Give some examples of compound substances.

Substances can be classified into three categories: elements, compounds and mixtures. An element is the purest form of a substance and cannot be further subdivided into non-identical fragments. A compound is made up of 2 or more elements in a fixed ratio. For example, water (H2O) is a compound and is formed by two elements: hydrogen and oxygen, mixed in a 2:1 ratio. Similarly, carbon dioxide (CO2) is made up of carbon and oxygen in a 1:2 ratio. Common salt, sodium chloride (NaCl), is composed of sodium and chlorine in a 1:1 ratio. We can find several examples of compounds in our daily lives. Methane (CH4), glucose (C6H12O6), hydrogen sulphide (H2S), sulfuric acid (H2SO4), etc., are just some of the common examples.

In comparison, a mixture is made up of elements or compounds in a non-fixed ratio and can be divided into individual constituents easily. For example, trail mix is a mixture.

Hope this helps. 

What are medical screenings?

Indications and Procedures

In its natural course, a disease usually starts asymptomatically, gradually develops symptoms, and becomes severe when no treatment is given. If the disease can be identified early, especially before it shows any signs or symptoms, then treatment can be initiated early. Early or prompt treatment usually produces a better and more effective cure for a disease. Treatment at the early stage of a disease also has a lower cost than treatment for a disease at its late stages.

The most effective way to detect diseases before they develop symptoms is through screening. Screening is the application of a test or procedure to detect a potential disease or condition in individuals who have no known signs or symptoms of that disease or condition. For example, some people are unaware that they have a high cholesterol level, which can increase the risk for the development of cardiovascular disease. Through screening for cholesterol levels, these individuals can be identified, and proper dietary consultation, exercise prescription, and treatment can be followed to decrease the risk for cardiovascular disease. Screening tests use criteria to classify people according to the likelihood of disease. Screening is just an initial examination. Individuals with positive results from a screening test are required to have a secondary diagnostic examination, which is often more comprehensive and in depth, to confirm the positive finding from their screening test.

Screening tests can be classified into three categories: mass, multiple or multiphasic, and prescriptive. Mass screening means the screening of all individuals in a defined area or population. Multiple or multiphasic screening involves the use of a variety of tests or procedures during the same screening visit. Prescriptive screening is the early detection in presumptively healthy individuals of disease that can be controlled better if treated early in its natural history. From a public health perspective, the following factors are of importance to consider before implementing a screening program. The disease or condition should be a major medical problem. Effective treatment should be available for the disease discovered from the screening test. Follow-up diagnosis and treatment should be available to individuals with positive results from the screening test. The disease should have identifiable early and latent stages. An effective test or examination for the disease should be available. The test or procedure used in screening should be acceptable to the general population. The natural history of the disease should be adequately understood. Policies, procedures, and threshold levels on tests should be determined in advance to clarify who should be referred for further
diagnosis and possible treatment. The process should be simple enough to encourage large groups of people to participate. Finally, screening should be done as a regular and ongoing process, not as an occasional activity. Based on these considerations, screening is not necessarily available or suitable for every disease.

Accuracy and effectiveness are important for a screening test; they are evaluated by the characteristics of validity, predictive value, reliability, and yield. The validity of a test means how well the test actually measures what it is supposed to measure. Validity has two components: sensitivity and specificity. Sensitivity is defined as the ability of a test to identify correctly those who have the disease, while specificity is defined as the ability of a test to identify correctly those who do not have the disease. Both sensitivity and specificity are determined by comparing the results obtained from the screening test with the results derived from some definitive diagnostic procedure. Sensitivity is calculated as the proportion of subjects with the disease who have a positive screening test (true positive). Specificity is calculated as the proportion of subjects without the disease who have a negative screening test (true negative). If a screening test has a low sensitivity, then it could misclassify healthy individuals as disease cases (false positive). If a screening test has a low specificity, then it could fail to identify individuals with the disease (false negative). Thus, high levels of sensitivity and specificity are the foundation
for the accuracy of a screening test, although it is impossible to have 100 percent of both sensitivity and specificity in practice.

The ability of a screening test to predict the presence or absence of the disease indicates the quality of the test. The predictive value of a screening test is influenced by the sensitivity and specificity of the test as well as the prevalence of the disease, which means how common the disease is in populations. The higher the prevalence of a disease in a population, the more likely a positive test will represent a true positive; the lower the prevalence of a disease in a population, the more likely a positive test will represent a false positive. The predictive value of a screening test can be measured as either positive or negative. The predictive value of a positive test is the probability that individuals with a positive test actually have the disease. On the other hand, the predictive value of a negative test is the probability that individuals who have a negative result from a screening test do not have the disease. Thus, along with sensitivity and specificity, a high level of predictive value is also desirable for an effective screening test. In comparison, sensitivity and specificity are calculated from the screening test results of the diseased or nondiseased individuals, while predictive value depends on the proportion of diseased individuals in the population.

Reliability, also called precision, is another important characteristic of a screening test. A reliable screening test is one that gives consistent results when the test is performed more than once on the same individual under the same conditions. Two common factors affect the consistency of results: the variation of the method used in a screening test and the variation between different observers. These variations usually can be reduced by standardization of procedures or protocols used in a screening test, by training the observers of a screening test, by using more than one observer at the same time with each making independent observations, and by quality control measures, such as periodic checks.

The yield of a screening program is defined as the number or proportion of cases of a previously unrecognized disease that are diagnosed and brought to treatment as a result of the screening program. Several factors can affect the yield of a screening program. If a screening test has a low sensitivity, and therefore identifies only a portion of the diseased individuals, then the yield of the screening test could be poor. If the prevalence of the disease being screened for is low, then the yield of the test could be low even though the sensitivity of the test is high. Using multiphasic screening approaches often increases the cost-effectiveness of a screening program and results in a high level of yield. Frequency of screening is another factor influencing the yield of a screening program. The optimal interval between screenings should be determined by a particular disease’s natural course—how long it takes to develop from its first detectability of symptoms—and by different individuals with different risk factors. For example, certain cancers may need to be screened more frequently in older individuals than in younger individuals. The yield of a screening program can also be affected by the proportion of the population participating in the program. Low participation rates could turn out low yields. To increase
participation rates in a disease screening program, the population needs to be educated about the disease, including information about the fact that the disease is understood as a serous threat to health, that all individuals are vulnerable to the disease, that the method of the screening test is safe, and so on. The cost of a screening test can also have a significant effect on the participation rate.

Screening is usually concerned with chronic illness. Physicians may prescribe specific screening tests based on the age, gender, occupation, overall health status, lifestyle, and medical and family history of the individuals being tested. Mass screening programs may be carried out in communities to detect common diseases such as hypertension, high blood cholesterol, type 2 diabetes, breast cancer, colorectal cancer, prostate cancer, and osteoporosis.

Uses and Complications

Some diseases are good candidates for screening. For example, data from the National Health and Nutrition Examination Survey showed that 24 percent of the adult population in the United States had high blood pressure, or hypertension. Almost one in every three African Americans was hypertensive. More than one-third of the individuals with hypertension were unaware of their condition, since hypertension is usually asymptomatic. Hypertension is defined as a blood pressure reading of 140/90 millimeters of mercury (mmHg) or higher. The higher the blood pressure, the higher is the chance of developing hypertension complications, such as coronary heart disease, stroke, renal dysfunction, and sudden death. The treatment of hypertension is very effective. Reduction in blood pressure through treatment can significantly decrease the risk for stroke, coronary heart disease, renal disease, and sudden death. Screening is the best way to detect hypertensive individuals without symptoms. The common method of screening for hypertension is
sphygmomanometry that measures cuff pressures. Ambulatory blood pressure monitoring is an alternative method, which uses an automated sphygmomanometer that records blood pressure at frequent intervals over twenty-four hours. Although ambulatory blood pressure monitoring is more accurate, it is also more expensive and impractical, thus, it is not as commonly used as sphygmomanometry. As the benefit of the screening is evident and the risk of sphygmomanometry is nearly none, it is recommended that every adult should be screened for hypertension.

