Invading aliens' low tech weapons are no match for Earth's modern weapons
SF Short Story: alien apes invade during nuclear war
Why do the major and minor groove exist in DNA? So I know that the major/minor groove arise from the offset pairing of the two strands in the helix.  All my textbook tells me is that "pitch causes the off-set pairing of DNA and this gives rise to the major and minor grooves."  I'm not too sure what this is saying.  What exactly is pitch and how does it give rise to the grooves? What is the bug about: Keyword gets duplicated even when the query is not modified.  Impact: As far as i can tell - cosmetic.  How to replicate: Go to:  and keep pressing Search button. With each search there will be a duplicate python keyword appended to search box.  Best guess for what is causing it: I think you have somewhere a piece of code that appends tag as a keyword without checking if it is already present. My reasoning comes from this url:  not having the same issue - the tag is not present in it. If my power supply is 700w, do I need a 700w UPS? if my power supply is 700w, do I need a 700w UPS?  I am running dual 20" dell LCD's, a i7 quad core system with a radion 4870 1gb video card, 2 hard drives. Is it feasible to transform each variable differently while doing multiple regression I try to write a simple Markdown parser in JavaScript. Therefore I want to check for the [link content][link id] syntax. I use the following code:  data = data.replace( /\[(.*?)\][ ]*\[([0-9]+)\]/g, '&lt;a href="$2"&gt;$1&lt;/a&gt;' );   It works well, but now I want to do this with a RegExp object. So I set up the following bit of code:  var r = new RegExp( '\[(.*?)\][ ]*\[([0-9]+)\]', 'g' ); data = data.replace( r, '&lt;a href="$2"&gt;$1&lt;/a&gt;' );   But it doesn't work. It even says that my regular expression (which works since the first example does a good job) is invalid:     unmatched ) in regular expression   I think it must have to do with some RegExp-object peculiarities I am not aware of. What am I doing wrong and how can the problem be solved? $m$ is a perfect square iff $m$ has an odd number of divisors? I can run faster than _____. (1) him (2) he? How to create a YouTube playlist from a list of links? I have very long lists of YouTube links/bookmarks. I want to create playlists for my YouTube channel with them. Is there any way to do it automatically without having to add each individual URL to a playlist? Why does the speed of light in vacuum have no uncertainty? I could understand that the definition of a second wouldn't have an uncertainty when related to the transition of the Cs atom, so it doesn't have an error because it's an absolute reference and we measure other stuff using the physical definition of a second, like atomic clocks do.  But why doesn't the speed of light have uncertainty? Isn't the speed of light something that's measured physically?  Check out that . showing that a group of order 45 is abelian I'm trying to understand the following proof from Dummit &amp; Foote (pg. 137) which shows why a group of order 45 is abelian. I understand everything but the last two sentences. Why is it that $|G/C_G(P)|=1$? Also, is it always true that $G/Z(G)$ is abelian? Thank you! How can a structure have infinite length and infinite surface area, but have finite volume? Server login attempts NOT blocked after configuring fail2ban So, I installed (and configured) fail2ban on three Ubuntu VPS servers. I configured (imo) a maximum of 3 failed login attempts (via Putty as root) within 2 minutes. Then I restarted the fail2ban service (according to ).    But when I look at my auth.log files in /var/log/ I still see 4, 5 or more failed attempts from certain IP's. So obviously I did something wrong as the IP is not blocked after 3 failed attempts.   It might have to do something with iptables, but that's where it gets a bit "foggy" for me..   Not sure how to setup a max-three-failed-login-attempts rule..  Additional: I see that the login attempts mostly have different ports for every attempt. Does that influence the count to max-three?  Because I see a port being "poked" twice and then no more attempts. Then the IP tries a different port (again 2 times). (all bots of course) Pass PHP variables to Javascript/jquery Is it possible to change the colors in the command prompt for the user@computer, as well as the the current directory and command parts of the prompt display?   I've already seen something like this done by OSX users, but I don't know how to do the same thing in gnome terminal (I can only change foreground and background colors).   