Alternatives to Familiars in DnD 3.X

Question: Players tend to not keep very effective track of their familiars. Where can I find (or equally what can I use as) alternative Class Features for Wizards and Sorcerers to replace Familiars which will be more interesting and exciting for the players, while maintaining class balance?
Comment: I'd like to add "In D&D 3.0 and 3.5" to the question, because this issue is somewhat specific to those games- earlier editions have a different benefit (plus it's an Opt-in spell, so it's a non-issue), and later editions handle familiars as a feat (so it's an opt-in like AD&D- and also a non-issue). But I defer to the community.
Answer: Check out the D20 SRD.
There are some class variants that might appeal to your players. Specifically, many of the Specialist Wizard Variants involve replacing the familiar with some other bonus related to specializing in a specific school.
There's also an option to take an animal companion rather than a familiar.
Comment: There's a similar but slightly different implementation of the same idea (specialist wizards get specialist toys) in the excellent PHB2, which also has an option for sorcerers that lets them eschew a familiar in favor of not expanding casting times to use metamagic feats.
Answer: I like what Pathfinder did with Familiars. Instead of being forced to either take a familiar or ignore a benefit of your class, you can instead choose to take an Arcane Bond with an item. This item gives the caster the ability to cast any spell in their spellbook or that they know once per day. It can also be made magical without having the requisite item creation feats (must still meet other prerequisites of the magical enhancement).
If for some reason the caster loses their bonded item, they have to make a concentration check to cast any of their spells until it is replaced. A character with an Arcane Bond can choose to have it with a staff, wand, ring, amulet, or weapon.
Answer: The issue in 3.5 is that (Wizard and Sorcerer, and certain other) arcane characters automatically qualify for a familiar, regardless of character concept.
If they aren't interested in roleplaying out what amounts to an additional NPC (and the DM doesn't want to either), that's kind of a problem. Although players usually don't balk at the idea of the little benefits they get from the familiar when they come up.
At low levels, the 3.5 Familiar generally grants benefits equal to a feat: A skill focus feat, toughness (for the toad), etc. PLus the Alertness feat.
One idea is that you just take the equivalent bonus of the familiar and attach it to something Non-animate (thus removing the NPC qualities of it)- for example- a tattoo or a personal Hex/charm/totem..  that the wizard might have-- that grants the exact same benefits of the Familiar.
A Wizards Tome or grimoire could be the focus of such a benefit- as long as she carries the grimoire, she gains the equivalent of a Skill focus feat (chosen at the beginning of a campaign). To account for the loss of Alertness, you might say that the Skill focus feat is reconfigurable between adventures- these are magical books, after all, able to grant advice on any manner of subjects.
Whatever you choose- I recommend that you don't go far beyond the established structure of a feat (possibly with or without alertness) as the benefit.
Comment: Somewhat related to this is the 3.5 Binder class- because the Vestiges are the equivalent of NPCs that have roleplaying personas (and grant benefots). But if the Player doesn't want to roleplay them, and the DM can't be bothered to either, you have a problem. I love both familiars and the Binder class, so I'm looking forward to hearing other answers. I had this exact problem myself.
Answer: As familiar-keeping characters in D&D 3.x are generally saddled with the often problematic d4 hit die, I've always liked the solution of trading the familiar in for a d6.  It's mechanically almost identical to taking the Toughness feat (the 3.5 version, anyway), and Familiars are just about worth a feat, anyway.  (Arguably, they're worth more at higher levels, but a high-level D&D 3.x spellcaster does not need any further compensation.)
Comment: +1 That's not a bad idea, since the player often forgets about the benefits the familiar offers just as much as the familiar itself.
Comment: In 3.5, it's almost identical to taking the Improved Toughness feat, which gives one extra HP *per level*. Toughness only ever adds 3 HP, full stop.
Answer: The later issues of the Paizo run of Dragon Magazine had some pretty good options - if you're okay with Eberron content, there's an awesome prestige class in issue #357 (Demogorgon on the cover) that lets you take a living spell as a familiar, and it always looked to me like a terribly fun class. Because really, why cast a fireball when you can summon an animate, sentient fireball instead?
Answer: There were various class replacement options including swapping out familiars in the PHB2 and Unearthed Arcana, I believe. I hate familiars, they are lame and almost always ignored even by wizards that have them IME.  They go into the magical wizard familiar dimension 99% of the time till mentioned (usually for either roleplaying or "go get the key, we're locked in a cell" purposes). Last time I played a wizard, I used the Conjurer replacement @veritascitor mentions above to get Rapid Summoning rather than a familiar and that was a huge, huge improvement.
And now I play Pathfinder, which as @MikeBohlmann mentions has arcane bonds instead.  Yay!

Alternatives to Familiars in DnD 3.X


What features should you add to a homepage to help sign-up conversion?

Question: There are a few give-ins...simple social sign-up, tours, testimonials... but what have you found in your experience that really puts the icing on the cake when getting users to sign-up with the site. its a fitness site
Answer: 37Signals did an amazing job with Highrise. They've been testing  the signup page using different designs and sharing the results.
http://37signals.com/svn/posts/1525-writing-decisions-headline-tests-on-the-highrise-signup-page
http://37signals.com/svn/posts/2977-behind-the-scenes-highrise-marketing-site-ab-testing-part-1
http://37signals.com/svn/posts/2983-behind-the-scenes-ab-testing-part-2-how-we-test
http://37signals.com/svn/posts/2991-behind-the-scenes-ab-testing-part-3-final
There are a number of ideas validated with a/b testing in these articles. One of them, a bit of a cliché:

Big photos of smiling customers work

Check the articles, and see if that's what you want. I am developing and testing a signup page right now. I think it worth doing a/b testing in the specific case of your page, I'm doing the same. When I have concrete results, I'll edit the answer to add them.
Answer: Personally whenever I see a site that tells me exactly what it does, looks elegant, and lists out exactly what it's capable of doing, and I'm interested in what it's telling me, I tend to register.
When people are informed without actually wanting to be informed, they're happy people, and are more likely to register to your site. I did a mini web-psychology experiment on something like this a few years ago. People are lazy, so your design has to help them!
A Login and Signup button should be displayed in an area that makes them very visible, sign up could start in the same window if you have the space. You should definitely inform the users what you're trying to do, what you DO do, and how you do it -- that definitely entices or un-entices users in to registering or going away. Then again, this should have some classic happy people, and other 'usual' marketing techniques to try and get them to be interested, it's no good losing customers!
Good Luck!


How do you know when a cultured item is no longer safe to consume?

Question: How do you know when yougurt (for example) is no longer safe to consume?
Do I know it from the taste, how it smells, or something else?
Answer: Cultured milk products rarely become unsafe.
Yogurt in particular is so acidic and teeming with bacteria already that it can't really go bad per se. It will get moldy as others have said.
I culture my own buttermilk, yogurt, kefir, cheese, etc. Many times they stay on the counter for days at a time. They get more and more sour (if they are the kind that incubate at room temperature) but they can't really go bad. Even sour cream doesn't become dangerous- the mold just tastes bad.
To second what kajaco said: if I do have cultured dairy get too sour or moldy I will wipe off the mold and bake something with it.
It should be noted that non-cultured milk is completely different. Of course it goes bad fast but after even a short time it is too bad to bake with. And never ever EVER use old milk to culture your own yogurt or cheese. The bad bacteria will overwhelm the good and you will end up with liquid that will haunt you in your nightmares!
-- Edit --
https://web.archive.org/web/20161129153701/http://nchfp.uga.edu:80/publications/nchfp/factsheets/yogurt.html (OR pdf)
I did some research and it seems that they can eventually go bad. It doesn't fit my experience but I'll defer to the scientists. Trust your nose.
Answer: Before something is unsafe to eat, it usually becomes unappetizing or unappealing. This is observed more by how it looks and smells than how it tastes (why would you taste it if it looks or smells bad?). Unless your choice is to eat something unappetizing or to go hungry, most people would not use it but throw it out if it is unappetizing.
There are exceptions, however. I would not drink sour milk, for instance, but I will bake with it (this requires adjusting or changing ingredients such as baking powder vs. baking soda, but that's another question).
Answer: "When in doubt, throw it out..."  (Or compost it, etc.)
Seriously, all it takes is one good bout of food poisoning and you form a habit of not eating anything suspicious.  I will still cut off a moldy end of hard cheese and eat the other part, but if milk or yogurt seems at all suspicious, I get rid of it.
Comment: Why not compost dairy?
Answer: Personally, I sniff and if it smells right I'll generally take the risk of using it. The hygiene department may not agree though. I really trust my sense of smell. On the other hand if I see an ugly mold growing, I may change my mind.
FWIW - It's usually yogurt and a few cheeses where I run into this issue...
Answer: It is not safe to eat anything with mold on it !  See,  some of the spores are microscopic so it is not visible to your eye, I  would dump it.
Mold is  a mycotoxin it can cause biotoxin illness,.
This is what I do I put  a sticky on the lid of my homemade yogurt and I just keep it for two weeks max that is it.


Is it a legal requirement / building regulation to have a stopcock within a property?

