Research Identifies 10 Basic Categories of Odor

Researchers have classified 10 basic categories of odor. These categories describe the fundamental descriptors for the sense of smell. The categories are fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, popcorn, lemon and two kinds of sickening odors: pungent and decayed.

The sense of smell (olfaction) utilizes sensory cells of the nasal cavity. Odor molecules bind to specific sites on the olfactory receptors which sends the signal to the brain for processing. These signals are then interpreted by the brain into the odor categories described above. Just like with the sense of taste, these descriptors can be combined to form complex odors.

Properties of the perceptual basis set W. (A) Plot of normalized odor descriptor amplitude vs. odor descriptor number for the basis vector W1. Each point along the x-axis corresponds to a single odor descriptor, and the amplitude of each descriptor indicates the descriptor's relevance to the shown perceptual basis vector. Colored circles show the seven largest points in the basis vector, and descriptors corresponding to these points are listed to the right. (B) Waterfall plot of the 10 basis vectors constituting W, used in subsequent analyses. Note that each vector contains many values close to or equal to zero.
Credit: Castro JB, Ramanathan A, Chennubhotla CS (2013) Categorical Dimensions of Human Odor Descriptor Space Revealed by Non-Negative Matrix Factorization. PLoS ONE 8(9): e73289. doi:10.1371/journal.pone.0073289

Scientists Discover the Reason for Rudolph the Red Nosed Reindeer's Red Nose

Researchers have discovered the scientific basis of why Rudolph the red nosed reindeer's nose is red.

Rudolph the red nosed reindeer was created by Robert L. May. He first appeared in a 1939 booklet published by Montgomery Ward for its Christmas giveaway promotion. Prior to the booklet, Montgomery Ward was giving away coloring books and it was more economical for them to publish their own booklet.

Montgomery Ward was reported to have distributed 2.5 million of the booklets that year alone. The book featured the familiar story of Rudolph and how he became the lead reindeer of Santa Claus' sleigh.

Approximately ten years later, the song Rudolph the Red Nosed Reindeer was recorded and since then has become one of the most popular holiday songs. The song was written by Johnny Marks, who was May's brother in law.

The song was first sung commercially by Harry Brannon on November 1949 before Gene Autry's recording came out that same year and became the number 1 song for the holiday season.

Rudolph has since been considered a Christmas icon next in popularity to Santa Claus. The embedded video below is a cartoon based on the original story of May. This version is the reissued version with the popular song inserted. It is written by Robert May and Joe Stultz, and directed by Max Fleischer.