What is the latest scientific consensus on megadoses of Vitamin C?

Question: Vitamin C megadoses were first championed by extraordinary chemist and physicist Linus Pauling, I believe, and as prescription for good health they gained by association with him.  I have read conflicting assessments of whether or not they work in different articles.   What's the latest scientific consensus?
Comment: I don't know the scientific consensus, but 1000mg a day of vitamin C for a week and I started scratching myself to the blood, repeatable. Did it twice. but I'm just a single point, so I don't statistically count.
Comment: I take 1000mg most days and I feel much better for it.  Don't know what that does to the statistics..
Answer: Cancer
Linus Pauling published a study claiming that high doses of Vitamin C can extend survival times in terminal human cancer. A weakness of this study is the selection of the control group as described in the paper

The control group was obtained by a
random search of the case record index
of similar patients treated by the
same clinicians in Vale of Leven
Hospital over the last 10 years.

This method does not ensure that the treated and the control group are properly matched. Two later fully randomized clinical studies (1, 2) conclude that high doses of Vitamin C are not effective as a cancer therapy.
Common Cold
It is also claimed that high doses of Vitamin C can prevent the common cold or at least shorten its duration. There is a Cochrane review stating

Long term daily supplementation with
vitamin C in large doses daily does
not appear to prevent colds. There
appears to be a modest benefit in
reducing duration of cold symptoms
from ingestion of relatively high
doses of vitamin C. The relation of
dose to therapeutic benefit needs
further exploration.
Comment: What about the efficacy in countering acute amanitine (death cap) poisoning? If I remember correctly, some physician deliberately poisoned himself on amanitine and survived due to an intravenous injection of vitamin C.
Answer: Pauling believed that large doses of vitamin C could achieve many health benefits and he was powerful and persuasive advocate of his theories. But his persuasiveness didn't sway the scientific consensus.
One early (1976) review of the idea that the vitamin protects against the common cold reported this:

A more recent American study of adult employees of the National Institutes of Health reported in 1975 found no significant prophylactic or therapeutic benefit from ascorbic acid. The same conclusion was also reached in another British double-blind trial against placebo in 295 persons.
What practical recommendations emerge from this new evidence? Major advances in treatment are usually apparent after a few well-conducted studies, and at present no strong evidence can be found to support the routine prophylactic use of ascorbic acid in well-nourished people.

More recent systematic reviews support this early conclusion. More revealing is this comment in a BMJ article about how to do proper systematic reviews (my italics):

Professor Paul Knipschild has described how Nobel prize winning biochemist Linus Pauling used selective quotes from the medical literature to "prove" his theory that vitamin C helps you live longer and feel better. When Knipschild and his colleagues searched the literature systematically for evidence for and against this hypothesis they found that, although one or two trials did strongly suggest that vitamin C could prevent the onset of the common cold, there were far more studies which did not show any beneficial effect.

This selective advocacy should make skeptics careful when looking at the evidence base as it will, most likely, be easy to find some studies showing benefits when the full weight of evidence is strongly negative.
A more recent (2002) BMJ editorial summarising reviews of the supposed benefits of supplementary vitamins says this of vitamin C:

Vitamin C is an antioxidant, and it also inhibits the formation of carcinogenic nitrosamines from dietary amines and nitrites. It might therefore be expected to have protective action against the development of cancer and cardiovascular disease. The evidence with respect to cardiovascular disease is unconvincing. The epidemiological evidence linking a high intake of vitamin C with reduced cancer incidence is confounded by the fact that the fruits and vegetables that are sources of vitamin C are also rich in a variety of other compounds that may be protective. There is a long held belief that vitamin C (perhaps in very large amounts) is protective against the common cold. A systematic review did not support this but did find some evidence of a modest benefit in reducing the duration of symptoms of colds.

I think it is safe to say that the consensus is that megadoses of the vitamin don't have clear benefits.
Answer: Paul Jaminet of Perfect Health Diet did a good review of some current science in Fighting Viral Infections by Vitamin C at Bowel Tolerance.
Interesting bit:

Recall that in animals, vitamin C synthesis rises as much as 100-fold under disease. In humans, the limit of bowel tolerance rises up to 20-fold during illness. This suggests that bowel tolerance limit is an indicator of need.

His conclusion:

Based on Cathcart's testimony, thousands of patients with infectious diseases have benefited from high-dose vitamin C. Although mechanisms are not well understood, vitamin C probably helps along multiple pathways.
A well-tested therapeutic strategy would be to take 4 g vitamin C every hour with water until bowel intolerance is reached. The therapy is extremely safe, and its effectiveness is usually apparent within days.
Given its safety and the ease of testing its effectiveness, why shouldn't every seriously ill person try this therapeutic strategy? Is there any good reason NOT to try it for at least a few days to see if it has an effect?

The only recent studies he references are

[9] Furuya A et al. Antiviral effects of ascorbic and dehydroascorbic acids in vitro. Int J Mol Med. 2008 Oct;22(4):541-5. http://pmid.us/18813862.
[10] Riordan HD et al. A pilot clinical study of continuous intravenous ascorbate in terminal cancer patients. P R Health Sci J. 2005 Dec;24(4):269-76. http://pmid.us/16570523. Hoffer LJ et al. Phase I clinical trial of i.v. ascorbic acid in advanced malignancy. Ann Oncol. 2008 Nov;19(11):1969-74. http://pmid.us/18544557.

He goes on to say in the comments

Based on Cathcart's work I rather like the idea of bowel intolerance telling me when I might be taking too much.

and

In the case of C, our advice is more precautionary. Deficiency is tremendously harmful, but excess is virtually harmless. In trials, the benefit may be non-existent for 95%, but 5% may see big benefits and 0% harm. In trials the 95% dilute the benefits to the 5% out of statistical significance.
Comment: *Perfect Health Diet*? Baad reference. First warning flag: "diet". Second: neither of the authors are actually experts in the field. Third: "An Anti-Cancer Diet". This has all the hallmarks of pseudoscience. In all fairness, they don't advocate a miracle cure, just a healthy diet to boost the immune system, but still …
Comment: The references cited there don't support the claims, the first one is *in vitro* and cannot be generalized to effectiveness in humans. The second and third reference only observe that ascorbic acid is relatively safe, they don't observe any effectiveness against cancer.
Comment: Yeah that was my first impression of the site too. However I've been reading the blog for a while now and I can't find flaws with his reasoning (not that I'm an endocrinologist), and neither is are his claims very out there. If you read the comments you'll find that the discourse is steeped in well-reasoned logic based on actual studies and dissention is welcomed. In fact I've been following the diet (it's a Paleo/Primal type diet) since February and I have many objectively improved health markers. So if he has a fault it's in the rather corny naming of his site.
Comment: @Fabian, I only point to the review that Paul Jaminet made, I don't claim to have a full list of all relevant recent work. Paul shows that large doses, up to bowel tolerance of vitamin C seem to be safe and it is likely helpful against infections. The in vitro study only shows a possibly mechanism of how VitC might help against infections and was recent. Nobody is claiming it works against cancer.


Rabbits and cats

Question: I just got a rabbit about two weeks ago.  I've had my kitten for about three months/ The cat/kitten is six months old. They were fine together at first but now they seem to fight.  The cat chases the rabbit but the rabbit also chases the cat and the cat is pouncing on the rabbit. I was wondering what I could do to maybe stop the behavior of the cat trying to attack the rabbit, any suggestions to how to get them to get along?
Answer: Your cat and rabbit should not be left alone unsupervised until they have learned to behave well with each other. Cats and rabbits can do very well together, but supervision is required when introducing any new members to a household.
See related What should we look for in a kitty companion for our rabbit?

Rabbits and cats


How do publishers expect authors to use social media to promote their books?

Question: I am new to the world of writing, and was initially surprised to read on some publishing advice website (eek) that authors should use social media to interact with readers and promote their books. How does this really play out in practice? Do publishers see more potential in you if you maintain a blog or have an active online presence? Is this essential for success?
Answer: It varies. Some publishers really require you to be "social". Some don't.
But having social presence helps. It attracts a specific audience that may or may not be reachable through traditional means. It also garners feedback that usually is absent in traditional one-way communication.
But for certain categories, not being "social" kills sales. It doesn't take too much energy and time to be "social" unless you have thousands of views and if you reach those numbers - you could probably contract someone to handle the social presence.
I suggest that writers create a Facebook page (or a Linked In article, depending on the published material), and share it with friends and family. If you have an accessible marketing team with a publisher, they might share some of the book's graphics to be used on the Facebook page (else get ahold of some local graphics designer). Either build a story line in the posts or parallel-plot. Engage the visitors with comments or online events.
It takes a bit of time. Alternately, outsourcing it to a local social media expert saves time. (P.S. Facebook is just an example here.)
Comment: Do you think you could expand on exactly *how* writers are expected to use social media?
Comment: Create Facebook page (or linked in article depending on published material). Share it with F&F. If you have an accessible marketing team with publisher, they might share some book's graphics to be used in the Facebook page (else get hold of some local graphics designer). Either build a story line in the posts or parallel-plot. Engage the visitors with comments or online events. It takes a bit of time. Alternately, outsourcing it to a local social media expert saves time. [P.s. facebook is just an example here]
Answer: I'd say that it's in your best interests to be social. If you're writing for a niche, then find where this niche hang out and observe. If the opportunity arises (or you can encourage it to), hold a Q&A session. Any fan likes a little attention.
Failing that, use Twitter to monitor people discussing you or your work. Get involved in conversations. Don't argue, be decent and take feedback on the chin.
Good luck
Answer: Social media is a powerful weapon when yielded correctly. From monitoring trends to creating a network of potential readers, it is truly a necessary evil.
Introverts and creatives may find it difficult or nonsensical to utilize social media. It is my belief that it should be utilized whether or not your publisher requires or recommends.
Comment: Welcome to Writers! Stack Exchange Q&A sites like this one work a little differently from discussion forums; answers need to directly address the question asked. Can you expand on *how* writers are expected to use social media?


When should I replace a circular saw blade?

