The third major part of the neuron is the axon, coming out of the soma like a hose. The axon carries the output messages of a neuron (nerve impulses) along its length to its axon terminals (axon endings). There is only one axon per neuron, although it can branch into multiple axon terminals. In a typical neuron, the root end of the axon emerges out of the soma at a small swelling called the axon hillock. Between the axon hillock and the first segment of the axon is where the nerve impulse is first generated (see discussion of the action potential, the nerve impulse, that follows below).

Myelinated and Unmyelinated Axons Some axons have a glial cell covering known as the myelin sheath. The glial cells capable of producing myelin include oligodendrocytes of the CNS and the Schwann cells of the PNS. This fatty, insulating, myelin sheath has gaps in it, revealing the bare axon, at regular intervals along the axon's length. These bare spots along the length of a myelinated axon are called nodes, or nodes of Ranvier, after their discoverer. Figure 5.1.35.1.3\PageIndex{3}: Nodes of Ranvier. Nodes of Ranvier are gaps in the myelin sheath which covers myelinated axons. Nodes contain voltage-gated potassium (K+) and sodium (Na+) channels. Action potentials travel down the axon by "jumping"from one node to the next, speeding conduction of the action potential down the length of the axon toward the axon ending, also known as the axon bouton, axon button, or axon terminal. The function of the myelin sheath and the nodes is to speed up the rate at which nerve impulses travel down the length of the axon toward their destination, the axon terminal. In myelinated axons, the impulses sort of "jump" from node to node allowing the action potential to move more rapidly down the axon. This leaping of the nerve impulse (action potential) from node to node is called saltatory conduction, from the Latin "saltatore" which means to dance. Imagine the romantic image of the impulse dancing from node to node. More details on the electrical nature of this conduction will be addressed in the next section of this chapter. Not all axons are myelinated. Unmyelinated axons tend to be older in evolution and to be the smaller diameter axons (classified as C fibers based on their small diameters; large diameter myelinated axons are called A fibers). In unmyelinated axons, in order to move, the nerve impulse must be regenerated at every successive point along the axon. This takes time and slows the conduction of the nerve impulse (the action potential) down the length of the axon. Therefore, conduction of the action potential down the length of an unmyelinated axon is relatively slow. An example of unmyelinated C fibers are axons that are part of slow pain pathways. These pathways mediate the slower aching pain that follows tissue damage. The quick, sharp pain from an injury is mediated by larger diameter A fibers (axons). Not sure if figure below is needed.

Neuron Anatomy and The Synapse To understand neuron function, it is important to review the neuronal anatomy presented previously. Although there are some exceptions, neurons have three major structural parts - - the soma or cell body, dendrites (the "receivers" of the neuron), and the axon (the ouput end of the neuron). The entire neuron is bounded by a cell membrane, the neuronal membrane. The neuronal membrane of a neuron has channels or "doors" for ions (electrically charged atoms) which are able to pass through the membrane when specific channels are opened. Figure 5.1.15.1.1\PageIndex{1} shows this basic neuron anatomy. The soma or cell body contains organelles, such as ribosomes and mitochondria which are common to most types of cells in the body. These are involved in the basic metabolism of the cell. The soma also contains the nucleus, where the genes and chromosomes (containing DNA) are located. The second main part of the neuron are the dendrites, the information receivers of the neuron. Dendrites in some neurons can branch profusely (dendritic trees), expanding the region of the neuron that can receive inputs from other neurons. The receptor sites (or more technically, postsynaptic receptor sites because of their location on the receiving or postsynaptic neuron) which receive molecules of neurotransmitter are located on the dendrites (and, to a lesser degree, on the soma) of the receiving neuron. On the dendrites are small dendritic spines which are associated with the connections between neurons (the synapses) and can change shape rapidly when learning occurs. Notice that the spines are not the same thing as dendritic branches. In Figure 5.1.25.1.2\PageIndex{2}, a dendritic branch with dendritic spines is shown on the left in microscopic detail, and on the right, are dendritic trees of two types of neuron found in the retina. Spines are not visible in the images of dendritic trees on the right because the dendritic spines are too small, while dendritic branches comprising the dendritic trees can easily be seen (see caption for Figure 5.1.25.1.2\PageIndex{2}). Note: A detailed discussion of the structure of the synapse and synaptic communication will be covered later in this chapter.

In this section, we continue our exploration of neurons, the building blocks of the nervous system. We examine how they generate electrochemical signals, and how the billions of neurons in the nervous system communicate with one another, a process known as synaptic transmission. Before tackling these topics, we review and expand the basic anatomy and functioning of neurons covered in part in Chapter 4. A sound grasp of these facts provides the groundwork for understanding how neuron potentials are generated within neurons and how they combine to trigger synaptic transmission. As you read, remember that the voltages and chemical events we discuss in this section, operating in large populations of brain cells, somehow generate our perceptions, thoughts, emotions, and the entirety of our mental experience. To date, how this happens, how patterns of neuron potentials in brain circuits become conscious minds, remains the greatest mystery of all facing modern science.

