Salesforce Professional, Profiles

Question: Just curious,  my organization has some requirements to limit certain users from creating specific records etc within the standard objects of salesforce.  Currently,  because we are on professional edition, I don't have to ability to limit this due to the lack of profiles on Salesforce.  I created a work around by assigning these users the Read Only standard profile, and then creating a permission set that allows these read only profile users to create certain records that we deem ok.  Obviously, this isn't the best way of doing things, but it seems to work.  Is there something I might be missing by doing this that could come back to haunt me in the future?  If we upgrade to Enterprise, I will have to rework the profiles again anyway so that isn't a huge issue.  Thanks in advance!
Comment: that is the only way I can see as well.
Answer: As a note, you can get custom profiles and page layouts for a nominal charge in Professional Edition. See this chart for a bit of info. Ask your account executive about pricing.
As for the main question, there really isn't any inherent problems with properly planned out permission sets. The effects of permission sets are cumulative, not restrictive, so you can build them out as you like to give appropriate permissions to users.
The only actual downside is remembering to assign the permission sets to users after they've been created, and having to manage those permission sets as users change offices/job positions/etc. It's basically the same problem as having custom profiles to begin with, but with a few extra clicks involved with not having custom profiles available.
Overall, I don't see a problem with this configuration, as it's a perfectly acceptable use case. Technically, it's almost a bit more superior because you can enact fine-grained controls over similar users that would otherwise require completely separate profiles.
Comment: Totally makes sense.  I would love to spend more money on our salesforce instance, unfortunately it takes some convincing of the management haha.  I know there are work arounds for a lot of different things that are missing from the professional edition. I also know that some of them can be a pain to reverse.  Anyway,  thanks for the confirmation!

Salesforce Professional, Profiles


Is it possible to enable TLS v 1.2 in Debian squeeze

Question: I am currently running a Debian Squeeze server with Apache.  My OpenSSL version is 0.9.8, and I would like to get up to a version capable of running TLS v 1.2.  So far my research shows that this is not possible, but I feel like I am missing something.  Is there an upgrade path that would allow me to do this, or do I need to rebuild my server with a newer version of Debian?
Answer: OpenSSL supports TLSv1.2 since version 1.0.1. However, the latest version for Squeeze is 0.9.8. You can find backport here or build it from source.
Comment: @Sverre enabling TLSv1.2 is described in Apache [documentation](http://httpd.apache.org/docs/2.2/mod/mod_ssl.html#sslprotocol)
Comment: FYI the build that's compiled there is 1.0.1c, my understanding is that heartbleed affects everything up to 1.0.1g. Up to you if that matters, but it seems like if you want the newer (and theoretically more secure) protocol, reintroducing that particular beasty along the way may not be a total win. Bah I didn't put this as a comment in the place I meant to. Sorry, long time visiter but first time I've actually felt well enough read to have anything to add :)
Comment: how does Apache react to this?
Comment: How do you install the linked backport, i.e. https://github.com/mezentsev/OpenSSL-Backport? The readme doesn't explain s**t
Comment: It is compiled from source as any other version of OpenSSL. You can look openssl-1.0.1c/debian/rules for direct commands if you're not familiar with dpkg.
Installation of .deb package is described in Readme. For non-debian installation you should just run "make install" as a superuser the same way as for any other package.

However, for security reasons I'd strongly recommend to google for a backport of any newer version of OpenSSL.
Answer: Debian Squeeze comes with OpenSSL 0.9.8o, which only supports TLS 1.0.
I think your two options are:

Get a backport of OpenSSL 1.0.1g or higher.
Use GnuTLS instead of OpenSSL.

For the second option, see e.g. https://www.nnbfn.net/2011/05/tls-1-2-support-in-apache2/
Comment: link does not work any more (HTTP 404)
Answer: Debian 7 (squeeze) is End-Of-Live for a while now, please upgrade to at least Debian 8 (jessie) which comes with openssl 1.0.1 which supports TLSv1.2


Existing contents get deleted on Live Preview when adding new content on a matrix field

Question: When I add a new content for a matrix block field on an existing entry, all its previous contents gets deleted from the Live Preview, except for the editor which still has the previous contents. And then, when I try to save the entry, it seems that what is shown in the Live Preview was the only one saved and the previous data were gone.
Answer: Do you have this problem in a multisite-installation? If so, it could be something with your propagation mode on the matrix field.
Please give us some more details to your setup: which version of Craft CMS, which propagation mode, multisite or not.


possible Heteroskedasticity?

Question:
Based on the graph, would you say that there is some sort of heteroscedasticity in the data? Y-axis is residual squared and X-axis is predicted values of Y
Comment: Have you tried a White test to test for heteroskedasticity?
Comment: This looks like a hard case: there is some concentration of larger residuals around the centre of the range of predicted Y values, but not so much that it couldn't plausibly be due to random variation.  A little more detail might be helpful.   What is your predictive model?  Are you concerned about possible heteroscedasticity because ít may affect the reliability of standard errors of regression parameter estimates, or perhaps for some other reason?
Comment: I'm voting to close this question as off-topic because this is not about economics. If anything, this is about data analysis and should be migrated to cross.validated.
Answer: The question should be: Does there appear to be enough heteroskedasticity so that not taking it into account would lower the quality of inference? And this is because "taking heteroskedasticity into account" (even if only for robust standard errors) is not without costs -with small sample sizes it may worsen the reliability of results. And it becomes even riskier if you want to implement the more traditional approach where you will specify a functional relationship between the error variances and the regressors.
From the graph, my initial conjecture would be "no, not enough". But peform an "influential observations" analysis, since you obvioulsy have a few large residuals.
Also, with today's software, it is cheap to estimate a heteroskedasiticity robust variance covariance matrix, and see whether standard errors differ visibly or not, whether they reverse statistical sigificance tests or not, etc.

possible Heteroskedasticity?


Kill all currently running cron jobs

Question: For some reason my cron job scripts aren't exiting cleanly and they're backing up my server. There are currently a couple hundred processes running for one of my users. I can use the following command to kill all processes by that user, but how can I simplify this to kill only crons?
pgrep -U username | while read id ; do kill -6 $id ; done

It would be dangerous to run the above command as is, correct? Wouldn't that kill mysql and other important things?
Answer: To kill all processes for the user, you have a few options. I like:
su - username then kill -9 -1
To see which "cron" processes belong to user :
pgrep -u username cron

To kill those processes:
pkill -u username cron

Comment: I think this might work if I add an -f
Comment: Sure. Pointed in the right direction.
Answer: Use:
kill -6 $(pgrep -U username cron)

You can search with pgrep full string with -f arg if you need to kill specific cron jobs, while let others live.
kill signal is pretty dangerous really, so you should check what you are going to kill. If username is 'root' then you can kill important things, yes.

Kill all currently running cron jobs


The new path of concrete slopes towards the house and is causing mould

Question: This was part of a renovation / build done by a licensed builder. All works are still not finished but they say it's nothing to worry about . Is it a problem that they should be responsible for as mould is growing up the lower part of the house wall .. I am concerned the foundation will all be mouldy or create issues long term ???
Comment: Also, no landscape/hardscape features should _ever_ slope toward the house. It shouldn't actually slope toward the fence/wall, either. In this situation, it should be slightly raised on each side to funnel water toward the center and the whole walkway should either be sloped toward the gate or toward where you're standing for the picture (or toward a drain in the walkway) to drain water out of this area. If your contractor thinks this is OK, you might want to get a city/county inspector involved and withhold any further payments until it's corrected.
Comment: Looks like mold will be the least of your worries. With standing water against the foundation, the wood at the bottom of the wall there will rot out much sooner. There's a solid white cover in the pavement, is that supposed to be a perforated cover leading to a drain to help clear water from this area?
Comment: @FreeMan Post that as an answer, that should be pitched as you say. Never is any water to be intentionally pitched towards a foundation, or even set level enough to puddle there to the amount that water is. I can only hope it doesn't freeze in that region. Quite the dangerous proposition.
Comment: Your wish, @Jack, is my command. ;)
Answer: No landscape or hardscape features should ever slope toward the house. It shouldn't actually slope toward the fence/wall, either.
In this situation, it should be slightly raised on each side to funnel water toward the center of the walkway. In order to drain water out of this area, the whole walkway should then either be sloped:

toward the gate
toward where you're standing for the picture
toward a drain in the center of the walkway
toward both gate and photographer ends

At a minimum, you're directing water toward your house, allowing it to puddle. If anything gets on the wall and manages to touch wood, it will be wicked up into the wall and start rotting away at the wall.
If there's a joint (as I imagine there is) between the concrete house (or fence/wall) foundation and the sidewalk, the water will, very slowly, drain through there and, in the winter, freeze. Freezing water expands and it will rather quickly crack the sidewalk (if things go well) and/or the foundation (if things don't go well).
If your contractor thinks this is OK as-is, you might want to get a city/county inspector involved and withhold any further payments until it's corrected.

I note that there's a solid white plastic cover in the sidewalk. Is this supposed to be a cover for a drain for this area? If so, it should be replaced with a perforated cover to actually allow water out. It could, reasonably, also be a screw down flush cover to a sewer line clean out. If that's the case, you do not want to open that up. You'll be allowing sewer gas directly out of the sewer lines and you don't want that - it smells like... sewer.


Microsoft Office updates fail to install

Question: I have one computer (Windows XP) which is updating via update services.  Most updates are installing successfully, however updates to MS Office are failing to install.  Windows updates then pops up again with the list of pending office updates still listed.  Repeated attempts to install the updates fail again.
Comment: +1. This seems like a reasonable sysadmin question. If I may make a suggestion: Consider rewording the subject to be in a more focused format, such as how to re-enable Office updates which are not applying. Also, consider giving more details about what it means when "installation fails."
Answer: Appears to be a problem with the windows installer service.  Resolve by command line:
<code>msiexec /unregister
msiexec /regserver
</code>


Can you recommend suction-cup microphone holder ?

