“I have the audacity to believe that people everywhere can have three meals a day for their bodies, education and culture for their minds, and dignity, equality and freedom for their spirits.” Martin Luther King, Jr.
Survivalists have a rule of three: you can survive without food for three weeks, without water for 3 days, without shelter from a harsh environment for 3 hours, and without air for 3 minutes.
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If a human goes without any of these resources for a long enough time, death will eventually be the result. It stands to reason that when we talk about American families’ needs we would talk about all of these; in this chapter we will look at both food and water.
Abraham Maslow’s Hierarchy of Needs theory (1943) describes these physiological needs as being a key motivator in human behavior.
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Obtaining food, water, shelter, sleep and oxygen to survive consumes a large amount of our time and resources both directly and indirectly. Think about how much time your family spends working to pay for food. In general, families pay a smaller percentage of their income for food than they did 50 years ago. That’s not because food expenses have decreased, but because other costs, primarily shelter and health care, have increased. We discuss shelter (housing and living environments) in the Housing chapter. Now consider your family’s access to water. While we may not think about paying for it as a percentage of our incomes, access to plentiful, clean, safe water is influenced by where we live. The financial resources that are invested into our community infrastructure which includes water and sanitation, impact our safety and overall health. Where we live matters when it comes to having available and safe water.
Personal finances are only one part of the cost, benefits, and societal dynamics that play into meeting these basic needs. We must pay attention to where foods come from, business and government investment in food production, and the business of food charity. Time is another cost of food; families decide how much time is spent purchasing, preparing, eating, and cleaning up meals. Turning on a faucet to access clean, toxin free drinking water requires building, maintaining, and monitoring water and sanitation systems, and this comes at a cost that not all municipalities can afford. While the federal government has invested in water infrastructure, there is not an ongoing commitment, so these needs must be balanced with competing needs such as schools, parks, police, and libraries. There are variations and influences on how food and water needs are met, but ultimately they must be met in some way.
Producing Food
Prior to the formation of the United States, families found food in a variety of ways including foraging, hunting, fishing, and growing food. As the country progressed toward a formal organizational structure managed by the Euro-American settlers Native Americans were restricted to designated reservations, often on land that was not as fertile for farming. Food production via farms became a major economic factor. Industrialization created more efficiencies and more wealth for landowners.
It is important to note that these new ways of sourcing food would not have been possible without three institutional structures:
Oppression of the way of life that Native Americans had established here for thousands of years;
Enslavement of African immigrants brought to this country for the explicit purpose of free labor without attention to their rights and needs;
Laws that controlled immigrants from other countries by limiting who could immigrate by gender, familial, and employment status; laws that discriminate based on nationality and immirgration status related to wage, housing options, and kind of employment.
These structures affected the functionality of all families in the United States, favoring White families, especially those who owned land. Which of these structures affect families today? If you answered all three, you are correct. Native Americans are still fighting for rights related to their family needs that have been disrupted and restricted; the aftereffects of slavery including the restrictions of wealth attainment on Black people affects both the families who were able to accumulate wealth and the ones who were not; and current immigration laws still place the needs of the employers first.
Black Farmers
Black farmers in America have had a long and arduous struggle to own land and to operate independently. For more than a century after the Civil War, deficient civil rights and various economic and social barriers were applied to maintaining a system where many Blacks worked as farm operators with a limited and often total lack of opportunity to achieve ownership and operating independence. Although some formerly enslaved people were deeded land in the famous “Forty Acres and a Mule” division of lands in 1868, the same land was later deeded back to the original Confederate owners and the Black families became sharecroppers rather than owners. Other Black farm owners saw their properties diminished throughout the 20th century as described in this fifteen-minute video.
These personal stories help us understand how families that worked hard still were treated unjustly. Black farmers often ended up working for landowners once again. Even as employees they received less protection than factory and office workers. When Social Security and Unemployment laws meant to protect workers were passed,they excluded people who worked on farms or as domestic help, of which the majority were immigrants and minoritized groups, including African Americans. Diminished civil rights also limited collective action strategies, such as cooperatives and unions.
It is tempting to think that these past laws and practices do not affect us today. Many of the structures survive, however, in both subtle and obvious ways. In addition, because these structures limited access and land ownership in proximity to the vital resources of food and water, Euro-Americans were able to build wealth more quickly and easily than any other group of families. We discuss the institutional factors related to housing, location and wealth in the Housing chapter.
Farm and Field Workers
Farm workers are and have been an essential part of the United States economy and food system. They come in varying immigration statuses, United States citizens or residents, folkx on guest worker visas, or they could be undocumented workers. The following USDA table describes the demographic characteristics of farm workers in the United States in 2018 from the USDA, collected from data on the American Community Survey (part of the Census project). The data shows that about 55% of farm laborers are born in countries other than the United States.
Demographic Characteristics of Farm Workers in the United States in 2018
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Note: Counts all private sector wage and salary workers employed in the crop, livestock, and agricultural support industries.
Item
Farm laborers, graders and sorters
Farm managers, inspectors, and supervisors
All other occupations in agriculture
Agriculture: All occupations
All U.S. private wage and salary workers
Percent female
25
13
32
26
45
Average age in years
39
43
42
40
40
Percent under age 25
22
13
15
19
18
Percent over age 44
38
46
47
41
41
Percent married
47
61
52
51
48
Race/Ethnicity/Ancestry
Percent White, not Hispanic
32
64
59
43
60
Percent Black, not Hispanic
3
3
5
3
12
Percent other, not Hispanic
2
3
3
2
9
Percent Hispanic: Mexican origin
57
27
28
45
12
Percent Hispanic: Other
7
3
6
6
7
Percent born in U.S. (includes Puerto Rico)
45
76
75
57
80
Percent U.S. citizens
54
84
83
65
90
Education
Percent lacking high school diploma
48
24
20
38
9
Percent with high school diploma (includes equivalency)
32
31
33
32
29
Percent with at least some college
20
45
47
30
62
Differences in demographics are also evident between crop and livestock workers (not shown in table). A larger share of laborers in crops and related support industries are female (28 percent versus 20 percent in livestock). Crop laborers are also less likely to be non-Hispanic White (25 percent versus 48 percent for livestock), and less likely to have been born in the United States (39 percent for crop workers in manual labor occupations versus 60 percent for manual livestock workers). Finally, crop laborers have lower levels of educational attainment: 52 percent lack a high school degree, compared with 37 percent in livestock.
Notably, the U.S. Department of Labor’s National Agricultural Workers Survey (NAWS), discussed below, finds larger shares of foreign-born, Hispanic, and less educated employees among crop and support workers than does the ACS (livestock workers are not surveyed in NAWS). For example, NAWS estimates that in Fiscal Years 2015-16, just 25 percent of crop farm workers in manual labor occupations were U.S. born, compared with 39 percent in the ACS.
Since this data is gathered from a written survey related to the Census, it is important to note that there is likely some underreporting from groups that are the hardest to reach, including people of color, children under five, renters, immigrants, people with limited English proficiency, multiple-family homes, Native tribal and urban communities, disabled people, people who distrust the government, and LGBTQ individuals. This is discussed at length in the Representation chapter.
The survey also tells us that the average age for farmworkers is on the rise and more likely to be female. Younger immigrants are less likely to go into farm work than into other professions, so the population is aging. It is hypothesized that as men move toward agricultural employment (rather than working with crops) and there is increased machine usage, women are moving into these jobs.
Immigrants, especially those who are not yet documented, or who live in mixed-status families are more likely to experience poor treatment and be less likely to complain about bad work conditions.
Field Workers
By Carla Medel, Bachelor’s Degree candidate: Psychology with Spanish and HDFS minors, Oregon State University, 2021.
103 degrees Fahrenheit, picking zucchini, I turn to the sound of “water, water, we need water!” and to the woman with the purple bandana and a hurt shoulder on the ground; she had fainted of dehydration. She sits underneath a tree for 15 minutes with a bottle of water that one of our coworkers was able to give her and before I even know it, she is back on the field picking zucchini along my side.
That afternoon as I made my way home, I could not help but to begin crying out of frustration. I was only 16 but I knew that what I had just witnessed was not correct. Feeling hopeless, the next day I no longer wanted to go back to work. What I did instead, was go grocery shopping with my mom. When we headed to produce, and I saw people grabbing zucchini the tears came again. They did not know what those .76¢ zucchini really cost. This is my story, but this is definitely not a unique one. Immigrant farm workers in the United States are treated terribly and with little to no protection, others are ready to take advantage.
Food Factory Workers
The recent Coronavirus pandemic has brought necessary attention to the important function of meat production and the preservation of fruits and vegetables in factories. The federal government has determined them to be essential workers. Many of these workers are immigrants and people of color.
We’ll discuss getting food, and what causes some families to be hungry, or the more technical term, “food insecure”. We acknowledge that food insecurity is a symptom of another social problem, poverty. First, let’s look at some of the systems that affect food availability in the United States.
Equitable access to food is hampered by governmental systems that focus on subsidizing specific farm crops. Federal government subsidies help farmers reduce their risk due to weather, commodities brokers, economic downturns, and changes in demand. There are only five crops that receive these major government subsidies: corn, soybeans, wheat, cotton, and rice. Producers of fruit, vegetables and meat only benefit from crop insurance and disaster relief.
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Farm subsidies have increased dramatically in the last four years, totaling $28 billion dollars for a two year period (2018-2020, not including the additional Coronavirus payments authorized in the spring of 2020).
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This incentivizes the production of certain crops in the United States. and provides stability for the families involved in producing those crops.
