What is a good item build for support with Blitzcrank?

Question: I want to play Blitzcrank in a support role. Should I start out with a Philosopher's Stone like other supports, or should I get a Tear of the Goddess for the mana to start off? What are other core items that would make Blitzcrank a viable support, and why?
Comment: This type of question is not the best fit for this site. It has no definite answer and responses are likely to be based largely on opinion rather than fact.
Answer: As Drmixable mentioned, it is very situational. If you're intending to solely be a kill lane, it might make sense to go Sapphire Crystal, ward, health pot, then tears.If you do this, you are gambling completely on your lane getting first blood and then compounding that advantage into laning dominance for the rest of the laning phase.
If you are wanting to be a more traditional support early game, then definitely do the standard Faerie Charm, wards, health pots mix.
Even if you do start with the mana crystal and go straight into tears, I think it still makes sense to move towards the more traditional support build after you pick up the tears. Philo stone, Heart of Gold, lots and lots of wards, oracles, etc. Build your gp10 items into their upgrades, prioritizing Shurelya's if your team is winning team fights and Locket if they are not.
And - as always - buy boots on your second trip back to base. For Blitzcrank, Boots of Mobility upgrade later makes a lot of sense for getting into position to yoink someone or knock them up to protect your carry. However, if the team is full of hard CC you will of course want the tenacity from merc treads instead.
Other good items include getting an early catalyst(which will build into Banshee's later), to sustain your lane harass and increase your passive shield proc if necessary. An aegis, of course, is always welcome from a support. Frozen Heart could be viable if the enemy team has more than two sources of straight auto attack damage, but generally won't be worth it.
Hopefully this wall of text gets you started on the path to thinking about how to apply your items to each situation. There is no single item guide that any hero should follow. Anything from who you are facing, how much gold you have, and how late it is in the game can vary your items and the order you build them in.
GL HF!
Answer: It as all situational and a build you find online is never fool proof. I don't play blitz much but here are a couple guides I found
http://www.mobafire.com/league-of-legends/build/all-about-blitzcrank-support-ad-ap-jungle-162242
http://www.solomid.net/guides.php?g=12419
Comment: Welcome to Gaming! Whilst this may answer the question, [it would be preferable](http://meta.stackexchange.com/q/8259) to quote the essential parts of the answer here, and provide the link for reference.
Comment: ah okay. I apologize. I should have listed the item builds I guess seeing is that is what he asked for mainly.


FAFSA implications of filing jointly?

Question: Recently our accountant filed a tax return as married for my partner and me (we live together). She is applying for FAFSA and is not sure whether she should be reflecting her marital status from our tax return. Our accountant explained that since we share an asset (home), our state basically considers us in a civil union. However, if she files FAFSA single, she's being asked for the adjusted gross income of our combined fax return. Would it be beneficial to amend our tax return so that she would be more eligible for FAFSA aid?
Comment: According to this link, there's no "common law" marriage in Illinois... http://www.illinoislegalaid.org/index.cfm?fuseaction=home.dsp_content&contentID=2447
Comment: owning a house = married? What state is it?
Comment: @littleadv Illinois. House is under both our names.
Answer: It sounds like it would be worth it for you to get a second opinion from a different accountant.  Hopefully that second opinion will correctly determine whether or not filing as married was the correct thing.  If Illinois doesn't have common law marriage or civil unions, your first accountant may have erred in having you file as married.
I don't know if you can (or should) submit multiple federal forms with different marital statuses.

FAFSA implications of filing jointly?


Why is there a dispute as to which tefillin are the correct ones?

Question: Since the mitzvah of tefillin is observed every day except for Shabbos and festivals, there should have been continuous knowledge as to the correct order of the parshas. So how did it come about that we now have two opinions on this matter, known as Rashi and Rabbeinu Tam?
Comment: There are lots and lots of Machlokot about regular things. Just read the Mishna. Look at lots of Machlokot about Tzitzit, Brachot, Tefillin, lots of rules of Kashrut, etc.
Comment: @msh210: you're probably thinking of this one: http://judaism.stackexchange.com/questions/18735/why-dont-we-just-follow-the-shittah-of-moshe-rabeinu
Comment: How about Davening where we have even more than 2 Nuschaos?
Comment: The Shevatim had their own nusach
Comment: http://olamot.net/shiur/%D7%AA%D7%A4%D7%99%D7%9C%D7%99%D7%9F-%D7%A9%D7%9C-%D7%A8%D7%91%D7%A0%D7%95-%D7%AA%D7%9D
Comment: I thought we have this question already, but cannot find it. +1, anyway: good question.
Comment: There's actually four types of tefillin: there's also the Shimusha Rabba and Raavad. The Kabbalistic discussion surrounding tefillin answers this question quite well.
Answer: The Ben Ish Chai (Shana alef parshas vayeira 21) brings the Levush who writes that by the kever of Yicheskal HaNavi something fell and revealed a very old pair of teffilin and it was keseder Rashi .At first we thought that it is like every machlokes that one shittah iis batel to the other one.That was until the Arizal came and said bkabbalah from the mouth of  Eliyahu HaNavi zachar Latov   that both shittahs are true and one should do both and from the time of Moshe Rabbeinu until the Geonim they wore both pairs.This is what the gemara in eirvuin 95b is to have two pairs ,is the place of teffilin.
Comment: The [Semag and Mordechai](http://beta.hebrewbooks.org/tursa.aspx?a=oc_x98) said it earlier
Comment: I wonder why the Ben Ish Chai chose the levush
Answer: The sefer Tal Oros gives a wonderful answer to this question. The complete piece, which I recommend reading to fully understand his answer, can be found here, but I will quote the most essential paragraphs:

The mitzvah of tefillin requires them to be worn the whole day. However, probably at a time later than that of the Amoraim, that is, during the period of the Rabban Savorai and the Gaonim, due to the difficult yoke of their exile, their increased dispersion and increased suffering, they became physically very weak, and so the concern of having an unclean body with regard to the wearing of tefillin became a regular concern, and from then on they were not able to wear tefillin all day.
However, in order not to abandon the tradition of wearing tefillin all day they made for themselves two pairs of tefillin. One pair was made according to the laws and holiness of tefillin which they wore once per day, during the morning prayers, and another they made as an amulet which were made and ordered not in accordance with halachah, and thus were not sanctified with the holiness of tefillin. These tefillin they wore all day as an amulet like the custom of the time of the gemara to make an amulet in the form of tefillin. The main difference between these two pairs of tefillin was that those which they wore for the mitzvah of tefillin they ordered the four parshas in accordance with the laws of tefillin, whereas those which they wore as an amulet they ordered the parshas not in accordance with these laws, and thus they did not have the holiness of tefillin and were merely an amulet.
Therefore, when subsequently there came along a period of one or two generations during which, due to the decrees of apostasy, they were not able to wear tefillin at all, after the decrees were abolished they found that the tefillin of their forefathers consisted of two types: one type had their parshas ordered like the opinion of Rashi, and another had their parshas ordered like the opinion of Rabbeinu Tam. And they forgot which were the real tefillin and which were amulets.
From this came about the dispute of the early authorities, with Rashi holding that those that were ordered according to his opinion were the genuine tefillin and the others were amulets, and Rabbeinu Tam holding the opposite. And each one supported his opinion with logical proofs, proving that only those which were ordered according to their opinion had been worn for the mitzvah of tefillin. This was the basis upon which the early authorites founded their differing opinions, and each one thought that the truth was on his side.
Comment: Does he have any evidence for this elaborate historical story? When was _Tal Oros_ first published that he had this tradition?
Comment: @DoubleAA For what it's worth, I heard this entire idea quoted from the Chida by my Rebbe.
Answer: Rabbi Menachem Mendel Kasher suggests that at the biblical level, any order is kosher; at some later point there was a formal enactment of a "right" order, which led to this dispute.
Comment: How does this answer the question? If people wear tefillin every day, then how did uncertainty arise a millennium or more, after this suggested enactment?
Comment: @mevaqesh Rav Kasher suggests the uncertainty arose almost immediately after it was enacted. He brings sources that indicate the machlokes could be even as early as late amora'im, and brings other examples to  justify this idea (such as what constitutes Teruah for Rosh HaShanah). Everyone wore whatever tefillin they wanted, and it later became disputed which became the authoritative pair. I'd edit this in the answer, but I don't want to overpower Shalom's answer. He can add this in himself if he wants.
Comment: Based on your description, ikkar hasser min hasefer. I don't he'd mind if you edit the essential answer into the post. @robev
Answer: Another answer is that in those days they didn't all wear Tefillin. This can be seen from a few places. Tosafos explains that קרקפתא דלא מנח תפילין means either someone who never put it on or someone who purposely has something against it.
From שאלת ותשובות מן השמים as well, in more than one place, it looks like people didn't put on Tefillin.
Another fact to keep in mind is that Rabbeinu Tam didn't claim to invent this Shita. It is actually first brought in the name of Rav Hai Gaon.
We find by Shofar that there was more than one way how to blow before it was consolidated into one coherent, uniform practice. There is every reason to think that many types of Tefillin were floating around until Rashi decided between them, followed by his grandson.
Interestingly, the
שאלת ותשובות מן השמים
says that Eilu Va'Eilu Divrei Elokim Chayim, and just as there is a Mochlokes down here there is a Machlokes up there.
Comment: http://judaism.stackexchange.com/questions/41099/at-what-point-do-we-reject-a-minhag/45564#comment120867_45564


What are the sources of signal loss in cables and their connections?

