3,018 research outputs found
Response to The Changing Perspectives of U.S. and Japanese Nuclear Energy Policies in the Aftermath of the Fukushima Daiichi Disaster (By Daniel A. Dorfman)
The Stroke-related Effects of Hip Flexion Fatigue on Over Ground Walking
Individuals post stroke often rely more on hip flexors for limb advancement during walking due to distal weakness but the effects of muscle fatigue in this group is not known. The purpose of this study was to quantify how stroke affects the influence of hip flexor fatigue on over ground walking kinematics and performance and muscle activation. Ten individuals with chronic stroke and 10 without stroke (controls) participated in the study. Maximal walking speed, walking distance, muscle electromyograms (EMG), and lower extremity joint kinematics were compared before and after dynamic, submaximal fatiguing contractions of the hip flexors (30% maximal load) performed until failure of the task. Task duration and decline in hip flexion maximal voluntary contraction (MVC) and power were used to assess fatigue. The stroke and control groups had similar task durations and percent reductions in MVC force following fatiguing contractions. Compared with controls, individuals with stroke had larger percent reductions in maximal walking speed, greater decrements in hip range of motion and peak velocity during swing, greater decrements in ankle velocity and lack of modulation of hip flexor EMG following fatiguing dynamic hip flexion contractions. For a given level of fatigue, the impact on walking function was more profound in individuals with stroke than neurologically intact individuals, and a decreased ability to up regulate hip flexor muscle activity may contribute. These data highlight the importance of monitoring the effect of hip flexor muscle activity during exercise or performance of activities of daily living on walking function post stroke
Legitimation, Endorsement, and Compliance
The theoretical development distinguishes three objects of legitimation, of persons, of positions, and of actions; and three types of legitimacy, propriety, endorsement, and authorization. Propriety is normative support of power, endorsement is group support, and authorization is support of an actor higher in the organizational structure. They conducted an experiment varying levels of endorsement. Results showed strong effects of endorsement on compliance. Related publications include Walker et al. (1986), Ridgeway et al. (1994), and Younts (2008)
MOST detects variability on tau Bootis possibly induced by its planetary companion
(abridged) There is considerable interest in the possible interaction between
parent stars and giant planetary companions in 51 Peg-type systems. We
demonstrate from MOST satellite photometry and Ca II K line emission that there
has been a persistent, variable region on the surface of tau Boo A which
tracked its giant planetary companion for some 440 planetary revolutions and
lies ~68deg (phi=0.8) in advance of the sub-planetary point. The light curves
are folded on a range of periods centered on the planetary orbital period and
phase dependent variability is quantified by Fourier methods and by the mean
absolute deviation (MAD) of the folded data for both the photometry and the Ca
II K line reversals. The region varies in brightness on the time scale of a
rotation by ~1 mmag. In 2004 it resembled a dark spot of variable depth, while
in 2005 it varied between bright and dark. Over the 123 planetary orbits
spanned by the photometry the variable region detected in 2004 and in 2005 are
synchronised to the planetary orbital period within 0.0015 d. The Ca II K line
in 2001, 2002 and 2003 also shows enhanced K-line variability centered on
phi=0.8, extending coverage to some 440 planetary revolutions. The apparently
constant rotation period of the variable region and its rapid variation make an
explanation in terms of conventional star spots unlikely. The lack of
complementary variability at phi=0.3 and the detection of the variable region
so far in advance of the sub-planetary point excludes tidal excitation, but the
combined photometric and Ca II K line reversal results make a good case for an
active region induced magnetically on the surface of tau Boo A by its planetary
companion.Comment: 7 pages, 7 figures; accepted for publication in A&
Sonification Mapping Configurations: Pairings Of Real-Time Exhibits And Sound
Presented at the 19th International Conference on Auditory Display (ICAD2013) on July 6-9, 2013 in Lodz, Poland.Visitors to aquariums typically rely on their vision to interact
with live exhibits that convey rich descriptive and aesthetic
visual information. However, some visitors may prefer or need to
have an alternative interpretation of the exhibitÕs visual scene to
improve their experience. Musical sonification has been explored
as an interpretive strategy for this purpose and related work
provides some guidance for sonification design, yet more
empirical work on developing and validating the music-to-visual
scene mappings needs to be completed. This paper discusses
work to validate mappings that were developed through an
investigation of musician performances for two specific live
animal exhibits at the Georgia Aquarium. In this proposed study,
