In what ways are life on Earth and life on the space frontier contrasted in Tom Godwin's story "The Cold Equations"?

One important difference this story shows between life on Earth and life in space is that on Earth, there is room to make mistakes and rules are not so harsh. On Earth, people are allowed to try again if they fail at something. If we make a miscalculation, we have the opportunity to retrace our steps and start over. We can come up with creative solutions to difficult problems that might seem to have only one answer from the start. In space, however, the rules are much more harsh and strict. Because of the risk that comes with space travel, there is only one chance, one answer, and no room for error.

In “The Cold Equations,” the space ship on which the story takes place is equipped with exactly the right amount of fuel to complete its mission, which involves transporting medical supplies. When the pilot of the spaceship, Barton, discovers the stowaway, Marilyn, he is faced with a choice. Her weight was not part of the calculation when they fueled the ship, so it’s going to throw off the mission. The only option is to get rid of the stowaway, which will mean ending Marilyn’s life. Failure to eject Marilyn will cost the life of the colonists who are awaiting the medical supplies.

If this situation were to happen on Earth, it might have a much rosier outcome. When Barton first finds Marilyn and she expects to simply have to pay a fine as a stowaway, he thinks:

In a way, she could not be blamed for ignorance of the law; she was of Earth and had not realized that the laws of the space frontier must, of necessity, be as hard and relentless as the environment that gave them birth.

This line epitomizes the difference between Earth and the space frontier. Where Marilyn comes from, rules are made to be broken, and she expects to discover a similar attitude when she is found on the ship. Sadly, though, there is absolutely nothing Barton can do to save her, and they both must face the cold, hard facts of reality.

What is the history of vaccines?

Definition

Vaccines are substances administered through inoculation, ingestion, or nasal inhalation to stimulate a person’s immune system to fight infection.

Development History

In 1796, Edward Jenner (1749–1823) developed the first successful vaccine. Jenner, as the tale of discovery goes, had heard a milkmaid declare “I shall never have smallpox for I have had cowpox. I shall never have an ugly pockmarked face.” Jenner, after hearing this, took some pus from a cowpox lesion on the hand of a milkmaid named Sarah Nelmes and used it to inoculate an eight-year-old boy. A few days later, the boy had a mild case of vaccinia, a form of cowpox contracted by humans, but he soon recovered. Six weeks later, Jenner inoculated the boy with smallpox, yet the boy was unaffected by this and subsequent exposures; he had gained immunity from smallpox through the inoculation with cowpox.

Jenner’s was the first safe and successful attempt to artificially induce active immunity. To describe this particular style of inoculation, Jenner coined the term “vaccine,” from the Latin word vaccinus, or “of cows.”

About eighty years later, in 1879, Louis Pasteur (1822–1895) furthered the vaccination concept through his work in microbiology. Pasteur was employed to find a solution for chicken cholera, which could wipe out an entire flock in as few as three days. One summer, the cholera cultures used for infecting the test chickens were inadvertently stored in the heat. These cultures produced some symptoms of disease but were no longer deadly to the chickens. When subsequently inoculated with young virulent cultures, the chickens remained unaffected. Pasteur reasoned that the “stale” cultures were actually attenuated (weakened), and with these attenuated organisms, the chickens had become immune.

In the laboratory, Pasteur learned that by prolonged growth and exposure to
oxygen, the microbes could be manipulated to the ideal virulence.
This experiment marked the first time a pathogenic microbe was isolated and used
as a bacterial vaccine. In 1881, applying the methodology he had developed for the
chicken cholera virus, Pasteur and his associates heated anthrax germs, exposed
them to the oxidizing agent potassium dichromate, and inoculated a number of
sheep.

The rabies vaccine was initially created by Émile Roux, a French doctor and a colleague of Pasteur who had been working with a killed vaccine produced by desiccating the spinal cords of infected rabbits. In 1885, Pasteur successfully vaccinated a shepherd boy who had been bitten fourteen times by a rabid dog. He produced his vaccine for rabies by growing the virus in rabbits and then weakening it by drying the affected nerve tissue. The vaccine had been tested only on eleven dogs before its first human trial. The delay in rabies germs reaching the brain enabled the rabies vaccine to be effective after the bite had occurred.

The first toxoid vaccine was for diphtheria. The diphtheria bacillus was discovered by Edwin Klens in 1883. In 1884, Frederick Loeffler isolated it and grew it in culture. In 1890, Emil Von Behring discovered an antitoxin and subsequently developed a vaccine with a combination of diphtheria toxin and antitoxin. However, he did not deem the vaccine safe for widespread use. In 1924, a researcher at the Pasteur Institute weakened diphtheria toxin with formaldehyde to make a “toxoid” to kill the bacteria. He was able to immunize guinea pigs with his toxoid. Mass vaccination began in New York within three years.

As vaccines continued to be developed and released (bubonic plague, 1897;
cholera and typhoid, 1917; pertussis, or whooping cough, 1926; tetanus, 1927; and
tuberculosis, 1927), they became more and more integral to utilitarian and public
health notions of security, productivity, and protection. Licensing of vaccines
began and vaccination became ever more managed by government from the municipal
level to the federal level. For example, vaccination became mandatory for infants
in the United Kingdom in 1853. In the United States, in 1902, the Biologies
Control Act was passed after the deaths of thirteen children in St. Louis,
Missouri, in 1901; the children had received diphtheria antitoxin that had been
accidentally contaminated with tetanus.

Golden Age of Vaccines

The golden age of vaccines began after World War II. Scientific knowledge had developed enough so that large-scale vaccine production was possible, and several important new vaccines were developed in a relatively short time: influenza (1945), polio (1952), measles (1963), mumps (1967), and rubella (1969). The success in preventing diseases such as polio and measles, of which parents had been terrified, was revolutionary. When the polio vaccine was licensed in 1955, its developer, Jonas Salk, was heralded as a hero. In 1967, the World Health Organization (WHO) led a huge campaign against smallpox. Within ten years, naturally occurring smallpox had been vaccinated out of existence.

Important vaccines from the late twentieth century include those against meningitis (1975), chickenpox (1996), rotavirus (1998), and the first acellular vaccine (pertussis, 1997). In acellular vaccine production, only the antigenic part of the microbe (for example, the capsule, the flagella, or part of the cell wall) is used. Prompting the replacement of whole-cell pertussis vaccines by acellular variations was the potential for severe side effects after vaccination and the reported shift in the age distribution of pertussis. Haemophilus influenzae type B (Hib) vaccine is also acellular. Neither killed nor acellular vaccines induce the strongest immune response and may therefore require booster shots, yet they are safer for use in immunocompromised persons.

In the early twenty-first century, vaccines for adults are becoming increasingly common. For example, a shingles vaccine was licensed in 2008. Unlike childhood vaccines, adult vaccines are not mandated. The first formalized adult immunization schedule was published in 2002 and is updated annually.

New Vaccine Development

Researchers have examined many possible approaches for vaccines against malaria. One of the most promising approaches has been a subunit vaccine. Researchers have begun testing another approach: a vaccine that combines killed parasites with an adjuvant to boost immune response.

Researchers also are trying to develop an influenza vaccine that can provide broad protection, including against future strains, so that a single shot would be enough to protect a person from the seasonal flu for ten years or longer.

The human immunodeficiency virus (HIV) is a challenging target for vaccine researchers for many reasons, not the least of which is the virus’s lack of stability. The surface proteins of the virus frequently change, keeping the immune system from recognizing it and keeping researchers from pinpointing a surface protein as a successful target for a vaccine.

A number of other vaccine strategies are under experimental investigation. These include deoxyribonucleic acid (DNA) vaccination and recombinant viral vectors.

In the midst of an Ebola virus disease epidemic that raged in West Africa throughout 2014 and 2015, two promising experimental vaccines was being fast-tracked for development in early 2015. The Ebola virus, like HIV and influenza, can mutate rapidly, making effective vaccination a challenge. Moreover, debate has been waged about the ethics and logistics of such vaccines: whether to administer candidate vaccines in the absence of clinical trials, who should receive the vaccines if they are effective, and whether they truly represent the best means of fighting such deadly diseases in resource-poor regions that lack other health care measures.

Opposition to Vaccination

Vaccination efforts have met with some controversy since their inception. To a great extent, nation-states have responded to this opposition by articulating the right to immunize for the common good. In 1905, for example, the U.S. Supreme Court ruled that the need to protect the public health through compulsory smallpox vaccination outweighed an individual’s right to privacy. This principal has been consistently reiterated and is supported by the concept of herd immunity, whereby a certain target of the population (approximately 90 percent, depending on the disease) must be immunized for protection to be conferred upon the entire group. In the United States, states have granted exemptions to mandatory vaccination for religious beliefs (as, for example, with Christian Science), for medical reasons (such as a compromised immune system), or for philosophical objections (in twenty states).

As a small but vocal antivaccine movement has gained ground, some rates for vaccine-preventable diseases have risen. This is of special concern because many diseases entail complications. In the case of measles, which is extremely virulent, complications include pneumonia and encephalitis. The modern antivaccine movement also claims that vaccines cause autism, either from the additive thiomersal (known in the United States as thimerosol), which has been used as a vaccine preservative since the 1930’s, or from an overload of the combined mumps, measles, and rubella (MMR) vaccine.

