Cell division protein ftsZ: running rings around bacteria, chloroplasts and mitochondria

Of all the proteins involved in prokaryotic cell division FtsZ is one of the earliest acting and most widely distributed, being found in all but a few species. We discuss several recent discoveries of FtsZ in eukaryotic cells and the protein’s role in the division of chloroplasts and mitochondria, organelles that are of bacterial origin.

Bacterial lessons on organelle division

Mitochondria and chloroplasts arose from bacterial endosymbionts about a billion years ago. This ancestry is now showing us how these organelles divide in modem cells.

Polanyi's presagement of the incommensurability concept

Kuhn and Feyerabend have little to say about the thought of Michael Polanyi, and the secondary literature on Polanyi's relation to them is meagre. I argue that Polanyi's view, in Personal knowledge and in other writings, of conceptual frameworks ‘segregated’ by a ‘logical gap’ as giving rise to controversies in science foreshadowed Kuhn and Feyerabend's theme of incommensurability. The similarity between the thinkers is, I suggest, no coincidence.

Two dictyostelium orthologs of the prokaryotic cell division protein ftsZ localize to mitochondria and are required for the maintenance of normal mitochondrial morphology

In bacteria, the protein FtsZ is the principal component of a ring that constricts the cell at division. Though all mitochondria probably arose through a single, ancient bacterial endosymbiosis, the mitochondria of only certain protists appear to have retained FtsZ, and the protein is absent from the mitochondria of fungi, animals, and higher plants. We have investigated the role that FtsZ plays in mitochondrial division in the genetically tractable protist Dictyostelium discoideum, which has two nuclearly encoded FtsZs, FszA and FszB, that are targeted to the inside of mitochondria. In most wild-type amoebae, the mitochondria are spherical or rod-shaped, but in fsz-null mutants they become elongated into tubules, indicating that a decrease in mitochondrial division has occurred. In support of this role in organelle division, antibodies to FszA and FszA-green fluorescent protein (GFP) show belts and puncta at multiple places along the mitochondria, which may define future or recent sites of division. FszB-GFP, in contrast, locates to an electron-dense, submitochondrial body usually located at one end of the organelle, but how it functions during division is unclear. This is the first demonstration of two differentially localized FtsZs within the one organelle, and it points to a divergence in the roles of these two proteins.

Application of the fair-value concept : evidence from Australian legal decisions

The concept of "fair value" is increasingly being incorporated into Australian and international accounting standards and pronouncements. The fair-value concept has also been established and developed in Australian legal cases, and an examination of pertinent court decisions is of interest to accountants. By examining and analysing relevant cases, the paper highlights some of the principles and difficulties involved in operationalising the fair-value concept for accounting and legal purposes, particularly in situations where the asset being valued is subject to imperfect or incomplete markets.

Diverse eukaryotes have retained mitochondrial homologues of the bacterial division protein FtsZ

Mitochondrial fission requires the division of both the inner and outer mitochondrial membranes. Dynamin-related proteins operate in division of the outer membrane of probably all mitochondria, and also that of chloroplasts – organelles that have a bacterial origin like mitochondria. How the inner mitochondrial membrane divides is less well established. Homologues of the major bacterial division protein, FtsZ, are known to reside inside mitochondria of the chromophyte alga Mallomonas, a red alga, and the slime mould Dictyostelium discoideum, where these proteins are likely to act in division of the organelle. Mitochondrial FtsZ is, however, absent from the genomes of higher eukaryotes (animals, fungi, and plants), even though FtsZs are known to be essential for the division of probably all chloroplasts. To begin to understand why higher eukaryotes have lost mitochondrial FtsZ, we have sampled various diverse protists to determine which groups have retained the gene. Database searches and degenerate PCR uncovered genes for likely mitochondrial FtsZs from the glaucocystophyte Cyanophora paradoxa, the oomycete Phytophthora infestans, two haptophyte algae, and two diatoms – one being Thalassiosira pseudonana, the draft genome of which is now available. From Thalassiosira we also identified two chloroplast FtsZs, one of which appears to be undergoing a C-terminal shortening that may be common to many organellar FtsZs. Our data indicate that many protists still employ the FtsZ-based ancestral mitochondrial division mechanism, and that mitochondrial FtsZ has been lost numerous times in the evolution of eukaryotes.

Intra-organisational marketing culture and market orientation: a case study of the implementation of the marketing concept in a public library

The measurement of both marketing culture and behaviour provides the opportunity to gain more insight into the overall market focus of organisations. This article seeks to determine the market orientation and marketing culture of all staff within organisations, to ascertain to what extent other members of an organisation support or create barriers to the successful implementation of the marketing concept. This paper will provide a brief overview of the existing literature in the field of market orientation and marketing culture. After detailing the research design and methodology, a summary developed from 11 focus group sessions - consisting of all staff in one public library service in Victoria, Australia - is presented. The findings indicate that while all areas within this organisation are committed to marketing, there are various interpretations of marketing and how it should be implemented. In addition, the research finds a number of factors that could be instrumental in the successful implementation of the marketing concept in public libraries.