Question: I recently moved into a property (in the UK) - it's a 1930's semi which was renovated about 2 years ago. I am wanting to have a water meter fitted - utilities company came to have a look and couldn't find a stopcock in the house. There is a mains stopcock in my front garden which controls the supply to both mine and adjoining neighbours, but nothing we could find in the house. I struggle to believe that i can't turn my water off without disturbing next door - is it a legal requirement or building regs requirement to have an individual stopcock in each property?
Answer: If it is a requirement to have independent control of the water supply now then it won't be applied retrospectively unless and until you have some work done on the water supply.
The first thing you should do is arrange with your neighbour a mutually convenient time to fit individual stop cocks. Then when this is done you can then arrange with the water company to fit the water meter.
Having said that, we have a house built in the 1890's that has it's own stop cock so it might be that you just haven't found it yet. Have you checked close to the house?
Another possibility is that the stop cock has been buried in a floor. This was the case in our previous house where the kitchen floor had been relaid and the stop cock - which was just below floor level inside the house - had been partially buried.


How can I thicken an already cooked pie filling?

Question: I made a coconut cream filling using 2% milk as that was all I had.  Now, more than 6 hours later, it still has not set although it was thick while I was waiting for it to cool before pouring into the prebaked crust.  Does it need to stay overnight to set?  Can I pour it back into a saucepan and warm it up and add more cornstarch?  I hate to waste the ingredients.
Comment: What did you substitute the 2% milk for? Dairy cream, or coconut cream? They're very different things. Would help if you posted the recipe or at least the ingredients.
Answer: If your filling is similar to a custard, consider adding a lightly whisked egg and baking on medium-low heat for maybe 20 minutes. If you must stove-cook it, stir only enough to combine the ingredients well, as whisking too much will weaken/break the proteins.
Protein is the key to thickening things like custards and other fillings. Coconut milk is lower in protein than cow milk. The heat will allow the proteins to coagulate and form a sort of net that traps the rest of the ingredients, causing a thickening action. Refrigerating it for a short time will also contribute to solidifying the protein network and help set it.


xubuntu 12.04 hang on boot of kernel 3.2.0-44-generic

Question: I just updated and got the 3.2.0-44-generic kernel on my desktop Dell T3400. When I rebooted as required it hung in the XUbuntu screen with the moving bar... the bar stopped moving and nothing else happened (I gave up after 5 minutes).
I forced a power cycle and using grub booted 3.2.0-44-generic in recovery mode. The fsck selection reports "Superblock last mount time is in the future"... and "FIXED", the dpkg selection reports no broken packages, and the resume selection runs briefly before hanging. The last things reported are:
swapon:/dev/disk/by-uuid/613f8c15-413f-4339-81b4-a3b2b092480f: swapon failed: device or resource busy

swapon terminated with status 255

init ctl: Event failed

and DAHDI then prints some stuff with the last thing being "dahdi_transcode:" then it hangs. On one try (but only one of several) after about 15 seconds I got another msg that started with:
rcu_sched detected stalls on CPU/taksk: { 1}

(EDIT Every few tries I get rcu_sched detecting a stall, and most of the time this happens it starts endlessly dumping a bunch of debug info... too fast to make sense of. But once it froze with rcu_sched actually reporting that dahdi_transcode was the actual task that was hung. I dont know how accurate this is since memory may be corrupted by something earlier in the boot process)
Grub memory test was OK. And I can boot the prev kernel (3.2.0-43-generic) OK.
Any thoughts or clues on how to fix this?

More info since it looks like a swap partition problem (all from the 3.2.0-43-generic boot):
my /etc/fstab is:
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# / was on /dev/sda1 during installation
UUID=c88a26e8-a137-4910-9601-6274caebc1f4 /               ext4    errors=remount -ro,user_xattr 0       1
# swap was on /dev/sda5 during installation
UUID=613f8c15-413f-4339-81b4-a3b2b092480f none            swap    sw               0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0

and "fdisk -l" shows:
Disk /dev/sda: 250.0 GB, 250000000000 bytes
255 heads, 63 sectors/track, 30394 cylinders, total 488281250 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa42d04a3

Device Boot         Start         End      Blocks   Id  System
/dev/sda1   *          63   476214794   238107366   83  Linux
/dev/sda2       476214795   488279609     6032407+   5  Extended
/dev/sda5       476214858   488279609     6032376   82  Linux swap / Solaris

where gparted shows sda5 to be within sda2
Answer: Since it looked like the dahdi_transcode initialization was hanging the kernel 3.2.0-44-generic boot, I rebooted into kernel 3.2.0-43-generic and removed all dahdi modules using the Ubuntu Software Center, then rebooted into kernel 3.2.0-44-generic. That did it, no more hang during boot. Since I dont use my desktop box for telephony this solution works for me.


Key out white of embedded image in Illustrator

Question: I have an Illustrator document with a number of images embedded. The images are all illustrations on a white background. I need to remove the white so that the art behind shows through. I know there are a variety of ways to do this in Photoshop, but is there a way to do it in Illustrator?
Answer: You can draw a path around the portion of the image you wish to remain visible, then select the image and your path and choose Object > Clipping Mask > Make.
Essentially, you simply create a masking shape the same as you would in Photoshop.
Answer: Also you can try to trace copy of your image with b/w threshold and then use traced shape as mask.
Right way to deal with transparancy is to use the format that supports it. Like PSD or PNG.


Is a fetus's level of activity a good way to predict their personality?

Question: Right now, my wife is having a 7 month pregnancy. :D
Everytime we see our baby through USG when we visit our doctor, our baby looks very calm. He only made a simple movement such as chewing.
Will my boy be a calm/introvert boy?
Answer: Here is research that I found on this topic at http://www.ncbi.nlm.nih.gov/pubmed/12115294.
It appears that the relationship between fetal movement and neonatal behavior is inconsistent. Fetal activity did appear to predict temperament related to self regulatory behaviors in early childhood. Small positive associations were detected between motor behavior at 36 weeks gestation and neonatal irritability and motor development.
So, no it does not appear that fetal activity is a good predictor of personality even though there may be some statistical association.
Answer: This is entirely based on my experience so your mileage may vary, and it's not at all scientific.  I felt I knew some aspects of my child's personality while she was still in my womb.  I knew she would be strong and stubborn because of the way she kicked.  I love my baby to the hilt but she's been stubborn since the day she was born.
That said, babies in the womb spend a lot of time sleeping.  Chances are, your baby is sleeping during an ultrasound.  They recommended I drink orange juice 1 hr - 1/2 hr before the ultrasound, figuring that the natural sugar would wake her up.  It didn't work once (she slept the whole time and had her body turned so we couldn't see her face) but worked well the second time, although the second u/s she was asleep for some of it.
I'd ask your wife what her sense of the baby is, but not put too much stock in what the ultrasound shows to guess how extroverted or active the baby will be.
Comment: +1 for the juice trick to wake up the baby. We had several doctors and nurses recommend this for us, and it really did seem to work.
Answer: I am not aware of any studies or even rumors that calm fetuses make for calm babies.
My personal experience is similar to yours, our son was very calm during ultrasound. But believe me: he is anything but calm in the outside world...!
Comment: Thanks for your sharing. I'm really excited to know every single information about my son. ^^
Answer: My son was very, very active during ultrasounds. It wasn't until roughly 7 months that we could even get a look at his face because he kept moving around so much.
However, despite his rowdy pre-birth behavior, he's generally very calm and even-tempered.
Activity on ultrasound is not really an indication of personality, in my (admittedly limited) experience.  As Corvus Melori pointed out, babies spend a lot of time sleeping before they are born, and you may have just been unlucky in the timing of your ultrasounds.  The juice trick she mentioned is an excellent idea, and may result in your baby being considerably more active.
Answer: This may be true, but may work in the other that way you expect.
If you decide your child seems calm/active/stubborn while watching her/him in the womb it may affect the way you treat the child and what character features she/he develops.
I think giving labels to the unborn child or any child at all is not proper thing to do. I think there's related situation described in one of this books (or a supplement to it):
http://www.amazon.com/Talk-Kids-Will-Listen-Listen/dp/0743525086
http://www.amazon.com/How-Talk-Kids-Can-Learn/dp/0684824728
The woman heard her child is stubborn during giving birth and one day she noticed it somehow affected the way she thought of him ever since.
Comment: your answer is very interesting, how's your experience?
Answer: I think it's hard to give a conclusive answer.
My mother told me when my she was carrying me, that she could feel that I would be a calm boy, unlike by brother. Indeed I was and still am much calmer than my brother. This was something my mother could feel by carrying me around in her womb.
I doubt that a few USG sessions will give you the same idea. Maybe you should instead ask your wife how she perceives your boy. She is the one carrying him around after all.
Comment: I see. And as your suggestion, I already asked her. She feel that our son will be a calm boy :)


What's the category name of "city" and "rural"?

