incidence rates, identify optimal diagnostic tests, enumerate efficacious treatment strategies and outline risk reduction guidelines for breast cancer-related lymphedema (BCRL), few groups have consistently agreed on any of these issues. As a result, standardized recommendations are still lacking. This review will summarize the latest data addressing all of these concerns in order to provide patients and health care providers with optimal, contemporary recommendations. Published incidence rates for BCRL vary substantially with a range of 2-65% based on surgical technique, axillary sampling method, radiation therapy fields treated, and the use of chemotherapy. Newer clinical assessment tools can potentially identify BCRL in patients with subclinical disease with prospective data suggesting that early diagnosis and management with noninvasive therapy can lead to excellent outcomes. Multiple therapies exist with treatments defined by the severity of BCRL present. Currently, the standard of care for BCRL in patients with significant LE is complex decongestive physiotherapy (CDP). Contemporary data also suggest that a multidisciplinary approach to the management of BCRL should begin prior to definitive treatment for breast cancer employing patient-specific surgical, radiation therapy, and chemotherapy paradigms that limit risks. Further, prospective clinical assessments before and after treatment should be employed to diagnose subclinical disease. In those patients who require aggressive locoregional management, prophylactic therapies and the use of CDP can help reduce the long-term sequelae of BCRL.

  17. Growth rates of North Sea macroalgae in relation to temperature, irradiance and photoperiod

    NASA Astrophysics Data System (ADS)

    Fortes, M. D.; Lüning, K.

    1980-03-01

    Three eulittoral algae (Ulva lactuca, Porphyra umbilicalis, Chondrus crispus) and one sublittoral alga (Laminaria saccharina) from Helgoland (North Sea) were cultivated in a flow-through system at different temperatures, irradiances and daylengths. In regard to temperature there was a broad optimum at 10 15° C, except in P. umbilicalis, which grew fastest at 10 °C. A growth peak at this temperature was also found in four of 17 other North Sea macroalgae, for which the growth/temperature response was studied, whereas 13 of these species exhibited a growth optimum at 15 °C, or a broad optimum at 10 15 °C. Growth was light-saturated in U. lactuca, L. saccharina and C. crispus at photon flux densities above 70 µE m-2s-1, but in P. umbilicalis above 30 µE m-2s-1. Growth rate did not decrease notably in the eulittoral species after one week in relatively strong light (250 µE m-2s-1), but by about 50 % in the case of the sublittoral L. saccharina, as compared with growth under weak light conditions (30 µE m-2s-1). In contrast, chlorophyll content decreased in the sublittoral as well as in the eulittoral species, and the greatest change in pigment content occurred in the range 30 70 µE m-2s-1. Growth rate increased continuously up to photoperiods of 24 h light per day in L. saccharina and C. crispus, whereas daylength saturation occurred at photoperiods of more than 16 h light per day in U. lactuca and P. umbilicalis.

  18. Former athletes' health-related lifestyle behaviours and self-rated health in late adulthood.

    PubMed

    Bäckmand, H; Kujala, U; Sarna, S; Kaprio, J

    2010-10-01

    The aim of this study was to examine the associations between self-rated health (SRH), physical activity and other lifestyle habits among former athletes and referents in late adulthood. Male athletes (N=514) who represented Finland from 1920 through 1965 and referents (N=368) who were classified healthy at the age of 20 years participated in this population-based cohort study. The present analysis was based on a questionnaire study in 2001. SRH was assessed by a single question. Univariate binary and multivariate logistic regression analyses were used to examine the associations of health-related behaviours with SRH. The majority of former athletes (64%) rated their health better than referents (48%). A higher percentage of the athletes (54%) compared to the referents (44%) belonged to the most physically active groups (MET quintiles IV-V). A high percentage of the athletes (77%) and referents (79%) were occasional or moderate alcohol users. The proportion of never smokers among athletes was 59% and among referents 37%. Among current smokers there were no differences in nicotine dependence between athletes and referents (p=0.07). In the univariate analysis the odds of reporting good SRH was 2 times higher for athletes (OR 2.01, 95% CI 1.53-2.64, p<0.001) than for referents. In multivariate logistic regression analysis, former participation in team and power athletic groups had significantly higher SRH than the referents even after adjusting for age, level of physical activity, alcohol and smoking habit, and occupation. People who participated in very active physical exercise in their youth, as indexed by participation in competitive sports by elite athletes, continue a physically active lifestyle, and maintained healthier lifestyle. They had significantly higher SRH than the referents in their senior years, which was not totally explained by their physically active and healthier lifestyles. © Georg Thieme Verlag KG Stuttgart · New York.

  19. The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise.

    PubMed

    Killen, Shaun S; Reid, Donald; Marras, Stefano; Domenici, Paolo

    2015-01-01

    When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fueled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope (AS) or recovery time after exhaustive exercise. Slower recovery ability or a reduced AS could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how AS and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden gray mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26°C, then measured for standard and maximal metabolic rates and AS using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasize that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with vigilance and recovery from anaerobic exercise.

  20. A Computational Study on the Relation between Resting Heart Rate and Atrial Fibrillation Hemodynamics under Exercise

    PubMed Central

    Anselmino, Matteo; Scarsoglio, Stefania; Gaita, Fiorenzo; Ridolfi, Luca

    2017-01-01

    Aims Clinical data indicating a heart rate (HR) target during rate control therapy for permanent atrial fibrillation (AF) and assessing its eventual relationship with reduced exercise tolerance are lacking. The present study aims at investigating the impact of resting HR on the hemodynamic response to exercise in permanent AF patients by means of a computational cardiovascular model. Methods The AF lumped-parameter model was run to simulate resting (1 Metabolic Equivalent of Task—MET) and various exercise conditions (4 METs: brisk walking; 6 METs: skiing; 8 METs: running), considering different resting HR (70 bpm for the slower resting HR—SHR—simulations, and 100 bpm for the higher resting HR—HHR—simulations). To compare relative variations of cardiovascular variables upon exertion, the variation comparative index (VCI)—the absolute variation between the exercise and the resting values in SHR simulations referred to the absolute variation in HHR simulations—was calculated at each exercise grade (VCI4, VCI6 and VCI8). Results Pulmonary venous pressure underwent a greater increase in HHR compared to SHR simulations (VCI4 = 0.71, VCI6 = 0.73 and VCI8 = 0.77), while for systemic arterial pressure the opposite is true (VCI4 = 1.15, VCI6 = 1.36, VCI8 = 1.56). Conclusions The computational findings suggest that a slower, with respect to a higher resting HR, might be preferable in permanent AF patients, since during exercise pulmonary venous pressure undergoes a slighter increase and systemic blood pressure reveals a more appropriate increase. PMID:28076389

  1. [Hospital malnutrition: relation between the hospital length of stay and the rate of early readmissions].

    PubMed

    Lobo Támer, Gabriela; Ruiz López, María Dolores; Pérez de la Cruz, Antonio Jesús

    2009-03-21

    In hospitalized patients, malnutrition ranges between 30% and 55% and is associated with a higher rate of complications, prolonged hospitalization and increased cost of health services. Despite this, there is no awareness of the clinical and economic implications involving hospital malnutrition and its treatment. We analyzed the relationship between hospital malnutrition, average length of stay and early readmissions. It is a prospective and dynamic cohort study, in which patients were observed from the time of their admission and throughout their hospitalization on a weekly basis. The selection was carried out using a systematic random method. Patients were all older than 18 and admitted to the services with an average stay 5 days. It was decided that a patient had malnutrition when some anthropometric (biceps circumference, tricipital, abdominal and subscapular skinfold thickness) or biochemical (albumin, prealbumin, and transferrin) parameter was below normal values. Early readmission was defined as a patient's return to hospital in a period < 31 days from the last date of discharge. Hospital entries were classified in relation to the average stay (hospital and services) and we analyzed the stays below and the stays above the average expected. Results have been expressed in average and standard deviation (X +/- SD) and frequency (%). Intergroup comparisons by Student's t test and chi(2), remain significant to P < .05. The risk and confidence intervals (CI) were applied to malnourished cohorts, with a significance level of 95%. The study included 817 patients (50.9 +/- 18.5 years), 62.9% men and 37.1% women. 45.9% (n = 375) of patients were malnourished, and malnutrition was most common in those with digestive diseases (22.5%), neoplasm (20.8%), circulatory (16.5%) and respiratory pathologies (11.6%). The average stay (hospital and services) and the premature readmission rate were higher in patients admitted to hospital with malnutrition. Nearly half of the

  2. Temperature-dependent, relative-rate study of the reactions of 1- and 2-butoxyl radicals

    NASA Astrophysics Data System (ADS)

    Johnson, D.; Cassanelli, P.; Cox, R. A.

    2003-04-01

    Alkoxyl radicals (RO\\cdot) are important intermediates in the chains of free radical reactions that constitute the gas-phase oxidation of volatile organic compounds (VOCs). Generally there are a number of different reaction pathways available to alkoxyl radicals and, depending on conditions of temperature and the structure of RO\\cdot, these may be in competition. The major reactions of RO\\cdot are (1) reaction with O_2 to yield a carbonyl product and a hydroperoxy, HO_2, radical, (2) decomposition to yield a carbonyl product and a radical fragment, and (3) isomerisation via a six-membered transition state to yield a d-hydroxylated radical species. Thus the chemistry of alkoxyl radicals determines the atmospheric impact of the oxidation of a given VOC, in terms of the immediate effects of closed-shell products, and as a result of the further chemistry of free radical products. HO_2 can react with NO to yield photolabile NO_2 (and hence contribute to photochemical ozone formation), and organic radical fragments act to propagate the oxidation chain of reactions. As ozone has been identified to be an important greenhouse gas in the upper troposphere/lower stratosphere (UTLS) region it is important to understand how temperature affects the relative rates of reactions (1) to (3), and thus how the presence of VOCs in the UTLS region affects the coupled chemistries of HO_x and O_3. In the present study, we have looked at the reactions of 1- and 2-butoxyl radicals (formed in the reaction of OH with butane) in terms of the relative rates of their bimolecular reactions with O_2 (1) and unimolecular processes (2,3). The two butoxyl radicals were studied separately and were formed directly from the photolysis of 1- or 2-butylnitrite. Experiments were carried out using a metre-long photochemical flow cell made of quartz. The temperature of the cell could be controlled and for the experiments carried out in the present study was operated between about 250 and 340 K. Reactant

  3. Terminology and Methodology Related to the Use of Heart Rate Responsivity in Infancy Research

    ERIC Educational Resources Information Center

    Woodcock, James M.

    1971-01-01

    Methodological problems in measuring and interpreting infantile heart rate reactivity in research are discussed. Various ways of describing cardiac activity are listed. Attention is given to the relationship between resting state and heart rate responsivity. (Author/WY)

  4. Terminology and Methodology Related to the Use of Heart Rate Responsivity in Infancy Research

    ERIC Educational Resources Information Center

    Woodcock, James M.

    1971-01-01

    Methodological problems in measuring and interpreting infantile heart rate reactivity in research are discussed. Various ways of describing cardiac activity are listed. Attention is given to the relationship between resting state and heart rate responsivity. (Author/WY)

  5. Protein crystal growth rates are face-specifically modified by structurally related contaminants

    NASA Astrophysics Data System (ADS)

    Hirschler, Joachim; Fontecilla-Camps, Juan Carlos

    1997-02-01

    Growth rates of turkey egg-white lysozyme (TEWL) crystal faces have been measured in uncontaminated solutions as well as in solutions contaminated by the homologous hen egg-white lysozyme (HEWL). Comparison of growth rates from uncontaminated and contaminated solutions shows that the growth rate of the {112} faces drops significantly in the presence of the contaminant, whereas the growth rate of the {110} faces does not change. This demonstrates that HEWL acts specifically on the growth process of the {112} faces.

  6. Peer Ratings of Aggression: Relation to Social Skills, Behavior Problems, and Friendships.

    ERIC Educational Resources Information Center

    McIntosh, Ruth; Vaughn, Sharon

    This study examined the aggressive behaviors of children through peer ratings to teacher ratings of problem behaviors and social skills and peer ratings of friendship. Peer data are valid measures and may be more accurate than teacher or self measures because peers are more likely to be present when aggression occurs. This study examines a peer…

  7. Effectiveness Ratings of Counselors by Coached Clients Related to Attractiveness-Fitness Variables.

    ERIC Educational Resources Information Center

    Wiggins, J. D.