Question: What are the major sources of loss when sending a signal over cables?  What is the impact of digital vs analog, cable material/length and the number and quality of cable connectors?  Are there any other major factors that could result in signal loss that impacts audio quality?
Answer: There are several major ways a signal can become distorted, these impact both digital and analog signals, but in different ways.
One of the largest sources (on long runs and at connectors) is attenuation, which is the loss of signal strength due to resistance on the line resulting in electricity converting to heat.  It generally impacts the signal in a fairly uniform fashion, but reduced signal level doesn't change the noise floor of the equipment reading the signal and thus the SNR (signal to noise ratio, ie the amount of signal that is present on the live vs the amount of noise on the line) is reduced, making the signal either noisier (for analog) or with sufficient noise, more error prone for digital. (Ones may be mistakenly read as 0s.)
Another major source of trouble is induction.  A wire of any length passing through a magnetic field is going to act as an antenna (including from the magnetic field produced by the signal itself to the neutral wire).  The longer the wire, the more signal can be induced over the length of the wire.  Shielding helps reduce electricity being induced in the cable, but doesn't prevent it entirely.  Since induced voltages put power on the line in a noisy and random way, they increase the noise level of the line, which also decreases the signal to noise ratio.  For an analog signal, this presents as increased hiss on the line, for digital, it can present, if sufficiently bad, as the inability to recognize 0s correctly as the induced voltage may make some 0s look like 1s.
Cables which are made of materials that have lower resistivity will help prevent attenuation.  Cables with shielding will help prevent induction.
Connectors can be another source of loss for cable systems.  There will always be a certain amount of attenuation caused by jumping from one pin of the connector to the other.  They may be in direct contact, but it still is limited surface area and not actually the same material, so there will be resistive loss.  This has a much larger impact on analog signals than digital though since that loss won't result in any impact on the 0s and 1s that the digital signal is interpreted as unless there are either a large number of connectors, poor quality connectors, or other problems in the system that push it to the limit of reliably recognizing 0s and 1s.
For digital signals, it is also possible to include checksums in the data stream that will verify it made it from one end to the other without error, but if such systems actually try to correct this error by resending, it will induce variable latency in getting the signal across the line, which could itself potentially be considered a form of quality loss.
One final point of note about analog vs digital systems is that in general, small amounts of signal loss are far more noticeable for analog systems.  A digital signal with checksum either makes it or doesn't.  Even without the checksum, it will either be mostly intact or almost not intact at all, as the gap between being readable and error prone is generally pretty small.
Analog on the other hand will suffer a quality loss from any change in the SNR, but it will also still have a signal present no matter how much noise you get, it will just become increasingly hard to pick out from the noise.
Comment: A few remarks: **1.** wire resistance becomes only significant for _very_ long lines, it's usually not an issue at all for audio connections. A far more important property of cables is their _capacitance_; together with an ohmic or inductive output impedance it forms a low-pass filter. **2.** the most effective weapon against inductive interference is to use [balanced connections](https://en.wikipedia.org/wiki/Balanced_line).
Comment: **3.** in digital signals, misinterpreting 1s for 0s is actually not the only problem. Long before that starts to happen, [jitter](https://en.wikipedia.org/wiki/Jitter) can degrade quality; a separate and well-shielded wordclock connection prevents this. ("Variable latency due to resending" is basically an extreme kind of jitter, and, yes, it should be considered a _huge_ quality loss. However with a large fixed latency, if you can afford it, error correction is also possible.) — Anyway, of course you're right that digital connections are far more "all or nothing" than analogue ones.
Comment: In regards to cable length, I have added clarification that this is mostly an issue for long runs for live venues or for lots of connections, which have much higher resistivity.  I have also added a note that the signal itself will induce to the neutral (via the capacitive action you describe.)  Jitter I'm less clear on, but I'm pretty sure that is caused by loss of signal timing from the noise causing misreads of ones and zeroes in the manner described.  If you have a good resource that describes it more clearly I'd be quite happy though as most resources don't describe it well.
Answer: Every single physical connection will in fact degrade the signal and you will experience at least some amount of signal loss whether its audible or not.  By quality I'm assuming you mean integrity of audio from source to medium. In that case the answer is yes.
Comment: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/19405/discussion-between-aj-henderson-and-miiinimallogic).


How to change monitor refresh rate (ATI Radeon HD 6450) on Ubuntu 12.04?

Question: I want to change refresh rate from 60Hz to 75Hz, but xrandr shows that this card
does not support 75Hz refresh rate. On Windows this not work too. Can somebody help me?
Answer: Your video card does not support 75Hz refresh rate for current resolution. You may decrease resolution to see if 75Hz become available. If satisfied, keep it, if not, you have to change the video card for a better one.
Answer: Did you installed the driver. After installing driver in both if you can't change the refresh rate. That means the device doesn't support it. It is a hardware limitation. Noone can do anything.


Violation of Usage of Android Advertising ID policy

Question: I made a game in Unity with admob  integration, and I published it on the Google Play store.
After 2 days I got a mail from the Play store mentioning a policy violation (reproduced below). I l researched the issue and updated a privacy policy document on my app, then resubmitted the game.
It came went live, but then I got the same mail from the Play store again and they removed it.
From the beginning onwards my ads are also not showing in game, but the test ad is working fine.
Can you tell me what mistake I made and how I can fix it?
Message from Google:

Notification from Google Play about Green Puzzle Truck
Google Play Support
Hi developers at **** **** Studio,
After review, "my game name" , package name, has been removed from
Google Play due to a policy violation. This app won't be available to
users until you submit a compliant update.
Issue: Violation of Usage of Android Advertising ID policy and section
4.8 of the Developer Distribution Agreement
Google Play requires developers to provide a valid privacy policy when
the app requests or handles sensitive user or device information.
We've identified that your app collects and transmits the Android
advertising identifier, which is subject to a privacy policy
requirement. If your app collects the Android advertising ID, you must
provide a valid privacy policy in both the designated field in the
Play Console, and from within the app.
Next steps: Submit your app for another review
Read through the Usage of Android Advertising ID and User
Data policies, as well as the Developer Distribution Agreement, and
make appropriate changes to your app. If you decide to collect
sensitive user information, be sure to abide by the above policies,
and include a link to a valid privacy policy on your app's store
listing page and within your app.
Make sure that your app is compliant with all other Developer Program
Policies. Additional enforcement could occur if there are further
policy violations.
Sign in to your Play Console and submit the update to your app.
Alternatively, you may opt-out of this requirement by removing any
requests for sensitive permissions or user data.
If approved, your app will again be available with all installs,
ratings, and reviews intact.
If you've reviewed the policy and feel this removal may have been in
error, please reach out to our policy support team. One of my
colleagues will get back to you within 2 business days.
Thanks for helping us provide a clear and transparent experience for
Google Play users.
Regards,
The Google Play Team
Answer: You must implement something for GDPR if you're shipping in the EU. Your customers need to be able to opt out of the use of tracking IDs and have an option to delete any existing tracking info you have.
I had to do this for Cognizer, for both iOS and Android. I was using Unity, so they made it easy with a plugin.
Cognizer is free (no ads either), so you can download it and take a look at how that is interfaced as an example of what is acceptable. Go to the Credits screen, and click the Privacy icon in the lower left.
Comment: Out of curiosity, isn't GDPR meant to be "opt-in" ? As in, if you plan to track users, they should get a notification of what information is being sent online and why?
Comment: Can you please tell me what policy voilation i made? And what is this "Issue: Violation of Usage of Android Advertising ID policy and section 4.8 of the Developer Distribution Agreement"?
Comment: Good question, but I think games are covered under the cases where there's implicit consent.

https://www.itgovernance.eu/blog/en/gdpr-when-do-you-need-to-seek-consent
Comment: @ManojBalajiM You are probably not giving an option to opt out of tracking via the ID. The Unity plugin for this takes care of it.


Word "panhandle" translation to Russian

Question: Panhandle is a narrow strip of territory projecting from the main territory of one state into another state.
Google translates panhandle as попрошайка, попрошайничать (beggar, beg). Is there a one Russian word for panhandle in a geographical context, as in "Florida panhandle" for example.
Comment: Panhandle may be called "полуостров" (peninsula) - but this not a common term for the land borders and it is used somewhat metaphorically.
Comment: "Panhandle is a narrow strip of territory projecting from the main territory of one state into another state." - if it's about smth political and adminstrative, it could be translated as анклав... But анклав usually mean an political "island", not a "peninsula"
Answer: Actually, the direct translation for "panhandle" would be "ручка скоровородки" - this is the reason why it is called that way in English in first place. However we don't have a 100% matching term in Russian.
If one want to talk of specifically of Florida panhandle, one would just say something like "неполуостровная часть Флориды", or "материковая часть Флориды". Technically, panhandles are salients, that is "elongated protrusions of a geopolitical entities, such as a subnational entity or a sovereign state". This term is translated to Russian as "выступ" but de-facto it's usage (in this context) is not that wide-spread as usage of panhandle in English.
For instance, "Aляскинский выступ" is nowhere close in usage to Alaska panhandle, "Юго-Восточная Аляска" is way more popular. "Северный выступ Западной Виргинии" (another example mentioned in Wikipedia) sounds very artificial - actually in each individual case the actual Russian term varies. Though I have to admit that I miss a Russian counterpart.
Comment: @OohLaLa it's definitely no accurate and this is exactly what I claim in my answer ) unfortunately it's the closest we have. And actually we have panhandle-like territories in Russia as well -  for instance, northernmost part of North Ossetia. We do have such territories, we don't have a term.
Comment: May be the word "вдающийся» is more accurate. A Stretch of land вдающаяся в другую administrative territory.
Comment: вдающийся  is a participle, not a noun, and it's just not used as a synonym to panhandle.
Comment: Ручка сковородки, makes sense for it visually resembles panhandle in a geographical context . "Выступ" is probably the closest Russian word for panhandle, however it is very inaccurate since Russia doesn't have panhandles, and there are no actual выступов neither in Russia, nor in the USA.
Comment: thank you. Quite interesting, at least for me.
Answer: I think it should be "перешеек" (isthmus).

