28.7: Patterns of Inheritance
Learning Objectives
- Differentiate between genotype and phenotype
- Describe how alleles determine a person’s traits
- Summarize Mendel’s experiments and relate them to human genetics
- Explain the inheritance of autosomal dominant and recessive and sex-linked genetic disorders
We have discussed the events that lead to the development of a newborn. But what makes each newborn unique? The answer lies, of course, in the DNA in the sperm and oocyte that combined to produce that first diploid cell, the human zygote.
From Genotype to Phenotype
Each human body cell has a full complement of DNA stored in 23 pairs of chromosomes. Figure \(\PageIndex{1}\) shows the pairs in a systematic arrangement called a karyotype . Among these is one pair of chromosomes, called the sex chromosomes , that determines the sex of the individual (XX in females, XY in males). The remaining 22 chromosome pairs are called autosomal chromosomes . Each of these chromosomes carries hundreds or even thousands of genes, each of which codes for the assembly of a particular protein—that is, genes are “expressed” as proteins. An individual’s complete genetic makeup is referred to as his or her genotype . The characteristics that the genes express, whether they are physical, behavioral, or biochemical, are a person’s phenotype .
You inherit one chromosome in each pair—a full complement of 23—from each parent. This occurs when the sperm and oocyte combine at the moment of your conception. Homologous chromosomes—those that make up a complementary pair—have genes for the same characteristics in the same location on the chromosome. Because one copy of a gene, an allele , is inherited from each parent, the alleles in these complementary pairs may vary. Take for example an allele that encodes for dimples. A child may inherit the allele encoding for dimples on the chromosome from the father and the allele that encodes for smooth skin (no dimples) on the chromosome from the mother.
Although a person can have two identical alleles for a single gene (a homozygous state), it is also possible for a person to have two different alleles (a heterozygous state). The two alleles can interact in several different ways. The expression of an allele can be dominant, for which the activity of this gene will mask the expression of a nondominant, or recessive, allele. Sometimes dominance is complete; at other times, it is incomplete. In some cases, both alleles are expressed at the same time in a form of expression known as codominance.
In the simplest scenario, a single pair of genes will determine a single heritable characteristic. However, it is quite common for multiple genes to interact to confer a feature. For instance, eight or more genes—each with their own alleles—determine eye color in humans. Moreover, although any one person can only have two alleles corresponding to a given gene, more than two alleles commonly exist in a population. This phenomenon is called multiple alleles. For example, there are three different alleles that encode ABO blood type; these are designated I A , I B , and i.
Over 100 years of theoretical and experimental genetics studies, and the more recent sequencing and annotation of the human genome, have helped scientists to develop a better understanding of how an individual’s genotype is expressed as their phenotype. This body of knowledge can help scientists and medical professionals to predict, or at least estimate, some of the features that an offspring will inherit by examining the genotypes or phenotypes of the parents. One important application of this knowledge is to identify an individual’s risk for certain heritable genetic disorders. However, most diseases have a multigenic pattern of inheritance and can also be affected by the environment, so examining the genotypes or phenotypes of a person’s parents will provide only limited information about the risk of inheriting a disease. Only for a handful of single-gene disorders can genetic testing allow clinicians to calculate the probability with which a child born to the two parents tested may inherit a specific disease.
Mendel’s Theory of Inheritance
Our contemporary understanding of genetics rests on the work of a nineteenth-century monk. Working in the mid-1800s, long before anyone knew about genes or chromosomes, Gregor Mendel discovered that garden peas transmit their physical characteristics to subsequent generations in a discrete and predictable fashion. When he mated, or crossed, two pure-breeding pea plants that differed by a certain characteristic, the first-generation offspring all looked like one of the parents. For instance, when he crossed tall and dwarf pure-breeding pea plants, all of the offspring were tall. Mendel called tallness dominant because it was expressed in offspring when it was present in a purebred parent. He called dwarfism recessive because it was masked in the offspring if one of the purebred parents possessed the dominant characteristic. Note that tallness and dwarfism are variations on the characteristic of height. Mendel called such a variation a trait . We now know that these traits are the expression of different alleles of the gene encoding height.
Mendel performed thousands of crosses in pea plants with differing traits for a variety of characteristics. And he repeatedly came up with the same results—among the traits he studied, one was always dominant, and the other was always recessive. (Remember, however, that this dominant–recessive relationship between alleles is not always the case; some alleles are codominant, and sometimes dominance is incomplete.)
Using his understanding of dominant and recessive traits, Mendel tested whether a recessive trait could be lost altogether in a pea lineage or whether it would resurface in a later generation. By crossing the second-generation offspring of purebred parents with each other, he showed that the latter was true: recessive traits reappeared in third-generation plants in a ratio of 3:1 (three offspring having the dominant trait and one having the recessive trait). Mendel then proposed that characteristics such as height were determined by heritable “factors” that were transmitted, one from each parent, and inherited in pairs by offspring.
In the language of genetics, Mendel’s theory applied to humans says that if an individual receives two dominant alleles, one from each parent, the individual’s phenotype will express the dominant trait. If an individual receives two recessive alleles, then the recessive trait will be expressed in the phenotype. Individuals who have two identical alleles for a given gene, whether dominant or recessive, are said to be homozygous for that gene (homo- = “same”). Conversely, an individual who has one dominant allele and one recessive allele is said to be heterozygous for that gene (hetero- = “different” or “other”). In this case, the dominant trait will be expressed, and the individual will be phenotypically identical to an individual who possesses two dominant alleles for the trait.
It is common practice in genetics to use capital and lowercase letters to represent dominant and recessive alleles. Using Mendel’s pea plants as an example, if a tall pea plant is homozygous, it will possess two tall alleles ( TT ). A dwarf pea plant must be homozygous because its dwarfism can only be expressed when two recessive alleles are present ( tt ). A heterozygous pea plant ( Tt ) would be tall and phenotypically indistinguishable from a tall homozygous pea plant because of the dominant tall allele. Mendel deduced that a 3:1 ratio of dominant to recessive would be produced by the random segregation of heritable factors (genes) when crossing two heterozygous pea plants. In other words, for any given gene, parents are equally likely to pass down either one of their alleles to their offspring in a haploid gamete, and the result will be expressed in a dominant–recessive pattern if both parents are heterozygous for the trait.
Because of the random segregation of gametes, the laws of chance and probability come into play when predicting the likelihood of a given phenotype. Consider a cross between an individual with two dominant alleles for a trait ( AA ) and an individual with two recessive alleles for the same trait ( aa ). All of the parental gametes from the dominant individual would be A , and all of the parental gametes from the recessive individual would be a (Figure \(\PageIndex{2}\)). All of the offspring of that second generation, inheriting one allele from each parent, would have the genotype Aa , and the probability of expressing the phenotype of the dominant allele would be 4 out of 4, or 100 percent.
This seems simple enough, but the inheritance pattern gets interesting when the second-generation Aa individuals are crossed. In this generation, 50 percent of each parent’s gametes are A and the other 50 percent are a . By Mendel’s principle of random segregation, the possible combinations of gametes that the offspring can receive are AA , Aa , aA (which is the same as Aa ), and aa . Because segregation and fertilization are random, each offspring has a 25 percent chance of receiving any of these combinations. Therefore, if an Aa × Aa cross were performed 1000 times, approximately 250 (25 percent) of the offspring would be AA ; 500 (50 percent) would be Aa (that is, Aa plus aA ); and 250 (25 percent) would be aa . The genotypic ratio for this inheritance pattern is 1:2:1. However, we have already established that AA and Aa (and aA ) individuals all express the dominant trait (i.e., share the same phenotype), and can therefore be combined into one group. The result is Mendel’s third-generation phenotype ratio of 3:1.
Mendel’s observation of pea plants also included many crosses that involved multiple traits, which prompted him to formulate the principle of independent assortment. The law states that the members of one pair of genes (alleles) from a parent will sort independently from other pairs of genes during the formation of gametes. Applied to pea plants, that means that the alleles associated with the different traits of the plant, such as color, height, or seed type, will sort independently of one another. This holds true except when two alleles happen to be located close to one other on the same chromosome. Independent assortment provides for a great degree of diversity in offspring.
Mendelian genetics represent the fundamentals of inheritance, but there are two important qualifiers to consider when applying Mendel’s findings to inheritance studies in humans. First, as we’ve already noted, not all genes are inherited in a dominant–recessive pattern. Although all diploid individuals have two alleles for every gene, allele pairs may interact to create several types of inheritance patterns, including incomplete dominance and codominance.
Secondly, Mendel performed his studies using thousands of pea plants. He was able to identify a 3:1 phenotypic ratio in second-generation offspring because his large sample size overcame the influence of variability resulting from chance. In contrast, no human couple has ever had thousands of children. If we know that a man and woman are both heterozygous for a recessive genetic disorder, we would predict that one in every four of their children would be affected by the disease. In real life, however, the influence of chance could change that ratio significantly. For example, if a man and a woman are both heterozygous for cystic fibrosis, a recessive genetic disorder that is expressed only when the individual has two defective alleles, we would expect one in four of their children to have cystic fibrosis. However, it is entirely possible for them to have seven children, none of whom is affected, or for them to have two children, both of whom are affected. For each individual child, the presence or absence of a single gene disorder depends on which alleles that child inherits from his or her parents.
