Hair

Hair refers to naturally growing, thread-like projections made from bundles of keratin – a protein also found in teeth and nails (which is why hair removal products can damage all three). Although organisms like insects and spiders sport similar filamentous structures, hair is unique to mammals. 

Hair is produced by follicles, narrow cavities found in the skin. Mammals express hair on all non-glabrous skin – the glabrous skin on lips, eyelids, palms, soles, back of the ears, and parts of the genitals lack follicles. Each follicle’s sebaceous glands produce oily sebum that lubricates and waterproofs the skin and hair. A hair matrix at the follicle's base generates hair through rapid cell division; cancer treatments such as chemotherapy specifically target rapidly dividing cells, causing hair loss side effects.

Diacritical Marks

Diacritcal marks or diacritics are linguistic marks (or glyphs) placed above or below a letter. Diacritics – often called accents – can indicate or change a letter’s sound – though not all diacritical marks alter pronunciation.

One of the most basic English diacritics, the macron – a single bar (ā) – indicates a long vowel. In most dialects of American English, long vowels are pronounced like each letter’s name, like in cake, Pete, mice, grove, and rule. Conversely, the breve – shaped like the bottom half of a circle (ă) – marks a short vowel, like in cat, bet, fit, rot, and nut. Although these diacritics help with pronunciation, they don’t appear in the actual word.

Déjà Vu

Déjà vu is a French expression meaning "already seen," coined by French parapsychologist ÉmileBoirac in 1876 to describe an inexplicable – and often unsettling – sensation of familiarity while experiencing something for the first time. Although déjà vu has become a blanket term for any experience of this feeling, it technically only applies to visual information. Later researchers further divided this sensation into déjà visite ("already visited"), déjà vecu ("already lived through"), déjà senit (“already felt”), and déjà entendu ("already heard").

Fruits and Vegetables

You may be privy to recent internet outrage over Congress declaring pizza a vegetable. In reality, Congress blocked a US Department of Agriculture proposal to increase the amount of tomato paste necessary to qualify as a school-lunch vegetable – for the past 20 years, two tablespoons has been sufficient.

Yet, to some, the true display of ignorance is calling tomato a vegetable, for – as even the most casual one-upper knows – they are really fruits. Which brings us to today’s post.

Happy Thanksgiving, America (and to a lesser extent, The Netherlands)! And if you happen to live in Canada, Liberia, Japan, or Grenada, happy belated Thanksgiving! 

But not you Norfolk Island... You wait your turn.

Source: 1, 2, 3

Zombies

What better way to mark learnalittle’s return from the dead than a short history of zombies?

Tales of the living dead abound in cultures across the world. The Norse draugar are the bodies of slain Vikings, said to inhabit their graves and jealously guard the treasures buried with their former selves. In Chinese folklore, jiang shi are reanimated corpses that hop around with their arms outstretched, sucking the life-force qi out of the living. And according to Medieval British accounts, deceased ne’er-do-wells may return as revenants – risen bodies bloated with blood – to terrorize their families and neighbors.

Daddy Long Legs

Sometimes, inspiration comes from the most unexpected places.

Endearing accent aside, this indignant German does bring up an excellent point: what exactly is the deal with daddy long legs?

As it turns out, the name "daddy long legs" is shared by three separate creatures, which all sport - you guessed it - notably long legs. The critters our Deutsch friend refers to are called Opiliones (or harvestmen). These eight-legged animals have two-segment oval bodies, have barely changed in the past 400 million years, and can be found across the globe. Though arachnids, harvestmen are not spiders, and lack both silk and venom glands; still, an erroneous urban legend contests harvestmen are the most venomous creatures on earth, yet lack fangs strong enough to pierce human skin.