The movement was catalyzed by a British doctor, Andrew Wakefield. In 1998, he published a study of twelve children, several of whom developed signs of autism and intestinal symptoms following MMR immunization. He suggested that the vaccine inflamed the gut in a manner that allowed an unspecified toxic substance to cross into the bloodstream. Although he has stated that his paper does not prove an association between the MMR vaccine and autism, his paper does include parental allegations that he adopted as fact. Wakefield recommended separating the components of the injections by a minimum of one year.

The antivaccination movement gained traction because parents tend to first notice symptoms of autism in their child around the time of the MMR; another factor in the movement’s success has been parental fear of mercury: Thimerosol metabolizes to ethyl mercury, which is often confused with methyl mercury, a neurotoxin. A 2006 review of scientific studies found “no convincing evidence” that thimerosol had a causal role in the onset of autism. Also, courts have ruled that there is no connection. After a lengthy investigation by a medical fraternity, Wakefield’s paper was determined unethical. In February 2010, The Lancet retracted Wakefield’s 1998 article, noting that elements of his submitted manuscript had been falsified.

Despite the medical community discrediting Wakefield, the antivaccination movement remains strong in the United States and Britain. Among parents' reasons for not vaccinating children are concern over serious potential side effects from vaccines, fear regarding the number or timing of vaccines in young children, lack of conviction that vaccination is necessary for good health, mistrust of the medical system, or belief that the government is interfering unduly in their medical and parental decisions.

An outbreak of measles occurred in Ohio in 2014, affecting more than 380 individuals, and about 190 sickened were sickened in 2015 outbreaks, the largest of which spread from California to other states. These public health crises reignited debate over the MMR vaccine and the antivaccination movement as the rate of outbreaks had increased significantly year over year from 2008 on, primarily among those who were unvaccinated.

Impact

Jenner’s assertion “that the cow-pox protects the human constitution from the infection of smallpox” laid the foundation for modern vaccination. The principle that guided Jenner in developing vaccines is still followed—namely, develop harmless preparations that will induce immune responses and thereby protect persons from pathogens.

Most vaccines today are safe, highly effective, mass produced, and administered to millions of people for long-term protection against infectious diseases. Nothing, except perhaps clean, safe water, has had a more positive effect on reducing deaths and helping populations around the world than vaccines, making vaccination one of the most important public health advances in history.

Vaccines also contribute significantly to the economic strength of nations. A study in Kenya, for example, concluded that the Hib vaccine remains a cost-effective intervention, having saved that nation close to one million dollars in treatment costs for children born in 2004. Vaccines also enhance economic growth by protecting persons from the long-term effects of an illness on their physical, emotional, and cognitive development. For example, approximately 28,000 cases of pneumonia and meningitis, 5,000 deaths, and 1,000 severe neurologic complications are prevented each year in Uganda alone.

At the end of the nineteenth century, the infant mortality rate in the United States was 20 percent, and the childhood mortality rate before age five was another 20 percent. Infectious diseases such as measles, diphtheria, smallpox, and pertussis once topped the list of childhood killers. Many of these devastating diseases have been contained, especially in industrialized nations, because of the development and widespread distribution of safe, effective, and affordable vaccines.

Before the development of the diphtheria vaccine in 1923, diphtheria accounted for about 15,500 child deaths and 200,000 illnesses. However, there were only fewer than a handful of reported cases of diphtheria between 2003 and 2013, according to the US Centers for Disease Control and Prevention. Likewise, in the 1950’s, about 20,000 people per year in the United States were affected by polio. The number of paralytic polio cases fell to fewer than 100 per year after the introduction of the vaccine.

After a carefully orchestrated and long-fought eradication effort by the WHO, an effort that was supported by national immunization programs, smallpox was eradicated in 1979. This is perhaps the greatest triumph since the development of vaccines. No naturally occurring cases of smallpox have been found since 1977, and smallpox now exists only in two laboratories: one in the United States and one in Russia. Vigorous debate exists on whether these two stores of the virus should be destroyed; were smallpox released into the environment, the results could be devastating. Smallpox vaccination is no longer routine, so the world’s population is once again highly susceptible to the disease, a susceptibility rate that rises each year.

No other pathogen has been eradicated on a global scale, but diphtheria has largely been eradicated in industrialized nations. Also, in 1994, the WHO declared the Western Hemisphere free of the wild-type polio virus.

Compelling evidence of the impact of vaccination on disease incidence was clearly seen in the United Kingdom in 2000. Meningococcal group C infection had been increasing and was responsible for many deaths, particularly in adolescents. In October 1999, the United Kingdom’s health department introduced a vaccination program, and the number of new cases fell from about 145 to about 65 in one year.

Nonimmunized children still die every day from vaccine-preventable diseases. They may also be rendered physically weakened, developmentally delayed, or permanently disabled. As of 2015, 1.5 million children were dying each year worldwide because they did not receive vaccinations against preventable disease.

Bibliography

Allen, Arthur. Vaccine: The Controversial Story of Medicine’s Greatest Lifesaver. New York: W. W. Norton, 2007.

Artenstein, Andrew W., ed. Vaccines: A Biography. New York: Springer, 2010.

Atkinson, W., et al., eds. Epidemiology and Prevention of Vaccine-Preventable Diseases. 11th ed. Washington, D.C.: Public Health Foundation, 2009.

Barquet, N., and P. Domingo. “Smallpox: The Triumph over the Most Terrible of the Ministers of Death.” Annals of Internal Medicine 127, no. 8 (1997): 635-642.

Delves, Peter J., et al. Roitt’s Essential Immunology. 11th ed. Malden, Mass.: Blackwell, 2006.

Levs, Josh. "The Unvaccinated, by the Numbers." CNN. Cable News Network, 4 Feb. 2015. Web. 30 Dec. 2015.

National Center for Immunization and Respiratory Diseases, Division of Viral Diseases, Division of Viral Diseases. "Measles Cases and Outbreaks." CDC. Centers for Disease Control and Prevention, 16 Dec. 2015. Web. 30 Dec. 2015.

Plotkin, Stanley A., Walter A. Orenstein, and Paul A. Offit. Vaccines. 5th ed. Philadelphia: Saunders/Elsevier, 2008.

Vezina, Kenrick. "Experimental Vaccine for Ebola." Points of View: Experimental Vaccine For Ebola Virus (2015): 1. Points of View Reference Center. Web. 30 Dec. 2015.

During the frozen time period for the MRP production schedule, changes in the production plan are typically not allowed. True or False?

True! That's why it's called the "frozen period"; it's like your plans are frozen in place, unable to move. Another common term is time fence; I like to imagine it as a fence that you need to climb over to reach the other side.The reason you have a frozen period is that changing schedules is costly; you don't want to be constantly shifting back and forth at the drop of a hat. The...

True! That's why it's called the "frozen period"; it's like your plans are frozen in place, unable to move. Another common term is time fence; I like to imagine it as a fence that you need to climb over to reach the other side.

The reason you have a frozen period is that changing schedules is costly; you don't want to be constantly shifting back and forth at the drop of a hat. The optimal length of your frozen period will depend on how costly it is to change strategies; as technologies like 3D printing and just-in-time manufacturing get more commonplace, this switching cost might actually get so low that there's no need for a frozen period, or at least make it extremely short.

That doesn't mean that you stop thinking about your plans during the frozen period; in fact, it's quite typical to observe what is and isn't working during the frozen period and use it to plan the schedule for future periods. But the idea is that unless you have a really compelling reason, you don't try to change the plan for this particular run while you're still in the frozen period, because the change would be too costly.

What is a physical description of Atticus Finch in To Kill a Mockingbird?

It is difficult to imagine Atticus as looking much different than Gregory Peck, who memorably portrayed him in the 1962 film adaptation of the book. But Scout describes Atticus in a few instances. She says that he has black hair, that of course turns increasingly gray throughout the book, both in response to advancing age and no doubt to the stress he is under as a result of the trial.

Above all, she says he...

It is difficult to imagine Atticus as looking much different than Gregory Peck, who memorably portrayed him in the 1962 film adaptation of the book. But Scout describes Atticus in a few instances. She says that he has black hair, that of course turns increasingly gray throughout the book, both in response to advancing age and no doubt to the stress he is under as a result of the trial.

Above all, she says he is "feeble;" Scout and Jem both think of him as being very old, far older than the fathers of their friends. They do not think of him as physically imposing in any way. He is nearly blind in one eye and wears glasses. He is somewhat bookish and unassuming, and he does not fit their model of masculinity. He does not, for example, play football with Jem. This is why the children are so surprised when Atticus takes down Tim Johnson, a dog that has gone mad with rabies, with a single shot from a rifle.

In chapter 15, Scout contrasts Atticus's appearance with that of Jem, whose "soft brown hair and eyes" and "oval face and snug-fitting ears" are inherited from his mother. Atticus, she says, has "graying black hair" and "square cut features," even if they both share a resoluteness and "mutual defiance." 