Autosomal Dominant Inheritance
In the case of cystic fibrosis, the disorder is recessive to the normal phenotype. However, a genetic abnormality may be dominant to the normal phenotype. When the dominant allele is located on one of the 22 pairs of autosomes (non-sex chromosomes), we refer to its inheritance pattern as autosomal dominant . An example of an autosomal dominant disorder is neurofibromatosis type I, a disease that induces tumor formation within the nervous system that leads to skin and skeletal deformities. Consider a couple in which one parent is heterozygous for this disorder (and who therefore has neurofibromatosis), Nn , and one parent is homozygous for the normal gene, nn . The heterozygous parent would have a 50 percent chance of passing the dominant allele for this disorder to his or her offspring, and the homozygous parent would always pass the normal allele. Therefore, four possible offspring genotypes are equally likely to occur: Nn , Nn , nn , and nn . That is, every child of this couple would have a 50 percent chance of inheriting neurofibromatosis. This inheritance pattern is shown in Figure \(\PageIndex{3}\), in a form called a Punnett square , named after its creator, the British geneticist Reginald Punnett.
Other genetic diseases that are inherited in this pattern are achondroplastic dwarfism, Marfan syndrome, and Huntington’s disease. Because autosomal dominant disorders are expressed by the presence of just one gene, an individual with the disorder will know that he or she has at least one faulty gene. The expression of the disease may manifest later in life, after the childbearing years, which is the case in Huntington’s disease (discussed in more detail later in this section).
Autosomal Recessive Inheritance
When a genetic disorder is inherited in an autosomal recessive pattern, the disorder corresponds to the recessive phenotype. Heterozygous individuals will not display symptoms of this disorder, because their unaffected gene will compensate. Such an individual is called a carrier . Carriers for an autosomal recessive disorder may never know their genotype unless they have a child with the disorder.
An example of an autosomal recessive disorder is cystic fibrosis (CF), which we introduced earlier. CF is characterized by the chronic accumulation of a thick, tenacious mucus in the lungs and digestive tract. Decades ago, children with CF rarely lived to adulthood. With advances in medical technology, the average lifespan in developed countries has increased into middle adulthood. CF is a relatively common disorder that occurs in approximately 1 in 2000 Caucasians. A child born to two CF carriers would have a 25 percent chance of inheriting the disease. This is the same 3:1 dominant:recessive ratio that Mendel observed in his pea plants would apply here. The pattern is shown in Figure \(\PageIndex{4}\), using a diagram that tracks the likely incidence of an autosomal recessive disorder on the basis of parental genotypes.
On the other hand, a child born to a CF carrier and someone with two unaffected alleles would have a 0 percent probability of inheriting CF, but would have a 50 percent chance of being a carrier. Other examples of autosome recessive genetic illnesses include the blood disorder sickle-cell anemia, the fatal neurological disorder Tay–Sachs disease, and the metabolic disorder phenylketonuria.
X-linked Dominant or Recessive Inheritance
An X-linked transmission pattern involves genes located on the X chromosome of the 23rd pair (Figure \(\PageIndex{5}\)). Recall that a male has one X and one Y chromosome. When a father transmits a Y chromosome, the child is male, and when he transmits an X chromosome, the child is female.
When an abnormal allele for a gene that occurs on the X chromosome is dominant over the normal allele, the pattern is described as X-linked dominant . This is the case with vitamin D–resistant rickets: an affected father would pass the disease gene to all of his daughters, but none of his sons, because he donates only the Y chromosome to his sons (see Figure28.7.5.a). If it is the mother who is affected, all of her children—male or female—would have a 50 percent chance of inheriting the disorder because she can only pass an X chromosome on to her children (see Figure \(\PageIndex{5}\).b). For an affected female, the inheritance pattern would be identical to that of an autosomal dominant inheritance pattern in which one parent is heterozygous and the other is homozygous for the normal gene.
X-linked recessive inheritance is much more common because females can be carriers of the disease yet still have a normal phenotype. Diseases transmitted by X-linked recessive inheritance include color blindness, the blood-clotting disorder hemophilia, and some forms of muscular dystrophy. For an example of X-linked recessive inheritance, consider parents in which the mother is an unaffected carrier and the father is normal. None of the daughters would have the disease because they receive a normal gene from their father. However, they have a 50 percent chance of receiving the disease gene from their mother and becoming a carrier. In contrast, 50 percent of the sons would be affected (Figure \(\PageIndex{6}\)).
With X-linked recessive diseases, males either have the disease or are genotypically normal—they cannot be carriers. Females, however, can be genotypically normal, a carrier who is phenotypically normal, or affected with the disease. A daughter can inherit the gene for an X-linked recessive illness when her mother is a carrier or affected, or her father is affected. The daughter will be affected by the disease only if she inherits an X-linked recessive gene from both parents. As you can imagine, X-linked recessive disorders affect many more males than females. For example, color blindness affects at least 1 in 20 males, but only about 1 in 400 females.
Other Inheritance Patterns: Incomplete Dominance, Codominance, and Lethal Alleles
Not all genetic disorders are inherited in a dominant–recessive pattern. In incomplete dominance , the offspring express a heterozygous phenotype that is intermediate between one parent’s homozygous dominant trait and the other parent’s homozygous recessive trait. An example of this can be seen in snapdragons when red-flowered plants and white-flowered plants are crossed to produce pink-flowered plants. In humans, incomplete dominance occurs with one of the genes for hair texture. When one parent passes a curly hair allele (the incompletely dominant allele) and the other parent passes a straight-hair allele, the effect on the offspring will be intermediate, resulting in hair that is wavy.
Codominance is characterized by the equal, distinct, and simultaneous expression of both parents’ different alleles. This pattern differs from the intermediate, blended features seen in incomplete dominance. A classic example of codominance in humans is ABO blood type. People are blood type A if they have an allele for an enzyme that facilitates the production of surface antigen A on their erythrocytes. This allele is designated I A . In the same manner, people are blood type B if they express an enzyme for the production of surface antigen B. People who have alleles for both enzymes ( I A and I B ) produce both surface antigens A and B. As a result, they are blood type AB. Because the effect of both alleles (or enzymes) is observed, we say that the I A and I B alleles are codominant. There is also a third allele that determines blood type. This allele ( i ) produces a nonfunctional enzyme.  If a person has I A and i alleles, the person will have blood type A. Notice that it does not make any difference whether a person has two I A alleles or one I A and one i allele. In both cases, the person is blood type A. Because I A masks i , we say that I A is dominant to i . Table \(\PageIndex{1}\) summarizes the expression of blood type.
Table \(\PageIndex{1}\)
| Expression of Blood Types | ||
|---|---|---|
| Blood type | Genotype | Pattern of inheritance |
| A | I A I A or I A i | I A is dominant to i |
| B | I B I B or I B i | I B is dominant to i |
| AB | I A I B | I A is co-dominant to I B |
| O | ii | Two recessive alleles |
Certain combinations of alleles can be lethal, meaning they prevent the individual from developing in utero, or cause a shortened life span. In recessive lethal inheritance patterns, a child who is born to two heterozygous (carrier) parents and who inherited the faulty allele from both would not survive. An example of this is Tay–Sachs, a fatal disorder of the nervous system. In this disorder, parents with one copy of the allele for the disorder are carriers. If they both transmit their abnormal allele, their offspring will develop the disease and will die in childhood, usually before age 5.
Dominant lethal inheritance patterns are much more rare because neither heterozygotes nor homozygotes survive. Of course, dominant lethal alleles that arise naturally through mutation and cause miscarriages or stillbirths are never transmitted to subsequent generations. However, some dominant lethal alleles, such as the allele for Huntington’s disease, cause a shortened life span but may not be identified until after the person reaches reproductive age and has children. Huntington’s disease causes irreversible nerve cell degeneration and death in 100 percent of affected individuals, but it may not be expressed until the individual reaches middle age. In this way, dominant lethal alleles can be maintained in the human population. Individuals with a family history of Huntington’s disease are typically offered genetic counseling, which can help them decide whether or not they wish to be tested for the faulty gene.
Mutations
A mutation is a change in the sequence of DNA nucleotides that may or may not affect a person’s phenotype. Mutations can arise spontaneously from errors during DNA replication, or they can result from environmental insults such as radiation, certain viruses, or exposure to tobacco smoke or other toxic chemicals. Because genes encode for the assembly of proteins, a mutation in the nucleotide sequence of a gene can change amino acid sequence and, consequently, a protein’s structure and function. Spontaneous mutations occurring during meiosis are thought to account for many spontaneous abortions (miscarriages).
Chromosomal Disorders
Sometimes a genetic disease is not caused by a mutation in a gene, but by the presence of an incorrect number of chromosomes. For example, Down syndrome is caused by having three copies of chromosome 21. This is known as trisomy 21. The most common cause of trisomy 21 is chromosomal nondisjunction during meiosis. The frequency of nondisjunction events appears to increase with age, so the frequency of bearing a child with Down syndrome increases in women over 36. The age of the father matters less because nondisjunction is much less likely to occur in a sperm than in an egg.
Whereas Down syndrome is caused by having three copies of a chromosome, Turner syndrome is caused by having just one copy of the X chromosome. This is known as monosomy. The affected child is always female.
