Prosociality and Pentecostalism in the D.R. Congo

This paper explores an empirical puzzle: individuals in urban D.R. Congo who were unsure if they would be able to provide sufficient food for their families gave more of their money away to anonymous receivers in behavioral games. They were especially likely to share money evenly. We argue that this surprising prosocial behavior reflects sharing norms associated with informal insurance, for which more materially insecure individuals presumably have higher demand. We further argue that such sharing norms are sustained in urban Congo by Pentecostal churches, a nexus of risk-spreading in this context. The same group of highly insecure individuals is more likely to participate in public religious ceremonies—but not private ones—and to share money evenly in behavioral games. Moreover, the gap in money sharing between individuals facing high and low insecurity is largest when participants are primed with Christian images

Magnesium analogues of aluminosilicate inorganic polymers (geopolymers) from magnesium minerals

Attempts to synthesise magnesium-containing analogues of aluminosilicate geopolymers from the 1:1 and 2:1 layer magnesiosilicate minerals chrysotile and talc, as well as the magnesium mineral sepiolite are reported. The effect of pre-treating these starting minerals by grinding and/or dehydroxylation was also investigated by XRD, 29Si and natural-abundance 25Mg solid-state magic angle spinning (MAS) NMR spectroscopy. The products from sepiolite most closely resembled an aluminosilicate geopolymer, setting at 40 °C to an X-ray amorphous product containing a broad characteristic 29Si MAS NMR resonance at −90 ppm. The 25Mg MAS NMR spectrum of this product also showed evidence that some of the Mg was located in tetrahedral sites, as expected for a conventional geopolymer. A similar 25Mg MAS NMR result was obtained for chrysotile, but talc proved to be extremely resistant to geopolymer synthesis, requiring treatment at 120 °C for 3 days to set to a friable material retaining the XRD and NMR characteristics of the original talc or its crystalline dehydroxylation products. This lack of reactivity may be related to the 2:1 layer-lattice talc structure, or to the fact that a suitably reactive amorphous product is not formed upon dehydroxylation