Stenosis triggers spread of helical Pseudomonas biofilms in cylindrical flow systems

Biofilms are multicellular bacterial structures that adhere to surfaces and often endow the bacterial population with tolerance to antibiotics and other environmental insults. Biofilms frequently colonize the tubing of medical devices through mechanisms that are poorly understood. Here we studied the helicoidal spread of Pseudomonas putida biofilms through cylindrical conduits of varied diameters in slow laminar flow regimes. Numerical simulations of such flows reveal vortical motion at stenoses and junctions, which enhances bacterial adhesion and fosters formation of filamentous structures. Formation of long, downstream-flowing bacterial threads that stem from narrowings and connections was detected experimentally, as predicted by our model. Accumulation of bacterial biomass makes the resulting filaments undergo a helical instability. These incipient helices then coarsened until constrained by the tubing walls, and spread along the whole tube length without obstructing the flow. A three-dimensional discrete filament model supports this coarsening mechanism and yields simulations of helix dynamics in accordance with our experimental observations. These findings describe an unanticipated mechanism for bacterial spreading in tubing networks which might be involved in some hospital-acquired infections and bacterial contamination of catheters.

TRPV4 activation triggers the release of melatonin from human non-pigmented ciliary epithelial cells

Melatonin is a neurohormone mainly produced in the pineal gland; nevertheless, various ocular structures such as the ciliary body, lens and the retina produce it. One of the roles of melatonin in the eye is the modulation of intraocular pressure, although little is known about the mechanisms that causes its presence in the aqueous humour. TRPV4 is a membrane channel which is activated by both physical and chemical stimuli. Therefore, this channel is sensitive to osmotic and hydrostatic pressure. As a consequence, TRPV4 results as an interesting candidate to study the relation between the activation of the TRPV4 channel and the production of melatonin. In this sense we have studied the role of the TRPV4 agonist GSK1016790A to modulate the production of melatonin in a cell line derived from human non-pigmented ciliary epithelial cells. The stimulation of the TRPV4 produced an increase in the extracellular melatonin levels changing from 8.5 ± 0.6 nM/well/30 min (control) to 23.3 ± 2.1 nM/well/30 min after 10 nM GSK1016790A application, this action being blocked by the selective antagonist RN 1734. The activation of the TRPV4 by GSK1016790A permitted to observe a melatonin increase which was concentration-dependent, and provided a pD2 value of −8.5 ± 0.1 (EC50 of 3.0 nM). In conclusion, the activation of the TRPV4 present in human non-pigmented ciliary epithelial cells can modulate the presence of extracellular melatonin, this being of relevance since this substance controls the dynamics of the aqueous humour.

Extreme sports as a facilitator of ecocentricity and positive life changes

Extreme sports and extreme sports participants have been most commonly explored from a negative perspective, for example the 'need to take unnecessary risks'. This study reports on findings that indicate a more positive experience. A phenomenological method was used via unstructured interviews with 15 extreme sports participants and other first hand accounts. The extreme sports included B.A.S.E. jumping, big wave surfing, extreme skiing, waterfall kayaking, extreme mountaineering and solo rope-free climbing. Results indicate that participating in activities that involve a real chance of death, fear and the realisation that nature in its extreme is far greater and more powerful than humanity triggers positive life changes, and an eco-centric standpoint.

Keeping giving going : charitable bequests and Australians

The potential of bequests to contribute to the sustainability of charities1 is immense, with social and economic trends opening up the bequest landscape. Yet so much is unknown about how Australians think about charitable bequests – particularly about the motivations, barriers and triggers surrounding this behaviour. Do bequestors differ from other donors? What prevents good intentions from becoming good actions? Where do charities figure in this process? This study aims at a better understanding of those Australians who make a charitable bequest and those who might. It offers individual charities, and the sector as a whole, empirical evidence to support and extend the anecdotal knowledge of those working with donors around this sensitive, but vital, area. This research has been supported by the Perpetual Foundation, the EF and SL Gluyas Trust and the Edward Corbould Charitable Trust under the management of Perpetual Trustee Company Ltd.