CAREER CONNECTIONS
Genetic Counselor
Given the intricate orchestration of gene expression, cell migration, and cell differentiation during prenatal development, it is amazing that the vast majority of newborns are healthy and free of major birth defects. When a woman over 35 is pregnant or intends to become pregnant, or her partner is over 55, or if there is a family history of a genetic disorder, she and her partner may want to speak to a genetic counselor to discuss the likelihood that their child may be affected by a genetic or chromosomal disorder. A genetic counselor can interpret a couple’s family history and estimate the risks to their future offspring.
For many genetic diseases, a DNA test can determine whether a person is a carrier. For instance, carrier status for Fragile X, an X-linked disorder associated with mental retardation, or for cystic fibrosis can be determined with a simple blood draw to obtain DNA for testing. A genetic counselor can educate a couple about the implications of such a test and help them decide whether to undergo testing. For chromosomal disorders, the available testing options include a blood test, amniocentesis (in which amniotic fluid is tested), and chorionic villus sampling (in which tissue from the placenta is tested). Each of these has advantages and drawbacks. A genetic counselor can also help a couple cope with the news that either one or both partners is a carrier of a genetic illness, or that their unborn child has been diagnosed with a chromosomal disorder or other birth defect.
To become a genetic counselor, one needs to complete a 4-year undergraduate program and then obtain a Master of Science in Genetic Counseling from an accredited university. Board certification is attained after passing examinations by the American Board of Genetic Counseling. Genetic counselors are essential professionals in many branches of medicine, but there is a particular demand for preconception and prenatal genetic counselors.
Visit the National Society of Genetic Counselors website for more information about genetic counselors.
Visit the American Board of Genetic Counselors, Inc., website for more information about genetic counselors.
Chapter Review
There are two aspects to a person’s genetic makeup. Their genotype refers to the genetic makeup of the chromosomes found in all their cells and the alleles that are passed down from their parents. Their phenotype is the expression of that genotype, based on the interaction of the paired alleles, as well as how environmental conditions affect that expression.
Working with pea plants, Mendel discovered that the factors that account for different traits in parents are discretely transmitted to offspring in pairs, one from each parent. He articulated the principles of random segregation and independent assortment to account for the inheritance patterns he observed. Mendel’s factors are genes, with differing variants being referred to as alleles and those alleles being dominant or recessive in expression. Each parent passes one allele for every gene on to offspring, and offspring are equally likely to inherit any combination of allele pairs. When Mendel crossed heterozygous individuals, he repeatedly found a 3:1 dominant–recessive ratio. He correctly postulated that the expression of the recessive trait was masked in heterozygotes but would resurface in their offspring in a predictable manner.
Human genetics focuses on identifying different alleles and understanding how they express themselves. Medical researchers are especially interested in the identification of inheritance patterns for genetic disorders, which provides the means to estimate the risk that a given couple’s offspring will inherit a genetic disease or disorder. Patterns of inheritance in humans include autosomal dominance and recessiveness, X-linked dominance and recessiveness, incomplete dominance, codominance, and lethality. A change in the nucleotide sequence of DNA, which may or may not manifest in a phenotype, is called a mutation.
Review Questions
Q. Marfan syndrome is inherited in an autosomal dominant pattern. Which of the following is true?
A. Female offspring are more likely to be carriers of the disease.
B. Male offspring are more likely to inherit the disease.
C. Male and female offspring have the same likelihood of inheriting the disease.
D. Female offspring are more likely to inherit the disease.
Answer: C
Q. In addition to codominance, the ABO blood group antigens are also an example of ________.
A. incomplete dominance
B. X-linked recessive inheritance
C. multiple alleles
D. recessive lethal inheritance
Answer: C
Q. Zoe has cystic fibrosis. Which of the following is the most likely explanation?
A. Zoe probably inherited one faulty allele from her father, who is a carrier, and one normal allele from her mother.
B. Zoe probably inherited one faulty allele from her mother, who must also have cystic fibrosis, and one normal allele from her father.
C. Zoe must have inherited faulty alleles from both parents, both of whom must also have cystic fibrosis.
D. Zoe must have inherited faulty alleles from both parents, both of whom are carriers.
Answer: D
Critical Thinking Questions
Q. Explain why it was essential that Mendel perform his crosses using a large sample size?
A. By using large sample sizes, Mendel minimized the effect of random variability resulting from chance. This allowed him to identify true ratios corresponding to dominant–recessive inheritance.
Q. How can a female carrier of an X-linked recessive disorder have a daughter who is affected?
A. The only way an affected daughter could be born is if the female carrier mated with a male who was affected. In this case, 50 percent of the daughters would be affected. Alternatively, but exceedingly unlikely, the daughter could become affected by a spontaneous mutation.
Glossary
- allele
- alternative forms of a gene that occupy a specific locus on a specific gene
- autosomal chromosome
- in humans, the 22 pairs of chromosomes that are not the sex chromosomes (XX or XY)
- autosomal dominant
- pattern of dominant inheritance that corresponds to a gene on one of the 22 autosomal chromosomes
- autosomal recessive
- pattern of recessive inheritance that corresponds to a gene on one of the 22 autosomal chromosomes
- carrier
- heterozygous individual who does not display symptoms of a recessive genetic disorder but can transmit the disorder to his or her offspring
- codominance
- pattern of inheritance that corresponds to the equal, distinct, and simultaneous expression of two different alleles
- dominant
- describes a trait that is expressed both in homozygous and heterozygous form
- dominant lethal
- inheritance pattern in which individuals with one or two copies of a lethal allele do not survive in utero or have a shortened life span
- genotype
- complete genetic makeup of an individual
- heterozygous
- having two different alleles for a given gene
- homozygous
- having two identical alleles for a given gene
- incomplete dominance
- pattern of inheritance in which a heterozygous genotype expresses a phenotype intermediate between dominant and recessive phenotypes
- karyotype
- systematic arrangement of images of chromosomes into homologous pairs
- mutation
- change in the nucleotide sequence of DNA
- phenotype
- physical or biochemical manifestation of the genotype; expression of the alleles
- Punnett square
- grid used to display all possible combinations of alleles transmitted by parents to offspring and predict the mathematical probability of offspring inheriting a given genotype
- recessive
- describes a trait that is only expressed in homozygous form and is masked in heterozygous form
- recessive lethal
- inheritance pattern in which individuals with two copies of a lethal allele do not survive in utero or have a shortened life span
- sex chromosomes
- pair of chromosomes involved in sex determination; in males, the XY chromosomes; in females, the XX chromosomes
- trait
- variation of an expressed characteristic
- X-linked
- pattern of inheritance in which an allele is carried on the X chromosome of the 23rd pair
- X-linked dominant
- pattern of dominant inheritance that corresponds to a gene on the X chromosome of the 23rd pair
- X-linked recessive
- pattern of recessive inheritance that corresponds to a gene on the X chromosome of the 23rd pair


8.8: Symphonic Poem
We have already explored the interest of early Romantic composers in program music and the application of programmatic principles to traditional genres like the symphony. In this page you’ll read about later Romantic composers’ pursuit of a new structure in which to use instrumental music as a means of depicting a story, picture, or landscape. As you’ll read, composers turned from the symphony to the overture. We have encountered overtures in previous eras. An overture is a prelude to a larger work, usually a staged work such as an opera or ballet, that often previews some of the important melodic themes that will be heard over the course of the work. Overtures from popular operas were often later performed as standalone concert pieces. Audiences enjoyed the musical reminder of the story and production they had previously seen. In time, composers began to write overtures that were not connected to a larger musical work, but rather referred to some other well-known story or scene. The linked article details how this practice evolved into the genre known as the symphonic poem.
Introduction
A symphonic poem or tone poem is a piece of orchestral or concert band music, usually in a single continuous section (a movement) that illustrates or evokes the content of a poem, short story, novel, painting, landscape, or other (non-musical) source. Hungarian composer Franz Liszt first applied the term to his 13 works in this vein. In its aesthetic objectives, the symphonic poem is in some ways related to opera. Whilst it does not use a sung text, it seeks, like opera, a union of music and drama.
While many symphonic poems may compare in size and scale to symphonic movements (or even reach the length of an entire symphony), they are unlike traditional classical symphonic movements, in that their music is intended to inspire listeners to imagine or consider scenes, images, specific ideas or moods, and not to focus on following traditional patterns of musical form (e.g. sonata form). This intention to inspire listeners was a direct consequence of Romanticism, which encouraged literary, pictorial and dramatic associations in music. Musical works that attempt to inspire listeners in this way are often referred to as program music, while music that has no such associations may be called absolute music.
Some piano and chamber works, such as Arnold Schoenberg’s string sextet Verklärte Nacht , have similarities with symphonic poems in their overall intent and effect. However, the term symphonic poem is generally accepted to refer to orchestral works. A symphonic poem may stand on its own, or it can be part of a series combined into a symphonic suite. For example, The Swan of Tuonela (1895) is a tone poem from Jean Sibelius’s Lemminkäinen Suite . A symphonic poem can also be part of a group of interrelated works, such as Vltava ( The Moldau ) as part of the six-work cycle Má vlast by Bedřich Smetana. Also, while the terms “symphonic poem” and “tone poem” have often been used interchangeably, some composers such as Richard Strauss and Jean Sibelius have preferred the latter term for pieces that were less symphonic in design and in which there is no special emphasis on thematic or tonal contrast.
