OpenLLM-France/wikimedia huggingface dataset:
# Principles of Economics/Opportunity Costs
## Opportunity Costs

The opportunity cost of a good or of performing an action, also known as the greatest cost, is the lost value of alternate options that could have been chosen, rather than the one that was chosen. If A gives twice as much pleasure as B, and there is no C that gives more pleasure than B and is comparable (such as uses time, effort, or some other resource), then A's opportunity cost is the benefit of B because that is the difference in resulting happiness. In this particular scenario, the opportunity cost of A is not a good indicator of its value, because it says that A is worth only as much as B, which is not the case.
Normally, there would be many alternate uses for the resources of A/B, so that there would not be such a notable difference, and so A and B would be similar in benefits, B and C would be similar in benefits, etc. In such a case where the differences are minor, the opportunity cost of A would be similar to that of B, and that would reflect their similar benefits.
Oftentimes, opportunity cost is seen as what one would have to give up for something else:
    Opportunity cost of A (in terms of B) = $-{\frac {\Delta B}{\Delta A=1}}$
where
* $\Delta A$ is the gain of marginal utility because of a gain of A = 1
* $\Delta B$ is the loss of marginal utility because of a loss of B
Opportunity costs can also be thought of as the resources lost, or alternate products forgone, through taking a particular action or producing a certain product. The lost resources could be time, effort, money, goods, etc.
Opportunity Cost Principle: Heaberler and Taussing have developed this important cost principle. This principle studies about the various alternatives and their benefits. According to this principle the managerial decision must be such that from the selected alternative benefits.
# Principles of Economics/PPF
## The PPF

The Production possibilities curve or frontier (PPF) is a graphical means of depicting the concept of diminishing returns and opportunity costs. The basic quandary here is how to use a limited (hence, scarce) set of resources to satisfy infinite wants by as much as possible.
A single PPF curve is for an unchanging set of resources. If the resources change, so does the PPF. Insufficient resources for a second product mean a vertical/horizontal curve; insufficient resources for a single product means a curve that lies on the origin (these are trivial cases).
A two-dimensional PPF works with two products, each of them taking an axis (which one doesn't matter). The curve, or frontier, is formed from all the possible combinations of resources that produce the most products. The definition of most products is indeterminate due to the subjective value associated with both; hence, the curve of points. All points along the curve are productively efficient, but depending on society's goals, only one point will be allocatively efficient.
All points outside of the curve are unattainable (because they require more resources than are available) without trade with an external producer (such as is the case with international trade). All points within the curve are attainable but productively inefficient.

## The basic frontier

For smaller entities such as individuals, the PPF curve will be almost exactly a straight line (at least for the majority of goods), which will reflect the budget constraints. However, for large entities that make a noticeable difference on the quantity of resources available, diminishing returns become apparent. Here is the PPF curve for such an entity. Note that at high values of either good, much of the other good must be sacrificed for a bit more of that one good.

## Shifts in the frontier

When a change in the economy causes more or less of a good to be produced when others are held constant, that is considered a shift in the one good's production possibility. The positive version shifts the frontier outward along the axis the good is placed at, so here an increase in good 1's production possibility stretches the PPF along the x axis. It is possible for that to actually increase production of good 2, depending on how society apportions its resources.

## Growth in the frontier

General economic growth increases all of the available goods (both in this case). The growth does not have to be proportionate, nor even hold the same shape, as this graph demonstrates.

## Flattening of the PPF

When a technological advance makes it relatively easier to exchange between two goods, a flattening of the PPF occurs as is demonstrated in the graph. When a firm takes a smaller percentage of industry market share, its PPF also flattens because its actions have a less significant effect on the total resource/good supply to the point that it has to exert fewer and fewer sacrifices of one good to obtain the next unit of the other good. It should also be easy to imagine situations when the opposite is true.
# Principles of Economics/Philips
## Short Run Philips Curve

The Short run Philips curve is down-ward sloping, showing an inverse relationship between unemployment (u) and inflation. A decrease in interest rates can only be brought about by an increase in interest rates (another reason why Economics is a dismal science - just wait, it gets worse). At any time, the government/Central Bank can determine which interest rate to use, and the economy will adjust to have the unemployment rate that meets the curve at that interest rate.

## Long Run Philips Curve

The Long run Philips curve is perfectly vertical, the idea being that in the long run, the Philips curve will assume that form. If the government stays at any point on the short run Philips curve for any significant period of time, people will begin to expect that particular rate of inflation and wages will increase to adjust for that expectation, spurring another round of inflation. This increases the inflation process, raising the inflation rate. To mirror this, the short run Philips curve shifts rightward (with low levels of unemployment and high interest rate) until the point the economy reaches the long run Philips curve (a shift from SRPC1 to SRPC2).

