Why is displacement a vector quantity and not a scalar quantity?

A scalar quantity is one which can be described by its magnitude only and does not require a direction. Speed is a scalar quantity. A vector quantity, on the other hand, needs both magnitude and direction for its complete description. Velocity is a vector quantity.

Displacement is the difference between the initial position and the final position of a body. Displacement is a vector quantity and not a scalar quantity because it can be only described by using both magnitude as well as direction. Distance, on the other hand, is a scalar quantity, since we need to know only about the path taken. In comparison, the path does not matter in the case of displacement. 

When describing the displacement of a body, we usually ask something like, "a body started from origin and reached the coordinates (4,5) in 10 seconds. Determine its displacement." 

Hope this helps. 

What if Macbeth had not acted upon his wife's advice?

If Macbeth's wife had not goaded him into committing the murder, it seems unlikely that he actually would have gone through with it.  After he considers the myriad potential consequences of killing Duncan, he tells her, "We will proceed no further in this business" (1.7.31).  He has considered the fact that he is Duncan's subject, kinsman, host, and friend; he is supposed to protect him against attackers, not wield the murder weapon himself.  He has also considered the fact that simply killing Duncan will not make him king, there will be other deceptions he will have to carry out.  Further, he knows that Duncan is such a great leader and a good person, and this makes it even harder for him to commit to the deed.  It isn't until his wife calls him a "coward" who is "green and pale" and tells him that she will no longer think of him as a man if he refuses to go forward with their plan that he finally agrees. Therefore, had she not wounded his pride and insulted his masculinity, it seems unlikely that Macbeth would have actually committed the murder, although his marriage would likely have declined in trust and love (although, it seems to do that anyway, even when he takes her advice).

What mood is created by the description of the setting in "To Build a Fire"?

In Jack London’s short story “To Build a Fire,” important elements of setting include the location, time of day, weather, and the environment itself, which all combine to create an increasingly cold and hopeless mood. By the second paragraph we learn that the main character is a lone, inexperienced traveler in the Yukon in Alaska during the winter. Such a location gives readers an instant sense of remote loneliness, isolation even. Specifically, the man has already left the main trail and veered onto “a little-traveled trail [that] led east through the pine forest.” So although he is even more isolated, the sun is before him, since it is 9:00 a.m. This fact does give a sense of hopefulness. After all, he has all day to get to his destination: a camp on Henderson Creek where “the boys were already.”

Yet the weather is foreboding from the start. The first sentence tells us “Day had dawned cold and gray,” and we soon learn that it is 75 degrees below zero. It is so cold that the man’s lips freeze together (aided by his tobacco drool), making it difficult for him to eat his lunch. He gradually becomes so numb that he can’t even feel himself running. The weather itself actually remains constant throughout, but it creates a building sense of panic in readers as we watch this foolish man slowly freeze to death.

Tied to the weather, the environment is his antagonist all the way. The tricky ice that his wolf-dog falls through weakens them both, as the man has to remove his mittens to help it get ice out of its toes. The first fire gives us some sense of relief and hope, but when his second fire is put out by snow falling from a tree, the mood darkens to one of hopelessness.

By the end when the man sits in the snow to fall asleep into death, “The brief day ended in a long evening.” The dog, part of the natural environment, curls its tail around its feet and passively watches the man, waiting. On smelling death, it lifts its head in a long, lonely howl, then trots off toward the camp at Henderson Creek as the stars “leaped and danced and shone brightly in the cold sky.” Nature is impervious to man’s struggles, leaving us with a hopeless mood, feeling cold and insignificant.

How did Rome become politically unstable?

There are a plethora of reasons why Rome, one of history's longest-lasting and most powerful empires, finally fell.  Although the reasons and their level of importance are highly debated among historians, most agree that there were certain factors that clearly led to the Roman empire's demise.

Rome had always struggled against invasions by Germanic tribes, but in 476 the Roman emperor Romulus Augustulus was deposed by Germanic leader Odoacer.  After this happened, no Roman emperor ever again ruled from a post in Italy.

Rome also began to struggle economically due to its constant wars and overspending on outside conquests. Its over-expansion made it difficult to administer and run the empire across such great distances, while military overspending emptied its treasury.  These problems were exacerbated by the rampant corruption that existed in the Roman government.  Roman citizens began to lose trust in their leadership, setting the stage for civil revolt.

How can a teacher gain control of his/her class?

The first thing to realize here is that you are not alone.

Working at a school, you have a community of teachers who will almost definitely be glad to help you. Admitting that you need some tips from other teachers does not make you look bad. It makes you look like you want to get better as an instructor (and also signals to other instructors that you respect their professional knowledge). After all, every teacher was new once and almost no one masters the craft of teaching on the first day. It takes time to become a good teacher.

I will offer some ideas here that I feel work across disciplines, but I would also encourage you to ask another science teacher for some instruction and class management ideas that have worked for him/her.

In addressing issues of student confidence, your own confidence and classroom management, these ideas may be helpful:

• Use quizzes.


• Create definite and predictable routines.


• Let students work together. 


• Use as many activities as you can in every class period.


• Be consistent and have a list of responses for behavior management.

Use quizzes to check for understanding and strive to construct questions on several levels of difficulty. Make the quizzes brief and make some quizzes really easy and basic. Use the quizzes as a means to (1) check for understanding, (2) review concepts and encourage studying and (3) to build student confidence.

Offering students regular and realistic chances to get an “A” can go a long way to helping students realize that they can succeed. You might consider also creating a system where the worst quiz grades in a unit are eliminated and only the top three, four or five quiz scores count toward the grade. This can reduce performance anxiety.

Create definite and predictable routines. For all grade levels, students thrive on routine. This is true outside of the classroom as well. Routine is comforting. In the classroom, where students are dealing with many personalities every day and also engaging in challenging course material, routine can reduce anxiety and help students learn.

This may be somewhat counter-intuitive because routines may at first seem boring or repetitive, but in my experience starting every class period with by asking students to copy down two or three subject-related vocabulary terms helps to set the tone, get students settled in and anchor the class period in a predictable activity. Many options are available, naturally, and using vocabulary is just one example. 

(Combining these first two ideas, I had good results with giving students eight vocabulary terms per week (two per day, Monday to Thursday) and then a vocabulary quiz on Friday. Students knew what would happen at the start of each class. They got some easy points on the weekly vocabulary quizzes. And I used the time they were copying terms and definitions from the board to take attendance at the beginning of the period.)

Routines also communicate the idea that you, as an instructor, are organized. If you have a system, students feel confident that you can teach them. If you are looking to build up your students’ confidence in you, routines can be a great and big step in that direction.

Let students work together. Behavior issues, in my experience, diminish when students have opportunities to talk in class. Also, when students work in pairs or small groups you can move around the room and interact with individual students or groups, allowing students who do not want to ask questions in front of the whole class to ask questions in this context without drawing unwanted attention. An additional benefit here is that students see other students struggling and might realize that their own difficulties are normal.

Use as many activities as you can in every class period. Keep things moving during a class period and also put the class agenda on the board. The agenda can work as a count-down for students, letting them track their progress through the class session on any given day. The agenda also communicates your sense of organization and planning, letting students know that you are fully prepared for the class (thereby building confidence).

Using many activities helps to eliminate some behavior problems. If students can see that they will be doing many things (on the agenda) and then are engaged in multiple activities, they are less likely to succumb to boredom. Boredom is not necessarily always a response to a lack of stimulus. Sometimes boredom comes from a sense of being stuck in one place for a long time. Bad behavior results from this but can be circumvented, to some extent, by letting students move from activity to activity and thus not be stuck doing one thing for an entire class session.

Be consistent and have a list of responses for behavior management. If you have a student that is interrupting class with a panic about “not getting it,” you might consider immediately responding by telling that student you are available after school to answer any and all questions. The rest of the class needs to learn and so must move on, but any questions can and will be answered, the student will be caught up, after school. Say this every time. Say it to everyone.

Let students know that you are tracking their behavior. Make a chart for yourself where you mark five points for each event of bad behavior. Tell students that when they reach fifteen points, you will send an email to the principal to let the administration know you are concerned with this student’s ability to behave in class. When they reach twenty-five points, you will send an email to the student’s parents asking for a conference.

Write the email ahead of time and think about showing the students. Let them know that you have a plan. Their choices have consequences. This system of cause-and-effect is in their control. They can choose to have these emails sent or choose not to. Consider adding a plan to get students back to zero somehow, if that seems like a good idea to you.

Whatever happens, stick to the script. Be consistent. Your consistency speaks to your professionalism and to the authority of your systems. You do not have to be the authority, per se. Your routines and behavior management program can be the authority. And you can just teach. This is not you versus them. They should know that you are on their side and rooting for them to learn, get the “A” and avoid getting those emails sent out.

Giving advice is always easier than implementing advice, but hopefully you can see some relatively easy ways to put some of these ideas into practice.  

What connection does John O’Sullivan make between manifest destiny and the idea of American freedom?

John O'Sullivan, writing in 1839, made a strong correlation between American exceptionalism, freedom, and manifest destiny. In other words, he believes that America's love of liberty makes it unique and destined to do great things on the continent. He cites the nation's founding document to support his claim:

Declaration of National Independence being entirely based on the great principle of human equality, these facts demonstrate at once our disconnected position as regards any other nation; that we have, in reality, but little connection with the past history of any of them, and still less with all antiquity,.....

O'Sullivan also believes that a country's destiny is determined by the level of freedoms that it allows its citizens. In making the earlier case that the United States is the leader in civil liberties, this passage assures the reader that the United States has a positive future.

It is so destined, because the principle upon which a nation is organized fixes its destiny, and that of equality is perfect, is universal........its greatness, its duration, were always proportionate to the democratic equality in its system of government. . .

He finally connects his argument that the United States is destined to dominate the continent because of the unbridled freedoms that are granted to its citizens:

America is destined for better deeds. It is our unparalleled glory that we have no reminiscences of battle fields, but in defence of humanity, of the oppressed of all nations, of the rights of conscience, the rights of personal enfranchisement.

What is the science of genetics?

Genetics, put simply, is the study of genes! A geneticist may be interested in heredity (how genes are passed on), variability (the many forms of one gene), interaction (how genes work with one another), or large-scale population phenomena. One of the really exciting things about genetics is that it allows us to compare and contrast different organisms, both living and dead. Genome mapping offers insight into how close we as Homo sapiens are to other organisms like the extinct Homo neandertalensis or even a banana! 

The study of genetics is also very important to health and the medical community. People living with genetic conditions like Von Willebrand's Disease, Ehlers-Danlos Syndrome, and muscular dystrophy rely on the work of geneticists for a better understanding of their illness. Genetic medicine can help doctors develop better treatments and even cures for genetic disorders.

Who is the author of The Communist Manifesto and what is the position or title of the author?

Published in 1848, The Communist Manifesto has two authors: Karl Marx and Friedrich Engels. These two men were intellectuals from Germany who, in 1847, took part in the first meeting of the Congress of the League of the Just in London. This organisation then changed its name to the Communist League and Marx and Engels were commissioned to write down the views, aims and "tendencies" of this League for dissemination across Europe, as mentioned in the Preamble to the text. 

