Reflections on amyloidosis in Papua New Guinea

The amyloidoses comprise a heterogeneous group of diseases in which 1 out of more than 25 human proteins aggregates into characteristic beta-sheet fibrils with some unique properties. Aggregation is nucleation dependent. Among the known amyloid-forming constituents is the prion protein, well known for its ability to transmit misfolding and disease from one individual to another. There is increasing evidence that other amyloid forms also may be transmissible but only if certain prerequisites are fulfilled. One of these forms is systemic AA-amyloidosis in which an acute-phase reactant, serum AA, is over-expressed and, possibly after cleavage, aggregates into amyloid fibrils, causing disease. In a mouse model, this disorder can easily be transmitted from one animal to another both by intravenous and oral routes. Also, synthetic amyloid-like fibrils made from defined small peptides have this property, indicating a prion-like transmission mechanism. Even some fibrils occurring in the environment can transmit AA-amyloidosis in the murine model. AA-amyloidosis is particularly common in certain areas of Papua New Guinea, probably due to the endemicity of malaria and perhaps genetic predisposition. Now, when kuru is disappearing, more interest should be focused on the potentially lethal systemic AA-amyloidosis

In the social factory? Immaterial labour, precariousness and cultural work

This article introduces a special section concerned with precariousness and cultural work. Its aim is to bring into dialogue three bodies of ideas -- the work of the autonomous Marxist 'Italian laboratory'; activist writings about precariousness and precarity; and the emerging empirical scholarship concerned with the distinctive features of cultural work, at a moment when artists, designers and (new) media workers have taken centre stage as a supposed 'creative class' of model entrepreneurs. The paper is divided into three sections. It starts by introducing the ideas of the autonomous Marxist tradition, highlighting arguments about the autonomy of labour, informational capitalism and the 'factory without walls', as well as key concepts such as multitude and immaterial labour. The impact of these ideas and of Operaismo politics more generally on the precarity movement is then considered in the second section, discussing some of the issues that have animated debate both within and outside this movement, which has often treated cultural workers as exemplifying the experiences of a new 'precariat'. In the third and final section of the paper we turn to the empirical literature about cultural work, pointing to its main features before bringing it into debate with the ideas already discussed. Several points of overlap and critique are elaborated -- focusing in particular on issues of affect, temporality, subjectivity and solidarity

Equations of Substrate-inhibition Kinetics Applied to Pig Kidney Diamine Oxidase (DAO, E.C. 1.4.3.6)

Pig kidney diamine oxidase (DAO) and other semicarbazide-sensitive amine oxidases (SSAO) show clear substrate-inhibition kinetics and a reaction-scheme mechanism based on two substrate binding sites. We evaluated several reaction scheme mechanisms with a non-linear regression program (NCSS), estimating R2, the constants of the equations and their standard errors and we determined the deviation of experimental data from theoretical equations. The best fit was obtained with a "dead end" mechanism with two binding sites. Based on this scheme, other schemes for a two-substrate reaction and for mechanisms of inhibition were constructed. These reaction schemes, even at low substrate concentration, fitted experimental data better than Michaelis-Menten kinetics, and provided information on the mechanisms of action of inhibitors. The presence of two substrate-binding sites on pig kidney DAO was confirmed by all experimental data