10.12: Alternating Current versus Direct Current
Learning Objectives
- Explain the differences and similarities between AC and DC current.
- Describe rms voltage, current, and average power.
- Explain why AC current is used for power transmission.
Alternating Current
Most of the examples in electric circuits, and particularly those utilizing batteries, have constant voltage sources. Once the current is established, it is thus also a constant. Direct current (DC) is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Many well-known applications, however, use a time-varying voltage source. Alternating current (AC) is the flow of electric charge that periodically reverses direction. If the source varies periodically, particularly sinusoidally, the circuit is known as an alternating current circuit. Examples include the commercial and residential power that serves so many of our needs. Figure \(\PageIndex{1}\) shows graphs of voltage and current versus time for typical DC and AC power. The AC voltages and frequencies commonly used in homes and businesses vary around the world. The AC voltages range from 100 V to 240 V; the frequencies range from 50 Hz to 60 Hz.
Figure \(\PageIndex{2}\) shows a schematic of a simple circuit with an AC voltage source. The voltage between the terminals fluctuates as shown. For this example, the voltage and current are said to be in phase, as seen in Figure \(\PageIndex{1}\)(b).
Current in the resistor alternates back and forth just like the driving voltage, since \(I=V / R\). If the resistor is a fluorescent light bulb, for example, it brightens and dims 120 times per second as the current repeatedly goes through zero. A 120-Hz flicker is too rapid for your eyes to detect, but if you wave your hand back and forth between your face and a fluorescent light, you will see a stroboscopic effect evidencing AC. The fact that the light output fluctuates means that the power is fluctuating. The power supplied is \(P=I V\).
 Do you observe the same thing with the headlights on your car? Explain what you observe. Warning: Do not look directly at very bright light .
We are most often concerned with average power rather than its fluctuations—that 60-W light bulb in your desk lamp has an average power consumption of 60 W, for example. As illustrated in Figure \(\PageIndex{3}\). One common way to express an average is "root-mean-square," or " rms ." For example, rms voltage of an AC voltage source is found by first squaring the voltage ("square"), taking an average of this value over one period of oscillation ("mean"), and taking the square root ("root").
It is standard practice to quote \(I_{\text {rms }}\), \(V_{\text {rms }}\), and \(P_{\text {ave }}\) rather than the peak values. For example, most household electricity is 120 V AC, which means that \(V_{\text {rms }}\) is 120 V. The common 10-A circuit breaker will interrupt a sustained \(I_{\text {rms }}\) greater than 10 A. Your 1.0-kW microwave oven consumes \(P_{\text {ave }}=1.0 \mathrm{~kW}\), and so on. You can think of these rms and average values as the equivalent DC values for a simple resistive circuit.
To summarize, when dealing with AC, Ohm’s law and the equations for power are completely analogous to those for DC, but rms and average values are used for AC. Thus, for AC, Ohm’s law is written
\[I_{\mathrm{rms}}=\frac{V_{\mathrm{rms}}}{R} . \nonumber \]
The various expressions for AC power \(P_{\text {ave }}\) are
\[P_{\text {ave }}=I_{\text {rms }} V_{\text {rms }}, \nonumber \]
\[P_{\mathrm{ave}}=\frac{V_{\mathrm{rms}}^{2}}{R}, \nonumber \]
and
\[P_{\mathrm{ave}}=I_{\mathrm{rms}}^{2} R. \nonumber \]
Why Use AC for Power Distribution?
Most large power-distribution systems are AC. Moreover, the power is transmitted at much higher voltages than the 120-V AC (240 V in most parts of the world) we use in homes and on the job. Economies of scale make it cheaper to build a few very large electric power-generation plants than to build numerous small ones. This necessitates sending power long distances, and it is obviously important that energy losses en route be minimized. High voltages can be transmitted with much smaller power losses than low voltages, as we shall show below. (See Figure \(\PageIndex{4}\).) For safety reasons, the voltage at the user is reduced to familiar values. The crucial factor is that AC voltages can be increased and decreased efficiently with transformers (which uses electromagnetic induction to produce time-varying voltages), while it is more difficult to change DC voltages without power losses. So AC is used in most large power distribution systems.
Example \(\PageIndex{1}\): Power Losses Are Less for High-Voltage Transmission
(a) What current is needed to transmit 100 MW of power at 200 kV? (b) What is the power dissipated by the transmission lines if they have a resistance of \(1.00 ~\Omega\)? (c) What percentage of the power is lost in the transmission lines?
Strategy
We are given \(P_{\text {ave }}=100 ~\mathrm{MW}\), \(V_{\mathrm{rms}}=200 ~\mathrm{kV}\), and the resistance of the lines is \(R=1.00 ~\Omega\). Using these givens, we can find the current flowing (from \(P=I V\)) and then the power dissipated in the lines (\(P=I^{2} R\)), and we take the ratio to the total power transmitted.
Solution
To find the current, we rearrange the relationship \(P_{\text {ave }}=I_{\text {rms }} V_{\text {rms }}\) and substitute known values. This gives
\[I_{\mathrm{rms}}=\frac{P_{\text {ave }}}{V_{\text {rms }}}=\frac{100 \times 10^{6} \mathrm{~W}}{200 \times 10^{3} \mathrm{~V}}=500 \mathrm{~A}. \nonumber\]
Solution
Knowing the current and given the resistance of the lines, the power dissipated in them is found from \(P_{\text {ave }}=I_{\text {rms }}^{2} R\). Substituting the known values gives
\[P_{\text {ave }}=I_{\text {rms }}^{2} R=(500 \mathrm{~A})^{2}(1.00 \Omega)=250 \mathrm{~kW}. \nonumber\]
Solution
The percent loss is the ratio of this lost power to the total or input power, multiplied by 100:
\[\% \text { loss }=\frac{250 \mathrm{~kW}}{100 ~\mathrm{MW}} \times 100=0.250 ~\%. \nonumber\]
Discussion
One-fourth of a percent is an acceptable loss. Note that if 100 MW of power had been transmitted at 25 kV, then a current of 4000 A would have been needed. This would result in a power loss in the lines of 16.0 MW, or 16.0% rather than 0.250%. The lower the voltage, the more current is needed, and the greater the power loss in the fixed-resistance transmission lines. Of course, lower-resistance lines can be built, but this requires larger and more expensive wires. If superconducting lines could be economically produced, there would be no loss in the transmission lines at all. But, as we shall see in a later chapter, there is a limit to current in superconductors, too. In short, high voltages are more economical for transmitting power, and AC voltage is much easier to raise and lower, so that AC is used in most large-scale power distribution systems.
Section Summary
- Ohm’s law for AC is \(I_{\mathrm{rms}}=\frac{V_{\mathrm{rms}}}{R}\).
- Expressions for the average power of an AC circuit are \(P_{\text {ave }}=I_{\text {rms }} V_{\text {rms }}\), \(P_{\text {ave }}=\frac{V_{\text {rms }}{ }^{2}}{R}\), and \(P_{\mathrm{ave}}=I_{\mathrm{rms}}^{2} R\), analogous to the expressions for DC circuits.
Glossary
- direct current
- (DC) the flow of electric charge in only one direction
- alternating current
- (AC) the flow of electric charge that periodically reverses direction
- AC voltage
- voltage that fluctuates sinusoidally with time.
- AC current
- current that fluctuates sinusoidally with time.
- rms
- a type of average taken for a time-varying quantity by squaring it, taking the mean of the square, and then taking the square-root of the mean.


11.4: Cataclysmic Variables
Cataclysmic variables are binary stars, which consist of a white dwarf primary and an orbiting secondary star. The secondary star is transferring matter to the primary star. This causes the primary star to irregularly outburst a significant increase in brightness. Cataclysmic variables were originally called novae (singular: nova) from the Latin term new , since the star seemingly appeared out of nowhere. After the outburst, the cataclysmic variable will eventually dim back down significantly until more stellar fuel is transferred from the secondary star to the primary star. This process will go on until there is no more stellar fuel to transfer.
The primary star (upper right) is pulling stellar material off the secondary star (lower left). Once a significant amount of mass builds up on the primary star, it will outburst and brighten significantly. Then the star will dim back down, repeating the process as long as fuel is available from its secondary star.