Both Marx and Engels were ideally suited to this purpose. Marx, for example, studied philosophy at university before becoming a journalist, while Engels, the son of a textile manufacturer, had witnessed first-hand the exploitation of the working classes while employed in his father's factories. 

Marx and Engels possessed neither an official title nor role of any great importance (they were not politicians, for example), but, working together, they had the writing ability and the ideological understanding necessary to produce such a document.

How does the gulf stream affect the Eastern seaboard of the United States?

The Gulf Stream is a warm, fast moving ocean current coming from the Western Caribbean Sea and flowing through the Gulf of Mexico, Eastern Florida and moving along the eastern seaboard of the United States towards North Carolina where it now turns northeast.

The Gulf Stream brings along with it warm moisture creating a warming effect along the east coast of the U.S. This makes the area warmer than other places on the same latitude as the east coast. The increase in moisture in the atmosphere increases the general humidity along the coast.

The stream plays an important role in the growth and distribution of aquatic organisms which serve as food for various kinds of fish. The presence of the Gulf Stream brings an incredible diversity to wildlife and plant population which wouldn’t have been found on this latitude were it not for the effect of the Gulf Stream.

Ships sailing along this coast get a boost from the swift flow of the Gulf Stream current. The Gulf Stream has a remarkable ability to feed into hurricanes and tropical storms by intensifying them as they pass over warm water.

What is a measure of the average kinetic energy of the individual particles in an object?

Temperature is a measure of average kinetic energy of particles in an object. The hotter the substance, higher is the average kinetic energy of its constituent particles. When we heat a substance, the particles that constitute the substance gain some energy and begin to move faster. This increase in kinetic energy causes them to travel more distance in the same amount of time (as compared to their motion prior to heating the substance). This causes more collisions between the particles and between the particles and the container walls (in case of fluids). These collisions raise the temperature of the substance as a whole, and thus the temperature can be measured as a measure of average kinetic energy of the particles. 

Note that not all the particles move in the same direction and with kinetic energy. Temperature is a measure of average kinetic energy of all the particles and not that of each individual particle.

Hope this helps. 

Should the peasants of England have bothered to rebel in 1381?

Probably not, but hindsight is 20/20.

Wat Tyler's rebellion in 1381 was largely triggered by the poll tax levied to pay for the war with France, as well as the perception that the king's ministers (not the king himself!) were responsible for their economic misery and deserved to be punished---some said even beheaded. They also had some more general demands for reduced economic inequality.

But the rebellion was quite small, and failed very quickly; in about a month it was completely suppressed and the leaders were executed. Almost none of their demands were met, and in fact the government cracked down on peasants even harder, making things worse.

So, with the benefit of hindsight, it seems like the revolt was probably not a good idea. But at the time, that was probably a lot less clear. Other peasant revolts had succeeded to various degrees in the past; many of their objectives were sensible and popular; and even the targeting of the king's ministers rather than the king himself probably seemed like a sound strategy at the time. Even if they knew they probably wouldn't win, apparently enough people were simply fed up enough with the current system that they were willing to take the chance.

What are best examples of the way the second section links the first and third sections? Think especially about the things Oberirka says to Okonkwo.

Chinua Achebe’s Things Fall Apart is segmented into three distinct sections that reflect the major stages of tragic protagonist Okonkwo’s life. Indeed, the first section shows Okonkwo as he strives to be one of the great, dominant men in Umuofia. The second section illustrates his life in exile in Mbanta. The final section details Okonkwo’s return to Umuofia, and his realization that his traditional way of life is now incongruous with the colonial values that now dominate the region. Interestingly, Okonkwo’s best friend Obierika’s perspective becomes very important in tying the three sections together. The first section ends with Obierika questioning the traditional norms of Umuofia and lamenting the fate of his best friend:

“Obierika was a man who thought about things. When the will of the goddess had been done, he sat down in his obi and mourned his friend's calamity. Why should a man suffer so grievously for an offense he had committed inadvertently?” (125).

Similarly, Obieirka’s perspective is the last native view that readers encounter in the end of the novel. Obeirika grieves the loss of his friend, and blames the colonial presence in Umuofia:

“That man was one of the greatest men in Umuofia. You drove him to kill himself; and now he will be buried like a dog” (208).

While Obierika does not close out the second section in the same way that he does the first and third, his presence in the middle portion of the novel is nevertheless very important in tying the three sections together. Umuofia is changing drastically while Oknonkwo is away, and Obierika serves to report the alterations of the area. He is Okonkwo’s sole connection to his former land, and he visits Okonkwo with news from Umuofia. Indeed, Obierika portends the great changes that Umuofia will experience when he gives Okonkwo money from his crops:

“That is the money from your yams.... I sold the big ones as soon as you left. Later on I sold some of the seed-yams and gave out others to sharecroppers. I shall do that every year until you return. But I thought you would need the money now and so I brought it. Who knows what may happen tomorrow? Perhaps green men will come to our clan and shoot us” (142).

Thus, Obierika is a deceptively crucial character in tying the three sections of the novel together.

Did Odysseus develop as a leader through his journey?

Not particularly. Odysseus seems like a pretty static character, meaning that he really doesn't change in any significant or fundamental way throughout the text. He is courageous and cares deeply about the men he leads at the beginning of his journey.  When the crew stops at Ismarus immediately following the end of the Trojan War, they sack the city and Odysseus shares the spoils with them.  He continues to care about them through the duration of their journey, and he sincerely mourns each one when they perish.  He gives good advice, even in the beginning, and he looks out for his crew members' best interests even when they are unable to look after it themselves (such as when they stop at the land of the Lotus-eaters).  To be sure, Odysseus does have his flaws, but they neither resolve nor increase as time passes.  In other words, he is much the same at the end as he was in the beginning.

What is an analysis of Act I, Scene 7, in Macbeth?

This scene is one of the most fascinating in Macbeth, and represents an important turning point in the play. At the beginning of the play we find Macbeth alone in his castle, and his soliloquy reveals that he is having serious second thoughts about murdering Duncan. Recognizing that Duncan is first his kinsman and second a good and decent man, he has to admit that "vaulting ambition" is his only motive to kill him. Duncan is also his guest, and to harm a guest was an especially grievous crime in Macbeth's society. By the end of his speech, he seems to have resolved not to carry out the crime. At this point Lady Macbeth enters the scene and after her husband says that they will "proceed no further in this business," she immediately begins to goad him into committing the murder. In one of the most chilling speeches in this very dark play, she says that she would have "dash'd the brains out" of her own infant before breaking a pledge to kill Duncan, which is what Macbeth has determined to do. She challenges Macbeth's masculinity, clearly recognizing that this appeal will resonate with her husband:

When you durst do it, then you were a man;
And, to be more than what you were, you would
Be so much more the man.

She goes on to essentially lay out the plan: Macbeth will murder the king in his sleep, and they will smear the dead man's blood on his sleeping guards, who Lady Macbeth plans to get very drunk. This scene is a turning point for Macbeth. By the end, he is "settled" on committing the deed, and he cannot turn back. He is embarking on a path of murder that will eventually consume his wife as well as him, and Lady Macbeth plays a very prominent role in ensuring he starts down this path. 

How are Scout and Jem open minded in To Kill a Mockingbird?

The open-mindedness of Scout and Jem has been instilled by their father, Atticus Finch, who advises them to understand a person by "consider[ing] things from his point of view." Atticus also conveys his open-mindedness to his children by prohibiting Scout and Jem from antagonizing Boo Radley, or criticizing those the children may find different from themselves. Atticus seems determined to encourage both to retain the innocent view of life and people that often accompanies youth, without succumbing to prejudices and falsehoods. 

When the innocence of Scout and Jem is challenged by some of the harsh realities of life in Maycomb, Alabama, Atticus and others, like Calpurnia, Miss Maudie, and Dolphus Raymond, are often available to help the children navigate the tangled thoughts and emotions that darken their experience.

Jem is infuriated by the town's attitude towards Tom Robinson and is crushed when the jury finds Robinson guilty of the charge of raping Mayella Ewell. Unlike the majority of townspeople who routinely take the side of a white person against that of a black person, Jem rages against the prejudice of the people of Maycomb, whom he believes are content to send an innocent black man to die for something he didn't even commit:

"I always thought Maycomb folks were the best folks in the world, least that's what they seemed like."

Scout, though her path to tolerance is smoothed repeatedly by Atticus, comes to put aside many of her prejudices against the likes of Boo Radley, poor souls like Walter Cunningham, and even some of the irritating and eccentric ladies of the town, and learns to take to heart Atticus' advice to understand a person through by "climb[ing] into his skin and walk[ing] around in it."

While both benefit from the natural openness of youth, Scout's and Jem's open-mindedness is hard won. While Jem's may spring from his position as the older sibling better able to understand Atticus' moral (and legal) expositions, Scout's seems to come from the loving discipline her father shows her.

`int_0^(pi/2) sin^7(theta) cos^5(theta) d theta` Evaluate the integral

`int_0^(pi/2)sin^7(theta)cos^5(theta)d theta`

Let's first compute the indefinite integral by rewriting the integrand,

`intsin^7(theta)cos^5(theta)d theta=intsin^6(theta)sin(theta)cos^5(theta)d theta`

Now use the identity:`sin^2(x)=1-cos^2(x)`

`=int(1-cos^2(theta))^3sin(theta)cos^5(theta)d theta`

Now apply integral substitution,

Let `u=cos(theta)`

`=>du=-sin(theta)d theta`

`=int(1-u^2)^3u^5(-du)`

`=-int(1-u^2)^3u^5du`

`=-int(1-u^6-3u^2+3u^4)u^5du`

`=-int(u^5-u^11-3u^7+3u^9)du`

`=-intu^5du+intu^11du+3intu^7du-3intu^9du`

`=-u^6/6+u^12/12+3(u^8/8)-3(u^10/10)`

`=u^12/12-3/10u^10+3/8u^8-1/6u^6`

Substitute back `u=cos(x)`

`=1/12cos^12(x)-3/10cos^10(x)+3/8cos^8(x)-1/6cos^6(x)`

Add a constant C to the solution,

`=1/12cos^12(x)-3/10cos^10(x)+3/8cos^8(x)-1/6cos^6(x)+C`

Now let's evaluate the definite integral,

`int_0^(pi/2)sin^7(theta)cos^5(theta)d theta=[1/12cos^12(x)-3/10cos^10(x)+3/8cos^8(x)-1/6cos^6(x)]_0^(pi/2)`

`=[1/12cos^12(pi/2)-3/10cos^10(pi/2)+3/8cos^8(pi/2)-1/6cos^6(x)]-[1/12cos^12(0)-3/10cos^10(0)+3/8cos^8(0)-1/6cos^6(0)]`

Plug in the values of `cos(pi/2)=0.cos(0)=1`

`=[0]-[1/12-3/10+3/8-1/6]`

`=-[(10-36+45-20)/120]`

`=-[-1/120]`

`=1/120`

What are hinduism's roots?

Unlike many modern religions, Hinduism has no definitive founder.  Hinduism started as a culture in India that then grew into a religion. Hinduism can be traced back to 2000 BC. Hinduism is based on teachings from Vedas. Hindus believe Vedas are sent by God to earth as human beings. Thus, God, according to Hindus, is the founder of Hinduism. Teachings were handed down from word of mouth. Hinduism also draws from the teachings of Rishis, saints, customs and culture. 

