Myosin light chain kinase plays a role in the regulation of epithelial cell survival

Myosin II activation is essential for stress fiber and focal adhesion formation, and is implicated in integrin-mediated signaling events. In this study we investigated the role of acto-myosin contractility, and its main regulators, i.e. myosin light chain kinase (MLCK) and Rho-kinase (ROCK) in cell survival in normal and Ras-transformed MCF-10A epithelial cells. Treatment of cells with pharmacological inhibitors of MLCK (ML-7 and ML-9), or expression of dominant-negative MLCK, led to apoptosis in normal and transformed MCF-10A cells. By contrast, treatment of cells with a ROCK inhibitor (Y-27632) did not induce apoptosis in these cells. Apoptosis following inhibition of myosin II activation by MLCK is probably meditated through the death receptor pathway because expression of dominant-negative FADD blocked apoptosis. The apoptosis observed after MLCK inhibition is rescued by pre-treatment of cells with integrin-activating antibodies. In addition, this rescue of apoptosis is dependent on FAK activity, suggesting the participation of an integrin-dependent signaling pathway. These studies demonstrate a newly discovered role for MLCK in the generation of pro-survival signals in both untransformed and transformed epithelial cells and supports previous work suggesting distinct cellular roles for Rho-kinase- and MLCK-dependent regulation of myosin II

Recovering a lost baseline: missing kelp forests from a metropolitan coast

© 2008 AuthorThere is concern about historical and continuing loss of canopy-forming algae across the world’s temperate coastline. In South Australia, the sparse cover of canopy-forming algae on the Adelaide metropolitan coast has been of public concern with continuous years of anecdotal evidence culminating in 2 competing views. One view considers that current patterns existed before the onset of urbanisation, whereas the alternate view is that they developed after urbanisation. We tested hypotheses to distinguish between these 2 models, each centred on the reconstruction of historical covers of canopies on the metropolitan coast. Historically, the metropolitan sites were indistinguishable from contemporary populations of reference sites across 70 km (i.e. Gulf St. Vincent), and could also represent a random subset of exposed coastal sites across 2100 km of the greater biogeographic province. Thus there was nothing ‘special’ about the metropolitan sites historically, but today they stand out because they have sparser covers of canopies compared to equivalent locations and times in the gulf and the greater province. This is evidence of wholesale loss of canopy-forming algae (up to 70%) on parts of the Adelaide metropolitan coast since major urbanisation. These findings not only set a research agenda based on the magnitude of loss, but they also bring into question the logic that smaller metropolitan populations of humans create impacts that are trivial relative to that of larger metropolitan centres. Instead, we highlight a need to recognise the ecological context that makes some coastal systems more vulnerable or resistant to increasing human-domination of the world’s coastlines. We discuss challenges to this kind of research that receive little ecological discussion, particularly better leadership and administration, recognising that the systems we study out-live the life spans of individual research groups and operate on spatial scales that exceed the capacity of single research providers.Sean D. Connell, Bayden D. Russell, David J. Turner, Scoresby A. Shepherd, Timothy Kildea, David Miller, Laura Airoldi, Anthony Cheshir

Data management to information portals

pp. 215-21

Nano-scale mechanical probing of supported lipid bilayers with atomic force microscopy

We present theory and experiments for the force-distance curve $F(z_0)$ of an atomic force microscope (AFM) tip (radius $R$) indenting a supported fluid bilayer (thickness $2d$). For realistic conditions the force is dominated by the area compressibility modulus $\kappa_A$ of the bilayer, and, to an excellent approximation, given by $F= \pi \kappa_A R z_0^2/(2d-z_0)^2$. The experimental AFM force curves from coexisting liquid ordered and liquid disordered domains in 3-component lipid bilayers are well-described by our model, and provides $\kappa_A$ in agreement with literature values. The liquid ordered phase has a yield like response that we model by hydrogen bond breaking.Comment: 6 pages, 6 figures, accepted for publication in Physical Review

