Cyclin A/CDK2 regulates multiple G2 phase pathways

The cell cycle is a carefully choreographed series of phases that when executed successfully will allow the complete replication of the genome and the equal division of the genome and other cellular content into two independent daughter cells. The inability of the cell to execute cell division successfully can result in either checkpoint activation to allow repair and/or apoptosis and/or mutations/errors that may or may not lead to tumourgenesis. Cyclin A/CDK2 is the primary cyclin/CDK regulating G2 phase progression of the cell cycle. Cyclin A/CDK2 activity peaks in G2 phase and its inhibition causes a G2 phase delay that we have termed 'the cyclin A/CDK2 dependent G2 delay'. Understanding the key pathways that are involved in the cyclin A/CDK2 dependent G2 delay has been the primary focus of this study. Characterising the cyclin A/CDK2 dependent G2 delay revealed accumulated levels of the inactive form of the mitotic regulator, cyclin B/CDK1. Surprisingly, there was also increased microtubule nucleation at the centrosomes, and the centrosomes stained for markers of cyclin B/CDK1 activity. Both microtubule nucleation at the centrosomes and phosphoprotein markers were lost with short-term treatment of CDK1/2 inhibition. Cyclin A/CDK2 localised at the centrosomes in late G2 phase after separation of the centrosomes but before the start of prophase. Thus G2 phase cyclin A/CDK2 controls the timing of entry into mitosis by controlling the subsequent activation of cyclin B/CDK1, but also has an unexpected role in coordinating the activation of cyclin B/CDK1 at the centrosome and in the nucleus. In addition to regulating the timing of cyclin B/CDK1 activation and entry into mitosis in the unperturbed cell cycle, cyclin A/CDK2 also was shown to have a role in G2 phase checkpoint recovery. Known G2 phase regulators were investigated to determine whether they had a role in imposing the cyclin A/ CDK2 dependent G2 delay. Examination of the critical G2 checkpoint arrest protein, Chk1, which also has a role during unperturbed G2/M phases revealed the presence of activated Chk1 in G2 phase, in a range of cell lines. Activated Chk1 levels were shown to accumulate in cyclin A/CDK2 depleted/inhibited cells. Further investigations revealed that Chk1, but not Chk2, depletion could reverse the cyclin A/CDK2 dependent G2 delay. It was confirmed that the accumulative activation of Chk1 was not a consequence of DNA damage induced by cyclin A depletion. The potential of cyclin A/CDK2 to regulate Chk1 revealed that the inhibitory phosphorylations, Ser286 and Ser301, were not directly catalysed by cyclin A/CDK2 in G2 phase to regulate mitotic entry. It appeared that the ability of cyclin A/CDK2 to regulate cyclin B/CDK1 activation impacted cyclin B/CDK1s phosphorylation of Chk1 on Ser286 and Ser301, thereby contributing to the delay in G2/M phase progression. Chk1 inhibition/depletion partially abrogated the cyclin A/CDK2 dependent G2 delay, and was less effective in abrogating G2 phase checkpoint suggesting that other cyclin A/CDK2 dependent mechanisms contributed to these roles of cyclin A/CDK2. In an attempt to identify these other contributing factors another G2/M phase regulator known to be regulated by cyclin A/CDK2, Cdh1 and its substrates Plk1 and Claspin were examined. Cdh1 levels were reduced in cyclin A/CDK2 depleted/inhibited cells although this had little effect on Plk1, a known Cdh1 substrate. However, the level of another substrate, Claspin, was increased. Cdh1 depletion mimicked the effect of cyclin A depletion but to a weaker extent and was sufficient at increasing Claspin levels similar to the increase caused by cyclin A depletion. Co-depletion of cyclin A and Claspin blocked the accumulation of activated Chk1 normally seen with cyclin A depletion alone. However Claspin depletion alone did not reduce the cyclin A/CDK2 dependent G2 delay but this is likely to be a result of inhibition of S phase roles of Claspin. Together, these data suggest that cyclin A/CDK2 regulates a number of different mechanisms that contribute to G2/M phase progression. Here it has been demonstrated that in normal G2/M progression and possibly to a lesser extent in G2 phase checkpoint recovery, cyclin A/CDK2 regulates the level of Cdh1 which in turn affects at least one of its substrates, Claspin, and consequently results in the increased level of activated Chk1 observed. However, the involvement of Cdh1 and Claspin alone does not explain the G2 phase delay observed with cyclin A/CDK2 depletion/inhibition. It is likely that other mechanisms, possibly including cyclin A/CDK2 regulation of Wee1 and FoxM1, as reported by others, combine with the mechanism described here to regulate normal G2/M phase progression and G2 phase checkpoint recovery. These findings support the critical role for cyclin A/CDK2 in regulating progression into mitosis and suggest that upstream regulators of cyclin A/CDK2 activation will also be critical controllers of this cell cycle transition. The pathways that work to co-ordinate cell cycle progression are very intricate and deciphering these pathways, required for normal cell cycle progression, is key to understanding tumour development. By understanding cell cycle regulatory pathways it will allow the identification of the pathway/s and their mechanism/s that become affected in tumourgenesis. This will lead to the development of better targeted therapies, inferring better efficacy with fewer side effects than commonly seen with the use of traditional therapies, such as chemotherapy. Furthermore, this has the potential to positively impact the development of personalised medicines and the customisation of healthcare.

