Does the debt load affect the volatility of equity?

Question: Does the debt load of a company have an impact on the stock price of a company and its volatility? Also, how does the market react to the announcement of a company issuing bonds?
Answer: Q1 - Yes, debt load has an impact on the stock price.  For instance, say you are valuing a company with a discounted cash flow model, while the interest won't affect the operational cash flows, it will increase the cost of capital.  With that, the perceived value will be less than a similar company with less debt.  Debt will also affect the volatility of the equity.  As debt becomes a larger portion of the old Assets = Liabilities + Equity equation, changes in asset value will have a larger sway on Equity.
Q2 - Depends.  If the market perceives that the company needs more debt to fund capital expenditures due to opportunity, then the market should react positively.  If they're issuing debt and the market thinks this is a poor choice, the market with punish the stock.  As a caveat, if they issue debt to buy back stock the market will almost always act positively due to less shares for trade.
Answer: The standard theoretical model for examining this question is the Merton Model.  The Merton Model views the company's equity as a call option on its assets.

This model assumes that a company has a certain amount of zero-coupon
  debt that will become due at a future time T. The company defaults if
  the value of its assets is less than the promised debt repayment at
  time T. The equity of the company is a European call option on the
  assets of the company with maturity T and a strike price equal to the
  face value of the debt.

Hence the equity volatility for a company with very low debt converges to the asset volatility, since the equity value (call option price) is about equal to the total assets.  As the debt load rises, the option becomes closer to the money, and, assuming total assets remain unchanged, the equity value shrinks.  If the underlying volatility of the assets also remains essentially unchanged, then the volatility of the equity increases as asset volatility is larger relative to the lower equity value.
The Merton Model has been shown to be a empirically accurate for non-financial firms.
Answer: Let's start with an empirical test of the relationship between leverage and stock price returns and see if this connects to corporate finance theory.
Below is a bivariate chart that show the one-year forward return of a security vs. leverage. The x-axis is the leverage characteristic "Total Liabilities to Total Assets" in the current quarter. The characteristic is binned in six equally sized buckets and the harmonic mean of the one-year forward return is the y-coordinate of each dot. The population is S&P 500 securities from 2004 to mid-2011.
Notice there is U-shape relationship between leverage and returns. Some observations:

Firms with top quartile (right-most bin) debt have the worst forward returns.
Firms with very low debt (left-most bin) have low returns
The Goldilocks firms in the middle have higher returns.

How to reconcile this with theory? This confirms Miller & Modigliani propositions in a world with taxes (where interest expense is tax-deductible). On the margin, firms can increase enterprise value by generate a tax shield by increasing leverage. However, an indifference point is reached where the benefits of marginal debt are offset by the marginal increase of default. This is also called static trade-off theory (and investment bankers and CFOs think hard about this optimal capital structure problem).
This is why you see firms in bucket 4 have the highest returns. With some simplification in this static analysis, you can argue that firms to the left of this bucket can benefit from increasing leverage and firms to the right should de-lever.
All things being equal, as firms increase leverage the volatility of their earnings and therefore the volatility of the share price.

The last part of your question regarding market perception to debt issuance is related to Pecking Order theory. The theory starts in a principal-agent world where agents (firm managers) have more information regrading the firm than their principals (shareholders). The wikipedia link is a bit light - but the idea is that managers will prefer forms of raising capital that reveal the least amount of information as possible. Cash from operations reveals the least amount of information whereas equity issuance reveals the most. Managers that issue stock may be revealing information that their share price is overvalued whereas managers that have favorable views of the firm prospects would favor issuance of debt.
Finally, take a look at Jensen's Free Cash Flow hypothesis. Jensen argues that debt constrains manager behavior by removing discretion in the use of cashflows which therefore leads to better shareholder value creation.


Is it possible to program the entire logic and flow of a game without ever touching a graphic's engine?

Question: I'm not interested in rendering engines or level design, but I'm very interested in programming the AI that drives all of the characteristics of game play. I'm thinking of how the d20 system drives the rules behind D&D games. Is there a person that programs that logic, and is it possible to program almost all of an API without ever touching a graphic's engine? I'm a software engineer by trade (Java with some C# experience), so I'm looking to use those programming skills.
Comment: See my post on Open Source Bot API's.  Programming the AI not the engine. http://gamedev.stackexchange.com/questions/8920/open-source-ai-bot-interfaces
Answer: Yes
It is possible to program games without touching a graphics or rendering engine. But it will limit you to text based games. Some good examples of these games would be nethack, dwarf fortress, and online MUDS(multi-user-dungeons).
If you want to make a game with graphics, I suggest you join a team where you can program logic and AI without having to know to much about graphics.
Comment: Also think of simple dynamic websites, where you generate every result into HTML and keep the values on the server in some sort of local storage (SQL, ascii, xml or whatever)
Answer: Yes,
a game engine is made of lots subsystems. Graphics Engine, AI Engine, the input system, the sound system, a game editor and many more.
A game is composed by a game engine ( and for small games it's not a need ) and much content: textures, levels, 3d models, sounds, and GAME LOGIC, yes, the game logic is a content.
You can made a game without a engine, or with a engine with only two or three subsystems. A game without graphics, only on text mode. On a great company, small groups are dedicated only a part of the game. ( AI scripting, lighting, network, etc..)
Answer: Are you interested in creating a new game, or just trying to implement various AI techniques? In the second case, there are many video games that offer APIs to interact with the game. For example, you could create a bot for StarCraft using BWAPI.
Answer:
Is there a person that programs that
  logic, and is it possible to program
  almost all of an API without ever
  touching a graphic's engine? I'm a
  software engineer by trade (Java with
  some C# experience), so I'm looking to
  use those programming skills.

Definitely. Gameplay programmers often never touch actual rendering code. We're a few layers separated (dealing with actors and controllers and such). That being said, as a gameplay programmer on triple-A FPS's, I found myself frequently working with animation code.
And, you still have to know your math and, depending on the platform, understand what's happening under the covers with the decisions you make.
Your mileage will vary depending on the technology and company; but, generally, you're talking about gameplay or AI programming.
Answer: Yes, I think you can. Although you should know that usually the AI system communicates with the animation system to manage character movement and actions.
It really depends on the game you're going to implement.
Answer: It is possible.
Microsoft recently released Kodu.
You should watch the series of videos made on Kodu.
Answer: IF you have a good game engine available you don't have to focus on the graphics part and let the engine handle it.
Answer: I think the great thing about this approach, which I have done myself, is that you are free to reuse your "rules engine" after you complete it.
This gave me a chance to apply it to many different engines/renderers. I just layer the UI on top and can easily create (almost) completely different games.  I could make one a 2d sidescroller using sprites, another a 3d dungeon, another a isometric rotating map.


RACE pcr product

Question: I'm a molecular bio novice, and I'm trying to understand the differences between regular PCR and RACE PCR.  If it wanted to sequence my PCR product that might be hundreds, if not thousands of bps long, I should use RACE PCR correct?  My goal is to sequence the active site of some enzymes I'm interested in, but I'm not sure how to go about designing PCR primers for a specific site on my protein.  Additionally, the active site is over 100 amino acids long, which would imply that my PCR product has to be over 300 bps long.  Regular PCR amplicons have trouble amplifying long strands of DNA correct?  I was thnking about using RACE PCR to amplify my entire cDNA strand that is 4000 bps long and then just sequencing the RACE product.  Would RACE work for that many bps in my cDNA?
Comment: This is a lot of questions in one very compressed paragraph.  It would probably be best if you asked separate questions.
Answer: Judging by your post history, it seems like you may want to pick up an introductory book on molecular biology. This question is really asking a number of questions. I will attempt to answer the difference between PCR and RACE, and I would suggest asking the others as separate questions, as @dd3 has suggested.
Polymerase Chain Reaction (PCR) is the basic method of amplifying a small amount of DNA (the template) into an exponentially large amount of DNA. This method assumes the knowledge of the sequence of (at least) the regions of DNA flanking what you wish to amplify. Using these flanking sequences, two short oligonucleotides (e.g., 18-24 nucleotides), called primers, are ordered such that one primer matches the 5' strand at the start of the sequence, while the other primer matches the 3' strand at the end of the sequence. When these primers are mixed together with the template DNA, and a DNA polymerase enzyme, and subjected to specific temperature cycles, amplification occurs.
RACE PCR is a specific type of PCR. RACE (Rapid Amplification of cDNA Ends) PCR is used when the template strand to be amplified is a specific mRNA message. In other words, this form of PCR produces a DNA copy of cDNA from an mRNA starting product. The exact details of RACE depends on which type you wish to use and can be looked up elsewhere.

RACE pcr product


Image of a Linear Operators Eigenspace

Question: Given a Linear Operator T and a vector or linear combination of vectors from within a single eigenspace of T, will those vectors always be projected back into that eigenspace when given as input to T?  I tend to think yes since that kind of seems to be the definition of an eigenvector.
Answer: Yes. Let $v_i$ be an eigenvector to the eigenvalue $\lambda_i$. Let $x=\sum_{i=1}^n \mu_i v_i$, then $Tx = \sum_{i=1}^n \lambda_i \mu_i v_i$.
To prove your case, let $\lambda_i = \lambda_j =: \lambda$ for $i,j$. Then $Tx = \lambda x$ by the above calculation.
Answer: Supposing that $\vec v_1,...,\vec v_n$ are vectors in the eigenspace of $T$ corresponding to the eigenvalue $\lambda$, and if $a_1,...,a_n$ are constants, then we have $$T(a_1\vec v_1+...+a_n\vec v_n)=a_1T(\vec v_1)+...+a_nT(\vec v_n)=a_1\lambda\vec v_1+...+a_n\lambda\vec v_n=\lambda(a_1\vec v_1+...+a_n\vec v_n),$$ so you're correct.