3.10: Christmas Carols
In this chapter you will
- learn about the music associated with the Christian celebration of Christmas, the holiday commemorating the birth of Jesus
- consider how traditions of biblical interpretation and the popularity of these songs have influenced one another and continue to do so
Christmas carols are songs of a religious character associated with the celebration of the Christian holiday of Christmas, which focuses on the birth of Jesus. This holiday is celebrated on December 25 by Roman Catholics and thus also by Protestants, since Protestantism emerged from Catholicism. Eastern Orthodox churches celebrate the holiday on January 7 . Neither date is indicated in the Bible, and the difference reflects a historical use of two different calendars, Gregorian and Julian. Many churches also consider the weeks before Christmas the season of Advent. Historically, Western churches also recognize twelve days of Christmas, beginning on Christmas and ending with Epiphany on January 6, which focuses on the arrival of the magi. Christmas carols provide another opportunity not only to consider the connection between music and the celebration of holidays but also to see how music influences people’s interpretation of the text. Song lyrics of course reflect the interpretation of their author, but they may in turn communicate that interpretation to others. For example, the very idea that Jesus was actually born on December 25 (rather than this being a date chosen by Christians to celebrate the event) is communicated and reinforced by the many songs that say “Christ was born today” or something similar. In the same way, songs like “Away in a Manger” (with its line “the little Lord Jesus no crying he makes”) and “Silent Night” convey the impression of the birth being a serene and reverent event, which is not typically the case when it comes to human childbirth and is not supported by anything in the Bible.
Christmas carols continue to be written, even as many favorites of the past continue to be familiar and are sometimes given new arrangements and adaptations. Most of the carols that continue to be heard and sung regularly are from the eighteenth and nineteenth centuries. One of the oldest that is still very familiar is “While Shepherds Watched Their Flocks,” which dates from 1700. Jeremy Dibble, a professor of Musicology at Durham University , discovered while doing research on the history of hymns that “‘While shepherds watched’ was the first carol to cross over from secular traditions to the church. It was the only Christmas hymn to be approved by the Church of England in the eighteenth century and this allowed it to be disseminated across the country with the Book of Common Prayer. Only at the end of the eighteenth century was it joined by other well-known texts such as ‘Hark the herald angels sing.’” [1] The lyrics by Nahum Tate stick closely to the narrative in Luke chapter 2 , and this is probably one reason it was quickly accepted for use in church. The words have been sung to a number of melodies, including some written specifically for that purpose, including famously by George Frideric Handel .
The carol “Adam Lay Ybounden” is from about three centuries earlier than “While Shepherds Watched Their Flocks.” As a result, the English lyrics require translation to be understood today even by a native English speaker, since the language has changed and evolved over the past six hundred years, just as musical language has. Its reference to Adam having eaten an apple reflects a long-standing tradition about the type of fruit produced by the tree of knowledge in the Garden of Eden, whereas Genesis doesn’t specify this. The idea of Mary becoming heaven’s queen is likewise postbiblical. The song’s overall conclusion that it was a good thing that the forbidden fruit was taken because of what ultimately resulted will surprise many modern listeners. Here is John Rutter, whose work as a composer was the focus of the previous chapter, conducting the Cambridge Singers. [2]
“The First Noel” combines the shepherds tending their sheep from the Gospel of Luke with the wise men and the star from the Gospel of Matthew. This is common in Christmas pageants as well as music, but it obscures the fact that significant differences exist between the two accounts. They are, at the very least, set at different times in the childhood of Jesus, and a careful look at the details, such as the geographical movements of the family, suggests they may be impossible to harmonize. Musical treatments, on the other hand, make doing so appear quite simple. The song also states that there were three wise men, another detail not actually found in the Bible. In order to convey a more culturally appropriate sense of the story in Luke’s Gospel, New Testament scholar Kenneth Bailey created a Christmas drama called Open Hearts in Bethlehem . In all these examples, you can see how Christmas carols spread and perpetuate frameworks of interpretation that impact how stories in the Bible are perceived and understood by those who read them at any point during the year, not merely at Christmas.
For Further Reading
Bailey, Kenneth. “The Manger and the Inn: A Middle Eastern View of the Birth Story of Jesus.” Presbyterian Outlook, December 21, 2006, https://pres-outlook.org/2006/12/the-manger-and-the-inn-a-middle-eastern-view-of-the-birth-story-of-jesus/ .
———. “The Manger and the Inn: The Cultural Background of Luke 2:7.” Theological Review of the Near East School of Theology 2, no. 2 (1979): 33–44.
Larsen, Timothy, ed. The Oxford Handbook of Christmas . New York: Oxford University Press, 2020.
Whiteley, Sheila, ed. Christmas, Ideology and Popular Culture . Edinburgh: Edinburgh University Press, 2008.
- Jeremy Dibble, quoted in “While Shepherds Watched Their Flocks on ‘Ilkley Moor,’” Durham University News, December 15, 2009, https://www.dur.ac.uk/news/newsitem/?itemno=9179#:~:text=Prof Dibble said: “'While,the Book of Common Prayer . ↵
- Performance by John Rutter and the Cambridge Singers of Boris Ord’s arrangement of “Adam Lay Ybounden.” Shared by John Rutter and the Cambridge Singers on their own YouTube channel. ↵


10.3B: Disease Development
- Outline the stages of disease: incubation, prodromal, acute and convalescence periods
Stages of Disease
After an infectious agent invades a host (patient), it undergoes a series of phases (stages) that will eventually lead to its multiplication and release from the host.
STAGE 1: INCUBATION PERIOD
This refers to the time elapsed between exposure to a pathogenic organism, and from when symptoms and signs are first apparent. It may be as short as minutes to as long as thirty years in the case of variant Creutzfeldt–Jakob disease. While the term latency period is used as synonymous, a distinction is sometimes made between incubation period, the period between infection and clinical onset of the disease, and latent period, the time from infection to infectiousness. Whichever is shorter depends on the disease.
A person may be a carrier of a disease, such as Streptococcus in the throat, without exhibiting any symptoms. Depending on the disease, the person may or may not be contagious during the incubation period. During clinical latency, an infection is subclinical. With respect to viral infections, in clinical latency the virus is actively replicating. This is in contrast to viral latency, a form of dormancy in which the virus does not replicate.
STAGE 2: PRODROMAL PERIOD
In this phase, the numbers of the infectious agents start increasing and the immune system starts reacting to them. It is characterized by early symptoms that might indicate the start of a disease before specific symptoms occur. Prodromes may be non-specific symptoms or, in a few instances, may clearly indicate a particular disease. For example fever, malaise, headache and lack of appetite frequently occur in the prodrome of many infective disorders. It also refers to the initial in vivo round of viral replication.
STAGE 3: ACUTE PERIOD
This stage is characterized by active replication or multiplication of the pathogen and its numbers peak exponentially, quite often in a very short period of time. Symptoms are very pronounced, both specific to the organ affected as well as in general due to the strong reaction of the immune system.
Viral infections present with systemic symptoms. This means they involve many different parts of the body or more than one body system at the same time; i.e. a runny nose, sinus congestion, cough, body aches, etc. They can be local at times as in viral conjunctivitis or “pink eye” and herpes. Only a few viral infections are painful, like herpes. The pain of viral infections is often described as itchy or burning.
The classic symptoms of a bacterial infection are localized redness, heat, swelling and pain. One of the hallmarks of a bacterial infection is local pain, pain that is in a specific part of the body. For example, if a cut occurs and is infected with bacteria, pain occurs at the site of the infection. Bacterial throat pain is often characterized by more pain on one side of the throat. An ear infection is more likely to be diagnosed as bacterial if the pain occurs in only one ear.
After the pathogen reaches its peak in newly-produced cells or particles (for viruses), the numbers begin to fall sharply. Symptoms are still present but they are not as strong as in the acute illness phase.
STAGE 4: CONVALESCENCE PERIOD
The patient recovers gradually and returns to normal, but may continue to be a source of infection even if feeling better. In this sense, “recovery” can be considered a synonymous term.
Key Points
- The first phase is characterized by complete lack or very few symptoms.
- As the pathogen starts to reproduce actively, the symptoms intensify. Bacterial and viral infections can both cause the same kinds of symptoms but there are some differences too.
- The last phases are characterized by decline in symptoms severity until their disappearance. However, even if the patients recover and return to normal, they may continue to be a source of infection.
Key Terms
- subclinical : Of a disease or injury, without signs and symptoms that are detectable by physical examination or laboratory test; not clinically manifest.
- clinical latency : The period for which an infection is subclinical.
- viral latency : A form of viral dormancy in which the virus does not replicate at all.


1.4: Naming Right Triangle Sides
What is this big fancy word, trigonometry?
Trigonometry is the study of the relationship that exists between the sides and the angles of a triangle.
That sounds complicated and scary.
It can be, but lucky for us we are only dealing with right triangles. This makes it very simple and almost fun. (Nerd alert!)
First steps
We have already learned how to determine the sides of a triangle using the Pythagoras’ theorem. Next up is using those sides to determine the angles. Lucky for us we know that in a right triangle we already have one 90-degree angle. We also know that if we can solve any of the other two angles, the third one is easy. (All triangles have 180 degrees.) Our next step is to name the sides of the triangle. The names of these sides are dependent on something called the designate angle or theta . Theta is an angle that you determine or is determined for you.
Now once you have figured out which angle is your theta, we can get to business naming the sides.
Adjacent . This is the side that sits adjacent to the designate angle.
Opposite . This is the side that sits opposite to the designate angle.
Hypotenuse. This is the side that sits opposite the 90-degree angle.
The hypotenuse is always the longest side of the triangle and doesn’t care where the designate angle is. It only cares that it is opposite the 90-degree angle.
And if we switch the designate angle, the names of the sides change as in Figure 19.
The next chapter tells us what to do with these names.


17.4A: Predicting Disease Risk at the Individual Level
- Explain how analysis of an individual’s genome can aid in predicting disease risk
Predicting Disease Risk at the Individual Level
The introduction of DNA sequencing and whole genome sequencing projects, particularly the Human Genome project, has expanded the applicability of DNA sequence information. Genomics is now being used in a wide variety of fields, such as metagenomics, pharmacogenomics, and mitochondrial genomics. The most commonly-known application of genomics is to understand and find cures for diseases.
Predicting the risk of disease involves screening currently-healthy individuals by genome analysis at the individual level. Intervention with lifestyle changes and drugs can be recommended before disease onset. However, this approach is most applicable when the problem resides within a single gene defect. Such defects only account for approximately five percent of diseases in developed countries. Most of the common diseases, such as heart disease, are multi-factored or polygenic, which is a phenotypic characteristic that involves two or more genes interacting with environmental factors such as diet. In April 2010, scientists at Stanford University published the genome analysis of a healthy individual (Stephen Quake, a scientist at Stanford University, who had his genome sequenced); the analysis predicted his propensity to acquire various diseases. A risk assessment was performed to analyze Quake’s percentage of risk for 55 different medical conditions. A rare genetic mutation was found, which showed him to be at risk for sudden heart attack. He was also predicted to have a 23 percent risk of developing prostate cancer and a 1.4 percent risk of developing Alzheimer’s. The scientists used databases and several publications to analyze the genomic data. Even though genomic sequencing is becoming more affordable and analytical tools are becoming more reliable, ethical issues surrounding genomic analysis at a population level remain to be addressed.
In 2011, the United States Preventative Services Task Force recommended against using the PSA test to screen healthy men for prostate cancer. Their recommendation was based on evidence that screening does not reduce the risk of death from prostate cancer. Prostate cancer often develops very slowly and does not cause problems, while the cancer treatment can have severe side effects. The PCA3 test is considered to be more accurate, but screening may still result in men suffering side effects from treatment who would not have been harmed by the cancer itself.
Key Points
- Genome sequencing can predict the risk of developing diseases brought on by a single gene defect, but these defects only account for five percent of common diseases.
- Most diseases are polygenic or are brought on by environmental factors; genome sequencing cannot predict the risk of acquiring these diseases.
- Genome sequencing is becoming more reliable, but many scientists still question if it reduces the risk of death from certain diseases such as prostate cancer.
Key Terms
- Human Genome Project : an organized international scientific endeavor to determine the complete structure of human genetic material (DNA) to identify all the genes and understand their function
- genome sequencing : a laboratory process that determines the complete DNA sequence of an organism’s genome at a single time
- polygenic : a phenotypic characteristic controlled by the interaction of two or more genes with the environment