Some recent debate has occurred whether or not the Aryans started Hinduism. Initially, it was believed that Hinduism religion and culture were the result of an Aryan invasion. However, recent scholars have suggested otherwise. Some scholars believe that Hinduism resulted as a mixture of cultures between those native to India and the Aryans travelling around the continent. 

Provide physical and behavioral descriptions of Myrtle and explain the connotations behind these descriptors.

Myrtle's characterization presents her as a coarse, crass, yet ultimately pitiable character driven by social mobility, which she defines only in a materialistic sense.  Physically, she is the antithesis of the willowy, slightly androgynous flapper of the 1920's; Nick describes her as "thickish" and "faintly stout" and though lacking beauty, she possesses "an immediately perceptive vitality."  Her voice ("soft, coarse") and unrefined and uniformed manner of speaking at the party she and Tom host ("...I had a woman up here to look at my feet, and when she gave me the bill you'd of thought she had my appendicitis out") reveal her vulgarity.  Her use of racial slurs ("kike"), denigration of her hard-working husband, and blithe pursuit of a married man sketch an unlikable woman who embodies the shallow desires Fitzgerald is critiquing. Myrtle is a woman driven by base appetites for sex, alcohol, and the trivial things money can buy: scandal magazines, cold cream, drug store perfume, a trick ashtray, and most sadly, a dog she has forgotten by mid-afternoon--thereby catching Nick's attention as the antithesis of the core values with which he has been raised.  

Fitzgerald, F. Scott.  The Great Gatsby. Charles Scribner's Sons, 1925.

How might Bottom be a foil to Theseus?

In literature, a foil is a character who by contrast accentuates the traits of another character in the story. A few famous examples would be how sports-mind Ron makes the bookish Hermione looks even more bookish, or how the gentle and considerate Watson makes Sherlock Holmes look even more cold and rational. 

Bottom is an idiot and a clown. He is a comedic character. He frequently misuses words, demands to play every character in his play, makes a fool of himself at every possible chance, and even physically becomes a jackass. 

Theseus, on the other hand, is the very model of intelligence and good judgment. He is named after the Greek hero, who through smarts and bravery defeated the Minotaur. The duke speaks well but plainly. He is articulate. He is anything but a fool.

By watching the two characters' opposite traits the audience can more easily see the qualities in the other. In fact, Bottom is only the most extreme example. Nearly every character behaves foolishly in some way while in the forest, which only makes Theseus' reasoned approach stand out more.

A decrease in the price of pesticides and increase in the demand for wheat will lead to an increase in the supply of wheat. True or False?

The answer to this depends on how picky and precise you believe that your instructor is.  This is because the supply of wheat will go up in this case, but only one of the two factors you mention actually causes it to go up.  In other words, if the price of pesticides drops, the supply of wheat will rise, but an increase in the demand for wheat does not cause supply to rise.

One of the main determinants of supply is the cost of inputs, which are the things that are needed to create a product.  In most cases, farmers need pesticides in order to produce good crops of wheat.  Therefore, pesticide is an input of wheat.  When the price of an input drops, a producer gets more profit for selling their product at any given price.  This means that they will want to sell more of that product at that price.  When you want to sell more of a product at a given price than you did before, that is an increase in supply.  Thus, a decrease in the price of pesticides causes an increase in the supply of wheat.

Demand is not a determinant of supply.  If demand rises, it has no effect on how much of a product the producer wants to sell at a given price.  Instead, when demand rises, the price of the product rises.  Producers want to sell more than they previously did, but it is at a different price, so it is not a change in supply.  When demand goes up, we see a change in quantity supplied, not a change in supply.

So, a drop in the price of pesticides will cause the supply of wheat to rise, but an increase in demand for wheat has no impact on the supply of wheat.  In your view, does that make the whole statement true or false?  What do you think your instructor will say?  (If I put a question like this on homework for  my students, I would expect them to say it is false because I would be testing to see if they know the difference between a change in supply and a change in quantity supplied, but I do not know what your instructor is trying to achieve with this question so I do not know what answer you should give.)

What motivates Macbeth: Violence? Compassion?

The events that take place in Macbeth center around the violence caused by one couple's pride and ambition and greed.  When Macbeth is confronted by the Weird Sisters and their statements about his becoming Thane of Cawdor and then king, it sets into motion a chain of events that lead to the murder of a good man, kind friend, and noble king.  Once Macbeth acquaints his wife with the Weird Sisters' words, she immediately begins to plot the "nearest way" to the throne.  Although Macbeth considered violence early on, he eventually decides that they "will go no further in this business," and he resolves not to injure his friend until his wife wounds his pride by insulting his masculinity.  When she insists that he will have to live a "coward in [his] own esteem" if he reneges on his promise to her to kill Duncan, he relents and recommits to their plan.  Therefore, it is, ultimately, his pride which prompts him to go forward with the murder.  It seems to be greed and ambition, primarily, that prompt her. 

What are some of the qualities of the nurse in Shakespeare's Romeo and Juliet and why are they important to her character?

The nurse is incredibly loyal and loving to Juliet, though not particularly intelligent. She still seems to think of Juliet as a child, as she fails to recognize the strength of Juliet's devotion to Romeo.  With the nurse, it seems that what you see is what you get, and her loyalty to Juliet allows the love between Romeo and Juliet to reach fruition when she agrees to be their go-between.  Juliet depends on her and trusts her implicitly, at least until she advises Juliet to marry the County Paris after Lord Capulet threatens to throw her out if she disobeys him.  Even then, however, the nurse is trying to advise Juliet as she thinks best, but it is that crucial moment -- when she fails to recognize the strength of Juliet's loyalty to Romeo -- that severs something between them.  If the nurse were a little smarter or understood the strength of Juliet's loyalty to Romeo a little better, she would have advised her differently and not completely alienated Juliet.  The tragedy of Romeo's and Juliet's deaths might have been averted if the nurse had not sided with her father.

What is the mood of Act 3, Scene 2 of Shakespeare's A Midsummer Night's Dream?

There are a couple of moods present in Act 3, Scene 2 of Shakespeare's A Midsummer Night's Dream. First of all, the scene has a humorous mood. Puck gleefully recounts how he gives Bottom a donkey's head and causes Titania to fall in love with him, humorously describing how "Titania wak'd, and straightaway lov'd an ass" (34). Furthermore, Oberon and Puck spend most of the scene watching Hermia, Helena, Lysander, and Demetrius hurl insults at one another in hilarious fashion.

However, humor is not the only mood present in this scene. There is also a dreamlike, confusing mood at work. For instance, the Athenians' relationships have gotten mixed up, and so it's hard to remember or understand exactly how the pairings work. Additionally, because the scene can be so confusing, it begins to feel like a surreal dream, rather than reality. This dreamlike mood is present throughout the play, and Shakespeare uses it to invite us to question whether or not the narrative is actually real. 

Why is the American military's presence in Hawaii important?

The United States has maintained a series of military installations on the Hawaiian Islands because the country has long considered itself "a Pacific nation." Once Americans settled the long western coast of the U.S. portion of the North American continent, they began to look across the Pacific Ocean, both for economic and security reasons. The Pacific, like the Atlantic, is an enormous expanse of water that both connects continents and provides a form of sustenance in its natural resources. As the United States grew as a nation, both geographically and economically, its ability to secure its western coastline while forging economic ties with Asia grew in importance. The Hawaiian Islands, situated at the midway point between Asia and North America, with their natural deep-water ports and agricultural potential, became a strategic asset, prompting the construction of sizable military installations there, particularly the large naval base at Pearl Harbor and, as air power grew in importance, Hickam Air Force Base. 

The importance of U.S. naval facilities in Hawaii were apparent not only to American officials, but to military planners in Imperial Japan as well. The December 7, 1941 surprise attack on U.S. military installations on the islands was intended to radically-degrade the American capabilities to project military power across the ocean. Japan sought to colonize Southeast Asia, as well as China and the Korean Peninsula, and eliminating, even if only for a few years, America's ability to project military power to Asia was central to its planning. 

With the end of World War II and the emergence of the Soviet Union as a potential military threat--Russia also has a long coastline along the Pacific Ocean, and maintains a sizable Pacific Fleet within its navy--the military bases on Hawaii remained extremely important. U.S. aircraft carriers and ballistic missile and attack submarines all operate out of the naval bases on Hawaii, and played a major role in protecting U.S. access to important maritime trade routes, protecting U.S. allies like Japan and the Philippines, and defending against Soviet (and, today, Russian) naval forces and long-range bombers, which are increasingly patrolling closer and closer to American shores, just as was the case during the Cold War. 

Economically, protection of maritime trade routes across the Pacific is essential to the United States. Asia is, collectively, vitally important to the U.S. economy. The overwhelming bulk of trade in goods takes place via maritime cargo traffic. Large container ships sail back-and-forth across the Pacific everyday, and any threat to a disruption in that traffic is considered a very serious issue. The U.S. Navy plays the major role in protecting that movement of ships, and the growth of Chinese naval capabilities, along with a resurgence in Russian naval activities, means the importance of the military bases in Hawaii will not end anytime soon.

Give an example of a legal indictment in the Declaration of Independence.

The Declaration of Independence had an entire section of indictments against King George of England.  The purpose of the document, written by Thomas Jefferson, was to make the case for a legal separation between the colonies and the king.  The indictment section listed over twenty grievances that the colonists had against the king.  Most of them charged the king with acting as a tyrant. This is especially true of the actions that related to legislation and the fact that the colonists were not able to represent themselves in Parliament.  An example of a legal indictment from this section:  

He (the king) has refused his Assent to Laws, the most wholesome and necessary for the public good.

In this instance, Jefferson charged that the king had not respected the laws of the colonial assemblies.  The king used his veto power to cancel legislation that the colonists deemed necessary for their survival.

In To Kill a Mockingbird, why did Scout grow closer to Miss Maudie Atkinson?

Jem and Dill started to exclude Scout from their playtime and adventures.  Previously, they had all played together.  Scout began to withdraw and "kept aloof from their more foolhardy schemes for a while, and on pain of being called a girl, [she] spent most of the remaining twilights that summer sitting with Miss Maudie Atkinson on her front porch" (To Kill a Mockingbird, Chapter 5).  Jem sometimes tried to insult Scout by calling her a girl.  Scout usually did not spend time with other girls, but she did enjoy talking to Miss Maudie, a lady who was their neighbor.

Miss Maudie had always been kind to Scout, Jem, and Dill.  When Scout started spending less time with her brother and Dill, she found comfort and enjoyment in talking to Miss Maudie.  They spent time together on her front porch and talked.  Scout found a friend in Miss Maudie.  They discussed topics ranging from Boo Radley to religion.  Miss Maudie treated Scout as an equal.  Miss Maudie knew many things about many people.  She offered insight, rather than tales of gossip.  She also answered Scout's many questions.

What are helicopter parents?

The term "helicopter parents" originated in the late 1980s to describe parents who so closely supervise their children that they could discourage the youngsters from establishing independence. Helicopter parents hover nearby, always ready to instruct, correct, or rescue children from challenges or problems.

Overview

Helicopter parenting is a style of parenting characterized by a micromanagement of children's lives that goes beyond normal involvement, support, and discipline. In some cases, helicopter parenting begins as soon as children are able to reach for toys and can last into adulthood. Helicopter parents hinder children's play, schooling, and relationships with other kids and make too many decisions for older children. When parents become too deeply involved in their lives, children find it difficult to learn to solve their own problems. Children need the opportunity to learn from experience.