Word “panhandle” translation to Russian


Damage to Audi differential with new front tires and old rear tires

Question: I just bought two new front tires for my Audi A8 with Quattro all-wheel drive and was told I should replace the back tires as well. I can't afford those tires for a week or so. How long can I drive the car with old tires on the rear before it starts to ruin my differential?
Answer: See Is it OK to replace only 2 tires on an AWD car?.
If you call different Audi dealers you're likely to get differing answers regarding how much tread depth difference is OK for the all-wheel-drive system. Nonetheless, I would advocate calling to get specific recommendations for your vehicle, as some all-wheel drive systems are more sensitive to differences in tire size than others.
I would add, however that if you choose to stick with only two new tires, and if the tires you're not replacing have significantly less tread, the current "safety-minded" recommendation is often to put the new tires on the rear (not the front, as you have indicated). The thinking is that if you have new tires on the front and old tires at the rear that the car may be inclined to oversteer (i.e. go into a spin, "hang the tail out"), which is potentially more dangerous than if you had less grip at the front.
Comment: You could probably get your hands on the actual service recommendations for your vehicle.  Shop manuals aren't necessarily cheap but they can be had.  Another point to consider is that, while traction might continue to be fine, mismatched sets of tires are putting more load on the center diff.  Maybe not enough to fail but definitely enough to increase wear and shorten its life.
Answer: You won't ruin your differential by not replacing a worn tire.
As long as all the tires are the same size specified in your user's manual and not completely bare, you shouldn't damage any critical mechanical parts.
However, you should replace worn tires, as soon as possible.
Answer: I agree with Daniel, and also comfirmed this with Audi. As long as they are the same size and there isnt a major difference in thread wear you should be fine.
Answer: Your drivers handbook will carry Audi recommendations for your tyre fitment. With an A8 it is to have matching tyres on an axle. Tyre shops will suggest it is a good idea to have a complete set in any event. (All the major chains in the UK pay their staff where the more sales they make, the more money they are paid. One of the reasons why they are held in such disregard.) The adoption of fitting new tyres to the rear came about from the fact that the new tyre has a coating on it to release the tyre from its mould during manufacture. The reasoning was that if you drove 200 miles with new tyres on the rear, not only is the coating removed but the tyre is 'proven to be good'. The front tyres do the real work when it comes to steering, braking and load carrying and should be the best. The big thing about tread depths, when compared front to rear, came about when the Vauxhall Frontera from some years ago was destroying transmissions because of trans windup with tyres differing by about 3mm. It does not happen today. Especially with a VAG vehicle.
Comment: See [Should one fit the least-worn tires to the rear wheels?](http://mechanics.stackexchange.com/questions/6916/should-one-fit-the-least-worn-tires-to-the-rear-wheels?rq=1)
Comment: With quality tyres in good condition and with an excess of 2mm of tread, on a road going vehicle, in good state of repair, loss of directional stability is not of real concern. Modern tyres, improvements in suspension design and technology, and ABS braking systems more then negate it.
Comment: I can't work out the answer to the question from this; it's a bit rambling. The historical bits and information about tire coatings are interesting, but don't point to a conclusion. Can you clarify?
Answer: The damage comes from your differential heating up excessively due to increased load. If you drive slow and keep it short, you can go on for months or even years without a problem. You'll only have a problem if you go on a roadtrip.
Answer: I drive Landrover. Had my front tyres changed today and driven approx 6 miles and differential had enough and playing up. Disappointed that garage didn't even mention that it's beter to have rear tyres changed for 4wd first. Now it's going to cost me atleast £1k to have it fixed. Follow the advice, rear tyres should always be better than front tyres.
Comment: You are welcome to the site. It seems to me that it is best practice to change all four tires of a 4 wheel drive at the same time, and not either front or rear. The last sentence certainly does not apply to a four wheel drive vehicle to the best of my knowledge and belief.


How do I reset iCloud podcasts syncing?

Question: So, since I updated iTunes to version 11.1, my podcasts library went a little crazy. Some episodes were deleted from my Mac and all episodes are now marked with the little blue pin  (saying they're unwatched/unplayed). I'm not sure this is the default behaviour now in this iTunes version, I hope it's just a bug.
So I decided I want to get rid of everything and just start over. I unsubscribe from all podcasts and delete all the episodes from my MacBook and iPad. The problem is that it seems iCloud is still holding info about my podcasts and brings back the weird situation mentioned above. How do I wipe out everything iCloud knows about my podcasts and start again freshly?
Answer: Unsubscribe from your podcasts and resubscribe.  It really sucks but it is the only option.

How do I reset iCloud podcasts syncing?


Convert files to PDF when uploading to media library

Question: Is there any built-in mechanism to convert files to PDFs when uploading them to the media library, or does someone know of functionality that can accomplish same?
Comment: Could you please specify further what type of "files" you would like to convert to PDF? Also for which version of Sitecore?
Comment: This question lacks sufficient detail to be able to answer in a meaningful way apart from "No, there is nothing OOTB, yes you can do anything you want in Sitecore". More detail and what you have tried so far would be a good start.
Answer: No, there is no built-in way to do this.
You can build a module that converts the files to PDF using iTextSharp, PhantomJS or Puppeteer.
Once upon a time @adamnaj wrote a script to export media items to PDF using Sitecore PowerShell Extensions. Maybe you can use that idea to import them back into the media library after PDF generation.


Does changing web hosting affect search engine rankings?

Question: I have been hosting in a server from last 2 years. I am planning to change the hosting server. Before I change the hosting server I would like to know whether it affects my site's rankings or not?
Answer: As long as your domain name and hosting country stay the same, switching from one reliable host to another should have no SEO impact. See question 4 in this Seomoz article link
Comment: The point about hosting country should be noted. It may have impact in some cases because a website hosted in a country usually gets more SEO points for search results in that country.
Answer: No. And why should it? Your hosting has nothing to do with the quality or relevancy of your content. (1)
Just try to minimize downtime and avoid if possible. A seamless transition is ideal.
(1) Really slow loading webpages may cause google to lower your page rankings but you have to be in the bottom 1% or so for this to happen. So as long as your host isn't poor you will be fine.
Comment: Those SEO companies are perfect examples of why it's so hard to get good SEO information. They're flat out wrong.
Comment: Some of the SEO companies say that the webhosting matters as about 25% in the ranking. So there is no truth in that?
Comment: I am really a fan of your experience in SEO. I have posted another separate question for it and linked [it](http://webmasters.stackexchange.com/questions/31238/web-hosting-does-not-matter).
Comment: I think it's actually too broad a question to give a firm answer to. Assuming all else is equal, simply being on a different server shouldn't matter. But impact on load speed could affect ranking, CTR, PPC, etc; server IP address can, in certain circumstances, be an issue for geotargeting. So not a flat out "no", but "probably not".
Answer: In a similar vein as John Conde's suggestion (though picking up on a few things I've noticed) you can also expect problems when switching hosts if your new host has security issues.
If you share an Apache server with malicious users, you may find some problems including malicious content apparently hosted under your domain if your host has not disabled features like Apache's mod_userdir (it doesn't help to be recognized as a phishing or malware site)
Answer: Yes. Actually, it can!
If the new host is permissive and has issues with quality sites, hacker activity, spamming (all types), and past issues with search engines, your site could be given an IP address that is either specifically known or within a block that is known as a bad neighborhood. As well, the host itself can be considered as a bad neighborhood. Google tracks not only IP addresses and IP address blocks, but hosts that are known for these issues. Not choosing a high quality host can literally drop you from search existence almost over night (actually over a period of just a few days). This is also true for using a CDN and is quite common.
Answer: No it will not effect your links on the internet since your just changing ip's the url of your content should stay the same ultimately


Can Perforce backup files?

Question: From reading the Perforce docs it sounds like only changelists and version history can be backed up. Is it possible to get Perforce to create a backup of files too, so that in the event of loss, through hardware failure for example, a complete set of files could be recovered?
Answer: As far as I understand, no, perforce is not doing that.
The perforce back-up process is two-fold:
1 - You need to back-up the files in the depot, using standard files back-up procedures. The files in the depot are in RCS format, and are called yourfiles.ext,v
Those are the "sources" data. AFAIK, something as simple as getting a tar/zip copy of the depot in a safe place regularly is enough (USB key, etc... if you are worry of a server hardware failure).
2 - You need to use the perforce admin checkpoint command to back-up the content of the db files in the perforce depot. This is for all the perforce metadata.
One without the other is useless. So both should be synchronised.
Two things I have learned is that:
A - You cannot open the archive files easily without restoring the metadata. I.e. I have not found a "RCS archives reader" tool that can open the perforce files from the backup without perforce itself. I.e. to get the content of one single files of the archive you need to restore the depot, including the metadata.
B - the db.* metadata perforce files are using a proprietary DB system and cannot be open with standard db tools (like a SQL client or something)
Best regards,
Thomas
Comment: Thank you for that info, I'll give it a go later on and see if I can restore a backup onto another computer using this method.
Answer: I'm not sure which docs you've been reading, but there's a fairly comprehensive guide in the Admin manual here.
If you are after something fairly simply - i.e. yours is not an industrial strength installation, then there's a few notes here that describes a way to get you backups going quickly and easily in just a few minutes.
Answer: The Perforce checkpoint is only a backup in so far as you can restore from it.  You still need to backup the checkpoint file, and all subfolders of you perforce directory (by default where all depots are stored) where the files actually are to tape, remote storage etc as you would normally do with any backup.
What we have done elsewhere is run the checkpoint script and then add that file and the subfolder to our standard backup script.
Answer: The manual for the 2009.2 version of perforce server p4d has pretty clear documentation on this topic, see Greg Whitfield's answer above. I'd hyperlink to the last manual, but I don't have enough reputation.
The system administrator's guide pages on replication have more industrial solutions; making hot spares of metadata for no-downtime metadata backups, for example. The replicate command reference clearly explains you want to use 3rd party tools to backup the file data.
Answer: In 2015 you can use the DVCS feature to clone part/all of your Perforce server to a remote location.
It does require some time to setup but I'm pretty happy with the result. I'm backing up 20TB+ worth of data this way as I write this. ^_^

Can Perforce backup files?


my wife just got an iphone 3GS. we both have apple IDs, but her iTunes on her iPhone shows my username

Question: my wife just got an iphone 3GS. we both have apple IDs and use a macbook together, but her iTunes on her iPhone shows my username and the credit amount that I have. When buying a song or an app, my user account info pops up. How can we have her username and log in information appear on her iPhone?
Answer: Are you using the same user on your MacBook? If so, you're probably using the same iTunes too, which probably is set to your Apple ID. To use a different ID, you need to switch accounts every time you sync the iPhones. To sign out, choose "Store" > "Sign out" in the iTunes menu bar.
Thankfully, this whole hassle will be over when iOS 5 is released.
Answer: You could also simply authorize both accounts to run on your computers at home (store--> authorize this computer), and then, on the actual IPhone, go to settings--> store--> log out, then just log back in using her account.


