12,867 research outputs found
Recommended from our members
Spatial attention shifting and phonological processing in adults with dyslexia
According to Hari and Renvall’s (2001) sluggish attentional shifting (SAS) hypothesis people with dyslexia have a central deficit in attention shifting. Here we assessed whether a group of adults with dyslexia showed impaired performance on shifting visual spatial attention. Twelve adults with dyslexia and 12 control adult participants took part in a Posner style focused attention orientation task and a shift attention orientation task. The participants also completed standardized measures of single word reading, spelling, IQ, phonological processing, speed of processing and non-word reading. Overall, the dyslexic participants showed the same pattern of performance as the control participants on the attention-orienting task, but completed the tasks at a consistently slower pace. Specifically, participants in both groups found short target presentation intervals more difficult than longer target presentation intervals, and participants in both groups were more impaired when cue-to-target information was invalid 20% of the time (shift task) than when it was valid all of the time (focused task). However, the group with dyslexia was significantly more impaired across the board
Water separator
An apparatus for separating liquids from gases or gaseous fluids is described. Features of the apparatus include: (1) the collection and removal of the moisture in the fluid is not dependent upon, or affected by gravity; (2) all the collected water is cyclically drained from the apparatus irrespective of the attitude of the separator; and (3) a fluid actuator is utilized to remove the collected water from the separator
Numerical computations on one-dimensional inverse scattering problems
An approximate method to determine the index of refraction of a dielectric obstacle is presented. For simplicity one dimensional models of electromagnetic scattering are treated. The governing equations yield a second order boundary value problem, in which the index of refraction appears as a functional parameter. The availability of reflection coefficients yield two additional boundary conditions. The index of refraction by a k-th order spline which can be written as a linear combination of B-splines is approximated. For N distinct reflection coefficients, the resulting N boundary value problems yield a system of N nonlinear equations in N unknowns which are the coefficients of the B-splines
Swing switching of spin-torque valves
We propose a method for inducing magnetization reversal using an AC spin
current polarized perpendicular to the equilibrium magnetization of the free
magnetic layer. We show that the critical AC spin current is significantly
smaller than the corresponding DC one. The effect is understood as a
consequence of the underdamped nature of the spin-torque oscillators. It allows
to use the kinetic inertia to overcome the residual energy barrier, rather than
suppressing the latter by a large spin current. The effect is similar to a
swing which may be set into high amplitude motion by a weak near-resonant push.
The optimal AC frequency is identified as the upper bifurcation frequency of
the corresponding driven nonlinear oscillator. Together with fast switching
times it makes the perpendicular AC method to be the most efficient way to
realize spin-torque memory valve.Comment: 8 pages, 11 figure
Application of two design methods for active flutter suppression and wind-tunnel test results
The synthesis, implementation, and wind tunnel test of two flutter suppression control laws for an aeroelastic model equipped with a trailing edge control surface are presented. One control law is based on the aerodynamic energy method, and the other is based on results of optimal control theory. Analytical methods used to design the control laws and evaluate their performance are described. At Mach 0.6, 0.8, and 0.9, increases in flutter dynamic pressure were obtained but the full 44 percent increase was not achieved. However at Mach 0.95, the 44 percent increase was achieved with both control laws. Experimental results indicate that the performance of the systems is not so effective as that predicted by analysis, and that wind tunnel turbulence plays an important role in both control law synthesis and demonstration of system performance
Immunoglobulin variable-region gene mutational lineage tree analysis: application to autoimmune diseases
Lineage trees have frequently been drawn to illustrate diversification, via somatic hypermutation (SHM), of immunoglobulin variable-region (IGV) genes. In order to extract more information from IGV sequences, we developed a novel mathematical method for analyzing the graphical properties of IgV gene lineage trees, allowing quantification of the differences between the dynamics of SHM and antigen-driven selection in different lymphoid tissues, species, and disease situations. Here, we investigated trees generated from published IGV sequence data from B cell clones participating in autoimmune responses in patients with Myasthenia Gravis (MG), Rheumatoid Arthritis (RA), and Sjögren's Syndrome (SS). At present, as no standards exist for cell sampling and sequence extraction methods, data obtained by different research groups from two studies of the same disease often vary considerably. Nevertheless, based on comparisons of data groups within individual studies, we show here that lineage trees from different individual patients are often similar and can be grouped together, as can trees from two different tissues in the same patient, and even from IgG- and IgA-expressing B cell clones. Additionally, lineage trees from most studies reflect the chronic character of autoimmune diseases
Mechano-transduction: from molecules to tissues.
External forces play complex roles in cell organization, fate, and homeostasis. Changes in these forces, or how cells respond to them, can result in abnormal embryonic development and diseases in adults. How cells sense and respond to these mechanical stimuli requires an understanding of the biophysical principles that underlie changes in protein conformation and result in alterations in the organization and function of cells and tissues. Here, we discuss mechano-transduction as it applies to protein conformation, cellular organization, and multi-cell (tissue) function
Photon signature analysis using template matching
We describe an approach to detect improvised explosive devices (IEDs) by using a template matching procedure. This approach relies on the signature due to backstreaming ? photons from various targets. In this work we have simulated cylindrical targets of aluminum, iron, copper, water and ammonium nitrate (nitrogen-rich fertilizer). We simulate 3.5 MeV source photons distributed on a plane inside a shielded area using Monte Carlo N-Particle (MCNP TM) code version 5 (V5). The 3.5 MeV source gamma rays yield 511 keV peaks due to pair production and scattered gamma rays. In this work, we simulate capture of those photons that backstream, after impinging on the target element, toward a NaI detector. The captured backstreamed photons are expected to produce a unique spectrum that will become part of a simple signal processing recognition system based on the template matching method. Different elements were simulated using different sets of random numbers in the Monte Carlo simulation. To date, the sum of absolute differences (SAD) method has been used to match the template. In the examples investigated, template matching was found to detect all elements correctly
Feeling Good about Giving: The Benefits (and Costs) of Self-Interested Charitable Behavior
In knowledge-intensive settings such as product or software development, fluid teams of individuals with different sets of experience are tasked with projects that are critical to the success of their organizations. Although building teams from individuals with diverse prior experience is increasingly necessary, prior work examining the relationship between experience and performance fails to find a consistent effect of diversity in experience on performance. The problem is that diversity in experience improves a team's information processing capacity and knowledge base, but also creates coordination challenges. We hypothesize that team familiarity - team members' prior experience working with one another - is one mechanism that helps teams leverage the benefits of diversity in team member experience by alleviating coordination problems that diversity creates. We use detailed project- and individual-level data from an Indian software services firm to examine the effects of team familiarity and diversity in experience on performance for software development projects. We find the interaction of team familiarity and diversity in experience has a complementary effect on a project being delivered on time and on budget. In team familiarity, we identify one mechanism for capturing the performance benefits of diversity in experience and provide insight into how the management of experience accumulation affects team performance.Diversity, Experience, Knowledge, Software, Team Familiarity
- …