Analysing the internationalisation readiness of firms

The internationalisation of firms has gained much research attention since the 1970s. However, the behavioural aspect of firms’ during their pre-internationalisation phase has not been sufficiently explored. This research proposes that a pre-internationalisation focus would not only offer an additional perspective to the study of firm internationalisation but would also address the significant research gap in studies that are theoretically based around the Uppsala Model. This study views the development of a firm from its pre-internationalisation phase into an international firm in accordance with the Uppsala Model’s ‘state’ to ‘change’ aspect transition, with ‘internationalisation readiness’ established as the missing link between these two aspects. During the pre-internationalisation phase, a firm is exposed to a wide variety of internal and external stimuli that triggers an impulse for foreign market expansion. The perception of these stimuli and the attitudinal commitment taken by the firm’s decision-makers, as well as the firm’s resource capabilities and the moderating effect of lateral rigidity, are influential towards an internationalisation decision. This paper argues the significance of adopting the pre-internationalisation phase as a research platform and the importance of analysing firms’ internationalisation readiness. A method is proposed for the development of an Internationalisation Readiness Index that could be used for measuring a firm’s propensity to commence its first export operation.

Age-related maculopathy : linking aetiology and pathophysiological changes to the ischaemia hypothesis

Age-related maculopathy (ARM) has remained a challenging topic with respect to its aetiology, pathomechanisms, early detection and treatment since the late 19th century when it was first described as its own entity. ARM was previously considered an inflammatory disease, a degenerative disease, a tumor and as the result of choroidal hemodynamic disturbances and ischaemia. The latter processes have been repeatedly suggested to have a key role in its development and progression. In vivo experiments under hypoxic conditions could be models for the ischaemic deficits in ARM. Recent research has also linked ARM with gene polymorphisms. It is however unclear what triggers a person's gene susceptibility. In this manuscript, a linking hypothesis between aetiological factors including ischaemia and genetics and the development of early clinicopathological changes in ARM is proposed. New clinical psychophysical and electrophysiological tests are introduced that can detect ARM at an early stage. Models of early ARM based upon hemodynamic, photoreceptor and post-receptoral deficits are described and the mechanisms by which ischaemia may be involved as a final common pathway are considered. In neovascular age-related macular degeneration (neovascular AMD), ischaemia is thought to promote release of vascular endothelial growth factor (VEGF) which induces chorioretinal neovascularisation. VEGF is critical in the maintenance of the healthy choriocapillaris. In the final section of the manuscript the documentation of the effect of new anti-VEGF treatments on retinal function in neovascular AMD is critically viewed.

Why adopt now? Multiple case studies and survey studies comparing small, medium and large firms

While a number of factors have been highlighted in the innovation adoption literature, little is known about the key triggers of innovation adoption across differently-sized firms. This study compares case studies of small, medium and large manufacturing firms who recently decided to adopt a process innovation. We also employ organizational surveys from 134 firms investigating the factors which influence innovation adoption. The quantitative results support the qualitative findings that the external pressures are a trigger among small to medium firms, while the larger firm’s adoption was associated with internal causes.

Homophobia, heteronormativism and hegemonic masculinity : male same-sex intimate violence from the perspective of Brisbane service providers

Few studies have explored the problem of male same-sex intimate partner violence, especially in the context of Australia. Utilizing in-depth interviews with gay-friendly service providers in Brisbane, the research presented in this article sought to ascertain whether (a) intimate partner violence occurs in male same-sex intimate relationships, (b)if so, what form this violence takes,(c) what contextual triggers underpin this violence,(d) what barriers victims face in exiting abusive relationships and seeking support, and (e) what services are available and appropriate to the needs of men in violent intimate relationships with other men. Results suggest that the prevalence, types and contextual triggers of violence in male same-sex relationships parallel abuse in opposite-sex relationships. Heteronormativism, homophobia, and its close association with hegemonic masculinity, however, emerge as features unique to the male same-sex intimate partner violence experience.