Can anyone explain what passive offers achieve?

Question: I've read https://www.stellar.org/developers/guides/concepts/list-of-operations.html#create-passive-offer but I can't quite wrap my head around the purpose of a passive offer. Can anyone explain their use with a real world example?
Answer: The link provides purpose in a nutshell:

Passive offers allow market makers to have zero spread. If you want to trade EUR for USD at 1:1 price and USD for EUR also at 1:1, you can create two passive offers so the two offers don't immediately act on each other.

As in the example above, with normal offers those two offers would cancel each other out and you would be left with, i.e. EUR/USD 0.9999:1 and USD/EUR 1:1.
Usecase examples:

Let's say you have EUR@Deutchebank and EUR@Swedbank, and they have a mutual contract in-between to accept each others EURs. In that case, from their perspective both EUR assets are identical, thus they most likely will put up 1:1 passive offers to ease the exchange for themselves and their clients.
There may be reasons for smart contracts to provide offers between two assets at zero-spread exchange rate, so that people could always exchange one asset for other and back without losses. With normal offers that's impossible, because smart contract's both offers would cancel each other out. Hence the passive offer to make this possible.
Comment: @PaulHill perhaps another example would make more sense? Let's say you have EUR@DeutcheBank and EUR@Swedbank, and they have a mutual contract in-between to accept each others EURs. In that case, from their perspective both EUR assets are identical and most likely will put up 1:1 passive offers between them to ease the exchange.
Comment: I understand the mechanics of the offers themselves.
I guess my struggle is understanding why one would want to have those sitting around. I guess just to facilitate a transaction chain through the distributed exchange?
Would a passive USD (foo) / USD (bar) be a use case?
That would map a fiat asset path from one issuer to another and open up access to trades that trust their asset.


Moving the fridge for Pesach cleaning

Question: Is one required to move the fridge and clean out all the chametz that has gotten stuck underneath? This question assumes that the fridge will not be moved at all during Pesach.
Comment: Why is there Chametz stuck beneath the fridge??
Comment: @DoubleAA I don't understand your question... Your question leads me to believe you have never owned a fridge and moved it. Or maybe you're just extremely careful about dropping food in your kitchen.
I would venture to say that everyone's fridge has some amount of chametz underneath it.
Comment: Isn't there an idea that only actual pieces of chametz are chayiv tashbisu, but that crumbs one doesn't need to twist themselves into a pretzel (so to speak) to look for?
Comment: Except for ones like mine that are sealed into the wall and floor such that there is no space under there for chametz to get into.
Answer: The Radvaz (Teshuvos, chelek aleph: 135) and the Chayey Adam (119:6) explain that the reason we clean cracks and crevices from chametz is because maybe we may come to eat it on Pesach (because it might get into food).
Otherwise, the Gemara Pesachim on 6b says that crumbs are not important at all. The Magen Avraham (S.A. 434) even says that crumbs are "batel" (nullified) by themselves, and do not need your declaration.
The Chazon Ish 122:18 (brings the Gra) and says that visible bits of chametz stuck in between cracks in the floor, do not need cleaning. This is because no one will be suspected of gathering these bits to eat them. The Bes Yosef, Magen Avraham, and Mishnah Berurah (see Tur + S.A. 442) all agree that once chametz pieces are slightly dirty, there is no further reason to actually clean them, since no one will come to eat them. Your "bitul" declaration takes care of everything.
This explains why the Chazon Ish (bringing the Gra again), is strict to clean books for crumbs (but not clean the floor cracks). He explains that books brought to the table with crumbs in the pages may fall out into the food. (BTW Many poskim are lenient even by books for various reasons.)
Shulchan Aruch HaRav 433:19 specifically discusses a case of an actual larger than kezayis piece of good chametz that falls between the floorboards and remains visible. He says that one does not need to actually remove the floorboard and fish it out. The declaration of "bitul" is enough. This is because a person is not going to go there, so there is no risk of coming to eat it. In his Kuntres Acharon, the Rav objects by suggesting that if a valuable object (like jewelry) also fell in between the boards next to the chametz there on Pesach, we would rip out the board to recover the valuable? He answers that you still do not have to go get the bread out, because the chances of dropping a valuable there on Pesach are very slim.
Therefore, one need not move the fridge (or large appliances that are meant to remain stationary) to clean chametz under, or behind it; even if you know there is chametz there. Those who do so anyway (while making sure not to annoy family members or neglect real Halachic issues in the process), are trying to voluntarily serve Hashem with extra fervor for chumras Pesach.
I hope this helps.
Comment: About the visible chometz between the floorboards-+-Why wouldn't it be an issue of "lo yera'eh lecha chametz ... bechol gevulecha"?
Comment: @SAH good question. The answer is because the person performed "bitul" by declaring the chametz (in between the boards) ownerless. Hashem accepts your nullification and the chametz is rendered as dirt. (as long as you do it before Pesach starts. :) ) Now since it is too hard to reach and it won't be eaten, bitul is enough.
Comment: @SAH you too :)
Answer: As long as there's no reasonable chance of encountering it on Pesach, then no. (This comes up more often as people try to find any chametz behind their fridge, but the same idea -- try sweeping underneath if you can, but you don't have to move the fridge!)
Rabbi Hershel Welcher in Queens has a pre-Pesach shiur on this. "Let's pick one day a year for people to clean out behind their refrigerators -- I don't know, May 15 or something -- but it's not a Pesach requirement! (He later found out that when he said you don't have to clean out behind your fridge, someone eventually misquoted him as saying when cleaning the interior walls of your refrigerator [which you should do], you don't have to clean the rear interior wall.
The mishna in the first chapter of Pesachim talks about what places need to be checked (or for our purposes, cleaned); the concerns are whether chametz is likely there; whether you would really want to keep chametz if it was there; and whether you'd encounter it on Pesach.
Answer: Going a bit further than the previous answers, my Rabbi specifically said not to move it within 30 days of Pesach. If it is moved within 30 days, there might be a chiuv bedika.

Moving the fridge for Pesach cleaning


Can one fork a decentralized exchange smart contract since the code is out in the open?

Question: Since ethdelta and idex are decentralized exchanges, meaning there is no "central" server. The smart contract code is in the ethereum blockchain. Can one just copy this smart contract and launch a similar service? Or is the dex smart contract code not transparent?
Answer: I dont know about the smart contract itself. ForkDelta is a fork of EtherDelta. The web interface is hosted at: https://forkdelta.github.io/ the Github repo is here: https://github.com/forkdelta although, I think this is just a fork of an interface for the smart contract, not a fork of the smart contract itself but it might give you somewhere to look.
Answer: The smart contract is out in open indeed, and anyone can interact with that using public functions defined. Some functions require admin account (with private key), like changing fees (within parameters) or fee collection address. I forked EtherDelta contract, and you or your code can interact with that (transfers, deposits, trades) as you wish. It's open and transparent. See https://ropsten.etherscan.io/address/0xc46321efe8883d22d81ed65cb4f0766e1004129d#readContract
Get some Ropsten ETH and LINKs, connect with MetaMask and play around! You can't break it!
https://faucet.metamask.io/
https://faucet.ropsten.be/
https://ropsten.chain.link/


Why does deflation cause banks to increase their interest rates?

Question: I have read that in a deflationary spiral, lower prices cause banks to increase their interest rates. Is this true and what is the logic behind it?
Comment: Linking to the source of your claim would improve your question.
Comment: Unfortunately, my source is notes I have received from my Econ teacher.
Answer: I suspect there is a small mistake in your notes.
Deflation does not cause banks to increase their interest rates. However it is true that a deflationary spiral (or plain deflation for that matter) causes real interest rates to increase. These are the interest rates that matter for the economy anyway, which is why in macroeconomics we often refer to the real interest rate even if it's not explicitly stated so.
The nominal interest rate, set by banks in part, is the interest rate in terms of money. It determines how much money we have to pay back for credit.
The real interest rate  is the rate in terms of goods and services. It determines how many goods and services we have to pay back for credit.
The real interest rate is defined as:
$ (1+r) = (1 + i) / (1 + \pi) $, which can be approximated by:
$r = i - \pi$, where r is the real interest rate, i is the nominal interest rate set by banks and $\pi$ is the inflation rate.
When we have deflation we get a negative $\pi$, which, as can be seen from the equations above, increases the real interest rate r. The smaller $\pi$ is, the bigger r gets. When $\pi$ is negative, even if we set $i$ to its lowest possible value, which is 0, the real interest paid on it will be positive. This means the amount paid back in goods and services is larger than the amount borrowed and increasingly so the bigger the deflation (smaller $\pi$) is.
Answer: To understand the situation you have to realize that there are two types of money in the economy.
Government base money & bank money (mostly deposits).
Bank deposits great outnumber government base money (MB).
When deflation happens, is conceptually very similar to a bank run.  Depositors demand short term assets or base money instead of long term assets.  Because banks operate by mismatching long term assets with short term liabilities, this result in an inevitable liquidity crunch.  Put another way during deflation, bank money is being destroyed.
The banking system is very interconnected.  Most banks constantly rely on short term lending from other banks to sustain their maturity mismatching.  Imaging in an economy there is 20,000 in bank deposits and 10,000 in base money.  If 5,000 is withdrawn that leaves 15,000 deposits to cover 5000 in base money.  The ratio changed from 2 to 1 and is now 3 to 1.  Banks are even more desperate for reserves to hold off insolvency so will pay more for base money than before.  This is why interest rates rise during a deflationary spiral.
Now....the Fed attempts to control the fed funds rate so in theory you don't see this happen (well you do see it in that you see massive acquisitions from the Fed in an effort to keep the banking system solvent).
Conventional interest rate equations do not apply to banks because banks are unique.  They create their own liquidity and even their own money.


What is the Islamic ruling regarding making the grave of the Prophet as places of worship?