    1980-01-01

    Rated normal-weight and overweight male and female counselors on perceived cognitive effectiveness, warmth and empathy, leadership qualities, and global counseling effectiveness. Although all counselors were rated as competent, both male and female counselors who were overweight were rated as less able in all areas tested. (Author)

  8. Elevated rates of testosterone-related disorders in women with autism spectrum conditions.

    PubMed

    Ingudomnukul, Erin; Baron-Cohen, Simon; Wheelwright, Sally; Knickmeyer, Rebecca

    2007-05-01

    The androgen theory of autism proposes that autism spectrum conditions (ASC) are in part due to elevated fetal testosterone (FT) levels, which are positively correlated with a number of autistic traits and inversely correlated with social development and empathy. A medical questionnaire was completed by n=54 women with ASC, n=74 mothers of children with ASC, and n=183 mothers of typically developing children to test whether women with ASC have an increased rate of testosterone-related medical conditions, and to see whether mothers of children with ASC show similar abnormalities, as part of the 'broader autism phenotype'. Compared to controls, significantly more women with ASC reported (a) hirsutism, (b) bisexuality or asexuality, (c) irregular menstrual cycle, (d) dysmenorrhea, (e) polycystic ovary syndrome, (f) severe acne, (g) epilepsy, (h) tomboyism, and (i) family history of ovarian, uterine, and prostate cancers, tumors, or growths. Compared to controls, significantly more mothers of ASC children reported (a) severe acne, (b) breast and uterine cancers, tumors, or growths, and (c) family history of ovarian and uterine cancers, tumors, or growths. These results suggest current hormone abnormalities in women with ASC and their mothers. Direct investigations of serum testosterone levels and genetic susceptibility to high testosterone production or sensitivity in women with ASC would illuminate the origin of these conditions. The relationship between FT and current testosterone levels also needs to be clarified. The present results may be relevant to understanding the increased male risk to developing autism.

  9. Protein expression and oxygen consumption rate of early postmortem mitochondria relate to meat tenderness.

    PubMed

    Grabež, V; Kathri, M; Phung, V; Moe, K M; Slinde, E; Skaugen, M; Saarem, K; Egelandsdal, B

    2015-04-01

    Oxygen consumption rate (OCR) of muscle fibers from bovine semimembranosus muscle of 41 animals was investigated 3 to 4 h and 3 wk postmortem. Significant relations (P < 0.05) were found between OCR measurements and Warner-Bratzler shear force measurement. Muscles with high mitochondrial OCR after 3 to 4 h and low nonmitochondrial oxygen consumption gave more tender meat. Tender (22.92 ± 2.2 N/cm2) and tough (72.98 ± 7.2 N/cm2) meat samples (4 samples each), separated based on their OCR measurements, were selected for proteomic studies using mitochondria isolated approximately 2.5 h postmortem. Twenty-six differently expressed proteins (P < 0.05) were identified in tender meat and 19 in tough meat. In tender meat, the more prevalent antioxidant and chaperon enzymes may reduce reactive oxygen species and prolong oxygen removal by the electron transport system (ETS). Glycolytic, Krebs cycle, and ETS enzymes were also more abundant in tender meat

  10. Factoring vs linear modeling in rate estimation: a simulation study of relative accuracy.

    PubMed

    Maldonado, G; Greenland, S

    1998-07-01

    A common strategy for modeling dose-response in epidemiology is to transform ordered exposures and covariates into sets of dichotomous indicator variables (that is, to factor the variables). Factoring tends to increase estimation variance, but it also tends to decrease bias and thus may increase or decrease total accuracy. We conducted a simulation study to examine the impact of factoring on the accuracy of rate estimation. Factored and unfactored Poisson regression models were fit to follow-up study datasets that were randomly generated from 37,500 population model forms that ranged from subadditive to supramultiplicative. In the situations we examined, factoring sometimes substantially improved accuracy relative to fitting the corresponding unfactored model, sometimes substantially decreased accuracy, and sometimes made little difference. The difference in accuracy between factored and unfactored models depended in a complicated fashion on the difference between the true and fitted model forms, the strength of exposure and covariate effects in the population, and the study size. It may be difficult in practice to predict when factoring is increasing or decreasing accuracy. We recommend, therefore, that the strategy of factoring variables be supplemented with other strategies for modeling dose-response.

  11. Reduced heart rate variability in pet dogs affected by anxiety-related behaviour problems.

    PubMed

    Wormald, Dennis; Lawrence, Andrew J; Carter, Gabrielle; Fisher, Andrew D

    2017-01-01

    We present here the first evidence of correlation between canine anxiety-related behavioural problems and heart rate variability (HRV). HRV is known to be related to a range of mental disorders in humans; however this has not been explored in dogs. Behavioural problems in dogs can result in suffering, property destruction and human injury. Dog behaviour problems were assessed by owner questionnaire and the extreme high and low scoring dogs were recruited into either affected (n=10) or unaffected (n=20) groups. HRV was assessed in dogs at their homes, while being held in lateral recumbency for 5min using manual restraint. Salivary cortisol samples were taken before and after HRV testing. Dogs were assessed as either being reactive to the procedure (barking, growling, struggling or shaking) or unreactive. There was no effect of reactivity or behaviour problems on salivary cortisol levels at baseline or in response to the treatment. There was a significant effect of reactivity on HR (F1,26=5.54; P=0.026), and no effect of behaviour problems (F1,26=1.07; P=0.311). There was no effect of reactivity on any of the HRV measures. The presence of behaviour problems had a significant effect on a range of measures of HRV, with unaffected dogs having higher standard deviation of RR intervals (F1,26=6.39; P=0.018), higher high frequency spectrum (F1,26=5.23; P=0.031) and higher low frequency spectrum (F1,26=9.25; P=0.005) power. There was no effect of behaviour problems on very low frequency spectrum power (F1,26=1.40; P=0.248). Together these results provide evidence for a fundamental physiological difference between dogs affected or unaffected with behaviour problems. This study provides evidence for further investigation into the role of HRV in the pathophysiology of canine anxiety-related behaviour problems. Copyright © 2016. Published by Elsevier Inc.

  12. Global stability of a transport-related infection model with general incidence rate in two heterogeneous cities.

    PubMed

    Liu, Lili; Liu, Xianning

    2014-12-01

    To further understand the effects of travel on disease spread, a transport-related infection model with general incidence rate in two heterogeneous cities is proposed and analyzed. Some analytical results on the global stability of equilibria (including disease free equilibrium and endemic equilibrium) are obtained. The explicit formula for the basic reproduction number R0 is derived and it is proved to be a threshold for disease spread. To reveal how incidence rate and travel rate influence the disease spread, effects of general incidence rate and travel rate on the dynamics of system are shown via numeric simulations.

  13. Relative user ratings of MMPI-2 computer-based test interpretations.

    PubMed

    Williams, John E; Weed, Nathan C

    2004-12-01

    There are eight commercially available computer-based test interpretations (CBTIs) for the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), of which few have been empirically evaluated. Prospective users of these programs have little scientific data to guide choice of a program. This study compared ratings of these eight CBTIs. Test users were randomly assigned to rate either a single authentic CBTI report on one of their clients or a single CBTI report generated from a modal MMPI-2 profile for their clinical setting. In all, 257 authentic and modal CBTI reports were rated by 41 clinicians on 10 dimensions. Each of the authentic reports received substantially higher ratings than the modal reports, with ratings of perceived accuracy and opinion confirmation best differentiating between authentic and modal reports. Automated Assessment Associates' report received the highest overall ratings; reports published by Western Psychological Services, Pearson Assessments, and the Caldwell Report were also distinguished on one or more ratings dimensions.

  14. The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies

    SciTech Connect

    Allen, Steven W.; Dunn, R.J.H.; Fabian, A.C.; Taylor, G.B.; Reynolds, C.S.; /Maryland U.

    2006-03-10

    Using Chandra X-ray observations of nine nearby, X-ray luminous elliptical galaxies with good optical velocity dispersion measurements, we show that a tight correlation exists between the Bondi accretion rates calculated from the observed gas temperature and density profiles and estimated black hole masses, and the power emerging from these systems in relativistic jets. The jet powers, which are inferred from the energies and timescales required to inflate cavities observed in the surrounding X-ray emitting gas, can be related to the accretion rates using a power law model of the form log (P{sub Bondi}/10{sup 43} erg s{sup -1}) = A + B log (P{sub jet}/10{sup 43} erg s{sup -1}), with A = 0.62 {+-} 0.15 and B = 0.77 {+-} 0.18. Our results show that a significant fraction of the energy associated with the rest mass of material entering the Bondi accretion radius (2.4{sub -0.7}{sup +1.0} per cent, for P{sub jet} = 10{sup 43} erg s{sup -1}) eventually emerges in the relativistic jets. Our results have significant implications for studies of accretion, jet formation and galaxy formation. The observed tight correlation suggests that the Bondi formulae provide a reasonable description of the accretion process in these systems, despite the likely presence of magnetic pressure and angular momentum in the accreting gas. The similarity of the P{sub Bondi} and P{sub jet} values argues that a significant fraction of the matter entering the accretion radius flows down to regions close to the black holes, where the jets are presumably formed. The tight correlation between P{sub Bondi} and P{sub jet} also suggests that the accretion flows are approximately stable over timescales of a few million years. Our results show that the black hole ''engines'' at the hearts of large elliptical galaxies and groups feed back sufficient energy to stem cooling and star formation, leading naturally to the observed exponential cut off at the bright end of the galaxy luminosity function.

  15. Why have relative rates of class mobility become more equal among women in Britain?

    PubMed

    Bukodi, Erzsébet; Goldthorpe, John H; Joshi, Heather; Waller, Lorraine

    2017-09-01

    In a previous paper it has been shown that across three cohorts of men and women born in Britain in 1946, 1958 and 1970 a gender difference exists in regard to relative rates of class mobility. For men these rates display an essential stability but for women they become more equal. The aim of the present paper is to shed light on the causes of this trend-or, that is, of increasing social fluidity-among women. We begin by considering a refined version of the perverse fluidity hypothesis: that is, one that proposes that part-time work leads to increasing downward worklife mobility among women that also entails downward intergenerational mobility and thus promotes greater fluidity. We do in fact find that the increase in fluidity is very largely, if not entirely, confined to women who have had at least one period of part-time work. However, a more direct test of the hypothesis is not supportive. We are then led to investigate whether it is not that part-time working itself is the crucial factor but rather that women who subsequently work part-time already differ from those who do not at entry into employment. We find that eventual full- and part-timers do not differ in their class origins nor, in any systematic way, in their educational qualifications. But there is a marked and increasing difference in the levels of employment at which they make their labour market entry. Eventual part-timers are more likely than eventual full-timers to enter in working-class positions, regardless of their class origins and qualifications. Insofar as these women are from more advantaged origins, they would appear not to seek to exploit their advantages to the same extent as do full-timers in order to advance their own work careers. And it is, then, in the downward mobility accepted by these women-who increase in number across the cohorts-that we would locate the main source of the weakening association between class origins and destinations that is revealed among women at large.

  16. Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity

    PubMed Central

    Beall, Erik B.; Frankemolle, Anneke M.M.; Penko, Amanda; Phillips, Michael D.; Lowe, Mark J.; Alberts, Jay L.

    2016-01-01

    Abstract Forced-rate lower-extremity exercise has recently emerged as a potential safe and low-cost therapy for Parkinson's disease (PD). The efficacy is believed to be dependent on pedaling rate, with rates above the subjects' voluntary exercise rates being most beneficial. In this study, we use functional connectivity magnetic resonance imaging (MRI) to further elucidate the mechanism underlying this effect. Twenty-seven PD patients were randomized to complete 8 weeks of forced-rate exercise (FE) or voluntary-rate exercise (VE). Exercise was delivered using a specialized stationary bicycle, which can augment patients' voluntary exercise rates. The FE group received assistance from the cycle. Imaging was conducted at baseline, end of therapy, and after 4 weeks of follow-up. Functional connectivity (FC) was determined via seed-based correlation analysis, using activation-based seeds in the primary motor cortex (M1). The change in FC after exercise was compared using linear correlation with pedaling rate. Results of the correlation analysis showed a strong positive correlation between pedaling rate and change in FC from the most affected M1 to the ipsilateral thalamus. This effect persisted after 4 weeks of follow-up. These results indicate that a plausible mechanism for the therapeutic efficacy of high-rate exercise in PD is that it improves thalamo-cortical connectivity. PMID:26414696

  17. Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity.

