Changes in the expression of cell surface sialoglycoproteins during transition of human monocytes into macrophages

Cell surface sialoglycoproteins of human mononuclear phagocytes in different maturation stages were labelled by the periodate/borohydride method and separated by SDS-polyacrylamide gel electrophoresis. The main surface glycoproteins of peripheral blood monocytes had molecular masses of 115 and 95 kDa. During in vitro transition into adherent macrophages, the monocyte-characteristic surface glycoproteins disappeared. Most of the changes in the surface glycoprotein pattern occurred during the first 24 h and after 96 h the changes were completed. The major sialoglycoproteins of the macrophage cell surface had molecular masses of 130 and 55 kDa. The macrophage cell surface showed further changes when cultured in the presence of synovial fluid (10%). These results may reflect the in vivo maturation of monocytes into tissue macrophages. In synovium, tissue-derived factors may also take part in differentiation.     

Linear analysis solves two puzzles in population dynamics: the route to extinction and extinction in coloured environments

In this paper, we give simple explanations to two unsolved puzzles that have emerged in recent theoretical studies in population dynamics. First, the tendency of some model populations to go extinct from high population densities, and second, the positive effect of autocorrelated environments on extinction risks for some model populations. Both phenomena are given general explanations by simple, linear, sto-chastic models. We emphasize the predictive and explanatory power of such models.     

Public perceptions of climate change adaptation in Singapore dealing with forecasted sea level rise

Abstract

Perceptions of the populace play a central and decisive role in advancing pro-environmental policies. To study attitudes and perceptions towards environmental measures, we apply several items of New Ecological Paradigm (NEP) and Value-Belief-Norm (VBN) theories to cross-examine the public perceptions of climate change in the urban city-state of Singapore through analysis of quantitative questionnaires and qualitative semi-structured interviews. The perceptions were explored about ecological orientation (two dimensions of NEP: level of concern, self-reported knowledge) and environmental behavior (two dimensions of VBN: acceptance and support of national adaptation measures, confidence in adaptation). There is a moderate to high concern for climate change, in general, and sea level rise and flooding, in particular, and the concern is expected to increase in the future. Individuals who indicated a higher level of concern are likely to be more accepting and supportive of climate change measures. Also, while the majority of the populace are amenable to legislative measures from the government, such as enacting pro-environmental laws and more are agreeable to accepting cuts on living standards, as opposed to paying more in prices and taxes. Ecological orientation does not translate directly into environmental behavior, highlighting the gulf between perception and behavior in Singapore.