It is more complicated to measure the effects of these subsidies on consumers. We know that these subsidized food crops (corn, soybeans, wheat and rice) are more easily stored and utilized in processed foods, which nutritionists advise should be eaten in the smallest amounts. Crops in their raw forms, such as fruits, vegetables, legumes, meat, and dairy products provide more health benefits but are not subsidized consistently by the government. Here we may deduce that governmental subsidies of less healthy crops contributes to food availability and cost, affecting food purchases. Lower income families and those living in food deserts (described in the next section) are most affected.
Another challenge to food accessibility is the societal approach which focuses on governmental programs (such as the Supplemental Nutrition Assistance Program–SNAP, which will be described later) and charity, which in itself has become a business. Grocery stores and other businesses are provided with tax benefits when they overproduce food and donate it to food banks. Andy Fisher, the author of Big Hunger, describes hearing from grocery store owners who acknowledge the overproduction of sheet cakes, birthday cakes, pastries, and other baked goods. Consumers do not wish to purchase the last cake on the shelf, and so stores overproduce these items. When they are no longer considered fresh, they are donated to food banks. This is one of the reasons that about 25% of the donations that Food Banks give away food that is categorized as unhealthy.
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Not only is overproduction of food is supported by tax deductions, but food banks themselves have become multi-million dollar businesses (also described in the above podcast). Food banks serve a charitable purpose that meets an immediate and important need. At the same time, if the real problem–poverty–were addressed, people could have the dignity of providing and choosing the food that is best for their own family.
Poverty affects Americans of every racial-ethnic group, including those descended from European immigrants, but continues to affect the previously mentioned groups (Native Americans, Black or African Americans, and people descended from Latinx and some Asian countries) in disproportionately larger numbers.
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The United States is an individualistic country and people are sometimes blamed for being poor. This makes the problem of hunger more approachable than the problem of poverty. It is encouraging to note, however, that Americans increasingly understand that poverty stems not from personal shortcomings but from differentiation in circumstance and opportunity. Pew Center survey results released in March 2020 note that almost ⅔ of American adults say that people who are rich have experienced more advantages than those who are poor; only ⅓ say that it is because rich people have worked harder. These viewpoints are uneven related to political affiliation and age with Democrats and younger people more likely to hold the majority view.
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If more people view poverty as a social problem than a personal problem, it is more likely to be solved with a systemic solution.
Food Deserts
Perhaps you are familiar with this term, or have lived in a food desert. If you travel by bicycle or via public transport you may be more aware of food deserts in your community. Food deserts are geographic locations where there is not a variety of healthy food readily available (within a mile in urban environments or within 10-20 miles in a rural area.) Food deserts occur nationally, with a greater concentration of food deserts in the midwest and southern states.
Think about the community that you live in. Where are the grocery stores? Convenience stores don’t count, because they do not typically have fresh fruits and vegetables. Are the stores even spaced out amongst the neighborhoods? Probably not, and typically the dearth of stores is in lower income neighborhoods. The same parts of Portland, Oregon that are identified as redlined neighborhoods in the Housing chapter are also food deserts. The Oregon State (OSU) Barometer wrote about food deserts in Corvallis in 2019, pointing out that the majority of grocery stores in Corvallis are clustered around Ninth Street and Walnut Boulevard.
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Two of the four stores that are more distantly spaced are among the healthiest, emphasizing organic produce and natural foods, but also the most expensive.
What if there were federal funding to support equitable distribution of grocery stores that had a full selection of healthy foods? In the same way that federal subsidies protect farmers of selected crops from economic problems, they could protect grocery businesses in the same way and create greater equity for many consumers.
To learn more about food deserts, or to access an interactive map that displays different ways of viewing food deserts read
NPR’s article “How to find a food desert near you”
and follow the link to the USDA’s Food Atlas.
The Poverty Line and Food Costs
How is poverty defined? While there are multiple measures, a common and shared one is the Poverty Threshold, also known as the Poverty Line. While poverty will affect all of the families related to all of the topics in this text, we will discuss it here because it was originally tied to the cost of food, specifically an “economy food plan”. In 1963 the poverty line was designated at three times the economy food plan and assumed, “that the housewife will be a careful shopper, a skillful cook, and a good manager who will prepare all the family’s meals at home.”
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When US officials became concerned about poverty during the 1960s, they quickly realized they needed to find out how much poverty we had. To do so, a measure of official poverty, or a poverty line, was needed. A government economist, Mollie Orshanky, first calculated this line in 1963 by multiplying the cost of a very minimal diet by three, as a 1955 government study had determined that the typical American family spent one-third of its income on food. Thus a family whose cash income is lower than three times the cost of a very minimal diet is considered officially poor.
This way of calculating the official poverty line has not changed since 1963, although the amount is adjusted by inflation. It is thus out of date for many reasons. For example, many expenses, such as heat and electricity, child care, transportation, and health care, now occupy a greater percentage of the typical family’s budget than was true in 1963. In addition, this official measure ignores a family’s non cash income from benefits such as food stamps and tax credits. As a national measure, the poverty line also fails to take into account regional differences in the cost of living. All these problems make the official measurement of poverty highly suspect. As one poverty expert observes, “The official measure no longer corresponds to reality. It doesn’t get either side of the equation right—how much the poor have or how much they need. No one really trusts the data.”
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This is a good time to ask yourself, if looked at food as a percentage of your budget, would it be the equivalent of 33%? That’s how the poverty line is still calculated.
The poverty line is adjusted annually for inflation and takes into account the number of people in a family: The larger the family size, the higher the poverty line. In 2010, the poverty line for a nonfarm family of four (two adults, two children) was $22,213. A four-person family earning even one more dollar than $22,213 in 2010 was not officially poor, even though its “extra” income hardly lifted it out of dire economic straits. Poverty experts have calculated a no-frills budget that enables a family to meet its basic needs in food, clothing, shelter, and so forth; this budget is about twice the poverty line. Families with incomes between the poverty line and twice the poverty line (or twice poverty) are barely making ends meet, but they are not considered officially poor.
When we talk here about the poverty level, then, keep in mind that we are talking only about official poverty and that there are many families and individuals living in near poverty who have trouble meeting their basic needs, especially when they face unusually high medical expenses, motor vehicle expenses, college debt, or the like. For this reason, many analysts think families need incomes twice as high as the federal poverty level just to get by.
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They thus use twice-poverty data (i.e., family incomes below twice the poverty line) to provide a more accurate understanding of how many Americans face serious financial difficulties, even if they are not living in official poverty.
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Food Security and Food Insecurity
Identified in 1995 as a measurable problem, the USDA introduced new language to describe ranges of severity of food insecurity in 2006. The methods used to assess households’ food security remained unchanged. Here are the current definitions of food security and food insecurity.
Food Security
High food security (old label=Food security): no reported indications of food-access problems or limitations.
Marginal food security (old label=Food security): one or two reported indications—typically of anxiety over food sufficiency or shortage of food in the house. Little or no indication of changes in diets or food intake.
Food Insecurity
Low food security (old label=Food insecurity without hunger): reports of reduced quality, variety, or desirability of diet. Little or no indication of reduced food intake.
Very low food security (old label=Food insecurity with hunger): Reports of multiple indications of disrupted eating patterns and reduced food intake.
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According to the USDA,
hunger
“… refer(s) to a potential consequence of food insecurity that, because of prolonged, involuntary lack of food, results in discomfort, illness, weakness, or pain that goes beyond the usual uneasy sensation.” Nationally food insecurity has been a problem as long as it has been measured and the rate has changed very little; the number of food insecure families was 12% in 1995 and was still 11.1% in 2018. Let’s look more closely at Oregon where food insecurity has been one of the toughest challenges to overcome. According to the Oregon Public Health Division, Oregon ranks 13th in the nation for food insecurity among children, and 21st for adults. While efforts have been made to combat hunger in Oregon, it is still a big problem for the state. According to United States Department of Agriculture (USDA) data, more than
one in seven
of Oregon households were food insecure between 2014 and 2016.
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Renters in Oregon had food insecurity rates as high as
one in four
between 2015-2017.
[16]
The Oregon Center for Public Policy says that over 527,000 people in Oregon suffer from food insecurity.
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To put that into perspective, the population of Portland, our largest city is around 647,800 people. Overall, minorities and single mothers are disproportionately impacted by food insecurity; food insecurity is strongly linked to socioeconomic status.
While there are programs to help families who are food insecure, there are still families who are food insecure who do not qualify for any food assistance.
Food Insecurity at Linn-Benton Community College
In a recent survey conducted by the HOPE Center at Temple University, LBCC was one of 400 community colleges queried about food and housing insecurity over the past five years. Linn-Benton Community College students participated in 2019, the fifth year of the study. The survey was sent to 5,700 students and 558 students responded.
A surprising 48% of students reported experiencing food insecurity within the last 30 days, slightly higher than the nation-wide average of community college students.
Sixty-six% of the students that participated in the survey reported experiencing either food insecurity, housing insecurity, or homelessness within the past year.
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Here is how LBCC students responded when asked whether they had experienced any of the following items in the last 30 days.
Food stamps: SNAP
Many people in the United States rely on the Supplemental Nutrition Assistance Program (SNAP) to provide food for their families. SNAP is a federal program that in some states is supplemented with local funds whose goal is to supplement nutrition and the food budget of families who are moving toward self-sufficiency. According to the 2018 American Community Survey, 12.4% of people in the United States use food stamps and the majority of those families have at least one person working, with ⅓ of recipients having two family members working.
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Oregon has one of the highest usage rates in the country at a rate of fourteen percent.
Here you can see a map of SNAP usage across the country.