Question: Can you recommend suction-cup microphone holder ?
Recording cars etc...
Answer: I use a pair or Manfrotto pump-cups, and have never had one fall off.  They are 60mm in diameter, and you need to remember to take something with you to clean the surface afterwards as they usually leave a visible ring.
http://www.manfrotto.com/pump-cup-with-flat-base
Answer: I used for this standard camera car rig suction caps - 2 for boom pole, 1 for single microphone on mic holder.
Follow this video: http://vimeo.com/33421306


How can I find a reference pitch when I practice singing a song by ear?

Question: If I listened to a song for enough time, memorized the melody and the vocals of the original singer removed and now I am left with just the accompaniments playing in the background and I am going to sing how can I know which note in the accompaniments I should use as my reference pitch to start singing in key? (If I don't know anything about the song's chords or melody)
Comment: If you have listened to that song for "enough time", you should already know something about the song's melody, especially since you say you have memorized it.
Answer: If you've 'memorised the melody', I can't see why you should have problems starting on the wrong note! Take singing 'Happy birthday'. Without accompaniment, in a crowd, there will be many wrong start notes, which will often end with (most) folk ending on the right note. But, given an intro, which should end on the V, everyone (almost!) will start on the right note.
Not that more than 10% of those folks will be musicians. It's something innate, that most of us are blessed with, not something like absolute or relative pitch. I'm certain that 90% of folk will just pitch naturally, without any actual mental reference to the introduction. They'll spontaneously start on the correct note.
And if you've 'memorised the melody' you're already pretty close - it's rather like muscle memory - having speared that piece of food on your fork, you don't ever have to stop and think 'Now, where's my mouth'...
Comment: A very likely intro for 'Happy birthday' would be the final couple of bars, which end on the tonic.
Comment: @Laurence - that's often the case, but I tend to start with a rolling V chord, which actually gives the start note ^5. Works just as well, for me at least.
Comment: Yes, both are possible. I was challenging "... an intro, which SHOULD end on the V..."
Comment: (Whoa... now I want to do an experiment: If you just have a roomful of people start "happy birthday," with no intro, they might all pick a different starting key but coalesce into one. What governs this? The loudest voice? (that's my guess) Some kind of "best key for most voices"? It would be intriguing to try...)
Comment: @phoog - not necessarily 'right', but the consensus. Wrong terminology.
Comment: Tim, what is the "right" note for singing "Happy Birthday"?  I don't suppose there is one, so I'm struggling to make sense if this answer.  @AndyBonner in my experience, the crowd typically settles on a key by the end of the second phrase, and the key is too high for most of them to make the octave leap, which they then fail to do, causing them to switch keys in the middle of the phrase.  My 11-year-old nephew sent a video of himself singing the song like this, so I thought, "oh, his piano lessons aren't paying off, and he's got a horrible sense of pitch."
Comment: @AndyBonner But then I noticed that with other songs he actually has a very good sense of pitch, so it must be that this phenomenon of starting too high and not making the octave leap is so common that he actually learned the melody that way.
Comment: @phoog - there is no 'right' note (or key) for Happy Birthday, but usually, I've played it in key F or key G. That way, it covers an octave which is within most folks' range.
Comment: @Tim then how does it make sense to say "in a crowd, there will be many wrong start notes, which will often end with (most) folk ending on the right note"?
Comment: @phoog - maybe you haven't sung 'Happy B'day' in as many crowds as I have, but I find that's often the case, given no proper start note or cue. Most seem to gravitate to a similar note at the end.
Comment: @Tim I've sung happy birthday in many a crowd.  What I don't understand is why you're calling the note to which the crowd gravitates "right."
Answer: This is something for which each singer has to find their own, perhaps individually unique, approach. And the issue isn't limited to the first pitch of the song, but can apply after a lengthy rest, where there is a difficult-to-hear interval, where the vocal conflicts with the harmony, or where there are key changes or chromaticism.
To get you started in finding your approach ...
Method 1

Using a full recording of the song (or the sheet music, or whatever is available), find the pitch in question, so it's in your voice/ear.
Begin the accompaniment-only recording shortly before the pitch you're trying to find, and listen for a pitch that you can relate to the one you're trying to learn — the one currently in your voice/ear, because you found it in step 1.

Method 2
Transcribe the accompaniment recording so that you know every note in the accompaniment part. It does not have to be the entire recording, of course; just a part close to the note for which you need a reference pitch.
Method 3(A)
Except for the first note of the song, your reference pitch can be the last note you sang. It's good ear training to practice holding onto a pitch while the accompaniment is doing other things.
Method 3(B)
If it's the first note of the song, but not the first note of the concert, practice holding onto the last note of the previous song and find your pitch from there.
Method 4
Hide a tuning fork somewhere in your clothing (up a sleeve, in a pocket, etc.) and find a subtle way to listen to it before the pitch you need. Find your pitch relative to the tuning fork.
Comment: @Sarah Re-reading the question, I wonder whether you're using an accompaniment that has no introduction? You're just starting to sing immediately? If this is the case, even professional singers would have to resort to methods similar to 3 or 4. There's a reason, before a choir starts a song, someone plays a note on a piano or pitch pipe. Most humans (with some exceptions) just aren't reliable at "nailing" a given pitch out of the blue, unprepared.
Answer: From an other question you raised I see you are using sheet notes and your piano to explore the melody and (some) chords, which I like as an approach.
So you can make an experiment, like this, i.e. deliberately change your reference pitch:

playing chords (accompanying), adjust your voice to root, 3rd, 5th and so on, and see/hear, where it leads you to; in the same octave or higher or lower, in different parts or measures of the song
same for notes you sing off-chord on purpose (which probably many times will lead to a strange voicing, but not always, which we need also for learning purposes)
thinned-out chords, e.g. don't play its 3rd, 5th etc. to make room for your voice (like a placeholder)
try singing on purpose one or several semitones off-melody or off-chord, and try staying there

The purpose is to further develop your feel for harmony (and harmonic progression, harmonic rhythm).
Bands sometimes talk about "playing in the pocket", meaning, all fits nicely together. You can't beat that feeling, when all instruments are on-rhythm, on-chord, on-tempo and so on, they let if flow and follow the flow, resting in music. However, even slight deviations can "ruin this feeling" easily, but there is some tolerance. In harmony, your overarching topic, there are similar effects.
Or said from a different perspective: In the end accompanying chords and melody form just an other chord together, perhaps the same one, perhaps a different one. The better your feeling for chord-harmonies becomes, the better your results will be as a singer.


Karate and Newton's 3rd law

Question: In the case of board breaking by a karate practicioner there are two possible scenarios. First is that the board isn't broken so the karateka's hand really hurts. In the second possibility the board is broken and the hand hurts a lot less. So, by the pain on the hand, we can assume that in the first case the force exerted by the board towards the hand is greater than the second case. Accordingly to Newton's third law, this force is the same with that of the hand's exerted to the board in each case. So, a relatively low force can break the board and a higher one can't?
Answer: Try it yourself - you don't need a board, you can just use a wall and a piece of paper. Let's assume that your punch is of standard strength. If you punch the wall, chances are you'll hurt a lot. If you punch the piece of paper, chances are you won't hurt at all. Since your punch is of standard and unchanging strength, why is there a difference?
The reason is the acceleration your hand feels at the moment of impact. When you punch the paper, the paper deforms around your arm before breaking. That means your arm takes (comparatively) more time to decelerate - say, 0.1s. When you punch the wall, the wall doesn't budge and your arm takes much less time to decelerate - say, 0.001s. That translates to an acceleration that's 100 times larger. By $F = ma$, the force you feel in the second case is also a hundred times larger than in the first case.
For the same reason, if you jump off a table, it's preferable to bend your knees upon landing. The more you bend, the more comfortable the jump is going to be.
Comment: I am sure it will happen. If you punch a board with medium power and speed it won't break and you will hurt your hand. If you punch it with much more speed it will break and the pain on your hand will be much less.
Comment: Thanks for the answer. I believe that the two speculations you make can't be both true. It is not possible that the force I apply to the wall and the piece of paper is the same and that each of these exert to me a different force. This would violate Newton'w third law. I agree that the wall applies more force to me, but that should mean that I also apply a greater force to the wall than the paper.
Comment: Sorry my answer wasn't complete enough. When your fist goes through the paper, it both takes more time to decelerate _and_ doesn't decelerate as much. To put some numbers, say your fist moves at 10 m/s. After going through the paper, it's slowed to 9 m/s. With the times given above, the acceleration is 1 m/s divided by 0.1s = 10 N, and that's the force you feel. On the other hand when your fist rebounds from the wall, it would have something like -10 m/s velocity after rebounding. That's a force of 20000 N. Newton's 3rd law is not violated.
Comment: I totally agree with what you said now. But if paper and wall are replaced by a board which breaks in the first case and doesn't in the second. Does this mean that a 10N force was able to break the board but a 20000N one wasn't?
Comment: If it's the same board that won't happen. If they're different boards then it just means that the first board is made of a material that's a lot weaker than the second board's.
Comment: Yes, that's what I just explained. Let me try again. When you punch a board, you don't actually use a certain force, you only move your hand to a given speed before impacting. If your hand moves fast enough, the board breaks, and since your hand decelerates less you feel less force. If your hand doesn't move fast enough, the board does not break. Your hand decelerates a lot more, hence you feel more force.
Comment: I agree, I wrote these on my initial question. So, when you feel more force, the board also feels more force (Newton's third law). This means that when a greater force is applied towards the board it doesn't break, but it breaks with a smaller force? This is what I'm asking from the very beginning.
Comment: I repeat, when you punch a board, you don't actually use a certain force, you only move your hand to a given speed before impacting.
Comment: But this is what I'm saying from the start. If I reckoned that a certain force was applied in each case, there would not exist the initial problem. A different force is applied each time by the impact. I believe we agree until this point. My question was "how are the forces of the 2 cases compared?"
Comment: I don't think this analysis is right. You're varying a parameter (mass of the object being hit) that is fixed in the question.
Answer: A karate punch is much more than exerting as much force as possible. It's important to hit the target in a precise way that

minimizes the impact area in order to maximize pressure, and
makes use of the body hardened spots and damping structures in order to minimize damage to self.

