Petrodollars-The Recycling Problem: Some Introductory Remarks

Whatever the actual size and volume of surplus funds that ultimately accrue to the oil producing countries as a result of the quadrupling of oil prices in late 1973 and early 197 4, there is no doubt that a dramatic and unprecedented shift in financial resources from the oil importing to the oil exporting countries has occurred. This trend will continue for at least the immediate future and probably will not reverse before the end of this decade, when new or alternative energy sources and changes in consumption patterns may begin to show their effects. To be sure, early forecasts on the implications of the oil revolution painted a bleak prospect for the world at large, and particularly for the industrial world. It is now, however, generally accepted that the estimates of amounts involved were exaggerated by many in the early crisis days, and have more recently been revised downward. These new and more modest estimates are the result of various factors

The effects of authentic leadership and a positive organisational context

This research concerns itself with the effects of authentic leadership and a positive organisational context. Gardner, Avolio, Luthans, May and Walumbwa’s (2005) authentic leader and follower development model suggests that authentic leadership within a positive organisational context leads to increased authentic followership, which in turn influences positive follower outcomes, and finally leads to sustainable and veritable organisational performance. A research contextual framework, based on Gardner et al.’s (2005) model, is developed with one significant change being the repositioning of a positive organisational context as a relatively more significant construct in the development of authentic followership. The research contextual framework and in particular the correlations between the various constructs are tested. This is performed through a quantitative study based on the completion of a research questionnaire by employees at four South African based services companies. In addition to a general testing of the various correlations, the role of a positive organisational context is specifically investigated in order to shed light on which model better reflects the authentic leadership development process: Gardner et al.’s (2005) model or the research contextual framework. It is also intended that this research will provide insights into whether general authentic leadership theory can be generalised to a South African context. CopyrightDissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte

Embryonic deregulation of muscle stress signaling pathways leads to altered postnatal stem cell behavior and a failure in postnatal muscle growth

AbstractPW1 is a mediator of p53 and TNFα signaling pathways previously identified in a screen to isolate muscle stem cell regulators. We generated transgenic mice carrying a C-terminal deleted form of PW1 (ΔPW1) which blocks p53-mediated cell death and TNFα-mediated NFκB activation fused to the myogenin promoter. Embryonic/fetal muscle development appears normal during transgene expression, however, postnatal transgenic pups display severe phenotypes including runtism, reduced muscle mass and fiber diameters resembling atrophy. Atrogin-1, a marker of skeletal muscle atrophy, is expressed postnatally in transgenic mice. Electron microscopic analyses of transgenic muscle reveal a marked decrease in quiescent muscle satellite cells suggesting a deregulation of postnatal stem cells. Furthermore, transgenic primary myoblasts show a resistance to the effects of TNFα upon differentiation. Taken together, our data support a role for PW1 and related stress pathways in mediating skeletal muscle stem cell behavior which in turn is critical for postnatal muscle growth and homeostasis. In addition, these data reveal that postnatal stem cell behavior is likely specified during early muscle development

The zinc finger transcription factor PW1/PEG3 restrains murine beta cell cycling

Aims/hypothesis: Pw1 or paternally-expressed gene 3 (Peg3) encodes a zinc finger transcription factor that is widely expressed during mouse embryonic development and later restricted to multiple somatic stem cell lineages in the adult. The aim of the present study was to define Pw1 expression in the embryonic and adult pancreas and investigate its role in the beta cell cycle in Pw1 wild-type and mutant mice. Methods: We analysed PW1 expression by immunohistochemistry in pancreas of nonpregant and pregnant mice and following injury by partial duct ligation. Its role in the beta cell cycle was studied in vivo using a novel conditional knockout mouse and in vitro by lentivirus-mediated gene knockdown. Results: We showed that PW1 is expressed in early pancreatic progenitors at E9.5 but becomes progressively restricted to fully differentiated beta cells as they become established after birth and withdraw from the cell cycle. Notably, PW1 expression declines when beta cells are induced to proliferate and loss of PW1 function activates the beta cell cycle. Conclusions/interpretation: These results indicate that PW1 is a co-regulator of the beta cell cycle and can thus be considered a novel therapeutic target in diabetes

Does cardiac development provide heart research with novel therapeutic approaches? [version 1; referees: 2 approved]

Embryonic heart progenitors arise at specific spatiotemporal periods that contribute to the formation of distinct cardiac structures. In mammals, the embryonic and fetal heart is hypoxic by comparison to the adult heart. In parallel, the cellular metabolism of the cardiac tissue, including progenitors, undergoes a glycolytic to oxidative switch that contributes to cardiac maturation. While oxidative metabolism is energy efficient, the glycolytic-hypoxic state may serve to maintain cardiac progenitor potential. Consistent with this proposal, the adult epicardium has been shown to contain a reservoir of quiescent cardiac progenitors that are activated in response to heart injury and are hypoxic by comparison to adjacent cardiac tissues. In this review, we discuss the development and potential of the adult epicardium and how this knowledge may provide future therapeutic approaches for cardiac repair

FAP-1 Association with Fas (Apo-1) Inhibits Fas Expression on the Cell Surface

As revealed by intracellular pools of nonactive Fas (Apo-1), export of Fas to the cell surface is often impaired in human tumors, thereby inactivating Fas ligand-mediated apoptosis. Here, we demonstrate that association with Fas-associated phosphatase 1 (FAP-1) attenuates Fas export to the cell surface. Forced expression of FAP-1 reduces cell surface Fas levels and increases the intracellular pool of Fas within the cytoskeleton network. Conversely, expression of dominant-negative forms of FAP-1, or inhibition of FAP-1 expression by short interfering RNA, efficiently up-regulates surface expression of Fas. Inhibition of Fas surface expression by FAP-1 depends on its association with the C terminus of Fas. Mutation within amino acid 275 results in decreased association with FAP-1 and greater export of Fas to the cell surface in melanomas, normal fibroblasts, or Fas null cells. Identifying the role of FAP-1 in binding to, and consequently inhibition of, Fas export to the cell surface provides novel insight into the mechanism underlying the regulation of Fas trafficking, which is commonly impaired in advanced tumors with FAP-1 overexpression

Identification and characterization of a non-satellite cell muscle resident progenitor during postnatal development

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