Designing interaction, voice, and inclusion in AAC research

The ISAAC 2016 Research Symposium included a Design Stream that examined timely issues across augmentative and alternative communication (AAC), framed in terms of designing interaction, designing voice, and designing inclusion. Each is a complex term with multiple meanings; together they represent challenging yet important frontiers of AAC research. The Design Stream was conceived by the four authors, researchers who have been exploring AAC and disability-related design throughout their careers, brought together by a shared conviction that designing for communication implies more than ensuring access to words and utterances. Each of these presenters came to AAC from a different background: interaction design, inclusive design, speech science, and social science. The resulting discussion among 24 symposium participants included controversies about the role of technology, tensions about independence and interdependence, and a provocation about taste. The paper concludes by proposing new directions for AAC research: (a) new interdisciplinary research could combine scientific and design research methods, as distant yet complementary as microanalysis and interaction design, (b) new research tools could seed accessible and engaging contextual research into voice within a social model of disability, and</p

Structural and functional role of the disulfide bridges in the hydrophobin SC3

Hydrophobins function in fungal development by self-assembly at hydrophobic-hydrophilic interfaces such as the interface between the fungal cell wall and the air or a hydrophobic solid. These proteins contain eight conserved cysteine residues that form four disulfide bonds. To study the effect of the disulfide bridges on the self-assembly, the disulfides of the SC3 hydrophobin were reduced with 1,4-dithiothreitol. The free thiols were then blocked with either iodoacetic acid (IAA) or iodoacetamide (IAM), introducing eight or zero negative charges, respectively. Circular dichroism and infrared spectroscopy showed that after opening of the disulfide bridges SC3 is initially unfolded. IAA-SC3 did not self-assemble at the air-water interface upon shaking an aqueous solution. Remarkably, after drying down IAA-SC3 or after exposing it to Teflon, it refolded into a structure similar to that observed for native SC3 at these interfaces. Iodoacetamide-SC3 on the other hand, which does not contain extra charges, spontaneously refolded in water in the amyloid-like β-sheet conformation, characteristic for SC3 assembled at the water-air interface. From this we conclude that the disulfide bridges of SC3 are not directly involved in self-assembly but keep hydrophobin monomers soluble in the fungal cell or its aqueous environment, preventing premature self-assembly

Use of hydrophobins in formulation of water insoluble drugs for oral administration

The poor water solubility of many drugs requires a specific formulation to achieve a sufficient bioavailability after oral administration. Suspensions of small drug particles can be used to improve the bioavailability. We here show that the fungal hydrophobin SC3 can be used to make suspensions of water insoluble drugs. Bioavailability of two of these drugs, nifedipine and cyclosporine A (CyA), was tested when administered as a SC3-based suspension. SC3 (in a 1:2 (w/w) drug:SC3 ratio) or 100% PEG400 increased the bioavailability of nifedipine to a similar degree (6±2- and 4±3-fold, respectively) compared to nifedipine powder without additives. Moreover, SC3 (in a 7:1 (w/w) drug:hydrophobin ratio) was as effective as a 20-fold diluted Neoral® formulation by increasing bioavailability of CyA 2.3±0.3-fold compared to CyA in water. Interestingly, using SC3 in the CyA formulation resulted in a slower uptake (p < 0.001 in Tmax) of the drug, with a lower peak concentration (Cmax 1.8 mg ml−1) at a later time point (Tmax 9±2 h) compared to Neoral® (Cmax 2.2 mg ml−1; Tmax 3.2±0.2). Consequently, SC3 will result in a more constant, longer lasting drug level in the body. Taken together, hydrophobins are attractive candidates to formulate hydrophobic drugs.

Structural Characterization of the Hydrophobin SC3, as a Monomer and after Self-Assembly at Hydrophobic/Hydrophilic Interfaces

AbstractHydrophobins are small fungal proteins that self-assemble at hydrophilic/hydrophobic interfaces into amphipathic membranes that, in the case of Class I hydrophobins, can be disassembled only by treatment with agents like pure trifluoroacetic acid. Here we characterize, by spectroscopic techniques, the structural changes that occur upon assembly at an air/water interface and upon assembly on a hydrophobic solid surface, and the influence of deglycosylation on these events. We determined that the hydrophobin SC3 from Schizophyllum commune contains 16–22 O-linked mannose residues, probably attached to the N-terminal part of the peptide chain. Scanning force microscopy revealed that SC3 adsorbs specifically to a hydrophobic surface and cannot be removed by heating at 100°C in 2% sodium dodecyl sulfate. Attenuated total reflection Fourier transform infrared spectroscopy and circular dichroism spectroscopy revealed that the monomeric, water-soluble form of the protein is rich in β-sheet structure and that the amount of β-sheet is increased after self-assembly on a water-air interface. α-Helix is induced specifically upon assembly of the protein on a hydrophobic solid. We propose a model for the formation of rodlets, which may be induced by dehydration and a conformational change of the glycosylated part of the protein, resulting in the formation of an amphipathic α-helix that forms an anchor for binding to a substrate. The assembly in the β-sheet form seems to be involved in lowering of the surface tension, a potential function of hydrophobins

Influences between online-exclusive, conjoint and offline-exclusive friendship networks: The moderating role of shyness

Prior research has indicated that shy adolescents are more motivated to form friendships online than to form friendships offline. Little is known about whether having friendships found exclusively online may impact self-esteem and forming offline friendships for these adolescents. This study therefore aimed to provide insight into the moderating role of shyness in the longitudinal interplay between friendships in online and offline contexts in early adolescence. Adolescents and their friends (193 girls, 196 boys; Mage = 13.29) were followed with three consecutive measurements with intervals of eight months. Results showed that particularly for shy adolescents, having friends exclusively online predicted increases in self-esteem. Self-esteem, in turn, was found to predict forming more friendships found both offline and online and forming more friendships found exclusively offline. Thus, findings supported the social compensation perspective that shy adolescents may benefit from having friends exclusively online, as these friendships may increase self-esteem, thereby facilitating the formation of friendships found partially and completely offline