What is chlamydia? |

Causes and Symptoms

Chlamydia is one of the most common sexually transmitted bacterial diseases
, with a prevalence of about 2 to 12 percent in sexually active men and women worldwide. Chlamydia is caused by a bacterium, Chlamydia trachomatis, that infects cells on mucosal surfaces, such as the genital tract, urinary tract, anorectal tract, eyes, and throat. These infections cause inflammation of the cervix, urethra, prostate, or epididymis. In women, symptoms may include urinary discomfort, lower abdominal pain, and abnormal vaginal discharge. Women are commonly asymptomatic in the early stages of the disease. In men, symptoms may involve urinary discomfort and unusual discharge from the urethra. Men may also be asymptomatic in early stages of the disease.

Most cases of chlamydia are asymptomatic, and many patients are diagnosed based on screening procedures. Nevertheless, asymptomatic patients are able to infect others and can suffer serious consequences of chlamydia infection, such as Pelvic inflammatory disease (PID)
and infertility. PID occurs when chlamydia infection ascends the female reproductive tract to involve the uterus, Fallopian tubes, and pelvic cavity. This infection of the upper reproductive tract can lead to scarring of these organs and puts the patient at increased risk of infertility and ectopic pregnancy.

In rare cases, chlamydia can travel to regional lymph nodes and cause abscesses, a condition termed lymphogranuloma venereum. This condition is commonly accompanied by systemic symptoms such as fever, chills, and muscle and joint aches.

An infant may contract chlamydia as it passes through the birth canal of an infected mother. The disease can lead to eye infection that results in visual impairment and blindness, as well as infection of the respiratory tract.

Treatment and Therapy

A patient receives antibiotic therapy if laboratory tests indicate infection with C. trachomatis. Uncomplicated chlamydia infection can be treated effectively with antibiotics such as doxycycline, azithromycin, erythromycin, or ofloxacin. A patient with risk factors for Sexually transmitted diseases (STDs) or symptoms of the disease may be treated presumptively with antibiotic therapy, even before the results of laboratory tests for chlamydia return.

Because chlamydia is associated with other STDs, such as gonorrhea,
Human immunodeficiency virus (HIV), syphilis, and hepatitis B and C, the patient should be advised to undergo testing for these diseases as well. Approximately 35 to 50 percent of patients with gonorrhea also have chlamydia, so an antibiotic against chlamydia is given along with an antibiotic for gonorrhea, unless laboratory tests have declared the patient free of chlamydia. If chlamydia and gonorrhea are treated early, complications such as PID or infertility can be avoided.

In addition to antibiotics, a key component of chlamydia treatment involves counseling in the prevention of STDs. To minimize future exposure to chlamydia and other STDs, patients are encouraged to use barrier methods such as condoms during intercourse and to avoid high-risk sexual behaviors.

Another key component to the treatment of chlamydia and other STDs is contact tracing, which occurs once the infection is confirmed with laboratory testing. With the cooperation of the patient, all sexual partners of the patient are notified regarding their exposure to disease. Partners are encouraged to seek medical attention, even if they have no symptoms themselves, in order to prevent reinfection of the patient during subsequent sexual encounters or further spread of the disease to other sexual partners.

In the United States, erythromycin eyedrops are given prophylactically to all newborns to prevent eye infections with chlamydia that could lead to visual impairment.

Perspective and Prospects

Diseases caused by C. trachomatis have been described as early as ancient Egyptian times. It was not until 1907, however, that the bacterium was actually identified, and there was some controversy about whether it was a true bacterium because it requires host cells to live (obligate intracellular parasite). The organism favors cells that are more available on the cervix of young (versus older) women, which is partly why rates of chlamydia are so much higher in the young. In the 1960s, a clinically useful diagnostic test was developed that allowed screening of a large number of specimens within a few days. The development of a relatively easy test for chlamydia enabled clinicians to screen a large number of asymptomatic but at-risk patients (such as those under age twenty-five or those with multiple sexual partners).

A promising area of research is the search for a vaccine to C. trachomatis. This research focuses on identifying antigens on the bacterium that are important for its function, such as proteins responsible for bacterial attachment to or uptake into cells. The premise is to use these proteins to generate an immune response in patients so that when patients are exposed to chlamydia, their immune systems are prepared to respond against it.

Bibliography:

Badash, Michelle. "Chlamydia." Health Library, October 11, 2012.

Centers for Disease Control and Prevention. "Chlamydia—CDC Fact Sheet." Centers for Disease Control and Prevention, December 2012.

Centers for Disease Control and Prevention. "Sexually Transmitted Diseases Treatment Guidelines, 2010." Morbidity and Mortality Weekly Report 59, no. RR-12 (2010).

Holmes, King K., et al., eds. Sexually Transmitted Diseases. 4th ed. New York: McGraw-Hill Medical, 2008.

Longo, Dan, et al., eds. Harrison’s Principles of Internal Medicine. 18th ed. New York: McGraw-Hill, 2011.

Ryan, Kenneth J., et al., eds. Sherris Medical Microbiology: An Introduction to Infectious Diseases. 5th ed. New York: McGraw-Hill, 2010.

What are ears? |

Structure and Functions

The ear is composed of three parts: the outer ear, the middle ear, and the inner ear. All three parts are involved in hearing, while only the inner ear is involved in balance.

Sound can be thought of as pressure waves that travel through the air. These waves are collected by the fleshy part of the outer ear and are funneled down the ear canal to the eardrum. The eardrum, being a thin membrane, vibrates as it is hit by the sound waves. Attached to the eardrum is the first of the ossicles (the hammer or malleus), which moves when the eardrum moves. The second ossicle (the anvil or incus) is attached to the first, and the third to the second. Therefore, as the first bone moves, the others move also. The base of the third bone (the stirrup or stapes) is in contact with the oval window at the beginning of the inner ear. Movement of the oval window sets up vibrations in the fluid of the cochlea. These vibrations are detected by hair cells. Depending on their position in the cochlea, the
hair cells are sensitive to being moved by vibrations of different frequencies. When the hair of a hair cell is bent by the fluid, an impulse is generated. The impulses are transmitted to the brain via the auditory nerve. The nerve impulses are processed in the brain, and the result is the sensation of sound, in particular the sense of pitch. Thus the three parts of the ear turn sound waves into “sound” by changing air vibrations into eardrum vibrations, then ossicle movement, then fluid vibrations, and finally nerve impulses.

Disorders and Diseases

Each of the three parts of the ear can be affected by diseases that can lead to temporary or, in some cases, permanent hearing loss. Damage to the eardrum, ossicles, or any part of the ear before the cochlea results in conductive hearing loss
, as these structures conduct the sound or vibrations. Damage to the hair cells or to the auditory nerve results in sensorineural hearing loss
. Sound may be conducted normally but cannot be detected by the hair cells or transmitted as nerve impulses to the brain.

Disorders of the outer ear include cauliflower ear, blockage by earwax, otitis externa, and tumors. Cauliflower ear is a severe hematoma (bruise) to the outer ear. In some cases, the blood trapped beneath the skin does not resorb and instead turns into fibrous tissue that may become cartilaginous or even bonelike.

Earwax is secreted by the cells in the lining of the ear canal. Its function is to protect the eardrum from dust and dirt, and it normally works its way to the outer opening of the ear. The amount secreted varies from person to person. In some people, or in people who are continually exposed to dusty environments, excessive amounts of wax may be secreted and may block the ear canal sufficiently to interfere with its transmission of sound waves to the eardrum.

Otitis externa can take two forms, either localized or generalized. The localized form, a boil or abscess, is a bacterial infection that results from breaks in the lining of the ear canal and is often caused by attempts to scratch an itch in the ear or to remove wax. The generalized form can be a bacterial or fungal infection, known as otomycosis. Generalized otitis externa is also called swimmer’s ear because it often results from swimming in polluted waters or from chronic moisture in the ear canal.

Tumors of the ear can be benign (noncancerous) or malignant (cancerous) growths of either the soft tissues or the underlying bone. Bony growths, or osteomas, can cause sufficient blockage, by themselves or by leading to the buildup of earwax, to result in hearing loss.

The middle ear consists of the eardrum, three small bones called the ossicles, and the eustachian tube. The bones of the middle ear move in an air-filled cavity. Air pressure within this cavity is normally the same as the outside air pressure because air is exchanged between the middle ear and the outside world via the eustachian tube. When this tube swells and closes, as it often does with a head cold, one experiences a stuffy feeling, decreased hearing, mild pain, and sometimes ringing in the ears (tinnitus) or dizziness. The middle ear is susceptible to infection, such as otitis media
, because bacteria and viruses can sometimes enter via the eustachian tube. Young children are especially prone to middle-ear infections because a child’s eustachian tubes are shorter and more directly in line with the back of the throat than those of adults. Untreated ear infections can sometimes spread into the surrounding bone (mastoiditis) or into the brain (meningitis).

Fluid in the middle ear during an ear infection interferes with the free movement of the ossicles, causing hearing loss that, although significant while it lasts, is temporary. In other instances, there is the prolonged presence of clear fluid in the middle ear, resulting from a combination of infection or allergy and eustachian tube dysfunction, which itself can result from swelling caused by an allergy. This condition, known as glue ear or persistent middle-ear effusion, can last long enough to cause detrimental effects on speech, particularly in young children. Middle-ear infections can sometimes become chronic, as in chronic otitis media; permanent damage to the hearing can result from the ossicles being dissolved away by the pus from these chronic infections.

