11.5: Market Segmentation
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5. What are the five basic forms of consumer and business market segmentation?
Most organizations cannot target the total market for a specific product. For each separate part of the market that an organization wants to target, a marketing mix (a set of 5Ps) must be created. It would be very expensive to try to create a marketing mix for every part of the target market. Instead, companies cut up those targets into specific “segments” of the market that the organization is more strategically positioned to be successful in targeting. Segmentation also varies based on the target market being a consumer market or a business market.
The study of buyer behavior helps marketing managers better understand why people make purchases. To identify the target markets that may be most profitable for the firm, marketers use market segmentation , which is the process of separating, identifying, and evaluating the layers of a market to identify a target market. For instance, a target market might be segmented into two groups: families with children and families without children. Families with young children are likely to buy hot cereals and presweetened cereals. Families with no children are more likely to buy health-oriented cereals. Cereal companies plan their marketing mixes with this difference in mind. A business market may be segmented by large customers and small customers or by geographic area.
The five basic forms of consumer market segmentation are demographic, geographic, psychographic, benefit, and volume. Their characteristics are summarized in Table 11.2 and discussed in the following sections.
Demographic Segmentation
Demographic segmentation uses categories such as age, education, gender, income, and household size to differentiate among markets. This form of market segmentation is the most common because demographic information is easy to obtain. The U.S. Census Bureau provides a great deal of demographic data, especially about metropolitan areas. For example, marketing researchers can use census data to find areas within cities that contain high concentrations of high-income consumers, singles, blue-collar workers, and so forth. However, even though demographic information is easier to obtain than other types of information, it may not always be the best approach to segmentation because it is limited on what it can reveal about consumers.
| Form General | Characteristics |
|---|---|
| Demographic segmentation | Age, education, gender, income, race, social class, household size |
| Geographic segmentation | Regional location (e.g., New England, Mid-Atlantic, Southeast, Great Lakes, Plains States, Northwest, Central, Southwest, Rocky Mountains, Far West), population density (urban, suburban, rural), city or county size, climate |
| Psychographic segmentation | Lifestyle, personality, interests, values, attitudes |
| Benefit segmentation | Benefits provided by the good or service |
| Volume segmentation | Amount of use (light versus heavy) |
| Name Derivation | Year Introduced | Main Ingredients | Demographic | Niche, According to Frito Lay | |
|---|---|---|---|---|---|
| Fritos | “Little fried bits” (Spanish) | 1932 | Corn, vegetable oil, salt | 33- to 51-year-old males | “Hunger satisfaction” |
| Doritos | “Little bits of gold” | 1964 | Corn, vegetable oil, cheddar cheese, salt | Teens, mostly males | “Bold and daring snacking” |
| Tostitos | “Little toasted bits” (Spanish) | 1981 | White corn, vegetable oil, salt | Upscale consumers born between 1946 and 1964 | “Casual interaction through friends and family . . . a social food that brings people together” |
Table 11.3 Source: Adapted from Frito Lay website, accessed October 1, 2017.
Many products are targeted to various age groups. Most music CDs, Pepsi, Coke, many movies, the Honda Fit, and thousands of other products are targeted toward teenagers and persons under 25 years old. In contrast, most cruises, medical products, fine jewelry, vacation homes, Teslas, and denture products are targeted toward people 50 years old and up. An example of how Frito Lay targets various age groups for three of its most popular products is shown in Table 11.3 .
Income is another popular way to segment markets. Income level influences consumers’ wants and determines their buying power. Housing, clothing, automobiles, and alcoholic beverages are among the many markets segmented by income. Budget Gourmet frozen dinners are targeted to lower-income groups, whereas the Stouffer’s line and California Pizza Kitchen frozen pizzas are aimed at higher-income consumers.
Geographic Segmentation
Geographic segmentation means segmenting markets by region of the country, city or county size, market density, or climate. Market density is the number of people or businesses within a certain area. Many companies segment their markets geographically to meet regional preferences and buying habits. Pizza Hut, for instance, gives easterners extra cheese, westerners more ingredients, and midwesterners both. Both Ford and Chevrolet sell more pickup trucks and truck parts in the middle of the country than on either coast. The well-defined “pickup truck belt” runs from the upper Midwest south through Texas and the Gulf states. Ford“owns” the northern half of this truck belt and Chevrolet the southern half.
Psychographic Segmentation
Race, income, occupation, and other demographic variables help in developing strategies but often do not paint the entire picture of consumer needs. Demographics provide basic data that can be observed about individuals, but psychographics provide vital information that is often much more useful in crafting the marketing message. Demographics provide the skeleton, but psychographics add meat to the bones. Psychographic segmentation is market segmentation by personality or lifestyle. People with common activities, interests, and opinions are grouped together and given a “lifestyle name.” For example, Harley-Davidsondivides its customers into seven lifestyle segments, from “cocky misfits” who are most likely to be arrogant troublemakers, to “laid-back camper types” committed to cycling and nature, to “classy capitalists” who have wealth and privilege. Two different managers could be described by demographics as male, managers, 35 years old, with $80,000 per year income. A marketer who just saw the demographics might create one advertisement to reach both of them. However, if the marketer knew that one of the managers was president of his homeowner’s association and captain of a rugby league team and the other manager was a holder of opera season tickets and president of the Friends of the Public Library, the messages might be designed very differently in order to be more successful.
Benefit Segmentation
Benefit segmentation is based on what a product will do rather than on consumer characteristics. For years Crest toothpaste was targeted toward consumers concerned with preventing cavities. Recently, Crest subdivided its market. It now offers regular Crest, Crest Tartar Control for people who want to prevent cavities and tartar buildup, Crest for kids with sparkles that taste like bubble gum, and another Crest that prevents gum disease. Another toothpaste, Topol, targets people who want whiter teeth—teeth without coffee, tea, or tobacco stains. Sensodyne toothpaste is aimed at people with highly sensitive teeth.
Volume Segmentation
The fifth main type of segmentation is volume segmentation , which is based on the amount of the product purchased. Just about every product has heavy, moderate, and light users, as well as nonusers. Heavy users often account for a very large portion of a product’s sales. Thus, a firm might want to target its marketing mix to the heavy-user segment. For example, in the fast-food industry, the heavy user (a young, single male) accounts for only one in five fast-food patrons. Yet this heavy user makes over 60 percent of all visits to fast-food restaurants.
Retailers are aware that heavy shoppers not only spend more, but also visit each outlet more frequently than other shoppers. Heavy shoppers visit the grocery store 122 times per year, compared with 93 annual visits for the medium shopper. They visit discount stores more than twice as often as medium shoppers, and they visit convenience/gas stores more than five times as often. On each trip, they consistently spend more than their medium-shopping counterparts.
Business Market Segmentation
Business markets are segmented differently than consumer markets. Business markets may segment based on geography, volume, and benefits, just as consumer markets are. However, organizations might also segment based on use of the product (such as a petrochemical company having one market segment for purchasers who use polyethylene for instrumentation panels and one for purchasers who use polyethylene for car seats), characteristics of purchasing function (such as purchasing committees, purchasing managers, or purchasing departments), size of the client (one segment for large customers who have different needs than smaller customers), or industry (such as segmenting food systems into restaurants or government agencies such as schools or military bases), as well as other considerations related to characteristics of business customers.
Using Marketing Research to Serve Existing Customers and Find New Customers
How do successful companies learn what their customers value? Through marketing research, companies can be sure they are listening to the voice of the customer. Marketing research is the process of planning, collecting, and analyzing data relevant to a marketing decision. The results of this analysis are then communicated to management. The information collected through marketing research includes the preferences of customers, the perceived benefits of products, and consumer lifestyles. Research helps companies make better use of their marketing budgets. Marketing research has a range of uses, from fine-tuning existing products to discovering whole new marketing concepts.
For example, everything at the Olive Garden restaurant chain, from the décor to the wine list, is based on marketing research. Each new menu item is put through a series of consumer taste tests before being added to the menu. Hallmark Cards uses marketing research to test messages, cover designs, and even the size of the cards. Hallmark’s experts know which kinds of cards will sell best in which places. Engagement cards, for instance, sell best in the Northeast, where engagement parties are popular. Birthday cards for “Daddy” sell best in the South because even adult southerners tend to call their fathers Daddy.
Marketing research can use either primary data (where the organization actually gets the data and analyzes it) or secondary data (where the organization uses data that has already been developed and published by another entity and the organization is able to utilize the data for its own purposes). There are three basic research methods used for gathering primary data: survey, observation, and experiment.
With survey research , data is gathered from respondents—in person, through the internet, by telephone, or by mail—to obtain facts, opinions, and attitudes. A questionnaire is used to provide an orderly and structured approach to data-gathering. Face-to-face interviews may take place at the respondent’s home, in a shopping mall, or at a place of business.
Observation research is research that monitors respondents’ actions without direct interaction. In the fastest-growing form of observation research, researchers use cash registers with scanners that read tags with bar codes to identify the item being purchased. Technological advances are rapidly expanding the future of observation research. Arbitron research has developed a portable people meter (PPM) about the size of a cell phone that research participants clip to their belts or any article of clothing. They agree to wear it during all waking hours. Before the study participants go to sleep, they put the PPM in a cradle that automatically sends data back to Arbitron (now Nielsen Audio). The PPM will tell the marketing research company exactly which television programs the person watched and for how long. It also records radio programs listened to, any web streaming, supermarket piped-in music, or any other electronic media that the research participant encountered during the day. 5
In the third research method, experiment , the investigator changes one or more variables—price, package, design, shelf space, advertising theme, or advertising expenditures—while observing the effects of those changes on another variable (usually sales). The objective of experiments is to measure causality. For example, an experiment may reveal the impact that a change in package design has on sales.
CONCEPT CHECK
- Define market segmentation.
- List and discuss the five basic forms of consumer market segmentation.
- What are some additional forms of business segmentation?
- How does marketing research help companies make better use of their marketing budgets?