    PubMed

    Shah, Chintan; Beall, Erik B; Frankemolle, Anneke M M; Penko, Amanda; Phillips, Michael D; Lowe, Mark J; Alberts, Jay L

    2016-02-01

    Forced-rate lower-extremity exercise has recently emerged as a potential safe and low-cost therapy for Parkinson's disease (PD). The efficacy is believed to be dependent on pedaling rate, with rates above the subjects' voluntary exercise rates being most beneficial. In this study, we use functional connectivity magnetic resonance imaging (MRI) to further elucidate the mechanism underlying this effect. Twenty-seven PD patients were randomized to complete 8 weeks of forced-rate exercise (FE) or voluntary-rate exercise (VE). Exercise was delivered using a specialized stationary bicycle, which can augment patients' voluntary exercise rates. The FE group received assistance from the cycle. Imaging was conducted at baseline, end of therapy, and after 4 weeks of follow-up. Functional connectivity (FC) was determined via seed-based correlation analysis, using activation-based seeds in the primary motor cortex (M1). The change in FC after exercise was compared using linear correlation with pedaling rate. Results of the correlation analysis showed a strong positive correlation between pedaling rate and change in FC from the most affected M1 to the ipsilateral thalamus. This effect persisted after 4 weeks of follow-up. These results indicate that a plausible mechanism for the therapeutic efficacy of high-rate exercise in PD is that it improves thalamo-cortical connectivity.

  18. Relative Metallographic Cooling Rates: Can They be Measured Using Co/Ni Ratios at Taenite/Kamacite Interfaces?

    NASA Astrophysics Data System (ADS)

    Goldstein, J. I.; Yang, J.; Scott, E. R. D.

    2012-09-01

    The relative cooling rates of IVA and IIIAB irons obtained recently by Wasson and Hoppe must be treated with much caution as they were obtained with inadequate spatial resloution and a flowed phase diagram and methodology.

  19. Decreases in Smoking-Related Cancer Mortality Rates Are Associated with Birth Cohort Effects in Korean Men.

    PubMed

    Jee, Yon Ho; Shin, Aesun; Lee, Jong-Keun; Oh, Chang-Mo

    2016-12-05

    Background: This study aimed to examine trends in smoking-related cancer mortality rates and to investigate the effect birth cohort on smoking-related cancer mortality in Korean men. Methods: The number of smoking-related cancer deaths and corresponding population numbers were obtained from Statistics Korea for the period 1984-2013. Joinpoint regression analysis was used to detect changes in trends in age-standardized mortality rates. Birth-cohort specific mortality rates were illustrated by 5 year age groups. Results: The age-standardized mortality rates for oropharyngeal decreased from 2003 to 2013 (annual percent change (APC): -3.1 (95% CI, -4.6 to -1.6)) and lung cancers decreased from 2002 to 2013 (APC -2.4 (95% CI -2.7 to -2.2)). The mortality rates for esophageal declined from 1994 to 2002 (APC -2.5 (95% CI -4.1 to -0.8)) and from 2002 to 2013 (APC -5.2 (95% CI -5.7 to -4.7)) and laryngeal cancer declined from 1995 to 2013 (average annual percent change (AAPC): -3.3 (95% CI -4.7 to -1.8)). By the age group, the trends for the smoking-related cancer mortality except for oropharyngeal cancer have changed earlier to decrease in the younger age group. The birth-cohort specific mortality rates and age-period-cohort analysis consistently showed that all birth cohorts born after 1930 showed reduced mortality of smoking-related cancers. Conclusions: In Korean men, smoking-related cancer mortality rates have decreased. Our findings also indicate that current decreases in smoking-related cancer mortality rates have mainly been due to a decrease in the birth cohort effect, which suggest that decrease in smoking rates.

  20. Decreases in Smoking-Related Cancer Mortality Rates Are Associated with Birth Cohort Effects in Korean Men

    PubMed Central

    Jee, Yon Ho; Shin, Aesun; Lee, Jong-Keun; Oh, Chang-Mo

    2016-01-01

    Background: This study aimed to examine trends in smoking-related cancer mortality rates and to investigate the effect birth cohort on smoking-related cancer mortality in Korean men. Methods: The number of smoking-related cancer deaths and corresponding population numbers were obtained from Statistics Korea for the period 1984–2013. Joinpoint regression analysis was used to detect changes in trends in age-standardized mortality rates. Birth-cohort specific mortality rates were illustrated by 5 year age groups. Results: The age-standardized mortality rates for oropharyngeal decreased from 2003 to 2013 (annual percent change (APC): −3.1 (95% CI, −4.6 to −1.6)) and lung cancers decreased from 2002 to 2013 (APC −2.4 (95% CI −2.7 to −2.2)). The mortality rates for esophageal declined from 1994 to 2002 (APC −2.5 (95% CI −4.1 to −0.8)) and from 2002 to 2013 (APC −5.2 (95% CI −5.7 to −4.7)) and laryngeal cancer declined from 1995 to 2013 (average annual percent change (AAPC): −3.3 (95% CI −4.7 to −1.8)). By the age group, the trends for the smoking-related cancer mortality except for oropharyngeal cancer have changed earlier to decrease in the younger age group. The birth-cohort specific mortality rates and age-period-cohort analysis consistently showed that all birth cohorts born after 1930 showed reduced mortality of smoking-related cancers. Conclusions: In Korean men, smoking-related cancer mortality rates have decreased. Our findings also indicate that current decreases in smoking-related cancer mortality rates have mainly been due to a decrease in the birth cohort effect, which suggest that decrease in smoking rates. PMID:27929405

  1. Observations on the relation between alcohol absorption and the rate of gastric emptying.

    PubMed Central

    Holt, S

    1981-01-01

    Alcohol (ethanol) is absorbed slowly from the stomach and rapidly from the small intestine, and the rate of its absorption depends on the rate of gastric emptying. When gastric emptying is fast, the absorption of alcohol is fast. When gastric emptying is slow the absorption of alcohol is delayed and peak blood alcohol concentrations are reduced. Alterations of the gastric emptying rate, which may have a physiologic, pharmacologic or pathologic cause, markedly influence the rate of alcohol absorption. The gastric emptying rate makes an important contribution to inter- and intraindividual variations in the rate of alcohol absorption and therefore the timing and magnitude of the acute intoxicating effect of an oral dose of alcohol. PMID:7459787

  2. Photon dose rates from spent fuel assemblies with relation to self-protection (Rev. 1)

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1996-02-01

    Photon dose rates as a function of fission product decay times have been calculated for spent fuel assemblies typical of MTR-type research and test reactors. Based upon these dose rates, the length of time that a spent fuel assembly will be self-protecting (dose rate greater than 100 rem/h at 1 m in air) can be estimated knowing the mass of fuel burned, the fraction of fuel burned, and the fuel assembly specific power density.

  3. Spin-down of radio millisecond pulsars at genesis.

    PubMed

    Tauris, Thomas M

    2012-02-03

    Millisecond pulsars are old neutron stars that have been spun up to high rotational frequencies via accretion of mass from a binary companion star. An important issue for understanding the physics of the early spin evolution of millisecond pulsars is the impact of the expanding magnetosphere during the terminal stages of the mass-transfer process. Here, I report binary stellar evolution calculations that show that the braking torque acting on a neutron star, when the companion star decouples from its Roche lobe, is able to dissipate >50% of the rotational energy of the pulsar. This effect may explain the apparent difference in observed spin distributions between x-ray and radio millisecond pulsars and help account for the noticeable age discrepancy with their young white dwarf companions.

  4. Spin-Down of the North Atlantic Subpolar Circulation

    NASA Technical Reports Server (NTRS)

    Hakkinen, S.; Rhines, P. B.

    2004-01-01

    Dramatic changes have occurred in the mid-to-high-latitude North Atlantic Ocean as evidenced by TOPEX/Poseidon observations of sea surface height (SSH) in the subpolar gyre and the Gulf Stream. Analysis of altimeter data shows that subpolar SSH has increased during the 1990s and the geostrophic velocity derived from altimeter data shows a decline in the gyre circulation. Direct current-meter observations in the boundary current of the Labrador Sea support the trend in the 199Os, and, together with hydrographic data show that in the mid-late 1990s the trend extends deep in the water column. We find that buoyancy forcing over the northern North Atlantic has a dynamic effect consistent with the altimeter data and hydrographic observations: a weak thermohaline forcing and the subsequent decay of the domed structure of the subpolar isopycnals would give rise to the observed anticyclonic circulation trend.

  5. The spin down of the radio pulsars: Braking index

    NASA Technical Reports Server (NTRS)

    Beskin, V. S.; Gurevich, A. V.; Istomin, Ya. N.

    1991-01-01

    Presently, the value of the retardation dP/dt is well known for most radio pulsars. It is negative for all cases except one and is of the order of 10(exp -15). That single case is when the pulsar, which is located in the star globular system, can have a considerable acceleration leading to the opposite sign of P'= dP/dt due to the Doppler effect. Careful measurements of the period, P, also allow one to determine the variation of this retardation with the course of time- P'' = d(exp 2)P/dt(exp 2). The results of these measurements are usually represented in the form of the dimensionless retardation index n = omega'' omega/omega(exp 2)= 2 - P''P/P(exp 2) (omega is the angular velocity). The data for 21 pulsars are given. The parameter, n, is strongly undetermined both in value and sign in all cases except for four pulsars. Changes of the rotation period, P, and the inclination angle, chi, the angle between the axes of rotation and the magnetic moment are caused by two processes: the regular retardation and nutation due to deviation from the strict spherical shape of the neutron star. Losses which are caused by the currents flowing in the magnetosphere of the neutron star and by being closed on the star surface are considered. Such losses are critical for the neutron star magnetosphere which is full of dense plasma. Since the radio emission is generated in the dense plasma of the polar magnetosphere, then practically all radio pulsars are retarded by the current mechanism. The formula for the braking index is presented along with other aspects of the investigation.

  6. The spin down of the radio pulsars: Braking index

    NASA Technical Reports Server (NTRS)

    Beskin, V. S.; Gurevich, A. V.; Istomin, Ya. N.

    1991-01-01

    Presently, the value of the retardation dP/dt is well known for most radio pulsars. It is negative for all cases except one and is of the order of 10(exp -15). That single case is when the pulsar, which is located in the star globular system, can have a considerable acceleration leading to the opposite sign of P'= dP/dt due to the Doppler effect. Careful measurements of the period, P, also allow one to determine the variation of this retardation with the course of time- P'' = d(exp 2)P/dt(exp 2). The results of these measurements are usually represented in the form of the dimensionless retardation index n = omega'' omega/omega(exp 2)= 2 - P''P/P(exp 2) (omega is the angular velocity). The data for 21 pulsars are given. The parameter, n, is strongly undetermined both in value and sign in all cases except for four pulsars. Changes of the rotation period, P, and the inclination angle, chi, the angle between the axes of rotation and the magnetic moment are caused by two processes: the regular retardation and nutation due to deviation from the strict spherical shape of the neutron star. Losses which are caused by the currents flowing in the magnetosphere of the neutron star and by being closed on the star surface are considered. Such losses are critical for the neutron star magnetosphere which is full of dense plasma. Since the radio emission is generated in the dense plasma of the polar magnetosphere, then practically all radio pulsars are retarded by the current mechanism. The formula for the braking index is presented along with other aspects of the investigation.

  7. Spin-Down of Radio Millisecond Pulsars at Genesis

    NASA Astrophysics Data System (ADS)

    Tauris, Thomas M.

    2012-02-01

    Millisecond pulsars are old neutron stars that have been spun up to high rotational frequencies via accretion of mass from a binary companion star. An important issue for understanding the physics of the early spin evolution of millisecond pulsars is the impact of the expanding magnetosphere during the terminal stages of the mass-transfer process. Here, I report binary stellar evolution calculations that show that the braking torque acting on a neutron star, when the companion star decouples from its Roche lobe, is able to dissipate >50% of the rotational energy of the pulsar. This effect may explain the apparent difference in observed spin distributions between x-ray and radio millisecond pulsars and help account for the noticeable age discrepancy with their young white dwarf companions.