Question: When I ask whether someone's living situation is rural or city, what's the category I'm asking about? Living situation includes many other things, but there's gotta be a word summarizing those two things, right?
Comment: Surely it should be _urban_ and _rural_, not _city_ and _rural_?
Comment: Related: [Generic name for places like village, town and cities](http://english.stackexchange.com/questions/65325/generic-name-for-places-like-village-town-and-cities/)
Comment: @Matt But if I understand this question correctly, he wants the person to answer "urban" or "rural". In the related question you cite, the desired answer would be "London" or "Murphreesboro" or some such.
Comment: A google search shows a definition of  *cityness* as "the quality or state of being citified" and some links to studies that use *cityness* to denote the degree of citification in an area, but it appears to be questionable.
Answer: Urbanization.
Or Population density.  (Advantage: quantifiable)
The above are more often (perhaps exclusively) applied to a place rather than a person.  That is, they are geographic terms, I understand you want a demographic term.
Great question.  And timely as the world recently (2007) crossed into 50% urban.  Some more ideas, with tongue half in cheek, for a single-word term:

urbanity
citification
citizence
citizensity

Okay I'll stop.  The U.N. seems to call this demographic dimension "urban/rural".
I noticed during a elementary-school research project that kid happiness seemed to increase the further I drove from D.C. (the more rural direction of your spectrum).  Also increased were noise and freedom and agedness of clothing and buildings.
Comment: I did mean the geographical property, I think. Thanks for this answer!
Comment: Geographical really?  Thrilled to have helped, and on any other site this would be whiny and nitpicky of me to say, but when you said "someone's living situation" it sounds like the perspective is more on people (demo) than places (geo).  If Fred moves to the city that's demographics.  If Freiburg's population increases to the point it becomes a city that's geographics.  I still believe "Urbanization" would make sense applied to people (demography) though that usage may be unconventional.
Answer: I don't know of a special word to describe this relation.  From a geographic data perspective, the more accurate phrase would be "urban" versus "rural".  The US Census Bureau has a very precise definition here where they call it simply the "Urban and Rural Classification".
Answer: If you are meaning urban, rural and so on, the only thing I can really think of to describe them is Areas. This could lead to some confusion though, as if someone asked me what Area I worked in I would say Trafford park or Computing, not an industrial area.
I think this is one of those times when the oddness and ambiguity of the English language shines through!
Answer: If you are talking about a heading to put on a column of a report, where you are supplying the answer, then I agree with BobStein that "Urbanization" would be a good choice.
But if you are looking for a label to put on a box on a form that would lead the person filling in the form to answer "rural", "city", or "urban", I don't think there's any choice of words that would get the desired response other than listing the choices. If I was filling out a form and came to a box labeled "Urbanization", I'd have no idea what to put there. I think your best bet would be to give the user a multiple choice question, where the choices are "urban", "rural", "suburban", whatever. If it's a form on a computer, give them check boxes or a dropdown; if it's a paper form, give them a set of check boxes or have them circle one or whatever.
Even if you do find some term officially sanctioned by the census bureau or whomever for this idea, it's unlikely that most of the people filling out the form would know what it meant.
Comment: It's a term used internally in my code. The name's already picked, but I figured I could still check english.stackexchange to see what the properer word would be. So the answer to your unstated question is "Report", but no one will ever see the column name anyway.
Comment: @lowerkey In that case, I think "urbanization" would be a good field name. :-)
Answer: If you want a category where the members (not subcategory) are 'urban' and 'rural' (and I guess additional elements like 'suburban', 'town', 'village') it would be:

density of settlement

or more generally

type of settlement

(the latter allows variation: a village may be more dense than a suburb, but also more rural).
As an aside, it looks like you desire a single word. There's no guarantee of a single word...ever. The description may be the best there is. But there usually is a minimum succinct one.
Also, there may be an official term which is in some sense technical (meaning stipulated by authority and whose natural meaning may be imperfect for the concept or even irrelevant: e.g. 'metropolitan statistical area').
Or one can also just name the category with a (hopefully) short list of members (e.g 'urban/rural').
Answer: I'd say "urbanicity" (although I note that someone on the internet is claiming to have copyrighted a process for determining this, so not sure what implications this may have in using it in a survey) or "rurality", depending on what question you are asking. I'd consider the two terms to be inverse to each other (i.e. high urbanicity = closer to urban area, high rurality = further from urban area).
I'd tend to use urbanicity more than rurality, as usually when measuring things, it's in relation to urban areas (as rural areas are more geographically diverse). Of course, if you were measuring proximity to some rural aspect, then rurality would be more appropriate.
Not sure if these are official terms, but I'm sure I've read them somewhere in geographical literature.
It would be nice to have one common term though.
Answer: Consider "type of community".  Although "type of locality" might be closer to it, non-native English speakers might not know the word locality, but community is a more common word.


Finding decision boundary from empirical distribution

Question: Based on measuring a certain characteristic, we want to classify measurements as coming from either of two populations. The true population distributions are unknown (and we don't want to take any strong assumptions on this), but we have a number of measurements from each population providing us with two empirical distributions. Thus, we are looking for a method to determine a good (i.e., approximating the optimal) decision boundary based on the empirical distributions. Do any of you happen to know a general and accurate way to determine optimal decision boundaries given two arbitrary empirical distributions ?
Answer: There's always going to be a prior. Even a method that doesn't explicitly use one will be hiding one. The fact of the matter is, you expect your distributions to be simple in some respect, somewhat smooth, maybe belonging to a parametric family, etc. The more data you have, the less this assumption will matter, but it always will. You also need a prior on whether you think observations tend to come from $A$ or from $B$.
What you will prefer hearing:
Pick a gaussian kernel with variance $s$ and compare
$$f_a(x) = \sum_{\mathbf{x_i} \in A} g(\mathbf{x}-\mathbf{x_i})$$
$$f_b(x) = \sum_{\mathbf{x_i} \in B} g(\mathbf{x}-\mathbf{x_i})$$
if $f_a < f_b$, assign to bin $A$, otherwise assign to bin $B$
(note, this assumes that the cardinal of $A$ and $B$ are indicative of the prior probability of an element to be drawn from either)
Adjust $s$ according to the variance of your empirical distributions.
Answer: There are many well known ways to do this: logistic regression, probit regression, Bayesian logistic regression, Bayesian probit regression, Fisher's linear discriminant, perceptron, backpropigation networks, Bayesian neural networks, SVM, RVM, Bayesian graphical networks, Markov random fields...


How can I get beer out of a keg without CO2?

Question: I've run out of gas; how can i get the beer out of the keg?
Answer: Put a cobra picnic tap and tubing on a grey gas IN connector and attach it to the gas post.
Attach a longer open ended piece of tubing to the beverage out post.
Lay it on its side with a 2x4 block under the end of it.  Lay the keg so that the IN post is down at 6 O'clock and the beverage out post is at 12 O'clock.
Now keep the open ended running above the keg so beer doesn't run out of it.  Then you can drain the keg as if it was a  cask via gravity.  Be careful about hooking up that tubing to the beverage out end.  If the keg is charged/pressurized beer will come screaming out of it, so be sure the keg is laying on its side first, and have something to catch what beer might come out initially... I'd suggest a bucket, large glass, or your mouth.
Answer: This probably isn't too helpful for your current problem, but they have small CO2 hand-chargers for corny kegs that use small CO2 vials.
This is one option.
I use one with a small picnic tap to bring a keg places without lugging the entire gas cylinder and regulator with me. You just have to be careful to monitor the pressure in the keg by feel. It also comes in handy if I run out of gas and haven't had time to get it refilled.
Answer: There is an alternative way I have found to work. If you have your keg in a kegerator and have run out of CO2, then follow these steps.
First start by disconnecting the CO2 from the keg coupler. Use a bicycle pump with a needle used for blowing up sports ball to replace the CO2. Attach the needle to the CO2 line and use duct tape etc. to secure it.
Once you have made sure there is no leakage occurring, begin pumping and open the tap. The liquid will begin to flow out of the tap without the need for siphoning. As long as the bicycle pump stays attached with the CO2 line, this method will continue to work until the pressure is let out.
I agree with the above answers and think that is a very good method if you are using a picnic tap, but if your keg is at home and you can't pull it out of the keg and lay it on its side, this is a very effective method. I have used it multiple times myself when I didn't feel like going across town to refill CO2. If the need or opportunity arises, please try. If my given directions are followed, you won't be disappointed.
Comment: Bicycle pumps are typically lubricated with oil, you definitely *don't* want to hook one up to your keg!
Comment: You probably won't get any oil in your beer with this method. (Try pumping into a plastic bag - see any oil?) A real concern is that you are introducing oxygen and the beer will go bad very quickly. Drink fast.
Answer: Similar to brewchez' answer, if you already have a picnic tap with a black beer-out disconnect on a long enough beer line, you should be able to syphon the beer out by filling the beer line and keeping the tap below the level of the beer in the keg. Obviously you'd also need the pressure relief valve open while pouring. You could start the syphon by either filling the beer line with water (or another beer), or sucking on the end of the tap, or gently shaking the keg with the relief valve closed and the tap open.
I've also heard of someone using a soup ladle to scoop beer out of the top of a corny keg, but I'd leave that as a last resort!
Answer: I would suggest using an autosiphon.  Everything stays upright, and nobody's mouth is on anything.  Rest it on the lip of bung until it gets down about halfway and then lower the autosiphon into the bottom.  Really what you're looking to do here isn't that much different than racking from a carboy.
Answer: I would use gravity. Start by taking a liquid line with a picnic tap and filling with sanitizer. Next, put your keg on a counter. Take the lid off your keg (to de-pressurize). Connect your liquid tap to your keg, then open the tap. You should be good to go. Make sure to catch the first bit into a bucket, as you'll want to dump it since it has the sanitizer.


