68 research outputs found
Augmenting Hand and Arm Function for Persons with Hemiparesis
Background. Hand and arm dysfunction due to neural disorders significantly influences quality of life. Activity-based training has been found to improve function. These improvements could be augmented with transcutaneous spinal cord stimulation (tSCS) due to the modulatory effect it has on spinal and supraspinal networks. Objective. The primary aim is to determine if a 4-week training program will improve hand and arm function. The secondary aim is to determine if the addition of tSCS to a second 4-week training session will further improve function. Design. This is a pre-posttest, controlled trial for persons 10-75 years of age, \u3e6 months post stroke or with unilateral cerebral palsy.Methods. Participants will engage in two 4-week training periods, 3x/week for 2 hours/day. The 1st period will include unimanual and bimanual training alone. The 2nd period will be augmented with low frequency tSCS to the C5-T1 spinal region. Stimulation intensity will be based on individual muscle activation during 3 tasks: 1) grip dynamometry; 2) grip-lift; and 3) target pointing. Outcome measures taken before, midway, and after training are: Canadian Occupational Performance Measure (COPM), dexterity, daylong arm use, grip/pinch strength, sensibility, questionnaires, bilateral hand/arm surface electromyography, and Upper Extremity Fugl-Meyer (UEFM). Results: Nine participants have completed the 1st 4-week training period without tSCS. Individual data reveals improvements in the COPM, Grip strength, dexterity, and the UEFM. Findings for other measures after the 1st period are mixed or in process. Conclusion: Preliminary findings from this ongoing study reveal that participants made improvements in most measures. The next phase of the study will determine if the addition of tSCS to training further augments hand and arm function
Spectroscopic properties of cool Ursa Major group members
Until now, most members of the Ursa Major (UMa) group of stars have been
identified by means of kinematic criteria. However, in many cases kinematic
criteria alone are insufficient to ascertain, whether an individual star is
really a member of this group. Since photometric criteria are ineffective in
the case of cool dwarf members, one must use spectroscopic criteria.
Nevertheless, resulting membership criteria are inconclusive. We reanalyse
spectroscopic properties of cool UMa group dwarfs. In particular, we study the
distribution of iron abundance, the strength of the Li I absorption at 6708 A
and the Li abundance, and the infilling of the core of the H alpha line.
Twenty-five cool and northern bona-fide members are carefully selected from the
literature. Homogeneously measured stellar parameters and iron abundances are
given for all Sun-like stars selected, based on spectra of high resolution and
high signal-to-noise ratio. In addition, we measure the Li equivalent width and
abundance as well as the relative intensity of the H alpha core and the
corresponding chromospheric flux. The studied stars infer an average Ursa Major
group iron abundance of -0.03+-0.05 dex, which is higher by about 0.06 dex than
determined elsewhere. The Li abundance derived of Ursa Major group dwarf stars
is higher than in the Hyades at effective temperatures cooler than the Sun, but
lower than in the younger Pleiades, a result which is independent of the exact
value of the effective temperature adopted. The Sun-like and cooler dwarfs also
display chromospheric infilling of the H alpha core. We present spectroscopic
criteria that may be used to exclude non-members.Comment: accepted for publication in A&A, 19 pages, 10 figures, 7 table
A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: VI. s-Process and Titanium Abundance Variations Along the Sagittarius Stream
We present high-resolution spectroscopic measurements of the abundances of
titanium (Ti), yttrium (Y) and lanthanum (La) for M giant candidates of the
Sagittarius (Sgr) dwarf spheroidal (dSph) + tidal tail system pre-selected on
the basis of position and radial velocity. The majority of these stars show
peculiar abundance patterns compared to those of nominal Milky Way (MW) stars.