21.7: Darwin's Critics
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Although the theory of evolution initially generated some controversy, by 20 years after the publication of On the Origin of Species it was almost universally accepted by biologists, particularly younger biologists. Nevertheless, the theory of evolution is a difficult concept and misconceptions about how it works abound. In addition, there are those that reject it as an explanation for the diversity of life.
CONCEPT IN ACTION
This website addresses some of the main misconceptions associated with the theory of evolution.
Evolution Is Just a Theory
Critics of the theory of evolution dismiss its importance by purposefully confounding the everyday usage of the word “theory” with the way scientists use the word. In science, a “theory” is understood to be a concept that has been extensively tested and supported over time. We have a theory of the atom, a theory of gravity, and the theory of relativity, each of which describes what scientists understand to be facts about the world. In the same way, the theory of evolution describes facts about the living world. As such, a theory in science has survived significant efforts to discredit it by scientists, who are naturally skeptical. While theories can sometimes be overturned or revised, this does not lessen their weight but simply reflects the constantly evolving state of scientific knowledge. In contrast, a “theory” in common vernacular means a guess or suggested explanation for something. This meaning is more akin to the concept of a “hypothesis” used by scientists, which is a tentative explanation for something that is proposed to either be supported or disproved. When critics of evolution say evolution is “just a theory,” they are implying that there is little evidence supporting it and that it is still in the process of being rigorously tested. This is a mischaracterization. If this were the case, geneticist Theodosius Dobzhansky would not have said that “nothing in biology makes sense, except in the light of evolution.” 1
Individuals Evolve
An individual is born with the genes it has—these do not change as the individual ages. Therefore, an individual cannot evolve or adapt through natural selection. Evolution is the change in genetic composition of a population over time, specifically over generations, resulting from differential reproduction of individuals with certain alleles. Individuals do change over their lifetime, but this is called development; it involves changes programmed by the set of genes the individual acquired at birth in coordination with the individual’s environment. When thinking about the evolution of a characteristic, it is probably best to think about the change of the average value of the characteristic in the population over time. For example, when natural selection leads to bill-size change in medium ground finches in the Galápagos, this does not mean that individual bills on the finches are changing. If one measures the average bill size among all individuals in the population at one time, and then measures the average bill size in the population several years later after there has been a strong selective pressure, this average value may be different as a result of evolution. Although some individuals may survive from the first time to the second, those individuals will still have the same bill size. However, there may be enough new individuals with different bill sizes to change the average bill size.
Evolution Explains the Origin of Life
It is a common misunderstanding that evolution includes an explanation of life’s origins. Conversely, some of the theory’s critics complain that it cannot explain the origin of life. The theory does not try to explain the origin of life. The theory of evolution explains how populations change over time and how life diversifies—the origin of species. It does not shed light on the beginnings of life including the origins of the first cells, which is how life is defined. The mechanisms of the origin of life on Earth are a particularly difficult problem because it occurred a very long time ago, over a very long time, and presumably just occurred once. Importantly, biologists believe that the presence of life on Earth precludes the possibility that the events that led to life on Earth can be repeated because the intermediate stages would immediately become food for existing living things. The early stages of life included the formation of organic molecules such as carbohydrates, amino acids, or nucleotides. If these were formed from inorganic precursors today, they would simply be broken down by living things. The early stages of life also probably included more complex aggregations of molecules into enclosed structures with an internal environment, a boundary layer of some form, and the external environment. Such structures, if they were formed now, would be quickly consumed or broken down by living organisms.
However, once a mechanism of inheritance was in place in the form of a molecule like DNA or RNA, either within a cell or within a pre-cell, these entities would be subject to the principle of natural selection. More effective reproducers would increase in frequency at the expense of inefficient reproducers. So while evolution does not explain the origin of life, it may have something to say about some of the processes operating once pre-living entities acquired certain properties.
Organisms Evolve on Purpose
Statements such as “organisms evolve in response to a change in an environment,” are quite common. There are two easy misunderstandings possible with such a statement. First of all, the statement must not be understood to mean that individual organisms evolve, as was discussed above. The statement is shorthand for “a population evolves in response to a changing environment.” However, a second misunderstanding may arise by interpreting the statement to mean that the evolution is somehow intentional. A changed environment results in some individuals in the population, those with particular phenotypes, benefiting and, therefore, producing proportionately more offspring than other phenotypes. This results in change in the population if the characters are genetically determined.
It is also important to understand that the variation that natural selection works on is already in a population and does not arise in response to an environmental change. For example, applying antibiotics to a population of bacteria will, over time, select for a population of bacteria that are resistant to antibiotics. The resistance, which is caused by a gene, did not arise by mutation because of the application of the antibiotic. The gene for resistance was already present in the gene pool of the bacteria, likely at a low frequency. The antibiotic, which kills the bacterial cells without the resistance gene, strongly selects for individuals that are resistant, since these would be the only ones that survived and divided. Experiments have demonstrated that mutations for antibiotic resistance do not arise as a result of antibiotic application.
In a larger sense, evolution is also not goal directed. Species do not become “better” over time; they simply track their changing environment with adaptations that maximize their reproduction in a particular environment at a particular time. Evolution has no goal of making faster, bigger, more complex, or even smarter species. This kind of language is common in popular literature. Certain organisms, ourselves included, are described as the “pinnacle” of evolution, or “perfected” by evolution. What characteristics evolve in a species are a function of the variation present and the environment, both of which are constantly changing in a non-directional way. What trait is fit in one environment at one time may well be fatal at some point in the future. This holds equally well for a species of insect as it does the human species.
Evolution Is Controversial among Scientists
The theory of evolution was controversial when it was first proposed in 1859, yet within 20 years virtually every working biologist had accepted evolution as the explanation for the diversity of life. The rate of acceptance was extraordinarily rapid, partly because Darwin had amassed an impressive body of evidence. The early controversies involved both scientific arguments against the theory and the arguments of religious leaders. It was the arguments of the biologists that were resolved after a short time, while the arguments of religious leaders have persisted to this day.
The theory of evolution replaced the predominant theory at the time that species had all been specially created within relatively recent history. Despite the prevalence of this theory, it was becoming increasingly clear to naturalists during the nineteenth century that it could no longer explain many observations of geology and the living world. The persuasiveness of the theory of evolution to these naturalists lay in its ability to explain these phenomena, and it continues to hold extraordinary explanatory power to this day. Its continued rejection by some religious leaders results from its replacement of special creation, a tenet of their religious belief. These leaders cannot accept the replacement of special creation by a mechanistic process that excludes the actions of a deity as an explanation for the diversity of life including the origins of the human species. It should be noted, however, that most of the major denominations in the United States have statements supporting the acceptance of evidence for evolution as compatible with their theologies.
The nature of the arguments against evolution by religious leaders has evolved over time. One current argument is that the theory is still controversial among biologists. This claim is simply not true. The number of working scientists who reject the theory of evolution, or question its validity and say so, is small. A Pew Research poll in 2009 found that 97 percent of the 2500 scientists polled believe species evolve. 2 The support for the theory is reflected in signed statements from many scientific societies such as the American Association for the Advancement of Science, which includes working scientists as members. Many of the scientists that reject or question the theory of evolution are non-biologists, such as engineers, physicians, and chemists. There are no experimental results or research programs that contradict the theory. There are no papers published in peer-reviewed scientific journals that appear to refute the theory. The latter observation might be considered a consequence of suppression of dissent, but it must be remembered that scientists are skeptics and that there is a long history of published reports that challenged scientific orthodoxy in unpopular ways. Examples include the endosymbiotic theory of eukaryotic origins, the theory of group selection, the microbial cause of stomach ulcers, the asteroid-impact theory of the Cretaceous extinction, and the theory of plate tectonics. Research with evidence and ideas with scientific merit are considered by the scientific community. Research that does not meet these standards is rejected.
Other Theories Should Be Taught
A common argument from some religious leaders is that alternative theories to evolution should be taught in public schools. Critics of evolution use this strategy to create uncertainty about the validity of the theory without offering actual evidence. In fact, there are no viable alternative scientific theories to evolution. The last such theory, proposed by Lamarck in the nineteenth century, was replaced by the theory of natural selection. A single exception was a research program in the Soviet Union based on Lamarck’s theory during the early twentieth century that set that country’s agricultural research back decades. Special creation is not a viable alternative scientific theory because it is not a scientific theory, since it relies on an untestable explanation. Intelligent design, despite the claims of its proponents, is also not a scientific explanation. This is because intelligent design posits the existence of an unknown designer of living organisms and their systems. Whether the designer is unknown or supernatural, it is a cause that cannot be measured; therefore, it is not a scientific explanation. There are two reasons not to teach nonscientific theories. First, these explanations for the diversity of life lack scientific usefulness because they do not, and cannot, give rise to research programs that promote our understanding of the natural world. Experiments cannot test non-material explanations for natural phenomena. For this reason, teaching these explanations as science in public schools is not in the public interest. Second, in the United States, it is illegal to teach them as science because the U.S. Supreme Court and lower courts have ruled that the teaching of religious belief, such as special creation or intelligent design, violates the establishment clause of the First Amendment of the U.S. Constitution, which prohibits government sponsorship of a particular religion.
The theory of evolution and science in general is, by definition, silent on the existence or non-existence of the spiritual world. Science is only able to study and know the material world. Individual biologists have sometimes been vocal atheists, but it is equally true that there are many deeply religious biologists. Nothing in biology precludes the existence of a god, indeed biology as a science has nothing to say about it. The individual biologist is free to reconcile her or his personal and scientific knowledge as they see fit. The Voices for Evolution project ( http://ncse.com/voices ), developed through the National Center for Science Education, works to gather the diversity of perspectives on evolution to advocate it being taught in public schools.
Section Summary
The theory of evolution is a difficult concept and misconceptions abound. The factual nature of evolution is often challenged by wrongly associating the scientific meaning of a theory with the vernacular meaning. Evolution is sometimes mistakenly interpreted to mean that individuals evolve, when in fact only populations can evolve as their gene frequencies change over time. Evolution is often assumed to explain the origin of life, which it does not speak to. It is often spoken in goal-directed terms by which organisms change through intention, and selection operates on mutations present in a population that have not arisen in response to a particular environmental stress. Evolution is often characterized as being controversial among scientists; however, it is accepted by the vast majority of working scientists. Critics of evolution often argue that alternative theories to evolution should be taught in public schools; however, there are no viable alternative scientific theories to evolution. The alternative religious beliefs should not be taught as science because it cannot be proven, and in the United States it is unconstitutional. Science is silent on the question of the existence of a god while scientists are able to reconcile religious belief and scientific knowledge.
Contributors and Attributions
-
Samantha Fowler (Clayton State University), Rebecca Roush (Sandhills Community College), James Wise (Hampton University). Original content by OpenStax (CC BY 4.0; Access for free at https://cnx.org/contents/b3c1e1d2-83...4-e119a8aafbdd ).


