Learning from multimedia and hypermedia

Computer-based multimedia and hypermedia resources (e.g., the world wide web) have become one of the primary sources of academic information for a majority of pupils and students. In line with this expansion in the field of education, the scientific study of learning from multimedia and hypermedia has become a very active field of research. In this chapter we provide a short overview with regard to research on learning with multimedia and hypermedia. In two review sections, we describe the educational benefits of multiple representations and of learner control, as these are the two defining characteristics of hypermedia. In a third review section we describe recent scientific trends in the field of multimedia/hypermedia learning. In all three review sections we will point to relevant European work on multimedia/hypermedia carried out within the last 5 years, and often carried out within the Kaleidoscope Network of Excellence. According to the interdisciplinary nature of the field this work might come not only from psychology, but also from technology or pedagogy. Comparing the different research activities on multimedia and hypermedia that have dominated the international scientific discourse in the last decade reveals some important differences. Most important, a gap seems to exist between researchers mainly interested in a “serious” educational use of multimedia/ hypermedia and researchers mainly interested in “serious” experimental research on learning with multimedia/hypermedia. Recent discussions about the pros and cons of “design-based research” or “use-inspired basic research” can be seen as a direct consequence of an increasing awareness of the tensions within these two different cultures of research on education

Effects of linseed meal and whole linseed and supplemental α-tocopherol acetate on broiler growth performance, and tissue C18:2n-6, C18:3n-3 and TBARS content

It is recognised that n-3 polyunsaturated fatty acids (PUFA) are important components of a healthy human diet. There is, therefore, considerable interest in manipulating animal tissue fatty acid composition to enhance n-3 PUFA intakes. Linseed is a rich source of the n-3 fatty acid, linolenic acid (C18:3n-3). When whole linseed (WL) is included in poultry diets this fatty acid can be incorporated into tissue lipids and may also serve as a precursor for the synthesis of longer chain C20 and C22 n-3 PUFA in chicken tissues. To counteract the increased susceptibility of PUFA-enriched tissues to peroxidation, α-tocopherol acetate (ATA) supplementation of the diet may be required. In this study the effect of WL and supplementary ATA on broiler growth performance and leg and breast muscle fatty acid profiles and lipid peroxidation were studied</jats:p

Effects of linseed meal and whole linseed and supplemental α-tocopherol acetate on broiler growth performance, and tissue C18:2n-6, C18:3n-3 and TBARS content

It is recognised that n-3 polyunsaturated fatty acids (PUFA) are important components of a healthy human diet. There is, therefore, considerable interest in manipulating animal tissue fatty acid composition to enhance n-3 PUFA intakes. Linseed is a rich source of the n-3 fatty acid, linolenic acid (C18:3n-3). When whole linseed (WL) is included in poultry diets this fatty acid can be incorporated into tissue lipids and may also serve as a precursor for the synthesis of longer chain C20 and C22 n-3 PUFA in chicken tissues. To counteract the increased susceptibility of PUFA-enriched tissues to peroxidation, α-tocopherol acetate (ATA) supplementation of the diet may be required. In this study the effect of WL and supplementary ATA on broiler growth performance and leg and breast muscle fatty acid profiles and lipid peroxidation were studied</jats:p

Effect of protected methionine supplementation of the diet on the partitioning of dietary nitrogen in the Angora goat

Angora goats are efficient producers of hair fibre. They produce more fibre in relation to their size than sheep(Shelton et al., 1973). In skin and Mohair fibre cystine, which may be synthesised from methionine, is present in relative excess (5-10 times) to the other amino acids, when compared with major protein stores, such as skeletal muscle. Consequently a limitation in the supply of sulphur amino acids, may have disproportionate effects on the amount of nitrogen partitioned to other body tissues. The objective of this study was to investigate the effect of additional rumen protected intestinally available methionine in the diet on the partitioning of nitrogen between mohair and other body tissues in the Angora goat.</jats:p

Effect of biotin on growth, viability and apparent DNA synthesis in cultured secondary hair follicles of the Angora goat

Biotin is a water soluble vitamin which has a well proven function in corboxylation reactions in animal tissues. It is well documented that biotin deficiency in mammals causes pathological changes in the skin and its appendages such as desquamative dermatitis and alopecia. Previous work (Tahmasbi et al 1996) has suggested that deficiency of biotin in the culture medium reduced the viability of wool hair follicles in vitro by mechanisms unknown, but which may involve interference with cell division and or differentiation. The objective of this work was to investigate the effect of biotin deficiency and adequacy on cell proliferation and DNA synthesis as determined by incorporation of [methyl-3H]thymidine in isolated mohair follicles.</jats:p

Conversion of methionine to cysteine by transulphuration in isolated anagen secondary hair follicles of the Angora goat

Enzymes catalysing the conversion of methionine to cysteine via the transulphuration pathway are found in liver and kidney of sheep (Radcliffe and Eggan, 1974), but their presence has not been established in the hair follicle. The aims of this study were (a) to establish the presence of transulphuration and (b) to determine quantitatively the conversion of methionine to cysteine in isolated secondary hair follicles of the Angora goat.</jats:p

Conversion of methionine to cysteine by transulphuration in isolated anagen secondary hair follicles of the Angora goat

Enzymes catalysing the conversion of methionine to cysteine via the transulphuration pathway are found in liver and kidney of sheep (Radcliffe and Eggan, 1974), but their presence has not been established in the hair follicle. The aims of this study were (a) to establish the presence of transulphuration and (b) to determine quantitatively the conversion of methionine to cysteine in isolated secondary hair follicles of the Angora goat.</jats:p