Maria Claudia Curadi

Capillary electrophoresis of sialylated oligosaccharides in milk from different species

Oligosaccharides are relevant components of human milk, which have been quite well studied for their pre-biotic effect and their capacity in stimulating the immune system. Since oligosaccharides from milk of non-human mammals received so far less attention, the aim of this work was the application of capillary electrophoresis (CE) for the analysis of sialylated oligosaccharides in cow, goat and equine (mare and donkey) milk to possibly identify potential sources of oligosaccharides to use as health promoting ingredients in functional foods. Human milk was used as reference milk. A recent CE technique was applied to resolve and quantify 3-sialyllactose (3-SL), 6-sialyllactose (6-SL) and disialyl-lacto-N-tetraose (DSLNT). Analysis of non-human milk samples confirmed differences among species and individuals: DSLNT, which was the most abundant compound in human milk (455-805μg/mL) was missing in most of the samples. In most cases, 3-SL showed to be the most concentrated of the quantified analytes, with values ranging from 12 to 77μg/mL.

Latent variable models on performance tests in guide dogs. 1. Factor analysis

Abstract The research has been conducted on behavioural test results obtained from 143 dogs of pedigreed stock reared in the National Guide Dog School (SNCG) of Scandicci (Firenze, Italy), consisting mostly of Labradors and Golden Retrievers, but also including German Shepherds. All dogs have been reared under quite uniform conditions and tested individually under similar conditions. The results following the 11 administered subtests, [that constitute variables in our analysis], were expressed in scores ranging from 1 to 5 and used after calculation of the rank averaged scores. The analysis of the Pearson and partial correlations between the variables points out a clean distinction in two groups. The first consists of variables related to characters of sociability and to relationship with the handler, with expression of dominance/submissiveness and the second to characters of reaction to external stimuli with expressions of fearfulness/curiosity. Results of factor analysis led us to reject the one factor model and accept a model with two factors, in which: 1) Factor I identifies variables of the group tied to the fearfulness/curiosity; 2) Factor II identifies the variables of the group tied to sociability and to relationship with the handler. The two factors are correlated, indicating the presence of some non negligible, indirect effects. One out of the eleven variables has not shown important evidence of contribution to any of the factors.