Thesis (Ph. D.)--Columbia university, 1921. / Vita. "Reprinted from Journal of American leather chemists association, February, March, April, May, 1921." Bibliography: p. 74-76. Also available in digital form on the Internet Archive Web site.

No description available.

Streptomyces fradiae is a bacterium which has been previously found to produce extracellular enzymes which are capable of wool degradation and skin depilation. Streptomyces fradiae 3739 and other strains of Streptomyces were found in this study to be able to degrade a keratin source (wool) to a considerable degree. However according to the evidence of SEM micrographs presented here the highly keratinised spindle cells of the paracortex are fairly resistant to protease attack, and it is the cementation material which binds these cells together which is initially degraded by the proteases. A large degree of correlation was found with the strains of Streptomyces studied, between the ability of the individual strains to degrade wool and the ability of their extracellular proteases to reduce the depilation load of sheepskins. With further analysis S. fradiae 3739 was found to produce at least one amylase and four or more proteases. The proteases as a group had maximal proteolytic activity in the 8.0-9.0 pH unit range, and were considerably thermostabilised by the inclusion of calcium ions into the reaction solution. The protease group was found to cause depilation of merino sheepskins. For comparative purposes a protease produced by a strain of Proteus vulgaris isolated from a staling hide with hair slip (natural depilation) was studied. The protease activity was maximal in the alkaline region between 8.0-9.0 pH units. Tbe protease appeared to be a single enzyme with a molecular mass of approximately 44 000 daltons. The protease was maximally active at 40°C, although it was only thermostable to 30°C. The enzyme was ineffectual as a depilant except when the skin was pre-treated with a strong alkali, preferably including sodium sulphite in the protease preparation. One of the most important differences between the extracellular proteases of S. fradiae and P. vulgaris was that the former were greater in variety and caused a greater decrease in the depilation load of sheepskins than the latter. Further research with mixtures of commercial proteases provided evidence that a synergistic depilatory effect occurs when proteases of complementary bond specificities are used in conjunction in enzymic depilatory preparations. Some form of strong alkali treatment of skins was found to be necessary to produce leather of the prerequisite quality when the skin was depilated by proteases, otherwise the skin was found to be depleted and stiff. Calcium hydroxide alone was found to be inadequate for this task, probably owing to the fact that it is less alkaline than the lime-sulphide mixture. The calcium hydroxide (lime) must therefore be used in conjunction with sodium hydroxide (which makes the solution as alkaline as that of the lime-sulphide solution) to produce leather comparable to that produced by the lime sulphide treatment. A combination of the information provided by the present research and that gleaned from the relevent literature allows for the construction of a model to represent the possible mechanism of enzymic depilation of skins, in which depilation is caused by the disruption of the basement membrane at the dermal-epidermal junction by the degradation of its constituent molecular components by general proteases, resulting in the removal of the epidermis and its associated wool or hair

Various oxygen- and nitrogen-donor ligands were investigated as potential zirconium masking agents in zirconium tanning. α-Hydroxycarboxylic acid ligands were identified as effective zirconium(IV) chelators in acidic aqueous solution. Glycolic acid, lactic acid, mandelic acid, 4-hydroxymandelic acid, 4-chloromandelic acid and 4-bromomandelic acid complexes were synthesised, isolated and characterised using a range of analytical techniques. Linear Free Energy Relationships were examined to optimise the stability of the zirconium complexes. Hammett [sigma] plots and Yukawa-Tsuno modified σ plots of the mandelate ligand and zirconium complex series indicated that inductive effects dominate within the benzene ring, however, mesomeric effects are significant outside the ring. Zirconium 4-hydroxymandelate complex solutions were identified as the most effective tanning agents and achieved shrinkage temperatures of 80 and 97ºC for hide powder and goatskin, respectively. The zirconium and 4-hydroxymandelic acid interact synergistically to yield leather equivalent to combination tanned leather in one step. Tanning was performed similarly to vegetable tanning processes with a pickle pH of approximately 5 and fixation was achieved upon acidification. Pilot-scale tanning of goatskin produced white tanned leathers and crust leathers which were physically and aesthetically comparable to matched chromium tanned material.

No description available.

No description available.

