The self-assembled monolayer modification of electrodes - some recent advances in biological application

The modification of an electrode surface at the molecular level using the technique of depositing self-assembled monolayers (SAM) is a typical example of the techniques used in nanotechnology, from the process "bottom up", which is to create a nanostructure by successive additions of molecular or atomic entities on a surface. This article presents some recent advances in the field, with examples: the development of systems Sat hybridized with biomolecules, nanoparticles or nanotubes in bioelectronics, the use of switchable electrodes to study the adhesion and migration of biological cells , and the integration of molecular son in the SAM to recognize and allow the transduction of a biological response allowing the practice of electrochemistry in a complex biological environment.

Unusual suspects : a newspaper's coverage of a scuba diving rescue and journalism's role in narrating Australia

Brisbane’s Courier-Mail newspaper ran a fantastic story a couple of years ago about a couple left at sea behind by their tour boat, after going scuba diving. The story suggested American diver Allyson Dalton and her British partner Richard Neely ignored advice when they ventured away from a lagoon where the tour boat was anchored. But the focus was on how Neely and Dalton survived by treading water for 19 hours at Paradise Reef, part of Queensland’s Great Barrier Reef, not so much (yet) on how fortunate they were not to be attacked by sharks. It would not be long, however, before that old journalistic maxim that implores practitioners to ‘question every assertion, doubt every claim’ shaped the reportage into an extended narrative about chequebook journalism, credibility, and culpability.

The scuba dive rescue story analysis presented here reflects contemporary journalism’s role in the formation of ideas about cultural value and character, and in more complex determinations of who gets a participatory stake in the formation of national narratives. As such, the article concludes with some signposts toward a critical approach to journalism-centred studies of culture in Australia.

Flock inspired area coverage using wireless boid-like sensor agents

Simulated flocking is achievable using three boid rules [13]. We propose an area coverage model inspired by Reynolds’ flocking algorithm, investigating strategies for achieving quality coverage using flocking rules. Our agents are identical and autonomous, using only local sensory information for indirect communication. Upon deployment, agents are in the default separation mode. The cohesion rule would then guarantee that agents remain within the swarm, covering spaces with explored neighbour spaces. Four experiments are conducted to evaluate our model in terms of coverage quality achieved. We firstly investigate agents’ separation speed before the speed with which isolated agents re-organizes is investigated. The third experiment compares coverage quality achieved using our model with coverage quality achieved using random guessing. Finally, we investigate fault tolerance in the event of agents’ failures. Our model exhibits good separation and cohesion speed, achieving high quality coverage. Additionally, the model is fault tolerant and adaptive to agents’ failures.

Influence of particle concentration on initial collection efficiency and surface coverage in porous media filtration

Four sizes (0.095, 0.53, 1.0 and 2.01 μm) of polystyrene latex particles were used to prepare monodispersed suspensions at three different ionic strengths (10−3, 10−2.5 and 10−2M KCl). Filtration experiments were conducted using those suspensions in a filter column with glass beads as porous medium. The filter bed depth and the filtration velocity were kept at 5 cm and 1 m/h, respectively. When suspensions with equal mass concentrations (0.2 mg/L) or equal surface area concentrations (0.12 cm2/mL) were filtered through the system, the largest particles exhibited higher initial single collector efficiency, η. The difference between the η of largest particles and the smaller particles was prominent for suspensions with equal surface area concentrations at higher ionic strengths. The collision efficiency, α of those particles exhibits higher values at higher ionic strengths. Both at equal mass concentration and equal surface area concentration, α is only slightly dependent on particle sizes when compared to its dependence on ionic strength. Further, it was found that the specific surface coverage was similar for 0.095 μm, 0.53 μm and 1.0 μm particles during the transient stage of filtration at any ionic strength when the surface area concentrations of those suspension were equal.

Contact electrification induced by monolayer modification of a surface and relation to acid-base interactions

Electrical charge separation following contact between two materials (contact electrification or the triboelectric effect) is well known to occur between different materials as a consequence of their different electronic structures. Here we show that the phenomenon occurs between two surfaces of the same material if one is coated with a single chemisorbed monolayer. We use the surface force apparatus to study contact electrification and adhesion between two silica surfaces, one coated with an amino-silane. The presence of this monolayer results in significantly enhanced adhesion between the surfaces, owing to electrostatic attraction following contact electrification, in accord with Derjaguin's electrostatic theory of adhesion. At the same time, the observed increase in adhesion is consistent with Fowkes' acid-base model (in which acid-base interactions between surface groups are considered to be the predominant factor determining adhesion), as the monolayer converts the originally acidic silica surface to a basic (amine-terminated) one. These observations demonstrate a link between acid- base interactions and contact electrification.

