Students on the fly: Preliminary data from a year‐long

As part of an ongoing, year‐long ethnographic study on laptop adoption and usage, selected families, young professionals, and students in Tempe Arizona and the Puget Sound area in Washington State have been given some form of laptop computer, based on activity maps participants furnished to researchers. These 32 participants, 12 of them students, are being followed for one year as they report on their experiences. Preliminary data after one month reveal some surprises: A quarter of the students expressed desire/need for larger font sizes on their laptops; all students receiving a laptop without a CD/DVD drive complained that it depressed some of their mobile desires; and stylishness, even in a larger device, played a prominent role for some students. After initial excitement over Tablet functionality (rotating screen, pen), usage at this stage for the most part entails using the pen to navigate.Mobile and Tailored Platforms, Microsoft Corporatio

Methods of NMR structure refinement: molecular dynamics simulations improve the agreement with measured NMR data of a C-terminal peptide of GCN4-p1

The C-terminal trigger sequence is essential in the coiled-coil formation of GCN4-p1; its conformational properties are thus of importance for understanding this process at the atomic level. A solution NMR model structure of a peptide, GCN4p16-31, encompassing the GCN4-p1 trigger sequence was proposed a few years ago. Derived using a standard single-structure refinement protocol based on 172 nuclear Overhauser effect (NOE) distance restraints, 14 hydrogen-bond and 11 ϕ torsional-angle restraints, the resulting set of 20 NMR model structures exhibits regular α-helical structure. However, the set slightly violates some measured NOE bounds and does not reproduce all 15 measured 3J(HN-HCα)-coupling constants, indicating that different conformers of GCN4p16-31 might be present in solution. With the aim to resolve structures compatible with all NOE upper distance bounds and 3J-coupling constants, we executed several structure refinement protocols employing unrestrained and restrained molecular dynamics (MD) simulations with two force fields. We find that only configurational ensembles obtained by applying simultaneously time-averaged NOE distance and 3J-coupling constant restraining with either force field reproduce all the experimental data. Additionally, analyses of the simulated ensembles show that the conformational variability of GCN4p16-31 in solution admitted by the available set of 187 measured NMR data is larger than represented by the set of the NMR model structures. The conformations of GCN4p16-31 in solution differ in the orientation not only of the side-chains but also of the backbone. The inconsistencies between the NMR model structures and the measured NMR data are due to the neglect of averaging effects and the inclusion of hydrogen-bond and torsional-angle restraints that have little basis in the primary, i.e. measured NMR dat

Neural networks engaged in tactile object manipulation: patterns of expression among healthy individuals

<p>Abstract</p> <p>Background</p> <p>Somatosensory object discrimination has been shown to involve widespread cortical and subcortical structures in both cerebral hemispheres. In this study we aimed to identify the networks involved in tactile object manipulation by principal component analysis (PCA) of individual subjects. We expected to find more than one network.</p> <p>Methods</p> <p>Seven healthy right-handed male volunteers (aged 22 to 44 yrs) manipulated with their right hand aluminium spheres during 5 s with a repetition frequency of 0.5-0.7 Hz. The correlation coefficients between the principal component temporal expression coefficients and the hemodynamic response modelled by SPM (ecc) determined the task-related components. To establish reproducibility within subjects and similarity of functional connectivity patterns among subjects, regional correlation coefficients (rcc) were computed between task-related component image volumes. By hierarchically categorizing, selecting and averaging the task-related component image volumes across subjects according to the rccs, mean component images (MCIs) were derived describing neural networks associated with tactile object manipulation.</p> <p>Results</p> <p>Two independent mean component images emerged. Each included the primary sensorimotor cortex contralateral to the manipulating hand. The region extended to the premotor cortex in MCI 1, whereas it was restricted to the hand area of the primary sensorimotor cortex in MCI 2. MCI 1 showed bilateral involvement of the paralimbic anterior cingulate cortex (ACC), whereas MCI 2 implicated the midline thalamic nuclei and two areas of the rostral dorsal pons.</p> <p>Conclusions</p> <p>Two distinct networks participate in tactile object manipulation as revealed by the intra- and interindividual comparison of individual scans. Both were employed by most subjects, suggesting that both are involved in normal somatosensory object discrimination.</p

Distinguishing transient from persistent tactile agnosia after partial anterior circulation infarcts - Behavioral and neuroimaging evidence for white matter disconnection.