Involvement alone does not define helicoptering. Parents are expected to supervise their children, show interest in their schoolwork, and comfort them when they are hurt. Helicopter parents cross this line by refusing children enough space to develop their independence and individuality. The mother who redistributes party favors because her son cried about the color of his lollipop, the father who storms into his daughter's classroom to question every test grade, or the parents who settle their child's minor arguments with a friend do not give their children the chance to experience disappointment, take responsibility for mistakes, or deal with conflict. As a result, these children receive the message that they are unable to handle their own problems. If helicopter parents continue to hover as children grow into adolescents and go off to college—for example, texting or calling their children many times a day—the road to independence becomes long and indefinite.

Usually propelled by love and a fear of harm coming to the child, excessive supervision also may reflect anxiety about the child's future success. Parents who have advanced degrees and work as professionals are more likely to become helicopter parents than those with bachelor's degrees or high school diplomas. Their taking control is motivated by a great concern about the child's ability to someday receive acceptance into a prestigious university and maintain a place in a higher social class, in addition to the worries other parents share.

A major concern about helicopter parenting is when it continues through adolescence, when most children strive for greater independence. Since technology has erased the child's ability to avoid the hovering parent's eye, even while at school or out with friends, the child learns to forgo some level of privacy. Parents can electronically monitor grades, homework, discipline reports, and lunch choices at school. They have access to the child's cell phone records and social media sites and even have technology that allows them to track their child's whereabouts in real time. Dedicated helicopter parents take responsibility for creating a portfolio of experience for the child to use for college applications, running him or her to music lessons, sports practices, and tutoring to ensure success. They also manage whatever paperwork and legwork are necessary to arrange college admissions tests and visits and meet college application deadlines. If helicopter parents always remain one step ahead of their child's needs, the young person never learns to take initiative or follow through on responsibilities.

After their children leave for college, helicopter parents continue to stay close—so close that some colleges have developed ceremonies to escort parents from campus after freshman orientation. Other colleges assign staff members to cope with the growing number of calls from parents who demand information or action on behalf of their child. Students who never have been allowed to experience failure—or even discomfort—generally have a hard time adjusting to the relative independence of campus life, where they are responsible for their own assignments and deadlines. At the first sign of trouble, these students text or call parents for advice, without attempting to solve the problem. College personnel even have a name for students who are too fragile to cope with ordinary challenges of college without parental involvement—"teacups." As college graduation approaches, the most persistent helicopter parents press career counselors for help in getting their child a job, and a few even accompany children to job interviews. The final outcome of helicopter parents' micromanagement of their children's lives can be adults who feel empty, indecisive, and vaguely unhappy in spite of having had so many advantages and so few problems.

Helicopter parents' overinvestment in their children also affects their own lives. Such all-consuming relationships leave little or no time for close friends, family members, or even spouses. In addition to taking care of their own demanding work schedules, home responsibilities, and other children, these parents take on hours of extra work each week to drive to activities, supervise homework, and monitor progress. Many parents consider their sons or daughters their best friends and suffer acute loneliness when their children leave for college. Helicopter parents mean well and make sacrifices so their children will succeed, but their efforts may hinder both their children's goals and their own.

Bibliography

Agadoni, Laura. "Reasons for Helicopter Parents." Global Post, n.d. Global Post—International News, 2014. Web. 18 Jul. 2014. <http://everydaylife.globalpost.com/reasons-helicopter-parents-5434.html>

Boyd, Hannah. "Are You a Helicopter Parent?" Education.com, 25 Jun. 2013. Education.com, Inc., 2014. Web. 18 Jul. 2014. <http://www.education.com/magazine/article/Are_You_Helicopter_Parent/>

Buzzese, Anita. "Self-Sufficiency Elusive to Young Adults of Hovering Parents." USA Today, 24 Jul. 2012. USA Today, 2012. Web. 18 Jul. 2014. <http://usatoday30.usatoday.com/money/jobcenter/workplace/bruzzese/story/2012-08-26/helicopter-parents-hurt-generation-of-workers/57292900/1>

Gottlieb, Lori. "How to Land Your Kid in Therapy." The Atlantic, 7 Jun. 2011. The Atlantic Monthly Group, 2014. Web. 18 Jul. 2014. <http://www.theatlantic.com/magazine/archive/2011/07/how-to-land-your-kid-in-therapy/308555/>

Marano, Hara Estroff. A Nation of Wimps: The High Cost of Invasive Parenting. New York: Crown Publishing Group, 2008. Print.

Nelson, Margaret K. Parenting Out of Control: Anxious Parents in Uncertain Times. New York: New York University Press, 2010. Print.

What is the color change of the litmus paper for each of these cases?

This question relates the change in color of the litmus paper when it is dipped in solutions of different pH values. In general, a blue litmus paper turns red when dipped in acidic solution and a red litmus paper turns blue when dipped in a basic or alkaline solution. The color of the neutral litmus paper is purple. 

Note that the color change takes place between a pH of 4.5 and 8.3, thus, the paper remains blue above a pH of 8.3 and red, below a pH of 4.5.

Also, remember that pH is related to the hydrogen ion concentration of a solution as:

`pH = -log_10[H^+]`

For these cases, where the hydrogen concentration is given, convert them to pH.

For case A: 

pH = `-log_10[1.3 xx 10^(-9)]`

or, pH = 8.9

Thus, the red litmus will turn blue, while blue litmus paper will show no change.

Similarly, for case C: pH = -log(1 x 10^-7) = 7. 

The pH is around neutral and hence the red litmus as well as the blue litmus paper will exhibit no change in color.

Similarly, for solutions E and F, pH = 7 and hence the litmus papers will show no change of color.

For case D, pH =4.5, hence red litmus will have no change, while blue litmus paper will turn red.

Similarly, all other cases can also be solved.

Hope this helps. 

What is a culture of plant cells?

Culturing Plant Cells

Plant cell cultures are typically initiated by taking explants—such as root, stem, leaf, or flower tissue—from an intact plant. These explants are surface-sterilized and then placed in vitro on a formulated, artificial growth medium containing various inorganic salts, a carbon source (such as sucrose), vitamins, and various plant growth regulators, depending on the desired outcome. There are many commercially available media formulations; the two most common include MS (murashige and skoog) and WPM (woody plant media). Alternatively, customized formulations may be necessary for culturing certain plant species. One of the most important uses of plant tissue culture has been for the mass propagation of economically important agricultural and horticultural crops. Since the 1980s, however, plant cell culture has become an important tool allowing for direct genetic manipulations of several important agricultural crops, including corn, soybeans, potatoes, cotton, and canola, to name only a few.

Appearance in Culture

The underlying basis for the prevalent and continued use of plant cell culture is the remarkable totipotent ability of plant cells and tissues. They are able to dedifferentiate in culture, essentially becoming a nondifferentiated clump of meristematic, loosely connected cells termed callus. Callus tissue can be systematically subcultured and then, depending on exposure to various plant growth regulators incorporated in the growth media, induced to undergo morphogenesis. Morphogenesis refers to the redifferentiation of callus tissue to form specific plant organs, such as roots, shoots, or subsequent whole plants. Many plant species can also be manipulated in culture to form somatic embryos, which are asexual embryoid structures that can then develop into plantlets. The totipotency of plant cells thus allows for a single cell, such as a plant protoplast, to be able to regenerate into a complete, whole plant. An analogous comparison of the totipotency of plant cells would be that of stem cells in animals. Genetic manipulation of individual plant cells coupled with their totipotency makes plant cell culture a powerful tool for the plant geneticist.

Role of Plant Growth Regulators

Hormones or plant growth regulators (PGRs) are naturally occurring or synthetic compounds that, in small concentrations, have tremendous regulatory influence on the physiological and morphological growth and development of plants. There are several established classes of PGRs, including auxins, cytokinins, gibberellins, abscisic acid (ABA), and ethylene. Additionally, several other compounds, such as polyamines, oligosaccharides, and sterols, exert hormone-like activity in plant cell cultures. While each class has a demonstrative and unique effect on overall whole plant growth and development, auxins and cytokinins continue to be the most widely used in manipulating plant growth in vitro. Auxins (such as IAA, NAA, and 2,4-D) and cytokinins (such as zeatin, kinetin, and BAP) are frequently used in combination in plant tissue culture. Generally, a high auxin-to-cytokinin ratio results in the induction of root tissue from callus, while a high cytokinin-to-auxin ratio results in the induction of shoot formation. For many plant species, an intermediate ratio of auxin to cytokinin results in continued callus formation.

There are also specific uses of certain PGRs in plant cell culture. For example, 2,4-D is typically used to induce somatic embryogenesis in cultures but then must be removed for subsequent embryoid development. Gibberellins, such as GA4 and GA7, can be inhibitory to morphogenesis. Some PGRs may even elicit opposite morphogenic effects in two different plant species. Nevertheless, the use of PGRs remains essential in plant cell culture to direct morphological development.

Applications and Potential

Plant cell culture as a tool has greatly enhanced the ability of the plant geneticist in the area of crop improvement. Haploid cell cultures initiated from pollen can result in homozygous whole plants, which are very useful as pure lines in breeding programs. In such plants, recessive mutations are easily identified.

The enzymatic removal of the plant cell wall yields naked plant protoplasts, which are more amenable to genetic manipulation. Protoplasts of different species can be chemically or electrically fused to give somatic hybrids that may not be obtained through traditional sexual crossing due to various types of sexual incompatibility. As they divide and regenerate cell walls, these somatic hybrids can then be selected for desired agriculture characteristics, such as insect or disease resistance.

The isolation of plant protoplasts from leaves results in millions of individual cells. As they divide, grow, and differentiate into whole plants, some may contain spontaneous mutations or other changes which can be selected for. Screening for such characteristics, such as salt tolerance or disease resistance, can be done in vitro, thereby saving time and space.

Another use of plant cell culture in crop improvement involves directed genetic transformation. Genes from other species, including bacteria, animals, and other plants, have been introduced into cell cultures, resulting in genetically modified (GM) plants. The most common technique used to transfer desired genes uses the bacterium Agrobacterium tumefaciens. Other techniques include electroporation, microinjection, and particle bombardment with “gene guns.” As genetic engineering of plants proceeds and is refined, plant cell culture will continue to play a vital role as a tool in this effort.

Key Terms



callus

:

a group of undifferentiated plant cells growing in a clump





morphogenesis


:

the induction and formation of organized plant parts or organs




plant growth regulators

:

hormone-like substances that profoundly affect plant growth and development




somatic embryos

:

asexual embryoid structures derived from somatic cells





totipotency


:

the ability of a plant cell or part to regenerate into a whole plant





Bibliography

Anderson, L. A., et al. Plant Cell Culture. Berlin: Berlin Springer, 2013. Print.

George, Edwin F., Michael A. Hall, and Geert-Jan De Klerk, eds. Plant Propagation by Tissue Culture. 3d ed. 2 vols. London: Springer, 2008. Print.

Loyola-Vargas, Victor M., and Neftal&iacute; Ochoa-Alejo. Plant Cell Culture Protocols. New York: Humana, 2012.