1
A nurse is educating a pregnant client about factors that affect the fetal microbiome. Which choice, when asked what factors affect their fetus’s microbiome, indicate the need further teaching?
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The father’s microbiome
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The mother’s microbiome
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The child’s diet
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Interaction with the environment
2
What is the caloric intake a nurse should expect the provider to order for a premature infant?
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2000 kcal/day
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120 kcal/kg/day
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100 kcal/kg/day
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1500 kcal/day
3
The nurse is educating a group of pregnant clients about genetic diseases. Which disease should the nurse explain will need lifelong management due to the individual’s inability to convert lactose into glucose?
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Diverticulitis
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Ulcerative colitis
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Crohn’s disease
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Galactosemia
4
The nurse is teaching a client about the nutritional needs of their adolescent child. Which information should be included in the education?
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Young males need fewer calories than young females do.
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Adolescent females require 3000 kcal/day.
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Fast foods need to be supplanted with healthier options.
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Adolescents need less iron intake daily than other age groups.
5
The nurse is teaching an adult client how to maintain good gut bacteria. Which foods would be appropriate for the client to include in their diet to maintain good gut bacteria?
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Blueberries, strawberries, and kiwi
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Salmon and tuna
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Broccoli and cauliflower
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Yogurt, kimchi, and honey
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An older adult reports a problem with constipation. Which dietary recommendation is appropriate for this client?
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Decrease water intake.
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Increase sodium intake.
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Decrease calcium intake.
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Increase fiber intake.
7
The nurse is providing teaching to a client with ulcerative colitis. Which nutritional component should be adjusted when the client is in remission?
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Water intake
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Fiber intake
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Iron intake
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Potassium intake
8
The nurse is teaching a client about food substitutions to help improve gut health. Which substitution is appropriate for milk?
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Ice cream
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Greek yogurt
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Kefir
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Kombucha
9
The nurse is working with a client who has diverticulitis and has been prescribed ciprofloxacin. Which food should this client avoid while taking this medication?
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Red meat
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Milk
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Tomatoes
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Oatmeal
10
The nurse is providing discharge education to a client who has been prescribed amoxicillin. Which food should the nurse instruct the client to incorporate into their diet to help prevent medication-related nutrient depletion?
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Beans
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Whole grains
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Sunflower seeds
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Kale


31.5: Some Useful Constants for Astronomy (Appendix E)
| Name | Value |
|---|---|
| speed of light ( c ) | 2.9979 × 10 8 m/s |
| gravitational constant ( G ) | 6.674 × 10 −11 m 3 /(kg s 2 ) |
| Planck’s constant ( h ) | 6.626 × 10 −34 J-s |
| mass of a hydrogen atom ( M H ) | 1.673 × 10 −27 kg |
| mass of an electron ( M e ) | 9.109 × 10 −31 kg |
| Rydberg constant ( ) | 1.0974 × 10 7 m −1 |
| Stefan-Boltzmann constant (σ) | 5.670 × 10 −8 J/(s·m 2 deg 4 ) 1 |
| Wien’s law constant (λ max T) | 2.898 × 10 −3 m K |
| electron volt (energy) (eV) | 1.602 × 10 −19 J |
| energy equivalent of 1 ton TNT | 4.2 × 10 9 J |
| Name | Value |
|---|---|
| astronomical unit (AU) | 1.496 × 10 11 m |
| Light-year (ly) | 9.461 × 10 15 m |
| parsec (pc) | 3.086 × 10 16 m = 3.262 light-years |
| sidereal year (y) | 3.156 × 10 7 s |
| mass of Earth ( M Earth ) | 5.974 × 10 24 kg |
| equatorial radius of Earth ( R Earth ) | 6.378 × 10 6 m |
| obliquity of ecliptic | 23° 26’ |
| surface gravity of Earth ( g ) | 9.807 m/s 2 |
| escape velocity of Earth ( v Earth ) | 1.119 × 10 4 m/s |
| mass of Sun ( M Sun ) | 1.989 × 10 30 kg |
| equatorial radius of Sun ( R Sun ) | 6.960 × 10 8 m |
| luminosity of Sun ( L Sun ) | 3.85 × 10 26 W |
| solar constant (flux of energy received at Earth) (S) | 1.368 × 10 3 W/m 2 |
| Hubble constant (H 0 ) | approximately 20 km/s per million light-years, or approximately 70 km/s per megaparsec |


11.17: Quiz 16-Health Hazards in Construction
Indicate whether the statement is true or false.
________ 1. The purpose of the Hazard Communication Standard was to ensure that the hazards of all chemicals produced or imported into this country are evaluated and that information regarding any health hazards be transmitted to employers and their employees.
________ 2. OSHA requires that employers provide employees with effective training on the hazardous chemicals in their work places within 6 months of their initial assignment, and whenever new hazardous materials are introduced into the work place.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
3. When employees are subjected to sound levels exceeding ________ DBA for 8 hours, feasible administrative or engineering controls shall be utilized to protect against hearing loss.
a. 115 b. 92 c. 90 d. 95
4. Only _ _ and trained employees shall be assigned to install, adjust, and operate laser equipment.
a. competent b. qualified c. certified d. None of the above
5. Employers shall develop, implement and maintain at each workplace, a written Hazard Communication Program consisting of which of the following elements:
a. Labels and other forms of warning. b. SDS c. Employee training and information. d. List of known hazardous chemicals at workplace.e. Methods used to inform employees of hazards. f. All of the above.
6. Means of ________ shall be continually maintained free of all obstructions or impediments to full instant use in the case of fire or other emergency.
a. Exit b. Egress c. Entry d. Openings
Multiple Response
Identify one or more choices that best complete the statement or answer the question.
7. Under the provisions of Subpart C, every employer must ensure that each employee does not work under conditions which are ________ or otherwise dangerous to their safely or health,
a. unclean b. hazardous c. unsanitary e. Both a and d d. unhealthful f. Both b and c
8. Which of the following construction areas are required to be lit with either natural or artificial lighting during construction period?
a. Aisles b. Storage areas c. Ramps d. Runways e. All areas
Completion
Complete each statement.
9. Name the three means that the Hazard Communication standard uses to get information about health hazards into the hands of employers and their employees.
10. Define a competent person.
11. For the purposes of Subpart C, Define a confined space.


15.2: FAQ
How to access Spanish punctuation on my keyboard
For Windows users:
- Step 1 – Click on the Start button and then gear shaped icon to Open settings.
- Step 2 – Click on Time & Language.
- Step 3 – Click on Language from the left menu.
- Step 4 – Click on English (United states) to expand and then click on Options.
- Step 5 – Scroll down and then click on + Sign beside Add a language.
- Step 6 – Select United states – International from the list.
- Step 7 – Now, in the Taskbar , click on your language .
- Step 8 – Now, select United states – International from the list.
For step by step instruction please see the following article .
If you follow all the steps that you have the US International keyboard set then,
Make sure it is turned on (look at the bottom right side corner of your screen and you should see ENG INTL)
Use the right side ALT key and then the vowel and it should put the accent on the vowel


