Conjugated polymer−titania nanoparticle hybrid films : random lasing action and ultrasensitive detection of explosive vapors

We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO₂ nanoparticles can be used to detect 2,4,6-trinitrotoluene (TNT) vapors. The hybrid film was fabricated by spin-casting SOP solution dispersed with nanosized TiO₂ particles on quartz glass. The SOP in the hybrid film functioned as both the gain medium and the sensory transducer. A random lasing action was observed with a certain pump power when the size (diameter of 50 nm) and concentration (8.9 - 10¹²/cm³) of TiO₂ nanoparticles were optimized. Measurements of fluorescence quenching behavior of the hybrid film in TNT vapor atmosphere (10 ppb) showed that attenuated lasing in optically pumped hybrid film displayed a sensitivity to vapors of explosives more than 20 times higher than was observed from spontaneous emission. This phenomenon has been explained with the four-level laser model. Since the sensory transducer used in the hybrid polymer/nanoparticles system could be replaced by other functional materials, the concept developed could be extended to more general domains of chemical or environment detection.

Contested Publics: Racist rants, bystander action and social media acts of citizenship

While social media tools enable new kinds of creativity, cultural expression and forms of public, civic and political participation, we often hear more about the harms that arise from instances of trolling and 'aberrant' online participation, including racist provocation. In media and communications research, these issues have been framed in a number of ways, usually focusing on new tools for civic engagement, political participation and digital inclusion. Government policy has been shifting steadily towards potential regulation of social media 'misuse' in relation to appropriate forms of 'digital citizenship'. It is in this evolving context that we consider several instances of cultural or nationalistic provocation and conflict in which social media platforms (YouTube and Facebook in particular) have been central to the social dynamic that has unfolded. We examine the recording and uploading of racist rants and associated bystander actions on public transport in Australia and elsewhere around the world. In this article, we contend that while racism remains an issue in uses of social media platforms such as YouTube, this focus often overshadows these platforms' productive potential, including their capacity to support agonistic publics from which productive expressions of cultural citizenship and solidarity might emerge.

Translating osteoporosis prevention guidelines: a case study of participatory action and the development of an oversized jigsaw

OBJECTIVE: In Australia, the social gradient of chronic disease has never been as prominent as in current times, and the uptake of preventive health messages appears to be lower in discrete population groups. In efforts to re-frame health promotion from addressing behavior change to empowerment, we engaged community groups in disadvantaged neighborhoods to translate published preventive guidelines into easy-to-understand messages for the general population. METHOD: Our research team established partnerships with older aged community groups located in disadvantaged neighborhoods, determined by cross-referencing addresses with the Australian Bureau of Statistics, to translate guidelines regarding osteoporosis prevention. RESULTS: We developed an oversized jigsaw puzzle that we used to translate recommended osteoporosis prevention guidelines. DISCUSSION: Successful participatory partnerships between researchers, health promotion professionals, and community groups in disadvantaged neighborhoods build capacity in researchers to undertake future participatory processes; they also make the best use of expert knowledge held by specific communities.

Literacy into action: digital games as action and text in the English and literacy classroom

Using data gathered from a three-year research project exploring digital literacy and pedagogy with respect to video games, including classroom games-based pedagogy and curriculum and ethnographic research on students' digital game playing, this article locates and explores a key conceptual problem facing the incorporation of digital games into English and literacy classroom activities. This challenge is defined as "action" and refers to the non-visual and non-textual elements of gameplay. This challenge is explored both theoretically and through a practical discussion of various strategies developed by teachers in the project to approach this issue. The article draws on contemporary game studies in order to map out and highlight several key areas where action-based projects lead to critical reflection.

Joint action and the expression of shared intentions: an expanded Taylorian account

After having identified several shortcomings of the so-called 'standard accounts' of shared intentions, this paper will develop a novel framework for understanding such intentions. The framework to be advanced hinges on a notion of ‘expression’, as well as on the claim that shared intentions are expressed—that is, manifested, grasped, shaped and clarified—throughout the unfolding of the joint actions they animate, as well as in the various expressive activities and behaviours that accompany joint action. This claim will be defended with particular reference to the work of Charles Taylor on expression, as well as recent work on embodied cognition.

Visual perception of movement kinematics and the acquisition of "action prototypes"

Recognizing a class of movements as belonging to a "nominal" action category, such as walking, running, or throwing, is a fundamental human ability. Three experiments were undertaken to test the hypothesis that common ("prototypical") features of moving displays could be learned by observation. Participants viewed moving stick-figure displays resembling forearm flexion movements in the saggital plane. Four displays (presentation displays) were first presented in which one or more movement dimensions were combined with 2 respective cues: direction (up, down), speed (fast, slow), and extent (long, short). Eight test displays were then shown, and the observer indicated whether each test display was like or unlike those previously seen. The results showed that without corrective feedback, a single cue (e.g., up or down) could be correctly recognized, on average, with the proportion correct between .66 and .87. When two cues were manipulated (e.g., up and slow), recognition accuracy remained high, ranging between .72 and .89. Three-cue displays were also easily identified. These results provide the first empirical demonstration of action-prototype learning for categories of human action and show how apparently complex kinematic patterns can be categorized in terms of common features or cues. It was also shown that probability of correct recognition of kinematic properties was reduced when the set of 4 presentation displays were more variable with respect to their shared kinematic property, such as speed or amplitude. Finally, while not conclusive, the results (from 2 of the 3 experiments) did suggest that similarity (or "likeness") with respect to a common kinematic property (or properties) is more easily recognized than dissimilarity.