In 2019 President Trump proposed dramatic cuts and restrictions to the food stamp program. The rule was finalized by the administration in 2020, but a federal judge blocked its implementation in March 2020 due to the coronavirus epidemic. Between May and July 2020 the USDA appealed this judgement. While the SNAP program is currently unchanged, if the proposedwork restrictions go into effect, it is estimated that about 700,000 people will lose benefits.
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Fraud is often mentioned as a concern when it comes to food stamps, but when recipient and vendor fraud is totaled it is estimated at less than one percent of all funds disbursed. That means that more than 99% of the funds are used correctly.
[21]
The USDA maintains a webpage that reports on their efforts to stop fraud and to recoup delinquent funds. These authors advocate for the focus to shift toward solving the social problems of poverty and hunger, rather than letting the small amount of fraud distract the country from these efforts.
People struggling to feed themselves and their families face other challenges as well. Accepting governmental assistance and charity is stigmatized. Some families feel too embarrassed to seek or accept needed resources. Constant stress related to food insecurity and choosing which bills to pay contributes to mental health challenges. Do you or someone you know have experience with using SNAP? Click here to read
Voices From ‘Hunger In Oregon’
for short descriptions from Oregonians who have used this program.
What are families eating and why?
Hearing the phrase “you are what you eat” might conjure a distinct image in a person’s mind. This phrase is often associated with encouraging a healthy diet to promote an individual’s overall well-being. Yet, food is not only a form of sustenance, but it is also used to communicate culture as well as a way of forming social ties and communicating love.
It is important to recognize the multi-dimensional influence food has on family life, and therefore how it can impact families in various ways. In this chapter we have focused on the ways that institutional forces and family social class shape access to food. Let’s spend a little time here on other factors that affect food choices; this text will explore more aspects of food and family in the Routines, Traditions, and Culture chapter.
Early food experiences
The way our family approaches food when we are children affects us the rest of our lives. What we eat matters, as do the social aspects of meals.  People who were not exposed to a variety of foods as children, or who were forced to swallow every last bite of overcooked vegetables may make limited food choices as adults. Children who do not have practice socializing during meals may not develop social skills or understand dining table social norms.
Habits
It can be easy to establish a habit around things we do each day. For example, having a dessert can become a habit. Having a snack after school or a drink with dinner can develop into a habit. Healthy habits such as “an apple a day” can be developed as well and may require intention on the part of the individual.
Culture
The culture in which one grows up affects how one sees food in daily life and on special occasions. Food and family recipes are important ways to transmit culture across families and from generation to generation. Traditions and celebrations often include food.
Geography
Where a person lives influences food choices. For instance, people who live in Midwestern US states have less access to fresh seafood than those living along the coasts.
Advertising
The media greatly influences food choice by persuading consumers to eat certain foods. Have you ever found yourself suddenly hungry after watching an advertisement for the local pizza place The media affects both when we eat and what we eat.
Social factors
Any school lunchroom observer can testify to the impact of peer pressure on eating habits, and this influence lasts through adulthood. People make food choices based on how they see others and want others to see them. For example, individuals who are surrounded by others who consume fast food are more likely to do the same.
Health concerns
Some people have significant food allergies, to peanuts for example, and need to avoid those foods. Others may have developed health issues which require them to follow a low salt or gluten free diet. In addition, people who have never worried about their weight have a very different approach to eating than those who have long struggled with excess weight.
Emotions
There is a wide range in how emotional issues affect eating habits. When faced with a great deal of stress, some people tend to overeat, while others find it hard to eat at all.
Green food/Sustainability choices
Based on a growing understanding of diet as a public and personal issue, more and more people are starting to make food choices based on their environmental impact. Realizing that their food choices help shape the world, many individuals are opting for a vegetarian diet, or, if they do eat animal products, striving to find the most “cruelty-free” or sustainable options possible. Purchasing local and organic food products and items grown through sustainable means also helps shrink the size of one’s dietary footprint.
Religion and Belief Systems
People design their diets for various reasons, including religious doctrines, health concerns, ecological and animal welfare concerns. For example, Jewish people may observe kosher eating practices and Muslim people fast during the ninth month of the Islamic calendar.
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Knowledge
Knowledge about healthful foods and calorie amounts affect food choices. This can be gained through family, peer, or media influence. Cooking knowledge is impactful. For example, knowing how to hydrate dried beans or prepare fresh vegetables could increase consumption of healthier foods. There has been a dramatic increase in television cooking shows in the 21st century, as well as nutrition, recipe, and cooking websites, blogs, and videos. The amount of information can make it hard to choose, but there are many options to learn about nutrition and cooking.
Time
One thing that contemporary families in the United States have less now than they did fifty years ago is time. This is primarily due to the decreasing number of jobs with enough pay and benefits to support a family and the need for more adults in the house to be working. With less time, efficiencies such as fast food, processed food, and prepared food become more appealing. Having more time means that families have the flexibility to cook and prepare their own food if they choose.
Children
Several other chapters in this text (Nurturance; and Routines, Traditions, and Culture) will focus more closely on children. But they deserve a special mention when it comes to food, and especially to hunger. Children are heavily impacted by poverty and hunger in the United States. In 2017, 17.5% of all children in the United States lived in poverty; Latino and Black children were more often in poverty than were White children. This contributes to diet deficiency. A high quality diet is a major contributing factor to children’s health and well-being and to their health outcomes as adults. Poor eating patterns in childhood are associated with obesity during childhood and adolescence; obese children are more likely to become obese adults. Obesity in children has been increasing dramatically since 1980 and is likely related to diet, physical activity, family environment and other factors. Obesity leads to increased risks for a wide variety of chronic diseases, including diabetes, stroke, heart disease, arthritis, and some cancers.
[23]
Hunger and a poor diet can have other effects on children. Hungry children cannot learn as efficiently as well nourished children. According to the American Psychological Association (APA) they are more likely to develop anxiety and depression along with other health problems. Brain development, learning, and information processing can all be affected by lack of an adequate diet. Children experience stigma around being food insecure and accessing free and reduced meals, part of the federal response to poverty. For more information on this program,
access the USDA website here
. They may feel isolated and ashamed about being poor or about being food insecure although many children share this experience in the United States.
[24]
“What are Families Eating and Why” is adapted from
Human Nutrition
by Marie Kainoa Fialkowski Revilla, Alan Titchenal, Allison Calabrese, Cheryl Gibby, & William Meinke. License:
CC BY 4.0
.
Figure 9.1.
Photo
by Keith Weller/USDA. Public domain.
Figure 9.5. “Poverty rate by race/ethnicity, Oregon, 2018.” Based on
data
from the American Community Survey/Kaiser Family Foundation. License:
CC BY 4.0
.
Figure 9.6. “Share of food insecure Oregonians with too much income to qualify for SNAP assistance, 2016.” Based on
data
from the Oregon Center for Public Policy. License:
CC BY 4.0
.
Figure 9.7. “Food security among survey respondents at Linn-Benton Community College” in
#2019 RealCollege Survey: Linn-Benton Community College
by
The Hope Center
. Used with permission.
Figure 9.8. “Food insecurity among survey respondents at Linn-Benton Community College” in
#2019 RealCollege Survey: Linn-Benton Community College
by
The Hope Center
. Used with permission.
Rule of threes (survival). (2020, February 2). Retrieved February 10, 2020, from en.Wikipedia.org/wiki/Rule_o...ees_(survival) ↵
Maslow's hierarchy of needs. (2020, February 6). Retrieved February 10, 2020, from en.Wikipedia.org/wiki/Maslow...archy_of_needs ↵
DeParle, J., Gebeloff, R., & Tavernise, S. (2011, November 4). Bleak portrait of poverty is off the mark, experts say. New York Times, p. A1. ↵
Wright, V. R., Chau, M., & Aratani, Y. (2011). Who are America’s poor children? The official story. New York, NY: National Center for Children in Poverty. ↵
Edwards, M. (2018, December). Widespread declines, yet persistent inequalities: Food insecurity in Oregon and the U.S. Oregon State University School of Public Policy.
https://liberalarts.oregonstate.edu/...ortdec2018.pdf
↵
American Psychological Association. (n.d.). What are the psychological effects of hunger on children? Retrieved August 19, 2020, from www.apa.org/advocacy/socioec...tus/hunger.pdf ↵


2.11: Websites
Classification
- http://www.mcwdn.org/Animals/AnimalClassQuiz.html Animal classification quiz
In fact much more than that. There is an elementary cell biology and classification quiz but the best thing about this website are the links to tables of characteristics of the different animal groups, for animals both with and without backbones.
- http://animaldiversity.ummz.umich.edu/site/index.html Animal diversity web
Careful! You could waste all day exploring this wonderful website. Chose an animal or group of animals you want to know about and you will see not only the classification but photos and details of distribution, behaviour and conservation status etc.
- http://www.indianchild.com/animal_kingdom.htm Indian child
Nice clear explanation of the different categories used in the classification of animals.


1.4: Writing
People don’t often think of writing as a form of technology, but it serves as the second-oldest form of communication technology, pre-dating all innovations in the field except for formal language. Most people often take writing for granted because they tend to learn how to do it at an early age, but despite such familiarity, writing remains an ancient but useful form of technology. Depending on the region of the world studied, scholars estimate the act of writing originated between 3200 B.C.E. (Middle East), 1200 B.C.E. (Asia), and 600 B.C.E. (North America). Unlike iconic, or pictorial, depictions of historical events, humans began to develop arbitrary systems of writing, which means the symbols or letters used did not look like the form they were used to represent.