13.3: Feminism versus Feminisms
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If you have a gender communication course on your campus you may have heard students refer to it as a “women’s class,” or even more misinformed, as a course in “male bashing.” When professors that teach this course hear such remarks, they are often saddened and frustrated: sad because those descriptors define the course as an unsafe place for male students, and frustrated because there is often a common misconception that only females are gendered. Courses in gender and communication serve as powerful places for both female and male students to learn about their own gender constructions and its influence on their communication with others.
Perhaps one of the reasons for the popular misconception that gender is exclusively female is that it has somehow been linked with the other f-word—-feminism. What sorts of images or thoughts come to mind when you hear or read the word feminism? Are they positive or negative? Where did you learn them? Is this a label you would use to define yourself? Why or why not?
Just as gender is not synonymous with biological sex, it is also not synonymous with feminism. As we stated earlier, gender refers to the socially constructed definitions of what it means to be female or male in a given culture. Feminism is a socio-political and philosophical position about the relationships between men, women and power. As a result, there is not one kind of feminism (Lotz; Bing; Marine), thus this section is entitled feminisms. Just as members of republican, democratic, green, and independent political parties disagree and agree about values, causes of social conditions, and policy, so do feminists. Below we provide brief descriptions of thirteen types of feminism. These are not all the feminisms that exist but some of the most common in which you may have already come into contact.
- Liberal Feminism . Liberal Feminism is one of the most common types of feminism and is institutionalized in the organization, the National Organization of Women (NOW). Basic beliefs of this position are that women and men are alike in important ways and should receive equal treatment. Accordingly, supporters work for causes such as “equal pay for equal work,” gender equity in political representation, as well as equality in other social, professional, and civic causes. This is movement is often referred to as second wave feminism.
- Radical Feminism . Growing out of a discontentment with their treatment in New Left political movements of the 1960’s, many women began addressing issues of oppression on a systematic level.  Communication strategies such as “consciousness raising” and “rap groups,” and positions such as the “personal is political” grew out of this movement.
- Ecofeminism . Coming into consciousness in 1974, Ecofeminism unites feminist philosophy with environmental and ecological ideas and ethics. Ecofeminists see the oppression of women as one example of an overall oppressive ideology. Thus, supporters of this position are not just concerned with ending oppression of women but changing the value structure that supports oppression of the earth (i.e. deforestation), oppression of children (i.e. physical and sexual abuse), and oppression of animals (i.e. eating meat.).
- Marxist Feminism . Stemming from the work of Karl Marx, Marxist feminism focuses on the economic forces that work to oppress women. Specifically, Marxist feminists question how a capitalist system supports a division of labor that privileges men and devalues women. If you thought that women were catching up to men economically, think again. The U.S. census found that the salary gap between men and women is not improving. In 2014 women earned 78 cents for every dollar men made – the yearly wage difference could be about $39,157 for women and $50,033 for men. This is a classic example of economic oppression of women in our society.
- Socialist Feminism . Extending Marxist feminist thought, Socialist Feminists believe that women’s unpaid labor in the home is one of the fundamental causes of sexism and oppression of women. Moreover, patriarchy, the system of sex oppression is connected with other forms of oppression, such as race and class.
- Womanist . One criticism of liberal and radical feminism is that these two movements have been largely a movement for and about white women. These movements have often failed to address issues such as the interlocking nature of race, class, and sex oppression. Womanists, then, connect issues of race and sex when working against oppression.
- Lesbian Feminism . This type of feminism is connected with one’s sexual orientation. Important issues for this feminist perspective include fighting for marriage and adoption rights, fair and safe treatment in the workplace, and women’s health issues for gay and lesbian couples.
- Separatist Feminism . Instead of fighting against the patriarchal system, this position maintains that patriarchal systems of oppression cannot be changed. Thus, the best way to deal with patriarchy is to leave it. Separatists work toward the formation of women-centered communities that are largely removed from the larger society.
- Power Feminism . Power Feminism emerged in the 1990’s and urges women not to be victims. Power is derived not by changing a patriarchal structure but by gaining success and approval from traditionally male dominated activities. Although it labels itself feminist, this position is actually contradictory to some very basic feminist tenants. Instead of recognizing the interplay of cultural institutions and sexual oppression, Power Feminism takes a “blame the victim” position and asserts that if women are denied opportunity then it is their fault.
- Revalorist Feminism . Those who are Revalorist Feminists are dedicated to uncovering women’s history through writings, art, and traditional activities such as sewing. Once uncovered, they can be incorporated into educational curriculum, used as a basis for reevaluating existing theoretical and methodological perspectives, and receive a more positive or accepted place in society. Their approach is to move women’s positions, ideas, and contributions from the margin to the center.
- Structural Feminism . Unlike Liberal Feminists who contend that women and men are alike in important ways, Structural Feminism holds that men and women are not alike due to different cultural experiences and expectations. These different experiences produce dissimilar characteristics. Because women can bear children, for example, they are more nurturing and caring.
- Third Wave Feminism . Third Wave Feminism believes the best way to change patriarchy is to not replicate the strategies of second wave feminism, although it is vital to acknowledge their contributions. Instead, a feminist agenda should focus more on practice than theory, foster positive connections and relationships between women and men, and be inclusive of diversity issues and diverse people.
- Post Feminism . Post Feminism suggests that feminism has made sufficient progress at eliminating sexism in our society. There is a move away from sex (women and men) and a focus on the human experience. Though its members aren’t in 100% agreement of the meaning, they generally agree that feminism is over and we have reached equality. However, there is much disagreement about post feminism because many women and men experience inequality daily.
Just as there are many women’s movements, did you know that there are men’s movements too? Men’s movements also vary in their goals and philosophies. Some men’s movements are strong supporters of feminist positions while others resist feminist movements and seek to return to a time where sex roles were clearly defined and distinct. Just as women can consider themselves feminists, many men consider themselves as feminists too!
- Pro-Feminist Men . Pro-feminist men are the most closely aligned with the Liberal Feminist position. They share the belief that women and men are alike in important ways, thus, should have access to equal opportunities in work, politics, and the home. They do not stop at challenging the traditional roles for women. They also work for expanding the roles and opportunities of men. The ability to express emotions, to seek nurturing relationships, and to fight against cultural sexism are all concerns of Pro-Feminist Men. The organization NOMAS (National Organization for Men Against Sexism) represents this group of men.
- Free Men . Compared to Pro-Feminist men, Free Men – represented by organizations such as NOM (National Organization of Men), the National Coalition for Free Men, and MR, Inc. (Men’s Rights, Incorporated) – seek to restore the macho and independent image of men in culture. While they may acknowledge that women do suffer gender and sex oppression, the oppression leveled at men is far greater. Arguing that feminism has emasculated men, Free Men want women to return to roles of subordination and dependence.
- Mythopoetic . Founded by poet, Robert Bly, this group of men is a combination of the previous two perspectives. Although they believe that the man’s role is limiting and damaging to both men and women, they argue that there was a time when this was not the case. Masculinity, they claim, was originally tied to connection with the earth and it was the advent of technology, resulting in modernization and industrialization, and feminism that ripped men from their roots.
- Promise Keepers . Strongly aligned with a Christian belief system, Promise Keepers urge men to dedicate themselves to God and their families. They ask men to take a servant leadership role in their families, being involved in their homes as well as in work contexts.
- Million Man March . Like the Womanists who believe that a majority of feminisms do not adequately address issues of race and class oppression, many African-American males do not feel represented in the majority of men’s movements. Thus, on October 18, 1995, the leader of the nation of Islam, Minister Louis Farrakhan, organized the Million Man March to bring African American men together in Washington, D.C. Like, the Promise Keepers, this group asked men to dedicate themselves spiritually with the belief that this will help strengthen families. Since the march, two decades ago, people gather to observe the Holy Day of Atonement and reflect on the messages spoken that day and the ideas they wish to spread.
- Walk a Mile in Her Shoes . This annual event raises awareness of sexualized violence against women–by men. It was founded in 2001 by Frank Baird as a mile walk for men in women’s heels. The idea is to get men to walk the walk and then talk the talk to end sexualized violence. It is not only an event to raise awareness of violence against women but to offer resources to those needed and ultimately creating a united gender movement.
With the different groups or philosophical positions all communicating aspects of gender, the next section examines how gender is related to communication. Specifically we discuss what we study, gender development theories, prominent scholars in this specialization, and research methods used to study gender and communication.
Contributions and Affiliations
- Survey of Communication Study. Authored by : Scott T Paynton and Linda K Hahn. Provided by : Humboldt State University. Located at : en.wikibooks.org/wiki/Survey_of_Communication_Study/Preface. License : CC BY-SA: Attribution-ShareAlike


During the evolution of the human species, we appear to have lost the ability to rely on instinctive behavior as we developed extraordinary abilities to learn and adapt to the conditions facing us in our environment. In addition, we can pass on that learning to other members of our social group. This is the basis for culture, and the success of the human species is a testament to the advantages of this approach to survival. However, this transition from instinct to learning and culture has not resulted in the elimination of biological influences on our behavior. Certain groups of people, usually a minority of the population, retain biological predispositions to behave and react in certain distinct ways. To a lesser extent, all of us have some degree of these biological predispositions.


13.8: Alarm Will Sound
Alarm Will Sound is an instrumental ensemble based in New York City. The group was initially formed by students at the Eastman School of Music in Rochester, NY. While pursuing degrees in music, founders Gavin Chuck and Alan Pierson got into conversation about the limited opportunities for the performance of New Music (a standard term for recent, often experimental, art music compositions, many of which might be classified as avant-garde )—and especially minimalist music. They recruited a group of interested performers and started a concert series. Upon graduating from Eastman, the members of the ensemble decided that they wanted to keep working together, and in 2001 Alarm Will Sound was founded.
The group’s first concert under their new name took place on May 24, 2001, in New York City’s Miller Theater. Unsurprisingly, given their collective interests, the program explored the music of minimalist composer Steve Reich (b. 1936). Reich was at the forefront of the development of minimalism in the 1960s. Although minimalist composers take a variety of approaches to their work, they share an interest in developing extended compositions from limited musical material. Reich himself has always detested the term “minimalism,” preferring the more descriptive “pattern and process music.” This is fitting: Most minimalist composers employ fixed transformative processes in their work.
Reich’s Compositional Processes
Reich’s earliest experiments were completed using tape loops . He discovered that if he played two identical loops of audio tape at slightly different speeds, he could produce a dazzling and constantly shifting array of effects, opening up a world of sound that could never be detected in the untransformed material. Reich’s first completed tape piece did not even use musical sounds. Instead, he built Come Out 9 (1966) using a clip from an interview with Daniel Hamm, one of the Harlem Six—a group of black men (mostly teenagers) who were coerced into confessing to a 1964 murder and denied adequate representation by the courts. Although the men were convicted by an all-white jury in 1965, all but one of the charges were eventually overturned. In Come Out , we hear Hamm explaining the means to which he had to resort in order to convince police that he and his co-defendants had been beaten in jail and required medical attention.
Steve Reich created his pioneering tape loop composition Come Out in 1966.
Come Out was initially a byproduct of a sound collage that Reich built at the request of civil rights activist Truman Nelson, but it ended up being a broadly influential minimalist experiment. Over the course of the 13-minute work, Hamm’s voice slowly dissolves into a cacophony of rhythms and timbres. The words soon become unintelligible as the listener’s interest shifts to the element of pure sound. Although it is almost impossible to detect the gradual changes that are taking place, no two seconds of the recording are the same. Sustained attention is rewarded with an inimitable sonic experience.
Reich soon applied similar techniques to musical material, at the same time developing new approaches to facilitating gradual change over extended periods of time. Reich was a highly trained musician, having studied at the Juilliard School in New York City and Mills College in Oakland, CA. He also had omnivorous tastes: He was equally enthralled with jazz, the music of Bach and Vivaldi, rock, and Stravinsky’s The Rite of Spring . Later, he took opportunities to study non-Western traditions, including Balinese gamelan and West African drumming. All of these influenced his mature style.
Tehillim
On their inaugural concert, Alarm Will Sound performed two large-scale Reich works for orchestral ensemble and singers: Tehillim (1981) and The Desert Music (1983). We will consider Tehillim , which, by Reich’s own account, represented his first attempt to engage musically with his Jewish heritage. The texts, sung in Hebrew by four female voices, are taken from the Book of Psalms (the original Hebrew word for which is “Tehillim,” which literally means “praises”). In the first movement, we hear four lines from Psalm 19:
The heavens declare the glory of God;
the skies proclaim the work of his hands.
Day after day they pour forth speech; night after night they reveal knowledge.
They have no speech, they use no words; no sound is heard from them.
Yet their voice goes out into all the earth, their words to the ends of the world.
In the heavens God has pitched a tent for the sun.
At first, a solo voice is accompanied only by a tambourine without jingles (intended by Reich to evoke the small drum mentioned in Psalm 150) and clapping—another mode of rhythmic accompaniment that was in use during Biblical times. We hear the entire Psalm text sung to a continuous melody, which is shaped by the rhythms of the Hebrew words. This is an atypical way for Reich to open a piece of music, but he soon begins applying transformations.
|
Time |
Form |
What to listen for |
|---|---|---|
|
0’00” |
Melody |
The Psalm text is presented by a solo singer and accompanied by tambourine and clapping |
|
0’36” |
Melody (repetition) |
Another singer repeats the melody, which is now doubled by clarinet |
|
1’12” |
Canon in 2 voices |
The two singers perform the melody in canon |
|
1’47” |
Canon in 2 voices (two repetitions) |
The strings enter with sustained harmonies |
|
2’59” |
Canon in 4 voices |
The tempo slows; each phrase is repeated many times; the voices are doubled by reed organ and accompanied by maracas; the string harmonies continue |
|
8’49” |
Melody |
The solo singer is doubled by clarinet and accompanied by tambourine, clapping, and maracas |
|
9’24” |
Melody (repetition) |
The string harmonies return |
|
9’58” |
Melody (repetition) |
A second singer harmonizes below the melody |
|
10’32” |
Melody (final statement) |
The texture thins as elements disappear one by one |
The second time through the melody, the singer is doubled by a clarinet, while a second percussive accompaniment of tambourine and clapping enters in canon with the first. Next, we hear the melody in a two-voice canon, one singer echoing the other. Soon after the canon begins, the strings enter with sustained harmonies. At the conclusion of this turn through the complete melody, the tempo slows and the texture fractures into a four-voice canon. The four singers repeat each individual line of the Psalm many times. They are doubled by electric organ, which contributes a reedy timbre, and accompanied by maracas. The sustained string harmonies gradually shift, seemingly out of time with the voices. Finally, the original soloist—again doubled by clarinet—assumes the melody once more, to the accompaniment of drums and maracas. She is briefly harmonized by one of the other singers, but the movement ends much as it began.
While Tehillim is quite different from Come Out in all surface respects, we can see how Reich’s basic compositional process is consistent. The textures in Tehillim —as in Come Out —are created from the increasingly complex layering of limited sound material. In the case of Tehillim , Reich relies on rhythmic and melodic canons, augmented by slow-moving, kaleidoscopic harmonies.
Orchestrating Aphex Twin
The members of Alarm Will Sound were brought together by their love for music like Tehillim , and in their early years they found a great deal of success staging concerts that highlighted the work of individual living composers. However, they also shared a passion for popular music— in particular, the innovative electronic dance music of Aphex Twin. Members of the ensemble began discussing the possibility (and purpose) of recreating Aphex Twin’s music using acoustic instruments.
According to founder Gavin Chuck, the idea was controversial: “There were heated debates about the nature of digital vs. acoustic sound, and of machine precision vs. human expressiveness. There were disagreements about whether we should be as faithful as possible to the originals, or interpret them more openly.” Despite the varied opinions about the merit of such a project, Alarm Will Sound eventually took it on. Their work culminated in the 2005 album Acoustica , which primarily featured arrangements taken from Aphex Twin’s 2001 album Drukqs .
Whether or not all of the work required to make and record these arrangements was worthwhile is debatable. We will consider the opening track from Acoustica , “Cock/Ver10.”10 One might argue that Alarm Will Sound’s limited sound palette and acoustic means of production are inferior to the programmed beats, digitally- refined timbres, and studio effects of Aphex Twin’s original11—or one might prefer the sounds of orchestral instruments. It is hard not to be impressed by the skill of the arranger, Stefan Freund, who translated Aphex Twin’s track into an orchestral score, and by the individual performers, who place complex rhythms and melodic gestures in exactly the right place.
|
“Cock/Ver10” 10. Composer: Aphex Twin (arr. Stefan Freund) Performance: Alarm Will Sound (2011) |
|
11. “Cock/Ver10” was included in Aphex Twin’s 2001 album Drukqs. |
From Chuck’s perspective, the strength of the project lay in its capacity to connect the ensemble with new audiences and put their artistic values on display. It became, in his words, “an important platform from which to pursue a wide-ranging artistic vision that doesn’t worry too much about genre—electronic vs. acoustic, high-modernist vs. pop-influenced, conventional classical concert vs. multimedia experience.” In short, by recording the works of Aphex Twin, Alarm Will Sound proved that they were eager to embrace good music from unexpected quarters.