1.2.5: Orders
Many of our comparisons involve describing some objects as being “less than”, “equal to”, or “greater than” other objects, in a certain respect. These involve order relations. But there are different kinds of order relations. For instance, some require that any two objects be comparable, others don’t. Some include identity (like \(\le\) ) and some exclude it (like \(<\) ). It will help us to have a taxonomy here.
A relation which is both reflexive and transitive is called a preorder.
A preorder which is also anti-symmetric is called a partial order .
A partial order which is also connected is called a total order or linear order.
Every linear order is also a partial order, and every partial order is also a preorder, but the converses don’t hold.
Every linear order is also a partial order, and every partial order is also a preorder, but the converses don’t hold. The universal relation on \(A\) is a preorder, since it is reflexive and transitive. But, if \(A\) has more than one element, the universal relation is not anti-symmetric, and so not a partial order.
Consider the no longer than relation \(\preccurlyeq\) on \(\Bin^*\) : \(x \preccurlyeq y\) iff \(\len{x} \le \len{y}\) . This is a preorder (reflexive and transitive), and even connected, but not a partial order, since it is not anti-symmetric. For instance, \(01 \preccurlyeq 10\) and \(10 \preccurlyeq 01\) , but \(01 \neq 10\) .
An important partial order is the relation \(\subseteq\) on a set of sets. This is not in general a linear order, since if \(a \neq b\) and we consider \(\Pow{\{a, b\}} = \{\emptyset, \{a\}, \{b\}, \{a,b\}\}\) , we see that \(\{a\} \nsubseteq \{b\}\) and \(\{a\} \neq \{b\}\) and \(\{b\} \nsubseteq \{a\}\) .
The relation of divisibility without remainder gives us a partial order which isn’t a linear order. For integers \(n\) , \(m\) , we write \(n\mid m\) to mean \(n\) (evenly) divides \(m\) , i.e., iff there is some integer \(k\) so that \(m=kn\) . On \(\Nat\) , this is a partial order, but not a linear order: for instance, \(2\nmid3\) and also \(3\nmid2\) . Considered as a relation on \(\Int\) , divisibility is only a preorder since it is not anti-symmetric: \(1\mid-1\) and \(-1\mid1\) but \(1\neq-1\) .
A strict order is a relation which is irreflexive, asymmetric, and transitive.
A strict order which is also connected is called a strict linear order.
\(\le\) is the linear order corresponding to the strict linear order \(<\) . \(\subseteq\) is the partial order corresponding to the strict order \(\subsetneq\) .
A strict order which is also connected is called a total order . This is also sometimes called a strict linear order .
Any strict order \(R\) on \(A\) can be turned into a partial order by adding the diagonal \(\Id{A}\) , i.e., adding all the pairs \(\tuple{x, x}\) . (This is called the reflexive closure of \(R\) .) Conversely, starting from a partial order, one can get a strict order by removing \(\Id{A}\) . These next two results make this precise.
If \(R\) is a strict order on \(A\) , then \(R^+ = R \cup \Id{A}\) is a partial order. Moreover, if \(R\) is total, then \(R^+\) is a linear order.
Proof. Suppose \(R\) is a strict order, i.e., \(R \subseteq A^2\) and \(R\) is irreflexive, asymmetric, and transitive. Let \(R^+ = R \cup \Id{A}\) . We have to show that \(R^+\) is reflexive, antisymmetric, and transitive.
\(R^+\) is clearly reflexive, since \(\tuple{x, x} \in \Id{A} \subseteq R^+\) for all \(x \in A\) .
To show \(R^+\) is antisymmetric, suppose for reductio that \(R^+xy\) and \(R^+yx\) but \(x \neq y\) . Since \(\tuple{x,y} \in R \cup \Id{X}\) , but \(\tuple{x, y} \notin \Id{X}\) , we must have \(\tuple{x, y} \in R\) , i.e., \(Rxy\) . Similarly, \(Ryx\) . But this contradicts the assumption that \(R\) is asymmetric.
To establish transitivity, suppose that \(R^+xy\) and \(R^+yz\) . If both \(\tuple{x, y} \in R\) and \(\tuple{y,z} \in R\) , then \(\tuple{x, z} \in R\) since \(R\) is transitive. Otherwise, either \(\tuple{x, y} \in \Id{X}\) , i.e., \(x = y\) , or \(\tuple{y, z} \in \Id{X}\) , i.e., \(y = z\) . In the first case, we have that \(R^+yz\) by assumption, \(x = y\) , hence \(R^+xz\) . Similarly in the second case. In either case, \(R^+xz\) , thus, \(R^+\) is also transitive.
Concerning the “moreover” clause, suppose \(R\) is a total order, i.e., that \(R\) is connected. So for all \(x \neq y\) , either \(Rxy\) or \(Ryx\) , i.e., either \(\tuple{x, y} \in R\) or \(\tuple{y, x} \in R\) . Since \(R \subseteq R^+\) , this remains true of \(R^+\) , so \(R^+\) is connected as well. ◻
If \(R\) is a partial order on \(X\) , then \(R^- = R \setminus \Id{X}\) is a strict order. Moreover, if \(R\) is linear, then \(R^-\) is total.
Proof. This is left as an exercise. ◻
Give a proof of Proposition \(\PageIndex{2}\).
\(\le\) is the linear order corresponding to the total order \(<\) . \(\subseteq\) is the partial order corresponding to the strict order \(\subsetneq\) .
The following simple result which establishes that total orders satisfy an extensionality-like property:
If \(<\) totally orders \(A\) , then: \[(\forall a, b \in A)((\forall x \in A)(x < a \leftrightarrow x < b) \rightarrow a = b)\nonumber\]
Proof. Suppose \((\forall x \in A)(x < a \leftrightarrow x < b)\) . If \(a < b\) , then \(a < a\) , contradicting the fact that \(<\) is irreflexive; so \(a \nless b\) . Exactly similarly, \(b \nless a\) . So \(a = b\) , as \(<\) is connected. ◻


12.28: Iberia and the Atlantic- New Worlds
To the southwest of Europe, events in Iberia would eventually bring about several changes that would usher in the end of Europe’s Middle Ages and the beginnings of modern times.
Portugal, Castile, and Aragon were steeped in the traditions of the Reconquista , of expanding the dominion of the Christian world by force of arms. The Reconquista had established a habit in the Iberian kingdoms of conquering Muslims lands and reducing their Muslim and Jewish inhabitants to subordinate status (or in some cases to outright slavery). By the fifteenth century, these kingdoms had nearly completed the Reconquista . As stated earlier, only Granada remained under Muslim rule.
Meanwhile, over the fourteenth century, both Venice and the Ottoman Empire had forced the Italian city-state of Genoa out of the Eastern Mediterranean, so its sailors and ship owners turned their focus to the western half of the Mediterranean Sea. Constantly on the lookout for new markets, Genoese merchants already knew from trade with the Islamic Maghreb that West Africa was a source of gold. In 1324, Mansa Musa’s hajj to Mecca (see Chapter Nine) had put so much gold into circulation that the price of gold fell by twenty-five percent in the Mediterranean market. If the Muslim rulers of Morocco controlled the overland routes by which gold traveled from Mali to the Mediterranean, then perhaps certain sailors could bypass the overland route by sailing into the Atlantic and around the Sahara and arrive at the source of Africa’s gold.
By 1300, the combination of the compass, a map called the portolan (a map that could accurately represent coastlines), and ships that by operating on sails rather than oars needed fewer people meant that European navigators could begin venturing into open waters of the Atlantic that the Arabs and Ancient Romans had largely avoided.
Genoese merchants began tentatively sailing into the Atlantic. In the early 1300s, they were regularly visiting the Canary Islands. These merchants (and others from Western Europe) increasingly served in the employ of Iberian kings. In 1404, King Henry III of Castile (r. 1390 – 1406) began Spanish efforts to conquer the Canaries and convert their indigenous peoples to Christianity. Over the next century, the Spanish would conquer and settle the islands, driven by the Reconquista ideal of the military spread of the Christian faith. In the mid-fifteenth century, the kingdom of Portugal began the conquest and colonization of the Azores, nearly 700 miles to the southwest of Iberia in the Atlantic.
Genoese merchants established sugar plantations on these chains of islands, and those plantations were worked by slave labor. Earlier, in the thirteenth century, Venetian merchants had begun to grow sugar (long cultivated in the Muslim world) in their island colonies in the Mediterranean, and labor for these colonies came from the Mediterranean slave trade. Genoese merchants copied this economic model first in Sicily and then, when they began to operate in the Atlantic, in the Canaries and Azores. Often they would purchase the slaves for these plantations from Africans on the continent’s Atlantic coast. Thus began a slave trade that would be as lucrative for its operators as it was brutal for its victims.
The lure of African gold drew mariners serving Iberian monarchs south and west. By 1482, the Portuguese had established the fort and trading post of São Jorge da Mina on the coast of Guinea. And in the Iberian peninsula, in 1479, Isabella, the Queen of Castile, married King Ferdinand II of Aragon, creating a united Spanish kingdom. In 1492, these monarchs, devout Catholics both, completed the Reconquista , conquering Granada, the last Muslim territory in Spain. All of Spain was now under Christian rule, and the king and queen were eager to continue spreading the Catholic religion.
They sponsored a voyage by the Genoese sailor Christopher Columbus. Columbus had miscalculated the size of the world, so he believed that it would be possible to sail to Asia by traveling west across the Atlantic Ocean. European mariners knew the world was a sphere but believed that it was impossible to carry adequate supplies to sail around the world due to the sheer distance between Europe and Asia. When Columbus made landfall in 1492, it was not in East Asia (for he had in fact been wrong, drastically underestimating the size of the world), but rather in a set of lands previously unknown to the peoples of the Eastern Hemisphere. The world was about to be forever changed.