According to Macdonald, the symphonic poem met three 19th century aesthetic goals: it related music to outside sources; it often combined or compressed multiple movements into a single principal section; and it elevated instrumental program music to an aesthetic level that could be regarded as equivalent to, or higher than opera. The symphonic poem remained popular from the 1840s until the 1920s, when the genre suffered a severe decline in popularity.
Background
In the second quarter of the 19th century, the future of the symphonic genre came into doubt. While many composers continued to write symphonies during the 1820s and 30s, “there was a growing sense that these works were aesthetically far inferior to Beethoven’s. . . . The real question was not so much whether symphonies could still be written, but whether the genre could continue to flourish and grow.” Felix Mendelssohn, Robert Schumann and Niels Gade achieved successes with their symphonies, putting at least a temporary stop to the debate as to whether the genre was dead. Nevertheless, composers increasingly turned to the “more compact form” of the concert overture “as a vehicle within which to blend musical, narrative and pictorial ideas.” Examples included Mendelssohn’s overtures A Midsummer Night’s Dream (1826) and The Hebrides (1830).
Between 1845 and 1847, Franco-Belgian composer César Franck wrote an orchestral piece based on Victor Hugo’s poem Ce qu’on entend sur la montagne . The work exhibits characteristics of a symphonic poem, and some musicologists, such as Norman Demuth and Julien Tiersot, consider it the first of its genre, preceding Liszt’s compositions. However, Franck did not publish or perform his piece; neither did he set about defining the genre. Liszt’s determination to explore and promote the symphonic poem gained him recognition as the genre’s inventor.
Liszt
The Hungarian composer Franz Liszt desired to expand single-movement works beyond the concert overture form. The music of overtures is to inspire listeners to imagine scenes, images, or moods; Liszt intended to combine those programmatic qualities with a scale and musical complexity normally reserved for the opening movement of classical symphonies. The opening movement, with its interplay of contrasting themes under sonata form, was normally considered the most important part of the symphony. To achieve his objectives, Liszt needed a more flexible method of developing musical themes than sonata form would allow, but one that would preserve the overall unity of a musical composition.
Contributors and Attributions
- Authored by : Elliott Jones. Provided by : Santa Ana College. Located at : http://www.sac.edu . License : CC BY: Attribution
- Symphonic poem. Provided by : Wikipedia. Located at : http://en.Wikipedia.org/wiki/Symphonic_poem . License : CC BY-SA: Attribution-ShareAlike


15.7: Blood Pressure
By the end of this section, you will be able to:
- Describe correlation in blood pressure readings with severity of hypertension
- Discuss the importance of blood pressure cuff and size
- Identify factors that affect blood pressure
Blood pressure is the pressure exerted by the blood on arterial walls and must be measured to ensure the pressure is adequate to perfuse the body and not too great to rupture the blood vessels. It consists of two numbers, a higher systolic and lower diastolic, and is reported as a fraction with the systolic on top and the diastolic on the bottom. Systole is the pressure of blood during contraction of the left ventricle. Diastole is the pressure of the blood when the ventricles are at rest and filling.
Variations in Blood Pressure
The normal adult blood pressure ranges between 90 to 120 systolic and 60 to 80 diastolic, but it can vary due to medical conditions and age. An elevated blood pressure is known as hypertension and a lowered one is called hypotension . Either of these conditions can lead to serious health consequences. Hypertension increases the pressure placed on the arterial walls leading to complications such as hemorrhagic stroke but also increases the risk of a myriad of health conditions if it occurs with other comorbidities, particularly myocardial infarction , heart failure , cerebrovascular accident , and end-stage renal disease. Hypotension also presents various dangers.  Hypotension is a hallmark characteristic of shock, a life-threatening condition that develops from multiple medical causes.
The presence of hypertension is considered a modifiable risk factor for cardiac and neurological conditions. Because it is often due to lifestyle choices, blood pressure is monitored annually and then more frequently if hypertension begins to develop. As a patient’s trends begin to increase outside of normal ranges, blood pressure is further categorized based on its risk to the individual and the recommended treatments (Table 15.9). An elevated blood pressure requires more frequent monitoring because the risk of hypertension is present. Hypertension is classified as either stage one or the more severe stage two. These classifications can help guide the plan of care for the patient.
| Category | Blood Pressure Reading |
|---|---|
| Normal | 90 to 119/60 to 80 |
| Elevated | 120 to 129 systolic and ≤80 diastolic |
| Stage I hypertension | 130 to 139 systolic or 80 to 89 diastolic |
| Stage II hypertension | ≥140 systolic or ≥90 diastolic |
Blood Pressure Cuff and Size
Blood pressure cuffs are available in a variety of sizes and are meant to wrap around the upper arm. The nurse is responsible for obtaining a proper size cuff for the patient (Figure 15.26). Within the cuff is the inflatable bladder, which, when inflated, impedes the blood flow through the brachial artery . The edges of the cuff will encircle the upper arm and be secured with Velcro to ensure that the cuff does not pop off during inflation of the bladder.
The first step is selecting which arm to use, this can be patient preference or the need to avoid the arm with IVs, lymphedema , fistulas, and so on. The width of the cuff should cover approximately 80 percent of the upper arm from shoulder to elbow, and the bladder within the cuff should encircle about 40 percent of the arm. An improper blood pressure cuff size leads to an inaccurate reading. If a blood pressure cuff is too large, the reading will be lower. If it is too small, the reading will be higher. At times, hypertension has been missed by medical personnel simply due to improper equipment.
The individual’s position can also affect the blood pressure reading. It is important for the nurse to instruct the patient to remain seated with the hand at the level of the heart and feet flat on the floor. Simply crossing the legs or ankles can lead to an inaccurate reading. It is also important to instruct the patient not to talk; to avoid caffeine and smoking thirty minutes prior, if possible; and to try to sit quietly for five minutes before, if possible.
See the competency checklist for Vital Signs: Blood Pressure. You can find the checklists on the Student resources tab of your book page on openstax.org.
Korotkoff Sounds
To place the cuff, the nurse will align the cuff on the patient’s arm, aligning the artery with the artery position indicator label on the cuff. The valve of the inflation bulb should be fully closed, then the nurse will place the diaphragm of the stethoscope over the brachial artery and inflate the cuff by squeezing the bulb. The gauge will inform the nurse of the pressure as the cuff inflates. Once the cuff is inflated to pressures greater than normal ranges and those indicated by the patient’s blood pressure trends, the nurse will begin to slowly deflate the bladder while carefully listening for the return of the pulse. This is done by turning the knob on the valve counterclockwise approximately 2 mm/s while listening and watching the pressure indicated on the gauge. The pulsating, tapping sound heard with a stethoscope as blood flows through the brachial artery is known as a Korotkoff sound . The first Korotkoff sound is the systolic blood pressure reading, and the last Korotkoff sound is the diastolic reading. Once the diastolic number is obtained and there are no more Korotkoff sounds heard, the bladder can be quickly deflated and the cuff removed. Remember that if the blood pressure does not align with the patient’s previous trends, the nurse should recheck in the other arm, recheck with a manual cuff if the reading was taken using an electronic machine, or let the patient rest for five minutes and recheck.
A demonstration of what to listen for when listening for the Korotkoff sounds is presented in this video.
Pulse Pressure
The difference between the systolic and diastolic blood pressure is the pulse pressure , which should normally be about 40 mm Hg. The pulse pressure is directly related to the blood volume, meaning that a decrease in blood volume will cause a decrease in pulse pressure. The pulse pressure is indirectly related to arterial compliance, meaning that inelastic arteries will have a wider pulse pressure. Abnormal pulse pressures are defined as either narrowed or low or widened or high. A narrowed pulse pressure is defined as a pulse pressure less than 25 percent of the systolic blood pressure (i.e., 110/85). A widened pulse pressure is defined as more than 100 mm Hg (i.e., 174/69). In athletes or those with increased muscle mass, a widened pulse pressure may be normal, and as people age, the pulse pressure continues to widen due to the loss of arterial compliance. Widened pulse pressure is a sign of other health conditions such as aortic valve abnormalities (regurgitation or sclerosis), hyperthyroidism, arteriosclerosis, and iron deficiency anemia. In contrast, narrow pulse pressure is present when the ventricles are unable to fully contract. These conditions include heart failure, cardiac tamponade, and aortic stenosis. Blood loss, dysautonomia, and postural orthostatic tachycardia syndrome also cause a narrow pulse pressure.
The risk for heart disease and atrial fibrillation increases in individuals with a widened pulse pressure. Even a 10 mm Hg rise in the pulse pressure can increase the risk of cardiovascular disease by 20 percent. Because of this risk, the pulse pressure should be monitored and kept in a normal range. The only proven way to maintain a healthy pulse pressure is by aerobic exercises, as these increase the arterial elasticity (Homan, 2022).
Auscultatory Gap
When a manual blood pressure is obtained, the nurse listens carefully for the Korotkoff sounds, noting both the origin and the disappearance of these sounds to record as the systolic and diastolic blood pressure measurements. Between the origin and the disappearance of the Korotkoff sounds is the auscultatory gap , a brief absence in the sounds. The auscultatory gap may be confused with the diastolic blood pressure if the nurse does not continue to listen for a few more seconds, leading to an inaccurate measurement. The auscultatory gap can also be missed in individuals with elevated blood pressures if the cuff pressure is not pumped high enough (Rehman, 2022).