Outdoor education and bush adventure therapy: A social-ecological approach to health and wellbeing.

Together, outdoor education and bush adventure therapy can be seen to constitute a population-wide health intervention strategy. Whether in educational or therapeutic settings, the intentional use of contact with nature, small groups, and adventure provides a unique approach in the promotion of health and wellbeing for the general population, and for individuals with identified health vulnerabilities. This paper explicitly emphasises human and social health, however, an integral assumption is that a healthy and sustainable environment is dependent on healthy human relationships with nature. We invite outdoor educators and bush adventure therapy practitioners to examine the proposition that healthy interactions with nature can create a unique stream of socio-ecological interventions. A spectrum of outdoor adventure programs is provided, allowing outdoor educators and bush adventure therapy practitioners to locate their work according to program context and aims, and participant aims and needs.

Ion exchange, anisotropic structure and thermal stability of polypyrrole films

The thermal stability of electrochemically prepared polypyrrole (PPy) films with p-toluene sulfonate (pTS) or perchlorate (CIOP₄⁻) counter ion (PPy/pTS and PPy/ClO₄⁻) is improved by simple treatment with aqueous sulfuric acid, sodium sulfate or sodium bisulfate. The degree of stabilization achieved depends on the solution, temperature and duration of treatment. PPy/pTS is easily stabilized and thick films (43μm) retain 90 % of the initial conductivity after long period (300 h) at 150 °C, while thinner films (12 μm) retain slightly less (70 %). A model for the conductivity decay has been proposed. Although the mechanism for improved stability is not yet clear it is apparent that the level of ion exchange and the original polymer microstructure are important. The early stages of ion exchange are not symmetrical and diffusion is facilitated at the electrode side of the film. Furthermore, X-ray diffraction shows no evidence of morphological change after treatment of thick PPy/pTS but in thin PPy/pTS and PPy/ClO₄⁻ films an additional peak is indicative of more ordered structure following treatment. These observation may imply that there is a higher density of crosslinks and branching at the growth side than at the electrode side of the film.

Constructing the conditions of and environments for interdisciplinary research on perception and action

This paper suggests ways in which art processes may contribute to the interdisciplinary study of perception and action and the relationships between body, person, and environment. Artists-turned-architects Arakawa and Gins serve as the most advanced example of an interdisciplinary research project in terms of coordinating material processes with contemporary findings, methods, and orientations from across the arts, humanities, and hard and soft sciences. In the first section of the paper, I discuss Arakawa and Gins's Reversible Destiny Lofts at Mitaka as an example of their procedural approach to long-term sustainable experimental environments. In the second section, the tactics through which Arakawa and Gins have repositioned art for the nonart purposes and common research goals are posited. Finally, I briefly outline the disciplinary positions and research values needed in order to move toward a more inclusive and interdisciplinary research practice.

Blend films of natural wool and cellulose prepared from an ionic liquid

Natural wool/cellulose blends were prepared in an ionic liquid green solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl) and the films were formed subsequently from the coagulated solutions. The wool/cellulose blend films show significant improvement in thermal stability compared to the coagulated wool and cellulose. Moreover, the blend films exhibited an increasing trend of tensile strength with increase in cellulose content in the blends which could be used for the development of wool-based materials with improved mechanical properties, and the elongations of the blends were considerably improved with respect to the coagulated films of wool and cellulose. It was found that there was hydrogen bonding interaction between hydroxyl groups of wool and cellulose in the coagulated wool/cellulose blends as determined by Fourier transform infrared (FTIR) spectroscopy. The ionic liquid was completely recycled with high yield and purity after the blend film was prepared. This work presents a green processing route for development of novel renewable blended materials from natural resource with improved properties.

De-tooling technology : networked computing as an environment, purpose and medium for social action

Network technologies are very desirable for social action, allowing activists to achieve more with less, more quickly and with broader impact; on the other hand, the very advantages they bring are equally important to the world of contemporary capitalism that social action seeks to change. Thus, we must look beyond network technologies as the easy solution to every problem, and focus instead on the human relationships which might be enabled by them. This focus on relationships requires us to ‘de-tool’ information technology. Instead, for social action, it is more valuable to think of networked computing as part of the environment within which action can occur; an important purpose for such action; and as a medium that nurtures expression and engagement of self and belief.

In vitro and in vivo assessment of docetaxel formulation developed for esophageal stents

Esophageal cancer (EC) mostly affects the elderly population and is frequently diagnosed at an advanced stage. Self-expanding metal stents (SEMS) are the most popular mode of palliation, but they are associated with reocclusion caused by tumor growth. To overcome this problem, docetaxel (DTX)-loaded polyurethane formulations were prepared for stent application. The films were evaluated against the cancer cell lines, OE-19 and OE-21, and normal esophageal cell line Het-1A. The DTX and the formulations were evaluated in vitro for the cytotoxicity and in vivo in nude mice. It was found that DTX and the formulations have a weak activity against the EC cell lines and an even weaker activity against Het-1A cell line. Preliminary in vivo studies showed skin toxicity in nude mice necessitating modification of the formulation. Reevaluation in a mouse xenograft model resulted in toxicity at high dose formulations while the low dose formulation exhibited modest advantage over commercial IV formulation; however, there was no significant difference between the commercial IV and blank formulation. DTX combination with an anti-cancer agent having complementary mode of action and non-overlapping toxicity could yield better outcome in future.