Question: What is the Islamic ruling regarding making the grave of the Prophet (pbuh) as a place of worship?
Is making shrines on graves of the Prophets and respecting them an important part of Islam? Is it done in order to please God and gain his favour?
Answer: It is not allowed in Islam to take any grave even the Prophet's {Peace Be Upon Him} grave as a place of Worship.  The Prophet {Peace Be Upon Him} said that Allah cursed the Jews because they had built places of worship at the graves of their Prophets,  here is the hadith in Sahih Bukari narrated by Abu Huraira
It is forbidden to build any kind of structures over any grave,

Narrated Jabir: I heard the Prophet (sallallahu 'alaihi wa sallam)
forbid to sit on the grave, to plaster it with gypsum, and to build
any structure over it.
حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ،
أَخْبَرَنَا ابْنُ جُرَيْجٍ، أَخْبَرَنِي أَبُو الزُّبَيْرِ، أَنَّهُ
سَمِعَ جَابِرًا، يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم
نَهَى أَنْ يُقْعَدَ عَلَى الْقَبْرِ وَأَنْ يُقَصَّصَ وَيُبْنَى
عَلَيْهِ .
Sunnan Abi Dawood

The Prophet's {Peace Be Upon Him} grave is in the Masjid yes but it is cut off from the Masjid so it cannot be entered through the Masjid but you have to go out of the Masjid to get to it, His {Peace be Upon Him} grave has a dome on top of it for people to know where the grave is.  Worshiping the Grave of the Prophet {Peace Be Upon Him} is forbidden and the Prophet himself even asked Allah to prevent his grave from being Worshiped.
Yes we should respect the Prophet {Peace Be Upon Him} but there is or should be a distinction between respect and worship, worshiping the grave of the Prophet {Peace be Upon Him} is Shirk, and that is no way of respecting the Prophet {Peace Be Upon Him} or even gaining Allah's pleasure.
Answer: As a general rule, worshiping of the graves could be counted as a haram/forbidden act. But there is a significant point regarding its ruling that could be related to the intention of the person who says prayer. Actually intention is counted as the reason which specifies it as a halal or haram act (Shirk). As it mentioned before, if you go to the graves to worship them, it could be counted as a haram act. But in the case that you consider them as the mediator between you and Allah (not worshiping them), then it won't be haram. The following site has elaborated it.

www.islamquest.net

It could be considered from another angle as well. In truth, it couldn't be haram if you solely intend to say prayer beside those graves as holy places (or shrines). Actually their intention is for God and they just selected them as some holy places of saint individual(s) which can better for worshipping Allah through that holy situation more than common situations, not as idol (as if some groups strive to pretend/accuse us/them as if we regard them as idol! ...). Since as a usual rule, the place of the worshiping is significant as well and it could be better if your place be saint. So we can invoke the Surah al-Kahf (verse 21th) that says:

وَكَذَٰلِكَ أَعْثَرْنَا عَلَيْهِمْ لِيَعْلَمُوا أَنَّ وَعْدَ اللَّـهِ
  حَقٌّ وَأَنَّ السَّاعَةَ لَا رَيْبَ فِيهَا إِذْ يَتَنَازَعُونَ
  بَيْنَهُمْ أَمْرَهُمْ ۖ فَقَالُوا ابْنُوا عَلَيْهِم بُنْيَانًا ۖ
  رَّبُّهُمْ أَعْلَمُ بِهِمْ ۚ قَالَ الَّذِينَ غَلَبُوا عَلَىٰ
  أَمْرِهِمْ لَنَتَّخِذَنَّ عَلَيْهِم مَّسْجِدًا ﴿٢١
And similarly, we caused them to be found that they [who found them]
  would know that the promise of Allah is truth and that of the Hour
  there is no doubt. [That was] when they disputed among themselves
  about their affair and [then] said, "Construct over them a structure.
  Their Lord is most knowing about them." Said those who prevailed in
  the matter, "We will surely take [for ourselves] over them a Masjid."

This verse mentions it as a permissible practice. So it is related to the verse 21 Surah Al-Kahf, this verse clearly declares that the believers insisted on building a mosque over the cemetery of the people in the cave, so there was no criticism or objection of that in the holy Quran. If this practice contradicts with the principles and creed of religion, the holy Quran would have rebuked them for doing that, and would refer to their deviancy from fact.
As another reason, paying attention to this issue could be profitable to know that Shias have a due (a Mustahab or recommended dua) that when they intent to say prayer, they recite it at first. It consists of:

وجّهت وجهي للذي فطر السماوات والأرض، عالم الغيب و الشهادة، حنيفاً
  مسلماً و ما أنا من المشرکين، اِنّ صلاتي ونسکي ومحياي ومماتي للَّه رب
  العالمين، لا شريک له و بذلک أمرت و أنا من المسلمين .
(I've come to the lord who is creator of the heavens and the earth …,
  verily my prayers and worship are for Allah and he has no partner…)

Hence by paying attention the above-mentioned dua, we see that their intention is for all Allah.
Or as another reply to those group of people who accuse some other people that they are doing it as Shirk, we can mention that:
If it is Shirk (worshiping beside the graves), why Since first of Islam so far other people prayer in Masjid al-Haram where there are several graves of prophets and other people such as Hajar (the mother of Ismaeel) and children of … ? Besides, they prayer in Masjid al-Nabi around the grave of Prophet Muhammad (s), Abu-Bakr and Umar. Then we should not consider it as a Shirk. Because if they prayer around those graves, but their intention is for Allah not them.

Sources:

tanzil.net
www.islamquest.net
rohollah110.blogfa.com


Methods for reducing or coping with sleep deprivation

Question: Sleep deprivation is a major problems for parents of a newborn child. Are there methods which could help young parents cope with sleep deprivation or reduce it? Have you tried any of them? What is your personal experience?
Answer: Sleep deprivation comes with being a parent of a baby, however you will cope. It isn't fun but you will get through it. Although you cannot avoid it here are some general recommendations:

Get your baby on a routine: Every parent I know that tried baby-led sleep patterns gave up and instituted a routine, because they really help get your child on a sleep pattern that is compatible with your life
Make sure you keep taking care of yourself: it's easy to get so involved in your baby's day to day that you forget to look after your own well-being. Try to keep a good healthy diet and some sort of exercise. Work some time to look after yourself into your schedule
Share responsibilities with your partner: If you plan on breast feeding then expressing some into bottles will allow both parents to feed the baby. This is good for bonding as well as allowing the mother to get some sleep
Learn to nap: when your baby naps try to get some rest as well. Try not to obsess about cleaning up and being tidy, if you really need some rest take the opportunity. Keep a nap spot ready to go so you can just dive into it
Keep on top of the essential tasks: If you let crucial things pile up they can get overwhelming, keep a list of what really needs to be done and when so you can refer to it. When you're exhausted your memory can be like a sieve!
Comment: I would only add one thing here -as hard as it is, avoid caffeine.  If you are drinking caffiene, it is harder to take advantage of a nap opportunity when it arises.  If you are having a little first thing or early in the day, while at work, then avoid it for the few hours before you head home (and certainly after lunch) for the same reason.
Comment: And avoid lots of booze as well, it doesn't help much to be hung over and tired.
Comment: I'd add 'learn to go to bed on time' too. Many parents I know are tired and after some quick questioning, it's clear that they are having trouble getting themselves off to bed.
Comment: Definitely @JBRWilkinson, forget about late nights. Turning in early is the way to go!
Answer: To reduce sleep deprivation, sleep when the baby sleeps and do not prioritize tidying or cleaning over sleeping. Work out what things you can do in the company of an awake baby and do those things then so that you can sleep. Many babies love to be in a sling while you shop, vacuum, or read something, or to be in a baby seat or swing while you cook or tidy. They are less happy to be in a sling while you type on a keyboard or talk on the phone, though.
To manage to function well on less sleep than you really need or most certainly less uninterrupted sleep, make sure your room is perfect for sleeping - if you need to, change your mattress, change the kind of blankets or pillows you have, get blackout curtains, a white-noise thingy if there is noise from outside, and so on. Don't use alcohol or caffeine for a while. If you have trouble falling asleep in the little time you have and then you stress anxiously "I can't get asleep and now it's going to be even worse!" then learn relaxation exercises or meditation.
Try to set your life up so you can be safe and functional even if you're a little groggy. This might mean taking the bus or walking instead of driving, or outsourcing the bookkeeping for your family business. To prepare for things like losing your keys, locking yourself out of the car or house, etc, make plenty of copies of keys and hide them on the property or leave them with a neighbor. When you cook, cook a large batch and freeze some so that another time you don't need to cook. Plan your meals in advance and put the plan on the fridge where you can see it, so when you forget, you will be reminded what has defrosted or what has been bought and needs to be cooked before it spoils. Use "information radiators" like wall calendars, bulletin boards, written todo lists and the like to spare yourself from having to remember or from having to tell your spouse that something important is or isn't done. Sleep deprived people forget things. Technology can help to remind you. This sort of preparation can smooth over the rough patches dramatically.
Many families choose one parent whose sleep will get back to normal much sooner (eg Daddy is going back to work so his sleep can't be messed with) and one who handles nighttime parenting and possibly gets a nap in the daytime. Even if both parents have returned to work sometimes they make this deal, with the up-at-night parent napping in the evening when the other parent is also home, or the up-at-night parent holding a job that doesn't require a lot of mental acuity or physical dexterity. If this is what you plan to do, make sure both parents agree this is the plan.
Usually somewhere between 6 months and a year your sleep is close to normal, and then eventually you will forget the details of it. That's how second children come to be :-)
Comment: +1 for "Do not prioritise X over sleeping". Spent 2 hours tidying and now want to sleep? DAUGHTER CARES NOT.
Comment: The last sentence made my ... night;) Thanks for the answer.
Comment: Well, sleep might be close to normal for awhile - then adolescence hits and your rebellious sex-crazed lunatics keep you awake again :-)
Comment: Great advice. I've read this over and over the past sleepless weeks. :)
Answer: I have two thoughts on the matter.

While money might be tight, consider hiring someone to clean your house once a week or so. I wish that my wife and I had done that.
Take turns caring for the baby if you're not breastfeeding or have bottles available to heat up. It sometimes means sleeping in another room, but even getting one night of good solid rest can help a lot. My daughter is a horrible sleeper as of late, and we generally alternate nights getting up with her in the middle of the night. Or alternatively, I generally get up with her between 12 and 5 AM.