Factors Affecting Blood Pressure
Blood pressure is determined by the force of heart contractions, the diameter of the blood vessels, and the amount of circulating blood. If any of these factors are abnormal, blood pressure will be abnormal.
The force of heart contractions will determine the force that blood exerts on the arterial walls. During exercise, the heart will strongly contract, increasing the blood pressure temporarily during the activity. When the heart contractions are weak, blood pressure drops. If the heart is unable to contract and pump blood through the vasculature , it is known as cardiogenic shock . A primary cause of this is heart failure.
Nurse:
Sarah, RN
Clinical setting:
Outpatient clinic
Years in practice:
5
Facility location:
Bedford, New Hampshire
A 35-year-old male comes into the clinic for a routine preventive visit. Because it was the early afternoon, we were not busy and were able to call him back as soon as he arrived. The first thing I do is have him take a seat and apply the blood pressure cuff while I ask him some general questions. To our surprise, the blood pressure began alarming at 144/70. I checked his results from the previous year and noticed normal readings. I verified that his ankles were uncrossed, and the cuff was in the right position. He asked me if that was normal. I asked if he was nervous since white coat syndrome—anxiety in healthcare settings—can temporarily increase blood pressure. He denied any anxiety.
After a recheck with the blood pressure slightly lower but still elevated, we tried to figure out what may have caused it. Perhaps a family history, lifestyle change. Nothing. “I’m running around all the time. I was almost late to this appointment and had to run up the stairs since the elevator wasn’t working.” Then I realized his blood pressure was elevated because he was running up the stairs to make it to his appointment on time.
The diameter of the blood vessels also affects blood pressure. If the diameter increases, the blood pressure decreases. If the diameter decreases, the blood pressure increases. An increase in the diameter of the blood vessel is called vasodilation . A decrease in blood vessel diameter is called vasoconstriction . To illustrate this relationship, consider drinking water through a narrow coffee stirrer versus a wider smoothie straw. It takes more effort or pressure to suck the water through the coffee stirrer than it would through the smoothie straw because of the narrow diameter of the stirrer. The same concept applies to blood vessel diameter and blood pressure. Severe vasodilation, with resultant hypotension, occurs in cases of septic and anaphylactic shock and drug overdoses, such as with opioids and cardiac medications. Severe vasoconstriction, leading to life-threatening hypertension, occurs in cases of cocaine overdose. Vasoconstriction also occurs as a compensatory mechanism in cases of extreme blood loss or cold. The fight-or-flight response, also known as the activation of the sympathetic nervous system, triggers vasoconstriction. In emergency situations, explained further in Table 15.10, blood is shunted from the periphery to the heart, lungs, and brain to provide additional stores to the vital organs for the response, known as shock. Shock is fatal if left untreated. The amount of available blood also affects blood pressure. Even if heart contractility and vasculature are healthy, if blood volume decreases, blood pressure will decrease. This is observed in hypovolemic shock, which occurs with hemorrhage or severe dehydration.
| Types of Shock | Description | Causes |
|---|---|---|
| Cardiogenic | Heart unable to contract efficiently, which decreases the amount of circulating blood | Heart failure, myocardial infarction, arrhythmias, cardiomyopathy, cardiac tamponade |
| Distributive | Systemic vasodilation | Sepsis, anaphylaxis, burns |
| Hypovolemic | Loss of blood volume | Hemorrhage, dehydration |
| Neurogenic | Inability to maintain heart rate and blood pressure | Central nervous system injury (brain or spinal cord) |
A 19-year-old female visits the emergency department complaining of dizziness, vaginal pain and discharge, abdominal pain, nausea, and vomiting. She appears diaphoretic. The nurse obtains a set of vital signs.
- Temperature 103.3°F (39.6°C)
- Pulse 134 bpm
- Respiratory rate 28 breaths per minute
- Blood pressure 86/58 mm Hg
A vaginal specimen is obtained to determine the presence of a sexually transmitted infection. The culture is positive for gonorrhea.
Analyzing this information, the decreased blood pressure, increased pulse, and presence of dizziness would lead to a diagnosis of shock.
After obtaining all the data, the nurse contacts the healthcare provider immediately for further orders and may suspect septic shock from untreated gonorrhea.
Lifestyle factors can instigate the development of hypertension. An unhealthy diet and a sedentary lifestyle can lead to atherosclerosis, plaque buildup in the arteries. This plaque in the arteries decreases the diameter and elasticity of the blood vessels leading to hypertension. Obesity itself will increase the risk of hypertension because the distance that the blood must travel is increased. With this increased distance, the heart must work harder, increasing the blood pressure. A healthy diet and exercise can help maintain a healthy blood pressure.
As previously mentioned, an incorrect cuff size or even patient position could alter the reading and yield an inaccurate result.
It is well documented that those of certain ethnicity or descent are at an increased risk of hypertension. A multitude of hypotheses exist for why this group suffers disproportionately from this condition, such as genetic factors and lifestyle, but perhaps another explanation is relevant. Could healthcare inequality and social determinants of health, particularly finances and access to health care, affect the development of hypertension among ethnicities such as Black, Asian, and Hispanic? Researchers are beginning to ask this same question. Nurses should be aware of social determinants of health that may affect the timely identification and treatment of hypertension, such as unreliable transportation or unfavorable and inaccessible office hours. Noting these social determinants of health during the initial assessment can help provide cues into personalized treatment plans. It is the nurse's responsibility to be patient advocates and nurture equality in health care to help alleviate some of the health burdens placed on at-risk populations (Aggarwal et al., 2021)


15.13: Finding Potential Employees
- Identify methods for finding qualified potential employees.
CareerBuilder’s advice for building an employer brand is equally applicable to getting the word out about a job opportunity—specifically: “be everywhere.” [1] As noted above, job candidates search for jobs essentially the same way they make purchase decisions, managing multiple points of contact including college and company career pages, job boards, and social media sites as well as attending live events. If the possibilities seem overwhelming, use the candidate research you conducted to narrow the options. That is, if you have a clear understanding of who your ideal candidate is—a specific person in mind—you can use that information to inform your choice of touch points.
So how do you find the perfect candidate for a job opening? There are several techniques. Advertising in newspapers and trade publications can be effective. Most recruiters also use online sources to find job candidates. For example, sites such as Indeed, Monster, and CareerBuilder are very popular. Employers can list jobs on these sites and can search through resumes to find potential employees.
Is Facebook, Instagram or Twitter a better means of connecting with potential employees? Pew Research Center social media use data can inform that decision. A few excerpts from their Social Media Use 2018 findings:
- Americans ages 18 to 24 are substantially more likely to use platforms such as Snapchat, Instagram and Twitter even when compared with those in their mid- to late-20s.
- Pinterest remains substantially more popular with women (41 percent of whom say they use the site) than with men (16 percent).
- LinkedIn remains especially popular among college graduates and those in high-income households. Some 50 percent of Americans with a college degree use LinkedIn, compared with just 9 percent of those with a high school diploma or less.
- The messaging service WhatsApp is popular in Latin America, and this popularity also extends to Latinos in the United States—49 percent of Hispanics report that they are WhatsApp users, compared with 14 percent of white Americans and 21 percent of black Americans.
In hiring, you should also consider candidates suggested by existing employees, talk to people who walk in to inquire about jobs, reach out through college recruitment events and job fairs, and contact individuals who have received certification through programs such as Udacity. Another option is to work through recruiters called “Headhunters” who find individuals with the right skills and invite them to apply for a particular position.
In many cases, jobs are opened up to internal candidates before they are advertised to the wider world. When that happens, jobs are advertised through company newsletters and bulletin boards and candidates go to HR to apply for the job.
To that point, employee referrals are one of the best sources of qualified candidates. In Fundamentals of Human Resource Management, the authors state that
“Employee referrals tend to be more acceptable applicants, who are more likely to accept an offer and, once employed, have a higher job survival rate.”
Three caveats to be aware of with regards to employee referrals:
- An employee might mistakenly assume job performance competence based on friendship.
- Employee referrals may lead to nepotism or hiring individuals who are related to persons already employed by the company.
- Employee referrals may reinforce the status quo rather than advance a diversification objective.
- resources.careerbuilder.com/employer-blog/5-best-practices-defining-employment-brand
Contributors and Attributions
- Recruiting and Selecting Qualified Job Applicants. Authored by : Lisa Jo Rud. Provided by : Lumen Learning. Located at : https://courses.lumenlearning.com/wm-principlesofmanagement/chapter/recruiting-and-selecting-qualified-job-applicants/ . License : CC BY: Attribution
- Social media manager want ad. Authored by : geralt. Located at : pixabay.com/en/social-media-manager-ad-job-1958770/. License : CC0: No Rights Reserved


9.4: Preview
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This chapter examines how we, as early childhood professionals, create important relationships with families to build effective home-school relationships. As a professional, we need to include families at the center of the work we do with their children. Valuing the input of families creates a sense of belonging that promotes success in school and home.