Question: Is there a rule of thumb for how often a circular saw blade should be replaced? Is visually inspecting the blade condition enough?
Comment: when it gets dull = when it starts binding/tearing/chipping/burning/just a pain to use.
Comment: @DA01: Can you add that as an answer?
Comment: sure! Will make it an answer...
Comment: If you are thinking about replacing the blade, it's probably time to replace the blade. At worst, it doesn't help and the blade you removed becomes your spare, or you swap back. That's assuming you aren't abusing the tool, of course.
Answer: You should replace your blade when its dull. Ways to tell its dull:

it starts binding
it tears/chips the substance more than usual
it burns the wood
just a pain to use = a sharp blade should let you push the saw forward with minimum effort. If you find yourself forcing the saw forward (not ideal from a safety perspective), change the blade.
Comment: How many carbide teeth can be missing on a 40T blade before you change it out?  I typically find this to be the main reason the blades are not cutting well.
Answer: Looks for worn or chipped carbide teeth. If the teeth are merely coated in pitch, you can remove it with oven cleaner (or in a pinch windex), and old tooth brush, and some elbow grease.
Blades should be replaced when they get dull or after you hit a screw or a hard knot.Cleaning saw blades
Comment: Edited my post above. The article on newwoodworker.com says that oven cleaner can attack the binder that holds the carbide to the blade. The article recommends simple green or a store bought cleaning solution. I've cleaned my blades for years with oven cleaner with no negative effects, but I think I'm going to try simple green next time.
Comment: Obviously baking the blades would ruin the temper and edge, but is it safe to soak the blades in cold application oven cleaner?
Comment: It's all fun and games until the carbide teeth on your saw blade start flying off, huh?
Comment: That's all I normally use. You don't have to use much, just let it soak for about 5 min and scrub it with the toothbrush (wear safety goggles!) and rinse thoroughly with water.
Answer: Sometimes you're using a sharp blade and it still cuts poorly.  You might be ripping with a crosscutting blade or crosscutting with a ripping blade.  Just like you do with your fish hooks, run the back of a finger nail over the saw teeth: if it scrapes, the teeth are sharp; if it slips over your nail without scraping, it's not sharp.
Answer: There is a fantastic way to clean pitch off of saw blades. It is something that everyone has at home. Laundry detergent. Yeah, that's right simple laundry detergent! I put a heavily burnt/pitch covered blade in a 12"x12"x5" plastic tub with a gallon of hot water and quarter cup laundry detergent. Let it soak for three hours. Use a nylon brush/toothbrush, and be amazed. The pitch comes off like soot. Rinse off. Dry the blade thoroughly (I used a heat gun). Apply thin Coat of oil, or blade oil on carbide tips.


Does the latest print edition of Dark Heresy contain errata?

Question: Does the most recent printing of Dark Heresy have the errata worked into it?  I am using a damaged, first print run, Fantasy Flight Games copy of the book and want to know if it would be worth buying a newer print.
Answer: A crawl through the FFG forums reveals this:
http://new.fantasyflightgames.com/edge_foros_discusion.asp?efid=70&efcid=3&efidt=430473&efpag=0#430570
In short, it looks like the v1.0 Errata was included in the first reprint by FFG.  The Errata is currently up to v3.0, and there are currently no plans in place (so it seems) for a reprint that includes this.
Truthfully, if you have not picked up Black Crusade as of yet, I thoroughly reccomend it.  The rules refinements alone are worth the price, and it has been rumored that the changes being deployed (to the core rules, not necessarily character creation and advancement) there are going to reflect in the next iteration of Dark Heresy.
EDIT: Just noticed you have posted a black-crusade question, so I guess you already know that last part. :-)
Answer: Yes, the FFG edition includes some errata.
Note that the other games have differences mechanically from each other. Each is very close, but not the same mechanics, so if running a multi-corebook game, you'll need to pick which is dominant, anyway.


Elements with no solid state

Question: Helium superfluid-3 has got at around 2K a special liquid state with 0 viscosity with interesting properties. I am really interested in what would happen at 0K. With no kinetic energy in the particles of the compound, would it be solid? Do elements with no solid state at all exist?
Comment: Helium won't really turn solid at atmospheric pressure, but at higher pressures it can. Google image search "helium phase diagram" for an illustration
Comment: I'm not sure "at 0K" is well defined enough (since 0K is [not reachable](https://physics.stackexchange.com/questions/32830/is-it-theoretically-possible-to-reach-0-kelvin)) to answer the first part of your question.
Comment: In quantum mechanics there is no such thing as zero kinetic energy.  The Heisenberg Uncertainty Principle does not allow it.  In helium the base, minimum level of kinetic energy allowed by the HUP is enough to never have a solid unless it's compressed.
Comment: In fact superfluid helium below critical temperature can not be solidified only lowering temperature. Below critical temperature if pressure is increased 25 atm or more then it solidifies.
Comment: https://chemistry.stackexchange.com/questions/60860/why-is-absolute-zero-unattainable
Comment: https://chemistry.stackexchange.com/questions/31870/is-helium-4-a-liquid-at-zero-temperature-and-zero-pressure
Answer: First of all, we cannot achieve temperatures of 0 kelvin in experiments, that is forbidden by quantum thermodynamics.
Currently, experiments can go down to seriously low temperatures of nanokelvins (source: a friend is working in that field, but spontaneously the only reference I can give  you is Wikipedia.)
At those temperatures the phases of 'solid' or 'liquid' don't really exist anymore. Rather collective quantum effects play a role, that make new phases appear, namely Bose-Einstein condensates and Fermi gases. What phase appears depends on the particles spin, which allows or disallows them to occupy the lowermost energy level.
Those exotic phases of matter count however still as 'condensed matter', which all elements at cold temperatures will have. The classical solid phase, which you're asking about, can be circumvented this way, but not at all pressures, as others correctly pointed out.

Elements with no solid state


Can I hide all comments from a particular user on friend's posts on my Facebook feed?

Question: There are a couple "friends-of-friends" that just give me the heebie-jeebies. Often I'll see their comments on my friend's posts on my feed. Is there any way that I can hide these from my view? I'm only looking to affect how it appears to me - I realize I cannot actually remove their comments from others posts.
Answer: You could block the respective user(s).

If I share mutual friends with the user I am blocking, will they be able to see my comments to this mutual friend?
Blocking allows you to prevent most interactions with someone on Facebook. People you block won't be able to find you in searches, view your profile, or contact you with pokes, Wall posts, or personal messages. In addition, they will not be able to see your Wall posts, comments on mutual friends' Walls, or that you are a member of the same group as them.

However, this might not work in certain situations:

Why am I able to see content added by a user that I've blocked on the site?
Blocking a user will prevent any type of direct interaction between you and that user. However, for technical reasons, there are certain instances when an individual you have blocked from your account may be able to view your comments on the site and vice versa, including comments on a mutual friend's photo. Please be assured that your listing will appear in black text, with no profile picture visible or contact links available.
Answer: Try using the Better Facebook Plugin (or a similar extension) and see if there is a filter that will remove any instance of that friend. On second thought, since it is a friend of a friend then I don't think Better Facebook has that option.
Your best bet is to find an extension that removes comments based on a Facebook user id.


Geometrically, what is the span of vectors?

Question: Simple question from a calc 3 beginner. Visually I cannot imagine the span of two vectors, what does this necessarily mean? For example my text mentions if two vectors are parallel their span is a line, otherwise a plane. Can anyone elaborate?
Answer: In $R^n$:
If two vectors are linearly dependent their span is the line determined by the vectors (the line made by a vector starting at the origin).
If two vectors are linearly independent their span is the plane.
For three linearly independent vectors the span is the entire three dimensional space.
If the three vectors are linearly dependent then it is either a plane or a line depending on "how linearly dependent" the vectors are.
Comment: i found this to be very enlightening.
Answer: Well, the span of a single vector is all scalar multiples of it.  For example, if you have $\mathbf{v} = (1,1)$, $\text{span}(v)$ is all multiples of $(1,1)$.  So $2v = (2,2)$ is in the span, $-3.75v = (-3.75,-3.75)$ is in the span, and so on.  What you end up with is the whole line $y=x$, which is what you get if you extend $v$ infinitely in either direction.  Note that this is determined by it's slope.  So the span of two vectors with the same slope is still just the same line.
Now, the span of two vectors are all of the combinations $a\mathbf{v} + b\mathbf{w}$.  So if you have $\mathbf{v} = (1,1,0), \mathbf{w} = (0,1,0)$, you can get
$$(3,5,0) = 3\mathbf{v} + 2\mathbf{w},\quad (7.14,-3.86,0) = 7.14\mathbf{v} - 11\mathbf{w},$$
and in fact any other vector in the plane determined by the 3 points $(0,0,0), (1,1,0), (0, 1,0)$ (since 3 points determine a plane).  In this case, you get the $xy$-plane.
The span of more than two vectors is defined similarly.
Answer: Assuming it makes sense that the span of a single vector is a line, we can imagine the two vectors in 3-space.  Because the span of each vector lies within the space of each of them, we can draw the two lines that are in the direction of these two vectors:

if the two lines are equal, then this is all of the span.
otherwise, we can imagine picking one of the lines and sliding it along the other line such that it stays parallel to its original placement.

To make the above intuition precise, the point is that the span of a single vector is the result of performing scalar multiplication on that single vector: that is, contracting it, shrinking it, or even flipping its orientation (making the direction go the other way).  Then we can get any other point of the plane by finding the projection of the point onto the first line, and then translating by the projection of the point onto the second line; this is why when the lines are the same we do not leave the line.
As far as the formal definition of the span goes, the span of a set $S=\{v_1,\ldots, v_n\}$ of vectors is given by the set
$$\mathrm{span}(S)=\left\{ \sum_{i=1}^n{c_iv_i} \mid c_i\in \mathbb{F}, v_i\in S\right\}$$ where $\mathbb{F}$ is the field that you're working over (likely the real numbers $\mathbb{R}$).
In the case where $S=\{v_1,v_2\}$, we're looking at the set of vectors of the form $c_1v_1+c_2v_2$.  Now, if $v_1$ and $v_2$ are in the same direction, then there is $c$ such that $v_1=cv_2$, so we can rewrite this as $c_1v_1+c_2v_2=c_1v_1+c_2cv_1=(c_1+c_2c)v_1$, which is just any element in the span of $\{v_1\}$.  This is why it is possible for the span to be a line.
Now, when they aren't in the same direction, they lie precisely in a unique plane.  Any point in the line that goes along the direction of the vector $v_1$ can be written as $c_1v_1$, and any point in the line that goes along the direction of the vector $v_2$ can be written as $c_2v_2$.  Every point in the plane will then be of the form $c_1v_1+c_2v_2$ by projecting the point onto $v_1$ and $v_2$ to find $c_1$ and $c_2$, respectively.
Answer: Here is a visual way of thinking about this (at least in small enough dimension that you can visualize it).
Say you have some collection of vectors and you place yourself at the origin. Each vector determines a direction (the span does not care if you replace a vector by some non-zero scalar multiple), and the span is everywhere you are able to go by only going in the specified directions (though you are allowed to go both forwards and backwards).
So, if you were in $3$ dimensions and had the vectors $(1,0,0)$ and $(0,1,0)$ then you could for example go to $(-1,2,0)$ by first going backwards $1$ unit in the direction of the first vector and then going forwards $2$ units in the direction of the second vector.


Should a responsive site include  in its sitemap?

Question: Should a website built with responsive design include Google's <mobile:mobile/> xml tag in its sitemap.xml? In other words, will marking each of my urls as "mobile" in the sitemap for a responsive site indicate to Google that these urls are not desktop friendly (when, in fact they are)? What is the best practice in terms of sitemaps for responsive sites? One sitemap with <mobile:mobile/> in each <url>? Two identical sitemaps, one containing <mobile:mobile/>, and the other not? One sitemap without <mobile:mobile/>?
Comment: Responsive design is not necessarily a mobile site though a mobile site can be responsive. Responsive designs are intended to, generally speaking, avoid having a separate mobile site. This feature is for a separate mobile site. If you do not have a separate mobile site, then you you do not have to create a mobile sitemap.
Answer: Google seems a little fuzzy about it, but I would say no, you shouldn't mark responsive pages as mobile.
The page you linked to states:

A Mobile Sitemap can contain only URLs that serve mobile web content. Any URLs that serve only non-mobile web content will be ignored by the Google crawling mechanisms.

Taking this exactly as written, it could mean that all URLs in your mobile sitemap must be formatted for mobiles (which they are), but technically they could be simultaneously formatted for desktop too.
But I think the implication is that the URLs should be only for mobiles and not responsive.
The fact is, Google detects responsive sites perfectly well, so if those URLs are in a standard XML sitemap it knows they work fine on both mobile and desktop.


Rights of others

Question: I wanted to know, i rented a hotel with another friend. The hotel booking was under my name and because i am of a western nationality, the room did not have to pay a tourist fee. I shared the room with my friend from asian nationality and forgot to disclose it to the hotel.  If the hotel knew, then the room would be charged a tourist fee where i would have asked my friend to pay it.
Can i know that since the hotel says both people who rent the hotel room are liable the tourist fee, am i still responsible to pay the fee on the room in allahs eyes? As my friend was the one who was charged because she was from a different nationality. I have lost contact with that friend, so if i dont pay is this considered not returning the rights of the hotel?
Comment: Need to add that this happened 4 years ago. My concern is about the rights of the hotel. Will i be in trouble with allah for not fullfilling the rights of the hotel or will it be my friend. Or is it since the hotel didnt know we should just let his go and allah will repay the hotel in the here after
Answer: Assalam aleykum brother, this should be a comment, but I have no reputation for it. So here goes:
You should at least inform the person that the stay there entails additional costs.
And after that the next step would be to have the confirmation of the person who will pay that cost. So that there is no late liability, or lack of information about the possible debts to the Hotel. Everything must be made clear so that there is no unnecessary concern.

Rights of others


2002 Hyundai Elantra power locks?

Question: My friend just bought a 2002 Hyundai Elantra and neither of us can figure out how the door locks work. It doesn't have any separate lock/unlock button on the inside of the door like most vehicles have, just the mechanical switches attached to the levers to open the doors. However, the vehicle has power windows, and I would be really surprised if it's lacking power locks. Are the mechanical switches on the front doors (and possibly also the key) supposed to activate power lock/unlock on all doors? If so, aside from the fuse, are there common things that go wrong with this system that we should check out?
Comment: Your premise may be faulty.  I learned to drive on a car that had power windows but not power door locks.
Comment: I had considered that possibility, but as the rear door lock switches are not easily accessible from the front seats (they're by the levers, not up by the window like on older cars) it seems like a really odd design for a vehicle without power locks...
Comment: By the way, is there any way to lookup which options a vehicle has based on the VIN?
Comment: Dealer should be able to do the VIN option lookup.  Also, the one I mentioned earlier did not have the locks easily accessible from the front seat either.
Answer: Checking with Kelly Blue Book the power window and power locks are listed as separate options.  Looking at past reviews some state that the power door locks were standard equipment and are operated by the key fob (remote). The fob is supposed to unlock all the doors according to the original sales information I have found. I would check the fuse panel to see if a fuse is labeled power door locks. If a fuse is in the holder the car most likely came with power locks.  With some research you may find a universal key fob remote and program it to the car.
Comment: KBB always lists a bunch of options that don't apply to the make/model/year you're looking up, so I wouldn't take that as an indication that they options are separate. I'm still not 100% sure it's supposed to have power locks. Might be best to call a dealer and see if they know (and if it's supposed to have a key fob).
Answer: I just got this same car for my daughter.  Same thing: power window button, but no separate button to lock/unlock the doors.
However the doors will all sync to the drivers door, at least they're supposed to, using either the key from the outside or the toggle next to the door handle.
In our particular case, all the doors will synch to lock, but they're inconsistent in synching to unlock.  However I found that if I can get them all to unlock from the inside of the car if I push the backside of the toggle inwards rather than pulling the front side of the toggle outwards.   So I suspect something is wearing out in how it's supposed to work
In your case I suspect a fuse has gone out.
Answer: If it has power locks, typically all locks can be unlocked without a remote by unlocking the driver's door with they key twice in quick succession. The locks for the other doors will unlock then if it has power locks.

2002 Hyundai Elantra power locks?


How to write a post-measurement state, if we don't know the measurement result?

Question: Once a state is measured, but we don't look at the result, is the state now written as a density matrix, that is, the probability that it could land on a measurement operator multiplied by the operator applied on the state, this summed up for every measurement operator that it could land on contained in the measurement?
Comment: [This answer](https://quantumcomputing.stackexchange.com/a/4837/1837) is highly relevant.
Answer: Suppose you have a state $\rho$, and a random process that changes this to a state $\rho_j$ with probability $p_j$. If you know what the value of $j$ is, your knowledge of the resulting state will be described by the corresponding $\rho_j$. If you have no information regarding $j$, your knowledge will be described by
$$\sum_j ~ p_j ~ \rho_j$$
This is a general statement that holds for any random process. For the case you describe, which is measurement, the possible outcomes can often be described by a set of projectors $\{P_j\}$. For these
$$ p_j = {\rm tr}~(~P_j~\rho~), ~~~ \rho_j = \frac{P_j \rho P_j}{p_j}.$$
Probabilities for more general measurements can be calculated by more general operators, but figuring out the post-measurement states for these is not always as easy.
Answer: In the Copenhagen interpretation, there are only two kinds of things that one can do, one is evolution and other is the measurement. Measuring but not looking is equivalent to measuring the system and hence projecting it to one of the possible eigenstates. (Or maybe you can clarify more what you meant by not looking?)
And after the system is probed in the measurement, it is no longer in a superposition and no longer in the statistical mixture anymore. It just becomes a decohered density matrix with a single element in the measurement (projector) basis. Density matrix representation then becomes trivial.
(I think in the latter part of your question you are pointing the completeness of probability in the measurement which summed over all the measurement projectors will be unity. But this has to do with the act of measurement, once that is performed, there is only one deterministic state.)


SQL Server 2008 cluster freezing

Question: We have run into a strange situation in which a SQL Server 2008 single-node cluster hangs.  As background, we are rebuilding a Windows Server 2003/SQL Server 2005 two-node cluster using Windows 2008 and SQL Server 2008.  Here's the timeline:

Evicted the passive node (server B) from the Windows 2003/SQL 2005 cluster.  The active node now functions as a single-node cluster with no problems.
Wiped server B's disks and installed Windows 2008 and SQL Server 2008 as a single-node cluster.  Since we do not want to the two clusters to communicate yet, we left the cluster's private network "heartbeat" adapter unconfigured.  The cluster comes up and functions normally.
Moved all databases to the new cluster.  Cluster continues to function normally.
Turned off server A (old cluster) in preparation for rebuilding as the second node of the new cluster.
SQL Server instance on server B (new cluster) locks up, even though it should have no knowledge of or interaction with server A.
Restarted server A.  SQL Server instance on server B (new cluster) immediately begins working again.

Things we have tried:

The new cluster's name responds to ping and NETBIOS requests, even while the SQL Server is hung.
We have confirmed that no IP address is assigned to the old heartbeat adapter, and it is not pulling an IP address from DHCP.
Disabling the heartbeat's network card has the same effect.
No errors were generated in any logs - Windows or SQL.
When the error first occurred, it sat in the hung state for quite some time (well over 10 minutes) before anyone figured out what was going on.  This would seem to eliminate any sort of normal cluster timeout in which it would have been searching for the other node (even if one had been configured).

Server B is running Windows 2008 SP2, fully patched, and SQL Server 2008 SP1 CU7 (10.0.2775).
Answer: Looks similar to my issue: Intermittent unavailability of an instance in a failover cluster while a standby node is offline in a SQL Server 2008 failover cluster
Cluster hung while heartbeat card was unavailable.
Comment: That *does* sound a lot like this issue.  Were you ever able to resolve it?

