Journal articles: 'Hair characteristics'

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Wyrostek, Anna, Katarzyna Roman, Katarzyna Czyż, Marzena Janczak, and Bożena Patkowska-Sokoła. "Analysis of the hair coat of domestic cats with special focus on histological structure." Roczniki Naukowe Polskiego Towarzystwa Zootechnicznego 13, no. 1 (March 31, 2017): 47–58. http://dx.doi.org/10.5604/01.3001.0013.5309.

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The aim of the study was to characterize the hair coat of domestic cats. The research material consisted of hairs of different fractions collected in winter from female cats with a uniform hair coat colour: white,cream, red, brown and black. The hairs were divided into individual fractions, i.e. underhair, bristle hair and guard hair, and the following characteristics were evaluated: thickness, length, long and short axis length, stress at break and elongation. SEM (scanning electron microscope) images of all types of hair were taken and used to characterize each hair type and to calculate the number of scales per mm of hair length. The content of ions of various chemical elements was determined as well. Underhairs, which accounted for the largest percentage in the coat, were the thinnest and shortest, and had the most regular and distinct scale pattern. Guard hairs were the least numerous, but were the longest and thickest of all hairs examined. Both guard and bristle hairs had irregular scales with jagged edges. The cross-sections of these hairs revealed the presence of all the layers, i.e. the cuticle, cortex and medulla. In the underhair fraction the medulla was observed only in red cats. In all hairs the share of carbon, oxygen and sulphur ions was largest; these are the main omponents of hair protein, i.e. keratin.

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Tintner, Johannes, Jennifer Hatlauf, Heidi Weber, and József Lanszki. "Molecular Recalcitrance of Hair Passing the Digestive System of a Canid." Molecules 25, no. 19 (September 25, 2020): 4404. http://dx.doi.org/10.3390/molecules25194404.

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Hair is an important component in scat that is commonly used for prey analyses in carnivores. Chemically, hair predominately consists of keratin. The recalcitrant fiber protein is degraded in nature only by a few insects and soil microorganisms. Common proteases such as pepsin do not decompose keratin. Infrared spectroscopy was used to detect chemical differences caused by pretreatment and fate of hairs. Three sample sets were compared: original untreated hair, original milled hair, and hairs extracted from scats of golden jackals (Canis aureus L.). The results revealed that only milling affected the infrared spectral pattern, whereas digestion had no impact. Moreover, hairs from different species (e.g., boar) could be distinguished due to their spectral characteristics. They did not change through the passage of the digestive system.

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Takahashi, Toshie. "Unique Hair Properties that Emerge from Combinations of Multiple Races." Cosmetics 6, no. 2 (June 21, 2019): 36. http://dx.doi.org/10.3390/cosmetics6020036.

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The fusion of ethnicity in human populations is becoming increasingly common, so the conventional definition of ethnicity is going to become deficient. The aim of this study was to investigate the hair properties which emerge from combinations of multiple races. Hair fibers collected from mixed-race subjects were investigated and classifications of hair shape as well as measurements of thickness, ellipticity and surface damage were carried out. The results show that hair shapes varied widely: straight hair and very curly hair often existed together on the heads of individuals with mixed ethnicity. Curly hair tended to be thicker than loose wavy hair. As for damage to the hair surface, the hairs of mixed-race subjects showed a very unique property in that they were much more severely damaged near the root (the proximal end) than the hairs of monoracial subjects. The hair shape (curly or loose wavy) was not related to the level of damage. The severe damage near the proximal end is thought to be caused by entanglement, due to the presence of various curl phases. This study reports the unique characteristics of hairs of subjects with mixed ethnicity, which have never been noted in the previous studies on subjects with a monoracial background.

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Thozhur, S. M., A. D. Crocombe, P. A. Smith, K. Cowley, and M. Mullier. "Cutting characteristics of beard hair." Journal of Materials Science 42, no. 20 (January 4, 2007): 8725–37. http://dx.doi.org/10.1007/s10853-006-1338-3.

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Zhang, Yi, Qiu Ting Zheng, Xiao Qing Wang, and Hua Wu Liu. "Structure Structural Characteristics of Rabbit Hair." Advanced Materials Research 332-334 (September 2011): 1073–76. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.1073.

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Key morphological features of rabbit hair were investigated and compared with these of cashmere fiber. When the rabbit fiber diameter was about 10um, the angle of scale edge to the fiber axis was small. When the fiber diameter was around 40um, scale edges inclined larger angles to the axis. In addition, no overlapping and checks along the scale edges were observed in such coarse hair. The rabbit fiber diameters were normally between 10um and 20um and the scales of these fibers were long strip shaped with sharp tip at the middle. There was obvious boundary in the cashmere fiber after dyeing. One side is far darker than the other. On the contrast, this bilateral structure was not observed in the rabbit hair samples. The cortical cells presented in an uneven distribution in the rabbit hair. The mean ratio of medulla (filled with plenty of air) to fiber diameter was about 40%, which provide excellent thermal insulation to the rabbit hair assemblies.

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Yates, B. C. "Utility Of Secondary Guard Hairs In Animal Hair Identification." Microscopy and Microanalysis 5, S2 (August 1999): 1344–45. http://dx.doi.org/10.1017/s1431927600020043.

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Variability among hairs of humans is dependent on body source and ethnicity. Variability in the hairs of non-human mammals is also dependent on somatic source, but may exhibit a wide range of characteristics among hairs from any given site. Humans do not have secondary guard hairs as defined below, but forensic scientists involved in trace analysis must recognize a different suite of variability that exists when examining animal hairs. Hairs other than primary guard hairs from the dorsum, which are often the only representative hairs illustrated in animal hair atlases, may be present as trace evidence in a forensic case in which the origin of the hair is unknown. An overview of the different grades of animal hair that could be present in a forensic case or natural history inquiry places the secondary, tertiary, etc. guard hairs in a continuum that is based on relative diameters.

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Charpin, D. A., V. Penel, C. Charpin-Kadouch, C. Pichot, and M. Calleja. "Recovery Of Pollen From Hair Washes According To Hair Characteristics." Journal of Allergy and Clinical Immunology 125, no. 2 (February 2010): AB19. http://dx.doi.org/10.1016/j.jaci.2009.12.106.

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Ito, M., T. Tazawa, K. Ito, N. Shimizu, K. Katsuumi, and Y. Sato. "Immunological characteristics and histological distribution of human hair fibrous proteins studied with anti-hair keratin monoclonal antibodies HKN-2, HKN-4, and HKN-6." Journal of Histochemistry & Cytochemistry 34, no. 2 (February 1986): 269–75. http://dx.doi.org/10.1177/34.2.2418103.