I dreamed I stood in a studio
And watched two sculptors there,
The clay they used was a young child's mind
And they fashioned it with care.
One was a teacher; the tools she used were books and music and art;
One was a parent with a guiding hand and a gentle loving heart.
And when at last their work was done
They were proud of what they had wrought.
For the things they had shaped into the child
Could never be sold or bought.
And each agreed she would have failed
If each had worked alone
For behind the parent stood the school,
And behind the teacher; the home.
-Anonymous


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Parentheses (grouping symbols)
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equal
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not equal to
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approximately equal to
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greater than
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greater than or equal to
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less than or equal to
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variable or constant
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negative of \(x\) (opposite of \(x\))
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absolute value of \(x\)
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reciprocal of \(x\)
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ordered pair with component \(a\) and second component \(b\)
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the irrational number pi, often approximated by \(3.14\)
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the principal square root of \(a\)
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the secondary square root of \(a\)
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8: Discussion Questions
Better and worse thinking : a goal of this book is, among other things, to try to help improve the quality of discussion on the topic of abortion.
- What would it look like to think about abortion in better ways? What would it look like to think about abortion in worse ways? What are some examples of each? Who are some people (or arguments) you’ve encountered that represent “better” and “worse” thinking in the ways you’ve described? Where are you and your thinking on these concerns, and how might you improve, if you should?
- What knowledge, skills, and attitudes and anything else are apt to make someone a better thinker on this topic? What are apt to make someone a worse thinker about abortion? Can people gain these attitudes or skills? How?
Knowing others’ views : abortion is a topic where people tend to not know or understand the views of people who they disagree with.
- Why are people often unfamiliar with what other people think about these topics and their reasons?
- If you have views on the topic of abortion, do you know what people with different views from you think and say about that topic? If you told them, “Here is what you think, and here are your reasons for thinking it” would they agree that you understand their view? (Try this, perhaps at home!). If your answer is “no,” is this a problem? Why or why not?
Methods and techniques : the authors suggest that “critical thinking” involves carefully defining words, carefully and fully stating arguments , and thinking about what best explains things, such as some common moral beliefs, to be in a better position to decide whether we should accept some claim or not.
- Are these useful methods? If so, why?
- What other techniques or skills or perspectives are useful for critical thinking, especially about abortion?
- What can be done to encourage the use of these types of methods in thinking?
Definitions : this essay begins by reviewing three definitions of abortion and argues that one definition is best, compared to the others.
- Which definition of abortion do you think is best? Why?
- Later, in the discussion of Judith Thomson and the right to life, the essay presents a fourth definition: is that a good or bad definition?
- Are there other definitions of abortion worth discussing? Are any other definitions good definitions? Are any bad? Why?
Question-begging arguments : this type of arguments involve circular reasoning and assuming the conclusion that the person is trying to argue for. This type of argument is common on all “sides” of the issue, as well as other issues.
- Why are question-begging arguments so common? Why do people give them? Why don’t they realize that these arguments are poor?
- What are some other question-begging arguments given about abortion, beyond those discussed in this essay?
- How can question-begging arguments be avoided?
“Everyday arguments” : this essay reviews many common arguments, given by many people, on the topic, on all sides, and argues that these aren’t good arguments.
- What are some other common arguments (ideally, not question-begging arguments) that often hear about abortion? Are they good or bad arguments? Why?
- If these arguments are indeed bad, why do people keep giving them? What can be done to help people realize this and “move on” to better arguments?
Abortion and religion: people’s views on abortion are sometimes thought of as determined by their religious views.
- Is this true, meaning if you are of some religion, must you accept a certain view about abortion? Or does each major religion usually have some “internal” disagreements on this issue? How do members of these religions explain this disagreement? Are their explanations convincing?
- Are there any problems “linking” the topic of abortion with any particular religious perspectives, morally or legally?
- Are there any benefits in “linking” the topic of abortion with any religious perspectives, morally or legally?
“Philosophers’ arguments” : this essay discusses the main arguments presented by philosophers on the issue. These are the typical arguments addressed in an Introduction to Ethics, Contemporary Moral Problems or even Introduction to Philosophy or Critical Thinking course.
- Which of the arguments that this essay reports that philosophers tend to focus on are familiar to you, and which are unfamiliar, if any?
- Are there any that you don’t think you really understand and have questions about?
- Which seem to be good arguments, and what seem to be bad arguments? Why?
- Are there any other arguments that you think are important but were overlooked? If so, are these arguments good or bad arguments? Why?
“Persons” and “personhood” : many people assume that the question of whether fetuses are persons is the core moral and legal concern about abortion.
- If you asked other people what “persons” are, how would they probably answer? Are their answers good answers?
- What are the strengths to the proposal about what persons are , what the “essence” of personhood is, that is presented in this essay? What are the weaknesses, if any?
- This definition of persons is developed from clear cases of persons or beings that exhibit personhood. Suppose someone says they think embryos and early fetuses clearly are persons and so they will build that into their definition of personhood. Is there any problem with that claim and maneuver? That is, are there any difficulties or challenges in making that claim, if the goal is to determine what, in general , persons are? (Is this claim question-begging? Does this claim help explain why we are persons? Does it help us understand why personified beings exhibit personhood?)
- When, if ever, does someone’s “potential” give them rights to something?
- This is discussed below, but does being a person give you a right to another person’s body, or make it such they must help you, irrespective of the cost to themselves (and what costs are too high, if any?)? In short, how important is fetuses being persons, or not being persons, to the overall debate about abortion?
“Essences” and “kinds” : some argue that us, say readers of this essay, and embryos and fetuses are the same “kind” of being, that we have the same “essence,” essential characteristics or “nature.”
- What is your essence? What qualities or characteristics make you you , and so if these were lost, you would no longer exist? How do you figure this out?
- What, if anything, is the essence of human fetuses? How can you tell? How many answers are there to the question, “What kind of beings are fetuses?”
- Do us and fetuses have the same essence? Are we the same kind of being? Are we also different kinds of beings? Which “kind” of being(s) determines how something or someone should be treated?
 Is this the case for a fetus?
The “right to life” : most people believe they have the right to life, or are otherwise wrong to kill (unless there is a very, very good reason to do so , like an exceptional circumstance that they hope to never be in!).
- If you asked people why they have the right to life, how would they probably answer? Are their answers good answers?
- What are the strengths to the proposal(s) about what the right to life is, and why we have it, are that are presented in this essay? What are the weaknesses, if any?
- When, if ever, would someone have a right to someone else's body? How could they come to have that right? Could someone legitimately give someone else that right? If so, how?
Factual information : this essay provides some brief factual information about fetal development and when and why abortions occur.
- How would the authors’ arguments change if this information is wildly incorrect? For example, what if fetuses become conscious far, far earlier than current evidence suggests they do? What if most abortions happened far, far later than they do?
- What if all abortions were done very early in pregnancy, not just most of them? Would that change the nature of the debate in any ways?
- Suppose someone thought this information was incorrect and the sources unreliable: how could they try to demonstrate this? What are apt to be the most reliable and accurate sources on these factual matters? If sources disagree on these factual matters, how do we try to figure out which is correct?
The law: abortion is both an ethical or moral issue, and a question about what laws we should have, what actions should be criminalized, and what we should allow as a society.
- Some wrong actions are, and should be, illegal. Other wrong actions are not illegal and should not be illegal. When, in general, should actions be illegal and criminalized? When, in general, should an action be legal?
- The authors argue that if later abortions were illegal, that could have bad effects for women who need later abortions for medical reasons. Do you agree? Why or why not? How likely is this potential problem? Do you see any way to make any abortions illegal without having this result?


1.34: When love hurts- caring for patients experiencing interpersonal violence
At the end of this case, students will be able to:
- Define intimate partner violence (IPV), elder abuse, and child abuse
- Estimate the prevalence of IPV, elder abuse, and child abuse in the United States
- Examine the impact IPV has on patients and its ramifications for patient care
- Identify methods to appropriately respond to IPV in a pharmacy setting
Introduction
Interpersonal violence is a prevalent health threat. Intimate partner violence (IPV; also called domestic violence), child abuse, and elder abuse are all forms of interpersonal violence. Because of unique positioning as the most accessible healthcare professionals, pharmacists have a tremendous opportunity, and in some states, a legal obligation, to intervene when they suspect that a patient is a victim of interpersonal violence or abuse.