Neuron Structure The main thing that makes neurons special and differentiates them from other cells in the body is that they have many extensions of their cell membranes, generally referred to as processes. Neurons are usually described as having one, and only one, axon—a fiber that emerges from the cell body and projects to target cells. That single axon can branch repeatedly to communicate with many target cells. It is the axon that propagates the nerve impulse (also called an action potential), which is communicated to one or more cells. The other processes of the neuron are dendrites, which receive information from other neurons across specialized areas called synapses. The dendrites are usually highly branched processes, providing locations for other neurons to communicate with the cell body. Information flows through a neuron from the dendrites, across the cell body, and down the axon. Figure 4.1.54.1.5\PageIndex{5} shows the structure of a typical neuron. The main parts of a neuron are labeled in the figure and described below. Figure 4.1.54.1.5\PageIndex{5}: Neuron. A somatic motor neuron (in the CNS) with labeled structures: cell membrane, dendrites, cell body (soma), axon, axon hillock, node of Ranvier, myelin sheath, axon terminal, and synaptic end bulbs (also called axon terminal buttons). The oligodendrocyte shown to the side of the axon is a glial cell that forms the myelin sheath surrounding the axon. The cell body (or soma; soma = "body") is the part of a neuron that contains the nucleus (shown as an oval structure in the center of the cell body, but not labeled) and most of the major organelles. The cell body is usually quite compact, and may not be much wider than the nucleus. The cell membrane is the structure that surrounds all the surfaces of the cell (including the dendrites and axon) and separates the inside of the cell from the outside of the cell. Dendrites are thin structures that are extensions of the cell body. Their function is to receive messages (excitatory and inhibitory post-synaptic potentials, EPSPs/IPSPs- see the nervous system communication chapter) from other cells and carry them to the cell body. A neuron may have many dendrites, and each dendrite may branch repeatedly to form a dendrite “tree” with more than 1,000 dendritic branches. Dendritic spines (small extensions on the surface of the dendritic branches) further increase surface area for receiving messages, allowing a given neuron to communicate with thousands of other cells. The axon is a long, thin extension of the cell body. It transmits nerve impulses away from the cell body and toward other cells. The axon hillock is a small bulge found at the base of motor neuron axons. The nerve impulse (or action potential) starts from the axon hillock. The axon branches at the end, forming the axon terminal. Branches of the axon terminal end in axon terminal buttons (also called axon endings, synaptic end bulbs, synaptic buttons/boutons, bouton terminaux, etc.) These are the points where the message is transmitted to other cells (via the release of chemicals called neurotransmitters), often to the dendrites of other neurons. A small gap called a synapse (also called a synaptic gap or synaptic cleft) is located between the end of the axon terminal and the surface of the receiving cell. An axon may branch hundreds of times, but there is never more than one axon per neuron. Many axons (especially the long axons of nerves in the peripheral nervous system) are covered by sections of myelin (also called the myelin sheath). The myelin sheath is composed of lipid layers that surround the axon. Myelin is a very good electrical insulator, like the plastic or rubber that encases an electrical cord. Axons that are covered by sections of myelin are called myelinated, whereas axons without myelin sheaths are called unmyelinated. Regularly spaced gaps between sections of myelin occur along the axon. (The gaps are actually much further apart than is shown in the figure- it is necessary to shrink the distance to fit all the structures in a diagram!) These gaps are called nodes of Ranvier, and they allow the transmission of nerve impulses along the axon. Nerve impulses jump from node to node in a process called saltatory conduction, allowing nerve impulses to travel along the axon very rapidly. The oligodendrocyte shown in the figure is a glial cell that produces myelin sheaths in the central nervous system (brain and spinal cord)- see the Glia section below.

Neuron Structure The main thing that makes neurons special and differentiates them from other cells in the body is that they have many extensions of their cell membranes, generally referred to as processes. Neurons are usually described as having one, and only one, axon—a fiber that emerges from the cell body and projects to target cells. That single axon can branch repeatedly to communicate with many target cells. It is the axon that propagates the nerve impulse (also called an action potential), which is communicated to one or more cells. The other processes of the neuron are dendrites, which receive information from other neurons across specialized areas called synapses. The dendrites are usually highly branched processes, providing locations for other neurons to communicate with the cell body. Information flows through a neuron from the dendrites, across the cell body, and down the axon. Figure 4.1.54.1.5\PageIndex{5} shows the structure of a typical neuron. The main parts of a neuron are labeled in the figure and described below. Figure 4.1.54.1.5\PageIndex{5}: Neuron. A somatic motor neuron (in the CNS) with labeled structures: cell membrane, dendrites, cell body (soma), axon, axon hillock, node of Ranvier, myelin sheath, axon terminal, and synaptic end bulbs (also called axon terminal buttons). The oligodendrocyte shown to the side of the axon is a glial cell that forms the myelin sheath surrounding the axon. The cell body (or soma; soma = "body") is the part of a neuron that contains the nucleus (shown as an oval structure in the center of the cell body, but not labeled) and most of the major organelles. The cell body is usually quite compact, and may not be much wider than the nucleus. The cell membrane is the structure that surrounds all the surfaces of the cell (including the dendrites and axon) and separates the inside of the cell from the outside of the cell. Dendrites are thin structures that are extensions of the cell body. Their function is to receive messages (excitatory and inhibitory post-synaptic potentials, EPSPs/IPSPs- see the nervous system communication chapter) from other cells and carry them to the cell body. A neuron may have many dendrites, and each dendrite may branch repeatedly to form a dendrite “tree” with more than 1,000 dendritic branches. Dendritic spines (small extensions on the surface of the dendritic branches) further increase surface area for receiving messages, allowing a given neuron to communicate with thousands of other cells. The axon is a long, thin extension of the cell body. It transmits nerve impulses away from the cell body and toward other cells. The axon hillock is a small bulge found at the base of motor neuron axons. The nerve impulse (or action potential) starts from the axon hillock. The axon branches at the end, forming the axon terminal. Branches of the axon terminal end in axon terminal buttons (also called axon endings, synaptic end bulbs, synaptic buttons/boutons, bouton terminaux, etc.) These are the points where the message is transmitted to other cells (via the release of chemicals called neurotransmitters), often to the dendrites of other neurons. A small gap called a synapse (also called a synaptic gap or synaptic cleft) is located between the end of the axon terminal and the surface of the receiving cell. An axon may branch hundreds of times, but there is never more than one axon per neuron. Many axons (especially the long axons of nerves in the peripheral nervous system) are covered by sections of myelin (also called the myelin sheath). The myelin sheath is composed of lipid layers that surround the axon. Myelin is a very good electrical insulator, like the plastic or rubber that encases an electrical cord. Axons that are covered by sections of myelin are called myelinated, whereas axons without myelin sheaths are called unmyelinated. Regularly spaced gaps between sections of myelin occur along the axon. (The gaps are actually much further apart than is shown in the figure- it is necessary to shrink the distance to fit all the structures in a diagram!) These gaps are called nodes of Ranvier, and they allow the transmission of nerve impulses along the axon. Nerve impulses jump from node to node in a process called saltatory conduction, allowing nerve impulses to travel along the axon very rapidly. The oligodendrocyte shown in the figure is a glial cell that produces myelin sheaths in the central nervous system (brain and spinal cord)- see the Glia section below.

