What is a computer? How does it work?

A computer, in simple terms, is a machine that can be used to collect, store, analyze and present information, among many other functions. The information can be in the form of words, numbers, symbols, audio, video, images, etc. A computer has a number of key components, including input/output devices (such as keyboard, mouse, speakers, printer, etc.), display system (a monitor or a screen), processing device (central processing unit or CPU), storage device (hard-drive), etc. 

A computer runs by using an operating system, which allows us to input the information, analyze it, store and output it. Computers are used in all aspects of our lives and have made it easy, especially by taking control of a number of operations that are impossible for human beings. Imagine working with thousands and millions of data points and advanced modeling. 

Hope this helps. 

What are cluster headaches?

Causes and Symptoms

Cluster headache is a well-defined, rare, but often misdiagnosed syndrome characterized by excruciatingly severe unilateral headaches that last from a half hour to three hours, with an average duration of forty-five minutes. Its features include paroxysmal onset of one side of the head, a short duration, and episodic occurrence. The pain often wakes sufferers one to two hours after they fall asleep. “Cluster” refers to the original perception that the headaches emerged in groups over a period of time (called the cluster period) lasting weeks to months, followed by periods that are free of pain and attacks (called remission or interim periods). The International Headache Society divides cluster headaches into episodic cluster and chronic cluster, with chronic further subclassified into primary and secondary variants. Chronic cluster headaches do not have a cessation, or interim, period but recur for years.

The precise cause of cluster headaches is unknown, although the season of the year is the most common trigger. Because they usually begin with spring or autumn, cluster headaches are often misattributed to seasonal allergies (such as hay fever) or seasonal-related stress (such as the beginning of school, final examinations, or the height of business cycles).

Positron emission tomography (PET) scanning has revealed that in cluster headaches the hypothalamus activates the trigeminal nerve, which is responsible for most of the severe pain. Located deep in the brain, the hypothalamus is also responsible for the internal biological clock that regulates the approximately twenty-four-hour sleep-wake cycle. The production and activity of the neurotransmitter serotonin, which is important in the self-regulation of these circadian rhythms, is also altered during attacks. Cluster headache is not related to the development of tumors or lesions.

Cluster headaches are rare. No more than .03 percent of the population ever experiences them. Men suffer them more than women do, although with improvements in epidemiological techniques the known ratio has been changed from 7:1 to 2:1. The age of onset is usually in the late twenties. As with migraine headaches, cluster headaches tend to run in families, with a fourteenfold increase in the chances of having them if a first-degree relative (mother, father, son, daughter, brother, or sister) suffers from the syndrome. In addition, a statistically significant incidence of migraine headaches exists in families with a cluster headache sufferer.

Cluster headache attacks, which are excruciatingly severe, debilitating, and dramatic, are almost always unilateral and occur from one to six times a day. They are most intense in, around, or behind one eye. Because the pain, commonly described as “boring” or “stabbing,” often spreads into the upper teeth, jaw, neck, or temple, the headaches can be misdiagnosed as coming from dental or sinus problems. The attacks are rapid, peaking in five to ten minutes, and are occasionally, but not frequently, preceded by a visual aura. Attacks are much more likely to occur if tobacco and/or alcohol have been recently used, and they even more frequently will awaken sufferers during their first hour of napping or sleeping.

While migraine headache sufferers seek quiet, darkened places and try to remain still, cluster headache sufferers feel more pain if they try to lie down or recline in a chair. Typically, cluster headache sufferers are restless, pacing back and forth, or want to sit upright, holding their heads with their hands. A sufferer may even bang his or her head against a wall to obtain relief.

Treatment and Therapy

Treatments are oriented either toward abortive therapies or prophylactic therapies. Abortive approaches attempt to shorten the duration and/or intensity of an individual attack. Prophylactic approaches attempt to shorten or prevent the cluster periods themselves. While a fortunate characteristic of the attacks is their brevity, this feature also limits the range of abortive measures that can be undertaken; by the time that some agents are metabolized, the attack is over.

Although not always practical, a successful and safe abortive treatment is simply breathing 100 percent oxygen for ten to twenty minutes through a nonrebreathing mask. Also not always practical but effective are subcutaneous injections of sumatriptan (Imitrex) or intravenous, intramuscular, or subcutaneous injections of dihydroergotamine (Migranal). Other effective first-line therapies for acute intervention include zolmitriptan (Zomig) tablets, intranasal lidocane, or ergotamine (Cafergot).