High blood cholesterol is another common condition that is asymptomatic but increases the risk of coronary heart disease and stroke. More than 37 percent of people in the United States have blood cholesterol levels higher than the normal range. Cholesterol comes from food or is produced in the body. When there is too much cholesterol in the blood, it builds up in the walls of the arteries and hardens them, so that the arteries become narrowed and blood flow to the heart or the brain is slowed down or blocked, resulting in coronary heart disease or stroke. Since high cholesterol is asymptomatic, many people are unaware that their level is too high. Cholesterol screening is performed using a blood test after a fourteen-hour fast. This test includes measurements of total cholesterol: both low-density lipoproteins (LDLs), or “bad” cholesterol, the main source of cholesterol buildup and blockage in the arteries, and high-density lipoproteins (HDLs), or “good”
cholesterol, which helps keep cholesterol from building up in the arteries. Triglyceride, another form of fat in the blood, may be checked at the same time. A healthy individual should have a total cholesterol level less than 200 milligrams per deciliter, an LDL level less than 100 milligrams per deciliter, and an HDL level greater than 45 milligrams per deciliter. The normal triglyceride level is less than 200 milligrams per deciliter. Individuals aged twenty years or older are recommended to have their cholesterol level checked every five years. Cholesterol screening can raise awareness of high blood cholesterol, so that individuals can modify their lifestyle by consuming less saturated fat and engaging in more physical activity and drug treatment can be initiated, if necessary, to prevent heart disease and stroke. The American Heart Association recommends mass screening for high cholesterol at worksites to identify high-risk populations of middle-aged men and women and in communities targeting low-income, low-education, and minority groups who are often underrepresented in other voluntary screenings.

The number of people with type 2 diabetes is increasing in the United States as a result of the high prevalence of obesity. Complications of diabetes are severe, such as increased risks for cardiovascular disease, kidney failure, blindness, and amputation of the legs. Many people with diabetes are undiagnosed. The natural history of diabetes includes an asymptomatic preclinical phase. The length of this preclinical phase varies and may last ten years or longer. Screening tests can detect diabetes in the preclinical phase. Different tests have been used for diabetes screening: the two-hour postload plasma glucose test, the fasting plasma glucose test, and the test of hemoglobin A1c. The third test has been proposed as a standard reference for diagnosing diabetes. Research studies showed that after diabetes was detected during its preclinical phase, interventions, such as aggressive control of hypertension and cholesterol levels and use of aspirin during the preclinical phase, could reduce the risk of cardiovascular disease. The benefit of tight control of blood sugar levels during the preclinical phase,
however, was unclear or minimal. Overall, screening for diabetes has been controversial. The most important gap in the understanding of screening is the lack of information on the added benefits of starting various interventions and treatments earlier, during the preclinical period, compared with at clinical detection.

More than 215,000 women are diagnosed with breast cancer
every year in the United States. Approximately one in every eight women will develop breast cancer during her lifetime. Breast cancer is the second leading cause of cancer death in women. Early detection and effective treatment can reduce the number of women who die from breast cancer. Three approaches are considered for screening for breast cancer: breast self-examination (BSE), x-ray mammography, and clinical breast examination. The sensitivity of BSE and clinical breast examination is unclear, but the sensitivity of mammography is relatively high. The American Cancer Society recommends screening with mammography every one to two years, with annual clinical breast examinations beginning at the age of forty and annual mammography with clinical breast examinations beginning at the age of fifty.

Prostate cancer is the most common cancer and the second leading cause of cancer death in men in the United States. After fifty, the risk of prostate cancer increases with age. African American men have a higher risk for prostate cancer. The principal screening tests for prostate cancer are the digital rectal examination, a blood test of serum
tumor markers called prostate-specific antigen (PSA), and transrectal ultrasound. The reference standard for these tests is pathologic confirmation of malignant disease in tissue obtained by biopsy or surgical resection. Because biopsies are not generally performed on patients with negative screening test results, the sensitivity and specificity of screening tests for prostate cancer cannot be determined with certainty. The American Cancer Society
recommends an annual digital rectal examination for prostate cancer beginning at age forty. It recommends an annual measurement of serum tumor markers for average men aged fifty and older; however, this measurement should begin at age forty for African American men and those with a family history of prostate cancer. The natural history of prostate cancer is still poorly understood, and there is no direct evidence that prostate cancer screening decreases mortality. The cost associated with the screening tests for prostate cancer is another concern. Thus, screening for prostate cancer remains controversial.

Colorectal cancer is the second most common form of cancer, as well as one of the leading causes of death from cancer in the United States. Since it is asymptomatic at its early stage, about 60 percent of patients with colorectal cancer have regional or distant metastases at the time of diagnosis. The principal screening tests for detecting colorectal cancer are fecal occult blood testing,
sigmoidoscopy, and digital rectal examination. Less frequently used screening tests include barium enema and colonoscopy, which have been advocated primarily for high-risk groups, such as persons with a family history of hereditary syndromes associated with a high risk of colon cancer. Screening for colorectal cancer is recommended for men and women aged fifty years and older with annual fecal occult blood testing, sigmoidoscopy,
or both. There is good evidence that periodic fecal occult blood testing reduces mortality for colorectal cancer, and there is fair evidence that sigmoidoscopy alone or in combination with the fecal occult blood testing reduces mortality. There is no direct evidence, however, that colonoscopy or barium enemas reduce mortality. The digital rectal examination is of limited value as a screening test for colorectal cancer. The examining finger, which is only seven to eight centimeters long, has limited access even to the rectal mucosa, which is usually eleven centimeters in length. Thus, a negative digital rectal examination performed by a physician provides little reassurance that the patient is free of colorectal cancer.

It is estimated that in the United States 1.3 million people experience a fracture each year as a result of osteoporosis, or fragile bones. Osteoporosis can progress painlessly until a bone breaks. Over half of all postmenopausal women will develop a spontaneous fracture as a result of osteoporosis. Hip fractures and vertebral deformities, two common consequences of osteoporosis, can result in significant pain, disability, decreased functional independence, and death. Low bone density is strongly associated with an increased risk of fracture. The World Health Organization (WHO) defines osteoporosis as a bone mineral density of 2.5 or more standard deviations below the mean of healthy young adult women. A number of tests are available to measure bone density, including conventional skeletal radiographs, quantitated computed tomography, single photon absorptiometry, dual photon absorptiometry, and dual energy x-ray absorptiometry. The correlations among different bone density devices are low. Dual energy x-ray absorptiometry is considered the gold standard because it is the most extensively validated test against fracture outcomes. The likelihood of being diagnosed with osteoporosis depends on the number of tested sites, which include the forearm, hip, spine, or heel. Because women over age sixty-five have a significantly increased risk of osteoporosis, routine screening in this population is recommended. For women aged sixty to sixty-four, screening may be needed if they have risk factors, such as low body weight, family history, smoking, and removal of the ovaries before age forty-five. The screening intervals should be two years for women aged sixty-five years and older and five years for women younger than sixty-five. Once osteoporosis is diagnosed, changing lifestyle, such as an increase in dietary calcium and vitamin D intake, weight-bearing exercise, and smoking cessation, along with drug treatment, can help prevent fractures.

Other common screening procedures include those meant to detect cervical cancer, testicular cancer, skin cancer, carotid artery stenosis, peripheral arterial disease, abdominal aortic aneurysm, thyroid disease, iron deficiency anemia, sexually transmitted diseases, visual impairment, hearing impairment, Phenylketonuria (PKU), Down syndrome, dementia, and depression.

Perspective and Prospects

By the middle of the twentieth century, infectious diseases were gradually replaced by chronic diseases as the leading causes of death in developed countries. This transition occurred as a result of improvement in living standards and nutritional status, the prevention of infectious diseases through immunization, and increased life expectancy. Hence, prevention of chronic disease became an important task in public health and medicine practices in developed countries. In 1951, the United States multisponsored Commission on Chronic Illness organized the Conference on Preventive Aspects of Chronic Diseases and advocated screening for diseases. Since then, more and more screening tests and procedures have become available for different diseases and conditions because of development in medical technologies.

At the beginning of the twenty-first century, however, chronic diseases were still the leading cause of death in developed countries as well as some developing countries. The most important chronic diseases that contribute to mortality are heart disease, cancer, and stroke. Many aspects of screening for these chronic diseases remain unclear. For some diseases, no tests or no effective tests are available, such as for lung cancer. For other conditions, powerful methods of detection exist but no effective treatments are available. Many screening procedures still lack evidence to support their effectiveness or justification for the balance between benefit, harm, and cost. Therefore, further investigations, epidemiological studies, development of low-cost and effective screening methods, and increases in participation in screening through health education are the future challenges.

Bibliography

Holland, Walter W., and Susie Stewart. Screening in Disease Prevention: What Works? Seattle: Radcliffe, 2005.

MedlinePlus. "Health Screening." MedlinePlus, June 10, 2013.

Snow, Vincenza, ed. Screening for Diseases: Prevention in Primary Care. Philadelphia: American College of Physicians, 2004.

Thorner, Robert M., and Quentin R. Remein. Principles and Procedures in the Evaluation of Screening for Disease. Washington, D.C.: Government Printing Office, 1961.

U.S. Preventive Services Task Force. Guide to Clinical Preventive Services. Washington, D.C.: Agency for Healthcare Research and Quality, 2006.

How is Benvolio a foil to Romeo?

