1.5: Words of Wisdom- Practice, Practice, Practice
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Dr. Kristine Duffy
Dr. Kristine Duffy
Life in college will be like no other time in your life—I can guarantee you that! This is your time to explore who you are, who you want to become, and how you wish to play a part in this world. Don’t squander this unique time in your life. I hope to share some thoughts that might help you avoid regrets when reflecting on your college years.
I want to be clear—there are many paths through college and we know that no one path is right for all. You may be starting at a community college, taking courses part-time, starting college again after an unsuccessful start, or returning to education after many years away, but no matter who you are or what path you’ve chosen, make the most of it.
I took the fairly traditional path. I graduated from high school and went directly to college (which was three hours away from home). Because I wasn’t really sure what else I should do, I chose to be a business major by default. My parents thought it was a good route to take and would lead me to a good job (mainly to ensure I made some money and didn’t live with them forever).
There are three things I learned quickly in college:
- I had lived a very nice life, but in a very homogeneous environment.
- There were people different from me.
- Although I was a decent student, I had a ways to go to be a good student!
Learning to appreciate what you have is just as important as earning As on exams and papers. I share this because part of college is preparing for life, not just a job. Ask yourself some questions:
- What’s important to me and why?
- What do I know about other people’s lives, beliefs, and passions?
- Am I confident in my abilities to study, listen and learn, take notes, and be a learner?
What’s Important to Me and Why?
Is it only to make money to buy things? If so, do you truly believe that money makes everything better? Don’t be fooled by that. Yes, money certainly makes life more comfortable, but it absolutely doesn’t buy happiness. I had friends in college that came from a significant amount of money and they would have traded it all to have a family they can depend upon and love in their homes. Consider this very carefully as you dream of the life ahead of you.
What Do You Know about Other People’s Lives, Beliefs, and Passions?
You are not the center of the world. You should be confident and proud of who you are, but be humble and be open to others’ experiences and worldviews.  In the end, these types of classes will test your assumptions, beliefs, and make you a more well-rounded and interesting person. The roommate or classmate who is different from you can teach you about yourself. Be open to this.
Are You Confident in Your Abilities to Study, Listen and Learn, Take Notes, and Be a Learner?
Remember, if college were easy, everyone would do it! You have full control and responsibility for your learning. Yes, your professors have the responsibility of teaching well and helping you learn, but they cannot and should not do the work for you. Part of college is learning to learn: learning to study, listen better, take notes, and most importantly asking for help when you need it.
In my own research I have learned that students are confronted with a paradoxical situation. On the one hand, students in high school are warned that college will be hard—the professors won’t care if you do the work or not, and you need to do it on your own. However in reality, college professors and support professionals do care and will tell you to come and see them if you need help.
So what is a student to do? You may feel bad in class if you just aren’t getting it and are embarrassed to ask for help. Stop that thought in its tracks! Colleges offer many opportunities for help and in almost all cases, for free! Professors hold office hours specifically to address students’ questions and tutoring is available to help you do better, not to punish you for not getting it. Remember you are paying a substantial amount of money for your tuition; find out what resources you have and take advantage of them.  There is no shame in asking for help. I always compare it to a job. When you start out on any job there is usually some type of training to teach you how to do that job. College is no different. We are teaching you how to be a student—you’ve been practicing since Kindergarten, and doesn’t end when you get to college.
Finally, here are some words of advice based on some of my regrets when I reflect on my college experience:
- I didn’t study abroad during my four years of college.
- I didn’t do any type of internship.
- I didn’t get involved with many clubs or organizations.
- I didn’t get involved with any type of research opportunities until graduate school.
Study Abroad
Whether it is a short-term experience (some are as short as three weeks) or a semester to a year—do it! This goes back to my point about understanding people different than you. The United States is a great nation, but we are not the only nation and our world is filled with amazing stories to share. One of my favorite quotes by Neale Walsch is: “Life begins at the end of your comfort zone.” [1] You will not miss much being gone from your college for a short period of time, and you will return from your adventure a changed person. How do I know this if I didn’t study abroad myself? I know many who have and the end result is the same for all—no regrets, life changing moments, and better appreciation for the world we live in.
Internships
Going to college in the 1980’s was different from today. The job market was relatively strong and the push for an internship or co-op was not as strong. But if I had gotten some hands on experience and discovered my likes, dislikes, strengths, and weaknesses, I would have had more direction for my career when I graduated.  So talk to your professors, academic advisors, counselors, and mentors about getting some internship experience while in school or during the summer. There are many companies that welcome interns, and you may find the direction you are seeking.
Clubs and Organizations
For years, employers have been surveyed by colleges to ask them what type of skills they are seeking in college graduates. Although having discipline specific skills is important (in other words, the courses you take in your major), employers are very consistent in seeking out employees with what they call “soft skills,” such as writing well, public speaking, getting along with others, and having leadership abilities. You’ll develop these skills in your courses, but you can really hone and apply them by joining a club or organization on campus, where you will have opportunities to work with others, lead efforts, and have something to show for it—a campaign you ran, funds you raised, or an event you organized. Colleges offer many types of clubs to attract students in areas of interest. For example, if you are a business major, you could join the business club. More than likely the activities the club offers will allow you to meet business leaders, go on field trips to learn more about the business world, and meet people who have similar interests as yourself. I was a college athlete so my time was limited, and while I support athletics in college as an opportunity to continue your passion and to grow and learn, try to make time to join a special interest group. Take a leadership role in a group, and later, when you go on that job interview, talk about your leadership experience. The employer will be impressed and it may help you get the job.
Research
Finally, develop your research skills. You may think that research is most important in the sciences and medicine. But research occurs in all fields of study, and much of what you do in college is research in some form. If you are a music major you may need to research how other musicians developed their talent, the history of genres, or new ways music is applied in our world. Problem solving through effective research and knowing how to test your ideas and hypotheses will make you a valuable employee and citizen of your community. If your professor offers a chance to work on a special research project—sign up.
Question everything, and don’t take the answers at face value. Question how people come to their conclusions, develop your own set of research questions, and be willing to dig to find the answers. This is not only important as a student but also as an employee. Strive to be an engaged citizen in our world and don’t believe what everyone tells you. An adult needs to make informed decisions to buy products, pay taxes, and vote for government leaders. Don’t be complacent and put your life in the hands of others without fully researching the pros and cons—draw your own conclusions.
In conclusion, come to the classroom with an open mind and a willingness to exercise your right to take full advantage of all a college offers. Done correctly, college will be challenging and frustrating, and will test every part of you. Life will be the same way so use this time to practice, practice, practice.
Licenses and Attributions:
CC licensed content, Shared previously:
Foundations of Academic Success: Words of Wisdom. Edited by Thomas Priester. Essay authored by Dr. Kristine Duffy. Located at: milnepublishing.geneseo.edu/...tice-practice/ License: CC BY: Attribution.
Adaptions: Reformatted reference for consistency with footnotes.
-
Neale Donald Walsch,
Neale Donald Walsch’s Little Book of Life: A User’s Manual
(Charlottesville, VA: Hampton Roads, 2010). ↵


9.11: Electromagnetic Induction (Summary)
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Key Terms
| back emf | emf generated by a running motor, because it consists of a coil turning in a magnetic field; it opposes the voltage powering the motor |
| eddy current | current loop in a conductor caused by motional emf |
| electric generator | device for converting mechanical work into electric energy; it induces an emf by rotating a coil in a magnetic field |
| Faraday’s law | induced emf is created in a closed loop due to a change in magnetic flux through the loop |
| induced electric field | created based on the changing magnetic flux with time |
| induced emf | short-lived voltage generated by a conductor or coil moving in a magnetic field |
| Lenz’s law | direction of an induced emf opposes the change in magnetic flux that produced it; this is the negative sign in Faraday’s law |
| magnetic damping | drag produced by eddy currents |
| magnetic flux | measurement of the amount of magnetic field lines through a given area |
| motionally induced emf | voltage produced by the movement of a conducting wire in a magnetic field |
| peak emf | maximum emf produced by a generator |
Key Equations
| Magnetic flux | \(\displaystyle Φ_m=∫_S\vec{B}⋅\hat{n}dA\) |
| Faraday’s law | \(\displaystyle ε=−N\frac{dΦ_m}{dt}\) |
| Motionally induced emf | \(\displaystyle ε=Blv\) |
| Motional emf around a circuit | \(\displaystyle ε=∮\vec{E}⋅d\vec{l}=−\frac{dΦ_m}{dt}\) |
| Emf produced by an electric generator | \(\displaystyle ε=NBAωsin(ωt)\) |
Summary
13.2 Faraday’s Law
- The magnetic flux through an enclosed area is defined as the amount of field lines cutting through a surface area A defined by the unit area vector.