Opatrn&yacute, Zdenek, and Peter Nick. Applied Plant Cell Biology: Cellular Tools and Approaches for Plant Biotechnology. Berlin: Springer, 2014. Digital file.

Neumann, Karl-Hermann Neumann, Ashwani Kumar, and Jafargholi Imani. Plant Cell and Tissue Culture—a Tool in Biotechnology: Basics and Application. Berlin: Springer, 2009. Print.

Nick, Peter, and Zdenek Opatrn&yacute;. Applied Plant Cell Biology: Cellular Tools and Approaches for Plant Biology. Dordrecht: Springer, 2014. Digital file.

Razdan, M. K. Introduction to Plant Tissue Culture. 2d ed. New Delhi: Oxford, 2011. Print.

Trigiano, Robert, and Dennis Gray, eds. Plant Development and Biotechnology. Boca Raton: CRC, 2005. Print.

Trigiano, Robert, and Dennis Gray, eds. Plant Tissue Culture Concepts and Laboratory Exercises. 2d ed. Boca Raton: CRC, 2000. Print.

How can I compare the short story "So Much Water So Close to Home" by Raymond Carver and the film adaptation "Jindabyne"? What are the most...

The film "Jindabyne" (d. Ray Lawrence) features several crucial differences from the short story by Raymond Carver on which it is based. The most critical of these is that the dead woman in Carver's version is white, whereas the dead woman in the movie is aboriginal. Since the central conflicts in the narrative stem from the men's relative disregard for the body, having a white corpse facilitates the short story's existential perspective on the meaningless of life that transcends cultural barriers. In contrast, Lawrence's decision to make the body aboriginal makes the story specific in time and place; Australia has a complicated history of race relations between whites and aboriginals, which the movie directly invokes to explore an ongoing political situation.

Another difference between the short story and movie concerns character perspective. In Carver's story, Claire is the narrator and the narrative flows from her first-person perspective; the story becomes about her experience of the girl's death and what it signifies for her relationship with her husband. However, "Jindabyne" is told from multiple characters' points of views, which fuels the political exploration of racial tension from a broader perspective of different characters and communities -- including the aboriginal family of the dead girl. This allows the viewer to take in a bird's eye view of the whole situation because there are so many character reactions to consider.

In Dubus's "Killings," how is the title significant?

Andre Dubus's "Killings" is about two murders; therefore, the title is quite appropriate. First, Matt Fowler's son Frank is killed by Richard Strout; then, Fowler kills Strout to avenge his son and because of his and his wife's grief. The story is written from Matt Fowler's point of view and discusses the events that lead up to both killings. Fowler's view is limited to his son's perspective on the first killing; but the agonizing grief that leads Fowler to avenge his son's death is quite detailed. The effect of Frank's murder is assessed deeply because Richard killed him in front of his own two sons and his wife. Not only that, but Frank's parents and siblings are stricken with unfathomable grief that they never expected to feel.

Unfortunately, Matt and his wife's grief is intensified when Ruth sees Richard at the store one day. They had not thought about Richard getting out on bail and walking around the city a free man. After discussing this with his friend Willis, they plan to kill Richard to ease the pain and suffering as well as to get justice that might be limited through the court system. Finally, the last few pages of the short story detail the plan, the deception and the violence wrought on Richard during the last few hours of his life. In the end, Matt returns to his wife after killing Richard and resumes his life. Nothing is said as far as the consequences Matt must face after he kills Richard.

What good things did Maximilian Robespierre do?

Maximilian Robespierre is best-known for instigating the Terror, a short but dark period of the French Revolution under which thousands of people were killed by an increasingly overzealous revolutionary government. But that is not all he did in his life.

The reason he had enough power to do the Terror in the first place was that he played a vital role in the French Revolution, overthrowing the absolute monarchy and (eventually, after a long and tumultuous period including none other than Napoleon) establishing democracy. He led a group called the Jacobins who were vital to the success of the revolution. Without their help, the Revolution might have failed and France might have stayed under monarchy for generations to come.

He was a classic example of a Well-Intentioned Extremist; while his goals were good---he wanted freedom and democracy for all the people of France---he was willing to use extreme methods including torture and murder in order to get there. As he grew more extreme, he also became less popular, and was eventually overthrown in much the same way he had originally overthrown the king.

What is an internal and external conflict in "An Occurrence at Owl Creek Bridge"?

The story is set during the American Civil War, so one external conflict that is present is the conflict that is raging between the Union and the Confederacy.  The war was over many things, but the two main issues were states' rights and slavery.  

Another external conflict is the conflict between Peyton and the Union soldiers that are going to hang him.  Peyton was caught trying to sabotage a bridge, and his punishment is death by hanging.  Peyton's escape could be viewed as an external conflict.  He is struggling to not drown, get shot, etc.  Of course that is all happening in his imagination, so maybe it is an internal conflict too.  

A better choice for internal conflict is the conflict going on inside of Peyton before he gets captured.  The story tells readers that Peyton really wanted to take a more active part in the war, but he was prevented from doing so for some reason.  

Circumstances of an imperious nature, which it is unnecessary to relate here, had prevented him from taking service with that gallant army which had fought the disastrous campaigns ending with the fall of Corinth, and he chafed under the inglorious restraint, longing for the release of his energies, the larger life of the soldier, the opportunity for distinction. 

Now he has been given the chance to earn some distinction for himself, but he must wrestle with the risk.  If he fails, he will die and leave his family without a provider.  

Another internal conflict occurs in the beginning of the story.  Peyton is about to be dropped to his death, but he isn't panicking, nor is he begging for his life.  He could be doing either, but he attempts to maintain a proud southern outward show of bravery.  Even seconds before he dies, he is still thinking of escape.  

"If I could free my hands," he thought, "I might throw off the noose and spring into the stream."

How does the use of dialect contribute to "Thank You Ma'm" by Langston Hughes?

By using urban dialect in “Thank You M’am,” Langston Hughes adds to the authenticity of the short story.

During his many years as an author, Hughes used the native dialect of African-Americans living in Harlem in his work. He used his writing as a vehicle to advocate for “his” people, and to provide them with literature they could identify with.

In “Thank You, M’am,” Hughes incorporates the urban dialect in dialogue between characters, and through the statements presented by the narrator. In both cases, the dialect adds validity to the story. In addition, the intended audience can relate to the situations in the story because they are familiar.

As you read the dialogue between Mrs. Jones and Roger, you experience urban dialect that shows how the young man responds to the woman he attempted to victimize. Although he tried to steal her purse while she walked home from work, he calls her “M’am,” which is a term of respect. Langston Hughes shows the young man’s desperation, but also demonstrates how he was taught to respond to his elders. Mrs. Jones knows which questions are appropriate to ask Roger, and which ones to leave out of their conversation.

“Um-hum! And your face is dirty. I got a great mind to wash your face for you. Ain’t you got nobody home to tell you to wash your face?”

 “No’m,” said the boy.

 “Then it will get washed this evening,” said the large woman starting up the street, dragging the frightened boy behind her.

What are bunions?

Causes and Symptoms

A bunion, or hallux valgus, is a swelling on the foot, usually at the joint of the big toe, that is caused by a misaligned bone in the joint. Bunions often develop with aging as a result of widening of the feet, arthritic conditions, or the wearing of improperly fitted shoes. Typically, the misaligned bone protrudes outward at the joint of the big toe, giving the bunion its bulging appearance. The bursa, a fluid-filled sac in the joint, becomes inflamed and swells, often twisting the big toe toward the second toe. Since the big toe supports most of the body’s weight every time an individual pushes off the ground, a bunion can cause severe pain and discomfort. In addition, because bunions can change the shape of the feet, it becomes much harder for an aging sufferer to find shoes that fit properly.

While bunions themselves cannot be inherited, an individual can inherit the tendency to develop bunions by being born with extra bone near a toe joint. The risk of developing bunions can be reduced by exercising daily to keep the muscles of the feet and legs in good condition and by wearing wide-toed shoes that fit well. Women tend to develop bunions more than men do, possibly because many women wear shoes that are too small or narrow. Symptoms of bunions include pain, redness, stiffness, swelling, thickness of the skin over the bunion, fluid accumulation under the thickened skin, and the eventual development of osteoarthritis that impairs the joint’s flexibility.

Treatment and Therapy

If a bunion is not severe, greater comfort can come from simply wearing a different style of shoe, including those that have been stretched in the big toe area, that are made of soft leather, or that have cushioned insoles. Sandals with cross straps and athletic shoes are best for providing maximum comfort for people with bunions. Other ways to relieve the pain include using shoe inserts called bunion pads, using a moist heating pad on the bunion at night, applying an ice pack to reduce swelling, and taking an over-the-counter anti-inflammatory drug such as aspirin or ibuprofen (Advil or Motrin). Aging persons with medical conditions should read product labels carefully and consult their doctor or a pharmacist before taking pain-relieving medications. If home care measures do not provide relief, a podiatrist (foot doctor) may prescribe a special shoe insert known as an orthotic device.

For severe bunions, outpatient surgery may be required. The most common surgery reduces the angle between the big and second toes. Bones in the big toe are realigned, and the bunion is shaved away. Ligaments and tendons on the outside of the toe may be tightened to hold the joint properly, while any tight tendons on the inside of the toe are released. Bunion surgery can reduce pain and improve the appearance of the feet. Recovery involves the use of crutches to keep weight off the foot, and the majority of healing typically occurs within a few weeks. After surgery, pain will gradually subside and deformity of the foot will improve. However, tight shoes must still be avoided.

Bibliography

Bentley, George, and Robert B. Greer, eds. Orthopaedics. 4th ed. Oxford, England: Linacre House, 1993.

"Bunion Removal." Medline Plus, March 1, 2012.

"Bunions." Medline Plus, February 27, 2012.

Copeland, Glenn, and Stan Solomon. The Foot Doctor: Lifetime Relief for Your Aching Feet. Rev. ed. Toronto, Ont.: Macmillan Canada, 1996.

Frowen, Paul, et al., eds. Neale’s Disorders of the Foot. 8th ed. New York: Churchill Livingstone/Elsevier, 2010.

Lippert, Frederick G., and Sigvard T. Hansen. Foot and Ankle Disorders: Tricks of the Trade. New York: Thieme, 2003.

Rose, Jonathan D. The Foot Book: A Complete Guide to Healthy Feet. Baltimore: John Hopkins University Press, 2011.

"What to Ask Your Foot and Ankle Surgeon about Bunion Surgery." American College of Foot and Ankle Surgeons, December 15, 2009.

What do girls' hair ribbons stand for in The Giver? Where and when do they appear in The Giver?

The hair ribbons girls wear are an indication and symbol of their youth.  They reinforce conformity.  Girls wear them until age Nine.  Girls must wear them at all times, and they are specifically mentioned in Chapters 2, 3, 6 and 13.

Lily complains about the hair ribbons.  When her mother fixes them, she tells her she can tie them herself.  Lily’s ribbons are always untied.

"I know that," Mother replied, straightening the hair ribbons on the little girl's braids. "But I also know that they constantly come loose and more often than not, they're dangling down your back by afternoon. Today, at least, we want them to be neatly tied and to stay neatly tied." (Ch. 6)

There are several symbols of a child’s age, and everyone is alike.  For example, the clothes the children wear vary by year.  As they get older, the community symbolizes the children’s growing independence with hair and wardrobe changes.