So, the more intense pain of a failed attempt doesn't necessarily correspond to a larger force, but it may instead simply result from the force being applied to the hand in a more damaging way. And, even if a stronger force is involved, it might fail to break the board because it's spread over a larger area or not applied abruptly enough, allowing the board to deform instead of break.
Comment: Also, physical damage often depends on the third derivative $x'''$ (jerk), not just on the acceleration $x''$. For example, a constant acceleration can never cause vibration, and vibration often damages things.
Comment: @BenCrowell, good point, I hadn't thought of it.
Answer:
Accordingly to Newton's third law, this force is the same with that of the hand's exerted to the board in each case.

This is an incorrect assumption, and perhaps part of the problem you are facing.
As mentioned in other answers; an important factor is the time required to slow down your hand.  Something softer will compress more.  The more it compresses, the longer it should take to slow down the hand (assuming the same impact speed for comparison).  Since it takes longer to slow down, it has less acceleration on your hand.  Net force is proportional to acceleration; so the less the object deforms; the more force it applies to your hand.
Another important factor that seems to have gotten overlooked in these answers is the difference in motion between going through a block, and hitting into it.
Another way to think of applied force is to think of the acceleration required to reach your new speed.
In the case of going through the block; your final speed is not $0$.  You still have some velocity after breaking it, which is used to keep your hand going.
When you hit into the block, your hand stops completely.  This means the force applied by the block to your hand is based on the acceleration required to stop your hand.
When you go through, since you still have some velocity, you must have experienced less acceleration due to the block than in the scenario where you are stopped by the block.
This means that not only does the hardness of the surface effect the impact force; but the impact force is actually less when you go right through, as compared to when you hit the block and are stopped by it.
That's not really to say that it should be easier to go through a block than to hit into it; but really it means that blocks that you are able to break through will apply less force to your hand than ones that you cannot break through; even if impact times are the same.
Comment: I agree, this is exactly what I claimed in my original post. So, as said yourself, when you go right through the impact force is less. By Newton's third law the impact force your hand feels is the same as the force applied by your hand onto the board. So, a smaller force is able to break the board but a greater force isn't?
Comment: @johnk No.  That's a separate problem entirely.  If the board is too strong; you wont have enough force to make it through anyways; and you get the full reaction on your hands.  If the board is weak enough to chop through, you should experience less of a reaction force than a stronger board that you don't break through; even if you supply the same force to your arm in both scenarios.

Karate and Newton's 3rd law


What happened to Phillip in On Stranger Tides?

Question: At the end of the movie Pirates of the Caribbean 4: On Stranger Tides,

 Phillip is badly wounded and seems to be telling Syrena not to heal him but only to forgive him. She then drags him into the water and we never see him again.

Am I meant to assume he's dead now? Or was there some symbolic meaning to this gesture that I didn't catch?
Answer: Earlier in the movie I recall Derrick saying

"I heard it said a kiss from a mermaid protects a sailor from
  drowning"

It's worth noting that the mermaid kisses him before pulling him down so I think she is saving Philip rather than allowing him to drown.
Answer: I have no real answer for this, because I don't recall the movie clearing that up. But to me it looked like this.
Phillip thinks himself unworthy and only asks for her forgiveness, not for life, because he is that kind of humble. Unlike Blackbeard who wanted to sacrifice his daughter for his own life.
Syrena however tells him again to just ask. In my opinion, it's no really clear if she means for him to ask for forgiveness or if she refers to her earlier statement, that he only need to ask to be saved. He then asks for forgiveness bevor she takes him with her.
I thought this meant that she wanted to do more than simply forgive him. That she wanted to save him and be with him.
In some stories mermaids can grant the ability to breathe and thus live under water too.
So I thought she took him into the sea to be with him happily ever after. Because she did not seem sad when she took him down.
In this he would be a counterpart to Blackbeard, finding happiness in the end because he was selfless. Again unlike Blackbeard, who died beeing selfish.
Also, why would she take him with her, if she wanted to let him die? She could have just left him there. Unless for some reason she wanted him to have a watery grave. But I don't see why she would want that.
Comment: @Yamikuronue I just rewatched the scene and you're right. She is not saying anything about saving him, but simply says 'ask'. That could mean for forgivness, like he does. But I still think she means more than that. In the end, it has most likely been kept vague so to leave it open for the viewer to decide what really happens to him. I will edit my answer accordingly.
Comment: Is that what she was saying? I thought that line meant "If you want forgiveness, you need only ask". And, er, I kind of thought maybe she, ah, wanted a baby as a souvenir, given the stories we heard earlier? But your answer seems a lot more like a moral Disney would support so...
Answer: From the POtC Wiki:

Alone and mortally wounded, Philip drags himself to the nearest pool
  to get some water to drink and use to try and heal his wounds. As he
  splashes the water, Syrena returned and appeared in front of him.
  Reunited and free from Blackbeard and his crew, the two profess their
  love once more. Syrena then told Philip that she could save him from
  dying. Philip then begged Syrena for forgiveness for all the trouble
  he brought to her, as she would never have been captured had it not
  been for him. Syrena kissed Philip, confirming the legend that a
  mermaid's kiss prevents drowning by giving him the ability to breathe
  underwater, and pulls him into the pool. Philip was taken by Syrena as
  they swim through the pools to freedom. His further fate is
  unknown.
Comment: this looks very much like you are quoting something; if so, please don't forget to attribute it properly
Answer: Hm. Apparently, from things that I have read and watched, a mermaids kiss can grant air to breath underwater for a short period of time. If you look clearly at the scene when she pulls him into the water you see them swimming down, though she is actually taking him through a ring of light and thus she is not heading down further into the ocean because it would be darker. Therefore she was heading to land supposingly. Just like when she suddenly disappeared before and resurfaced to aid Captain Jack with the Chalices. She did not wish to kill him, I would not think so anyway. :) I hope I cleared some things up for you.
Answer: I think she saved him because when got in to the water they were hugging each other and Syrena saved Philip in the beginning, remember? So I think SYrena is diffrent, she doesnt looked like she was meant to kill and eat him. But when I first watched that part, I cried like a litle girl. I ship Syrena and Philip forever. I hope in the 5th movie they will appear.
Answer: There's speculation that at the end of the scene when Syrena's taking him into the water that it looks like Philip's legs become a tail, but it's unconfirmed and hard to tell.
Comment: It might be helpful if you added a link or even a video to this answer.
Answer: If you recall, when Blackbeard's men are trying to trap the mermaids using the men in the boat as bait, one pirate said that a mermaids kiss can - according to legend - grant eternal life.
Comment: [Niamh's answer](http://scifi.stackexchange.com/a/57026/41082) said basically the same thing.
Answer: Philip slid across the ground towards the water to get himself a drink of water, during that Syrena came up infront of him, saying that she could save him from dying, instead Philip apologizes for all the troubke he caused her, for she would not have been captured if it wasn't for her. After Philip asked for Syrena's forgiveness she kissed him, therefore granting him with the power to breathe underwater, they went into the sea to be with eachother happily, to get away from Blackbeard! Syrena did NOT take Philip down there to kill him, otherwise why would she kiss him? True love if you ask me
Comment: I don't see how that contributes anything new to existing answers.
Answer: I have to wonder, I just finished watching the movie for the 2nd time and wanted to know more about what happened to the pair. I had heard that another movie was coming out soon and, much to my excitement, it is about Jack trying to find Poseidon's trident... I'm going to let that sink in. This COULD mean that Phillip is going to become Poseidon!!!! This theory is by no means fool proof, but why else would they leave the viewers on a cliff hanger and make the next movie surrounding the idea of a merman's trident? It makes sense, but I don't think that Phillip's actor was on the cast list. Although there has been times when an actor doesn't always know, or can say, if they are going get to play in the next movie. If you want to check my answer, go and look at what the next movie is going to be about.
Comment: Well thank you for putting me in my place, you have been very helpful and I hope you do not think of me negatively. There's a first for everything ; )
Comment: If yours is the same that was deleted hours back, the community disagrees ^^ might help if you provide some evidence -- that the new film has that plot, for instance. Esp as I recall hearing the next movie will be a straight up pirate film with no mythological aspects...
Comment: Ok I'm sorry for rewriting my answer, but I truly think that this is an answer at its least. Look I wanted to supply an addition to the other answers. The other answers only say that her kiss allows him to breath underwater, but no one has anymore than that. This is a possibility that no one has put out there and I am sincerely sorry for the trouble. I did say that I was only making a hypothesis, so please don't hate so much.
Comment: No hate at all -- im sorry if I came off like that :) I think if you add in some proof about what the film will be about (not doubting you, but we like everything to be in the answer) it might do better. It's still wild mass guessing though -- not that your guesses are any less important than anyone else's, but a good answer should have proof - it should *be* correct, not just possibly so. (If you wanna debate the idea, pop into chat where everyone can discuss theories)
Comment: And I had just gotten on this site about a day ago, so I hadn't known my "way" around the site per say
Comment: Of course. I didn't mean anything negative, but I could have been more helpful. It's okay, this site is quite unique in that speculation and theories aren't so favoured. We all have to start somewhere (my first answer, long since deleted, is easily one of the worst this site has seen).


What is the origin of the word "dead-tree"?

Question: What is the origin of the word dead-tree? I know that it basically refers to the print edition of a book that is also available in electronic format but would like to understand of the etymology the word dead-tree. In particular why the combination of the terms dead and tree to refer to books?
Comment: Books are made of paper, which is made from wood.
Comment: ...that's ***dead*** wood. They haven't yet invented the kind of supertree that could survive being chopped down, pulped, and rolled out to a fraction of a millimetre thick. I think this is General Reference.
Comment: @rena yup, that's the exact construction that's commonly used - primarily in contrast to digital editions.
Comment: How does one put dead-tree in a sentence? Something like: The dead-tree version of Harry Potter is available at every bookshop now?!? Would that sentence work?
Answer: Paper is typically made from wood pulp, which is produced by grinding up dead trees.
It's really nothing more complicated than that.
Comment: There is a level of negative implication.  Consider the spectrum: "harvested tree", "dead tree" and "killed tree"
Comment: @User58220 You'd think that, but I've found the term 'dead tree' used more by lovers and defenders of old fashioned print than by it's detractors. I think it's the fact that the term carries a strong connotation of *physicality* with it.
Comment: @LessPop_MoreFizz: If "dead tree" were to have had a negative connotation when used by book-lovers, it would have made the most sense in the early twentieth century, to distinguish the newer papers made from wood fiber from those made of other fibers.
Answer: Dead tree (noun, adjective) refers to the fact that paper copies of a document require trees to be killed.
The term is somewhat jocular and slightly negative, reminding of the sometimes unnecessity of the printed page in the computing world.
The term originates from the computing world. The first entry in the OED is from the 1991 New Hacker's Dictionary:

Hackers seldom read documentation... A common comment on this is 'You can't grep dead trees'.