- The units for magnetic flux are webers, where \(\displaystyle 1Wb=1T⋅m^2\).
- The induced emf in a closed loop due to a change in magnetic flux through the loop is known as Faraday’s law. If there is no change in magnetic flux, no induced emf is created.
13.3 Lenz's Law
- We can use Lenz’s law to determine the directions of induced magnetic fields, currents, and emfs.
- The direction of an induced emf always opposes the change in magnetic flux that causes the emf, a result known as Lenz’s law.
13.4 Motional Emf
- The relationship between an induced emf εε in a wire moving at a constant speed v through a magnetic field B is given by \(\displaystyle ε=Blv\).
- An induced emf from Faraday’s law is created from a motional emf that opposes the change in flux.
13.5 Induced Electric Fields
- A changing magnetic flux induces an electric field.
- Both the changing magnetic flux and the induced electric field are related to the induced emf from Faraday’s law.
13.6 Eddy Currents
- Current loops induced in moving conductors are called eddy currents. They can create significant drag, called magnetic damping.
- Manipulation of eddy currents has resulted in applications such as metal detectors, braking in trains or roller coasters, and induction cooktops.
13.7 Electric Generators and Back Emf
- An electric generator rotates a coil in a magnetic field, inducing an emf given as a function of time by \(\displaystyle ε=NBAωsin(ωt)\) where A is the area of an N -turn coil rotated at a constant angular velocity \(\displaystyle ω\) in a uniform magnetic field \(\displaystyle \vec{B}\).
- The peak emf of a generator is \(\displaystyle ε_0=NBAω\).
- Any rotating coil produces an induced emf. In motors, this is called back emf because it opposes the emf input to the motor.
13.8 Applications of Electromagnetic Induction
- Hard drives utilize magnetic induction to read/write information.
- Other applications of magnetic induction can be found in graphics tablets, electric and hybrid vehicles, and in transcranial magnetic stimulation.


26.8: Peptide Synthesis
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- Steven Farmer, Dietmar Kennepohl, & William Reusch
- University of Illinois Springfield
Objectives
After completing this section, you should be able to
- describe why it is necessary to protect certain amino and carboxyl groups during the synthesis of a peptide.
- describe, using appropriate equations, how carboxyl groups are protected by ester formation and amino groups are protected by the formation of their tert ‑butoxycarbonyl amide derivatives.
- write a detailed mechanism for the formation of a peptide link between an amino acid with a protected amino group and an amino acid with a protected carboxyl group using dicyclohexylcarbodiimide.
- outline the five steps required in order to form a dipeptide from two given amino acids.
In order to synthesize a peptide from its component amino acids, two obstacles must be overcome. The first of these is statistical in nature, and is illustrated by considering the dipeptide Ala-Gly as a proposed target. If we ignore the chemistry involved, a mixture of equal molar amounts of alanine and glycine would generate four different dipeptides. These are: Ala-Ala, Gly-Gly, Ala-Gly & Gly-Ala . In the case of tripeptides, the number of possible products from these two amino acids rises to eight. Clearly, some kind of selectivity must be exercised if complex mixtures are to be avoided.
The second difficulty arises from the fact that carboxylic acids and 1º or 2º-amines do not form amide bonds on mixing, but will generally react by proton transfer to give salts (the intermolecular equivalent of zwitterion formation ).
From the perspective of an organic chemist, peptide synthesis requires selective acylation of a free amine. To accomplish the desired amide bond formation, we must first deactivate all extraneous amine functions so they do not compete for the acylation reagent. Then we must selectively activate the designated carboxyl function so that it will acylate the one remaining free amine. Fortunately, chemical reactions that permit us to accomplish these selections are well known.
First, the basicity and nucleophilicity of amines are substantially reduced by amide formation . Consequently, the acylation of amino acids by treatment with acyl chlorides or anhydrides at pH > 10, as described earlier , serves to protect their amino groups from further reaction.
Second, acyl halide or anhydride -like activation of a specific carboxyl reactant must occur as a prelude to peptide (amide) bond formation. This is possible, provided competing reactions involving other carboxyl functions that might be present are precluded by preliminary ester formation . Remember, esters are weaker acylating reagents than either anhydrides or acyl halides, as noted earlier .
Finally, dicyclohexylcarbodiimide (DCC) effects the dehydration of a carboxylic acid and amine mixture to the corresponding amide under relatively mild conditions. The structure of this reagent and the mechanism of its action have been described . Its application to peptide synthesis will become apparent in the following discussion.
The strategy for peptide synthesis, as outlined here, should now be apparent. The following example shows a selective synthesis of the dipeptide Ala-Gly.
An important issue remains to be addressed. Since the N-protective group is an amide, removal of this function might require conditions that would also cleave the just formed peptide bond. Furthermore, the harsh conditions often required for amide hydrolysis might cause extensive racemization of the amino acids in the resulting peptide. This problem strikes at the heart of our strategy, so it is important to give careful thought to the design of specific N-protective groups. In particular, three qualities are desired:
- The protective amide should be easy to attach to amino acids.
- The protected amino group should not react under peptide forming conditions.
- The protective amide group should be easy to remove under mild conditions.
A number of protective groups that satisfy these conditions have been devised; and two of the most widely used, carbobenzoxy (Cbz) and t-butoxycarbonyl (BOC or t-BOC), are described here.
The reagents for introducing these N-protective groups are the acyl chlorides or anhydrides shown in the left portion of the above diagram. Reaction with a free amine function of an amino acid occurs rapidly to give the "protected" amino acid derivative shown in the center. This can then be used to form a peptide (amide) bond to a second amino acid. Once the desired peptide bond is created the protective group can be removed under relatively mild non-hydrolytic conditions. Equations showing the protective group removal will be displayed above by are shown above. Cleavage of the reactive benzyl or tert-butyl groups generates a common carbamic acid intermediate (HOCO-NHR) which spontaneously loses carbon dioxide, giving the corresponding amine. If the methyl ester at the C-terminus is left in place, this sequence of reactions may be repeated, using a different N-protected amino acid as the acylating reagent. Removal of the protective groups would then yield a specific tripeptide, determined by the nature of the reactants and order of the reactions.


11.2: Faster Than Light?