Image of a Linear Operators Eigenspace


Correct (preferred) blinding in NLTE tourneys when blinds or the button bust out

Question: What is the correct process in moving the blinds when either the next dealer and/or the next blinds get busted out of the tourney? A good description of how dead blinds work would be greatly appreciated.
Answer: Dead button - Spots vacated by leaving players who would pay the small blind or get the button during the next hand remain open for the purposes of shifting blinds and button. Thus, the small blind may not be paid in the subsequent hand if the player due to pay the small blind has vacated the spot and, therefore, is considered "dead". However, there is always a big blind even if the spot is vacated by the player who is due to pay the big blind; in such case, the player seated to the left of the vacated spot pays the big blind. When the dealer button moves to an empty seat, it also is considered "dead", and the last active player before the empty seat retains the "privilege of last action" by default. While simple in tournament formats and the most equitable in terms of paying blinds as due and when normally expected, it can result in inequitable strategic situations regarding last action, and becomes harder to track if the table is "open" (players can come and go) as in a casino.
Comment: What sort of inequitable strategic situations regarding last action do you have in mind? Is it because if there's no small blind, then if the button opens, the big blind has less pot odds to call? EDIT: I see Chris Marasti-Georg's answer explains the situation when the would-be button busts.
Answer: The Traveling Button is one method of dealing with the button or small blind getting up before the next hand.  It is occasionally used in cash games.
When the person who would become the button busts out, the button skips them to the person who was the big blind the last hand. That person becomes last to act for the hand, but posts a small blind anyways.  The person to their left posts a big blind, as does the person to that person's left.  So you have the big blind position paying a big blind, the small blind position paying a big blind, and the button position paying a small blind.  The following hand, the button moves as usual.  The new button position pays a small blind, the person to their left pays a small blind, and the person to that person's left pays a big blind.  After that, normal blinds resume.
An illustration:
Original setup:
P1 on button
P2 in small blind
P3 in big blind
P4 UTG
P5 UTG+1
P6 UTG+2

P2 posts a small blind, P3 posts a big blind.  In this hand, P2 busts out.
Next hand:
P1 Cut-off
P3 Button
P4 SB
P5 BB
P6 UTG

P3 posts a small blind, P4 posts a big blind, P5 posts a big blind.  P3 has now posted both blinds.
next hand:
P1 Hi-jack
P3 Cut-off
P4 Button
P5 SB
P6 BB

P4 posts a small blind, as does P5.  P6 posts a big blind.  P4 has now posted both blinds, and P5 and P6 have resumed normal blind procedures.
When the person that will be the small blind busts out, the button stays where it was, and the 2 people to the button's left each pay big blinds.  On the next hand, those 2 players each pay a small blind, and the person to their left pays a big blind.  This results in a standard small and big blind, plus the button paying a small blind.  On the next hand, normal blinds resume.
One added benefit to this method over the dead button method is that when the person who was going to be the button busts out, the button from the previous hand doesn't get to act last on a second consecutive hand.


Cohomology of complexes

Question: I sometimes see cohomologies of complexes of sheaves. What is the definition of these? Say if $\mathcal F^* $ is a complex of sheaves on $C$, what is $H^i(C,\mathcal F^*) $?
Comment: It is hypercohomology.
Comment: (look into Weibel's H-book, chapter 10.5 ff.)
Answer: There are two concepts defined for complexes of sheaves, both called "cohomology", which are related but different.  The more basic concept is the kind of cohomology that is defined for any complex $A^\bullet$ of objects in an abelian category:
$$\DeclareMathOperator{\im}{im}H^n(A^\bullet) = \ker d^\bullet / \im d^{\bullet - 1},$$
where $d^\bullet$ are the differentials.  This is not the kind you're asking about.  What you are seeing is the derived functor kind of cohomology, in this case the derived functor of global sections of sheaves.  If $X$ is a topological space (or site) and $\def\sh#1{\mathcal{#1}}\sh{F}^\bullet$ is a complex of sheaves on $X$, then:
$$H^n(X, \sh{F}^\bullet) = H^n \bigl(R\Gamma(X, \sh{F}^\bullet)\bigr).$$
The $H^n$ on the right is the "complex cohomology" and the $H^n$ on the left is what we are defining to be the "sheaf cohomology".  Here, $R\Gamma(X, -)$ is the functor obtained in the manner described by Sandor in his answer: find (any) quasi-isomorphism of $\sh{F}^\bullet$ with a complex of injective sheaves $\sh{I}^\bullet$, and define:
$$R\Gamma(X,\sh{F}^\bullet) = \Gamma(X,\sh{I}^\bullet);$$
in other words, just apply global sections directly to the complex of injectives.  For why this works, and what it means, you'll need to read a book; Weibel is a great reference, though I really like Gelfand–Manin for learning.  YMMV.
Answer: If $\mathscr F$ is a sheaf, you define cohomology by first taking an injective resolution. But that's really just a complex of injective sheaves quasi-isomorphic to $\mathscr F$. That does not need $\mathscr F$ to be a sheaf. If $F$ is a complex, then take a complex of injective sheaves quasi-isomorphic to $F$. From that point do the same as you do in the case of sheaves.
Answer: I apologize for the shameless self promotion, but you can also try these notes.
Comment: Nicolaescu: Thank you for these notes!

Cohomology of complexes


Choose tests cases to run from Fitnesse test suite

Question: We have a complex Fitnesse suite with tens of subsuites, includes and symbolic links. Sometimes we don't want to run the whole thing and would like to run selected test cases and not run the others. We see two ways to do it:

By managing page properties (Suite - Test - Normal), we can turn on/off test cases.
But this is inconvenient. First of all, it's boring. And second, we can't see the suite current state (what test cases are turned on and gonna be run).
In Fitnesse, there are tags, and we can specify desired tags in suiteFilter or excludeSuiteFilter.
This is inconvenient too. You have to remember tag names and don't forget or misspell them in filters. Of course, we can store predefined links with carefully selected lists of tags, but in our case it's not the option, since the lists are subject to frequent changes.

Also, we don't want to divide our suite on several parts, since we benefit from having the general Scenario Library and variable lists.
The ideal solution for us would be having a Fitnesse suite configurator, which could display and change settings of Fitnesse pages. Say, it may be a Fitnesse plugin, which read Fitnesse folder structure and display current settings in an html page or with Windows Form, letting change these settings and save the changes. Or an external tool with similar functionality.
Have you heard of such tools? Did you bump into the same troubles? What would be your suggestions?
Thanks,
Answer: Unfortunately I do not know of any plugin which will do what you ask. However, you could use the tags option by adding a top level page to the wiki that you can choose to run tests from.
One final idea would be to use something like Selenium IDE or iMacros to run each suite. Not really a permanent solution, but perhaps enough to keep you going until one comes up.


How can I control the heat when cooking on a campfire?