It took a long time for writing to resemble its modern form. The Chinese first invented paper around 100 B.C.E., but paper didn’t make its way to Europe and the rest of Western civilization until around the 10th century. This means that, for about 4,200 years, much of the Western world was taking notes and writing things down on media other than the paper. What did they write on, if not paper? For four millennia, writing took place on media such as slate, leather, bark, and clay. Due to the limitations of replication, storage, and portability these media offered, writing during this time period did not provide the potential for mass communication due to the limited audience who could engage with such rudimentary messages.
Throughout history, individuals and societies have often looked at innovative technologies with mistrust and fear, and this holds true for the second-oldest. Even the now cherished art of writing had its detractors when first developed.
Home Socrates (d. 399 B.C.E.), often credited as the founder of Western philosophy, said this about writing in his famous dialogue, The Phaedrus :
…this discovery of yours [writing] will create forgetfulness in the learners’ souls, because they will not use their memories; they will trust to the external written characters and not remember of themselves. The specific which you have discovered is an aid not to memory, but to reminiscence, and you give your disciples not truth, but only the semblance of truth; they will be hearers of many things and will have learned nothing; they will appear to be omniscient and will generally know nothing; they will be tiresome company, having the show of wisdom without the reality.
In other words, Socrates’ complained that the latest “fad” of writing could potentially create a society of idiots who relied so heavily on technology that they could no longer function for themselves. Does it sound surprising that one of the great philosophical minds held such a negative opinion against writing? Arguments against new communication technologies resurface every time society welcomes a new tool that enhances the process.
The advantages of writing, however, far outweighed any negative tradeoffs, and people continue to engage in the process to this day. Suddenly, individuals could 1) store information more permanently without having to rely on someone with a remarkable memory, 2) transmit messages over greater distances, and 3) record and analyze communications [1] . Every rapid change in communication begets winners and losers, grants benefits and drawbacks, and catalyzes change. Such change becomes permanent if the benefits outweigh any disadvantages society experiences to adopt the new technology. This pattern will continue in the next three revolutions.
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A detriment to politicians, for they could no longer count on getting away with changing their stories so rapidly!
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16: Hanan al-Shaykh (1945- )
Thumbnail: Lebanese writer Hanan Al-Shaykh at Helsinki Book Fair 2003. (CC BY-SA 3.0 Unported; Anneli Salo via Wikipedia )
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Hanan al-Shaykh (1945- ) The Women's Swimming Pool Lebanese Contemporary Literature Hanan al-Shaykh is a critically acclaimed Lebanese writer, who currently lives in London. Growing up in a restricted patriarchal environment created by her father (a devout Shia Muslim) and brother, she started to write to express her freedom. She first attended a traditional Muslim girls' primary school but later went to the more culturally diverse Ahliyyah School for Girls and the American College for Girls in Cairo, Egypt. Al-Shaykh first worked as a journalist in Beirut for a women's magazine called al-Hasna and later devoted herself to creative writing. Her first book was Intihar Rajul Mayyit [ Suicide of a Dead Man ] (1970), which is told by a male narrator. Her other works, translated into English, include Only in London (2001), Beirut Blues (1992), and The Story of Zahra (1994). The Locust and the Bird: My Mother's Story (2009) is about how her mother was forcibly married at age thirteen and later left her family to live with her lover. "The Women's Swimming Pool" (1982) is a short story revealing some of her ongoing concerns, such as the conflict between modernity and tradition in the Middle East, and women and their desire for freedom in the Arab World. Consider while reading:
Written by Kyounghye Kwon
Thumbnail: Lebanese writer Hanan Al-Shaykh at Helsinki Book Fair 2003. (CC BY-SA 3.0 Unported; Anneli Salo via Wikipedia )


6.1: Introduction
Notes to Teachers and Students:
Filtering is one of the most important things that electrical and computer engineers do. In this chapter we extend everyday understanding of filters to numerical filters. We then study weighted moving averages and exponential averages. We define the important test signals for electrical and computer engineering and show how filters respond to them. The idea that filters are characterized by their response to simple test signals is fundamental. In the numerical experiment , students explore the frequency response of a simple filter, a concept that forms the basis of circuit theory, electronics, optics and lasers, solid-state devices, communications, and control.
Introduction
A filter is any device that passes material, light, sound, current, velocity, or information according to some rule of selectivity. Material (or mechanical) filters are commonplace in your everyday life:
- coffee filters pass flavored water while filtering out coffee grounds;
- Goretex fibers pass small, warm perspiration droplets while filtering out large, cool droplets of rain or snow;
- fiberglass strands in a furnace filter pass warm air while filtering out particles of dirt and dust;
- a centrifuge retains material of low density while spinning out (or filtering out) material of high density; and
- an electrostatic precipitator filters out dust and other effluents by attaching charge to them and using an electric field to move the charged particles to a high potential drain.
The first three of these examples selectively pass material according to size; the last two selectively pass material according to its mass density.
Typical filters for light are
- UV filters on camera lenses and eyeglasses that pass light in the range of visible wavelengths while blocking light in the invisible (but damaging) ultraviolet range;
- polaroid lenses that pass light that is randomly polarized while blocking out glare that is linearly polarized;
- green fabrics that reflect green light and absorb other colors;
- red taillights that pass light in the long wavelength red range and reflect light in the short wavelength violet range (look at the inside of your taillights to see violet); and
- glacial ice that absorbs all but the blue wavelengths so that it appears blue.
List as many examples of natural and man-made sound filters as you can.
Satellite Television
Among current filters, the tuner in a super-heterodyne receiver is, perhaps, the first example that comes to mind. But satellite TV filters are another fascinating example. A typical C-band satellite has twelve transponders (or repeaters), each of which transmits microwave radiation in a personalized 36 MHz band. (The abbreviation MHz stands for megahertz, or 10\(^6\) Hz, or 10\(^6\) cycles per second. Other common abbreviations are Hz for 1 Hz, kHz for 10\(^3\) Hz, and GHz for 10\(^9\) Hz.) Each transponder actually transmits two channels of information, one vertically polarized and one horizontally polarized. There is an 8 MHz guard band between each band, and the vertical and horizontal channels are offset by 20 MHz. The transmission scheme for the 24 channels is illustrated in Figure 1. The entire transmission band extends over 540 MHz, from 3.7×10\(^9\) Hz to 4.24×10\(^9\) Hz. The satellite receiver has two different microwave detectors, one for vertical and one for horizontal polarization, and a microwave tuner to tune into the microwave band of interest.
Check that the transmission scheme of Figure 1 consumes 540 MHz of bandwidth.
List as many examples of natural and man-made devices for velocity filtering as you can.
An Aside on Hertz and Seconds
The abbreviation Hz stands for hertz, or cycles/second. It is used to describe the frequency of a sinusoidal signal. For example, house current is 60 Hz, meaning that it has 60 cycles each second. The inverse of Hz is seconds or, more precisely, seconds/cycle, the period of 1 cycle. For example, the period of 1 cycle for house current is 1/60 second. When we are dealing with sound, electricity, and electromagnetic radiation, we need a concise language for dealing with signals and waves whose frequencies range from 0 Hz (called DC or direct current) to 10\(^{18}\) Hz (visible light). Table 1 summarizes the terms and symbols used to describe the frequency and period of signals that range in frequency from 0 Hz to 10\(^{12}\) Hz.
| Frequency | Period | |||||
|---|---|---|---|---|---|---|
| Hz | Term | Units | Seconds | Term | Units | Example |
| Hz | hertz | 1 Hz | sec | second | 1 sec |
battery current: 0 Hz
house current: 60 Hz |
| kHz | kilohertz | 10 3 Hz | msec | millisecond | 10 -3 sec | midfrequency sound |
| MHz | megahertz | 10 6 Hz | µsec | microsecond | 10 -6 sec | clock frequencies in microcomputers |
| GHz | gigahertz | 10 9 Hz | nsec | nanosecond | 10 -9 sec | microwave radiation for satellite communication |
| THz | terahertz | 10 12 Hz | psec | picosecond | 10 -12 sec | infrared radiation |
Numerical Filters
Rather amazingly, these ideas extend to the domain of numerical filters, the topic of this chapter. Numerical filters are just schemes for weighting and summing strings of numbers. Stock prices are typically averaged with numerical filters. The curves in Figure 2 illustrate the daily closing average for Kellogg's common stock and two moving averages. The 50-day moving average is obtained by passing the daily closing average through a numerical filter that averages the most current 50 days' worth of closing averages. The 200-day moving average for the stock price is obtained by passing the daily closing prices through a numerical filter that averages the most current 200 days' worth of daily closing averages. The daily closing averages show fine-grained variation but tend to conceal trends. The 50-day and 200-day averages show less fine-grained variation but give a clearer picture of trends. In fact, this is one of the key ideas in numerical filtering: by selecting our method of averaging, we can filter out fine-grained variations and pass long-term trends (or vice versa), or we can filter out periodic variations and pass nonperiodic variations (or vice versa). Figure 2 illustrates that moving averages typically lag increasing sequences of numbers and lead decreasing sequences. Can you explain why?
We will call any algorithm or procedure for transforming one set of numbers into another set of numbers a numerical filter or digital filter . Digital filters, consisting of memories and arithmetic logic units (ALUs), are implemented in VLSI circuits and used for communication, control, and instrumentation. They are also implemented in random–or semicustom–logic circuits and in programmable microcomputer systems. The inputs to a digital filter are typically electronic measurements that are produced by A/D (analog-to-digital) conversion of the output of an electrical or mechanical sensor. The outputs of the filter are “processed,” “filtered,” or “smoothed” versions of the measurements. In your more advanced courses in electrical and computer engineering you will study signal processing and system theory, assembly language programming, microprocessor system development, and computer design. In these courses you will study the design and programming of hardware that may be used for digital filtering.