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By use of a mouse hybridoma technique, monoclonal antibodies were produced against hair fibrous proteins, which were extracted from normal human hairs. Three monoclonal antibodies, designated as HKN-2, HKN-4, and HKN-6, were chosen and used to investigate the immunological characteristics of hair fibrous proteins. Epidermal fibrous proteins were also extracted from human sole callus horny materials. Hair or epidermal fibrous proteins were electrophoretically separated on polyacrylamide gels with sodium dodecyl sulfate. By immunoblot analyses, HKN-2 and HKN-4 marked the electrophoretic bands of both proteins; however, HKN-6 reacted only with the bands of hair fibrous proteins. Immunohistochemically, all three monoclonal antibodies stained the keratogenous zone of anagen hairs. HKN-6 did not react with any other skin components or with tissues of other organs examined. Although HKN-2 showed reactions with skin epithelial tissues, except for epidermal basal cells and secretory cells of sweat glands, the reactivity of HKN-2 was limited within the skin. HKN-4 displayed a broad crossreactivity with all of the skin epithelial cells and various epithelial cells of other organs. These findings indicate that some components of hair fibrous proteins are immunologically specific to hair cells, whereas others broadly crossreacted with the fibrous proteins of other skin epithelial cells or with those of various epithelial cells. The anti-hair keratin monoclonal antibodies seem useful to examine the differentiation patterns of epithelial cells and tissues.

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Kamalakannan, Manokaran. "The identification of Takin Budorcas taxicolor (Mammalia: Bovidae) through dorsal guard hair." Journal of Threatened Taxa 10, no. 15 (December 26, 2018): 13014–16. http://dx.doi.org/10.11609/jott.3357.10.15.13014-13016.

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The dorsal guard hairs of Takin Budorcas taxicolor was examined using the optical light and scanning electron microscopes for species identification. It is found that the dorsal guard hair of B. taxicolor is possessed a completely unique microscopic characteristic especially the medullary character-uniserial ladder structure, which differs from other species of mammals. The ‘irregular wave’ of scale patterns and ‘rippled’ scale margins of cuticular, and the ‘circular’ shape of a transverse section of hair also determines the species identity of B. taxicolor, because these characteristics are infrequent in other species of mammals. The micro-photographs and characters of hairs are presented here can be used in the forensic science, as an appropriate reference for species identification of B. taxicolor.

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Cuyler, Christine, and Nils A. Øritsland. "Do seasonal changes in Svalbard reindeer fur have relevance for heat transfer?" Rangifer 22, no. 2 (March 1, 2002): 133. http://dx.doi.org/10.7557/2.22.2.1532.

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Physical characteristics of Svalbard reindeer (Rangifer tarandus platyrhynchus) fur samples were examined with respect to season. A total of 33 dorsal fur sections including adults and calves were investigated. A direct relationship between hair density and heat transfer was not observed, and optimal hair density may depend on an interaction with other fur characteristics. Seasonal changes in fur length and depth were inversely proportional to, and appear to be the main determinants of, seasonal changes in calm air conductance. Fur length and depth, however did not explain the exceptional wind resistance of Svalbard reindeer fur. Since wind has little effect on heat transfer through Svalbard reindeer fur regardless of season or animal age, fur characteristics, which change are not likely critical. Instead, constant physical characteristics, which trap still-air within the fur and resist wind compaction and penetration, are probably responsible. These could include hair stiffness, the crimped wave, hollow hairs, intertwining distal tips and the fine wool fuzz about the hair roots. The extent and means are not well understood at present.

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Wittmann, Christiane, Barbara Kelsch, Franziska Reßing, and Hardy Pfanz. "Can stress turn trees hair white? Hair covering of stems improves resilience of corticular photosynthesis against heat-stress." Theoretical and Experimental Plant Physiology 33, no. 2 (April 13, 2021): 157–72. http://dx.doi.org/10.1007/s40626-021-00201-5.

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AbstractThe hypothesis was tested that hair covering of stems improves resilience of corticular photosynthesis against heat stress. Hairy and non-hairy outer bark of Quercus ilex L. and Quercus robur L. trees was removed and optical properties measured. Additionally, structural bark traits and chlorophyll fluorescence parameters during heat stress treatment were studied. Optical analysis revealed a protective role of hairy outer bark (OB) against overheating of the underlying cortex of the stems. Hairiness decreased OB transmittance and increased thermal insulation of stems by an increased absorptance and reflectance of OB in the visible (380–720 nm) and an increased reflectance in the infrared part of the spectrum (720–900 nm). Simple linear regression analysis revealed no significant effect of stem structural traits (OB thickness (OBT), cortex density (Dcortex), cortex water content (Wcortex)) on corticular photochemistry (PScort), while optical traits of outer bark were significantly (P < 0.01) correlated with PScort. OB reflectance explained up to 91% of the variation in PSII quantum yield under heat stress. At high temperatures (> 45 °C) PScort of the hairy species showed a higher resilience and a better post-stress-recovery as compared to the non-hairy one. It is concluded that stem hairs play a physiologically significant role in modulating the stem energy balance due to a close interaction between optical characteristics of hairy OB and stem photochemical processes.

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Pikhtirova, A. V., V. D. Ivchenko, and O. I. Shkromada. "Characteristics of the microscopic hair structure of domestic mammals from Equidae family." Ukrainian Journal of Veterinary and Agricultural Sciences 2, no. 2 (December 3, 2019): 31–36. http://dx.doi.org/10.32718/10.32718/ujvas2-2.07.

