240 research outputs found
A Preliminary Discussion of the Kinematics of BHB and RR Lyrae Stars near the North Galactic Pole
The radial velocity dispersion of 67 RR Lyrae variable and blue horizontal
branch (BHB) stars that are more than 4 kpc above the galactic plane at the
North Galactic Pole is 110 km/sec and shows no trend with Z (the height above
the galactic plane). Nine stars with Z < 4 kpc show a smaller velocity
dispersion (40 +/-9 km/sec) as is to be expected if they mostly belong to a
population with a flatter distribution. Both RR Lyrae stars and BHB stars show
evidence of stream motion; the most significant is in fields RR2 and RR3 where
24 stars in the range 4.0 < Z < 11.0 kpc have a mean radial velocity of -59 +/-
16 km/sec. Three halo stars in field RR 2 appear to be part of a moving group
with a common radial velocity of -90 km/sec. The streaming phenomenon therefore
occurs over a range of spatial scales. The BHB and RR Lyrae stars in our sample
both have a similar range of metallicity (-1.2 < [Fe/H] < -2.2). Proper motions
of BHB stars in fields SA 57 (NGP) and the Anticenter field (RR 7) (both of
which lie close to the meridional plane of the Galaxy) show that the stars that
have Z 4 kpc have a Galactic V motion that is
< -200 km/sec and which is characteristic of the halo. Thus the stars that have
a flatter distribution are really halo stars and not members of the metal-weak
thick-disk.Comment: Accepted for publication in the March 1996 AJ. 15 pages, AASTeX V4.0
latex format (including figures), 2 eps figures, 2 separate AASTeX V4.0 latex
table
Potilasluokittelujärjestelmä NordDRG ja kustannusseuranta ikääntyneillä aivoverenkiertohäiriön sairastaneilla kävelyn ja käden tehostetun käytön kuntoutuksen aikana
Vuosina 2008–2012 toteutettiin Kelan geriatrisen kuntoutuksen kehittämishanke 65–85-vuotiaiden aivoverenkiertohäiriön (AVH:n) sairastaneiden (N = 270) kuntoutuksessa. Osana hanketta tutkittiin kontrolloimattomassa seurantatutkimusasetelmassa laitos- ja avomuotoisen kävely- sekä käsikuntoutuksen aikana tapahtuneita muutoksia toimintakykyyn. Lisäksi toteutettiin kustannusseuranta kuntoutuksen resursoimisen ja NordDRG-luokittelulogiikan arvioimiseksi AVH:n sairastaneilla. Kävelykuntoutus sisälsi kävelyharjoittelua sekä painokevennettynä että ilman painokevennystä. Käsikuntoutus sisälsi halvaantuneen käden monimuotoista harjoittelua. Kuntoutuksessa käytetyt menetelmät olivat osin moniammatillisia ja laaja-alaisesti toteutettuja. Vuoden kestävässä kuntoutusprosessissa perusjaksoa seurasi kaksi seurantajaksoa. Kävelykuntoutuksen perusjakson kesto oli 20 vrk laitos- ja 18 vrk avokuntoutuksessa, käsikuntoutuksen vastaavasti 14/13 vrk. Seurantajakso I (6 vrk) toteutettiin 6 kk ja seurantajakso II (2 vrk) 12 kk perusjakson päättymisestä. Kävelykuntoutujilla oli avofysioterapiaa perusjakson ja seurantajakso I:n välissä. Kävelyn laitoskuntoutujien motorinen ja kognitiivinen toimintakyky (FIM) parani seuranta-aikana, käden avokuntoutujilla motorinen toimintakyky. Ottaen huomioon kuntoutujien iän ja sairastumisesta kuluneen ajan saavutetulla toimintakyvyn paranemisella ja avuntarpeen vähenemisellä voi kuntoutujakohtaisesti olla merkitystä itsenäiseen päivittäisistä toimista selviytymiseen. NordDRG-luokittelu soveltui käytettäväksi kävely- ja käsikuntoutujien DRG-ryhmittelyyn. Ryhmittely luokitteli kuntoutujat DRG-ryhmiin FIM-toimintakykymittarin pisteiden suunnan mukaisesti loogisesti, ryhmittelyn olematta kuitenkaan liian herkkä FIM-toimintakykymittarin pisteiden muutoksille. Kustannushomogeenisuuden periaate toteutui hyvin, sillä kävely- ja käsikuntoutujien tutkimusjoukossa DRG-ryhmittäin tarkasteltuna jaksojen kustannusten variaatiokerroin jäi alle 60 prosentin
The investigation of absolute proper motions of the XPM Catalogue
The XPM-1.0 is the regular version of the XPM catalogue. In comparison with
XPM the astrometric catalogue of about 280 millions stars covering entire sky
from -90 to +90 degrees in declination and in the magnitude range 10^m<B<22^m
is something improved. The general procedure steps were followed as for XPM,
but some of them are now performed on a more sophisticated level. The XPM-1.0
catalogue contains star positions, proper motions, 2MASS and USNO photometry of
about 280 millions of the sources. We present some investigations of the
absolute proper motions of XPM-1.0 catalogue and also the important information
for the users of the catalogue. Unlike previous version, the XPM-1.0 contains
the proper motions over the whole sky without gaps. In the fields, which cover
the zone of avoidance or which contain less than of 25 galaxies a quasi
absolute calibration was performed. The proper motion errors are varying from 3
to 10 mas/yr, depending on a specific field. The zero-point of the absolute
proper motion frame (the absolute calibration) was specified with more than 1
million galaxies from 2MASS and USNO-A2.0. The mean formal error of absolute