A Dialog - a reason to examine the Lorentz tranformation
| No object travels faster than light. | |
| So YOU say, but watch ME: I travel in a rocket that you observe to move at \(4 / 5\) light speed. Out the front of my rocket I fire a bullet that I observe to fly forward at 4/5 light speed. Then you measure this bullet to streak forward at \(4 / 5+4 / 5=8 / 5=1.6\) light speed, which is greater than the speed of light. There! | No! |
| Velocities do not add | |
| Why not? Is it not true that \(4 / 5+4 / 5=1.6\) ? | As a mathematical abstraction: always true. As a description of the world: only sometimes true! Example 1: Add 4/5 liter of alcohol to \(4 / 5\) liter of water. The result? Less than \(8 / 5=1.6\) liter of liquid! Why? Molecules of water interpenetrate molecules of alcohol to yield a combined volume less that the sum of the separate volumes. Example 2: Add the speed you measure for the bullet \((4 / 5)\) to the speed I measure for your rocket \((4 / 5)\). The result? The speed I measure for the bullet is \(40 / 41=0.9756\). This remains less than the speed of light. |
| Why? And where did you get that number 40/41 for the bullet speed you measure? | I got the number from the Lorentz transformation, the subject of this Special Topic. The Lorentz transformation embodies a central feature of relativity: Space and time separations typically do not have the same values as observed in different frames. |
| Space and time separations between what? | Between events. |
| What events are we talking about here? | Event 1: You fire the bullet out the front of your rocket. Event 2: The bullet strikes a target ahead of you. |
| Events define velocities | |
| What do these events have to do with speed?  Then the space separation between event 1 and event 2 is 4 meters. Suppose the time of flight is 5 meters as measured by your clocks, the time separation between the two events. Then your bullet speed measurement is ( 4 meters of distance) \(/(5\) meters of time) \(=4 / 5\), as you said. |
| And what do YOU measure for the space and time separations in your laboratory frame? | For that we need the Lorentz coordinate transformation equations. |
| Interval: Only a start in reckoning spacetime separations in different frames | |
| Phooey! I know how to reckon spacetime separations in different frames. We have been doing it for several chapters!' From measurements in one frame we figure the spacetime interval, which has the same value in all frames. End of story. | No, not the end of the story, but at least its beginning. True, the invariant interval has the same value as derived from measurements in every frame. That allows you to predict the time between firing and impact as measured by the passenger riding on the bullet - and measured directly by the bullet passenger alone. |
| Predict how? |
You know your space separation \(x^{\prime}=4\) meters (primes for rocket measurements), and your time separation, \(t^{\prime}=5\) meters. You know the space separation for the bullet rider, \(x^{\prime \prime}=0\) (double primes for bullet measurements), since she is present at both the firing and the impact. From this you can use invariance of the interval to determine the wristwatch time between these events for the bullet rider:
\[ \left(t^{\prime \prime}\right)^2-\left(x^{\prime \prime}\right)^2=\left(t^{\prime}\right)^2-\left(x^{\prime}\right)^2 \nonumber \] or \[ \left(t^{\prime \prime}\right)^2-(0)^2=(5 \text { meters })^2-(4 \text { meters })^2=(3 \text { meters })^2 \nonumber \] so that \(t^{\prime \prime}=3\) meters. This is the proper time, agreed on by all observers but measured directly only on the wristwatch of the bullet rider. |
| Need more to compare velocities in different frames | |
| Fine. Can't we use the same procedure to determine the space and time separations between these events in your laboratory frame, and thus the bullet speed for you? | Unfortunately not. We do reckon the same value for the interval. Use unprimed symbols for laboratory measurements. Then \(t^2-x^2=(3 \text { meters })^2\). That, however, is not sufficient to determine \(x\) or \(t\) separately. Therefore we cannot yet find their ratio \(x / t\), which determines the bullet's speed in our frame. |
| Compare velocities using Lorentz transformation | |
| So how can we reckon these \(x\) and \(t\) separations in your laboratory frame, thereby allowing us to predict the bullet speed you measure? | Use the Lorentz transformation. This transformation reports that our laboratory space separation between firing and impact is \(x=40 / 3\) meters and the time separation is slightly greater: \(t=41 / 3\) meters. Then bullet speed in my laboratory frame is predicted to be \(v=x / t=40 / 41=0.9756\). The results of our analysis in three reference frames are laid out in Table L-1. |
| Lorentz transformation previewed | |
|
Is the Lorentz transformation generally useful, beyond the specific task of reckoning speeds as measured in different frames? |
Oh yes! Generally, we insert into the Lorentz transformation the coordinates \(x^{\prime}, t^{\prime}\) of an event determined in the rocket frame. The Lorentz transformation then grinds and whirs, finally spitting out the coordinates \(x, t\) of the same event measured in the laboratory frame. Following are the Lorentz transformation equations. Here \(v_{\text {rel }}\) is the relative velocity between rocket and laboratory frames. For our convenience we lay the positive \(x\)-axis along the direction of motion of the rocket as observed in the laboratory frame and choose a common reference event for the zero of time and space for both frames.
\[
Check for yourself that for the impact event of bullet with target (rocket coordinates: \(x^{\prime}=4\) meters, \(t^{\prime}=5\) meters; rocket speed in laboratory frame: \(v_{\text {rel }}=4 / 5\) ) one obtains laboratory coordinates \(x=40 / 3\) meters and \(t=41 / 3\) meters. Hence \(v=x / t\) \(=40 / 41=0.9756\). |
Table \(\PageIndex{1}\): How Fast the Bullet
| Bullet fired (coordinates of this event) | Bullet hits (coordinates of this event) |
Speed of bullet
(computed from frame coordinates) |
|
|---|---|---|---|
| Rocket frame (moves at \(v_{\text {rel }}=4 / 5\) as measured in laboratory) |
\[
\begin{aligned} x^{\prime} & =0 \\ t^{\prime} & =0 \end{aligned} \ n\nonumber \] |
\[ \begin{aligned}
|
as measured in rocket frame:
\[ v^{\prime}=4 / 5=0.8 \ n\nonumber \] |
| Bullet frame (moves at \(v^{\prime}=4 / 5\) as measured in rocket) |
\[
\begin{aligned} x^{\prime \prime} & =0 \\ t^{\prime \prime} & =0 \end{aligned} \ n\nonumber \] |
\[\begin{aligned}x^{\prime \prime} & =0 \\ t^{\prime \prime} & =3 \text { meters }
= \end{aligned} \ n\nonumber \] (from invariance of the interval) |
as measured in bullet frame:
\[ v^{\prime \prime}=0 \ n\nonumber \] |
| Laboratory frame |
\[
\begin{array}{l} x=0 \\ t=0 \end{array} \ n\nonumber \] |
\[
\begin{array}{c} x=40 / 3 \text { meters } \\ t=41 / 3 \text { meters } \end{array} \ n\nonumber \] (from Lorentz transformation) |
as measured in laboratory frame:
\[ v=40 / 41=0.9756 \ n\nonumber \] |
| Lorentz transformation: Useful but not fundamental | |
| You say the Lorentz transformation is general. If it is so important, then why is this a special topic rather than a regular chapter? | The Lorentz transformation is powerful; it brings the technical ability to transform coordinates from frame to frame. It helps us predict how to add velocities, as outlined here. It describes the Doppler shift for light (see the exercises for this chapter). On the other hand, the Lorentz transformation is not fundamental; it does not expose deep new features of spacetime. But no matter! Physics has to get on with the world's work. One uses the method of describing separation best suited to the job at hand. On some occasions the useful fact to give about a luxury yacht is the 50-meter distance between bow and stern, a distance independent of the direction in which the yacht is headed. On another occasion it may be much more important to know that the bow is 30 meters east of the stern and 40 meters north of it as observed by its captain, who uses North-Star north. |
| Two foundations of Lorentz transformation | |
|
What does the Lorentz transformation rest on? On what foundations is it based? |
On two foundations: (1) The equations must be linear. That is, space and time coordinates enter the equations to the first power, not squared or cubed. This results from the requirement that you may choose any event as the zero of space and time. (2) The spacetime interval between two events must have the same value when computed from laboratory coordinate separations as when reckoned from rocket coordinate separations. |
| All right, I'll reserve judgment on the validity of what you claim, but show me the derivation itself. | Read on! |


Classification Errors: Preoperational children have difficulty understanding that an object can be classified in more than one way. For example, if shown three white buttons and four black buttons and asked whether there are more black buttons or buttons, the child is likely to respond that there are more black buttons. As the child’s vocabulary improves and more schemes are developed, the ability to classify objects improves.
Conservation of Liquid. Does pouring liquid in a tall, narrow container make it have more?
Conservation Errors: Conservation refers to the ability to recognize that moving or rearranging matter does not change the quantity. Imagine a 2 year old and a 4 year old eating lunch. The 4 year old has a whole peanut butter and jelly sandwich. He notices, however, that his younger sister’s sandwich is cut in half and protests, “She has more!” Watch the following examples of conversation errors of quantity and volume:
Theory of Mind
Imagine showing a child of three a bandaid box and asking the child what is in the box. Chances are, the child will reply, “bandaids.” Now imagine that you open the box and pour out crayons. If you ask the child what they thought was in the box before it was opened, they may respond, “crayons”. If you ask what a friend would have thought was in the box, the response would still be “crayons”. Why? Before about 4 years of age, a child does not recognize that the mind can hold ideas that are not accurate. So this 3 year old changes his or her response once shown that the box contains crayons. The theory of mind is the understanding that the mind can be tricked or that the mind is not always accurate. At around age 4, the child would reply, “Crayons” and understand that thoughts and realities do not always match.
This awareness of the existence of mind is part of social intelligence or the ability to recognize that others can think differently about situations. It helps us to be self-conscious or aware that others can think of us in different ways and it helps us to be able to be understanding or empathic toward others. This mind reading ability helps us to anticipate and predict the actions of others (even though these predictions are sometimes inaccurate).
The awareness of the mental states of others is important for communication and social skills. A child who demonstrates this skill is able to anticipate the needs of others. This video describes a research in which theory of mind is linked to popularity.
Language Development
Vocabulary growth: A child’s vocabulary expands between the ages of 2 to 6 from about 200 words to over 10,000 words through a process called fast-mapping. Words are easily learned by making connections between new words and concepts already known. The parts of speech that are learned depend on the language and what is emphasized. Children speaking verb-friendly languages such as Chinese and Japanese as well as those speaking English tend to learn nouns more readily. But those learning less verb-friendly languages such as English seem to need assistance in grammar to master the use of verbs (Imai, et als, 2008). Children are also very creative in creating their own words to use as labels such as a “take-care-of” when referring to John, the character on the cartoon, Garfield, who takes care of the cat.