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Hair is an indispensable component of the animal body. Having structural features of the structure, it allows you likely to identify the type and age of animals, conditions of keeping animals, feeding and even sex. Paleontologist's findings prove, the hairline stores the undisputed information on its “owner” for thousands of years. According to the results of the conducted research it is established, that the hair coat of the studied animal species – Equinus asinus and Equus caballus – has significant differences in the structure of the brain substance and superficial drawing of the cuticle. Microscopic examination of discolored samples of animal hair well-recognizes the structure of the brain substance, which makes it possible to differentiate the species of animal. The brain substance in the donkey mane hair occupies most of the hair, is represented by densely grouped cells, sometimes interrupted, whereas in the horse mane hair, it has the appearance of grouped rounded cells with small intervals between sections of 6–10 cells. The brain substance of the donkey covering hair is represented by cells of different size and shape, which disappear from the middle of the hair to the peripheral end. This tendency is also typical for the brain substance of the horse covering hair, but unlike donkey hair – cells of the same size, begin with a continuous cord at a distance of 1–1.5 mm from the root of the hair, towards the peripheral end of the hair the gaps between them increase to the complete disappearance of cells. Ultramicroscopic examination of the cuticle superficial drawing of hair samples allowed to establish the peculiarities of two species of the same animal genus. The donkey and horse mane hair had almost the same thickness, the number of scales (waves) per 100 μm of hair length and the size of the scales (wavelength), however, the overall drawing was significantly different. Superficial drawing of hair cuticle from horse mane represented by irregular waves with sharp pointed edges of scales, instead, the donkey has fringed edges of scales. The horse's covering hair was thicker than the donkey's hair and had differences in the location and shape of the scales. Superficial drawing of covering hair cuticle of donkey represented by a regular wave of scales with clear and even edges, while the scales on the surface of the covering hair of the horse have indistinct torn edges and collected in intermittent (irregular) waves.

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Pikhtirova, A. V., V. D. Ivchenko, and O. I. Shkromada. "Characteristics of the microscopic hair structure of domestic mammals from Equidae family." Ukrainian Journal of Veterinary and Agricultural Sciences 2, no. 2 (December 3, 2019): 31–36. http://dx.doi.org/10.32718/ujvas2-2.07.

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Hair is an indispensable component of the animal body. Having structural features of the structure, it allows you likely to identify the type and age of animals, conditions of keeping animals, feeding and even sex. Paleontologist's findings prove, the hairline stores the undisputed information on its “owner” for thousands of years. According to the results of the conducted research it is established, that the hair coat of the studied animal species – Equinus asinus and Equus caballus – has significant differences in the structure of the brain substance and superficial drawing of the cuticle. Microscopic examination of discolored samples of animal hair well-recognizes the structure of the brain substance, which makes it possible to differentiate the species of animal. The brain substance in the donkey mane hair occupies most of the hair, is represented by densely grouped cells, sometimes interrupted, whereas in the horse mane hair, it has the appearance of grouped rounded cells with small intervals between sections of 6–10 cells. The brain substance of the donkey covering hair is represented by cells of different size and shape, which disappear from the middle of the hair to the peripheral end. This tendency is also typical for the brain substance of the horse covering hair, but unlike donkey hair – cells of the same size, begin with a continuous cord at a distance of 1–1.5 mm from the root of the hair, towards the peripheral end of the hair the gaps between them increase to the complete disappearance of cells. Ultramicroscopic examination of the cuticle superficial drawing of hair samples allowed to establish the peculiarities of two species of the same animal genus. The donkey and horse mane hair had almost the same thickness, the number of scales (waves) per 100 μm of hair length and the size of the scales (wavelength), however, the overall drawing was significantly different. Superficial drawing of hair cuticle from horse mane represented by irregular waves with sharp pointed edges of scales, instead, the donkey has fringed edges of scales. The horse's covering hair was thicker than the donkey's hair and had differences in the location and shape of the scales. Superficial drawing of covering hair cuticle of donkey represented by a regular wave of scales with clear and even edges, while the scales on the surface of the covering hair of the horse have indistinct torn edges and collected in intermittent (irregular) waves.

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Steinmann, Thomas, and Jérôme Casas. "The morphological heterogeneity of cricket flow-sensing hairs conveys the complex flow signature of predator attacks." Journal of The Royal Society Interface 14, no. 131 (June 2017): 20170324. http://dx.doi.org/10.1098/rsif.2017.0324.

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Arthropod flow-sensing hair length ranges over more than an order of magnitude, from 0.1 to 5 mm. Previous studies repeatedly identified the longest hairs as the most sensitive, but recent studies identified the shortest hairs as the most responsive. We resolved this apparent conflict by proposing a new model, taking into account both the initial and long-term aspects of the flow pattern produced by a lunging predator. After the estimation of the mechanical parameters of hairs, we measured the flow produced by predator mimics and compared the predicted and observed values of hair displacements in this flow. Short and long hairs respond over different time scales during the course of an attack. By harbouring a canopy of hairs of different lengths, forming a continuum, the insect can fractionize these moments. Short hairs are more agile, but are less able to harvest energy from the air. This may result in longer hairs firing their neurons earlier, despite their slower deflection. The complex interplay between hair agility and sensitivity is also modulated by the predator distance and the attack speed, characteristics defining flow properties. We conclude that the morphological heterogeneity of the hair canopy mirrors the flow complexity of an entire attack, from launch to grasp.

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Chang, Chia-Ling, Tsung-Han Ho, and Te-Hua Fang. "Topographical and Tribological Characteristics of Asian Human Hair Cuticles." Mathematical Problems in Engineering 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/985393.

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The topography and frictional force of Asian black male and female hair cuticles at different locations are determined using atomic force microscopy (AFM) and friction force microscopy (FFM). The frictional values, mapped for comparison with surface morphology, corresponded qualitatively with the structures’ plane surface characteristics. The results indicate that the hair surface was damaged and modified at different temperatures and heating times. The height of the female hair at a blowing temperature of 60°C after a duration of 2 min between the cuticle edge and cuticle surface was approximately 440–556 nm. The adhesion phenomenon occurs on the hair surface and interface. The cuticles do not vary after the heating; however, the hair damage sustained increases with serious deterioration.

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Velasco, Maria Valéria Robles, Tania Cristina de Sá Dias, Anderson Zanardi de Freitas, Nilson Dias Vieira Júnior, Claudinéia Aparecida Sales de Oliveira Pinto, Telma Mary Kaneko, and André Rolim Baby. "Hair fiber characteristics and methods to evaluate hair physical and mechanical properties." Brazilian Journal of Pharmaceutical Sciences 45, no. 1 (March 2009): 153–62. http://dx.doi.org/10.1590/s1984-82502009000100019.

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The hair thread is a natural fiber formed by keratin, a protein containing high concentration of sulfur coming from the amino acid cystine. The main physical proprieties of the hair depend mostly on its geometry; the physical and mechanical properties of hair involve characteristics to improve: elasticity, smoothness, volume, shine, and softness due to both the significant adherence of the cuticle scales and the movement control (malleability), as well as the easiness of combing, since they reduce the fibers static electricity. The evaluation of these effects on hair may be carried out by several methods, as: optical and electron microscopy, mechanical resistance measuring, shine evaluation and optical coherence tomography (OCT).

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Hwang, Sungjoo, Jung Chul Kim, Hyo Sub Ryu, Young Chang Cha, Seok Jong Lee, Gun Yoen Na, and Do Won Kim. "Does the Recipient Site Influence the Hair Growth Characteristics in Hair Transplantation?" Dermatologic Surgery 28, no. 9 (September 2002): 795–99. http://dx.doi.org/10.1046/j.1524-4725.2002.02041.x.

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HWANG, SUNGJOO, JUNG CHUL KIM, HYO SUB RYU, YOUNG CHANG CHA, SEOK JONG LEE, GUN YOEN NA, and DO WON KIM. "Does the Recipient Site Influence the Hair Growth Characteristics in Hair Transplantation?" Dermatologic Surgery 28, no. 9 (September 2002): 795–99. http://dx.doi.org/10.1097/00042728-200209000-00003.

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Kamijo, Hiroto, Megumi Shinohara, Ikutaro Fuchigami, Naofumi Yoshida, Akitoshi Tomita, and Kazunori Morikawa. "Harmony between Hair Color and Gloss and Perceptual Characteristics of ‘Clear’ Hair." Journal of Society of Cosmetic Chemists of Japan 55, no. 3 (September 20, 2021): 262–70. http://dx.doi.org/10.5107/sccj.55.262.

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Manjunath, A., and M. Habte. "Root morphological characteristics of host species having distinct mycorrhizal dependency." Canadian Journal of Botany 69, no. 3 (March 1, 1991): 671–76. http://dx.doi.org/10.1139/b91-089.

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Greenhouse and growth chamber investigations were undertaken using selected Leucaena and Sesbania species to determine the extent to which root morphological characteristics and rhizosphere acid production could explain differences in mycorrhizal dependency of host plants. Compared with the moderately to very highly mycorrhizal-dependent Leucaena species, the marginally to moderately dependent Sesbania species were characterized by higher root mass, higher root density, higher root surface area, higher root length, smaller root diameter, higher percentage of root hair incidence, higher shoot to root ratio, and higher total P uptake. The two groups of species were not consistently different from each other with respect to mycorrhizal colonization level, root hair diameter, root hair length, P uptake per unit root surface area, and acid production in agar media. A stepwise regression model in which mycorrhizal dependency (MD) was used as the dependent variable and root characteristics as independent variables suggested that root mass, root hair length, root diameter, root density, and root hair incidence were important determinants of MD, with root mass accounting for 65.5% of the variability. The results suggest that differences in the mycorrhizal dependency of host species can be largely predicted from root characteristics data. Key words: Brassica, Leucaena, Sesbania, P uptake, root hair, root mass.

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Kamalakannan, Manokaran. "Characterization of dorsal guard hair of the wild goats and sheep (Bovidae: Caprinae) occurring in the Himalaya and Western Ghats of India." Journal of Threatened Taxa 11, no. 3 (February 26, 2019): 13304–9. http://dx.doi.org/10.11609/jott.3344.11.3.13304-13309.

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The morphological and microscopic characteristics of dorsal guard hair of six species of the Indian goat-antelopes are described. Although the cuticular characteristics of hair of all the six species studied are similar, the morphological, medulla and transverse section characteristics of hair are varied between the species. The hair of Indian caprines can easily be identified on the basis of their unique medulla and transverse section. The high-resolution microphotographs and key characteristics of hair are presented here and can be used as an appropriate reference for species identification of the wild goats and sheep occurring in the Himalaya and Western Ghats of India.

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Choi, Gwang Seong. "Hair characteristics and androgenetic alopecia in Koreans." Journal of the Korean Medical Association 56, no. 1 (2013): 45. http://dx.doi.org/10.5124/jkma.2013.56.1.45.

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Sahajpal, V., S. P. Goyal, R. Jayapal, K. Yoganand, and M. K. Thakar. "Hair characteristics of four Indian bear species." Science & Justice 48, no. 1 (March 2008): 8–15. http://dx.doi.org/10.1016/j.scijus.2007.05.001.

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Dallos, P. "Response characteristics of mammalian cochlear hair cells." Journal of Neuroscience 5, no. 6 (June 1, 1985): 1591–608. http://dx.doi.org/10.1523/jneurosci.05-06-01591.1985.

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Riley, Patrick, Dennis S. Weiner, Bonnie Leighley, David Jonah, D. Holmes Morton, Kevin A. Strauss, Michael B. Bober, and Martin S. Dicintio. "Cartilage hair hypoplasia: characteristics and orthopaedic manifestations." Journal of Children's Orthopaedics 9, no. 2 (April 2015): 145–52. http://dx.doi.org/10.1007/s11832-015-0646-z.

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FURDON, SUSAN A., and DAVID A. CLARK. "SCALP HAIR CHARACTERISTICS IN THE NEWBORN INFANT." Advances in Neonatal Care 3, no. 6 (December 2003): 286–96. http://dx.doi.org/10.1016/j.adnc.2003.09.005.

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Keough, R., B. Powell, and G. Rogers. "Targeted expression of SV40 T antigen in the hair follicle of transgenic mice produces an aberrant hair phenotype." Journal of Cell Science 108, no. 3 (March 1, 1995): 957–66. http://dx.doi.org/10.1242/jcs.108.3.957.

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Directed expression of SV40 large T antigen (TAg) in transgenic mice can induce tissue-specific tumorigenesis and useful cell lines exhibiting differentiated characteristics can be established from resultant tumor cells. In an attempt to produce an immortalised mouse hair follicle cortical cell line for the study of hair keratin gene control, SV40 TAg expression was targeted to the hair follicles of transgenic mice using a sheep hair gene promoter. Expression of SV40 TAg in the follicle cortex disrupted normal fiber ultrastructure, producing a marked phenotypic effect. Affected hairs were wavy or severely kinked (depending on the severity of the phenotype) producing an appearance ranging from a ruffled coat to a stubble covering the back of the mouse. The transgenic hairs appeared to be weakened at the base of the fibers, leading to premature hair-loss and a thinner pelage, or regions of temporary nudity. No follicle tumors or neoplasia were apparent and immortalisation of cortical cells could not be established in culture. In situ hybridisation studies in the hair follicle using histone H3 as a cell proliferation marker suggested that cell proliferation had ceased prior to commencement of K2.10-TAg expression and was not re-established in the differentiating cortical cells. Hence, TAg was unable to induce cell immortalisation at that stage of cortical cell differentiation. However, transgenic mice developed various other abnormalities including vertebral abnormalities and bladder, liver and intestinal tumors, which resulted in reduced life expectancy.

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Huan, Nguyen Van. "A HAIR AND HAIR VORTEX SIMULATION TECHNIQUE BASED ON VECTOR FIELDS ON A MANIFOLD." Vietnam Journal of Science and Technology 54, no. 1 (February 20, 2016): 109. http://dx.doi.org/10.15625/0866-708x/54/1/6016.

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Hair is an important component in the virtual human simulation system. During hair simulation, not only the time required to ensure that there are required to express the physical characteristics, chemical such as hair styles, colors, curves, twists, parting one’s hair and hair vortex (swirl), ... to represent the authenticity of the hair and improve hair simulation quality. While the studies has announced today that they mainly focus on simulating the styles, the motion of the hair that has not been expressed characteristics of hair as hair vortex,... The paper introduces the concept of scalp model as a manifold in 3-dimensional space. Based on the nature of the singularity of the vector field on the manifold, the paper proposes a hair simulation technique on the scalp surface model based on vector field on the manifold. Thus, we can simulate appropriately the hair vortex on the scalp model.

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Hyun, Ji-Won, and Seoung-Tack Hwang. "Evaluation of Changes and Characteristics of Hair According to the Application of the Hair Dryer Plasma Functional Module." Journal of the Korean Society of Cosmetology 27, no. 4 (August 31, 2021): 940–48. http://dx.doi.org/10.52660/jksc.2021.27.4.940.

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Hairdryers are commonly known to cause hair damage such as “roughness”, “dryness”, and “hair color loss”. while using it. So, numerous studies have tried to find ways to dry hair with no damage or minimized level. In this study, we examined hair damage levels by varying drying applications during the process and analyzed hair changes either in essential characteristics such as “oil and moisture balance” or “microstructure”. As a result, hair was severely damaged when treated with a general hot air dryer for 90 minutes, causing cuticle crack or layer separation. In contrast, the plasma hairdryer caused just a little or even no damage to hair for the same exposure time. It may be because ions and moisture molecules generated when using a plasma hairdryer can protect hair structure from the harsh hot air condition.

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Pedersen, Elaine L., Nancy L. Markee, and Carol J. Salusso. "Gender Differences in Characteristics Reported to Be Important Features of Physical Attractiveness." Perceptual and Motor Skills 79, no. 3_suppl (December 1994): 1539–44. http://dx.doi.org/10.2466/pms.1994.79.3f.1539.

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The purpose of this study was to ascertain whether characteristics of physical attractiveness named by respondents as important would differ from those attributes previously examined by researchers. Gender differences related to the identification of important characteristics of physical attractiveness were also explored. Subjects, 230 male and 240 female undergraduates at two western state universities, completed a self-administered questionnaire. Respondents agreed that body build was the characteristic of greatest importance for both physically attractive males and females. Other important characteristics for physically attractive males were eyes, face, height, and hair and for females, hair, face, and eyes. Other than body build, there was no consistent ranking of characteristics by male and female respondents.

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Tiampasook, Pratya, Chaiyavat Chaiyasut, Bhagavathi Sundaram Sivamaruthi, Thanaroat Timudom, and Duangporn Nacapunchai. "Effect of Phyllanthus emblica Linn. on Tensile Strength of Virgin and Bleached Hairs." Applied Sciences 10, no. 18 (September 10, 2020): 6305. http://dx.doi.org/10.3390/app10186305.

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In Ayurveda medicine, Phyllanthus emblica Linn. (emblica) has been used as a hair nourisher for more than a decade by soaking it overnight, but no study has proved the effect of emblica on hair. This research aims to determine the effect of emblica solution on the tensile strength of three types of hair: virgin hair (VH), bleached hair (BH), and twice bleached hair (TH). The investigated active substances were deionized water (DI water) as a control, 3% emblica extract solution (3% EXS), 6% emblica extract solution (6% EXS), and 9% emblica extract solution (9% EXS). Black Virgin Asian hair was measured and analyzed before bleaching with a 12% bleaching agent once (BH) and twice (TH). Three treatments and the control were applied to each type of hair under a controlled condition. The tensile characteristics and surface morphology of all treated hairs were measured and analyzed by texture analysis (TA.XT Plus Texture Analyzer, Stable Micro Systems), Aramo (Aramo-SG Skin & Hair analysis system), and scanning electron microscopy (SEM model JSM-5410LV JEOL). The results of the nanoindentation test proved that the tensile strength and extensibility of all three types of hair increased in all concentrations (DI water, 3% EXS, 6% EXS, and 9% EXS). High magnification SEM images were taken from the cuticle surfaces and cross-sections. Emblica extracted solution (EXS) formed a coating around the hair, especially cuticle damaged by bleaching (BH and TH). The breaking pattern from the cross-section images showed that emblica extract solution reinforced all hair types. In conclusion, the emblica extract solution has a significant positive effect on the tensile strength and extensibility of VH, BH, and TH. The result has proved the ancient intelligence that the emblica nourishes the hair. In addition, our results show additional benefit by strengthening virgin hair and bleached hair.

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Ocampo- Blandón, C. F., E. Restrepo-Parra, J. C. Riaño-Rojas, and F. Jaramillo. "Multiscale Morphological Reconstruction for Hair Removal in Dermoscopy Images." Modern Applied Science 12, no. 12 (November 16, 2018): 90. http://dx.doi.org/10.5539/mas.v12n12p90.

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The automatic diagnosis of melanoma is usually affected by the noise that is often included in an image, during the acquisition stage or by superficial factors such as hair. Specifically, hair on the surface of a lesion can cause enough distortion, resulting in an erroneous diagnosis of the region of interest. To solve this issue, several techniques have been presented to detect hair on the surface of a dermoscopy image and substitute a surface approximation for these regions. Nonetheless, the existing methods are prone to false detections or reconstructions that are not uniform, demand high computing resources and modify the textures of important characteristics. Therefore, we proposed a method that detects the hairs by means of a convolution of the image with a kernel belonging to the first derivative of the Gaussian function and replaces the hairs using a multiscale morphological reconstruction. In addition, we integrated a refining stage that contributes to maintaining the quality of the patterns on the lesion. We used 36 dermoscopy images in the evaluation, which included a total of 586 hairs that were automatically detected with the proposed process and validated with their respective manual segmentations. Our results showed sensitivity and specificity performance measurements of 94.14% and 99.89%, respective.

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Kamalakannan, Manokaran, Kailash Chandra, Joy Krishna De, and Chinnadurai Venkatraman. "The identification of pika and hare through tricho-taxonomy (Mammalia: Lagomorpha)." Journal of Threatened Taxa 11, no. 10 (August 26, 2019): 14301–8. http://dx.doi.org/10.11609/jott.4014.11.10.14301-14308.

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The macroscopic and microscopic characters of dorsal guard hairs of Indian lagomorphs (four species of pikas and three species of hare) are described; the cuticular and medullary characters are similar between the species studied. The cuticular and medullary characters, however, are dissimilar between the family Ochotonidae and Leporidae. The cross-section of hair of the species had shown two identical shapes between the family Ochotonidae and Leporidae. The cross-section was observed as an oval shape in all the four ochotonid species, whereas there was a dumb-bell shape in all three leporid species. The hair of the Indian lagomorphs can easily be differentiated up to the family level on the basis of their unique cuticula, medulla and cross-section of the dorsal guard hair. The high-resolution microphotographs and key characteristics of hair that are presented here can be used as an appropriate reference for family-level identification of Indian lagomorphs.

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Skoluda, Nadine, Isabell Piroth, Wei Gao, and Urs M. Nater. "HOME vs. LAB hair samples for the determination of long-term steroid concentrations: a comparison between hair samples collected by laypersons and trained research staff." Journal of Neural Transmission 128, no. 9 (July 20, 2021): 1371–80. http://dx.doi.org/10.1007/s00702-021-02367-3.

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AbstractHair segment analysis is a valuable tool for the assessment of cumulative long-term steroid secretion. Preliminary findings suggest comparable cortisol concentrations in hair collected by instructed laypersons and research staff. However, it remains unclear whether hair sample quality and hair steroids other than cortisol are affected by level of experience (laypersons vs. research staff), home collection circumstances (instructions, familiarity to participant, performance confidence), and characteristics of the layperson (conscientiousness). Sixty participants (23.6 ± 3.9 years; 43 females) provided hair samples twice: first collected by laypersons (HOME) according to provided instructions (written vs. written/video-based instructions) and second by trained research staff (LAB) on the same day or the day after the HOME collection. Hair steroid concentrations (cortisol, cortisone, DHEA, progesterone) were determined using LC–MS/MS. Hair sample quality was evaluated using nine predefined criteria. Laypersons completed questionnaires for the assessment of potential factors of hair outcome measures (hair steroid concentrations, hair sample quality). Hair steroids from HOME and LAB samples were positively correlated (rs between 0.76 and 0.89) and did not significantly differ, with the exception of cortisone. The quality of hair samples was significantly higher for LAB than for HOME samples. Neither HOME collection circumstances nor layperson-related characteristics had an impact on hair outcome measures. However, a low self-reported performance confidence predicted a high absolute difference between HOME and LAB DHEA. In summary, our findings suggest higher quality of hair samples collected by trained research staff compared to instructed laypersons. However, these differences might be negligible, considering the high correlation between HOME and LAB hair steroid concentrations, with the characteristics of the layperson or collection circumstances having a minor impact on hair steroids and hair sample quality. These findings provide further support for the notion that well-instructed laypersons can be enabled to collect hair samples.

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Prin, Yves, and Mireille Rougier. "Cytological and histochemical characteristics of the axenic root surface of Alnus glutinosa." Canadian Journal of Botany 64, no. 10 (October 1, 1986): 2216–26. http://dx.doi.org/10.1139/b86-296.

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The aim of the present study was to investigate the Alnus root surface using seedlings grown axenically. This study has focused on root zones where infection by the symbiotic actinomycete Frankia takes place. The zones examined extend from the root cap to the emerging root hair zone. The root cap ensheaths the Alnus root apex and extends over the root surface as a layer of highly flattened cells closely appressed to the root epidermal cell wall. These cells contain phenolic compounds as demonstrated by various histochemical tests. They are externally bordered by a thin cell wall coated by a thin mucilage layer. The root cap is ruptured when underlying epidermal cells elongate, and cell remnants are still found in the emerging root hair zone. Young emerging root hairs are bordered externally by a cell wall covered by a thin mucilage layer which reacts positively to the tests used for the detection of polysaccharides, glycoproteins, and anionic sites. The characteristics of the Alnus root surface and the biological function of mucilage and phenols present at the root surface are discussed in relation to the infection process.

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이귀영 and 장병수. "General Characteristics on the Fine Structure of Scalp Hair - I. Ultrastructure of Hair Shaft -." Journal of Investigative Cosmetology 6, no. 3 (September 2010): 265–71. http://dx.doi.org/10.15810/jic.2010.6.3.006.

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Desai, Bipin S. Phal, Avelyno H. D'costa, and S. K. Shyama. "A comparative analysis of hair morphology of wild and domestic ungulate prey species of Leopard Panthera pardus fusca (Mammalia: Carnivora: Felidae) from Goa, India." Journal of Threatened Taxa 11, no. 15 (December 26, 2019): 14971–78. http://dx.doi.org/10.11609/jott.4894.11.15.14971-14978.

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Guard hairs were collected from four live domesticated ungulate species and shed guard hairs of six wild ungulate species from zoo captive animals from five individuals each. Photographic reference was prepared showing analytic features of hair characteristics. Study results were analysed and cuticle and medulla patterns were identified along with pigmentation features from the literature available for wild and domestic ungulates from India and abroad. Clear and easily distinguishable morphological characters of hair medulla and cuticle were used in the present study. Scat analysis of big cats used in this study is easy, speedy and efficient which can be used in routine investigations related to wildlife, crime forensics as well as human animal conflicts by studying carnivore feeding habits. In a majority of the animal species, the distal part of the hair showed maximum variation from the rest of the hair portions. The cuticle scales were imbricate in all tested animals. Scale position in almost all the tested animals was transversal except in goat (proximal part and medial part) and mouse deer (Distal part). Majority of the species showed smooth margins at proximal and medial part. Whereas the distal part scale margin was crenate and rippled in appearance the proximal part and medial part of hair of the majority of sampled animals showed a regular wave -type scale pattern whereas the distal part of hair showed irregular wave-type scale pattern in dominance. The composition of the medulla was multicellular in all the sampled deer species. Only the cow calf’s hair medulla was unicellular and uniseriate in appearance. A comparison of the hair of the domestic pig with that of the wild boar and gaur hair with that of cow calf and buffalo calf hair was made for the first time in the present study. Similarly goat hair morphology can also be differentiated from other cervids in this study. Medulla and cuticle characters in combination with each other can help differentiate wild ungulate species from the domestic ones since these wild ungulate species are frequently involved in hunting crime investigations. Therefore, the photographic reference presented in this study can be used in wildlife forensic science as well as predator diet analysis as an appropriate reference for prey species identification.

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Tridico, Silvana R., Sandra Koch, Amy Michaud, Gordon Thomson, K. Paul Kirkbride, and Michael Bunce. "Interpreting biological degradative processes acting on mammalian hair in the living and the dead: which ones are taphonomic?" Proceedings of the Royal Society B: Biological Sciences 281, no. 1796 (December 7, 2014): 20141755. http://dx.doi.org/10.1098/rspb.2014.1755.

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Although the taphonomic (post-mortem) degradation processes relevant to teeth and bones have been well described, those taking place with regards to mammalian hairs have not been characterized to the same extent. This present article describes, in detail, microscopic changes resulting from the actions of biological agents that digest and degrade hairs. The most noteworthy and prevalent agents responsible for the destruction of hair structure are fungi, which use a range of strategies to invade and digest hairs. One of the most important finds to emerge from this study is that taphonomic structures and processes can easily be interpreted by the unwary as ‘real’, or as class characteristics for a particular animal taxon. Moreover, under certain conditions, ‘taphonomic’ processes normally associated with the dead are also present on the hairs of the living. This work will improve the reliability of hair examinations in forensic, archaeological and palaeontological applications—in addition, the finding has relevance in the protection of mammalian collections susceptible to infestation. This article also addresses the popular myth that ancient peoples were often red-haired and discusses phenomena responsible for this observation. Insights gained from detailed characterization of taphonomic processes in 95 hairs from a variety of species demonstrate the range and breadth of degradative effects on hair structure and colour. Lastly, the study demonstrates that hairs often tell a story and that there is value of extracting as much morphological data as possible from hairs, prior to destructive sampling for biomolecules.

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장병수. "Morphological Characteristics of Vellus Hair on Face Skin." Journal of Investigative Cosmetology 14, no. 2 (June 2018): 161–67. http://dx.doi.org/10.15810/jic.2018.14.2.003.

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Reynolds, Amanda J., and Colin A. B. Jahoda. "Hair Follicle Stem Cells: Characteristics and Possible Significance." Skin Pharmacology and Physiology 7, no. 1-2 (1994): 16–19. http://dx.doi.org/10.1159/000211268.

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Keen, E. C., and A. J. Hudspeth. "Transfer characteristics of the hair cell's afferent synapse." Proceedings of the National Academy of Sciences 103, no. 14 (March 27, 2006): 5537–42. http://dx.doi.org/10.1073/pnas.0601103103.

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Shin, Jung Won, Soon Hyo Kwon, Sung Ae Kim, Joo Yong Kim, Jung Im Na, Kyoung Chan Park, and Chang Hun Huh. "Characteristics of robotically harvested hair follicles in Koreans." Journal of the American Academy of Dermatology 72, no. 1 (January 2015): 146–50. http://dx.doi.org/10.1016/j.jaad.2014.07.058.

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Ohbu, K., T. Tamura, N. Mizushima, and M. Fukuda. "Binding characteristics of ionic surfactants with human hair." Colloid & Polymer Science 264, no. 9 (September 1986): 798–802. http://dx.doi.org/10.1007/bf01500756.

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Thozhur, S. M., A. D. Crocombe, P. A. Smith, K. Cowley, and N. Mullier. "Structural characteristics and mechanical behaviour of beard hair." Journal of Materials Science 41, no. 4 (February 2006): 1109–21. http://dx.doi.org/10.1007/s10853-005-3648-2.

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ცხვედიანი ნ., Tskhvediani N., Tsibadze A. ციბაძე ა., Chikvaidze E. ჩიკვაიძე ე., Kvachadze I. კვაჭაძე ი., and Khutsishvili L. ხუციშვილი ლ. "SPECIFIC CHARACTERISTICS OF ELECTRON PARAMAGNETIC RESONANCE SPECTRUM OF DIFFERENT COLORS OF HAIR." TSMU COLLECTION OF SCIENTIFIC WORKS 49 (November 6, 2019): 144–45. http://dx.doi.org/10.52340/csw.v49i0.211.

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In the result of interaction of the metabolic processes of the human organism and external factors free radicals are formed in tissues including hair. An objective assessment of an intensity of this process is possible by means of electronic paramagnetic resonance’s (EPR) signal and its intensity indices. The purpose of the survey was a comparative evaluation of the EPR spectrum’s specificity of black and brown hair and a study of a photo dynamic in the condition of a treating with blue light. The survey was conducted among young volunteers of age 17-21 on the base of their informed consent and with adherence of all bioethical requirements established for this type of research. No single person’s hair involved in the survey was treated with chemical dye or active, specific remedy for hair care. This article analyzes data of young men donors. All measurements were carried out at standard conditions: room temperature (22-240C), humidity - 60-70%, the measurement error - ± 5%. EPR spectrum was determined at the Department of Biophysics,TSU by means of a radio-spectrometer TSR - V. Study results have determined a uniform EPR spectrum and no difference in the intensity of the photoinduced EPR spectrum that indicates the equal concentrations of eumelanin in black and brown hair.

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Hallberg, Ε., J. N. C. Yan Den Pers, and G. E. Haniotakis. "Funicular sensilla of Dαcus oleαe: fine structural characteristics." ENTOMOLOGIA HELLENICA 2 (May 25, 2017): 41. http://dx.doi.org/10.12681/eh.13902.

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The funicular sensilla in Dacus oleae (Gmelin) (Diptera: Tephritidae) are found both on the surface and in the single olfactory pit. The surface sensilla are of three types: two are single-walled, the third is double-walled. The fine structure of these three sensillar types indicates olfactory function capabilities. The single-walled sensilla are, as a rule, innervated by two sensory cells. The long single-walled sensilla have unbranched sensory processes, whereas in the short they are branched. The double-walled sensilla usually possess three sensory cells that send unbranched sensory processes towards the tip of the hair. The olfactory pit sensilla are of two types: one type is identical to the double-walled type found on the funicular surface. The second type is poreless and found only in the olfactory pit. The poreless sensilla are innervated by three sensory cells, two of which terminate inside the cuticular hair, while the third does not enter inside the hair but terminates freely below it. The functional capabilities of this sensillar type are unknown.

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Tymoshenko, O. P., O. S. Snopenko, G. A. Papeta, G. V. Vikulina, S. B. Borovkov, and M. I. Korenev. "Morphological characteristics of hair cuticle of clinically healthy domestic cats and dogs." Veterinary science, technologies of animal husbandry and nature management, no. 6 (2020): 90–95. http://dx.doi.org/10.31890/vttp.2020.06.16.

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It is known that the typical for animals of different species the nature of the serrations of the free edges of the scales of the hair cuticle, the density of their location and proximity to each other can determine the species of animal hair samples. The aim of the study was to establish the value of the cuticular index in clinically healthy domestic cats and dogs. The area of the outer surface of the scales of the hair cuticle, or cuticular index, was determined in 20 clinically healthy domestic cats and 18 dogs. Examination of the cuticle was performed using prints on a colorless lacquer, which was applied to a glass slide, pressing the hair to the paint layer. The imprint was examined under a microscope (enlargement ×400) and the cuticular index value was established in the root zone, in the thickest part of the hair shaft, expressed in μM2. It was found that in domestic cats and dogs without clinical signs of any pathology, the values of the cuticular index are in the range of 80-170 and 100-210 μM2accordingly. The value of the cuticular index in domestic cats 60-70 μM2 and in dogs 60-90 μM2in 100 % accidents does not meet in healthy animals. The obtained results can be used as a control during diagnostic activities for numerous variants of internal pathology of domestic cats and dogs, as additional diagnostic tests.

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Galchenko, A. V., M. Y. Yakovlev, А. А. Skalny, A. A. Kirichuk, O. Yu Orlova, R. Almasry, A. V. Barinov, N. V. Titov, and T. V. Korobeynikova. "ASSOCIATION OF CHEMICAL HAIR CONTENT WITH NUTRITIONAL CHARACTERISTICS IN FIRST GRADE PFUR STUDENTS." Trace Elements in Medicine (Moscow) 21, no. 2 (2020): 41–48. http://dx.doi.org/10.19112/2413-6174-2020-21-2-41-48.

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The aim of the study was to determine the relationship of the content of chemical elements in the hair with the nature of nutrition. We examined 107 people (75 women and 32 men), first-year students of the Peoples` Friendship University of Russia from 33 countries. The average age of the subjects was 22 years. The hair was taken from the occipital part of the head. Hair was analyzed for qualitative and quantitative elemental composition by induced coupled plasma mass spectrometry. The average dietary intake of students was assessed by the method of frequency analysis using the Nutrilogic software. The results of the study showed that more than half of the students had a deficiency in consumption of P (61.68%), I (57.01%), Mo (75.70%), Cr (78.50%), choline (71.96%). The strongest correlations of the content of the chemical elements in the hair with the intake of nutrients in men were found for (chemical element in the hair - nutrient, dependence, direct or inverse, p value) W - Mo, ↓, 0.007; Co - vitamin B12, ↑, 0.003, Hg - β-carotene, ↓, 0.002; Mg - folate, ↑, 0.001; Mg - pantothenic acid, ↓, 0.0001; P - vitamin B12, ↑, 0.0001; P - pantothenic acid, ↑, 0.001. No such relationships were found among women, with the exception of beryllium concentrations: its content in the hair decreased with an increase in the intake of protein, fats, vitamins B1 and B12, as well as Na and Fe (in all cases, p≤0.001). Thus, the data obtained indicate that insufficient intake of various nutrients can significantly affect the status of a number of chemical elements. Moreover, the list of chemical elements is different for different nutrients.

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Rezende, Soraia Rage, Mara Regina Bueno de Mattos Nascimento, Susiandra Kloster Munhoz, and Natascha Almeida Marques da Silva. "Effect of season on haircoat characteristics and physiological parameters of Holstein-Gyr x Guzerá crossed heifers." Semina: Ciências Agrárias 38, no. 1 (March 2, 2017): 381. http://dx.doi.org/10.5433/1679-0359.2017v38n1p381.

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This study aimed to investigate haircoat characteristics and physiological parameters in summer and winter, morning and afternoon periods, of Holstein-Gyr x Guzerá crossed heifers in tropical environment. For this, twenty crossbred dairy heifers (Holstein-Gyr x Guzerá), reared in the city of Ibiá, Minas Gerais state, Brazil. Haircoat thickness, i.e. distance from skin surface until hairend, average hair length, number of hairs per unit area, hair angle to the skin surface, cardiac and respiratory rates, rectal and body surface temperatures were measured. Data underwent analysis of variance and the means were compared by F test at 5% significance, except heart and respiratory rates and skin temperature within the season, which were compared by Mann Whitney test at 5%. For rectal temperature, the maximum value found was 39.53 °C in the summer afternoon. In the afternoon, rectal temperature was higher in summer compared to winter. Respiratory and heart rates and coat surface temperature were higher in the summer (34.00 movements min-1; 78.60 beats min-1; 37.97 °C respectively) compared to the winter (27.47 movements minutes -1; 58.72 beats min-1; 34,94ºC, respectively). Haircoat thickness and hair length were larger in winter (0.73; 1.82 cm, respectively) compared to summer (0.49; 1.11 cm, respectively). We concluded that the season of the year and day period interfere with most of the physiological parameters for thermoregulation and haircoat characteristics of crossbred heifers (Holstein-Gyr x Guzerá); however, they keep homeothermy, therefore are adapted to the region, and may be an alternative to be used by farmers of this region.

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Naue, Jana, Julia Winkelmann, Ulrike Schmidt, and Sabine Lutz-Bonengel. "Analysis of age-dependent DNA methylation changes in plucked hair samples using massive parallel sequencing." Rechtsmedizin 31, no. 3 (April 30, 2021): 226–33. http://dx.doi.org/10.1007/s00194-021-00487-4.

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AbstractThe analysis of age-dependent DNA methylation changes is a valuable tool in epigenetic research and forensic genetics. With some exceptions, most studies in the past concentrated on the analysis of blood, buccal, and saliva samples. Another important sample type in forensic investigations is hair, where age-dependent DNA methylation has not been investigated so far. In this pilot study a deeper look was taken at the possibilities and challenges of DNA methylation analysis in hair. The DNA methylation of selected age-dependent 5’-C-phosphate-G‑3’ (CpG) sites were characterized for their potential use as a biomarker for age prediction using plucked hair samples and massive parallel sequencing. Plucked hair roots of 49 individuals were included in the study. The DNA methylation of 31 hairs was successfully analyzed. The DNA methylation pattern of 10 loci, including ELOVL2, F5, KLF14, and TRIM59, was determined by amplicon-based massive parallel sequencing. Age-dependent changes were found for several markers. The results demonstrate the possible use of already established age-dependent markers but at the same time they have tissue/cell type-specific characteristics. Special challenges such as low amounts of DNA and degraded DNA as well as the possible heterogeneous cellular composition of plucked hair samples, have to be considered.

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Journal articles on the topic 'Hair characteristics'

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