<IP_ADDRESS>: Preface
Preface
Preface License: Public Domain
This book is not about heroes. English poetry is not yet fit to speak of them.
Nor is it about deeds, or lands, nor anything about glory, honour, might, majesty, dominion, or power, except War.
Above all I am not concerned with Poetry.
My subject is War, and the pity of War.
The Poetry is in the pity.
Yet these elegies are to this generation in no sense consolatory. They may be to the next. All a poet can do today is warn. That is why the true Poets must be truthful.
(If I thought the letter of this book would last, I might have used proper names; but if the spirit of it survives - survives Prussia - my ambition and those names will have achieved fresher fields than Flanders...)


3.21: Primary extinction
The primary extinction is responsible for the loss of intensity due to dynamic effect inside every block of a mosaic crystal . At the Bragg angle, each incident wave can undergo multiple reflections from different atomic planes; each scattering introduced causes a phase difference of λ/4 = π/2 so that along each direction waves differing by an even number of scattering, i . e . by nπ in phase, interfere , whose intensity decreasing rapidly with the number of scatterings. Because of the decrease in intensity of waves multiply scattered, the effect of waves differing by more than two scatterings can normally be neglected: in each direction one observes then the destructive interference between waves having a significant difference in intensity and an overall reduction of the intensity with respect to the intensity given by the kinematical theory .


7.1: Effective Classroom Management
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Icebreaker
Consider these two scenarios and imagine yourself as a teacher in that situation. In small groups, reflect on what could be some of the strategies you would implement to create an effective learning atmosphere? What could be some of the changes that you would make in your classroom to overcome such situations?
Scenario A: This is an excerpt from a professional journal kept by Kelvin Seifert, a Kindergarten teacher.
20xx-11-14: Today my student Carol sat in the circle, watching others while we all played Duck, Duck, Goose (in this game, one student is outside the circle, tags another student who then chases the first person around the circle). Carol’s turn had already passed. Apparently, she was bored, because she flopped on her back, smiling broadly, rolling around luxuriously on the floor in the path of the other runners. Several classmates noticed her, smiled or giggled, began flopping down as well. One chaser tripped over a “flopper” “Sit up, Carol,” said I, the ever-vigilant teacher. “You’re in the way.” But no result. I repeated this twice, firmly; then moved to pick her up. Instantly Carol ran to the far side of the gym, still smiling broadly. Then her best friend ran off with her. Now a whole new game was launched, or really two games: “Run-from-the-teacher” and “Enjoy-being-watched-by-everybody.” A lot more exciting, unfortunately, than Duck, Duck, Goose! (Seifert & Sutton, 2009)
Scenario B: An excerpt from Kelvin’s same journal several years later, when he was teaching math in high school:
20xx-3-4: The same four students sat in the back again today, as usual. They seem to look in every direction except at me, even when I’m explaining material that they need to know. The way they smile and whisper to each other, it seems almost like they are “in love” with each other, though I can’t be sure who loves whom the most. Others—students not part of the foursome—seem to react variously. Some seem annoyed, turn the other way, avoid talking with the group, and so on. But others seem almost envious—as if they want to be part of the “in” group, too, and were impressed with the foursome’s ability to get away with being inattentive and almost rude. Either way, I think a lot of other students are being distracted. Twice during the period today, I happened to notice members of the group passing a note, and then giggling and looking at me. By the end, I had had enough of this sort of thing, so I kept them in briefly after class and asked one of them to read the note. They looked a bit embarrassed and hesitant, but eventually one of them opened the note and read it out loud. “Choose one.” it said. “Mr. Seifert looks (1) old ____, (2) stupid____, or (3) clueless____.” (Seifert & Sutton, 2009)
Kelvin’s experiences in managing these very different classrooms taught him what every teacher knows or else quickly learns ; management matters a lot. But his experiences also taught him that management is about more than correcting the misbehaviors of individuals and more than just discipline. Classroom management is also about orchestrating or coordinating entire sets or sequences of learning activities so that everyone , misbehaving or not, learns as easily and productively as possible. Educators sometimes , therefore , describe good management as the creation of a positive learning environment , because the term calls attention to the totality of activities and people in a classroom, as well as to their goals and expectations about learning (Jones & Jones, 2007). Management according to Kelvin refers to individual students’ behavior and learning, and in speaking of the learning environment he more often meant the overall “feel” of the class as a whole ( Seifert & Sutton, 2009).
Why is Classroom Management crucial?
Managing the learning environment is both a major responsibility and an on-going concern for all teachers, even those with years of experience (Good & Brophy, 2002). There are several reasons. In the first place, a lot goes on in classrooms simultaneously, even when students seem to be doing only one task in common. Twenty-five students may all seem to be working on a sheet of math problems. But look more closely: several may be stuck on a particular problem, each for different reasons. A few others have worked only the first problem or two and are now chatting quietly with each other instead of continuing. Still, others have finished and are wondering what to do next. At any one moment, each student needs something different, such as different information, different hints, or different kinds of encouragement. Such diversity increases even more if the teacher deliberately assigns multiple activities to different groups or individuals (for example, if some students do a reading assignment while others do the math problems).
Another reason that managing the environment is challenging is because a teacher cannot predict everything that will happen in a class. A well-planned lesson may fall flat on its face, or take less time than expected, and you find yourself improvising to fill class time. On the other hand, an unplanned moment may become a wonderful, sustained exchange among students, and prompt you to drop previous plans and follow the flow of discussion. Interruptions happen continually: a fire drill, a drop-in visit from another teacher or the principal, a call on the intercom from the office. An activity may indeed turn out well, but also rather differently than you intended; you, therefore, have to decide how, if at all, to adjust the next day’s lesson to allow for this surprise.
A third reason for the importance of management is that students may form opinions and perceptions about your teaching that are inconsistent with your own. What you intend as encouragement for a shy student may seem to the student herself like “forced participation.” An eager, outgoing classmate watching your effort to encourage the shy student, moreover, may not see you as either encouraging or coercing, but as overlooking or ignoring other students who already want to participate. The variety of perceptions can lead to surprises in students’ responses—most often small ones, but occasionally major.
At the broadest, society-wide level, classroom management challenges teachers because public schooling is not voluntary. Students’ presence in a classroom is therefore not a sign, in and of itself, that they wish to learn. Instead, students’ presence is just a sign that an opportunity exists for teachers to motivate students to learn. Some students, of course, do enjoy learning and being in school, while others enjoy school because teachers have worked hard to make classroom life pleasant and interesting. Those students become motivated because you have successfully created a positive learning environment and have sustained it through skillful management.
Fortunately, it is possible to earn this sort of commitment from many students, and this chapter describes ways of doing so. We begin with ways of preventing management problems from happening by increasing students’ focus on learning. The methods include ideas about arranging classroom space, about establishing procedures, routines, and rules, and about communicating the importance of learning to students and parents. After these prevention-oriented discussions, we look at ways of refocusing students when and if their minds or actions stray from the tasks at hand. As you probably know from being a student, bringing students back on task can happen in many ways, and the ways vary widely in the energy and persistence required of the teacher. We try to indicate some of these variations, but because of space limitations and because of the richness of classroom life, we cannot describe them all (Seifert & Sutton, 2009).
Contributors and Attributions
- Foundations of Education. Authored by : SUNY Oneonta Education Department. License : CC BY: Attribution
- Reading time in a pre-k classroom photo. Authored by : Verda L. Parker. Provided by : Marine Corp Logistics Base Albany. Located at : https://www.albany.marines.mil/Photos/igphoto/2001476084/ . License : Public Domain: No Known Copyright