  8. Adolescent body mass index and erythrocyte sedimentation rate in relation to colorectal cancer risk.

    PubMed

    Kantor, Elizabeth D; Udumyan, Ruzan; Signorello, Lisa B; Giovannucci, Edward L; Montgomery, Scott; Fall, Katja

    2016-08-01

    Adult obesity and inflammation have been associated with risk of colorectal cancer (CRC); however, less is known about how adolescent body mass index (BMI) and inflammation, as measured by erythrocyte sedimentation rate (ESR), relate to CRC risk. We sought to evaluate these associations in a cohort of 239 658 Swedish men who underwent compulsory military enlistment examinations in late adolescence (ages 16-20 years). At the time of the conscription assessment (1969-1976), height and weight were measured and ESR was assayed. By linkage to the national cancer registry, these conscripts were followed for CRC through 1 January 2010. Over an average of 35 years of follow-up, 885 cases of CRC occurred, including 501 colon cancers and 384 rectal cancers. Cox regression was used to estimate adjusted HRs and corresponding 95% CIs. Compared with normal weight (BMI 18.5 to <25 kg/m(2)) in late adolescence, upper overweight (BMI 27.5 to <30 kg/m(2)) was associated with a 2.08-fold higher risk of CRC (95% CI 1.40 to 3.07) and obesity (BMI 30+ kg/m(2)) was associated with a 2.38-fold higher risk of CRC (95% CI 1.51 to 3.76) (p-trend: <0.001). Male adolescents with ESR (15+ mm/h) had a 63% higher risk of CRC (HR 1.63; 95% CI 1.08 to 2.45) than those with low ESR (<10 mm/h) (p-trend: 0.006). Associations did not significantly differ by anatomic site. Late-adolescent BMI and inflammation, as measured by ESR, may be independently associated with future CRC risk. Further research is needed to better understand how early-life exposures relate to CRC. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. Tri-Axial Accelerometry and Heart Rate Telemetry: Relation and Agreement with Behavioral Observation in Elementary Physical Education

    ERIC Educational Resources Information Center

    Scruggs, Philip W.; Beveridge, Sandy K.; Clocksin, Brian D.

    2005-01-01

    The relation and agreement of tri-axial accelerometry and heart rate telemetry in measuring moderate to vigorous physical activity were examined in association to behavioral observation during 1st- and 2nd-grade physical education. In Study 1, physical activity measures of heart rate and behavioral observation were collected on 346 participants…

  10. Tri-Axial Accelerometry and Heart Rate Telemetry: Relation and Agreement with Behavioral Observation in Elementary Physical Education

    ERIC Educational Resources Information Center

    Scruggs, Philip W.; Beveridge, Sandy K.; Clocksin, Brian D.

    2005-01-01

    The relation and agreement of tri-axial accelerometry and heart rate telemetry in measuring moderate to vigorous physical activity were examined in association to behavioral observation during 1st- and 2nd-grade physical education. In Study 1, physical activity measures of heart rate and behavioral observation were collected on 346 participants…

  11. Relations between Perceived Competence, Importance Ratings, and Self-Worth among African American School-Age Children

    ERIC Educational Resources Information Center

    Grier, Leslie K.

    2013-01-01

    The purpose of this research was to investigate how domain-specific importance ratings affect relations between perceived competence and self-worth among African American school-age children. Importance ratings have been found to affect the strength of the relationship between perceived competence and self-worth and have implications for…

  12. Do Small Rural High Schools Differ from Larger Schools in Relation to Absentee Rates in Physical Education?

    ERIC Educational Resources Information Center

    Lagestad, Pal; Ranes, Vebjorn; Welde, Boye

    2015-01-01

    The aims of the study were twofold: (a) to investigate how school size affects absentee rates in physical education (PE) and (b) to examine the experiences of students and teachers at a small rural high school in relation to attendance in PE at their school. The absentee rates in PE among all students (N = 6928 students) in a county in Norway were…

  13. DENTAL CARIES AND SYSTEMIC STATUS. PAROTID FLUID FLOW RATE, PAROTID FLUID, AND SERUM CHLORIDE AS RELATED TO DENTAL CARIES EXPERIENCE

    DTIC Science & Technology

    Chloride determinations were carried out on blood serum and parotid fluid obtained at a very low flow rate from 527 apparently healthy young adult...males classified as to dental caries experience (DMFS). There was no indication that parotid fluid flow rate or the chloride concentration of either of the fluids could be in any way related to dental caries experience. (Author)

  14. Rate of vision loss in neovascular age-related macular degeneration explored.

    PubMed

    Real, Juan P; Granero, Gladys E; De Santis, Mariana O; Juarez, Claudio P; Palma, Santiago D; Kelly, Simon P; Luna, José D

    2015-11-01

    To explore decline in visual acuity in patients with neovascular age-related macular degeneration (n-AMD) awaiting intravitreal bevacizumab or ranibizumab treatment following initial diagnosis and after disease reactivation. Retrospective analysis of 74 treatment-naïve patients (84 eyes) in two centers in Córdoba, Argentina. The time between treatment indication and intravitreal injection, and the changes in BCVA produced during this delay were studied in both periods. A linear regression model to search the impact of time on progression visual impairment was conducted. In both periods, a significant reduction in vision occurred awaiting intravitreal injection. The longer the delay, the greater the vision loss (R2 = 0.55 p < 0.01) and the less improvement following treatment (Pearson coefficient -0.26). The result of the model shows that the change in vision as a function of initial delay were best described by a polynomic model with a mean loss of 5 letters in the first 3 weeks, a slowdown in the rate of change of VA, and a dependence of visual acuity at the moment of diagnosis . The loss of visual acuity after reactivation shows the same behavior as at the onset of the disease but independent of visual acuity prior to reactivation. Visual loss awaiting injection intravitreal anti-VEGF is clinically significant and with an asymptotic pattern, with early rapid loss of vision in both the onset of the disease and the reactivation. Initiation of anti-VEGF treatment must be undertaken urgently, as should retreatment of disease activation to reduce visual loss.

  15. Relation between heart rate recovery after exercise testing and body mass index.

    PubMed

    Barbosa Lins, Tereza Cristina; Valente, Lucila Maria; Sobral Filho, Dário Celestino; Barbosa e Silva, Odwaldo

    2015-01-01

    Impaired heart rate (HR) recovery after exercise testing is considered a predictor of cardiovascular mortality as it reflects vagus nerve dysfunction. To assess the relationship between body mass index (BMI) and HR recovery after exercise. We analyzed the records of 2443 patients of both sexes, aged between 20 and 59 years, in sinus rhythm, not using negative chronotropic agents and with no myocardial ischemic response to exercise testing carried out at a specialist clinic, between 2005 and 2011. BMI was categorized as normal (18.5-<25 kg/m(2)), overweight (25-≤30 kg/m(2)) or obese (>30 kg/m(2)). The different BMI groups were compared in terms of HR recovery after exercise, which was calculated as the difference between maximum HR during exercise and in the first minute of recovery. Recovery was considered impaired when the difference was ≤12 bpm. Eighty-seven (3.6%) patients presented impaired recovery, which was three times more prevalent in the obese group and twice as prevalent in the overweight group compared with the normal group (p<0.001 and p=0.010, respectively). Obese patients presented higher basal HR and lower maximum HR, as well as reduced chronotropic reserve (p<0.001). In multivariate analysis, impaired HR recovery was associated with overweight (relative risk [RR]=1.8; p=0.035), obesity (RR=2; p=0.016), number of metabolic equivalents (RR=0.82; p<0.001) and resting HR (RR=1.05; p<0.001). The hazard ratio for hypertension was 2 (p=0.083, NS). Impaired HR recovery was associated with higher BMI, demonstrating that obese individuals present vagus nerve dysfunction. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  16. A Bayesian hierarchical model for reconstructing relative sea level: from raw data to rates of change

    NASA Astrophysics Data System (ADS)

    Cahill, N.; Kemp, A. C.; Horton, B. P.; Parnell, A. C.

    2015-10-01

    We present a holistic Bayesian hierarchical model for reconstructing the continuous and dynamic evolution of relative sea-level (RSL) change with fully quantified uncertainty. The reconstruction is produced from biological (foraminifera) and geochemical (δ13C) sea-level indicators preserved in dated cores of salt-marsh sediment. Our model is comprised of three modules: (1) A Bayesian transfer function for the calibration of foraminifera into tidal elevation, which is flexible enough to formally accommodate additional proxies (in this case bulk-sediment δ13C values), (2) A chronology developed from an existing Bchron age-depth model, and (3) An existing errors-in-variables integrated Gaussian process (EIV-IGP) model for estimating rates of sea-level change. We illustrate our approach using a case study of Common Era sea-level variability from New Jersey. USA We develop a new Bayesian transfer function (B-TF), with and without the δ13C proxy and compare our results to those from a widely-used weighted-averaging transfer function (WA-TF). The formal incorporation of a second proxy into the B-TF model results in smaller vertical uncertainties and improved accuracy for reconstructed RSL. The vertical uncertainty from the multi-proxy B-TF is ∼ 28 % smaller on average compared to the WA-TF. When evaluated against historic tide-gauge measurements, the multi-proxy B-TF most accurately reconstructs the RSL changes observed in the instrumental record (MSE = 0.003 m2). The holistic model provides a single, unifying framework for reconstructing and analysing sea level through time. This approach is suitable for reconstructing other paleoenvironmental variables using biological proxies.

  17. A Bayesian hierarchical model for reconstructing relative sea level: from raw data to rates of change

    NASA Astrophysics Data System (ADS)

    Cahill, Niamh; Kemp, Andrew C.; Horton, Benjamin P.; Parnell, Andrew C.

    2016-02-01

    We present a Bayesian hierarchical model for reconstructing the continuous and dynamic evolution of relative sea-level (RSL) change with quantified uncertainty. The reconstruction is produced from biological (foraminifera) and geochemical (δ13C) sea-level indicators preserved in dated cores of salt-marsh sediment. Our model is comprised of three modules: (1) a new Bayesian transfer (B-TF) function for the calibration of biological indicators into tidal elevation, which is flexible enough to formally accommodate additional proxies; (2) an existing chronology developed using the Bchron age-depth model, and (3) an existing Errors-In-Variables integrated Gaussian process (EIV-IGP) model for estimating rates of sea-level change. Our approach is illustrated using a case study of Common Era sea-level variability from New Jersey, USA We develop a new B-TF using foraminifera, with and without the additional (δ13C) proxy and compare our results to those from a widely used weighted-averaging transfer function (WA-TF). The formal incorporation of a second proxy into the B-TF model results in smaller vertical uncertainties and improved accuracy for reconstructed RSL. The vertical uncertainty from the multi-proxy B-TF is ˜ 28 % smaller on average compared to the WA-TF. When evaluated against historic tide-gauge measurements, the multi-proxy B-TF most accurately reconstructs the RSL changes observed in the instrumental record (mean square error = 0.003 m2). The Bayesian hierarchical model provides a single, unifying framework for reconstructing and analyzing sea-level change through time. This approach is suitable for reconstructing other paleoenvironmental variables (e.g., temperature) using biological proxies.

  18. A Systemic Review of Autologous Fat Grafting Survival Rate and Related Severe Complications

    PubMed Central

    Yu, Nan-Ze; Huang, Jiu-Zuo; Zhang, Hao; Wang, Yang; Wang, Xiao-Jun; Zhao, Ru; Bai, Ming; Long, Xiao

    2015-01-01

    Objective: Clinical application of autologous fat grafting (AFG) is quickly expanding. Despite the widely acceptance, long-term survival rate (SR) of AFG remains a question not yet solved. Meanwhile, although rare, severe complications related to AFG including vision loss, stroke even death could be seen in the literature. Data Sources: A comprehensive research of PubMed database to June 2013 was performed according to guidelines of the American Society of Plastic Surgeons Fat Graft Task Force Assessment Methodology. Articles were screened using predetermined inclusion and exclusion criteria. Study Selection: Data collected included patient characteristics, surgical technique, donor site, recipient site, graft amount, and quantified measurement methods. Patient cohorts were pooled, and SR was calculated. All the severe complications were also summarized according to the different clinical characteristics. Results: Of 550 articles, 16 clinical articles and 10 animal studies met the inclusion criteria and provided quantified measurement methods. Totally, 596 patients were included. SR varied from 34% to 82% in breast and 30–83% in the facial area. Nude mice were applied to investigate human fat grafting SR (38.3–52.5% after 15 weeks). Rabbits were commonly used to study animal AFG SR (14.00–14.56% after 1-year). Totally, 21 severe complications were reported, including death (2), stroke (10), vision loss (11, 8 of which accompanied with stroke), sepsis (3), multiple abscess (1) and giant fat necrotic cyst (2). Ten of these complications happened within 10 years. Conclusions: There is no unified measurement method to evaluate fat graft SR until now and no clinical evidence to show better SR according to different donor and recipient cite. Body mass index change between pre- and postoperation may be the bias factor in evaluating fat SR. Fat embolisms of the ophthalmic artery and the middle cerebral artery are the most severe complication of AFG and still lack of

  19. Interannual variability of the atmospheric CO2 growth rate: relative contribution from precipitation and temperature

    NASA Astrophysics Data System (ADS)

    Wang, J.; Zeng, N.; Wang, M. R.