## Vicious Spiral Upward

As a result of this shift, the new position involves just as high an interest rate as before, but the unemployment rate has returned to its natural position. The natural unemployment rate is the rate of unemployment that would cause no shift in the short run Philips Curve, and is somewhere around 10%. This is, for most political situations, an unacceptably high unemployment, hence the need to artificially reduce it by increasing interest rate. Hence, the economy enters a spiral in which interest rates continually increase for only temporary decreases in unemployment (told you it gets worse).

## Vicious Spiral Downward

The opposite is also true. If the government persistently sets the interest rate below the position where the short and long run Philips curves cross, then there will be higher than normal unemployment. If this is held for a significant period of time, the short run Philips curve will begin to shift downward, resulting in continually decreasing inflation for temporarily higher-than-normal unemployment. However, the suffering that such an economic policy, while effective, would bring to people is politically unpopular, and the general trend has been to rising inflation rates.
# Principles of Economics/Quota

A Quota restricts the amount of goods that may be produced, imported, made available, etc. This effectively cuts off the supply curve anywhere beyond the quota. The quota itself shows up as a vertical line; all trade to the right of the quota line ceases. Prices are kept unnaturally high due to the unnaturally reduced quantity available. This is what the figure shows.
# Principles of Economics/S-D Shifts
## Shift in supply

If the supply curve increases (such as an excise tax burden), the new equilibrium will have higher quantity and lower price; if it is lowered, the reverse happens.

## Shift in demand

If the demand curve increases (such as something being in fashion), the new equilibrium will have higher quantity and higher price; if it is lowered, the reverse happens.

## Shift in supply and demand

If both curves shift, their individual effects are added, although with slight alterations due to warping in the shape of the curves. If both curves increase, quantity increases for sure but price is indeterminate; if both curves decrease, quantity decreases for sure but price is indeterminate.
# Principles of Economics/Multipliers
## The Concept

The multiplier effect refers to the idea that an initial spending rise can lead to even greater increase in national income. In other words, an initial change in aggregate demand can cause a further change in aggregate output for the economy. This is because the newly circulated money changes hands several times, each time shrinking in amount due to savings yet adding more to economic activity. Eventually, this cycle involves infinitesimally small amounts of money, so the cycle actually does come to an end, based on the basic geometric series rule:
    $(r)^{1}+(r)^{2}+(r)^{3}+...={\frac {1}{1-r}}-1={\frac {r}{1-r}}$
    For example: A company spends $1 million to build a factory. This money goes to builders, who in total now have $1 million. They may save 25% of that and use the rest to buy goods. The producers of those goods obtain 75% of the original $1 million and save 25% of that, then spend some more. The multiplier here is 4, because an initial $1 million injected into the economy eventually becomes used the equivalent of four times.

## The Multipliers

Note: In the following examples the multiplier is the right-hand-side equation without the first component.
* y is original output (GDP)
* $b_{C}$ is marginal propensity of consumption (MPC)
* $b_{T}$ is original income tax rate
* $b_{M}$ is marginal propensity to import
* $\Delta y$ is change in output (equivalent to GDP)
* $\Delta a_{T}$ is change in lump-sum tax rate
* $\Delta b_{T}$ is change in income tax rate
* $\Delta G$ is change in government spending
* $\Delta T$ is change in aggregate taxes
* $\Delta I$ is change in investment
* $\Delta X$ is change in exports

### Standard Lump-sum Tax Equation

$\Delta y=\Delta a_{T}*{\frac {-b_{C}}{1-b_{C}(1-b_{T})+b_{M}}}$
Note: only $\Delta a_{T}$ is here because if this is a change in lump-sum tax rate then $\Delta b_{T}$ is implied to be 0.

### Standard Income Tax Equation

$\Delta y=\Delta b_{T}*{\frac {-b_{C}*y}{1-b_{C}(1-b_{T})+b_{M}}}$
Note: only $\Delta b_{T}$ is here because if this is a change in income tax rate then $\Delta a_{T}$ is implied to be 0.

### Standard Government Spending Equation

$\Delta y=\Delta G*{\frac {1}{(1-b_{C})(1-b_{T})+b_{M}}}$

### Standard Investment Equation

$\Delta y=\Delta I*{\frac {1}{1-b_{C}(1-b_{T})+b_{M}}}$

### Standard Exports Equation

$\Delta y=\Delta X*{\frac {1}{1-b_{C}(1-b_{T})+b_{M}}}$

### Balanced-Budget Government Spending Equation

$\Delta y=\Delta G*1$
$\Delta y=\Delta T*1$
# Proteomics/Protein Sample Preparation/References

