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Toan Nguyen

Publications and source records attributed to Toan Nguyen.

4 recordsLinked to original sources
PubMed2006

Microtubule protofilament number is modulated in a stepwise fashion by the charge density of an enveloping layer.

Microtubules are able to adjust their protofilament (PF) number and, as a consequence, their dynamics and function, to the assembly conditions and presence of cofactors. However, the principle behind such variations is poorly understood. Using synchrotron x-ray scattering and transmission electron microscopy, we studied how charged membranes, which under certain conditions can envelop pre-assembled MTs, regulate the PF number of those MTs. We show that the mean PF number, , is modulated primarily by the charge density of the membranes. decreases in a stepwise fashion with increasing membrane charge density. does not depend on the membrane-protein stoichiometry or the solution ionic strength. We studied the effect of taxol and found that increases logarithmically with taxol/tubulin stoichiometry. We present a theoretical model, which by balancing the electrostatic and elastic interactions in the system accounts for the trends in our findings and reveals an effective MT bending stiffness of order 10-100 k(B)T/nm, associated with the observed changes in PF number.

Animals↗
PubMed2006

Telecommunications access--matching available technologies to people with physical disabilities.

People with a disability do not have equitable access to the modern telecommunication medium. Many experience difficulty typing, handling the phone, dialling or answering calls. For those who are unable to speak, the only option is to type messages using whatever functional control site exists on their body. The provision of accessible mobile phones for people with disabilities can significantly improve their quality of life through an increased range of accessible activities, and can improve their independence, safety, security and self-esteem. This research was aimed at providing practical ways for people with a disability to participate in the extensive community of home and mobile phone users. The outcomes of ten participants taking part in the evaluation and trial of off-the-shelf telecommunication options are presented. Nine out of ten participants showed high to very high results in terms of their overall performance and satisfaction with the use of the telecommunication equipment provided. With the right policies, processes and support through equipment matching, education, training and delivery, current off-the-shelf solutions can help people with disabilities to effectively communicate with other members of our society and to access the same range of information systems and services enjoyed by able-bodied members of the community.

Adolescent↗
PubMed2005

Enhanced microarray performance using low complexity representations of the transcriptome.

Low abundance mRNAs are more difficult to examine using microarrays than high abundance mRNAs due to the effect of concentration on hybridization kinetics and signal-to-noise ratios. This report describes the use of low complexity representations (LCRs) of mRNA as the targets for cDNA microarrays. Individual sequences in LCRs are more highly represented than in the mRNA populations from which they are derived, leading to favorable hybridization kinetics. LCR targets permit the measurement of abundance changes that are difficult to measure using oligo(dT) priming for target synthesis. An oligo(dT)-primed target and three LCRs detect twice as many differentially regulated genes as could be detected by the oligo(dT)-primed target alone, in an experiment in which serum-starved fibroblasts responded to the reintroduction of serum. Thus, this target preparation strategy considerably increases the sensitivity of cDNA microarrays.

Cell Line↗