    2015-12-01

    The interannual variability (IAV) in atmospheric CO2 growth rate (CGR) is closely connected with the El Niño-Southern Oscillation. However, sensitivities of CGR to temperature and precipitation remain largely uncertain. This paper analyzed the relationship between Mauna Loa CGR and tropical land climatic elements. We find that Mauna Loa CGR lags precipitation by 4 months with a correlation coefficient of -0.63, leads temperature by 1 month (0.77), and correlates with soil moisture (-0.65) with zero lag. Additionally, precipitation and temperature are highly correlated (-0.66), with precipitation leading by 4-5 months. Regression analysis shows that sensitivities of Mauna Loa CGR to temperature and precipitation are 2.92 ± 0.20 Pg C yr-1 K-1 and -0.46 ± 0.07 Pg C yr-1 100 mm-1, respectively. Unlike some recent suggestions, these empirical relationships favor neither temperature nor precipitation as the dominant factor of CGR IAV. We further analyzed seven terrestrial carbon cycle models, from the TRENDY project, to study the processes underlying CGR IAV. All models capture well the IAV of tropical land-atmosphere carbon flux (CFTA). Sensitivities of the ensemble mean CFTA to temperature and precipitation are 3.18 ± 0.11 Pg C yr-1 K-1 and -0.67 ± 0.04 Pg C yr-1 100 mm-1, close to Mauna Loa CGR. Importantly, the models consistently show the variability in net primary productivity (NPP) dominates CGR, rather than soil respiration. Because NPP is largely driven by precipitation, this suggests a key role of precipitation in CGR IAV despite the higher CGR correlation with temperature. Understanding the relative contribution of CO2 sensitivity to precipitation and temperature has important implications for future carbon-climate feedback using such "emergent constraint".

  20. Initial foot contact and related kinematics affect impact loading rate in running.

    PubMed

    Breine, Bastiaan; Malcolm, Philippe; Van Caekenberghe, Ine; Fiers, Pieter; Frederick, Edward C; De Clercq, Dirk

    2017-08-01

    This study assessed kinematic differences between different foot strike patterns and their relationship with peak vertical instantaneous loading rate (VILR) of the ground reaction force (GRF). Fifty-two runners ran at 3.2 m · s(-1) while we recorded GRF and lower limb kinematics and determined foot strike pattern: Typical or Atypical rearfoot strike (RFS), midfoot strike (MFS) of forefoot strike (FFS). Typical RFS had longer contact times and a lower leg stiffness than Atypical RFS and MFS. Typical RFS showed a dorsiflexed ankle (7.2 ± 3.5°) and positive foot angle (20.4 ± 4.8°) at initial contact while MFS showed a plantar flexed ankle (-10.4 ± 6.3°) and more horizontal foot (1.6 ± 3.1°). Atypical RFS showed a plantar flexed ankle (-3.1 ± 4.4°) and a small foot angle (7.0 ± 5.1°) at initial contact and had the highest VILR. For the RFS (Typical and Atypical RFS), foot angle at initial contact showed the highest correlation with VILR (r = -0.68). The observed higher VILR in Atypical RFS could be related to both ankle and foot kinematics and global running style that indicate a limited use of known kinematic impact absorbing "strategies" such as initial ankle dorsiflexion in MFS or initial ankle plantar flexion in Typical RFS.

  1. Baroreflex sensitivity assessment and heart rate variability: relation to maneuver and technique.

    PubMed

    Carrasco-Sosa, S; Gaitán-González, M J; González-Camarena, R; Yáñez-Suárez, Oscar

    2005-10-01

    In the present study, we examined two baroreflex sensitivity (BRS) issues that remain uncertain: the differences among diverse BRS assessment techniques and the association between BRS and vagal outflow. Accordingly, the electrocardiogram and non-invasive arterial pressure were recorded in 27 healthy subjects, during supine with and without controlled breathing, standing, exercise, and recovery conditions. Vagal outflow was estimated by heart rate variability indexes, whereas BRS was computed by alpha-coefficient, transfer function, complex demodulation in low- and high-frequency bands, and by sequence technique. Our results indicated that only supine maneuvers showed significantly greater BRS values over the high frequency than in the low-frequency band. For maneuvers at the same frequency region, supine conditions presented a larger number of significant differences among techniques. The plots between BRS and vagal measures depicted a funnel-shaped relationship with significant log-log correlations (r=0.880-0.958). Very short latencies between systolic pressure and RR interval series in high-frequency band and strong log-log correlations between frequency bands were found. Higher variability among different baroreflex measurements was associated with higher level of vagal outflow. Methodological assumptions for each technique seem affected by non-baroreflex variation sources, and a modified responsiveness of vagal motoneurons due to distinct stimulation levels for each maneuver was suggested. Thus, highest vagal outflows corresponded to greatest BRS values, with maximum respiratory effect for the high-frequency band values. In conclusion, BRS values and differences across the tested techniques were strongly related to the vagal outflow induced by the maneuvers.

  2. Catch rates relative to angler party size with implications for monitoring angler success

    USGS Publications Warehouse

    Miranda, L.E.

    2005-01-01

    Angler catch rates often are used to monitor angler success, assess the need for additional management actions, and evaluate the effectiveness of management practices. Potential linkages between catch rate and angler party size were examined to assess how party size might affect the use of catch rate as an index of angler success in recreational fisheries. Data representing 22,355 completed interviews conducted at access points in lakes and reservoirs throughout Mississippi during 1987-2003 were analyzed. Total party catch was not proportional to total party effort; thus, catch rate decreased as party size increased. Depending on the taxa targeted, the average catch rate per angler decreased 40-50% between parties of one and parties of two, although subsequent decreases were less substantial. Because party size accounted for a considerable portion of the variability in catch rate over time and space, failure to remove this variability weakens the manager's ability to detect differences or changes in catch rates. Therefore, the use of catch rates to monitor fisheries may be inappropriate unless party size is taken into account. Party size may influence the angler's ability to catch fish through a variety of processes, including partitioning a limited number of catchable fish among members of a party and party composition. When catch rates are used to estimate total catch rather than to index angler success, party size is not a concern.

  3. How is the rate of climatic-niche evolution related to climatic-niche breadth?

    PubMed

    Fisher-Reid, M Caitlin; Kozak, Kenneth H; Wiens, John J

    2012-12-01

    The rate of climatic-niche evolution is important to many research areas in ecology, evolution, and conservation biology, including responses of species to global climate change, spread of invasive species, speciation, biogeography, and patterns of species richness. Previous studies have implied that clades with higher rates of climatic-niche evolution among species should have species with narrower niche breadths, but there is also evidence suggesting the opposite pattern. However, the relationships between rate and breadth have not been explicitly analyzed. Here, we examine the relationships between the rate of climatic-niche evolution and climatic-niche breadth using phylogenetic and climatic data for 250 species in the salamander family Plethodontidae, a group showing considerable variation in both rates of climatic-niche evolution and climatic-niche breadths. Contrary to some expectations, we find no general relationship between climatic-niche breadth and the rate of climatic-niche evolution. Climatic-niche breadths for some ecologically important climatic variables considered separately (temperature seasonality and annual precipitation) do show significant relationships with the rate of climatic-niche evolution, but rates are faster in clades in which species have broader (not narrower) niche breadths. In summary, our results show that narrower niche breadths are not necessarily associated with faster rates of niche evolution. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  4. Structure/property relations of aluminum under varying rates and stress states

    SciTech Connect

    Tucker, Matthew T; Horstemeyer, Mark F; Whittington, Wilburn R; Solanki, Kiran N

    2010-11-19

    In this work we analyze the plasticity, damage, and fracture characteristics of three different processed aluminum alloys (rolled 5083-H13, cast A356-T6, and extruded 6061-T6) under varying stress states (tension, compression, and torsion) and strain rates (0.001/, 1/s., and 1000/s). The stress state difference had more of a flow stress effect than the applied strain rates for those given in this study (0.001/sec up to 1000/sec). The stress state and strain rate also had a profound effect on the damage evolution of each aluminum alloy. Tension and torsional straining gave much greater damage nucleation rates than compression. Although the damage of all three alloys was found to be void nucleation dominated, the A356-T6 and 5083-H131 aluminum alloys incurred void damage via micron scale particles where the 6061-T6 aluminum alloy incurred void damage from two scales, micron-scale particles and nanoscale precipitates. Having two length scales of particles that participated in the damage evolution made the 6061-T6 incur a strain rate sensitive damage rate that was different than the other two aluminum alloys. Under tension, as the strain rate increased, the 6061-T6 aluminum alloy's void nucleation rate decreased, but the A356-T6 and 5083-H131 aluminum alloys void nucleation rate increased.

  5. Differences in Hispanic Access and Success Rates for Health-Related Studies in Texas Health-Related Institutions: A Multiyear, Statewide Investigation

    ERIC Educational Resources Information Center

    Cox, Shelley M.

    2013-01-01

    Purpose: The purpose of this study was to examine Hispanic student access and success in health-related degrees by examining enrollment and graduation rates over a period of 13 years. Archival data were obtained from the THECB consisting of the number of Hispanic students enrolled and number of degrees awarded in the health-related degrees at…

  6. Differences in Hispanic Access and Success Rates for Health-Related Studies in Texas Health-Related Institutions: A Multiyear, Statewide Investigation

    ERIC Educational Resources Information Center

    Cox, Shelley M.

    2013-01-01

    Purpose: The purpose of this study was to examine Hispanic student access and success in health-related degrees by examining enrollment and graduation rates over a period of 13 years. Archival data were obtained from the THECB consisting of the number of Hispanic students enrolled and number of degrees awarded in the health-related degrees at…

  7. Social connections, immigration-related factors, and self-rated physical and mental health among Asian Americans.

    PubMed

    Zhang, Wei; Ta, Van M

    2009-06-01

    Focusing on Asian Americans, this study examines how self-rated physical and mental health depends on the layered social connections (including 4 types: family cohesion, relative support, friend support, and neighborhood cohesion), socioeconomic status, and immigration-related factors (including nativity, length of residence in the U.S., and proficiency of the English language). It draws on the 2002-2003 National Latino and Asian American Study, a nationally representative household survey of Latino and Asian Americans. Findings of this study include: (1) there are significant differences in self-rated physical health among Asian Americans of different national origin, but their self-rated physical health differences diminish after indicators of socioeconomic status and immigration-related factors are considered; (2) four types of social connections are all related to the self-rated physical and mental health of Asian Americans, but the patterns of the associations as well as the mechanisms linking the associations vary; and (3) family cohesion has independent and direct effects on both self-rated physical and mental health over and above controls and mediators, whereas the effects of other social connection measures are partially mediated by socioeconomic status and immigration-related factors. In sum, this study indicates the significant effects of social connections, socioeconomic status, and immigration-related factors on the self-rated physical and mental health of Asian Americans.

  8. [Age-related dynamics of roach infection rate with Ligula intestinalis (Cestoda: Ligulidae) plerocercoids and probability of its usage for the calculation of host death rate].

    PubMed

    Pronin, N M; Pronina, S V

    2014-01-01

    Results of special parasitological dissections of roach samples from catches with the same fishing gear and at the same station (Monakhovo Cove, Chivyrkui Bay of the Lake Baikal) and at the same time in different years (1998-2002) are given. Stability of age-related dynamics of roach infection rate with Ligula intestinalisis in different years with the maximum of prevalence and mean abundance in fish of 3+ age, and the following sharp decrease in these rates in elder age groups, was revealed. Basing on prevalence decreasing of a single roach generation, the rate of fish mortality during its growth from age group 3+ to 4+ was estimated as 15.9-20.7%.

  9. Research on Mail Surveys: Response Rates and Methods in Relation to Population Group and Time.

    ERIC Educational Resources Information Center

    Boser, Judith A.; Green, Kathy

    The purpose of this review was to look for trends across time in response rates and variables studied for published mail surveys and to compare response rates and variables studied for different target populations. Studies were identified in databases in four fields: education, psychology, business and marketing, and sociology. A total of 225…

  10. Teacher Education Follow-up Surveys: Variables Related to Response Rate.

    ERIC Educational Resources Information Center

    Boser, Judith A.