Question: In a few weeks a group of us will be camping and rafting.  My wife and I have been assigned dinner responsibility. I've done the hamburger/hot-dog thing on campfires, but I was looking for something more. We are thinking about Carne Asada, and Beef/Chicken Kabobs, but I'm concerned about controlling the heat so the kabobs don't burn.  Any suggestions?
Answer: The key is mostly to cook over coals rather than open flame if you want decent control. This is a principle you find all over slow smoking/BBQ. You start the fire with plenty of wood and let it burn down to a pile of red coals, which you then can cook over with nice control.
Personally, when I want to cook over an open fire, I treat the fire pit as 2 zones: fire and coals. I use the "fire" side for anything where I want an open flame, like roasting marshmallows or hot dogs. As a chunk of wood on that side of the pit burns down to coals, I move it over to the other side, for more controlled cooking.
Another way to handle the variability in campfires is to cook with things with a lot of thermal mass to even the heat out. In practical terms, that boils down to cast iron and clay/ceramics. Whether it's a dutch oven or a little "cave" of fire bricks, these materials spread the heat out so nicely you can often just bury them in the coals and "bake" or "roast" a lot of options that you might not have considered as "camping foods".
The same is true of other cast iron pans and much of the stoneware from places like Pampered Chef, meaning you can pan fry, saute, and do many of the other more typical "kitchen" tasks over a campfire.
One word of warning regarding this principle though is that it might seem like collecting rocks from a nearby stream to use as the thermal mass is a good idea. It is not. Rocks that have spent long periods under water can crack and/or explode when suddenly heated up.
Comment: Good point about river rocks,  I could see myself collecting rocks for mass...
Answer: Not sure how much equipment you're hauling, but my advice is to employ aluminum-foil generously.  Once you get a nice sear on your meat or kebobs, cooking over direct flame will only dry-out the meat.  Wrapping food in foil helps evenly distribute heat, and it keeps moisture and juices inside the pouch. I particularly like sausage , onions and peppers done this way. Just make sure to double-wrap the foil, in case you get a tear.
Answer: There are so many variables here, I can't address them all. Whether are not you are hiking or driving to the camping spot, whether you can bring frozen/refrigerated ingredients in a cooler, whether you have permission to modify the camp fire area, etc.
If you are hiking a fair distance, you will need to stick to safe-at-room-temperature ingredients, use light cooking implements (no cast iron pots).
If you're driving right to the camping spot, you can bring more and heavier cookware, a steel rod to put across the fire to hang a pot from, a grate for BBQ and frying pans, a cooler for frozen things.
If you have permission to set up/change the campfire area, an ideal shape is like an old fashioned keyhole, surrounded with stones. Point the slot towards where the wind is coming from, and put flat rocks of equal height on either side of it. The slot is also where you will rake the coals to, and put the grate on top of for any frying pan/sauce pan cooking. Food wrapped in aluminum foil can go into the coals underneath. Coffee pots and dutch ovens can hang from a steel rod put directly across the fire.
It's important to remember that you're going to need to be cleaning dishes, likely without running water. After you scrub food out, you can sterilize pots by reheating them after the meal.
Take local wildlife into consideration. Avoid too many leftovers to temp raccoons. If you're in an area with a lot of bears, reconsider that rotisserie chicken idea. ;-)
Other than that, imagination is the limit. You really can cook almost anything over a good campfire.
Comment: Foil cooking directly on the coals is tasty.  You can even get the cheap foil baking pans. This last hunting season, we filled a small foil bread pan with ground beef, peppers, onions, carrots, celery, potatoes, and a bit of butter and seasoned salt.  Made for a tasty meal after stomping around the woods all day in the rain.
Answer: Another great idea I've done before when portaging (i.e., in the situation where you want to travel very light) is aluminum foil envelopes filled with a fish fillet and veggies (sugarsnap peas come to mind). Bring the fish fillets deep frozen, then they should stay frozen during the first day if you insulate them well enough from the sun (e.g. wrap them in multiple layers of the the aluminum foil you need to bring anyway) and you can prepare this stuff the first evening. To make the envelopes, just fold a sheet or two of (extra strength) aluminum foil in two, then double fold a 1cm strip on two opposite open sides. You now have a pouch that you can fill with goodies. Double fold the remaining open side and you should be good to go.
Answer: In addition to what everyone else has said:
Roast root vegetables are a really good idea. Squash, parsnip and sweet potatoes are usually nice. Wrap them in a layer of tinfoil and put them in some hot coals and leave for an hour or two. If you cut them open first you can put in things like butter, honey, dried fruit and so on, but they will sometime start leaking!
Flatbread is always good as a side or for desert. If you mix the dry ingredients (flour, baking powder, salt) before the trip, you can take it with you and just add water and oil the evening you're cooking. You can cook in a pan or on a flat rock, or you can wrap it around the end of a stick and roast it like a marshmallow! (recipie here, though I can't vouch for the quantities)
Answer: In a non toting-the-hardware-on-your-own-poor-back context, you can't beat cast iron. Dutch oven, skillet, and griddle. This will even allow you to cheat a little (but only a little!) on the coals not flames advice.
With these tool you can do some serious cooking, limited only by your prep-space and ingredients on hand: you can even bake by putting a second vessel in the dutch oven (use pebble or such to prevent direct contact with the hot iron.
Answer: You can do just about anything on a campfire -- even some baking if you're willing to carry a dutch oven.
The important rules to cooking over a grill or campfire it so be prepared to move whatever you're cooking to a lower heat part of the fire (this might require bringing fireplace gloves with you), and to not turn your back on it for too long unless it's over low coals.
I've done curries (onion, chicken, coconut milk, green apple), stew, pasta, chilli ... you can do most anything.
For the kebabs, I'd recommend turning them regularly, and not mixing the skewers -- make them all meat, or all a given type of vegetable, and mix afterwards.  You don't want a bunch of singed vegetables next to under cooked meat.
Answer: One option to consider it to make "dirty steak".  The basic idea is to burn the fire down to a bed of hot coals and then just put the steak right onto the burning coals.  I have done this with a London Broil and it works out very nice.  It sounds crazy but the steak really doesn't get dirty nor does it burn up like you might think.  The lack of oxygen a small bit of juice from the steak seems to make a nice interface between the steak and the coals.  There are a lot of interesting articles on the web:
http://www.google.com/search?hl=en&source=hp&q=dirty+steak&btnG=Google+Search
It's great, you can hike with a frozen steak and have it thaw during your walk.  There is no pans or other stuff to clean and it's super easy.


What are the origins of the "totalitarian genes" theory?

Question: What are the origins of the infamous "totalitarian genes" theory that alleged that Russians, Serbs, Belorussians had genes favoring totalitarianism and autharitarian government, so to protect democracy those people should be restricted and/or eliminated; and which has been used to justify the restriction of the rights of ethnic Russians in the Baltic states?
Comment: Google only has 269 results for "totalitarian genes", and most results are puns or verbal attacks. Maybe the expression is more widespread in another language? Where did you hear about this theory?
Comment: Perhaps Minister Medinsky with his extra chromosome theory can provide an answer ;)
Answer: I have never heard this theory, and I suspect it's rooted in racism from victors who want to get rid of their enemies. I do not think it has any basis in science or biology.
You might as well ask about the theory that Jews have deceitful genes and bad blood that will make them treacherous, another thinly cloaked racist pseudotheory.
Answer: You might be better placed than most to dig up an answer to that one. Here in the USA, I have never heard that one before. My guess is its a modern invention in a specific area (and thus probably isn't really "History").
Such arguments in the USA generally revolve around culture, not genes. The idea being that Despotic Culture X goes back thousands of years, and thus the people there don't know any better, and even if someone handed them a Democracy they'd have no idea how to run it properly and wouldn't appreciate it at all.
I still think they are wrong. Such people move here all the time, and I play soccer (and have beers afterwards) with them. In my experience, nobody loves freedom more than an immigrant who grew up behind the Iron Curtain. (Arab-Americans come a close second).


Creating a mail server on Amazon EC2?

Question: Does anyone know the latest AMI that has the preconfigured Postfix mail server on it, for use with a "micro" instance of Amazon EC2?   I'm having trouble searching for a AMI instance using ElasticFox .   I can't find anything newer than like 2009...
Answer: Never look for AMIs using ElasticFox or using the community tab in Amazon's EC2 console or using the ec2-describe-images -a command.  These tools make it difficult to know who publishes the AMIs which is critical in determining what AMIs you can trust.
Always look for an AMI id in a list that is published by a source that you trust.  For an Ubuntu AMI, that would be a place like:
http://cloud.ubuntu.com/ami/
If you trust me, you can also look in the table I publish at the top of:
http://Alestic.com
This table is updated automatically from the list of AMIs published by Canonical.
Scott Moser has written a longer article that talks about the challenge of finding the right Ubuntu AMI:
http://ubuntu-smoser.blogspot.com/2011/07/how-to-find-right-ubuntu-ami-on-ec2.html
There's no need to look for an AMI with Postfix pre-installed or pre-configured.  Not only are these unlikely to come from trusted sources, but they are also unlikely to be configured in exactly the way that you need them to be.
Postfix can be used for many different purposes and you need to make sure yours is configured with the correct values for your installation (outbound, inbound, domain names, relays, certificates, etc.).
You can start with a standard Ubuntu server AMI and install Postfix yourself using apt-get or aptitude.  Here's the section for Postfix in the Server Guide for Ubuntu 11.10 Oneiric:
https://help.ubuntu.com/11.10/serverguide/C/postfix.html
Comment: Thats good advice. Thanks.   In the past I read that people had been making mail server instances that are preconfigured with all the necessary software packages.  I was looking for one of those.

Creating a mail server on Amazon EC2?


Is it OK to swap batteries while phone is connected to wall charger?

Question: It takes a few minutes to shut down and restart the phone, it would sometimes be handy to be able to swap batteries without shutting down (i.e. swap in a fully charged battery before going out).     Will the phone operate without a battery while connected to a wall charger?   Is it safe to swap the battery without shutting down?
Answer: It's device dependent, if the manufacturer can fit in the circuitry to use the wall charger without the battery then yes you'd be able to do that. Most laptops can run without batteries, I doubt many smartphone does though; phones are primarily designed to be used while on the go, while laptops are more likely to be plugged in.
A safe test is to shutdown the phone normally, plug the phone into charger, and pull out the battery, then try booting up the phone with only wall charger. If you can boot up, then it's 90% likely that you'll be able to pull out the battery while it's running without causing a reboot.

Is it safe to swap the battery without shutting down?

If the phone doesn't have the appropriate circuitry, it will be no less safe than just unplugging the battery. There is no moving parts in a mobile phone and all modern hardware are designed such that complete loss of power will just reinitialize the hardware as if it's just booting up. Therefore the only possible damage you can do is to the file system.
Modern journalled file systems are designed to be able to withstand power loss. If you're using journaled filesystem, e.g. ext3 or ext4, then your data should be safe; if using unjournalled filesystem, e.g. FAT or ext2, then there is a small chance of file system corruption.
Answer: Does your user manual have any prohibitions about removing the battery while plugged in? That would be my first point of information. And I probably wouldn't try it myself, but that's just me.
The issue is that you have no idea of whether the folks who designed the charge circuit accounted for this or not, and you don't know how they did the charging circuit, so you don't know for sure whether it's safe or not to try it.
I'm GUESSING that it won't hurt your phone because the designer should be doing something safe for the 'battery goes missing' case. I also wouldn't be surprised if the phone either just cut out, or went into it's 'oh noez, the battery is out of juice' routine and turned itself off right away.
Comment: Just re-read the user manual, no information at all on this topic.
Answer: I just tried this on two phones, a Samsung Galaxy 551 and a Samsung Galaxy S. It doesn't work. The phones typically just shut off. However, one time the Galaxy S didn't shut off right away but I wasn't able to put the battery back in before it shut off. My Google Nexus S is made so that you can't even take the back cover off without unplugging it.
I suspect that this is simply not a supported feature in most phones and that you're not likely to find that it works anywhere. Not to mention the fact that power-loss may damage components or corrupt data. This is one reason why the phone monitors the battery life and shuts down if there isn't enough battery power.
Comment: For my moto Droid Bionic, when I removed the battery, it instantly went to the hardware startup screen, and then displayed a missing battery icon.
Answer: This feature is supported on the Samsung Galaxy Nexus.  I routinely change out batteries while the phone is plugged in to the wall charger.  The only issue I've noticed is that the battery level doesn't update to the new level right away, but instead slowly increases over time.
Answer: Just for completeness sake I want to share that I've operated my old LG GT 540 countless times with the battery removed, while the USB cable is plugged in. I can power it up on in these situations (and run CWM). So I guess that there might be more LG Android phones with similar circuitry.
Since I've upgraded to my new Galaxy S2, I've been too reluctant to try it out.
Answer: A smartphone's most limited resource is its battery. This means phones are specifically designed to survive power losses. And imagine a hang up with a subsequent reboot would brick with some probability. How many complaints would that cause?
So the answer is simple:
Just try out to switch your battery. If it works: Fine.


