I know the Internet is full of lists with citiesâ nicknames, but I decided to make my own, composed of the worldâs most important cities, and I hope this will be useful for my readers. 1. Paris â The City of Love, The City of Light, La Ville-Lumiere. 2. Prague â The City of Hundred Spires, The Golden City, The Mother of Cities.
Sleep debt or sleep deficit is the cumulative effect of not getting enough sleep. A large sleep debt may lead to mental or physical fatigue. There are two kinds of sleep debt: the results of partial sleep deprivation and total sleep deprivation. Partial sleep deprivation occurs when a person or a lab animal sleeps too little for several days or weeks. Total sleep deprivation means being kept awake for at least 24 hours. There is debate in the scientific community over the specifics of sleep debt
To understand sleep deficiency, it helps to understand how sleep works and why it's important. The two basic types of sleep are rapid eye movement (REM) and non-REM. Non-REM sleep includes what is commonly known as deep sleep or slow wave sleep. Dreaming typically occurs during REM sleep. Generally, non-REM and REM sleep occur in a regular pattern of 3â5 cycles each night. Your ability to function and feel well while you're awake depends on whether you're getting enough total sleep and enough of each type of sleep.