8.6: Real needs, all families
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- Elizabeth B. Pearce
- Linn-Benton Community College via OpenOregon
There is a great deal of discussion in this country about the politics, legality, and ethics of our immigration practices. In this text we discuss some of the aspects that directly affect immigrant families and their descendants who are living in the United States right now. As discussed in the Social Constructions chapter, laws have primarily been designed to foster inexpensive labor (the immigrants) to benefit the existing landowners, business owners, and consumers already residing in the country. Regardless of employment status, wage, and purpose for coming to this country, these families have the same needs as other residents. In addition, they are navigating new structures such as the health care and insurance system, differing government practices, and perhaps a new language at the same time as they are caring for their children, accessing schooling, finding a place to live, and fostering healthy family routines.
The authors view all families, regardless of documentation status, as “contemporary families in the United States”, the subjects of this course and this textbook. We believe that the well-being of each family in the U.S. is of value in and of itself. In addition, every family affects all the other families within the spheres of the neighborhood, the places of worship, the retail establishments, schools, parks, and employment. As we discuss the laws that affect immigrant families, and the ways in which employment and citizenship practices reflect a lack of justice, think about these families’ needs and rights just as you would for any other family.
It is not only laws that work institutionally to foster immigration, but also businesses and corporations. In this excerpt of an article from The Conversation, applied research demonstrates how undocumented labor practices are encouraged.
A Preference for the Undocumented
by Lise Nelson, Associate Professor of Women’s, Gender, and Sexuality Studies and Associate Professor of Geography, Pennsylvania State University
My colleagues and I have conducted research in U.S. communities where undocumented Latino immigrants live and work, including interviews with their employers. We focused on small businesses in rural Colorado and Georgia. We investigated how and why entrepreneurs in construction, landscaping and low-wage service industries began actively seeking to hire undocumented Latino immigrants starting in the mid-1990s even though immigrant workers were largely absent from these places prior to that time.
What started for many as a short-term solution to fill a labor gap turned into a preference for hiring undocumented workers. Recruitment efforts thus intensified, causing a significant growth in the Latino immigrant population in both places. In a rural Georgia county, the Latino population increased 1,760 percent between 1990 and 2010, due to the increase in these recruitment efforts by businesses involved in construction, landscaping, cleaning and food provision.
Why did businesses that rely on low-wage workers develop a preference for immigrants and particularly undocumented ones?
In interviews, employers describe the undocumented Latino immigrants they hire as among the most reliable, honest and hardworking employees they have ever had. As one Georgia employer described it:
“I think about, if I had to get rid of the nine Hispanics that I’ve got tomorrow and replace them with locals, to get the same amount of output, I would have to hire fifteen instead of nine and I’d probably have to pay them $1 an hour more each, and that figures up quick. And there’s sometimes that you just can’t find people to do the work.”
Most employers we interviewed began by the late 1990s to organize their businesses around the productivity and discipline offered by an undocumented immigrant workforce.
When we talk about how immigrant families affect other families in the United States we must understand that immigrant families are deeply interwoven into communities, schools, for-profit businesses, services, and all aspects of society. Kinship groups themselves can be mixed, made up of recent immigrants, second-generation citizens, indigenous, and citizens whose families have lived in the United States for hundreds of years. It’s difficult to unwind the complexity of these relationships, but it is critical to understand that we are intertwined and to continue to educate ourselves about these economic, familial, and societal relationships.
Licenses and Attributions
Open Content, Shared Previously
“A Preference for Undocumented” is from “ Trump’s wall ignores the economic logic of undocumented immigrant labor ” by Lise Nelson in The Conversation . License: CC BY-ND 4.0 .
Figure 8.12. “ Vietnamese members speak to Representative Gerry Pollett ” by OneAmerica . License: CC BY-NC-SA 2.0 .
Figure 8.13. “ Quilt – stars and interwoven steps ” by Ramson . License: CC BY-NC-SA 2.0 .


3.3.1: The First Book of Moses--Called Genesis (1-1-2-3)
The First Book of Moses: Called Genesis (1:1-2:3)
(The King James Version of the Bible)
In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
And God said, “Let there be light: and there was light.” And God saw the light, that it was good: and God divided the light from the darkness. And God called the light “Day,” and the darkness he called “Night.” And the evening and the morning were the first day.
And God said, “Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.” And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament, and it was so. And God called the firmament “Heaven.” And the evening and the morning were the second day. And God said, “Let the waters under Heaven be gathered together unto one place, and let the dry land appear,” and it was so.
And God called the dry land “Earth,” and the gathering together of the waters called the “Seas,” and God saw that it was good. And God said, “Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth,” and it was so. And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind, and God saw that it was good.
And the evening and the morning were the third day. And God said, “Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years. And let them be for lights in the firmament of the heaven to give light upon the earth,” and it was so. And God made two great lights: the greater light to rule the day, and the lesser light to rule the night. He made the stars also. And God set them in the firmament of heaven to give light upon the earth, and to rule over the day and over the night, and to divide the light from the darkness. And God saw that it was good. And the evening and the morning were the fourth day.
And God said, “Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.” And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind. And God saw that it was good. And God blessed them, saying, “Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.” And the evening and the morning were the fifth day.
And God said, “Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind,” and it was so. And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind, and God saw that it was good.
And God said, “Let us make man in our image, after our likeness; and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.” So God created man in his own image, in the image of God created he him; male and female created he them. And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
And God said, “Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat. And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat,” and it was so.
And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day. Thus the heavens and the earth were finished, and all the host of them.
And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made. And God blessed the seventh day, and sanctified it; because that in it he had rested from all his work which God created and made.


5.1E: Power Functions (Exercises)
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section 3.1 EXERCISE
Find the long run behavior of each function as \(x \to \infty\) and \(x \to -\infty\)
1. \(f(x)=x^{4}\)
2. \(f(x)=x^{6}\)
3. \(f(x)=x^{3}\)
4. \(f(x)=x^{5}\)
5. \(f(x)=-x^{2}\)
6. \(f(x)=-x^{4}\)
7. \(f(x)=-x^{7}\)
8. \(f(x)=-x^{9}\)
Find the degree and leading coefficient of each polynomial
9. \(4x^{7}\)
10. \(5x^{6}\)
11. \(5-x^{2}\)
12. \(6+3x-4x^{3}\)
13. \(-2x^{4} - 3x^{2} + x-1\)
14. \(6x^{5} -2x^{4} + x^{2} + 3\)
15. \((2x+3)(x-4)(3x+1)\)
16. \((3x+1)(x+1)(4x+3)\)
Find the long run behavior of each function as \(x \to \infty\) and \(x \to -\infty\)
17. \(-2x^{4} - 3x^{2} + x-1\)
18. \(6x^{5} -2x^{4} + x^{2} + 3\)
19. \(3x^{2} + x-2\)
20. \(-2x^{3} + x^{2} -x+3\)
21. What is the maximum number of \(x\)-intercepts and turning points for a polynomial of degree 5?
22. What is the maximum number of \(x\)-intercepts and turning points for a polynomial of degree 8?
What is the least possible degree of the polynomial function shown in each graph?
23. 24 .25. 26.
27. 28. 29. 30.
Find the vertical and horizontal intercepts of each function.
31. \(f(t)=2(t-1)(t+2)(t-3)\)
32. \(f(x)=3(x+1)(x-4)(x+5)\)
33. \(g(n)=-2(3n-1)(2n+1)\)
34. \(k(u)=-3(4-n)(4n+3)\)
- Answer
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1. As \(x \to \infty\), \(f(x) \to \infty\) As \(x \to -\infty\), \(f(x) \to \infty\)
3. As \(x \to \infty\), \(f(x) \to \infty\) As \(x \to -\infty\), \(f(x) \to -\infty\)
5. As \(x \to \infty\), \(f(x) \to -\infty\) As \(x \to -\infty\), \(f(x) \to -\infty\)
7. As \(x \to \infty\), \(f(x) \to -\infty\) As \(x \to -\infty\), \(f(x) \to \infty\)
9. \(7^{\text{th}}\) Degree, Leading coefficient 4
11. \(2^{\text{nd}}\) Degree, Leading coefficient -1
13. \(4^{\text{th}}\) Degree, Leading coefficient -2
15. \(3^{\text{rd}}\) Degree, Leading coefficient 6
17. As \(x \to \infty\), \(f(x) \to -\infty\) As \(x \to -\infty\), \(f(x) \to -\infty\)
19. As \(x \to \infty\), \(f(x) \to \infty\) As \(x \to -\infty\), \(f(x) \to \infty\)
21. intercepts: 5, turning points: 4
23. 3
25. 5
27. 3
29. 5
31. Horizontal Intercepts (1, 0), (-2, 0), (3, 0) Vertical Intercept (0, 12)
33. Horizontal Intercepts (1/3, 0) (-1/2. 0) Vertical Intercept (0, 2)