Grep is a tool for searching for text in an electronic document, and this shows having a printed document is worse as it's harder and slower to find what you want. The OED compares it to a similar computing term for paper, treeware.
Wiktionary has an antedating:

1986 Apr 15: Barry Shein, Re: job control, net.unix-wizards, 1

My question is basically do you need
    better on-line programs to search the
    docs ... , or actually different dead-tree style.

And I found a 1985 antedating in net.lang.c from Usenet, in the signature of Thomas Johnsson in a 23 July 1985 post to net.lang.c:

Mail on dead trees: Dept. of CS, Chalmers University of Technology,
                        S-412 96 Goteborg, Sweden


How to dynamically populate a dropdown

Question: I am tasked with creating a subnav in the body of our custom-built pages. The nav's last item is supposed to be a clickable dropdown (a "more" button) that can dynamically populate if extra pages are added via the dashboard. I'm trying to figure out how to code this in PHP and JS without a plug-in. Any sort of point in the right direction is greatly appreciated!
Answer: Well, here's my best shot, although when I add another item to the dropdown, the styling gets weird. https://codepen.io/bfoley650/pen/PoZwKeb

How to dynamically populate a dropdown


Is there one word for the 4 not vertical and not horizontal directions of the 8 directions?

Question: Here are 8 directions: up, down, left, right, upleft, upright, downleft, downright.
Is there one word that covers "upleft, upright, downleft, downright" ?
Comment: They are all **diagonal**, aren't they?
Comment: I challenge the assertion that "upleft" and so on are words in standard English. You may see them used in computer programming (as identifier names) but you would never say "I threw the ball upleft.".  Indeed, I think having these directions only really makes sense on a screen.  So the answer is "No".  Could you accept "No" as an answer?
Comment: @MichaelHarvey: Or *They are all **diagonals**, aren't they?* - ***diagonal*** works fine as a countable noun as well as an adjective (which might not be obvious to learners).
Comment: @JamesK I don't mean a word precisely for "upleft, upright, downleft, downright".
It is also OK, if it is a word for "north-east, north-west, south-east, south-west".
Here are 8 directions, and what is the word for the 4 not straight ones?
Comment: @MichaelHarvey Yes!
Comment: They are all diagonal (adjective) and they are all diagonals (noun).
Answer: Of the eight main compass directions, the four main north, east, south, and west directions are called the cardinal directions, and the four 'diagonal' directions you show (north-east, south-east, south-west, and north-west) are called the intercardinal directions. These terms will probably be familiar to e.g. meteorologists and navigators, and maybe people interested in geometry, but are probably not familiar to others. Google 'Wikipedia points of the compass'.
Of course, an infinite number of other diagonal directions exist between the intercardinal ones.
Comment: @JamesK - yes. Horses for courses. The precision and clarity needed for aiming e.g. an anti-aircraft gun or an astronomical telescope would not be needed or appropriate for discussing throwing a ball. Anything more than 'up and to the left' would probably be perceived as clumsy and ridiculous. You might name a target, e.g. I threw the ball at my neighbour's window, which was above me to my left.
Comment: However, I wouldn't say "I threw the ball in an intercardinal direction"  to mean  I threw it up and to the left.
Answer: The word that describes both of those is diagonal. A square or a rectangle has two equal diagonals.
If you had to differentiate between one diagonal and another you could do so in plain English by saying something like 'upper left to lower right. In mathematical diagrams, the sides or corners of a shape may be labelled and you can refer to those.
Just like the directions you referred to - left, right, up and down - diagonals are relative, unlike compass directions which are absolute.


Good starting point for a workshop about web form UX?

Question: I have to put in place a workshop dedicated to the UX of web forms and I need ideas/starting points because I have no previous experiences with workshops.
Comment: I'm really not sure what you're asking. Are you asking how to start a workshop? Or what makes a workshop successful? I'm not even sure this is in the realm of this site
Comment: @Majo0od As dennislees figured out, it's more along the line of "How to make UX knowledge into a workshop?" ... but also "are there existing workshop templates for UX out there?"
Answer: A good starting point is determine and outline the structure of your content. This will likely be based on fundamental principles and best practices, and these can easily be researched.
To answer the obvious follow up question "How to make this into a workshop?" is too broad to answer here because there are too many unknowns, but in general, you should aim to:

present a concept/topic (e.g form labels)
discuss why certain approaches work/don't work
offer opportunity to critique examples (either informally, via group discussion or formally in timed individual/paired/group sessions)
repeat for major content areas and topics
finish by providing participants with requirements for a form, and challenging them to apply their new knowledge to design a usable form
Comment: Well, that's the interactive part that I can't figure out. For example "offer opportunity to critique examples (either informally, via group discussion or formally in timed individual/paired/group sessions) " doesn't ring a bell ... would you have some practical example in mind? Do you know about tutorials/templates for workshops that can become truly interactive?
Comment: Never attended any workshop before :(
Comment: But surely you've been in a situation where you've been asked to talk about, think about, or work on something in pairs or small groups?  This is what's involved. It's hard to recommend this without sounding patronizing, but have you googled "how to run an interactive workshop"? The results for that search look interesting. If you genuinely have no idea what one looks like, the the best example I can think of (that I can find easily on Youtube) is this Design Thinking workshop. You can get a sense of the basic structure. https://www.youtube.com/watch?v=Z4gAugRGpeY


DVR burning out

Question: I'm at a loss here. So Everytime I plug the Ethernet cable into my computer from the modem the DVR shorts out. Had the cable company out here and he said there's a lot of current on my coax. We disconnected the computer and still a lot of current on the line. He checked the voltage coming off the TV and it was pegging the needle. We changed plug and it dropped to 20 v. No voltage feedback off the computer. Tried it after changing plugs and as soon as I plug the Ethernet cable in boom box goes out. With the TV computer off the coax the power is still on the return line he said. I'm not technically savvy so I can use suggestions on this. Is it electrical could it be the modem? The cable is grounded to the metal pipe coming out of the electric meter. Any help would be greatly appreciated.
Comment: The question may be framed as  "electronics troubleshooting" but the real question is why the house's grounding system isn't actively preventing this from happening.
Comment: @isherwood The one part that may be for this site is the question of "electrical" - e.g., if things are **really** messed up and ending up with a ground loop or something like that.
Comment: Sorry, but electronics troubleshooting doesn't fall under "home improvement" as this site defines it.
Comment: That occurred to me, but we don't have much to work with here in that arena. Doug, you could revise to ask about troubleshooting voltage on your coax line instead of mixing in all the device issues.
Comment: Are you new to this house? Did the prior owner have satellite dish?  20v sounds strangly like an 18v powered splitter/amplifier for directv is still wired in.
Answer: It's worse than that.  Aside from the fact that all that current down your cable is spinning your electric meter and wasting money, there's also the life-safety problem that something is floating your grounds to potentially hazardous voltages.  You could get a shock off anything grounded.  Which is the opposite of how grounds are supposed to work!
Grounding Electrode System
A house that floats has a problem with its grounding electrode system.  This is what connects your house "ground" to actual earth. Go over that system with a fine tooth comb -- but watch it - it's energized!
If you find it is energized and flowing current, try turning off breakers in groups until you narrow down which breaker must be on for that condition to occur.  Once I had that problem and did that test before I fixed it: it uncovered a second problem, a circuit with a ground fault.
The neutral-ground bond
It's also worth checking your neutral-ground bond in your main panel only. Sometimes these burn out, especially when they are simply a green #10 screw going from neutral bar to panel: the screw head may look fine but behind, the screw is vaporized.   I prefer manually installing a fat #8 or #4 copper wire between neutral bar and ground bar... if it's the only connection, you can put a clamp ammeter around it!
Be wary of a dangerous voltages and arc flash when connecting the neutral-ground bond. Better to turn off the main breaker while installing it.  But there's even a small possibility the source of the current is external to your home.  Just watch it.
Current flows on a neutral-ground bond because current actually wants to get back to source. For man-made power, source is the pole transformer and its neutral wire. The neutral wire is grounded to earth at the transformer.  For lack of a neutral-ground bond, fault current may be traveling via your house's grounding system, to the DVR and TV cable jacket, the dirt around your home and back to the transformer's ground rod. A lot more current wants to flow, but dirt is a poor conductor.  That'll change somewhat when it rains.
The second problem: a ground fault
A broken grounding electrode or N-G bond, alone, will not cause current flow.  That would simply give you an isolated system.  What's causing current to flow is a second problem: A hot-ground fault somewhere in your house.  This could be in the wiring of a circuit, or more likely in an appliance.
It's easy to test an appliance with a 3-prong plug: take it into the bathroom and plug it into the bathroom GFCI.  This test will best work if the GFCI is grounded, and your neutral-ground bond is in working order.
If you fix the neutral-ground bond and the grounding electrode system, current will flow down the intended emergency paths instead of the cable TV cable.  (Actually it will flow down all at once, in proportion to their conductance; conductance is 1/resistance... But if your grounding systems are tip top, they should carry 99.9% of it and that will keep thongs from burning out.)  This will be safer, but still spinning your electric meter.  So it is costing you money not to find this ground fault.  coughcheapCheesePCpowersupplycough
Your house needs a working grounding system. But if that's too much right now, you can put a band-aid on the problem by doing a bathroom GFCI test and fixing any appliances which trip the GFCI.