1.4: Applications
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Learning Objectives
In this section, you will learn to use linear functions to model real-world applications
Now that we have learned to determine equations of lines, we get to apply these ideas in a variety of real-life situations.
Read the problem carefully. Highlight important information. Keep track of which values correspond to the independent variable (x) and which correspond to the dependent variable (y).
Example \(\PageIndex{1}\)
A taxi service charges $0.50 per mile plus a $5 flat fee. What will be the cost of traveling 20 miles? What will be cost of traveling \(x\) miles?
Solution
\(x\) = distance traveled, in miles and \(y\) = cost in dollars
The cost of traveling 20 miles is
\[y = (0.50)(20) + 5 = 10 + 5 = 15 \nonumber \]
The cost of traveling \(x\) miles is
\[y = (0.50)(x) + 5 = 0.50x + 5 \nonumber \]
In this problem, $0.50 per mile is referred to as the variable cost , and the flat charge $5 as the fixed cost . Now if we look at our cost equation \(y = .50x + 5\), we can see that the variable cost corresponds to the slope and the fixed cost to the \(y\)-intercept.
Example \(\PageIndex{2}\)
The variable cost to manufacture a product is $10 per item and the fixed cost $2500. If \(x\) represents the number of items manufactured and \(y\) represents the total cost, write the cost function.
Solution
- The variable cost of $10 per item tells us that \(m = 10\).
- The fixed cost represents the \(y\)-intercept. So \(b = 2500\).
Therefore, the cost equation is \(y = 10x + 2500\).
Example \(\PageIndex{3}\)
It costs $750 to manufacture 25 items, and $1000 to manufacture 50 items. Assuming a linear relationship holds, find the cost equation, and use this function to predict the cost of 100 items.
Solution
We let \(x\) = the number of items manufactured, and let \(y\) = the cost.
Solving this problem is equivalent to finding an equation of a line that passes through the points (25, 750) and (50, 1000).
\[ m = \frac{1000-750}{50-25} = 10 \nonumber \]
Therefore, the partial equation is \(y = 10x + b\)
By substituting one of the points in the equation, we get \(b = 500\)
Therefore, the cost equation is \(y = 10x + 500\)
To find the cost of 100 items, substitute \(x = 100\) in the equation \(y = 10x + 500\)
So the cost is
\[y = 10(100) + 500 = 1500 \nonumber \]
It costs $1500 to manufacture 100 items.
Example \(\PageIndex{4}\)
The freezing temperature of water in Celsius is 0 degrees and in Fahrenheit 32 degrees. And the boiling temperatures of water in Celsius, and Fahrenheit are 100 degrees, and 212 degrees, respectively. Write a conversion equation from Celsius to Fahrenheit and use this equation to convert 30 degrees Celsius into Fahrenheit.
Solution
Let us look at what is given.
| Celsius | Fahrenheit |
| 0 | 32 |
| 100 | 212 |
Again, solving this problem is equivalent to finding an equation of a line that passes through the points (0, 32) and (100, 212).
Since we are finding a linear relationship, we are looking for an equation \(y = mx + b\), or in this case \(F = mC + b\), where \(x\) or \(C\) represent the temperature in Celsius, and y or F the temperature in Fahrenheit.
\[ \text{slope m } = \frac{312-32}{100-0} = \frac{9}{5} \nonumber \]
The equation is \(F = \frac{9}{5}C + b\)
Substituting the point (0, 32), we get
\[F = \frac{9}{5}C + 32 \nonumber. \nonumber \]
To convert 30 degrees Celsius into Fahrenheit, substitute \(C = 30\) in the equation
\begin{aligned}
&\mathrm{F}=\frac{9}{5} \mathrm{C}+32\\
&\mathrm{F}=\frac{9}{5}(30)+32=86
\end{aligned}
Example \(\PageIndex{5}\)
The population of Canada in the year 1980 was 24.5 million, and in the year 2010 it was 34 million. The population of Canada over that time period can be approximately modelled by a linear function. Let x represent time as the number of years after 1980 and let y represent the size of the population.
- Write the linear function that gives a relationship between the time and the population.
- Assuming the population continues to grow linearly in the future, use this equation to predict the population of Canada in the year 2025.
Solution
The problem can be made easier by using 1980 as the base year, that is, we choose the year 1980 as the year zero. This will mean that the year 2010 will correspond to year 30. Now we look at the information we have:
| Year | Population |
| 0 (1980) | 24.5 million |
| 30 (2010) | 34 million |
a. Solving this problem is equivalent to finding an equation of a line that passes through the points (0, 24.5) and (30, 34). We use these two points to find the slope:
\[ m = \frac{34-24.5}{30-0}=\frac{9.5}{30} = 0.32 \nonumber \]
The \(y\)-intercept occurs when \(x = 0\), so \(b = 24.5\)
\[ y =0.32x + 24.5 \nonumber \]
b. Now to predict the population in the year 2025, we let \(x=2025-1980=45\)
\begin{aligned}
&y=0.32 x+24.5\\
&y=0.32(45)+24.5=38.9
\end{aligned}
In the year 2025, we predict that the population of Canada will be 38.9 million people.
Note that we assumed the population trend will continue to be linear. Therefore if population trends change and this assumption does not continue to be true in the future, this prediction may not be accurate.


27.1: Introduction
The steps of the nursing process provide direction for nurses when making patient care decisions. Each decision affects the patient’s health status because safe and effective decisions made by nurses enhance patient outcomes (Nibbelink & Brewer, 2018). Clinical judgment is an essential part of safe and effective decision making in nursing practice (Tanner, 2006). The process of clinical judgment is cognitive and is the integrated thinking performed by nurses when making patient care decisions (Lasater, 2007). This chapter focuses on how to use clinical judgment when providing nursing care for gynecologic and obstetric patients. The unfolding case study offers opportunities for practice of clinical judgment and NCLEX-style questions.


<IP_ADDRESS>: Data Types
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Data Types
When defining the fields in a database table, we must give each field a data type. For example, the field Birth Year is a year, so it will be a number, while First Name will be text. Most modern databases allow for several different data types to be stored. Some of the more common data types are listed here:
- Text: for storing non-numeric data that is brief, generally under 256 characters. The database designer can identify the maximum length of the text.
- Number: for storing numbers. There are usually a few different number types that can be selected, depending on how large the largest number will be.
- Yes/No: a special form of the number data type that is (usually) one byte long, with a 0 for “No” or “False” and a 1 for “Yes” or “True”.
- Date/Time: a special form of the number data type that can be interpreted as a number or a time.
- Currency: a special form of the number data type that formats all values with a currency indicator and two decimal places.
- Paragraph Text: this data type allows for text longer than 256 characters.
- Object: this data type allows for the storage of data that cannot be entered via keyboard, such as an image or a music file.
There are two important reasons that we must properly define the data type of a field. First, a data type tells the database what functions can be performed with the data. For example, if we wish to perform mathematical functions with one of the fields, we must be sure to tell the database that the field is a number data type. So if we have, say, a field storing birth year, we can subtract the number stored in that field from the current year to get age.
The second important reason to define data type is so that the proper amount of storage space is allocated for our data. For example, if the First Name field is defined as a text(50) data type, this means fifty characters are allocated for each first name we want to store. However, even if the first name is only five characters long, fifty characters (bytes) will be allocated. While this may not seem like a big deal, if our table ends up holding 50,000 names, we are allocating 50 * 50,000 = 2,500,000 bytes for storage of these values. It may be prudent to reduce the size of the field so we do not waste storage space.
Sidebar: The Difference between a Database and a Spreadsheet
Many times, when introducing the concept of databases to students, they quickly decide that a database is pretty much the same as a spreadsheet. After all, a spreadsheet stores data in an organized fashion, using rows and columns, and looks very similar to a database table. This misunderstanding extends beyond the classroom: spreadsheets are used as a substitute for databases in all types of situations every day, all over the world.
To be fair, for simple uses, a spreadsheet can substitute for a database quite well. If a simple listing of rows and columns (a single table) is all that is needed, then creating a database is probably overkill. In our Student Clubs example, if we only needed to track a listing of clubs, the number of members, and the contact information for the president, we could get away with a single spreadsheet. However, the need to include a listing of events and the names of members would be problematic if tracked with a spreadsheet.
When several types of data must be mixed together, or when the relationships between these types of data are complex, then a spreadsheet is not the best solution. A database allows data from several entities (such as students, clubs, memberships, and events) to all be related together into one whole. While a spreadsheet does allow you to define what kinds of values can be entered into its cells, a database provides more intuitive and powerful ways to define the types of data that go into each field, reducing possible errors and allowing for easier analysis.
Though not good for replacing databases, spreadsheets can be ideal tools for analyzing the data stored in a database. A spreadsheet package can be connected to a specific table or query in a database and used to create charts or perform analysis on that data.


24.4: Viral Infections of the Gastrointestinal Tract
- Identify the most common viruses that can cause infections of the GI tract
- Compare the major characteristics of specific viral diseases affecting the GI tract and liver
In the developing world, acute viral gastroenteritis is devastating and a leading cause of death for children. 1 Worldwide, diarrhea is the second leading cause of mortality for children under age five, and 70% of childhood gastroenteritis is viral. 2 As discussed, there are a number of bacteria responsible for diarrhea, but viruses can also cause diarrhea. E. coli and rotavirus are the most common causative agents in the developing world. In this section, we will discuss rotaviruses and other, less common viruses that can also cause gastrointestinal illnesses.
Gastroenteritis Caused by Rotaviruses
Rotaviruses are double-stranded RNA viruses in the family Reoviridae. They are responsible for common diarrheal illness, although prevention through vaccination is becoming more common. The virus is primarily spread by the fecal-oral route (Figure \(\PageIndex{1}\)).