1. Patnaik, S. (2004) Protein Handling. obtained from http://stanxterm.aecom.yu.edu/wiki/index.php?page=Protein_handling in April, 2006
2. Ion Exchange Chromatography. Obtained from http://www.rit.edu/~pac8612/webionex/website/html/ione6eyb.html in April, 2006
3. Blaber, M. (1998) Protein Purification: Column Chromatography - Ion exchange; Dialysis and Concentration. obtained from http://wine1.sb.fsu.edu/bch5425/lect30/lect30.htm in April, 2006
4. Sample Preparation. Obtained from http://www.piercenet.com/Proteomics/browse.cfm?fldID=7FAD146E-B43B-4110-9F71-7F749D41BEC5#samp%20hand in April, 2006
5. Young, D. Protein Precipitation. Obtained from http://www.rpi.edu/dept/chem-eng/Biotech-Environ/PRECIP/precpintro.html in April, 2006
6. http://en.wikipedia.org/wiki/Affinity_chromatography
7. Single-step purification of bacterially expressed polypeptides containing an oligo-histidine domain. Gene. 1992 Feb 1;111(1):99-104.
8. Solubilization and purification of enzymatically active glutathione S-transferase (pGEX) fusion proteins. Anal Biochem. 1993 Apr;210(1):179-87.
9. Glaser, V. (2006) Sample Prep Upstream of Mass Spectrometry: Advances Focus on Sample Clean-Up, Fractionation, and Separation. Genetic Engineering & biotechnology News (Vol. 26, No. 10). Obtained from http://www.genengnews.com/articles/chitem.aspx?aid=1667&chid=1
# Proteomics/Protein Separations- Electrophoresis/Capillary Electrophoresis
## Procedure

In capillary electrophoresis (CE), electrophoresis is conducted inside small tubes filled with buffer, called narrow-bore capillaries. The capillaries used in the electrophoresis instrument typically have an internal diameter in the range of 25 to 100 μm.
The ends of a capillary are placed in separate buffer solutions and electrodes connected to a high-voltage power supply are placed in the buffers. One of the buffer reservoirs, usually at the anode, is replaced by sample. The sample is introduced into the capillary by capillary action, siphoning, or pressure. When an electric current is passed across the capillary, molecules are separated. Separated analytes are detected directly through the capillary wall by a UV or fluorometric detector connected near the opposite end.

## Flow and dispersion

In other separation techniques like high pressure liquid chromatography, separations are driven by pressure. That results in frictional forces in places where the mobile phase is in contact with solid surfaces. These frictional forces cause the velocity of mobile phase close to the wall to be zero while the force in the center is large, resulting in a parabolic flow profile in the capillary. This profile results in solute zones being broadened as they move through the capillary, reducing the resolution of the separation. In CE, the flow is flat, which results in much higher resolution than comparative pressure driven techniques.

## Visualization

The data output from CE is an electropherogram, which is a plot of migration time versus detector response. The response by detector is usually concentration dependent fluorescence or UV-visible absorbance. Different peaks are shown in the electropherogram for separated analytes depending on different retention times. The electropherogram shows separation peaks of cationic, anionic and neutral solutes in the mixture.

## Advantages

CE is advantageous in many ways. The heating that takes place due to high voltage loads on slab gels can have a negative effect on the separation of the proteins, and the use of capillaries lessens said heat buildup. Also, because the gel will not need to be handled, it can allow one to use liquid polymers for separation, and can be replaced between runs. Automation is also much more possible with this technique, lessening the time it takes, and making reproducible results.

## See also

The Wikipedia page for capillary electrophoresis can be found here. Wikipedia details for electropherograms can be found here.

## References

^ "Capillary Electrophoresis: A Simple Technique." http://www.beckmancoulter.com/resourcecenter/labresources/ce/cedefinitionmodes.asp
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# Proteomics/Protein Sample Preparation/Prepts for Chromatography
## Preps for Chromatography

* Solubilization and Solution Preparation
For High Performance LC (HPLC), it is very important that the sample solution (mobile phase) be free of particulate matter. Due to the sensitive nature of a HPLC column and the extreme pressures involved, such contaminants can be extremely damaging and Protein_Sample_Preparation|Contaminant_Elimination#Contaminant_Elimination is very important.
* Recombinant techniques for affinity chromatography
Affinity chromatography is a protein separation technique where substrates with affinities for specific proteins are used in the solid phase of a chromatography column. One highly specific technique is to use recombinant technology to isolate proteins expressed from recombinant DNA. If a gene is inserted into a cloning vector for the purpose of fermenting large amounts of a protein, the gene can be altered to include additional amino acids in the protein. This subsequence can then be utilized as a binding site for the stationary phase substrate. Two examples of this are the additions of histidine residues that bind covalently to certain metal ions and the addition of glutathione-S-transferase protein that will bind with glutathione.
http://en.wikipedia.org/wiki/Affinity_chromatography
Single-step purification of bacterially expressed polypeptides containing an oligo-histidine domain. Gene. 1992 Feb 1;111(1):99-104.
Solubilization and purification of enzymatically active glutathione S-transferase (pGEX) fusion proteins. Anal Biochem. 1993 Apr;210(1):179-87.
# Proteomics/Protein Separations- Electrophoresis/Applications
## Applications

Gel electrophoresis is used in forensics, molecular biology, genetics, microbiology and biochemistry.