Prophylactic, or preventive, treatments prevent attacks or at least lessen their intensity. All cluster headache sufferers should be on a prophylactic regimen (unless their cluster periods are less than two weeks, which is rarely the case). Verapamil (marketed as Calan, Covera, Isoptin, Tarka, and Verelan) is the most commonly prescribed medication because its mechanism as a calcium-channel blocker is well understood and it is usually effective. Occasionally, higher-than-typical doses must be employed. For those who do not respond well or receive sufficient relief on verapamil alone, a second medication such as ergotamine, lithium, methysergide (Sansert), or prednisone is often added. Sometimes, these second medications are effectively used alone, as are valproic acid and divalproex (Depakote).

In the event that pharmacology proves ineffective, several surgical or radiation techniques can block the trigeminal-autonomic reflex pathway. The benefits of these, or any, invasive treatments must be weighed against potential harm. For example, corneal anesthesia, needed to carry out these procedures, can put the eye at risk.

Perspective and Prospects

People have suffered from cluster headaches as long as people have suffered from headaches, although the rarity, seasonal occurrence, and symptoms of cluster headaches have made their recognition as a distinct syndrome difficult. Through PET scanning, neurovascular research has identified three areas of the brain particularly affected by cluster headaches. Because two of these areas are affected every time any sort of pain is felt, research is being concentrated on the third area, hypothalamic gray matter. Researchers expect that probes here will resolve their biggest debate: Is the vasodilation associated with cluster headache the primary problem or the result of activation of the trigeminal vascular system? Researchers do agree that cluster headaches, while distinct, belong to a family of related conditions, the cranial neuralgias.

Bibliography:

Dalessio, Donald J. “Relief of Cluster Headache and Cranial Neuralgias.” Postgraduate Medicine 109, no. 1 (January, 2001): 69–78.

Jasmin, Luc. "cluster Headache." MedlinePlus, Mar. 22, 2013

Kudrow, L. “Cluster Headache: Diagnosis and Management.” Headache 19 (1979): 141–48.

Newman, Lawrence C., Peter Goadsby, and Richard B. Lipton. “Cluster and Related Headaches.” In Headache, edited by Ninan T. Mathew. Philadelphia: Saunders, 2001.

Wood, Debra. "Cluster Headache." Health Library, Feb. 21, 2013.

What ideas did the Free Soil Party promote?

The Free Soil Party was against the continuation of slavery. It was a political party whose members were originally from the Democratic party. In 1848 at its convention in New York State, members of the Democratic party failed to endorse a ban on slavery in any territories that were won in the Mexican-American war--Texas being one such territory. Some of the members of the Democratic party were opposed to this continuation of slavery and broke away to form the Free Soil Party. One of its members, Martin Van Buren had already served as president from 1837-1841 when the party was formed in 1848. The Free Soil Party was not an abolitionist movement. It was against slavery not because slavery was cruel but because the existence of slavery would undermine the dignity of almost all physical labor that was not slavery.

What was the low point of the Civil War for the Union?

One of the lowest points in the Civil War for the Union occurred during a series of battles in the summer of 1862. In the Seven Days' Battle, which lasted from June 25 to July 1 1862, Robert E. Lee commanded a Confederate army that drove Union troops out of Richmond. Soon after, Lee led yet another defeat of Union troops during the Bull Run, or Second Battle of Manassas. That August, Confederate troops drove the Union presence in Tennessee back into Kentucky, and Lee led an invasion of Maryland. This rapid series of victories by the Confederacy lowered morale for the Union, and many consider this the lowest point of the war. The New York Times even predicted in early September that the Union was bound to lose the war, and anti-war Democrats began to urge the Union to enter peace negotiations to end the war. However, the Battle of Antietam, in late September, resulted in a Union victory and President Lincoln issued the Emancipation Proclamation soon after.

What is a good thesis statement for this topic? Throughout the novel, we learn that Gatsby’s goal in life since he was a young man is to win...

You could argue that Fitzgerald denies Gatsby his dream just as it seems as though it is about to come true in order to make a point about the impossibility of the American Dream.  Tom Buchanan has old money, money that he has inherited from his wealthy family, money for which he has never had to work.  Gatsby was not born into such a family; instead, if he wanted to provide Daisy with the kind of life to which she has been accustomed, he would have to earn his money another way.  Unable to find any honest way to quickly acquire the funds he needed (even an inheritance that was left to him was stolen away from him), he resorted to bootlegging, profiting from the illegal production, distribution, and sale of alcohol during Prohibition.  He longs to achieve the same status as someone like Tom Buchanan, and he seems to believe that money is all that is required to get there.  However, he doesn't realize that new money, money that has been earned, is of much less value to the upper classes than old money.  Further, the fact that Gatsby has had to resort to illegal means to earn that money corrupts the dream all the more.  When Daisy learns that Gatsby has made his money illegally, it is enough to push her back into her husband's legally rich arms.