DVR burning out


Difference between a markov process and a semi- markov process

Question: As the title suggest, i have a little problem grasping the main difference between markov and semi-markov processes. Anyone up for the challenge? :)
Answer: I will discuss only Markov processes on finite or countable state spaces. My answer is based off of this page.
Suppose $s > t_n > ... > t_1$.  A Markov process is a stochastic process where the conditional distribution of $X_s$ given $X_{t_1}, X_{t_2}, ... X_{t_n}$ depends only $X_{t_n}$.
One consequence of this definition is that the time until the next jump is exponentially distributed. This property arises because only the exponential distribution satisfies the "memoryless" property $P(X_t | X_s=x) = P(X_{t-\delta s} | X_{s - \delta s}=x)$. Another consequence is that, given a transition occurs at time $s$, the distribution over the next state depends only on the state immediately before. Thus, the upcoming transition's distribution is completely described by a product of an exponential PDF (for the waiting time) and a categorical distribution (for the next state).
For semi-Markov processes, upcoming transition's distribution is described by a product of an arbitrary PDF (for the waiting time) and a categorical distribution (for the next state). The waiting time is no longer required to be exponential; in other words, the process is allowed to "remember" not only the current state, but also how long it has been in the current state. One interesting wrinkle is that, although it remembers how long the current state has lasted, that knowledge must not affect the decision about which state to enter next. This may make semi-Markov models unsuitable for some applications: if someone is getting sicker and sicker of her job, for instance, she might be more apt to take anything that comes up, and the distribution over her next state might flatten.
Comment: Thanks!

That was actually a really good way of explaining it, thank you :)
Comment: Glad I could help! I learned something new, too.
Comment: @ Eric_kernfeld: great answer! I posted a similar question here - can you please take a look at it? https://stats.stackexchange.com/questions/585287/understanding-the-difference-between-different-types-of-markov-chains Thank you so much!
Comment: I will try to take a look this weekend, but no guarantees. Sorry if I am not able to.


Allow a user to run a script as sudo with sudo commands in the script

Question: So I created a script that live in /usr/local/bin called Linux-Permissions. In the script, there are some sudo cp commands. I need a user to be able to run the command as sudo, which I was able to do by adding this into the sudoers file: username ALL=(root) /usr/local/bin/Linux-Permissions.
However, after he puts in his password to run that command, it asks for his password again to run the sudo cp inside the script. Since he doesn't have permission to run cp as sudo, this fails. The sudo commands inside the script are within a selection menu if that matters at all.
Comment: if you run the script with sudo everything inside also runs as "sudo".
Comment: I removed sudo from everything inside and it works great! Not sure how to set your comment as the best answer.
Answer: So, you have successfully identified the problem; adding an entry like that to sudoers only gives the ability to run /usr/local/bin/Linux-Permissions with sudo, so all of those other sudo commands will fail since, even though the script is being run with root privileges, sudo still sees that it's being executed by a normal user.
There are probably several different ways to approach this problem, but I would modify the script so that it only uses the sudo command if it is running as a non-root user.  Here's a very simple example of a script like that:
#!/usr/bin/env bash

if [ "$USER" != "root" ]; then
  SUDO_CMD="sudo "
fi

$SUDO_CMD ls

In that example, the ls command will be run with sudo if the script is being run as a normal user, but it will not use sudo if the $USER environment variable is set to root, which will be the case if you run the script with sudo.


Security Exception when Uploading From Silverlight to PHP

Question: I am using the official Microsoft example and this example as the basis for my code to upload a file from Silverlight to a PHP script.
I am calling **HttpWebRequest.BeginGetRequestStream()**, writing the file over a file stream, and then calling **HttpWebRequest.BeginGetResponse()** to get the response. When I call HttpWebResponse.EndGetResponse() I get the following exception every single time:
{System.Security.SecurityException ---> System.Security.SecurityException: Security error.
   at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
   at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
   at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)
   --- End of inner exception stack trace ---
   at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
   at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at FileUpload.FileUploadProcess.GetReponseCallback(IAsyncResult AsyncResult)}

I have both clientaccesspolicy.xml and crossdomain.xml files in the base directory that allow access. I ran Fiddler and have seen it download the clientaccesspolicy.xml file so it is hitting it correctly.
The PHP file is running on Apache2 and just does a fread on php://input to read the data as the examples show. It is not receiving any data which leads me to believe that the SecurityException is forcing it to abort the write.
Has anybody seen this issue before and can point me in the right direction of a solution?
Answer: Have you checked to make sure the webserver/php application has write access to the directory you plan on storing the uploaded file to?
This could be causing it to abort prematurely.


Example of a problem for which Zero-Knowledge proof is not sequentially composable

Question: There are notions that a Zero-knowledge proof with auxiliary input is necessary for sequential composition. However, the authors here give a very convoluted example of a system which is not sequentially composable under the original ZK definition. Could you please give me an example where the original definition by Goldwasser et al. is not enough for sequential composability?
Answer: The paper you cited gives that exact example. It shows that zero-knowledge that is NOT zero-knowledge for auxiliary input is not strong enough. The fact is that most known zero-knowledge proofs are secure for auxiliary input and thus are secure under sequential composition.
Comment: Yes, you are right. I think I was just looking for a more 'down-to-earth' example of such a problem. :)


Validating data contracts using business logic (entity based)

Question: All my service methods use a facade to talk to the business logic. This means that in the facade the DataContracts (I'm using WCF) are translated to entities (Entity Framework) and then passed on to the business layer. The problem I'm facing right now is that I want to put certain validation logic in the business logic, but this keeps from from translating the data contract to an entity.
Example: I have a method on my facade called CreateUser(). The incoming UserDataContract has a property Name. This is a mandatory field in the database, so Entity Framework has put a not-nullable attribute above this member (<code>[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]</code>to be exact). I can put the validation logic in the business layer, no problem there. But when a UserDataContract with a null in the Name field is translated a ConstraintException is thrown: Entity Framework prohibits me from setting a null value in the Name field of the UserEntity class.
What's an elegant way to avoid this?
Can I somehow remove the check of this field in Entity Framework (setting the nullable property to true will make EF complain about a mapping to a not-nullable column).
Is there some pattern I can use to introduce a validation mechanism into the business layer and use this from the facades?
I have multiple facades, with multiple data contracts for the same entity. But still one entity type and one business layer.
I'm using .Net 4.0 here.
Thanks!
Answer:
Use POCOs: Same class/object in database layer and business layer  = business object
Add validation attributes to your business objects using for instance DataAnnotations.


Download pdf from a URL instead of opening in a new tab

Question: Is there any possible way in Angular 10 / Typescript to download a PDF from a URL instead of opening it in a new tab?
Sample URL: http://www.africau.edu/images/default/sample.pdf
Comment: https://www.npmjs.com/package/downloadjs
Answer: If you need to download and save it an anchor tag with the download attribute as @sasa suggests should suffice. Here's some sample code for Angular.
Click to download

If you'd like to programatically download the file you need to use the HttpClient from Angular:
Install this dependency to make your life easier:
npm install file-saver --save
npm install -D @types/file-saver

And have a generic service
import {saveAs} from 'file-saver'
@Injectable({ providedIn: 'root' })
export class DownloadService {

  constructor(private http: HttpClient) {}

  downloadUrl(url: string, filename: string): Observable<Blob> {
    return this.http.get(url, {responseType: 'blob' }).pipe(
      map(res => res.blob()),
      tap(blob => saveAs(blob, filename))
    )
  }
}

Notice that calling the function won't download the file; you will need to subscribe to the Observable<Blob> returned or transform it into a Promise and await it
Comment: Click to download This is taking to the new tab
Comment: You may use the service I provided you with. That pops up a dialog to save the file
Answer: You need to set the content type as application/octet-stream typically to inform the browser that it should download it instead of displaying it in a tab.  Not sure specifically how in Angular 10 / Typescript:
Answer: Sorry if I'm being too obvious but the download attribute to the a tag doesn't work?
Comment: Thank you. I am trying to download file using code.


sed one-liner to replace word-medial capitals

Question: I used OCR to turn some scans into plaintext, but unfortunately the letters 'fi' which are commonly joined in some fonts, got read in as capital W's. Now I need to replace all the W's with 'fi', and these can easily be distinguished by the fact that a capital W does not ever occur in the middle of a word in true English. So, I need a sed one-liner that replaces all word-medial capital W's with the letters fi.
Answer: A quick and simple answer that should solve most cases is:
sed "s/\([^ ]\)W\([^ ]\)/\1fi\2/"

This will replace any W that is does not have a space before or after it with fi. It catches the error in these simple test cases:
$ echo "blah blah blah trafWc" | sed "s/\([^ ]\)W\([^ ]\)/\1fi\2/"
blah blah blah traffic

$ echo "blah blah blah Wallaby" | sed "s/\([^ ]\)W\([^ ]\)/\1fi\2/"
blah blah blah Wallaby

However, it won't capture things such as:
$ echo "blah blah blah Wnger" | sed "s/\([^ ]\)W\([^ ]\)/\1fi\2/"
blah blah blah Wnger

As you can see this should have changed to finger. So unfortunately you'll still need to check for those.
Comment: Two corner cases that your pattern won't match: `SuW` and `wild-Wre` (Sufi and wild-fire, the second example being broken between lines). Not sure that you can match a broken hyphenated word in a one-liner, however. Upvote anyway, as we arrived at the same pattern to get most of the job done.
Answer: A capital W doesn't occur at the end of a word either, but it may occur in an all-caps abbreviation. So I'd replace W when it's immediately after a lowercase letter, or when it follows an uppercase letter and precedes a lowercase letter (aWre).
sed -e 's/\([[:lower:]]\)W/\1fi/g' -e 's/\([[:alpha:]]\)W\([[:lower:]]\)/\1fi\2/g'

This doesn't cover fifi (which my biggest word list only finds it in "fifing"). More importantly, this doesn't cover W at the beginning of a word; you can capture some cases by looking at the second letter, but that's still going to miss many words that begin with fi. In English, many letters never appear after a W:
… -e 's/\([^[:alnum:]]\)W\([b-dfgj-npqstv-xz]\)/\1fi\2/g' \
  -e 's/^W\([b-dfgj-npqstv-xz]\)/fi\2/'

For more precise results and to cope with other languages, you can switch to a more complex dictionary-based approach (which fancy OCR systems often use, evidently yours isn't fancy enough).
Answer: The guys have already covered the basic sed stuff, but there are a couple more things you could do to help your text along.
The first is to train your OCR program to recognize these in the first place. Most OCR systems have some sort of system to teach it new letters and learn from common mistakes like this one. If your corpus is big enough to need to to search and replaces like this, it should be big enough to teach the OCR engine not to make that mistake.
Secondly, you can run your text through a spell check engine. Many OCR programs include this step as part of an internal self check, a sort of "does this word even make sense transcribed this way". You can certainly do this yourself as a way of validating that everything got sanely converted.
Comment: Yes, a spell-check is a good idea. I've done this type of thing many times..  and there is no one-stop solution (in my experience)... I used four steps. 1. Tune the OCR; 2. sed; 3. a case-statement script for quirky 'specials'; and 4. A spell checker...


