Arachidonic acid release from mammalian cells transfected with human groups IIA and X secreted phospholipase A(2) occurs predominantly during the secretory process and with the involvement of cytosolic phospholipase A(2)-alpha

Stable expression of human groups IIA and X secreted phospholipases A(2) (hGIIA and hGX) in CHO-K1 and HEK293 cells leads to serum- and interleukin-1beta-promoted arachidonate release. Using mutant CHO-K1 cell lines, it is shown that this arachidonate release does not require heparan sulfate proteoglycan- or glycosylphosphatidylinositol-anchored proteins. It is shown that the potent secreted phospholipase A(2) inhibitor Me-Indoxam is cell-impermeable. By use of Me-Indoxam and the cell-impermeable, secreted phospholipase A(2) trapping agent heparin, it is shown that hGIIA liberates free arachidonate prior to secretion from the cell. With hGX-transfected CHO-K1 cells, arachidonate release occurs before and after enzyme secretion, whereas all of the arachidonate release from HEK293 cells occurs prior to enzyme secretion. Immunocytochemical studies by confocal laser and electron microscopies show localization of hGIIA to the cell surface and Golgi compartment. Additional results show that the interleukin-1beta-dependent release of arachidonate is promoted by secreted phospholipase A(2) expression and is completely dependent on cytosolic (group IVA) phospholipase A(2). These results along with additional data resolve the paradox that efficient arachidonic acid release occurs with hGIIA-transfected cells, and yet exogenously added hGIIA is poorly able to liberate arachidonic acid from mammalian cells.

Optimal strategies in political elections

In the Majoritarian Parliamentary System, the government has a constitutional right to call an early election. This right provides the government a control to achieve its objective to remain in power for as long as possible. We model the early election problem mathematically using opinion polls data as a stochastic process to proxy the government's probability of re-election. These data measure the difference in popularity between the government and the opposition. We fit a mean reverting Stochastic Differential Equation to describe the behaviour of the process and consider the possibility for the government to use other control tools, which are termed 'boosts' to induce shocks to the opinion polls by making timely policy announcements or economic actions. These actions improve the government's popularity and have some impact upon the early-election exercise boundary. © Austral. Mathematical Soc. 2005.

A political analysis of the PRSP initiative: Social struggles and the organization of persistent relations of inequality

The current global development project appears to be premised on the assumption that underlying political debates over development have been settled. An upshot of this is that development is reduced to the theoretical, ideological and legal framework of a neo-liberal political order. However, implicit, and sometimes explicit, political dynamics of development can be rendered from a perspective that foregrounds social struggles. I offer a political analysis of the PRSP initiative by examining its evolution and implications considered within social and political contexts, and by specific reference to the 'poverty reduction' interventions that emerged in the 1980s. I argue that the PRSP initiative is best understood as the formation of a comprehensive extension of neo-liberal strategic responses that emerged in the 1980s. In this context, I discuss the example of microcredit schemes in relation to the PRSP process and demonstrate the analytical significance of micro-political social relations for political analyses of development. The approach I adopt reveals social struggles as relationally constitutive of formations of a hegemonic development discourse otherwise ostensibly rendered in de-contextualized terms. From the perspective of critical development analysis such struggles are the concrete expressions of the contradictions immanent to the dialectic of development through inequality and immiseration in the (re)production of social power.