    This study of teacher education graduate follow-up surveys examined the relationship between response rate and number of graduates, questionnaire length, and follow-up contacts. Also, the study investigated survey practices differentiating between surveys which had high and low return rates in such areas as number of follow-up contacts,…

  11. Problem Behavior and Heart Rate Reactivity in Adopted Adolescents: Longitudinal and Concurrent Relations

    ERIC Educational Resources Information Center

    Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.

    2008-01-01

    The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…

  12. Addition by Subtraction: The Relation between Dropout Rates and School-Level Academic Achievement

    ERIC Educational Resources Information Center

    Glennie, Elizabeth; Bonneau, Kara; vanDellen, Michelle; Dodge, Kenneth A.

    2012-01-01

    Background/Context: Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding…

  13. Addition by Subtraction: The Relation between Dropout Rates and School-Level Academic Achievement

    ERIC Educational Resources Information Center

    Glennie, Elizabeth; Bonneau, Kara; vanDellen, Michelle; Dodge, Kenneth A.

    2012-01-01

    Background/Context: Efforts to improve student achievement should increase graduation rates. However, work investigating the effects of student-level accountability has consistently demonstrated that increases in the standards for high school graduation are correlated with increases in dropout rates. The most favored explanation for this finding…

  14. Understanding the Declining Canadian Homicide Rate: A Test of Holinger's Relative Cohort Size Hypothesis

    ERIC Educational Resources Information Center

    Leenaars, Antoon A.; Lester, David

    2004-01-01

    Homicide rates in Canada have shown a decline since 1975, but there has been little empirical study of this trend. P. Holinger (1987) predicted and confirmed that the size of the cohort aged 15-24 in the United States population was associated with the rise and fall of the homicide rate in that country. This study was designed to test this…

  15. Problem Behavior and Heart Rate Reactivity in Adopted Adolescents: Longitudinal and Concurrent Relations

    ERIC Educational Resources Information Center

    Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.

    2008-01-01

    The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…

  16. Rate constants and temperature dependences for the reactions of hydroxyl radical with several halogenated methanes, ethanes, and propanes by relative rate measurements

    NASA Technical Reports Server (NTRS)

    Hsu, K.-J.; DeMore, W. B.

    1995-01-01

    Rate constants of 15 OH reactions with halogen-substituted alkanes, C1 to C3, were studied using a relative rate technique in the temperature range 283-403 K. Compounds studied were CHF2Cl (22), CHF2Br (22B), CH3F (41), CH2F2 (32), CHF3 (23), CHClFCCl2F (122a), CHCl2CF3 (123), CHClFCF3 (124), CH3CF3 (143a), CH3CH2F (161), CF3CHFCF3 (227ea), CF3CH2CF3 (236fa), CF3CHFCHF2 (236ea), and CHF2CF2CH2F (245ca). Using CH4, CH3CCl3, CF3CF2H, and C2H6 as primary reference standards (JPL 92-20 rate constants), absolute rate constants are derived. Results are in good agreement with previous experimental results for six of the compounds studied, including CHF2Cl, CHF2Br, CH2F2, CH3CF3, CHFClCFCl2, and CF3CHFCF3. For the remainder the relative rate constants are lower than those derived from experiments in which OH loss was used to measure the reaction rate. Comparisons of the derived Arrhenius A factors with previous literature transition-state calculations show order of magnitude agreement in most cases. However, the experimental A factors show a much closer proportionality to the number of H atoms in the molecule than is evident from the transition state calculations. For most of the compounds studied, an A factor of (8 +/- 3)E-13 cm(exp 3)/(molecule s) per C-H bond is observed. A new measurement of the ratio k(CH3CCl3)/k(CH4) is reported that is in good agreement with previous data.

  17. Assessment of daily profiles of ADHD and ODD symptoms, and symptomatology related to ADHD medication, by parent and teacher ratings.

    PubMed

    Breuer, Dieter; Görtz-Dorten, Anja; Rothenberger, Aribert; Döpfner, Manfred

    2011-10-01

    DAYAS is a new two-part rating scale that assesses: (1) ADHD and ODD symptoms (externalising symptom ratings) and (2) symptomatology potentially related to ADHD medication (potentially medication-related symptoms) in real-world settings at different time periods throughout a normal school day. Data from a proof-of-concept study and two observational trials (Medikinet(®) retard [methylphenidate] and the Equasym XL(®) [methylphenidate] OBSEER study) evaluated: (1) validity of weekly externalising symptom ratings using DAYAS, in place of daily ratings; (2) reliability and internal consistency of DAYAS ratings for externalising symptoms and potentially medication-related symptoms; and (3) convergent and divergent validity of the externalising symptom ratings with existing validated scales. From the proof-of-concept study, daily scores by period of day and during the whole day correlated strongly with equivalent weekly scores (r = 0.83-0.92). Internal consistency of externalising symptom rating scales calculated from pooled data were acceptable or good by period of day (Cronbach's alpha = 0.68-0.90) and very high for whole day scores (Cronbach's alpha = 0.88-0.95). Internal consistency of the rating scale for potentially medication-related symptoms was also good for both teacher and parent ratings. From OBSEER data, correlations between FBB-ADHD total symptom scores and ratings on both parent and teacher versions of DAYAS were high (r = 0.73 and r = 0.84, respectively). Correlations between DAYAS and SDQ were highest for the SDQ subscales hyperactivity and conduct problems and substantially lower for pro-social behaviour, peers and emotional problems. The DAYAS rating scale had good internal consistency, and DAYAS scores correlated well with existing validated scales and the SDQ subscales hyperactivity and conduct problems. Weekly DAYAS scores (whole day and by period of day) could be considered a suitable replacement for daily assessment scores.

  18. Ratings of managerial skill requirements: comparison of age- and job-related factors.

    PubMed

    Avolio, B J; Waldman, D A

    1989-12-01

    This article examines how individual characteristics (age, experience) and organizational characteristics (department, level) influence the skill requirements rated as being important for managerial jobs. One hundred ninety-seven managerial employees completed a survey composed of 20 skill dimensions pertinent to supervisory positions in the mining industry. Organizational level and departmental affiliation were correlated with job skill importance ratings. Ratings of skill importance were also correlated with the age of the person being rated, years of experience, and the age of the rater. As predicted, correlations with ratee age varied across different skill dimensions. This study has implications for fair employment practices to the degree that raters base evaluations of a job on the age of incumbents vs. job relevant characteristics.

  19. Photon dose rates from spent fuel assemblies with relation to self- protection

    SciTech Connect

    Pond, R.B.; Matos, J.E.

    1995-12-01

    Photon dose rates as a function of fission product decay times have been calculated for spent fuel assemblies typical of MTR-type research and test reactors. Based upon these dose rates, the length of time that a spent fuel assembly will be self-protecting (dose rate greater than 100 rem/h at 1 m in air) can be estimated knowing the mass of fuel burned, the fraction of fuel burned, and the fuel assembly specific power density. The calculated dose rates cover 20 years of fission product decay, spent fuel with up to 80% {sup 235}U burnup and assembly power densities ranging from 0.089 to 2.857 MW/kg{sup 235}U. Most of the results are unshielded dose rates at 1 m in air with some shielded dose rates at 40 cm in water. Dose rate sensitivity estimates have been evaluated for a variety of MTR fuel assembly designs and for uncertainties in both the physical and analytical models of the fuel assemblies.

  20. Components of the cannabinoid system in the dorsal periaqueductal gray are related to resting heart rate

    PubMed Central

    Dean, Caron; Hillard, Cecilia J.; Seagard, Jeanne L.; Hopp, Francis A.; Hogan, Quinn H.

    2016-01-01

    The present study was undertaken to examine whether variations in endocannabinoid signaling in the dorsal periaqueductal gray (dPAG) are associated with baseline autonomic nerve activity, heart rate, and blood pressure. Blood pressure was recorded telemetrically in rats, and heart rate and power spectral analysis of heart rate variability were determined. Natural variations from animal to animal provided a range of baseline values for analysis. Transcript levels of endocannabinoid signaling components in the dPAG were analyzed, and endocannabinoid content and catabolic enzyme activity were measured. Higher baseline heart rate was associated with increased anandamide content and with decreased activity of the anandamide-hydrolyzing enzyme and fatty acid amide hydrolase (FAAH), and it was negatively correlated with transcript levels of both FAAH and monoacylglycerol lipase (MAGL), a catabolic enzyme for 2-arachidonoylglycerol (2-AG). Autonomic tone and heart rate, but not blood pressure, were correlated to levels of FAAH mRNA. In accordance with these data, exogenous anandamide in the dPAG of anesthetized rats increased heart rate. These data indicate that in the dPAG, anandamide, a FAAH-regulated lipid, contributes to regulation of baseline heart rate through influences on autonomic outflow. PMID:27280429

  1. Relation of body weight and food consumption to metabolic rate of juvenile Japanese sea bass, Lateolabrax japonicus

    NASA Astrophysics Data System (ADS)

    Xian, Wei-Wei; Zhu, Xin-Hua

    2000-12-01

    The metabolic rate of Japanese sea bass, Lateolabrax japonicus (C & V), was estimated in laboratory at temperature 25.2±0.5°C. The fresh weight of the fish was 4.64 52.28 g (average of 17.81±0.33 g). The routine metabolism was related to body weight by the exponential equation: R r =14.966 W 0.74 ( r=0.934). The rate of feeding metabolism increased linearly with food consumption. Feeding metabolic rate was 1.8 2.4 times the routine metabolic rate.

  2. Oxygen ionization rates at Mars and Venus - Relative contributions of impact ionization and charge exchange

    NASA Technical Reports Server (NTRS)

    Zhang, M. H. G.; Luhmann, J. G.; Nagy, A. F.; Spreiter, J. R.; Stahara, S. S.

    1993-01-01

    Oxygen ion production rates above the ionopauses of Venus and Mars are calculated for photoionization, charge exchange, and solar wind electron impact ionization processes. The latter two require the use of the Spreiter and Stahara (1980) gas dynamic model to estimate magnetosheath velocities, densities, and temperatures. The results indicate that impact ionization is the dominant mechanism for the production of O(+) ions at both Venus and Mars. This finding might explain both the high ion escape rates measured by Phobos 2 and the greater mass loading rate inferred for Venus from the bow shock positions.

  3. Strongly magnetized rotating dipole in general relativity

    NASA Astrophysics Data System (ADS)

    Pétri, J.

    2016-10-01

    Context. Electromagnetic waves arise in many areas of physics. Solutions are difficult to find in the general case. Aims: We numerically integrate Maxwell equations in a 3D spherical polar coordinate system. Methods: Straightforward finite difference methods would lead to a coordinate singularity along the polar axis. Spectral methods are better suited for such artificial singularities that are related to the choice of a coordinate system. When the radiating object rotates like a star, for example, special classes of solutions to Maxwell equations are worthwhile to study, such as quasi-stationary regimes. Moreover, in high-energy astrophysics, strong gravitational and magnetic fields are present especially around rotating neutron stars. Results: To study such systems, we designed an algorithm to solve the time-dependent Maxwell equations in spherical polar coordinates including general relativity and quantum electrodynamical corrections to leading order. As a diagnostic, we computed the spin-down luminosity expected for these stars and compared it to the classical or non-relativistic and non-quantum mechanical results. Conclusions: Quantum electrodynamics leads to an irrelevant change in the spin-down luminosity even for a magnetic field of about the critical value of 4.4 × 109 T. Therefore the braking index remains close to its value for a point dipole in vacuum, namely n = 3. The same conclusion holds for a general-relativistic quantum electrodynamically corrected force-free magnetosphere.

  4. Correlation of mutagenic assessment of Houston air particulate extracts in relation to lung cancer mortality rates

    SciTech Connect

    Walker, R.D.; Connor, T.H.; MacDonald, E.J.; Trieff, N.M.; Legator, M.S.; MacKenzie, K.W. Jr.; Dobbins, J.G.

    1982-08-01

    Air particulate extracts from a series of solvents were tested in the Ames mutagen detection system and were found to be mutagenic in varying degrees as a function of the particulate collection site in Houston, Texas. The mutagenicity level at seven sites was compared with age-adjusted mortality rates in the same areas. Significant correlation was found with the lung cancer mortality rates but not with mortality rates for other causes. These findings support the hypothesis of a contribution of urban air particulate to the lung cancer rates. Furthermore, these findings suggest that an index of the mutagenicity of air particulate is a more powerful measure of the human health hazard of air pollution than the traditional indices of particulate concentration.