11.20: Growth Perpetuities
A “growth” perpetuity is a perpetual cash flow stream ( CF ) that grows at a constant rate of growth, which we shall call “ g .” It is a special case of perpetuity. If, in the last period, we received a cash flow of $100 and its growth rate is 5%, the next cash flow would follow this formula: (Last Cash flow: CF 0 ) (1 + g ) = Cash flow in next period (CF 1 ). “G” represents a constant rate of growth in the cash flow over time.
CF 1 = CF 0 (1 + g)
$105 = $100 (1.05)
The formula for a growth-perpetuity is: (Cash flow next period ) ÷ ( Discount rate – Growth rate). Symbolically, this may be expressed as:
PV = CF 1 ÷ ( r – g )
In the above example ( where r = 0.10 ), if the growth rate had been 5%, the present value would be (assuming here that the next CF is $105, that is, [$100] [1.05] = $105):
$105 ÷ (.10 – .05) = $2,100
Notice that for this formula to work, “ g ” cannot equal or exceed “ r .” Mathematically, if g exceeds r we would get a negative denominator, resulting in a negative present value, which makes no sense. A mathematical rationale, while necessary, is however not sufficient to justify this relationship. There must be a financial explanation.
One , theoretically, earns some positive return – “ r ” – for investing in a no-risk asset [1] ; otherwise , no one would invest at all. Even with no risk (and no growth!) , there is a positive return. Therefore r > g . As g rowth rates increase (in linear manner) , so too does risk; higher growth rates are more difficult to achieve and hence are riskier . R (“r”) should exceed g , as a practical, non-mathematical matter. This is depicted in the diagram below.
This formula may also come in handy for cases of negative growth . Since “ g ” would be negative, in this case, the formula would require that one add the growth rate to the interest rate in order to determine the present value.
Suppose the last cash flow ( CF 0 ) was $100 , there is a nominal cash flow growth rate of negative 5% , and a discount rate of 10%. What would the present value be ?
[($100) (1 – (0.05)] ÷ [.10 – (-.05)] =
$95 ÷ .15 = $633.34
Of course , the PV in the case of positive growth far exceeds the outcome we observed with negative growth. Is that not as it should be?
This formula is applicable to common stock, whose dividends may grow – positively or negatively.
Note :
- As this is being written (2021), we observe an unusual environment wherein interest rates in many parts of the world are negative. ↵


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Chandrasekhar limit
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the upper limit to the mass of a white dwarf (equals 1.4 times the mass of the Sun)
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degenerate gas
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a gas that resists further compression because no two electrons can be in the same place at the same time doing the same thing (Pauli exclusion principle)
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millisecond pulsar
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a pulsar that rotates so quickly that it can give off hundreds of pulses per second (and its period is therefore measured in milliseconds)
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neutron star
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a compact object of extremely high density composed almost entirely of neutrons
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nova
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the cataclysmic explosion produced in a binary system, temporarily increasing its luminosity by hundreds to thousands of times
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pulsar
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a variable radio source of small physical size that emits very rapid radio pulses in very regular periods that range from fractions of a second to several seconds; now understood to be a rotating, magnetic neutron star that is energetic enough to produce a detectable beam of radiation and particles
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type II supernova
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a stellar explosion produced at the endpoint of the evolution of stars whose mass exceeds roughly 10 times the mass of the Sun


9.2: Activity 2 - Sorting Algorithms by selection method
Introduction
This activity will present two selection based sorting algorithms, the selection sort and the heap sort algorithms.
Activity Details
Selection sort
The selection sort algorithm works by repeatedly exchanging elements: first finds the smallest in the array and exchange it with the element in the first position, then find the second smallest element and exchange it with the element in the second position, and continue in this way until the entire array is sorted. Below we present the selection sort algorithm:
SELECTION_SORT (A)
for i ← 1 to n-1 do min j ← i; min x ← A[i] for j ← i + 1 to n do If A[j] < min x then min j ← j min x ← A[j] A[min j] ← A [i] A[i] ← min x
Selection sort is among the simplest of sorting techniques and it work very well for small files. Furthermore, despite its evident “simplistic approach”, selection sort has a quite important application because each item is actually moved at most once, thus selection sort is a method of choice for sorting files with very large objects (records) and small keys. Below we present the selection sort implementation:
void selectionSort(int numbers[], int array_size) { int i, j; int min, temp; for (i = 0; i < array_size-1; i++) { min = i; for (j = i+1; j < array_size; j++) { if (numbers[j] < numbers[min]) min = j; } temp = numbers[i]; numbers[i] = numbers[min]; numbers[min] = temp; }
The complexity of the selection sort algorithm is as follows. The worst case occurs if the array is already sorted in descending order. Nonetheless, the time required by selection sort algorithm is not very sensitive to the original order of the array to be sorted: the test “if A[j] < min x” is executed exactly the same number of times in every case. The variation in time is only due to the number of times the “then” part (i.e., min j ← j; min x ← A[j] of this test are executed. Selection sort is quadratic in both the worst and the average case, and requires no extra memory.
Note that for each i from 1 to n - 1, there is one exchange and n - i comparisons, so there is a total of n -1 exchanges and (n -1) + (n -2) + . . . + 2 + 1 = n(n -1)/2 comparisons. These observations hold no matter what the input data is. In the worst case, this could be quadratic, but in the average case, this quantity is O(n log n). It implies that the running time of selection sort does not depend on how the input may be organized.
Heaps Sort
We can use heap for sorting a collection in a specific order efficiently. Suppose we want to sort elements of array Arr in ascending order. We can use max heap to perform this operation through the following steps:
- Build a max heap of elements in Arr.
- Now the root element, Arr[1], contains maximum element of Arr. Exchange this element with the last element of Arr and again build a max heap excluding the last element which is already in its correct position. Thus decreases the length of heap by one.
- Repeat step (ii) until all elements are in their correct position.
- Get a sorted array.
In the following the implementation of heap sort algorithm is provided (Assuming there are N elements stored in array Arr):
void heap_sort(int Ar[ ]) { int heap_size = N; build_maxheap(Arr); for(int i = N; i>=2 ; i-- ) { swap|(Arr[ 1 ], Arr[ i ]); heap_size = heap_size-1; max_heapify(Arr, 1, heap_size); }
The time complexity of the heap-sort algorithm is as follows: Recall from Chapter 8 that max_heapify has complexity O(logN), build_maxheap has complexity O(N) and the fact that the algorithm calls max_heapify N-1 times, therefore the complexity of heap_sort function is O(N logN).
We now demonstrate the steps of the heap sort algorithm using an example of an unsorted array Arr having 6 elements and corresponding max-heap as in Figure \(\PageIndex{1}\).
After building the corresponding max-heap, the elements in the array Arr are now as in Figure \(\PageIndex{2}\).
The subsequent algorithm processing steps are outlined below and further depicted in Figure \(\PageIndex{3}\).
- 8 is swapped with 5.
- 8 is disconnected from heap as 8 is in correct position now and.
- Max-heap is created and 7 is swapped with 3.
- 7 is disconnected from heap.
- Max heap is created and 5 is swapped with 1.
- 5 is disconnected from heap.
- Max heap is created and 4 is swapped with 3.
- 4 is disconnected from heap.
- Max heap is created and 3 is swapped with 1.
- 3 is disconnected.
Upon completion of all the steps, we obtain a sorted array shown in Figure \(\PageIndex{4}\).
Conclusion
In this activity the selection based sorting algorithms were presented, the selection sort and the heap sort. The complexity analysis for the two algorithms shows that the heap sort is more efficient, since the selection sort has a quadratic worst case performance. The selection sort is suited to sorting small collections, and the order of input does not influence its performance.
Assessment
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Show the steps taken when sorting the following list of integers [80, 30, 50, 70, 60, 90, 20, 30, 40] using
- Selection sort