google app engine proxy workaround

Question: I am trying to build a google app engine app in Java.  The app is trying to get information from another site.  On my computer I am behind a firewall and need to connect to the site through a proxy.  Google app engine does not allow the use of java.net.proxy.  Is there a way to configure eclipse so it knows that when I use URL.getContent() my local host will connect to that url through a proxy??
Answer: Look at this thread issue, there's a patched jar that allows you to connect through a Proxy.
Answer: It seems there's no way to do this, at least with current release of the SDK. I've gone through suffering from this problem.
The workaround is to make your system inherently aware of proxy. For example, use VPN, or use iptables to configure your proxy on Linux system.
It seems when your use normal way to specify a proxy as with other Java application it will invoke a class not in the JRE white list of GAE/J.

google app engine proxy workaround


Does where your employees sit affect the quality of games they produce?

Question: In Game Dev Story, you are able to change where your employees sit. Does this have any affect on how well they perform (for example, a seat closer to the boss will result in more points added to a game), or are these changes purely cosmetic?
Answer: You can get a very slight advantage by putting the employees with the smallest power bars at desks closest to the door.  They will have to go home and rest more often, and it will shave off a few seconds of walk time with each trip.  However, using a lot of Dead Bulls allows you to almost completely avoid this problem anyway.
I've also wondered if certain employees tend to go talk to each other more (giving + research) or propose trying to increase the __________ of the game.  If that's true, then it would make sense to seat them close to each other, or next to the boss, again decreasing walk time.  This is just speculation though.
Answer: Not much. The accepted wisdom is, "Put the employees with the lowest energy bars closest to the doors" so their transit time to and from their seats is low.
It seems logical that you'd also put them near the people they talk to most, but I've never been able to figure out if there is any way to predict that.
Comment: Both great points on how to position your employees. Another thing to note is if you have one employee constantly coming to your desk for boost attempts it might make sense to move them closer to you. Less time walking between their desk and your desk = more time working.
Answer: Good answers, and possibly true and helpful, but I believe that the true use of "Move Seats" is to give a fine-grained delay to launch your game at "Christmas Break". Move Seats will take about 3 days in the game, during which period of time, they will be unproductive.


The concept of gradient, related to lagrange multipliers, surface areas, tangent hyper planes

Question: As we all know, gradient is always perpendicular to the level curve. On the other hand, $\nabla f(a,b) \dot\ h$ where $h=(x-a\     \ \ \ \ \ y-b)^T$, give a  tangent hyper plane which is tangent to the point on a surface, you can find in many texts that such hyper plane is in general, $z=f(a,b)+\nabla f(a,b) \dot\ h$ at some point $(a,b,f(a,b))$.  For instance, when we are calculating the surface area, we would denote $T_s\triangle s$ and $T_t\triangle t$ as the vector which is spanning a paralleogram to approximate the rectangle $ \triangle s \times \triangle t$ where $T_s =\frac{\partial F}{\partial s} $ and F is the surface. In lagrange multiplier, we know f has extremum point if $\nabla f= \lambda\nabla g$, from this expression, we know the grandient f should be perpendicular to the level set g, where it is the domain of f. From the proof, the idea is if $\nabla f $ is not parallel to $\nabla g$ then there is change in f, but here come the question, why if $\nabla f $ is not parallel to
$\nabla g$, then there will be a change in f either increase or decrease. Any explaination to gradients would be appreciate.d
Comment: What is $g$? ..
Comment: @sai: The Lagrange problem in this context can be stated as: maximize $f(x,y)$ subject to $g(x,y)=c$.
Comment: g can be considered as the constraint.
Answer: This is not rigorous, but might give you some intuition.
If you have a manifold given by $g(x_0, x_1, \ldots) = 0$ (this is the same as $g = c$, just move constant $c$ inside $g$), then near some point $P$ it can be approximated well by tangent space $T_P$ calculated in that point. Then, if you would want to maximize $f|_{T_P}$ (i.e. the function $f$ constrained to space $T_P$), you need to calculate the derivative, however, observe that the gradient of $f|_{T_P}$ is just the orthogonal projection of gradient of unconstrained $f$ onto $T_P$ (derivative is a linear transformation). But then, the condition $\nabla(f|_{T_P}) = 0$ can be rewritten to $\pi_{T_P}(\nabla f) = 0$ which is precisely $ \nabla f \| \nabla g$.
All this also can be said in terms of projections "along the normals" with no "tangent space step" between, however, there are some issues, so I won't elaborate on that. Please note, this is only intuition.
Hope that helps!
Answer: Okay, some background on the gradient. Since $\gamma$ carves out the level set $g(x,y)=c$, we clearly must have $g\circ\gamma=c$ identically. The derivative of a constant is zero, so we obtain
$$\frac{d}{dt}g\circ\gamma=(\nabla g\circ\gamma)\cdot\gamma\,'=0.$$
As above, when two vectors' dot product is zero they are perpendicular, thus $\nabla g$ is perpendicular to the tangent of the curve at any point on the curve. This is all in $\Bbb R^2$, two dimensions. Now go to $\Bbb R^3$.
Recall that a plane's equation is determined by its normal vector and one point. Indeed, if $n$ is the normal and $p$ a point on a plane $\pi$, then $\pi-p$ (the plane translated by $-p$) is a parallel plane (so it has the same normal) containing the origin, and therefore has equation $n\cdot x=0$ (the plane is defined to be all points perpendicular to given normal). Therefore $\pi$ has equation $n\cdot(x-p)=0$.
Now consider the graph of $g:\Bbb R^2\to\Bbb R$ as a surface in $\Bbb R^3$. The function is given by
$$h:(x,y)\mapsto(x,y,g(x,y)).$$
Two vectors tangent to the surface can be obtained partial differentiation
$$\frac{\partial h}{\partial x}=\left(1,0,\frac{\partial g}{\partial x}\right), \qquad \frac{\partial h}{\partial y}=\left(0,1,\frac{\partial g}{\partial y}\right).$$
A vector is normal to the plane iff it is normal to both of the above, and we can check that
$$n=\left(\frac{\partial g}{\partial x},\frac{\partial g}{\partial y},-1\right)$$
satisfies this. Our equation of a tangent plane is therefore
$$\left(\frac{\partial g}{\partial x},\frac{\partial g}{\partial y},-1\right)\cdot\big((x,y,z)-(a,b,g(a,b))\big)=0.$$
Rearranging, we obtain
$$z=g(a,b)+\nabla g(a,b)\cdot\big((x,y)-(a,b)\big),$$
where now the gradient and dot product above are two dimensional.
Answer: We'll assume $\Bbb R^2$ so that level sets $g(x,y)=c$ are indeed contours. Thus such a level curve can be parametrized by $\gamma:[a,b]\to \Bbb R^2$ such that $g\circ\gamma=c$ (or at least a single component of the full level set anyway). Of course we can also look at the values of $f$ while we travel along the line, and turn this problem into a one-dimensional one by involving $t$. Indeed, $f$ restricted to the curve is $f\circ\gamma$, and just like in usual calculus a nonzero derivative (wrt $t$) signifies a nonzero rate of change.
We have, explicitly,
$$\frac{d}{dt}f\circ\gamma= (\nabla f\circ\gamma)\cdot\gamma\,'=0,$$
which geometrically implies $\nabla f \perp \gamma\,'$ at the pertinent $t=t_0$ value. Remember that $\gamma\,'$ is the tangent vector of the curve, and $\nabla g$ is perpendicular to the curve, so we also have $\nabla g\perp\gamma\,'$ here. Since we're only in two dimensions, if both $\nabla f$ and $\nabla g$ are perpendicular to $\gamma\,'$, they are parallel; $\nabla f\,\|\nabla g$.
Comment: Thx for explaination! Can you briefly talk about grandient? That's the part most confuesed me.
Comment: @Mathematics: Can you be more specific $-$ what about the gradient would you like to know? The condition that $f$ (restricted to the curve) has a local extrema at $t$ (according to the $\gamma$ parametriz-ation) *implies* that $\nabla f$ and $\nabla g$ are parallel. By [contraposition](http://en.wikipedia.org/wiki/Contraposition), if the gradients are not parallel, the derivative $(f\circ\gamma)'$ does not vanish. In predicate language, $A\implies B$ is equivalent to $\neg B\implies\neg A$. Is that your question? Or do you want to know why e.g. $\nabla g\perp\gamma\,'$?
Comment: actually my question isn't only stick to lagrange multiplier, its all about gradient applie in different cases. I understand your explaination to lagrange multiplier but what i dont quite get is gradient. Like gradient is always perpendicular to the level curve, but gradient can also be used to form a tangent hyper plane which is tangent to some point on some surface curves. THat's what confused me as i couldn't figure out how should one interpret gradient. You may read the question neglecting the part about lagrange multiplier. Thx in advance!
Comment: @Mathematics: Please look back at the words in your original post. The **only** discernable question is *"why if $\nabla f$ is not parallel to $\nabla g$, then there will be a change in f either increase or decrease"*. There is no hint of confusion over the information in the first few sentences of your post. Please keep in mind potential answerers are not mind-readers and cannot address questions you don't clearly express for us! :-(