The overall [Ti/Fe], [Y/Fe], [La/Fe] and [La/Y] patterns with [Fe/H] of the Sgr
stream plus Sgr core do resemble those seen in the Large Magellanic Cloud (LMC)
and other dSphs, only shifted [Fe/H] by ~+0.4 from the LMC and by ~+1 dex from
the other dSphs; these relative shifts reflect the faster and/or more efficient
chemical evolution of Sgr compared to the other satellites, and show that Sgr
has had an enrichment history more like the LMC than the other dSphs. By
tracking the evolution of the abundance patterns along the Sgr stream we can
follow the time variation of the chemical make-up of dSph stars donated to the
MW halo by Sgr. This evolution demonstrates that while the bulk of the stars
currently in the Sgr dSph are quite unlike those of the MW halo, an increasing
number of stars farther along the Sgr stream have abundances like MW halo
stars, a trend that shows clearly how the MW halo could have been contributed
by present day satellite galaxies even if the present chemistry of those
satellites is now different from typical halo field stars. Finally, we analyze
the chemical abundances of a moving group of M giants among the Sgr leading arm
stars at the North Galactic Cap, but having radial velocities unlike the
infalling Sgr leading arm debris there. Through use of "chemical
fingerprinting", we conclude that these northern hemisphere M giants also are
Sgr stars, likely trailing arm debris overlapping the leading arm in the north.Comment: Accepted for publication in Ap
A Complete Spectroscopic Survey of the Milky Way Satellite Segue 1: The Darkest Galaxy
We present the results of a comprehensive Keck/DEIMOS spectroscopic survey of
the ultra-faint Milky Way satellite galaxy Segue 1. We have obtained velocity
measurements for 98.2% of the stars within 67 pc (10 arcmin, or 2.3 half-light
radii) of the center of Segue 1 that have colors and magnitudes consistent with
membership, down to a magnitude limit of r=21.7. Based on photometric,
kinematic, and metallicity information, we identify 71 stars as probable Segue
1 members, including some as far out as 87 pc. After correcting for the
influence of binary stars using repeated velocity measurements, we determine a
velocity dispersion of 3.7^{+1.4}_{-1.1} km/s, with a corresponding mass within
the half-light radius of 5.8^{+8.2}_{-3.1} x 10^5 Msun. The stellar kinematics
of Segue 1 require very high mass-to-light ratios unless the system is far from
dynamical equilibrium, even if the period distribution of unresolved binary
stars is skewed toward implausibly short periods. With a total luminosity less
than that of a single bright red giant and a V-band mass-to-light ratio of 3400
Msun/Lsun, Segue 1 is the darkest galaxy currently known. We critically
re-examine recent claims that Segue 1 is a tidally disrupting star cluster and
that kinematic samples are contaminated by the Sagittarius stream. The
extremely low metallicities ([Fe/H] < -3) of two Segue 1 stars and the large
metallicity spread among the members demonstrate conclusively that Segue 1 is a
dwarf galaxy, and we find no evidence in favor of tidal effects. We also show
that contamination by the Sagittarius stream has been overestimated. Segue 1
has the highest measured dark matter density of any known galaxy and will
therefore be a prime testing ground for dark matter physics and galaxy
formation on small scales.Comment: 24 pages, 4 tables, 11 figures (10 in color). Submitted for
publication in ApJ. V3 revised according to comments from the refere
Eigenvalue analysis of structures with interval parameters using the second-order Taylor series expansion and the DCA for QB
The Bulge/Disk Connection in Late-type Spirals
Recent ground-based photometric investigations suggest that central regions of late-type spirals are closely coupled to the inner disk and probably formed via secular evolution. Evidence presented in support of this model includes the predominance of exponential bulges, the correlation of bulge and disk scale lengths, blueness of the bulge and small differences between bulge and central disk colors, detection of spiral structure into the core, and rapid rotation. Recent HST observations show that our own bulge and that of M31, M32, and M33 probably harbor both an old and intermediate-age populations in agreement with models of early collapse of the spheroid plus gas transfer from the disk. Secular evolution provides a mechanism to build-up central regions in late-type spirals; mergers or accretion of small satellites could explain the brighter, kinematically distinct bulges of Sa's and SO's
Cryptic diversity in Hipposideros commersoni sensu stricto (Chiroptera: Hipposideridae) in the western portion of Madagascar
The supernatural characters and powers of sacred trees in the Holy Land
This article surveys the beliefs concerning the supernatural characteristics and powers of sacred trees in Israel; it is based on a field study as well as a survey of the literature and includes 118 interviews with Muslims and Druze. Both the Muslims and Druze in this study attribute supernatural dimensions to sacred trees which are directly related to ancient, deep-rooted pagan traditions. The Muslims attribute similar divine powers to sacred trees as they do to the graves of their saints; the graves and the trees are both considered to be the abode of the soul of a saint which is the source of their miraculous powers. Any violation of a sacred tree would be strictly punished while leaving the opportunity for atonement and forgiveness. The Druze, who believe in the transmigration of souls, have similar traditions concerning sacred trees but with a different religious background. In polytheistic religions the sacred grove/forest is a centre of the community's official worship; any violation of the trees is regarded as a threat to the well being of the community. Punishments may thus be collective. In the monotheistic world (including Christianity, Islam and Druze) the pagan worship of trees was converted into the worship/adoration of saints/prophets; it is not a part of the official religion but rather a personal act and the punishments are exerted only on the violating individual
Green Infrastructure Development in Cisangkuy Subwatershed, Bandung Regency: Potential and Problems
MR1 recycling and blockade of endosomal trafficking reveal distinguishable antigen presentation pathways between Mycobacterium tuberculosis infection and exogenously delivered antigens
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