During a middle-ear infection, fluid can build up and increase pressure within the middle-ear cavity sufficiently to rupture (perforate) the eardrum
. Very loud noises are another form of increased pressure, in this case from the outside. If a loud noise is very sudden, such as an explosion or gunshot, then pressure cannot be equalized fast enough and the eardrum can rupture. Scuba diving without clearing one’s ears (that is, getting the eustachian tube to open and allow airflow) can also result in ruptured eardrums. Other causes of ruptured eardrums include puncture by a sharp object inserted into the ear canal to remove wax or relieve itching, a blow to the ear, or a fractured skull. Some hearing is lost when the eardrum is ruptured, but if the damage is not too severe, the eardrum heals itself and hearing returns.

The middle ear does not always fill with fluid if the eustachian tube is blocked. In some instances, the middle-ear cavity remains filled with trapped air. This trapped air is taken up by the cells lining the middle-ear cavity, decreasing the air pressure inside the middle ear and allowing the eardrum to push inward. Cells that are constantly shed from the eardrum collect in this pocket and form a ball that can become infected. This infected ball, or cholesteatoma, produces pus, which can erode the ossicles. If left untreated, the erosion can continue through the roof of the middle-ear cavity (causing brain abscesses or meningitis) or through the walls (causing abscesses behind the ear). The symptoms of a cholesteatoma go beyond the symptoms of an earache to include headache, dizziness, and weakness of the facial muscles.

Permanent conductive hearing loss can also result from calcification of the ossicles, a condition called osteosclerosis. Abnormal spongy bone can form at the base of the stirrup bone, interfering with its normal movement against the oval window. Hearing loss caused by osteosclerosis occurs gradually over ten to fifteen years, although it may be accelerated in women by pregnancy. There is a hereditary component.

The inner ear begins at the oval window, which separates the air-filled cavity at the middle ear from the fluid-filled cavities of the inner ear. The inner ear consists of the cochlea, which is involved in hearing, and the labyrinth, which maintains balance.

Disorders of the cochlea result in permanent sensorineural hearing loss. Hair cells can be damaged by the high fever accompanying some diseases such as meningitis. They may also be damaged by some drugs. The largest, and most preventable, sources of damage to the hair cells are occupational and recreational exposure to loud sounds, particularly if they are prolonged. In some occupations, the hearing loss from working without ear protection may be confined to certain frequencies of sounds, while other occupations lead to general loss at all sound frequencies. Prolonged exposure to overamplified music will likewise cause permanent hearing loss at all frequencies. This is more severe and has much earlier onset than presbycusis—the progressive loss of hearing, particularly in the high frequencies, that occurs with normal aging.

The labyrinth is the part of the ear that maintains one’s balance; therefore the major system of disorders of the labyrinth is vertigo (dizziness). Labyrinthitis is an infection, generally viral, of the labyrinth. The vertigo can be severe but is temporary.

With Ménière disease, there is an increase in the volume of fluid in the labyrinth and a corresponding increase in internal pressure, which distorts or ruptures the membrane lining. The symptoms, which include vertigo, noises in the ear, and muffled or distorted hearing especially of low tones, flare up in attacks that may last from a few hours to several days. The frequency of these attacks varies from one individual to another, with some people having episodes every few weeks and others having them every few years. This condition, which may be accompanied by migraine headaches, usually clears spontaneously but in some people may result in deafness.

Diagnostic and Treatment Techniques

The most common ear disorders, outer-ear or middle-ear infections, are diagnosed visually with an otoscope. This handheld instrument is a very bright light with a removable tip. Tips of different sizes can be attached so that the doctor can look into ear canals of various sizes. Infections or obstructions in the outer ear are readily visible. Middle-ear infections can often be discerned by the appearance of the eardrum, which may appear red and inflamed. Fluid in the middle ear can sometimes be seen through the eardrum, or its presence can be surmised if the eardrum is bulging toward the ear canal. In other cases, the eardrum will be seen to be retracted or bulging inward toward the middle-ear cavity. Holes in the eardrum can also be seen, as can scars from previous ruptures that have since healed.

Impedance testing may be used in addition to the otoscope for the diagnosis of middle-ear problems. Impedance testing is based on the fact that, when sound waves hit the eardrum, some of the energy is transmitted as vibrations of the drum, while some of the energy is reflected. If the eardrum is stretched tight by fluid pushing against it or by being retracted, it will be less mobile and will reflect more sound waves than a normal eardrum. In the simplest form, the mobility of the eardrum is tested with a small air tube and bulb attached to an otoscope. The doctor gently squeezes a puff of air into the ear canal while watching through the otoscope to see how well the eardrum moves.

A far more quantitative version of impedance testing can be done in cases of suspected hearing loss. This type of impedance testing is generally administered by an audiologist, a professional trained in administering and interpreting hearing tests. The ear canal is blocked with an earplug containing a transmitter and receiver. The transmitter releases sounds of known frequency and intensity into the ear canal while also changing the pressure in the ear canal by pumping air into it. The receiver then measures the amount of energy reflected back. The machine analyzes the efficiency of reflection at various pressures and prints out a graph. By comparison of the graph to that from an eardrum with normal mobility, conclusions can be drawn about the degree of immobility and, consequently, about the stage of the middle-ear infection. Many pediatricians or family physicians have handheld versions of this instrument, which resembles an otoscope but is capable of transmitting sound and measuring reflected sound intensity.

When an ear infection has been diagnosed, the treatment is generally with antibiotics. For outer-ear infections, drops containing antibiotic or antifungal agents are prescribed. For middle-ear infections, antibiotics are prescribed that can be taken by mouth. The patient is rechecked in about three weeks to ensure that the ear has healed.

In some cases, the ear does not heal, or the fluid in the middle ear does not go away. This can occur if a new infection starts before the ear is fully recovered or if the infecting microorganisms are resistant to the antibiotic used for treatment. In cases of chronic or repeated otitis media, a surgical procedure called a myringotomy can be performed in which a small slit is made in the eardrum to release fluid from the middle ear. Often, a small tube is inserted into the slit. These ear tubes, or tympanostomy tubes, keep the middle ear ventilated, allowing it to dry and heal. In most cases, these tubes are spontaneously pushed out by the eardrum as healing takes place, usually within three to six months. Patients must be cautious to keep water out of their ears while the tubes are in place.

A permanently damaged eardrum—from an explosion, for example—can be replaced by a graft. This procedure is called tympanoplasty, and the tissue used for the graft is generally taken from a vein from the same person. If the ossicles are damaged, they too can be replaced, in this case by metal copies of the bones. For example, when otosclerosis has damaged the stapes (stirrup) bone, hearing can often be restored by replacing it with a metal substitute.

Tumors, osteomas in the ear canal, or cholesteatomas on the eardrum may need to be removed surgically. Surgery may also be needed if infections have spread into the surrounding bone. Bone infections or abnormalities of the inner ear are diagnosed by X-rays or by computed tomography (CT) scans.

For some persons who have complete sensorineural hearing loss, some awareness of sound can be restored with a cochlear implant. This electronic device is surgically implanted and takes the place of the nonexistent hair cells in detecting sound and generating nerve impulses.

Problems of balance may sometimes be treated successfully with drugs to limit the swelling in the labyrinth. Ringing in the ears (tinnitus) is usually resolved when the underlying condition is resolved. In some cases, tinnitus is caused by drugs (large doses of aspirin, for example) and will cease when the drugs are stopped. However, it is difficult to identify the cause of most tinnitus cases, and there is no specific cure.

Doctors who specialize in the diagnosis and treatment of disorders of the ear and who do these surgeries are called otorhinolaryngologists (ear, nose, and throat doctors; also called otolaryngologists). They are medical doctors who have several years of training beyond medical school in surgery and in problems of the ear, nose, and throat.

Perspective and Prospects

The basic anatomy of the ear has been known for some time. Bartolommeo Eustachio (1520–1574), an Italian anatomist, first described the eustachian tube as well as a number of the nerves and muscles involved in the functioning of the ear. An understanding of how the ear functions to discriminate the pitch of sounds, however, was not arrived at until the twentieth century. Georg von Békésy won the Nobel Prize in Physiology or Medicine in 1961 for his work on the acoustics of the ear and how it functions to analyze sounds of varying frequencies (pitch).

Treatment of diseases of the ear has been radically changed by the advent of antibiotics. Older texts describe rupture of the eardrum by middle-ear fluid as a desired outcome of middle-ear infection, one which would ensure that the infection drained and healed, rather than becoming chronic.

Chronic ear infections used to be associated with diseases such as tuberculosis, measles, and syphilis, which themselves became far less common with the widespread use of antibiotics or vaccines. In the past, chronic ear infections were much more likely to result in mastoiditis, or infection of the air spaces of the mastoid bone, requiring surgical removal of the infected portions of the mastoid bone.

Adenoids and tonsils
were frequently removed from patients with recurrent ear infections, as these were thought to be the source of the reinfection. It is now known that these tissues are involved in the formation of immunity to infectious bacteria and viruses. Their removal is not advocated in most circumstances—except, for example, when they are large enough to block the opening of the eustachian tube.