Literal meanings: Children can repeat words and phrases after having heard them only once or twice. But they do not always understand the meaning of the words or phrases. This is especially true of expressions or figures of speech which are taken literally. For example, two preschool aged girls began to laugh loudly while listening to a tape-recording of Disney’s “Sleeping Beauty” when the narrator reports, “Prince Phillip lost his head!” They image his head popping off and rolling down the hill as he runs and searches for it. Or a classroom full of preschoolers hears the teacher say, “Wow! That was a piece of cake!” The children began asking “Cake? Where is my cake? I want cake!”
Overregularization: Children learn rules of grammar as they learn language but may apply these rules inappropriately at first. For instance, a child learns to ad “ed” to the end of a word to indicate past tense. Then form a sentence such as “I goed there. I doed that.” This is typical at ages 2 and 3. They will soon learn new words such as went and did to be used in those situations.
The Impact of Training: Remember Vygotsky and the Zone of Proximal Development? Children can be assisted in learning language by others who listen attentively, model more accurate pronunciations and encourage elaboration. The child exclaims, “I’m goed there!” and the adult responds, “You went there? Say, ‘I went there.’ Where did you go?” Children may be ripe for language as Chomsky suggests, but active participation in helping them learn is important for language development as well. The process of scaffolding is one in which the guide provides needed assistance to the child as a new skill is learned.
Private Speech: Do you ever talk to yourself? Why? Chances are, this occurs when you are struggling with a problem, trying to remember something, or feel very emotional about a situation. Children talk to themselves too. Piaget interpreted this as egocentric speech or a practice engaged in because of a child’s inability to seeing things from others points of views. Vygotsky, however, believed that children talk to themselves in order to solve problems or clarify thoughts. As children learn to think in words, they do so aloud before eventually closing their lips and engaging in private speech or inner speech. Thinking out loud eventually becomes thought accompanied by internal speech and talking to oneself becomes a practice only engaged in when we are trying to learn something or remember something, etc. This inner speech is not as elaborate as the speech we use when communicating with others (Vygotsky, 1962).


8.7.0: Review Questions
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Review Questions
1 .
Identify an example of an intentional wound.
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bullet
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stab wound
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surgical incision
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fracture
2 .
The nurse recognizes that what factor does not put a patient at risk for pressure injury development?
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altered mental status
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loss of appetite
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advanced age
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weightlifting
3 .
Maceration can be defined as
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a loss of superficial layers of the skin.
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tissue that has been softened by prolonged wetting or soaking.
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tissue that has been hardened by pressure.
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tissue that has development of slough.
4 .
The nurse is assessing a patient with a deep red area of intact skin that does not blanch. As what stage of pressure injury is this classified?
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stage I injury
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deep tissue injury
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unstageable injury
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stage II injury
5 .
The nurse is educating a new graduate nurse on pressure injuries and knows that the new graduate nurse understands the teaching when they say what?
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“The difference in stage III and IV pressure injuries is the visibility of fascia, tendon, ligament, muscle, cartilage, and bone.”
-
“Slough and eschar are present at every stage.”
-
“If the area blanches, it is stage I.”
-
“A diabetic ulcer is also called a deep-tissue pressure injury.”
6 .
Identify the type of exudate from the wound shown.
-
sanguineous
-
purulent
-
foul purulent
-
serous
7 .
A patient is being assessed for risk for surgical complication using the SSERA model. The duration of the surgery is expected to be 180 minutes. The nurse recognizes that this surgical length automatically makes the patient what level of risk?
-
low risk
-
no risk
-
high risk
-
moderate risk
8 .
Identify the Wagner Ulcer Classification of the wound shown.
-
grade 1
-
grade 2
-
grade 4
-
grade 5
9 .
When the skin surrounding the wound is spongy and saturated, how should it be described?
-
edematous
-
boggy
-
attached
-
macerated
10 .
What phase of the healing process do leukocytes move into the interstitial space to ingest bacteria and cellular debris?
-
hemostasis
-
inflammatory phase
-
proliferation phase
-
maturation phase
11 .
The nurse is explaining complications associated with wound healing to a new patient at the clinic. How should the nurse describe maceration?
-
occurs when hydration leads to cell death
-
occurs when there is trauma the wound
-
occurs when there is swelling that interrupts blood flow
-
occurs where the cells are overhydrated leading to skin softening and breakdown
12 .
What nursing intervention is appropriate when performing a dressing change?
-
administering pain medication prior to wound care when the patient states that wound care is painful
-
telling the patient that they just need to look at the wound
-
explaining to the patient that the smell from the wound is not that bad
-
encouraging the patient that they do not have to make any changes in their activities of daily living
13 .
What type of debridement promotes the body’s own defense mechanisms?
-
enzymatic debridement
-
mechanical debridement
-
autolytic debridement
-
wet-to-dry debridement
14 .
A patient comes into the emergency room with a burn on their forearm from boiling water. It is red, painful, and blistered. The nurse correctly identifies this as what type of burn?
-
first degree
-
second degree
-
third degree
-
fourth degree
15 .
A farmer comes into the emergency room after being exposed to chemicals while fertilizing their crops. The nurse correctly recognizes what to be true about this type of burn?
-
The tissue injury ceased after the chemicals were removed.
-
The injury will require surgical treatment.
-
The chemicals may continue to impact the tissues after decontamination.
-
The nurse needs to look for an entry and exit point.
16 .
A patient is admitted to the burn unit after a severe burn. They weigh 143 lb (65 kg) and have a TBSA of 25 percent. Using the Parkland burn formula, how much fluid should the nurse expect the patient to receive over twenty-four hours?
-
6,500 mL
-
8,300 mL
-
3,500 mL
-
12,000 mL
17 .
The nurse expects the physician to order a consultation with what type of provider to prevent contractures in a patient with severe burns?
-
nutritionist
-
recreational therapist
-
physical therapist
-
respiratory therapist


5.16: Why It Matters
Financial analysis is a crucial element of business, but it can be used in personal finance as well. It differs depending on the role and perspective of those performing the analysis. For example, your personal accountant will have different goals and needs in making recommendations to you about your personal finances. All accounting professionals use financial analysis to check for validity, accurate data, compliance in reporting, and more.
Some tactics for managing your personal finances can be the same as for managing business finances. For example, reducing expenses and maximizing returns on long-term investments are always good practices. Debt can also be a beneficial tool in both personal and professional finances when used appropriately. Debt is neither inherently good nor bad; it simply needs to be properly managed in order to achieve a reasonable return in exchange for the cost and risk it poses.
Though the process and tools may be similar, financial analysis from a business perspective has different goals and needs. Investors are looking to identify firm performance, financial health, and profitability. Financial analysts closely review information found on financial statements so they can make informed business decisions. The income statement, statement of retained earnings, balance sheet, and statement of cash flows, among other financial information, are analyzed for internal and external stakeholders and provide a company with valuable information about its overall performance and specific areas for improvement. The analysis can help with budgeting and making decisions about where the company could cut costs, how it might increase revenues, and what capital investment opportunities it should pursue.
Link to Learning: Financial Analyst
Lots of individuals and companies perform financial analysis. One of these roles is that of a financial analyst . The skills and qualifications of a financial analyst vary widely from one industry to another, but there are a number of similarities in individuals who hold these roles. As you watch the video about financial analysts , consider your own career path and how your skills, abilities, and interests may fit this role.


5.2: Constrained and predetermined kinematics
In the next chapter on kinetics we will discuss how the motion of objects in time and space can be described based on the knowledge of forces and masses. However, often there is also different information about the motion available. For example when a train is constrained by a rail-track, when a measurement of the motion of a bird’s trajectory was made, or when it is assumed that a rolling ball always touches a curved surface. This information can be cast in the form of constraint equations.
5.2.1 Constraint equations
Although all dynamics is governed by Newton’s laws, rigorously applying these laws for every atom can be very inefficient. For instance, when a hockey puck is sliding on ice, modelling the forces of all ice molecules would be a tremendous task. Instead, we know that the ice molecules generate forces on the puck that prevent it from entering the ice, while gravity prevents the puck from
Thus in such cases, where we know the effective properties of a number of forces, it is much more efficient to describe their combined effect on the motion by constraint equations instead of applying Newton’s laws. Remember however, that such constraint equations always are the result of forces, and the accuracy of the resulting dynamics will depend on the accuracy by which the constraint equations represent these forces. In the next chapter we will also discuss how constraint equations can be combined with Newton’s laws to determine the forces generated by the constraints.