Benvolio and Romeo are both Montagues, similar in age, and good friends. Where Romeo is given to intense emotions, however, Benvolio is much more level-headed. Romeo is pretty self-centered; Benvolio is not. Benvolio seeks peace; he tries to break up a fight between his house and the Capulets in Act I, Scene 1, and sttempts to prevent another such fight just before Tybalt kills Mercutio, an action that prompts Romeo to kill Tybalt. While Benvolio is constantly the voice of reason, Romeo is impulsively emotional, killing Tybalt in the street, with witnesses present. Benvolio has to tell Romeo to run afterward because Romeo seems unable to think for himself. Benvolio honestly seems like the most mature out of Romeo and all his friends; he's not interested in fighting, doesn't make the same kinds of bawdy and sexual jokes as the others do, and usually acts in a measured and calm way.

What three quotes show friendship in To Kill a Mockingbird?

In chapter 5, Jem and Dill become closer friends because they are on a mission to get Boo Radley to come out of his house. Scout, on the other hand, has been reluctant to do anything related to Boo Radley since Atticus caught them playing a game about his life. As a result, Scout is left out of some of the boys' planning and scheming. Scout explains Jem's and Dill's friendship as follows:

Dill was becoming something of a trial anyway, following Jem about. He had asked me earlier in the summer to marry him, then he promptly forgot about it... said I was the only girl he would ever love, then he neglected me. I beat him up twice but it did not good, he only grew closer to Jem. They spent days together in the treehouse plotting and planning, calling me only when they needed a third party (41-42).

This passage shows the decline of one friendship and the emergence of a new one. Other than Cecil Jacobs, Scout has no other friends to play with, so Scout visits Miss Maudie when the boys are playing together. Miss Maudie is an adult friend who treats the children with respect and kindness. When she bakes cakes, she will bake three little ones just for Scout, Jem, and Dill. Scout describes her appreciation for Miss Maudie's friendship as follows:

Jem and I had considerable faith in Miss Maudie. She had never told on us, had never played cat-and-mouse with us, she was not at all interested in our private lives. She was our friend (44-45).

Another time when friendship is finally realized is in chapter 8, during the night of Miss Maudie's house fire. While Jem and Scout watch the fire from across the street at the Radleys' house, Boo Radley comes out and slips a blanket around Scout's shoulders without her knowing. This act of kindness comes after Jem and Scout find gifts from Boo in the knothole of the oak tree on the Radleys' lot. When the children get home after the fire and discover the blanket, Jem tells his father and sister, respectively:

Atticus, I swear to God he ain't ever harmed us, he ain't ever hurt us, he coulda cut my throat from ear to ear that night but he tried to mend my pants instead... he ain't ever hurt us, Atticus.

...Boo Radley. You were so busy looking at the fire you didn't know it when he put the blanket around you (72).

This is a fun passage because Jem feels he has enough evidence to declare Boo Radley is not an enemy, but a friend. Boo Radley has never done anything but kind things for the children, such as mending Jem's pants, giving them anonymous gifts, and watching over them during the night of the fire. Boo is very quiet and shy, but that doesn't mean he isn't one of the children's friends. In fact, he later proves to be one of the best friends they have because he saves their lives. 

What is a specific example that exists for each biochemical, pharmaceutical, and diagnostic chemical reaction type. Why might they be of...

You are looking for specific examples of biochemical, pharmaceutical, and diagnostic chemical reactions.  A specific biochemical reaction is amide bond formation.  Small monomer units called amino acids bind together in long polymeric chains called proteins.  The order in which specific amino acids bind together gives rise to the specific protein generated.  All of these amino acids are bonded together by amide bonds.  Amide bonds are formed when a carboxylic acid is condensed with an amine to produce an amide with a water molecule as a byproduct.

A specific example of a pharmaceutical reaction would be the inhibition of the COX-2 enzyme.  COX-2 is an enzyme that is involved with inflammation and pain.  When a small pharmaceutical molecule can bind with the enzyme in its active site, it can disrupt and inhibit the COX-2 enzyme's ability to perform its function and reduce pain and inflammation.

A specific example of a diagnostic chemical reaction is a test for serum albumin levels.  Albumin is the main protein found in blood serum that is involved with the transport of many species through the circulatory system.  When a blood serum sample is treated with a chemical called bromocresol green, it binds with the albumin to produce a colored complex whose light absorbance can be measured with a spectrometer to calculate albumin levels in the blood.

All of these reactions are important to healthcare professionals.  There are millions of different chemicals and chemical reactions in the human body and the study of medicine and pharmaceuticals relies heavily on gaining a better understanding of this chemistry.

What role does gender play in the novel Murder in Amsterdam? Are there competing understandings of gender in the novel?

Ayaan Hirsi Ali's short film Submission, which is the word "Islam" translated into English, features one actress portraying four Muslim women wearing transparent veils with verses from the Koran projected onto their naked bodies. Theo Van Gogh, the film's director, was murdered by Mohammed Bouyeri, who shot, stabbed, and nearly decapitated him on a Dutch street in the middle of the day. It was clear from the letter Bouyeri left staked in Van Gogh's chest, a death threat against Hirsi Ali, that it was Van Gogh's role in making the film that led to Bouyeri's rampage.

One could potentially view Van Gogh in his role as the film's director as a defender of women, a crusader taking up the mantle against a religion and culture that propagates violence against women. But when we take a look at Van Gogh's memorial party, which he himself had meticulously planned during a flight to New York--he was deathly afraid of flying and thought he may perish during the flight--we see a man who participated fully in his own kind of gender discrimination. Of Van Gogh's memorial party, Buruma (2006) writes, "There was a rock band and there were cabaret acts. Pretty cigarette girls in miniskirts plied their wares, as in a prewar movie theater. Female guests wore strings of pearls and twinsets, a style that Theo had found a turn-on" (p. 9). Cigarette girls were common in the 1920's until the post-WWII era. The most common uniform was a low-cut, cleavage-revealing top matched with a short skirt. Depending on the venue, skirt length varied from just above the knee to just below the buttocks. According to Tenney (2014), the cigarette girl's job was not just selling tobacco: "Most customers were paying as much for her company as they were for her wares." Thus, the cigarette girl was a sort of prostitute. A 'twinset' is a matching sweater and cardigan set, like the ones popular in the 50's and early 60's. Most media depictions of the "little woman" and the "model wife," whether a magazine ad or a TV show--picture June Cleaver in  the sitcom Leave it to Beaver--featured the wife/mother wearing a pearl necklace and a twinset. 

So in Theo Van Gogh, we have a man, murdered for his derring-do in shedding light on the oppressive and discriminatory practices against women in Islam, who is simultaneously "turned on" by living images of young women who prostituted themselves for cigarette sales and those who represented an era when women were little more than house servants. This is one of the most glaring examples of competing views of gender in the book.

`int_0^(pi/4) sqrt(1 - cos(4 theta)) d theta` Evaluate the integral

`int_0^(pi/4)sqrt(1-cos(4theta))d theta`

Let' first compute the indefinite integral,

`intsqrt(1-cos(4theta))d theta`  

Apply the integral substitution.

Let `theta=u/2`

`=>d theta=1/2du`

`=int1/2sqrt(1-cos2u)du`

`=1/2intsqrt(1-cos2u)du`

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

`=1/2intsqrt(1-(1-2sin^2u))du`

`=1/2intsqrt(2sin^2u)du`

`=1/2intsqrt(2)sqrt(sin^2(u))du`

`=sqrt(2)/2intsqrt(sin^2(u))du`

`=(1/sqrt(2))intsin(u)du`

Change the bounds from 0 to pi/4 to lower bound 0 and upper bound pi/2.

`int_0^(pi/2) sin(u) du`

`-cos(u)/sqrt(2)) |_0^(pi/2)`  

`= 0 - -1/sqrt(2) = 1/sqrt(2)`

Was it Hoover's administration that caused the Great Depression that affected the USA and the rest of the world?

No, Hoover's policies were not the cause of the Great Depression---though they may have made it worse.

The consensus among economists and historians as to the cause of the Great Depression is that the stock market panic of 1929 triggered a financial crisis which threw hundreds of banks into insolvency. Droughts also contributed by reducing food production and raising food prices.

The response---or lack thereof---was crucial to what made the Great Depression so great. Banks were allowed to fail; the FDIC did not yet exist to insure banks against failure. This created a cascade through the financial system, where suddenly billions of dollars effectively evaporated from existence as the collapse of one bank which owed to another bank collapsed the next bank, and so on. There was effectively far less money supply than there had been previously, so there was not enough money to purchase the products being sold. Because the US was still on the classical gold standard, the Federal Reserve had very little power to expand the money supply.

This led to deflation, which made debts even worse, and also triggered layoffs because workers are loathe to accept lower nominal wages even if their inflation-adjusted wage has not changed.

