EVALUATION OF UV HAIR DAMAGE BY AFM 281 AFM was also successfully employed to investigate the changes in hair surface roughness when hair fibers undergo long-term exposure to UV radiation. By means of the Student t-test, it was possible to prove statistically that the AFM parameters of roughness and surface distance developed in this work, and cuticle thickness, are able to discriminate the two sets of samples--a set of unexposed hair samples and a set of damaged hair samples. ACKNOWLEDGMENTS The authors acknowledge the Brazilian funding support agencies CNPq, RHAE, and FAPESP. REFERENCES (1) E. Tolgyesi, Weathering of hair, Cosmet. Toilerr., 98, 29-33 (1983). (2) E. Hoting et aL, Photochemical alterations in human hair. I. Artificial irradiation and investigation of hair proteins, J. Soc. Cosmet. Chem., 46, 85-99 (1995). (3) S. Ratnapandian, Photodegradation of Human Hair, M.S. Thesis, University of Massachusetts, Amherst, 1997. (4) C. R. Robbins and M. Bahl, Analysis of hair by electron spectroscopy for chemical analysis, J. Soc. Cosmet. Chem., 35, 379-390 (1984). (5) J. B. Speakman and P. R. McMahon, The action of light on wool and related fibers, N.Z.J. Sci. Tech., 20 (1939). (6) L.J. Wolfram, in Hair Research, Status and Future Aspects, Organos, Montagna, and Sturtgen, Eds., 1981, pp. 479-500. (7) S. Wei, Efficts of Graying Process on Hair Properties, M.S. Thesis, Philadelphia College of Textiles and Science, 1995. (8) S. B. Ruetsch, Y. Kamath, and H. D. Weigmann, Photodegradation of human hair: An SEM study, J. Cosmet. Sci., 51, 103-125 (2000). (9) J. A. Swift and J. R. Smith, Atomic force microscopy of human hair, Scanning, 22, 310-318 (2000). (10) L. H. C. Mattoso, F.C. Ferreira, P.S. P. Herrmann, A.R. Martin, M.A. Pereira-Da-Silva, L.G. Paterno, M. A. Piza, A. A. S. Cuvelo, L. A. Coinago, and F. Denes, Atomic force microscopy as a tool for the evaluation of natural fibers and polymers surface, Fifth International Confirence on Woodfiber- Plastic Composites (Madison, Wisconsin, 1999), pp. 43-56. (11) M. L. Tare, Y. K. Kamath, S. B. Ruetsch, and H.-D. Weigmann, Quantification and prevention of hair damage, J. Soc. Cosmet. Chem., 44, 347-371 (1993).

j. Cosmet. sci., 54, 283-288 (May/June 2003) A comparison of the mosquito-repelling efficacy of methyl neodecanamide (IVINDA) to that of Deer THOMAS G. POLEFKA, LI-JUNG LIANG, and TARACAD NARAYANAN ANANTHAKRISHNAN, Co/gate-Palmolive Company, 909 River Road, Piscataway, NJ 08854 (T.G.P., L.L.), and Entomology Research Institute, Loyola College, Madras-600 034, India (T.N.A.). Accepted for publication July i, 2002. Synopsis The objective of this small pilot study was to assess the mosquito-repelling efficacy of methyl neodecana- mide (MNDA) relative to N,N-diethyl-3-methylbenzamide (Deer) against Anopheles stephensi, Culex quin- quefasciatus, and Aedes aegypti under controlled laboratory conditions. In this study, subjects inserted both forearms (sham- and repellent-treated) into a test chamber containing 50 female mosquitoes. The number of mosquitoes landing on or probing each forearm during the 5-minute "forced-choice" test session was recorded each hour for a total of eight hours. Effectiveness was calculated according to Abbott's formula. Experimental results indicate that topical application of 1% MNDA provided significantly better protection and a broader spectrum of repellency than application of 1% Deer against the three species of mosquitoes. These promising results support further study of MNDA as a topical mosquito repellent. INTRODUCTION In some parts of the world, biting insects are nothing more than an annoyance to individuals involved in outdoor activities (1). However, in other parts of the world, mosquitoes and flies represent a major health concern since they are key contributors to the spread of serious diseases such as malaria, filariasis, dengue fever, leishmaniasis, and trypansomiasis (2). Currently, N,N-diethyl-3-methylbenzamide (Deer) is the most effective and widely used topical insect repellent (3). However, excessive application of this popular insect repel- lent by consumers may result in serious adverse health effects, such as disorientation, toxic encephalopathy, insomnia, and irritability (4). Indeed, several cases of death have been reported (5). In spite of these adverse reactions, it is unlikely that Deer will be withdrawn from the marketplace anytime soon. Recently, methyl neodecanamide (MNDA) was shown to be a highly effective cockroach repellent (6,7). Because MNDA and Deer are chemically similar (i.e., both are secondary amides), we decided to assess the mosquito-repelling efficacy of MNDA (relative to Address all correspondence to Thomas G. Polefka. 283