### GE of nucleiacids

Electrophoresis is used in DNA fingerprinting. Certain DNA segments that vary vastly among humans are cut at recognition sites by restriction endonuclease enzymes. The DNA fragments are run through electrophoresis and the distance between bands are measured and recorded as the DNA "fingerprint Electrophoresis is used for DNA sequencing.

### GE of proteins

Used for separation, identification, and purification of proteins. SDS-PAGE is used for finding the molecular mass of protins. SDS-PAGE is also used for protein identification and quantitation, determining purity of sample,identifying disulfide bonds,and also in blotting applications. Native-PAGE is used to separate proteins in their native form without denaturing. QPNC-PAGE is used to isolate active or native metalloproteins in biological samples. Since 2D-PAGE separates modified proteins and staining intensity of spots roughly reflects the protein amount, it can provide information about various modified states. 2D-PAGE and DIGE are used to study differential expression of proteins.
# Muggles' Guide to Harry Potter/Magic/Which Broomstick
## Overview

Which Broomstick is apparently a magazine with comparative reviews of brooms.

## Extended Description

After Harry's Nimbus 2000 broom is destroyed by the Whomping Willow, Harry is at a loss for a replacement. Oliver Wood suggests that he should look through Which Broomstick to select a replacement, and order one, over Christmas.

## Analysis

From Harry's first exposure to a Nimbus 2000 broom in Harry Potter and the Philosopher's Stone, we gather that there is something of a cult for performance brooms, as there was in the Muggle world for stereos and cars through the earlier part of the 20th century, and for computers at the time the series was written. Clearly there must be publications for the enthusiast. In the UK, the best-known of these magazines are, for stereos, Which HiFi, and for computers, Which PC. It is only to be expected that such a popular name would be used to publish for the Wizarding enthusiast community.
In the article on Brooms, it is suggested that performance brooms may, in the Wizarding world, be linked with older wizards trying to regain their lost youth, just as performance cars are linked to older Muggles. We can guess that the editorial and advertising policies of Which Broomstick will be slanted towards this demographic, despite never seeing the inside of a copy.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Muggles' Guide to Harry Potter/Magic/Winged horse
## Overview

Winged horses are found in a variety of breeds worldwide.

## Extended Description

The owner of a winged horse is required by law to regularly enchant the creature with a Disillusionment Charm to deceive any onlooking Muggles.
Fantastic Beasts and Where to Find Them describes the following varieties of winged horse:
* Abraxan — A powerful and large-sized palomino. In Harry's fourth year at Hogwarts, the Triwizard delegation from Beauxbatons arrives in a carriage drawn by twelve enormous winged palominos that, according to Madame Maxime who breeds them, require "forceful handling" and drink only single-malt whiskey.
* Aethonan — A chestnut-coated British breed.
* Granian — A relatively agile breed, grey in color.
* Thestral — A large, skeletal winged horse, invisible to anyone who has not witnessed death. Thestrals are bred at Hogwarts.
A Hippogriff, while being a winged creature with the body of a horse, is not mentioned as being a variety of winged horse.

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.
# Muggles' Guide to Harry Potter/Magic/Wrackspurt
## Overview

Wrackspurts are invisible creatures that fly in through your ears and cause momentary confusion. As Luna Lovegood seems to be the only character who believes in their existence, we can guess that they spring from the fertile imagination of Xeno Lovegood.

## Extended Description

On the Hogwarts Express in Harry Potter and the Half-Blood Prince, Luna Lovegood, seeing Harry's momentarily befuddled expression, asks, "Wrackspurt got you?" She then proceeds to explain that they are invisible and "fly in your ears and make your brain go fuzzy." She then waves her arms about her head as if warding off flies, upon which Harry and Ron look at each other and hastily begin to talk about Quidditch.
When the Trio visit Xenophilius Lovegood's house in Harry Potter and the Deathly Hallows, Xenophilius explains that one of the components of his recreation of the diadem of Ravenclaw is the Wrackspurt siphon (which looks like a golden ear trumpet), "to remove all sources of distraction from the thinker's immediate area."

## Analysis

One wonders whether Xeno truly believes in Wrackspurts, or has consciously created them to explain what is known in the Muggle world as a "senior moment."

## Questions

Study questions are meant to be left for each student to answer; please don't answer them here.