Hoover was also quite conservative in terms of his fiscal policy response; he could have initiated huge government investment projects to employ workers and increase spending---as FDR would later do in the New Deal---but he largely avoided doing so, believing that the market would simply correct itself in due time and any such intervention would do more harm than good. He also adamantly refused to engage in deficit spending, even though a depression is exactly the time when deficit spending is necessary.

Hoover cannot be blamed for the stock market panic itself, and of course he cannot be blamed for droughts. So in that sense he did not cause the Great Depression. But his response was far too passive and ineffectual, and resulted in a much more prolonged and severe depression than would have occurred under better fiscal and monetary policy.

What is the first thing that happens to the Jewish people when they arrive at Birkenau in Night?

Men and women were sorted when the Jews first arrived at the camp.

When they first arrive at Birkenau, a subcamp of the Auschwitz concentration camp, the prisoners can smell burning human flesh.  This is particularly disturbing because of the fit that Mrs. Schächter has had in the train car about fire.  It seems to have been a premonition.  When they reach the camp, they find out that the Nazis are sorting people and burning them alive.

First, what possessions they have left are taken from them.  Then, the men and women are sorted and separated from each other.

"Men to the left! Women to the right!"

Eight words spoken quietly, indifferently, without emotion. Eight simple, short words. Yet that was the moment when I left my mother. (Ch. 3) 

With this moment, Elie Wiesel was separated from his mother and his sisters forever.  He went with his father.  Of course, he didn’t realize it at the time that he would never see his mother and sisters again. 

An inmate asked Wiesel how old he was.  He told him that he was fifteen. 

"No. You're eighteen."

"But I'm not," I said. "I'm fifteen."

"Fool. Listen to what I say."

Then he asked my father, who answered:

"I'm fifty."

"No." The man now sounded angry. "Not fifty. You're forty.

Do you hear? Eighteen and forty." (Ch. 3) 

This was lifesaving advice.  If Elie Wiesel was older and his father was younger, they would both be more useful to work.  That was all the Nazis cared about.  If you were old enough or young enough to work, and strong enough to work, you would be spared.  If you were weak, into the ovens you would go. 

When Elie Wiesel and his father arrived at Birkenau, it was 1944.  The war had been going on for some time at that point.  The goal by then was to ramp up the efforts to kill as many Jews as possible as fast as possible, as long as they were not useful for slave labor.

What is the difference between the pig Napoleon and Joseph Stalin in George Orwell's Animal Farm?

One difference is the sheer number of deaths.  Other than a few animals in show trials--most notably the Minorca hens, who destroy their own eggs and a few sheep--Napoleon kills very few.  On the other hand, Stalin killed millions of people.  Napoleon is willing to let Moses the raven spread his view of religion in the form of Sugarcandy Mountain while Stalin forced religion underground by killing priests and repurposing the old Cathedrals.  Stalin after WWII declared his nation the first nation that was fully atheistic.  Stalin also kept all of the focus on his person and killed anyone who seemed to garner too much favor with the people; hence, he killed many of his top generals in the 1937 Purges.  Napoleon, on the other hand, maintains his own loyal following of pigs that he does not thin out.  Maybe these pigs are of doubtless loyalty to Napoleon, but many allegedly loyal Stalinists were killed in his purges.  

What are natural treatments for hypertension?

Introduction

Most people cannot tell when their blood pressure is high, which is why
hypertension is called the “silent killer.” Elevated blood
pressure can lead to a greatly increased risk of heart attack, stroke, and many
other serious illnesses. Along with high cholesterol and smoking, hypertension is
a major cause of atherosclerosis. In turn, atherosclerosis causes heart
attacks, strokes, and other diseases of impaired circulation.

The mechanism by which high blood pressure produces atherosclerosis is somewhat similar to what happens in a hose fitted with a high-pressure nozzle. All such nozzles come with a warning label that states that pressure in the hose should be discharged after use. Many people, however, leave the hose with full pressure after using it. This rather common practice does not produce any immediate consequences. The hose does not develop leaks at the seams or burst outright on the first occasion it is left untended. However, a garden hose that is frequently left under pressure will begin to age more rapidly than it would otherwise. Its lining will begin to crack, its flexibility will diminish, and within a season or two the hose will develop and show leaks.

When human blood vessels are exposed to constant high pressure, a similar process is set in motion. Blood pressure that elevates to, for example, a reading of 220/170 (systolic pressure/diastolic pressure), which is quite common during certain physical activities such as weight lifting, do no harm. Only when excessive pressure is sustained do blood vessel linings begin to be injured and undergo the unhealthy changes known as atherosclerosis.

Although it is important to lower blood pressure, only rarely does it need to be lowered instantly. In most situations, a person has plenty of time to work on bringing down blood pressure. However, this does not mean that one should ignore it. Over time, high blood pressure can damage nearly every organ in the body.

The best way to determine one’s blood pressure is to take several readings at different times during the day and on different days of the week. Blood pressure readings will vary from moment to moment; what matters most is the average blood pressure. Thus, if many low readings balance out a few high readings, the net result may be satisfactory. However, it is essential not to ignore a high value that may have been caused by stress, for example. To record an accurate number, all measurements must be included in the calculations.

In most cases, the cause of hypertension is unknown. The kidneys play an important role in controlling blood pressure, and the level of squeezing tension in the blood vessels also makes a large contribution.

Lifestyle changes, such as quitting cigarettes, losing weight, and increasing exercise, can dramatically reduce blood pressure. One study found that engaging in aerobic exercise sixty to ninety minutes weekly may be sufficient for producing maximum benefits. Another study found that taking ten-minute brisk walks four times per day significantly improves blood pressure.

For many years doctors advised persons with hypertension to cut down on salt in the diet. Today, however, the value of this dietary change has undergone significant questioning. Considering how rapidly knowledge is evolving, it is suggested that one consult a physician to learn the latest recommendations.

If lifestyle changes fail to reduce blood pressure, or if one cannot make these alterations, many effective drugs are available. Sometimes experimentation with a few drugs helps in finding the most effective one.

Principal Proposed Natural Treatments

There are no herbs or supplements for hypertension with solid scientific support. However, the supplement coenzyme Q10 and extracts from the herb Stevia rebaudiana have shown some promise in preliminary trials.

Coenzyme Q
10. The supplement coenzyme Q10

(CoQ10) has shown promise as a treatment for high blood pressure,
but the evidence that it works is not strong. An eight-week, double-blind,
placebo-controlled study of fifty-nine men already taking medication for high
blood pressure found that 120 milligrams (mg) daily of CoQ10 reduced
blood pressure by about 9 percent compared with placebo. In addition, a
twelve-week, double-blind, placebo-controlled study of eighty-three people with
isolated systolic hypertension (a type of high blood pressure in which only the
“top” number is high) found that the use of CoQ10 at a dose of 60 mg
daily improved blood pressure measurements to a similar extent.

Also, in a twelve-week, double-blind, placebo-controlled trial of seventy-four people with diabetes, the use of CoQ10 at a dose of 100 mg twice daily significantly reduced blood pressure compared with placebo. Antihypertensive effects were also seen in earlier smaller trials, but most of them were not double-blind, so they mean little.

Stevia rebaudiana. The herb Stevia rebaudiana is best known as a sweetener. Its active ingredients are known as steviosides. In a one-year, double-blind, placebo-controlled study of 106 people in China with moderate hypertension (approximate blood pressure of 165/103), steviosides at a dose of 250 mg three times daily reduced blood pressure by approximately 10 percent. Full benefits took months to develop. However, this study is notable for finding no benefits in the placebo group. This is unusual and tends to cast doubt on the results.

Benefits also were reported in a two-year, double-blind, placebo-controlled study, also in China, of 174 people with milder hypertension (average initial blood pressure of approximately 150/95). This study used twice the dose of the previous study: 500 mg three times daily. A reduction in blood pressure of approximately 6 to 7 percent was seen in the treatment group compared with the placebo group, beginning within one week and enduring throughout the two years of the study. At the end of the study, 34 percent of those in the placebo group showed heart damage from high blood pressure (left ventricular hypertrophy), while only 11.5 percent of the stevioside group did, a difference that was statistically significant. No significant adverse effects were seen. However, once again, no benefits were seen in the placebo group. This is a red flag for problems in study design. Furthermore, a study by an independent set of researchers failed to replicate these findings.

Another study involving people with diabetes and healthy persons found that
stevia, at a dose of 250 mg three times daily, had no
significant effect on blood pressure after three months of treatment. A study by
an independent set of researchers failed to replicate these findings.

Relaxation therapies. Although it seems intuitive that relaxation
should lower blood pressure, the evidence for the benefits of relaxation
therapies for treating hypertension is far from convincing.
In a review of twenty-five studies investigating various relaxation therapies
(totaling 1,198 participants), researchers found that those studies employing a
control group reported no significant effect on lowering blood pressure compared
to sham (placebo) therapies.