In other cases, information about the motion of an object has been obtained from a measurement, or is assumed to be known, and a constraint equation that describes the measured trajectory can be used to analyse the kinematics, and determine velocities and accelerations.
Equation that provides information on the motion and trajectories of objects in time and space, without providing direct information on the forces and mass. Constraint equations describe the kinematic constraints, which are the constraints that limit the potential motion of a mechanical system.
A constraint equation \(f\) can often be written as a function of the position vectors of the objects \(\overrightarrow{\boldsymbol{r}}_{i}\), and their time derivatives as:
\[f\left(\overrightarrow{\boldsymbol{r}}_{i}, \dot{\overrightarrow{\boldsymbol{r}}}_{i}, \ddot{\overrightarrow{\boldsymbol{r}}}_{i}, \ldots, t\right)=0 \tag{5.1} \label{5.1}\]
Where \(\overrightarrow{\boldsymbol{r}}_{i}\), with \(i=1,2, \ldots, N\) (or \(i=A, B, \ldots\) ) are the position vectors of the objects in the system. By taking the time-derivative or time-integral of a constraint equation, additional constraint equations can be derived. We will now discuss several examples of constraint equations.
5.2.2 Spatially constrained kinematics
Although space is always three-dimensional, in some cases there are forces on the object that constrain the motion to a certain part of space. The analysis of the dynamics in these cases can be significantly simplified. For instance, when a hockey puck \(A\) slides over a flat ice surface, and we know or assume that it will not lift from the surface, this can be described by the constraint equation:
\[z_{A}(t)=0 \tag{5.2} \label{5.2}\]
Since in this case the puck will not move along the \(z_{A}\) coordinate, its dynamics can be fully dealt with in 2 dimensions (2D) using \((x, y)\) coordinates or polar
\((\rho, \phi)\) coordinates, simply applying the Cartesian and cylindrical coordinate systems from the previous sections with \(z=0\). In fact this textbook deals with many examples of this \(2 \mathrm{D}\) in-plane dynamics situation, the derived equations and techniques are valid in 3D unless explicitly stated otherwise.
5.2.3 Path curve and path coordinate
An even more constrained situation is when the motion of an object is limited to a one-dimensional (1D) curvilinear path. This situation arises for instance when a train, marble or other point mass \(i\) moves along a predefined track, guided by a rail or tube.
As shown in by the blue curve in Figure 5.2 such a curvilinear path traces out a 1D path in 3D space, and this path can be described by a parametrised path curve \(\overrightarrow{\boldsymbol{r}}_{s}(s)\), such that for every value of the scalar path coordinate \(s\) there is 1 vector \(\overrightarrow{\boldsymbol{r}}_{s}(s)\) that defines the position on the track. It is convenient (although not always easy), to choose this function such that \(s\) is a measure of the distance along the track with respect to a certain origin \(\overrightarrow{\boldsymbol{r}}_{s}(s=0)\), for instance this can be done by taking a flexible tape measure, and measuring the distance \(s\) along the track. Since it is known that the point mass \(i\) always resides on the path curve, we have the following constraint equation:
\[\overrightarrow{\boldsymbol{r}}_{i}(t)=\overrightarrow{\boldsymbol{r}}_{s}(s) \tag{5.3} \label{5.3}\]
At every time \(t\), the path coordinate of object \(i\) has to obey equation (5.3), such that: \(\overrightarrow{\boldsymbol{r}}_{i}(t)=\overrightarrow{\boldsymbol{r}}_{s}\left(s_{i}(t)\right)\). This has the advantage that, because the path curve \(\overrightarrow{\boldsymbol{r}}_{s}(s)\) is known, the motion of \(i\) in \(3 \mathrm{D}\) can be described by a scalar function \(s_{i}(t)\), instead of requiring a more complex \(3 \mathrm{D}\) vector function \(\overrightarrow{\boldsymbol{r}}_{i}(t)\). Equation (5.3) and also the equation \(z_{i}(t)=0\) from the previous subsection are examples of constraint equations.
5.2.4 Relatively constrained kinematics and pulleys
Besides spatial constraints that limit the motion of a point mass to a certain plane or curve in space discussed in the previous subsection 5.2, it is also possible to have constraints that limit motion of a point mass with respect to one or more other point masses. Consider for example two point masses \(A\) and \(B\) with their motion described by separate path curves and path coordinates \(s_{A}(t)\) and \(s_{B}(t)\), see Figure 5.3. When making such a drawing, you are free to choose for each path coordinate the positive direction of the path curve and also the point at which the path coordinate is zero, which is called the datum. It is important to indicate those in the drawing.
We can write down a relative constraint equation for the length \(L_{\text {rope }}\) of the rope. From Figure 5.3 we see that always:
\[s_{A}(t)+s_{B}(t)+R \pi=L_{\mathrm{rope}} \tag{5.4} \label{5.4}\]
The term \(R \pi\) comes from the part of the rope that touches the pulley with radius \(R\) over half of its perimeter. By taking the time derivatives of this equation and using that the length of the rope \(L_{\text {rope }}\) and the radius of the pulley \(R\) is constant in time we find:
\[\begin{align} s_{A}(t)+s_{B}(t) & =c_{1}=\text { constant } \tag{5.5} \label{5.5}\\[4pt] \dot{s}_{A}(t)+\dot{s}_{B}(t) & =0 \tag{5.6} \label{5.6}\\[4pt] \ddot{s}_{A}(t)+\ddot{s}_{B}(t) & =0 \tag{5.7} \label{5.7}\end{align}\]
This shows that at all times the velocity and acceleration of the masses are equal and in opposite directions \(\left(\ddot{s}_{A}=-\ddot{s}_{B}\right)\). These relative constraint equations facilitate analysis of dynamic problems, since one does not need to determine the force in the rope. Since one is usually only interested in the constraint equation for the velocities, it is often not necessary to determine the exact value of the constant \(c_{1}=L_{\text {rope }}-R \pi\).
The shown procedure for obtaining the constraint equations is also quite generally applicable:
- Determine the path coordinates of all moving objects and point masses based on the geometry.
- Determine the constraint equations for the positions of the objects and simplify them.
- Take two times the time derivative of the constraint equation to obtain the constraint equations for the velocities, and for the accelerations.
Figure 5.4 shows a more complicated pulley system. The question is: find the relative constraint equation that relates the velocities \(\dot{s}_{A}, \dot{s}_{B}\) of point masses \(A\) and \(B\).
Exemplary solution
Since pulleys \(C\) and \(D\) are also moving, it is useful to also monitor their path coordinates \(s_{C}\) and \(s_{D}\), which have been indicated in Figure 5.4. Now we write down all constraint equations and combine them to obtain a single equation relating \(s_{A}\) and \(s_{B}\) :
\[\begin{align} L_{\mathrm{rope}} & =s_{A}+2 s_{C}+s_{D}+L_{C D}+c_{1} \tag{5.8} \label{5.8}\\[4pt] s_{C} & =s_{B}-\left(L_{C D}+L_{B}\right) \tag{5.9} \label{5.9}\\[4pt] s_{D} & =s_{B}-L_{B} \tag{5.10} \label{5.10}\\[4pt] L_{\mathrm{rope}} & =s_{A}+3 s_{B}+c_{2} \tag{5.11} \label{5.11}\end{align}\]
The actual value of the constant \(c_{2}\) is not needed to solve the problem, since we now take the time derivative to obtain the relative constraint equation for the velocities:
\[\begin{align} s_{A}+3 s_{B} & =c_{3}=\text { constant } \tag{5.12} \label{5.12}\\[4pt] \dot{s}_{A}+3 \dot{s}_{B} & =0 \tag{5.13} \label{5.13}\\[4pt] \dot{s}_{A} & =-3 \dot{s}_{B} \tag{5.14} \label{5.14}\end{align}\]
The three constraint equations (5.8-5.10) represent the effect of the three constraining elements in Figure 5.4: the rope, the rigid rod between pulleys \(C\) and \(D\) and the short rope between pulley \(D\) and point mass \(B\). Initially there are four unknown scalar variables: \(s_{A}, s_{B}, s_{C}\) and \(s_{D}\). Generally each (scalar) constraint equation eliminates one unknown, such that in the end we are left with one constraint equation (with one unknown). Besides pulleys and ropes there are of course many other elements that constrain motion, which will be discussed later.