How to move a sound back and forth or up and down

Question: It's easy to move a sound from left to right with panning. But is it possible to give the illusion the sound is moving away / toward / up / down the listener ?
Answer: Yes! The effect is referred to as a binaural recording. The idea is to capture and playback the audio stream in a manner similar to how your ears would have heard the audio stream to begin with, were you sitting in the room when the capture was made.
Take, for example, someone walking from left to right across a floor that is over your hear. If you're looking straight ahead you know right away that: the sound is above you, it starts on the left, and it moves to the right. You can figure this out because your brain takes the two sources it has (your left and right ears) and analyzes the delays between each source to produce a location for the sound in three dimensional space. It's pretty darn cool when you think about it.
You can make a binaural recording by using a binaural microphone setup: it's two mics mounted on either side of a dummy human head. An object that has roughly the same size, shape and density as a typical human head. What the mics capture in this case is audio data that's encoded very much as your ears would have encoded it if they were in the room listening to the sound.
Here's an image of a Neumann KU-100 binaural microphone:

I grabbed that image from this site which has some awesome, high quality binaural recordings you can listen to. For best results headphones are recommended.
But, since we live in The Age of Wonder and Amazing, you can now turn any audio recording in to binaural recording through the use of plugins like Wave Arts Panorama. These handy plugins will take a source signal and let you "place it" in three dimensional space. They take care of all the left and right channel delays as well as any filtering and phase shifting that needs to happen to make your brain think the sound is in some particular place in space. So anyone can make a binaural recording now, even if you don't have the microphone setup.
Comment: +1 for mentioning Wave Arts Panorama. (with which I am in no way affiliated, it's just a darn good plugin).
Answer: Not exactly 3D movement, but you can 'displace' sounds, or make them sound like coming from interesting places, with short delays -- I like FabFilter Timeless presets for this.
For the theory behind it, http://www.moultonlabs.com/more/principles_of_multitrack_mixing_the_phantom_image/.


Are there genes in humans from the common ancestor of all organisms?

Question: How long ago can human genes be traced? Are there any genes that go back unchanged to the beginning of life on Earth? And if so, how many?
Comment: Glycolysis seems to be a core pathway of all domains of life: http://biology.stackexchange.com/questions/2934/why-is-glucose-our-primary-source-of-energy
Comment: The term to look for is 'ubiquitous' (genes/proteins). Apart from glycolysis and ribosome there is nucleotide synthesis and some (but not all) amino acid synthesis. This list is still not complete.
Answer: I very much agree with bitwise's answer. I just want to point out that even in terms of nucleotide sequence there are some extremely conserved genes.
The most highly conserved are ribosomal RNA genes. The image below shows the conservation of 16S rRNAs from archaea, bacteria, and eukaryotes (eukaryotes do not have 16S in their cellular genome but the gene is present in the DNA of mitochondria and chloroplasts). Residues in red are conserved across all domains of life (image source):

A very nice study from 2008 [1] identified tRNA genes as the next most conserved and ABC transporter nucleotide binding domains (NBDs) after that. The alignment below (taken from the paper) shows the conservation of NBDs from various species. Note that they include eukaryotes, archaea and bacteria:
[2]

If you look at orthologous genes in general, without specifying a specific level of sequence identity, then you can find various genes (notably those coding for the enzymes of the glycolysis pathway as mentioned in the comments) that are conserved across most, if not all, cellular life.
So, to answer your question probably yes. At least, there are genes in humans today that can be found in all or almost all other life forms. Whether there were present in LUCA we cannot know for sure, it does seem likely however given how widespread they are today.
Reference

Isenbarger T.A. et al, The most conserved genome segments for life detection on Earth and other planets, Orig Life Evol Biosph. 2008 Dec;38(6):517-33.
Answer: Depends on what you mean by unchanged. If you mean a gene that maintained the same nucleotide sequence, then the answer is no.
If you meant a gene that descends from a very ancient gene, i.e. one can find orthologs in very distant species, then the answer is yes. Many of the basic molecular systems are relatively conserved, including several metabolic paths and information processing machinery. This homology is one of the strongest molecular supports for evolution and also one of the reasons that genetic engineering works so nicely.
Answer: One thing still missing from the other answers: How many genes? One answer: about 6400, i.e. ~30% of all human genes can be traced back to LUCA.
To come up with this number, I used the eggNOG database of orthologous groups. This database contains clusters of proteins that are probably homologous. So I checked how many human genes are in clusters that also contain bacterial genes. These are 6416 human genes, belonging to 1320 clusters.
Caveats: In some cases, the genes are too diverged and so their homology is missed. It is also possible that a protein evolved in bacteria after LUCA and then got transferred to eukaryotes, and vice versa.


Can you shift both the front and back gears simultanously?

Question: Is it advisable to shift both the front and back gear simultaneously? Can this cause any damage?
Answer: There's nothing wrong with doing this. It works well to shift the rear 1 or 2 shorter when shifting the front 1 taller (and vice versa) to avoid big steps in gearing.
Comment: That's alright. Don't pay any mind to the experienced bike mechanic when he answers your mechanical question with an answer other than the one you were hoping to hear.
Comment: Your shifting pattern works well. But you should not shift both derailleurs at the same time. See Below.
Comment: At the very least, I would be careful to avoid [cross-chaining](http://www.activesports.co.zw/train_health_nutrition/mtb_cross_chain.htm) when doing this.
Comment: Note that I shift the front to a larger & the rear to a smaller (or vice versa). I am not creating slack at both ends at the same time. I am not cross-training.
Comment: As I said, that pattern makes sense. But mechanically speaking, using both derailleurs at the same time means you are creating slack in the system that should not be there.
Answer: The simple answer is, no, it is not advisable, and yes it can cause damage. The chain uses tension to shift. Shifting with both front and rear derailleurs at the same time will remove that tension. The answer above is absolutely correct, but they are a bit too phlegmatic about the risks involved. Drop a chain due to poor shifting habits, and you risk wrapping the chain in the derailleur. This can and often does pull the derailleur around into the wheel.
In that case, you have lost the derailleur and chain, and you may have lost the wheel. You may even lose the frame if you are unlucky.
There is no real benefit to shifting that way, as it will likely slow down your shifting response, (because of the aforementioned loss of tension on the chain), so why would you do it?
Edit:
Per the request by @amcnabb, I'm updating this answer to include instruction on the proper way to to shift both your front chain ring and rear chain ring simultaneously.
Simple answer is, you don't. You shift one and then the other. Depending on your need (large gear change, or small gearing change) then you choose the front or rear to shift first. Shift, that one, then if necessary, ass soon as the chain settles on the new gear you've chosen, shift the other.
This is a mechanical necessity. It has nothing to do with choice, preference, or best practice. Your chain requires a certain amount of tension to shift properly. If you shift both the front and rear gears at the same time, then you will not have any tension on the chain shifting down or too much if shifting up. That will cause poor, slow, or no shifting, at best, and at worst, it will cause serious damage to your bike.
With practice and timing, you can make near simultaneous shifts, which will function properly.
The best practice, of course, is to plan ahead, use a gear cluster which takes into account the terrain you intend to ride, and to plan your necessary shifts ahead of time, so that major gear jumps are not ever required. This is safer mechanically, and makes for a more enjoyable ride.
I hope that helps.
Comment: I understand your viewpoint. But I have been a professional mechanic for 15 years. I often see bikes brought into my shop for derailleur replacement, derailleur hanger replacement, wheel replacement, and the occasional frame replacement because someone chose not to learn appropriate shifting patterns, or wasn't ever really taught by the person selling the bike how to shift properly. You may not have had an issue. But you are only one point of data, as you said, and I've seen thousands of riders, and the problem I've described hundreds of times.
Comment: You use the word "often" but I have never had this problem. I realize I'm only one person, not enough data to be conclusive.
Comment: zenbike, would you consider updating your answer with the best way to shift when you need to simultaneously go up a gear in front and down a gear in back (or vice versa)?
Comment: More anecdotal evidence to support this answer; I just sent my rear derailleur into my back wheel by shifting both @ the same time.
Answer: Depending on the tension of the chain, you might be slightly more likely to jump, e.g. going from big to little on both front and back at the same time is increasing the slack in the chain and moving it in both directions (front to the left, back to the right).
So depending on the timing, not only will the slack need to be damped out and the indexing might not be as accurate as you'd like, you're also possibly pulling the chain from one end, away from its target at the other.
I don't think is damaging per se, but a jumped chain is to be avoided if you can help it.
Answer: You absolutely can shift front and back simultaneously. However, there is only one scenario where it makes sense and it does require that your mechs to be in tip-top working order and some level of finesse on your part. Moreover, it might only apply to modern Campy derailleurs (don't know about sram, shimano).
The one scenario where it makes sense is if you have rapidly come to the bottom of a steep hill where you KNOW you're going to HAVE TO be in your small chainring. In that situation, I will use both my thumbs to simultaneously thrust the chain to the small chainring and to a small cog (on campy you can sweep across more than one cog with a shift). Doing this will keep you from suffering a huge discontinuity in cadence and you'll be ready to shift one at a time to bigger cogs before your cadence is about to drop. Everyone I know who uses campy does this type of shift at the bottom of very steep hills.
This is good to do because shifting the chainring is somewhat dicey under high torque and low cadence. Better to do it earlier rather than later, and if you are doing it earlier, you'll ALSO want to be in a smaller cog initially so you don't mess up your cadence.
Answer: Just to build upon the points of view already presented, I think that shifting at the same time would not be a big problem provided that:

You DON'T PEDAL HARD while shifting;
You have enough forward momentum to complete the shifting without having to pedal hard in the meantime. Actually, you just slowly move the cranks to complete the shifting, while the bike sort of "coasts", with no tension on the chain or engagement of the freewheel clutch.