Tanning bed use, especially among young, white females, has become a serious health problem in the United States. Those who use tanning beds value a tanned appearance; thus, one possible way to get individuals to stop using tanning beds is to persuade them to begin using an alternative method: a sunless tanner. This study sought to use persuasive messages to encourage individuals to both stop using tanning beds and start using a sunless tanner. Deviance Regulation Theory (DRT) was used to design three messages, and source expertise was manipulated (high and low). In addition, attitudes, perceived norms, benefits and threats about tanning were examined. Results indicate that the combination of DRT message design and source expertise produced several message conditions that were effective at decreasing tanning bed use intent. No combined message condition was effective at changing sunless tanner use intent. DRT message design alone did not produce results, nor did source expertise. Tanning attitudes were influenced by reference groups, and perceived norms about tanning predicted individual‘s tanning bed use for several reference groups. In addition, there was an interaction between benefits and threats of tanning.

Tanning bed use, especially among young, white females, has become a serious health problem in the United States. Those who use tanning beds value a tanned appearance; thus, one possible way to get individuals to stop using tanning beds is to persuade them to begin using an alternative method: a sunless tanner. This study sought to use persuasive messages to encourage individuals to both stop using tanning beds and start using a sunless tanner. Deviance Regulation Theory (DRT) was used to design three messages, and source expertise was manipulated (high and low). In addition, attitudes, perceived norms, benefits and threats about tanning were examined. Results indicate that the combination of DRT message design and source expertise produced several message conditions that were effective at decreasing tanning bed use intent. No combined message condition was effective at changing sunless tanner use intent. DRT message design alone did not produce results, nor did source expertise. Tanning attitudes were influenced by reference groups, and perceived norms about tanning predicted individual‘s tanning bed use for several reference groups. In addition, there was an interaction between benefits and threats of tanning.

Thesis (Ph. D.)--Columbia University, 1928. / Vita. "Reprinted from the Journal of the American leather chemists association, January, 1927."

AN ABSTRACT OF THE DISSERTATION OF DIANE M. LAND, for the Doctor of Philosophy degree in Health Education, presented on December 3, 2014, at Southern Illinois University Carbondale. TITLE: PSYCHOSOCIAL PREDICTORS OF HIGH SCHOOL ADOLESCENTS' SUN-TANNING AND SUN-PROTECTIVE BEHAVIORS MAJOR PROFESSOR: Dr. Roberta Ogletree Background: The incidence of skin cancer among adolescents and young adults is increasing in the United States (American Cancer Society, 2014). Ultraviolet radiation (UVR) exposure via sun-tanning is considered an important risk factor for development of melanoma. Sun-induced skin damage and sun-tanning habits are initiated in early life and promoted through later sun exposure patterns. Social norms, appearance attitudes, and perceptions of fitness and health attributed to sun-tanned skin and tanning bed usage have been established. The primary aim of this study was to investigate high school adolescents' sun-related attitudes and behaviors through a theoretical framework of psychosocial constructs grounded primarily in Bandura's (1986) Social Cognitive Theory. Assessing the differences in predictors of adolescents' UVR sun-tanning and sun-protective behaviors (including sunless tanning) has the potential to aid in developing age-appropriate strategies to prevent the adoption of sun-tanning habits and reinforce more health enhancing behaviors. Methods: This research study utilized a quantitative, cross-sectional, descriptive research design to assess the attitudes, motivations, and behaviors regarding sun-tanning and sun-protective practices of high school adolescents in rural Southern Illinois. A purposeful sample of 9 - 12th grade students (n = 900) enrolled in physical education class during the fall 2014 semester were invited to complete a self-report paper and pencil survey consisting of 56 Likert-type items and five demographic variables. Results: A total of 156 adolescents received parental permission and completed the survey, providing a 17.3% response rate. Intentional sun-tanning (UVR exposure) continues to be prevalent. Study participants reported sun-tanning more often and had a higher number of sunburns within the past twelve months that in previous national studies. Participants from low socio-economic status (SES) were more likely to outdoor suntan and use sunless tanning lotions, gels or creams than their not low SES counterparts. For sun-tanning behaviors, a significant amount of the variance in mean sun-risk behavior score was explained by the constructs situation, outcome expectations, and value expectancies. Situation, outcome expectations, value expectancies, and self-efficacy were all predictive of outdoor sun-tanning; whereas only outcome expectations were predictive of indoor sun-tanning. Self-efficacy explained a significant proportion of variance in sun-protective behavior mean score. Outcome expectations were predictive of both sunless tanning with lotions, creams or gels and spray tanning product use. Sunless tanning appears to be used as both an additive behavior for those reporting the highest frequency of indoor tanning and a substitution behavior for adolescents who reported never indoor tanning.