Listening while reading promotes word learning from stories

Reading and listening to stories fosters vocabulary development. Studies of single word learning suggest that new words are more likely to be learnt when both their oral and written forms are provided, compared to when only one form is given. This study explores children’s learning of phonological, orthographic and semantic information about words encountered in a story context. Seventy-one children (8 - 9 years) were exposed to a story containing novel words in one of three conditions: 1) listening, 2) reading, or 3) simultaneous listening and reading (‘combined condition’). Half of the novel words were presented with a definition and half without. Phonological and orthographic learning were assessed through recognition tasks. Semantic learning was measured using three tasks assessing recognition of the word’s category, sub-category and definition. Phonological learning was observed in all conditions, showing that phonological recoding supported the acquisition of phonological forms when children were not exposed to phonology (the reading condition). In contrast, children showed orthographic learning of the novel words only when they were exposed to orthographic forms, indicating that exposure to phonological forms alone did not prompt the establishment of orthographic representations. Semantic learning was greater in the combined condition than in the listening and reading conditions. The presence of the definition was associated with better performance on the semantic sub-category and definition post-tests but not the phonological, orthographic or category post-tests. Findings are discussed in relation to the lexical quality hypothesis and the availability of attentional resources

Sequential detection of multiple phase transitions in model biological membranes using a red-emitting conjugated polyelectrolyte.

The anionic conjugated polyelectrolyte, poly[3-(6-sulfothioatehexyl)thiophene] (P3Anionic), functions as a highly sensitive probe of membrane order, uniquely capable of sequentially detecting the three key phase transitions occurring within model phospholipid bilayers. The observed sensitivity is the result of charge-mediated, selective localisation of P3Anionic within the head-groups of the phospholipid bilayer

Unlocking Structure-Self-Assembly Relationships in Cationic Azobenzene Photosurfactants.

Azobenzene photosurfactants are light-responsive amphiphiles that have garnered significant attention for diverse applications including delivery and sorting systems, phase transfer catalysis, and foam drainage. The azobenzene chromophore changes both its polarity and conformation (trans-cis isomerization) in response to UV light, while the amphiphilic structure drives self-assembly. Detailed understanding of the inherent relationship between the molecular structure, physicochemical behavior, and micellar arrangement of azobenzene photosurfactants is critical to their usefulness. Here, we investigate the key structure-function-assembly relationships in the popular cationic alkylazobenzene trimethylammonium bromide (AzoTAB) family of photosurfactants. We show that subtle changes in the surfactant structure (alkyl tail, spacer length) can lead to large variations in the critical micelle concentration, particularly in response to light, as determined by surface tensiometry and dynamic light scattering. Small-angle neutron scattering studies also reveal the formation of more diverse micellar aggregate structures (ellipsoids, cylinders, spheres) than predicted based on simple packing parameters. The results suggest that whereas the azobenzene core resides in the effective hydrophobic segment in the trans-isomer, it forms part of the effective hydrophilic segment in the cis-isomer because of the dramatic conformational and polarity changes induced by photoisomerization. The extent of this shift in the hydrophobic-hydrophilic balance is determined by the separation between the azobenzene core and the polar head group in the molecular structure. Our findings show that judicious design of the AzoTAB structure enables selective tailoring of the surfactant properties in response to light, such that they can be exploited and controlled in a reliable fashion

Indexing In Memoriam Assignment

Curatorial note from Digital Pedagogy in the Humanities: The origin of humanities computing is usually dated to 1949, when Father Roberto Busa began working with IBM computers to produce a concordance to the works of Saint Thomas Aquinas (Hockey). Of course, concordances and indexes long predate electronic computers and, as Geoffrey Rockwell suggests, are premised upon hermeneutical assumptions of coherence and generative rule-bound procedures (Rockwell 211). The index is thus another example of “digital” or “hands-on” technology that expands beyond the electronic. Rachel Sagner Buurma’s assignment asks students to create an index to Tennyson’s In Memoriam or to use an existing index to create a new edition of the poem, foregrounding how informational technologies like the index create, constrain, or complicate the interpretation of literary works

Multimodal Control of Liquid Crystalline Mesophases from Surfactants with Photoswitchable Tails