14.2: Nonopioid Analgesics
By the end of this section, you should be able to:
- 14.2.1 Identify the characteristics of nonopioid analgesic drugs used to treat pain.
- 14.2.2 Explain the indications, actions, adverse reactions, and contraindications of nonopioid analgesic drugs used to treat pain.
- 14.2.3 Describe the nursing implications of nonopioid analgesic drugs used to treat pain.
- 14.2.4 Explain the client education related to nonopioid analgesic drugs used to treat pain.
A nonopioid analgesic refers to any pharmacologic agent that treats the symptoms of pain and does not involve activation of opioid receptors. These agents generally work by inhibiting cyclooxygenase (COX), a major pro-inflammatory enzyme that causes many signs and symptoms of inflammation, including redness, swelling, and sensitization of nociceptors, thereby increasing the transmission of painful signals to the brain. COX causes this increase in inflammation and pain by increasing the production of cytokines such as prostaglandins, prostacyclin, and thromboxane. It is also partly responsible for the pyrexia that occurs with infection, which is why many nonopioid analgesics that block the activity of COX also work as antipyretics to reduce fever.
Cyclooxygenase has two major isoforms: COX-1 and COX-2. COX-1 helps with normal homeostatic functions in the body, including maintaining normal platelet and renal functions. It also is important for producing prostaglandins that stimulate production of the mucosal barrier that protects the stomach from its own acids. If COX-1 is inhibited through the actions of medications such as glucocorticoids or nonsteroidal anti-inflammatory drugs (NSAIDs), this protective barrier can erode, which is a major cause of peptic ulcers. COX-2 is responsible for much of the inflammation and pain brought about by tissue injury.
Other nonopioid analgesics may serve as adjunctive agents for treating neuropathic sources of pain. These include antidepressant drugs (e.g., duloxetine, amitriptyline), antiseizure drugs (e.g., carbamazepine, pregabalin), and local anesthetics (e.g., lidocaine and bupivacaine). These are useful because they target the abnormal neuronal function that is the source of neuropathic pain. These medications are covered in their respective chapters, and health care professionals should keep these additional tools in mind to ensure adequate management of this type of pain.
Acetaminophen
Acetaminophen is a common over-the-counter nonopioid analgesic. It is one of the most popular analgesics due to its low cost, efficacy in treating mild to moderate pain, and excellent safety profile when used within the recommended dosages. Acetaminophen’s complete mechanism of action to relieve pain is not currently known. Some experts theorize that it inhibits COX in the central nervous system (CNS), providing analgesic and antipyretic actions, but notably it does not inhibit COX peripherally, meaning it has no anti-inflammatory action as compared with other nonopioid analgesics.
Acetaminophen comes in a variety of dosage forms, including intravenous and rectal options, to aid clients who cannot take medications by mouth. Acetaminophen is commonly found in combination products with opioid agonists, antihistamines, and medications for coughs and colds. Because acetaminophen is present in so many products, and because its overuse can lead to serious adverse events, nurses must be alert for all sources of acetaminophen that clients may be taking.
Clinical Tip
Check for All Sources of Acetaminophen
Many over-the-counter and prescription medications include acetaminophen, including many cough and cold products. Clients should be aware that they need to count all sources of acetaminophen to ensure they do not exceed the limit of 4000 mg per 24 hours and put themselves at risk for liver injury.
Aspirin, Ibuprofen, and Naproxen Sodium
Aspirin, ibuprofen, and naproxen sodium are classified as nonsteroidal anti-inflammatory drugs (NSAIDs) . This classification means they possess analgesic, antipyretic, and anti-inflammatory actions without belonging to the group of medications known as the glucocorticoids (e.g., prednisone and dexamethasone, which are discussed in Introduction to the Immune System and the Inflammatory Response). NSAIDs are often preferred over glucocorticoids as anti-inflammatory agents because they cause fewer adverse drug reactions such as hyperglycemia, hypertension, and increased risk for infection. NSAIDs work by inhibiting the enzyme COX centrally and in peripheral tissues to decrease inflammation and reduce pain. NSAIDs are also very popular analgesics because they are readily available over the counter.
Aspirin is notable for its antiplatelet actions, so it can be used during myocardial infarctions to aid in maintaining coronary blood flow by inhibiting platelet aggregation. (See Cardiac Emergency and Shock Drugs for more about aspirin’s use in cardiovascular emergencies.) The reason for aspirin’s unique actions is that it is an irreversible inhibitor of COX in platelets, preventing them from aggregating and initiating the clotting cascade. Aspirin’s irreversible inhibition of COX means that platelets are affected for their entire lifetime, which is approximately 7–10 days. Nurses should instruct clients taking blood thinners (e.g., warfarin, apixaban) to be cautious about using aspirin to treat pain because of increased risk for bleeding and bruising.
Safety Alert
NSAIDs
Clients reporting severe abdominal pain, dark tarry stools, or vomiting or coughing up of blood should stop using any NSAIDs immediately and be assessed by a health care provider for possible stomach ulcers.
Tramadol
Tramadol is a partial opioid receptor agonist and inhibitor of reuptake of the neurotransmitters norepinephrine and serotonin. These characteristics make tramadol a potential analgesic option for clients with neuropathic pain because they benefit from both the partial opioid effect and the pain-modulating effects of increased norepinephrine and serotonin. However, due to its actions at the opioid receptors, tramadol has been linked to cases of misuse and addiction, leading the Drug Enforcement Administration (DEA) to categorize tramadol as a Schedule IV medication (CIV). The DEA scheduling of a medication puts certain restrictions on who can prescribe the medication and how much of the medication can be prescribed at a time.
Table 14.1 lists common nonopioid analgesics and typical routes and dosing for adult and pediatric clients .
| Drug | Routes and Dosage Ranges |
|---|---|
|
Acetaminophen
( Tylenol ) |
Pain and/or fever:
Adults: 325–650 mg orally every 4–6 hours as needed; maximum dose: 4000 mg/day. Children: 10–15 mg/kg/dose orally every 4–6 hours as needed; maximum dose: 75 mg/kg/day, not to exceed 4000 mg/day. |
| Aspirin |
Pain and/or fever:
Adults: 325–1000 mg orally every 4–6 hours as needed; usual maximum dose is 4000 mg/day. Secondary prevention of atherosclerotic cardiovascular disease: Adults: 75–325 mg once daily. |
|
Ibuprofen
( Advil , Motrin ) |
Pain and/or fever:
Adults: 200–800 mg orally every 4–8 hours as needed; maximum dose: 3200 mg/day. Children: 10 mg/kg/dose orally every 6–8 hours; maximum dose: 600 mg/dose, not to exceed 2400 mg/day. |
|
Naproxen sodium
( Aleve , Naprosyn ) |
Pain and/or fever:
Adults: 200–400 mg orally, followed by 200 mg every 8–12 hours as needed; maximum dose: 600 mg/day. |
|
Tramadol
( Ultram ) |
Pain:
Adults: 25–100 mg orally every 6 hours as needed; maximum dose: 400 mg/day. |
Adverse Effects and Contraindications
Nonopioid analgesics as a class are relatively safe to use for many clients but do carry some notable adverse effects in susceptible individuals. Acetaminophen is a preferred analgesic for mild to moderate pain because it has relatively few adverse effects, but it must not be taken in amounts greater than those recommended by the drug’s manufacturers. This limit is 4000 mg per 24 hours; taking acetaminophen in doses beyond that increases the chances of developing potentially fatal hepatotoxicity . Clients with a history of liver disease will have lower recommended dosages because they are at greater risk for liver injury when using acetaminophen. Hepatotoxicity from acetaminophen can present as nausea, fatigue, and jaundice (yellowish skin and sclera) and may require antidotal therapy with the drug n-acetylcysteine to help prevent further liver injury.
NSAIDs such as aspirin, ibuprofen, and naproxen sodium are known to increase the risk for bleeding and bruising and can cause kidney injury in older adults and in clients with a history of chronic kidney disease. NSAIDs taken at high doses for long periods of time can also potentially cause stomach ulcers that can progress to bleeding and perforation by eroding the protective stomach lining over time.
Due to its opioid receptor activity, tramadol can cause CNS and respiratory depression in overdose or when mixed with other CNS depressants such as alcohol. It is associated with risk for problematic use and addiction, and individuals with a history of substance use disorder should avoid it. Tramadol can lower the seizure threshold and should be used with caution in clients with a history of seizure disorder.
NSAIDs carry a risk for asthma exacerbations in clients with a history of aspirin-induced asthma. Aspirin should be avoided in children younger than 16 years old with a recent history of viral illness because the medication may cause a potentially fatal condition called Reye’s syndrome .
All of these agents should be avoided in clients with a known allergy to the individual agents or any of their components.
Table 14.2 is a drug prototype table for nonopioid analgesics featuring ibuprofen. It lists drug class, mechanism of action, adult and pediatric dosage , indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Nonsteroidal anti-inflammatory drug (NSAID) Mechanism of Action Inhibits the enzyme cyclooxygenase to decrease the production of inflammatory cytokines and thereby reduce inflammation and pain |
Drug Dosage
Adults: 200–800 mg orally every 4–8 hours as needed; maximum dose: 3200 mg/day. Children: 10 mg/kg/dose orally every 6–8 hours; maximum dose: 600 mg/dose, not to exceed 2400 mg/day. |
|
Indications
Temporarily relieves minor aches and pains Temporarily reduces fever Therapeutic Effects Reduces fever Reduces inflammation Decreases pain |
Drug Interactions
Angiotensin II receptor blockers (e.g., candesartan) Angiotensin-converting enzyme (ACE) inhibitors (e.g., lisinopril) Lithium Warfarin Food Interactions No significant interactions |
|
Adverse Effects
Decreased hemoglobin Edema Skin rash Abdominal cramps Constipation Diarrhea Nausea Gastric ulcer Heartburn Dizziness |
Contraindications
Hypersensitivity Aspirin-sensitive asthma Allergic reaction to aspirin Caution: Asthma Hepatic impairment Renal impairment Bariatric surgery |
Nursing Implications
The nurse should do the following for clients who are taking a nonopioid analgesic:
- Assess the client for pain by using a pain scale before and 15–20 minutes after a dose of a nonopioid analgesic to determine its efficacy.
- Ensure that the client does not receive more than the recommended amount of acetaminophen in 24 hours.
- Check for any contraindications, allergies, or potential drug interactions before beginning therapy with a nonopioid analgesic.
- Ask the client when they last used an analgesic medication.
- Ask the client about any types of nonpharmacologic pain treatment they may be using, such as ice, stretching, or heat/cold therapy.
- Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.
Client Teaching Guidelines
The client taking a nonopioid analgesic should:
- Alert their health care provider about any signs of allergic reactions, including throat swelling, severe itching, rash, or chest tightness.
- Alert their health care provider about any signs of bleeding, including black tarry stools, coffee-ground emesis, or blood-streaked sputum.
- Alert their health care provider that they are taking this medication, including the dose and frequency.
- Avoid drinking alcohol while using acetaminophen.
- Take the drug with food if it causes upset stomach.
- Take a missed dose as soon as they remember it; however, they should not take double doses.
- Contact their health care provider for further advice if pain persists longer than 3 days.
FDA Black Box Warning
Nonopioid Analgesics
Acetaminophen has been associated with cases of acute liver failure, at times resulting in death or the need for liver transplantation.
NSAIDs increase the risk for serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use.
NSAIDs increase the risk for serious gastrointestinal adverse events, including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Older adults and individuals with a prior history of peptic ulcer disease or gastrointestinal bleeding are at greater risk for serious gastrointestinal events.
Unfolding Case Study
Part A
Read the following clinical scenario to answer the questions that follow. This case study will evolve throughout the chapter.
Maria Vega is a 63-year-old client who presents to her health care provider’s office with reports of abdominal pain, diarrhea that is occasionally black and tarry in appearance, and dizziness.
History
Coronary artery disease
Osteoarthritis (both knees and hips are affected)
Current Medications
Aspirin 81 mg orally once daily
Metoprolol 50 mg orally twice daily
Over-the-counter ibuprofen 400 mg orally every 4–6 hours as needed for joint pain
| Vital Signs | Physical Examination | |
|---|---|---|
| Temperature: | 98.8°F |
|
| Blood pressure: | 126/86 mm Hg | |
| Heart rate: | 74 beats/min | |
| Respiratory rate: | 16 breaths/min | |
| Oxygen saturation: | 97% on room air | |
| Height: | 5'3" | |
| Weight: | 122 lb |
Based on the information above, what is the most important question for the nurse to ask Maria?
- Answer
-
“How much ibuprofen do you take each day?”
The nurse determines that the client is taking 2 or 3 200 mg tablets nine times daily to control her arthritic pain. Which instruction should the nurse give the client?
- Answer
-
“This dose is too high and can cause gastric bleeding.”