7.10: The F Distribution and the F-Ratio
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The distribution used for the hypothesis test is a new one. It is called the \(F\) distribution, named after Sir Ronald Fisher, an English statistician. The \(F\) statistic is a ratio (a fraction). There are two sets of degrees of freedom; one for the numerator and one for the denominator.
For example, if \(F\) follows an \(F\) distribution and the number of degrees of freedom for the numerator is four, and the number of degrees of freedom for the denominator is ten, then \(F \sim F_{4,10}\).
The \(F\) distribution is derived from the Student's \(t\)-distribution. The values of the \(F\) distribution are squares of the corresponding values of the \(t\)-distribution. One-Way ANOVA expands the \(t\)-test for comparing more than two groups. The scope of that derivation is beyond the level of this course.
To calculate the \(F\) ratio, two estimates of the variance are made.
- Variance between samples: An estimate of \(\sigma^{2}\) that is the variance of the sample means multiplied by \(n\) (when the sample sizes are the same.). If the samples are different sizes, the variance between samples is weighted to account for the different sample sizes. The variance is also called variation due to treatment or explained variation.
- Variance within samples: An estimate of \(\sigma^{2}\) that is the average of the sample variances (also known as a pooled variance). When the sample sizes are different, the variance within samples is weighted. The variance is also called the variation due to error or unexplained variation.
- \(SS_{\text{between}} = \text{the sum of squares that represents the variation among the different samples}\)
- \(SS_{\text{within}} = \text{the sum of squares that represents the variation within samples that is due to chance}\).
To find a "sum of squares" means to add together squared quantities that, in some cases, may be weighted. We used sum of squares to calculate the sample variance and the sample standard deviation in discussed previously.
\(MS\) means "mean square." \(MS_{\text{between}}\) is the variance between groups, and \(MS_{\text{within}}\) is the variance within groups.
Calculation of Sum of Squares and Mean Square
- \(k =\) the number of different groups
- \(n_{j} =\) the size of the \(j^{th}\) group}
- \(s_{j} =\) the sum of the values in the \(j^{th}\) group
- \(n =\) total number of all the values combined (total sample size): \[n= \sum n_{j}\]
- \(x =\) one value: \[\sum x = \sum s_{j}\]
- Sum of squares of all values from every group combined: \[\sum x^{2}\]
- Between group variability: \[SS_{\text{total}} = \sum x^{2} - \dfrac{\left(\sum x^{2}\right)}{n}\]
- Total sum of squares: \[\sum x^{2} - \dfrac{\left(\sum x\right)^{2}}{n}\]
- Explained variation: sum of squares representing variation among the different samples: \[SS_{\text{between}} = \sum \left[\dfrac{(s_{j})^{2}}{n_{j}}\right] - \dfrac{\left(\sum s_{j}\right)^{2}}{n}\]
- Unexplained variation: sum of squares representing variation within samples due to chance: \[SS_{\text{within}} = SS_{\text{total}} - SS_{\text{between}}\]
- \(df\)'s for different groups (\(df\)'s for the numerator): \[df = k - 1\]
- Equation for errors within samples (\(df\)'s for the denominator): \[df_{\text{within}} = n - k\]
- Mean square (variance estimate) explained by the different groups: \[MS_{\text{between}} = \dfrac{SS_{\text{between}}}{df_{\text{between}}}\]
- Mean square (variance estimate) that is due to chance (unexplained): \[MS_{\text{within}} = \dfrac{SS_{\text{within}}}{df_{\text{within}}}\]
\(MS_{\text{between}}\) and \(MS_{\text{within}}\) can be written as follows:
\[MS_{\text{between}} = \dfrac{SS_{\text{between}}}{df_{\text{between}}} = \dfrac{SS_{\text{between}}}{k - 1}\]
\[MS_{\text{within}} = \dfrac{SS_{\text{within}}}{df_{\text{within}}} = \dfrac{SS_{\text{within}}}{n - k}\]
The one-way ANOVA test depends on the fact that \(MS_{\text{between}}\) can be influenced by population differences among means of the several groups. Since \(MS_{\text{within}}\) compares values of each group to its own group mean, the fact that group means might be different does not affect \(MS_{\text{within}}\).
The null hypothesis says that all groups are samples from populations having the same normal distribution. The alternate hypothesis says that at least two of the sample groups come from populations with different normal distributions. If the null hypothesis is true, \(MS_{\text{between}}\) and \(MS_{\text{within}}\) should both estimate the same value.
The null hypothesis says that all the group population means are equal. The hypothesis of equal means implies that the populations have the same normal distribution, because it is assumed that the populations are normal and that they have equal variances.
\(F\)-Ratio or \(F\) Statistic
\[F = \dfrac{MS_{\text{between}}}{MS_{\text{within}}}\]
If \(MS_{\text{between}}\) and \(MS_{\text{within}}\) estimate the same value (following the belief that \(H_{0}\) is true), then the \(F\)-ratio should be approximately equal to one. Mostly, just sampling errors would contribute to variations away from one. As it turns out, \(MS_{\text{between}}\) consists of the population variance plus a variance produced from the differences between the samples. \(MS_{\text{within}}\) is an estimate of the population variance. Since variances are always positive, if the null hypothesis is false, \(MS_{\text{between}}\) will generally be larger than \(MS_{\text{within}}\).Then the \(F\)-ratio will be larger than one. However, if the population effect is small, it is not unlikely that \(MS_{\text{within}}\) will be larger in a given sample.
The foregoing calculations were done with groups of different sizes. If the groups are the same size, the calculations simplify somewhat and the \(F\)-ratio can be written as:
\(F\)-Ratio Formula when the groups are the same size
\[F = \dfrac{n \cdot s_{\bar{x}}^{2}}{s^{2}_{\text{pooled}}}\]
where ...
- \(n = \text{the sample size}\)
- \(df_{\text{numerator}} = k - 1\)
- \(df_{\text{denominator}} = n - k\)
- \(s^{2}_{\text{pooled}} = \text{the mean of the sample variances (pooled variance)}\)
- \(s_{\bar{x}^{2}} = \text{the variance of the sample means}\)
Data are typically put into a table for easy viewing. One-Way ANOVA results are often displayed in this manner by computer software.
| Source of Variation | Sum of Squares (\(SS\)) | Degrees of Freedom (\(df\)) | Mean Square (\(MS\)) | \(F\) |
|---|---|---|---|---|
|
Factor (Between) |
\(SS(\text{Factor})\) | \(k - 1\) | \(MS(\text{Factor}) = \dfrac{SS(\text{Factor})}{(k - 1)}\) | \(F = \dfrac{MS(\text{Factor})}{MS(\text{Error})}\) |
|
Error (Within) |
\(SS(\text{Error})\) | \(n - k\) | \(MS(\text{Error}) = \dfrac{SS(\text{Error})}{(n - k)}\) | |
| Total | \(SS(\text{Total})\) | \(n - 1\) |
Example \(\PageIndex{1}\)
Three different diet plans are to be tested for mean weight loss. The entries in the table are the weight losses for the different plans. The one-way ANOVA results are shown in Table.
| Plan 1: \(n_{1} = 4\) | Plan 2: \(n_{2} = 3\) | Plan 3: \(n_{3} = 3\) |
|---|---|---|
| 5 | 3.5 | 8 |
| 4.5 | 7 | 4 |
| 4 | 3.5 | |
| 3 | 4.5 |
\[s_{1} = 16.5, s_{2} =15, s_{3} = 15.7\]
Following are the calculations needed to fill in the one-way ANOVA table. The table is used to conduct a hypothesis test.
\[\begin{align} SS(\text{between}) &= \sum \left[\dfrac{(s_{j})^{2}}{n_{j}}\right] - \dfrac{\left(\sum s_{j}\right)^{2}}{n} \\ &= \dfrac{s^{2}_{1}}{4} + \dfrac{s^{2}_{2}}{3} + \dfrac{s^{2}_{3}}{3} + \dfrac{(s_{1} + s_{2} + s_{3})^{2}}{10} \end{align}\]
where \(n_{1} = 4, n_{2} = 3, n_{3} = 3\) and \(n = n_{1} + n_{2} + n_{3} = 10\) so
\[\begin{align} SS(\text{between}) &= \dfrac{(16.5)^{2}}{4} + \dfrac{(15)^{2}}{3} + \dfrac{(5.5)^{2}}{3} = \dfrac{(16.5 + 15 + 15.5)^{2}}{10} \\ &= 2.2458 \end{align}\]
\[\begin{align} S(\text{total}) =& \sum x^{2} - \dfrac{\left(\sum x\right)^{2}}{n} \\ =& (5^{2} + 4.5^{2} + 4^{2} + 3^{2} + 3.5^{2} + 7^{2} + 4.5^{2} + 8^{2} + 4^{2} + 3.5^{2}) \\ &− \dfrac{(5 + 4.5 + 4 + 3 + 3.5 + 7 + 4.5 + 8 + 4 + 3.5)^{2}}{10} \\ =& 244 - \dfrac{47^{2}}{10} = 244 - 220.9 \\ =& 23.1 \end{align}\]
\[\begin{align} SS(\text{within}) &= SS(\text{total}) - SS(\text{between}) \\ &= 23.1 - 2.2458 \\ &= 20.8542 \end{align}\]
One-Way ANOVA Table: The formulas for \(SS(\text{Total})\), \(SS(\text{Factor}) = SS(\text{Between})\) and \(SS(\text{Error}) = SS(\text{Within})\) as shown previously. The same information is provided by the TI calculator hypothesis test function ANOVA in STAT TESTS (syntax is \(ANOVA(L1, L2, L3)\) where \(L1, L2, L3\) have the data from Plan 1, Plan 2, Plan 3 respectively).
| Source of Variation | Sum of Squares (\(SS\)) | Degrees of Freedom (\(df\)) | Mean Square (\(MS\)) | \(F\) |
|---|---|---|---|---|
|
Factor
(Between) |
\(SS(\text{Factor}) = SS(\text{Between}) = 2.2458\) | \(k - 1= 3 \text{ groups} - 1 = 2\) | \(MS(\text{Factor}) = \dfrac{SS(\text{Factor})}{(k– 1)} = \dfrac{2.2458}{2} = 1.1229\) | \(F = \dfrac{MS(\text{Factor})}{MS(\text{Error})} = \dfrac{1.1229}{2.9792} = 0.3769\) |
|
Error
(Within) |
\(SS(\text{Error}) = SS(\text{Within}) = 20.8542\) | \(n – k = 10 \text{ total data} - 3 \text{ groups} = 7\) | \(MS(\text{Error})) = \dfrac{SS(\text{Error})}{(n– k)} = \dfrac{20.8542}{7} = 2.9792\) | |
| Total | \(SS(\text{Total}) = 2.2458 + 20.8542 = 23.1\) | \(n - 1 = 10 \text{ total data} - 1 = 9\) |
Exercise \(\PageIndex{1}\)
As part of an experiment to see how different types of soil cover would affect slicing tomato production, Marist College students grew tomato plants under different soil cover conditions. Groups of three plants each had one of the following treatments
- bare soil
- a commercial ground cover
- black plastic
- straw
- compost
All plants grew under the same conditions and were the same variety. Students recorded the weight (in grams) of tomatoes produced by each of the \(n = 15\) plants:
| Bare: \(n_{1} = 3\) | Ground Cover: \(n_{2} = 3\) | Plastic: \(n_{3} = 3\) | Straw: \(n_{4} = 3\) | Compost: \(n_{5} = 3\) |
|---|---|---|---|---|
| 2,625 | 5,348 | 6,583 | 7,285 | 6,277 |
| 2,997 | 5,682 | 8,560 | 6,897 | 7,818 |
| 4,915 | 5,482 | 3,830 | 9,230 | 8,677 |
Create the one-way ANOVA table.
Answer
Enter the data into lists L1, L2, L3, L4 and L5. Press STAT and arrow over to TESTS. Arrow down to ANOVA. Press ENTER and enter L1, L2, L3, L4, L5). Press ENTER. The table was filled in with the results from the calculator.
| Source of Variation | Sum of Squares (\(SS\)) | Degrees of Freedom (\(df\)) | Mean Square (\(MS\)) | \(F\) |
|---|---|---|---|---|
| Factor (Between) | 36,648,561 | \(5 - 1 = 4\) | \(\dfrac{36,648,561}{4} = 9,162,140\) | \(\dfrac{9,162,140}{2,044,672.6} = 4.4810\) |
| Error (Within) | 20,446,726 | \(15 - 5 = 10\) | \(\dfrac{20,446,726}{10} = 2,044,672.6\) | |
| Total | 57,095,287 | \(15 - 1 = 14\) |
The one-way ANOVA hypothesis test is always right-tailed because larger \(F\)-values are way out in the right tail of the \(F\)-distribution curve and tend to make us reject \(H_{0}\).
Notation
The notation for the \(F\) distribution is \(F \sim F{df(\text{num}),df(\text{denom})}\)
where \(df(\text{num}) = df_{between} and df(\text{denom}) = df_{within}\)
The mean for the \(F\) distribution is \(\mu = \dfrac{df(\text{num})}{df(\text{denom}) - 1}\)
References
- Tomato Data, Marist College School of Science (unpublished student research)
Review
Analysis of variance compares the means of a response variable for several groups. ANOVA compares the variation within each group to the variation of the mean of each group. The ratio of these two is the \(F\) statistic from an \(F\) distribution with (number of groups – 1) as the numerator degrees of freedom and (number of observations – number of groups) as the denominator degrees of freedom. These statistics are summarized in the ANOVA table.
Formula Review
\(SS_{between} = \sum \left[\dfrac{(s_{j})^{2}}{n_{j}}\right] - \dfrac{\left(\sum s_{j}\right)^{2}}{n}\)
\(SS_{\text{total}} = \sum x^{2} - \dfrac{\left(\sum x\right)^{2}}{n}\)
\(SS_{\text{within}} = SS_{\text{total}} - SS_{\text{between}}\)
\(df_{\text{between}} = df(\text{num}) = k - 1\)
\(df_{\text{within}} = df(\text{denom}) = n - k\)
\(MS_{\text{between}} = \dfrac{SS_{\text{between}}}{df_{\text{between}}}\)
\(MS_{\text{within}} = \dfrac{SS_{\text{within}}}{df_{\text{within}}}\)
\(F = \dfrac{MS_{\text{between}}}{MS_{\text{within}}}\)
\(F\) ratio when the groups are the same size: \(F = \dfrac{ns_{\bar{x}}^{2}}{s^{2}_{\text{pooled}}}\)
Mean of the \(F\) distribution: \(\mu = \dfrac{df(\text{num})}{df(\text{denom}) - 1}\)
where:
- \(k =\) the number of groups
- \(n_{j} =\) the size of the \(j^{th}\) group
- \(s_{j} =\) the sum of the values in the \(j^{th}\) group
- \(n =\) the total number of all values (observations) combined
- \(x =\) one value (one observation) from the data
- \(s_{\bar{x}}^{2} =\) the variance of the sample means
- \(s^{2}_{\text{pooled}} =\) the mean of the sample variances (pooled variance)
Contributors and Attributions
Barbara Illowsky and Susan Dean (De Anza College) with many other contributing authors. Content produced by
OpenStax College
is licensed under a Creative Commons Attribution License 4.0 license. Download for free at
<EMAIL_ADDRESS>.