Nervous Tissue Cell Types Nervous tissue is composed of two types of cells: neurons (also called nerve cells) and glia (also called glial cells or neuroglia), as shown in Figure 4.1.34.1.3\PageIndex{3}. Neurons are responsible for the computation and communication that the nervous system provides. They are electrically active and release chemical signals to target cells. Glia are known to play a supporting role for nervous tissue. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. Neurons are important, but without glial support they would not be able to perform their function.

Summary The nervous system coordinates all of the body’s voluntary and involuntary actions by transmitting electrical and chemical signals to and from different parts of the body. The two main divisions of the nervous system are the central nervous system (CNS, the brain and the spinal cord), and the peripheral nervous system (PNS, all other nervous tissue in the body). Nervous tissue contains two major cell types, neurons and glial cells. Neurons are the cells responsible for communication through electrical signals. Glial cells are supporting cells, maintaining the environment around the neurons. The structures that differentiate neurons from other body cells are the extensions of their cell membranes, namely one axon that projects to target cells, and one or more dendrites, which receive information from other neurons across specialized areas called synapses. The axon propagates nerve impulses (action potentials), which are communicated to one or more cells. Neurons can be classified depending on their structure, function, or other characteristics. One structural classification is based on the number of processes the neuron has- one (unipolar), two (bipolar) or many (multipolar). One functional classification groups neurons into those that participate in sensation (sensory neurons), integration (interneurons) or motor (motor neurons) functions. Some other ways of classifying neurons include what they look like, where they are found, who found them, what they do, or what neurotransmitters they use. The nervous tissue in the brain and spinal cord consists of gray matter and white matter. Gray matter contains the cell bodies and dendrites of neurons and white matter contains myelinated axons. Typically, neurons cannot divide to form new neurons. Recent animal research indicates that some limited neurogenesis is possible, but the extent to which this applies to adult humans is unknown. Several types of glial cells are found in the nervous system, including astrocytes, oligodendrocytes, microglia, and ependymal cells in the CNS, and satellite cells and Schwann cells in the PNS. Astrocytes contribute to the blood-brain barrier that protects the brain. Oligodendrocytes and Schwann cells create the myelin that insulates many axons, allowing nerve impulses to travel along the axon very rapidly.

Overview of the Nervous System The nervous system, illustrated in Figure 4.1.24.1.2\PageIndex{2}, is the human organ system that coordinates all of the body’s voluntary and involuntary actions by transmitting electrical and chemical signals to and from different parts of the body. Specifically, the nervous system extracts information from the internal and external environments using sensory receptors. It then usually sends signals encoding this information to the brain, which processes the information to determine an appropriate response. Finally, the brain sends signals to muscles, organs, or glands to bring about the necessary response. The two main divisions of the nervous system are the central nervous system (CNS), consisting of the brain and the spinal cord, and the peripheral nervous system (PNS), which includes all other nervous tissue, such as ganglia and nerves, outside the brain and spinal cord. The CNS and PNS are covered in greater detail in separate sections. In the example above, your eyes detected the skateboarder, the information traveled to your brain, and your brain instructed your body to act to avoid a collision.

The phenomenon of working memory is made all the more complex by the fact that it takes place over time. For example, the experimental results illustrated below show how various areas of the subjects’ brains alter their activity levels as the subjects are presented with various visual stimuli. When the subjects are shown a blurred image, the activity level (represented by the blue bars in the graph) becomes highest in area 1, the visual part of the brain. When the subjects are shown an image of a face, brain activity (black bars) becomes highest in the associative and frontal regions (4, 5, and 6). Lastly, when the subjects are retaining an image of a face in their working memory, brain activity (red bars) is highest in the frontal regions, while the visual areas are scarcely stimulated at all.

considered here is sometimes referred to as organic amnesia,

memory within the confines of the cerebral cortex"

A fascinating research enterprise contributing greatly to our understanding of memory is the case of H.M. (e.g. Henry Molianson)

classical conditioning,

By contrast, learned behavioral adaptations can change moment to moment and, as discussed above, may be transmitted (in some species) to future generations by cultural transmission

Figure 44\PageIndex{4}: Titration of a Weak Polyprotic Acid. Another 10 mL, or a total of 20 mL, of the titrant is added to the weak polyprotic acid to reach the second equivalence point. (CC BY; Heather Yee via LibreTexts)

hese human-made elements are heavier in atomic terms than the naturally occurring elements and are typically generated by smashing atoms of natural elements into one another; they break down, or decay, rapidly into atoms of other elements. As examples of how science can remove some of the mystery from the universe: our understanding of atoms and elements means that no new natural, light elements are theoretically possible. We know of all the light elements that can possibly exist anywhere in the universe, a pretty amazing fact

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Cold north winds are blowing, Heavy falls the snow. Friend, thy hand, if thou art friendly! Forth together let us go. Long, too long, we loiter here: Times are too severe. How the north wind whistles, Driving snow and sleet! Friend, thy hand, if thou art friendly! Let us, thou and I, retreat. Long, too long, we loiter here: Times are too severe. Nothing red, but foxes! Nothing black, but crows! Friend, thy hand, if thou art friendly! Come with me my waggon goes. Long, too long, we loiter here: Times are too severe.