SQL Server 2008 cluster freezing


WiFi dropouts with router but not with mobile WiFi hotspot in elementary OS

Question: Recently I dual booted my laptop HP Pavilion Notebook ab219tx with Windows 10 and elementary OS 0.3.2. At first it connected to my WiFi but poor signal and internet speed is also very slow even through I am near to the router and after some time it just continuously connecting and disconnecting but when I tried with my mobile hotspot it just worked fine.So
Comment: To know your chipset wifi card, try in a terminal: sudo lshw -C network.  Copy & paste the results.
Comment: /0/100/1c.2/0  wlano  network  RTL8723BE  PCIe wireless network adapter @bitseater
Answer: HP has recently been using only one antenna on a wireless card with two connectors.  Larry Finger with some help from Realtek came up with the solution
sudo apt-get install git linux-headers-generic build essential
git clone git://github.com/lwfinger/rtlwifi_new.git
cd rtlwifi_new
git checkout rock.new_btcoex
make
sudo make install
Reboot. Then try
sudo modprobe -rv rtl8723be
sudo modprobe -v rtl8723be ant_sel=1
Check to see if wireless access points are detected
iwlist scan | egrep -i 'ssid|signal'
If nothing is detected or very weak signal, then try
sudo modprobe -rv rtl8723be
sudo modprobe -v rtl8723be ant_sel=2
Then test to check wifi signal strength
iwlist scan | egrep -i 'ssid|signal'
One or the other ant_sel parameter settings should result in better wifi signal strength and you can set it with
echo "options rtl8723be ant_sel=X" | sudo tee /etc/modprobe.d/rtl-ant-sel.conf
Where X is either 1 or 2 based on what gave you better results
Answer: This wifi network card has some issues with kernels in Trusty Ubuntu and derivates. You can try from terminal:
echo "options rtl8723be fwlps=N ips=N" | sudo tee /etc/modprobe.d/rtl8723be.conf

This trick makes possible a new management of the card and its prevent the card to go to suspend mode.
You must restart your computer after use this command,  or reload the driver with these commands:
sudo modprobe -r rtl8723be
sudo modprobe rtl8723be

More info about this known bug for Ubuntu 14.04 and derivates at:
Ubuntu bugs at Launchpad
If this option doesn't work, you can install a new Realtek driver from the rtwifi_new repo:
sudo apt-get install linux-headers-generic build-essential git
git clone http://github.com/lwfinger/rtlwifi_new
cd rtlwifi_new
make
sudo make install

And then reboot or reload the driver how it explain before.


What are good resources to get fantasy names?

Question: I have trouble coming up with fantasy names. I've used random name generators but they weren't very helpful. Is there a website that would have fantasy names or Norse, or Celtic names?
Comment: You could add a bit of more information on why they weren't heplful, maybe? What didn't work with them?
Comment: Try to find out the kind of sound you want - rough, smooth, wobbly. Study the dictionary, concoct your own words or borrow and twist from  language that suits your requirement. I would suggest you build your own names so that you can control the sound and have exclusivity, which might be lost if you use random generators on the web.
Comment: You might be interested in my old question [Coming up with names for species in fiction?](https://writers.stackexchange.com/q/6002/2533)
Answer: Read literature from the country or period you want to write about.
If you want to write about norse mythology, open the Edda and get names there. If you want to write about the french revolution, open Diderot and find names there. And so on. Read history, read sagas, read original literature. There is your source.
If you want to write about a fantasy world, which is inspired by some historical period, it's a bit more tricky than that. You can still use existing names from inspiring works (for instance, all the dwarves in "The Hobbit" take their names from characters from the norse Edda. "Gandalf" comes from there too. And no, they are not copyrighted). But if you want your fantasy world to be more original, you need to work on your world building and decide some linguistic rules, so that your names are consistent with that. This is probably what doesn't work with random generators: they are not based on a language-world. Adherence to a true language is what makes names be meaningful: this is all which Tolkien's work is based upon. (On a personal note, I strongly believe that fantasy is based on language mostly).
A final additional hint: if you want to write about a contemporary world, just watch the ending credits of a movie, and pick a random guy from there.
Answer: Since many authors use name generators, the names on these sites would have been used already. One tip I found helpful is to grab two or three names and try to create your own unique one. That way, you won't open a book and find the same exact name.
Ex: Take girls baby names: Ase and Alvilda and combine- Asevild.
As for where to find them, just Goggle: Celtic baby names or Norse names and you'll get results.
Comment: Remember to check for the name in a dictionary, as well... For example, people liked the name Katrina but found it too common, so they decided to alter it a bit and named their daughter Latrine.
Comment: Why do you believe names should be absolutely unique? I think it's kind of the idea behind names to have a small corpus of names which people can easily remember, but big enough that most people in any circle have unique names.
Comment: "Since many authors use name generators, the names on these sites would have been used already. One tip I found helpful is to grab two or three names and try to create your own unique one."

- This is exactly what name generators do: they split names from existing datasets into pseudo-morphemes and combine them to produce new names.
Comment: @DavidMulder: There's not very much overlap between names from unrelated cultures. Since the OP is asking for names for a fantasy universe, it makes sense to avoid names already used in different fantasy universes. (Personally I'm skeptical that the names from name generators have been skunked by overuse, but it's not an unreasonable concern.)
Answer: An easy way to get names is to first define a few characteristics about the person you want to name. Are they:

humble?
fast?
strong?
reliable?
tall?
tiny?
beautiful?

Then enter these words into a translation engine of your choice in a handful of languages and look at the result. You will probably get a few ideas for possible names by playing around with these translations. It definitely helps in getting to know your character more, so this procedure can't hurt. And even if you don't find a good name, you might get ideas for nicknames.
Examples from above with google translator:

humble -> Latin: humilem -> Humi sounds like an interesting nickname
fast -> Greek: grígora -> Grigor sounds like a good name, similar to Gregor
strong -> Irish: láidir -> Laidir sounds similar to leader; possibly a good name for a person of high rank
reliable -> Hungarian: megbízható -> Megbiz sounds interesting and Meg as a short nickname sounds pretty normal, which is unusual and therefore interesting in fantasy
tall -> Belarusian: vysoki -> Vysok sound good after taking out a single letter
tiny -> Arabic: saghir jiddaan -> Sagh Jiddaa sounds like a good name for a noble person
beautiful -> Malagasy: tsara tarehy -> Tsara sounds like a good name already and I even got a second name, Tarehy

You should probably use a language that your readers might not necessarily be familiar with so that the names sound more foreign - using a German translator for a German audience might not yield the best results for example.
If you already have a preference for the orignating language you can should of course focus on that one in your translator-assisted search. But getting input from other languages can be good, too. In some cases you may want to combine one or two of them. Or you could use the names for something else.
From the examples above:

I could use Laidir as a rank in my fictional military, not as a name. Then I focus on the strongest warriors being able to get into that rank. Suddenly I have a perfectly valid name for a part of my military structure, with a defining characteristic that I can use to portray members of this rank.
I could use the name Grigor Megbiz. Doesn't sound like anything I have ever heard, shows two characteristics and the last name looks quite memorable, making it a perfect start for a family that values honour highly.
I could make the names I found titles like "The honourable Sagh Jiddaa enters the room: Tsara Tarehy. Under their breath I can hear people murmur her nickname from the time when she was still in the army: The little charmer. Nobody would expect someone with such an appearance, small and with eyes that would entice everyone who dared to look into them, to fight this fierce in battle. People were afraid - and thrilled at the same time." Suddenly I have a title and a full name, leading to a backstory that I could potentially use. Normally it would be the other way around, but if you use this approach you might learn something about your characters you didn't know before.

Probably only a handful of readers, if any, will realize these connections, making your names for characters, organizations, ... feel authentic and assisting you in always keeping in mind their most defining characteristics.
Comment: That's a nice method. In latin there is a sentence - *nomen omen* - meaning that your name says something about you.
Comment: most people just go with a name of a state plus the name of a flower..  like Texas Daisy.
Comment: @ashleylee I can't remember any fantasy creatures that were called "Texas". That might be good for real world related people or creatures in an American urban fantasy setting or something like that, but the moment you are outside the US and especially in a high fantasy setting I would use a different method.
Comment: @Secespitus: some might argue.. that depends on the fantasy.. :P
Answer: One of the latest Dungeons & Dragons 5E expansions, Xanathar's Guide to Everything, has a nice long list of fantasy name from different settings. It's available at Amazon for about 40 euros (or your regional equivalent). It might be overkill to buy the whole book just for the last pages, though, but you might be able to find a screenshot or scan around the internet?
Answer: Names can be pulled from real life or they could be pulled from eras or you could use a word mixer like scrabble or such and then just make it up.
For instance here are some real names people have gone by

Blooddarth (m) first name
Peteris (m) first
Dexus (m) first
Helly (unisex) first
Creature (unisex) first
Freegift (unisex) first
Amity (f)
Keina (f)
Custa (f)

Now lets take Keina for instance lets redo this lets try Kyna or Kelina or Ania now I made up a name.
Real last names

Barebones
Deper
Dethick
Railston
Burwenna

A name can be whatever you want or need it to be. I find taking the time to look for free readable sources is well and good.
This is a selection of nicknames for the 12th century https://ctstatelibrary.org/access-services/nicknames/
This is a dictionary of English surnames female https://www.s-gabriel.org/names/talan/reaney/
surnames but male: https://www.s-gabriel.org/names/juetta/parish/surnames.html
Baby names sites people often use these: http://www.babynology.com/
Answer: I personaly don't think high of random generators. They are often too cliché based and don't apply to the story I write.
I would suggest, that you think about an area, where your story takes place and where your character originates from. As example: If your character comes from a little, eastern island with a high regarded culture, full of honor and pride ... you wouldn't name him Karl or something like that. Then you would automaticly assume, that a name like Takeshi would fit a bit more.
Take the origin of your character in mind and mark out, what fits the characteristics most. If you have a snobbish, gentleman-like culture, you know that you should watch for british names as basics. If you have a wild, barbarian background with a warriors pride, then you should check norse names. Try to associate as much to the real world as possible, take names out of the context and then try to make your names, based on that context.
I think this method gives you more reliable names, with a large variation possibility and more authentic names, that match the setting much more.
This is not an ultimate weapon for name generation, but in my opinion it is the easiest way to get a good name.


How can I cut this semi rigid aluminum duct for my dryer?

Question: I want to cut a piece of semi rigid aluminum dryer vent duct - though in doing so I will be cutting one of the ends off that goes either into the dryer or the wall outlet for the hose - the "lip" will be missing on one end - what to do?
Answer: If it is simple Type A vent pipe you can just cut the pipe and then use a 4" coupling that has male ends on both sides.  You should use some mastic around the male ends of the union or just simply wrap some aluminum tape around to seal the joint.
Do wear gloves when you're cutting the pipe with tin snips to prevent cuts.
Comment: the vent pipe I have already has male ends though I have to cut one off to make the vent shorter...??? please clarfiy


Dragon 2 Propellant Capacity

Question: According to its wikipedia article, the Dragon 2 is powered by 8 SuperDraco engines. And according to the SuperDraco's article, each one of them can store up to 1,388kg of propellant at an Isp of 240s. Does that mean each engine has that amount of propellant? Even if I generously give the Dragon 2 a dry mass of 10t (e.g. including crew plus cargo), that would amount up to 1,7km/s delta-v. That seems to be quite a lot for a LEO-ferry. On the other hand, it is not enough for a moon landing. So what motivates this budget?
Answer: That's 1,388 kg of propellant for the whole vehicle, not per engine.
Reading the original document referred to by Wikipedia, it says 3,060 pounds of propellant for the Crew Dragon capsule.
(It's on page 8. The fuels are NTO and MMH and the combined weight of both is given.)
Answer: The Super Dracos are used for two purposes in the initial design.
Launch Abort System, and powered landing.
For LAS usage, they need to get away from an exploding booster, faster than the explosion wavefront.
For powered landing the ultimate goal is to let the capsule hits its aerodynamic terminal velocity and then finally brake in the last few seconds for a powered landing. Initial attempts (at least of DragonFly test vehicle) will be parachutes to reduce terminal velocity and then powered landing.
Their budget of thrust and time is designed around those two criteria. Using this as a Red Dragon (to Mars) is an interesting question as to how they will improve the fuel load for that mission, if at all.

Dragon 2 Propellant Capacity


Deck stairs pulling apart and railing wobbly

Question: My deck stairs which are supported by ledger strips keep pulling away the stringer.  Last year I used a clamp to squeeze them back together but they pulled away again.  The railing also is wobbly.  What would be the best way to fix the stairs so they are more stable?
Thank you
Comment: Flexing tread working on those minimal supports. that is a wide span for any tread.   even with standard stringers cut I would have one in the center
Comment: Do you know where I could find good instructions on how to add a middle stringer to pre-existing stairs?
Answer: Hard to tell whether you have screws or nails holding everything together right now. It is either nails - which can, relatively easily, come apart, or screws which can come apart but not as easily.
If you have nails then I would reinforce using some long (e.g., 3") screws and you should be set. I would want two screws into the end of each tread. The railing is sometimes a bit trickier, but screws to supplement the existing nails is a good start. If that doesn't take care of all the wobbling of the railing then you may need to replace parts or add some additional supports. Of course, if you find any cracked or rotted pieces, or if anything cracks when you drive in screws, then you need to replace those pieces.
If you already have screws then I'd be a bit more concerned as that may be a sign of the wood rotting (and therefore not holding the screws any more) or that there is just too much movement of the ground causing everything to come apart.
Comment: It is nails holding it together.  I will try the screws.  The railing is more difficult, I'm not completely sure where I would drive the screws in, possibly from the outside of the posts.
Comment: From the picture it looks like both stringers are easily accessible. Just drive screws straight through the stringers into the treads.
Comment: Misread your comment. Rail posts could be trickier. Screws at an angle may work.
Answer: Screws are a good idea.
Another fix that also would help vs flex would be to put a 2x4 under each step, oriented so the 2 inch side is up against the bottom of the step.  Attach the 2x4 to the step and the ends of the 2x4 to your stringers.
I would scout the neighborhood for scrap 2x4s for that use.  If you are going to buy new wood, replace that splintery looking top railing with the nice new 2x4s and use that old railing wood for under the steps.
Comment: I advise against scouting as you are unlikely to find pressure treated; I recommend buying a PT board.


Facebook message notification

Question: Is there away to make my phone stop beeping when I get a Facebook message if I'm already on Facebook on a different computer?
Answer: In my experience, if you reply on a PC to the person who is sending you the messages, the notifications will be silent on your phone. Other than that, it doesn't seem to be currently possible.
Answer:
Is there away to make my phone stop beeping when I get a Facebook message if I'm already on Facebook on a different computer?

Emphasis mine. No, there is currently no way for the Facebook app to only send you messages when the phone is the only device connected. The only option you have is shutting of certain kinds of notifications completely.

Facebook message notification


Paris CDG Arrival

Question: My flight will be landing at 7PM (Paris time) at CDG. So I think I would probably be reaching my hotel around 10:30 PM. Can anyone tell me how long does it take in Immigration Control? I will also be coming to Airport Terminal 2C. Can anyone please tell me how do I take the RER b train to Central Paris from that terminal?
Comment: Which airport? RER B runs both to CDG (direct) and to ORY (via Antony).
Comment: I will be coming to CDG. Do I have to switch terminals to take the RER B? Or its there in all terminals?
Comment: RER B has two stops at CDG: CDG 1, and CDG 2/TGV. The RER stations are directly beneath the terminals.
Answer:
As you can see Terminal 2C is directly connected to the RER Station. "Just follow the signs". It's a bit tricky to find the station first time and even trickier to get the right ticket from the machines, but there is staff there that can help you. Expect 13 € for the train ticket. Get some one-time tickets for the metro while you're at it - you'll need them.

The time at immigrations could be anything from 10 seconds to 2 hours. I haven't passed it there.
There are multiple stores there that will sell you a SIM Card - don't get scammed by them, some are super expensive.

I suggest using Google Maps for finding directions in Paris, it works really well with RER, metro and everything. Also, the kickscooters are very fun and the fastest way to get anywhere - just drive safe.
Answer: How long it takes at immigration varies a lot depending on your citizenship, your type of visa, whether you have status (elite frequent flyers and premium passengers often have access to fast track, depending on the airline), how busy it is, and so on. It is quite difficult to predict (unless you are an EU national with a e-passport and fast track, in which case it's usually a few minutes). I would probably budget up to 2 hours, though it may be much faster.
Charles de Gaulle has 2 RER stations, one of which is in the train station which sits right between terminals A, B, C and D on one side and terminals E and F on the other.
From Terminal 2C, once you have gone through passport control, reclaimed your bags, and gone through customs, turn right, and walk 300 meters, and there you are, the train station!
Take the first escalators on your left down two levels (follow the signs for "trains to Paris" / RER B), on your right you will find ticket windows and ticket machines. Make sure you are using the windows/machines for local trains and not for long distance. Buy a ticket, go through the ticket gates, and go down one more level to the platform (again, follow signs for "trains to Paris" / RER B).
All RER B trains go to Paris (and then on to various destinations south of Paris), though some are non-stop until Gare du Nord, while others will stop in stations along the way, it's usually better to take the non-stop (you'll have more space for luggage).
Comment: Could you explain how you purchase tickets? I found it very confusing.
Comment: @MikaelDúiBolinder At a window or at a machine? A regular one-way ticket to Paris? At a window it should be as easy as "X tickets to Paris please" and at a machine it's probably the first option on the screen.
Comment: I'm wondering... Maybe you tried to use the long-distance ticket machines instead of those for regional trains?
Comment: I used [the machines right above the platform](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT9G8XcU8Cg4NV3xT6l88sRgjtweu0yR94K5tCUvnPOVuMvZjfgCg). I refused to set it to English which made it a bit harder (only used Google translate for the numbers at McDonalds, practising my french). I tried to find some suitable multi day ticket, maybe even a return ticket to the airport etc.
Comment: Fast track on arrival immigration? Also, how does the type of visa figure into it? It's mostly French/EU/EEA vs. other passports. Even if you don't need a visa, you will end up in line with everybody else.
Answer: This webpage contains the following current details about taking the RER B from CDG to central Paris:
CDG to Paris Train Overview
Line => RER B (Blue) RER B Train
Direction => Paris (Robinson, Antony, St-Rémy-lès-Chevreuse)
Arrival Stations => Gare du Nord, Châtelet les Halles, St Michel/Nôtre Dame, Luxembourg, Port Royal, Denfert-Rochereau, Cité Universitaire
Ticket => "Billet Ile-de-France" Aéroport CDG – Paris (Zone 5 -> Zone 1)
Cost => 10.30€ (adult fare) / 7€ (children 4 – 9) / free (children under 4) Prices as of June 1, 2019
Passes Accepted => Paris Visite, Navigo Pass, Navigo Day Pass, Ticket Mobilis
First Train / Last RER B Train CDG to Paris => 04:56 / 23:50
Comment: I follow the signs. Works every time.
Comment: Could you explain how to get to the station from Terminal 2C?

Paris CDG Arrival


Upgrade from Loki to Juno

Question: I know if elementary Juno still development, but for waiting new version i want to ask ease way to upgrade without clean install?
Answer: There is no upgrade path from Loki to Juno (at least for now).
As Juno is not yet released you also can´t really install it now. You could install Ubuntu 18.04 and use the unstable PPA to setup an environment very similar to Juno, but that is not recommended unless you are an developer.
Comment: Could you update your answer? Mention that Juno is available. (Clean install recommended)
Answer: There is a project page for it on GitHub, but everything there is still on the to-do list. We would need some word from the project lead as to whether this will certainly be implemented, and if so, when can one expect it relative to Juno's release.
https://github.com/orgs/elementary/projects/20
Answer: Long story short, the team recommends doing a clean install.
You could also try using a backup tool like Aptik, but when upgrading this will requires a couple of advanced extra steps.

Use Aptik to backup almost everything to an external disk. Exclude the Dconf database, because this will most likely include version specific information and structures. (This is one of the checkboxes in Easy mode).
Do a clean install of the new version of elementary OS.
Use Aptik to restore everything from the external disk.
Go through your repositories (ppa's) and remove the ones that are unused or unsupported.

Run the following command to pretty print your current repositories:
grep -r --include '*.list' '^deb ' /etc/apt/ | sed -re 's/^\/etc\/apt\/sources\.list((\.d\/)?|(:)?)//' -e 's/(.*\.list):/\[\1\] /' -e 's/deb http:\/\/ppa.launchpad.net\/(.*?)\/ubuntu .*/ppa:\1/'
Go through them and update or remove all repositories which ubuntu code name doesn't match the codename of your new version. (If you don't know how, you should probably not be doing this)
Attempt running sudo apt update.
Remove repo's that can't be retrieved.

I've not tried this myself but one could also try not backupping the Repo's and Packages, but then you'll need to reinstall them manually on the new version.
I'm definitely open for better ideas on the packages and repo's.
Answer: elementary OS does not officially support an upgrade from 0.4 to 5.0.
That being said elementary OS is based on Ubuntu which is based on Debian. So the Debian upgrade path should work, right?
Big fat disclaimer: This is for experienced users and is obviously unsupported. It might break your system or it might leave your system in a way that is almost-but-not-exactly elementary OS 5.0. If something doesn't work quite right after the upgrade, don't expect help from the nice folks from elementary, who specifically chose not to support this kind of upgrade.
I did the following in a VM and it worked flawlessly for my installation.

Update all packages and make a backup!
Save all your work and logout (so you get to the login screen)
Drop to a console terminal with Ctrl + Alt + F1;
Do NOT do the following in a UI terminal, it will most probably fail and leave you with a broken system
Login and start a root shell with sudo -s
Stop the UI: systemctl stop lightdm
You need to update /etc/apt/sources.list and /etc/apt/sources.list.d/{appcenter,elementary,patches}:
Change every occurence of xenial in those 4 files to bionic. Save and exit your editor.
apt update
apt dist-upgrade
When it asks you about a modified config file, install the new one with 'Y'
reboot

If everything went well, you will boot into your updated elementary OS 5.0. I can't tell if the experience is exactly the same, but to me it looked perfectly fine and I couldn't find anything that doesn't seem right, other than some missing app icons on the dock that were previously there. That is a quick fix, though. Just add them back with drag'n'drop.
Comment: Don't do this. If you look at the following project you'll notice that it's more than updating the sources.
https://github.com/orgs/elementary/projects/20
You'll be much better of using a tool like Aptik. (don't backup the dconf database)
Comment: It worked for me perfectly fine and I am using this system regularly. I clearly stated that this method is not supported. And indeed the OP asked specifically about a way to upgrade *without* clean install.

Upgrade from Loki to Juno


Which tools can help limit maximum page view per IP to limit scrapers and bots?

Question: I would like to prevent scrapers grabbing all my content except Google, Bing and other search engines. I am thinking of going with Fail2ban and limiting hits from an IP maybe at around 1000 per day. Is this a good idea? Would there be a better way?
Comment: There could be thousands of people behind 1 ip address.
Comment: Fail2ban uses iptables which is before Apache, maybe Fail2ban is more efficient from that point of view, as the request never reaches apache.
Comment: Can be done on Apache Level.
Comment: @bybe Do you have an example how this can be done "on Apache level"?
Comment: @DisgruntledGoat added many possibilities for you in my answer below.
Answer: There are many ways this can be done within Apache using Modules, or alternatively you can setup IP tables to do the job though personally I just use the modules.
mod_security
I've personally used this and it does the job well, a good article about limiting requests can be found here.
mod_evasive

Detection is performed by creating an internal dynamic hash table of
IP Addresses and URIs, and denying any single IP address from any of
the following:
Requesting the same page more than a few times per second
Making more than 50 concurrent requests on the same child per second
Making any requests while temporarily blacklisted (on a blocking list)

Another one here:
mod_qos

The current release of the mod_qos module implements control
mechanisms to manage:
The maximum number of concurrent requests to a location/resource (URL) or virtual host.
Limitation of the bandwidth such as the maximum allowed number of requests per second to an URL or the maximum/minimum of downloaded
kbytes per second.
Limits the number of request events per second (special request conditions).
It can also "detect" very important persons (VIP) which may access the web server without or with fewer restrictions.
Generic request line and header filter to deny unauthorized operations.
Request body data limitation and filtering (requires mod_parp).
Limitations on the TCP connection level, e.g., the maximum number of allowed connections from a single IP source address or dynamic
keep-alive control.
Prefers known IP addresses when server runs out of free TCP connections.

mod_dosevasive

The IP address of the client is checked in the temporary blacklist of the hash table. If the IP address is listed, then the client is denied access with a 403 Forbidden.
If the client is not currently on the blacklist, then the IP address of the client and the Universal Resource Identifier (URI) being requested are hashed into a key. Mod_Dosevasive will then check the listener's hash table to verify if any of the same hashes exist. If it does, it will then evaluate the total number of matched hashes and the timeframe that they were requested in versus the thresholds specified in the httpd.conf file by the Mod_Dosevasive directives.
If the request does not get denied by the preceding check, then just the IP address of the client is hashed into a key. The module will then check the hash table in the same fashion as above. The only difference with this check is that it doesn't factor in what URI the client is checking. It checks to see if the client request number has gone above the threshold set for the entire site per the time interval specified.

Iptables Solution
iptables -A FORWARD -m state --state NEW -m recent --rcheck --seconds 600 --hitcount 5 --name ATACK --rsource -j REJECT --reject-with icmp-port-unreachable

iptables -A FORWARD -d 127.0.0.1/32 -o eth1 -p tcp -m tcp --dport 80 -m recent --set --name ATACK --rsource -j ACCEPT

Comment: Great answer! After a bit of research yesterday I also found `mod_evasive` which looks good.
Answer: A CDN service could sit in front of your site and filter out known crawlers; they also filter out spammers and since they cache your images at locations around the world your site would be faster.
I have been using CloudFlare for about a month on a site for a client and they have seen a decrease in bandwidth use, and an increase in traffic. CloudFlare also offer a free app called scrapeshield https://www.cloudflare.com/apps/scrapeshield but scraping isn't a big problem for that site, so its not caught anybody yet
Answer: There is an Apache module called "robotcop" that is designed for this particular purpose.
Unfortunately, the website for that Apache module (www.robotcop.org) is no longer in service.    Here is a slashdot article announcing the launch of the robotcop module.
The (open source - Apache license) source code for the module is still available from various places:

http://fossies.org/linux/privat/old/robotcop-src_0.6.tar.gz/
http://slackware.org.uk/people/alphageek/pending/robotcop/http://slackware.org.uk/people/alphageek/pending/robotcop/
Answer: Another approach to limiting scrapers and bots would be to implement a honey pot.  Put a page up that only bots would be able to find and restrict bots from accessing it via robots.txt.  Any bot that then hits this url would get blacklisted.
WPoison is a project that provides the source code for doing exactly that.
Answer: I think the most efficient ways to limit unwanted hosts and IP's are:

Block them outside your server to reduce the load on it.
Use internal IP filtering/firewall rules, which reduces the load on your web server application.
Bock them using your web server.

The first requires dedicated hardware or a proxy server.
The second can be done via a control panel (e.g., cPanel, Plesk, etc...), or manually by creating IP filtering/firewall rules (covered in other answers).
The third can be done in IIS via its GUI, in Apache using modules (covered in other answers), or in Apache's configuration like this:
# Block unwanted host domains
RewriteEngine on
RewriteCond %{HTTP_REFERER} baddomain01\.com [NC,OR]
RewriteCond %{HTTP_REFERER} baddomain02\.com [NC]
RewriteRule .* - [F]

The later is a good option since you won't be banning specific IP addresses or classes, which might preclude schools, large businesses, or libraries that use NAT (a single outgoing IP address).
You can often spot frequent scraper and bot hosts in your web server's access and errors logs, which is easy to do using a stats application.


Can't find Faendal Skyrim Remastered

Question: I told him it's time to part ways when I was working with the Grey Beards but now I went to re recruit him and I cannot find him. I'm nervous that he died on his way home - can that happen or do I just need to wait a while? He has all my good loot that I didn't want to carry, so I really need to find him.
Comment: Are you looking around Riverwood? It's possible that he died on the way home, but unlikely. I've sent him home dozens of times without an issue.
Answer: Where Do I Find Him?
Faendal lives at the town of Riverwood, so try going to Riverwood. Normally he's seen carrying wood back and fourth near the lumber mill, or even at his house (near the back of the town, near Ralof's friend's house).
If you can't find him, wait for a few hours/days and he might appear.
Did He Die On The Way Home?
The fact that he died on his way home is false, due to game chunks (the only exception is if you were at the location where Faendal is getting killed, but you said you looked in Riverwood and you were at High Hrothgar.
Comment: I wouldn't say that the possibility of Faendal dying is completely out of the question... the exterior cells for High Hrothgar are pretty large, and he could have died as soon as he started down the mountain (or fell off) without the player noticing. I agree with the suggestion to wait for a while -- that's worked for me in the past when I've had trouble finding him.
Comment: Glad we agree. I only responded with that comment, because the wording of your answer suggested (at least to me) that such an occurrence was impossible.
Comment: @pushasha what do you mean? We don't know where the player was right after Faendal left. Perhaps the player was still in High Hrothgar talking to the Greybeards, since he said he was working with the Greybeards. He might be going outside, but most likely, Faendal is gone due to chunks.
Comment: You're right -- we don't know where he was. That's why I said it's not something to completely rule out. He didn't say he was in the interior cells of High Hrothgar, so he could have been outside for all we know. Perhaps the part of the game where the graybeards help you learn Whirlwind Sprint? I'm not saying that your answer is wrong, I'm just saying not to rule out the possibility without further details from the asker.
Comment: @pushasha it's possible, of course, but most likely not.
Answer: One should be aware that Faendal's commute between home and work is, to say the least, "scenic".  I frequently find him on the path in the hills south of town.
Answer: I would follow this page:
https://gamefaqs.gamespot.com/pc/615805-the-elder-scrolls-v-skyrim/answers/300694-what-is-the-console-command-for-moving-an-npc-to-you-or-you-to-it
and this page to find his code:
http://elderscrolls.wikia.com/wiki/Faendal
then press the key to the left of the 1 (`) to open the in-game console.
Press the (`) key, then type
prid 0001348c (then the ENTER key)
resurrect (then the ENTER key)
(which should now give you some letters and numbers)
then type
player.moveto 0001348c (then the ENTER key). to bring him to you.  If he's dead, you may have to enter "resurrect 0001348C".

Can't find Faendal Skyrim Remastered


Display 1 of each item in a sharepoint list

Question: I'm trying to configure a sharepoint list view in Sharepoint services 3.0 to display one each (based on a column) of the latest item. For example, I have 4 Items in my list, two are "Apples" and two are "Oranges". I would like my list view to just display 1 of the latest Apple and 1 of the latest Orange (I would still like this to be the case if there were 500 apples and oranges in my entire_ list. Is there any way to do this in one view without having to setup two seperate views ?
Comment: I think you also don't like using a data view webpart or coding your own custom webpart?
Comment: Dataview or Sharepoint designer work is ok, but if it can be done in sharepoints web interface that would be best.
Answer: Unfortunately I just couldn't find a way to do this with Sharepoint, nor Sharepoint designer or with XSL (not that I tried much XSL). My solution in the end was to apply the following style to the page to remove borders around webparts (you can just use a content editior webpart to apply it to one page )

<code>.ms-PartSpacingVertical
{
    margin-top: 0px;
}

.ms-PartSpacingHorizontal
{
   width: 0px;
}
</style>
</code>
(Source:http://havivi.blogspot.com/2009/08/removehide-empty-space-between-web.html)
Then using sharepoint designer add a dataview item with paging set to one, add a filter for the item type you want, and sort by date modified descending, to make sure you get the latest item. Delete the header row and set the chrome to none You'll have to fix column widths to get it to line up correctly and do some formatting to get it right. Not sexy but it works.
Answer: I think scenario is complex enough not to be achieved by OOB views. I even doubt if you could achieve this CAML query. Regardless, if you find the answer, please post it.
This can be achieved with Event Receivers and View though. You can have an additional field (try to make it hidden) (say ShowMe) with default value "false". In ItemAdding event, you can query the list and see if there is any record already exist and if yes, Set the ShowMe=false for that record and ShowMe =true for current record. Afterwards, you can filter the view with ShowMe=true.


How do I uninstall Ubuntu from my MacBook and replace it back to mac?

Question: I recently switched my old 2006 I believe MacBook to Ubuntu because I wanted to try it out for a couple of things. I decided to reformat since I didn't have the space to dual-boot, but now when I want Snow Leopard back for my MacBook it doesn't let me install. It asks what disk I want to install to, but none show up. Any help? Thanks.
Answer: You have to format your HD back to HFS+ first, thats the filesystem OS X needs to be installed on, you can do this using the installation disk.
So after booting from cd just click on Utilities on the top tabs, select Disk utility and reformat your HD to Mac OS Extened Journaled
after this is done you'll be able to install OS X again.
Answer: You should first boot from Live CD and there format with gparted, then install OSX again.
Answer: You need to have either a Linux Live CD like System Rescue CD or Ubuntu Desktop CD to boot and reformat the HDD (gparted is a good GUI tool) to HFS+ so as to install OS X (10.6). Otherwise if you have a OS X 10.6 Install DVD, you can boot (press option) with the install DVD and use the Disk Utility to delete the Linux partitions (or LVM stuff) and recreate partitions, reformat as HFS+, then install on the desired partition.
If you just want to try something out on Linux, running it as guest OS using VirtualBox may be a better/free option;-)


What is the risk of leaving the MAN START PB 'ON' on the A320?

Question: During a manual start on a A320, the ENG MAN START P/B opens the start valve which then runs the starter motor. During the MAN START process, at some point, the start valve closes automatically. What are the risks associated with continuing to leave the MAN START P/B ON at this point?
Answer: Well, documentation is a bit vague about this, and I suppose a technician would know more about the different things the ENG MAN START bp is doing, but from a quick glance at the FCOM there is one major difference that I can spot:

[The FADEC durring a manual start]  (...) Closes the engine start valve, and cuts off the ignition when N2 reaches 43 %.

Bold emphasis is mine, no other conditions except N2>43%.
Leaving the ENG MAN START pb on means FADEC keeps assuming we are trying a manual start, and will cut off ignition anytime the N2 is above 43%. No prob as long as engines are running, right?
But that means (I assume) when you then enter turbulent/stormy weather in flight and turn on  IGN/START to prevent a flameout, nothing happens as FADEC is happy that N2 is above 43% and you manual start has been 'succesfull'.
I don't really know if it will even attempt an auto restart when you get a flameout, as the N2 will probably keep windmilling for some time depending on your airspeed, so you could end up with a big problem.
Comment: From a technician standpoint, your answer is very close. I can't give an official answer because I don't work the A320, but these systems are pretty standard on any jet. Starter cutout on most aircraft engines is usually somewhere between 42-50%. In the case where starter disengagement fails to happen, you don't have long before the starter shaft shears - which will usually happen somewhere in the ballpark of 55-60%. If you want to make friends with your local mechanic, this is not the way to do it. In the rollback scenario, engines should automatically "continuously relight."
Comment: I too agree the FCOM is vague, but few things I noticed: 1) 'Man start' can be used in flight for an in flight relight 2) In flight, the continuous ignition "*is on when the ENG START selector is on IGN/START, **if** the corresponding engine is running.*" I take it that means if the engine is running, the logic is different 3) No warning message if the pb is left in the pressed position.
Answer: To my understanding, the input from the MAN START switch (a ground/open discrete into the Engine Interface Unit), is only taken into account by the FADEC logic if the engine is not already running. Once the engine control logic goes into running mode (i.e. N2 rises above idle), it will stay in that mode until the engine master lever (EML) is set to Off, regardless of whether the engine is lit or not.
In other words, once the engine has started, the position of the MAN START p/b is irrelevant, even if the engine flames out (however, note that the FCOM procedures for engine failure often call for the EML to be set to Off, at which point the position of the MAN START switch comes to play in any subsequent attempt to relight the engine).
One risk I can think of is that if you are on the ground, shut the engines down, or even power off the aircraft, then when you power everything back on and attempt to start an engine (i.e. turn the engine start selector to IGN), the autostart procedure will be inhibited by the MAN START switch being already on, and the FADEC will go into manual start mode instead.
If you then immediately set the EML to On (which wouldn't be a problem during a normal autostart), fuel would start to flow right away, while the engine may still be below the required minimum N2 for fuel admission (16%), therefore the engine could fail to start or worse (an engine fire).


How do I make sure I'm sitting straight on a recumbent?

Question: I have recently (at the time of original posting) taken up cycling a recumbent (a now discontinued Azub Eco 20" bicycle). My perineum thanks me, but immediately after a ride I feel a bit lopsided (more than usual). I presume I'm not sitting quite straight on the bike (or the seat isn't quite straight) so I am always leaning slightly. Is there an easy way to check whether I'm correctly positioned? (Or is it just my body that's asymmetric?)
Comment: Did you ever resolve this?  I know I don't sit perfectly straight.   In these days of cameras, is it possible to get someone to ride with you and record your ride from front, side, and from the rear?  You could try a selfie stick but holding that will modify your body position anyway.   Please feel free to add your own answer that shows what's happened since this question was asked.
Comment: @Criggie No. Other than moving somewhere with roads too scary to ride anything at all.
Answer: I'm not aware of a 'specific' way but I'm fairly certain that if you got the bike frame vertically level then placing a level across your seat would show you if the seat is level.
Answer: Part of the problem is that you're riding a trike, and that roads aren't flat, so you're continuously on a slight lean.
Its totally normal and to a large extent unavoidable.
You might be able to fit shims in your seat mounts to help angle the seat away from the camber of the road.  The boom might be able to rotate a couple of degrees too, without causing significant problems to the chainline.
Comment: Good advice if it was a trike, but it's the now discontinued bicycle. Shame as it was much cheaper than the Azub Bufo (the frame isn't bent - cheaper to build but longer and, I assume, less stiff).


Specify GPU device with OpenCV Python API

Question: When working on a project using Tensorflow (w/ GPU support) to process some features extracted from OpenCV (3.4.3, using Python API) captures in real time, I am getting the following error from cuDNN whenever I try to read from the capture after I start the tf session:

F1028 02:37:31.456640 xxxxx cudnn_conv_layer.cu:28] Check failed: status == CUDNN_STATUS_SUCCESS (8 vs. 0)  CUDNN_STATUS_EXECUTION_FAILED

I suppose that the issue is with OpenCV and Tensorflow both using GPU via CUDA at the same time and that the GPU ran out of memory. The workaround I am currently using is to start capturing with OpenCV first, and then start the tf session whenever it is actually needed. This way, TensorFlow knows that the GPU is busy and opted to use CPU only. However, the frame rate drops significantly as a result.
Considering that I only use OpenCV for capturing and basic preprocessing, I don't think GPU support is necessary and it would be preferable to let TensorFlow use the GPU.
Is there a way to specify which GPU device to use with OpenCV Python API (or if it should use GPU at all)? I see with the C++ API there is a setDevice() method under the gpu namespace. Is there an equivalent for the Python API?
Answer: Here is the equivalent call for the Python API, it is under 'cuda':
cv2.cuda.setDevice(int device_id)

Source


How well can we test for deadly reactions to a drug, like anesthetics for an operation?

Question: Since I still hear about people dying from adverse effects of anesthesia, prescription drugs, and clinical trials, we obviously don't have a perfect ex vivo test for adverse reactions to arbitrary drugs. But what DO we have, how effective are they, and are there any up-and-coming techniques in research?
Comment: What have you discovered so far in your research on this question?
Comment: I think a better version of this question would be through which stages a medication has to go through until it can be officially used, which wouldn't be too broad and answerable.
Answer: The only way to know if a drug is going to kill you, or have a serious side affect is to take it and see what happens. However, there are usually many ways to predict risk of such reactions. Researchers do their best to figure this out in the drug development and testing stage, so each drug that get's approved will come with a list of contraindications (conditions that have been determined to put you at greater risk of the side effects).
There's no such thing as a general drug safety test - nor could there ever be, since each potentially deadly reaction happens in it's own way. Researchers do attempt to identify the mechanism behind serious drug reactions. Once that mechanism is identified, then they are sometimes able to develop tests for susceptibility to that particular mechanism, but this is typically on a case by case basis. In some cases, a particular mechanism might apply to a whole class of drugs so one test can help predict a potential negative affect to any drug in the class.
Anesthesia
There are various risks associated with anesthesia - all of which are very rare. They include interactions with other drugs and conditions, as well as human error (overdose, etc.). One significant cause of death directly due to a reaction to anesthesia itself is due to something called malignant hyperthermia. The first manifestation of this is typically in the operating room, so it's difficult to predict. It seems the only approved test involves a muscle biopsy (they have to take a cell sample from a muscle), so this is only done if you have a family history of the condition. Research on less invasive tests is ongoing and promising, including a genetic test and an injection test
Drug allergies
Many drug reactions (including some deadly ones) fall under the category of what you know as an 'allergy'. Often times these reactions can be tested with a skin or blood test.
Other types of reactions
This list can go on and on, so I'll just refer the interested reader to a paper that does a much better job than I could: Adverse Drug Reactions: Types and Treatment Options
Comment: "*The main deadly reaction caused by general anesthesia is due to something called malignant hyperthermia*" - this does not sound correct to me at all, can you provide a citation? You might be correct if you limit to interactions with a known genetic contribution, but I think the statement as-is is far too general a claim.
Comment: Ok, I added a source and clarified what I'm saying. Anesthesia is dangerous for various reasons. However - as far as I can find - the only common cause of death due to a *reaction* to the anesthesia itself, is malignant hyperthermia. Since the question was about reactions, I didn't really say anything about overdoses, preexisting conditions, etc.
Comment: I think you are using the term "reaction" more narrowly than I am familiar with it being used. "Reaction" in my view is broad enough to encompass things that you might more often hear referred to as "side effects." Respiratory/cardiac depression, aspiration, etc. Certainly preexisting conditions can influence susceptibility to those sorts of side effects, as well as other unknown contributors to the person-to-person variance of drug effects.
Comment: I don't think things like overdoses were what the author was referring to. Most of the other causes of death seemed to be related more to human error, or other unrelated medical complications - in other words, they aren't really caused by the drug itself - so I don't think they are what the OP was asking about. I changed the language in any case to not give the impression that MH is the only risk associated with anesthesia.
Comment: Okay, thanks for the edits. I'm probably just being a bit pedantic because it's an area I am active in research, and all those 'other causes' are actually quite important to anesthesiologists; there is a constant desire to help identify those patients who are at risk of anesthesia-related complications, with knowledge that some simply cannot be avoided (e.g., when you are trying to save lives with surgery, no matter the skill and knowledge of everyone involved there will be a border where people cannot be saved).


Which studio strobes are compatible with the Yongnuo YN-622C?

Question: I currently have 2 pairs of Yongnuo YN-622C Wireless TTL Flash Triggers for Canon. I'd like to use them to wirelessly trigger studio strobes and I'm wondering if anyone knows the compatibility of the different monolights with these units. I tried using them with a pair of Impact 300Ws but couldn't get them to work at all. Possibly I'm not using them properly? I'm shooting with a Canon 60D and it doesn't have a PC port, (what's up with that anyway??) so I used a YN-622C and a PC cable to sync one from camera to the strobe and had misfires and random firing issues. I ended up bagging it and turned the slaves on the units and bounced my flash off the ceiling... totally a newbie in the studio here... I'd like to get some monolights, and and I see Yongnuo has one but I'd prefer them to have a built-in battery pack, anybody know if there are other options?
Comment: You'll do a lot better here on Photo.SE if you separate out multiple questions into, well, multiple questions. I'd recommend editing this one to be just about using the YN-622C triggers with monolights.
Answer: All studio strobes are compatible with YN-622C's.  YN-622C's are overkill though because the studio strobes will not be able to take full advantage of the ETTL and HSS features. You really just need a simple radio trigger.
Yes, you may be using them improperly.
To make the YN-622C's work with your 60D and strobes you just need to mount one YN-622C in the hotshoe. (no need for a PC cord)
The other YN-622C will need a PC cord in order to trigger the studio slaves.
Comment: "To make the YN-622C's work with your 60D and strobes you just need to mount one YN-622C in the hotshoe. (no need for a PC cord)

The other YN-622C will need a PC cord in order to trigger the studio slaves."
Comment: Hi Mike! Thanks for your response!  I connected one YN-622C transmitter on my camera's hotshoe, and the other YN-622C on the monolight with the proper PC cord, and exactly nothing happened... I checked that they were on the same channel...and still did not get a result. So I have no idea what I'm doing wrong, or if it's a compatibility issue? (I watched a youtube video on how to do this, and it seemed so easy peasy....)
Answer: The PC sync ports on a YN-622C are output-only, not input.  They are solely to be used to hook a flash up to a receiver 622 unit, NOT to be used as an output signal from a camera hotshoe.  If you want to sync over a PC cable, you have to get a hotshoe-to-PC adapter for your camera, and then cable the hotshoe to the flash's PC port.
To use YN-622C units with a studio flash, you put a YN-622C as your transmitter unit on the camera flash hotshoe. Then you cable the PC connector on your receiver YN-622C unit up to whatever sync connector the monolight uses--most typically 3.5mm miniphone or 6.35mm phone connector, but could also be household (HH), or just about any connector that can communicate a simple short.
A quick checklist for radio triggers misfiring:

Are all the batteries in everything (camera, flashes, and trigger) in good health and fully charged?
Set both units to the same channel. Then, off the camera and flashes, does hitting the TEST button on your transmitter unit fire the receiver unit? If not, your triggers may be bad.
Connect the receiver to the studio flash with the PC cable. Make sure all connectors are fully seated.  Does hitting the test button on your transmitter fire the flash? If not, the cable or ports are probably the issue.
Connect the transmitter to your camera. Check that the unit is fully seated (push it forward as far as it will go).  Is your camera's flash menu control set to use flashes in M mode (not TTL)?  Studio strobes cannot do TTL, HSS, 2nd curtain, etc.  You have to have the camera assuming the flash is in M.  Does firing the camera fire the flash? If not, something may be mis-set, the unit may be misseated, or your hotshoe may need cleaning.

See also: The Other Yongnuo YN-622C User Guide and the YN-622C/YN-622C-TX thread on POTN.
Comment: Thanks so much for your response, inkista.The first part of your response really helped me understand what the PC output on the transmitters are meant to be used for! But as far as the rest, I think I did try exactly that... I connected one YN-622C transmitter on my camera's hotshoe, and the other YN-622C on the monolight with the proper PC cord, and exactly nothing happened... I checked that they were on the same channel, and tried different channels, but nothing, nada, zip. (I watched a youtube video on how to do this, and it seemed so simple....)
Comment: @M.Lutz, since we can't see how your gear is set up by telepathy, and asking you individual questions one by one isn't how this works, I've added a general troubleshooting checklist, and some references, so you can try and suss it out yourself. Good luck!!
Comment: Thanks again for your response, the checklist and the link to the Other User Guide, I found it immensely helpful!


"Duplicate" Posts Appearing Since 3.1.2 Update

Question: I've encountered some issues on a clients site since upgrading to WP 3.1.2, and have this evening updated to version 3.1.3, only to find that the problems still persist.
http://www.harmonyreins.com.au
The website is for a local animal shelter, and each post represents a different animal that lives at the shelter.  There are a number of categories that specifically relate to the type of animal, such as dogs, cats, horse as well as a "recently adopted" and an "old friends" category.  Those last two categories were excluded from the full post list (under 'Meet The Gang' in the navigation) using the following code:
<?php query_posts($query_string . '&cat=-10,-12'); ?>

The upgrade to WordPress 3.1.2 (or the accompanying database update, I'm not sure which) made this code redundant, and the excluded posts began appearing in the 'Meet The Gang' section.  I enquired about the issue on WordPress.org, and the following fix was suggested:

Chris,
Replace the following in your theme's index.php
<?php query_posts($query_string . '&cat=-10,-12'); ?>
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>

with
<?php query_posts('cat=-10,-12'); ?>
<?php if ( have_posts() ) : while  ( have_posts() ) : the_post(); ?>

and you should be good.

Unfortunately this resulted in another issue, displaying the posts from page one of the list on page two also (you can see what I mean if you go to the site).  I've tried multiple pagination plugins with no success.  Regardless of what page you're on, only the first ten animals are displayed.
My client has been really good regarding this issue, but it's been going on for weeks now, and I really need to get it solved.  Hoping someone can help me out.  :-)
Comment: just checking: are you using `global $query_string;` before the query? alternatively, you could try: ``
Comment: @Michael please add that as an answer so it can be voted on and/or accepted
Answer: are you using global $query_string; before the query?
so that the full line looks like:
<?php global $query_string; query_posts($query_string . '&cat=-10,-12'); ?>

alternatively, you could try:
<?php query_posts('cat=-10,-12&paged='.get_query_var('paged')); ?>

Answer: Your query_posts() should also contain information about the page you are on, for example by passing the paged parameter.
But doing your own query_posts() with paging is a recipe for problems. WordPress already does a query for you, it's better to change this query. Otherwise it is possible that WordPress finds more or less posts than your query, which will mess up paging.
Can you explain how your Meet the gang page works? Is is a Page with a special template that loads the posts? Or do you work with a static front page and is this the posts page? I would hook into pre_get_posts and add the correct category part of the query there.