Understanding chronic pain complicating disability: Finding meaning through focus group methodology

Over the past few decades a major paradigm shift has occurred in the conceptualisation of chronic pain as a complex multidimensional phenomenon. Yet, pain experienced by individuals with a primary disability continues to be understood largely from a traditional biomedical model, despite its inherent limitations. This is reflected in the body of literature on the topic that is primarily driven by positivist assumptions and the search for etiologic pain mechanisms. Conversely, little is known about the experiences of and meanings attributed to, disability-related pain. Thus the purpose of this paper is to discuss the use of focus group methodology in elucidating the meanings and experiences of this population. Here, a distinction is made between the method of the focus group and focus group research as methodology. Typically, the focus group is presented as a seemingly atheoretical method of research. Drawing on research undertaken on the impact of chronic pain in people with multiple sclerosis, this paper seeks to theorise the focus group in arguing the methodological congruence of focus group research and the study of pain experience. It is argued that the contributions of group interaction and shared experiences in focus group discussions produce data and insights less accessible through more structured research methods. It is concluded that a biopsychosocial perspective of chronic pain may only ever be appreciated when the person-in-context is the unit of investigation.

The problem of greenwash: Rhetorical elements in communicating environmental CSR practices

The field of rhetoric can be highly useful for researchers to focus on and understand the specific textual strategies used by organizations when communicating about CSR practices. To date however, while there have been studies that consider the use of rhetoric to communicate about environmental practices, there have been few studies that have used a rhetorical analysis to consider both green communication and public response to that communication as a way of understanding public issues with organizational practice. This study seeks to address this gap by using a rhetorical analysis of both environmental communication by organizations, and the claims made by a regulatory body acting on behalf of the public about why that communication was deemed ‘greenwash’ or inappropriate. In doing so, the paper applies a rhetorical analysis to understand the grounds on which environmental communication is deemed not legitimate, and suggests that whilst all three elements of ethos should be considered when communicating a CSR practice, the element of phronesis is the most crucial element, whereby organizations must ensure that they accurately justify any claims in relation to CSR.

Through-focus performance with multifocal contact lenses : effect of binocularity, pupil diameter and inherent ocular aberrations

Purpose to evaluate the effects of the wearer’s pupil size and spherical aberration on visual performance with centre-near, aspheric multifocal contact lenses (MFCLs). The advantage of binocular over monocular vision was also investigated. Methods Twelve young volunteers, with an average age of 27±5 years, participated in the study. LogMAR Visual Acuity (VA) was measured under cycloplegia for a range of defocus levels (from +3.0 to -3.0D, in 0.5D steps) with no correction and with three aspheric MFCLs (Air Optix Aqua Multifocal, Ciba Vision, Duluth, GA, US) with a centre-near design, providing correction for “Low”, “Med” and “High” near demands. Measurements were performed for all combinations of the following conditions: i) artificial pupils of 6mm and 3mm diameter, ii) binocular and monocular (dominant eye) vision. Depth-of-focus (DOF) was calculated from the VA vs. defocus curves. Ocular aberrations under cycloplegia were measured using iTrace. Results VA at -3.0D defocus (simulating near performance) was statistically higher for the 3mm than for the 6mm pupil (p=0.006), and for binocular rather than for monocular vision (p<0.001). Similarly, DOF was better for the 3mm pupil (p=0.002) and for binocular viewing conditions (p<0.001, ANOVA). Both VA at –3.0D defocus and DOF increased as the “addition” of the MFCL correction increased. Finally, with the centre-near MFCLs a linear correlation was found between VA at –3.0D defocus and the wearer’s ocular spherical aberration (R2=0.20 p<0.001 for 6mm data), with the eyes exhibiting the higher positive spherical aberration experiencing lower VAs. By contrast, no correlation was found between VA and spherical aberration at 0.00D defocus (distance vision). Conclusions Both near VA and depth-of-focus improve with these MFCLs, with the effects being more pronounced for small pupils and binocular than for monocular vision. Coupling of the wearer’s ocular spherical aberration with the aberration profiles provided by MFCLs affects their functionality.