George Wilson, husband of Myrtle, the woman having an affair with Tom, has also attempted to reach the American Dream, but legally, and he's been unsuccessful as well.  He lives in the valley of ashes with his cheating wife, trying to turn a profit but lacking in opportunity and being misled again and again by Tom.  In the end, Wilson kills himself and Gatsby, believing that Gatsby had been sleeping with Myrtle, who was killed in an accident by Daisy, and so everyone who'd been attempting to achieve the American Dream is gone.  Who remains?  Daisy and Tom: the selfish, racist, elitist couple who basically barrel over everyone in their path.  They have all the power and can essentially do whatever they want, and they survive.  If society didn't privilege people like this, then such an outcome would not have been possible.  If society truly valued loyalty and hard work, then Gatsby and Wilson would have lived prosperously.  The fact that these two men, the ones who were most cheated of the dream, die shows that the American Dream is really only a corruption of an ideal at best.

How can Whitman and Dickinson be considered Romantic poets?

While Walt Whitman and Emily Dickinson came to prominence at the end of the Romantic/Transcendentalist movement, they both share aspects of the Romantic writers. First and foremost, they both share a love of Nature and find a spirituality in Nature. For instance, in Whitman's Song of Myself, particularly in canto 6, he speaks of the grass, where he contemplates the many definitions of it. First, he sees the positive aspects of the grass, calling it "the handkerchief of the Lord" (94), "the produced babe of the vegetation" (97), and "a uniform hieroglyphic" (98). But the tone shift to a more somber meaning of the grass in line 102 when he envisions the grass as "the uncut hair of graves." In this second section of the canto, Whitman attempts to come to terms with those who have died, especially those who were in the prime of their lives, like young men who were taken because of war (104) or children who died in infancy (106). But the spirituality of this contemplation comes when he realizes that "They are alive and well somewhere; / The smallest sprout shows there is really no death; / And if ever there was, it led forward life, and does not wait at the end to arrest it" (117-119). This cycle of life aspect is reminiscent of other Romantic writers such as William Cullen Bryant in his poem "Thanatopsis."

Emily Dickinson shows another characteristic of Romanticism, namely that knowledge can be gained through intuition, which is shown in poetry through strong senses, emotions, and feelings. This characteristic can be found in Dickinson's poem "Success Is Counted Sweetest." In this poem, Dickinson uses two metaphors to explain feelings of success and victory. In the first stanza, she attributes feeling success to someone who has a great thirst; that person tastes nectar in the drink because he "Requires sorest need" (4). Thus, if one is not truly thirsty, he will not think the water (or other drink) tastes as sweet. The second metaphor Dickinson uses is that of the fallen in battle. They "Can tell the definition...of victory" (7-8) far better than the winners because of the agony and defeat they feel while listening to the celebration of the winners. In this poem, Dickinson uses the two metaphors to make concrete an abstract concept. She cannot define success or victory through reasonable means; she must use emotions and feelings that the reader understands in order to come to her conclusion, thus making her poem a Romantic piece.

Overall, Whitman and Dickinson share aspects of Romanticism in their poetry even though many take their works as unique from all other poets of their time.

In Zora Neale Hurston's essay "How It Feels to be Colored Me," what happens when she goes to The New World Cabaret?

She goes to The New World Cabaret, a popular nightclub in Harlem during the 1920s, with a white male friend to listen to a jazz band. There, she says, "[her] color comes." That is, she feels this music on an instinctive level:

I dance wildly inside myself; I yell within, I whoop; I shake my assegai above my head, I hurl it true to the mark yeeeeeooww! I am in the jungle and living in the jungle way...But the piece ends...I creep back slowly to the veneer we call civilization with the last tone and find the white friend sitting motionless in his seat smoking calmly.

Notice that she writes that all of this is happening "inside" of her. She does not express herself physically, but remains seated while listening and responding privately. The music evokes a sensibility that is non-Western -- hence, the reference to the "assegai." 

Arguably, Hurston romanticizes Africa and African-inspired themes, particularly by referencing "the jungle" and "living in the jungle way." She is not fetishizing Africa, but contrasting African forms of expression with those in Europe and America. In Africa, one can feel music and channel that feeling into an individualized physical response. In Europe, music is more cerebral and dance movements are subjected to rules about form; that way, everyone is in sync and knows what to do (e.g., waltzes).

"The white friend" has a cerebral, or analytic, response to the music:

"Good music they have here," he remarks, drumming the table with his fingertips. 

Music. The great blobs of purple and red emotion have not touched him. He has only heard what I felt...

He has "only heard" it, meaning he has responded passively to the music. His judgment of it being "good" is an analytic response, not an emotional one. 

In this scene, Hurston illustrates what she perceives to be a difference between black and white people. She does not judge the man negatively for this, but merely sees that they are different and distant from each other on this matter, whereas, when they arrived at the club, they "[entered] chatting about any little nothing that we have in common."