A review and reappraisal of information technologies within a conceptual framework for individuals with disabilities

With over thirty million individuals with disabilities being reported in the United States, and with information systems permeating nearly every aspect of society, there is a growing urgency to ensure that everyone has equal access to technology. To render information technologies universally accessible, researchers must have at their disposal an accurate and reliable user model. Through the use of the conceptual framework presented here, accurate assumptions can be generated from knowledge of an individual’s impairments, and functional abilities to influence the creation of a user profile. Ultimately, user profiles serve as a vital attribute of user models applied to the design of technology in an effort to achieve universal access. Published online: 18 May 2001     

Development of sustained, focused attention in young children during free play.

The purpose of this project was to investigate the maintenance of focused attention in the first 5 years. In Study 1, 67 children were seen at 1, 2, and 3.5 years of age in free play with a number of age-appropriate toys. The duration of focused attention increased significantly over the ages studied. At 1 year, the children's focused attention showed a decline within the session; at the 2 older ages, however, focused attention neither decreased nor increased. In Study 2, children at 2.5, 3.5, and 4.5 years were also seen in free play. The results replicated the significant increase in focused attention over age and the lack of change within the session. Older children focused attention significantly more on construction and problem solving than did younger children, and manifested less inattention by physical movement away from the toys. The observed development in focused attention, therefore, is probably related both to the increased variety and complexity of the child's activities and to increasing inhibitory control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrating micro metal-air batteries in lateral flow test for point-of-care applications

Lateral flow test assay requires integrated micro power sourcesto realize quantitative testing as well as to enhance accuracy. Conventional dry batteries generally havepollution issues for this task, while the recently emerged paper-based fuel cells are both expensive and low-voltage that restrict their usage. In comparison, the metal-air battery (MAB) using a metal anode and an air-breathing cathode could be a much better solution. In this study, different micro metal-air batteries are integrated onto paper substrates, producing micro power sources that are low-cost, high-voltage and environmentally friendly. Their performances are compared under both alkaline and salt electrolytes in terms of power output, fabrication cost and specific energy. Among them, the Al-air battery with an alkaline electrolyte and the Mg-air battery with a salt electrolyte are more advantageous than others, achieving high voltage outputs of 1.55 V and 1.53 V at 1 mA cm^?2, respectively. By using acarbon grid instead of asilver grid as current collector, and nitrogen-doped carbon nanotubesinstead of MnO₂ as oxygen reduction catalyst, the as-fabricated micro MABs can be much cheaper and greener for disposable lateral flow test devices. Finally, a two-cell micro Al-air battery pack, which is integrated into a digital pregnancy tester, provides powersuccessfully for its operation for more than 5 minutes.     

Adjunctive psychotherapy for bipolar disorder: Effects of changing treatment modality.

In a randomized, controlled trial, the authors studied an adjunctive, individual psychotherapy, interpersonal and social rhythm therapy (IPSRT) for bipolar disorder. After stabilizing participants with episode appropriate pharmacotherapy and either IPSRT or intensive clinical management (CM), participants were reassigned to IPSRT or CM in conjunction with pharmacotherapy for 2 years of preventative treatment. Early results (n?=?82) suggest that altering participants' treatment assignment at entry to the preventative phase is related to risk of recurrence. Participants remaining in the same treatment for both acute and preventative phases had lower rates of recurrence (40%) and levels of symptomatology over the subsequent 52 weeks than those reassigned to the alternate modality. This finding, consistent with the authors' philosophy that bipolar patients benefit from stable routines, suggests that disruptions in the psychosocial treatment plan contribute to worse outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tissue lead concentration during chronic exposure of Pimephales promelas (fathead minnow) to lead nitrate in aquarium water

The fathead minnow is a useful species for evaluating the toxicity of wastewater effluents. While this fish is widely used for "survival" studies of metal toxicity, little or no work has been done on the tissue distribution of metals in fathead minnows. To determine the distribution of tissue lead, aquarium studies were conducted for several weeks with fish maintained in soft synthetic freshwater. Lead- (II) nitrate was added to three aquaria attaining concentrations of 20-30 ppb (aquarium B), 100-140 ppb (aquarium C), and roughly 200 ppb (aquarium D). Results were compared to controls (aquarium A). During the initial week, the majority of aquarium D fish died, whereas few deaths occurred in the other groups. Lead accumulation was dose- and tissue-dependent, with highest uptake by the gills. Gill concentrations of aquarium D fish averaged about 4-fold higherthan in skeleton or skin and muscle. In vitro, lead (2.5-25 ppm) caused dose-dependent reductions in the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) in gills incubated in physiological buffer. These findings demonstrate that fathead minnow gills bind and accumulate waterborne lead rapidly and preferentially and raise the possibility that gill lipid peroxidation contributes to lead toxicity at low water hardness.     