Family-wise error boundary: Does re-using data sets on different studies of independent questions lead to multiple testing problems?

Question: If a team of researchers perform multiple (hypothesis) tests on a given data set, there is a volume of literature asserting that they should use some form of correction for multiple testing (Bonferroni, etc), even if the tests are independent. My question is this: does this same logic apply to multiple teams testing hypotheses on the same data set? Said another way-- what is the barrier for the family-wise error calculations? Should researchers be limited to reusing data sets for exploration only?
Answer: I disagree strongly with @fcoppens leap from recognizing the importance of multiple-hypothesis correction within a single investigation to claiming that "By the same reasoning, the same holds if several teams perform these tests."
There is no question that the more studies are performed and the more hypotheses are tested, the more Type I errors will occur. But I think there's a confusion here over the meaning of "family-wise error" rates and how they apply in actual scientific work.
First, remember that multiple-testing corrections typically arose in post-hoc comparisons for which there were no pre-formulated hypotheses. It is not at all clear that the same corrections are required when there is a small pre-defined set of hypotheses.
Second, the "scientific truth" of an individual publication does not depend on the truth of each individual statement within the publication. A well-designed study approaches an overall scientific (as opposed to statistical) hypothesis from many different perspectives, and puts together different types of results to evaluate the scientific hypothesis. Each individual result may be evaluated by a statistical test.
By the argument from @fcoppens however, if even one of those individual statistical tests makes a Type I error then that leads to a "false belief of 'scientific truth'". This is simply wrong.
The "scientific truth" of the scientific hypothesis in a publication, as opposed to the validity of an individual statistical test, generally comes from a combination of different types of evidence. Insistence on multiple types of evidence makes the validity of a scientific hypothesis robust to the individual mistakes that inevitably occur. As I look back on my 50 or so scientific publications, I would be hard pressed to find any that remains so flawless in every detail as @fcoppens seems to insist upon. Yet I am similarly hard pressed to find any where the scientific hypothesis was outright wrong. Incomplete, perhaps; made irrelevant by later developments in the field, certainly. But not "wrong" in the context of the state of scientific knowledge at the time.
Third, the argument ignores the costs of making Type II errors. A type II error might close off entire fields of promising scientific inquiry. If the recommendations of @fcoppens were to be followed, Type II error rates would escalate massively, to the detriment of the scientific enterprise.
Finally, the recommendation is impossible to follow in practice. If I analyze a set of publicly available data, I may have no way of knowing whether anyone else has used it, or for what purpose. I have no way of correcting for anyone else's hypothesis tests. And as I argue above, I shouldn't have to.
Comment: I gave the question a bounty because I wanted to bring it 'upfront'.  The reason why I wanted to do that was that I think that it doesn't get enough attention and that and that - apparently, as I experienced with my answer - there is 'no discussion' about it anymore.  As shows, it may be an interesting discussion, so you get a (+1)
Comment: A paper by Breiman also addresses this topic: http://projecteuclid.org/euclid.ss/1009213726 . I hope these papers can serve as an easy reference for those who are interested in the current research and published discussions on this topic.
Comment: @fcoppens thanks for bringing this "upfront"
Comment: Since this post, I stumbled upon a great paper that addresses this topic as well by Salzberg called "On Comparing Classifiers: Pitfalls to Avoid and a
Recommended Approach" (http://www.cs.ru.nl/~tomh/onderwijs/lrs/lrs_files/salzberg97comparing.pdf). I appreciate the discussion. This type of questions brings up the divide between statistics and machine learning / other applied fields that was discussed in this post: http://stats.stackexchange.com/questions/1194/practical-thoughts-on-explanatory-vs-predictive-modeling ....
Comment: There is also the following paper "[On the generation and ownership of alpha in medical studies](http://dx.doi.org/10.1016/j.cct.2004.07.006)". It is clearly a controversial topic. One of the few cases where the answer is clear is with regulatory label claims for pharmaceutical products, where there is more or less a single $\alpha=0.05$ for a medical study. Once we get into scientific publications, there is for better or wose nobody to enforce any such thing.
Answer: The ''multiple testing'' correction is necessary whenever you 'inflate the type I error':  e.g. if you perform two tests, each at a confidence level $\alpha=5\%$, and for the first we test the null $H_0^{(1)}$ against the alternative $H_1^{(1)}$ and the second hypothesis $H_0^{(2)}$ versus $H_1^{(2)}$.
Then we know that the type I error for e.g. the first hypothesis is the probability of falsely rejecting $H_0^{(1)}$ and is it $\alpha=5\%$.
If you perform the two tests, then the probability that at least one of the two is falsely rejected is equal to the 1 minus the probability that both are accepted so $1 - (1-\alpha)^2$ which, for $\alpha=5\%$ is equal to $9.75\%$, so the type one error of having at least one false rejection is has almost doubled !
In statistical hypothesis testing one can only find statistical evidence for the alternative hypothesis by rejecting the null, rejecting the null allows us to conclude that there is evidence in favour of the alternative hypothesis. (see also What follows if we fail to reject the null hypothesis?).
So a false rejection of the null gives us false evidence so a false belief of ''scientific truth''.  This is why this type I inflation (the almost doubling of the type I error) has to be avoided; higher type I errors imply more false beliefs that something is scientifically proven.  Therefore people ''control'' the type Ierror at a familywise level.
If there is a team of researchers that performs multiple tests, then each time they reject the null hypothesis they conclude that they have found statitiscal evidence of a scientific truth.  However, by the above, many more than $5\%$ of these conclusions are a false believe of ''scientific truth''.
By the same reasoning, the same holds if several teams perform these tests (on the same data).
Obviously, the above findings only hold if we the teams work on the same data.  What is different then when they work on different samples ?
To explain this, let's take a simple and very unrealistic example.  Our null hypothesis is that a population has a normal distribution, with known $\sigma$ and the null states that $H_0: \mu = 0$ against $H_1: \mu \ne 0$. Let's take the significance level $\alpha=5\%$.
Our sample ('the data') is only one observation, so we will reject the null when the observation $o$ is either larger than $1.96\sigma$ or smaller than $-1.96\sigma$.
We make a type I error with a probability of $5\%$ because it could be that we reject $H_0$ just by chance, indeed, if $H_0$ is true (so the population is normal and $\mu=0$) then there is (with $H_0$ true) a chance that $o \not \in [-1.96\sigma;1.96\sigma$].
So even if $H_0$ is true then there is a chance that we have bad luck with the data.
So if we use the same data, it could be that the conclusions of the tests are based on a sample that was drawn with ''bad chance''.  With another sample the context is different.
Comment: Formal "proof," in my opinion, belongs in mathematics. Or, less formally, belongs in jurisprudence. To me proof does not belong to science, because that implies the end of inquiry and the start of dogma, and science is fundamentally about inquiry. In English (and in the USA), for example, we have a rhetorical game where anti-evolution individuals will say "biological evolution is just a theory, and hasn't been scientifically *proven*." Of course, the trick is getting the listeners to forget that science never proves, only provides evidence.
Comment: I am not a fan of using "proof" with respect to scientific evidence.
Comment: @Alexis: it is certainly  because English is not my native language, but I thought that 'evidence' and 'proof' are more or like synomym, but that does not seem to be the case ?


Is there any regulations on buying and selling Bitcoin on eBay?

Question: I see a lot of people selling Bitcoin on eBay. Since the government began regulating exchanges, are there any rules you have to follow now to sell Bitcoins on a site like eBay? Additionally, are there any rules you have to follow when buying from eBay?
Answer: According to eBay's Stamps, Currency and Coins Policy:

Virtual currency must be listed in the Classified Ad format in the Coins & Paper Money > Virtual Currency category. These requirements apply regardless of whether the virtual currency is digitally or physically delivered. Examples of items subject to this policy include Bitcoins, Litecoins and other similar cryptocurrencies.

In particular, it appears you are currently not allowed to auction Bitcoins.


GIMP - Search/filter single brush inside brush panel?

Question: I am working with gimp-2.8, when we try to change Brush, we need to scroll all brushes or we can filter by group. Problem is that when we filter by group we can select only one group, and it takes too much loading when we filter/remove-filter(though I did not added additional brushes, except that comes default with gimp). Also it needs to remove filter first and then it will allow to add new filter. Is there any way to change this behaviour or any way to search by brush name? (Note: Filter here means not filter programs, but to filter out Brushes.)
Answer: If you change the Brushes dialog from a raster view to a List view, then you can hit Ctrl+f and type a brush name. This expects the whole name and not a part of it, though, so you won't get a filter per se.
I couldn't get this to work in the popup you get from the button in e.g. the Paint tool options, so I guess this isn't available there.


Can U.S. car dealerships pull your entire credit report or just your FICO score?

Question: In the U.S. can car dealerships pull your entire credit report, or just your score if you go into them to apply for a loan? Of all the research I've done, it sounds like its just your FICO score that they're allowed to pull, not the entire report, but I haven't found any concrete evidence to support either one.
Comment: When I bought my car a few years ago they definitely had the full report. Can they even pull "just your score"?
Comment: Remember that even when a lender/financier pulls a "full report", it isn't as complete as the report you see when you pull your own report.
Comment: What difference does it make?
Answer: If the credit is provided through an outside lender (basically always) then only they would have access to the full report, and through discussions with the finance rep at the dealership, they can provide details about the report (approved or not approved and why).
Answer: When they pull your credit report you generally sign a paper giving them the right to do it. So they can pull whatever you give them permission to do.