Nginx reverse proxy forces 301 on subdomain (and it shouldn't)

Question: So I'm using Nginx (1.4.3) to reverse proxy a domain and sub-domains. I installed SSL certs to handle the main domain (example.com) and a couple sub-domains (lets say test.example.com and mail.example.com). So I naturally used a 301 return to move http requests to https.
server {
   listen 80 default_server;
   server_name example.com www.example.com;
   return 301 https://example.com$request_uri;
}

Works great. But if I introduce another sub-domain that I don't want under the HTTPS SSL Certs (because I don't have a wildcard cert and don't need it for this subdomain). Nginx still seems to apply the 301 to it, even though the server_name has been implicitly set. Since it's 1.4.3 I've split them up in the conf.d folder.
I figure it is doing this because if I clear my browser cache, and navigate to the new sub domain (sd.example.com) it works fine and doesn't rewrite to https. But then if I go to the main site (example.com) the rewrite kicks in, I get sent to https://example.com, and no problems there. But then, if I try and go back to sd.example.com, I get rewritten to https://sd.example.com and the big red chrome error pops up.
Any ideas why this is happening? I'd prefer to stop banging my head around on this one.
Comment: Did you set secure cookies or HSTS?
Comment: Well that was dumb of me. The HSTS did include the `includeSubDomains` directive. I comment it out and it works now. HSTS is new to me so I forgot about it.
Comment: That was quick. No to the secure cookies, but there is a HSTS I noticed. Never thought of that, would that do it?
Answer: posted answers from OP comment
The problem was caused by HSTS header. In main domain, there is entry includeSubDomains in HSTS header . If a browser visits main domain and receive that HSTS header, the browser will force to connect via HTTPS in main domain and subdomain too. So, its pretty clear that nginx doesn't cause the redirection.
If you don't want subdomain use HTTPS, the solution is remove includeSubDomains in HSTS header.


Clip lines by overlapping polygons

Question: I want to cut a line shape into parts by polygon areas. No problem so far. But the polygons overlaps each other at the border. I need one line result for the whole area of every polygon. Any ideas for an automatic solution? Gdal ogr can't do it because of self intersecting polygons.
Answer: My solution is a GRASS GIS v.select iteration. So I get full line-shapes for each polygon, without getting self-intersection problems.
Comment: How exactly this should work? I have lines which intersects/crosses polygons and whatever I do - intersects, overlay etc. I never get lines clipped to polygons. And with basic clip under Vector menu I get only one line for all touching/overlapping polygons.

Clip lines by overlapping polygons


array and curve modifiers (bezier) - distorted texture

Question: I have created a simple road using bezier curve, array and curve modifiers. As you can see on the picture some faces looks weird - a texutre is distorted. Why ? Did I do something wrong ? How to  fix that ?
Comment: could you please pack the image and share the file?
Comment: http://s000.tinyupload.com/?file_id=04552707576784415557
Answer: So I hope my answer is accurate enough.
Your faces are projected as squares on the image in the UV Editor. But your faces are actually not squares, they are twisted quads. Also, in any 3D software a face is made of 2 triangles. So when Blender will map this face the UV map it will simply map 2 triangles, and it will give the following result.

If you subdivide your face a bit with some Ctrl R, the same thing will happen, but as your faces are much smaller the effect will be much less visible.
Comment: I didn't unwrap anything, I just added a single plane object which was already unwrapped and I only used scale/translate in uv editing mode. Then that single plane object has been used with modifiers and bezier curve. But it looks like your explanation is correct.


Faithful normal states on C-Star algebras

Question: Let $A$ be a c-star algebra acting on a non separable Hilbert space. Can one always define a faithful normal state on it?
Answer: No. That's the reason one considers weights.
For an easy example consider the von Neumann algebra $\ell^\infty(\mathbb R)$. Then, if $\{e_t\}$ denotes the canonical elements (that is, $e_t(r)=\delta_{r,t}$) you have the net of projections
$$
p_t=\sum_{s\leq t}e_t.
$$
This net converges strongly to the identity. If you had a faithful normal state $f$, we would have $f(p_t)\to f(I)=1$. This would imply that $f(e_t)=0$ for all $t$, a contradiction (you can check this by getting $f(p_{t+\varepsilon}-p_t)$ arbitrarily small, and putting a sequence in between).


VirtualBox "Bridged" network analog in GNS3?

Question: There is "Bridged adapter" network solution in VirtualBox when your virtual machine gets IP-address from your real physical router (like 192.168.1.62). Is there a similar thing in GNS3 (on Linux preferably)? All i found is loopback solutions, which helps with internet connection, but i still can not connect to GNS3 router from any PC in real home network.
Comment: Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer.
Answer: A switch is a (MAC) bridge, so simply use one of those.
The "bridged adapter" is actually a virtual NIC connected to a virtual switch that uses the host NIC as physical interface.


Are aerodynamic car rims really aerodynamic?

Question: Especially new electric cars often come with aerodynamic wheels that look like a turbine with twisted blades. What is the point of this? I mean, e.g. in cycling they use just a simple disc wheel when aerodynamic efficiency matters during individual time trial. Why is this "turbine" better than a disc? Or is it?
Answer: Theoretically, the blades can act as a fan drawing air sideways. This cross flow can help cool the brakes and other techno-gubbins tucked inside there, at the expense of a small increase in aerodynamic drag. Whether they achieve this on any particular design varies from a closely-guarded secret to anybody's guess. But it looks cool (or do I mean hot?), which in many cases is its primary design purpose.


Why was TKR's answer converted to a comment?

Question: TKR's answer to the question here What is minimalist about the minimalist program? was reduced to a comment. Why was that done? Who did it? That answer had many positive upvotes. I see no legitimate reason to reduce it to a comment.
Comment: @Alenanno well it's mostly gone for most people!
Comment: It also seems to have been cut short to the maximum length of a comment, which means it's mostly gone.
Comment: @curiousdannii No it's not. The answer still exists, it's only "hidden".
Answer: Like I said under your answer, a moderator acted on a flag. We cannot disclose the name of the user that flagged the answer of course, that's confidential information.
The answer still exists, by the way, it's only hidden. So we can undelete it if necessary. So if this user disagrees with the deletion of his own answer he can appeal to us here by posting an answer.
I want to make this clear though: We don't delete answers because we don't like the user, but we need to make sure that an answer conforms to the rules. So if other users or we see that your answer has problems, we need to act, otherwise this site might lose quality and therefore users.
So, to you and TKR, I ask to listen to the comments that told you that your answers do not really answer the question. They are not bad posts, actually they are very informative and I like them, but they need to answer the question first.
Ask yourself: does my answer addresses the points in the question as much as possible?

So Tim, your answer had some comments claiming it didn't really address the question, and you admitted so yourself in a comment. So I asked you to highlight the parts that did address the question in your answer, but I still see no edits.
If your answer doesn't answer the question, and you agree with this, don't you think that deleting it would be justified? We can't make exceptions for you or for anyone else, so please, edit it and answer the question or consider removing it. It's good information but it's not related to the question.
Comment: So I'm the original asker of the question in question, and I too am disturbed by the demotion. It

1. answered the question
2. had many upvotes
3. didn't break any of SE's rules.