From a cohort of 36 patients presenting apperceptive tactile agnosia after first cortical ischemic stroke, 14 showed temporary impairment at admission. A previous multi-voxel analysis of the cortical lesions, using as explanatory variable the course of tactile object recognition performance over the recovery period of 9 months, partitioned the cohort into three subgroups. Of the 14 patients constituting two of the subgroups, 7 recovered from their impairment whereas 7 did not. These two subgroups could not be distinguished at admission. The primary aim of the present study is to present two assessments that can do so. The first assessment comprises a pattern of behavioral measures, determined via principal component analysis, encoded in three tests: picking small objects, macrogeometrical discrimination and tactile object recognition. The receiver operating characteristic curve derived from permutation of the behavioral test scores yielded an 80% probability of correct identification of the patient subgroup and an 8% probability for false identification. As done with the permuted scores, the pattern could predict the persistence of affliction of new stroke patients with tactile agnosia. The second predictive assessment extends our previous evaluation of cortical MRI lesion maps to include subcortical regions. Confirming our previous study, the lesions of the persistently impaired subgroup disrupted significantly the anterior arcuatus fasciculus and associated superior longitudinal fasciculus III in the ipsilesional hemisphere, impeding reciprocal information transfer between supramarginal gyrus and both the ventral premotor cortex and Brodmann area 44. Due to the importance of interhemispheric information transfer in tactile agnosia, we performed a supplementary analysis of tactile object recognition scores. It showed that haptic information transfer from the non-affected to the affected hands in the persistent cases partly restored function during the nine months, possibly following restoration of functional interhemispheric haptic information transfer at the border of posterior corpus callosum and splenium. In conclusion, the combined findings of the cortical lesion at subarea PFt of the inferior parietal lobule and the associated subcortical tract lesions permit almost perfect prediction of persistent impairment of tactile object recognition. The study substantiates the need for combined analysis of both cortical lesions and white matter tract disconnections

Kennedy Space Center (KSC) Launch Pad Avian Abatement Efforts Including Related KSC Road Kill Reduction Effort

While birds might seem harmless, there's a good reason for the concern. During the July 2005 launch of Discovery on mission STS-1 14, a vulture soaring around the launch pad impacted the shuttle's external tank just after liftoff. With a vulture's average weight ranging from 3 to 5 pounds. a strike at a critical point on the Shuttle -- like the nose or wing leading thermal protection panels -- could cause catastrophic damage to the vehicle. The foam chunk that fatefully struck Columbia's wing in 2003 weighed only 1.7 pounds. (Cheryl L. Mansfield "Bye Bye Birdies" 2006) To address this issue, NASA formed an "Avian Abatement Team". The team goal is to have safer Shuttle missions by reducing the vulture population at KSC near the pad area thereby reducing the probability of another vulture strike during a Shuttle launch

Lesions to Primary Sensory and Posterior Parietal Cortices Impair Recovery from Hand Paresis after Stroke

Neuroanatomical determinants of motor skill recovery after stroke are still poorly understood. Although lesion load onto the corticospinal tract is known to affect recovery, less is known about the effect of lesions to cortical sensorimotor areas. Here, we test the hypothesis that lesions of somatosensory cortices interfere with the capacity to recover motor skills after stroke

Adaptive mappings for mouse-replacement interfaces

Users of mouse-replacement interfaces may have difficulty conforming to the motion requirements of their interfacesystem. We have observed users with severe motor disabilities who controlled the mouse pointer with a head tracking interface. Our analysis shows that some users may be able to move in some directions easier than other directions. We propose several mouse pointer mappings that adapt to the user's movement abilities. These mappings will take into account the user's motions in two-or three-dimensions to move the mouse pointer in the intended direction

Adaptive mouse-replacement interface control functions for users with disabilities

We discuss experiences employing a video-based mouse-replacement interface system, the Camera Mouse, at care facilities for individuals with severe motion impairments and propose adaptations of the system. Traditional approaches to assistive technology are often inflexible, requiring users to adapt their limited motions to the requirements of the system. Such systems may have static or difficult-to-change configurations that make it challenging for multiple users to share the same system or for users whose motion abilities slowly degenerate. As users fatigue, they may experience more limited motion ability or additional unintended motions. To address these challenges, we propose adaptive mouse-control functions to be used in our mouse-replacement system. These functions can be changed to adapt the technology to the needs of the user, rather than making the user adapt to the technology. We present observations of an individual with severe cerebral palsy using our system.National Science Foundation (IIS-0713229, IIS-0855065, IIS-0910908

On the neural networks of empathy: A principal component analysis of an fMRI study

© 2008 Nomi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens