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Consider the weighted voting system \([q: 7, 3, 1]\)
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Which values of \(q\) result in a dictator (list all possible values)
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What is the smallest value for \(q\) that results in exactly one player with veto power but no dictators?
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What is the smallest value for \(q\) that results in exactly two players with veto power?
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Consider the weighted voting system \([q: 9, 4, 2]\)
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Which values of \(q\) result in a dictator (list all possible values)
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What is the smallest value for \(q\) that results in exactly one player with veto power?
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What is the smallest value for \(q\) that results in exactly two players with veto power?
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Using the Shapley-Shubik method, is it possible for a dummy to be pivotal?
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If a specific weighted voting system requires a unanimous vote for a motion to pass:
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Which player will be pivotal in any sequential coalition?
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How many winning coalitions will there be?
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Consider a weighted voting system with three players. If Player 1 is the only player with veto power, there are no dictators, and there are no dummies:
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Find the Banzhaf power distribution.
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Find the Shapley-Shubik power distribution
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Consider a weighted voting system with three players. If Players 1 and 2 have veto power but are not dictators, and Player 3 is a dummy:
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Find the Banzhaf power distribution.
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Find the Shapley-Shubik power distribution
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An executive board consists of a president (P) and three vice-presidents \(\left(\mathrm{V}_{1}, \mathrm{V}_{2}, \mathrm{V}_{3}\right)\). For a motion to pass it must have three yes votes, one of which must be the president's. Find a weighted voting system to represent this situation.
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On a college’s basketball team, the decision of whether a student is allowed to play is made by four people: the head coach and the three assistant coaches. To be allowed to play, the student needs approval from the head coach and at least one assistant coach. Find a weighted voting system to represent this situation.
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In a corporation, the shareholders receive 1 vote for each share of stock they hold, which is usually based on the amount of money the invested in the company. Suppose a small corporation has two people who invested $30,000 each, two people who invested $20,000 each, and one person who invested $10,000. If they receive one share of stock for each $1000 invested, and any decisions require a majority vote, set up a weighted voting system to represent this corporation’s shareholder votes.
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A contract negotiations group consists of 4 workers and 3 managers. For a proposal to be accepted, a majority of workers and a majority of managers must approve of it. Calculate the Banzhaf power distribution for this situation. Who has more power: a worker or a manager?
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The United Nations Security Council consists of 15 members, 10 of which are elected, and 5 of which are permanent members. For a resolution to pass, 9 members must support it, which must include all 5 of the permanent members. Set up a weighted voting system to represent the UN Security Council and calculate the Banzhaf power distribution.


1.2: More Sounds and Punctuation
Module 2
© 2021 Philip S. Peek, CC BY 4.0 https://doi.org/ 10.11647/OBP.0264. 02
Iota Subscript and Adscript
When the long vowels, ᾱ , η , and ω are combined with a short iota, the iota is written beneath the long vowels as an iota subscript. The prefix sub- means under.
|
ᾳ |
ῃ |
ῳ |
If the long vowel is capitalized, the iota is written beside the long vowel and is called an iota adscript. The prefix ad- means beside.
|
Αι |
Ηι |
Ωι |
The iota is not pronounced and the pronunciation of these combined letters is the same as it is for the plain vowels, ᾱ , η , and ω . Practice pronouncing the name of Hades, the Greek god of the dead, Ἅ ιδης .
Note that the writing of the iota as a subscript or adscript is a writing convention begun in the Middle Ages. Originally the iota was pronounced with the long vowels, ᾱ , η , ω , as a combination of two sounds. From the fourth century to the second century BCE the iota weakened to a glide, similar to the way the English y can affect vowels. Pronounce out loud late and day , noting how the y influences the sound of the vowel a . After the second century BCE the iota was not pronounced. When reading ancient Greek, you will soon discover that the iota adscript or subscript often helps you identify the form of the word it appears in.
Gamma Clusters
When followed by a gamma γ , kappa κ , xi ξ , or chi χ , gamma γ , forms a cluster that creates the combined sound indicated by the bold letters below.
|
γγ |
diphtho ng |
δί φθο γγ ος |
|
γκ |
a nch or |
ἄ γκ υρα |
|
γξ |
lary nx , Sphi nx |
λάρυ γξ , Σφί γξ |
|
γχ |
sy nch rony |
σύ γχ ρονος |
Punctuation
Greek uses the same period and comma as English. A single mark ( · ) serves as either a colon ( : ) or a semicolon ( ; ) depending on context.
῾´Ελληνες· Σοφοκλῆς , Περικλῆς , Δημοσθένης .
Greeks: Sophokles, Perikles, Demosthenes.
ὁ δὲ λέγει· ἡ δὲ ποιέει .
He speaks; she acts.
The question mark in Greek is represented by ( ; ) and looks the same as the English semicolon ( ; ).
σὺ δὲ τίς καὶ τί βούλει ;
Who are you and what do you want?
Capitalization
Proper names and adjectives are capitalized, as are the first words of paragraphs and of quotations. The first word of a sentence is not typically capitalized. Note the capitalized words bolded in the paragraph below:
Ἡροδότου Ἁλικαρνησσέος ἱστορίης ἀπόδεξις ἥδε , ὡ ς μήτε τὰ γενόμενα ἐξ ἀνθρώπων τῷ χρόνῳ ἐξί τηλα γένηται , μήτε ἔργα μεγάλα τε καὶ θωμαστά , τὰ μὲν Ἕλλησι τ ὰ δὲ βαρβάροισι ἀποδεχθέντα , ἀκλεᾶ γένηται , τά τε ἄλλα κα ὶ δι᾽ ἣν αἰτίην ἐπολέμησαν ἀλλήλοισι .
Ἕλλησι is the Greek word for Greeks .
Who Were the Greeks?
The non-Greek Minoan civilization of Krete (Crete) flourished from c. 2200–1500 BCE and influenced the Greeks. The Iliad and the Odyssey mention Minos, legendary king of Krete (Crete), who ruled the island and those nearby with his many ships. Around 2100 BCE Greek-speaking people arrived on mainland Greece, bringing with them their customs, language, and religion. The geographic area we call ancient Greece or Hellas never became a nation state, but rather was a collection of independent city-states which were diverse, comprising many different customs and dialects. Though diverse, Greek culture shared important features, including architecture, athletics, literature, music, religion, and science. The ancient Greek love for athletics led to our establishing the modern Olympic games. Their polytheistic religion and the accompanying stories of gods and heroes, their mythology, permeated much of what they accomplished and believed. Through their music, poetry, and prose writings they made sense of the world and their place in it. The richness the Greeks created continues to influence people all over the globe.
Greek Dialects
The earliest known dialect is the Mycenaean, attested in the Linear B syllabic script deciphered by the self-taught linguist, Michael Ventris. In the Classical period, roughly 750–350 BCE, there were about twenty-three Greek dialects, including Aeolic, Attic, Doric, and Ionic. At the end of the 4th century, the koine or common dialect began to be used, spreading to Asia and Egypt and eventually replacing the dialects that preceded it. The many dialects correspond roughly with Greek geography and their diversity was caused by many factors, including conquest, lineage, migrations, and natural barriers. Another influence on dialect was literature itself. The Homeric or epic dialect is a literary dialect, comprised of elements of the Ionic, Aeolic, and Arcado-Cypriot dialects. Later writers such as Apollonios Rhodios in his Argonautica , and Nonnos in his Dionysiaca , imitate Homer’s literary dialect. Ionic was the dialect used to write elegiac poetry and poets used Doric for composing choral lyric poetry. For specifics on the Ionic-Attic dialect, see Appendix XII.
Arkhilokhos of Paros, Ἀρχίλοχος Πάρου, c. 680–645 BCE. The son of Telesikles, an aristocrat, and a slave woman, Arkhilokhos was a mercenary soldier and poet from Paros, a chief center for the worship of Demeter. In association with Demeter and Dionysos there was a tradition of iambic poetry, ἴαμβοι , a genre of poetry marked first by invective and scurrility, scatology, and sex, and second by its iambic meter. This iambic genre may have originated in the cult of Demeter, where insulting and abusive language, αἰσχρολογία , formed part of the ritual worship of the deity. In iamboi a first person narrator regales the audience with accounts of extravagant orgies or other escapades in which he claims to have taken part. Some of Arkhilokhos’ iamboi were concerned with Lykambes and his two daughters, one of whom was named Neobule. In addition to iambics, he wrote about current events and military, personal, and political concerns. It is believed that his poetry was banned at Sparta because of its seditious qualities. In 708 B.C. his fellow islanders colonized Thasos, a northern Aegean island. The Parians who colonized it were often attacked by tribes from Thrakia. At some point Arkhilochos went to Thasos and fought against the Thrakians. The Saians, mentioned in the poem below, are a Thrakian tribe.