Mudding over plaster walls with pre-mixed joint compound

Question: I just read a blog stating that pre-mixed joint compound should not be put over pre-existing plaster walls.  Why?  What is the best product to use?
Comment: Are you doing a skim coat, or patching holes/cracks?
Answer: The answer really depends on what you are trying to do.  A full skim coat, patching, or covering lead paint.  In general, many GP premixed compounds specifically say not to be used as a skim coat.
For the sake of argument, let's assume you are doing a full skim coat. Start with a full bodied joint compound, not a lightweight. Divide the pail in half into another container.  Cut it a bit with water and Ivory dish soap, mix extremely well until it is the consistency of pudding.  Firm enough to stay on your hawk, but loose enough to glide on the wall. This mix will elimamate most of the air bubbles and give you a very smooth coat without a lot of sanding. Apply with a 12 to 16 trowel or knife.  Make your first coat about 1/16" thick. Sand it with a very fine sanding sponge or screen. Give it a second coat to fill the void spots and sand it again.  You can wet float it for a glass like finish.
Comment: Why divide the plaster in half before mixing? And what is fullbodied vs lightweight. My shop only has one type of premixed...
Answer: Use Durabond; remove any loose plaster, then prefill holes and let the Durabond set. Once set then mud and tape the prefilled hole spots and let it set. As far as spider cracks and straight line cracks take the tip of a screwdriver, line it up with the crack and slightly apply pressure and drag a concave little trench so the Durabond has a base to adhere to. If you do not do this the cracks can re-appear! Note: tape larger cracks. smaller cracks can usually be strung over. Mud over what you taped and let set. Note: float tape and feather in outside edges, let set well, then scrape any high spots flat, then recoat. Depending on your skill at this, you may need to skim (lightly coat and sand) the entire wall.


convex combination of two covariance estimates

Question: I am interested in covaraince matrix estimation. In brief: I have two estimates of the covariance matrix, and now I want to form a bona fide convex combination of the two.
Background: I have studied the work on regularization of covariance matrices. Assume the $R$ is the true $p\times p$ covariance matrix, and that I have $N$ observed vectors with covariance $R$. Then, a common technique, deeply studied by Ledoit and Wolf, is to regularize the estimate according to $$(1-\rho)\hat{S} + \rho I$$ where $\hat{S}$ is the sample covariance matrix. The optimal $\rho$, in a quadratic mean sense, depends on $R$ which is unknown. Therefore, a bona fide estimator is derived which is asymptotically consistent, that is as $N$ and $p$ grows, the bona fide estimator is as good as the optimal which requires knowledge of $R$.
Background of my problem: I have two sets of data, one set where N is huge but where the reliability is fairly low, and another set where N is smaller, but the accuracy per observed vector is higher than for the first set (this may seem as an utterly confusing statement, but the reason is that that in the first set, I observe $Hx+Gy$ where both $x$ and $y$ are random, and $R=HH^{H}+GG^{H}$. In the second set, I observe $Ht+Gy$, where $t$ are known training vectors so that the randomness is less.) This leaves me with two sample covariance matrices, $\hat{S}_1$ and $\hat{S}_2$, and my next step is to form a convex combination
$$\hat{S} = (1-\rho)\hat{S}_1+\rho \hat{S}_2$$
I can do this, but I do not get a bona fide estimator.
Question: In the regularization framework of, e.g., LW, is it important that one shrink towards the identity? Or will the general framework hold true for a convex combination of two arbitrary matrices?
Comment: Can you give a reference to the wprk by Ledoit and Wolf that you cite?
Comment: In what sense is $\hat{S}$ not a "bona fide" estimator?
Answer: Klart jag kan :-) Sure, see for example "Honey, I shrank the covariance matrix" by Ledoit and wolf. Another, more engineer oriented paper is Chen, XXX, Eldar, and Hero III "MMSE shrinkage of covariance matrices"
Comment: Since the optimal $\rho$ is dependent on $R$. I need something that is independent in online applications.


Which macro lens would you recommend for a full frame Nikon camera?

Question: I use a full frame Nikon camera and would love to play with macro photography. Is the Nikon 105 macro strong enough or would you rather recommend some bigger third party lens?
Answer: Which macro lens you get would probably depend on what kind of macro photography you want to do. There are a variety of macro subjects: flora, insects, still-life objects, abstract closeups.
If you wish to photograph insects, and are a beginner, a longer focal length that gives you more working room in front of the lens would probably be better. I am a Canon user, and I know that Canon offers a 180mm Macro lens that fits the bill. The greater distance between you and your subject reduces the chance you'll be scaring your subject off.
If you wish to photograph flora or still life objects, a 105mm Macro will do the job. I have the Canon 100mm Macro myself, and it is a great focal length. You have a lot of control over depth of field with this focal length. Its not too long, so you don't have to be over a foot away from your subject. If you need to get in really close, you can always get a set of extension tubes to reduce your distance to subject.
There are also macro lenses in the 50-60mm range. They tend to have a shallower depth of field, but let you get closer to your subjects. To me, DOF is one of the most important factors of a macro shot, and I like the extra DOF versatility a 100mm lens gives me.
So, to answer your question, the Nikon 105 Macro would probably be an ideal lens for most subjects, although if your subject of interest is the insect world, you might end up scaring off more of your subjects than you would wish (at least as a beginner.)
Comment: One drawback of the longer focal lengths you didn't mention is the difficulty in hand holding them.  For things like insects where you're going to be hand holding, it's a tradeoff between long focal length so you don't have to get too close, and short focal length so the relative wobbling from hand motion won't be so bad.
Comment: @Olin: That is very true, and an excellent point. To that end, I'd offer that with much better high ISO performance these days, macro photography in general, including hand-held insect photography, can be easier than it was in the past. Thanks to the intrinsic lens extension present in macro lenses, the effective aperture at 1:1 tends to be narrower by at least a stop or two from the indicated setting, so clean high ISO can greatly help in those situations.
Answer: jrista has given you a great answer already.  I shoot with a full frame Nikon so I can add a bit of Nikon flavour.  When I started to become interested in macro work I picked up a cheaper Tamron 90mm f2.5 MF lens which I used for many years.  It was a great lens and pretty good at portraits too.  It had two main draw backs - it only went to 1:2 with out adding an extension tube and its working distance was pretty short so insect photography was difficult.
Working distance is the distance from the focus point (the subject) to the front of the lens.
When I upgraded my gear in 2000 I replaced the Tamron macro lens with the Nikon 200 f4 micro.  I  am very happy with that lens.  It is really sharp and has a very good working distance and a very shallow angle of view.  The angle of view is important for controlling backgrounds.  The narrower the angle of view the easier it is to frame your subject with a nice background.  The longer focal length also makes it easier to have that background thrown out of focus.
In answer to your question the Nikon 105 f2.8 micro lens is excellent.  If  you want more working distance then the Nikon 200 f4 is the choice.  You can also consider the Nikon 70-180 micro but it is no longer made and it does not focus down to 1:1.
Some further reading I would recomend:
http://www.bythom.com/105AFSlens.htm (at the bottom of this there is information about the latest Tamron 90mm)
Answer: You may also want to consider the tamron 180mm 3.5 with a nikon mount.  It's much cheaper than the 200mm f/4, but about comparable quality.  I figured that out by writing a little program that sucks images down from pbase.com, which organizes images by equipment used to take them, and then scrubbing the equipment information and asking the rater to indicate the quality.  Neither I nor others who used this software could tell the difference between the tamron and the nikon.  The sigma in this category (180mm as well, I believe) was clearly lacking.
Comment: Thats pretty slick.
Answer: The Nikkor 105mm "Micro" lens is an awesome lens, considered to be one of the best out there.
I had one for years before I switched to Canon, and loved it. It actually makes a great portrait lens too, though mine was a bit slow focusing.
Personally, I would take a 105mm over any of the shorter lenses as the 105 gives you a bit more reach, which is really important when trying to shoot insects. A 50mm macro will put you a few inches away, where the 105mm will put you about a foot away. That can mean the difference between having a shot or just wandering the field hoping to get close. It can also mean not having shadows in your shot because the closer you are to the subject, the more likely you are to block your own light.
Answer: The strength of a macro lens is called its magnification.
The Nikkor 105mm Micro has a 1X (or 1:1) magnification. All but one (the Canon MP-E 65mm) macro lens of major camera brands have the exact same magnification. Some third-parties like Sigma also have 1:1 lenses but all their other lenses are less powerful, sometimes putting Macro on 0.5X (1:2) or 0.33X (1:3) magnification lenses.
So, as far as lenses for Nikon go, the 105mm has the highest magnification. Take a look at the list of macro lenses for Nikon mount.
The primary difference between various 1:1 macro lenses is the focal-length which determines how far you have to stand from your subject to get maximum magnification. You can see that it varies from 35mm to 200mm. At 35mm you have to focus at 14cm from the sensor which makes it hard to get the lens not to cast a shadow on your subject.
You can see a small variance in maximum aperture (F/2 to F/4). Most macro shooting though tends to be done at smaller apertures since DOF becomes so shallow at those distances.
Answer: My personal favorite is the Zeiss 100mm 1:2 macro lens.  I also use the Nikon 200mm f/4 macro.  They are both outstanding macro lenses and the differences between the sharpness and crispness of each is negligible.  This is only my personal taste, but I just like how the Zeiss "feels" when holding it and focusing it.  As sturdy and strong as most pro Nikon lenses are, the Zeiss feels like it was hewn from solid granite, and the focus ring is buttery smooth and incredibly precise.  The nikon 200 allows slightly closer focusing, and the fact that its a 200mm enables closer shots from further distance (roughly twice as far for the same reproduction size)...it's that reason alone why I have both lenses.  Sometimes I can't get as close as I need to with the Zeiss, so the 200 f/4 is invaluable in these circumstances.
But, all things being equal, if I'm in a situation where either lens can be used with equal efficiency, I'll go with the Zeiss every time.  It just feels like mechanical perfection.
Answer: I can't speak to the ability of the nikon 105, but I have a Canon 100mm f/2.8 USM macro (which i believe is the rough canon equivalent), and am completely happy with it. It is the sharpest lens I own, and gets in tight enough to get great detail for large insects and flowers.
I also have used this lens for portaits and have been very happy with the results, which wouldn't be as easy with a longer lens.
Answer: I use the old 60mm AF-D micro Nikkor (on my DX format camera): it's a very well built lens and supremely sharp for general shooting, so it's pretty versatile.
I'd say for serious macro work you want something longer than 60mm though, because being so close to your subject means:

It's very easy to accidentally shadow your subject
Bugs get scared away :)
Answer: Just note that this lens (Nikon 105 macro) goes up to f/57 but the quality degrades very much after f/22
This lens does not have manual aperture control which means that you cannot use extention tubes.
I have this lens and it is very very good, but I also had a Sigma 150macro which was a bit better and a very old sigma 90mm which is better than this lens.. so considering the price differences I would suggest a Sigma lens.
And finally, the VR is not really useful in serious macro photography so there is no reason to pay extra for it...
Answer: You already got a lot of good answers. So I add my experience on the 105. I use the 105mm f2.8 VR on my D7000 (not full frame) and I love it. The lens though is a full frame lens, so you will be just fine. I do not love it just because it's a great macro lens, but also because I can use it as a shorter tele lens, which happens more often than I imagined before I purchased it. At this point the VR makes pretty much sense. I also did get some pretty good results with the VR on some "walk-by hand-held" close ups.
However, one thing to consider is, that the frame size (image size) changes while focusing. For me this is no issue, but it might be for you. Personally I would not go below that focal length unless, as pointed out by others already, you know you will never need a longer working distance.
Answer: Well for the time being the 2 best macro lenses for Nikon (I won't mention Zeiss because they are 1:2, too bad) are the 200mm f/4 and don't believe those that say the Sigma 180mm is comparable, it's not!  The other is the Sigma 105mm F2.8 EX DG OS HSM which is better than Nikon's own 105mm in many point and is cheaper.
Avoid the Sigma 150mm macro...
Hope this helps.
Comment: Hi, and welcome to Stack Exchange. Why are the two lenses you recommend the best, and why should that particular Sigma lens be avoided?


Add an outline around type in Illustrator and then delete it from the letterform?

Question: I have a font that I want to be marginally thinner. I've typed out the word and then added a white outline around it.
What I want to do is delete the outline, whilst maintaining the thinner font. How can I do this?
Answer: Simply select the type with the selection tool.

Click the New Stroke button on the Appearance Panel
Drag the stroke below the characters in the Appearance panel
set the stroke options.

If you then want the stroke as a separate object, choose Object > Expand Appearance from the menu
Answer: You can use the Appearance panel (shift+f6) to achieve this, and have your text remain editable. Select the 'characters' in the Appearance panel and then select Effect > Path > Offset path... and enter a (small) negative value for the offset. If necessary, you can expand (Object > Expand Appearance) the result in order to be able to edit it.
Alternatively, for earlier versions of Illustrator, you will have to convert your text to outlines (shift+ctrl+O; Type > Create Outlines) in order to apply the offset effect.
Do note however, that this is not the proper way of treating your typefaces. Typeface weights are designed with certain propotions and line widths in mind. You faking a 'thin' variant in this way is ignoring all the effort the typeface designer put into their design.
Therefore, the really proper answer should be: obtain the lighter font variant and use that.
Answer: I do this quite often and as follows is my preferred way of completing this effect:
Select the text and click " Type > Create Outlines"
This will outline your text only but not the stroke!
To outline the stroke too click " Object > Path > Outline Stroke "
This will rendered the stroke and the text as outlined.
The two parts will be grouped together, ungroup these using " Object > Ungroup " (you will need to do this twice)
Now for the tedious part, select each shape that is part of the text and make this a compound path by clicking " Object > Compound Path > Make ".
Do the same for your outline.
Once done you can select both of these elements and you will now subtract the stroke from the original text making it your desired size.
To do this click " Window > Pathfinder " in the pathfinder toolbox click upon " Minus Front ", this will subtract the front shape from the one behind, leaving you with your lighter text.
Contrary to the techniques of simply placing a stroke above your text in a colour that matches the background, this allows you to place the text anywhere without the need to find a suitable blend with the artwork behind.
This technique can be utilized in many situations and it can be useful to start understanding how shapes work in groups and the rules of compound paths. I imagine you will encounter them a few times in your career and it can save you a good 20 minutes messing around if you are clued up on how to group, merge and subtract shapes from the get go.


Ways to respond to younger sibling asking for help to cheat

Question: How should one respond to a younger sibling asking for your help to cheat?
Lets say a high school exam.
How responsible is an older sibling for the younger sibling's decision to cheat?
Where would an older sibling's role end?
Comment: Our answers would depend on your personal opinion on cheating.
Comment: True DA01, I realize now this is a very subjective question. Sorry. What about if the cheating in this hypothetical (this actually hasn't happened, but could) was a mores.
Or a case were we can all agree was wrong.
Answer: I think the first step is to find out why they made the decision to cheat.  This isn't to justify the decision, but rather better understand what drove them to this (e.g. laziness, desperation, peer pressure, etc.) so that you can tailor your response.
I feel that an older sibling shares a (small) portion of the parental responsibility: they have the obligation to be a role model, and help with ensuring that the younger sibling(s) is protected from dangers.
The response should be influenced by the relationship between the siblings, the reasons behind the cheating, and the relationship with the parents.  First and foremost, though, the older sibling needs to respond with the younger siblings long term interests in mind.
I don't have any siblings, so I can't really speak to the obligation of sibling to sibling, but I do believe that it is the right thing to do to bring the situation to the parents, if this is in the long term interests of the sibling.  Sometimes you have to risk hard feelings in order to protect those you love.  Which is worse?  Your younger sibling feeling betrayed by you, or your younger sibling developing a pattern of avoiding responsibility, lying, and cheating to scrape by life's challenges?
Answer: If one's younger sibling asks you to cheat, then your responsibility as an older sibling is to tell them no, and explain why cheating is wrong.
If the older sibling is aiding the younger sibling in cheating, then the older is responsible for aiding the younger in avoiding consequences for not studying in classes.
The older sibling's role would end when they said no, and informed their parents that the younger sibling probably needs help in his/her classes.
Answer: The older sibling is not responsible for the younger siblings decision to cheat.  Lets say the younger had asked some one else - absolutely not the older child's fault.  However, the older sibling is responsible for "aiding" in cheating if he/she decides to go ahead and help.
Assuming the elder just wanted to help the younger and went ahead and gave the younger paper/answer key etc. so he/she could cheat:  I would personally discuss with the older sibling the idea that the older sibling already learned the material covered when he/she was in the class, but if his/her younger sibling is cheating than he/she isn't learning what he/she needs to learn.  By helping with cheating, the older sibling is actually hurting the younger's chances of ultimate success in feeling good about the accomplishment.
Another answer discusses an older sibling needing to be responsible enough to consider the child's long-term-interests.  While this is true, many parenting cultures can be quite punitive so I would just clarify that the older sibling is still a child and shouldn't be admonished for not having considered this.  Instead, use the infraction as a chance to teach the older sibling HOW to.  I would then let it go unless it happened again.
I also caution against instructing your kids to just tell on their sibling.  Tattling can create huge rifts between siblings and in this case, there are a lot of in-between responses an older kid can have.  Kids should involve an adult right away if anyone is getting physically hurt or has the potential of being physically hurt and that should always be CRAZY CLEAR.  However, In regard to this topic, there is a little more grey area and some in-between options (a couple outlined in paragraph below). This part depends upon age and level of maturity, but teaching a child how to have an influence themselves can be a far more valuable lesson for the child later on in life than just asking them to default to telling you about it.
Instead try this: After the older sibling understands the long view, ask him or her what he or she thinks could have been done to help the younger sibling not cheat.  Then play out the natural consequences of the solutions that are brainstormed in your discussion together.  Tattling can be one solution, but so can saying, "I won't help you because. . ." while trying to persuade the younger sibling away from cheating altogether, and "If you do decide to cheat, I may have to tell Mom and Dad about it" and then lett the younger sibling make the decision from there.   Try to be open to the older siblings ideas and give them time to get entire ideas out and developed.  Ask your older sibling questions like (just keep them calm and in an open tone), "How do you think that would have turned out?"   "How would you have felt doing that?"   "How do you think your sibling would respond?"  "What are the long-term benefits of that decision?  long-term negatives?"  Decide on a list of options the older sibling had together this way.  You can't predict every outcome and what is done is done, but the exercise is a good one for critical thinking and decision making.  It also gives your child the message that there are always options available - including going to Mom and Dad for help.
The younger sibling would also get a separate discussion.  First, a lot of listening about the justifications etc. the child offers up.  After assuring the child I understand through asking clarifying questions and paraphrasing, I would do what I needed as the instructive parent.  If I believe the child is feeling the weight of too much pressure I would start by doing what I could to alleviate that pressure (at the moment of the discussion I would admit to my own mistakes before discussing theirs).  Part of that statement can include, "I wish you had told me this BEFORE you cheated, because I am your parent, which means I am here to help and guide you.  No that you have cheated though we have to deal with that too."
AFTER hearing the child out, I would go about discussing the pitfalls of cheating, how it hurts friends/siblings to bring them into doing something wrong by putting the co-consiprator in a difficult position (because he/she loves you and wants to help) AND go from there.  This is also the time to discuss what school is for and the long-view in terms of learning goals etc.
In general, in my experience if you are a parent that focuses mostly on effort and the learning process, you are not likely to run into problems with cheating anyway (maybe once as an experiment, but not recurring).  In ten years of teaching (In private schools) my middle schoolers rarely cheated unless they had parents that were very outcome focused.
Answer: An older sibling can share the same responsibilities as parents do if the duty is within their realm of expertise such as but not limited to

