120 JOURNAL OF COSMETIC SCIENCE FRONTIERS OF SCIENCE AWARD LECTURE SPONSORED BY COSMETICS AND TOILETRIES® The Enigma of Beauty Jodi Cobb National Geographic Magazine, Washington, DC What exactly is beauty and why are we so obsessed by it? Evolutionary scientists claim that recognition of beauty is an ancient, innate and universal biological means to ensure the survival of the species. They say beauty is an advertisement for your value as a mate, for the quality of your genes. Not everyone agrees. But we all believe we know it when we see it. Standards of attractiveness are surprisingly universal. All cultures value symmetry, clear skin and thick shiny hair-markers of youth, health and fertility. But that's where the fun begins. From the exorbitant hair and makeup of the Huli wigmen of Papua New to the bizarre tradition of footbinding in China, humans have gone to obsessive, humorous and absurd lengths to achieve beauty, or prolong it or fake it. Or exploit it. Jodi Cobb, a staff photographer at National Geographic for over 20 years who has worked in more than 5 5 countries, will take you on a trip around the world and through the looking glass in search of answers to the enigma of beauty.

2003 ANNUAL SCIENTIFIC MEETING EFFEGT OF HAIR COLOR ON LUSTER Karin Keis, Ph.D., Ram Ramaprasad, Ph.D. and Yash Karnath, Ph.D. TRI/Princeton, Princeton, NJ 08542 Introduction The luster of hair is an essential quality for hair beauty. It is an optical phenomenon resulting from the specular reflection of light at the air-cuticle interface. So far many models of light reflection at air-cuticle interface have been described in the literature, however, there is no simple relationship between luster and the light reflected from hair (1-6). The large interest in luster has resulted in a large number of studies on the effect of various cosmetic products on luster and development of variety of methods for measuring it ( 1-12). For natural hair colors, such as blond, brown and black, the luster is the highest for the one with the darkest hue, explained by the low intensity of the diffusely scattered light, while the intensity of the specularly reflected light remains the same. In this work, the interest is in the instrumental evaluation of luster of hair dyed with different colors and depths of shade, to demonstrate the effect of artificial color on luster. Also, we make an attempt to study the effect of hair color on subjective evaluation of luster. Materials and Methods The naturally unpigmented Piedmont hair was dyed for 5, 20 and 45 minutes with commercially available semipermanent dyes. The colors were chosen to cover the extremes and middle of the visible spectrum. Also, the pure single-component dyes were used to saturate Piedmont hair fibers by dyeing under specific conditions. Using a UltraScan XE spectrophotometer equipped with integrating sphere, the total reflectance spectra and CIELAB color parameters were obtained. From measured L •, a• and b• parameters the changes in chroma, total color, lightness and hue were calculated. Luster was measured by using a modified Brice-Phoenix goniophotometer (GP) to record the intensity of scattered light as a function of angle. Measurements were carried out on 30 randomly chosen single hair fibers, for each color and dyeing time. He-Ne laser with a wavelength of 632 nm and white light from the Quartz Tungsten Halogen lamp was used as light sources. The dye penetration profiles on cross-sections of hair fibers were examined by optical microscope. Results and Discussion The largest change in reflectance curves was found to occur between 0 and 5 minutes of dyeing time. Thereafter the decrease in total reflectance is small indicating that additional dye uptake is small. Correspondingly, most change in luster occurred between 0 and 5 minutes dyeing time (see Figure 1). Even though the dye penetrates the fiber completely during 45 minutes, the dye concentration in cuticular sheath is much higher compared to fiber interior. The low color uptake is related to weak polar and van der Waals interactions of semipermanent dyes with hair. Red (sp) Green (sp) L----===�-r Blue (sp) 12 ------------------ - - 20 30 ◄O Dyeing time (min) Figure I. Luster for various dyeing times for different semipermanent colors (illumination A.=632 run). 121