It'd be very useful when, for example, trying to compile programs that have errors, since long, unformatted messages make it hard to distinguish which lines are commands and which are output. $A$ is normal and nilpotent, show $A=0$ Given a matrix $A \in R^{n \times n}$ which is normal ($AA^H=A^HA$ where $A^H$ is hermitian of $A$) and nilpotent ($A^k=0$ for some $k$). Now we need to show that $A=0$. (This is essentially exercise 5(b) in sec. 80 on p.162 of Paul R. Halmos' Finite-Dimensional Vector Spaces.) I tried to show in the following way, we know that, $AA^H=A^HA$ pre-multiply by $A^{k-1}\implies A^kA^H=A^{k-1}A^HA$ Now, we have $0 = A^{k-1}A^HA$, since $A$ nilpotent. I am not sure how to proceed from here to show $A=0$. Can someone help me in this problem? My neighbor keeps complaining about my music. How to soundproof my apartment? I live in an old apartment building and the walls are thin. This is a problem because I love to listen to music -- sometimes at odd hours of the night. Yes, I can be an asshole in this way. But my neighbor bangs against the wall even when I'm being perfectly reasonable (his bedroom seems to share a wall with my living room). And it's not just the low frequencies that get to him. He knocks against the wall even when I turn the subwoofer off on my speakers, which are located on the opposite wall.   This is kinda unacceptable. This is my home! What can I do so that I can live in it the way I want? Salesforce query on profile not working on user language change I have a query on profile like  profilename = [Select name from profile where id=:userinfo.getUserprofileid ].name  Now I have a check in  VF page  like  profilename  == 'System Administrator' . this works fine if the logged in user language is english. If the user language is different then profile name will be  'System admin' in that language . So how to prevent this beahviour?   Also  is there any particular field in profile which I can use  to identify the profile is system admin? so that I can have check on that field instead of checking for name which is causing the problem, for example I think modifyall filed is only checked for system admin. Most of us have seen on the profile page a loss of reputation citing as a reason "User was removed". This reason comes with the useful link:  which explains (emphasis mine):     This message means that a user who voted for one of your posts had their account deleted (either by request or due to violating the network's terms of service). As a result, all of their votes were removed, and the reputation you gained or lost from them was undone. The resultant reputation change could be any amount; it could even be a reputation gain if enough of the removed votes were downvotes. All the reputation changes from a single user's deletion are rolled into a single event in the reputation page labelled "User was removed".      This removal occurs whenever a user is deleted, unless that user had a very high reputation score. Because high-reputation users have usually cast a great many votes, removing all of them could be that much more disruptive to other users. In such cases, the staff use a special deletion that preserves the votes, resulting in no reputation change for those who had been voted on by that user.   However, I have got recently such a message on one of beta sites, where I have no posts. Here is  on that site. As you can see, I have only got points from association bonus,  and the last event in my reputation history is the reputation loss with the message 'User was removed'. (Notice that the post, where I made suggested edit, was not deleted. And the users who approved the posts are Community♦ and one another user, who did not delete their account.)  You can also see from  on that particular site that I have posted no questions/answers there so far. Which means there are no votes on my posts which could have been removed.     Why this did happen? How can I lose reputation points in this way if I have never made a post on that site?   I am not sure if this is a . (Feel free to remove the tag if it does not fit the question.) (EDIT: The answer and the comments posted so far indicate, that it is not a bug, so I have removed the tag from the question.) But if there is some reason why reputation posts can be lost even without having some posts and actual votes on the posts, then the description of "User was removed" seems to be a bit imprecise. (Of course, if it is a very rare edge case, it is probably not that important to have it included in the explanation.)    Just a short disclaimer: I do not care that much for the 2 points I lost. (Obviously, it would be very silly to make a fuss just for 2 points, and even more on a site which I do not frequent that much.) But if this could be indication of some hidden bug, it might be interesting to know more about this.    I have also noticed two related questions       In both cases in some answers or in comments as a possible explanation was given that probably a post, where a suggested edit was made, has been deleted. As you can see from the links I, this is not the case here. What are the existing datasets of world maritime routes? "wait more than" vs. "wait FOR more than"