Combining extension matrix and integer programming for optimal concept learning

This paper proposes two integer programming models and their GA-based solutions for optimal concept learning. The models are built to obtain the optimal concept description in the form of propositional logic formulas from examples based on completeness, consistency and simplicity. The simplicity of the propositional rules is selected as the objective function of the integer programming models, and the completeness and consistency of the concept are used as the constraints. Considering the real-world problems that certain level of noise is contained in data set, the constraints in model 11 are slacked by adding slack-variables. To solve the integer programming models, genetic algorithm is employed to search the global solution space. We call our approach IP-AE. Its effectiveness is verified by comparing the experimental results with other well- known concept learning algorithms: AQ15 and C4.5.

Integrated health impact assessment into the triple bottom line concept

This theoretical study explores the links between the Triple Bottom Line (TBL) concept and the principles of HIA and considers the potential role of HIA to provide a mechanism for integrating health concerns within a broader agenda of government and business. TBL is a framework linked to the broader sustainability agenda that underpins and reviews environmental, economic and social performance of organizations. In its simplest form, TBL acts as a tool for reporting to stakeholders/shareholders organizational performance and the nature of the impacts on the community. The links to HIA are clear as both seek to determine the impact (potential and actual) on the health and well-being of the population.

The study found that TBL can operate at four levels within organizations ranging from reporting through to full integration with the organization's goals and practices. Health is narrowly defined and there are tensions about how to undertake the social accountability functions. The study shows the potential role for HIA within the broader policy and accountability agenda. As health is one of the main outcomes of an organization's activities it needs to be taken into account at all levels of activity.

Financial reporting for environmental and social responsibility: a normative strategic concept

Corporate responsibility demands that firms address environmental and social values in their firms' policy and key performance indicators. These are integrated through strategic planning and require firms to merge the long-term environmental and social values with short-term economic objectives and performance measures. Each firm's strategy will differ. This paper provides a normative reporting concept to connect the financial implications associated with long-term planning for environmental and social values, with short-term accounting reports. Reporting variants adapted from total cost assessment, life cycle costing and variable costing are integrated to offer upstream information based on a product segment view.

Development of a cooling fabric from conducting polymer coated fibres: proof of concept

It is supposed that there should be a thermal electric effect if a dc current is applied across two dissimilar conducting polymers, similar to so called “Peltier effect” in metals or semiconductors. However, this hypothesis has not been tested on conducting polymers and using these materials to make cooling fabrics has never been attempted before. Polypyrrole coated fabrics were used to test the hypothesis in this preliminary study. Seebeck and the Peltier effects were proven to exist. However, thermoelectricity effect between two conducting polymer coated fabric samples was only about 10 μV/°C. Cooling effect by conductive polymer powder was achieved but performance was unsteady due to electrical degradation of the conducting polymer. Nevertheless, the concept was demonstrated and the development of a cooling fabric is possible.

Moving from the quality of life concept to a theory

BACKGROUND: The Special Interest Quality of Life Group has updated its set of statements defining the quality of life (QOL) construct to reflect emerging areas of agreement and the framework for understanding better the QOL construct.
METHOD: This article examines the major areas currently under discussion involving the objective-subjective dichotomy, needs, and core domains.
RESULTS: It is concluded that while the new statements constitute a significant advance, further progress requires testable theory. In order to facilitate such future research, a conceptual model is proposed that distinguishes causal and indicator variables within the framework of a homeostatic management system.
CONCLUSION: Several lines of empirical investigation are suggested to test this and similar theoretical models with a view to taking our conceptualization of QOL to the next level.

Modern dance, domestic life and civil society

In her book The Reluctant Modernism of Hannah Arendt (2000) Seyla Benhabib uses the concept of an ‘alternative genealogy of modernity’ to help her both to understand Arendt’s political philosophy and to rethink the potential for civil society to become a progressive political force at the beginning of the twenty first century. The idea of an alternative genealogy of modernity refers to a heterogeneity of social and political forms, spaces and acts that might be used to remap and redefine a modernity whose dominant topology has been shaped by the binary division between so-called public and private spheres. Alternative modernities have already been elaborated and explored from a range of different perspectives including feminist and postcolonial ones: for example, in Rita Felski’s Gender of Modernity (1995) and Dipesh Chakrabarty’s Provincialising Europe (2000). In this paper I want to elaborate upon the idea of an alternative genealogy of modernity from my perspective as a dancer. Thinking through the sociality of art and, more specifically, of some historical dance-making practices can make visible alternative spaces and processes of the (potentially) political. In the West, the modes of art-making form part of an as yet not fully explored arena of the social and of social practices. Modernist and Romantic ideologies have tended to preclude attention to the specific sociabilities of art-making. On the one hand Modernist ideology and art discourses have promoted the idea of an art work’s ‘autonomy’: its radical separation from the social relationships, the bodies and the conditions of its making. On the other hand Romantic ideology, still pervasive in popular conceptions of art practices, construes creation as interiority and individualistic expression. Socialist feminist and Marxist discussions of art have emphasized the social conditions of art-making but these have tended to be concerned with the social inequalities instituted within the public/private split rather than seeking to destabilize that division itself by posing questions of differences within the social. In my discussion below I draw on aspects of early modern dance practice and creation in taking up Benhabib’s concern to mobilise an alternative genealogy of modernity towards a renewal and reactivation of civic life. This project involves unsettling clear distinctions between the so-called ‘public’ and ‘private’ but, at the same time, as Benhabib cautions ‘the binarity of public and private spheres must be reconstructed and not merely rejected’. (2000:2006)