participants will provide feedback on musical mapping examples
which will help inform design of a real-time sonification system
for aquarium exhibits. Here, we describe our motivation,
methods, and expected contributions
Analysis of the MOST light curve of the heavily spotted K2IV component of the single-line spectroscopic binary II Pegasi
Continuous photometric observations of the visible component of the
single-line, K2IV spectroscopic binary II Peg carried out by the MOST satellite
during 31 consecutive days in 2008 have been analyzed. On top of spot-induced
brightness modulation, eleven flares were detected of three distinct types
characterized by different values of rise, decay and duration times. The flares
showed a preference for occurrence at rotation phases when the most spotted
hemisphere is directed to the observer, confirming previous similar reports. An
attempt to detect a grazing primary minimum caused by the secondary component
transiting in front of the visible star gave a negative result. The brightness
variability caused by spots has been interpreted within a cold spot model. An
assumption of differential rotation of the primary component gave a better fit
to the light curve than a solid-body rotation model.Comment: Accepteed to MNRA
An accurate calculation of the nucleon axial charge with lattice QCD
We report on a lattice QCD calculation of the nucleon axial charge, ,
using M\"{o}bius Domain-Wall fermions solved on the dynamical HISQ
ensembles after they are smeared using the gradient-flow algorithm. The
calculation is performed with three pion masses,
MeV. Three lattice spacings ( fm) are used with the
heaviest pion mass, while the coarsest two spacings are used on the middle pion
mass and only the coarsest spacing is used with the near physical pion mass. On
the MeV, fm point, a dedicated volume study is
performed with . Using a new strategy
motivated by the Feynman-Hellmann Theorem, we achieve a precise determination
of with relatively low statistics, and demonstrable control over the
excited state, continuum, infinite volume and chiral extrapolation systematic
uncertainties, the latter of which remains the dominant uncertainty. Our final
determination at 2.6\% total uncertainty is , with the
first uncertainty including statistical and systematic uncertainties from
fitting and the second including model selection systematics related to the
chiral and continuum extrapolation. The largest reduction of the second
uncertainty will come from a greater number of pion mass points as well as more
precise lattice QCD results near the physical pion mass.Comment: 17 pages + 11 pages of references and appendices. 15 figures.
Interested readers can download the Python analysis scripts and an hdf5 data
file at https://github.com/callat-qcd/project_gA_v
A search for p-modes and other variability in the binary system 85 Pegasi using MOST photometry
Context: Asteroseismology has great potential for the study of metal-poor
stars due to its sensitivity to determine stellar ages. Aims: Our goal was to
detect p-mode oscillations in the metal-poor sub-dwarf 85 Peg A and to search
for other variability on longer timescales. Methods: We have obtained
continuous high-precision photometry of the binary system 85 Pegasi with the
MOST space telescope in two seasons (2005 & 2007). Furthermore, we redetermined
vsini for 85 Peg A using high resolution spectra obtained through the ESO
archive, and used photometric spot modeling to interpret long periodic
variations. Results: Our frequency analysis yields no convincing evidence for
p-modes significantly above a noise level of 4 ppm. Using simulated p-mode
patterns we provide upper RMS amplitude limits for 85 Peg A. The light curve
shows evidence for variability with a period of about 11 d and this periodicity
is also seen in the follow up run in 2007; however, as different methods to
remove instrumental trends in the 2005 run yield vastly different results, the
exact shape and periodicity of the 2005 variability remain uncertain. Our
re-determined vsini value for 85 Peg A is comparable to previous studies and we
provide realistic uncertainties for this parameter. Using these values in
combination with simple photometric spot models we are able to reconstruct the
observed variations. Conclusions: The null-detection of p-modes in 85 Peg A is
consistent with theoretical values for pulsation amplitudes in this star. The
detected long-periodic variation must await confirmation by further
observations with similar or better precision and long-term stability. If the
11 d periodicity is real, rotational modulation of surface features on one of
the components is the most likely explanation.Comment: 11 pages, 9 figures, accepted for publication in A&
Legitimacy and Collective Action
This is a revision of WP 84-4. The authors develop an explicit theoretical foundation for the common belief that legitimation is somehow important in mobilizing collective action. They distinguish validity of a rule (collective support) from propriety (individual support) and predict that validity affects mobilization independent of propriety. Results of an experimental test support the derivations.This research was supported by NSF grant No. SOC-7817434
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