Module 2 Practice Reading Aloud. Practice reading this poem by Arkhilokhos. Read the poem a few times, trying to hear the rhythm of the words.
ἀσπίδι μὲν Σαΐ ων τις ἀγάλλεται , ἣν παρὰ θάμνῳ
ἔντος ἀμώμητον κάλλιπον οὐκ ἐθέλων ,
αὐτὸς δ᾽ ἐξέφυγον θανάτου τέλος . ἀσπὶς ἐκείνη
ἐρρέτω· ἐξαῦτις κτήσομαι οὐ κακίω .
Verse Translation
Dropped beside a bush, my shield no more some Saion
With grasp and grin takes up. I blame myself.
Sadly leaving, fleeing gladly, I sidestepped Death.
Without a shield I live to buy anew.
To hear me read, followed by Stefan Hagel’s expert reading with a pitch accent, follow the link below:
Arkhilokhos’ Ripsaspis Poem . 1


15.10: References
American Society of Quality. (2024). Quality glossary. American Society of Quality. https://asq.org/quality-resources/quality-glossary .
El-Naggar, M. (2013, July 7). In lieu of money, Toyota donates efficiency to New York charity. New York Times. https://www.nytimes.com/2013/07/27/nyregion/in-lieu-of-money-toyota-donates-e fficiency-to-new-york-charity.html?_r=0 .
International Organization for Standardization. (2022). The ISO survey. https://www.iso.org/the-iso-survey.html .
Kerzner, H. (2003). Project management: A systems approach to planning, scheduling, and controlling (8th ed.). Wiley.
National Institute of Standards and Technology. (2023). Frequently asked questions about the Malcolm Baldrige National Quality Award. https://www.nist.gov/baldrige/how-baldrige-works/about-baldrige/baldrige-faqs .
Samsung. (2016). Samsung expands recall to all Galaxy Note 7 devices. https://pages.samsung.com/us/note7/recall/index.jsp .


9.E: Flux (Exercises)
Q1
Rewrite the stress-energy tensor of a perfect ﬂuid in SI units. For air at sea level, compare the sizes of its components.
Q2
Prove by direct computation that if a rank-\(2\) tensor is symmetric when expressed in one Minkowski frame, the symmetry is preserved under a boost.
Q3
Consider the following change of coordinates:
\[t' = -t\]
\[x' = x\]
\[y' = y\]
\[z' = z\]
This is called a time reversal. As in Example 9.2.3, find the effect on the stress-energy tensor.
Q4
Show that in Minkowski coordinates in ﬂat spacetime, all Christoffel symbols vanish.
Q5
Show that if the differential equation for geodesics is satisfied for one affine parameter \(λ\), then it is also satisfied for any other affine parameter \(λ' = aλ+b\), where \(a\) and \(b\) are constants.
Q6
This problem investigates a notational conﬂict in the description of the metric tensor using index notation. Suppose that we have two different metrics, \(g_{µν}\) and \(g'_{µν}\). The difference of two rank-\(2\) tensors is also a rank-\(2\) tensor, so we would like the quantity \(\partial g_{\mu \nu } = g'_{\mu \nu } - g_{\mu \nu }\) to be a well-behaved tensor both in its transformation properties and in its behavior when we manipulate its indices. Now we also have \(g_{µν}\) and \(g'_{µν}\), which are defined as the matrix inverses of their lower-index counterparts; this is a special property of the metric, not of rank-\(2\) tensors in general. We can then define \(\partial g^{\mu \nu } = g'^{\mu \nu } - g^{\mu \nu }\).
- Use a simple example to show that \(\partial g_{\mu \nu }\) and \(\partial g^{\mu \nu }\) cannot be computed from one another in the usual way by raising and lowering indices.
- Find the general relationship between \(\partial g_{\mu \nu }\) and \(\partial g^{\mu \nu }\).
Q7
In
section 9.5, we analyzed the Bell spaceship paradox using the expansion scalar and the Herglotz-Noether theorem. Suppose that we carry out a similar analysis, but with the congruence defined by \(x^2 - t^2 = a^{-2}\). The motivation for considering this congruence is that its world-lines have constant proper acceleration \(a\), and each such world-line has a constant value of the coordinate \(X\) in the system of accelerated coordinates (Rindler coordinates) described in section 7.1. Show that the expansion tensor vanishes. The interpretation is that it is possible to apply a carefully planned set of external forces to a straight rod so that it accelerates along its own length without any stress, i.e., while remaining Born-rigid.


1.24: Assignment- Download Files
At the end of this course, you will submit a capstone assignment that will use everything you have learned and involve creating several documents.
For this portion of the assignment, you will download the files you will use in your final assignment.
Instructions
- Create a folder on your desktop called Rowan. This is where you will save all of your assignments. To keep your computer better organized, you may want to move previous assignments into this folder.
- Download this Word template . Save the file in the Rowan folder.
- Download this Excel workbook . Save the file in the Rowan folder.
- Download this PowerPoint presentation . Save the file in the Rowan folder.
- Take a screenshot of the three files in the Rowan folder on your desktop. Save the snip as BA132_LastName_RecycleBin.png , replacing “LastName” with your own last name. (Example: BA132_Hywater_RecycleBin.png)
Contributors and Attributions
CC licensed content, Shared previously
- Capstone Assignment: Download Templates. Authored by : Lumen Learning. License : CC BY: Attribution


1.4: Preventing Foodborne Illness
Food-handling and Storage Procedures
Proper food handling and storage can prevent most foodborne illnesses. In order for pathogens to grow in food, certain conditions must be present. By controlling the environment and conditions, even if potentially harmful bacteria are present in the unprepared or raw food, they will not be able to survive, grow, and multiply, causing illness.
There are six factors that affect bacterial growth, which can be referred to by the mnemonic FATTOM :
- F ood
- A cid
- T emperature
- T ime
- O xygen
- M oisture
Each of these factors contributes to bacterial growth in the following ways:
- Food: Bacteria require food to survive. For this reason, moist, protein-rich foods are good potential sources of bacterial growth.
- Acid: Bacteria do not grow in acidic environments. This is why acidic foods like lemon juice and vinegar do not support the growth of bacteria and can be used as preservatives
- Temperature: Most bacteria will grow rapidly between 4°C and 60°C (40°F and 140°F). This is referred to as the danger zone (see the section below for more information on the danger zone).
- Time: Bacteria require time to multiply. When small numbers of bacteria are present, the risk is usually low, but extended time with the right conditions will allow the bacteria to multiply and increase the risk of contamination
- Oxygen: There are two types of bacteria. Aerobic bacteria require oxygen to grow, so will not multiply in an oxygen-free environment such as a vacuum-packaged container. Anaerobic bacteria will only grow in oxygen-free environments. Food that has been improperly processed and then stored at room temperature can be at risk from anaerobic bacteria. A common example is a product containing harmful Clostridium botulinum (botulism-causing) bacteria that has been improperly processed during canning, and then is consumed without any further cooking or reheating.
- Moisture: Bacteria need moisture to survive and will grow rapidly in moist foods. This is why dry and salted foods are at lower risk of being hazardous.
Identifying Potentially Hazardous Foods (PHFs)
Foods that have the FATTOM conditions are considered potentially hazardous foods (PHFs) . PHFs are those foods that are considered perishable. That is, they will spoil or “go bad” if left at room temperature. PHFs are foods that support the growth or survival of disease-causing bacteria (pathogens) or foods that may be contaminated by pathogens.
Generally, a food is a PHF if it is:
- Of animal origin such as meat, milk, eggs, fish, shellfish, poultry (or if it contains any of these products)
- Of plant origin (vegetables, beans, fruit, etc.) that has been heat-treated or cooked
- Any of the raw sprouts (bean, alfalfa, radish, etc.)
- Any cooked starch (rice, pasta, etc.)
- Any type of soya protein (soya milk, tofu, etc.)
Table 2 identifies common foods as either PHF or non-PHF.
| PHF | Non-PHF |
|---|---|
| Chicken, beef, pork, and other meats | Beef jerky |
| Pastries filled with meat, cheese, or cream | Bread |
| Cooked rice | Uncooked rice |
| Fried onions | Raw onions |
| Opened cans of meat, vegetables, etc. | Unopened cans of meat, vegetables, etc. (as long as they are not marked with “Keep Refrigerated”) |
| Tofu | Uncooked beans |
| Coffee creamers | Cooking oil |
| Fresh garlic in oil | Fresh garlic |
| Fresh or cooked eggs | Powdered eggs |
| Gravy | Flour |
| Dry soup mix with water added | Dry soup mix |
The Danger Zone
One of the most important factors to consider when handling food properly is temperature. Table 3 lists the most temperatures to be aware of when handling food.
| Celsius | Fahrenheit | What happens? |
|---|---|---|
| 100° | 212° | Water boils |
| 60° | 140° | Most pathogenic bacteria are destroyed. Keep hot foods above this temperature. |
| 20° | 68° | Food must be cooled from 60°C to 20°C (140°F to 68°F) within two hours or less |
| 4° | 40° | Food must be cooled from 20°C to 4°C (68°F to 40°F) within four hours or less |
| 0° | 32° | Water freezes |
| –18° | 0° | Frozen food must be stored at −18°C (0°F) or below |
The range of temperature from 40°F and 140°F is known as the danger zone , or the range at which most pathogenic bacteria will grow and multiply.
Time-temperature Control of PHFs
Pathogen growth is controlled by a time-temperature relationship. To kill micro-organisms, food must be held at a sufficient temperature for a sufficient time. Cooking is a scheduled process in which each of a series of continuous temperature combinations can be equally effective. For example, when cooking a beef roast, the microbial lethality achieved at 121 minutes after it has reached an internal temperature of 130°F is the same as if it were cooked for 3 minutes after it had reached 145°F.
Table 4 show the minimum time-temperature requirements to keep food safe. (Other time-temperature regimens might be suitable if it can be demonstrated, with scientific data, that the regimen results in a safe food.)
| Critical control point | Type of food | Temperature |
|---|---|---|
| Refrigeration | Cold food storage, all foods. | 40°F or less |
| Freezing | Frozen food storage, all foods. | 0°F or less |
| Freezing | Parasite reduction in fish intended to be served raw, such as sushi and sashimi | −4°F for 7 days or −31°F in a blast freezer for 15 hours |
| Cooking | Food mixtures containing poultry, eggs, meat, fish, or other potentially hazardous foods | Internal temperature of 165°F for at least 15 seconds |
| Cooking | Rare roast beef | Internal temperature of 130°F to 140°F |
| Cooking | Medium roast beef | Internal temperature of 140°F to 150°F |
| Cooking | Pork, lamb, veal, beef (medium-well) | Internal temperature of 150°F to 155°F |
| Cooking | Pork, lamb, veal, beef (well done) | Internal temperature of 160°F |
| Cooking | Poultry | Internal temperature of 165°F for 15 seconds |
| Cooking | Stuffing in poultry | 165°F |
| Cooking | Ground meat (Includes chopped, ground, flaked, or minced beef, pork, or fish) | 155°F |
| Cooking | Eggs [1] | 145°F for 15 seconds |
| Cooking | Fish [2] | 155°F |
| Holding | Hot foods | 140°F |
| Cooling | All foods | 140°F to 68°F within 2 hours and 68°F to 40°F within 4 hours |
| Reheating | All foods | 165°F for at least 15 seconds |
The Top 10 List: Do’s and Don’ts
This section describes each food-handling practice outlined in the top 10 list and the ways to prevent each problem.
1. Improper cooling
Many people think that once a food has been properly cooked, all disease-causing organisms (pathogens) have been killed. This is not true. Some pathogens can form heat-resistant spores, which can survive cooking temperatures. When the food begins cooling down and enters the danger zone, these spores begin to grow and multiply. If the food spends too much time in the danger zone, the pathogens will increase in number to a point where the food will make people sick. That is why the cooling process is crucial. Cooked food must be cooled from 140°F to 70°F in two hours or less, AND then from 70°F to 40°F in four hours or less.
You can cool down foods quickly by using one or more of the following methods depending on the type of food being cooled:
- Place the food in the shallow pans (with the doos no deeper than 2 inches) and put the pans in the cooler.
- When the food is cooling, do not tightly cover. Doing so only seals in the heat.
- Do not stack the shallow cooling pans during the cooling step. This will defeat the purpose of shallow panning by preventing cold air from reaching the food. You may need to add more shelves to your cooler.
- Cut large cuts of meat or whole poultry into smaller or thinner portions. Then place these portions into shallow pans for cooling.
- Use cooling wands or cooling sticks to cool foods quickly.
- Use rapid cooling equipment such as walk-in coolers with wire shelving and good air flow. Home-style refrigerators or reach-ins do not cool food well.
- Stir the food in a container placed in an ice-water bath.
- Use containers that help heat transfer, such as stainless steel or aluminum. Plastic does not transfer heat well.
- Use ice as an ingredient (e.g., in stews or soups).
- For large pots of cooked desserts (e.g., custard), divide it into serving sizes and then cool.
2. Advance preparation
Advance preparation is the cause of many food-poisoning outbreaks, usually because food has been improperly cooled. Often, foods that are prepared well before serving spend too much time in the danger zone. This may happen for one or more of the following reasons:
- The food is left out at room temperature too long.
- The food is not heated or reheated properly (to a high enough temperature), or not cooled properly.
- The food is brought in and out of the danger zone too many times (e.g., cooked, hot held, cooled, reheated, hot held, cooled, reheated again).
To prevent problems of advance preparation:
- Try to prepare all foods for same-day use and as close to serving time as possible.
- To prevent outside contamination of foods prepared in advance, cover them tightly after they have been properly cooled.
- Reheat leftovers only once. If leftovers are not consumed after being reheated, throw them out.
- For foods prepared and held refrigerated in the cooler for more than 24 hours, mark the date of preparation and a “serve by” date. Generally, PHFs should be thrown out if not used within three days from date they were made.
- If you must prepare foods in advance, be sure you properly cool and refrigerate them.
3. Infected person
Many people carry pathogens somewhere on or in their bodies without knowing it—in their gut, in their nose, on their hands, in their mouth, and in other warm, moist places. People who are carrying pathogens often have no outward signs of illness. However, people with symptoms of illness (diarrhea, fever, vomiting, jaundice, sore throat with a fever, hand infections, etc.) are much more likely to spread pathogens to food.
Another problem is that pathogens can be present in the cooked and cooled food that, if given enough time, can still grow. These pathogens multiply slowly but they can eventually reach numbers where they can make people sick. This means that foods that are prepared improperly, many days before serving, yet stored properly the entire time can make people sick.
Some pathogens are more dangerous than others (e.g., salmonella, E. coli, campylobacter). Even if they are only present in low numbers, they can make people very sick. A food handler who is carrying these kinds of pathogens can easily spread them to foods – usually from their hands. Ready-to-eat food is extra dangerous. Ready-to-eat food gets no further cooking after being prepared, so any pathogens will not be killed or controlled by cooking.
To prevent problems:
- Make sure all food handlers wash their hands properly after any job that could dirty their hands (e.g., using the toilet, eating, handling raw meats, blowing their nose, smoking).
- Food handlers with infected cuts on their hands or arms (including sores, burns, lesions, etc.) must not handle food or utensils unless the cuts are properly covered (e.g., waterproof bandage covered with a latex glove or finger cot).
- When using gloves or finger cots , food handlers must still wash their hands. As well, gloves or cots must be replaced if they are soiled, have a hole, and at the end of each day.
- Food handlers with infection symptoms must not handle utensils or food and should be sent home.
- Where possible, avoid direct hand contact with food – especially ready-to-eat foods (e.g., use plastic utensils plastic or latex gloves).
4. Inadequate reheating for hot holding
Many restaurants prepare some of menu items in advance or use leftovers in their hot hold units the next day. In both cases, the foods travel through the danger zone when they are cooled for storage and again when they are reheated.
Foods that are hot held before serving are particularly vulnerable to pathogens. In addition to travelling through the danger zone twice, even in properly operating hot hold units, the food is close to the temperature that will allow pathogens to grow.
To prevent problems:
- Do not use hot hold units to reheat food. They are not designed for this purpose. Instead, rapidly reheat to 165°F (and hold the food at that temperature for at least 15 seconds before putting it in the hot hold unit. This will kill any pathogens that may have grown during the cool-down step and the reheat step.
- If using direct heat (stove top, oven, etc.), the temperature of the reheated food must reach at least 165°F for at least 15 seconds within two hours. Keep a thermometer handy to check the temperature of the food.
- If using a microwave, rotate or stir the food at least once during the reheat step, as microwaves heat unevenly. As well, the food must be heated to at least 165°F and then stand covered for two minutes after reheating before adding to the hot hold unit. The snapping and crackling sounds coming from food being reheated in a microwave do not mean the food is hot.
5. Improper hot holding
Hot hold units are meant to keep hot foods at 140°F or hotter. At or above this temperature, pathogens will not grow. However, a mistake in using the hot hold unit can result in foods being held in the super danger zone – between 70°F and 120°F, temperatures at which pathogens grow very quickly.
To prevent problems:
- Make sure the hot hold unit is working properly (e.g., heating elements are not burnt out; water is not too low in steam tables; the thermostat is properly set so food remains at 140°F or hotter. Check it daily with a thermometer.
- Put only already hot 165°F foods into the hot hold unit.
- Preheat the hot hold unit to at least 140°F before you start putting hot foods into it.
- Do not use the hot hold unit to reheat cold foods. It is not designed for or capable of doing this rapidly.
- After the lunch or dinner rush, do not turn off the heat in the hot hold unit and then leave the food there to cool. This is very dangerous. When you do this, the food does not cool down. It stays hot in the super danger zone and lets pathogens grow quickly. Foods in hot hold units should be taken out of the units after the meal time is over and cooled right away.
6. Contaminated raw food or ingredient
We know that many raw foods often contain pathogens, yet certain foods are often served raw. While some people believe these foods served raw are “good for you,” the truth is that they have always been dangerous to serve or eat raw. Some examples include:
- Raw oysters served in the shell
- Raw eggs in certain recipes (e.g., Caesar salad, eggnog made from raw eggs)
- Rare hamburger
- Sushi/sashimi
- Steak tartare
These foods have caused many food-poisoning outbreaks. Always remember: you cannot tell if a food contains pathogens just by look, taste, or smell.
To prevent problems:
- Buy all your foods or ingredients from approved suppliers.
- If available, buy foods or ingredients from suppliers who also have food safety plans for their operations.
- Where possible, use processed or pasteurized alternatives (e.g., pasteurized liquid eggs).
- Never serve these types of foods to high-risk customers (e.g., seniors, young children, people in poor health, people in hospitals or nursing homes).
7. Unsafe source
Foods from approved sources are less likely to contain high levels of pathogens or other forms of contamination. Approved sources are those suppliers that are inspected for cleanliness and safety by a government food inspector. Foods supplied from unreliable or disreputable sources, while being cheaper, may contain high levels of pathogens that can cause many food-poisoning outbreaks.
Fly-by-night suppliers (trunk sales) often do not care if the product is safe to sell to you, but approved suppliers do! As well, many fly-by-night suppliers have obtained their product illegally (e.g., closed shellfish fisheries, rustled cattle, poached game and fish) and often do not have the equipment to properly process, handle, store, and transport the food safely.
Of particular concern is seafood from unapproved sources. Seafood, especially shellfish, from unapproved sources can be heavily contaminated with pathogens or poisons if they have been harvested from closed areas.
To prevent problems:
- Buy your food and ingredients from approved sources only. If you are not sure a supplier has been approved, contact your local environmental health officer. He or she can find out for you.
- Do not take the chance of causing a food-poisoning outbreak by trying to save a few dollars. Remember, your reputation is on the line.
8. Use of leftovers
Using leftovers has been the cause of many outbreaks of food poisoning because of improper cooling and reheating (of “hot” leftovers). Leftovers that are intended to be served hot pass through the danger zone twice (during the initial cooling of the hot food and when reheating). Those leftovers intended to be served without reheating, or as an ingredient in other foods (e.g., sandwich filler), go through the danger zone during cooling and then, when being prepared and portioned, often stay in the danger zone for another long period. The time in the danger zone adds up unless the food is quickly cooled and then quickly reheated (if being served hot), or kept cold until serving (if not being served hot).
Contamination can also occur with leftover foods when they are stored in the cooler. Improperly stored leftovers can accidentally be contaminated by raw foods (e.g., blood dripping from a higher shelf).
To prevent problems:
- Reheat leftovers only once. Throw out any leftovers that have already been reheated once.
- Do not mix leftover foods with fresh foods.
- Be sure to follow the proper cooling and reheating procedures when handling leftovers. These are critical control points.
- Cool leftovers in uncovered containers separate from any raw foods. After they are cooled, cover them tightly.
9. Cross-contamination
You can expect certain foods to contain pathogens, especially raw meat, raw poultry, and raw seafood. Use extreme caution when you bring these foods into your kitchen. Cross-contamination happens when something that can cause illness (pathogens or chemicals) is accidentally put into a food where not previously found. This can include, for example, pathogens from raw meats getting into ready-to-eat foods like deli meats. It can also include nuts (which some people are very allergic to) getting into a food that does not normally have nuts (e.g., tomato sauce).
To prevent problems:
- Use separate cutting boards, separate cleaning cloths, knives/utensils, sinks, preparation areas, etc., for raw and for ready-to-eat foods. Otherwise, wash all of these items with detergent and sanitize them with bleach between use.
- Use separate storage areas for raw and ready-to-eat foods. Always store ready-to-eat foods on separate shelves and above raw foods. Store dry foods above wet foods.
- Prepare ready-to-eat foods at the beginning of the day before the raw foods are prepared.
- After handling raw foods, always wash your hands properly before doing anything else.
- Keep wiping or cleaning cloths in a container of fresh bleach solution (30 mL/1 oz. of bleach per 4 L/1 gal. of water) when not in use.
- Use clean utensils, not your hands, to handle cooked or ready-to-eat foods.
- If a customer indicates a food allergy, follow all the same steps to avoid cross contamination and use separate or freshly sanitized tools and utensils to prepare food for the individual with the allergy.
10. Inadequate cooking
Proper cooking is one of the best means of making sure your operation does not cause a food-poisoning outbreak. Proper cooking kills all pathogens (except spores) or at least reduces their numbers to a point where they cannot make people sick. Inadequate cooking is often done by accident: for example, cooking still-frozen poultry or meat; attempting to cook a stuffed bird using the same time and temperature as an unstuffed bird; using an inexperienced cook.
To prevent problems:
- Don’t rely on cooking times alone. Check the internal temperature of the food being cooked.
- For large cuts of meat or large batches of food, check the temperature in several spots.
- Be extra careful when cooking partially frozen foods. There can be cold spots in the food that are not properly cooked. The normal cooking time will have to be increased.
- When grilling or frying meat, cook until the juices run clear. Cooked fish until it flakes easily. Make thin, not thick, hamburgers.
- Customers requiring a runny yolk egg should be aware that pathogens are not destroyed until yolk has completely coagulated.
- Customers wishing raw marinated fish and raw shellfish, such as oysters, should be aware that they should be cooked to ensure safety.


2.3: Types of Service Retailers
- Name an assortment of service retailer types
To some degree, customer service is fundamental to all retail because it supports customer loyalty and contributes to the customer’s overall retail experience. However, retailers must decide what level of service they will provide for their customers:
- No service , such as Amazon Go concept stores that do not have associates or check lanes
- Self-service , such as most grocery shopping experiences where the product is available on-shelf for the shopper’s selection. This goes a step further when shoppers use the self-checkout and scan the items, process the transaction, and bag the product themselves.
- Full-service
The variety of supporting services, known as the service type, range from self-service operators that provide few basic services to full-service operators with a wide range of highly personalized services.
Full-service retailers compete by providing support to consumers at every touch-point in the shopping process. This isn’t just confined to the realm of personal interaction, but includes service types that can make the shopping process easier:
- Accepting multiple forms of payments, such as cash, check, or credit card
- Offering delivery services
- Making recommendations or providing demonstrations, such as offering recipes, cooking classes, or product samples
- Allowing exchanges or returns
- Allowing special orders
- Providing customer loyalty programs
However, it should be noted that services often come at some cost to the retailer, primarily in the form of increased labor. Thus, retailers must balance the desire to offer several services against customers’ willingness to pay for the additional supporting services. Full-service typically requires premium pricing. Thus, it’s extremely important that full-service retailers train their personnel well to provide excellent customer service enough to make their customer service a meaningful differentiator against competitors. By providing excellent customer service, retailers create opportunities to build customer relationships with the potential to increase loyalty and referrals.
There are several ways that food retailers deliver services to consumers. They can have counter service, where goods are out of reach of buyers and must be obtained from the seller. This type of retail is common for small expensive items, such as jewelry, and controlled items, like medicine and liquor. In food retail, counter service typically takes the form of the deli counter or meat department, where an associate will make recommendations, portion items, and package them for the shopper.
Another method is special orders, which can be online, in-person, or by phone. Many food retailers offer this service in their bakery departments, where cakes can be special ordered. The meat and floral departments may offer similar services.
Some retailers offer in-store pick (ship to store) or delivery to the consumer’s home (home delivery). Wal-Mart is experimenting with similar services for in-store pick-up or home delivery of online grocery orders. Several other retailers are doing the same through InstaCart.
There is also self-service, where goods may be handled and examined prior to purchase. In food retailing, this is much more common with sampling or product demonstrations. For example, warehouse club stores often offer sample items to overcome the large ticket price and quantities of their items.
Contributors and Attributions
- Types of Service Retailers. Authored by : Patrick Williams. Provided by : Lumen Learning. License : CC BY: Attribution


1.2: Integrated Development Environment
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Overview
An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of a source code editor, build automation tools, and a debugger. Most modern IDEs have intelligent code completion. Some IDEs contain a compiler, interpreter, or both. The boundary between an integrated development environment and other parts of the broader software development environment is not well-defined. Sometimes a version control system, or various tools to simplify the construction of a graphical user interface (GUI), are integrated. Many modern IDEs also have a class browser, an object browser, and a class hierarchy diagram, for use in object-oriented software development. [1]
Discussion
High-level language programs are usually written (coded) as ASCII text into a source code file. A unique file extension (Examples: .asm .c .cpp .java .js .py) is used to identify it as a source code file. As you might guess for our examples – Assembly, “C”, “C++”, Java, JavaScript, and Python, however, they are just ASCII text files (other text files usually use the extension of .txt). The source code produced by the programmer must be converted to an executable machine code file specifically for the computer’s CPU (usually an Intel or Intel-compatible CPU within today’s world of computers). There are several steps in getting a program from its source code stage to running the program on your computer. Historically, we had to use several software programs (a text editor, a compiler, a linker, and operating system commands) to make the conversion and run our program. However, today all those software programs with their associated tasks have been integrated into one program. However, this one program is really many software items that create an environment used by programmers to develop software. Thus the name: Integrated Development Environment or IDE.
Programs written in a high-level language are either directly executed by some kind of interpreter or converted into machine code by a compiler (and assembler and linker) for the CPU to execute. JavaScript, Perl, Python, and Ruby are examples of interpreted programming languages. C, C++, C#, Java, and Swift are examples of compiled programming languages. [2] The following figure shows the progression of activity in an IDE as a programmer enters the source code and then directs the IDE to compile and run the program.
Upon starting the IDE software the programmer usually indicates the file he or she wants to open for editing as source code. As they make changes they might either do a “save as” or “save”. When they have finished entering the source code, they usually direct the IDE to “compile & run” the program. The IDE does the following steps:
- If there are any unsaved changes to the source code file it has the test editor save the changes.
- The compiler opens the source code file and does its first step which is executing the pre-processor compiler directives and other steps needed to get the file ready for the second step. The #include will insert header files into the code at this point. If it encounters an error, it stops the process and returns the user to the source code file within the text editor with an error message. If no problems encountered it saves the source code to a temporary file called a translation unit.
- The compiler opens the translation unit file and does its second step which is converting the programming language code to machine instructions for the CPU, a data area, and a list of items to be resolved by the linker. Any problems encountered (usually a syntax or violation of the programming language rules) stops the process and returns the user to the source code file within the text editor with an error message. If no problems encountered it saves the machine instructions, data area, and linker resolution list as an object file.
- The linker opens the program object file and links it with the library object files as needed. Unless all linker items are resolved, the process stops and returns the user to the source code file within the text editor with an error message. If no problems encountered it saves the linked objects as an executable file.
- The IDE directs the operating system’s program called the loader to load the executable file into the computer’s memory and have the Central Processing Unit (CPU) start processing the instructions. As the user interacts with the program, entering test data, he or she might discover that the outputs are not correct. These types of errors are called logic errors and would require the user to return to the source code to change the algorithm.
Resolving Errors
Despite our best efforts at becoming perfect programmers, we will create errors. Solving these errors is known as debugging your program. The three types of errors in the order that they occur are:
- Compiler
- Linker
- Logic
There are two types of compiler errors; pre-processor (1st step) and conversion (2nd step). A review of Figure 1 above shows the four arrows returning to the source code so that the programmer can correct the mistake.
During the conversion (2nd step) the compiler might give a warning message which in some cases may not be a problem to worry about. For example: Data type demotion may be exactly what you want your program to do, but most compilers give a warning message. Warnings don’t stop the compiling process but as their name implies, they should be reviewed.
The next three figures show IDE monitor interaction for the Bloodshed Dev-C++ 5 compiler/IDE .
Key Terms
- compiler
- Converts source code to object code.
- debugging
- The process of removing errors from a program. 1) compiler 2) linker 3) logic
- linker
- Connects or links object files into an executable file.
- loader
- Part of the operating system that loads executable files into memory and directs the CPU to start running the program.
- pre-processor
- The first step the compiler does in converting source code to object code.
- text editor
- A software program for creating and editing ASCII text files.
- warning
- A compiler alert that there might be a problem.


18.8C: Bulk Flow: Filtration and Reabsorption
Capillary fluid movement occurs as a result of diffusion (colloid osmotic pressure), transcytosis, and filtration.
- Explain the process of filtration and reabsorption in capillaries
Key Points
- Bulk flow is a process used by small lipid-insoluble proteins to cross the capillary wall.
- Capillary structure plays a large role in the rate of bulk flow, with continuous capillaries limiting flow and discontinuous capillaries facilitating the greatest amount of flow.
- When moving from the blood to the interstitium, bulk flow is termed filtration.
- When moving from the interstitium to the blood, bulk flow is termed re-absorption.
- The kidney is a major site of bulk flow where waste products are filtered from the blood.
Key Terms
- filtration : In bulk flow, this refers to the movement of proteins or other large molecules from the blood into the interstitium.
- reabsorption : In bulk flow, this refers to the movement of proteins or other large molecules from the interstitium into the blood.
Bulk flow is one of three mechanisms that facilitate capillary exchange, along with diffusion and transcytosis.
Bulk Flow Process
Bulk flow is used by small, lipid-insoluble solutes in water to cross the the capillary wall and is dependent on the physical characteristics of the capillary. Continuous capillaries have a tight structure reducing bulk flow. Fenestrated capillaries permit a larger amount of flow and discontinuous capillaries allow the largest amount of flow.
The movement of materials across the capillary wall is dependent on pressure and is bidirectional depending on the net filtration pressure derived from the four Starling forces.
When moving from the bloodstream into the interstitium, bulk flow is termed filtration, which is favored by blood hydrostatic pressure and interstitial fluid oncotic pressure. When moving from the interstitium into the bloodstream, the process is termed reabsorption and is favored by blood oncotic pressure and interstitial fluid hydrostatic pressure.
Modern evidence shows that in most cases, venular blood pressure exceeds the opposing pressure, thus maintaining a positive outward force. This indicates that capillaries are normally in a state of filtration along their entire length.
The Kidneys and Bulk Flow
The kidney is a major site for bulk flow transport. Blood that enters the kidneys is filtered by nephrons, the functional unit of the kidney. Each nephron begins in a renal corpuscle composed of a glomerulus containing numerous capillaries enclosed in a Bowman’s capsule. Proteins and other large molecules are filtered out of the oxygenated blood in the glomerulus and pass into Bowman’s capsule and the tubular fluid contained within. Blood continues to flow around the nephron until it reaches another capillary-rich region the peritubular capillaries, where the previously filtered molecules are reabsorbed from the tubule of the nephron.
Tubular reabsorption is the process by which solutes and water are removed from the tubular fluid and transported into the blood. Reabsorption is a two-step process beginning with the active or passive extraction of substances from the tubule fluid into the renal interstitium, and then the transport of these substances from the interstitium into the bloodstream
Tubular Secretion : Diagram showing the basic physiologic mechanisms of the kidney and the three steps involved in urine formation.
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- Starling equation. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Starling_equation . License : CC BY-SA: Attribution-ShareAlike
- Colloid osmotic pressure. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Colloid_osmotic_pressure . License : CC BY-SA: Attribution-ShareAlike
- Microcirculation. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Microcirculation . License : CC BY-SA: Attribution-ShareAlike
- Starling equation. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Starling_equation . License : CC BY-SA: Attribution-ShareAlike
- OpenStax College, Capillary Exchange. January 16, 2014. Provided by : OpenStax CNX. Located at : http://cnx.org/contents/797b2238-a9ed-4012-b9af-ce0a25172732@3 . License : CC BY: Attribution
- Hydrostatic pressure. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Hydrostatic_pressure%23Hydrostatic_pressure . License : CC BY-SA: Attribution-ShareAlike
- endothelium. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/endothelium . License : CC BY-SA: Attribution-ShareAlike
- proteinuria. Provided by : Wiktionary. Located at : en.wiktionary.org/wiki/proteinuria . License : CC BY-SA: Attribution-ShareAlike
- oncotic pressure. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/oncotic%20pressure . License : CC BY-SA: Attribution-ShareAlike
- Capillary Microcirculation. Provided by : Wikimedia. Located at : upload.wikimedia.org/wikipedi...irculation.jpg . License : Public Domain: No Known Copyright
- Transcytosis. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Transcytosis . License : CC BY-SA: Attribution-ShareAlike
- Transcytosis. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Transcytosis . License : CC BY-SA: Attribution-ShareAlike
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- Capillary Microcirculation. Provided by : Wikimedia. Located at : upload.wikimedia.org/Wikipedia/commons/0/03/Illu_capillary_microcirculation.jpg . License : Public Domain: No Known Copyright
- Renal physiology. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Renal_p...y%23Mechanisms . License : CC BY-SA: Attribution-ShareAlike
- Starling equation. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/Starling_equation . License : CC BY-SA: Attribution-ShareAlike
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- active transport. Provided by : Wikipedia. Located at : en.Wikipedia.org/wiki/active%20transport . License : CC BY-SA: Attribution-ShareAlike
- Capillary Microcirculation. Provided by : Wikimedia. Located at : upload.wikimedia.org/Wikipedia/commons/0/03/Illu_capillary_microcirculation.jpg . License : Public Domain: No Known Copyright
- Urinary Excretion. Provided by : Wikimedia. Located at : upload.wikimedia.org/wikipedi...of_Nephron.png . License : CC BY-SA: Attribution-ShareAlike


27.7B: Stages of Labor
Vaginal delivery childbirth has three distinct phases: dilation of the cervix, delivery of the infant, and delivery of the placenta.
- Differentiate among the stages of labor
Key Points
- The first stage of labor begins when the effaced (thinned) cervix is 3 cm dilated. During effacement, the cervix is pulled upward during contractions. Full dilation occurs when the cervix is wide enough to allow passage of the baby’s head, about 10 cm for a full-term infant.
- The duration of labor varies widely, but the active phase averages some 20 hours for women giving birth to their first child (primiparae) and 8 hours for women who have previously given birth (multiparae).
- The second stage begins when the cervix is fully dilated, ending when the baby is born. Fetal movement through the birth canal is assisted by the additional maternal efforts of bearing down or pushing. The fetal head is seen to crown as the labia part, and the baby is born.
- The period from just after the fetus is expelled until just after the placenta is expelled is called the third stage of labor, which lasts, on average, 10–12 minutes.
- A fourth stage of labor may refer to the hour immediately after delivery of the placenta, or may refer to the weeks following delivery. It is the time in which the mother’s body returns to a nonpregnant state.
Key Terms
- multiparae : Women who have given birth to more than one viable fetus.
- Ferguson reflex : An example of positive feedback and the female body’s response to pressure application in the cervix or vaginal walls. Upon application of pressure, oxytocin is released and uterine contractions are stimulated (which will in turn increase oxytocin production, and hence, increase contractions even more), until the baby is delivered.
- primiparae : Women who have given birth to only one child, or who are giving birth for the first time.
The infant’s head and shoulders must go through a specific sequence of maneuvers in order to pass through the ring of the mother’s pelvis. The six phases of a typical vertex (head-first presentation) delivery are:
- Engagement of the fetal head in the transverse position.
- Descent and flexion of the fetal head.
- Internal rotation of the fetal head so that the baby’s face is towards the mother’s rectum.
- Delivery by extension (the fetal head passes out of the birth canal).
- Restitution: The fetal head turns through 45 degrees to restore its normal relationship with the shoulders, which are still at an angle.
- External rotation: The shoulders repeat the corkscrew movements of the head, which can be seen in the final movements of the fetal head.
The Bishop score defines several factors that midwives and physicians use to assess the laboring mother’s progress.
The score is used to predict whether the mother is likely to spontaneously progress into the second stage of labor and whether induction of labor will be required. It has also been used to assess the odds of spontaneous preterm delivery.
Stages of Labor
First Stage (Active Phase)
The first stage of labor classically starts when the effaced (thinned) cervix is 3 cm dilated, although there is variation as some women may or may not have active contractions prior to reaching this point. The onset of actual labor is defined when the cervix begins to progressively dilate. Rupture of the membranes or a bloody discharge may or may not occur at or around this stage.
Tterine muscles form opposing spirals from the top of the upper segment of the uterus to its junction with the lower segment. During effacement, the cervix becomes incorporated into the lower segment of the uterus. During a contraction, these muscles shorten the upper segment, drawing upwards the lower segment in a gradual expulsive motion.
The presenting fetal part is then permitted to descend. Full dilation is reached when the cervix has widened enough to allow passage of the baby’s head, around 10 cm dilation for a term baby. The duration of labor varies widely, but the active phase averages some 20 hours for women giving birth to their first child (primiparae), and 8 hours for women who have already given birth (multiparae).
Active phase arrest is defined, in a primigravid woman, as the failure of the cervix to dilate at a rate of 1.2 cm/hr over a period of at least two hours. This definition is based on Friedman’s Curve, which plots the typical rate of cervical dilation and fetal descent during active labor. Some practitioners may diagnose failure to progress, and consequently, perform a caesarean.
Second Stage (Fetal Expulsion)
The second stage begins when the cervix is fully dilated and ends when the baby is born. As pressure on the cervix increases, the Ferguson reflex increases uterine contractions.
At the beginning of the normal second stage, the head is fully engaged in the pelvis: the widest diameter of the head has passed below the level of the pelvic inlet. The fetal head then continues descending into the pelvis, below the pubic arch, and out through the vagina.
This is assisted by the additional maternal efforts of bearing down or pushing. The fetal head is seen to crown as the labia part. At this point, the woman may feel a burning or stinging sensation. The complete expulsion of the baby signals the successful completion of the second stage of labor.
The second stage of birth will vary by factors including parity, fetal size, anesthesia, or the presence of infection. Longer labors are associated with declining rates of spontaneous vaginal delivery and increasing rates of infection, perineal laceration, obstetric hemorrhage, as well as need for intensive care of the neonate.
Third Stage (Placental Delivery)
The third stage of labor is the period from just after the fetus is expelled until just after the placenta is expelled. The average time from delivery of the baby until complete expulsion of the placenta is estimated to be 10–12 minutes.
Placental expulsion can be managed actively, by giving a uterotonic, such as oxytocin, along with appropriate cord traction and fundal massage to assist in delivering the placenta by a skilled birth attendant. Alternatively, it can be managed expectantly, allowing the placenta to be expelled without medical assistance. The umbilical cord is routinely clamped and cut in this stage, but it would normally close naturally even if not clamped and cut.
When the amniotic sac has not ruptured during labour or pushing, the infant can be born with the membranes intact. This is referred to as being born in the caul. The caul is harmless and its membranes are easily broken and wiped away. With the advent of modern interventive obstetrics, the artificial rupture of the membranes has become common, so babies are rarely born in the caul (en-caul birth).
Fourth Stage (Postpartum Period)
The fourth stage of labor is a term used in two different senses:
- It can refer to the immediate puerperium, or the hours immediately after delivery of the placenta.
- It can be used in a more metaphorical sense to describe the weeks following delivery.
Birth. : A sequence of images showing the stages of ordinary childbirth.


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2: Symbiogenesis and the Plant Cell
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2.1: Introduction to Cells
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In 1838, Schleidern and Schwann stated that (1) all plants and animals are composed of cells and that (2) cell is the most basic unit (“atom”) of life. In 1858, Virchow stated that (3) all cells arise by reproduction from previous cells (“Omnis cellula e cellula” in Latin). These three statements became the base of the cell theory. Discovery of cells is tightly connected with the development of microscopy.
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2.2: Mitochondria and Chloroplasts
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To escape from competition, cells which were prokaryotic became larger. To facilitate communication between all parts of this larger cell, they developed cytoplasm mobility using actin protein. In turn, this mobility resulted in acquiring phagocytosis, which is when a large cell changes shape and can engulf (“eat”) other cells. This way, cells that used to be prey became predators. These predators captured prey by phagocytosis and digested bacteria in lysosomes, which use enzymes that destroy th
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2.3: Cell wall, Vacuoles, and Plasmodesmata
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Plant cells do not have well-developed internal cytoskeleton, but cell wall provides an external one. There are two kinds (or, better, two stages of development) of cell walls, the primary and the secondary. The primary cell wall is typically flexible, frequently thin and is made of cellulose, different carbohydrates and proteins. The secondary cell wall contains also lignin and highly hydrophobic suberin. These chemicals completely block the exchange between the cell and the environment.
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2.4: Other Parts of the Cell
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The central dogma of molecular biology states that DNA will be converted into RNA by a process called transcription and RNA will be converted to protein by a process called translation. Translation in non-reversible whereas transcription could be reverted: there are viruses, such as HIV, that can make DNA from RNA with the enzyme called reverse transcriptase. The nuclear envelope is built from a double-layered membrane.


2.3E: Water’s Solvent Properties
Water’s polarity makes it an excellent solvent for other polar molecules and ions.
- Explain why some molecules do not dissolve in water.
Key Points
- Water dissociates salts by separating the cations and anions and forming new interactions between the water and ions.
- Water dissolves many biomolecules, because they are polar and therefore hydrophilic.
Key Terms
- dissociation : The process by which a compound or complex body breaks up into simpler constituents such as atoms or ions, usually reversibly.
- hydration shell : The term given to a solvation shell (a structure composed of a chemical that acts as a solvent and surrounds a solute species) with a water solvent; also referred to as a hydration sphere.
EXAMPLES
- Sugar, sodium chloride, and hydrophilic proteins are all substances that dissolve in water.
- Oils, fats, and certain organic solvents do not dissolve in water because they are hydrophobic.