Reconstructive surgery began in the 1950s with the development by Samuel Rosen and others of the operation to free up the calcified stapes bone in cases of otosclerosis. Today, virtually all components of the middle ear can be replaced.

While ear infections used to be much more dangerous, perhaps there is an equal danger today of taking threats to the ears too lightly. Chronic ear infections can still cause permanent hearing loss and may even become life-threatening infections if left untreated. Damage involving the inner ear remains untreatable, as do many cases of tinnitus and loss of balance. Because the largest source of inner ear damage is prolonged exposure to noise, the prevention of damage is far more effective than treatment.

Bibliography

Carson-DeWitt, Rosalyn, and Kari Kassir. "Middle Ear Infection." Health Library, September 30, 2012.

"Ear Disorders." MedlinePlus, June 12, 2013.

"Ears, Nose, and Throat." MedlinePlus, January 7, 2013.

Gelfand, Stanley A. Essentials of Audiology. 3d ed. New York: Thieme, 2009.

Katz, Jack, ed. Handbook of Clinical Audiology. 6th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2009.

Leikin, Jerrold B., and Martin S. Lipsky, eds. American Medical Association Complete Medical Encyclopedia. New York: Random House Reference, 2003.

Mendel, Lisa Lucks, Jeffrey L. Danhauer, and Sadanand Singh. Singular’s Illustrated Dictionary of Audiology. San Diego, Calif.: Singular, 1999.

Nettina, Sandra M., ed. The Lippincott Manual of Nursing Practice. 9th ed. Philadelphia: Lippincott Williams & Wilkins, 2010.

Pender, Daniel J. Practical Otology. Philadelphia: J. B. Lippincott, 1992.

"Tinnitus." MedlinePlus, June 7, 2013.

Zuckerman, Barry S., and Pamela A. M. Zuckerman. Child Health: A Pediatrician’s Guide for Parents. New York: Hearst Books, 1986.

In the story Catherine, Called Birdy, how is Catherine discriminated against as a female?

Catherine faces sexism because she is not allowed to choose who she marries.

As a young woman in the middle ages, Catherine has few rights.  Her family has some money, but that does not make her free from problems.  Catherine’s main problem is that her father wants to marry her off, from a young age.  As a girl, she can’t choose her husband.

Catherine complains that although they are well off, they are not rich. ...

Catherine faces sexism because she is not allowed to choose who she marries.

As a young woman in the middle ages, Catherine has few rights.  Her family has some money, but that does not make her free from problems.  Catherine’s main problem is that her father wants to marry her off, from a young age.  As a girl, she can’t choose her husband.

Catherine complains that although they are well off, they are not rich.  For this reason, she has to learn to sew and act ladylike.  Catherine detests behaving like a lady.  She would much rather run around outdoors and have fun.

I can stand no more of lady-tasks, endless mindless sewing, hemming, brewing, doctoring, and counting linen!  Why is a lady to gentle to climb a tree or throw stones into the river when it is lady’s work to pick maggots from the salt meat? (October 1)

Feeling that he owns his daughter and has a right to auction her off, Catherine’s father thinks nothing of her feelings when choosing her husbands.  She considers most of them terrible, and they are usually older. 

Morwenna tried to make me understand why my father seeks a husband for me and why it is my duty to marry where he says.  I understand full well.  He is as greedy as a goat. (19th day of October)

Catherine fights back in the only way she can.  She tries to scare off potential husbands that she considers vile.  She does not succeed with "Shaggy Beard."  Her friend is married to a child, who dies before the marriage can really be a marriage.  Catherine is forced to marry Shaggy Beard, but when he dies she gets to marry his much more attractive son Stephen, whom Catherine prefers in both looks and personality.

In the middle ages, a lady was subject to the whims of the men in her life.  Catherine is bossed around and mistreated by her father and brothers.  She is told to accept that this is her lot in life. Catherine is ahead of her time in some ways, but she can’t escape her fate.  It is only luck that gets her to end up well matched.

 

What are the symptoms of substance abuse?

Risk Factors

Experimentation with alcohol and drugs is the most prominent risk to becoming a substance abuser. Whether the reward of the high is physical pleasure, the temporary removal of a traumatic memory from the mind, or simply acceptance by a peer group, experimenting with substances is always risky. Symptoms of the substance use and its effects begin to appear immediately.

Many neuroscientists and mental health professionals assert that some persons are more susceptible than others to becoming addicted to alcohol or drugs because of genetic, biological, or environmental tendencies or exposure. Risk factors include a family history of substance abuse, mental disorders, childhood trauma, and early experimentation with substances. For persons with or without these risk factors, experimentation with certain substances could lead to addiction.

The earlier a substance abuser recognizes the symptoms of substance abuse and acknowledges the dangers of continued use, the earlier he or she can advance toward treatment and recovery. At any point between a substance abuser’s experimentation and addiction, signs of dependency increasingly become apparent. Friends and family members may recognize the symptoms and then intervene to break a substance abuser’s destructive patterns. Not confronting a person suspected of substance abuse will likely allow the problem to worsen.

Though a substance abuser is likely to admit to using a substance, he or she is less likely to admit to abusing that substance, which makes the process of intervention difficult. Still, the more proficient a loved one or friend is in recognizing the symptoms of substance abuse, the more confident he or she can be in intervening.

Physical Symptoms

The most profound physiological symptoms of substance abuse stem from how substances radically alter the biochemical processes of the brain. Alcohol and drugs affect how the brain’s nerve receptors receive, process, and send information by overtaking the brain’s neurotransmitters and overstimulating its pleasure center.

This effect on the brain is manifested in a substance abuser’s mood. He or she will seem cheerful or “normal” when feeling the initial effects, or the high, of the substance. Once the high wears off, he or she will be noticeably agitated or depressed. A substance abuser also requires increasingly larger and more frequent dosing of the substance of choice to achieve the same effects after physical dependence develops.

Without increasing dosage and frequency, the abuser will experience disruptive withdrawal symptoms. Other common physical warning signs of substance abuse include bloodshot and glassy eyes, sudden weight loss or weight gain, change in appetite, deteriorating personal appearance and hygiene, odor of alcohol or smoke emanating from the person’s breath or clothing, tremors, lack of coordination, and changes in speech patterns, such as slurring.

Though all substances can generate short-term or long-term effects on the body, different substances affect the body differently and manifest different symptoms. Alcohol, for example, increases dopamine in the brain, and when abused it impedes the natural production and transmission of dopamine. As the brain’s organic ability to generate pleasure chemicals is impeded by chronic alcohol consumption, the alcoholic develops a tolerance for alcohol and has difficulty functioning in daily life without it. Physical signs of alcoholism include the odor of alcohol on the breath and skin, bloodshot eyes, redness in the face, a bloated stomach, slurred speech, and a lack of coordination and focus.

Marijuana’s main active chemical, delta-9-tetrahydrocannabinol (THC), impacts sites in the brain known as cannabinoid receptors. A marijuana user will have bloodshot and glassy eyes, impaired coordination, difficulty with thinking, and memory loss. Because THC weakens the immune system, a chronic marijuana smoker frequently contracts respiratory infections.

Cocaine stimulates the nervous system by increasing the level of dopamine in the brain, and it adversely affects the ability of the brain to transmit dopamine organically. A cocaine user is hyperactive and talkative when high and appears fatigued and melancholy later, when the high has worn off. Chronic cocaine snorting causes a chronic cough, frequent nose bleeds, and even permanent damage to the nasal cavity, including a loss of the sense of smell and loss of appetite. Those who smoke crack cocaine or methamphetamine (meth) experience blemishes on the skin, weight loss from decreased appetite, and rotting teeth. Stimulants such as cocaine, crack cocaine, and meth also will manifest physical signs of dilated pupils, dry mouth, unusual sleeping and eating patterns, and increased heart rate and blood pressure.

Nonstimulant drugs generate different symptoms. Abusers of heroin, for example, exhibit weight loss; tremors and twitching; track marks on the arms, legs, or feet; paleness; sweating; and reduced heart rate and respiration. Abusers of narcotic depressants, including prescription painkillers, appear drunk and exhibit poor judgment, clumsiness, sleepiness, and an inability to concentrate.

Behavioral Symptoms

Substance abuse inflicts long-term changes to the brain; the neuroadaptations the brain produces to control the release of dopamine and regulate emotions remain with the addict even after treatment and abstinence. Substance addiction also alters the prefrontal cortex of the user, causing the reduction in neuron activity in this part of the brain.

These changes to the brain also lead to the release of the neurotransmitter glutamate, which impairs the addict’s decision-making ability. Glutamate facilitates impulsiveness and intense focus on achieving the immediate reward of pleasure. Consequently, addicts often engage in reckless behavior, and rehabilitated addicts are prone to relapse when faced with substance-related stimuli. In the amygdala, the part of the brain involved in memory formation, emotional memories associated with being high are enhanced, thereby making it difficult for the addict to resist stimuli that trigger these memories.

Because substance abuse radically affects the physiology of the brain, abuse also profoundly affects behavior. The need to consume the substance of choice increasingly dominates a substance abuser’s sense of judgment and daily actions.