11.2.1: Adaptations to Reduce Transpiration
-
- Last updated
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- Tom Buckley
- University of California, Davis
Learning Objective
Describe the various adaptations that help plants reduce transpiration rate.
Plants have evolved over time to adapt to their local environment and reduce transpiration. Leaves are covered by a waxy cuticle on the outer surface that prevents the loss of water. Plants that grow in dry environments and plants that grow on other plants ( epiphytes ) have a much thicker waxy cuticle than those growing in more moderate, well-watered environments (Figure \(\PageIndex{1}\)). Additionally, they often have a thick covering of trichomes or of stomata that are sunken below the leaf’s surface (Figure \(\PageIndex{2}\)). These adaptations impede air flow across the stomatal pore and reduce transpiration. Multiple epidermal layers are also commonly found in these types of plants .
The size and shape of photosynthetic structures also influences transpiration rate. Succulent plants, common in deserts, have thick, fleshy leaves or stems (Figure \(\PageIndex{1}\), left). Other plants, such as the evergreen shrubs of the chaparral, have small, thick, tough leaves (Figure \(\PageIndex{3}\)). Compared to thin, broad leaves, these shapes reduce surface area-to-volume ratio and decreases the opportunity for water loss. Plants with thin, broad leaves that live in climates with hot, dry seasons (such as chaparral or tropical forests that have a wet and dry season) may be deciduous , losing their leaves during these seasons to limit transpiration (Figure \(\PageIndex{4}\)).
As discussed in 13.7: Photorespiration and Photosynthetic Pathways , CAM plants close their stomata during the day when light and high temperatures would otherwise increase transpiration rate. C 4 plants reduce the need to frequently open stomata by creating a high carbon dioxide concentration in the bundle sheath cells, which conduct the Calvin cycle. Regardless of photosynthetic pathway, plants can open and close stomata to regulate transpiration rate based on environmental conditions.
Attribution
- Curated and authored by Melissa Ha using 30.5 Transport of Water and Solutes in Plants from Biology 2e by OpenStax (licensed CC-BY ). Access for free at openstax.org .


5.11: Conclusion
The international scientific and medical communities view variations of sex, gender, and sexual orientation as normal. It is important to note the difference between sex and gender. Gender is a spectrum, and a person’s biological makeup does not define one’s gender identity. The term intersex is used to define individuals with a variation in sex characteristics, including chromosomes, gonads, or genitals, which highlights the false binary of two distinct sexes or genders. Transgender people have a gender identity or expression that differs from what they are assigned at birth. People who identify as transgender may participate in hormone therapy, which is an effective way to enhance secondary sex characteristics associated with a person’s gender identity. Gender is a social construct, meaning that it is not developed naturally, but is instead a concept, created by cultural and societal norms. Gender socialization begins at birth, and occurs through a variety of major agents of socialization, including family, education, peer groups, and mass media. As a result of gender socialization beginning at birth, it is often difficult for people to ‘come out’ as transgender.
U.S. society continues to consider the gender binary as the ‘norm’, which causes many transgender and non-binary people to experience gender dysphoria. Gender dysphoria can negatively impact a person’s quality of life, especially if a transgender person does not have resources to explore their gender identity. Prescribed gender roles can play a major role in gender dysphoria, and are based on a socially constructed idea of gender, which changes over time. Gender schemas are deeply embedded in a person’s cognitive framework, which is why many transgender and non-binary people have to go through a process of un-learning. This process can be quite difficult, as a result of people being policed at a young age, causing a series of gendered expectations that define the ways people should act, dress, and interact with society, based on the gender that they are assumed to hold.