2.2: Elements and Atoms - The Building Blocks of Matter
By the end of this section, you will be able to:
- Discuss the relationships between matter, mass, elements, compounds, atoms, and subatomic particles
- Distinguish between atomic number and mass number
- Identify the key distinction between isotopes of the same element
- Explain how electrons occupy electron shells and their contribution to an atom’s relative stability
The substance of the universe—from a grain of sand to a star—is called matter . Scientists define matter as anything that occupies space and has mass. An object’s mass and its weight are related concepts, but not quite the same. An object’s mass is the amount of matter contained in the object, and the object’s mass is the same whether that object is on Earth or in the zero-gravity environment of outer space. An object’s weight, on the other hand, is its mass as affected by the pull of gravity. Where gravity strongly pulls on an object’s mass its weight is greater than it is where gravity is less strong. An object of a certain mass weighs less on the moon, for example, than it does on Earth because the gravity of the moon is less than that of Earth. In other words, weight is variable, and is influenced by gravity. A piece of cheese that weighs a pound on Earth weighs only a few ounces on the moon.
Elements and Compounds
All matter in the natural world is composed of one or more of the 92 fundamental substances called elements. An element is a pure substance that is distinguished from all other matter by the fact that it cannot be created or broken down by ordinary chemical means. While your body can assemble many of the chemical compounds needed for life from their constituent elements, it cannot make elements. They must come from the environment. A familiar example of an element that you must take in is calcium (Ca). Calcium is essential to the human body; it is absorbed and used for a number of processes, including strengthening bones. When you consume dairy products your digestive system breaks down the food into components small enough to cross into the bloodstream. Among these is calcium, which, because it is an element, cannot be broken down further. The elemental calcium in cheese, therefore, is the same as the calcium that forms your bones. Some other elements you might be familiar with are oxygen, sodium, and iron. The elements in the human body are shown in Figure 2.2, beginning with the most abundant: oxygen (O), carbon (C), hydrogen (H), and nitrogen (N). Each element’s name can be replaced by a one- or two-letter symbol; you will become familiar with some of these during this course. All the elements in your body are derived from the foods you eat and the air you breathe.
In nature, elements rarely occur alone. Instead, they combine to form compounds. A compound is a substance composed of two or more elements joined by chemical bonds. For example, the compound glucose is an important body fuel. It is always composed of the same three elements: carbon, hydrogen, and oxygen. Moreover, the elements that make up any given compound always occur in the same relative amounts. In glucose, there are always six carbon and six oxygen units for every twelve hydrogen units. But what, exactly, are these “units” of elements?
Atoms and Subatomic Particles
An atom is the smallest quantity of an element that retains the unique properties of that element. In other words, an atom of hydrogen is a unit of hydrogen—the smallest amount of hydrogen that can exist. As you might guess, atoms are almost unfathomably small. The period at the end of this sentence is millions of atoms wide.
Atomic Structure and Energy
Atoms are made up of even smaller subatomic particles, three types of which are important: the proton , neutron , and electron . The number of positively-charged protons and non-charged (“neutral”) neutrons, gives mass to the atom, and the number of protons determines the element. The number of negatively-charged electrons that “spin” around the nucleus at close to the speed of light equals the number of protons. An electron has about 1/2000th the mass of a proton or neutron.
Figure 2.3 shows two models that can help you imagine the structure of an atom—in this case, helium (He). In the planetary model, helium’s two electrons are shown circling the nucleus in a fixed orbit depicted as a ring. Although this model is helpful in visualizing atomic structure, in reality, electrons do not travel in fixed orbits, but whiz around the nucleus erratically in a so-called electron cloud.
An atom’s protons and electrons carry electrical charges. Protons, with their positive charge, are designated p + . Electrons, which have a negative charge, are designated e – . An atom’s neutrons have no charge: they are electrically neutral. Just as a magnet sticks to a steel refrigerator because their opposite charges attract, the positively charged protons attract the negatively charged electrons. This mutual attraction gives the atom some structural stability. The attraction by the positively charged nucleus helps keep electrons from straying far. The number of protons and electrons within a neutral atom are equal, thus, the atom’s overall charge is balanced.
Atomic Number and Mass Number
An atom of carbon is unique to carbon, but a proton of carbon is not. One proton is the same as another, whether it is found in an atom of carbon, sodium (Na), or iron (Fe). The same is true for neutrons and electrons. So, what gives an element its distinctive properties—what makes carbon so different from sodium or iron? The answer is the unique quantity of protons each contains. Carbon by definition is an element whose atoms contain six protons. No other element has exactly six protons in its atoms. Moreover, all atoms of carbon, whether found in your liver or in a lump of coal, contain six protons. Thus, the atomic number , which is the number of protons in the nucleus of the atom, identifies the element. Because an atom usually has the same number of electrons as protons, the atomic number identifies the usual number of electrons as well.
In their most common form, many elements also contain the same number of neutrons as protons. The most common form of carbon, for example, has six neutrons as well as six protons, for a total of 12 subatomic particles in its nucleus. An element’s mass number is the sum of the number of protons and neutrons in its nucleus. So the most common form of carbon’s mass number is 12. (Electrons have so little mass that they do not appreciably contribute to the mass of an atom.) Carbon is a relatively light element. Uranium (U), in contrast, has a mass number of 238 and is referred to as a heavy metal. Its atomic number is 92 (it has 92 protons) but it contains 146 neutrons; it has the most mass of all the naturally occurring elements.
The periodic table of the elements , shown in Figure 2.4, is a chart identifying the 92 elements found in nature, as well as several larger, unstable elements discovered experimentally. The elements are arranged in order of their atomic number, with hydrogen and helium at the top of the table, and the more massive elements below. The periodic table is a useful device because for each element, it identifies the chemical symbol, the atomic number, and the mass number, while organizing elements according to their propensity to react with other elements. The number of protons and electrons in an element are equal. The number of protons and neutrons may be equal for some elements, but are not equal for all.
Interactive Link
Visit this website to view the periodic table. In the periodic table of the elements, elements in a single column have the same number of electrons that can participate in a chemical reaction. These electrons are known as “valence electrons.” For example, the elements in the first column all have a single valence electron, an electron that can be “donated” in a chemical reaction with another atom. What is the meaning of a mass number shown in parentheses?
Isotopes
Although each element has a unique number of protons, it can exist as different isotopes. An isotope is one of the different forms of an element, distinguished from one another by different numbers of neutrons. The standard isotope of carbon is 12 C, commonly called carbon twelve. 12 C has six protons and six neutrons, for a mass number of twelve. All of the isotopes of carbon have the same number of protons; therefore, 13 C has seven neutrons, and 14 C has eight neutrons. The different isotopes of an element can also be indicated with the mass number hyphenated (for example, C-12 instead of 12 C). Hydrogen has three common isotopes, shown in Figure 2.5.
An isotope that contains more than the usual number of neutrons is referred to as a heavy isotope. An example is 14 C. Heavy isotopes tend to be unstable, and unstable isotopes are radioactive. A radioactive isotope is an isotope whose nucleus readily decays, giving off subatomic particles and electromagnetic energy. Different radioactive isotopes (also called radioisotopes) differ in their half-life, the time it takes for half of any size sample of an isotope to decay. For example, the half-life of tritium—a radioisotope of hydrogen—is about 12 years, indicating it takes 12 years for half of the tritium nuclei in a sample to decay. Excessive exposure to radioactive isotopes can damage human cells and even cause cancer and birth defects, but when exposure is controlled, some radioactive isotopes can be useful in medicine. For more information, see the Career Connections.
Career Connection
Interventional Radiologist
The controlled use of radioisotopes has advanced medical diagnosis and treatment of disease. Interventional radiologists are physicians who treat disease by using minimally invasive techniques involving radiation. Many conditions that could once only be treated with a lengthy and traumatic operation can now be treated non-surgically, reducing the cost, pain, length of hospital stay, and recovery time for patients. For example, in the past, the only options for a patient with one or more tumors in the liver were surgery and chemotherapy (the administration of drugs to treat cancer). Some liver tumors, however, are difficult to access surgically, and others could require the surgeon to remove too much of the liver. Moreover, chemotherapy is highly toxic to the liver, and certain tumors do not respond well to it anyway. In some such cases, an interventional radiologist can treat the tumors by disrupting their blood supply, which they need if they are to continue to grow. In this procedure, called radioembolization, the radiologist accesses the liver with a fine needle, threaded through one of the patient’s blood vessels. The radiologist then inserts tiny radioactive “seeds” into the blood vessels that supply the tumors. In the days and weeks following the procedure, the radiation emitted from the seeds destroys the vessels and directly kills the tumor cells in the vicinity of the treatment.