  5. Age-adjustment and related epidemiology rates in education and research.

    PubMed

    Baker, John D; Kruckman, Laurence; George, Joyce

    2006-01-01

    A quick review of introductory textbooks reveals that while gerontology authors and instructors introduce some aspect of demography and epidemiology data, there is limited focus on age adjustment or other important epidemiology rates. The goal of this paper is to reintroduce a variety of basic epidemiology strategies such as incidence, prevalence, crude, age-specific and age-adjustment rates into the gerontology classroom. Background information and formulas for each rate, as well as examples of how they can be applied are provided. A recent change, encouraged by the U.S. Department of Health and Human Services, from a 1940 to a 2000 "standard million population" for ageadjusted rates, is reviewed. Finally, a teaching module with answers is provided for use in the gerontology classroom.

  6. Exposure to X-rated movies and adolescents' sexual and contraceptive-related attitudes and behaviors.

    PubMed

    Wingood, G M; DiClemente, R J; Harrington, K; Davies, S; Hook, E W; Oh, M K

    2001-05-01

    To examine the association between exposure to X-rated movies and teens' contraceptive attitudes and behaviors. Black females, 14 to 18 years old (n = 522) were recruited from adolescent medicine clinics, health departments, and school health clinics. Exposure to X-rated movies was reported by 29.7% of adolescents. Exposure to X-rated movies was associated with being more likely to have negative attitudes toward using condoms (odds ratio [OR]: 1.4), to have multiple sex partners (OR: 2.0), to have sex more frequently (OR: 1.8), to not have not used contraception during the last intercourse (OR: 1.5), to have not used contraception in the past 6 months (OR: 2.2), to have a strong desire to conceive (OR: 2.3), and to test positive for chlamydia (OR: 1.7). Additional research is needed to understand the impact of X-rated movies on adolescents' sexual and contraceptive health.

  7. Relation between gastric emptying rate and energy intake in children compared with adults.

    PubMed Central

    Maes, B D; Ghoos, Y F; Geypens, B J; Hiele, M I; Rutgeerts, P J

    1995-01-01

    Measurement of gastric emptying rate of solids in children is difficult because the available methods are either invasive or induce a substantial radiation burden. In this study the newly developed 13C octanoic acid breath test was used to examine the gastric emptying rate of solids and milk in healthy children and to compare gastric emptying in children and adults. Fifteen healthy children and three groups of nine healthy adults were studied, using three different test meals labelled with 50 mg of 13C octanoic acid: a low caloric pancake (150 kcal), a high caloric pancake (250 kcal), and 210 ml of milk (134 kcal). Breath samples were taken before and at regular intervals after ingestion of the test meal, and analysed by isotope ratio mass spectrometry. The gastric emptying parameters were derived from the 13CO2 excretion curves by non-linear regression analysis. No significant difference was found between children and adults in the emptying rate of the low caloric solid test meal. In children as well as in adults, increasing the energy content of the solid meal resulted in a significantly slower emptying rate. The milk test meal, however, was emptied at a faster rate in adults and at slower rate in children compared with the low caloric solid test meal. Moreover, the emptying rate of milk in children was significantly slower than in adults. In conclusion, a similar gastric emptying rate of solids but a slower emptying of full cream milk was shown in children of school age compared with adults, using the non-radioactive 13C octanoic acid breath test. PMID:7883214

  8. The influence of strain rate dependency on the structure-property relations of porcine brain.

    PubMed

    Begonia, Mark T; Prabhu, Raj; Liao, Jun; Horstemeyer, Mark F; Williams, Lakiesha N

    2010-10-01

    This study examines the internal microstructure evolution of porcine brain during mechanical deformation. Strain rate dependency of porcine brain was investigated under quasi-static compression for strain rates of 0.00625, 0.025, and 0.10 s(-1). Confocal microscopy was employed at 15, 30, and 40% strain to quantify microstructural changes, and image analysis was implemented to calculate the area fraction of neurons and glial cells. The nonlinear stress-strain behavior exhibited a viscoelastic response from the strain rate sensitivity observed, and image analysis revealed that the mean area fraction of neurons and glial cells increased according to the applied strain level and strain rate. The area fraction for the undamaged state was 7.85 ± 0.07%, but at 40% strain the values were 11.55 ± 0.35%, 13.30 ± 0.28%, and 19.50 ± 0.14% for respective strain rates of 0.00625, 0.025, and 0.10 s(-1). The increased area fractions were a function of the applied strain rate and were attributed to the compaction of neural constituents and the stiffening tissue response. The microstructural variations in the tissue were linked to mechanical properties at progressive levels of compression in order to generate structure-property relationships useful for refining current FE material models.

  9. [Morbidity and mortality rates in relation to the "surgeon factor" after duodenopancreatectomy].

    PubMed

    Targarona, Javier; Pando, Elizabeth; Garatea, Rafael; Vavoulis, Alexandra; Montoya, Eduardo

    2007-10-01

    The present study was designed to determine whether the surgeon factor has an independent effect on morbidity and mortality rates after duodenopancreatectomy. Between October 2002 and December 2006, we performed a study of 119 patients who underwent duodenopancreatectomy. The surgeons were divided into 3 groups according to the number of interventions they performed each year: a low volume group (three Whipple procedures per year), a medium volume group (four to 10 Whipple procedures per year) and a high volume group (> 10 Whipple procedures per year). The morbidity rate was higher in the low volume group (82%) than in the high volume group (35%). Length of hospital stay was clearly longer in the low and medium volume groups (27 days, and 21 days) than in the high volume group (17 days). Comparison of the results of the 3 groups revealed that the group performing three or less interventions per year (low volume) had the highest mortality rate (47%), while the group performing more than 10 interventions per year (high volume) had a very low mortality rate (4%). We found that the volume-to-surgeon ratio was inversely proportional to morbidity, length of hospital stay, return to oral intake, and mortality rates. Therefore, increasing surgical volume could improve morbidity and mortality rates.

  10. Heart rate in Palaemon northropi (Rankin) in relation to acute changes in thermal environment

    SciTech Connect

    Swanson, C.J.; Wingard, C.; Kitakis, F. )

    1991-03-15

    The Glass Shrimp (Palaemon northropi), common to shallow water/tide pool environs of Atlantic waters, was examined in a series of experiments whereby the temperature-dependence of steady-state heart rate was assessed after acute, controlled changed in their thermal environment. Collection site, tide pool variations averaged 17.2-31.6C/24 hr. period. Accordingly, steady-state heart rates were determined at 5, 15, 25, and 30C by using both timed, optical recording and impedance methods. Mean values obtained were 88bpm (5C), 181 bpm(15C), 236bpm(25C), and 52bpm(30C). Calculated Q{sub 10} determinations ranged from the limits of 1.3 to 2.1 excluding the highest temperature state used. Specimens used averaged 0.62gm wet body weight, and no significant difference between males and gravid females was found. Additionally, the impedance method employed allowed for more precise rate determinations at high heart rates: at the lower heart rates, there was no difference between optically-timed vs. impedance method. Measurement at 30C characteristically showed a severe depression of heart rate, and high mortality after determinations. It is concluded that in situ field survival of Palaemon northropi may involve a time-dependence and/or other mechanisms whereby upper environmental temperatures may be abated.

  11. Predicting self-rated mental and physical health: the contributions of subjective socioeconomic status and personal relative deprivation.

    PubMed

    Callan, Mitchell J; Kim, Hyunji; Matthews, William J

    2015-01-01

    Lower subjective socioeconomic status (SSS) and higher personal relative deprivation (PRD) relate to poorer health. Both constructs concern people's perceived relative social position, but they differ in their emphasis on the reference groups people use to determine their comparative disadvantage (national population vs. similar others) and the importance of resentment that may arise from such adverse comparisons. We investigated the relative utility of SSS and PRD as predictors of self-rated physical and mental health (e.g., self-rated health, stress, health complaints). Across six studies, self-rated physical and mental health were on the whole better predicted by measures of PRD than by SSS while controlling for objective socioeconomic status (SES), with SSS rarely contributing unique variance over and above PRD and SES. Studies 4-6 discount the possibility that the superiority of PRD over SSS in predicting health is due to psychometric differences (e.g., reliability) or response biases between the measures.

  12. GAS REGULATION OF GALAXIES: THE EVOLUTION OF THE COSMIC SPECIFIC STAR FORMATION RATE, THE METALLICITY-MASS-STAR-FORMATION RATE RELATION, AND THE STELLAR CONTENT OF HALOS

    SciTech Connect

    Lilly, Simon J.; Carollo, C. Marcella; Pipino, Antonio; Peng Yingjie; Renzini, Alvio

    2013-08-01

    A very simple physical model of galaxies is one in which the formation of stars is instantaneously regulated by the mass of gas in a reservoir with mass loss scaling with the star-formation rate (SFR). This model links together three different aspects of the evolving galaxy population: (1) the cosmic time evolution of the specific star-formation rate (sSFR) relative to the growth of halos, (2) the gas-phase metallicities across the galaxy population and over cosmic time, and (3) the ratio of the stellar to dark matter mass of halos. The gas regulator is defined by the gas consumption timescale ({epsilon}{sup -1}) and the mass loading {lambda} of the wind outflow {lambda}{center_dot}SFR. The simplest regulator, in which {epsilon} and {lambda} are constant, sets the sSFR equal to exactly the specific accretion rate of the galaxy; more realistic situations lead to an sSFR that is perturbed from this precise relation. Because the gas consumption timescale is shorter than the timescale on which the system evolves, the metallicity Z is set primarily by the instantaneous operation of the regulator system rather than by the past history of the system. The metallicity of the gas reservoir depends on {epsilon}, {lambda}, and sSFR, and the regulator system therefore naturally produces a Z(m{sub star}, SFR) relation if {epsilon} and {lambda} depend on the stellar mass m{sub star}. Furthermore, this relation will be the same at all epochs unless the parameters {epsilon} and {lambda} themselves change with time. A so-called fundamental metallicity relation is naturally produced by these conditions. The overall mass-metallicity relation Z(m{sub star}) directly provides the fraction f{sub star}(m{sub star}) of incoming baryons that are being transformed into stars. The observed Z(m{sub star}) relation of Sloan Digital Sky Survey (SDSS) galaxies implies a strong dependence of stellar mass on halo mass that reconciles the different faint-end slopes of the stellar and halo mass

  13. Genome-wide association analysis identifies multiple loci related to resting heart rate

    PubMed Central

    Eijgelsheim, Mark; Newton-Cheh, Christopher; Sotoodehnia, Nona; de Bakker, Paul I.W.; Müller, Martina; Morrison, Alanna C.; Smith, Albert V.; Isaacs, Aaron; Sanna, Serena; Dörr, Marcus; Navarro, Pau; Fuchsberger, Christian; Nolte, Ilja M.; de Geus, Eco J.C.; Estrada, Karol; Hwang, Shih-Jen; Bis, Joshua C.; Rückert, Ina-Maria; Alonso, Alvaro; Launer, Lenore J.; Hottenga, Jouke Jan; Rivadeneira, Fernando; Noseworthy, Peter A.; Rice, Kenneth M.; Perz, Siegfried; Arking, Dan E.; Spector, Tim D.; Kors, Jan A.; Aulchenko, Yurii S.; Tarasov, Kirill V.; Homuth, Georg; Wild, Sarah H.; Marroni, Fabio; Gieger, Christian; Licht, Carmilla M.; Prineas, Ronald J.; Hofman, Albert; Rotter, Jerome I.; Hicks, Andrew A.; Ernst, Florian; Najjar, Samer S.; Wright, Alan F.; Peters, Annette; Fox, Ervin R.; Oostra, Ben A.; Kroemer, Heyo K.; Couper, David; Völzke, Henry; Campbell, Harry; Meitinger, Thomas; Uda, Manuela; Witteman, Jacqueline C.M.; Psaty, Bruce M.; Wichmann, H-Erich; Harris, Tamara B.; Kääb, Stefan; Siscovick, David S.; Jamshidi, Yalda; Uitterlinden, André G.; Folsom, Aaron R.; Larson, Martin G.; Wilson, James F.; Penninx, Brenda W.; Snieder, Harold; Pramstaller, Peter P.; van Duijn, Cornelia M.; Lakatta, Edward G.; Felix, Stephan B.; Gudnason, Vilmundur; Pfeufer, Arne; Heckbert, Susan R.; Stricker, Bruno H.Ch.; Boerwinkle, Eric; O'Donnell, Christopher J.