12.7: Molecular Transport Phenomena- Diffusion, Osmosis, and Related Processes
Learning Objectives
Molecular Transport Phenomena: Diffusion, Osmosis, and Related Processes
- Define diffusion, osmosis, dialysis, and active transport.
- Calculate diffusion rates.
Diffusion
There is something fishy about the ice cube from your freezer—how did it pick up those food odors? How does soaking a sprained ankle in Epsom salt reduce swelling? The answer to these questions are related to atomic and molecular transport phenomena—another mode of fluid motion. Atoms and molecules are in constant motion at any temperature. In fluids they move about randomly even in the absence of macroscopic flow. This motion is called a random walk and is illustrated in Figure . Diffusion is the movement of substances due to random thermal molecular motion. Fluids, like fish fumes or odors entering ice cubes, can even diffuse through solids.
Diffusion is a slow process over macroscopic distances. The densities of common materials are great enough that molecules cannot travel very far before having a collision that can scatter them in any direction, including straight backward. It can be shown that the average distance \(x_{rms}\) that a molecule travels is proportional to the square root of time:
\[x_{rms} = \sqrt{2Dt,}\]
where \(x_{rms}\) stands for the root-mean-square distance and is the statistical average for the process. The quantity \(D\) is the diffusion constant for the particular molecule in a specific medium. Table \(\PageIndex{1}\) lists representative values of \(D\) for various substances, in units of \(m^2/s\).
| Diffusing molecule | Medium | D (\(m^2/s\)) |
|---|---|---|
| Hydrogen \((H_2)\) | Air | \(6.4 \times 10^{-5}\) |
| Oxygen \((O_2)\) | Air | \(1.8 \times 10^{-5}\) |
| Oxygen \((O_2)\) | Water | \(1.0 \times 10^{-9}\) |
| Glucose \((C_6H_{12}O_6)\) | Water | \(6.7 \times 10^{-10}\) |
| Hemoglobin | Water | \(6.9 \times 10^{-11}\) |
| DNA | Water | \(1.3 \times 10^{-12}\) |
Note that \(D\) gets progressively smaller for more massive molecules. This decrease is because the average molecular speed at a given temperature is inversely proportional to molecular mass. Thus the more massive molecules diffuse more slowly. Another interesting point is that \(D\) for oxygen in air is much greater than \(D\) for oxygen in water. In water, an oxygen molecule makes many more collisions in its random walk and is slowed considerably. In water, an oxygen molecule moves only about \(40 \, \mu m\) in 1 s. (Each molecule actually collides about \(10^{10}\) times per second!). Finally, note that diffusion constants increase with temperature, because average molecular speed increases with temperature. This is because the average kinetic energy of molecules, \(\frac{1}{2}mv^2\), is proportional to absolute temperature.
Example \(\PageIndex{1}\): Calculating Diffusion: How Long Does Glucose Diffusion Take?
Calculate the average time it takes a glucose molecule to move 1.0 cm in water.
Strategy
We can use \(x_{tms} = \sqrt{2Dt},\) the expression for the average distance moved in time \(t\), and solve it for \(t\).
All other quantities are known.
Solution
Solving for \(t\) and substituting known values yields
\[t = \frac{x_{rms}^2}{2D} = \frac{(0.010 \, m)^2}{2(6.7 \times 10^{-10} m^2/s)}\]
\[ = 7.5 \times 10^4 s = 21 \, h.\]
Discussion
This is a remarkably long time for glucose to move a mere centimeter! For this reason, we stir sugar into water rather than waiting for it to diffuse.
Because diffusion is typically very slow, its most important effects occur over small distances. For example, the cornea of the eye gets most of its oxygen by diffusion through the thin tear layer covering it.
The Rate and Direction of Diffusion
If you very carefully place a drop of food coloring in a still glass of water, it will slowly diffuse into the colorless surroundings until its concentration is the same everywhere. This type of diffusion is called free diffusion, because there are no barriers inhibiting it. Let us examine its direction and rate. Molecular motion is random in direction, and so simple chance dictates that more molecules will move out of a region of high concentration than into it. The net rate of diffusion is higher initially than after the process is partially completed (Figure \(\PageIndex{1}\)).
The net rate of diffusion is proportional to the concentration difference. Many more molecules will leave a region of high concentration than will enter it from a region of low concentration. In fact, if the concentrations were the same, there would be no net movement. The rate of diffusion is also proportional to the diffusion constant \(D\), which is determined experimentally. The farther a molecule can diffuse in a given time, the more likely it is to leave the region of high concentration. Many of the factors that affect the rate are hidden in the diffusion constant \(D\). For example, temperature and cohesive and adhesive forces all affect values of \(D\).
Diffusion is the dominant mechanism by which the exchange of nutrients and waste products occur between the blood and tissue, and between air and blood in the lungs. In the evolutionary process, as organisms became larger, they needed quicker methods of transportation than net diffusion, because of the larger distances involved in the transport, leading to the development of circulatory systems. Less sophisticated, single-celled organisms still rely totally on diffusion for the removal of waste products and the uptake of nutrients.
Osmosis and Dialysis—Diffusion across Membranes
Some of the most interesting examples of diffusion occur through barriers that affect the rates of diffusion. For example, when you soak a swollen ankle in Epsom salt, water diffuses through your skin. Many substances regularly move through cell membranes; oxygen moves in, carbon dioxide moves out, nutrients go in, and wastes go out, for example. Because membranes are thin structures (typically \(6.5 \times 10^{-9}\) to \(10 \times 10^{-9} \) m across) diffusion rates through them can be high. Diffusion through membranes is an important method of transport.
Membranes are generally selectively permeable, or semipermeable (Figure \(\PageIndex{3}\)). One type of semipermeable membrane has small pores that allow only small molecules to pass through. In other types of membranes, the molecules may actually dissolve in the membrane or react with molecules in the membrane while moving across. Membrane function, in fact, is the subject of much current research, involving not only physiology but also chemistry and physics.
Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration. Osmosis is driven by the imbalance in water concentration. For example, water is more concentrated in your body than in Epsom salt. When you soak a swollen ankle in Epsom salt, the water moves out of your body into the lower-concentration region in the salt. Similarly, dialysis is the transport of any other molecule through a semipermeable membrane due to its concentration difference. Both osmosis and dialysis are used by the kidneys to cleanse the blood.
Osmosis can create a substantial pressure. Consider what happens if osmosis continues for some time, as illustrated in Figure \(\PageIndex{4}\). Water moves by osmosis from the left into the region on the right, where it is less concentrated, causing the solution on the right to rise. This movement will continue until the pressure \(\rho gh\) created by the extra height of fluid on the right is large enough to stop further osmosis. This pressure is called a back pressure . The back pressure \(\rho gh\) that stops osmosis is also called the relative osmotic pressure if neither solution is pure water, and it is called the osmotic pressure if one solution is pure water. Osmotic pressure can be large, depending on the size of the concentration difference. For example, if pure water and sea water are separated by a semipermeable membrane that passes no salt, osmotic pressure will be 25.9 atm. This value means that water will diffuse through the membrane until the salt water surface rises 268 m above the pure-water surface! One example of pressure created by osmosis is turgor in plants (many wilt when too dry). Turgor describes the condition of a plant in which the fluid in a cell exerts a pressure against the cell wall. This pressure gives the plant support. Dialysis can similarly cause substantial pressures.
Reverse osmosis and reverse dialysis (also called filtration) are processes that occur when back pressure is sufficient to reverse the normal direction of substances through membranes. Back pressure can be created naturally as on the right side of Figure \(\PageIndex{4}\). (A piston can also create this pressure.) Reverse osmosis can be used to desalinate water by simply forcing it through a membrane that will not pass salt. Similarly, reverse dialysis can be used to filter out any substance that a given membrane will not pass.
One further example of the movement of substances through membranes deserves mention. We sometimes find that substances pass in the direction opposite to what we expect. Cypress tree roots, for example, extract pure water from salt water, although osmosis would move it in the opposite direction. This is not reverse osmosis, because there is no back pressure to cause it. What is happening is called active transport , a process in which a living membrane expends energy to move substances across it. Many living membranes move water and other substances by active transport. The kidneys, for example, not only use osmosis and dialysis—they also employ significant active transport to move substances into and out of blood. In fact, it is estimated that at least 25% of the body’s energy is expended on active transport of substances at the cellular level. The study of active transport carries us into the realms of microbiology, biophysics, and biochemistry and it is a fascinating application of the laws of nature to living structures.
Summary
- Diffusion is the movement of substances due to random thermal molecular motion.
- The average distance \(x_{rsm}\) a molecule travels by diffusion in a given amount of time is given by \[ x_{rsm} = \sqrt{2Dt},\] where \(D\) is the diffusion constant, representative values of which are found in Table .
- Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration.
- Dialysis is the transport of any other molecule through a semipermeable membrane due to its concentration difference.
- Both processes can be reversed by back pressure.
- Active transport is a process in which a living membrane expends energy to move substances across it.
Footnotes
1. At 20°C and 1 atm
Glossary
- diffusion
- the movement of substances due to random thermal molecular motion
- semipermeable
- a type of membrane that allows only certain small molecules to pass through
- osmosis
- the transport of water through a semipermeable membrane from a region of high concentration to one of low concentration
- dialysis
- the transport of any molecule other than water through a semipermeable membrane from a region of high concentration to one of low concentration
- relative osmotic pressure
- the back pressure which stops the osmotic process if neither solution is pure water
- osmotic pressure
- the back pressure which stops the osmotic process if one solution is pure water
- reverse osmosis
- the process that occurs when back pressure is sufficient to reverse the normal direction of osmosis through membranes
- reverse dialysis
- the process that occurs when back pressure is sufficient to reverse the normal direction of dialysis through membranes
- active transport
- the process in which a living membrane expends energy to move substances across


1.11: Reducing the Risk of Cardiovascular Disease
By the end of this chapter you will be able to:
- Describe how the cardiovascular system works
- Compare the risk and prevalence of cardiovascular disease
- Describe the common types of cardiovascular disease
- Identify risk factors for cardiovascular disease
- Interpret blood pressure and cholesterol readings
How does the heart work?
What happens when a person has a heart attack or a brain attack (stroke)?
What can you do to reduce your risk of cardiovascular disease?
Can you feel it if you have high blood pressure or high cholesterol?
One person dies every 36 seconds in the United States from cardiovascular disease. About 659,000 people in the United States die from heart disease each year—that’s 1 in every 4 deaths. Heart disease is the leading cause of death in the United States, and stroke is the fifth leading cause of death. Heart disease costs the United States about $363 billion each year from 2016 to 2017. It is important for everyone to understand how their cardiovascular system works and the common types of diseases of the cardiovascular system.


7.4: Sample Documentation
Sample Documentation of Expected Findings
Patient denies cough, chest pain, or shortness of breath. Denies past or current respiratory illnesses or diseases. Symmetrical anterior and posterior thorax. Anteroposterior-transverse ratio is 1:2. Respiratory rate is 16 breaths/minute, unlabored, regular, and inaudible through the nose. No retractions, accessory muscle use, or nasal flaring. Chest rise and fall are equal bilaterally. Skin is pink, warm, and dry. No crepitus, masses, or tenderness upon palpation of anterior and posterior chest. Lung sounds clear bilaterally in all lobes anteriorly and posteriorly. No adventitious sounds. SpO2 99% on room air.
Sample Documentation of Unexpected Findings
Patient reports shortness of breath for five to six hours. Patient has labored breathing at rest. Nail beds are cyanotic. Respiratory rate is tachypneic at 32/minute with neck and abdominal accessory muscle use. Lung expansion is symmetrical. Pursed-lip breathing noted with intermittent productive cough. Reports coughing up blood-tinged green sputum for two days. Anterior and posterior chest walls have no tenderness, masses, or crepitus upon palpation. On auscultation bilateral coarse crackles over lung bases. Expiratory wheezes are audible and heard with stethoscope scattered throughout lung fields. SpO2 93% on room air.


17: Gauss’ Law
- Understand the concept of flux for a vector field.
- Understand how to calculate the flux of a vector field through an open and a closed surface.
- Understand how to apply Gauss’ Law quantitatively to determine an electric field.
- Understand how to apply Gauss’ Law qualitatively to discuss charges on a conductor.
In this chapter, we take a detailed look at Gauss’ Law applied in the context of the electric field. We have already encountered Gauss’ Law briefly in Section 9.2 when we examined the gravitational field. Since the electric force is mathematically identical to the gravitational force, we can apply the same tools, including Gauss’ Law, to model the electric field as we do the gravitational field. Many of the results from this chapter are thus equally applicable to the gravitational force.
A neutral spherical conducting shell encloses a point charge, \(Q\) , located at the center of the shell. Due to separation of charge, the outer surface of the shell will acquire a net positive charge. What is the magnitude of that charge?
- less than \(Q\) .
- exactly \(Q\) .
- more than \(Q\) .