Characterization of presenilin-amyloid precursor interaction using bacterial expression and two-hybrid systems for human membrane proteins

An Escherichia coli system was used to produce the human membrane proteins presenilin 1 and amyloid precursor protein and to analyse their interaction. Our data indicate that the main binding site for amyloid precursor protein is located in the N-terminal three-transmembrane segments of presenilin and not in the proposed active site containing the two conserved aspartate residues. The data also suggest the presence of an additional segment of sufficient hydrophobicity at the C-terminus of PS1 to act potentially as a transmembrane segment. The implications of these findings for the function of γ-secretase are discussed.     

Land tenure and transfer in Chimbu,Papua New Guinea: 1958–1984—A study in continuity and change,accommodation and opportunism

A long-term study of land tenure, land transfer, and succession in one subclan of the Chimbu in the Papua New Guinea highlands takes up the relations between the agricultural cycle, family, and population growth in a period of rapid commercialization and cash cropping. Over a generation, land was held and allocated within families, among families within the subclan, and to kin and affines in neighboring groups. The land tenure, ownership, and use system allows for a very great deal of individual movement and land gifts, temporary or long-term, by land owner to kin and friends. Despite an agnatic ideology, individuals and local groups opportunistically accommodate to land needs. As cultivation becomes more intensive and semi-permanent, there appears to be a progression from fluidity of land rights in the clan or subclan to anchoring of rights and boundaries to individuals and families. It is suggested that this characterizes Chimbu land tenure; it is not a postcolonial phenomenon.     

Tono Reservoir fishery contribution to poverty reduction among fishers in northern Ghana

Fishery characteristics and livelihood status of fishers at Tono Reservoir, Ghana, were investigated between January 2015 and June 2016. Data on fisher demography, fishing gears, fishing methods, perceptions of the state of fish stocks, management practices, income and consumption of fishers were obtained through structured interviews. Censuses of fishers and fishing gears were conducted through direct observation and counts. The population of fishers was 950 and the majority (74%) of the sampled respondents fell within the ages of 24–41 years. Gillnet, cast net, trap and hook and line were the four main gears utilised. Illegal methods of fishing observed included the use of mosquito nets (nets with mesh <1.0 cm) and the use of brewer’s waste (pito mash) as bait. Brycinus nurse, Synodontis spp., Parailia spiniserrata and Chrysichthys spp. were perceived to have disappeared from the reservoir. The fishers were unaware of the existence of any fisheries regulations, hence there was no adherence to management practices. Their daily income was derived mainly from fishing. The incidence of poverty among fishers was low (8%). The Tono Reservoir has a great potential for supporting livelihood if it is properly managed.     

Colour development of immunogold-labelled antibodies for light microscopy

Summary We describe an improvement of the immunogold technique, which is based on the colour development of silver-intensified immunogold signals. This method (referred to as the coloured-SIG technique) was found to be as sensitive as the silver-intensified immunogold method and more sensitive (in two of the three tested systems) than immunoenzymatic procedures, such as the peroxidase/antiperoxidase technique or the avidin-biotin system. The coloured SIG-method results in either a magneta-red or a cyan-blue final reaction product. Therefore, this new improvement of the immunogold technique should be useful in (1) double-staining methods, (2) immunoblot methods and (3) conventional immunostaining methods.Supported by the Robert-Bosch-Foundation, Stuttgart