Bearing a load of sorrow and of care; Vulgarly poor am I, and sore bestead, And of my hardships all are unaware.

Long, long the stormwind blew, and wild. He turned to look at me: he smiled; But mockery was there, and scorn. Ah, how my very heart was torn!

The cedar boat is drifting, On currents never still. Sleepless I lie, vexed inly, As with some unknown ill. 'Tis not that wine is wanting, Or leave to roam at will. My heart is no mere mirror That cannot comprehend. Brothers I have, but may not On brothers e'en depend. Tush! when I go complaining 'Tis only to offend. No stone this heart of mine is, That may be turned and rolled; No mat this heart of mine is, To fold or to unfold. Steadfast and strict my life is; Nought 'gainst it can be told. Yet here I sit in sorrow, Scorned by a rabble crew. My troubles have been many, My insults not a few. Calmly I think then, starting, I beat my breast anew. O moon, why now the brighter? O sun, why now dost wane? My heart wears grief as garments Inured to soil and stain. Calmly I think then, starting, Would fly but all in vain.

Note. Although this is one of the shortest and apparently most trivial of the Odes in the Book of Poetry, it is credited by the Chinese editors with as much meaning as the largest. It is regarded, like so many more, as illustrating the extent of the reformation brought about by King Wăn. Not only was the kingdom better ruled, society better regulated, and individuals more self-disciplined and improved in manners, but the reformation affected all things: vegetation flourished, game became most abundant, hunting was attended to at the right seasons, and the benign influence of the King was everywhere felt by the people. The poet thinks it is sufficient to dwell upon these last characteristics. Probably the lines were written after some royal hunt.

In the wild there lies a dead gazelle, With the reed-grass round it wrapt; And a maid who loveth springtide well By a winsome youth is trapped. In the wood thick undergrowth is found, In the wild the dead gazelle,

Starlets dim are yonder peeping, In the East are five, and three. Softly, where our lord is (sleeping), Soon or late by night go we. Some have high, some low degree. Starlets dim are yonder peeping, Pleiades, Orion's band. Softly nightly go we creeping, Quilt and coverlet in hand. Some take high, some lower stand.

True-hearted husband, fain, oh fain Were I to have thee home again. Hearken! now the thunder Is down upon the plain. Hence why must he wander, Nor dare awhile remain? True-hearted husband, fain, oh fain Were I to find thee home again.

She goes to gather water-wort, Beside the streams south of the hills; She goes to gather water-grass Along the swollen roadside rills; Goes now to store her gathered herbs In basket round, in basket square; Goes now to seethe and simmer them In tripod and in cauldron there; Pours out libations of them all Beneath the light within the Hall. And who is she so occupied? Who, but (our lord's) young pious bride?

O to see him once again! O to meet him once again! Stilled were then the swelling sigh. Climbed I yonder up South Hill, Plucked sweet brackens as I went. But my lord I saw not still; Loud was yet my heart's lament. O to see him once again! O to meet him once again! So my heart were well content. Climbed I yonder up South Hill, Now to pluck the royal fern. Yet my lord I saw not still; Still my heart must pine and yearn. O to see him once again! O to meet him once again! So my heart's-ease might return.

And countless cars escort her.

Do a communication self-assessment. What are your strengths as a communicator? What are your weaknesses? What can you do to start improving your communication competence?

What communication concept has appealed to you most so far? How can you see this concept applying to your life?

What aspects of communication do you think are “common sense?” What aspects of communication do you think require more formal instruction and/or study?

What are some examples of unethical communication that you have witnessed?

Do you think we, as a society, have less value for FtF communication than we used to? Why or why not?

In a typical day, what types of CMC do you use?

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Us and our friends

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She and him

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group of women, including prominent Black lesbians, who wrote a collective statement demonstrating their political analysis and commitment to addressing interlocking structures of discrimination, including sexism, heterosexism, and racism

tradition of Black women using intellectual, social, cultural, and political strategies to end violence and exploitation.

activists and organizations around the world that advocate against police brutality and killing of Black people. The movement has become a centerpiece in contemporary struggles for rights, equity, justice, and recognition.

coined by sociologist Patricia Hill Collins that emphasizes the constellation of stereotypes that work to control and subordinate Black women in public society, including the Mammy, the Matriarch, and the Welfare Queen.

achieving equity in public institutions, companies, and other organizations that experienced considerable resistance. Affirmative action includes practices meant to eliminate historical patterns of discrimination and to provide corrective adjustments that recognize the barriers faced by historically underrepresented groups.

differs greatly compared to other groups or others within a group

Michelle Alexander that demonstrates the historical continuity between the systems of slavery, Jim Crow segregation, and mass incarceration today.

thriving Black-owned businesses and families prior to being targeted by white supremacists in 1921

abilities to own property, conduct business, lease land, and move freely through public spaces. These regulations worked to keep separate the established white society from the lives of Black people.

recognized and investigated the 400th anniversary of racialized slavery in the United States. The project has become the target of conservative attempts to censor discussions of race, history, slavery, and racial disparities today.

were fleeing to places where slavery was not legal so they could begin life anew.

segregation created an explicitly tiered version of citizenship. The Courts upheld this doctrine through the notion of “separate but equal,” which was codified in the 1896 decision in the Plessy v. Ferguson case. The term "Jim Crow" refers to minstrel shows where white actors would wear Blackface and portray negative stereotypes of Black men.

upport recently freed communities of Black people in the southern United States

means the way that Black people have to see themselves through the lens of a racist society, in addition to an authentic self-perception and identity.

anctioned discrimination that is supported by existing laws and political belief systems. De jure discrimination is the opposite of de facto discrimination

emphasizes pride in being Black, economic self-sufficiency, and Black separatism.

emphasizes building Black-serving institutions and leaders.

emphasized pride, empowerment, and economic prosperity for Black communities.