These viruses are widespread in children, especially in day-care centers. The CDC estimates that 95% of children in the United States have had at least one rotavirus infection by the time they reach age five. 3 Due to the memory of the body’s immune system, adults who come into contact with rotavirus will not contract the infection or, if they do, are asymptomatic. The elderly, however, are vulnerable to rotavirus infection due to weakening of the immune system with age, so infections can spread through nursing homes and similar facilities. In these cases, the infection may be transmitted from a family member who may have subclinical or clinical disease. The virus can also be transmitted from contaminated surfaces, on which it can survive for some time.
Infected individuals exhibit fever, vomiting, and diarrhea. The virus can survive in the stomach following a meal, but is normally found in the small intestines, particularly the epithelial cells on the villi. Infection can cause food intolerance, especially with respect to lactose. The illness generally appears after an incubation period of about two days and lasts for approximately one week (three to eight days). Without supportive treatment, the illness can cause severe fluid loss, dehydration, and even death. Even with milder illness, repeated infections can potentially lead to malnutrition, especially in developing countries, where rotavirus infection is common due to poor sanitation and lack of access to clean drinking water. Patients (especially children) who are malnourished after an episode of diarrhea are more susceptible to future diarrheal illness, increasing their risk of death from rotavirus infection.
The most common clinical tool for diagnosis is enzyme immunoassay, which detects the virus from fecal samples. Latex agglutination assays are also used. Additionally, the virus can be detected using electron microscopy and RT-PCR.
Treatment is supportive with oral rehydration therapy. Preventive vaccination is also available. In the United States, rotavirus vaccines are part of the standard vaccine schedule and administration follows the guidelines of the World Health Organization (WHO). The WHO recommends that all infants worldwide receive the rotavirus vaccine, the first dose between six and 15 weeks of age and the second before 32 weeks. 4
Gastroenteritis Caused by Noroviruses
Noroviruses, commonly identified as Norwalk viruses, are caliciviruses. Several strains can cause gastroenteritis. There are millions of cases a year, predominately in infants, young children, and the elderly. These viruses are easily transmitted and highly contagious. They are known for causing widespread infections in groups of people in confined spaces, such as on cruise ships. The viruses can be transmitted through direct contact, through touching contaminated surfaces, and through contaminated food. Because the virus is not killed by disinfectants used at standard concentrations for killing bacteria, the risk of transmission remains high, even after cleaning.
The signs and symptoms of norovirus infection are similar to those for rotavirus, with watery diarrhea, mild cramps, and fever. Additionally, these viruses sometimes cause projectile vomiting. The illness is usually relatively mild, develops 12 to 48 hours after exposure, and clears within a couple of days without treatment. However, dehydration may occur.
Norovirus can be detected using PCR or enzyme immunoassay (EIA) testing. RT-qPCR is the preferred approach as EIA is insufficiently sensitive. If EIA is used for rapid testing, diagnosis should be confirmed using PCR. No medications are available, but the illness is usually self-limiting. Rehydration therapy and electrolyte replacement may be used. Good hygiene, hand washing, and careful food preparation reduce the risk of infection.
Gastroenteritis Caused by Astroviruses
Astroviruses are single-stranded RNA viruses (family Astroviridae) that can cause severe gastroenteritis, especially in infants and children. Signs and symptoms include diarrhea, nausea, vomiting, fever, abdominal pain, headache, and malaise. The viruses are transmitted through the fecal-oral route (contaminated food or water). For diagnosis, stool samples are analyzed. Testing may involve enzyme immunoassays and immune electron microscopy. Treatment involves supportive rehydration and electrolyte replacement if needed.
Why are rotaviruses, noroviruses, and astroviruses more common in children?
A number of viruses can cause gastroenteritis, characterized by inflammation of the GI tract and other signs and symptoms with a range of severities. As with bacterial GI infections, some cases can be relatively mild and self-limiting, while others can become serious and require intensive treatment. Antimicrobial drugs are generally not used to treat viral gastroenteritis; generally, these illnesses can be treated effectively with rehydration therapy to replace fluids lost in bouts of diarrhea and vomiting. Because most viral causes of gastroenteritis are quite contagious, the best preventive measures involve avoiding and/or isolating infected individuals and limiting transmission through good hygiene and sanitation.
Hepatitis
Hepatitis is a general term meaning inflammation of the liver, which can have a variety of causes. In some cases, the cause is viral infection. There are five main hepatitis viruses that are clinically significant: hepatitisviruses A (HAV), B (HBV), C (HCV), D, (HDV) and E (HEV) (Figure \(\PageIndex{3}\)). Note that other viruses, such as Epstein-Barr virus (EBV), yellow fever, and cytomegalovirus (CMV) can also cause hepatitis and are discussed in Viral Infections of the Circulatory and Lymphatic Systems .
Although the five hepatitis viruses differ, they can cause some similar signs and symptoms because they all have an affinity for hepatocytes (liver cells). HAV and HEV can be contracted through ingestion while HBV, HCV, and HDV are transmitted by parenteral contact. It is possible for individuals to become long term or chronic carriers of hepatitis viruses.
The virus enters the blood (viremia), spreading to the spleen, the kidneys, and the liver. During viral replication, the virus infects hepatocytes. The inflammation is caused by the hepatocytes replicating and releasing more hepatitis virus. Signs and symptoms include malaise, anorexia, loss of appetite, dark urine, pain in the upper right quadrant of the abdomen, vomiting, nausea, diarrhea, joint pain, and gray stool. Additionally, when the liver is diseased or injured, it is unable to break down hemoglobin effectively, and bilirubin can build up in the body, giving the skin and mucous membranes a yellowish color, a condition called jaundice (Figure \(\PageIndex{4}\)). In severe cases, death from liver necrosis may occur.
Despite having many similarities, each of the hepatitis viruses has its own unique characteristics. HAV is generally transmitted through the fecal-oral route, close personal contact, or exposure to contaminated water or food. Hepatitis A can develop after an incubation period of 15 to 50 days (the mean is 30). It is normally mild or even asymptomatic and is usually self-limiting within weeks to months. A more severe form, fulminant hepatitis, rarely occurs but has a high fatality rate of 70–80%. Vaccination is available and is recommended especially for children (between ages one and two), those traveling to countries with higher risk, those with liver disease and certain other conditions, and drug users.
Although HBV is associated with similar signs and symptoms, transmission and outcomes differ. This virus has a mean incubation period of 120 days and is generally associated with exposure to infectious blood or body fluids such as semen or saliva. Exposure can occur through skin puncture, across the placenta, or through mucosal contact, but it is not spread through casual contact such as hugging, hand holding, sneezing, or coughing, or even through breastfeeding or kissing. Risk of infection is greatest for those who use intravenous drugs or who have sexual contact with an infected individual. Health-care workers are also at risk from needle sticks and other injuries when treating infected patients. The infection can become chronic and may progress to cirrhosis or liver failure. It is also associated with liver cancer. Chronic infections are associated with the highest mortality rates and are more common in infants. Approximately 90% of infected infants become chronic carriers, compared with only 6–10% of infected adults. 5 Vaccination is available and is recommended for children as part of the standard vaccination schedule (one dose at birth and the second by 18 months of age) and for adults at greater risk (e.g., those with certain diseases, intravenous drug users, and those who have sex with multiple partners). Health-care agencies are required to offer the HBV vaccine to all workers who have occupational exposure to blood and/or other infectious materials.
HCV is often undiagnosed and therefore may be more widespread than is documented. It has a mean incubation period of 45 days and is transmitted through contact with infected blood. Although some cases are asymptomatic and/or resolve spontaneously, 75%–85% of infected individuals become chronic carriers. Nearly all cases result from parenteral transmission often associated with IV drug use or transfusions. The risk is greatest for individuals with past or current history of intravenous drug use or who have had sexual contact with infected individuals. It has also been spread through contaminated blood products and can even be transmitted through contaminated personal products such as toothbrushes and razors. New medications have recently been developed that show great effectiveness in treating HCV and that are tailored to the specific genotype causing the infection.
HDV is uncommon in the United States and only occurs in individuals who are already infected with HBV, which it requires for replication. Therefore, vaccination against HBV is also protective against HDV infection. HDV is transmitted through contact with infected blood.
HEV infections are also rare in the United States but many individuals have a positive antibody titer for HEV. The virus is most commonly spread by the fecal-oral route through food and/or water contamination, or person-to-person contact, depending on the genotype of the virus, which varies by location. There are four genotypes that differ somewhat in their mode of transmission, distribution, and other factors (for example, two are zoonotic and two are not, and only one causes chronic infection). Genotypes three and four are only transmitted through food, while genotypes one and two are also transmitted through water and fecal-oral routes. Genotype one is the only type transmitted person-to-person and is the most common cause of HEV outbreaks. Consumption of undercooked meat, especially deer or pork, and shellfish can lead to infection. Genotypes three and four are zoonoses, so they can be transmitted from infected animals that are consumed. Pregnant women are at particular risk. This disease is usually self-limiting within two weeks and does not appear to cause chronic infection.
General laboratory testing for hepatitis begins with blood testing to examine liver function (Figure \(\PageIndex{5}\)). When the liver is not functioning normally, the blood will contain elevated levels of alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), direct bilirubin, total bilirubin, serum albumin, serum total protein, and calculated globulin, albumin/globulin (A/G) ratio. Some of these are included in a complete metabolic panel (CMP), which may first suggest a possible liver problem and indicate the need for more comprehensive testing. A hepatitis virus serological test panel can be used to detect antibodies for hepatitis viruses A, B, C, and sometimes D. Additionally, other immunological and genomic tests are available.