More specifically, biofeedback is widely advocated for
treating hypertension. However, in an analysis of twenty-two studies, real
biofeedback when used alone was found to be no more effective than sham (fake)
biofeedback. A subsequent review of thirty-six trials with 1,660 participants
found inconsistent evidence for the effectiveness of biofeedback for treatment of
hypertension in comparison to drug therapy, sham biofeedback, no intervention, or
other relaxation techniques.

However, some studies have been supportive. A review of nine randomized trials
concluded that the regular use of Transcendental Meditation significantly
reduced both systolic and diastolic blood pressure compared to a control.
Similarly, an analysis of seventeen randomized controlled trials of various
relaxation therapies found that only Transcendental Meditation resulted in
significant reductions in blood pressure. Biofeedback, progressive muscle
relaxation, and stress management training produced no
such benefit. In addition, a trial of eighty-six persons with hypertension
suggested that daily, music-guided, slow breathing reduced systolic blood pressure
measured in a twenty-four-hour period.

Other Proposed Natural Treatments

The Iranian herb Achillea wilhelmsii was tested in a
double-blind trial of sixty men and women with mild hypertension. The results
showed that treatment with an A. wilhelmsii extract significantly
reduced blood pressure readings. Also, in a double-blind study of forty-three men
and women with hypertension, the use of a proprietary Ayurvedic herbal combination
containing Terminali arjuna and about forty other herbs proved
almost as effective for controlling blood pressure as the drug methyldopa.

Although the research record is mixed, it appears that fish oil may
reduce blood pressure, at least slightly. Fish oil contains two major active
ingredients, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). Some
evidence suggests that it is the DHA in fish oil, not the EPA, that is responsible
for this benefit.

Several studies have found that glucomannan, a dietary fiber derived
from the tubers of Amorphophallus konjac, may improve high blood
pressure. Other forms of fiber also may be helpful.

Milk fermented by certain probiotics (friendly bacteria) may provide a small blood-pressure-lowering effect. Also, growing evidence supports the use of a green coffee bean extract for high blood pressure. Three preliminary double-blind studies found that chocolate (high in polyphenols) might help mild hypertension. A review including several additional studies drew a similar conclusion.

Numerous studies have found weak evidence that garlic lowers blood pressure slightly, perhaps 5 to 10 percent more than placebo. It remains unclear whether garlic supplements can help persons with high blood pressure safely eliminate or avoid antihypertensive medications.

People who are deficient in calcium may be at great risk of developing high blood pressure. Among people who already have hypertension, increased intake of calcium might slightly decrease blood pressure, according to some studies. In an extremely large, randomized, placebo-controlled trial involving 36,282 postmenopausal women, 1,000 mg of calcium plus 400 international units of vitamin D given daily did not significantly reduce blood pressure in seven years in women with or without hypertension. Weak evidence hints that the use of calcium by pregnant women might reduce the risk of hypertension in their children. Also, study results are mixed on whether magnesium or potassium supplements can improve blood pressure. At most, the benefit is likely quite small.

In a thirty-day, double-blind, placebo-controlled study of thirty-nine people
taking medications for hypertension, treatment with 500 mg of vitamin C
daily reduced blood pressure by about 10 percent. Smaller benefits were seen in
studies of people with normal blood pressure or borderline hypertension. One
double-blind study compared 500, 1,000, and 2,000 mg of vitamin C and found an
equivalent level of benefit in all three groups. (Because of the lack of a placebo
group, this study cannot be used as proof of effectiveness, only as a
demonstration of the equivalence of the doses.) However, other studies have failed
to find evidence of benefit with vitamin C. This mixed evidence suggests, on
balance, that if vitamin C does have any blood-pressure-lowering effect, it is at
most quite modest.

Unexpectedly, one study found that a combination of vitamin C (500 mg daily)
and grape seed oligomeric proanthocyanidins (1,000 mg daily) slightly increased
blood pressure. Whether this was a fluke of statistics or a real combined effect
remains unclear.

Other studies suggest possible benefit with the Ayurvedic herb Eclipta alba (also known as Bhringraja or Keshraja), beta-hydroxy-beta-methylbutyrate, theanine from black tea, blue-green algae products, chitosan, concord grape juice, garlic, gamma-aminobutyric acid, various forms of the herb hawthorn, kelp, lipoic acid combined with carnitine, quercetin, Salvia hispanica (a grain), and sweetie fruit (a hybrid between grapefruit and pummelo, high in citrus bioflavonoids). However, the supporting evidence cannot be considered reliable for any of these treatments.

There is mixed evidence on whether soy protein and its associated isoflavones are helpful for blood pressure. A comprehensive review of studies investigating the influence of phytoestrogens (including soy) on blood pressure found no meaningful effect. However, another review found that soy protein alone could significantly reduce blood pressure.

Three small, double-blind, placebo-controlled studies found evidence that melatonin may slightly reduce nighttime blood pressure. Getting adequate vitamin D may help prevent the development of hypertension. The vitamin folate may help decrease blood pressure (and might provide other heart-healthy effects) in smokers.

The herbs astragalus, barberry, Coleus forskohliibacailin, hibiscus, maitake, maca, and olive leaf, and the supplements beta-carotene, Cordyceps, flaxseed oil, royal jelly, and taurine, are sometimes recommended for high blood pressure, but there is no meaningful evidence that they work. Also, reducing homocysteine with B vitamins does not appear to reduce blood pressure in healthy people with high homocysteine.

One study was quoted as having showed that a traditional Chinese herbal formula
can reduce blood pressure, but the study actually failed to find any effect on
blood pressure. In a review of twenty-six published studies examining the
effectiveness of Tai Chi for high blood pressure, 85 percent demonstrated a
reduction in blood pressure. However, only five of these twenty-six studies were
of acceptable quality.

A substantial study (192 participants) failed to find acupuncture helpful for high blood pressure. However, another study, this one enrolling 160 people, did report benefit, but the study was small and had problems in its use of statistics. In a review of eleven randomized-controlled trials on the subject, researchers determined that acupuncture’s ability to lower blood pressure remains inconclusive.

The alternative therapies hatha yoga, qigong, and
Tai Chi have shown some potential benefit for high blood pressure, the mechanism
of action probably being similar for each. A later review of multiple studies
investigating the effectiveness of self-practiced qigong, for example, concluded
that this therapy was more effective at lowering blood pressure than no- treatment
controls. However, it was no more effective than standard treatments for
hypertension: antihypertensive medications or conventional exercise.

In a twelve-week study of 140 men and women with stage I hypertension, chiropractic spinal manipulation plus dietary change did not produce any greater benefit than dietary change alone. For many years, the American Heart Association and other major foundations have recommended reducing saturated fat and increasing carbohydrates in one’s diet. However, growing evidence suggests that it is preferable to keep carbohydrate levels relatively low while replacing saturated fat with monounsaturated fats such as olive oil.

Herbs and Supplements to Use Only with Caution

There is one highly credible case report of severe, dangerous hypertension caused by consumption of isoflavones made from soy during the course of a clinical trial on this supplement. This is most likely a rare, highly individual response, but if it could occur with one person, it also could occur with another.

As noted, in one study, a combination of vitamin C and grape seed oligomeric proanthocyanidins mildly increased blood pressure. In another study, the use of vitamin E raised blood pressure in people with type 2 diabetes.

The herb
Citrus aurantium
(bitter orange) may increase blood pressure. In addition, various herbs and supplements may interact adversely with drugs used to treat hypertension.

Bibliography

Anderson, J. W., C. Liu, and R. J. Kryscio. “Blood Pressure Response to Transcendental Meditation.” American Journal of Hypertension 21 (2008): 310–16. Print.

Erkkila, A. T., et al. “Effects of Fatty and Lean Fish Intake on Blood Pressure in Subjects with Coronary Heart Disease Using Multiple Medications.” European Journal of Nutrition 47 (2008): 319–28. Print.

Greenhalgh, J., R. Dickson, and Y. Dundar. “Biofeedback for Hypertension.” Journal of Hypertension 28 (2010): 644–52. Print.

Heather, O. D., et al. “Relaxation Therapies for the Management of Primary Hypertension in Adults.” Cochrane Database of Systematic Reviews (2008): CD004935. EBSCO DynaMed Systematic Literature Surveillance. Web. 27 Jan. 2016.

“High Blood Pressure.” MedlinePlus. US Natl. Lib. of Medicine, 6 Oct. 2015. Web. 27 Jan. 2016.

Hooper, L., et al. “Flavonoids, Flavonoid-Rich Foods, and Cardiovascular Risk.” American Journal of Clinical Nutrition 88 (2008): 38–50. Print.

Lee, H., et al. “Acupuncture for Lowering Blood Pressure.” American Journal of Hypertension 22 (2009): 122–28. Print.