Substance abuse may be attributed to several disruptive and harmful behavioral patterns, such as family disintegration, loss of employment, domestic violence, and child abuse. Common behavioral symptoms include the inability to refrain from consuming the substance, an obsession with achieving the next high, an abandonment of important responsibilities and interpersonal relationships, and a disregard for the obvious harm the substance is causing to the body.

Consistent with the effect that substance abuse has on the brain, a substance abuser is more likely to drop out of school or quit a job, may change peer groups often, may experience conflicts with the law, and may experience mood swings, recklessness, laziness, and paranoia.

The classic behavioral symptom of persons with a substance abuse problem is that they sever important relationships by betraying those closest to them. Because the quest for the next high is so prominent in their mind, substance abusers will lie, cheat, and steal from strangers and loved ones alike to get the next fix.

Bibliography

Fisher, Gary L., and Nancy A. Roget, eds. Encyclopedia of Substance Abuse Prevention, Treatment, and Recovery. 2 vols. Thousand Oaks: Sage, 2009. Print.

Hoffman, John, and Susan Froemke, eds. Addiction: Why Can’t They Just Stop? New York: Rodale, 2007. Print.

Lawford, Christopher Kennedy. Moments of Clarity: Voices from the Front Lines of Addiction and Recovery. New York: Morrow, 2009. Print.

“The Science of Drug Abuse and Addiction: The Basics.” National Institute on Drug Abuse. Natl. Insts. of Health, Sept. 2014. Web. 6 Nov. 2015.

What is a vasectomy? |

Indications and Procedures

The term
vasectomy
, literally meaning "cutting the tubes," describes a minor surgical procedure performed on a man who desires a permanent form of birth control. Vasectomy results in sterilization because it obstructs the passageway through which sperm travel to reach the female ovum. A man’s testicles produce both male hormones (that stimulate male characteristics and sex drive) and sperm. A collection of small tubes called the epididymis along each testicle mature and deliver sperm to a single tube called the vas (or vas deferens), which is about the width of a spaghetti noodle. Each vas runs through the scrotum, up the groin on each side, and through the wall of the abdomen, ending in a storage area called the seminal vesicle, which is next to the prostate gland near the base of the penis. From there, the sperm mix with semen from the prostate gland and are expelled from the penis during ejaculation.

Vasectomy occludes (closes off) the vas to block the passage of sperm without affecting the important hormonal functions of the testicle. The surgery is done in the first, straight part of the vas, above the testicle and through the skin of the scrotum, making the procedure relatively easy and safe to perform.

Physicians performing vasectomy come from the specialties of urology, family medicine, general practice, or general surgery. Since the procedure is relatively simple, in comparison with other surgeries, physicians’ expertise usually depends more on specific training and interest in performing vasectomies and following up on the procedure than on their particular specialty training.

Vasectomies are usually done on an outpatient basis, either in a physician’s office or in a hospital-based or freestanding ambulatory surgery facility. Local anesthesia of the skin and the vasae is produced by an injection into the scrotum, which can be briefly uncomfortable until the medication has taken its full effect (usually after several seconds). Because of anxiety on the part of many men about having any discomfort in this area, many patients and physicians also choose to use sedation in the form of either tranquilizer pills or an injection for both mental and physical relaxation during vasectomy.

A number of techniques can be used safely and effectively by a physician performing a vasectomy, but the procedure can be thought of in terms of accomplishing three basic goals: The first is anesthesia, or the placement of numbing or freezing medication into the scrotum; the second is to gain access to the vas; and the third is its occlusion to prevent the passage of sperm.

Vasectomy can be made almost completely painless when
local anesthesia in the form of medication such as lidocaine is used; this drug is similar to the anesthesia commonly used for dental procedures. By blocking the local nerves that send pain messages to the brain, normally painful procedures can be performed with little or no discomfort. A man having a vasectomy will feel the needle used to inject the medication into the skin and then a brief stinging sensation until it takes effect. The rest of the injection into the tubes themselves may or may not cause further discomfort, what some men describe as a pulling sensation.

The standard access procedure that the physician uses can vary with training and experience. It involves making either one incision into the scrotum in the middle of the front side or two incisions, one on either side. The incisions are made after the physician positions the vas directly under the skin, and then the other layers of tissue are separated to expose the vas itself. After each vas is occluded, the incision, which is between 1 and 1.5 centimeters long, must be closed with stitches, usually the type that dissolve and do not have to be removed.

A refinement of the access procedure, called the “no-scalpel” vasectomy, was introduced into the United States in the late 1980s. It originated in China in 1974, and a study comparing it with a standard technique found a more than 80 percent reduction in postoperative complications. It is being adopted only gradually by United States physicians, however, because performing it requires two simple but specially designed surgical instruments and because some physician retraining is required. Many physicians with experience in the new procedure believe that it should become the new standard for the vasectomy access procedure.

The occlusion of the vas is important because it determines the success of the vasectomy in preventing pregnancy. The physician can choose to occlude the vas ends by simple tying, folding back and tying, applying small metal clips, or cauterizing (burning with heat or special electrical current). In addition, one of the vas ends can be covered with a layer of the tissue that surrounds it to form a further barrier to sperm. Although all occlusion methods have been effective, cautery of the opening of the vasae may be the most reliable because it depends less on the technical precision of the physician doing the vasectomy than do the other methods, which can fail if applied too loosely or too tightly.

Finally, some physicians perform an open-ended technique, in which the end of the vas coming from the testicle is left open while only the outgoing end is occluded. This is thought to reduce the amount of backed-up sperm that can cause later complications and to make it easier to perform a vasectomy reversal. Some physicians believe, however, that the rate of vasectomy failure is higher with this technique.

Men from all over the world choose to have vasectomy performed, including about one-half million Americans every year. Vasectomy has been commonly available in the United States since the 1960s and is the fourth most commonly used birth control method overall, with one in eight women stating that they rely on this contraceptive method.

Some men who have undergone vasectomies choose, for various reasons, to reverse them. In such a reversal procedure, the patient, under general anesthesia, has a one- to two-inch incision made in the scrotum over the site of the previous vasectomy. The ends of the vas deferens are located and cut free of the surrounding scar tissue. A drop of fluid from the testicular end of the vas is placed on a glass slide and examined under an electronic microscope to determine precisely what kind of microsurgery is most appropriate.

Uses and Complications

Most physicians make recommendations to the patient about what should be done, or not done, following a vasectomy, including activity restriction, pain control strategies, and follow-up. A period of rest for about forty-eight hours after a vasectomy helps to prevent pain and complications such as postoperative bleeding into the scrotum, which causes swelling. All sexual activity should be avoided for up to a week. Many men find more relief from an ice pack applied to the scrotum for the first few days following the surgery than from any medication, although acetaminophen (such as Tylenol) or mild prescription narcotics are often helpful as well. Aspirin and ibuprofen, although effective for pain, are generally best avoided in the first few days following a vasectomy because they have a blood-thinning effect that may increase the tendency to bleed. Because aspirin has a longer-lasting blood-thinning effect on platelets (the small blood cells that initiate normal blood clotting and stop minor bleeding), it should also not be taken for about ten days prior to the vasectomy.

Follow-up with a physician should be available in case complications occur in the period immediately following the vasectomy. The physician must also check the semen to ensure that no sperm are present. If sperm remain, it may indicate that one or both vasae remain open or have grown back together, meaning that the procedure has failed and the man remains fertile. If there are no sperm in the semen three to six months after the vasectomy, then it is extremely unlikely that a failure can still occur. Most doctors do not recommend any further follow-up unless a problem arises.

Informed consent means that the patient who will undergo a treatment has been given the opportunity to understand the risks and benefits of that treatment. In the case of vasectomy, the risks are pain, complications, the chance that it will fail, and the possibility that there will be a change of heart and that the man will want to father more children. The benefit is having very reliable, safe, and permanent birth control without ongoing costs or effort required.

The complications of vasectomy are best thought of in terms of those occurring early and late. Early complications include infection and hematoma. Infection is fairly uncommon but can include symptoms of pain, swelling, fever, redness, and abnormal drainage from the vasectomy wound. Treatment consists primarily of antibiotic medication. A
hematoma is a collection of blood in a localized area such as the scrotum. Blood vessels in the scrotum that are cut or torn during vasectomy and not tied, clipped, or cauterized can ooze a small or large amount of blood. In the worst case, surgery to remove the blood may be considered to relieve pain and pressure. Fortunately, small hematomas resolve without surgery in a few weeks’ time, and the more serious ones are rare, probably occurring in far less than 1 percent of vasectomies.

Later complications include problems with the area between the vasectomy incision and the testicles. Because the sperm are blocked from leaving the vas, and therefore the testicle, they can accumulate and cause three possible problems. First, sperm may back up at the site of the vasectomy and form a knot of sperm and inflamed scar tissue known as a sperm granuloma. It can be a painless lump, tender to pressure, or in rare cases it may be painful enough to require surgery to remove it. If swelling occurs because of accumulated sperm along the collecting area between the straight vas and the testicle (called the epididymis), the area can become tender or painful; this is known as congestive epididymitis. If this process extends backward to the testicle, it is known as orchitis. Fortunately, it is also rare for surgical removal of the entire epididymis to be required for relief of pain; sperm production slows in response to the pressure, and the body reabsorbs old sperm, eventually eliminating the pressure. Therefore, it is usually recommended that congestive
epididymitis be treated with anti-inflammatory pain relievers such as ibuprofen, as well as with soaking in a warm bath.