Specific treatments other than supportive therapy, rest, and fluids are often not available for hepatitis virus infection, except for HCV, which is often self-limited. Immunoglobulins can be used prophylactically following possible exposure. Medications are also used, including interferon alpha 2b and antivirals (e.g., lamivudine, entecavir, adefovir, and telbivudine) for chronic infections. Hepatitis C can be treated with interferon (as monotherapy or combined with other treatments), protease inhibitors, and other antivirals (e.g., the polymerase inhibitor sofosbuvir). Combination treatments are commonly used. Antiviral and immunosuppressive medications may be used for chronic cases of HEV. In severe cases, liver transplants may be necessary. Additionally, vaccines are available to prevent infection with HAV and HBV. The HAV vaccine is also protective against HEV. The HBV vaccine is also protective against HDV. There is no vaccine against HCV.
Why do the five different hepatitis viruses all cause similar signs and symptoms?
Hepatitis B was once a leading on-the-job hazard for health-care workers. Many health-care workers over the years have become infected, some developing cirrhosis and liver cancer. In 1982, the CDC recommended that health-care workers be vaccinated against HBV, and rates of infection have declined since then. Even though vaccination is now common, it is not always effective and not all individuals are vaccinated. Therefore, there is still a small risk for infection, especially for health-care workers working with individuals who have chronic infections, such as drug addicts, and for those with higher risk of needle sticks, such as phlebotomists. Dentists are also at risk.
Health-care workers need to take appropriate precautions to prevent infection by HBV and other illnesses. Blood is the greatest risk, but other body fluids can also transmit infection. Damaged skin, as occurs with eczema or psoriasis, can also allow transmission. Avoiding contact with body fluids, especially blood, by wearing gloves and face protection and using disposable syringes and needles reduce the risk of infection. Washing exposed skin with soap and water is recommended. Antiseptics may also be used, but may not help. Post-exposure treatment, including treatment with hepatitis B immunoglobulin (HBIG) and vaccination, may be used in the event of exposure to the virus from an infected patient. Detailed protocols are available for managing these situations. The virus can remain infective for up to seven days when on surfaces, even if no blood or other fluids are visible, so it is important to consider the best choices for disinfecting and sterilizing equipment that could potentially transmit the virus. The CDC recommends a solution of 10% bleach to disinfect surfaces. 6 Finally, testing blood products is important to reduce the risk of transmission during transfusions and similar procedures.
Hepatitis involves inflammation of the liver that typically manifests with signs and symptoms such as jaundice, nausea, vomiting, joint pain, gray stool, and loss of appetite. However, the severity and duration of the disease can vary greatly depending on the causative agent. Some infections may be completely asymptomatic, whereas others may be life threatening. The five different viruses capable of causing hepatitis are compared in Figure \(\PageIndex{5}\). For the sake of comparison, this table presents only the unique aspects of each form of viral hepatitis, not the commonalities.
Key Concepts and Summary
- Common viral causes of gastroenteritis include rotaviruses, noroviruses, and astroviruses.
- Hepatitis may be caused by several unrelated viruses: hepatitis viruses A, B, C, D, and E.
- The hepatitis viruses differ in their modes of transmission, treatment, and potential for chronic infection.
Footnotes
- 1 Caleb K. King, Roger Glass, Joseph S. Bresee, Christopher Duggan. “Managing Acute Gastroenteritis Among Children: Oral Rehydration, Maintenance, and Nutritional Therapy.” MMWR 52 (2003) RR16: pp. 1–16. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5216a1.htm .
- 2 Elizabeth Jane Elliott. “Acute Gastroenteritis in Children.” British Medical Journal 334 (2007) 7583: 35–40, doi: 10.1136/bmj.39036.406169.80; S. Ramani and G. Kang. “Viruses Causing Diarrhoea in the Developing World.” Current Opinions in Infectious Diseases 22 (2009) 5: pp. 477–482. doi: 10.1097/QCO.0b013e328330662f; Michael Vincent F Tablang. “Viral Gastroenteritis.” Medscape . http://emedicine.medscape.com/article/176515-overview .
- 3 Centers for Disease Control and Prevention. “Rotavirus,” The Pink Book. Updated September 8, 2015. http://www.cdc.gov/vaccines/pubs/pinkbook/rota.html .
- 4 World Health Organization. “Rotavirus.” Immunization, Vaccines, and Biologicals. Updated April 21, 2010. www.who.int/immunization/topics/rotavirus/en/.
- 5 Centers for Disease Control and Prevention. “The ABCs of Hepatitis.” Updated 2016. http://www.cdc.gov/hepatitis/resourc...s/abctable.pdf .
- 6 Centers for Disease Control and Prevention. “Hepatitis B FAQs for Health Professionals.” Updated August 4, 2016. http://www.cdc.gov/hepatitis/HBV/HBVfaq.htm .


9.4: Sample Documentation
Sample Documentation of Expected Cardiac & Peripheral Vascular Findings
Patient denies chest pain or shortness of breath. Vital signs are within normal limits. Point of maximum impulse palpable at the fifth intercostal space of the midclavicular line. No lifts, heaves, or thrills identified on inspection or palpation. JVD absent. S1 and S2 heart sounds in regular rhythm with no murmurs or extra sounds . Skin is warm, pink, and dry. Capillary refill is less than two seconds. Color, movement, and sensation are intact in upper and lower extremities. Peripheral pulses are present (+2) and equal bilaterally. No peripheral edema is noted. Hair is distributed evenly on lower extremities.
Sample Documentation of Unexpected Cardiac & Peripheral Vascular Findings
Patient reports increase in breathing difficulty and increased swelling of bilateral lower extremities over the last three days. Diminished pulses (+1) bilaterally and pitting edema (+2) in the bilateral lower extremities. Upon auscultation, an S3 heart sound is noted and the patient has bilateral crackles in the posterior bases of the lungs. Skin is pink, warm, and dry with capillary refill of < 2 seconds. All other pulses are present (+2), and no other areas of edema are noted. JVD is absent.


16.8: Verb Tenses
- Identify and use the correct verb tense in a sentence
Tenses
There are three standard tenses in English: past, present and future. All three of these tenses have simple and more complex forms. For now we’ll just focus on the simple present (things happening now), the simple past (things that happened before), and the simple future (things that will happen later).
- Simple Present: work(s)
- Simple Past: worked
- Simple Future: will work
The present tense for singular third person is slightly different from the other persons. Look at the tables, below, to see the correct tenses for each person:
| Person | Past | Present | Future |
| I | verb + ed | verb | will verb |
| We | verb + ed | verb | will verb |
| You | verb + ed | verb | will verb |
| He, She, It | verb + ed | verb + s (or es ) | will verb |
| They | verb + ed | verb | will verb |
Let’s look at the verb to walk for an example:
| Person | Past | Present | Future |
| I | walked | walk | will walk |
| We | walked | walk | will walk |
| You | walked | walk | will walk |
| He, She, It | walked | walks | will walk |
| They | walked | walk | will walk |
Irregular Verbs
There are a lot of irregular verbs. Unfortunately, a fair amount of memorization is needed to keep them straight.
The following video shows some of the irregular verbs you’ll use most often ( to be , to have , to do , and to say ):
You can view the transcript for “Introduction to irregular verbs” here (opens in new window) .
For quick reference, below are the tables for to be and to have :
To be
| Person | Past | Present | Future |
| I | was | am | will be |
| We | were | are | will be |
| You | were | are | will be |
| He, She, It | was | is | will be |
| They | were | are | will be |
To have
| Person | Past | Present | Future |
| I | had | have | will have |
| We | had | have | will have |
| You | had | have | will have |
| He, She, It | had | has | will have |
| They | had | have | will have |
Here’s a list of several irregular past tense verbs.
https://lumenlearning.h5p.com/content/1290622346043861808/embed
[reveal-answer q=”474777″]Explain Answers[/reveal-answer]
[hidden-answer a=”474777″]
- Ysabella is really good at getting others to open up.
- Rodrigo had a B+ in his math class.
-
Amanda
will say
she
doesn’t
want to go to the party.
- Notice that when the tense of the first verb changed, the tense of the second verb did, as well.
- Jordan did two hundred sit-ups.
- Marcela runs a car wash down the street from my house.
[/hidden-answer]
Complex Verb Tenses
Verbs don’t have to be expressed only in present, past, or future tenses. There are more complex verb tenses that allow us to express actions with a little more variety and difference, which are created by changing the verb aspect . The verb aspect tells us whether a verb is stating a fact, a completed action, an ongoing action, or the end of an ongoing action. Here are a few examples of these different aspects, all in the present tense:
- Simple Aspect (expressing a fact): I eat.
- Perfect Aspect (expressing a completed action): I have eaten.
- Progressive or Continuous Aspect (expressing an ongoing action): I am eating.
- Perfect Progressive Aspect (expressing the end of an ongoing action): I have been eating.
Each of these aspects can be expressed in past, present, and future tenses. For example, the different verb tenses in the perfect aspect would be:
- Past Perfect: I had eaten
- Present Perfect: I have eaten
- Future Perfect: I will have eaten
These different tenses allow for much more flexibility in our language and expression.
Watch the video below for some more information about verb aspect, and to see all the different types of ways you can organize and use verbs.