Multimodal Characterization of Crystal Structure and Formation in Rubrene Thin Films Reveals Erasure of Orientational Discontinuities

Multimodal multiscale characterization provide opportunities to study organic semiconducting thin films with multiple length scales, across multiple platforms, to elucidate crystallization mechanisms of the various microstructures that impact functionality. With polarized scanning transmission X-ray and 4D-scanning transmission electron microscopy, hybrid crystalline structures in rubrene thin films in which large crystalline domains surround a common nucleus and transition to a spherulite morphology at larger radii is observed. These high-resolution techniques reveal how azimuthal orientational discontinuities at smaller radii are erased as spherulite morphology takes hold. In situ crystallization in the films with optical microscopy is also captured, discovering the importance of considering the initial temperature increase of a film during thermal annealing over the crystallization timescale. This kinetic information of the radial crystallization rate and of corresponding film heating kinetics is used to estimate the temperature at which the larger crystalline regions transition into a spherulite. By combining the results obtained from the different characterization modes, it is learned that thermal conditions can sensitively affect the crystallization of rubrene and other organic thin films. The observations suggest opportunities for more complex temperature-dependent processing to maximize hybrid structures’ functionality in organic thin films and demonstrate that multimodal studies deepen the understanding of structure-function dynamics.     

Molecular-level composition design for efficient synthesis of SiAlON ceramics

SiAlONs are a class of liquid-phase sintered ceramics with excellent room-temperature strength and toughness, but whose residual grain boundary glass softens at high temperatures, limiting use in extreme environments. For this reason, efforts are made to minimize the volume of the grain boundary glass while still facilitating full densification. This work describes a potential route for the densification of SiAlONs with very low concentrations of liquid-phase sintering additive (e.g., rare-earth oxides such as yttria) by using an organometallic precursor. Solid solution of Al and O in the Si₃N₄ lattice was accomplished through the incorporation of solute atoms via liquid organic precursor aluminum sec-butoxide (ASB). Al₂O₃ powder is conventionally used for this purpose, and the subsequent lattice softening associated with the solid solution helps to facilitate densification. However, a liquid-phase additive is still essential for the full densification of SiAlONs. Higher densities were obtained from SiAlON powder blends utilizing organometallic ASB than those utilizing alumina powder, allowing for greater densification at very low Y₂O₃ concentrations. The thermal decomposition of the organic precursor was investigated by high-temperature scanning electron microscopy, thermogravimetric analysis, and various X-ray diffraction experiments. Immersion density measurements and lattice parameter refinements were performed for samples sintered with varying Y₂O₃ concentrations and/or dwell times. Results indicate that ASB-containing powder blends favor SiAlON formation more strongly than Al₂O₃-containing powder blends and favor densification at very low Y₂O₃ concentration.     

Multiple Site‐Selective Insertions of Noncanonical Amino Acids into Sequence‐Repetitive Polypeptides

A simple and efficient method is described for the introduction of noncanonical amino acids at multiple, defined sites within recombinant polypeptide sequences. Escherichia coli MRA30, a bacterial host strain with attenuated activity of release factor 1 (RF1), was assessed for its ability to support incorporation of a diverse range of noncanonical amino acids in response to multiple encoded amber (TAG) codons within genes derived from superfolder GFP and an elastin‐mimetic protein polymer. Suppression efficiency and protein yield depended on the identity of the orthogonal aminoacyl‐tRNA synthetase/tRNA^CUA pair and the noncanonical amino acid. Elastin‐mimetic protein polymers were prepared in which noncanonical amino acid derivatives were incorporated at up to 22 specific sites within the polypeptide sequence with high substitution efficiency. The identities and positions of the variant residues were confirmed by mass spectrometric analysis of the full‐length polypeptides and proteolytic cleavage fragments from thermolysin digestion. The data suggest that this multisite suppression approach permits the preparation of protein‐based materials in which novel chemical functionalities can be introduced at precisely defined positions within the polypeptide sequence.