Ultradian Rhythms free essay sample

Ultradian rhythms are bodily rhythms that last less than 24 hours. The most obvious ultradian rhythm is the different stages of sleep, existing within the ciradian rhythm of the sleep-wake cycle. Sleep is dived into cycles, each lasting about 90 minutes. During these cycles, we will experience 5 different stages of sleep- the first four being characterized as non-rapid eye movement sleep (NREM), and the last stage being characterized as rapid eye movement sleep (REM). When human beings are awake, the electrical activity in their brain usually takes the form of fast, erratic brain waves. These waves are known as beta waves. During stage 1 of sleep, the brains electrical activity begins to change, with the brain waves becoming more slow and regular. This demonstrates that the persons mind is beginning to relax, and these waves are known as alpha waves. The presence of alpha waves in the brain can usually be used to indicate that the onset of sleep has occurred, and that the person is no longer awake. We will write a custom essay sample on Ultradian Rhythms or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page As well as a change in electrical activity, the persons core body temperature will also drop and their heart-beat slow down. As the sleeper goes into Stage 2 of sleep, their brain waves become even slower and a greater amplitude. These are called theta waves. This shows that the brain is becoming increasingly more relaxed. During this stage of sleep, it is common to experience sudden bursts of brain activity: known as K complexes and sleep spindles. Stages 1 and 2 of sleep are commonly referred to as being as being light sleep. This means that people in these stages of sleep can be easily awoken by external factors such as noise. Stages 3 and 4 of sleep are characterized by even slower brain waves, known as delta waves. Stages 3 and 4 are often referred to as being slow-wave sleep (SWS)- and sleep during this time is far more deep than in the previous two stages. However, the sleeper has not reached a state of unconsciousness, and can still be woken up by certain external factors (eg. Parents being woek nby the sound of their baby crying). These are the stages of sleep where most of the bodies physiological repair work occurs. It can also be associated with biochemical changes, such as the release of growth hormone taking place during this time. In these first four stages of NREM sleep, dreams have been shown to be unlikely to occur. During a study by Dement and Klietman, in which participants were woken up when their brain waves indicated certain stages of sleep, it was shown that only around 7% of participants had reported having dreams when their brain activity had indicated the stages of NREM sleep. Stage 5 of sleep, the final stage in the sleep cycle before it repeats, is known as REM sleep. This the stage of sleep where brain activity is most like that of the awake brain. It is also the stage of sleep where most dreams are likely to occur.

Significant Events of the Delaware Colony

Significant Events of the Delaware Colony The Delaware colony was founded in 1638 by European colonists from the Netherlands and Sweden. Its history includes occupations by the Dutch, Swedish, British- and the colony of Pennsylvania, which included Delaware until 1703. Fast Facts: Delaware Colony Also Known As: New Netherland, New SwedenNamed After: Then-governor of Virginia, Lord de la WarrFounding Country: Netherlands, SwedenFounding Year: 1638First Known European Landing: Samuel ArgallResidential Native Communities: Lenni Lenape and NanticokeFounders: Peter Minuit and the New Sweden CompanyImportant People: James, Duke of York, William Penn Early Arrivals The first European arrivals in the area occurred in the early 17th century when the Dutch were involved in establishing many trading posts and colonies around the world including in North America. Henry Hudson had been hired by the Dutch to explore the New World in 1609 and he discovered and named the Hudson River. By 1611, the Dutch had established fur trading enterprises with the Native Americans called the Lenni Lenape. In 1614, Fort Nassau, on what is the Hudson River near Gloucester, New Jersey, was the earliest Dutch settlement in the New World. Peter Minuit and the New Sweden Company In 1637, Swedish explorers and stockholders created the New Sweden Company to explore and trade in the New World, under a charter with Swedish king Gustavus Adolphus. Adolphus died in 1632, and his daughter and successor Queen Christina took over the charters administration. Christinas chancellor formed the New Sweden Company in 1637 and hired Peter Minuit. Minuit was a German-born Dutch resident likely of French Huguenot ancestry, who had previously been the governor of New Netherland from 1626 to 1631 and is most well known for the purchase of Manhattan Island. In March of 1638, Minuit and his two ships, Key of Kalmar and the Griffin, landed at the mouth of a river they named Christina, in what is now Wilmington and founded the first permanent colony in Delaware. Annexed to New Netherland While the Dutch and Swedes coexisted for some time, the incursion of the Dutch into New Sweden territory saw its leader, Johan Rising, move against some Dutch settlements. In 1655, Peter Stuyvesant, New Netherlands governor, sent armed ships to New Sweden. The colony surrendered without a fight.  Thus, the area that was once New Sweden then became part of New Netherland.   British Ownership The British and Dutch were direct competitors during the 17th century. England felt they had a claim to the prosperous New Netherland territory due to the explorations by John Cabot made in 1498. In 1660, with the restoration of Charles II to the throne of England, the Dutch feared the British would attack their territory and forged an alliance with the French against the British. In response, Charles II  gave his brother, James, the Duke of York, New Netherland in March 1664. This annexation of New Netherland required a show of force. James sent a fleet of ships to New Netherland to demand its surrender. Peter Stuyvesant agreed. While the northern part of the New Netherland was named New York, the lower part was leased to William Penn as the lower counties on the Delaware. Penn wanted access to the sea from Pennsylvania. Thus, the territory was part of Pennsylvania until 1703. In addition, Delaware continued to share a governor with Pennsylvania until the Revolutionary War, even though it had its own representative assembly.   Beginning the War of Independence In October 1765, Delaware sent two delegates to a congress of the colonies in New York to deliberate on a joint colonial response to recent British measures, in particular, the Sugar Act of 1764 and the Stamp Act of 1765. The two men were landholder Caesar Rodney and attorney Thomas McKean: the two men and assemblyman George Read would continue to play a role in the movement for independence.   Delaware declared its independence from Great Britain on June 15, 1776, and signed the declaration of independence with its fellow colonies on July 4. Sources Delaware Facts. Delaware Historical SocietyMunroe, John A. History of Delaware, 5th ed. Cranbury NJ: University of Delaware Press, 2006.Wiener, Roberta and James R. Arnold. Delaware: The History of Delaware Colony, 1638–1776. Chicago, Raintree, 2005.