Radioisotopes emit subatomic particles that can be detected and tracked by imaging technologies. One of the most advanced uses of radioisotopes in medicine is the positron emission tomography (PET) scanner, which detects the activity in the body of a very small injection of radioactive glucose, the simple sugar that cells use for energy. The PET camera reveals to the medical team which of the patient’s tissues are taking up the most glucose. Thus, the most metabolically active tissues show up as bright “hot spots” on the images (Figure 2.6). PET can reveal some cancerous masses because cancer cells consume glucose at a high rate to fuel their rapid reproduction.
The Behavior of Electrons
In the human body, atoms do not exist as independent entities. Rather, they are constantly reacting with other atoms to form and to break down more complex substances. To fully understand anatomy and physiology you must grasp how atoms participate in such reactions. The key is understanding the behavior of electrons.
Although electrons do not follow rigid orbits a set distance away from the atom’s nucleus, they do tend to stay within certain regions of space called electron shells. An electron shell is a layer of electrons that encircle the nucleus at a distinct energy level.
The atoms of the elements found in the human body have from one to five electron shells, and all electron shells hold eight electrons except the first shell, which can only hold two. This configuration of electron shells is the same for all atoms. The precise number of shells depends on the number of electrons in the atom. Hydrogen and helium have just one and two electrons, respectively. If you take a look at the periodic table of the elements, you will notice that hydrogen and helium are placed alone on either sides of the top row; they are the only elements that have just one electron shell (Figure 2.7). A second shell is necessary to hold the electrons in all elements larger than hydrogen and helium.
Lithium (Li), whose atomic number is 3, has three electrons. Two of these fill the first electron shell, and the third spills over into a second shell. The second electron shell can accommodate as many as eight electrons. Carbon, with its six electrons, entirely fills its first shell, and half-fills its second. With ten electrons, neon (Ne) entirely fills its two electron shells. Again, a look at the periodic table reveals that all of the elements in the second row, from lithium to neon, have just two electron shells. Atoms with more than ten electrons require more than two shells. These elements occupy the third and subsequent rows of the periodic table.
The factor that most strongly governs the tendency of an atom to participate in chemical reactions is the number of electrons in its valence shell. A valence shell is an atom’s outermost electron shell. If the valence shell is full, the atom is stable; meaning its electrons are unlikely to be pulled away from the nucleus by the electrical charge of other atoms. If the valence shell is not full, the atom is reactive; meaning it will tend to react with other atoms in ways that make the valence shell full. Consider hydrogen, with its one electron only half-filling its valence shell. This single electron is likely to be drawn into relationships with the atoms of other elements, so that hydrogen’s single valence shell can be stabilized.
All atoms (except hydrogen and helium with their single electron shells) are most stable when there are exactly eight electrons in their valence shell. This principle is referred to as the octet rule, and it states that an atom will give up, gain, or share electrons with another atom so that it ends up with eight electrons in its own valence shell. For example, oxygen, with six electrons in its valence shell, is likely to react with other atoms in a way that results in the addition of two electrons to oxygen’s valence shell, bringing the number to eight. When two hydrogen atoms each share their single electron with oxygen, covalent bonds are formed, resulting in a molecule of water, H 2 O.
In nature, atoms of one element tend to join with atoms of other elements in characteristic ways. For example, carbon commonly fills its valence shell by linking up with four atoms of hydrogen. In so doing, the two elements form the simplest of organic molecules, methane, which also is one of the most abundant and stable carbon-containing compounds on Earth. As stated above, another example is water; oxygen needs two electrons to fill its valence shell. It commonly interacts with two atoms of hydrogen, forming H 2 O. Incidentally, the name “hydrogen” reflects its contribution to water (hydro- = “water”; -gen = “maker”). Thus, hydrogen is the “water maker.”


29.14B: Galactosemia and Glycogen Storage Disease
- Differentiate between galactosemia and glycogen storage disease
Galactosemia (British Galactosaemia) is a rare genetic metabolic disorder that affects an individual’s ability to metabolize the sugar galactose properly. Although the sugar and lactose metabolizes to galactose, galactosemia is not related to and should not be confused with lactose intolerance. Galactosemia follows an autosomal recessive mode of inheritance that confers a deficiency in an enzyme responsible for adequate galactose degradation. Its incidence is about one per 60,000 births for Caucasians. In other populations the incidence rate differs.
Lactose in food (such as dairy products) is broken down by the enzyme lactase into glucose and galactose. In individuals with galactosemia, the enzymes needed for further metabolism of galactose are severely diminished or missing entirely, leading to toxic levels of galactose 1-phosphate in various tissues as in the case of classic galactosemia, resulting in hepatomegaly (an enlarged liver), cirrhosis, renal failure, cataracts, brain damage, and ovarian failure. Without treatment, mortality in infants with galactosemia is about 75%.
Diagnosis
Infants are routinely screened for galactosemia in the United States. Infants affected by galactosemia typically present with symptoms of lethargy, vomiting, diarrhea, failure to thrive, and jaundice. If the family of the baby has a history of galactosemia, doctors can test prior to birth by taking a sample of fluid from around the fetus or from the placenta.
Detection of the disorder through newborn screening (NBS) does not depend on protein or lactose ingestion, and, therefore, it should be identified on the first specimen unless the infant has been transfused. A specimen should be taken prior to transfusion. The enzyme is prone to damage if analysis of the sample is delayed or exposed to high temperatures.
Treatment
The only treatment for classic galactosemia is eliminating lactose and galactose from the diet. Even with an early diagnosis and a restricted diet, however, some individuals with galactosemia experience long-term complications such as speech difficulties, learning disabilities, neurological impairment (e.g., tremors, etc.), and ovarian failure in females. Infants with classic galactosemia cannot be breast-fed due to lactose in human breast milk and are usually fed a soy-based formula.
Galactosemia is sometimes confused with lactose intolerance, but galactosemia is a more serious condition. Lactose intolerant individuals have an acquired or inherited shortage of the enzyme lactase, and experience abdominal pains after ingesting dairy products, but no long-term effects. In contrast, a galactosemic individual who consumes galactose can cause permanent damage to their bodies.
Glycogen Storage Disease
Glycogen storage disease (GSD, also glycogenosis and dextrinosis) is the result of defects in the processing of glycogen synthesis or breakdown within muscles, liver, and other cell types. GSD has two classes of cause: genetic and acquired. Genetic GSD is caused by any inborn error of metabolism (genetically defective enzymes) involved in these processes. In livestock, acquired GSD is caused by intoxication with the alkaloid castanospermine. Overall, according to a study in British Columbia, approximately 2.3 children per 100,000 births (one in 43,000) have some form of glycogen storage disease. In the United States, they are estimated to occur in one per 20,000–25,000 births. A Dutch study estimated it to be one in 40,000.
There are 11 distinct diseases that are commonly considered to be glycogen storage diseases (some previously thought to be distinct have been reclassified).
Key Points
- Galactosemia follows is a rare genetic metabolic disorder that affects an individual’s ability to metabolize the sugar galactose properly.
- Infants affected by galactosemia typically present with symptoms of lethargy, vomiting, diarrhea, failure to thrive, and jaundice.
- A galactosemia test is a blood test (from the heel of the infant) or urine test that checks for three enzymes that are needed to change galactose sugar that is found in milk and milk products into glucose, a sugar that your body uses for energy.
- The only treatment for classic galactosemia is eliminating lactose and galactose from the diet.
- Glycogen storage disease (GSD, also glycogenosis and dextrinosis) is the result of defects in the processing of glycogen synthesis or breakdown within muscles, liver, and other cell types.
- The only treatment for classic galactosemia is eliminating lactose and galactose from the diet.
- There are eleven (11) distinct diseases that are commonly considered to be glycogen storage diseases.
Key Terms
- enzyme : A globular protein that catalyses a biological chemical reaction.
- glycogen : A polysaccharide that is the main form of carbohydrate storage in animals; converted to glucose as needed.