Margolis, K. L., et al. “Effect of Calcium and Vitamin D Supplementation on Blood Pressure.” Hypertension 52 (2008): 847–55. Print.

Modesti, P. A., et al. “Psychological Predictors of the Antihypertensive Effects of Music-Guided Slow Breathing.” Journal of Hypertension 28 (2010): 1097-1103.

Ried, K., et al. “Effect of Garlic on Blood Pressure.” BMC Cardiovascular Disorders 9 (2008): 13. Print.

Rogers, P. J., et al. “Time for Tea: Mood, Blood Pressure, and Cognitive Performance Effects of Caffeine and Theanine Administered Alone and Together.” Psychopharmacology 195 (2008): 569–77. Print.

Wahabi, H. A., et al. “The Effectiveness of Hibiscus sabdariffa in the Treatment of Hypertension.” Phytomedicine 17 (2010): 83–86. Print.

What does Jem think about his pants being left for him at the Radley place?

In Chapter 6, Jem attempts to get a look at Boo by sneaking into the Radley's yard and peeking through their window. Unfortunately, Nathan Radley hears them in his yard, and he comes out with a shotgun. While the children are running out of the yard, Jem gets his pants caught in the Radley fence and is forced to leave them behind. At the beginning of Chapter 7, Jem tells Scout that there is something he didn't tell her about that night. Jem explains to Scout that his pants were "sewed up" and folded neatly across the top of the fence. Jem is confused and mentions that someone had to have known he was coming back to get his pants. Jem is perplexed and cannot quite grasp who was responsible for mending and folding his pants. At this point in the novel, Jem is unaware that Boo Radley is a magnanimous individual who took the time to sew his pants.

Water is a great solvent for ionic compounds because of its ________?(check all that apply) a. polar nature b. high specific heat c. molecular...

Water molecules are composed of two hydrogen atoms (H) and one oxygen atom (O). The arrangement of the hydrogen and oxygen atoms forms a bent molecular structure.

The bent molecular structure of the water molecule causes it to be polar. A polar molecule is one that is asymmetric, causing the charge of the molecule to be uneven. The half of the water molecule with the two hydrogen atoms carries a partial positive charge. The half of the water molecule with the oxygen atom carries a partial negative charge.

Water is a good solvent because the partial positive and negative charges on the water molecule are able to interact with other charged particles and facilitate dissolving. 

Therefore, the water molecule is a good solvent because it has a molecular structure that causes it to also be a polar molecule.

In a decomposition reaction where hydrogen peroxide decomposes in the presence of manganese dioxide, how much of each (hydrogen peroxide and...

The decomposition of hydrogen peroxide (H2O2) is catalyzed by manganese dioxide and hence we do not need to show the catalyst in the chemical equation. The actual chemical equation can be written as:

`2H_2O2 -> 2H_2O + O_2`

In this reaction, 2 moles of hydrogen peroxide converts to 1 mole of oxygen and 2 moles of water. 

Assuming STP conditions, each mole occupies 22.4 l volume. Since the given volume of oxygen is 50 ml or 0.05 l, we have 0.05/22.4 moles of oxygen as a product.

To generate that product, we need 2 x 0.05/22.4 moles of hydrogen peroxide (using stoichiometry). In other words, we need

2 x 0.05/22.4 moles x 22.4 l/moles = 0.1 l = 100 ml.

Thus, 100 ml of hydrogen peroxide is needed to generate 50 ml of oxygen.

Manganese dioxide is a catalyst and hence is required in small quantities. The attached link suggests 1 spatula of catalyst for 50 ml, 30% hydrogen peroxide. Since, we have 100 ml of the peroxide, we can use 2 spatula full of the catalyst.

Hope this helps.

What are laboratory tests?

Indications and Procedures

Clinical laboratory testing is a vital element in diagnosis. After physical examination and the taking of the patient’s medical history, the physician will often request that specific tests be performed on blood, urine, or other body fluids. Appropriate specimens are collected and forwarded to the laboratory for specimen processing.

Blood
is the most common specimen submitted for testing in the clinical laboratory. In a hospital or large referral laboratory, there may be special personnel, called phlebotomists, employed to collect blood. In a small office laboratory, blood may be collected by the attending physician or nurse. Blood is collected in a syringe or in special tubes that may contain anticoagulants.

Urine
is the next most common laboratory specimen and is collected as a result of a single void (random urine specimen) or for a time period of twenty-four hours or more. In the latter case, the collection container may also contain substances that act as a preservative. If a long-term urine specimen is necessary, it is very important for the patient to follow the directions regarding collection. Failure to follow these directions can lead to erroneous laboratory results.

Less commonly collected specimens include
cerebrospinal fluid, gastric (stomach) fluid, and amniotic fluid. Cerebrospinal fluid is usually collected by a physician by direct sampling with a needle (lumbar puncture, or spinal tap). Gastric fluid is obtained by the insertion of a gastric collection tube. Amniotic fluid is collected by an obstetrician in the process called
amniocentesis, in which a sample of the fluid surrounding the fetus is removed by the insertion of a needle through the mother’s abdomen. Frequently, laboratory tests are also ordered on infectious material associated with a wound or surgical incision.

A major aspect of specimen collection is ensuring that the sample is correctly labeled and that no mix-up of specimens has occurred. Part of this process may involve checking identification armbands or asking patients or nursing staff to confirm identification. While this procedure may be exasperating to the patient or nursing personnel, it is a necessary part of detecting errors.

Immediately after the specimen is received in the laboratory, documentation of time of receipt and the tests requested is made, which is referred to as logging in the specimen. Each sample receives a special code called an accession number. The test performance and results are tracked with this number, since multiple specimens can be received on a single patient in a given day. This process is usually computerized and may use bar code labeling in a process very similar to that used for automatic cash-register pricing of grocery items.

In large hospital or referral laboratories, the processing center is responsible for distributing the sample to the laboratory sections, where various tests are performed. Since each test requires a specific amount of sample, specimen processing also involves determining that the correct amount of fluid has been collected and reserved for proper performance of the test.

For blood specimens, many laboratory determinations are made regarding plasma, or serum, which is the liquid component of blood that contains no cells. The whole blood specimen is separated into cellular and liquid components by centrifugation. The sample is spun rapidly so that the force of the spin sediments the cells, with the serum or plasma layer on top.

Once the specimen is distributed to the pertinent laboratory sections, testing is done using a variety of analytical techniques. The testing methodology is almost as varied as the types of analyses requested. A few general statements, however, are applicable. Automation is the guiding force behind laboratory test methodology development. Routinely ordered tests are done with instruments specifically designed to perform a group or panel of tests, rather than each test being performed individually by a technologist using manual chemistry methods. Automation coupled with computerization has greatly increased laboratory efficiency, decreased turnaround time (the time required for a test to be performed and results to be reported to the physician), eliminated human errors, and allowed more tests to be performed on smaller sample material. The latter advantage is particularly important for pediatric specimens, in which sample size is usually an important consideration. Automation also eliminates much of the technologist’s contact with the specimen, considerably reducing the risk of spreading infectious diseases.

Each section of the laboratory is responsible for a specific set of tests. The chemistry section performs chemical analyses of body fluids. Panels of tests related to kidney, heart, and liver function are also done. In addition, tests to measure amounts of therapeutic drugs, hormones, blood proteins, and cancer-related proteins are accomplished with immunoassay techniques. The development of antibody-related techniques has revolutionized testing in all areas of the clinical laboratory. The ability to customize antibody production and adapt it to specific analytical requirements has allowed the continual development of new tests and methodologies.

The
hematology section is responsible for monitoring the levels of blood cells and clotting factors. Other specialized tests to diagnose cancer of the blood cells may also be done. Blood typing and donor testing are technically hematology-related tests, but they are usually reserved for a separate section designated as
blood bank or transfusion services. Transfusion service is a specialty in its own right and is almost always reserved for hospital-associated laboratories.

Microbiology is the section where body fluids are checked for infectious microorganisms. Once an organism is identified, the section can also determine which antibiotics may be useful for treatment by performing antibiotic susceptibility tests.

As the laboratory tests are performed, the results are recorded and reported to the physician. Computerization has permitted the transfer of patient results directly from the instrument performing the test to the patient’s file, eliminating many tedious and error-prone clerical functions.

For hospital and reference laboratories, a laboratory director—either a physician (usually a pathologist) who specializes in laboratory medicine or a scientist with doctoral level training in a laboratory specialty—monitors the performance of the laboratory, helps physicians with the interpretation of ambiguous or complex laboratory results, and provides guidance on the introduction of new tests or instrumentation. Most laboratories also have a section supervisor or administrator who is an experienced medical technologist to oversee the daily laboratory routine.