teaching them how to ride a bike
driving them to school, sports practices, dances, mall, movies, etc.
how to break down homework problems (which may be easier for the sibling to remember than parents who may not have used that info for decades)

All one can do is offer guidance and help but ultimately the decision and ramifications are on the individual. In this circumstance, parents/siblings can only offer guidance and hope for the best. It's not like you can babysit the child as they take the test to ensure they don't cheat.
The older sibling can make the parents aware, not to tattle but so the parents can see if they have noticed patterns of stress or worry and offer their help too. Parents who are engaged in their kids' lives won't seem all of a sudden interested. They already know the exams are coming and can try to figure out the underlying cause of wanting to cheat.
If the parents are not that interested in the younger child's academics, then the older child can assume a higher responsibility if they can afford it with money or their own time (hiring a tutor, tutor their sibling themselves).
Usually a sibling has a better chance of getting through to the younger person and especially in this case since they have already enlisted their help (even though it was for cheating). What the older sibling says will affect the impression the younger child has of them. The younger sibling may not necessarily follow through even if an older sibling pushes them towards cheating. It may have just been worded like that as an attempt to ask for help, any help or just a form of venting.
If the older sibling/parents do not want to promote cheating, they should offer tutoring or direction on where to find tips/tricks. There are sometimes little mnemonics or short-cuts depending on the subject. The older sibling should definitely follow up at least after the test to find out how it went to show they care.
Here is a toll free number for help with school called Dial-A-Teacher and Homework Hotline funded by PBS: 1.888.986.2345


Programmer to Security Professional

Question: I am a software developer (mostly .NET and Python about 2-3 years exp.) looking to break into the Computer Security field. I have a GWAPT cert and will have both GSSP-NET and Network+ certs by the end of july. I am a member of OWASP and ISSA in order to network and keep up to date on various issues in the field (I attend the meetings and try to get involved). What can I do to help me get a job in the computer security field as a pen tester or security researcher or really anything that will get me started in that field?
Comment: This question should be of interest to you, though its not an exact duplicate (it doesnt discuss specifics of how to get the job): http://security.stackexchange.com/questions/3772/what-are-the-career-paths-in-the-computer-security-field
Comment: I want to follow the same path as you, but i am unsure. Did you got a job in IT Security and if yes what role/niche you chose? Isn't that a career suicide?
Comment: I ended up getting an entry level job doing vulnerability assessment. I think I now have more opportunities open to me than I did before. I still get requests to interview for programming jobs and am doing android dev on the side.
Answer: This is the career path I've just taken (or am in the middle of, really). As Guillaume says, the best start is to focus on security in your current work. This could mean at your current job, or it could mean taking a similar dev post where you have the chance to concentrate on security.
What do I mean by 'concentrating' on security? If your dev team already follows a security development lifecycle, take on responsibility for some of the tasks as part of that SDL. If it doesn't, start introducing those tasks and leading adoption of an SDL.
Where Guillaume and I differ is at step 2: I didn't get and still don't have a CISSP or any other industry cert, though I do have a postgraduate software engineering qualification that includes security content. That wasn't necessary to getting into software security though: the route I took was to go out and find developers and talk to them about security. This means conference talks, podcasts, blog posts...I even wrote a book. Pretty soon you get recognised as "the security guy" in your chosen field, and the work comes to you.
I also disagree that you lose the ability to code. A lot of what I do now is programming: either implementing security controls for client products, writing tests to research platform security features or sample code to demonstrate security issues to fellow-developers.
Comment: both answered with pretty much the same content at pretty much the same time. That's always reassuring validation:-)
Answer: I made the move about 6 years ago. In short :

Work on security in your current job
Get your CISSP or equivalent
Find a security job in an environment you know from your programming (Java, .Net, Linux, etc.)
Never look back

I started to tackle all security related assignements in my development projects (I was team lead back then).
I passed my CISSP certification and waited a few months.
There was an opportunity where a security team needed someone with strong technical expertise, to balance a team where there were mostly networking experts or security policy experts.
I went back to development for a whole year and let me warn you : it is a one way street. You will learn lost of new stuff, but you'll loose the ability to write code blind folded ;)
Comment: "you'll loose the ability to write code blind folded " - I should hope so, that way you're looking at the code you write and making it much more secure ;). But I agree, my coding skills are less fluent now, though of a higher quality.
Answer: My background was in IT - long term system and network administrator and I sort of fell into security through it taking more and more of my day job...but you can't count on that happening to you;
I would add to @Guillaume's points with this:
Networking - in the people sense - is key.
Find your local chapter of OWASP, ISACA, ISSA, ISF depending on what your focus is, and join the mailing list, go to meetings...better yet, volunteer to host, sit on the committee, even present a talk (even as a newbie in the industry you will have your perspective on your areas of expertise)
Get known - this will give you more opportunities. It's always a simple fact - you might be right for a role, but if people don't know you, you'll never know...
As for certs, CISSP is useful, as is CISM - they both score very highly among recruiters (in fact you should have a look at this question on professional certifications)
Comment: Your point about certs is a good one. The recruiter speaking at BSides London said that industry certs are given similar weight to relevant Masters' qualifications. As I said in my answer, I didn't need a cert, but that doesn't mean they won't help.

Programmer to Security Professional


What is the flute music for when in the frontier?

Question: I often run around in the frontier and at seemingly random spots I hear a native american flute play. Often I look around to try to see if there is something around me to look for but I don't see anything. What is this flute-toot for?
Answer: When the flute is played there is some unusual animal event happening near you. Examples I have seen so far;

Two deer bucks fighting
A wolf pack
A bear with cubs
A deer with children

Sometimes it can be difficult to see, and sometimes you may have scared off the animal that caused the alert. But it's happened enough times for me to be pretty certain this is it.
A sidenote; I think I heard a different flute note once and just after I was attacked by a wolfpack. Could be that it was signalling danger?
Comment: Verified. Thank you. I guess I should stop running all the time.
Answer: You might want to reconsider your approach when in unknown territory. Though the alert song is very useful, you can never know what will happen, and I am certain that you would not want to desynchronize if you are in an important mission.


Why do we need the quantity momentum?