The INTEGRAL/SPI response and the Crab observations

The Crab region was observed several times by INTEGRAL for calibration purposes. This paper aims at underlining the systematic interactions between (i) observations of this reference source, (ii) in-flight calibration of the instrumental response and (iii) the development and validation of the analysis tools of the SPI spectrometer. It first describes the way the response is produced and how studies of the Crab spectrum lead to improvements and corrections in the initial response. Then, we present the tools which were developed to extract spectra from the SPI observation data and finally a Crab spectrum obtained with one of these methods, to show the agreement with previous experiments. We conclude with the work still ahead to understand residual uncertainties in the response.Comment: 4 pages, 4 figures, Proc. of the 5th INTEGRAL Workshop (Feb. 16-20 2004), to be published by ES

Topology of amorphous tetrahedral semiconductors on intermediate lengthscales

Using the recently-proposed ``activation-relaxation technique'' for optimizing complex structures, we develop a structural model appropriate to a-GaAs which is almost free of odd-membered rings, i.e., wrong bonds, and possesses an almost perfect coordination of four. The model is found to be superior to structures obtained from much more computer-intensive tight-binding or quantum molecular-dynamics simulations. For the elemental system a-Si, where wrong bonds do not exist, the cost in elastic energy for removing odd-membered rings is such that the traditional continuous-random network is appropriate. Our study thus provides, for the first time, direct information on the nature of intermediate-range topology in amorphous tetrahedral semiconductors.Comment: 4 pages, Latex and 2 postscript figure

The appropriation of hegemonic masculinity within selected research on men's health

Connell's hegemonic masculinity thesis (HMT) has occupied a relatively dominant position within contemporary research exploring the lives of men. Messerschmidt has conducted a review of recent literature that purports to use HMT, he describes in detail some of the ways Connell's work has been appropriated. Taking Messerschmidt's lead, this paper explores a small selection of men's health research that employ HMT as a central organising theme. Such a narrow focus and limited sample enables the theoretical, conceptual and empirical contributions of engagements with Connell's work to be critically explored in detail. This paper provides colleagues with clear examples of ways in which reified and reductive account of masculinity, are still being reproduced in contemporary analyses of men's lives. In calling for researchers to critically reflect upon their usage of Connell's thesis in more detail, my aim is to increase the subtlety and sophistication of such works. A further hope is that by highlighting specific examples of the need to appraise the relevance and adequacy of HMT as a conceptual frame of lived experiences, we might encourage researchers to access the multitude of different theoretical positions that speak to the lives of men

'It's a Form of Freedom': The experiences of people with disabilities within equestrian sport

This paper explores the embodied, gendered experiences of disabled horse‐riders. Drawing on data from five in‐depth interviews with paradressage riders, the ways in which their involvement in elite disability sport impacts upon their sense of identity and confidence are explored, as well as the considerable health and social benefits that this involvement brings. Social models of disability are employed and the shortcomings of such models, when applied to disability sport, are highlighted. The data presented here demonstrates the necessity of seeing disability sport as an embodied experience and acknowledging the importance of impairment to the experiences of disabled athletes. Living within an impaired body is also a gendered experience and the implications of this when applied to elite disability sport are considered

Experiencing male infertility: A review of the qualitative research literature

This article examines the qualitative research literature that exists in relation to men’s experiences of male infertility. Since men have often been marginalized in the realm of reproduction, including academic research on infertility, it is important to focus on any qualitative research that gives voices to male perspectives and concerns. Given the distress documented by studies of infertile women, we focus in particular on the emotive responses and lived experiences of men in relation to infertility. In this article then, we present an analysis of the core themes across 19 qualitative articles, which include “infertility as crisis”; “emoting infertility- men as “being strong”’ “infertility as a source of stigma”; and the “desire for fatherhood.” In light of these insights, we identify key areas for future research and development including men’s emotional responses to infertility, how men seek support for infertility, the intersection between masculinity and infertility, the relationship between the desire to father and infertility, and the outcomes of infertility for men in terms of other aspects of their lives. We suggest that such research would facilitate making the experiences of men more central within our understandings of infertility within a field that has primarily been female focused