Australian data breach notification : avoiding the State/Federal overlap

Mandatory data breach notification has become a matter of increasing concern for law reformers. In Australia, this issue was recently addressed as part of a comprehensive review of privacy law conducted by the Australian Law Reform Commission (ALRC) which recommended a uniform national regime for protecting personal information applicable to both the public and private sectors. As in all federal systems, the distribution of powers between central and state governments poses problems for national consistency. In the authors’ view, a uniform approach to mandatory data breach notification has greater merit than a ‘jurisdiction specific’ approach epitomized by US state-based laws. The US response has given rise to unnecessary overlaps and inefficiencies as demonstrated by a review of different notification triggers and encryption safe harbors. Reviewing the US response, the authors conclude that a uniform approach to data breach notification is inherently more efficient.

Developing reflective practitioners online: The business of blogs in work integrated learning

Reflective practice is widely considered across discussions around educational psychology, professional identity, employability of graduates, and generic or graduate capabilities. Critical reflection is essential for providing a bridge between the university and the workplace, and for ultimately preparing work ready graduates (Patrick et al, 2008). Work integrated learning, particularly through internships and work placements for students, is viewed as a valuable approach for students developing skills in reflective practice. Reflective journals are one of the tools often used to encourage and develop student reflection. Shifting the reflective journal to an online interface as a reflective blog presents opportunities for more meaningful, frequent and richer interaction between the key players in a work integrated learning experience. This paper examines the adoption, implementation and refinement of the use of reflective blogs in a work integrated learning unit for business students majoring in advertising, marketing and public relations disciplines. The reflective blog is discussed as a learning and assessment tool, including the approaches taken to integrate and scaffold the blog as part of the work integrated learning experience. Graduate capabilities were used as cornerstones for students to frame students’ thinking, experiences and reflection. These capabilities emphasise the value of coherent theoretical and practical knowledge, coupled with critical, creative and analytical thinking, problem solving skills, self reliance and resilience. Underlying these graduate capabilities is a focus on assessment for learning matched with assessment of learning. Using specific triggers and prompts as part of the reflective process, and incorporating ongoing feedback from academic supervisors, students moved from descriptive levels of reflection, to more meaningful and critical reflection. Students’ blogs are analysed to identify key themes, challenges and achievements in the work integrated learning experience. Suggestions for further development and improvement, together with a model of best practice, are proposed.

Sodium niobate adsorbents doped with tantalum (TaV) for the removal of bivalence radioactive ions in waste waters

Sodium niobates doped with different amount of tantalum (TaV) were prepared via thermal reaction process. It was found pure nanofibril and bar-like solids can be obtained when tantalum was introduced into the reaction system. For the well-crystallized fibril solids, the Na+ ions are difficult to be exchanged, and the radioactive ions such as Sr2+ and Ra2+ ions just deposit on the surface of the fibers during the sorption process, resulting in lower sorption capacity and distribution coefficients (Kd)`. However, the bar-like solids are poorly-crystallized and have lots of exchangeable Na+ ions. They are able to remove highly hazardous bivalent radioactive isotopes such as Sr2+ and Ra2+ ions. Even in the presence of lots of Na+ ions, they also have higher Kd. More importantly, such sorption finally intelligently triggers considerable collapse of the structure, resulting in the entrapment of the toxic bivalent cations permanently in the solids so that they can be safely disposed. This study highlights new opportunities for the preparation of Nb-based adsorbents to efficiently remove the toxic radioactive ions from contaminated water.

Applications of wavelet transform for analysis of freeway traffic : bottlenecks, transient traffic, and traffic oscillations

This paper demonstrates the capabilities of wavelet transform (WT) for analyzing important features related to bottleneck activations and traffic oscillations in congested traffic in a systematic manner. In particular, the analysis of loop detector data from a freeway shows that the use of wavelet-based energy can effectively identify the location of an active bottleneck, the arrival time of the resulting queue at each upstream sensor location, and the start and end of a transition during the onset of a queue. Vehicle trajectories were also analyzed using WT and our analysis shows that the wavelet-based energies of individual vehicles can effectively detect the origins of deceleration waves and shed light on possible triggers (e.g., lane-changing). The spatiotemporal propagations of oscillations identified by tracing wavelet-based energy peaks from vehicle to vehicle enable analysis of oscillation amplitude, duration and intensity.