Question: Why do we need the quantity Momentum in physics when we have the quantities like Force and Energy? Isn't it possible to substitute the usage of Momentum with equivalent of Force and Energy?
Comment: It is *conserved*. Why not define a name for a thing which is *conserved*. That's a pretty useful thing.
Answer: Energy and momentum have a great deal of conceptual overlap, but they are conserved separately. There are some times when momentum is conserved but energy is not.
As for force, there are many situations where the momentum can be calculated easily, but the force is tough to find because we don't know how much time something takes. In a car crash, for instance, we might know how fast the cars were moving beforehand, but not how long they were in contact or what the force between them was. Momentum works even if we don't know those things. Some problems that would be unsolvable with force alone thus become solvable if we use momentum instead.
On the more-information-than-you-need level, all conserved quantities come from symmetries in our universe. Because the laws of physics are the same no matter what direction you look in, angular momentum is conserved. Because they're the same whether you move left or right, regular momentum is conserved. Because they're the same now as they will be later in time, energy is conserved. Energy and momentum conservation come from two separate symmetries; they're both true, so we need to keep track of both quantities.
Comment: Energy can be 'lost' from the system you're looking at; e.g. if I'm looking at a bouncing ball, it loses some of its energy to the surface it's bouncing off (sound, heat etc.), and in some sense we don't care about what's happening to the surface, so the system we're looking at (the ball) is losing energy.
Comment: Isn't energy always conserved? Can you give an example?
Comment: While it's true that energy can't be created or destroyed, it can end up in forms that aren't useful to us. In a car engine, for example, you use chemical energy in the fuel to give kinetic energy to parts in the engine, but some of the energy turns into heat, which isn't useful. (In fact, most of it ends up as heat; engines are not very efficient.) In introductory physics we often talk about energy "lost" to friction or deformation.
Comment: So it is conserved but not useful for calculations sometimes. I asked due to your 2nd statement.
Answer: The only thing you really need in classical mechanics is Newton's Laws. Energy and momentum conservation are just principles derived from them. That is why they are not called laws. If you integrate, with respect to displacement, both sides of Newton's 2nd law in the presence of forces that can be expressed as the negative gradient of some function (i.e. integral independent of pass) you gey classical conservation of energy. Momentum conservation is derived from Newton's third Law. Canonical momentum is not needed in lagrangian formulation of mechanics. Canonical momentum enters Hamilton's equations as a Legrende transformation in phase space. To answer your question, only force and mass is needed for a complete description of a classical particle. Energy and momentum are just constants of the motion only when there are no external forces on the system and no dissipative forces.
Answer: Colin did a good job answering this question but I can't help fill in some other things. As for the utility of force, momentum and energy:
First of all, when you are trying to solve a physics problem, you are never going to keep anything off the table - for difficult problems you need all the tools at you disposal. Rarely are do we have the luxury of selecting amongst a variety of ways to solve a problem - we do what we can with what we have, which in some cases may mean using the quantity of momentum is our only way forward.
Second of all, off hand, I honestly don't particularly care what momentum is, but there are some cases, namely when the net force on an object is zero, that momentum is conserved - and that is a very powerful statement. Without any knowledge of the details of say, the collision , the composition or structure of the objects, we can immediately say that $\vec{p}_i = \vec{p}_f$ which is a very useful statement. The case is similar for angular momentum, I could care even less what that is for a general system, but if the net torque on a system is zero and angular momentum is conserved you better believe I am using it if it helps solve me solve the problem.
Thirdly, energy is conserved, and thus particularly useful, when the net work done on a system is zero. This a completely different case than when momentum is conserved, so these are clearly not redundant concepts, although there may be times when both are aplicable.
Finally, there is simply no useful notion of 'force' in quantum systems in general. Yes you can do some calculations and sometimes handwave what a force is in a certain situation, but in most matters its of little particular use. Take the collisions at the LHC - there is no useful notion of 'force' you can ascribe to what is going on when all those particles collide. Yes, if you stand in the LHC beam pipe you will feel a force, and if you survive you can tell us about it, but from a standpoint of predicting what so-and-so particle got scattered into what angle, or what the lifetime of some particle is, force is never mentioned. As another example, take the spectrum of the hydrogen atom - we obtain this by solving for the allowed energy values of the Schrodinger equation, and again force is not useful and has nothing to say about the problem for that matter.
In conclusion, if you want to do real physics its all about utility. Use what you can to solve the problem, and momentum is a useful quantity.
Answer: simply no useful notion of 'force' in quantum systems in general. Yes you can do some calculations and sometimes handwave what a force is in a certain situation, but in most matters its of little particular use. Take the collisions at the LHC - there is no useful notion of 'force' you can ascribe to what is going on when all those particles collide. Yes, if you stand in the LHC beam pipe you will feel a force, and if you survive you can tell us about it, but from a standpoint of predicting what so-and-so particle got scattered into what angle, or what the lifetime of some particle is, force is never mentioned. As another example, take the spectrum of the hydrogen atom - we obtain this by solving for the allowed energy values of the Schrodinger equation, and again force is not useful and has nothing to say about the problem for that matter.

Why do we need the quantity momentum?


How do I start promoting a children's portrait business?

Question: Could someone guide me as to how I need to promote children's portraits? Could you please highlight the dos and don'ts? I have been looking at setting up this business for a while now but have been really apprehensive.
All inputs appreciated.
Comment: Hi @Pixpix and welcome to the site!
Comment: Great question.  Made me think "Why haven't I asked that?".  Welcome to the site :)
Answer: OK, this probably isn't what you want to hear, but I've been a professional photographer for more than 15 years now and this speech (or some form thereof) is something I regularly give to my students as this question (or some form thereof) is one of the 'top 5' that I get on a regular basis...
If you're looking for super general business advice 'tips' then you may get a few sorta-helpful answers here at photo-SE, but if you're looking for something more specific from actual photography professionals you may be in the wrong place... No actual professional is going to discuss the specifics of their business marketing efforts on the open internet and with a potential competitor (or if they do, they're an idiot). Furthermore, you don't really want to know what makes other people successful anyway (even if you think you do) because the vast majority successful professionals (in any industry) either don't know why they're successful (even if they think they do), or are successful because of something you can't replicate anyway (like their charisma).
Your best bet at true success is going to pick up a book or three geared towards helping you develop your own strategies, and then do all the homework recommended in the books before you start anything. There are lots out there, but my personal recommendations are:

Fast Track Photographer by Dane Sanders
Exposed: The Naked Uncensored Truth to Running A Successful Photography Business by Robert Provencher
Startup Guide to Guerrilla Marketing: A Simple Battle Plan for First-Time Marketers by Jay Conrad Levinson
The E-Myth Revisited: Why Most Small Businesses Don't Work and What to Do About It by Michael Gerber

By committing the time (and yes, a bit of money) to get these books, read them, and do all the homework in them you'll be able to demonstrate to yourself whether or not you're actually ready to start a business, or whether you're more interested in 'playing at' having a business... Otherwise known as having an expensive hobby. Also, if you get done with all this work and still want to be in the photography business the fact that you did the homework means that you'll have the answers at your fingertips for what you should do next to promote your business.
I realize all this may sound like 'old cranky photographer' talk, but please don't take it that way... I've helped more than a dozen photographers start their own businesses over the years and the only real secrets to success I've found are: don't take shortcuts, and don't believe that 'sure-fire' quick tips from anyone are going to be the 'key' to your success. There's money to be made in photography, but there's no real 'secret' to wealth in the photography industry (or any other industry for that matter) other than a whole lot of hard work and perseverance. Anyone who tells you different is trying to sell you something.
Comment: +1 - 'or any other industry for that matter' - so true.
Comment: +1 for "Anyone who tells you different is trying to sell you something"
Comment: "No actual professional is going to discuss the specifics of their business marketing efforts on the open internet..." - This is true, and it is pretty easy to find a local group of pros that get together and provide support, do shoots together, and share the details you need to become successful. Just don't expect that to be published for everyone(including clients) to see!
Comment: just +1, basically :-)
Answer: Here are a few tips: I'm sure others will contribute more:
Remember it's a business
Especially if this is going to be your main source of income (but even if it isn't), don't make the mistake of thinking you should start by doing freebies for friends and family. Believe in the quality of your work and charge reasonably for it from Day 1.
Invest in some basic equipment
You don't say whether you'll be running the business from your own premises or photographing people at their own homes, but either way decide what equipment you need and make a small investment up front. For example, if you're going to be photographing mostly single or pairs of children indoors, in other people's homes where you can't guarantee good light or lots of space, I'd recommend at least a couple of flashes with umbrellas/softboxes, remote triggers and stands, and a portable backdrop (if that's your style). If you have your own studio, a proper set of studio lights might be more appropriate. The portable set-up needn't cost more than a few hundred £/$. It's OK to start on a budget as long as you know how to make the most of it: the results are what counts.
It should go without saying that a decent camera (certainly an SLR) is a necessity. :)
Get a website
Sounds obvious but it's essential for a business nowadays, especially if you're in a visual medium. Make the most of it by putting a portfolio of your best work up on display. Make sure the domain name of your site matches the name of the business and use it for your e-mail address too. (Mail from firstname.lastname@example.com looks much more credible than from your Gmail address.)
...and permission to use photos on it
Don't forget to get permission before using photos from client shoots on your website. The simplest way is to incorporate it as standard in a set of terms & conditions that you sign off with clients prior to a shoot. Again, no need to hire a lawyer for this: a simple set of terms in plain English does the job just fine.
Promote yourself!
Again, depending on where you are there are a load of ways of doing this. Facebook is indispensable. Create a Page for your business and persuade all your friends and family to Like it and spread the word. Link to it from your website. Keep it lively by posting regular updates and samples of your shoots (again, worth including permission for this in the T&Cs). Get clients to connect to it too, and request/suggest/nag that they spread the word if they're happy with your work. If you want to, invest in some ads too (on Facebook and/or Google). Facebook really is a powerful tool for spreading the word beyond your own circle of friends: gotta love that social graph!
Twitter is some use too but it works in a different way: it's less socially-oriented. Friends hang out together and have conversations on Facebook.
Also consider ads in local press or flyers in local businesses. I haven't done these myself though so I can't say how useful they are.
I hope some of that's of use to you. Good luck!
Answer: More info at: Going Pro
I follow the guys over at http://GoingPro2010.com, who give a lot of advice, most of which is "common" sense - but no less useful for that!
Answer: One thing I see regularly around town here is photographers setting up events at local malls and supermarkets where people can get their children photographed for a small fee (cheaper than studiowork for sure, but of course less customisation and you have to queue). Seems popular, there's always crowds. And the parents get to know your name, get your businesscard and address sticker on the back of the prints. If they like it, they may tell others.
Of course make darn sure you can deliver a good product in a rapid progression (one child every few minutes or faster), as such a thing can also ruin your reputation very quickly.