I agree with Jay Bazuzi, I also do this "one front, two back", have done it for many years, know a lot of guys who do it, and we have no problem doing this.
BUT I have also seen stories, and being myself a victim, of the problems describes by Zenbike, crushing derailers, chains and hangers by literally pedalling them off after they had jammed.
Only the explanation differs, since I suppose the main problem is shifting under pedal load, and not shifting with both derailers at the same time. Actually, even shifting under load with only one derailer could bring those problems.
Of course, this is only one more theory, and each one should consider the essence of the problem, the facts and theories presented, and check them against its own observations, never forgetting that most probably there are many other factors involved.
Answer: I have had precisely this happen luckily I had an aftermarket alu derailleur bolt fitted which snapped saving damage to my frame but the mech, chain and the wheel were right offs ! It's an expensive lesson to learn so don't do it !
To add to my answer I wasn't shifting under load just the opposite in fact it was definitely a simultaneous shift down at the front and up at the back and I was riding cobbles at the time which I'm sure was a contributory factor ?


Can I play a Witch (the class) who is male and call him a Warlock?

Question: I am looking to play a Witch in Pathfinder, but I want to play a male witch. Can I do that, and if I can does the name matter? I'd like to call him a Warlock—can I do that?
Answer: While witch and warlock are arguably the female and male version of the same trope, just like a sorceress and a sorcerer, Pathfinder is intended to be retrocompatible with D&D 3.x material and D&D 3.x already has an official base class called Warlock (and a different Witch as an exaple of homebrewing a base class).
While I'd suggest to keep referencing to your character as a Witch (or a male Witch, when it could cause confusion), that is just a label the system places on the collection of powers, the class, and thus would only be used when speaking out of character, maybe when explaining your build to someone else or when reminding your Dungeon Master where to look for rules for your hexes.
On the other hand, in the game's fiction, it's perfectly fine to be calling a male Witch "a warlock". The same could be true for all Sorcerers/ress, or even all arcanists, depending on what "a warlock" is perceived to be in the game world.
And I'm not even talking of the possibility of refluffing your character so that, while using the Witch's mechanics, he actually is not a witch (or a warlock, if that matters) for the people in the fictional universe - e.g. maybe he's a psion whose powers work differently from other Psion psions because of some event in his past.

(For ease of reference, all classes names are written with a Capital Initial, all descriptive names are in italics)
Comment: Basically: http://www.giantitp.com/comics/oots0209.html
Comment: A rose by any other name...
Answer: In most cases, yes.
Let's break it down.
Can my character refer to himself as a Warlock during roleplaying encounters?
Yes.
In real life, I write programs for a living. When asked what I do, I can answer a lot of ways: Programer, Systems Developer, Web Application Designer, Male Model, Professional Adventurer, etc. Some of these are more accurate than others.
Your character has the same flexibility: he can describe himself however he wants. Witch, Warlock, Wizard, Fighter, Rogue, Adventurer... Regardless of what it says on your character sheet, you can say whatever you want.
Will the world acknowledge my choice of being called a Warlock?
Probably (ask your DM).
Are there others who call themselves Warlocks in the game?
When Bob, Captain of the Guard, hears that you're a warlock, does he know you mean a male witch?
If a Zone of Truth were cast on you, and you were asked your class, would you be able to say Warlock, or would you be compelled to say Witch?
These are all situations that are under the control of the DM. You'll have to ask him, but in most cases the DM will be cool with it.
Will the other players call me a Warlock?
It doesn't matter.
The other players will call you whatever they want to call you. Some will be respectful, some won't. You can express your preference of being called a Warlock, but they're under no real obligation to comply.
Can I write Warlock on my character sheet?
Whatever.
Unless your group are real sticklers for record keeping, it probably doesn't matter. Your character sheet is primarily for your reference, so put what makes you happy on it (as long as you can accurately recall the important parts of your character).
If I'm talking to someone (online or in person), and they ask what class my character is, can I say Warlock?
Nope.
Well, you can. And it might even work within your group. But no one else will know what the heck you're talking about. Just go with Witch, which everyone understands.
Answer: The real question is why not? If the GM has an issue with such a small stipulation then frankly he should lighten up on being a control freak, especially over such a small matter. Why wouldn't you be able to do things like "translate" the class for a male character. It's the model of your character, it's what engages you. Of course again this ultimately falls to the GM but unless they are absolute about the guides of the role play this shouldn't be a problem.
Answer: Of course. Different cultures have different names for things, and while your definition of a Warlock might not meet up with what someone else considers a Warlock, doesn't mean your opinion is any different.
It's the same as mages/sorcerers/clerics/druids being called Witches and the like in less magically inclined lands with less formal understanding of the intracises of magic.
On your character sheet, yes, you're a witch, but you can introduce yourself however you wish, though it may lead to all sorts of in-character problems from people who expect one thing and you are another due to having differing opinions of what a witch/warlock/wizard/mage/sorcerer/arcanist/bard/etc is.
Answer: If you want and your DM allows it, go ahead.
But if you are asking if a male witch is called a warlock, the answer is no.
"Warlock" is a lable for those who break a coven or an oath, and derives from the old English word warloghe, which means "oathbreaker". So if you want to stay true to terminology, write into your backstory that you broke an oath or betrayed your coven for some reason or another.
To summarize: A witch is a witch, male or female. A warlock is an oath breaker, male or female, witch or not — technicaly an antipaladin would even be called a warlock.
Comment: Etymology is **never** a substitute for an actual definition, and the [actual definition (in at least modern English)](http://www.merriam-webster.com/dictionary/warlock) is effectively a male witch. -1 for incorrect use of language.


changed password but still can't access my account

Question: My original computer with my itunes account crashed and burned. I am trying to make sense of the account on my new computer. I was able to buy musice and movies but now I can't do anything. I changed my password but I keep getting a message that says my password is incorrect. its not incorrect. Anybody have any ideas how to fix that. I am totally frustrated.
Answer: https://appleid.apple.com/cgi-bin/WebObjects/MyAppleId.woa/
Try signing in there. If it works, your Apple ID (and therefore iTunes account) are all working fine and there's an issue with your install of iTunes. If not, you can reset the password from there and hopefully it'll help you get it working on your iTunes.


How to register a .cn domain

Question: I would like to register a .cn domain. I found the below pages which list the officially accredited registrars:
-based in China: http://www.cnnic.net.cn/html/Dir/2007/06/05/4635.htm
-based outside China: http://www.cnnic.net.cn/html/Dir/2007/06/25/4671.htm
Needless to say that the registrars based in China have their website in Chinese which effectively prevents me from using them. There are 11 oversea registrars and I'm wondering which one I should be using.
If you look at the big names, they all have their .cn registered (facebook.cn, microsoft.cn...), and whois only shows a Sponsering registrar which doesn't seem to be offering domains registration services directly to consumers:
$ whois facebook.cn
Domain Name: facebook.cn
ROID: 20050304s10001s04039518-cn
Domain Status: ok
Registrant ID: tuv3ldreit6px8c7
Registrant Organization: Facebook Inc.
Registrant Name: Facebook, Inc.
Registrant Email: email@example.com
Sponsoring Registrar: Tucows, Inc.

http://www.tucowsdomains.com/ only seems to offer domain-related help but not registration.
$ whois microsoft.cn
Domain Name: microsoft.cn
ROID: 20030312s10001s00043473-cn
Domain Status: clientDeleteProhibited
Domain Status: clientUpdateProhibited
Domain Status: clientTransferProhibited
Registrant ID: mmr-44297
Registrant Organization: Microsoft Corporation
Registrant Name: Domain Administrator
Registrant Email: firstname.lastname@example.com
Sponsoring Registrar: MarkMonitor, Inc.

https://www.markmonitor.com/ seems to offer registration but only to "big" customers, and definitely not to consumers like me via a web portal.
Q: How do big companies register their .cn domains? How consumers like us should do it?
Answer: Here are some registrars to get your .CN domain
http://www.marcaria.com/domains/China/china-domain-registration-cn.asp
http://www.101domain.com/cn.htm

How to register a .cn domain


How to perform a task analysis?