Non-invasive manipulation of the hierarchical structure of functional materials is a key challenge in the advancement of optoelectronics, energy conversion and storage devices and drug delivery systems. Here, using a combination of small-angle X-ray scattering and polarised optical microscopy, we decipher the various structure/self- assembly relationships of neutral surfactants bearing photoswitchable tails, which self-organise into a rich variety of lyotropic liquid crystalline mesophases. Facile, multimodal control of the nanoscale morphology of these single-component systems is achieved through: i) molecular structure, via careful selection of the alkyl tail/ethylene oxide headgroup lengths; ii) concentration; iii) temperature; and iv) photoisomerisation. The nanoscale architectures range from the weakly concentrated hyperswollen lamellar phases, the more common lyotropic lamellar and hexagonal phases, to pure thermotropic liquid crystals; all of which are accessible at room temperature. Photoisomerisation with UV light leads to the reversible destruction of the liquid crystalline phase, which can be spatially controlled through the use of a mask. This extensive study demonstrates the versatility of neutral photosurfactants and paves the way for them to be investigated for new applications, such as photoresponsive templates or drug delivery systems.Isaac Newton Trust/University of Cambridge Early Career Support Scheme grant. Irish Research Council EU COST action MP120

Charge-modulated self-assembly and growth of conjugated polyelectrolyte-polyoxometalate hybrid networks.

Self-assembly of an anionic polyoxometalate with cationic conjugated polyelectrolytes leads to hybrid supramolecular networks whose dimensionality is controlled by the chain length and steric charge distribution

Charge-Mediated Localization of Conjugated Polythiophenes in Zwitterionic Model Cell Membranes.

The selective engineering of conjugated polyelectrolyte (CPE)-phospholipid interfaces is poised to play a key role in the design of advanced biomedical and biotechnological devices. Herein, we report a strategic study to investigate the relationship between the charge of the CPE side group and their association with zwitterionic phospholipid bilayers. The interaction of dipalmitoylphosphatidylcholine (DPPC) phospholipid vesicles with a series of poly(thiophene)s bearing zwitterionic, cationic, or anionic terminal groups (P3Zwit, P3TMAHT and P3Anionic, respectively) has been probed. Although all CPEs showed an affinity for the zwitterionic vesicles, the calculated partition coefficients determined using photoluminescence spectroscopy suggested preferential incorporation within the lipid bilayer in the order P3Zwit > P3Anionic ≫ P3TMAHT. The polarity probe Prodan was used to further qualify the position of the CPE inside the vesicle bilayers via Förster resonance energy transfer (FRET) studies. The varying proximity of the CPEs to Prodan was reflected in the Stern-Volmer quenching constants and decreased in the order P3Anionic > P3TMAHT ≫ P3Zwit. Dynamic light scattering measurements showed an increase in the hydrodynamic diameter of the DPPC vesicles upon addition of each poly(thiophene), but to the greatest extent for P3Anionic. Small-angle neutron scattering studies also revealed that P3Anionic specifically increased the thickness of the headgroup region of the phospholipid bilayer. Epifluorescence and atomic force microscopy imaging showed that P3TMAHT formed amorphous agglomerates on the vesicle surface, P3Zwit was buried throughout the bilayer, and P3Anionic formed a shell of protruding chains around the surface, which promoted vesicle fusion. The global data indicate three distinctive modes of interaction for the poly(thiophene)s within DPPC vesicles, whereby the nature of the association is ultimately controlled by the pendant charge group on each CPE chain. Our results suggest that charge-mediated self-assembly may provide a simple and effective route to design luminescent CPE probes capable of specific localization within phospholipid membranes

Light-responsive self-assembly of a cationic azobenzene surfactant at high concentration.

The formation of high-concentration mesophases by a cationic azobenzene photosurfactant is described for the first time. Using a combination of polarised optical microscopy and small-angle X-ray scattering, optically anisotropic, self-assembled structures with long-range order are reported. The mesophases are disrupted or lost upon UV irradiation

Probing the dynamic self-assembly behaviour of photoswitchable wormlike micelles in real-time.

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium cis- and trans-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, tetraethylene glycol mono(4',4-octyloxy,octyl-azobenzene) (C8AzoOC8E4) using small-angle neutron scattering (SANS). We show that the incorporation of in situ UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C8AzoOC8E4 could switch between wormlike micelles (trans native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked in situ through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly