Human head hair

Allen, M., Engstrom, A. S., Meyers, S., Handt, O., Saldeen, T., von Haeseler, A., et al. (1998). Mitochondrial DNA sequencing of shed hairs and saliva on robbery caps Sensitivity and matching probabilities. /. Forensic Sci. 43,453-464. Andrasko, J. and Stocklassa, B. (1990). Shampoo residue profiles in human head hair. /. Forensic Sci. 35, 569-579. 

Linch, C. A. and Prahlow, J. A. (2001). Postmortem microscopic changes observed at the human head hair proximal end. /. Forensic Sci. 46,15-20. 

I shall describe the useful properties of photoluminescence and the current application of these properties in forensic science. New applications of photoluminescence developed or being investigated in our laboratory are also described. We have used photoluminescence techniques to (a) locate and identify seminal stains, (b) detect lead and antimony gunshot residue at the nanogram level, and (c) discriminate between different glass and human (head) hair samples. All of these techniques can be carried out rapidly in the crime laboratory. 

Figure 5. Phosphorescence spectra at 77 K of the human (head) hair from two different individuals for different excitation wavelengths...

Human head hair grows about one half of an inch per month. How much hair grows in 1 s please use metric units ... 

Andrasko, J. and Stocklassa, B., Shampoo residue profiles in human head hair,. Forensic Sci., 35, 569,1990. 

Hausman, L. A., A comparative racial study of the structural elements of human head-hair. Am. 

Valkovic V (1977) Trace elements in human head hair. Garland STPM Press New York. 

Valkovic, V. (1977). Trace Elements in Human head hair, Garland STPM Press, New York. 

Akamine, A.U., Silva, M.A.D., Saiki, M. et al. (2007). Determination of uranium in human head hair of a Brazilian populational group by epithermal neutron activation analysis,... 

Human head hairs were obtained from seven different individuals. Some of the subjects provided multiple samples of hair treated in different ways. Hair samples that had been permanently waved, dyed and bleached were used in order to determine if these treatments had an effect on the deterioration of the hairs. All hair samples were cut from the donors heads consequently, roots were usually absent from the hairs. 

Nanometer (nm) One thousandth of one millionth of a meter. There are about 60,000 nm in the width of a typical human head hair. 

Kintz, P., Tracqui, A., and Mangin, R, Opiate concentrations in human head, axillary, and pubic hair, /. Forensic Sci., 38, 657, 1993. 

In 1980, Klug reported a method to detect morphine in head hair of drug abusers by TLC. He dissolved the hair in sodium hydroxide and hydrolyzed the solution with HCL. He extracted the solution with amyl alcohol and separated the components by TLC. Detection and quantitation were made by fluorimetry. The findings were between traces and 4 ng/mg. A HPTLC method was used to determine morphine in human hair. From 20 to 200 mg of hair were washed four times with water to remove surface contamination. Then the hair was incubated in sodium hydroxide and subsequently in HCL at 80°C in both cases. After SPE (type "Extrelut 3"/Merck) the solution was dansylated, analyzed by HPTLC (methanol (MeOH)/ammonia 99 1), and quantitated by densitometry. 

The jaguars with humans heads and hair made of snakes are called nitimushcanpoma, which means "crushing tigers."... 

Human scalp hair provides both protective and cosmetic or adornment functions. Scalp hair protects the head from the elements by functioning as a thermal insulator. Hair also protects the scalp against sunburn, other effects of light radiation, and mechanical abrasion. 

Figure 1 4. Light micrograph illustrating empty nits of the head louse Pediculus capitis on a human scalp hair. Kindly provided by John T. Wilson.

Suppose that the angle of rotation is (j>. Each point of the disc x is seen to be mapped to some unique point, x, which is the image of no other point. There is only one point, at the centre, that maps to itself for a rotation oi fixed-point theorem states that in this case no hxed point occurs. Such surfaces lack a special point. They have the alternative property that hair on such a surface can all be brushed to lie in the same direction, unlike the hair on a disc, a sphere, or a human head which develops a crown. This is a striking property of a Mobius band, showing that all points in the surface are quivalent and any of these can be considered to be the central point. 

Recently, crime has become more vicious and skilful than ever before, so minute substances (trace evidence), which are difficult to hide, are important for the detection of the suspect, especially in cases where he is in contact with the victim or the crime scene. These substances are hair, fibers, soil, etc. Among them hair is noteworthy and can be retrieved easily from the crime scene, because there are 100 000 hairs on an adult human head and they may be shed one by one every 15 min. The suspect therefore leaves his or her own head or pubic hairs at the crime scene unwittingly. Therefore, hair provides important physical evidence for solving of crime. 

At the crime scene, various fibers and hairs are collected by policemen. They are immediately examined at the forensic laboratory in order to identify the suspect and help solve the crime. The examination needs to establish (1) whether it is a hair or a fiber (synthetic or plant) (2) its species if it is a hair (3) its somatic origin if it is a human hair (4) whether it is similar to the suspect or the concerned persons. Microscopic examination will resolve the first point. It will also allow discrimination between human and animal hair, as the medulla of human hair does not develop well and shows less than 0.30 of medullary index (ratio of medulla diameter to hair diameter). But determining the species of animal requires experience in animal hair examination. Almost every animal hair shows specific shape of cuticule and medulla under microscopical observation. With regard to the somatic origin of human hair, there are some basic features that usually indicate the bodily origin of the hair. For example, head hair has long length, 30-120 pm diameter, tapered tip, little diameter variation, various medullation, sometimes cut tips, and treatment. Pubic hair has a twisted... 

Figure 3 Gas chromatograms of components remaining on human hair adhering to suspect s ciothing (A) and victim s head hair (B). Equipment Shimadzu GC-4CM with a flame ionization detector coiumn 3 mm i.d. x2m, 1% Silicone OV-17 on Chromosorb-W (AW-DMCS, 80-100 mesh) column temperature program from 100 to 280°C at 5°C min" carrier gas nitrogen, 40mi min .

If amphetamines are detected in a suspect s head hairs, the suspect may be arrested under stimulant control law and the hairs can be used as evidence in a trial. Furthermore, various drugs contained in human hairs not only provide evidence of crime under drug control laws but also important clues to hair comparison for other criminal investigations. Many cases of drug abuse have been established by using human hair. These drugs are stimulants (amphetamines), heroin, phencyclidine, cocaine, barb rates, etc. 

Hair is an important type of physical evidence that frequently occurs in criminal and civil cases. For example, human head and pubic hairs may be exchanged between the perpetrator and victim in a case of sexual assault (an example of the Locard exchange principle (DeForest et al., 1983)). Hairs may also be found embedded in upholstery or decorative plastics in the interior of automobiles following automobile accidents (Masakowski et al., 1986). 

The Nobel laureate Richard P. Feynman described, in a lecture delivered in 1959, the future of miniaturization. The published version of his lecture is called There s Plenty of Room at the Bottom and in it can be found a recipe for putting the entire Encyclopedia Britan-nica on the very small head of a very small pin. Feynman s comments set into motion an entirely new area of study and have lead to what have become known as the fields of nanoscience and nanotechnology. Chemists, physicists, materials scientists, and engineers have come together over the past several decades to produce with high accuracy and precision materials that have dimensions measured in nanometers (nm, 10 meters, about 1/100 000 the width of a human hair). Specifically, materials with one, two, or three dimensions of 100 nm or less (called, respectively, nanofilms, nanotubes, and nanoparticles) qualify as products of nanotechnology. It appears that almost any chemical substance that is a solid under ordinary conditions of temperature... 

The results presented demonstrate that auditory systems of animals and humans respond to pulsed microwaves. However, there is little likelihood of the microwave acoustic effect arising from direct interaction of microwave pulses with the cochlear nerve or neurons at higher structures along the auditory pathway. The pulsed microwave energy, instead, initiates a thermoelastic wave of pressure in the head that travels to the cochlea and activates the hair cells in the inner ear. This theory covers many experimental observations, but it may be incomplete and thus require further extension to account for certain additional experimental findings. Tyazhelov, et al. (1 1) found in their beat frequency experiment that matching of microwave pulses (10 ps, 8000 pps) to a phase-shifted 8 kHz sinusoidal sound input... 

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