So why downgrade it?
Comment: @player.mdl The moderator that converted the answer to a comment deemed it necessary. If he so desires, he can explain his reasons personally. However I would invite you all to discuss this politely.
Comment: @Alenanno sure thing. Excuse my ignorance (I'm a newcomer :), but who is the actual moderator?
Comment: If I flag an answer, any answer, does it get reduced to a comment? Can I do that, too?
Comment: It didn't answer the question, it talked about why people like minimalism for poor reasons, but it didn't talk about what is actually minimal in minimalism.
Comment: @TimOsborne No, flagging is something you must take seriously. We can take action if your behavior is disruptive. However, when something is flagged and we see merit we can decide to act. That is to say: there is no fixed response, it depends on the mod.
Comment: @player.mdl There are usually at least 3 or more per site. I'm one of them (the diamond next to my name). You can see who the mods are by going to Users -> Moderators. Or just [check this page](http://linguistics.stackexchange.com/users?tab=moderators).
Comment: @Alenanno, this post is a test to see you remove it, too.
Comment: @TimOsborne: Comments are disposable.  Their only sanctioned purpose is to clarify a post, or request clarification.  Any other use subjects them to removal.
Comment: @Alenanno, concerning my answer to the question. I conceded that it does not answer the question. I also stated that it was produced to respond to the general context that had developed. I would be very happy if my answer were removed entirely and TKR's original answer we're reinstated. That would end all this.
Comment: @TimOsborne See also this answer from  [How do comments work?](http://meta.stackexchange.com/a/19757/176533).
Comment: @TimOsborne No problem on my side, I'm inclined to undelete it. :) But I wanted to speak to the moderator that deleted it before doing anything. I'll post an answer with the update.
Comment: @Alenanno, you guys are obviously in a position to kill my voice, if you deem it to be counterproductive. Let this be my sincere request that you not act so quickly when it comes to answers that receive numerous upvotes. In my view, that move reduced a viewpoint that is legitimate and worthy of representation.
Comment: @TimOsborne Technically we can, but we don't. Don't assume that moderators act on evil intent. Usually we do what we think is right and appropriate for each case. If you disagree, then you're more than welcome to post here or reach out in Chat.
Answer: I think my answer does answer the question (and the OP obviously did too). Note that the body of the question asks for something more than its title implies: basically, I understand it to be asking not only why minimalism is called that, but what are the reasons for its popularity. "For the life of me I don't understand its appeal" and "Is there a sensible reason for the existence of these lumbering structures" seem to go beyond the question "What is minimalist about the minimalist program", and my answer was directed at those parts of the question: namely, that the main reason for these structures' existence and popularity is a historical and institutional one. Presumably, whoever flagged my answer did so because they correctly thought it doesn't answer the question as summarized in the title, but this is not the same as not answering the question as actually posed in the body of the post.
Comment: I see. I think it would have been helpful if you had stated which part of your answer referred to which part of the question. Probably that would have helped preventing a flag (or the action based on it).
Comment: @Alenanno: Maybe so. But in any case, since the OP (and judging from the comments, more than one professional linguist) clearly think my answer is relevant, can it now be reinstated? If not, I'd at least like the rest of the original answer to be posted as a comment along with the first part, since as it is, it's cut off in the middle.
Comment: See [this comment](http://meta.linguistics.stackexchange.com/questions/531/why-was-tkrs-answer-converted-to-a-comment#comment1065_532). I'll undelete your comment as soon as possible. I'll write an answer here when there is an update.
Answer: TKR's answer has been undeleted.
Comment: Can it be edited then? I genuinely can't see how it answers either what is minimal about minimalism or why there are so many structures. The question is **not** asking why it's popular!
Comment: @curiousdannii ["Not An Answer" is for posts that don't attempt to answer a question](http://meta.stackexchange.com/a/167632/215040), like when people post comments or new questions as answers.  In this case, it's clear that TKR *did* attempt to answer the question, so this doesn't apply.  If you think they haven't done so successfully, the right thing to do is to downvote, comment, or both.
Comment: @curiousdannii You can edit anything on this site, but without changing the core of its meaning. I mean, if the answer addresses some points of the question (which asks more than one question), then it's ok, incomplete but still ok. If you want you can discuss about this with TKR on chat, so you can properly talk about it (comments are not that comfortable for the task). You could also post an answer here saying how you think it should be edited! :) Let me know if you need more info.
Comment: I don't know how it should be edited because I don't know how TKR thought that it did answer it. I still think the answer should be deleted, but I won't bother flagging it.
Comment: If it's been undeleted, why is it still marked as deleted? Or has there been other tzurris?
Comment: @jlawler [TKR's answer](http://linguistics.stackexchange.com/a/6800/111) is undeleted. Do you see it differently? Sounds strange.
Comment: My mistake. It was Tim's that's been deleted, and that was the one that I thought was interesting. I don't understand why **that** was deleted. It certainly isn't possible to turn it into a comment, especially since the comments were interesting, too.
Comment: @jlawler The point is not whether it's interesting but if it answers the question addressing all (or at least most) points. Do you think it does?
Comment: @Alenanno: Answering questions, as they are posed, by people who are often innocent of linguistic knowledge, is not what we're here for. I couldn't care less whether a given answer "answers all points". The "points", as posed, are as often imaginary as real. What ***I'm*** here for is to provide answers, and like all teachers, I want to answer the questions the students should have asked, stripped of their false presuppositions, hasty assumptions, and unnecessary complexities. Whether the OQ gets answered or not is irrelevant; the purpose is educational, not personal.
Comment: If the answer does not answer the question, it shouldn't be an answer in the first place. We're here to answer questions, you're right, but if that post does not do it, then it's not an answer. It's not a matter of whether you care or not, but how the site works.
Comment: I'd just like you to understand that if it is not an answer to the question I must enforce the rules. However if someone posted a question that might have that as an answer, then that would be a valid way of keeping the answer around for others to read.


What do native speakers make of hearing the phrase "disputed land"

Question: Does the phrase "disputed land" emphasize being under control, or being a subject in an arguments between countries. Based on dictionaries, both might be correct. As a native what do you make of it?
Comment: Based on **which** dictionaries? See [Territorial disputes](https://en.wikipedia.org/wiki/Territorial_dispute).
Comment: At the national level, the first thing I think of is land that two countries both claim as their own. At a more local level, it can mean a number of things, depending on the property and the controversy.
Comment: What do you mean by "being under control"?
Answer: To me, as a native English speaker, the phrase 'disputed lands' means only lands whose ownership is a subject of dispute between two parties. I would use the phrase to describe the Falklands (with the UK and Argentina the disputants here), or the Crimean Peninsula (with the Ukraine and Russia as the disputants). To me, it doesn't matter for application of the term who actually holds the land; the important thing is that it's being fought over.
If one party has some kind of superior claim to the land, which is obvious to everyone (such as having lived there before the other party had ever heard of the place), but the other party has taken control of it, I would think of that as "occupied land" or "conquered land", not "disputed". This would describe land held under colonial occupations, for example. To me, "disputed" implies that no one's claim to the land is beyond doubt, so I wouldn't say that land held by a colonizing power is "disputed".
Answer: Unsettled States, Disputed Lands:
Britain and Ireland, France and Algeria, Israel and the West Bank-Gaza (The Wilder House Series in Politics, History and Culture) [Paperback]
The above book is illuminating on the this thorny issue.


SOA: Rails user authentication and api authorization with multiple clients

Question: How do we allow a second client to authenticate users and access our api authorized backend? Please correct any part of my understanding that is incorrect.
User authentication is register / login / logout portion of your app.
App authorization for an api is confirming your app has permission to access an api.
A user should be logged in to the app and the app should be authorized in order for the user to access the api.
It is important to keep user authentication separate from app authorization because different clients (apps) may access our services through our api. Accordingly different users may have different access rights.
Consider a simple web app. Rails with devise is used in the app (api client) for user authentication. The app then accesses the rails-api using doorkeeper for app authorization.
Consider then adding a simple mobile app. How would the mobile app access the same user authentication service? How would we allow mobile app access to our user authorization service?
Would we need to separate the user authentication service into its own api using a separate instance of doorkeeper to authorize the mobile app and web app before creating users and then after authenticating users again authorize the app plus logged in user to access the backend api?
I'm sure it should be easier than described. Any resources, books, videos also appreciated.
Comment: This question is waaay to broad.
Answer: If I understood your question correctly, what you are a looking for is a Service Oriented Authentication. Basically, the authentication provider could use Devise + Doorkeeper. Then the consumers could use omniauth-oauth2.
A good tutorial on oauth2: https://www.youtube.com/watch?v=zTsyeMV-N0c
Rails specific implementation: https://www.youtube.com/watch?v=L1B_HpCW8bs
Cheers!


Conventions in Old English for use of thorn and eth

Question: Somewhere I got the naive idea that, in Old English, thorn represented the unvoiced "th" sound and eth represented the voiced "th" sound. A little digging has suggested to me that each of the characters could be used for each of the sounds. I'm wondering what rules governed their use in writing, and how they changed over time.
Comment: For a start, the following answer says thorn was used for a longer time than eth: http://english.stackexchange.com/a/58489/77227
Answer: I agree @sumelic.   I do think there is a subtle difference between the 'thorn' and 'eth'.  Thorn is often used at the end of a word while eth is often in the middle of the word.  This leads to a subtle different phonemic pronunciation.
I found this brief explanation with Old English examples:  Also, ð and Ð (eth): Old English scribes could also represent the "th" sound with the letter ð (the capital letter version looks like a capital D with a short horizontal line: Ð). The letter is called "eth," pronounced so that it rhymes with the first syllable in the word "feather."
Comment: I think you're on to something. I just took a look at the beginning of Beowulf, and noticed that words ending with eth are followed either by words beginning with thorn or with a vowel. It's a nice puzzle.


Why does my nectarine tree have rotting fruit around seed?

Question: My nectarine tree has grown rapidly, it has been a great fruiter, however the fruit is always brown & rotten inside around the seed. Please help!
Answer: Brown Rot of stone fruits
Without seeing or knowing more, Brown Rot most certainly could be the culprit. The first and best remedy is cleaning up the ground every fall.  I would also try to remove any 'mummies' left hanging on your tree.
This article discusses spraying and timing of spraying with fungicide.  I have to disagree with this article about the use of a fungicide/pesticide.  Insects are not your problem yet and pesticide is never used as a preventative.  Fungicide is always used for a preventative.  It is like a little raincoat.  Spore + water drop = infection of the entire plant.
Never use 'Tangle Foot' or any sealant on pruning cuts.  Otherwise the information is basic.  Maybe I'll just go find a better article?  I also do not like, "...naturally rather than using toxic chemicals...".  Everything is chemistry. Chemicals can be considered toxic to some plants, yet safe for others.  Bad for humans, bad for insects, safe for plants. Chemistry is chemistry.
Another article on Brown Rot...
Brown Rot prevention
Comment: Thanks Stormy, I'm not a fan of pesticides so would prefer not to go there. I've no pics as yet as the fruit is still hard on the tree & I'm trying not to disturb them, bruise them or upset then in any way in hope that when they finally ripen they will be healthy though a few have already rotted on the bases
Comment: Cleaning up fruit leaves and debris regularly is the best preventative.  Dormant oils are very sane and very necessary.  You have a disease that is IN your tree and all fruit will be affected. Just takes ONE little spore that we can see only by microscopy. One spore, water hits your tree and your tree is infected.  Cleaning up, getting those mummies off your tree during the late summer, using dormant oils (use a professional spray company...dormant oils are a good thing as you are stopping the spread of spores to other trees)...I'd be pulling all the fruit off if I were you. Dispose carefully.


How do I deactivate a broken iphone 4s and switch to an old iphone 4s a friend gave me?