This meant that slave-owning states would have increased representation based on the number of enslaved people in their state despite those people not being represented in elections.

Transatlantic Triangular Trade: The economic system that supported the colonization of the United States and the Americas by European countries. This arrangement exploited the people and natural resources of West Africa and the eastern segments of North, Central, and South America for the financial benefit and production of industrialization in Europe and European colonies. Chattel Slavery: The specific form of slavery in which the children of enslaved people are automatically considered to be slaves themselves. This system contributed to the creation of racial categories in colonial America.

led by African Americans in the U.S. between the 1940s and 1970s that advocated for equality in education, employment, housing, voting, and other major civil rights areas.

experience of people's heritage. This includes African people, African immigrants, and communities with origins on the African continent that have been enslaved, trafficked, and settled

Freedmen's Bureau and affirmative action as efforts

struggles of Black women show other dimensions of Black experiences?

significant in the history of Black progress?

Black Power, Black Nationalism, Black Wall Street, Black Lives Matter, and Black Feminism contribute to uplifting the Black community and also for sub-identities

structural inequality, inequality through policies and laws within government, health, schooling, media, etc. subordinated Black Americans.

experience of slavery.

forms of resistance from the Black community whether during slavery, Reconstruction, contemporary times, etc.

solidarity with Black leaders advocating for change and finding ways to contribute directly to a more just and equitable society in our own communities and spaces.

gender roles have historically structured the assumptions about who can lead in what ways when it comes to social movement organizing. Religious institutions have long played an important role in Black communities, ranging from social services and economic prosperity to political organizing and community development.

intersectionality, and the significance of multiple interlocking systems

agency and group affirmation.

core theories and ideas

liberation struggles

When the wave touches the bottom, friction causes the wave to slow down. As one wave slows down, the one behind it catches up to it, thus decreasing the wavelength.

______

Contemporary forms of patriarchy in American and European contexts are linked to the European development of capitalism in the 1600s

To help explain why these phenomena proceed spontaneously in only one direction requires an additional state function called entropy (S), a thermodynamic property of all substances that is proportional to their degree of "disorder".

Now consider the same process in reverse. Suppose that a hot frying pan in a sink of cold water were to become hotter while the water became cooler. As long as the same amount of thermal energy was gained by the frying pan and lost by the water, the first law of thermodynamics would be satisfied

A crucial point to realize about fossil fuels is that the energy we release by burning them came originally from the sun. The plants from which the fuels were derived grew as a result of photosynthesis, the combination of carbon dioxide and water under the influence of sunlight to form organic compounds whose empirical formula is approximately

The second law of thermodynamics says in effect, that the extent to which any natural process can occur is limited by the dilution of thermal energy (increase in entropy)

Waves in the Southern Ocean are generally fairly large (the red areas in Figure 10.2.210.2.2\PageIndex{2}) because of the strong winds and the lack of landmasses, which provide the winds with a very long fetch, allowing them to blow unimpeded over the ocean for very long distances.

ocesses have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill, but uphill flow requires outside intervention such as the use of a pump. A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. A process that is spontaneous in one direction under a particular set of conditions is nonspontaneous in the reverse direction

They don't do it all at once, but according to a sort of clock: a certain fraction of the nuclei will decay in a certain period of time.

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r but embodies a character’s emotional truth

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Turbellaria, Monogenea, Trematoda, and Cestoda

carry forward strong traditions of resilience and well-being.

ot only shape individual identity, but also the communities, cultures, languages, and traditions that we practice.

to unify Chicanx and Mexican American student organizations

protest against the educational inequality

committed to advancing the economic condition, educational attainment, political influence, housing, health and civil rights of Latinxs through community-based programs

Indigenous ways of health and healing

self-identity category used by people, unlike Hispanic or Latinx which emerged from western institution

Why does it matter that people see others like them represented? How does this representation affect communities as a whole?

Why are students uniquely situated to advocate for their communities?

How do stories about where we come from shape our sense of self? How do these perspectives show a different understanding of the relationship between people and the land?

justice, equity, self-determination, and liberation.

struggles inform the significance of scholarship and inquiry

foundational concepts and debates in Chicanx and Latinx Studies

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ach decision will affect the look and feel of a scene

but each one of them will affect how we engage the cinematic experience.

While the cellular and molecular mechanisms that influence on physical and mental health have long been a central focus of neuroscience, only in recent years has attention turned to the epigenetic mechanisms behind the dynamic changes in gene expression responsible for normal cognitive function and increased risk for mental illness. Ongoing research will show if this increased attention on epigenetics can be exploited in the development of new therapeutic options that may alter the traces that early environment leaves on the genome. However, as discussed in this module, the epigenome is not static and can be molded by developmental signals, environmental perturbations, and disease states, which present an experimental challenge in the search for epigenetic risk factors in psychological disorders (Rakyan, Down, Balding, & Beck, 2011). The combination of genetic association maps studies with epigenome-wide developmental studies may help identify novel molecular mechanisms to explain features of inheritance of personality traits and transform our understanding of the biological basis of psychology. Importantly, these epigenetic studies may lead to identification of novel therapeutic targets and enable the development of improved strategies for early diagnosis, prevention, and better treatment of psychological and behavioral disorders.

