Fourier transform infrared difference spectroscopy has been used to obtain information about substrate-induced structural changes of the melibiose permease (MelB) from Escherichia coli reconstituted into liposomes. Binding of the cosubstrate Na(+) gives rise to several peaks in the amide I and II regions of the difference spectrum Na(+).MelB minus H(+).MelB, that denote the presence of conformational changes in all types of secondary structures (alpha-helices, beta-sheets, loops). In addition, peaks around 1400 and at 1740-1720 cm(-1) are indicative of changes in protonation/deprotonation or in environment of carboxylic groups. Binding of the cosubstrate Li(+) produces a difference spectrum that is also indicative of conformational changes, but that is at variance as compared to that induced by Na(+) binding. To analyze the following transport steps, the melibiose permease with either H(+), Na(+), or Li(+) bound was incubated with melibiose. The difference spectra obtained by subtracting the spectrum cation.MelB from the respective complex cation.melibiose.MelB were roughly similar among them, but different from those induced by cation binding, and more intense. Therefore, major conformational changes that are induced during melibiose binding/substrate translocation, like those denoted by intense peaks at 1668 and 1645 cm(-)(1), are similar for the three cotransporting cations. Changes in the protonation state and/or in the environment of given carboxylic residues were also induced by melibiose-MelB interaction in the presence of cations.

"Between 1 and 15 of August [1997], Mozambique had its second country-wide population census. This briefing will outline how the census ran--an operation of considerable scale in an extremely poor and war-damaged country--and will also raise some broader questions which relate the census to Mozambique's contemporary politics."

"In the 1990s analyses of [Zimbabwe's land resettlement program] by both supporters and critics of land reform have generally been negative. Yet there is evidence that resettled people themselves have made real welfare and income gains. Strong support for the programme was also expressed by a large sample of rural-urban migrants in Harare in 1994. Their views, reported in this article, showed an appreciation of most aspects of the academic and policy debates, but clearly also tended towards the perception that redistribution of land in Zimbabwe is a moral issue."

"This article reviews some recent key books on HIV/AIDS in Africa. It does so by examining the debates relating to the extent and possible future development of HIV/AIDS referring to the discussions about demographic, economic and social impacts in especially eastern and southern Africa. It explores the so-called doomsday scenarios and addresses themes linked to the important and increasing attention being paid to the gendered aspects of HIV/AIDS."

Malawi, the world's most tobacco dependent country, has long defended the tobacco industry as essential to its economy. The impoverished living conditions of tobacco farmers, however, raise questions about the true benefits accruing to the country. While the government and industry often blame public health advocates for declining leaf prices, and thus lower returns to farmers, this article scrutinises these claims from a historical perspective. It argues that a context of state capture has characterised Malawi's tobacco industry, originating with colonisation and evolving since to become increasingly entrenched. The analysis is divided into four periods: colonial (1890s-1964); national (1964-1981); liberalisation (1981-2004) and accelerated globalisation (2004 to present). Each period demonstrates how industry interests influenced government institutions and policies in ways that increased dependence on a crop that only benefits a minority of Malawians. Today, a transnational elite prospers at the expense of local growers.

This article explores the relationship between the 2014-2016 Ebola outbreak and the political economy of diamond mining in Kono District, Sierra Leone. The authors argue that foreign companies have recycled colonial strategies of indirect rule to facilitate the illicit flow of resources out of Sierra Leone. Drawing on field research conducted during the outbreak and in its aftermath, they show how this 'indirect rule redux' undermines democratic governance and the development of revenue-generation institutions. Finally, they consider the linkages between indirect rule and the Ebola outbreak, vis-à-vis the consequences of the region's intentionally underdeveloped health care infrastructure and the scaffolding of outbreak containment onto the paramount chieftaincy system.