Electrical charge separation following contact between two materials (contact electrification or the triboelectric effect) is well known to occur between different materials as a consequence of their different electronic structures. Here we show that the phenomenon occurs between two surfaces of the same material if one is coated with a single chemisorbed monolayer. We use the surface force apparatus to study contact electrification and adhesion between two silica surfaces, one coated with an amino-silane. The presence of this monolayer results in significantly enhanced adhesion between the surfaces, owing to electrostatic attraction following contact electrification, in accord with Derjaguin's electrostatic theory of adhesion. At the same time, the observed increase in adhesion is consistent with Fowkes' acid-base model (in which acid-base interactions between surface groups are considered to be the predominant factor determining adhesion), as the monolayer converts the originally acidic silica surface to a basic (amine-terminated) one. These observations demonstrate a link between acid-base interactions and contact electrification.

Passing the banner : the Australian media’s coverage of high profile court cases about women

An examination of the historical narrative patterns of gendered justice in Australian media representations of high profile court cases. Includes discussion of the Chamberlain Case, the Dianne Brimble cruise ship death case, and the Jill Meagher rape and murder

Scaling-up from an implementation trial to state-wide coverage : results from the preliminary Melbourne Diabetes Prevention Study

Background
The successful Greater Green Triangle Diabetes Prevention Program (GGT DPP), a small implementation trial, has been scaled-up to the Victorian state-wide ‘Life!’ programme with over 10,000 individuals enrolled. The Melbourne Diabetes Prevention Study (MDPS) is an evaluation of the translation from the GGT DPP to the Life! programme. We report results from the preliminary phase (pMDPS) of this evaluation.
Methods
The pMDPS is a randomised controlled trial with 92 individuals aged 50 to 75 at high risk of developing type 2 diabetes randomised to Life! or usual care. Intervention consisted of six structured 90-minute group sessions: five fortnightly sessions and the final session at 8 months. Participants underwent anthropometric and laboratory tests at baseline and 12 months, and provided self-reported psychosocial, dietary, and physical activity measures. Intervention group participants additionally underwent these tests at 3 months. Paired t tests were used to analyse within-group changes over time. Chi-square tests were used to analyse differences between groups in goals met at 12 months. Differences between groups for changes over time were tested with generalised estimating equations and analysis of covariance.
Results
Intervention participants significantly improved at 12 months in mean body mass index (−0.98 kg/m2, standard error (SE) = 0.26), weight (−2.65 kg, SE = 0.72), waist circumference (−7.45 cm, SE = 1.15), and systolic blood pressure (−3.18 mmHg, SE = 1.26), increased high-density lipoprotein-cholesterol (0.07 mmol/l, SE = 0.03), reduced energy from total (−2.00%, SE = 0.78) and saturated fat (−1.54%, SE = 0.41), and increased fibre intake (1.98 g/1,000 kcal energy, SE = 0.47). In controls, oral glucose at 2 hours deteriorated (0.59 mmol/l, SE = 0.27). Only waist circumference reduced significantly (−4.02 cm, SE = 0.95).

Intervention participants significantly outperformed controls over 12 months for body mass index and fibre intake. After baseline adjustment, they also showed greater weight loss and reduced saturated fat versus total energy intake.

At least 5% weight loss was achieved by 32% of intervention participants versus 0% controls.
Conclusions
pMDPS results indicate that scaling-up from implementation trial to state-wide programme is possible. The system design for Life! was fit for purpose of scaling-up from efficacy to effectiveness.

Managing news coverage around initial public offerings

We examine opportunistic behavior of initial public offering (IPO) firms in Taiwan where they are required to disclose their own earnings forecasts and are unrestricted in releasing news around the offerings. We find that prior to the offerings, IPO firms tend to report higher earnings, disclose inflated earnings forecasts, and manage more good news. News management, however, emerges as the most predominant factor in aftermarket stock prices. In particular, IPO firms have a strong preference for releasing good news related to strategy/policy that may simply provide a vision of a firm's future. Furthermore, the news releases are often forward-looking when they are positive about the firms but tend to be realized when they are negative. IPO firms also tend to engage in more window dressing activities before a larger sale of IPO shares from existing shareholders or a larger decline in insiders' holdings. Our analysis shows that managerial optimism cannot fully account for their behavior.