The primary epigenetic mark: DNA modification DNA methylation is the best-understood epigenetic modification influencing gene expression. DNA is composed of four types of naturally occurring nitrogenous bases: adenine (A), thymine (T), guanine (G), and cytosine (C). In mammalian genomes, DNA methylation occurs primarily at cytosine residues in the context of cytosines that are followed by guanines (CpG dinucleotides), to form 5-methylcytosine in a cell-specific pattern (Goll & Bestor, 2005; Law & Jacobsen, 2010; Suzuki & Bird, 2008). The enzymes that perform DNA methylation are called DNA methyltransferases (DNMTs), which catalyze the transfer of a methyl group to the cytosine (Adams, McKay, Craig, & Burdon, 1979). These enzymes are all expressed in the central nervous system and are dynamically regulated during development (Feng, Chang, Li, & Fan, 2005; Goto et al., 1994). The effect of DNA methylation on gene function varies depending on the period of development during which the methylation occurs and location of the methylated cytosine. Methylation of DNA in gene regulatory regions (promoter and enhancer regions) usually results in gene silencing and reduced gene expression (Ooi, O’Donnell, & Bestor, 2009; Suzuki & Bird, 2008; Sutter and Doerfler, 1980; Vardimon et al., 1982). This is a powerful regulatory mechanism that ensures that genes are expressed only when needed. Thus DNA methylation may broadly impact human brain development, and age-related misregulation of DNA methylation is associated with the molecular pathogenesis of neurodevelopmental disorders.

Early childhood is not only a period of physical growth; it is also a time of mental development related to changes in the anatomy, physiology, and chemistry of the nervous system that influence mental health throughout life. Cognitive abilities associated with learning and memory, reasoning, problem solving, and developing relationships continue to emerge during childhood. Brain development is more rapid during this critical or sensitive period than at any other, with more than 700 neural connections created each second. Herein, complex gene–environment interactions serve to increase the number of possible contacts between neurons, as they hone their adult synaptic properties and excitability. Many weak connections form to different neuronal targets; subsequently, they undergo remodeling in which most connections vanish and a few stable connections remain. These structural changes (or plasticity) may be crucial for the development of mature neural networks that support emotional, cognitive, and social behavior. The challenge for psychology has been to integrate findings from genetics and environmental (social, biological, chemical) factors into the study of personality and our understanding of the emergence of mental illness. These studies have demonstrated that common DNA sequence variation and rare mutations account for only a small fraction (1%–2%) of the total risk for inheritance of personality traits and mental disorders (Dick, Riley, & Kendler, 2010; Gershon, Alliey-Rodriguez, & Liu, 2011). Additionally, studies that have attempted to examine the mechanisms and conditions under which DNA sequence variation influences brain development and function have been confounded by complex cause-and-effect relationships (Petronis, 2010). Epigenetics has the potential to provide answers to these important questions. It refers to the transmission of observable characteristics (phenotype) in terms of gene expression in the absence of changes in DNA sequence (Waddington, 1942; Wolffe & Matzke, 1999). The advent of advanced techniques to study the distributions of regulators of gene expression throughout the genome led to the collective description of the “epigenome.” In contrast to the genome sequence, which is static and the same in almost all cells, the epigenome is highly dynamic, differing among cell types, tissues, and brain regions (Gregg et al., 2010). Recent studies have provided insights into epigenetic regulation of developmental pathways in response to a range of external environmental factors (Dolinoy, Weidman, & Jirtle, 2007). These environmental factors during early childhood and adolescence can cause changes in expression of genes conferring risk of mental health and chronic physical conditions. Thus, the examination of genetic–epigenetic–environment interactions from a developmental perspective may determine the nature of gene misregulation in psychological disorders. This module will provide an overview of the main components of the epigenome and review themes in recent epigenetic research that have relevance for psychology, to form the biological basis for the interplay between environmental signals and the genome in the regulation of individual differences in physiology, emotion, cognition, and behavior.

Some common questions about nature–nurture are, how susceptible is a trait to change, how malleable is it, and do we “have a choice” about it? These questions are much more complex than they may seem at first glance. Height seems like a trait firmly rooted in our nature and unchangeable, but the average height of many populations in Asia and Europe has increased significantly in the past 100 years, due to changes in diet and the alleviation of poverty. There are a few rare genes that have been found to have significant (almost always negative) effects, such as the single gene that causes Huntington’s disease, or the Apolipoprotein gene that causes early onset dementia in a small percentage of Alzheimer’s cases. Aside from these rare genes, however, the genetic impact on behavior is broken up over many genes, each with very small effects. In fact, the same is true of environmental effects. We know that extreme environmental hardship causes catastrophic effects for many behavioral outcomes, however, within the average range of environmental events, those responsible for differences (e.g., why some children in a suburban third-grade classroom perform better than others) are much more difficult to grasp. The difficulties with finding clear-cut solutions to nature–nurture problems bring us back to the other great questions about our relationship with the natural world: the mind-body problem and free will. Investigations into what we mean when we say we are aware of something reveal that consciousness is not simply the product of a particular area of the brain, nor does choice turn out to be an orderly activity that we can apply to some behaviors but not others. So it is with nature and nurture: What at first may seem to be a straightforward matter, able to be indexed with a single number, becomes more and more complicated the closer we look. It is tempting to predict that the more we understand the wide-ranging effects of genetic differences on all human characteristics—especially behavioral ones—our cultural, ethical, legal, and personal ways of thinking about ourselves will have to undergo profound changes in response. One of the most important things modern genetics has taught us is that almost all human behavior is too complex to be nailed down, even from the most complete genetic information, unless we’re looking at identical twins. The science of nature and nurture has demonstrated that genetic differences among people are vital to human moral equality, freedom, and self-determination, not opposed to them. As Mordecai Kaplan said about the role of the past in Jewish theology, genetics gets a vote, not a veto, in the determination of human behavior. We should indulge our fascination with nature–nurture while resisting the temptation to oversimplify it.