Since there are many misconceptions about the risks and complications of vasectomy, it is useful to point out some problems that are not associated with the procedure. The complications of vasectomy are relatively minor and very rarely require hospitalization. Deaths and major surgical complications are largely unheard of. Impotence, loss of sexual drive, and changes in male characteristics such as beard growth, body hair, and voice do not occur. An apparent link between vasectomy and the hardening of the arteries that causes heart attacks has been disproven since the only such study was publicized in the late 1970s. Although a slight statistical association between vasectomy and cancer of the prostate gland was noted in two studies published in 1993, experts do not believe that vasectomy causes or contributes to prostate cancer because there is no reasonable mechanism for it to do so. Many men with milder forms of
prostate cancer never die from it, and the statistics can be misleading because men who have seen a doctor for a vasectomy are also more likely to see a doctor for a prostate examination. Therefore, vasectomy may lead not to a greater risk of prostate cancer but to better detection of this disease.

Perspective and Prospects

Vasectomy has been performed to cause sterility since 1925, but its common use for that purpose started in the 1960s. The concepts of birth control and the desirability of limiting family size became increasingly valued in industrialized countries. Some states in the United States removed legal barriers to sterilization around this time, and the oral contraceptive or birth control pill became available to large numbers of women. These developments and the increased openness to discussion of sexual topics helped to form the basis for what was labeled the sexual revolution. In this environment, vasectomy became quite popular. It exceeded female sterilization by the early 1970s, driven in part by reports of the side effects of birth control pills. Sterilization for women (also called
tubal ligation, literally “tying the tubes”) is more invasive than vasectomy because the surgeon must enter the woman’s abdomen to occlude the tubes that enable eggs to pass into her uterus. Therefore, vasectomy is somewhat safer when seen in the perspective of family planning. The women’s movement of the 1960s placed a new emphasis on the control that women have over their bodies, especially in relation to health and medical decisions. Because the man can assume some of the reproductive responsibility and undergo a safer procedure, vasectomy also has a philosophical advantage for many couples.

Technological innovation by the mid-1970s had produced the first laparoscopic instruments, which enabled a gynecologic surgeon to enter a women’s abdomen through two pencil-sized openings and identify and occlude her Fallopian tubes. This procedure, safer than the old one, with visibly smaller scars, and performed by obstetrician-gynecologists (the physicians whom women see most often), quickly became more popular than vasectomy and has remained so ever since. In spite of its high degree of safety, laparoscopic tubal ligation still occasionally results in deaths from general anesthesia and abdominal complications necessitating major surgery. Yet, even though tubal ligation costs three to five times more than vasectomy, it is still done more than twice as often. There are probably several reasons for this discrepancy, one of the most important being that when a woman has to make the sterilization decision alone, only tubal ligation can be chosen. When a woman is single or in a relationship with a lower level of commitment, or when there is a lack of consensus or support for the decision between the two partners, it is often easier for the woman to choose a tubal ligation. When a decision is made by a couple together, however, the risks and benefits give a comparative advantage to the male sterilization procedure.

When a couple makes a well-informed and mutual decision to choose vasectomy, the feelings in the months following the procedure most commonly include an increased sense of relaxation about sex because of lack of fear of unwanted pregnancy and an absence of anxiety and/or side effects related to contraceptive methods. On the other hand, if one of the partners was not ready and feels pressured into acceptance, the vasectomy decision can create irreconcilable conflict in the relationship.

Most doctors and clinics that counsel men about vasectomy emphasize the fact that vasectomy should be regarded as permanent. Every year, thousands of men seek the reversal of their vasectomies. Although the vasae can be surgically “spliced” back together in a safe and minor operation called vasovasostomy, sometimes years after a vasectomy, there are many reasons not to expect a simple reversal of the procedure. Reversal is expensive and often not covered by medical insurance, and the chances of restored fertility (as measured by later pregnancy) are only about 50 percent. The odds of reversal can be improved if the surgeon (usually a urologist) has substantial experience in the procedure, a microsurgical technique is used, and the vasectomy was relatively recent, and perhaps if the open-ended technique was used as well.

Some highly experienced urologists claim a 95 percent success rate in reversals, so patients should be cautioned to seek out a urologist who has extensive experience in performing the procedure. Reversal certainly offers hope to someone who has undergone a divorce or personal tragedy and wants to start a new family, but an ambivalent couple should not be reassured that after vasectomy they can change their minds and easily reverse the procedure.

The decision process by a man or a couple to pursue a vasectomy for family planning reasons often begins years before the procedure is actually done. First, they must feel that they have completed their family and be aware of vasectomy as a birth control option. Dissatisfaction with other birth control methods because of inconvenience and real or feared side effects often presses the decision. Discussion about vasectomy with one or more patients who have had one is a very common prerequisite to the decision for many men. Finally, a scare that an unwanted pregnancy can occur—such as a late period or a broken condom discovered too late—or even an actual unplanned pregnancy itself may be the last straw for many couples. The high rates of satisfaction with vasectomy may be attributable to the strong sense of comfort that follows this long and thorough decision process.

Bibliography

Connell, Elizabeth B. The Contraception Sourcebook. Chicago: Contemporary Books, 2002.

Denniston, George C. Vasectomy. Victoria, B.C.: Trafford, 2002.

Haldar, N., et al. “How Reliable Is a Vasectomy? Long-Term Follow-up of Vasectomised Men.” The Lancet 356, no. 9223 (July 1, 2000): 43–44.

Health Library. "Vasectomy." Health Library, October 26, 2013.

MedlinePlus. "Vasectomy." MedlinePlus, May 20, 2013.

Miller, Karl E. “No-Scalpel Technique vs. Standard Incision.” American Family Physician 61, no. 5 (March 1, 2000): 1464.

Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Vasectomy. [N. p.]: ICON Group, 2007.

Paulson, David. “Diary of a Vasectomy.” American Health 12 (July, 1993): 70–75.

What is drunk driving? |

Drunk Driving Laws

Every US state has enacted a law making it illegal to drive with a blood alcohol content (BAC) of 0.08 percent or higher. Also, each US state has set the minimum drinking age to twenty-one years and has established a zero-tolerance law that prohibits people less than twenty-one years of age from driving after drinking. The majority of zero-tolerance laws set the drinking limit to a BAC of 0.02 percent. Drivers convicted of alcohol-impaired driving face suspension or revocation of their license.

Drivers who refuse to undergo BAC testing or who fail the test can have their
license taken away immediately under a process called administrative license
suspension, and the length of time a license is suspended ranges from seven days
to one year, depending on the state. Many states will consider restoring limited
driving privileges during a suspension if the person demonstrates a special
hardship (such as needing to drive to work).

A mechanism that prevents suspended or probationary drivers from operating a vehicle while impaired by alcohol is the ignition interlock device. This device is attached to the vehicle’s ignition and forces the driver, before being able to start the vehicle, to blow into the device for an analysis of the driver’s blood alcohol level; a device that registers a BAC of 0.08 or above will lock the vehicle’s ignition.

Effects of Alcohol

Alcohol is quickly absorbed into the bloodstream and travels throughout the body and to the brain within thirty to seventy minutes of having an alcoholic drink. A standard alcoholic beverage (such as a twelve-ounce beer, a five-ounce glass of wine, or one shot of liquor) contains about one-half ounce (exactly 0.54 ounces) of alcohol.

All of these types of alcohol will affect BAC in the same way. How quickly a
person’s BAC rises will depend on how quickly he or she drinks the beverage, the
amount he or she drinks, the amount of food in the person’s stomach, and his or
her weight and gender. Having food in the stomach helps slow the absorption of
alcohol through the stomach walls into the bloodstream. Moreover, heavier people
have more water in their body, and this water dilutes their BAC. Women typically
have less water and more body fat than men, and alcohol is not easily absorbed
into fat cells, so more alcohol is absorbed into the bloodstream.

The effects brought on by alcohol start to appear with a BAC of 0.02 percent. These effects include a loss of judgment and a decline in the driver’s ability to quickly track moving objects or perform two tasks at a time. Once a person’s BAC reaches 0.05, the risk of a fatal crash substantially increases. At this level, the person is less alert and coordinated, has trouble focusing, has trouble steering the vehicle, and is slower to respond to emergency driving situations. At a BAC of 0.08 percent, muscle coordination is poor and the driver will have problems concentrating and controlling the vehicle, will have short-term memory loss, will have problems processing information (for example, signal detection), and will show impaired reasoning and depth perception. With a BAC of 0.10 the driver’s reaction time and control deteriorates, thinking slows further, and driving becomes even more difficult. By the time a driver’s BAC reaches 0.15 percent, he or she shows a major loss of balance, impaired processing of information, inattention, and little control of the vehicle.