Lipoxygenase metabolism : roles in tumor progression and survival

The metabolism of arachidonic acid through lipoxygenase pathways leads to the generation of various biologically active eicosanoids. The expression of these enzymes vary throughout the progression of various cancers, and thereby they have been shown to regulate aspects of tumor development. Substantial evidence supports a functional role for lipoxygenase-catalyzed arachidonic and linoleic acid metabolism in cancer development. Pharmacologic and natural inhibitors of lipoxygenases have been shown to suppress carcinogenesis and tumor growth in a number of experimental models. Signaling of hydro[peroxy]fatty acids following arachidonic or linoleic acid metabolism potentially effect diverse biological phenomenon regulating processes such as cell growth, cell survival, angiogenesis, cell invasion, metastatic potential and immunomodulation. However, the effects of distinct LOX isoforms differ considerably with respect to their effects on both the individual mechanisms described and the tumor being examined. 5-LOX and platelet type 12-LOX are generally considered pro-carcinogenic, with the role of 15-LOX-1 remaining controversial, while 15-LOX-2 suppresses carcinogenesis. In this review, we focus on the molecular mechanisms regulated by LOX metabolism in some of the major cancers. We discuss the effects of LOXs on tumor cell proliferation, their roles in cell cycle control and cell death induction, effects on angiogenesis, migration and the immune response, as well as the signal transduction pathways involved in these processes. Understanding the molecular mechanisms underlying the anti-tumor effect of specific, or general, LOX inhibitors may lead to the design of biologically and pharmacologically targeted therapeutic strategies inhibiting LOX isoforms and/or their biologically active metabolites, that may ultimately prove useful in the treatment of cancer, either alone or in combination with conventional therapies. © 2007 Springer Science+Business Media, LLC.

Livable Housing Design : Who will take responsibility?

Current housing design and construction practices do not meet the needs of many people with disability and older people, and limits their inclusion and participation in community and family life. In spite of a decade of advocacy for regulation of access within residential environments, the Australian government has opted for a voluntary approach where the housing industry takes responsibility. Housing industry leaders have indicated that they are willing to transform their established practice, if it makes good business to do so, and if there is a demand from home buyers. To date, there has been minimal demand. In 2010, housing industry and community leaders formalised this commitment in an agreement, called Livable Housing Design, to transform housing design and construction practices, with a target of all new housing providing minimal access by 2020. This paper reports on a study which examined the assumption behind Livable Housing Design agreement; that is, individuals in the housing industry will respond voluntarily and take responsibility for the provision of inclusive housing. From interviews with developers, designers and builders in Brisbane, Queensland, the study found a complex picture of competing demands and responsibilities. Instead of changing their design and construction practices voluntarily to meet the future needs of users over the life of housing, they are more likely to focus on their immediate contractual obligations and to maintain the status quo. Contrary to the view of the government and industry leaders, participants identified that an external regulatory framework would be required if Livable Housing Design’s 2020 goal was to be met.