Question: I recently broke my iPhone 4s and am not due for an update for another year. My friend is going to let me use her old iPhone 4s. How do I deactivate my broken phone so that my friends phone will now be usable as mine? My carrier is Verizon
Comment: The so friendly ppl at Verizon can do that free of charge for you. Not sure about the free of charge so some negotiating skills might be needed.
Answer: You can call Verizon customer support @ 1 (800) 922-0204. They should be able to deactivate your phone and activate the replacement. Even in the case of newer phones that are unlocked like the iPhone 6 - you still need a Verizon rep to activate the device after placing the SIM in it due to how their network is configured.
Answer: I simply put the old sim card into the "new" phone to immediately have phone access. I plan to call ATT and have the new phone officially activated.
Answer: Try to put your device in DFU mode then do a full iTunes restore. If not fixed then vist the apple store or call Verizon Support.
Comment: Please include information as to how to do that.


My RPi 2 Model B will not detect the keyboard or my mouse?

Question: My RPi 2 Model B will not detect the keyboard or my mouse, the mouse I have is a logitech m185 with a iPazzport mini wireless keyboard. During a bootup of my RPi i noticed a red word that said FAILED on the boot-up screen and it won't detect the keyboard or mouse. What should I do to resolve this error and prevent it in the future?
Comment: Have you tried unplugging and plugging them back in while the system is running?  Can you access the system to do some diagnostics any other way (e.g., ssh)?
Answer: My guess is that you are not meeting the power requirements for the Raspberry Pi 2.
The Raspberry Pi Foundation recommends at least 1.8w of power for the Rpi2.
Not having enough power can cause seemingly random behavior like you are describing.
Please see here for details for more details.
https://www.raspberrypi.org/help/faqs/#powerReqs
Answer: If you have 2 separate USB devices that are failing it might be hardware.


Negating A Mathematical Statement

Question: Regard this statement $ x \ge 0$. According to my teacher, by negating this statement, it will become $ x < 0$. Why is this so; why does the $\ge$ morph into $<$, and not into $\le$?
Comment: ["Planning Algorithms" by LaValle](http://planning.cs.uiuc.edu/node161.html) sect. 4.3.2 defines a strangely different definition of interval negation where negating `[-1,2]` results in  `[-2,1]` (which also redefines Minkowski differences). There is very little information on this, all the book says on it is "In some contexts... the Minkowski difference ... is defined differently." without saying what context *the book* is using. It also introduces new properties where `A - B = A + (-B)`, which is [not normally true](https://math.stackexchange.com/q/1786871/344433).
Answer: There is no "morphing", and this is not just a game played arbitrarily with squiggles on the paper.  The symbols mean things, and you can reason out their behaviors if you understand the meanings.  $x\ge 0$ means that $x$ is equal to or greater than zero.  Negating the statement means constructing a statement whose meaning is "$x$ is not equal to or greater than zero".
Which of $x<0$ and $x\le 0$ means "$x$ is not equal to or greater than zero"?  It can't be $x\le 0$, because that means that $x$ is less than or equal to zero, and we are trying to say that it is not equal to zero.
$x<0$ is correct, because if $x$ is not greater than or equal to zero, then it must be less than zero, and that is exactly what $x<0$ means.
Answer: logically, there is no "morphing" going on here; your teacher is simply restating the same thing meant by $\,(x \ngeq 0)\,$, but just put differently $\,(x \lt 0)\,$:
NOT $\geq$ means:
"is NOT (greater than OR equal to)", $\iff$ ("is NOT greater than" AND "is NOT equal to")*...
...which leaves us with ("is less than")
that is "NOT $\geq$" must mean "is less than"
Formally, this is an application of (*) DeMorgan's Law (recall: $\lnot(p \lor q) \equiv \lnot p \land \lnot q$), and of the Trichotomy Law: between any two real numbers $a, b$, one and only one of the following relations holds:

$a \lt b $
$a = b$
$a \gt b$

The negation of $\,x\geq0\,$ ($x\ngeq0$) rules out $x = 0$ and rules out $x \gt o$ leaving us with just $x < 0$
Answer: Saying that $x \geq 0$ is the same as saying that $x$ is a number that is

greater than $0$ or
equal to zero.

If you wanted to negate that, you get that $x$ is not be a number greater than or equal to zero. And what are the numbers that are

not greater than $0$ and
not equal to $0$?

Those are exactly the negative numbers, so $x< 0$.
Answer: Try with sets if you don't see it with inequalities directly.
The statement $x\geq 0$ is equivalent, by definition of intervals, to saying that $x$ belongs to $[0,+\infty)$ where $0$ is included.
Therefore the negation is: $x$ belongs to the complement of $[0,+\infty)$, namely $(-\infty,0)$, where $0$ is now excluded.
The last condition is by definition equivalent to $x<0$.
Answer: the negation of $x \ge 0$ is $\neg x \ge 0$.
$\neg x \ge 0$ is equivalent to $x < 0$.
It's easy to see this if you consider the set of values of $x$ that make the formula hold true:

$x \ge 0$ holds for x in {0,1,2,3,4,5,...}
$\neg x \ge 0$ holds for x in {...,-4,-3,-2,-1} (that's everything not in the previous set)
$x < 0$ holds for x in {...,-4,-3,-2,-1}

Negating A Mathematical Statement


2015 MacBook Air display awake while lid closed

Question: I want my late 2015 MacBook Air to remain awake when the lid is closed. I have tried Caffeine, Stay Awake, and Theine, as well as changing my power saving settings to 'never' but nothing seems to work. The display still turns off when the lid is closed. Does anyone have a fix?
Answer: A friend of mine did it when we saw a movie this weekend.
He used my TV as monitor and of course I asked him for a tutorial.
He sent me this video https://www.youtube.com/watch?v=zbWQuswykec
I will try it tomorrow. I hope it be helpful for you too.
Answer: I also tried Caffeine, but it did not work. What seems to work for me is to have the laptop plugged in. It should not go to sleep.


What is this rubber seal under the grout in my shower?

Question: I have a shower which has a join between glass and marble which has recently started leaking. As a first step, I've removed the grout for replacement, but it looks like there's some sort of rubber seal underneath, which I believe I need to replace as well as it's located where the leak is coming from. What is this part called, and is it part of the waterproofing mechanism? Is this the only thing I'm likely to need to replace in addition to putting new grout and sealer on?
Comment: Please annotate your photo to point to where the "grout" you removed came from and what the "rubber seal" is. It's hard to tell for sure, but grout is usually installed between tiles to fill the gap, and the join between the glass and marble would likely be silicone caulk, though there could have been a rubber seal in the factory glass shower kit.
Comment: A second, wider angle picture would help us better understand the situation which is, currently, only obvious to you.
Answer: It appears to be a silicone/butyl rubber seal, that will prevent moisture intrusion and also allow for the expansion and contraction of the two different materials at that joint.  Each material has different expansion and contraction qualities and that silicone/butyl rubber seal is providing the space needed to allow those materials to do what is necessary.  So it is in place for more than one purpose.


Problem with UV mesh

Question: I seem to be having trouble with one of my UV meshes. For some reason, a number of vertices/faces have decided to detach themselves and, not only are there too many, but I can't re-attach them. The simplest thing to do is to unwrap the mesh again, but now I can't get it to align properly. The save I've attached is with the broken vertices... Any ideas what I could do? Thanks.
Comment: If you have multiple vertices sharing the same location, you can select all and press W -> Remove Doubles
Answer: I don't think you can avoid re unwrapping.
The reason why you have the separate UV island in the head unwrap is because that is the way the UV seams are marked   at the top of the head.

To make the head a single UV island clear the unwanted seams and mark a new one along the top of the head as in the screenshot below. Then UV unwrap again.
You will have to experiment a little to have the exact seams to get the correct unwrap island shape and then scale to match (align to) what you had before.

Just a note : usually the ears of a head will need UV seams so that they will be separate islands when unwrapped.
Comment: No, that's not the issue I'm having; that's intentional. When you load the save up, you'll see some of the faces/vertices of the UV map in the centre of the map. They've somehow become detached. However, if I unwrap again, I can't get the UV of the head/face to match up. No matter how much I resize it.
Answer: You're going to have to weld the vertices back in to place. There aren't that many, but if you're trying preserve your existing UVs, I don't think there's another way. I would turn on the Sync UV and Mesh Selection button and select a vertex. The vertex that it should be welded to will also highlight. Turn off the Sync button, move the vertex that is out of place over to the one that is in place and weld them together. That will work for the verts on the edges of the rips, and then it looks like you will have one or two loops in between the ripped edges that you will have to use your best guess at placing.
Edit: It looks like several vertices are mapped to a single point. You'll need to spread those out so you can see each vertex individually. You could possibly create new UVs for those to make your job a little easier.
Turn on slection Sync, select the bad faces in the UV editor and unwrap in the 3d View. This will give you something cleaner to start with.
Answer: What you are talking about is that you selected a face or mesh part and it came of with extra vertices, so accordingly when you select one of them the others get selected too, right?
This can happen when you are in face select mode and UV sync selection is on. To fix this you have to unwrap again with seams marked but this time turn on Live Unwrap, unselect the UV sync selection, select the ones you don't want rearranged in the editor and press P for pinning. This way it will keep those pinned vertices the way they are when unwrapping.

Problem with UV mesh


How does equilibrium change when pressure is increased?

Question: What happens to the equilibrium when an increase in pressure is applied to a system with the same number of moles of gas on both sides of the reaction, according to Le Chatelier's Principle?
For example:
$$
\ce{2 HBr (g) <--> H2 (g) + Br2 (g)}
$$
Answer: According to Le Chatelier's Principle, when there is an increase in pressure then the equilibrium will shift towards the side of the reaction which contains fewer moles of gas and when there is decrease in pressure, the reaction favors the side with more number of moles.
In your question, as both the side of the reaction contains there same number of moles of gas i.e. 2 moles of gas on the left and 2 moles of gas on the right side of the reaction, hence any change in pressure will have no effect on the system.
Therefore, there is no effect of any change in pressure.
Answer: There will be no change even if the pressure is increased. Because in both sides, the number of molecules are same.And by Le Chateliers principle, the equilibrium should move in the direction of lower pressure, but here, there is no such possibility as the number of molecules on either side is the same ie $\Delta$n = $0$