What is SerialVersionUID in serialization in java?

Question:
Possible Duplicate:
Why should I bother about serialVersionUID?

What is SerialVersionUID in serialization in java? What does it do?
Answer: From the Javadoc:

The serialization runtime associates with each serializable class a
  version number, called a serialVersionUID, which is used during
  deserialization to verify that the sender and receiver of a serialized
  object have loaded classes for that object that are compatible with
  respect to serialization. If the receiver has loaded a class for the
  object that has a different serialVersionUID than that of the
  corresponding sender's class, then deserialization will result in an
  InvalidClassException. A serializable class can declare its own
  serialVersionUID explicitly by declaring a field named
  "serialVersionUID" that must be static, final, and of type long:
ANY-ACCESS-MODIFIER static final long serialVersionUID = 42L;
If a serializable class does not explicitly declare a
  serialVersionUID, then the serialization runtime will calculate a
  default serialVersionUID value for that class based on various aspects
  of the class, as described in the Java(TM) Object Serialization
  Specification. However, it is strongly recommended that all
  serializable classes explicitly declare serialVersionUID values, since
  the default serialVersionUID computation is highly sensitive to class
  details that may vary depending on compiler implementations, and can
  thus result in unexpected InvalidClassExceptions during
  deserialization. Therefore, to guarantee a consistent serialVersionUID
  value across different java compiler implementations, a serializable
  class must declare an explicit serialVersionUID value. It is also
  strongly advised that explicit serialVersionUID declarations use the
  private modifier where possible, since such declarations apply only to
  the immediately declaring class--serialVersionUID fields are not
  useful as inherited members.


What are known examples of positive but not completely positive maps?

Question: The only example I know of a positive map which is not completely positive is the transpose map on $M_n(\mathbb{C})$.  Of course, one can come up with minor perturbations of this (compose it with, or add it to, a completely positive map, etc).  Are there other known examples?
Answer: In Theorem 4.6 of their paper
http://www.univie.ac.at/nuhag-php/bibtex/open_files/deha85_CanniereHaagerup.pdf
de Canni`ere and Haagerup construct an explicit sequence of finitely supported functions on the free group $\mathbb{F}_N$ ($N\geq 2$), defining positive multipliers of the reduced C*-algebra $C^*_r(\mathbb{F}_N)$, and such that the corresponding sequence of multipliers converges strongly to the identity of $C^*_r(\mathbb{F}_N)$. As $C^*_r(\mathbb{F}_N)$ is non-nuclear, it does not have the completely positive approximation property, so only finitely many of these multipliers are completely positive.
Answer: First, let me recall some definitions to make sure I understand (at least the matrix version of) the question correctly. All of what I say below is based on Chapter 3 of the delightful book Positive Definite Matrices by R. Bhatia.
Let $\mathbb{M}_n$ denote the space of $n \times n$ complex matrices over $\mathbb{C}$, and let $\mathbb{M}_k(\mathbb{M}_n)$ denote the set of $k \times k$ block matrices, having elements of $\mathbb{M}_n$ as its blocks. I'll just speak of positive and completely positive maps, and not restrict to linear maps (yet).
Consider the map $\Phi_k: \mathbb{M}_k(\mathbb{M}_n) \to \mathbb{M}_k(\mathbb{M}_p)$, is induced by a positive map $\Phi: \mathbb{M}_n  \to \mathbb{M}_p$, so that in particular for a $k\times k$ block matrix $A$, we have
\begin{equation*}
 \Phi_k(A) := [\Phi(A_{ij})].
\end{equation*}
If $\Phi_k$ is a positive map for all $k=1,2,\ldots,$, then $\Phi$ is called a completely positive (CP) map. Notice that $k=1$ coincides with "ordinary" positive maps.
Now, with this definition, it is quick matter to construct maps that are positive but not CP, for example, say the map $X \mapsto X^{-1}$ on positive matrices.

Additionally, if you are looking only at positive linear maps and and CP linear maps, then you can appeal to a theorem of Choi and Kraus that says that each CP map $\Phi$ must assume the representation $\Phi(A) = \sum_i V_i^*AV_i$, and you need only find a positive (linear) map that does not assume this representation.
Why the above should be true can also be seen from the following deeper observation. Suppose that every positive linear map $\Phi: \mathbb{M}_n \mathbb{M}_p$ could be written as $$\Phi(A) = \sum_i V_i^*AV_i + \sum_j V_j^*A^TV_j,$$
then it would follow that every real polynomial in $n$ variables that takes only nonnegative values is a sum of squares of real polynomials. But this claim was shown to be false by Hilbert.
Answer: Here's something neat: Here it is proved, by Sixia Yu, that in the finite-dimensional case, any positive map that isn't completely positive can be written as the difference of two completely positive maps. The paper also considers a necessary and sufficient condition for a positive map to fail complete positivity (also in finite dimensions). This paper apparently provides a mechanism for generating examples answering your question in the finite-dimensional case.
Comment: @Yemon: I don't see how your WLOG works. It seems to be saying that the algebra generated by any finite dimensional operator system is finite dimensional. Right? Surely this is not true, just take something in a free product.
Comment: @Owen: ah yes, of course, a silly oversight on my part. [Erroneous comment deleted]
Answer: A Jordan homomorphism between C*-algebras is always positive, but it is completely positive only if it is a homomorphism. To get some examples, say $C_r^*(G)$ is the reduced C*-algebra of a discrete group or groupoid $G$. Then the map $g\mapsto g^{-1}$  (a generalized transpose) induces  a Jordan homomorphism on $C_r^*(G)$ which is positive but not completely positive.
Answer: One example other than the transpose is Arveson's example of a non-contractive unital positive map (see Paulsen's book, Example 2.2). Since any unital completely positive map is contractive, Arveson's map cannot be completely positive. The example is like this: let $\mathcal{S}$ be the operator system
$$
\mathcal{S}=\text{span}\{1, z, \bar{z} \} \subset C(\mathbb{T}),
$$
and let $\phi:\mathcal{S}\to M_2(\mathbb{C})$ be given  by
$$
\phi(a+bz+c\bar{z})=\begin{bmatrix}a&2b\\ 2c& a\end{bmatrix}.
$$
This example might not be satisfactory for some operator algebraists because it cannot be extended to an example with a C$^*$-algebra domain. A way to produce examples between C$^*$-algebras would be this: we use Choi's theorem that characterizes completely positive maps $\varphi:M_n(\mathbb{C})\to B(H)$. Choi's result asserts that $\varphi$ is completely positive if and only if the matrix
$$
\left[\varphi(e_{kj})\right]\in M_n(B(H))
$$
is positive, where $\{e_{kj}:\ k,j=1,\ldots,n\}$ are the standard matrix units. The only caveat is that one needs to produce positive maps on the matrices by showing explicit computations on the matrix entries, and this might not be that easy. I'm familiar with examples on small operator systems, where positivity of the elements can be established with simpler formulas, but I cannot see right away a path to do this explicitly for full matrix algebras.
Answer: I know nothing but a quick google search gives http://www.quantiki.org/wiki/Separability_criteria where 2 other examples are given. Maybe somebody who knows more can flesh it out so I made this CW.
Answer: Continuation of the answer of Benjamin Steinberg; this paper gives a list of such known maps.
On the structure of entanglement witnesses and new class of positive indecomposable maps: by Dariusz Chruscinski and Andrzej Kossakowski; http://xxx.imsc.res.in/abs/quant-ph/0606211v1 and the journal version (if you want) is here.
It is slightly outdated but gives a good starting point. Not many classes of such maps are known in literature.


How to create a rectangle polygon with set lengths in QGIS?

Question: I have a search area i want to outline. and i need it to be 1km by 2km. is it possible to achieve this in QGIS.
I can create a rectangle polygon but only guess the lengths.
Answer: The "Improved Polygon Capturing" plugin will let you specify line lengths as you draw. The CAD Tools ortho tool will let you draw 90 degree angles. However, unfortunately it doesn't seem like the two will work together!
Answer: The way I will do it involve to steps
1)make a point layer where you can control the limits of the rectangle
2)Make a new polygon layer, set the proper snapping options, in order that you can trace the polygon by snapping the points,
Hope it helps
Answer: Another option is to use the GRASS plugin. GRASS has a module called v.mkgrid. You can either set the number of rows and columns, or the width/length of each grid cell. The grid is created within the current GRASS region.
The plugin interface within QGIS allows to set only the number of rows and columns. But if you run the module in the GRASS "shell" you can alternatively use the parameter "box=2000,1000" to get your required size.