Uses and Complications

Because of the variety of laboratory testing, it is impractical to cover its applications in depth in a brief review. Instead, a few illustrative tests that are performed often or are associated with familiar disorders will be presented. The most frequently ordered laboratory tests are serum glucose tests, serum electrolyte (salt) level measurements, and complete blood count (CBC) tests.

The maintenance of blood glucose (sugar) levels is essential for body activity and brain function. The laboratory measurement of blood glucose is one of the oldest known procedures performed in the clinical laboratory. It is part of the diagnostic procedures used to monitor and test for
diabetes mellitus. Glucose and electrolyte testing are performed in the chemistry section of the laboratory, while a CBC takes place in hematology. Certain levels of electrolytes—sodium, chloride, potassium, and calcium—are needed for proper cardiac function. An abnormal level of these salts could also indicate possible hormonal or kidney malfunction. The CBC is a measure of the cell populations that carry oxygen (red blood cells), fight infection or invasion by foreign substances (white blood cells), and activate the blood-clotting mechanism (platelets). The white cell population is elevated in infections but also in cases of leukemia (malignant growth of a white cell population). More specialized testing is needed when leukemia is suspected. An instrument called a flow cytometer can be used to count and detect subtypes of white cells. These data, along with a pathologist’s microscopic examination of a blood smear and the results of clinical examination, are used to arrive at a diagnosis of the specific type of leukemia present. The identification of the cell population causing the cancer is important for determining treatment and prognosis.

A deficiency of red cells or their oxygen-carrying hemoglobin
molecule is called anemia. It can be caused by iron deficiency and other impairments of red cell production, chronic bleeding, or accelerated red cell destruction (hemolysis). Each of the causes must be either confirmed or ruled out through additional testing or by clinical examination.

Platelet deficiency is a major cause of clotting disorders, although many other causes of bleeding disorders exist. The specific defect can be determined by measuring the clotting time and by using special immunoassays to measure clotting substances in the blood.

Many hormonal (endocrine) disorders can be diagnosed through laboratory testing. For example, the thyroid, the regulator gland for body metabolism, can produce a variety of symptoms when it is not functioning properly. Thyroid testing is the most common endocrine-related laboratory procedure requested by physicians. The blood levels of thyroid hormone and of the pituitary factor that stimulates the thyroid gland are measured in the laboratory using immunoassay methods. These types of assays can also be used to monitor other hormones involved in fertility, growth, and the function of the adrenal gland (the gland that helps maintain sugar metabolism and electrolyte balance).

Immunoassay methodology has also permitted the routine laboratory testing of therapeutic drugs as well as of drugs of abuse. In the past, the technology for analyzing drugs in biological fluids involved expensive, labor-intensive techniques that were impractical for routine laboratory use. With the introduction of immunologically based testing for drugs, however, it became possible to monitor patients on antibiotics, immunosuppressive agents, cardiac drugs, and antiseizure medication. Testing has been automated so that these drug levels can be performed as routine laboratory procedures. Assay results can be used to establish an individual dosage schedule so that dosage is maintained in the therapeutic range and does not exceed the concentration threshold, leading to toxic effects, or decline to values too low to achieve adequate treatment (subtherapeutic levels).

A continuing research effort is directed toward developing specific diagnostic cancer tests. These tests could be used to screen patients for tumors in order to detect them early, when therapy would be most effective. Substances that appear in body fluids coincident with the growth of tumors are referred to as tumor markers. The ideal tumor marker would appear only in patients afflicted with a specific type of cancer. Its concentration would reflect the size of the tumor as well as the presence of metastasis, in which tumor cells migrate from the initial cancer site to other sites in the body.

The ideal tumor marker has not yet been discovered. Most have not been specific or sensitive enough to use as a screening tool for detecting tumors, although they have been useful for monitoring the effects of therapy. One example of a useful marker is prostate-specific antigen (PSA). The level of this protein in serum is very low when the prostate gland is normal. When prostate cancer is present, however, the serum level, as measured by immunoassay, is elevated. The test can also be used for screening, provided that any positive result is confirmed by clinical examination. It is also used following prostate surgery or radiation therapy in order to determine the completeness of tumor removal. Continually high or rising levels of PSA in the serum following treatment indicate that residual tumor is still present.

In the
microbiology department, the culturing of body fluids and antibiotic susceptibility studies allow the selection of the most appropriate antibiotic for treatment. The course and duration of treatment can then be followed in the chemistry laboratory using the therapeutic drug monitoring techniques discussed above. When an infection is suspected, body fluids are cultured or incubated with media selected to grow only specific microorganisms. Antibiotic susceptibility studies are performed by culturing the organism with various antibiotics until growth is arrested. Many strains of bacteria and other microorganisms will become resistant to an antibiotic that had proven effective previously, and patients who are allergic to some antibiotics may need to be treated with an alternative regimen.

The detection and identification of viruses has become a subspecialty in microbiology with distinctly different culturing techniques. Newer immunoassay methods and other biotechnologically based methods have made virus diagnosis easier.
Acquired immunodeficiency syndrome (AIDS) testing is a prime example of the application of immunoassay techniques to virology testing. A detection technique that required growth of the
human immunodeficiency virus (HIV) in the laboratory would be extraordinarily difficult and tedious. It would also be prohibitively expensive and time-consuming to screen large populations such as blood donors and high-risk groups. Instead, laboratory screening for HIV uses an automated immunoassay technique based on the detection of patient antibodies to virus-specific antigens. Although this test is very specific, the possibility of false positives is greatly minimized by confirming all positive screening results with another antibody test called a Western blot. In this test, a serum sample from a suspected HIV-positive patient is applied to a membrane impregnated with virus proteins. The virus proteins are localized at a characteristic position determined by their migration rate when the membrane coated with virus proteins is subjected to an electric field in a process called protein electrophoresis. After the membrane has been treated with patient serum and color development reagents, the presence in the patient sample of an antibody to one or more of these proteins is revealed as a colored stripe on the membrane. A combination of the two tests is a cost-efficient and extremely accurate procedure to confirm a suspected diagnosis of HIV infection.

Perspective and Prospects

According to a 2002 study of the history of the clinical laboratory by J. Büttner, the concept of the modern hospital laboratory was first documented in 1791, when French physician and chemist Antoine-François de Fourcroy wrote that in hospitals, “a chemical laboratory should be set up not far away from a ward having twenty or thirty beds.” Büttner asserts that the two suppositions necessary for the creation of these laboratories were the idea that the results of laboratory examinations can be used as “chemical signs” in medical diagnosis and a new concept of disease that was the result of the “birth of the clinic” at the end of the eighteenth century.

During this phase of laboratory development, investigations were performed at patients’ bedsides by physicians themselves. In the period from 1840 to 1855, clinical laboratories were established as operations distinct from hospitals and clinics. Most of these laboratories were developed in German-speaking countries and staffed by scientists who performed tests for the hospitals and taught medical students physiological chemistry. From 1855 onward, the concept of the clinical laboratory spread rapidly, with clinicians assuming directorship roles. The laboratory ultimately serving as a model for clinical laboratories in the United States was established by the renowned pathologist Rudolf Virchow at Berlin University. As the chair for pathological anatomy, he set up a “chemical department” within the institute for pathology in 1856. This laboratory represented a center of clinical chemistry research and established the clinical laboratory as integral to pathology.

Laboratories have evolved as essential but distinctly separate specialties of medical services. Although there is little or no participation in the analytical process by the physicians ordering the tests, a major part of a physician’s diagnostic skill is knowing which tests to order as a supplement to examination and medical history. Laboratory tests cost money and time, and they may be useless in the diagnostic process if not ordered in a judicious fashion. The old medical admonishment to “treat the patient, not the laboratory result” is still an appropriate consideration. Moreover, responsibility for the correct interpretation of the results lies with the attending physician, who has access to all the pertinent patient data.

Laboratory results are usually interpreted with the help of a reference range. Reference ranges ideally represent laboratory values characteristic of a sample population that is free of known disease. If the results lie within this range, however, the laboratory result cannot always be assumed to rule out a specific diagnosis. Since considerable biological variation exists for most laboratory values, diseased individuals can sometimes yield test values in the normal range, and, conversely, healthy individuals can occasionally have low or elevated values.

To verify a diagnosis, all laboratory results and clinical impressions should complement one another. The detection of blood-clotting deficiencies by the hematology department could be related to a poorly functioning liver, which will also be reflected in changes in enzymes and blood proteins measured in the chemistry laboratory. Cardiac disorders are diagnosed not only by examining an electrocardiograph (EKG or ECG) but also by measuring the levels of specific cardiac-related enzymes that rise to abnormally high levels when cardiac blood supply is diminished (such as with myocardial infarction, or heart attack). In summary, the clinical laboratory provides a valuable tool for physicians, but it should never displace clinical examination and medical history as methods of determining the final diagnosis.