Question: What are your methods to understand the task the visitors to your web site want to solve? Surveys? Interviews? What questions do you ask? Simple asking them about their main reason for visiting the web site or is there any more clever and in depth questions and methods you use?
Answer: One way is simply ask visitors to the site to conduct a recorded "Video-in-Video" of them while they interact with the site (what they see, hear and do on screen, simultaneous with who they are, where they are, and what they say).
A number of platforms provide some type of qualitative user experience recording; some only record the screen + audio, some only the webcam view of the participants, and some do both simultaneously.
Answer: I am not a big fan of surveys since they just annoy me and I dislike it when some popup comes in my face and asks if I want to take survey in the end.Further more online surveys have not been shown to be too successful as demonstrated by this paper
The response rate for surveys is given in the screenshot

In my opinion the most effective way would be to use analytics to determine what keywords users used to get to your site.This coupled with information about how much time users spend on your site and the bounce rate will give you an idea about how useful users find the content on your site.You can also use aspects such as conversion rates (if you have an eCommerce site) to determine where users are dropping off.Once you have this information about your  users and the background and what drove them into the site,you can use methods like user interviews and hierarchical task analysis methods to determine how users go about their task.
Another option is to use click maps (or heatmaps) to determine where the focus of your users is on the site and compare that with the vision of your site.

How to perform a task analysis?


Downgrade iPad 2 from iOS 6 to iOS 5 using DFU mode

Question: I want to downgrade my iPad 2 from iOS 6 to 5.1 because Maps is useless. I read articles saying that you need to have saved the SHSH blobs to be able to do so, which I didn't, but I haven't seen any article talking about DFU mode. Has Apple restricted the use of DFU mode? Previously, I was able to downgrade an iPad using DFU mode, even if it's not officially supported. Note that I do not want to jailbreak my device. Thanks.
Answer: DFU is something built into the hardware, so the iPad 2 firmware could modify this, but I would presume it's even lower level and not something you can change. There are no reports that iOS 6 has stopped DFU, so it's very likely something else has happened.
I don't think Apple ever has released an iOS DFU article, but there certainly hasn't been one for the last two or more years, so I don't think that has changed either.


File transfer via ssh to local machine

Question: Sometimes at work I need to ssh into a local server on the command line to do some handiwork. A couple of times I've needed to copy a file onto my local machine. I can do this with the cp command locally or on a server, but is there any easy way I can do this from the server to my local machine?
Answer: I don't believe you can [easily].  To do this between Linux boxes is trivial - you just use SCP (in much the same way as you use CP), but as you are not running an ssh daemon on your Windows desktop that won't work to well.
You should be able to pull files from the server onto your Windows box using something like WinSCP though.
Alternatively (and don't use windows so can't test it) you might be able to get away with running something like something like freeSSHd (which I found by googling, never used it) and then using SCP in much the same way as you would Linux -> Linux. See http://www.techrepublic.com/blog/itdojo/set-up-a-free-ssh-server-on-windows-7-with-freesshd/3506
Comment: Actually, I have a Linux box at work
Answer: scp will copy files between 2 computers. sshd needs to be running on the remote system. if your local system is running under Windows - WinSCP is a great Windows client.
Answer: In addition to WinSCP, FileZilla is also a great tool.
Comment: The OP is using linux.
Answer: To copy files between Linux boxes using scp do (from the server):
scp local.txt firstname.lastname@example.com:/foo/bar

to copy a local file to the remote directory /foo/bar.
To copy a file from the remote server to your local $HOME (from your local machine) do:
scp firstname.lastname@example.com:/foo/bar/remote.txt ~/local_name.txt

If for some reason scp is not present in your machine (which is probably impossible if you have ssh installed) install the openssh package. For debian based distributions, do this:
sudo apt-get install openssh

File transfer via ssh to local machine


For a theoretical (not mathematical) physicist, is there a need to learn pure mathematics?

Question: For a theoretical physicist (not a mathematical physicist), is there a need to learn pure mathematics ?
Comment: if you have an absolutely strong abstract imagination, like as they say Stephen Hawking have, then you probably don't need much higher math!!
Comment: Yes - because pure math - is also interesting. It is - really!
Answer: If you never learn anything besides what other physicists do, the only advantage you will  have over them is being smarter or luckier, which means that you will have to be really smart or lucky to get a job/get tenure at a good university/win a Nobel prize.
However, if you learn some pure math that most physicists don't know, you might be able to apply it to physics somehow. This could help you get good results, which could help your career. If you enjoy learning pure mathematics, then by all means learn some. If you don't, then you probably don't need to, but you might want to consider studying a broader range of topics in physics.
Answer: I will also give my own story:  in 1959 I took a math course on sets and group theory, against the advice of my physics major adviser, because I found it interesting. Even though an experimental physicist, it sure came handy when the eightfold way came my way :).
My advise is to take maths courses that intrigue you, even though they are not a prerequisite for a current physics course.
Comment: What a brilliant advice!
Answer: I will tell a story about the Nobel prize winning physicist, Murray Gell-Mann.  He tells it himself, I forget where. As a grad student he took, purely out of intellectual curiosity, a course in the maths dept. where he was, a course in pure maths, representations of Lie groups, and in particular he learned pretty well SU(3) (since, after all, it is one of the ones easy to visualise, the Cartan weight diagram is two-dimensional).  Later in life when graphing the properties of some of the elementary particles known at that time he saw these weight diagrams in them, except for one, where one weight was missing.  So he hypothesised the existence of a new particle to fill in the missing weight...the omega minus particle, and called this arrangement "the eightfold way".  If you never want to make a discovery like that, then go ahead, never learn any pure maths simply out of intellectural curiosity...
Comment: Found this related BBC Horizon 1964 video: http://www.youtube.com/watch?v=BGeW6Nc6IMQ
Answer: Yes. If you attempt to learn quantum mechanics, understanding of the Heisenberg picture requires a reasonable grasp of linear algebra, which will at least require the correct definition of a vector space and some facts about matrix diagonalisation. This is usually rated "pure math". Every $21^{st}$ century course on quantum mechanics I have ever heard of has a huge fail rate because the students are not taught a sufficient amount of linear algebra. You have been warned.
Answer: Abstract algebra (Group and representation theory),Topology and functional analysis are very interesting and useful. More than learning a bunch of stuff, just as there is a "physics way" of thinking, there is also a 'math way" of thinking which is good to acquire. Believe me, the two are quite different!
Although you may find it difficult and superfluous at first, you develop an appreciation for the need for rigor. It is hard to put in words, but just stick with it and hopefully you will understand what I am trying to convey.
In summary, I would urge you to try to study pure Mathematics to expand your thinking.
Comment: Know any books to show difference between physics way of thinking and math way of thinking you mention? I would like to see how a theoret. physicist approaches a problem. I have heard many times of the physics approach to mathematics. People have mentioned the solution to some math problem can be gained by reverting to your knowledge of the physical situation it explains. Shortcuts to the solution can be found in the physicists way. Do you know any books which show this physics way of doing mathematics? It would be great to see how physics can guide the solution of a mathematical problem.
Comment: I am reading Mathematical Methods of Physics by Jon Matthews and Robert Walker and in the preface it says "This is a book about mathematics, for physicists. Both motivation and standards are drawn from physics; that is, the choice of subjects is dictaged by their usefulness in phyiscs, and the level of rigor is intended to reflect current practice in theoretical physics." This may help the OP with their question. I dont know if "current practice" has changed over time. But would you say this is a good book to teach how to do math the physicists way. Do you know of any other books? Thanks.
Answer: There is definitely plenty of math you need to learn that will not be in your required math coursework and will only be given a shaky basis if it is covered at all in the physics curriculum.  But I wouldn't say its necessary to sit through lots of math classes or wade  through math textbooks (especially since a lot of math is taught in a terrible fashion).
For example, I was never actually taught topology in a class, nor has any physics student I know. But the idea of a theoretical physics who doesn't know any topology is absurd. So you'll probably have patch these gaps yourself when the time comes.
Of course learning more math is never a bad idea, and if you enjoy learning theoretical physics you will probably enjoy learning pure math. Just do what comes naturally.
Comment: If you are going to be a theoretical physicist, abstract algebra (groups theory) is an absolute must.
Answer: For some things such as category theory, most theoretical physicists can do without (sorry John Baez). However, the less mathematics you understand, the harder it is to advance into many realms of physics. For example, it would be near impossible to study, say, canonical quantum gravity without knot theory. Even classical theoretical physicists need to be well versed in symplectic topology and jet manifolds.
However, this applies only to theoretical physics. I would also like to state that your education in mathematics need not be a technical. A lot of higher mathematics (like algebraic topology) is very intuitive and feels more like an art than a science so don't stress out. :)


The shapes of the USA map

Question: I'm newbie in GIS.
I want use the shapefiles of USA map for my Geoserver. Where can I download shapes for USA? I know about the TIGER\Line shapes but it is separate shapes of counties and thematic maps (e.g. american indian areas). I want something like OpenStreetMap.
P.S. Sorry for my english )
Answer: You can get polygon shapefiles of the US from http://www.naturalearthdata.com/. They cover the whole world.
Answer: For just the state boundaries, you can download data from data.gov. If you're interested in the actual OSM data, you can download it at cloudmade, but it takes some processing to work with and is a fairly complex dataset.
Comment: Indian Lands too: http://www.data.gov/geodata/g602058/
Answer: I think you'll be able to find the data for the native american people and much more on this site http://www.diva-gis.org/gData
@underdark: thanks for your link, i didnt know that site.
Answer: GeoServer comes with a US States layer by default. Look for http://localhost:8080/geoserver/wms?service=WMS&version=1.1.0&request=GetMap&layers=topp:states&styles=&bbox=-124.731,24.956,-66.97,49.372&width=780&height=330&srs=EPSG:4326&format=application/openlayers if you have GeoServer running on your local machine.

