Competitive adsorption of bile salts and milk protein in oil-in-water emulsions

The competitive adsorption of bile salts with milk proteins (whey protein concentrate (WPC) or sodium caseinate (SCN)) was studied in oil-in-water emulsions. The research confirmed previous findings that the degree of displacement of protein depends on the number of hydroxyl groups attached to the sterol ring of the bile salt, but also highlighted the importance of the presence (or absence) and nature of amino acid residues conjugated with the sterol ring. In general, decreasing the number of dihydroxy bile salts such as sodium deoxycholate (NaDC) displaced more protein from the oil droplet surface than trihydroxy bile salts such as sodium cholate (NaC). This is attributed to the greater hydrophobicity of the sterol ring of the NaDC. However, hydrophobicity is not the only factor that determines the ability of the bile salt to displace protein. If sodium taurocholate (NaTC) is used in the competitive adsorption experiments which contains a large charged hydrophilic sulphonate group attached to a taurine residue conjugated to a NaC molecule, the NaTC displaces much more protein from the emulsion droplet surface even though NaTC is less hydrophobic than NaC. A similar effect is seen with sodium glycodeoxycholate (NaGDC) when compared to NaDC. NaGDC is less hydrophobic than NaDC due to the conjugation of a glycine residue, but NaGDC is better at displacing protein from the oil-water interface. This observation is explained in terms of the greater steric hindrance that a conjugated bile salt (NaTC or NaGDC) experiences when it adsorbs to an oil-water interface. The charge amino acid group sits further into the aqueous side of the oil-droplet interface and disrupts the adsorbed protein layer to a greater extent than the non-conjugated bile salts. Another interesting feature of the competitive adsorption was the difference between degree of displacement for the different protein types SCN or WPC. For all bile salts SCN was significantly more resistant to displacement than WPC. The reason for this is not clear but may be due to either the greater surface activity of caseins, or to binding of bile salts to WPC or SCN proteins. To investigate further the adsorption of bile salt in emulsions the surface coverage of the bile salts was determined. Results indicated that NaC adsorb as a monomer over much of the concentration range used, whilst the other three bile salts adsorbed as micelles. The consequences of this for competitive displacement of protein are discussed. Finally, preliminary experiments were carried out to elucidate the effect of NaC concentration on lipase catalysed hydrolysis of the triglycerides in the emulsion droplets. The release of free fatty acids is observed to increase with increasing NaC concentration in the emulsion. This is discussed in relation to the effect of NaC on the WPC and SCN protein concentration at the droplet surface, and the likely effect of NaC micelles on the rate of lipase activit

Restructuring Seconday Social Studies: Results of the Humanities Project at Greece Athena High School

From Problem: A widely held belief is that American students are not learning enough to compete in today\u27s world. This belief was enhanced in April of 1983, when the report A Nation at Risk was released by the National Commission on Excellence in Education. The results caught much of the United States off guard. One quote from the report said the educational foundations of our society are presently being eroded by a rising mediocrity that threatens our very future as a Nation and a people. (p. 1) The alarm is still ringing, because results of recent studies are not showing significant improvements. One such report came from the Digest of Education Statistics in 1992 which compared S.A.T. scores. The average scores for 1980-81 were 424 in Verbal and 466 in Math. The scores for 1990-91 were 422 in Verbal and 474 in Math. (cited in Wilk From risk 1993) Recent findings also show a lack of knowledge in the field of Social Studies. In September 1987, researchers Diane Ravitch and Chester Finn reported, American 17 year-olds display a \u27shameful\u27 knowledge of U.S. history and literature (cited in Wilk, From risk 1993, p. S9) In January of 1989, The Joint Council on Economic Education reported, American students have a weak grasp of basic economic concepts (cited in Wilk, From risk 1993, p. S9) The National Assessment of Educational Progress announced in February of 1990, high school seniors had critical shortcomings in geography. (cited in Wilk, From risk 1993) Another report from the National Assessment of Educational Progress, two months later, revealed U.S. students only showed a limited understanding of important concepts in U.S. history. (cited in Wilk, From risk 1993) These studies and others that show similar results, have led to a call for change in Social Studies instruction and the structure of American schools in general

Friends with Benefits: Other Regard in Epicurean Ethics

Friendship and hedonism are both major components of Epicureanism. I attempt to relieve the tension that seems to follow from endorsing both of these. I argue that Epicurean friendships require valuing a friend’s well-being in the same way as one’s own and that embarking on such friendships is what David Schmidtz terms a maieutic end – one that is achieved by taking on a new set of ends. This conception fits with other-regarding concern that is espoused throughout the Epicurean texts discussing friendship and, as I argue, remains consistent with other psychological and ethical commitments of Epicureanism

The development of an ideal-type model of the coaching process and an exploratory investigation into the appropriateness of the model for coaches in three sports

The initial aim of the project was to devise and present an innovative model of the sports coaching process and to conduct an exploratory investigation into its aptness an an analytical tool for developing a more explicit understanding of the behaviour of coaches. Supported by the author's considerable experience as a coach and in working with senior, experienced coaches, and an analysis and evaluation of relevant literature, a logico-deductive methodology is employed to construct an ideal-type model of the coaching process. The model is conceptualised as a continuous cyclical coil, consisting of preparation and competition units, radiating around central goals and monitored via a potential performance constant. The coil represents a direct intervention core surrounded by indirect responsibilities and the external environment. The assumptions and key concepts around which the process is devised as described and the stages of the model explored in two-dimensional flow diagrams. The factors which constrain the application of the model are identified. A panel of thirty experienced, senior coaches was invited to respond to the model. Following an analysis of the data generated from the panel of coaches, it is clear that the ideal-type model fails to offer an adequate basis for an understanding of the full-range of the coaches' behaviour. To this extent the model had a limited utility as a 'model of' the coaching process. The aims of the project were revised in order to attempt to account for the unanticipated findings. The work of Schon (1983) is employed to provide a theoretical framework which offers a more useful interpretation of the research findings. The study concludes that the ideal-type model does not provide an adequate understanding of the behaviour of the panel of coaches employed in the study, but that proposals for further research which build constructively on the systematic framework offered by the model and incorporate Schon's incrementalist approach to professional practice, offer considerable promise for the future

Principles of Physics II (GA Southern)

This Grants Collection for Principles of Physics II was created under a Round Twelve ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/physics-collections/1009/thumbnail.jp

Arduino Lab Assignments for Principles of Physics II

This set of two Arduino assignments for Principles of Physics II includes an introductory assignment in exploring the Arduino\u27s capabilities, followed by a lab assignment on data collection using the Arduino. These assignments were created as part of a Round Twelve Textbook Transformation Grant for Principles of Physics II

Principles of Physics I (GA Southern)

This Grants Collection for Principles of Physics I was created under a Round Ten ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/physics-collections/1008/thumbnail.jp