Geometric control of myogenic cell fate.

This work combines expertise in stem cell biology and bioengineering to define the system for geometric control of proliferation and differentiation of myogenic progenitor cells. We have created an artificial niche of myogenic progenitor cells, namely, modified extracellular matrix (ECM) substrates with spatially embedded growth or differentiation factors (GF, DF) that predictably direct muscle cell fate in a geometric pattern. Embedded GF and DF signal progenitor cells from specifically defined areas on the ECM successfully competed against culture media for myogenic cell fate determination at a clearly defined boundary. Differentiation of myoblasts into myotubes is induced in growth-promoting medium, myotube formation is delayed in differentiation-promoting medium, and myogenic cells, at different stages of proliferation and differentiation, can be induced to coexist adjacently in identical culture media. This method can be used to identify molecular interactions between cells in different stages of myogenic differentiation, which are likely to be important determinants of tissue repair. The designed ECM niches can be further developed into a vehicle for transplantation of myogenic progenitor cells maintaining their regenerative potential. Additionally, this work may also serve as a general model to engineer synthetic cellular niches to harness the regenerative potential of organ stem cells

Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration.

The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation; however, systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin--a hormone best known for its role in lactation, parturition and social behaviours--is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signalling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation through activation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle but instead leads to premature sarcopenia. Considering that oxytocin is an FDA-approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle ageing

The political phenomenology of war reporting

Drawing on interviews with war correspondents, editors, political and military personnel, this article investigates the political dimension of the structuration and structuring effects of the reporter’s experience of journalism. Self-reflection and judgements about colleagues confirm that there are dominant norms for interpreting and acting in conflict scenarios which, while contingent upon socio-historical context, are interpreted as natural. But the prevalence of such codes masks the systematically misrecognized symbolic systems of mystification and ambivalence – systems which reproduce hierarchies and gatekeeping structures in the field, but which are either experienced as unremarkable, dismissed with irony and cynicism, or not present to the consciousness of the war correspondent. The article builds on recent theories of journalistic disposition, ideology, discourse and professionalism, and describes the political dimension of journalistic practice perceived in the field as apolitical. It addresses the gendering of war correspondence, the rise of the journalist as moral authority, and questions the extent to which respondent reflections can be defensibly analytically determined

Cal Poly and the Wayward Field of Home Economics

Since its establishment in 1901 California Polytechnic State University at San Luis Obispo has gone through a number of identity crises. What began as a progressive institution that aimed to educate the state’s future blue-collar workers has matured into a recognized academic institution. As the school grew, its faculty and administrators had to decide which features of Cal Poly fit into their vision of its future, and which should be left behind as the university progressed. Many aspects of Cal Poly’s curriculum were scrapped somewhere between rural-secondary school, and comprehensive polytechnic university. The now defunct Department of Home Economics falls into this unfortunate second category

Report of the working group on the measurement of triple gauge boson couplings

The working group discussed several aspects of triple gauge coupling analysis viewed in the light of experiences with the first high energy data recorded at energies above the W pair threshold. Some analysis methods were reviewed briefly, and consideration given to better ways of characterising the data. The measurement of CP violating parameters was discussed. Results were prepared to further quantify the precision attainable on anaomalous couplings in the four-quark channel using jet-charge methods, and finally the trade off between maximum LEP energy-vs-luminosity was quantified.The working group discussed several aspects of triple gauge coupling analysis viewed in the light of experiences with the first high energy data recorded at energies above the W pair threshold. Some analysis methods were reviewed briefly, and consideration given to better ways of characterising the data. The measurement of CP violating parameters was discussed. Results were prepared to further quantify the precision attainable on anaomalous couplings in the four-quark channel using jet-charge methods, and finally the trade off between maximum LEP energy-vs-luminosity was quantified

Biosynthesis of Mitochondrial Porin and Insertion into the Outer Mitochondrial Membrane of Neuruspora crassa

Mitochondrial porin, the major protein of the outer mitochondrial membrane is synthesized by free cytoplasmic polysomes. The apparent molecular weight of the porin synthesized in homologous or heterologous cell-free systems is the same as that of the mature porin. Transfer in vitro of mitochondrial porin from the cytosolic fraction into the outer membrane of mitochondria could be demonstrated. Before membrane insertion, mitochondrial porin is highly sensitive to added proteinase; afterwards it is strongly protected. Binding of the precursor form to mitochondria occurs at 4°C and appears to precede insertion into the membrane. Unlike transfer of many precursor proteins into or across the inner mitochondrial membrane, assembly of the porin is not dependent on an electrical potential across the inner membrane

Different Transport Pathways of Individual Precursor Proteins in Mitochondria

Transport of mitochondrial precursor proteins into mitochondria of Neurospora crassa was studied in a cellfree reconstituted system. Precursors were synthesized in a reticulocyte lysate programmed with Neurospora mRNA and transported into isolated mitochondria in the absence of protein synthesis. Uptake of the following precursors was investigated: apocytochrome c, ADP/ATP carrier and subunit 9 of the oligomycin-sensitive ATPase. Addition of high concentrations of unlabelled chemically prepared apocytochrome c (1–10 μM) inhibited the appearance in the mitochondrial of labelled cytochrome c synthesized in vitro because the unlabelled protein dilutes the labelled one and because the translocation system has a limited capacity [apparent V is 1–3 pmol × min−1× (mg mitochondrial protein)−1]. Concentrations of added apocytochrome c exceeding the concentrations of precursor proteins synthesized in vitro by a factor of about 104 did not inhibit the transfer of ADP/ATP carrier or ATPase subunit 9 into mitochondria. Carbonylcyanide m-chlorophenylhydrazone, an uncoupler of oxidative phosphorylation, inhibited transfer in vitro of ADP/ATP carrier and of ATPase subunit 9, but not of cytochrome c. These findings suggest that cytochrome c and the other two proteins have different import pathways into mitochondria. It can be inferred from the data presented that different 'receptors' on the mitochondrial surface mediate the specific recognition of precursor proteins by mitochondria as a first step in the transport process

Participatory politics, environmental journalism and newspaper campaigns

This is an Author's Accepted Manuscript of an article published in Journalism Studies, 13(2), 210 - 225, 2012, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/1461670X.2011.646398.This article explores the extent to which approaches to participatory politics might offer a more useful alternative to understanding the role of environmental journalism in a society where the old certainties have collapsed, only to be replaced by acute uncertainty. This uncertainty not only generates acute public anxiety about risks, it has also undermined confidence in the validity of long-standing premises about the ideal role of the media in society and journalistic professionalism. The consequence, this article argues, is that aspirations of objective reportage are outdated and ill-equipped to deal with many of the new risk stories environmental journalism covers. It is not a redrawing of boundaries that is needed but a wholesale relocation of our frameworks into approaches better suited to the socio-political conditions and uncertainties of late modernity. The exploration of participatory approaches is an attempt to suggest one way this might be done

Just enough structure at the edge of chaos: Agile information system development in practice

Agile information systems development is not well understood and suffers from a lack of sustainable theories, which are based on empirical research of practice. We use a framework that focuses on the ‘edge of chaos’ as the area, where agile information systems development takes place to fill in this gap. Our study identifies for a concrete project under investigation, where the beneficial balance between stability and instability lies. It discusses the circumstances, which influence this balance and the relationships of the elements, which constitute it