Statistics

The National Highway Traffic Safety Administration’s National Center for Statistics and Analysis (NCSA) tracks statistics on alcohol-impaired driving and reports these results annually. The NCSA states that any fatal crash in which a driver has a BAC of 0.08 percent or higher is an alcohol-impaired-driving crash, and fatalities resulting from this crash are alcohol-impaired-driving fatalities. They further clarify that alcohol-impaired does not mean that the crash or the fatality was solely caused by alcohol impairment.

Another source that monitors and reports statistics annually is the Insurance
Institute for Highway Safety (IIHS). This organization uses data from the US
Department of Transportation’s Fatality Analysis Reporting System to analyze and
report statistics.

Fatalities

Some progress has been made to reduce alcohol-impaired driving and related
injuries and deaths since about 1980. Reports from the NCSA and the IIHS show that
from 1982 to 1994, the United States had a 32 percent decline in deaths among
drivers with a BAC at or above 0.08. This decline has leveled off in fatalities
per year, and alcohol-related traffic fatalities declined by 23 percent between
2004 and 2013. Between the early 1980s and early 2010s, alcohol-related traffic
deaths per population have declined by 50 percent, with the greatest proportional
declines among individuals between the ages of sixteen and twenty. In the
mid-1970s, alcohol was a factor in nearly two-thirds of all traffic fatalities; by
2013, alcohol was involved in roughly one-third of all traffic deaths. From 2012
to 2013, deaths in alcohol-related traffic accidents declined by 2.5 percent.

There were 10,076 alcohol-impaired traffic fatalities in the United States in 2013
(or one death every fifty-one minutes), accounting for 31 percent of the total
motor vehicle traffic fatalities nationwide. Drunk drivers made up 65 percent of
persons killed; 16 percent were passengers in the drunk drivers’ vehicles, 11
percent were occupants in other vehicles, and 8 percent were not in a motor
vehicle.

Time of day and day of the week also were important indicators of an increased
incidence of alcohol-related-deaths. Midnight to 3 a.m. was the deadliest time for
intoxicated drivers involved in crashes: 66 percent of all traffic fatalities at
this time occurred in alcohol-related crashes and 55 percent of drivers involved
in fatal crashes between midnight and 3 a.m. were alcohol-impaired. The incidence
of alcohol-impaired drivers involved in fatal crashes was nearly four times higher
at night (35 percent) than at daytime (9 percent) and was two times higher on
weekends (30 percent) than on weekdays (15 percent).

The NCSA defined nighttime as starting at 6 p.m. and ending at 5:59 a.m. (daytime
began at 6 a.m. and ended at 5:59 p.m.) and defined weekend as starting Friday at
6 p.m. and as ending Monday at 5:59 a.m. (Weekday was defined as Monday from 5
a.m. to Friday at 5:59 p.m.). The IIHS narrowed the timeframe for what defined
nighttime (9 p.m. to 6 a.m.) and found that 59 percent of drivers with a BAC at or
above 0.08 had died during that time, compared with 19 percent during other hours
of the day.

Of 1,149 children age fourteen years and younger who were killed in motor vehicle
crashes, two hundred (or 17 percent) died in crashes involving alcohol-impaired
drivers. Of those two hundred children, 61 percent were in the vehicle of the
alcohol-impaired driver and 15 percent were pedestrians or cyclists who were
struck by the alcohol-impaired driver’s vehicle (data not reported on the
remaining 34 percent).

Driver Characteristics

Of the 11,307 drivers involved in a fatal crash with a recorded BAC of 0.01
percent or higher in 2013, 84 percent had a BAC of at least 0.08 and 56 percent
had a BAC of 0.15 or higher. Of the 10,076 alcohol-related traffic fatalities in
2013, 68 percent occurred in crashes in which at least one drive had a BAC of 0.15
or higher. The most common BAC recorded for drunk drivers involved in fatal
crashes was 0.17 percent.

Age was a significant predictor of a person driving drunk and being involved in a
fatal crash. In 2013, drivers between twenty-one and twenty-four years of age with
a BAC of 0.08 or higher topped the list of drivers involved in fatal crashes at 33
percent, followed by drivers aged twenty-five to thirty-four years (29 percent),
thirty-five to forty-four years (24 percent), forty-five to fifty-four years (20
percent), sixteen to twenty years (17 percent), fifty-five to sixty-four years (14
percent), sixty-five to seventy-four years (8 percent), and seventy-five years or
older (5 percent). There was a consistently higher percentage of male drivers with
a BAC at or above 0.08 percent who were involved in fatal crashes in every age
group. More than one-half of men age twenty-one to thirty years (58 percent) and
age thirty-one to forty years (53 percent) with a BAC at or above 0.08 and
involved in a crash were killed.

The proportion of drivers involved in fatal crashes with BACs of 0.08 or higher
was 23 percent among male drivers and 15 percent among female drivers, 27 percent
were motorcyclists, 23 percent were drivers of passenger vehicles, 21 percent were
drivers of light trucks, and 2 percent were drivers of large trucks. Drivers
involved in a fatal crash with a reported BAC level of 0.08 or higher were eight
times more likely than nondrinking drivers to have a previous impaired-driving
conviction. Among driver fatalities for which seatbelt use was reported, 68
percent were not wearing a seatbelt at the time of the crash.

Bibliography

“The ABCs of BAC: A
Guide to Understanding Blood Alcohol Concentration and Alcohol Impairment.”
National Highway Traffic Safety Administration. Natl.
Highway Traffic Safety Admin., n.d. Web. 17 Feb. 2012.

"Alcohol-Impaired Driving."
Insurance Institute for Highway Safety. Insurance
Institute for Highway Safety, 2013. Web. 27 Oct. 2015.

"Alcohol-Related Traffic Deaths."
NIH Research Portfolio Online Reporing Tools. US Dept.
of Health and Human Services, 29 Mar. 2013. Web. 27 Oct. 2015.

Dasgupta, Amitava.
The Science of Drinking: How Alcohol Affects Your Body and
Mind. Lanham: Rowman, 2011. Print.

"Drunk Driving Laws." Governors
Highway Safety Association. Governors Highway Safety Assn., Oct.
2015. Web. 27 Oct. 2015.

"Impaired Driving: Get the Facts."
Injury Prevention and Control: Motor Vehicle Safety.
Centers for Disease Control and Prevention, 19 May 2015. Web. 27 Oct.
2015.

Natl. Highway Traffic Safety Admin.
"Traffic Safety Facts, 2013 Data: Alcohol-Impaired Driving."
National Center for Statistics and Analysis. Natl.
Highway Traffic Safety Admin., Dec. 2014. Web. 27 Oct. 2015.

What is an analysis of Where Late the Sweet Birds Sang?

Structure is one aspect that must be examined in Kate Wilhelm’s 1998 apocalyptic novel Where Late the Sweet Birds Sang. It is written in three parts, each of which is titled after another well-known literary work. The first section shares its title with the novel, but more significantly, it also has a clear connection to Shakespeare’s Sonnet 73, whose first quatrain ends with the line “Bare ruin'd choirs, where late the sweet birds sang.” The gist of Sonnet 73 is the passage of time, the loss of youth, and the anguish of knowing one is moving inexorably toward death. The first section of the novel parallels this theme as the Sumners see Armageddon approaching and have to face their own mortality and the potential end of everything, including themselves. As we know, they cope with this by cloning themselves.

The second section of the novel, “Shenandoah,” is probably named after Carl Sandburg’s poem of the same name. The parallel here is the ultimately meaningless conflict, the forgotten soldiers of both sides, and the absence of any memory of it all. We can see this in the poem as Sandburg writes, “The blue nobody remembers, the gray nobody remembers, it’s all old” (line 6). In section two of the novel, only the clones survive, but they have no memories that keep them aware of or connected to the past. They are simply “repeating heads” (line 10). Another significant development in this section of the novel is Molly’s discovery of her artistry, her individuality, but it is ultimately this individuality that costs her relationship with her sisters, with whom she can no longer communicate. Her isolation leads to the conception of her child Mark, who in essence “is young, a butter of dandelions slung on the turf, climbing blue flowers of the wishing woodlands wondering: a midnight purple violet claims the sun among old heads” (lines 8-9). Mark is the future, the one who will eventually eclipse the old (clones).

The third section of the novel is most likely named after T.S. Eliot’s poem “Burnt Norton,” which explores the themes of timelessness and the connections among the past, present, and future:

Time present and time past
Are both perhaps present in time future,
And time future contained in time past. (lines 1-3)

This is significant when we consider that Mark represents the present time as well as time past because although conceived of two clones, he is really much more human. This is hard for Mark because as a collective society, the clones have no understanding of his individuality. They barely register emotions much less any ability to express love. It is this time that is most closely parallels the lines

At the still point of the turning world. Neither flesh nor fleshless;
Neither from nor towards; at the still point, there the dance is,
But neither arrest nor movement. (lines 64-66)

Mark wants to be accepted, but he knows he won’t be. He wants to leave but feels he can’t; the clones are all he has. So he is momentarily frozen “at the still point.” Eventually, though, Mark takes to the woods. He finds some books at the old house and begins to teach himself skills the old humans had: science, woodworking, art. As Mark becomes more proficient and more independent, he abandons the collective society of the clones, leaving them to die off as he, embodying time past, figures a way to preserve humanity and moves into the future.