Hair indicates a child’s age for boys too.

Jonas never found the Ceremony of Ten particularly interesting- only time-consuming, as each child's hair was snipped neatly into its distinguishing cut: females lost their braids at Ten, and males, too, relinquished their long childish hair and took on the more manly short style which exposed their ears. (Ch. 6) 

With everyone looking alike and dressing alike, the community reinforces Sameness.  Sameness means that no one is different, so no one is uncomfortable.  Everything is carefully regulated so that there are no choices about anything.  If children chose whether to wear hair in ribbons or not, then some would look different.  Therefore, there are rules that everyone wears ribbons.  They also must be properly tied. 

Not complying with the community’s rules or not being neat results in public shaming.  For example, if Lily’s ribbons are untied the Speaker may make an announcement to the whole community.  Even if Lily is not mentioned by name, everyone will know who the speaker is talking about.

In George Bernard Shaw's Arms and the Man, is Petkoff impressed to see Captain Bluntschli?

George Bernard Shaw was a satirist of the highest order, perhaps one of the greatest in modern history. And he was a cynic, imbued with a less-than-hospitable perception of the artifice and arrogance characteristic of Britain’s upper classes, the common target of his satirical barbs. In his anti-war play Arms and the Man, the family at the center of the story, the Petkoffs, are not necessarily rich, but they are financially-comfortable with aspirations of eventual acceptance into the ranks of the aristocracy. In his introductory comments, Shaw describes the family matriarch, Catherine, as an attractive woman who “might be a very splendid specimen of the wife of a mountain farmer, but is determined to be a Viennese lady.” It is clear, however, that this is a family of fortune relative to many in the Balkans region in which they live.

The Petkoffs are financially-comfortable, and do seek to associate themselves with society’s upper classes, and Shaw’s characters are replete with the kind of exaggerated pretensions that he loved to satirize, albeit, usually in the Victorian culture of his own life. As such, the initial encounter between Raina and the intruder who will be introduced as Captain Bluntschli, a Swiss officer serving in the Serbian Army, is typical of the author’s style of writing. As Raina, alone in her room, ponders her future with Sergius, she is startled by the intrusion, a reaction specified in Shaw’s directions. Note in the following passage the playwright’s description of this scene, in which “the man” who will be introduced as Bluntschli first observes the woman in whose room he has hidden. Note also, though, how quickly Raina regains her composure and confronts the stranger in her midst:

(He reckons up what he can guess about Raina—her age, her social position, her character, the extent to which she is frightened—at a glance, and continues, more politely but still most determinedly) Excuse my disturbing you; but you recognise my uniform—Servian. If I'm caught I shall be killed. (Determinedly.) Do you understand that?

RAINA. Yes.

MAN. Well, I don't intend to get killed if I can help it. (Still more determinedly.) Do you understand that? (He locks the door with a snap.)

RAINA (disdainfully). I suppose not. (She draws herself up superbly, and looks him straight in the face, saying with emphasis) Some soldiers, I know, are afraid of death.

MAN (with grim goodhumor). All of them, dear lady, all of them, believe me. It is our duty to live as long as we can, and kill as many of the enemy as we can. Now if you raise an alarm—

RAINA (cutting him short). You will shoot me. How do you know that I am afraid to die?

MAN (cunningly). Ah; but suppose I don't shoot you, what will happen then? Why, a lot of your cavalry—the greatest blackguards in your army—will burst into this pretty room of yours and slaughter me here like a pig; for I'll fight like a demon: they shan't get me into the street to amuse themselves with: I know what they are. Are you prepared to receive that sort of company in your present undress? (Raina, suddenly conscious of her nightgown, instinctively shrinks and gathers it more closely about her. He watches her, and adds, pitilessly) It's rather scanty, eh? (She turns to the ottoman. He raises his pistol instantly, and cries) Stop! (She stops.) Where are you going?

RAINA (with dignified patience). Only to get my cloak.

MAN (darting to the ottoman and snatching the cloak). A good idea. No: I'll keep the cloak: and you will take care that nobody comes in and sees you without it. This is a better weapon than the pistol. (He throws the pistol down on the ottoman.)

RAINA (revolted). It is not the weapon of a gentleman!

While the sight of the intruder initially, and understandably, startles Raina, she quickly regains her composure and, just as quickly, the upper hand. While Bluntschli obviously has an advantage in that he is a trained soldier armed with a pistol, he is no match for the confident to the point of arrogant Raina. Indeed, her sense of modesty, clothed only a nightgown, appears to be her main point of vulnerability. Beyond that, she is an immediate mental match for the foreign military officer in her bedroom, and she understands that she holds more cards in her hand than does the interloper. Bluntschli is a deserter and, as such, hunted by his own army as well as by that of the enemy he is supposed to stalk. He knows that he is in a precarious position, and Raina quickly comes also to understand that his predicament works to her advantage. Note Shaw’s stage instructions prefacing each of Raina’s comments: “disdainfully,” “cutting him short,” “with dignified patience,” “revolted.” Raina is too self-absorbed and insufficiently endowed with a true sense of situational awareness to be as frightened as one should expect. In short, she is not impressed by Captain Bluntschli. She is, however, curious.

Who wrote Hamlet?

The Tragedy of Hamlet, Prince of Denmark is a tragic play written by William Shakespeare. It was written in England around 1600-1602. Hamlet is a play about a prince whose father is murdered by his uncle, Claudius. Claudius marries Hamlet's mother and takes possession of the throne. Meanwhile, Hamlet speaks with his father's ghost who tells him that Claudius murdered him by pouring poison down his ear while he was sleeping. The Ghost also bids Hamlet to avenge his death on Claudius, but to let his mother live out her days with the guilt. Thus, Hamlet struggles to accept what his uncle and mother have done, how he can prove that they did it, and how to execute justice. Hamlet's tragic flaw is his indecision to act on what he knows about his uncle. This indecisiveness ultimately leads him to make mistakes and become too emotionally charged to save himself from destruction.

What are the environmental and social effects of deforestation in the Amazon Rain Forest?

Deforestation is the reduction of vegetation in forested areas. The reduction of vegetation, usually trees, may be a partial or complete removal of existing flora in the region. In the Amazon Rain Forest, deforestation is occurring at an alarming rate. The consequences of deforestation are both environmental and social, and both local and global.

Environmental Consequences

• On a local scale, the Amazon Rain Forest is host to a diverse ecosystem. The destruction of that ecosystem results in loss of both plants and animals, some of which live only in the Amazon and will become extinct if deforestation continues at its current rate. 


• On a global scale, the Amazon is a large carbon sink: it captures carbon and keeps that carbon out of the atmosphere. The Amazon Rain Forest is also home to a large quantity of plants that are valuable photosynthesizers that convert carbon dioxide to oxygen. Simultaneous loss of those two processes will result in much higher levels of carbon dioxide in the atmosphere, and atmospheric carbon dioxide gas increases global warming through the greenhouse effect.

Social Consequences

• On a local scale, Amazon deforestation negatively impacts local communities that reside there. Should deforestation continue, groups of people who have made their home in the Amazon will no longer have a home. Often, their livelihood will also cease to exist, as many local people subsist off local resources provided by the rainforest.


• On a global scale, Amazon deforestation affects the entire human population. Not only do we lose the invaluable aesthetic beauty of the Amazon, we also lose the environmental services it provides us as a carbon sink and large body of photosynthetic organisms. Global warming has negative consequences for all organisms on large and small scales, including humans.

Are there any similarities between the characteristics demanded of an entrepreneur and those demanded of a professional athlete?

There are definitely similarities between the qualities that an entrepreneur needs and those that a professional athlete needs.  Let us look at a few of these similarities.

First, both of these groups need to be willing to take on risks.  Entrepreneurs have to be willing to risk their money on ventures that may well fail.  Professional athletes have to be willing to risk injury and, in many cases, to risk their chances at a good life.  By this, I mean that many professional athletes have to forego the schooling that would allow them to have a good fallback position if they fail to achieve enough success to make a living through their sport.

Second, both of these groups have to be willing to deal with failure on the psychological level.  Many entrepreneurs fail, some more than once.  They have to be able to keep on trying rather than give up because they doubt their abilities.  Professional athletes fail constantly.  A professional basketball player, for example, may have to accept missing a shot or committing a turnover at a key point in the game.  They have to have the psychological makeup that allows them to fail and to still remain confident that they will succeed the next time.

Third, both of these groups have to be extremely ambitious and driven.  In both cases, people have to set their sights very high.  They have to want to achieve things that the vast majority of people do not and cannot achieve.  They also have to be willing to work very hard.  Entrepreneurs typically have to put in long hours and endure great amounts of stress in order to achieve their goals.  Professional athletes are the same way.  Most of them have to train constantly, watch their diets and their sleeping habits, and cope with extreme pressure from coaches, fans, and other players on a daily basis.

In all of these ways, entrepreneurs and professional athletes do have to possess some of the same characteristics.

How do scientists learn about the past conditions of Earth’s atmosphere?

Scientists are able to learn about the past conditions of Earth's atmosphere through direct chemical records and proxies of chemical records. The study of Earth's past climate is called paleoclimatology.

Polar ice cores are the only direct chemical records that exist on Earth. Scientists have removed large cores of ice from polar ice sheets such as Greenland and Antarctica - these polar cores act as a timeline for Earth's climate that reaches back almost one million years. In fact, the search for a true 1 mya ice core is currently underway. Scientists can analyze the air trapped within bubbles in the ice to infer temperature, ocean levels, and atmospheric carbon dioxide.

Other paleoclimate records exist indirectly in marine sediment cores, lake sediment cores, speleothems, tree rings cores, and fossils. Unlike ice cores, these records do not have anything to measure directly. (Ice cores contain ancient air, which is the same air that existed in the past!) Instead, these proxies record the effects of climate, which can be used to tell the entire paleoclimate story.

When was Dickinson's first poem published?

There is an element of mystery surrounding the subject of Emily Dickinson’s poetry, her desire (or lack of desire) to see her works published, and whether her poems were published with or without her knowledge. By studying sources like the Emily Dickinson Museum, however, we can answer this question accurately.

We do know that ten of Dickinson’s letters/poems were published while she was alive, the first being a letter to George H. Gould in February of 1850 (see The Publication Question and Letters from Dickinson). 

Her first poem to appear in public was “Sic Transit Gloria Mundi,” which was published in February of 1852 in the Springfield Daily Republican, according to the Emily Dickinson Museum (see The Publication Question and the poem itself). 

The Emily Dickinson Museum also shares that Dickinson received no public credit for her poetry during her lifetime—her works were published anonymously.

The rest of her poetry was discovered by her sister after her death in 1886, and published over the course of several decades by various family members (again, see the Emily Dickinson Museum).

What are natural treatments for cancer risk reduction?

Principal Proposed Natural Treatments

It is rather difficult to prove that taking a certain supplement will reduce the chance of developing cancer. One really needs enormous, long-term, double-blind, placebo-controlled studies in which some people are given the studied supplement while others are given placebo. However, relatively few studies of this type have been performed.

For most supplements, the evidence that they help prevent cancer comes from observational studies, which are much less reliable. Observational studies have found that people who happen to take in high levels of certain vitamins in their diets develop a lower incidence of specific cancers. However, in such studies it is difficult to rule out other factors that may play a role. For example, persons who take vitamins may also exercise more or take better care of themselves in other ways. Such confounding factors make the results of observational studies less reliable.