Water, which not only dissolves many compounds but also dissolves more substances than any other liquid, is considered the universal solvent. A polar molecule with partially-positive and negative charges, it readily dissolves ions and polar molecules. Water is therefore referred to as a solvent: a substance capable of dissolving other polar molecules and ionic compounds. The charges associated with these molecules form hydrogen bonds with water, surrounding the particle with water molecules. This is referred to as a sphere of hydration, or a hydration shell, and serves to keep the particles separated or dispersed in the water.
When ionic compounds are added to water, individual ions interact with the polar regions of the water molecules during the dissociation process, disrupting their ionic bonds. Dissociation occurs when atoms or groups of atoms break off from molecules and form ions. Consider table salt (NaCl, or sodium chloride): when NaCl crystals are added to water, the molecules of NaCl dissociate into Na + and Cl – ions, and spheres of hydration form around the ions. The positively-charged sodium ion is surrounded by the partially-negative charge of the water molecule’s oxygen; the negatively-charged chloride ion is surrounded by the partially-positive charge of the hydrogen in the water molecule.
Dissociation of NaCl in water : When table salt (NaCl) is mixed in water, spheres of hydration form around the ions.
Since many biomolecules are either polar or charged, water readily dissolves these hydrophilic compounds. Water is a poor solvent, however, for hydrophobic molecules such as lipids. Nonpolar molecules experience hydrophobic interactions in water: the water changes its hydrogen bonding patterns around the hydrophobic molecules to produce a cage-like structure called a clathrate. This change in the hydrogen-bonding pattern of the water solvent causes the system’s overall entropy to greatly decrease, as the molecules become more ordered than in liquid water. Thermodynamically, such a large decrease in entropy is not spontaneous, and the hydrophobic molecule will not dissolve.
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4.5: Choose a daily task management system
Some students prefer paper-based task management systems, while others prefer to use technology to manage daily tasks. Consider the following advantages and disadvantages of systems you might choose.
Choose a Daily Task Management System
| System | Advantages | Disadvantages |
|---|---|---|
| Paper planner |
• User is not required to learn new technology
• Eliminates possible distraction with apps • Flexible and adaptable to user preferences |
• Difficult to share tasks with team members in group projects
• May require time to create effective calendar and task list layouts |
| Online calendar (e.g. Outlook Calendar, Google Calendar) |
• Tasks and other life commitments are integrated in a single view
• Information is easily viewable on multiple devices • Easy to schedule meetings with team members or share events |
• May be difficult to integrate smaller tasks into the work plan
• May be difficult to move incomplete tasks to a new time slot on a later date |
| Time management app (e.g. Wunderlist, Remember the Milk, Microsoft To-Do) |
• Information can viewed on multiple devices
• Most apps allow project lists to be shared between team members • Easy to integrate small tasks into the daily task list • Easy to mark task completion • Incomplete tasks can be rescheduled simply |
• May require time to learn the platform
• Apps may become obsolete • Some apps require payment |
Reflection and Action
Consider what kind of task management system will help you most in your current study program:
- What kind of time management system do you prefer? Paper or technology-based?
- Do you plan to keep your current time management system, or make some changes to support your online learning? If you are trying a new system, when will you evaluate how effective it is for you?
- When will you organize your daily tasks? Will you set aside a longer block of time on a weekly basis for planning, or set aside a few moments for planning at the beginning or end of each day?
Click here to download a printable worksheet for your reflections.


10.3: Skeletal Muscle
By the end of this section, you will be able to:
- Describe the layers of connective tissues packaging skeletal muscle
- Explain how muscles work with tendons to move the body
- Identify areas of the skeletal muscle fibers
- Describe excitation-contraction coupling
The best-known feature of skeletal muscle is its ability to contract and cause movement. Skeletal muscles act not only to produce movement but also to stop movement, such as resisting gravity to maintain posture. Small, constant adjustments of the skeletal muscles are needed to hold a body upright or balanced in any position. Muscles also prevent excess movement of the bones and joints, maintaining skeletal stability and preventing skeletal structure damage or deformation. Joints can become misaligned or dislocated entirely by pulling on the associated bones; muscles work to keep joints stable. Skeletal muscles are located throughout the body at the openings of internal tracts to control the movement of various substances. These muscles allow functions, such as swallowing, urination, and defecation, to be under voluntary control. Skeletal muscles also protect internal organs (particularly abdominal and pelvic organs) by acting as an external barrier or shield to external trauma and by supporting the weight of the organs.
Skeletal muscles contribute to the maintenance of homeostasis in the body by generating heat. Muscle contraction requires energy, and when ATP is broken down, heat is produced. This heat is very noticeable during exercise, when sustained muscle movement causes body temperature to rise, and in cases of extreme cold, when shivering produces random skeletal muscle contractions to generate heat.
Each skeletal muscle is an organ that consists of various integrated tissues. These tissues include the skeletal muscle fibers, blood vessels, nerve fibers, and connective tissue. Each skeletal muscle has three layers of connective tissue (called “mysia”) that enclose it and provide structure to the muscle as a whole, and also compartmentalize the muscle fibers within the muscle (Figure \(\PageIndex{1}\) ). Each muscle is wrapped in a sheath of dense, irregular connective tissue called the epimysium , which allows a muscle to contract and move powerfully while maintaining its structural integrity. The epimysium also separates muscle from other tissues and organs in the area, allowing the muscle to move independently.
Inside each skeletal muscle, muscle fibers are organized into individual bundles, each called a fascicle , by a middle layer of connective tissue called the perimysium . This fascicular organization is common in muscles of the limbs; it allows the nervous system to trigger a specific movement of a muscle by activating a subset of muscle fibers within a bundle, or fascicle of the muscle. Inside each fascicle, each muscle fiber is encased in a thin connective tissue layer of collagen and reticular fibers called the endomysium . The endomysium contains the extracellular fluid and nutrients to support the muscle fiber. These nutrients are supplied via blood to the muscle tissue.
In skeletal muscles that work with tendons to pull on bones, the collagen in the three tissue layers (the mysia) intertwines with the collagen of a tendon. At the other end of the tendon, it fuses with the periosteum coating the bone. The tension created by contraction of the muscle fibers is then transferred though the mysia, to the tendon, and then to the periosteum to pull on the bone for movement of the skeleton. In other places, the mysia may fuse with a broad, tendon-like sheet called an aponeurosis , or to fascia, the connective tissue between skin and bones. The broad sheet of connective tissue in the lower back that the latissimus dorsi muscles (the “lats”) fuse into is an example of an aponeurosis.
Every skeletal muscle is also richly supplied by blood vessels for nourishment, oxygen delivery, and waste removal. In addition, every muscle fiber in a skeletal muscle is supplied by the axon branch of a somatic motor neuron, which signals the fiber to contract. Unlike cardiac and smooth muscle, the only way to functionally contract a skeletal muscle is through signaling from the nervous system.
Skeletal Muscle Fibers
Because skeletal muscle cells are long and cylindrical, they are commonly referred to as muscle fibers. Skeletal muscle fibers can be quite large for human cells, with diameters up to 100 μ m and lengths up to 30 cm (11.8 in) in the Sartorius of the upper leg. During early development, embryonic myoblasts, each with its own nucleus, fuse with up to hundreds of other myoblasts to form the multinucleated skeletal muscle fibers. Multiple nuclei mean multiple copies of genes, permitting the production of the large amounts of proteins and enzymes needed for muscle contraction.
Some other terminology associated with muscle fibers is rooted in the Greek sarco , which means “flesh.” The plasma membrane of muscle fibers is called the sarcolemma , the cytoplasm is referred to as sarcoplasm , and the specialized smooth endoplasmic reticulum, which stores, releases, and retrieves calcium ions (Ca ++ ) is called the sarcoplasmic reticulum (SR) (Figure \(\PageIndex{2}\) ). As will soon be described, the functional unit of a skeletal muscle fiber is the sarcomere, a highly organized arrangement of the contractile myofilaments actin (thin filament) and myosin (thick filament), along with other support proteins.
The Sarcomere
The striated appearance of skeletal muscle fibers is due to the arrangement of the myofilaments of actin and myosin in sequential order from one end of the muscle fiber to the other. Each packet of these microfilaments and their regulatory proteins, troponin and tropomyosin (along with other proteins) is called a sarcomere .
Interactive Link
Watch this video to learn more about macro- and microstructures of skeletal muscles. (a) What are the names of the “junction points” between sarcomeres? (b) What are the names of the “subunits” within the myofibrils that run the length of skeletal muscle fibers? (c) What is the “double strand of pearls” described in the video? (d) What gives a skeletal muscle fiber its striated appearance?