Another option for observing nature-nurture in humans involves twin studies. There are two types of twins: monozygotic (MZ) and dizygotic (DZ). Monozygotic twins, also called “identical” twins, result from a single zygote (fertilized egg) and have the same DNA. They are essentially clones. Dizygotic twins, also known as “fraternal” twins, develop from two zygotes and share 50% of their DNA. Fraternal twins are ordinary siblings who happen to have been born at the same time. To analyze nature–nurture using twins, we compare the similarity of MZ and DZ pairs. Sticking with the features of height and spoken language, let’s take a look at how nature and nurture apply: Identical twins, unsurprisingly, are almost perfectly similar for height. The heights of fraternal twins, however, are like any other sibling pairs: more similar to each other than to people from other families, but hardly identical. This contrast between twin types gives us a clue about the role genetics plays in determining height. Now consider spoken language. If one identical twin speaks Spanish at home, the co-twin with whom she is raised almost certainly does too. But the same would be true for a pair of fraternal twins raised together. In terms of spoken language, fraternal twins are just as similar as identical twins, so it appears that the genetic match of identical twins doesn’t make much difference. Twin and adoption studies are two instances of a much broader class of methods for observing nature-nurture called quantitative genetics, the scientific discipline in which similarities among individuals are analyzed based on how biologically related they are. We can do these studies with siblings and half-siblings, cousins, twins who have been separated at birth and raised separately (Bouchard, Lykken, McGue, & Segal, 1990; such twins are very rare and play a smaller role than is commonly believed in the science of nature–nurture), or with entire extended families (see Plomin, DeFries, Knopik, & Neiderhiser, 2012, for a complete introduction to research methods relevant to nature–nurture). For better or for worse, contentions about nature–nurture have intensified because quantitative genetics produces a number called a heritability coefficient, varying from 0 to 1, that is meant to provide a single measure of genetics’ influence of a trait. In a general way, a heritability coefficient measures how strongly differences among individuals are related to differences among their genes. But beware: Heritability coefficients, although simple to compute, are deceptively difficult to interpret. Nevertheless, numbers that provide simple answers to complicated questions tend to have a strong influence on the human imagination, and a great deal of time has been spent discussing whether the heritability of intelligence or personality or depression is equal to one number or another.

Overview There are three related problems at the intersection of philosophy and science that are fundamental to our understanding of our relationship to the natural world: the mind–body problem, the free will problem, and the nature–nurture problem. It seems that most people, even those without much knowledge of science or philosophy, have opinions about the answers to these questions that come simply from observing the world we live in. Our feelings about our relationship with the physical and biological world often seem incomplete. We are in control of our actions in some ways, but at the mercy of our bodies in others; it feels obvious that our consciousness is some kind of creation of our physical brains, at the same time we sense that our awareness must go beyond just the physical. This incomplete knowledge of our relationship with nature leaves us fascinated and a little obsessed, like a cat that climbs into a paper bag and then out again, over and over, mystified every time by a relationship between inner and outer that it can see but can’t quite understand. It may seem obvious that we are born with certain characteristics while others are acquired, and yet of the three great questions about humans’ relationship with the natural world, only nature–nurture gets referred to as a “debate.” In the history of psychology, no other question has caused so much controversy and offense: We are so concerned with nature–nurture because our very sense of moral character seems to depend on it. The problem is, most human characteristics aren’t usually as clear-cut as, for example height or instrument-mastery, affirming our nature–nurture expectations strongly one way or the other. In fact, even the great violinist might have some inborn qualities—perfect pitch, or long, nimble fingers—that support and reward his hard work. And the basketball player might have eaten a diet while growing up that promoted her genetic tendency for being tall. When we think about our own qualities, they seem under our control in some respects, yet beyond our control in others. And often the traits that don’t seem to have an obvious cause are the ones that concern us the most and are far more personally significant. What about how much we drink or worry? What about our honesty, or religiosity, or sexual orientation? They all come from that uncertain zone, neither fixed by nature nor totally under our own control.

Evolutionary Psychology and Cultural Influences In evolutionary psychology, culture also has a major effect on psychological adaptations. For example, status within one’s group is important in all cultures for achieving reproductive success, because higher status makes someone more attractive to mates. In individualistic cultures, such as the United States, status is heavily determined by individual accomplishments. But in more collectivist cultures, such as Japan, status is more heavily determined by contributions to the group and by that group’s success. For example, consider a group project. If you were to put in most of the effort on a successful group project, the culture in the United States reinforces the psychological adaptation to try to claim that success for yourself (because individual achievements are rewarded with higher status). However, the culture in Japan reinforces the psychological adaptation to attribute that success to the whole group (because collective achievements are rewarded with higher status). Evolutionary psychology, in short, does not predict rigid robotic-like “instincts.” That is, there isn’t one rule that works all the time. Rather, evolutionary psychology studies flexible, environmentally-connected and culturally-influenced adaptations that vary according to the situation. Psychological adaptations are hypothesized to be wide-ranging, and include food preferences, habitat preferences, mate preferences, and specialized fears. These psychological adaptations also include many traits that improve people's ability to live in groups, such as the desire to cooperate and make friends, or the inclination to spot and avoid frauds, punish rivals, establish status hierarchies, nurture children, and help genetic relatives. Research programs in evolutionary psychology develop and empirically test predictions about the nature of psychological adaptations.