Computer in the next room

Question: My computer is quite noisy. What is the best way of putting it in a different room? Right now I have two HD monitors and a usb audio interface, but I'd like to be future proof.
Answer: First, run some routine maintenance on your computer. If it's making some serious ticks, whirs and clicks there may be a bigger problem. If it sounds like a small turbine engine every time you boot up, open up the case and give it a good once over with a can (or two) of compressed air. Be sure to hit the fans, they're typically very noisy culprits. If the noises persist try hunting down any lose cabling that may be vibrating against the case. If it still ticks and clicks, it may be time to backup the discs and replace them. Ticking drives are 3.5" timebombs that are ready to go off at the most inopportune moment.
Having said that, if it's up to snuff and is just a distracting whine in the room, almost every place that I've worked in has used some variety of Gefen extenders. They allow you to make huge runs (200+ feet) for HDMI, DVI, S/PDIF, USB, Firewire, etc. using cat5/5e/6 cable. They're not cheap, but they're great little boxes that get the job done.
Comment: Thanks. It's quite new and clean. The problem is the intake and exhaust that seem to have two speeds: loud white noise, and loud white noise +3dB, and the CPU and GPU that tend to sound like jet engines. There doesn't seem to be something wrong other than cheap fans. Gefen extenders seem to be closest to what I have imagined, so we'll see what the future holds :)
Answer: I've thought about that very much before too, but for me I found that just making it silent was much easier and more safe.
To make it completely silent I got meself an aluminum alloy chassis with internal padding (doesn't resonate at all), noiseless Seagate Barracuda discs (only ever use 2 in the same computer for the sake of noise and vibrations), a passive PSU, and passive graphics- and video-cards.
It wasn't even what much more expensive than non-silent stuff, just a little less powerful in areas where I, as a sound designer and audio engineer, don't need that much juice anyway, mostly the graphic interface!
Answer: IF the distance you're running is under 30 feet, then you try getting really good quality extender cables. I currently run about 30 feet from my "machine room" (really just a large closet) with just hi-quality extender USB and DVI cables. Make sure you spend a few bucks on them, don't use the el-cheapo stuff. Over that point you should consider in investing in the Extenders Steve mentioned. You could also consider isolation racks... we've had good luck with the Middle Atlantic stuff: http://www.middleatlantic.com/studio/ec/ecracks.htm. An option if putting the machine in another room is problematic for one reason or another.
Answer: I use a USB switcher that connects me to 3 computers in a remote location.
Answer: just put it another room and be done with it. DVI / HDMI cable runs under 30ft are cheap and work fine. USB runs need an active repeater every 15ft, passive USB cables don't work at all.
I've worked with my computers in another room since 2001. you wont be disappointed.

Computer in the next room


Can I build a settlement if I don't have the building piece for it?

Question: Each player has 5 settlement tokens in hand at the beginning of the game. After placing the 5th settlement, considering I have not built a single city, can I build a 6th settlement?
Comment: This question makes me irrationally angry.
Comment: The way to place it on the board is a city on its side, but you can't build like that. It can only happen if a city gets reduced.
Answer: This is super clear in the rules.
Under Build in the Game Rules section:

You cannot build more pieces than what is available in your
  pool—a maximum of 5 settlements, 4 cities, and 15 roads.

Then, later, under Build (Building) in the Almanac:

You can build as many items and buy as many cards as
  you desire—as long as you have enough resources to "pay"
  for them and they are still available in the supply.
  [...]
  Each player has a supply of 15 roads, 5 settlements, and 4
  cities.

(Emphasis added.)
and again later, under Settlements:

Note: If you have built all 5 of your settlements, you must
  upgrade 1 of your settlements to a city before you can build
  another settlement. You will then have the settlement in your
  supply, so you can build another settlement.
Answer: No.
Supplies are finite. If you need more settlements, you have to upgrade some to cities. As soon as you upgrade one settlement to a city, the settlement returns to your supply.
The same goes for roads and cities, they too run out. As such, the longest possible road has length 15 (or 30 if you include ships from the Seafarers expansion).
Comment: @Joshua Maybe that's deserving of its own question and answer, then, but again I think the rules are pretty clear. See the quotes in my answer: you cannot build more than 4 cities. (So, you _can't_ win that way — which, by the way, makes the end game a lot more interesting!)
Comment: And, for completeness, for cities too — you can't upgrade 5 settlements.
Comment: @mattdm: Huh? Our understanding was there was no need for the fifth city counter because that nets 10 points which wins the game immediately.
Comment: @Joshua In my experience, 10-point games end too fast. We usually play to 12.
Comment: For three players, 12 is good. For four, it can make the endgame very boring and arbitrary, essentially betting against a particular roll of the dice that will give the lead player the last of a resource he needs for that one final point.
Answer: No, unless you have lost a settlement. Check the contents list of the game to see if you have every settlement pawn for that color.


Hudson Bay Has Low Gravity?

Question: Is there lower gravity at the Hudson Bay? How does this happen? And where exactly is this because I might want to go.
Comment: You won't be able to notice it.  Gravity is like some tiny fraction of one percent weaker there.
Comment: @Flavor you're right that it says that.  "In some places, it's almost half as strong as it is elsewhere." - but that's not only wrong but egregiously wrong.   Everything else they wrote seems correct to me, but that one sentence is way off.   Any gravitational anomaly on Earth is very small.   A few ounces on a 200 lb man perhaps.
Comment: Do you have a source that you can add to your question?
Comment: Oh I heard at some points and location it was half the gravity. "One mysterious gravitational anomaly is in the Hudson Bay of Canada..." https://www.theschoolrun.com/homework-help/gravity
Comment: Interesting. Thanks for the validation :)
Answer: Gravitational acceleration does vary.  It tends to be strongest at the poles and weakest at the equator, this is due to the oblate shape of the Earth which means that at the Equator you are further from the centre, and gravity decreases the further you are.
Also the spinning of the Earth makes gravity seem less at the Equator.  The combination of these effects causes felt gravity to vary from about 9.77 $\frac{N}{kg}$ at the Equator to 9.83 $\frac{N}{kg}$ as you travel from the equator to the pole (a difference of about 0.6% in weight).
On top of this there are local variations in gravity, which are called gravitational anomalies. They are caused by the structure of the rocks in a particular location.  There is a large scale anomaly over the Hudson Bay region, and so gravity there is slightly weaker than you would expect at its latitude. Gravitation anomalies are generally due some combination of two mechanisms:

The massive ice sheet that covered Canada during the Ice Age pushed mass down and south. Now that the ice has gone, the rocks are rebounding back but the mass has still been pushed aside. Less mass means less gravity.
There are mantle plumes - hot spots like Yellowstone and cold spots where the mantle sinks.  Hot spots tend to have high gravity and cold ones tend to have lower gravity.

These two effects combine in the Hudson Bay region to give a distinct gravitational anomaly.  However the difference is tiny. There is still lower gravity in Florida than in Hudson, simply because Florida is closer to the Equator (and thus further from the Earth's center). And you still wouldn't notice the difference between the strongest gravity and the weakest. It is much too small to feel (though pole vaulters still could have a small gain [1 or 2 cm] if they compete in countries close to the Equator). It is absolutely not the case that there is any part of Caanda where you can float or experience "half the strength of gravity".
Answer: The link you give seems largely plausible about the cause of the anomaly in that area:

a 2007 study found that now-melted glaciers were to blame. The ice that once covered the area during the last ice age has long since melted, but the Earth hasn't entirely snapped back from the burden. Since gravity over an area is proportional to the mass on top of that region, and the glacier's imprint pushed aside some of the Earth's mass, gravity is a bit less strong in the ice sheet's imprint. The slight deformation of the crust explains the unusually low gravity in the area.

However it is massively wrong about the scale of it. This site does indeed show a negative anomaly in that area, about 50 milliGals, or 0.05 $cm/s^2$ or about 50 parts per million of the Earths gravitational field.I wonder if someone confused 50 ppm with 50%?
Answer: The anomaly at Hudson's Bay is actually about 0.005% - or 1/200th of a percent. That tiny difference is likely caused by both the additional convection of molten rock underneath the area and the "crushing" of land due to the higher weight of a glacier presence in the depression back in the last ice age - the latter a temporary issue from which it has yet to rebound, but will in ~5000 years.

Credit: Mark Simons / California Institute of Technology, 1997 / Science Photo Library
Answer: In the Nature Letter Localization of the gravity field and the signature of glacial rebound by Mark Simons & Bradford H. Hager, Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 4 December, 1997:

The negative free-air gravity anomaly centred on Hudson Bay, Canada, shows a remarkable correlation with the location of the Laurentide ice sheet, suggesting that this gravity anomaly is the result of incomplete post-glacial rebound1–3. This region, however, is also underlain by higher-than-average mantle seismic velocities, suggesting that the gravity low might result instead from dynamic topography associated with convective downwellings4–7. Here we analyse the global gravity field as a simultaneous function of geographic location and spectral content. We find that the Hudson Bay gravity low is unique, with anomalously high amplitude in the spectral band where the power from the Laurentide ice load is greatest2 and the relaxation times predicted for viable models of viscous relaxation are longest8 . We estimate that about half of the Hudson Bay gravity anomaly is the result of incomplete post-glacial rebound, and derive a mantle viscosity model that explains both this gravity signature and the characteristic uplift rates for the central Laurentide and Fennoscandian regions6 . This model has a jump in viscosity at 670 km depth, comparable to that in dynamic models of the geoid highs over subducted slabs4,9, but lacks a low-viscosity asthenosphere, consistent with a higher viscosity in the upper mantle beneath shields than in oceanic regions.
Comment: Welcome to Earth! I made a small adjustment to your post to match standard Stack Exchange formatting. It's great when a new user finds an older question and adds a well-sourced and thorough answer!

Hudson Bay Has Low Gravity?


Do moved files leave a trace on the drive they created on?