calibration is less than 1 mas/yr.Comment: 11 pages, 9 figures, accepte
Astrometric Control of the Inertiality of the Hipparcos Catalog
Based on the most complete list of the results of an individual comparison of
the proper motions for stars of various programs common to the Hipparcos
catalog, each of which is an independent realization of the inertial reference
frame with regard to stellar proper motions, we redetermined the vector
of residual rotation of the ICRS system relative to the extragalactic
reference frame. The equatorial components of this vector were found to be the
following: mas yr,
mas yr, and mas yr.Comment: 8 pages, 1 figur
Optical Observations of the Binary Pulsar System PSR B1718-19: Implications for Tidal Circularization
We report on Keck and Hubble Space Telescope optical observations of the
eclipsing binary pulsar system PSR B1718-19, in the direction of the globular
cluster NGC 6342. These reveal a faint star (; Vega
system) within the pulsar's 0\farcs5 radius positional error circle. This may
be the companion. If it is a main-sequence star in the cluster, it has radius
\rcomp\simeq0.3 \rsun, temperature \teff\simeq3600 K, and mass
\mcomp\simeq0.3 \msun. In many formation models, however, the pulsar (spun up
by accretion or newly formed) and its companion are initially in an eccentric
orbit. If so, for tidal circularization to have produced the present-day highly
circular orbit, a large stellar radius is required, i.e., the star must be
bloated. Using constraints on the radius and temperature from the Roche and
Hayashi limits, we infer from our observations that \rcomp\simlt0.44 \rsun
and \teff\simgt3300 K. Even for the largest radii, the required efficiency of
tidal dissipation is larger than expected for some prescriptions.Comment: 10 pages, 2 figures, aas4pp2.sty. Accepted for publication in Ap
Effects of Insect Herbivory on Bilberry Production and Removal of Berries by Frugivores
The evolutionary purpose of a fleshy fruit is to attract seed dispersers and get the seeds dispersed by frugivorous animals. For this reason, fruits should be highly rewarding to these mutualists. However, insect herbivory can alter plant reproductive success e.g. by decreasing fruit yield or affecting the attractiveness of the fruits to mutualistic seed dispersers. Under natural conditions, we tested the effects of experimental larval-defoliation on berry ripening and consumption of a non-cultivated dwarf shrub, the bilberry (Vaccinium myrtillus L.), which produces animal-dispersed berries with high sugar and anthocyanin concentration. Bilberry ramets with high fruit yield were most likely to have their berries foraged, indicating that frugivores made foraging choices based on the abundance of berries. Moreover, the probability for berries being foraged was the lowest for non-defoliated ramets that grew adjacent to larval-defoliated ramets, even though larval-defoliation did not affect the biochemical composition (total concentrations of anthocyanins, sugars and organic acids) or the probability of ripening of berries. We hypothesise that the lower probability for berries being foraged in these ramets may be a consequence of rhizome- or volatile-mediated communication between ramets, resulting in a priming effect of the herbivore defence and lower attractiveness of the non-defoliated ramets.Peer reviewe
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The Distance To The Hyades Cluster Based On Hubble Space Telescope Fine Guidance Sensor Parallaxes
Trigonometric parallax observations made with the Hubble Space Telescope (HST) Fine Guidance Sensor (FGS) 3 of seven Hyades members in six fields of view have been analyzed along with their proper motions to determine the distance to the cluster. Knowledge of the convergent point and mean proper motion of the Hyades is critical to the derivation of the distance to the center of the cluster. Depending on the choice of the proper-motion system, the derived cluster center distance varies by 9%. Adopting a reference distance of 46.1 pc or m - M = 3.32, which is derived from the ground-based parallaxes in the General Catalogue of Trigonometric Stellar Parallaxes (1995 edition), the FK5/PPM proper-motion system yields a distance 4% larger, while the Hanson system yields a distance 2% smaller. The HST FGS parallaxes reported here yield either a 14% or 5% larger distance, depending on the choice of the proper-motion system. Orbital parallaxes (Torres et al.) yield an average distance 4% larger than the reference distance. The variation in the distance derived from the HST data illustrates the importance of the proper-motion system and the individual proper motions to the derivation of the distance to the Hyades center; therefore, a full utilization of the HST FGS parallaxes awaits the establishment of an accurate and consistent proper-motion system.NASA HST GTO, HF-1042.01-93A, HF-1046.01-93A, NAS526555Astronom
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