7,172 research outputs found
An Analysis of Kinetic Response Variability
Studies evaluating variability of force as a function of absolute force generated are synthesized. Inconsistencies in reported estimates of this relationship are viewed as a function of experimental constraints imposed. Typically, within-subject force variability increases at a negative accelerating rate with equal increments in force produced. Current pulse-step and impulse variability models are unable to accommodate this description, although the notion of efficiency is suggested as a useful construct to explain the description outlined
Children with autism spectrum disorder (ASD) attend typically to faces and objects presented within their picture communication systems
ackground Children with autism spectrum disorder (ASD) may require interventions for communication difficulties. One type of intervention is picture communication symbols which are proposed to improve comprehension of linguistic input for children with ASD. However, atypical attention to faces and objects is widely reported across the autism spectrum for several types of stimuli. Method In this study we used eye-tracking methodology to explore fixation duration and time taken to fixate on the object and face areas within picture communication symbols. Twenty-one children with ASD were compared with typically developing matched groups. Results Children with ASD were shown to have similar fixation patterns on face and object areas compared with typically developing matched groups. Conclusions It is proposed that children with ASD attend to the images in a manner that does not differentiate them from typically developing individuals. Therefore children with and without autism have the same opportunity to encode the available information. We discuss what this may imply for interventions using picture symbols
Sensation Seeking and Perceived Need for Structure Moderate Soldiers’ Well-Being Before and After Operational Deployment
This study examined associations between sensation seeking and perceived need for structure, and changes in reported well-being among deployed soldiers. Participants (n = 167) were assessed before and after a six-month deployment to south Afghanistan. Results indicated that although well-being declined in the soldier sample as a whole following deployment, the degree of decrease was significantly different among soldiers with different personality profiles. Differences were moderated by soldiers’ level of sensation seeking and perceived need for structure. Results are discussed in terms of a person-environment fit theory in the context of preparation and rehabilitation of deployed military personnel
Elliptic Phases: A Study of the Nonlinear Elasticity of Twist-Grain Boundaries
We develop an explicit and tractable representation of a twist-grain-boundary
phase of a smectic A liquid crystal. This allows us to calculate the
interaction energy between grain boundaries and the relative contributions from
the bending and compression deformations. We discuss the special stability of
the 90 degree grain boundaries and discuss the relation of this structure to
the Schwarz D surface.Comment: 4 pages, 2 figure
Dynamic concentration of motors in microtubule arrays
We present experimental and theoretical studies of the dynamics of molecular
motors in microtubule arrays and asters. By solving a convection-diffusion
equation we find that the density profile of motors in a two-dimensional aster
is characterized by continuously varying exponents. Simulations are used to
verify the assumptions of the continuum model. We observe the concentration
profiles of kinesin moving in quasi two-dimensional artificial asters by
fluorescent microscopy and compare with our theoretical results.Comment: 4pages, 4 figures revte
Design and Management of Saltbush-Based Forage Systems to Improve Productivity and Reproductive Performance of Sheep
There is evidence that effective shelter can significantly improve lamb survival, but the majority of Australian studies have occurred in small paddocks where the ewes had no choice but to use shelter. In mixed farming systems with large open paddocks, it is unclear if ewes will choose to use shelter for lambing. Our multidisciplinary collaboration examines the use of woody shrubs as an opportunity to improve the survival of twin lambs. In a series of large experiments on commercial farms, we will evaluate the impact of different shrub planting configurations, orientations, and densities on microclimates at the sub-paddock scale. Twin-bearing ewes with GPS trackers will graze a mosaic of shelter options to identify lambing sites relative to climatic conditions at the time of lambing. Relatively palatable and unpalatable shrubs have been planted to explore trade-offs between the attraction of ewes to shelter against declining shelter value, because palatable shrubs are defoliated faster than relatively unpalatable options. A linked project is investigating the use of the same shrub systems to provide shade and antioxidants during joining when temperatures exceed the sheep thermal comfort zone for extended periods in summer. Hardy perennial shrubs such as saltbush offer an opportunity to improve profitability and climate resilience of farming systems, while improving landscape health. Multidisciplinary research is required to understand the benefits and limitations of these systems
Application of Hansch’s Model to Capsaicinoids and Capsinoids: A Study Using the Quantitative Structure−Activity Relationship. A Novel Method for the Synthesis of Capsinoids
We describe a synthetic approach for two families of compounds, the capsaicinoids and capsinoids,
as part of a study of the quantitative relationship between structure and activity
Controlling pulse propagation in optical fibers through nonlinearity and dispersion management
In case of the nonlinear Schr\"odinger equation with designed group velocity
dispersion, variable nonlinearity and gain/loss; we analytically demonstrate
the phenomenon of chirp reversal crucial for pulse reproduction. Two different
scenarios are exhibited, where the pulses experience identical dispersion
profiles, but show entirely different propagation behavior. Exact expressions
for dynamical quasi-solitons and soliton bound-states relevant for fiber
communication are also exhibited.Comment: 4 pages, 5 eps figure
The Tenerife Cosmic Microwave Background Maps: Observations and First Analysis
The results of the Tenerife Cosmic Microwave Background (CMB) experiments are
presented. These observations cover 5000 and 6500 square degrees on the sky at
10 and 15 GHz respectively centred around Dec.~ +35 degrees. The experiments
are sensitive to multipoles l=10-30 which corresponds to the Sachs-Wolfe
plateau of the CMB power spectra. The sensitivity of the results are ~31 and
\~12 microK at 10 and 15 GHz respectively in a beam-size region (5 degrees
FWHM). The data at 15 GHz show clear detection of structure at high Galactic
latitude; the results at 10 GHz are compatible with these, but at lower
significance. A likelihood analysis of the 10 and 15 GHz data at high Galactic
latitude, assuming a flat CMB band power spectra gives a signal Delta
T_l=30+10-8 microK (68 % C.L.). Including the possible contaminating effect due
to the diffuse Galactic component, the CMB signal is Delta T_l=30+15-11 microK.
These values are highly stable against the Galactic cut chosen. Assuming a
Harrison-Zeldovich spectrum for the primordial fluctuations, the above values
imply an expected quadrupole Q_RMS-PS=20+10-7 microK which confirms previous
results from these experiments, and which are compatible with the COBE DMR.Comment: 17 pages, 7 figures. Submitted to Ap
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