You can view the transcript for “Introduction to verb aspect” here (opens in new window) .
https://assessments.lumenlearning.co...essments/20337
https://assessments.lumenlearning.co...essments/20338
https://lumenlearning.h5p.com/content/1290622570734869168/embed
Look at the following schedule for a Writer’s Workshop. Pretend that it’s Tuesday at 12:30 pm—you’re halfway through the workshop events. Write a short journal entry about the schedule, using both simple and complex verb tenses.
| Monday | Tuesday | Wednesday | |
|---|---|---|---|
| 10:00 | Check-In | Genre Speakers | Meet Editors/Agents |
| 11:00 | Group Orientation | Genre Speakers | |
| 12:00 | Lunch | Lunch | Checkout |
| 1:00 | Peer-to-Peer Critique | Professional Critiques | |
| 2:00 | |||
| 3:00 | Keynote Speaker |
[practice-area rows=”4″][/practice-area]
[reveal-answer q=”642911″]Show Answer[/reveal-answer]
[hidden-answer a=”642911″]While there are an infinite number of passages you could write, compare the tenses in your passage to ours:
This Writer’s Workshop has been going since yesterday. This morning, several genre speakers talked about the quirks of their genres. By the time attendees heard these talks, they had completed their peer-to-peer critiques and were ready to learn more specific things about the genre they aspire to write in. After lunch today, each attendee will meet with a professional writer for a critique of his or her work. When that has finished , the keynote speaker will give an address. Tomorrow there will be a meet-and-greet with editors and agents. By noon tomorrow, the workshop will have ended .
[/hidden-answer]
Contributors and Attributions
- Text: Verb Tenses. Provided by : Lumen Learning. License : CC BY: Attribution
- Revision and Adaptation. Provided by : Lumen Learning. License : CC BY-SA: Attribution-ShareAlike
- Introduction to irregular verbs. Authored by : David Rheinstrom. Provided by : Khan Academy. Located at : https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/introduction-to-irregular-verbs-the-parts-of-speech-grammar . License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
- Rhetoric and Composition/Parts of Speech. Provided by : Wikibooks. Located at : https://en.wikibooks.org/wiki/Rhetoric_and_Composition/Parts_of_Speech#Verbs . License : CC BY-SA: Attribution-ShareAlike
- Section on other tenses. Provided by : Excelsior OWL. Located at : https://owl.excelsior.edu/grammar-essentials/parts-of-speech/verbs/tenses/ . License : CC BY: Attribution
- Verb Tenses Interactive. Authored by : Excelsior OWL. Located at : https://owl.excelsior.edu/writing-refresher/grammar-refresher/verb-tense/ . License : CC BY: Attribution
- Introduction to verb aspect. Authored by : Khan Academy. Located at : https://www.youtube.com/watch?v=r7Psg-4vvsA&feature=youtu.be . License : Other . License Terms : Standard YouTube License


Chapter 9: Community Corrections Last updated Save as PDF Page ID 15877 Alison S. Burke, David Carter, Brian Fedorek, Tiffany Morey, Lore Rutz-Burri, & Shanell Sanchez Southern Oregon University via OpenOregon 9.1: Diversion 9.2: Intermediate Sanctions 9.3: Probation 9.4: Boot Camps and Shock Incarceration 9.5: Drug Courts 9.6: Halfway Houses 9.7: House Arrest 9.8: Community Residential Facilities 9.9: Restorative Justice 9.10: Parole 9.11: Current Issues in Corrections 9.12: Current Issues in Corrections- Mass Incarceration 9.13: Current Issues in Corrections- War on Drugs and Gangs 9.14: Current Issues in Corrections- Aging and Overcrowding 9.15: Current Issues in Corrections- Reentry and the Future of Corrections


33.1.3: Phylum Platyhelminthes
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Learning Objectives
- Differentiate among the classes of platyhelminthes
Phylum Platyhelminthes
Phylum Platyhelminthes is composed of the flatworms: acoelomate organisms that include many free-living and parasitic forms. Most of the flatworms are classified in the superphylum Lophotrochozoa, which also includes the mollusks and annelids. The Platyhelminthes consist of two lineages: the Catenulida and the Rhabditophora. The Catenulida, or “chain worms” is a small clade of just over 100 species. These worms typically reproduce asexually by budding. However, the offspring do not fully detach from the parents; therefore, they resemble a chain. The remaining flatworms discussed here are part of the Rhabditophora.
Many flatworms are parasitic, including important parasites of humans. Flatworms have three embryonic tissue layers that give rise to surfaces that cover tissues (from ectoderm), internal tissues (from mesoderm), and line the digestive system (from endoderm). The epidermal tissue is a single layer cells or a layer of fused cells (syncytium) that covers a layer of circular muscle above a layer of longitudinal muscle. The mesodermal tissues include mesenchymal cells that contain collagen and support secretory cells that secrete mucus and other materials at the surface. The flatworms are acoelomates: their bodies are solid between the outer surface and the cavity of the digestive system.
Physiological Processes of Flatworms
The free-living species of flatworms are predators or scavengers. Parasitic forms feed on the tissues of their hosts. Most flatworms have a gastrovascular cavity rather than a complete digestive system; in such animals, the “mouth” is also used to expel waste materials from the digestive system. Some species also have an anal opening. The gut may be a simple sac or highly branched. Digestion is extracellular, with digested materials taken in to the cells of the gut lining by phagocytosis. One group, the cestodes, lacks a digestive system. Flatworms have an excretory system with a network of tubules throughout the body with openings to the environment and nearby flame cells, whose cilia beat to direct waste fluids concentrated in the tubules out of the body. The system is responsible for the regulation of dissolved salts and the excretion of nitrogenous wastes. The nervous system consists of a pair of nerve cords running the length of the body with connections between them and a large ganglion or concentration of nerves at the anterior end of the worm, where there may also be a concentration of photosensory and chemosensory cells.
There is neither a circulatory nor respiratory system, with gas and nutrient exchange dependent on diffusion and cell-cell junctions. This necessarily limits the thickness of the body in these organisms, constraining them to be “flat” worms. In addition, most flatworm species are monoecious; typically, fertilization is internal. Asexual reproduction is common in some groups.
Diversity of Flatworms
Platyhelminthes are traditionally divided into four classes: Turbellaria, Monogenea, Trematoda, and Cestoda. The class Turbellaria includes mainly free-living, marine species, although some species live in freshwater or moist terrestrial environments. The ventral epidermis of turbellarians is ciliated which facilitates their locomotion. Some turbellarians are capable of remarkable feats of regeneration: they may regrow the entire body from a small fragment.
The monogeneans are ectoparasites, mostly of fish, with simple life cycles that consist of a free-swimming larva that attaches to a fish to begin transformation to the parasitic adult form. The worms may produce enzymes that digest the host tissues or simply graze on surface mucus and skin particles.
The trematodes, or flukes, are internal parasites of mollusks and many other groups, including humans. Trematodes have complex life cycles that involve a primary host in which sexual reproduction occurs and one or more secondary hosts in which asexual reproduction occurs. The primary host is almost always a mollusk. Trematodes are responsible for serious human diseases including schistosomiasis, a blood fluke.
The cestodes, or tapeworms, are also internal parasites, mainly of vertebrates. Tapeworms live in the intestinal tract of the primary host, remaining fixed by using a sucker on the anterior end, or scolex, of the tapeworm body. The remainder of the tapeworm is composed of a long series of units called proglottids. Each may contain an excretory system with flame cells and both female and male reproductive structures. Tapeworms do not possess a digestive system; instead, they absorb nutrients from the food matter passing through them in the host’s intestine.
Key Points
- The Platyhelminthes are acoelomate flatworms: their bodies are solid between the outer surface and the cavity of the digestive system.
- Most flatworms have a gastrovascular cavity rather than a complete digestive system; the same cavity used to bring in food is used to expel waste materials.
- Platyhelminthes are either predators or scavengers; many are parasites that feed on the tissues of their hosts.
- Flatworms posses a simple nervous system, no circulatory or respiratory system, and most produce both eggs and sperm, with internal fertilization.
- Platyhelminthes are divided into four classes: Turbellaria, free-living marine species; Monogenea, ectoparasites of fish; Trematoda, internal parasites of humans and other species; and Cestoda (tapeworms), which are internal parasites of many vertebrates.
- In flatworms, digested materials are taken into the cells of the gut lining by phagocytosis, rather than being processed internally.
Key Terms
- acoelomate : any animal without a coelom, or body cavity
- ectoparasite : a parasite that lives on the surface of a host organism
- scolex : the structure at the rear end of a tapeworm which, in the adult, has suckers and hooks by which it attaches itself to a host
- proglottid : any of the segments of a tapeworm; they contain both male and female reproductive organs


3.15: Putting It Together- Rocks and the Rock Cycle
Summary
In this section, you learned the following:
- The three rock types and how they are classified
- How each of the different rock types form
- The techniques geologist use to identify different rocks
- How to use these techniques to identify common rocks
- How the rock cycle works
Synthesis
In the rock cycle, illustrated in figure 1, the three main rock types—igneous, sedimentary, and metamorphic—are shown. Arrows connecting the three rock types show the processes that change one rock type into another. The cycle has no beginning and no end. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them.
The rock cycle is a continuous and dynamic cycle that has no starting or stopping point and no set progression. Rocks can move through different paths within the cycle. The rock cycle explains how each rock type forms and the processes involved. We saw how the processes within the cycle influence everything from soil formation to recording the history of the Earth to the role deformation plays in rocks. It is easy to see how the rock cycle influences our dynamic and ever changing earth.
Contributors and Attributions
- Authored by : Kimberly Schulte and Lumen Learning. Provided by : Lumen Learning. License : CC BY: Attribution
- 4.1: Types of Rocks. Provided by : CK-12. Located at : http://www.ck12.org/book/CK-12-Earth-Science-For-High-School/section/4.1/ . License : CC BY-NC: Attribution-NonCommercial