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Summary of the chapter 29 "Language Death and Dying" by WALT WOLFRAM from the book "The Handbook of Language Variation and Change".

"Language Death and Dying," by Walt Wolfram, is the 29th chapter from The Handbook of Language Variation and Change, a language and linguistics textbook edited by J.K. Chambers, Peter Trudgill, and Natalie Schilling-Estes.

A brief summary of the main points made by Wolfram in his article, "Language Death and Dying," include the four types of language death:

Sudden language death - Sudden language death is when the speakers of the language either suddenly die or are killed.

Radical language death - Radical language death is similar to sudden language death in that both occur suddenly, but the key difference is that with radical language death there is a shift to another language opposed to the complete loss of the speakers of the original language. In many cases of radical language death, the speakers are forced to stop speaking their language and to to start speaking a new one.

Gradual language death - Gradual language death is the most common way a language dies. It is caused by "the gradual shift to the dominant language in a contact situation" (p 766). A good example would be the Navajo language which is gradually dying in that young Navajo people cannot speak, read, or write it, and the Elders are the only ones who can.

Bottom-to-top language death - This is the final way that a language dies. This occurs when the colloquial and casual use of the language dies, but the formal uses continue to exist. An example of this would be the judiciary Latin used in court documents and laws. In many ways, Latin is thought to be a dead language since it is not often used, but it still have some uses in the judicial systems in the United States.

Which was not a cause of civil unrest in the United States in the 1960s? A. Black citizens were still fighting against...

There were many factors that led to civil unrest in the 1960s. The lack of civil rights for African-Americans was a big factor. African-Americans had been protesting peacefully for an end to discrimination and segregation. However, progress was very slow, and some people believed a more aggressive policy was needed than Dr. King’s non-violent methods. When people saw how non-violent protestors were treated, such as with the Selma March, more people became upset and demanded action.

The opposition to the Vietnam War grew in the 1960s. Many Americans, especially young Americans, were opposed to this war. They didn’t believe this was a conflict in which we should be involved. There were many anti-war protests, and some of them became violent.

Women were upset that they weren’t being treated fairly. They made less than men made for the same kind of work. Women also found it hard to break into male-dominated professions. The National Organization for Women formed to protest the lack of equal treatment and the lack of opportunities for women.

The correct answer to this question is answer D. It is not an accurate statement to say that most people in the cities were rich. Some of the violence in the cities occurred because there were many poor people living there. For various reasons, including discrimination, it was very hard for some people living in the cities to break away from poverty. It is not accurate to say most people living in the cities were rich.

The correct answer to your question is answer D.

How does Fahrenheit 451 relate to the allegory of the cave?

The allegory of the cave was developed by the philosopher, Plato, to explain reality. In Plato's cave, a group of people are chained up, unable to turn their heads, and are facing a blank wall. Behind them, puppeteers move objects so that they cast shadows onto the blank wall. Unable to see the objects behind them, the prisoners believe that the shadows are real objects which make up the world. By creating this analogy, Plato suggests that people are like these prisoners and are ignorant to the world around them. It is only by breaking free from their shackles can people experience and understand the real world. (Please see the reference links provided).

In Part Two of Fahrenheit 451, Montag references Plato's cave when he is talking to Mildred about the problems of their society:

"I've heard rumours; the world is starving, but we're well-fed. Is it true, the world works hard and we play? Is that why we're hated so much? I've heard the rumours about hate, too, once in a long while, over the years. Do you know why? I don't, that's sure! Maybe the books can get us half out of the cave. They just might stop us from making the same damn insane mistakes!"

Like Plato, Montag is suggesting that the only way to truly understand the world is by breaking free from the cave (represented in Fahrenheit 451 by censorship) and using books to learn the truth. Montag is, therefore, advocating direct rebellion and the beginning of a new and enlightened way of life. 

What is the Myers-Briggs Type Indicator (MBTI)?

Introduction

The Myers-Briggs Type Indicator (MBTI) is based on the theory of psychological types developed by Swiss-born psychiatrist Carl Jung
. Jung believed that human behavior was predictable and therefore could be classified. He viewed differences in behavior to be the result of innate preferences that remained fairly consistent throughout life. Behavior that is often viewed as random is actually orderly and consistent as a result of these preferences. The purpose of identifying these preferences was not for people to change them but, through life’s maturing process, to become more adept in areas that were not among their preferences. Jung’s orientation was more on wellness than on the abnormal.

The English edition of Jung’s Psychologische Typen (1921; Psychological Types, 1923) received limited attention when it was first published and remained relatively unknown for years. At the time, Freudian psychology was popular in Europe, and behaviorism was widely accepted in the United States. Jung’s orientation was holistic, viewing many physical and emotional illnesses as the result of an imbalance of the mind, body, and spirit. As Jung aged, he increased his emphasis on spiritual and religious aspects.

Following World War II, Katharine Cook Myers and her daughter, Isabel Myers Briggs, became interested in psychological typology and were especially intrigued by Jung’s work. After careful study of Jung’s theory, they designed an inventory based on his identification of psychological types; this inventory has become known as the Myers-Briggs Type Indicator.

Jungian Typology

Jung referred to extroversion and introversion as attitudes. Energy for the extrovert flows outward to people, things, and events in the external world. Energy for the introvert is directed inward toward subjective, internal awareness.

Jung identified four functions (polarities), two rational and two irrational. The two rational functions, thinking and feeling, are used for judging and evaluating information. The two irrational functions, sensing and intuition, are considered perception functions.

When people use the thinking polarity, they evaluate information according to a logical, impersonal analysis. Making a decision requires sufficient, valid data and reason. When people use the feeling polarity, they show a preference for making a subjective calculation. They will evaluate information by personal values, by the degree of importance given the judgment, and by the degree to which others might be affected by the decision.

In addition to Jung’s attitudes and two functions, Myers and Briggs added a fourth element, an orientation. (Myers consulted with Jung just before his death relative to the addition.) Orientation is the preference for ordering outer life and is labeled as either judging or perceiving. Those who prefer judging manage their outer world with organization, scheduling, and planning. Those with a perceiving orientation use a more open, adaptable, flexible style.

Development of the Indicator

Myers and Briggs designed the Myers-Briggs Type Indicator to provide a reliable instrument that would make Jung’s theory of psychological types understandable and useful for everyday living. The primary distinction of the Myers-Briggs inventory is its focus on normal personality, with all sixteen types being equally acceptable. The latest version, MBTI Step II (1962), includes specific facets to provide a more individualized approach for each letter in the code.

The basic form of the MBTI produces a four-letter code that simply identifies four categories of preference, each of which is described as slight, moderate, clear, or very clear preference The four dimensions of the code show preferences for stimuli from the outer world (E, for extroversion) or inner self (I, for introversion), for information that comes through the five senses (S, for sensing) or information that comes through intuiting the total picture (N, for intuition), for decision making based on logic and facts (T, for thinking) or on personal values and other people (F, for feeling), and an outside world that is planned and systematic (J, for judging) or open and spontaneous (P, for perceiving).

There has been criticism surrounding the instrument's reliability and validity. Some studies have called the instrument's test-retest validity—the ability of the same individual to get the same result after taking the test twice within a short period of time—into question; one 1996 study found that 50 percent of people remained the same type when tested twice within a nine-month period, while 36 percent remained the same type when retested after more than nine months. Several studies have also found that test-takers' results on each scale tended to follow a normal distribution, with the majority of people falling somewhere towards the middle of the scale and very few people showing a strong inclination towards one end or the other, which, some researchers believe, suggests that most people do not fall as strongly into a type as MBTI supporters have argued. Additionally, some have raised concerns regarding the fact that, unlike similar psychological instruments such as the Minnesota Multiphasic Personality Inventory, the MBTI has no built-in scale to determine inconsistency or exaggeration in responses, making it more difficult to tell when an individual is answering dishonestly. However, there are other studies which have found support for the construct validity, internal consistency, and test-retest reliability of the instrument, and the MBTI remains widely used both inside and outside of the psychological community.

The MBTI has become one of the more commonly used personality inventories for normal personality analysis. Results from interpretative reports are used in corporations, hospitals, and educational institutions for team building, personnel development, and career and student guidance.

Bibliography

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Myers, Isabel Briggs, and Peter B. Myers. Gifts Differing: Understanding Personality Type. Mountain View: Davies, 1995. Print.

Pittenger, David J. "Cautionary Comments Regarding the Myers-Briggs Type Indicator." Consulting Psychology Journal: Practice & Research 57.3 (2005): 210–21. Print.

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Rushton, Stephen, et al. “Teacher’s Myers-Briggs Personality Profiles: Identifying Effective Teacher Personality Traits.” Teaching and Teacher Education 23 (2007): 432–441. Print.

VanSant, Sondra S. Wired for Conflict. Gainesville: Center for Applications of Psychological Type, 2003. Print.