4,757 research outputs found
<development of on-line man-machine system performance measurement and display techniques< letter progress report, 1 mar. - 31 may 1965
Man-machine performance measurement
Development of on-line man-machine system performance measurement and display techniques Letter progress report, Jun. 1 - Aug. 31, 1965
Human performance characteristics in manual control tasks, and techniques for data analysis and systems simulatio
Shared Experiences of Women in Politics
What are the lived experiences of female politicians in the state of Maine who have made the active decision to run for elected office?
• What is the experience like for a woman running for political office?
• What motivates and hinders women in their aspirations to run for political office
Single- and Multiple-Shell Uniform Sampling Schemes for Diffusion MRI Using Spherical Codes
In diffusion MRI (dMRI), a good sampling scheme is important for efficient
acquisition and robust reconstruction. Diffusion weighted signal is normally
acquired on single or multiple shells in q-space. Signal samples are typically
distributed uniformly on different shells to make them invariant to the
orientation of structures within tissue, or the laboratory coordinate frame.
The Electrostatic Energy Minimization (EEM) method, originally proposed for
single shell sampling scheme in dMRI, was recently generalized to multi-shell
schemes, called Generalized EEM (GEEM). GEEM has been successfully used in the
Human Connectome Project (HCP). However, EEM does not directly address the goal
of optimal sampling, i.e., achieving large angular separation between sampling
points. In this paper, we propose a more natural formulation, called Spherical
Code (SC), to directly maximize the minimal angle between different samples in
single or multiple shells. We consider not only continuous problems to design
single or multiple shell sampling schemes, but also discrete problems to
uniformly extract sub-sampled schemes from an existing single or multiple shell
scheme, and to order samples in an existing scheme. We propose five algorithms
to solve the above problems, including an incremental SC (ISC), a sophisticated
greedy algorithm called Iterative Maximum Overlap Construction (IMOC), an 1-Opt
greedy method, a Mixed Integer Linear Programming (MILP) method, and a
Constrained Non-Linear Optimization (CNLO) method. To our knowledge, this is
the first work to use the SC formulation for single or multiple shell sampling
schemes in dMRI. Experimental results indicate that SC methods obtain larger
angular separation and better rotational invariance than the state-of-the-art
EEM and GEEM. The related codes and a tutorial have been released in DMRITool.Comment: Accepted by IEEE transactions on Medical Imaging. Codes have been
released in dmritool
https://diffusionmritool.github.io/tutorial_qspacesampling.htm
Patient access to complex chronic disease records on the internet
Background: Access to medical records on the Internet has been reported to be acceptable and popular with patients, although most published evaluations have been of primary care or office-based practice. We tested the feasibility and acceptability of making unscreened results and data from a complex chronic disease pathway (renal medicine) available to patients over the Internet in a project involving more than half of renal units in the UK.
Methods: Content and presentation of the Renal PatientView (RPV) system was developed with patient groups. It was designed to receive information from multiple local information systems and to require minimal extra work in units. After piloting in 4 centres in 2005 it was made available more widely. Opinions were sought from both patients who enrolled and from those who did not in a paper survey, and from staff in an electronic survey. Anonymous data on enrolments and usage were extracted from the webserver.
Results: By mid 2011 over 17,000 patients from 47 of the 75 renal units in the UK had registered. Users had a wide age range (<10 to >90 yrs) but were younger and had more years of education than non-users. They were enthusiastic about the concept, found it easy to use, and 80% felt it gave them a better understanding of their disease. The most common reason for not enrolling was being unaware of the system. A minority of patients had security concerns, and these were reduced after enrolling.
Staff responses were also strongly positive. They reported that it aided patient concordance and disease management, and increased the quality of consultations with a neutral effect on consultation length. Neither patient nor staff responses suggested that RPV led to an overall increase in patient anxiety or to an increased burden on renal units beyond the time required to enrol each patient.
Conclusions: Patient Internet access to secondary care records concerning a complex chronic disease is feasible and popular, providing an increased sense of empowerment and understanding, with no serious identified negative consequences. Security concerns were present but rarely prevented participation. These are powerful reasons to make this type of access more widely available
Mitigating Gyral Bias in Cortical Tractography via Asymmetric Fiber Orientation Distributions
Diffusion tractography in brain connectomics often involves tracing axonal
trajectories across gray-white matter boundaries in gyral blades of complex
cortical convolutions. To date, gyral bias is observed in most tractography
algorithms with streamlines predominantly terminating at gyral crowns instead
of sulcal banks. This work demonstrates that asymmetric fiber orientation
distribution functions (AFODFs), computed via a multi-tissue global estimation
framework, can mitigate the effects of gyral bias, enabling fiber streamlines
at gyral blades to make sharper turns into the cortical gray matter. We use
ex-vivo data of an adult rhesus macaque and in-vivo data from the Human
Connectome Project (HCP) to show that the fiber streamlines given by AFODFs
bend more naturally into the cortex than the conventional symmetric FODFs in
typical gyral blades. We demonstrate that AFODF tractography improves
cortico-cortical connectivity and provides highly consistent outcomes between
two different field strengths (3T and 7T)
Billions in Motion: Latino Immigrants, Remittances and Banking
Research on how remitters choose the means to send money home, including projections of remittance flows to Mexico and Central America that illustrate the extraordinary growth in recent years and the potential for continued growth and a demographic portrait of Latino remittance senders drawn from the Pew Hispanic Center/Kaiser Family Foundation National Survey of Latinos. Study is partially based on a Bendixen survey of Latino immigrants in USA.Remittances, Latino Immigrants, Remittances, Banking, USA Inmigrantes latinos, remesas, banca, EUA
- …