Modelling for the electricity distribution network

Global awareness for cleaner and renewable energy is transforming the electricity sector at many levels. New technologies are being increasingly integrated into the electricity grid at high, medium and low voltage levels, new taxes on carbon emissions are being introduced and individuals can now produce electricity, mainly through rooftop photovoltaic (PV) systems. While leading to improvements, these changes also introduce challenges, and a question that often rises is ‘how can we manage this constantly evolving grid?’ The Queensland Government and Ergon Energy, one of the two Queensland distribution companies, have partnered with some Australian and German universities on a project to answer this question in a holistic manner. The project investigates the impact the integration of renewables and other new technologies has on the physical structure of the grid, and how this evolving system can be managed in a sustainable and economical manner. To aid understanding of what the future might bring, a software platform has been developed that integrates two modelling techniques: agent-based modelling (ABM) to capture the characteristics of the different system units accurately and dynamically, and particle swarm optimization (PSO) to find the most economical mix of network extension and integration of distributed generation over long periods of time. Using data from Ergon Energy, two types of networks (3 phase, and Single Wired Earth Return or SWER) have been modelled; three-phase networks are usually used in dense networks such as urban areas, while SWER networks are widely used in rural Queensland. Simulations can be performed on these networks to identify the required upgrades, following a three-step process: a) what is already in place and how it performs under current and future loads, b) what can be done to manage it and plan the future grid and c) how these upgrades/new installations will perform over time. The number of small-scale distributed generators, e.g. PV and battery, is now sufficient (and expected to increase) to impact the operation of the grid, which in turn needs to be considered by the distribution network manager when planning for upgrades and/or installations to stay within regulatory limits. Different scenarios can be simulated, with different levels of distributed generation, in-place as well as expected, so that a large number of options can be assessed (Step a). Once the location, sizing and timing of assets upgrade and/or installation are found using optimisation techniques (Step b), it is possible to assess the adequacy of their daily performance using agent-based modelling (Step c). One distinguishing feature of this software is that it is possible to analyse a whole area at once, while still having a tailored solution for each of the sub-areas. To illustrate this, using the impact of battery and PV can have on the two types of networks mentioned above, three design conditions can be identified (amongst others): · Urban conditions o Feeders that have a low take-up of solar generators, may benefit from adding solar panels o Feeders that need voltage support at specific times, may be assisted by installing batteries · Rural conditions - SWER network o Feeders that need voltage support as well as peak lopping may benefit from both battery and solar panel installations. This small example demonstrates that no single solution can be applied across all three areas, and there is a need to be selective in which one is applied to each branch of the network. This is currently the function of the engineer who can define various scenarios against a configuration, test them and iterate towards an appropriate solution. Future work will focus on increasing the level of automation in identifying areas where particular solutions are applicable.

Student focus and prioritization of design parameters in first-year engineering design projects

BACKGROUND Research on engineering design is a core area of concern within engineering education and a fundamental understanding of how engineering students approach and undertake design is necessary in order to develop effective design models and pedagogies. Understanding the factors related to design experiences in education and how they affect student practice can help educators as well as designers to leverage these factors as part of the design process. PURPOSE This study investigated the design practices of first-year engineering students’ and their experiences with a first-year engineering course design project. The research questions that guided the investigation were: 1. From a student perspective, what design parameters or criteria are most important? 2. How does this perspective impact subsequent student design practice throughout the design process? DESIGN/METHOD The authors employed qualitative multi-case study methods (Miles & Huberman, 1994) in order to the answer the research questions. Participant teams were observed and video recorded during team design meetings in which they researched the background for the design problem, brainstormed and sketched possible solutions, as well as built prototypes and final models of their design solutions as part of a course design project. Analysis focused on explanation building (Yin, 2009) and utilized within-case and cross-case analysis (Miles & Huberman, 1994). RESULTS We found that students focused disproportionally on the functional parameter, i.e. the physical implementation of their solution, and the possible/applicable parameter, i.e. a possible and applicable solution that benefited the user, in comparison to other given parameters such as safety and innovativeness. In addition, we found that individual teams focused on the functional and possible/ applicable parameters in early design phases such as brainstorming/ ideation and sketching. When prompted to discuss these non-salient parameters (from the student perspective) in the final design report, student design teams often used a post-hoc justification to support how the final designs fit the parameters that they did not initially consider. CONCLUSIONS This study suggests is that student design teams become fixated on (and consequently prioritize) certain parameters they interpret as important because they feel these parameters were described more explicitly in terms how they were met and assessed. Students fail to consider other parameters, perceived to be less directly assessable, unless prompted to do so. Failure to consider other parameters in the early design phases subsequently affects their approach in design phases as well. Case studies examining students’ study strategies within three Australian Universities illustrate similarities with some student approaches to design.

The Use of Ecological Design to Achieve Sustainable Development in Queensland, Australia

This series of technical papers arose out of the action by a private entrepreneur to initiate a process beyond mere regulatory compliance in order to achieve best environmental practice at proposed large new visitor gateways to Australia’s Great Barrier Reef. Because of the complexity of issues involved at such urbanized downstream sites, the range of topics covered is wide – though still only those considered at this juncture to be of management priority. Included on this platform is one introductory paper reviewing the history of environmental management in the field in Queensland, and three papers which seek to appreciate the main techniques by which government contributes to the solutions viz. through the national park, threatened species list, and environmental impact assessment. The history paper was designed to allow the present series to be considered in broad context as well as performance to date. The work emphasizes that much of the fertile land that must be sustained nowadays lies in the province of the private sector, and that the initiative to create any new cost-effective paradigm in ecologically-sustainable practices lies mostly in their hands. In all instances, this strategic approach to large-scale property planning is through ecological design – using field case studies around the immediate biophysical catchment of the development, with attendant focus on the associated legal catchment (the actual development site) and the social catchment (the effective land managers). The first of these has given rise to a document termed a Regional Landscape Strategy, its implementation planned in concert with an Environmental Impact Assessment of the site and with a Strategic Regional Initiative (still being tested in the field) for community engagement. The first document takes into account the aspirations of government as expressed in its broad-scale regional plans.