The shapes of the USA map


Playback on ipod touch

Question: When I synch downloaded podcasts eg BBC History magazine podcast, they playback so fast on the ipod touch it is unlistenable even though it sounds normal on my laptop. Is there some setting on the ipod I need to change. Audio cds work fine on both.
Answer: When playing a podcast, a single tap in the album art area toggles the top bar on and off. The top bar shows position in the podcast, has an email icon on the left and a rewind 30 seconds icon in the middle. The icon on the right toggles between 1x, 2x and 1/2x speeds, so check that this is set to 1x. The icons on this bar are different for music tracks than for podcasts (repeat, genius and shuffle).
It's possible the ipod has got into 2x speed mode. I had this the other day, and either toggling the speed mode or pausing and playing again solved it, don't remember which.
Edit: today I had this problem. It seemed that the fast foward button was down, because the pause button was behaving oddly with this weeks "PC Pro" podcast, and the x1 x2 button didn't fix it. Strangley, clicking the home button until the spotlight search appeared seemed to be a temporary fix. Then playing with the transport buttons fixed it completely.

Playback on ipod touch


What are the differences between XBOX 360 Consoles?

Question: How many versions of Xbox 360 consoles exist, and what are the differences between them?
Answer: http://en.wikipedia.org/wiki/Xbox_360#Retail_configurations
Right now, only the "S, 250BG" is in production.
The "Elite" version came in two sizes "120 GB and 250 GB" but were mostly similar otherwise.

Every version offered after 2007 supported HDMI
Every Xbox 360 ever made will work with Kinect.

Hardware-compatibility wise, the systems we all very similar.  Microsoft has stated that the "S" series contains almost identical hardware to the "Elite, 250GB" because no game is pushing the limits of the hardware yet, even at 1080p.
Comment: really? even after 5 odd years?  Makes me wonder about how 'necessary' it is to buy a new gfx card each year to keep up on the PC *grumble grumble*
Answer: In 2013, there are just two versions of the 360 sold - both are classed as the "Xbox 360 S". Both models are identical in appearance, one has 250GB internal storage and the other 4GB. There are also other variants avalible as promontional packs such as a "Halo: 4" edition with a different colour scheme and start-up sound, or a "Gears of War" one with a special red print. Both these versions come with 320GB storage.
Both 4GB and 250GB models appear to have the model number of 1439. I just had a look at the rear of mine and there was no way to distingish if it was a 250GB or 4GB model.
All consoles sold now have HDMI ports, Wireless inbuilt, and a connection for the Kinect. I would expect they would stay like this until the next generation "Xbox 720" comes out.
Answer: Right now there are 3 Editions on the market:

360 Arcade
360 Elite
360 Slim

Now the Slim is replacing the Elite, so that one will be phased out.  There is also plans for a slim arcade version which will phase out the arcade.  As a result neither the Arcade nor the Elite are currently in production.
The major difference between the Elite and the Arcade is the presence of a Hard drive.  While the Arcade does have a small amount of on board memory, it isn't much.
Additionally, the Elite comes with a Headset and Ethernet cable.
The new Slim also comes with hard drive, headset, but lacks the Ethernet cable in favor of built in wifi (which must be purchased separately for Arcade and Elite).
You can still find the standard Elite with 120GB HD or 250GB HD and 1 or 2 Controllers (all others come with just 1 controller).
It is worth noting that the Slim is branded as Elite, even though it is different than the current Elite you can find on the market.  The noticeable difference is the slim being smaller and having a less rounded exterior.
Answer: Current Versions:

The XBox 360 S

Most other editions are getting phased out, but the new Kinect-ready edition is the only one that they're planning on keeping around. It's got a 250 gb HD, and built in Wi-Fi. Other previous editions don't have both of those features.
Answer:
As per the above image, there are only 7 different Xbox 360s out there.
Note that the real differences between the XBox 360s are only memory size and color schemes.  Having more memory allows you to buy more games from the marketplace, etc.
What it comes down to is that the only thing separating today's Xbox 360s from the first Xbox 360s are the memory size and color.
For me, I never bought the newer XBox's out on the market.  I stuck wit the XBox 360 Core, one of the very first to come out.
Comment: While I love the chart, this doesn't say anything about how to identify which one you have.
Answer: The various versions (Arcade, Pro, Elite, 'Slim') are mainly packaging differences (apart from the new Slim hardware).
There are actually multiple hardware revisions starting with the original Xenon which was the loudest, most power sucking version.
When the Elite first debuted, it had the newer 'Falcon' hardware which had a smaller cpu and ran on slightly less power and later all Pro/Arcade versions were released with this same hardware.
Subsequent revisions reduced the gpu size and overall power consumption leading up to the 'Slim'.
The 'Slim' is really the first major revision of the console, I would say (obvious by the new form factor, multiple usb ports, built-in wi-fi, etc), and running the smallest cpu & gpu and lowest power consumption by far.
Answer: There are two major families of Xbox 360:
Xbox 360 "Classic" - Comes in 0GB ("Core") 0.25GB ("Arcade"), 0.5GB ("Arcade"), 20GB, 60GB, 120GB ("Elite"), and 250GB (also "Elite") models.
Xbox 360 S (smaller, has a special power port for the Kinect, has built-in Wi-Fi) - Comes in 4GB, 250GB, and 320GB (Special Edition only) models.
The two families use different hard drive bays, so drives for one family of systems do not work in the other. All consoles that you can buy new are Slim models.
The Hard Drive has two main uses other than for saved games:
Some games give you an install option, which improves load times.
You can purchase downloadable games from the Xbox Live Marketplace.


What should I look for in strawberries at the market?

Question: When I'm selecting strawberries at the market or farmer's stand, what should I look for to indicate the most flavorful berries?  I don't need the strawberries to keep; I'll be using them immediately.
Answer: I mostly agree with Rumtscho, except that I think "red through and through" is a bit too strong: a bit of white at the top doesn't have to mean anything, as long as it is not too much, and as long as there is not white in the bottom half—so these look good:

Another thing to watch out for is how far apart the seeds are. I think one can never be sure of anything with strawberries, but, if the seeds are farther apart, that usually means they are sweeter. I also like the ones where the seeds are a bit deeper into the skin better. The ones above look good in both respects. These, however, do not:
Answer: Smell. Really, this is the most reliable criterion for practically any fruit.
Flavor contains both taste and smell. For a strawberry, you want a fragrant smell together with enough sweetness. For both, the berry has to be ripe enough. If it was picked underripe, it won't smell good enough yet, and it will also be hard and sour. If it was picked long ago and is not fresh any more, it will have lost the more volatile components of its fragrance. So ripe, fresh strawberries smell great. I have had occasions when I entered a supermarket to quickly buy one thing, aimed at the correct aisle, but when the smell of good strawberries reached me near the produce, I turned and added a pack of them. I have never been disappointed with such strawberries. Also, if you smell the slightest hint of mold, fermentation, or foulness, you know they may not keep even one night.
Another sign is that a ripe strawberry will be red through and through. A strawberry picked underripe will be white or even slightly greenish at the top. It doesn't taste good then. But this is a negative sign, because not all red strawberries taste good.
Don't ever go by shape. The tastiest sort of strawberries my grandparents grew produced ugly, lumpy strawberries of a light, slightly orange color. They also had a few rows of a sort which produced perfectly conical, deep red strawberries, they looked like an advertisement - but they were hard and dry, and didn't have much aroma. Probably, there are some strawberries which both look and taste good - just don't think that looks or color predict a good strawberry, because they are independent.
And of course, any strawberries which have visible mold or fouled spots are not good any more. You can usually also recognize overripened strawberries in their appearance, but I don't know how to describe it well. They just look old.
Comment: Older/overripen strawberries looks duller and has less sheen. And obviously if its starting to wrinkle and wilt, its old.
Answer: One thing I learnt from villagers in Central/Eastern Europe where wild strawberries were often seen growing along the sides of streets was that smaller strawberries have more flavor. It was though each strawberry was born with 'x' units of flavor, so the bigger it got, the less flavor-dense it became.
I've never done any scientific testing of this, but I must say since those days I've been only choosing smaller strawberries and my success rate feels like it has gone up.
Comment: This only holds true within a strawberry variety. There are big strawberry varieties which are very tasty and beat certain small strawberry varieties.
Comment: Yes correct, I should have indicated that.
Answer: This is anecdotal, but I think accurate. I am not a farmer, but buy strawberries at a farmer's market where there is quite a bit of friendly competition for things like "best tasting strawberries." From what I've heard, farmers here make a choice whether or not to irrigate their berry plants. Those who do tend to end up with bumper crops of not very exciting strawberries. Those who don't have lower yields, but more intensely-flavored strawberries. You can always ask the farmer, but it doesn't take much taste-testing to figure out which ones go for the concentrated flavor over a quick buck. I'm not sure about the science behind this, but I've heard it holds true for tomatoes as well.


iCloud storage is almost full

Question: I have an iPhone 4 and an iPad 2.  I've only had the iPad for three weeks, and iCloud is almost full.  How can I free up space?  I prefer not to buy more space.  It looks like the iPhone is using most of the space.
Answer: Go to Settings > iCloud > Storage & Backup > Manage Storage > under "Backups" select the device you want to free up space on (i.e. "Jim's iPhone"). Go through and turn off different apps that you would like to not backup to iCloud. You can also see the applications that store data in the cloud (i.e. Camera Roll) and how much space each application has in cloud. This should show you where you can go to delete things and free up space. Or you could just turn off that apps backup.
The iCloud backup list sorts applications with the greatest users of backup space are sorted to the top of the list, so you can quickly assess whether you can thin out the content or need to either purchase more backup space or perhaps disable iCloud backups and instead back up to iTunes and then delete your iCloud backups to allow the space there to serve document sync and email storage.

iCloud storage is almost full