New tools for epidemiology: a space odyssey

Geographical Information Systems (GIS) facilitate access to epidemiological data through visualization and may be consulted for the development of mathematical models and analysis by spatial statistics. Variables such as land-cover, land-use, elevations, surface temperatures, rainfall etc. emanating from earth-observing satellites, complement GIS as this information allows the analysis of disease distribution based on environmental characteristics. The strength of this approach issues from the specific environmental requirements of those causative infectious agents, which depend on intermediate hosts for their transmission. The distribution of these diseases is restricted, both by the environmental requirements of their intermediate hosts/vectors and by the ambient temperature inside these hosts, which effectively govern the speed of maturation of the parasite. This paper discusses the current capabilities with regard to satellite data collection in terms of resolution (spatial, temporal and spectral) of the sensor instruments on board drawing attention to the utility of computer-based models of the Earth for epidemiological research. Virtual globes, available from Google and other commercial firms, are superior to conventional maps as they do not only show geographical and man-made features, but also allow instant import of data-sets of specific interest, e.g. environmental parameters, demographic information etc., from the Internet

Physical Chemistry of Milk Fat Globules

Many properties of milk and dairy products are determined by the behaviour and physical chemistry of milk fat globules. Allowed to stand, raw milk quickly separates into fat-enriched and fat-depleted phases, i.e. cream and skim milk, respectively. This is partly due to simple density differences between the emulsified fat globules and milk serum, but gravitational separation occurs at a rate ultimately determined by a complex series of colloidal interactions mediated by the milk fat globule membrane (MFGM) that lead to aggregation of fat globules, particularly at low temperatures (i.e. so-called cold agglutination). Creaming properties of milk differ between mammalian species, and processing of milk can profoundly alter the creaming properties of bovine milk, particularly homogenization and centrifugal separation, but also heat treatment. In this chapter, the principal physical properties of bovine milk fat globules are discussed, along with methods for their analysis and the impact of common dairy processes on their stability