Attach the correct warning statement

Practitioners will be aware that s 366 (1) of the Property Agents and Motor Dealers Act 2000 provides that a relevant contract must have attached, as its first or top sheet, a warning statement in the approved form. A failure to attach a warning statement in the prescribed manner triggers a right of termination in the buyer. The factual circumstances in Devine Ltd v Timbs [2004] QSC 24 are indicative of the problems that may arise in the construction of this statutory provision. The application concerned put and call option agreements entered into concerning 4 lots. The agreements, in identical terms, were signed before the applicant seller had completed a proposed residential apartment building. In each case the option agreement provided that the agreement was not binding on the seller until and unless the purchaser returned to the seller, amongst other things, two copies of the warning statement under the Property Agents and Motor Dealers Ac 2000 signed by the purchaser and two copies of the contract document signed by the purchaser. The seller was required to hold the contract documentation in escrow and was forbidden to sign it until and unless either option was exercised.

Notch and NOXA-related pathways in melanoma cells

Notch receptor-mediated intracellular events represent an ancient cell signaling system, and alterations in Notch expression are associated with various malignancies in which Notch may function as an oncogene or less commonly as a tumor suppressor. Notch signaling regulates cell fate decisions in the epidermis, including influencing stem cell dynamics and growth/differentiation control of cells in skin. Because of increasing evidence that the Notch signaling network is deregulated in human malignancies, Notch receptors have become attractive targets for selective killing of malignant cells. Compared with proliferating normal human melanocytes, melanoma cell lines are characterized by markedly enhanced levels of activated Notch-1 receptor. By using a small molecule gamma-secretase inhibitor (GSI) consisting of a tripeptide aldehyde, N-benzyloxycarbonyl-Leu-Leu-Nle-CHO, which can block processing and activation of all four different Notch receptors, we identified a specific apoptotic vulnerability in melanoma cells. GSI triggers apoptosis in melanoma cells, but only G2/M growth arrest in melanocytes without subsequent cell death. Moreover, GSI treatment induced a pro-apoptotic BH3-only protein, NOXA, in melanoma cells but not in normal melanocytes. The use of GSI to induce NOXA induction overcomes the apoptotic resistance of melanoma cells, which commonly express numerous cell survival proteins such as Mcl-1, Bcl-2, and survivin. Taken together, these results highlight the concept of synthetic lethality in which exposure to GSI, in combination with melanoma cells overexpressing activated Notch receptors, has lethal consequences, producing selective killing of melanoma cells, while sparing normal melanocytes. By identifying signaling pathways that contribute to the transformation of melanoma cells (e.g. Notch signaling), and anti-cancer agents that achieve tumor selectivity (e.g., GSI-induced NOXA), this experimental approach provides a useful framework for future therapeutic strategies in cutaneous oncology.

Understanding innovation adoption : effects of orientation, pressure and control on adoption

We develop and test a theoretically-based integrative framework of key proximal factors (orientation, pressure, and control) that helps to explain the effects of more general factors (the organisation's strategy, structure, and environment) on intentions to adopt an innovation one year later. Senior managers from 134 organizations were surveyed and confirmatory factor analyses showed that these hypothesized core factors provided a good fit to the data, indicating that our framework can provide a theoretical base to the previous, largely a theoretical, literature. Moreover, in a subgroup of 63 organizations, control mediated the effects of organizational strategy and centralisation on organizational innovation adoption intentions one year later. We suggest this model of core factors enables researchers to understand why certain variables are important to organisational innovation adoption and promotes identification of fertile research areas around orientation, pressure and control, and it enables managers to focus on the most proximal triggers for increasing innovation adoption.