Distinguishing graded & ultrasensitive signalling cascade kinetics by the shape of morphogen gradients in Drosophila

Recently, signalling gradients in cascades of two-state reaction–diffusion systems were described as a model for understanding key biochemical mechanisms that underlie development and differentiation processes in the Drosophila embryo. Diffusion-trapping at the exterior of the cell membrane triggers the mitogen-activated protein kinase (MAPK) cascade to relay an appropriate signal from the membrane to the inner part of the cytosol, whereupon another diffusion-trapping mechanism involving the nucleus reads out this signal to trigger appropriate changes in gene expression. Proposed mathematical models exhibit equilibrium distributions consistent with experimental measurements of key spatial gradients in these processes. A significant property of the formulation is that the signal is assumed to be relayed from one system to the next in a linear fashion. However, the MAPK cascade often exhibits nonlinear dose–response properties and the final remark of Berezhkovskii et al. (2009) is that this assumption remains an important property to be tested experimentally, perhaps via a new quantitative assay across multiple genetic backgrounds. In anticipation of the need to be able to sensibly interpret data from such experiments, here we provide a complementary analysis that recovers existing formulae as a special case but is also capable of handling nonlinear functional forms. Predictions of linear and nonlinear signal relays and, in particular, graded and ultrasensitive MAPK kinetics, are compared

Logic is not the truest guide\u27 - R.S. Ross: Rationalism, Vision and Socialism in the Evolution of a Labour Editor

Whether the cup with sweet or bitter run, The Wine of Life keeps oozing drop by drop, The Leaves of Life keep falling one by one. Robert Samuel Ross, was born in 1873 and raised in Brisbane. A printer\u27s son, a printer\u27s apprentice, he went to work at seventeen. On his twenty-first birthday his journal records a solemn promise: \u27Now I must commence to take life seriously .... One must have some knowledge in life. Get knowledge, for knowledge is power!\u27 1 The next year, at the age of twenty two, he became a founding member of the Australian Socialist League with Ernie Lane. At twenty five he read the \u27The Rubaiyat of Omar Khayyam\u27 .... Myselfwhen young did eagerly frequent Doctor and Saint, and heard great argument. .. With them the seed of Wisdom did I sow, And with mine own hand wrought to make it grow; And this was all the Harvest that I reaped- I came like Water, and like Wind I go

Reconceptualising public relations in Australia: A historical and social re-analysis

An analysis of the history of public relations in Australia through a case study of the creation and promotion of Australia Day which shows PR deeply involved in the historical, social, and cultural fabric of society

An 'outside-in' PR history: Identifying the role of PR in history, culture and sociology

Historical, social and cultural understanding of public relations in Australia is limited because most histories of PR examine practices specifically labelled `public relations and almost all study PR from `inside out that is, from the subjective perspective of PR practitioners. This article reports an alternative approach to PR history which applies historical analysis of major events, icons, and institutions in society to identify the methods of their construction politically, culturally and discursively. This article specifically reports historical and critical analysis of the creation and celebration of Australias national day, Australia Day from soon after the British flag was hoisted in Sydney on 26 January 1788 to the sophisticated pageantry of the nations bicentenary in 1988 and its entry to the new millennium in 2000. This research challenges a `blind spot in social science and humanities disciplines in relation to public relations by showing that the practices of PR are deeply embedded in the social and cultural construction of societies. This study confirms Taylor and Kents claim that all nation building campaigns include large communication components that are essentially public relations campaign

Public Relations

A compendium of 500 articles on the history and contemporary practice of media corporations, individuals, industries, audiences, policy, and regulation in relation to Australian media from publication of the first Australian newspaper in 1803 to contemporary media developments

The construction of Australia Day: a study of public relations as 'new cultural intermediaries'

Australia Day is a foremost expression of Australian culture and identity, but historical and critical analysis shows that, far from being an organic or spontaneous expression and celebration of identity and culture, Australia's national day has been ma

Second chances: Investigating athletes’ experiences of talent transfer

Talent transfer initiatives seek to transfer talented, mature individuals from one sport to another. Unfortunately talent transfer initiatives seem to lack an evidence-based direction and a rigorous exploration of the mechanisms underpinning the approach. The purpose of this exploratory study was to identify the factors which successfully transferring athletes cite as facilitative of talent transfer. In contrast to the anthropometric and performance variables that underpin current talent transfer initiatives, participants identified a range of psychobehavioral and environmental factors as key to successful transfer. We argue that further research into the mechanisms of talent transfer is needed in order to provide a strong evidence base for the methodologies employed in these initiatives

The psychological impact of instrumental activities of daily living on people with simulated age-related macular degeneration

BACKGROUND: People with age-related macular degeneration (AMD) can report reduced mental health. There is also evidence that they struggle with daily tasks because of vision loss. AIMS: The purpose of this study was to assess the psychological impact of instrumental activities of daily living on people with simulated AMD. METHOD: Twenty-four normally sighted participants completed 12 household tasks, in a simulated home environment, under a moderate-to-severe AMD simulation. Participants’ psychological state was measured through self-report questionnaires and physiological measurements related to anxiety and stress. Tasks were completed twice, under counterbalanced vision conditions (normal and simulated AMD). RESULTS: Linear mixed models on vision condition (normal versus simulated AMD) and trial order (trial 1 versus trial 2) revealed a significant large negative effect of the AMD simulation on time to complete tasks, and the anxiety, task engagement and distress self-reports (all P 0.177). There were also significant medium-large effects of trial order on time, task incompletion, task errors, and the anxiety and task engagement self-reports (all P 0.130), whereby the results improved during the second attempt at the tasks. No physiological measures were significant (all P > 0.05). CONCLUSIONS: Completing instrumental activities of daily living under an AMD simulation had a negative impact on participants’ self-reported mental state. The observed trial order effects also illuminated how practice with tasks could ease anxiety and stress over time

Multilingual gendered identities: female undergraduate students in London talk about heritage languages

In this paper I explore how a group of female university students, mostly British Asian and in their late teens and early twenties, perform femininities in talk about heritage languages. I argue that analysis of this talk reveals ways in which the participants enact ‘culturally intelligible’ gendered subject positions. This frequently involves negotiating the norms of ‘heteronormativity’, constituting femininity in terms of marriage, motherhood and maintenance of heritage culture and language, and ‘girl power’, constituting femininity in terms of youth, sassiness, glamour and individualism. For these young women, I ask whether higher education can become a site in which they have the opportunities to explore these identifications and examine other ways of imagining the self and what their stories suggest about ‘doing being’ a young British Asian woman in London