The Centers for Disease Control and Prevention (CDC) defines IPV as a form of abuse including physical violence, sexual violence, stalking, and psychological aggression (including coercive tactics) by a current or former intimate partner. 1 Approximately 1 in 4 women and 1 in 10 men experience physical violence, sexual violence, and/or stalking by an intimate partner in their lifetime in the United States. 2 IPV has a serious impact on health, including physical injuries and exacerbation of chronic diseases. IPV victims experience anxiety, depression, sleep disturbances, and post-traumatic stress disorder. 3–9 Pregnant victims are at increased risk for preterm delivery and miscarriage. 9 Because of the multiple negative health impacts associated with IPV, victims access the healthcare system repeatedly. They are more often prescribed medications, including increased rates of potentially addictive medications, compared to women not experiencing IPV. 10 Patients experiencing IPV have higher pharmacy costs and greater challenges with medication adherence. 11–14 Contraceptive sabotage and STI-related care-seeking are also more common in patients experiencing IPV. 12,15,16 Pharmacy interactions provide an opportunity to intervene in the cycle of violence. Pharmacists, who are trusted members of the health care team and can be seen without appointments in many community settings, are ideally situated to assist victims. 17,18
Child maltreatment includes both abuse, which can be physical, emotional, or sexual, and neglect. 19 Most states have specific definitions of child maltreatment. Child neglect is the failure to provide for a child’s basic physical, medical, emotional, or educational needs, or failing to appropriately supervise a child. 19 The CDC reports that at least 1 in 7 children experienced child abuse and/or neglect in the past year. 20 Child abuse can have a serious impact on health and increases the risk of future negative health outcomes. 20
Elder abuse can be physical, emotional, sexual, or financial, and includes neglect and abandonment. Elder abuse includes both intentional acts and the failure to act by a caregiver or another person in a relationship involving an expectation of trust that causes or creates serious harm to an older adult. 21 In some states, elder abuse is included in statutes related to abuse of vulnerable individuals, which can include any adult with cognitive or other impairment that hinders their ability to make independent decisions. A US study estimated the one-year prevalence of elder abuse to be 10%. 22 Victims of elder abuse are at increased risk of being placed in a nursing home, being hospitalized, and dying, even after adjusting for existing chronic disease. 23,24
Patients may disclose abuse or pharmacists may suspect a patient is experiencing abuse based on care interactions or medication patterns. Pharmacists must be prepared to care for these patients safely and appropriately, including using the CARD ( C are, A ssess for safety, R efer, D ocument) method when a patient discloses abuse. 25 Furthermore, it is imperative that pharmacists understand what, if any, their legal responsibilities are related to mandatory reporting in their practice setting. While most states make clear that physicians are mandatory reporters, reporting requirements for pharmacists vary widely. A review of pharmacists reporting requirements indicated pharmacists were mandatory reporters of IPV in 10 states, of child abuse in 11, and of elder abuse in 20. 26 More states may include pharmacists as mandatory reporters as they may identify ‘healthcare providers’ as mandatory reporters, but do not specify which types of providers. 26 These requirements change over time, and it is important for pharmacists to keep current with reporting requirements.
Case
You are a pharmacist working in a small community pharmacy in your state, which gives you the opportunity to serve the same patients year after year.
CC: “I had a tooth pulled at the dentist today and it’d be great if you could fill this as fast as possible.”
Patient: LA is a 29-year-old female patient who is well known to you. She presents alone with a prescription for hydrocodone/acetaminophen (Norco).
PMH: Major depressive disorder
Medications:
- Sertraline 50 mg daily
- Ibuprofen PRN for pain
Interaction:
- Pharmacist: “Good morning LA, I will be happy to fill that for you. Just give me a few minutes to pull your profile up in our system.”
- LA : (appears nervous, looking over her shoulder) “Thank you. I really need to hurry back home before my husband gets there for lunch. Will this take long?”
Additional context: LA makes minimal eye contact and appears rushed and nervous. You see in the patient’s profile that she has no health insurance and a history of injury. You note that nine months ago she requested emergency contraception. She was in three months ago with a sprain to the wrist. She purchased a wrist brace at that time. Last month when she refilled her sertraline you noted that she had a black eye, but patient stated that she had fallen. As you prepare to counsel LA about the Norco and the potential interactions with OTC pain relievers, you notice some swelling and redness on her cheek, and she appears to be getting more upset with tears rimming her eyes. You ask her to join you in the counseling area to discuss the new prescription.
Case Questions
- What might lead you to believe LA was exposed to IPV?
- If this patient refuses to come to the counseling area with the excuse that she is in a hurry and she used Norco other times (so there is no need for counseling), what would you do?
- If LA was accompanied by her husband, what would you do?
- What questions would you ask LA once in the counseling area?
- If the patient discloses that she has is experiencing IPV, what should you do?
- Would you refer LA to other providers? If so, please give an example.
- LA discloses that her husband hits, shoves, and threatens her regularly. She tells you that he hit her in the face with a shovel and that caused her to need to have her tooth removed. She told the dentist she had fallen on the shovel to cover up the abuse. Consider the state in which you practice. As a pharmacist are you required to report this incident?
Author Commentary
Interpersonal violence is a prevalent threat to the health and well-being of patients. Exposure to interpersonal violence impacts pharmacy-related behavior and care. Pharmacists are well-positioned to serve as a referral resource for patients experiencing abuse given their accessibility in the community environment. Developing relationships with community agencies and other clinical providers who address violence and abuse are important steps pharmacists can take to be prepared to serve their patients who experience these issues. It is important to realize that victims stay in abusive situations for many reasons, including financial dependence, child custody concerns, and shame. 27
Pharmacists can also be proactive and provide violence-related education and screening initiatives. These efforts normalize discussing violence and can signal that there is no shame in being a victim of violence. Disclosure is rare, but experiencing violence is not. Shifting to a prevention approach can be helpful. Education and screening initiatives are an opportunity for prevention education. This can change the culture that violence is not ‘deserved’ or ‘tolerated’ and signals that there is support and resources available. Hang posters, display brochures/safety cards for related agencies, and wear pins indicating your support for victims. These steps signal to victims that you care and are available to discuss abuse with them.
Patient Approaches and Opportunities
Pharmacists can prepare to respond to patient disclosures by practicing the CARD method: respond with C are, A ssess for safety, R efer patients to local resources, and D ocument as appropriate for the practice setting. Pharmacists may have legal reporting requirements for interpersonal violence and should become aware of the requirements for their practice setting. Check your local requirements and resources for support on how to report interpersonal violence. In addition, pharmacists should identify local referral resources and prepare a practice protocol for abuse disclosures (examples available at the National Health Resource Center on Domestic Violence). The National Domestic Violence Hotline (1-800-799-SAFE[7233]) is a resource that can provide free, confidential help to victims 24 hours a day. Pharmacists can engage in prevention and education efforts by providing screening and educational materials and making patients aware that they are a safe and supportive healthcare provider with whom patients can discuss these issues.
Related chapters of interest:
- Interprofessional collaboration: transforming public health through teamwork
- Saying what you mean doesn’t always mean what you say: cross-cultural communication
- Expanding the pharmacists’ role: assessing mental health and suicide
External resources:
- Futures without Violence. https://www.futureswithoutviolence.org/
- The National Domestic Violence Hotline. https://www.thehotline.org/
- National Health Resource Center on Domestic Violence. https://www.futureswithoutviolence.org/health/national-health-resource-center-on-domestic-violence/
- National Resource Center on Domestic Violence. https://www.nrcdv.org/
- VAWnet. https://vawnet.org/
- IPV Health. https://ipvhealth.org/
- Centers for Disease Control and Prevention. Preventing intimate partner violence. https://www.cdc.gov/violenceprevention/pdf/ipv-technicalpackages.pdf
- Centers for Disease Control and Prevention. Intimate partner violence victimization assessment instruments. https://www.cdc.gov/violenceprevention/pdf/ipv/ipvandsvscreening.pdf
- Centers for Disease Control and Prevention. Intimate partner violence additional resources. https://www.cdc.gov/violenceprevention/intimatepartnerviolence/resources.html
- MedlinePlus. Domestic violence. https://medlineplus.gov/domesticviolence.html
- National Center on Elder Abuse. https://ncea.acl.gov/
- ElderCare Local Resource Locator. https://eldercare.acl.gov/public/resources/topic/Elder_Abuse.aspx
- UC-Irvine Center of Excellence on Elder Abuse and Neglect. http://www.centeronelderabuse.org/resources.asp
- Centers for Disease Control and Prevention. Elder abuse additional resources. https://www.cdc.gov/violenceprevention/elderabuse/resources.html
- ChildHelp. https://www.childhelp.org/story-resource-center/child-abuse-education-prevention-resources/
- Child Welfare Information Gateway. https://www.childwelfare.gov
References
- Breiding MJ, Basile KC, Smith SG, Black MC, Mahendra RR. Intimate partner violence surveillance: uniform definitions and recommended data elements, version 2.0. Center for Disease Control and Prevention, National Center for Injury Prevention and Control; 2015. https://www.cdc.gov/violenceprevention/pdf/ipv/intimatepartnerviolence.pdf . Accessed April 23, 2021.
- Smith S, Zhang X, Basile K, et al. The National Intimate Partner and Sexual Violence Survey: 2015 Data Brief — Updated Release . National Center for Injury Prevention and Control, Center for Disease Control and Prevention; 2018:32.
- Bonomi AE, Anderson ML, Rivara FP, Thompson RS. Health outcomes in women with physical and sexual intimate partner violence exposure. J Womens Health 2007;16(7):987-97.
- Bonomi AE, Thompson RS, Anderson M, et al. Intimate partner violence and women’s physical, mental, and social functioning. Am J Prev Med 2006;30(6):458-66.
- Coker AL, Davis KE, Arias I, et al. Physical and mental health effects of intimate partner violence for men and women. Am J Prev Med 2002;23(4):260-8.
- Coker AL, Hopenhayn C, DeSimone CP, Bush HM, Crofford L. Violence against Women Raises Risk of Cervical Cancer. J Womens Health 2009;18(8):1179-85.