Although this may sound like a theoretical issue, it has very practical
consequences. For example, based primarily on observational studies,
hormone
replacement therapy (HRT) was promoted as a heart-protective
treatment for postmenopausal women. However, when placebo-controlled studies were
performed, HRT proved to increase the risk of heart disease.

It is now thought that the apparent benefits of HRT arose because women who
used it often belonged to a higher socioeconomic class than those who did not use
it. (For a variety of reasons, some of which are obscure, higher income is
associated with improved health.) Only a few supplements have any evidence from
double-blind trials to support their potential usefulness for cancer
prevention, and even that evidence is weak. For all other
supplements, supporting evidence is limited to observational studies and to
preliminary evidence from animal and test-tube studies.

Vitamin E. The results of observational trials have been mixed,
but on balance, they suggest that high intake of vitamin E is
associated with reduced risk of many forms of cancer, including stomach, mouth,
colon, throat, laryngeal, lung, liver, and prostate cancer. However, the results
of observational studies are unreliable as guidelines to treatment. The results of
double-blind, placebo-controlled studies are far more persuasive in drawing
conclusions about cause and effect. On balance, these studies failed to find
vitamin E helpful for the prevention of cancer.

The one positive note came in a double-blind study of 29,133 smokers. Those who
were given 50 milligrams (mg) of synthetic vitamin E (dl-alpha-tocopherol) daily
for five to eight years showed a 32 percent reduction in the incidence of
prostate
cancer and a 41 percent drop in prostate cancer deaths.
Surprisingly, results were seen soon after the beginning of supplementation. This
was unexpected because prostate cancer develops slowly. A cancer that shows up in
a man’s prostate today actually started to develop many years ago. That vitamin E
almost immediately lowered the incidence of prostate cancer suggests that it may
somehow block one of the last steps in the development of detectable prostate
cancer.

Nonetheless, the negative results regarding most other types of cancer have made scientists hesitant to place too much hope in these findings. Some researchers believe that better results will be seen with a form of vitamin E called gamma-tocopherol rather than the alpha-tocopherol used in the foregoing trials. Others suggest that vitamin E might be more helpful for cancer prevention in low-risk people.

Selenium. It has long been known that severe selenium deficiency
increases the risk of cancer. One double-blind study found some evidence that
selenium supplements might help prevent cancer even in the absence of severe
deficiency. The study was designed to detect selenium’s effects on
skin
cancer. It followed 1,312 persons, one-half of whom were
given 200 micrograms (mcg) of selenium daily. People participating in the study
were not deficient in selenium. The participants were treated for an average of
2.8 years and were followed for about six years. Although no significant effect on
skin cancer was found, the researchers were startled when the results showed that
people taking selenium had a 50 percent reduction in overall cancer deaths and
significant decreases in cancer of the lung (40 percent), colon (50 percent), and
prostate (66 percent). The findings were so remarkable that the researchers felt
obliged to break the blind and allow all the participants to take selenium.

Subsequent reevaluation of the results, including additional data from follow-up, indicated that lung cancer and colon cancer benefits were seen only in participants with somewhat low levels of selenium in the blood to begin with. While this evidence is promising, it has one major flaw: The laws of statistics indicate that when researchers start to deviate from the question their research was designed to answer, the results may not be trustworthy. As an illustration of this, yet another after-the-fact statistical analysis of the data hints that selenium supplements might actually increase the risk of certain forms of skin cancer. This, however, may not be a real concern either, as all such statistical manipulation is suspect.

One study published in 2007 evaluated whether selenium supplements could help
prevent skin cancer in transplant patients. People who have undergone organ
transplants are at particularly high risk of skin cancer linked to the
human
papilloma virus (HPV). In this double-blind study, 184 organ
transplant recipients were given either placebo or selenium at a dose of 200 mg
daily. The results over two years failed to show benefit: Both the placebo group
and the selenium group developed precancerous and cancerous lesions at the same
rate. Further research will be necessary before it is known whether selenium
supplements actually help prevent cancer.

Mixed antioxidants. A large, double-blind, placebo-controlled
study evaluated the potential overall cancer-preventive benefits of a low-dose
combination antioxidant supplement providing 120 mg of ascorbic acid, 30 mg of
vitamin E, 6 mg of beta-carotene, 100 mcg of selenium, and 20 mg of zinc taken
daily for about 7.5 years. The results as a whole failed to show benefit. However,
analysis by gender showed a significant reduction in cancer incidence in men but
not in women. It is not clear whether these results are meaningful. The
researchers involved in this study concluded the following: Low-dose antioxidant
supplementation may be helpful in healthy people, without cancer risk, who are
deficient in antioxidant nutrition. High doses of antioxidants
may be harmful for people who are at higher risk for cancer and may already be in
the initial phases of cancer development. Finally, antioxidants in high or low
doses are probably not helpful in healthy people with good nutrition.

Another large study failed to find mixed antioxidants helpful for preventing
stomach cancer in particular. In a meta-analysis (a detailed mathematical
review) of twenty high-quality randomized trials (involving 211,818 participants),
researchers concluded that neither beta-carotene, vitamin A, vitamin C, vitamin E,
or selenium effectively lowered the risk of gastrointestinal
cancers. If anything, they may have slightly increased the
risk of death from these cancers.

Beta-carotene. The story of beta-carotene and
cancer is full of contradictions. It starts in the early
1980s, when the cumulative results of many studies suggested that people who eat a
lot of fruits and vegetables are significantly less likely to get cancer. A close
look at the data pointed to carotenes as the active ingredients in fruits and
vegetables. It appeared that a high intake of dietary carotene might significantly
reduce the risk of cancers of the lung, bladder, breast, esophagus, and
stomach.

However, once again, observational studies cannot prove cause and effect. When researchers gave beta-carotene to study participants, the results have been impressively negative.

Beta-carotene’s reported benefits came under question in 1994 with the results
of the Alpha-Tocopherol, Beta-Carotene study. These results showed that
beta-carotene supplements did not prevent lung cancer
but actually increased the risk of getting it by 18 percent. This trial followed
29,133 male smokers in Finland who took supplements of about 50 international
units (IU) of vitamin E (alpha-tocopherol), 20 mg of beta-carotene (more than ten
times the amount necessary to provide the daily requirement of vitamin A), both,
or placebo daily for five to eight years. (In contrast, vitamin E was found to
reduce the risk of cancer, especially prostate cancer.)

In January, 1996, researchers monitoring the Beta-carotene and Retinol Efficacy Trial (CARET) confirmed the earlier negative news with more of their own: The beta-carotene group had 46 percent more cases of lung cancer deaths. This study involved smokers, former smokers, and workers exposed to asbestos. Alarmed, the National Cancer Institute ended the $42 million CARET trial twenty-one months before it was scheduled to end.

At about the same time, the twelve-year Physicians’ Health Study of 22,000 male physicians was finding that 50 mg of beta-carotene (about twenty-five times the amount necessary to provide the daily requirement of vitamin A) taken every other day had no effect–good or bad–on the risk of cancer or heart disease. In this study, 11 percent of the participants were smokers and 39 percent were former smokers.

Similarly, another study of beta-carotene supplements failed to find any effect on the risk of cancer in women. In a final indictment of beta-carotene’s safety and effectiveness, researchers, who combined the results of twelve recent placebo-controlled trials investigating the association between antioxidant supplementation and cancer, found that beta-carotene use was associated with an increased incidence of cancer among smokers. However, the story does not end there. In yet another careful analysis of four randomized trials involving 109,394 smokers and former smokers, researchers found that smokers who consumed between 20 and 30 mg of beta-carotene were at significantly greater risk of developing lung cancer. There was no such risk among former smokers.

One possible explanation for these discrepancies is that beta-carotene alone is not effective. Fruits and vegetables contain many carotenoids (carotene-like substances) that may be more important for preventing cancer than beta-carotene. One researcher suggested that taking beta-carotene supplements actually depletes the body of other beneficial carotenoids. It is also possible that intake of carotenes as such is unrelated to cancer and that some unrelated factor common to persons with a high carotene diet is the cause of the benefits seen in observational trials.

Tomatoes (lycopene). Lycopene, a carotenoid like
beta-carotene, is found in high levels in tomatoes and pink grapefruit. Lycopene
appears to exhibit about twice the antioxidant activity of beta-carotene and may
be more helpful for preventing cancer.

In one observational study, elderly Americans consuming a diet high in tomatoes
showed a 50 percent reduced incidence of cancer. Men and women who ate at least
seven servings of tomatoes weekly developed less stomach and colorectal
cancers compared to those who ate only two servings
weekly.

In another study, 47,894 men were followed for four years in an observational study looking for influences on prostate cancer. Their diets were evaluated on the basis of how often they ate fruits, vegetables, and foods containing fruits and vegetables. High levels of tomatoes, tomato sauce, and pizza in the diet were strongly connected to reduced incidence of prostate cancer. After an evaluation of known nutritional factors in these foods compared to other foods, lycopene appeared to be the common denominator. Additional impetus has been given to this idea by the discovery of lycopene in reasonably high levels in the human prostate, evidence from test-tube studies that lycopene might slow DNA synthesis in prostate cells, and evidence that men with higher lycopene levels in the blood have a lower risk of prostate cancer. Similarly weak evidence suggests that foods containing lycopene might help prevent other forms of cancer, including lung, colon, and breast cancer. A few poorly designed intervention trials have also been performed, and these suggest that lycopene or a standardized tomato extract containing lycopene might be helpful for the prevention or treatment of prostate or breast cancer.

Vitamin C. Several observational studies have found a strong
association between high dietary vitamin C intake and a reduced
incidence of stomach cancer. It has been proposed that vitamin C may prevent the
formation of carcinogenic substances known as N-nitroso compounds in the
stomach.

Observational studies have also linked higher vitamin C in the diet with reduced risk of cancers of the colon, esophagus, larynx, bladder, cervix, rectum, breast, and perhaps lung. However, dietary vitamin C intake does not appear to be associated with reduced rate of prostate cancer.

One study found that vitamin C supplementation at 500 mg or more daily was associated with a lower incidence of bladder cancer. However, another study found no association. Similarly, in another observational study, 500 mg or more of vitamin C daily for six years was not associated with reduced incidence of breast cancer. Another study found similar results.

Green tea. Both green tea and black tea come from the plant Camellia sinensis, which has been cultivated in China for centuries. The key difference between the two is in preparation. For black tea, the leaves are allowed to oxidize, a process believed to lessen the potency of the presumed active ingredients in green tea, catechin polyphenols. Green tea is made by lightly steaming the freshly cut leaf, a process that prevents oxidation and possibly preserves more of the therapeutic effects.

Laboratory and animal studies suggest that tea consumption protects against cancers of the stomach, lung, esophagus, duodenum, pancreas, liver, breast, and colon. A 1994 study of skin cancer in mice found that both black and green teas, even decaffeinated versions, inhibited skin cancer in mice exposed to ultraviolet light and other carcinogens. After thirty-one weeks, mice given the teas brewed at the same concentration humans drink had 72 to 93 percent fewer skin tumors than mice that were given only water.