Question: I have created a word document on my computer, or any other file like txt, image, PSD etc. Now, I then take that file and move it to an external device, would that file leave a trace on the computer? Is it recoverable on the computer?
Comment: The situation is exactly the same as normally deleting the file.
Comment: Using `chattr` to add the `s` secure delete option will cause the OS to over-write the file immediately (as opposed to the usual, when the blocks are reused). However this does not prevent disk level exploits, such as ghosts left on the harddisk, or ware levelling on ssd causing block rotation, and thus the zeroing not zeroing the correct blocks. Have a look at shred, it can do destroy files when you ask it to, it also has a list of caveats in the manual.
Answer: YES, the files are recoverable even when they are moved or deleted from the disks. Let's begin with how OS places files in the hard disks. Files are saved on the hard disk in small chunks. These chunks may be scattered all over, rather being placed in contiguous manner.
Your File Manger of the Operating System keeps track of the files by knowing the addresses of all the chunks. These are inodes number, you can think of them as pointers.
When you delete a file, what your OS does is simply remove the data it has stored about these inode values. So, what really happens is that all the links are removed from the table of File Manager System that keeps tracks of the file. The important thing to observe is that the data is still there. HDDs never delete the data, they are always overwritten.
On a general level what recovery tools do is simply check for data on the disks that have no inode values pointing towards them. They use complex algorithms that help them to create something meaningful, such as a file with those small chunks.
It is even possible to recover the data even when you have overwritten the particular block with some other data. In case you are using Hard Disk Drives (HDD) data is stored in the form of magnetic waves. This is binarized prior to being processed by the processor. There are four possibilities when data is overwritten once. Two are when, initially the bit was 0 and then written with 0 or 1, two more when initially it was 1 and then overwritten with 0 or 1. These four values will give different traces on the disk. So, what usually a recovery tool does is simply create four regions via different thresholds and decide what the previous value was. This can be extended when data is overwritten multiple times.
You might have observed that the while formatting your disks or USB you are given two options, one is the fast format and one is the slow format. In the case of fast format, only the links are removed. In the case of slow format, the OS rewrites all the blocks multiple times with random data. This is a secure way of formatting a disk. A number of times this iteration goes can vary with OS and command (or utility) you are using. You can use UNIX command shred, which is a part of GNU core utilities.

shred -n 100 filename

By default, shred overwrites 25 times, but by using -n you can decide the value.

Edit: Solid State Disks (SSDs) have a very different mechanism of working when compared with HDDs. In SSDs whole storage unit is divided into blocks or pages, and each block can be asked to read/write. These blocks are index-addressable just like an array. Thus there is no overhead for data access as it was the case in HDDs. In order to write anything in these blocks, you need to delete the data first. OS of your device don't access all these blocks directly, instead, it talks to the microcontroller present in the SSD or Flash drive. This microcontroller keeps track of all these blocks using a table (or map). Since deletion takes a lot of time thus, the microcontroller of the Flash drive dynamically maps the requested location for write on some other block which is empty and keep a log for itself to delete the data in the block (that was asked) sometime later. This is what allows the room for recovery even when you have deleted your data. For more details, you can go over this paper.
Comment: shred should work on any Gnu or Unix system, including cygwin or mingu (Microsoft's Windows), and other legacy systems.
Answer: Moving a file to another computer is just copying it to another system and then deleting it locally. The usual way of deleting a file by the OS is just either mark it as deleted or remove any references to it so that it is no longer associated with a file name. This means that the data itself get not deleted immediately but usually only if the disk space needs to be reclaimed to write new data (and worse on SSD). In short: it is often possible to recover the original file content.
Answer: In Windows( or infact any OS ), there is always a MFT table (Master File Table) that maps the address space in the hard disk to the associated file. So when you either delete the file or move the file, both the operations just remove the address associated with the file, so the OS believes that the space is empty but it still holds the data and can be easily retrieved.
In order to completely delete or remove the data, you should also fill in the associated address location with another file or any garbage value so that the original file cannot be retrieved. You can use tools such as eraser to do so.


Special equipment for Nitrox Dive?

Question: Is there any special equipment needed for diving with Nitrox(more than 21% O2)? In Germany there are regulations and laws that say that you can only dive using Nitrox if you have this special equipment. I did my SSI Nitrox diver in Indonesia, where we used the regular equipment. Also, I've nowhere before heard of this special equipment. Does anyone have experience with this special equipment? And if so, what is it exactly and what does it cost?
Answer: Yes, and no, it kind of depends on the local laws.
So long as your equipment is covered by your manufacturer guarantee, and you will have to bear in mind as will all diving the local laws and legislations for equipment use in various countries / regions within a country, then it can use a higher FO2 than diving with Air.
However your equipment must be:

Oxygen Clean*.
Use Oxygen Compatible Air.
Be serviced regularly. (I believe with SSI they're making this more frequent)

Specialist Equipment in this sense is where you have separate equipment which does not use regular Air or other mixes. This will be things like:

O rings.
Cylinders.
Regs (first and second stages), etc.

Consider this as having a separate breathing system for higher FO2 mixes.
In some cases this can be your usual equipment after a service + oxygen cleaning. Cost varies.
This information is covered in the SSI Nitrox 32% and 40% courses (at least as of November 2016 for a certainty as that's when I did this course myself).
*Oxygen cleaning is a chemical cleaning, surface preparation service for products intended for use in oxygen. - in short, this is to remove particles etc from your gear, it also means you use oxygen compatible sealants, chemicals etc on the equipment as otherwise friction can cause fire and/or explosions due to the high pressures.
Comment: One thing to keep in mind is that certain types of O-rings can degrade faster or otherwise react poorly with oxygen rich air. Your best bet is to talk with your regulator technician at your dive shop and see what they recommend.
Comment: If breathing up to 40% (i.e. not the very rich O2 concentrations found in decompression gasses),  your regulators do not need to be specially O2 cleaned and certified.  Only the cylinders need to be as they may be exposed to very high concentrations of O2 when filling -- it is very common to put pure O2 into dive cylinders then top-off with clean air.
Comment: @GlennG this may depend on your dive store and who you study with - I did the up to 40% Nitrox course with SSI Nov 2016 and they stated that you do need to O2 clean anything that comes into contact with the higher FO2 gases.
Comment: That's different from other agencies and the actual requirements.  Might be that they're being particularly risk averse and strict (or selling O2 cleaning services??).  Regulators aren't exposed to very high concentrations of O2 within recreational Nitrox use (i.e. up to 40%).  However the cylinders & valves will need to be O2 cleaned as they're commonly filled with pure O2 and topped off (diluted) with clean air -- example:  an empty cylinder requiring 32% will need 32bar of pure O2 and topped off to 232bar with clean air.
Comment: Your first stage reg should still be O2 cleaned, and since you have HP ports on them then this would need O2 maintenance. Yes, SSI are a lot stricter than most, but you may or may not need to do your second depending on what your FO2 is - it maybe outside the remit of recreational diving and onto technical. The main thing is to always follow local area and manufacturer regulations.
Answer: The "special equipment" needed for Nitrox most likely refers to the M26 tank valve fitting, which in certain European countries replaces the classic 5/8" DIN valve for cylinders that are for use with Nitrox (oxygen clean, etc). They are much larger and so a DIN regulator first stage cannot be screwed in, meaning you need special regs for Nitrox too. However most of the world ignored M26 and continues to use the same DIN valve (with or without an insert) for both air and Nitrox. Adaptors between the two standards are available, expect to pay around £20.
Comment: You can use DIN regs with O2.
Comment: ... because most of the world ignored M26...
Comment: Yeah, not even heard of that in the UK, everywhere I dive is DIN - the only adaptor I've been warned to get is for Yolk if diving in the US. Perhaps a link as I can't even find it only for an example?
Comment: If you are extremely interested you can purchase a copy of the relevant standard here https://shop.bsigroup.com/ProductDetail/?pid=000000000030110092 - it costs considerably more than an adaptor!
Comment: I meant more to expand your answer with what the M26 valve looks like :)
Answer: The main 'special equipment' is to have an O2 analyser and use it.  You should also have waterproof tape (Gaffa tape) and marker pen.
Cylinders should be O2 cleaned according to local regulations (every 15 months in the UK).  Regulators don't need to be specialist O2-compatible devices (for example the green ones sold for twice the price of normal regulators).  Note that some (expensive) titanium regulators are not recommended for use with 100% oxygen.
Mark up your cylinders with tape on the cylinder neck with the analysed O2 percentage to one decimal place and the date.
Some agencies require the MOD (Max. Operating Depth)
MOD = (1.4 / O2_fraction) - 1

Example:  MOD of 32% in metres:
MOD = (1.4 / 0.32) - 1
    = 4.375 - 1
    = 33.75 metres

Special equipment for Nitrox Dive?


Pro Tools / show all written automation

Question: sorry if this question is too off-topic and far from sound design.
I'm wondering whether there's any way how to easily show all automation lanes that have any data written inside. I hope you know what I mean. I sometimes find myself struggling with English.
I did, of course, some research first before asking this question but no luck so far.
It seems that I have to open lanes one by one like I'm used to do but maybe I'm missing something.
Comment: Sorry Arnaud, I meant for a particular track and a particular plugin etc. For example, when I write automation for a surround panner I'd like to reveal all data that have just been written. Does it make any sense?
Comment: what do you exactly mean with 'all automation lanes that have any data written"? for a particular channel or for all channels?
Answer: I know of no way to do what you're asking. I'm fairly confident that opening individual automation lanes one by one is the only way.
Comment: I think so too. To add on, your best bet is to probably do an 'option + A" then show all automation and then quickly dismissing all those lanes with no breakpoints. Maybe useful to also know that 'CTRL + Command + Left/Right' arrow keys will let you cycle through each lane of automation.
Answer: "Option -" (minus sign) Shows all volume automation. Cntrl+Command Left and Right Arrow keys goes through all the automation paramters on a selected track. And Cntrl Option Cmnd left and right on arrow keys goes through all the automation paramters on ALL tracks.
Comment: The last response about ctrl-option-command-click is not what the OP was asking about. That is the function to enable automation for the entire plugin. It'll open a popup menu. I'm also looking for a key command to "show all used automation" for either an individual track, or the entire project. It looks like it doesn't exist.
Answer: Alt+click on the little arrow in any track. Alt-clicking will show/hide all automation lanes.
Comment: I seems the question was whether there is a way to quickly show ONLY the lanes that have points in them, while keeping the empty ones hidden. What you're suggesting simply shows all automation lanes, regardless of content.
Answer: After your response it's way easier to answer your question. Yes you can.
In Protools plugins just hold the ctrl-option-command keys together and click on the plugin button you want to automate (whatever it is from which you want to see the automation lane).
It works in eq plugins and also on channelstrips. Don't know about surround, just try it out.
Then you can ctrl-command and click on the same button. Easy does it.
SOS link

Pro Tools / show all written automation