Is there a way to determine if an recipient email address is invalid
How to validate an email address using a regular expression?
lsusb relevant output Bus 001 Device 006: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812AU 802.11a/b/g/n/ac WLAN Adapter  Upon plugging the device it is recognized by lsusb, however when I go to wireless settings no adapter is recognized. The driver is installed (by going to software and updates -> addition drivers and selecting the open source driver). How can I restrict the Normal user to run the only limited set of commands in RHEL? Allow sound file uploads in questions and answers? Should Stack Exchange introduce the ability to upload embedded sounds (maybe via HTML5/Flash, whichever the user has) as part of questions and answers to Stack Exchange?  It could require a certain amount of rep to stop new users from doing it frivolously.  My rationale behind this is the new language &amp; usage sites.  I often find myself thinking that it might be helpful, when discussing a regional dialect or something, for the person answering to just pronounce what they're trying to describe in words. R linear regression categorical variable "hidden" value I'm asking about someone who's employed by a company and does different jobs (both a qualified and unqualified person). Who knows; maybe in English those two are two different words? What are they called in English?  All I know is a navvy but that usually means physical work.  Let me just try a few things here. These are just wild guesses, nothing more.    odd job man/worker   shiftman   (unskilled) labourer Non-interleaved vertex buffers DirectX11 The  states that:      The scores are created by comparing the word in the list in step 2* with all the 3-letter words. By using the scoring matrix (substitution matrix) to score the comparison of each residue pair, there are 203 possible match scores for a 3-letter word. For example, the score obtained by comparing PQG with PEG and PQA is 15 and 12, respectively with the BLOSUM62 weighting scheme.   I do not understand how they got a score of 15 for PQG v. PEG. What is a scoring matrix, how is it computed, and how is it used?      Step 2 on that page is Make a k-letter word list of the query sequence: “Take k=3 for example, we list the words of length 3 in the query protein sequence (k is usually 11 for a DNA sequence) sequentially, until the last letter of the query sequence is included”. Can I completely disable Cortana on Windows 10? Windows 10 has Cortana, which I don't like. I disabled it as soon as I could. However, looking in Task Manager, the process for Cortana is still running, and can't be effectively terminated: ending the task simply results in the process respawning a few seconds later. Using the command  taskkill /IM Cortana.exe /F   has the same result: the process respawns.  Is there any way to disable Cortana so that the process doesn't keep running in the background, and doesn't respawn if terminated? What's the weight of the earth? What's the weight of the earth?  That is, what's the weight of the earth in the gravitational field of the sun? I imagine it's either   $0$, because there's no net fall toward the sun, so the downward component of acceleration is $0$ and $F=ma=0$, or $Gm_1m_2/r^2\approx7\cdot10^{-11}\cdot6\cdot10^{24}\cdot2\cdot10^{30}/(1.5\cdot10^{11})^2\approx4\cdot10^{22}$ Newtons,   but which, and why? Proving $A+A'B=A+B$ without truth tables How can I prove the Boolean algebraic rule $$A+A'B=A+B$$ without using a truth table?  With the truth table, it is easy to see that the two are equal, but how can I prove it using lesser Boolean identities? I want to encrypt a USB stick, and be able to decrypt it on Windows as well as Ubuntu. How do I do this &amp; what programs do I need to use? Show the existence of a certain subgroup of F2 How to enable ssh root access on Ubuntu 14.04 I´d like to enable the ssh root access on Ubuntu 14.04. Editing the /etc/ssh_config (PermitRootLogin yes) didn't affect anything. Colorize symbols with lstdefinelanguage in latex Error - SqlDateTime overflow. Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM I've been using this piece of code I've written and it's working in this most unclear manner. I wish to insert a row into the database which includes two columns of DateTime:  myrow.ApprovalDate = DateTime.Now myrow.ProposedDate = DateTime.Now   And yet, when I update the database I receive this error:     SqlDateTime overflow. Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM.    I've even tried copying an inserted value from the database and hard code it into the object being updated:  // I copied this value from the DB myrow.ApprovalDate =  Convert.ToDateTime("2008-12-24 00:00:00.000");   Still same error, the strange part is that the above trick worked for the first insert to the DB but failed from there on. Any ideas what's going on? How to get the Vista taskbar to span multiple monitors? I can't for the life of me get the vista taskbar to span multiple monitors.  I've searched and looked far and wide, and alas the only pseudo-solution i can find is Ultra-Mon, but a) it doesn't quite look the same  and b) i don't want to have to pay for something that Windows really ought to be able to do out of the box.   Does anyone have a solution for this?  Will this get addressed in Windows 7? The extension of smooth function If $U$ is a bounded domain in $\mathbb R^n$ whose boundary is smooth, and $f$ is a smooth function on $U$ whose partial derivatives of all orders have a continuous extensions to $\bar U$. For an arbitrary domain $V \supseteq \bar U$, is there a smooth function $\tilde f$ on $V$ extending $f$? about://(null) popup? I encountered a popup similar to this one this morning while checking the weather report at  in Safari, though I have not been able to reproduce it.  The title is "about://(null)" and the text "Why you no play Candy Crush!!"  The popup occurred twice.  I tapped Cancel both times.  I suspect the source of this is rogue JavaScript in an ad network, judging from the fact that the screenshot below shows it in an ad-supported application, and when I saw it, I was on an ad-supported website.  My phone is not jailbroken.  I'm wondering if anyone is able to identify the source of the popup definitively.  Speculation is running rampant on Apple's support communities and elsewhere, from push notifications (delete Facebook and all your games!) to carrier notifications (which don't work on iPod Touches…), and my gut tells me little of it is helpful.  But I could also be very wrong.  (This is not my screenshot; it comes from .)    UPDATE 1: The Candy Crush people have this to say, but I'm not (yet) convinced there's actually something installed that is to blame:   UPDATE 2: Just reproduced it in the iOS Simulator while clicking around woodtv.com, but I'm not sure how to track it down further from here. Sometimes I hear sentences that sound conditional to me, just because of the (unassertive) ordering of the words. I don't know if I can come up with a proper example. Consider this:          I'd be a lot better, had she stayed with me.        And I guess it's equivalent to this conditional form: If she had stayed with me, I would have been a lot better.  So, this is my question: In what ways can you make a sentence conditional without using conditional conjunctions (if, unless, etc)? And what are their equivalent conditional forms? Why does an environment's label have to appear after the caption? \documentclass{article} \usepackage{algorithm}  \begin{document} \setcounter{section}{54} \section{A section with no label} \begin{algorithm} \label{myalg} \caption{An algorithm with the label `myalg'.} \end{algorithm} Reference to myalg: \ref{myalg}. \end{document}   With this code, the reference givens 55 (the section number); if I move the label after the caption command, I get the correct reference (1).  Why should this be the case? I find it confusing: when thinking about an algorithm as an environment, you expect to be able to label it right after you began it. At the very least I would expect some kind of error or "??" to appear, rather than the previous environment or reference-able entity being used.