However, results from observational studies in humans have not been so clear-cut; some have found evidence of a protective effect, and others have not. One study followed 8,552 Japanese adults for nine years. Women who drank more than ten cups of green tea daily had a delay in the onset of cancer and also a 43 percent lower total rate of cancer occurrence. Men had a 32 percent lower cancer incidence, but this finding was not statistically significant.

A study in Shanghai, China, found that those who drank green tea had
significantly less risk of developing cancers of the rectum and pancreas than
those who did not. No significant association with colon cancer incidence was
found. A total of 3,818 residents age thirty to seventy-four years were included
in the population study. For men, those who drank the most tea had a 28 percent
lower incidence of rectal cancer and a 37 percent lower
incidence of pancreatic cancer compared to those who did not drink tea regularly.
For women, the respective differences in cancer frequency were even greater: 43
percent and 47 percent.

Another study in Shanghai found similar associations for stomach cancer. Green tea drinkers were 29 percent less likely to get stomach cancer than nondrinkers, with those drinking the most tea having the least risk. The risk of stomach cancer did not depend on the person’s age at which he or she started drinking green tea. Researchers suggested that green tea may disrupt the cancer process at both the intermediate and the late stages.

Green tea may exert an estrogen-blocking effect that is helpful in preventing
breast and uterine cancer, and another study suggests that it might
prevent the development of tumors by blocking the growth of new blood vessels. In
a review of nine studies (none of which were clinical trials) involving more than
5,600 persons, researchers found weak evidence for reduction in breast cancer
recurrence among people who consumed more than three cups of green tea every day,
but they failed to find reliable evidence for a reduction in the incidence of
breast cancer.

However, in an observational study of 26,311 Japanese persons, researchers saw no reduction in stomach cancer rates. Lack of benefit was also seen in a study conducted in Hawaii. Also, combining the results of thirteen observational studies, researchers found conflicting evidence for green tea’s effect on the risk of stomach cancer. However, in a small Japanese randomized trial, persons who supplemented their regular diet with an extra 1.5 grams of green tea extract per day for one year lowered their risk of recurrent colorectal polyps compared to those who took no supplement. In a review of multiple studies, including forty-three observational studies, four randomized trials and one meta-analysis (a mathematical summation of the results from several studies), researchers concluded that there was inconsistent evidence supporting green tea’s effectiveness for cancer prevention.

The main catechin polyphenol found in green tea is epigallocatechin gallate (EGCG). Preliminary experimental studies suggest that EGCG may help prevent skin cancer if it is applied directly to the skin.

Soy. In many animal studies, soybeans, soy protein, or other soy
extracts decreased cancer risk, and observational studies in people have found
suggestive associations between higher soy consumption and lower incidence of
hormone-related cancers such as prostate, breast, and uterine cancer. Soybeans
provide estrogen-like compounds known as isoflavones,
especially genistein and daidzein. These substances bind to the same sites in the
body as estrogen, occupying these sites and keeping natural estrogen
away. Estrogen stimulates certain forms of cancer, but soy isoflavones exert a
milder estrogen-like effect that may not stimulate cancer as much as natural
estrogen. This could help protect against cancer. Soy may additionally reduce
levels of the body’s own estrogen, which would also have a protective effect.

However, not all evidence on soy and cancer is positive. Because the
isoflavones work somewhat like estrogen, there are theoretical concerns that they
may not be safe for women who have already had breast
cancer. Studies in animals have found suggestive evidence that
under certain circumstances soy isoflavones might stimulate breast cancer cells.
Furthermore, evidence from two preliminary studies in humans found changes
suggesting that soy might slightly increase breast cancer risk. Other studies in
women have found reassuring results; nonetheless, women who have had breast
cancer, or are at high risk for it, should consult a physician before taking any
isoflavone product.

Men have very low levels of circulating estrogen, so the net effect of
increased soy consumption might be to increase estrogen-like activity in the body.
Because real estrogen is used as a treatment to suppress prostate cancer, it has
been hypothesized that the mild estrogen-like activity of isoflavones has a
similar effect. There are also indications that isoflavones might decrease
testosterone levels and alter ratios of certain forms of
estrogen, both of which would be expected to provide benefit. Thus, there are
several possible ways in which isoflavones might be useful for preventing or
treating prostate cancer. Whether or not they actually help has been tested in a
few preliminary trials.

For example, in one double-blind study, men with early prostate cancer were given either isoflavones or placebo, and their PSA levels were monitored. (PSA is a marker for prostate cancer, with higher values generally showing an increased number of cancer cells.) The results did show that the use of isoflavones (60 mg daily) slightly reduces PSA levels. Whether this meant that soy actually slowed the progression of the cancer or simply lowered PSA directly is not clear from this study alone. However, another study of apparently healthy men (not known to have prostate cancer) found that soy isoflavones at a dose of 83 mg per day did not alter PSA levels. Taken together, these two studies provide some direct evidence that soy isoflavones may be helpful for treating or preventing prostate cancer, but the case, nonetheless, remains highly preliminary.

A special highly concentrated extract of soy, Bowman-Birk inhibitor (BBI), has also shown promise for helping to prevent various types of cancer. There exists weak evidence that besides the isoflavone found in soy, flavonoids (found, for example, in beans, onions, apples, and tea) may reduce the recurrence of colorectal polyps, common precancerous lesions found in the colon and rectum.

Folate. Observational studies have suggested that folate deficiency may predispose persons toward developing cancer of the cervix, colon, lung, breast, pancreas, and mouth. Other observational studies have suggested that folate supplements may help prevent colon cancer, especially when they are taken for many years or by people with ulcerative colitis. However, observational studies are notoriously unreliable; large double-blind, placebo-controlled studies are needed to prove a treatment effective.

One such study performed on folate for cancer prevention among 1,000 people
over a five-year period found folate ineffective for preventing early colon
cancer. Also, in a large controlled trial involving more than 5,400 women,
supplements combining folate plus vitamins B6 and B12 taken
for seven years did not reduce the risk of a cancer compared with placebo.
However, a much smaller study involving ninety-four persons with colon polyps
(a precancerous condition) found that folate may reduce the risk of recurrent
polyps over a three-year period.

Other Proposed Natural Treatments

Some observational and intervention studies have found evidence that calcium
supplementation may reduce the risk of colon cancer. Risk reduction might continue
for years after calcium supplements are stopped. In men, however, calcium
supplements might increase risk of prostate cancer. For menopausal women, calcium
supplementation, especially when taken with vitamin D,
appears to reduce overall cancer incidence.

Some studies have connected higher vitamin D levels with a lower incidence of cancer of the breast, colon, pancreas, and prostate, and of melanoma, but overall research has yielded mixed results. In an extremely large study involving more than 36,000 postmenopausal women, supplementing the diet with 1,000 mg of calcium plus 400 IU of vitamin D daily did not lower the risk of breast cancer in a period of seven years. Based on the results of this placebo-controlled study, there does not appear to be a connection between vitamin D and breast cancer risk.

Increasing dietary fiber has long been thought to help reduce the incidence of colon polyps. However, several late studies found either little evidence of benefit or no evidence. For example, one large study enrolled almost two thousand people with a history of colon polyps and compared the ordinary American diet with a diet high in fiber, fruits, and vegetables and low in saturated fat. In the four years of the study, plus an additional four years of follow-up, this presumably healthier diet failed to reduce polyp recurrence.

Substances known as lignans are found in several foods and may produce anticancer benefits. Lignans are converted in the digestive tract to estrogen-like substances known as enterolactone and enterodiol. Like soy isoflavones, these substances prevent estrogen from attaching to cells and may thereby block its cancer-promoting effects. Lignans are found most abundantly in flaxseed, a high-fiber grain that has been cultivated since ancient Egyptian times. Both flaxseed and flaxseed oil have been recommended for the prevention or treatment of cancer, but the supporting evidence is still extremely preliminary. Contrary to some reports, flaxseed oil contains no lignans. Instead, it contains the alpha-linolenic acid, which is also hypothesized to have cancer-preventive effects.

Evidence from observational studies suggests that garlic taken in the diet as food may help prevent cancer, particularly cancer of the colon and stomach. In one of the best of these studies, the Iowa Women’s Study, women who ate significant amounts of garlic were found to be about 30 percent less likely to develop colon cancer. Similar results were seen in other observational studies performed in China, Italy, and the United States. In addition, one preliminary intervention trial also found some evidence that aged garlic may reduce risk of colon cancer.

Resveratrol is a phytochemical found in at least seventy-two
different plants, including mulberries and peanuts. Grapes and red wine are
particularly rich in resveratrol. This substance has shown anticancer properties
in test-tube studies.

One large observational study suggests that higher intake of boron may reduce the risk of prostate cancer. Provocative evidence suggests that a substance called sulforaphane, found in broccoli and related vegetables, may possess anticancer properties. Broccoli sprouts have been touted for cancer prevention on the basis of their high content of sulforaphane. However, this recommendation is still highly speculative. Another constituent of broccoli-family vegetables, indole-3-carbinol, has also shown promise as a cancer-preventive agent; however, there is some evidence that this substance might actually increase the risk of cancer in certain circumstances. Much the same is true of the related substance diindolylmethane.

In one large, randomized-controlled trial, diets rich in fish and omega-3 fatty acids from fish were associated with a significant reduction in the risk of developing colorectal cancer among men in a twenty-two-year period. Another study provides preliminary supporting evidence for the notion that fish oil reduces the risk of prostate cancer. However, on balance, there is still relatively little evidence that the consumption of fish oil reduces the risk of cancer.

Weak evidence hints that N-acetylcysteine treatment may help to prevent colon
cancer. Also, several studies have experimented with using very high doses of
vitamin
A to prevent skin cancer, doses considerably above levels
ordinarily considered safe. Some have found possible benefits regarding preventing
some forms of skin cancer, while others have not. This approach should not be
tried except under physician supervision. Vitamin K has
shown some promise for helping to prevent liver cancer
in people with chronic viral hepatitis.

Innumerable other herbs and supplements have shown minimal promise in test-tube and animal studies, including but not limited to active hexose correlated compound, Cordyceps, Coriolus versicolor, ligustrum, quercetin, citrus bioflavonoids, conjugated linoleic acid, Morina citrifolia (noni), turmeric, rosemary, betulin (from white birch tree), bromelain, ellagic acid (from grapes, raspberries, strawberries, apples, walnuts, and pecans), ginseng, glycine, grass pollen, inositol hexaphosphate (phytic acid, IP6), kelp, licorice, melatonin, methyl sulfonyl methane, milk thistle, nettle, oligomeric proanthocyanidins, papaw tree bark, probiotics (friendly bacteria), royal jelly, shiitake, schisandra, and blue-green algae.

While it is commonly stated as a fact that high consumption of fruits and vegetables reduces cancer risk, the evidence is limited to inherently unreliable observational studies, and even among these the results are inconsistent. As noted, a large study failed to find that a diet high in fruits and vegetables reduced risk of colon polyps. Similarly, meat consumption, widely stated to increase colon cancer risk, might or might not do so (the evidence is not compelling). Data do not suggest that diets high in sugar or other simple carbohydrates increase colon cancer risk or that reducing fat in the diet reduces colon, uterine, or breast cancer risk. Higher levels of exercise might potentially help reduce the risk of various forms of cancer, especially colon cancer.

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