34.12: Avatar is just Pocahontas with Blue People in Space
American Literature (though the true definition is disputed as to what American Literature is, let’s pretend we all agree right now) can be found sprinkled among many of today’s movies and TV shows. As more about American History is discovered and screen production gets better, the possibilities of the development of American Literature in media expands. The theme of racial injustice is still prominent among these forms of media. A movie that is a good example of this is Avatar . This is screenplay brings out the modern version of racial injustice while talking American Literature into the now.
Avatar is a movie directed and written by James Cameron that premiered in 2009 (Trailer linked at the bottom). It follows the protagonist Jake Sulley, a Marine who has lost the use of his legs. The movie takes place in the distant future but it is not exactly stated when. Jake finds out his brother, who was a scientist, has been killed and is offered by the RDA (Resources Development Administration) to take his place in the Avatar Program. They offer him the job because Jake and his brother are identical and can, therefore, use the Avatar that was designed for his brother. Jake is launched into space where he arrives, “five years, nine months and twenty-days” (Space Doctor 1) later on Pandora, a habitable moon orbiting a distant planet light years away. Humans can’t breathe the air but the planet is rich in life, animals, various elements, and an indigenous people called the Na’vi. Through the Avatar program, Jake can link with a body that looks like the Na’vi that can survive in the outside world. To essentially sum up the rest of the story, Jake meets a native woman (who just happens to the chief’s daughter) who changes his whole outlook on the planet and nature and he chooses to abandon his forest cutting- indigenous killing counterparts to stay with her and save the day.
It’s basically Pocahontas in space. I mean we all saw the Disney movie.
However, this is what makes it interesting. The story is familiar and has its roots in Native American racial injustice narratives but takes place on a distant planet far far away. This story is actually pretty close to the beginning of The Female American. Though she is not the main character, Neytiri (Ney-tier-e), the love interest, is a strong woman who’s native to the land but can also speak English. In fact, her and Jake’s love story is very similar to Unca Eliza’s mother and father’s. Jake, like Unca’s father, is captured by the natives and brought back to their home. They are then both asked about religion as religion is important is both Avatar and The Female American . “Men, for I see you have legs, arms, and heads as we have, look to the sun,’ here he pointed up to the luminary, “He is our God, is he yours?” (Winkfield 48). They are both saved from being killed by a sign of deliverance. Jake is saved by a sign of Eywa, the Na’vi’s goddess, and Unca’s father by the chief’s daughter who “stroked [my] father with a wand” (Winkfield 49). They are both then put in the care of the daughters of the leaders of the natives in each story. Each begins to fall in love with their counterpart and set out to “marry” their native women. However, as in the case of both stories, jealousy tries to sabotage this plan. In The Female American, the elder sister of Unca’s mother falls in love with her father. She professes her love but he turns her down in return she says, “If you will not love me, you shall die; my sister shall never enjoy an happiness that I aspire to; nor shall my vengeance be long delayed; this instant shall put a period to your life” (Winkfield 52). In Avatar a native man named Tsu’tey (Sue-tay), who is promised to Neytiri, is jealous of Jake and after finding out that she mated with him (oh scandalous) he attacks Jake and tried to kill him. Both jealous parties end up regretting their decision in the end and befriending and respecting Jake and Unca’s father.
The story of Avatar also brings in themes of colonization. White men, presumably American, invade an already inhabited place and start calling their own; killing off any natives who oppose the taking of their home. Both the Na’vi and Native Americas are far more connected to nature than their white counterparts. In Avatar, the humans need technology to live on the planet. Overall, the whole thing echoes America’s colonization and war with the Native Americans.
Avatar is proof American Literature now has adapted to new tastes and media while still maintaining its beginnings. Avatar shows that while it takes place on a new planet there is nothing really new about the story. Overall, it returns to the racial injustice narrative. This shows that these issues are still relevant and needed to be addressed through various medias. While we may not be able to travel to space, it doesn’t mean James Cameron wasn’t trying to say something. Whether he was making a statement about history repeating itself or atoning for America’s past sins, I’m not sure. But on this is clear, he knows what he was referencing.


11.8: Exercise- From the Command Line to a Script
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- Last updated
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In this exercise, we’ll see how commands that you type on the command line can be run from a script file. To start from a blank slate, you should quit EEGLAB, type clear all on the command line, and relaunch EEGLAB. Make sure that Chapter_11 is the current folder in Matlab, and open the file named Script1.m by double-clicking the name from Matlab’s Current Folder pane. This script consists of three lines, which open a dataset, add it to ALLEEG , and redraw the Matlab GUI.
Copy the first line of the file into your computer’s clipboard, and then paste it onto the command line to execute the command. You can determine whether it has successfully loaded the dataset into the EEG variable by looking at this variable in the Matlab Workspace pane. Now paste the second line of the file onto the command line to add the dataset to ALLEEG (which you can verify by looking at ALLEEG in the Workspace pane). Now paste the third line to the command line to update the GUI. You can see that the dataset is now in the Datasets menu.
Let’s take a closer look at the first line: EEG = pop_loadset('filename','1_N170.set'); This is just like the first line of the EEG.history in the previous exercise, except that it doesn’t specify the path. That’s because the 1_N170.set file is in the current folder (which you can see in Matlab’s Current Folder pane). When you open a file but don’t specify a path, Matlab will first look in the current folder. If it doesn’t find the file there, it will search the entire Matlab path. When you save a file but don’t specify a path, Matlab will save it in the current folder. In the next exercise, we’ll look at a robust way to specify the path.
First, though, we’ll see how to run an actual script. In theory, you could just put a set of commands in any text file and then copy-and-paste them onto the command line. The file would just be a way to store the commands so that you can easily reuse them. In fact, I sometimes use script files for this purpose. But there are easier ways to execute the commands in a script file. The simplest is just to click the Run button in the Matlab script editor. In my version of Matlab, it’s a green triangle (see Screenshot 11.3). To see this in action, quit EEGLAB, type clear all , restart EEGLAB, and click the Run button in the editor window for Script1.m . If you look at the EEG variable, the ALLEEG variable, and the Datasets menu, you can confirm that each line of the script has executed. It’s just as if you had copied all three lines into the clipboard and pasted them onto the command line (but faster and easier).
Now let’s look at three ways that we can execute a portion of a script rather than the whole thing. The first is simple: Copy the set of lines that you’d like to execute into the clipboard and paste them onto the command line. You’ve already done this with single lines of code, but you can do this with multiple lines.
The other two ways are easier to demonstrate with a script that has several distinct parts, so load the script named Script2.m (e.g., by double-clicking on this name in the Current Folder pane). This script loads the data from Subjects 1 and 2. I’ll explain how this script works in the next exercise. For now, we’ll just see how to execute parts of it.
Start by quitting EEGLAB, typing clear all , and restarting EEGLAB. Now, go into the text editor for Script2.m , and select the first 7 lines (by dragging your mouse over those lines; note that you can see the line numbers along the left side of the window). Now right-click (or control-click) on the selected text, and select Evaluate Selection from the menu that pops up. (You can also see a keyboard equivalent, which will be more convenient for using this approach in the future.) You’ll be able to see that the dataset from Subject 1 has been loaded (e.g., in the ALLEEG variable), but we haven’t yet updated the EEGLAB GUI. To do that, select the last line of the script (line 12, eeglab redraw ) and execute it (by selecting it, right-clicking, and selecting Evaluate Selection from the popup menu). Now the dataset should appear in the Datasets menu.
Now select and execute lines 9-12 to load the dataset for Subject 2 and update the GUI. You should now see the datasets from both Subject 1 and Subject 2 in the Datasets menu. Note that you didn’t execute the lines of the script in order. You executed line 12 after lines 1-7 and then again after lines 9-11. This approach gives you a lot of flexibility. The lines in a script usually need to go in a particular order to give you the desired result. For example, you can’t filter a file until after you’ve loaded it. But sometimes you’re just using the script as a convenient place to store a bunch of commands that you might execute in some other order.
Now we’re going to look at one more way to execute commands from a script, in which we divide the script into sections and run one section at a time. If you look at Script2.m , you’ll see that some lines begin with a % symbol. This symbol indicates that the line is just a comment, not code that will be executed. You can also put a % symbol after a command to provide a comment about that command.
You should also note that some of the lines begin with two consecutive % symbols. This indicates the start of a new section . If you click anywhere within a section, the background color of that section changes. Screenshot 11.4 shows what it looks like when I click in the last section of the script. Once you’ve highlighted a section in this way, you can run that section of code by clicking the Run Section button in the tool bar near the top of the script editor window.