    2010-01-01

    Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that influence pathologic heart rate states, modulate heart rate through cardiac structure and function or by improving our understanding of the physiology of heart rate regulation. To identify common genetic variants associated with heart rate, we performed a meta-analysis of 15 genome-wide association studies (GWAS), including 38 991 subjects of European ancestry, estimating the association between age-, sex- and body mass-adjusted RR interval (inverse heart rate) and ∼2.5 million markers. Results with P < 5 × 10−8 were considered genome-wide significant. We constructed regression models with multiple markers to assess whether results at less stringent thresholds were likely to be truly associated with RR interval. We identified six novel associations with resting heart rate at six loci: 6q22 near GJA1; 14q12 near MYH7; 12p12 near SOX5, c12orf67, BCAT1, LRMP and CASC1; 6q22 near SLC35F1, PLN and c6orf204; 7q22 near SLC12A9 and UfSp1; and 11q12 near FADS1. Associations at 6q22 400 kb away from GJA1, at 14q12 MYH6 and at 1q32 near CD34 identified in previously published GWAS were confirmed. In aggregate, these variants explain ∼0.7% of RR interval variance. A multivariant regression model including 20 variants with P < 10−5 increased the explained variance to 1.6%, suggesting that some loci falling short of genome-wide significance are likely truly associated. Future research is warranted to elucidate underlying mechanisms that may impact clinical care. PMID:20639392

  14. Variation in calcification rate of Acropora downingi relative to seasonal changes in environmental conditions in the northeastern Persian Gulf

    NASA Astrophysics Data System (ADS)

    Vajed Samiei, Jahangir; Saleh, Abolfazl; Shirvani, Arash; Sheijooni Fumani, Neda; Hashtroudi, Mehri; Pratchett, Morgan Stuart

    2016-12-01

    There is a strong interest in understanding how coral calcification varies with changing environmental conditions, especially given the projected changes in temperature and aragonite saturation due to climate change. This study explores in situ variation in calcification rates of Acropora downingi in the northeastern Persian Gulf relative to seasonal changes in temperature, irradiance and aragonite saturation state ( Ω arag). Calcification rates of A. downingi were highest in the spring and lowest in the winter, and intra-annual variation in calcification rate was significantly related to temperature ( r 2 = 0.30) and irradiance ( r 2 = 0.36), but not Ω arag ( r 2 = 0.02). Seasonal differences in temperature are obviously confounded by differences in other environmental conditions and vice versa. Therefore, we used published relationships from experimental studies to establish which environmental parameter(s) (temperature, irradiance, and/or Ω arag) placed greatest constraints on calcification rate (relative to the maximum spring rate) in each season. Variation in calcification rates was largely attributable to seasonal changes in irradiance and temperature (possibly 57.4 and 39.7% respectively). Therefore, we predict that ocean warming may lead to increased rates of calcification during winter, but decelerate calcification during spring, fall and especially summer, resulting in net deceleration of calcification for A. downingi in the Persian Gulf.

  15. Plant and soil natural abundance delta (15)N: indicators of relative rates of nitrogen cycling in temperate forest ecosystems.

    PubMed

    Templer, Pamela H; Arthur, Mary A; Lovett, Gary M; Weathers, Kathleen C

    2007-08-01

    Watersheds within the Catskill Mountains, New York, receive among the highest rates of nitrogen (N) deposition in the northeastern United States and are beginning to show signs of N saturation. Despite similar amounts of N deposition across watersheds within the Catskill Mountains, rates of soil N cycling and N retention vary significantly among stands of different tree species. We examined the potential use of delta (15)N of plants and soils as an indicator of relative forest soil N cycling rates. We analyzed the delta (15)N of foliage, litterfall, bole wood, surface litter layer, fine roots and organic soil from single-species stands of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), red oak (Quercus rubra), and sugar maple (Acer saccharum). Fine root and organic soil delta (15)N values were highest within sugar maple stands, which correlated significantly with higher rates of net mineralization and nitrification. Results from this study suggest that fine root and organic soil delta (15)N can be used as an indicator of relative rates of soil N cycling. Although not statistically significant, delta (15)N was highest within foliage, wood and litterfall of beech stands, a tree species associated with intermediate levels of soil N cycling rates and forest N retention. Our results show that belowground delta (15)N values are a better indicator of relative rates of soil N cycling than are aboveground delta (15)N values.

  16. The Relations Between HSG Proven Tubal Occlusion, Stimulated Intrauterine Insemination and Pregnancy Rate

    PubMed Central

    Yetkin Yıldırım, Gonca; Orta Korkut, Ahu; Köroğlu, Nadiye; Susan Türkgeldi, Lale

    2017-01-01

    Background: Tubal factor infertility is one of the main causes of female infertility. Although its sensitivity is low, hysterosalpingography (HSG) is remains the first-line method for evaluating tubal patency. Aims: To compare pregnancy rates in patients with HSG proven proximal or distal unilateral tubal occlusion, and unexplained infertility undergoing both controlled ovarian stimulation (COS) and intrauterine insemination (IUI). Study Design: Case control study. Methods: In total, 237 patients undergoing ovulation induction (OI) with gonadotropins and IUI were divided into two groups and evaluated. Study group consisted 59 patients with HSG proven unilateral tubal pathology, and 178 patients with unexplained infertility taken as control subjects. Cumulative pregnancy rate was the primary endpoint. Results: Cumulative pregnancy rates after three cycles of OI and IUI were 15.25% in study group and 20.79% in control group. Pregnancy rates between two groups were not statistically significant. Although, pregnancy rates in patients with proximal tubal occlusion (21.8%) were higher than in those with distal tubal occlusion (7.4%), the difference was not statistically significant. Conclusion: Our study data shows that, regardless of the HCG proven occlusion area, COS and IUI might be a preferred treatment modality in patient with unilateral tubal occlusion. PMID:28251025

  17. The forward rate of binding of surface-tethered reactants: effect of relative motion between two surfaces.

    PubMed Central

    Chang, K C; Hammer, D A

    1999-01-01

    The reaction of molecules confined to two dimensions is of interest in cell adhesion, specifically for the reaction between cell surface receptors and substrate-bound ligand. We have developed a model to describe the overall rate of reaction of species that are bound to surfaces under relative motion, such that the Peclet number is order one or greater. The encounter rate between reactive species is calculated from solution of the two-dimensional convection-diffusion equation. The probability that each encounter will lead to binding depends on the intrinsic rate of reaction and the encounter duration. The encounter duration is obtained from the theory of first passage times. We find that the binding rate increases with relative velocity between the two surfaces, then reaches a plateau. This plateau indicates that the increase in the encounter rate is counterbalanced by the decrease in the encounter duration as the relative velocity increases. The binding rate is fully described by two dimensionless parameters, the Peclet number and the Damköhler number. We use this model to explain data from the cell adhesion literature by incorporating these rate laws into "adhesive dynamics" simulations to model the binding of a cell to a surface under flow. Leukocytes are known to display a "shear threshold effect" when binding selectin-coated surfaces under shear flow, defined as an increase in bind rate with shear; this effect, as calculated here, is due to an increase in collisions between receptor and ligand with increasing shear. The model can be used to explain other published data on the effect of wall shear rate on the binding of cells to surfaces, specifically the mild decrease in binding within a fixed area with increasing shear rate. PMID:10049312

  18. Effectiveness of traffic-related elements in tree bark and pollen abortion rates for assessing air pollution exposure on respiratory mortality rates.

    PubMed

    Carvalho-Oliveira, Regiani; Amato-Lourenço, Luís F; Moreira, Tiana C L; Silva, Douglas R Rocha; Vieira, Bruna D; Mauad, Thais; Saiki, Mitiko; Saldiva, Paulo H Nascimento

    2017-02-01

    The majority of epidemiological studies correlate the cardiorespiratory effects of air pollution exposure by considering the concentrations of pollutants measured from conventional monitoring networks. The conventional air quality monitoring methods are expensive, and their data are insufficient for providing good spatial resolution. We hypothesized that bioassays using plants could effectively determine pollutant gradients, thus helping to assess the risks associated with air pollution exposure. The study regions were determined from different prevalent respiratory death distributions in the Sao Paulo municipality. Samples of tree flower buds were collected from twelve sites in four regional districts. The genotoxic effects caused by air pollution were tested through a pollen abortion bioassay. Elements derived from vehicular traffic that accumulated in tree barks were determined using energy-dispersive X-ray fluorescence spectrometry (EDXRF). Mortality data were collected from the mortality information program of Sao Paulo City. Principal component analysis (PCA) was applied to the concentrations of elements accumulated in tree barks. Pearson correlation and exponential regression were performed considering the elements, pollen abortion rates and mortality data. PCA identified five factors, of which four represented elements related to vehicular traffic. The elements Al, S, Fe, Mn, Cu, and Zn showed a strong correlation with mortality rates (R(2)>0.87) and pollen abortion rates (R(2)>0.82). These results demonstrate that tree barks and pollen abortion rates allow for correlations between vehicular traffic emissions and associated outcomes such as genotoxic effects and mortality data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Does Occupation Explain Gender and Other Differences in Work-Related Eye Injury Hospitalization Rates?

    PubMed Central

    Smith, Gordon S.; Lincoln, Andrew E.; Wong, Tien Y.; Bell, Nicole S.; Vinger, Paul F.; Amoroso, Paul J.; Lombardi, David A.

    2007-01-01

    Objective We sought to determine whether demographic differences in eye injury rates persist after adjusting for occupational exposure. Methods On-duty eye injury hospitalizations were linked to occupation among active-duty US Army personnel. Results Eye injury rates were higher for white solidiers, men, and for younger soldiers, even after adjusting for occupational group and specific job titles using multivariate models. Conclusions This finding contrasts with studies of other injuries, suggesting that occupation does not fully account for variations in eye injury risk. Because protective eyewear can prevent most serious eye injuries, we hypothesize that differences in protective eyewear use between men and women may contribute to differences in eye injury rates, although follow-up studies are needed to confirm this. Prevention efforts should consider targeting high-risk demographic groups in addition to high-risk occupations. PMID:15951724

  20. Age-related disappearance of Mayer-like heart rate waves

    NASA Technical Reports Server (NTRS)

    Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.

    1987-01-01

    The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.

  1. Age-related disappearance of Mayer-like heart rate waves

    NASA Technical Reports Server (NTRS)

    Jarisch, W. R.; Ferguson, J. J.; Shannon, R. P.; Wei, J. Y.; Goldberger, A. L.

    1987-01-01

    The effect of age on the principal spectral components of heart rate obtained immediately after passive upright tilt was investigated in human subjects who underwent a 60-deg tilt over 9 sec. Two groups were examined, the first of which consisting of healthy male subjects aged 22-26 years, while the second was comprised of subjects aged 65-84 years on no medication; radiograms were recorded continuously beginning just prior to tilt until 3 min posttilt. The results of spectral analysis showed that elderly subjects did not exhibit the Mayer-like heart rate waves (the 0.07-0.09 Hz oscillations) that were present in the spectra of young subjects immediately after passive upright tilt. The findings are consistent with the concept of a 'dysautonomia of aging'. It is suggested that postural stress testing with spectral analysis of heart rate fluctuations may provide a useful way of assessing physiologic vs chronologic age.

  2. Relation between the location of elements in the periodic table and various organ-uptake rates.

    PubMed

    Ando, A; Ando, I; Hiraki, T; Hisada, K

    1989-01-01

    Fifty four elements and 65 radioactive compounds were examined to determine the organ uptake rates for rats 3, 24 and 48 h after i.v. injection of these compounds. They were prepared as carrier free nuclides, or containing a small amount of stable nuclide. Generally speaking, behaviors of K, Rb, Cs and Tl in all the organs were very similar to one another, but they differed from that of Na. Bivalent hard acids were avidly taken up into bone; therefore, uptake rates in soft tissues were very small. Hard acids of tri-, quadri- and pentavalence which were taken up into the soft tissue organs decreased more slowly from these organs than other ions. Soft acids such as Hg2+ were bound very firmly to the component in the kidney. Anions (with few exceptions), GeCl4 and SbCl3 were rapidly excreted in urine, so that the uptake rates in organs were low.

  3. Ratings of journals for the dissemination of pharmacy-related social and administrative science.

    PubMed

    Bunniran, Suvapun; Holmes, Erin R