- Stene LE, Jacobsen GW, Dyb G, Tverdal A, Schei B. Intimate partner violence and cardiovascular risk in women: a population-based cohort study. J Womens Health 2013;22(3):250-8.
- Lagdon S, Armour C, Stringer M. Adult experience of mental health outcomes as a result of intimate partner violence victimisation: a systematic review. Eur J Psychotraumatology 2014;5(1).
- McFarlane J. Abuse during pregnancy: the horror and the hope. AWHONNs Clin Issues Perinat Womens Health Nurs 1993;4(3):350-62.
- Stene LE, Dyb G, Tverdal A, Jacobsen GW, Schei B. Intimate partner violence and prescription of potentially addictive drugs: prospective cohort study of women in the Oslo Health Study. BMJ Open 2012;2(2).
- Lopez EJ, Jones DL, Villar-Loubet OM, Arheart KL, Weiss SM. Violence, coping, and consistent medication adherence in HIV-positive couples. AIDS Educ Prev 2010;22(1):61-8.
- Maxwell L, Devries K, Zionts D, Alhusen JL, Campbell J. Estimating the effect of intimate partner violence on women’s use of contraception: a systematic review and meta-analysis. PLoS ONE 2015;10(2).
- Snow Jones A, Dienemann J, Schollenberger J, et al. Long-term costs of intimate partner violence in a sample of female HMO enrollees. Womens Health Issues 2006;16(5):252-61.
- Trimble DD, Nava A, McFarlane J. Intimate partner violence and antiretroviral adherence among women receiving care in an urban Southeastern Texas HIV clinic. J Assoc Nurses AIDS Care 2013;24(4):331-40.
- Decker MR, Miller E, McCauley HL, et al. Recent partner violence and sexual and drug-related STI/HIV risk among adolescent and young adult women attending family planning clinics. Sex Transm Infect 2014;90(2):145-9.
- Grace KT, Anderson JC. Reproductive coercion: a systematic review. Trauma Violence Abuse 2018;19(4):371-90.
- Barnard M, West-Strum D, Holmes E, Yang Y, Swain KA. Community pharmacists’ awareness of intimate partner violence: an exploratory study. Innov Pharm 2013;4(1):article 106.
- Barnard M, West-Strum D, Holmes E, Yang Y, Fisher A. The potential for screening for intimate partner violence in community pharmacies: an exploratory study of female consumers’ perspectives. J Interpers Violence 2018;33(6):960-79.
- Leeb RT, Paulozzi L, Melanson C, Simon T, Arias I. Child maltreatment surveillance: uniform definitions for public health and recommended data elements. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2008. https://www.cdc.gov/violenceprevention/pdf/CM_Surveillance-a.pdf . Accessed January 31, 2021.
- Centers for Disease Control and Prevention. Violence prevention: Preventing child abuse & neglect. Published September 3, 2020. https://www.cdc.gov/violenceprevention/childabuseandneglect/fastfact.html . Accessed January 31, 2021.
- Hall JE, Karch DL, Crosby AE. Elder abuse surveillance: uniform definitions and recommended core data elements for use in elder abuse surveillance. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2016. https://www.cdc.gov/violenceprevention/pdf/EA_Book_Revised_2016.pdf . Accessed January 31, 2021.
- Acierno R, Hernandez MA, Amstadter AB, et al. Prevalence and correlates of emotional, physical, sexual, and financial abuse and potential neglect in the United States: the National Elder Mistreatment Study. Am J Public Health 2010;100(2):292-7.
- Schofield MJ, Powers JR, Loxton D. Mortality and disability outcomes of self-reported elder abuse: a 12-year prospective investigation. J Am Geriatr Soc 2013;61(5):679-85.
- Dong X, Simon MA. Elder abuse as a risk factor for hospitalization in older persons. JAMA Intern Med 2013;173(10):911-7.
- Barnard M, White A, Bouldin A. Preparing pharmacists to care for patients exposed to intimate partner violence. Pharmacy (Basel) 2020;8(2):100.
- Barnard M, Sinha A, Sparkmon WP, Holmes ER. Reporting interpersonal violence and abuse: what pharmacists need to know. J Am Pharm Assoc (2003) 2020;60(6):e195-9.
- National Coalition Against Domestic Violence. Why do victims stay? https://ncadv.org/why-do-victims-stay . Accessed June 1, 2021.


6.4: Introduction
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World War I (“The Great War”) toppled empires, created new nations, and sparked tensions that would explode across future years. On the battlefield, gruesome modern weaponry wrecked an entire generation of young men. The United States entered the conflict in 1917 and was never again the same. The war heralded to the world the United States’ potential as a global military power, and, domestically, it advanced but then beat back American progressivism by unleashing vicious waves of repression. The war simultaneously stoked national pride and fueled disenchantments that burst Progressive Era hopes for the modern world. And it laid the groundwork for a global depression, a second world war, and an entire history of national, religious, and cultural conflict around the globe.


2: Emergency Management Stakeholders
This chapter will introduce the many actors in emergency management and examine some of the problems inherent in dealing with the complex emergency management policy process. The first section will address four basic issues. First, how is a “stakeholder” defined, especially in the context of emergency management? Second, who are the stakeholders emergency managers should be concerned about? Third, at what level in the system and by which different stakeholders are different types of emergency management decisions made? Fourth, how can emergency managers involve these stakeholders in the emergency management process? Last, what types and amounts of power do different stakeholder groups have and how do they influence the emergency management policy process?


12.5: Introduction to current measurements
As you have seen, the placement of meter leads for voltage measurements is straightforward. The leads are simply connected across, or in parallel with, the points of voltage to be measured.
For current measurements, however, the process is slightly more complex. First, the circuit must be opened at the test points and the meter inserted in series at that opening (Figure \(\PageIndex{1}\)). The total current must flow through the meter. To allow the measurement to be made without disturbing the circuit itself, the current meter must have very little internal resistance.
This is where the beginner must be particularly alert. If the meter is inadvertently connected across a P.D. (potential difference) or in parallel with a component instead of in series, the small internal resistance will permit a very large current to flow through the meter. This will most certainly damage the meter severely and perhaps the circuit as well.
With current measurements, shutting off the power before connecting the meter is essential. You will be disconnecting one end of a wire or component in order to connect the meter in series. If you leave the power on, you could easily receive a dangerous shock or do damage to the circuit.
On meters with manual range selection, start with the highest current setting and work your way down.
Current Measurement Procedures
Follow the steps below to measure current:
- Turn off the power to the circuit that will be measured.
- Open the circuit by disconnecting or unsoldering a connection at a point where you wish to measure current.
- Select the DC or AC amps function by turning the function switch to DC or AC amps.
- Plug the test probes into the appropriate probe jacks. Note that the jacks used may not be the same ones used to measure volts.
- Connect the tips of the probes across the break in the circuit as shown in Figure \(\PageIndex{2}\) so that the current to be measured flows through the meter. Note that this is a series connection. Never connect the ammeter in parallel with the source or load, as this will cause a short circuit and damage the meter
- Turn the circuit power back on.
- View the reading on the display unit. Be sure to note the unit of measurement.
- Switch power off and disconnect meter leads from the circuit.
- If testing is finished at this test point, restore the circuit by reclosing the connection. When current measurements are complete, turn the function switch to the OFF position and remove the test leads.
Some types of DMMs have a clamp-on ammeter or tong tester. These ammeters have two springloaded expandable jaws that allow you to clamp around a single conductor (Figure \(\PageIndex{3}\)). This feature allows you to measure the magnetic field created by the current flowing through the wire to give an ampere reading without having to make physical contact or disconnect the circuit.


11.21: Fractional Time Periods
So far, we have dealt only with whole periods and, therefore, whole exponents. True, you may argue that we have also broken whole periods into halves (or other pieces), such as (whole period) half years, so that, for example, an annual rate of 10% compounded / discounted semi-annually became 5% per period; exponents were still whole numbers. But let’s not stop here!
Occasionally, cash flows may occur before the end of a period. Suppose you earn 10% per year, compounded daily. What would be the FV after ¾ of a year?
If we assume a 360-day year 13 , ¾ × 360 = 270 days. (In short-term financial analysis, we often deal with, or otherwise assume, twelve 30-day months to a year.) Further, 10% ÷ 360 = .0002777. Therefore, after 270 days, you will have earned:
$1 (1 + .10/360) 270 =
$1 (1.0002777) 270 = 1.077850
By comparison, if the compounding period is three months or a quarter of a year, then:
1 (1 + .10/4) 3 = 1.0769
If, in fact, the compounding period is a whole year, then we may employ a fractional exponent:
1 (1.10) 3/4 = 1.0741
All of the foregoing choices are arithmetically correct. The compounding convention you use matters. In practice, you will have to know the proper convention commonly used in each situation.
Here are some more examples. Notice that if we calculate the FV of $1 at 10% annually, after half a year we would have arrived at an FV of $1.05 ($1 (1 + .10/ 2) 1 ) – as we may have assumed until now. However, if we use fractional exponents, we get a slightly different result:
$1 (1.10) 1/2 = $1.048809
$1 (1 + .10/2) 1 P ≠ $1 (1.10) 1/2
It is therefore very important to understand the context of the problem and the use of the appropriate compounding/discounting convention.
The Take-away : Compounding assumptions matter. Be sure you use the correct assumptions.