3.6: Collective capabilities
Several scholars have proposed the introduction of a category of ‘collective capabilities’ or ‘community capabilities’ (Evans 2002; Ibrahim 2006, 2009, 2017; Schlosberg and Carruthers 2010; Murphy 2014). The idea of ‘collective capabilities’ is used in different ways in the literature, and not always spelled out very carefully. I will try to reconstruct what ‘collective capabilities’ could mean, and then discuss to what extent these are different from human capabilities tout court.
It is instructive, first, to see in which contexts different authors introduce the idea of ‘collective capability’. Here are a few typical examples from the literature. Solava Ibrahim (2006, 2009, 2017) argues for the importance of collective capabilities from the perspective of the work done by self-help groups of poor people fighting to overcome their poverty, which is an issue also discussed by Stewart (2005). 9 David Schlosberg and David Carruthers (2010) argue for the importance of the idea of collective capabilities to understand the struggles of indigenous peoples for ecological justice. And Michael Murphy (2014) argues that political self-determination (of an indigenous group) should be considered to be a collective capability which should be a central aim for development.
What is shared in those cases, and what makes the idea of ‘collective capability’ plausible, is that a group or collective is needed to engage in collective action in order to reach the capability that the members of that group find valuable.
Sen (2002b) points out that we should be careful not to confuse this with a capability that he calls “socially dependent individual capability” — a person’s capability, which that person enjoys, but for which the person is dependent on others to have that capability realised. Perhaps we should not use the term ‘individual capability’ but rather ‘personal capability’, since for many defenders of ‘collective capabilities’ the word ‘individual’ evokes pejorative images of persons living by themselves on an island. There are no such human creatures; we all live interdependently, and none of us could grow up without prolonged care from others, or, as adults, have a decent chance of surviving and living a minimally adequate life. Human beings are, just as other mammals, animals who live in groups. Although philosophers are used to working with terms outside their everyday use, and most philosophers (especially those with an analytical background) will not have these pejorative connotations when they hear the term ‘individual capabilities’, I will proceed with the term ‘personal capabilities’ in order to facilitate the discussion in this section.
Now, if we are very strict in our terminological distinctions, then collective capabilities are also personal capabilities, since it is individual persons who enjoy the capabilities that are thus secured. Still, there are two justifications to proceed with the term ‘collective capability’ — one fundamental one, and one additional one which is especially weighty from a practical point of view.
The fundamental reason to keep and use the term ‘collective capability’ is that we may want to make a distinction between capabilities that are only realisable with the help of others, versus capabilities that require a group or collective to act in order to secure a capability for the members of that group. An example of the former would be learning a foreign language. It is impossible to do that without the help of others; one needs a teacher, or at the very least books and audio-tapes or internet lessons that help one with self-study. Still, that doesn’t suffice to say that learning a language is a collective capability. There is no group involved, and no collective action of that group is necessary in order to achieve the functioning. A different case is acquiring the capability to vote in elections for groups that are not yet given suffrage. Fighting for that capability is not possible on one’s own. One needs collective action — e.g. the first wave women’s movement, or the civil rights movement in the US, or the anti-apartheid movement in South Africa — to act collectively so that the group is granted the capability, and all persons who belong to that group can enjoy the newly won freedom.
The second reason to accept the notion of ‘collective capability’ is because it is already present in the practice of certain justice movements, whose demands fit very well with the capability approach, for example because they embody claims of diversity or because they fight for a notion of the good life or of justice that goes beyond a narrow materialist or economistic view of what is valuable. Examples include the disability movement, the women’s movement and indigenous struggles.
So the idea of a collective capability can be understood and can be justified. Nevertheless, two warnings are in order, which may be needed to avoid conceptual confusion as well as an overuse or inflation of the notion. The first comment is that all that has been said so far does not permit one to conclude that one has personal (individual) capabilities and collective capabilities as two mutually exclusive categories.  Secondly, we should be very careful to be clear to keep our concepts distinct and correct when developing a capability theory. The modular account of the capability approach has ample conceptual and theoretical space to account for collective processes, the social embedding of persons, the influence of social structures on our choices and opportunities, a proper acknowledgement of social processes of preference formation as well as the crucial role of social institutions and norms in shaping a person’s capability set. But if we want to account for a social process, we shouldn’t just jump to the claim that we have now found a collective capability. Rather, we should use the quite complex and multi-layered framework that was presented in figure 2.1, and be clear when something is a social structure that is shaping our capabilities, rather than a capability itself. Means to ends (capabilities) and the ‘capability determinants’ (the social structures, social norms, institutions, etc.) can all be part of our evaluation — we just need to keep in mind which parts of what we evaluate are the means, which are the ends and why we evaluate a certain dimension. In the case of the evaluation of the means, one important reason could be to see how those means have changed over time, as well as whether there is any scope to improve the contribution that those particular means can make to the increase of capability sets.
9 Self-help groups are “any informal income-generating or social activity initiated by a poor community to achieve permanent improvements in their individual and communal wellbeings” (Ibrahim 2006, 398–399).


5.2: The Meaning and Purpose of Law
What you’ll learn to do: explain the meaning and purpose of law
In this section you’ll be introduced to the terms and concepts needed to understand how law applies to business.
Learning Objectives
- Explain the purposes of law
- Explain “rule of law”
Understanding Law
Law has been defined as “a body of rules of action or conduct prescribed by a controlling authority, and having binding legal force. That which must be obeyed and followed by citizens subject to sanctions or legal consequence is a law.” [1]
Although intended to protect the fundamental rights and liberties of U.S. citizens, the legal system and its laws are not always readily understood by the average citizen. At what point do we cross that fine line between legal and illegal, and on what basis is that line even drawn in the first place? Most people understand (and accept) laws prohibiting acts of murder, thievery, physical harm, and financial malfeasance, but there are plenty of other laws that might give us pause. For example, in Minnesota, any game in which participants attempt to capture a greased or oiled pig is illegal. The same laws also prohibits turkey scrambles. [2] Don’t attempt to substitute a ferret for a hunting dog in West Virginia. Anyone who hunts, catches, takes, kills, injures, or pursues a wild animal or bird with a ferret will face a fine of no less than $100 (but no more than $500) and no fewer than 10 (but no more than 100) days in jail. [3]
While you may never have considered taking part in a turkey scramble or hunting with a ferret, chances are good that you have broken some law at some time—perhaps even in the last twenty-four hours. Did you exceed a speed limit while driving? Roll through a stop sign at an empty intersection while riding your bike? Drive to the minimart without wearing your seatbelt? Although unlikely that you will be prosecuted and jailed for these minor traffic offenses, the fact is that you broke the law. Why do we have so many laws? Let’s take a closer look at the role of law in society and why laws are created in the first place.
Purposes of Law
In a society such as the United States, the law informs everyday life in a wide variety of ways and is reflected in numerous branches of law. For example, contract law regulates agreements to exchange goods, services, or anything else of value, so it includes everything from buying a bus ticket to trading options on a derivatives market. Property law defines people’s rights and duties toward tangible property, including real estate (i.e., real property , such as land or buildings,) and their other possessions (i.e., personal property , such as clothes, books, vehicles, and so forth), and intangible property, such as bank accounts and shares of stock. Tort law provides for compensation when someone or their property is harmed, whether in an automobile accident or by defamation of character. Those are fields of civil law, which deals with disputes between individuals. Offenses against a federal, state, or local community itself are the subject of criminal law, which provides for the government to punish the offender.
origins of law
The establishment of a system of laws was not invented by the founding fathers of the United States. The idea of written laws goes back to ancient Mesopotamian culture that prospered long before the Bible was written or the civilizations of the Greeks or Romans flowered.
In fact, the oldest known evidence of a law code is tablets from the ancient city Ebla (Tell Mardikh in modern-day Syria). They date to about 2400 BCE. However, most scholars credit Hammurabi’s Code as the origin of written laws and a formal legal system. If you haven’t heard of Hammurabi, you have certainly heard one of his laws: “An eye for an eye, and a tooth for a tooth.” Hammurabi’s Code, a collection of 282 laws inscribed on an upright stone pillar, contains many fundamental legal concepts we would recognize in today’s legal system.
In fact, Hammurabi’s reasoning for creating this code is not that far removed from the rationale for our current legal system. In his preface, Hammurabi writes that he sets forth these laws “to bring about the rule of righteousness in the land, to destroy the wicked and the evil-doers; so that the strong should not harm the weak.”
Establishing Standards
The law is a guidepost for minimally acceptable behavior in society. Some activities, for instance, are crimes because society (through a legislative body) has determined that it will not tolerate certain behaviors that injure or damage persons or their property. For example, under a typical state law, it is a crime to cause physical injury to another person without justification—doing so generally constitutes the crime of assault. [4]
Maintaining Order
This is an offshoot of establishing standards. Some semblance of order is necessary in a civil society and is therefore reflected in law. The law—when enforced—provides order consistent with society’s guidelines. Wildlife management laws, for example, (such as West Virginia’s prohibition against using ferrets for hunting,) were first passed in an effort to conserve game that had nearly been hunted into extinction during the nineteenth century. Such laws reflect the value society places on protecting wildlife for future generations to enjoy. [5]
Resolving Disputes
Disputes are unavoidable in a society comprised of persons with different needs, wants, values, and views. The law provides a formal means for resolving disputes—the court system. [6]
Protecting Liberties and Rights
The constitutions and statutes of the United States and its states provide for various liberties and rights. One function of the law is to protect these various liberties and rights from violations or unreasonable intrusions by persons, organizations, or government. For example, subject to certain exceptions, the First Amendment to the Constitution prohibits the government from making a law that prohibits the freedom of speech. Someone who believes that his free speech rights have been prohibited by the government may pursue a remedy by bringing a case in the courts. [7]
Rule of Law
What is the rule of law? Aren’t laws and rules the same thing? You can think of the rule of law as the rules that govern the law . The rule of law is the legal principle that law should govern a nation, as opposed to being governed by arbitrary decisions of individual government officials. It primarily refers to the influence and authority of law within society, particularly as a constraint upon behavior, including behavior of government officials. The phrase can be traced back to sixteenth-century Britain, and in the following century, the Scottish theologian Samuel Rutherford used the phrase in his argument against the divine right of kings. The concept, if not the phrase, was familiar to ancient philosophers such as Aristotle, who wrote, “Law should govern.”
Rule of law implies that every citizen is subject to the law, including lawmakers themselves. In this sense, the rule of law stands in contrast to an autocracy, dictatorship, or oligarchy, in which the rulers are held above the law. Lack of the rule of law can be found in both democracies and dictatorships, because of neglect or ignorance of the law, for example, and the rule of law is more apt to deteriorate if a government has insufficient corrective mechanisms for restoring it. If you’ve ever read Alice’s Adventures in Wonderland (or seen the movie), and you can recall the Queen of Hearts yelling, “Off with their heads!” at the slightest infraction or offense, you have some idea of what it would be like to live in a society that is not governed by the rule of law.
The rule of law system in the United States is established in the U.S. Constitution. The U.S. Constitution itself became the law of the land well over two hundred years ago, and the tenets set forth in the document remain in full force today. The way in which the Constitution is applied, though, has always been subject to court interpretation. As circumstances and public opinion evolve through the years, so too do the interpretations offered by the courts. From time to time, it even becomes necessary to amend the Constitution to keep pace with changes in the country’s beliefs and values.
- Black’s Law Dictionary, 6th ed., s.v. “law.” ↵
- www.revisor.mn.gov/statutes/?id=343.36&year=2013&keyword_type=all&keyword=greased+pig ↵
- http://www.legis.state.wv.us/legisdocs/code/20/WVC%2020%20%20-%20%202%20%20-%20%20%205%20%20.htm ↵
- http://www.businesslawbasics.com/chapter-3-purposes-and-functions-law-1 ↵
- http://www.businesslawbasics.com/chapter-3-purposes-and-functions-law-1 ↵
- http://www.businesslawbasics.com/chapter-3-purposes-and-functions-law-1 ↵
- http://www.businesslawbasics.com/chapter-3-purposes-and-functions-law-1 ↵