The sarcomere is the functional unit of the muscle fiber. The sarcomere itself is bundled within the myofibril that runs the entire length of the muscle fiber and attaches to the sarcolemma at its end. As myofibrils contract, the entire muscle cell contracts. Because myofibrils are only approximately 1.2 μ m in diameter, hundreds to thousands (each with thousands of sarcomeres) can be found inside one muscle fiber. Each sarcomere is approximately 2 μ m in length with a three-dimensional cylinder-like arrangement and is bordered by structures called Z-discs (also called Z-lines, because pictures are two-dimensional), to which the actin myofilaments are anchored (Figure \(\PageIndex{3}\) ). Because the actin and its troponin-tropomyosin complex (projecting from the Z-discs toward the center of the sarcomere) form strands that are thinner than the myosin, it is called the thin filament of the sarcomere. Likewise, because the myosin strands and their multiple heads (projecting from the center of the sarcomere, toward but not all to way to, the Z-discs) have more mass and are thicker, they are called the thick filament of the sarcomere.
The Neuromuscular Junction
Another specialization of the skeletal muscle is the site where a motor neuron’s terminal meets the muscle fiber—called the neuromuscular junction (NMJ) . This is where the muscle fiber first responds to signaling by the motor neuron. Every skeletal muscle fiber in every skeletal muscle is innervated by a motor neuron at the NMJ. Excitation signals from the neuron are the only way to functionally activate the fiber to contract.
Interactive Link
Every skeletal muscle fiber is supplied by a motor neuron at the NMJ. (a) What is the definition of a motor unit? (b) What is the structural and functional difference between a large motor unit and a small motor unit? (c) Can you give an example of each? (d) Why is the neurotransmitter acetylcholine degraded after binding to its receptor?
Excitation-Contraction Coupling
All living cells have membrane potentials, or electrical gradients across their membranes. The inside of the membrane is usually around -60 to -90 mV, relative to the outside. This is referred to as a cell’s membrane potential. Neurons and muscle cells can use their membrane potentials to generate electrical signals. They do this by controlling the movement of charged particles, called ions, across their membranes to create electrical currents. This is achieved by opening and closing specialized proteins in the membrane called ion channels. Although the currents generated by ions moving through these channel proteins are very small, they form the basis of both neural signaling and muscle contraction.
Both neurons and skeletal muscle cells are electrically excitable, meaning that they are able to generate action potentials. An action potential is a special type of electrical signal that can travel along a cell membrane as a wave. This allows a signal to be transmitted quickly and faithfully over long distances.
Although the term excitation-contraction coupling confuses or scares some students, it comes down to this: for a skeletal muscle fiber to contract, its membrane must first be “excited”—in other words, it must be stimulated to fire an action potential. The muscle fiber action potential, which sweeps along the sarcolemma as a wave, is “coupled” to the actual contraction through the release of calcium ions (Ca ++ ) from the SR. Once released, the Ca ++ interacts with the shielding proteins, forcing them to move aside so that the actin-binding sites are available for attachment by myosin heads. The myosin then pulls the actin filaments toward the center, shortening the muscle fiber.
In skeletal muscle, this sequence begins with signals from the somatic motor division of the nervous system. In other words, the “excitation” step in skeletal muscles is always triggered by signaling from the nervous system (Figure \(\PageIndex{4}\) ).
The motor neurons that tell the skeletal muscle fibers to contract originate in the spinal cord, with a smaller number located in the brainstem for activation of skeletal muscles of the face, head, and neck. These neurons have long processes, called axons, which are specialized to transmit action potentials long distances— in this case, all the way from the spinal cord to the muscle itself (which may be up to three feet away). The axons of multiple neurons bundle together to form nerves, like wires bundled together in a cable.
Signaling begins when a neuronal action potential travels along the axon of a motor neuron, and then along the individual branches to terminate at the NMJ. At the NMJ, the axon terminal releases a chemical messenger, or neurotransmitter , called acetylcholine (ACh) . The ACh molecules diffuse across a minute space called the synaptic cleft and bind to ACh receptors located within the motor end-plate of the sarcolemma on the other side of the synapse. Once ACh binds, a channel in the ACh receptor opens and positively charged ions can pass through into the muscle fiber, causing it to depolarize , meaning that the membrane potential of the muscle fiber becomes less negative (closer to zero.)
As the membrane depolarizes, another set of ion channels called voltage-gated sodium channels are triggered to open. Sodium ions enter the muscle fiber, and an action potential rapidly spreads (or “fires”) along the entire membrane to initiate excitation-contraction coupling.
Things happen very quickly in the world of excitable membranes (just think about how quickly you can snap your fingers as soon as you decide to do it). Immediately following depolarization of the membrane, it repolarizes, re-establishing the negative membrane potential. Meanwhile, the ACh in the synaptic cleft is degraded by the enzyme acetylcholinesterase (AChE) so that the ACh cannot rebind to a receptor and reopen its channel, which would cause unwanted extended muscle excitation and contraction.
Propagation of an action potential along the sarcolemma is the excitation portion of excitation-contraction coupling. Recall that this excitation actually triggers the release of calcium ions (Ca ++ ) from its storage in the cell’s SR. For the action potential to reach the membrane of the SR, there are periodic invaginations in the sarcolemma, called T-tubules (“T” stands for “transverse”). You will recall that the diameter of a muscle fiber can be up to 100 μ m, so these T-tubules ensure that the membrane can get close to the SR in the sarcoplasm. The arrangement of a T-tubule with the membranes of SR on either side is called a triad (Figure \(\PageIndex{5}\) ). The triad surrounds the cylindrical structure called a myofibril , which contains actin and myosin.
The T-tubules carry the action potential into the interior of the cell, which triggers the opening of calcium channels in the membrane of the adjacent SR, causing Ca ++ to diffuse out of the SR and into the sarcoplasm. It is the arrival of Ca ++ in the sarcoplasm that initiates contraction of the muscle fiber by its contractile units, or sarcomeres.


4.3: U.S. Trademark Law
After completing this section, you will be able to
- Grasp the basics of trademark law.
- Analyze notable trademark cases.
As the young United States rapidly developed its commerce and industry in the late eighteenth and early nineteenth centuries, propelled in no small part by the nation’s unusually democratic and effective patent laws (see Chapter 1, “Section 1.5: What the U.S. Patent System Wrought”), the states developed increasingly sophisticated and complex trademark laws. Eventually, however, the transformation of America’s many local and regional markets into a single, unified, national economy propelled Congress to try to federalize trademark law despite the lack of any express constitutional authority to do so. So Congress passed the first national trademark laws in 1870 and 1876. But in a set of three court challenges consolidated into a single appeal before the U.S. Supreme Court in 1879, Justice Samuel Freeman Miller ruled for the majority that the Patent and Copyright Clause of the Constitution gave Congress no explicit authority to regulate trademarks, and declared the 1870 and 1876 trademark laws unconstitutional. vi
The Commerce Clause and the Lanham Act of 1946
Two years later, Congress instead acted under the Commerce Clause of the Constitution to pass the Trade Mark Act of 1881. This first national trademark law, however, only regulated trademarks used in commerce with other nations and with Indian tribes. It wasn’t until 1905 that Congress passed another trademark statute regulating the use of marks within the United States.
Those two trademark laws were subsequently overhauled by the Lanham Act of 1946 , which remains the principal law of the land on trademarks in the United States to this day. vii It broadened national registration of trademarks, and also gave owners of unregistered marks access for the first time to the federal courts. The act also established remedies such as bars on the sale or importation of infringing products, and required the renewal of trademarks every ten years to weed out the registry trademarks that are no longer in commercial use (known as the “deadwood” prevision). viii
After 119 years in business, for example, the world-famous retailer Woolworth’s went bankrupt in 1997 and its trademark was no longer protected. The 83-year-old Hostess Twinkies brand, however, was acquired by two private equity firms for $410 million because they see future profit in the iconic brand—and the customers who love it.
Requirements for a U.S. Trademark
The requirement that a trademark must be actively used or intended to be used in commercial activity in order to be protected by law has been a fundamental feature of U.S. trademark law since its inception. The Lanham Act specifically requires applicants to submit “a verified statement that the mark is in use in commerce, specifying the date of the applicant’s first use of the mark in commerce and those goods or services specified in the notice of allowance on or in connection with which the mark is used in commerce.” ix A trademark is presumed to have been abandoned when its owner ceases to use it for three or more years, after which anyone else can register and use the mark.
Footnotes
- vi See United States v. Steffens 100 U.S. 82 (1879); United States v. Wittemann 100 U.S. 82 (1879); United States v. Johnson 100 U.S. 82 (1879) Retrieved From http://caselaw.lp.findlaw.com/cgibin...l=100&invol=82 .
- vii Harvard University. (2012). Overview of Trademark Law . Retrieved from http://cyber.law.harvard.edu/metasch.../domain/tm.htm .
- viii Op. cit., Miller and Davis.
- ix 15 U.S.C. §1051 Retrieved from http://www.law.cornell.edu/uscode/text/15/1051 .