Gene Selection Theory In modern evolutionary theory, all evolutionary processes boil down to an organism’s genes. Genes are the basic “units of heredity,” or the information that is passed along in DNA that tells the cells and molecules how to “build” the organism and how that organism should behave. Genes that are better able to encourage the organism to reproduce, and thus replicate themselves in the organism’s offspring, have an advantage over competing genes that are less able. For example, take female sloths: In order to attract a mate, they will scream as loudly as they can, to let potential mates know where they are in the thick jungle. Now, consider two types of genes in female sloths: one gene that allows them to scream extremely loudly, and another that only allows them to scream moderately loudly. In this case, the sloth with the gene that allows her to shout louder will attract more mates—increasing reproductive success—which ensures that her genes are more readily passed on than those of the quieter sloth.

Basics of Evolutionary Theory Evolution simply means change over time. Many think of evolution as the development of traits and behaviors that allow us to survive this “dog-eat-dog” world, like strong leg muscles to run fast, or fists to punch and defend ourselves. However, physical survival is only important if it eventually contributes to successful reproduction. That is, even if you live to be a 100-year-old, if you fail to mate and produce children, your genes will die with your body. Thus, reproductive success, not survival success, is the engine of evolution by natural selection. Every mating success by one person means the loss of a mating opportunity for another. Yet every living human being is an evolutionary success story. Each of us is descended from a long and unbroken line of ancestors who triumphed over others in the struggle to survive (at least long enough to mate) and reproduce. However, in order for our genes to endure over time—to survive harsh climates, to defeat predators—we have inherited adaptive, psychological processes designed to ensure success. At the broadest level, we can think of organisms, including humans, as having two large classes of adaptations—or traits and behaviors that evolved over time to increase our reproductive success. The first class of adaptations are called survival adaptations: mechanisms that helped our ancestors handle the “hostile forces of nature.” For example, in order to survive very hot temperatures, we developed sweat glands to cool ourselves. In order to survive very cold temperatures, we developed shivering mechanisms (the speedy contraction and expansion of muscles to produce warmth). Other examples of survival adaptations include developing a craving for fats and sugars, encouraging us to seek out particular foods rich in fats and sugars that keep us going longer during food shortages. Some threats, such as snakes, spiders, darkness, heights, and strangers, often produce fear in us, which encourages us to avoid them and thereby stay safe. These are also examples of survival adaptations. However, all of these adaptations are for physical survival, whereas the second class of adaptations are for reproduction, and help us compete for mates. These adaptations are described in an evolutionary theory proposed by Charles Darwin, called sexual selection theory.

our shared cinematic language

how does the script page compare to the finished scene? What do you notice in the script that isn’t on the screen?

hey don’t want to miss anything, so you have to describe in detail everything you’re seeing and hearing by yelling across the apartment. What do you include? What do you leave out?

So, even though the process may be challenging, it can also be a time for learning and growth.

We also organize interactions and interpersonal experiences based on our firsthand experiences. When two people experience the same encounter differently, misunderstandings and conflict may result.

Our brain innately categorizes and files information and experiences away for later retrieval, and different parts of the brain are responsible for different sensory experiences.

Again, as communicators, especially in persuasive contexts, we can use this to our advantage by making it clear how our message or proposition meets the needs of our audience members.

We respond differently to an object or person that we perceive favorably than we do to something we find unfavorable

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Conversely, the breakdown in the ability of a person to intrapersonally communicate is associated with mental illness (Dance & Larson, 1976).

There was also a distinction of focus and interest among professors of speech. While some focused on the quality of ideas, arguments, and organization, others focused on coaching the performance and delivery aspects of public speaking (Keith, 2008).

The Age of Enlightenment in the 1700s marked a societal turn toward scientific discovery and the acquisition of knowledge, which led to an explosion of philosophical and scientific writings on many aspects of human existence.

Since this form of communication deals so directly with our personal relationships and is the most common form of communication, instances of miscommunication and communication conflict most frequently occur here (Dance & Larson, 1976).

The beginning of the “Manuscript Era,” around 3500 BCE, marked the turn from oral to written culture. This evolution in communication corresponded with a shift to a more settled, agrarian way of life (Poe, 2011). As hunter-gatherers settled into small villages and began to plan ahead for how to plant, store, protect, and trade or sell their food, they needed accounting systems to keep track of their materials and record transactions.

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Some communication behaviors indicate that we are not communicating mindfully, such as withdrawing from a romantic partner or engaging in passive-aggressive behavior during a period of interpersonal conflict.

many students still resist taking communication classes. Perhaps people think they already have good communication skills or can improve their skills on their own. While either of these may be true for some, studying communication can only help. In such a competitive job market, being able to document that you have received communication instruction and training from communication professionals (the faculty in your communication department) can give you the edge needed to stand out from other applicants or employees.

then you’re what some scholars have called “digital natives.”

Of course, we don’t just communicate verbally—we have various options, or channels for communication. Encoded messages are sent through a channel, or a sensory route on which a message travels, to the receiver for decoding. While communication can be sent and received using any sensory route (sight, smell, touch, taste, or sound), most communication occurs through visual (sight) and/or auditory (sound) channels. If your roommate has headphones on and is engrossed in a video game, you may need to get his attention by waving your hands before you can ask him about dinner.

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They develop their writing skills.

They don’t need to schedule study periods because they study at every available moment every day.

They know how to stay motivated.

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All of the above

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