Broadening the focus : the case for lifestyle journalism as a field of scholarly inquiry

This introduction to the special issue outlines the case for an increased focus on studying lifestyle journalism, an area of journalism which, despite its rapid rise over recent decades, has not received much attention from scholars in journalism studies. Criticised for being antithetical to public interest and watchdog notions of journalism, lifestyle journalism is still ridiculed by some as being unworthy of being associated with the term journalism. However, in outlining the field's development and a critique of definitions of journalism, this paper argues that there are a number of good reasons for broadening the focus. In fact, lifestyle journalism?here defined as a distinct journalistic field that primarily addresses its audiences as consumers, providing them with factual information and advice, often in entertaining ways, about goods and services they can use in their daily lives?has much to offer for scholarly inquiry and is of increasing relevance for society.

Consensus σ70 promoter prediction using hadoop

MapReduce frameworks such as Hadoop are well suited to handling large sets of data which can be processed separately and independently, with canonical applications in information retrieval and sales record analysis. Rapid advances in sequencing technology have ensured an explosion in the availability of genomic data, with a consequent rise in the importance of large scale comparative genomics, often involving operations and data relationships which deviate from the classical Map Reduce structure. This work examines the application of Hadoop to patterns of this nature, using as our focus a wellestablished workflow for identifying promoters - binding sites for regulatory proteins - Across multiple gene regions and organisms, coupled with the unifying step of assembling these results into a consensus sequence. Our approach demonstrates the utility of Hadoop for problems of this nature, showing how the tyranny of the "dominant decomposition" can be at least partially overcome. It also demonstrates how load balance and the granularity of parallelism can be optimized by pre-processing that splits and reorganizes input files, allowing a wide range of related problems to be brought under the same computational umbrella.

Rethinking the effects paradigm in porn studies

It has been an assumption of most anti-pornography discourse that porn damages women (and children) in a variety of ways. In Porno? Chic!, the author interrogated this assumption by examining the correlation between the incidence of sexual violence and other indicators of misogyny, and the availability and accessibility of pornography within a number of societies. This article develops that work with a specific focus on the regulatory environment as it relates to pornography and sexual representation. Does a liberal regulatory regime in sexual culture correlate with a relatively advanced state of sexual politics in a given country? Conversely, does an illiberal regime, where pornography and other forms of sexual culture are banned or severely restricted, correlate with relatively strong patriarchal structures? A comparative cross-country analysis seeks to explain the correlations identified, and to assess the extent to which the availability of porn can be viewed as a causal or a consequential characteristic of those societies where feminism has achieved significant advances.

Regulatory compliance as a means to achieve environmental sustainability at some large coastal developments in Queensland

The growing public concern about the complexity, cost and uncertain efficacy of the statuary environmental impact assessment process applying to large-scale projects in Queensland is reviewed. This is based on field data gathered over the past six years sat large-scale marina developments that access major environmental reserves along the coast. An ecological design proposal to broaden the process consisted with both government aspirations and regional ecological parameters - termed Regional Landscape Strategies - would allow the existing Environmental Impact Asessment to be modified alone potentially more practicable and effective lines.

Dancing to too many tunes : contemporary course design in teacher education

Contemporary course designers in schools and faculties of Education are finding themselves dancing to many tunes, arguably too many tunes, in order to have their initial teacher education courses accredited by external agencies whilst satisfying internal approval processes and, critically, maintaining the philosophical integrity of their programs and their institutional watermarks. The “tunes” here are the agendas driven by and the demands made by distinct independent agencies. The external agencies influencing Education include: TEQSA (Tertiary Education Quality and Standards Agency) which will assure alignment to the AQF (Australian Qualifications Framework); professional bodies such as AITSL (Australian Institute for Teaching and School Leadership) which now accredits all pre-service teacher Education courses across Australia and assures alignment with the Australian Professional Standards for Teachers; and the state and territory regulatory authorities that have an impact within a specific jurisdiction, for example, the Queensland College of Teachers (QCT) and the Teacher Registration Board of Western Australia (TRBWA). This paper – whose findings have been arrived at through a year-long OLT National Teaching Fellowship - will outline the complex and competing agendas currently at play and focus on the disjuncture evident in the fundamental defining of who is a “graduate.” It will also attempt to identify where there are synergies between the complex demands being made. It will argue that there are too many “tunes” and the task of finding a balance between compliance and delivering effective initial teacher education may not be possible because of the cacophony of their conflicting demands.