LICENSES AND ATTRIBUTIONS
CC LICENSED CONTENT, SHARED PREVIOUSLY
- Curation and Revision. Authored by : Boundless.com. Provided by : Boundless.com. License : CC BY-SA: Attribution-ShareAlike
CC LICENSED CONTENT, SPECIFIC ATTRIBUTION
- Phenylketonuria. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Phenylketonuria . License : CC BY-SA: Attribution-ShareAlike
- autosomal recessive. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/autosomal%20recessive . License : CC BY-SA: Attribution-ShareAlike
- Phenylketonuria. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Phenylketonuria . License : CC BY-SA: Attribution-ShareAlike
- phenylalanine. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/phenylalanine . License : CC BY-SA: Attribution-ShareAlike
- Phenylketonuria. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Phenylketonuria . License : Public Domain: No Known Copyright
- enzyme. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/enzyme . License : CC BY-SA: Attribution-ShareAlike
- Galactosemia. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Galactosemia . License : CC BY-SA: Attribution-ShareAlike
- Glycogen storage disease. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Glycogen_storage_disease . License : CC BY-SA: Attribution-ShareAlike
- glycogen. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/glycogen . License : CC BY-SA: Attribution-ShareAlike
- Phenylketonuria. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Phenylketonuria . License : Public Domain: No Known Copyright
- Galactosemia. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Galactosemia . License : Public Domain: No Known Copyright


3.5: Documentation
All aspects of the administration of blood products are documented. Documentation must minimally include the following components:
- Date and time that the blood transfusion began
- Name of the second nurse who did the two-person verification process
- Name and amount of the specific type of transfusion (for example, 1 unit of packed red blood cells)
- Blood product number
- Confirmation that written informed consent was obtained
- Indications for the transfusion
- Premedications administered
- Donor identification number
- IV site location
- Size and gauge of IV catheter access
- Duration of the transfusion
- Vital signs before, during, and post-transfusion according to agency policy
- Pre- and post-transfusion focused assessments (lungs, heart, etc.) according to agency policy
- Indication that the client was informed about when and why to contact the nurse after the initial 15-minute monitoring period
- Amount of normal saline solution infused
- Client response to the transfusion
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If a transfusion reaction occurs:
- Name of the provider notified
- Time of notification
- Interventions performed
- Client’s response to those interventions.
- Any teaching provided to the client and family, including their understanding of the teaching and any follow-up that was needed
Sample Documentation:
12/7/20XX 1445
Transfusion of one-unit (250mL) packed RBCs started at 1445 via 20-gauge saline lock in the right forearm. Unit product #G901 301 000 482. Blood product and client identification verified with Jane Smith, RN. Informed consent signed and in client chart. Infusion indication: symptomatic anemia with hemoglobin level at 7.4 mg/dL. Client verbalizes understanding of the reason for transfusion and the need to inform RN as soon as possible if any symptoms develop during transfusion. Microaggregate Y-tubing system attached to packed red blood cells and 0.9% normal saline. Pre-transfusion vital signs and assessments: T 98.2 F (temporal), HR 88 bpm, RR 20, BP 112/68, SpO2 97% on room air, lung sounds clear, regular heart rate with no extra sounds.
1500: Stayed with client for the first 15 minutes of initiation. Client tolerated infusion without any new or adverse signs or symptoms.
1715: Unit (250 mL) was infused within 2.5 hours, with 50 mL of normal saline 0.9%. Time of completion: 1715. Post-transfusion completion vital signs and assessments: T 97.6 F (temporal), HR, 78 bpm, RR 22, BP 128/72, SpO2 97% on room air, lungs sounds clear, regular heart rate with no extra sounds. IV site intact and patent without signs of phlebitis or infiltration. Client appears comfortable and denies discomfort.
Manuel Roberts, RN


1.5: Security
Learning Outcomes
- Discuss the importance of security in the business computing environment
A computer being secure depends on a number of technologies working properly. A modern operating system provides access to a number of resources, which are available to software running on the system, and to external devices like networks via the kernel.
The operating system must be capable of distinguishing between requests which should be allowed to be processed, and others which should not be processed. While some systems may simply distinguish between “privileged” and “non-privileged,” systems commonly have a form of requester identity, such as a username. To establish identity there may be a process of authentication. Often a username must be quoted, and each username may have a password. Other methods of authentication, such as magnetic cards or biometric data, might be used instead. In some cases, especially connections from the network, resources may be accessed with no authentication at all (such as reading files over a network share). Also covered by the concept or equester identity is authorization; the particular services and resources accessible by the requester once logged into a system are tied to either the requester’s user account or to the variously configured groups of users to which the requester belongs.
In addition to the allow or disallow model of security, a system with a high level of security also offers auditing options. These would allow tracking of requests for access to resources (such as, “who has been reading this file?”). Internal security, or security from an already running program is only possible if all possibly harmful requests must be carried out through interrupts to the operating system kernel. If programs can directly access hardware and resources, they cannot be secured.
External security involves a request from outside the computer, such as a login at a connected console or some kind of network connection. External requests are often passed through device drivers to the operating system’s kernel, where they can be passed onto applications, or carried out directly.
Why Does Security MatteR?
Security of operating systems has long been a concern because of highly sensitive data held on computers, both of a commercial and military nature. The United States Government Department of Defense (DoD) created the Trusted Computer System Evaluation Criteria (TCSEC) which is a standard that sets basic requirements for assessing the effectiveness of security. This became of vital importance to operating system makers, because the TCSEC was used to evaluate, classify and select trusted operating systems being considered for the processing, storage and retrieval of sensitive or classified information.
Network services include offerings such as file sharing, print services, email, web sites, and file transfer protocols (FTP), most of which can have compromised security. At the front line of security are hardware devices known as firewalls or intrusion detection/prevention systems. At the operating system level, there are a number of software firewalls available, as well as intrusion detection/prevention systems. Most modern operating systems include a software firewall, which is enabled by default. A software firewall can be configured to allow or deny network traffic to or from a service or application running on the operating system. Therefore, one can install and be running an insecure service, such as Telnet or FTP, and not have to be threatened by a security breach because the firewall would deny all traffic trying to connect to the service on that port.
Contributors and Attributions
- Practice Question. Authored by : Sherri Pendleton. Provided by : Lumen Learning. License : CC BY: Attribution
- Modification of Utility Software. Provided by : Northern Virginia Community College Extended Learning Institute. Located at : https://courses.lumenlearning.com/zeliite115/chapter/reading-utility-software/ . License : CC BY-SA: Attribution-ShareAlike
- Untitled. Authored by : Pete Linforth. Provided by : Pixabay. Located at : pixabay.com/illustrations/cyber-security-technology-network-3374252/. License : CC0: No Rights Reserved . License Terms : Pixabay License


11: The Central Nervous System (Brain)
The brain and the spinal cord are the central nervous system, and they represent the main organs of the nervous system. The spinal cord is a single structure, whereas the adult brain is described in terms of four major regions: the cerebrum, the diencephalon, the brain stem, and the cerebellum. A person’s conscious experiences are based on neural activity in the brain. The regulation of homeostasis is governed by a specialized region in the brain. The coordination of reflexes depends on the integration of sensory and motor pathways in the spinal cord.
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- 11.1: The Cerebrum
- This page describes the cerebrum as the largest brain part, divided into two hemispheres, covered by a folded cerebral cortex that enhances its surface area for advanced neurological functions. The cortex is organized into four lobes—frontal, parietal, temporal, and occipital—distinguished by grooves and ridges. These intricate folds help fit the brain within the skull and facilitate complex interrelated functions among the lobes.
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- 11.2: The Diencephalon
- This page explains the diencephalon, a vital brain structure that connects the cerebrum to the nervous system, facilitating information flow, except for the olfactory system. Positioned beneath the cerebrum, it forms the third ventricle's walls and encompasses the thalamus, hypothalamus, epithalamus, and subthalamus.
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- 11.3: The Brain Stem
- This page explains the structure and functions of the brain stem, which includes the midbrain, pons, and medulla. It emphasizes the midbrain's role in sensory information coordination and the pons as a vital connection to the cerebellum. The page also highlights the importance of the pons and medulla in regulating essential functions like cardiovascular and respiratory systems, while noting that the cerebellum, although attached to the brain stem, is considered a separate area.
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- 11.4: The Cerebellum
- This page describes the cerebellum, or "little brain," which resembles a smaller cerebrum and makes up about 10% of brain mass. It compares sensory feedback with its own information and is located on the posterior brain stem. The cerebellum receives input from the pons and inferior olive and sends output to the midbrain, facilitating communication of descending signals to the spinal cord.
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- 11.5: Exercises
- This page features labeling exercises centered on brain anatomy, including structures of the cerebrum, cerebellum, brainstem, and ventricular system.  It identifies specific components like gyri, sulci, and lobes, offering insights into the brain's complex organization and structural relationships.