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Individual Differences in the Programming of Rapid Bimanual Movements: Are Two Modes Better Than One?
International Journal of Exercise Science 9(3): 347-358, 2016. One of the challenges in performing simultaneous bimanual movements is to prevent interference from one limb to the other, thereby maintaining spatial accuracy in both limbs. Prior research has shown that when a longer distance movement is performed with a shorter movement, the shorter movement overshoots its target and the longer movement undershoots its target relative to control conditions where two shorter or two longer movements are made. The current experiment investigated the motor control strategies used by participants when performing simultaneous aiming movements combining both different and same distances. Participants (N = 20) made rapid lever-positioning movements (goal time to reversal was 350 ms) in the sagittal plane to 2 different spatial targets (20° and 60°) or the same targets (either 20° or 60°). Feedback about spatial accuracy was provided immediately after each trial. Constant error (CE) was measured for each distance based on 20 practice trials per condition. The CE from the same- and different-distance conditions were compared with separate one-way ANOVAs with repeated measures. Overshooting was shown of the 20° target and undershooting of the 60° target when the two distances were performed together. However, the movement amplitudes were positively correlated over trials in both the same- and different-distance conditions. A trial-by-trial analysis of the CE scores revealed both compensatory and non-compensatory strategies. The results suggest individual differences in how amplitude parameters are chosen for use with the generalized motor program in the control of bimanual aiming movements
Onset of slow dynamics in difluorotetrachloroethane glassy crystal
Complementary Neutron Spin Echo and X-ray experiments and Molecular Dynamics
simulations have been performed on difluorotetrachloroethane (CFCl2-CFCl2)
glassy crystal. Static, single-molecule reorientational dynamics and collective
dynamics properties are investigated. The orientational disorder is
characterized at different temperatures and a change in nature of rotational
dynamics is observed. We show that dynamics can be described by some scaling
predictions of the Mode Coupling Theory (MCT) and a critical temperature
is determined. Our results also confirm the strong analogy between
molecular liquids and plastic crystals for which -relaxation times and
non-ergodicity parameters are controlled by the non trivial static correlations
as predicted by MCT
Longitudinal patterns in an Arkansas River Valley stream: an Application of the River Continuum Concept
The River Continuum Concept (RCC) provides the framework for studying how lotic ecosystems vary from headwater streams to large rivers. The RCC was developed in streams in eastern deciduous forests of North America, but watershed characteristics and land uses differ across ecoregions, presenting unique opportunities to study how predictions of the RCC may differ across regions. Additionally, RCC predictions may vary due to the influence of fishes, but few studies have used fish taxa as a metric for evaluating predictions of the RCC. Our goal was to determine if RCC predictions for stream orders 1 through 5 were supported by primary producer, macroinvertebrate, and fish communities in Cadron Creek of the Arkansas River Valley. We sampled chlorophyll a, macroinvertebrates, and fishes at five stream reaches across a gradient of watershed size. Contrary to RCC predictions, chlorophyll a did not increase in concentration with catchment size. As the RCC predicts, fish and macroinvertebrate diversity increased with catchment size. Shredding and collecting macroinvertebrate taxa supported RCC predictions, respectively decreasing and increasing in composition as catchment area increased. Herbivorous and predaceous fish did not follow RCC predictions; however, surface-water column feeding fish were abundant at all sites as predicted. We hypothesize some predictions of the RCC were not supported in headwater reaches of this system due to regional differences in watershed characteristics and altered resource availability due to land use surrounding sampling sites
Estuary environmental flows assessment methodology for Victoria
This report sets out a method to determine the environmental water requirements of estuaries in Victoria. The estuary environmental flows assessment method (EEFAM) is a standard methodology which can be applied consistently across Victorian estuaries.The primary objective of EEFAM is to define a flow regime to maintain or enhance the ecological health of an estuary. The method is used to inform Victorian water resource planning processes.The output of EEFAM is a recommended flow regime for estuaries. This recommendation is developed from the known dependence of the estuary’s flora, fauna, biogeochemical and geomorphological features on the flow regime. EEFAM is an evidence-based methodology. This bottom-up or ‘building block’ approach conforms to the asset-based approach of the Victorian River Health Strategy and regional river health strategies.EEFAM is based on and expands on FLOWS, the Victorian method for determining environmental water requirements in rivers. The list of tasks has been modified and re-ordered in EEFAM to reflect environmental and management issues specific to estuaries. EEFAM and FLOWS can be appliedsimultaneously to a river and its estuary as part of a whole-of-system approach to environmental flow requirements. Like the FLOWS method, EEFAM is modular, and additional components can be readily incorporated
Estuary environmental flows assessment methodology : final specification report
This report provides a consistent and systematic approach to the determination of environmental water requirements for estuaries in Victoria.Victoria’s limited water resources are subject to competing demands. These demands, including town water supplies and irrigation requirements, often deplete the flow entering estuaries and put their environmental values at risk.The Estuary Environmental Flows Assessment Methodology (EEFAM) is a standard methodology which can be applied in a consistent manner across all Victorian estuaries, according to their priority. It is not anticipated that this method would be used for the Gippsland Lakes or Port Phillip or Western Port Bay.<br /
Random Sequential Adsorption: From Continuum to Lattice and Pre-Patterned Substrates
The random sequential adsorption (RSA) model has served as a paradigm for
diverse phenomena in physical chemistry, as well as in other areas such as
biology, ecology, and sociology. In the present work, we survey aspects of the
RSA model with emphasis on the approach to and properties of jammed states
obtained for large times in continuum deposition versus that on lattice
substrates, and on pre-patterned surfaces. The latter model has been of recent
interest in the context of efforts to use pre-patterning as a tool to improve
selfassembly in micro- and nanoscale surface structure engineering
Realization of logically labeled effective pure states for bulk quantum computation
We report the first use of "logical labeling" to perform a quantum
computation with a room-temperature bulk system. This method entails the
selection of a subsystem which behaves as if it were at zero temperature -
except for a decrease in signal strength - conditioned upon the state of the
remaining system. No averaging over differently prepared molecules is required.
In order to test this concept, we execute a quantum search algorithm in a
subspace of two nuclear spins, labeled by a third spin, using solution nuclear
magnetic resonance (NMR), and employing a novel choice of reference frame to
uncouple nuclei.Comment: PRL 83, 3085 (1999). Small changes made to improve readability and
remove ambiguitie
Experimental Realization of A Two Bit Phase Damping Quantum Code
Using nuclear magnetic resonance techniques, we experimentally investigated
the effects of applying a two bit phase error detection code to preserve
quantum information in nuclear spin systems. Input states were stored with and
without coding, and the resulting output states were compared with the
originals and with each other. The theoretically expected result, net reduction
of distortion and conditional error probabilities to second order, was indeed
observed, despite imperfect coding operations which increased the error
probabilities by approximately 5%. Systematic study of the deviations from the
ideal behavior provided quantitative measures of different sources of error,
and good agreement was found with a numerical model. Theoretical questions in
quantum error correction in bulk nuclear spin systems including fidelity
measures, signal strength and syndrome measurements are discussed.Comment: 21 pages, 17 figures, mypsfig2, revtex. Minor changes made to appear
in PR
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