I have current TXT record for my domain:     v=spf1 a mx ip4:{ip-of-my-server} -all   Both email traffic and website goes to same machine. Now, I have to point website (A record) to other server. Will it broke Sender Policy Framework - note the "a" in TXT record?  If so, should I just strip "a" form current TXT record or reconfigure current record differently, and how?
This is a  about setting up .     I have an office with many computers that share a single external ip (I'm unsure if the address is static or dynamic). Each computer connects to our mail server via IMAP using outlook. Email is sent and received by those computers, and some users send and receive email on their mobile phones as well.  I am using  to generate an SPF record and I'm unsure about some of the fields in the wizard, specifically:   Enter any other domains who may send or relay mail for this domain Enter any IP addresses in CIDR format for netblocks that originate or relay mail for this domain Enter any other hosts which can send or relay mail for this domain How stringent should SPF-aware MTA's treat this?   the first few questions i'm fairly certain about... hope i have given enough info.
Relation between confidence interval and testing statistical hypothesis for t-test It is well known that confidence intervals and testing statistical hypothesis are strongly related. My questions is focused on comparison of means for two groups based on a numerical variable. Let's assume that such hypothesis is tested using t-test. On the other side, one can compute confidence intervals for means of both groups. Is there any relation between overlapping of confidence intervals and the rejection of the null hypothesis that means are equal (in favor of the alternative that means differ - two-sided test)? For example, a test could reject the null hypothesis iff the confidence intervals do not overlap. Is there a word for happiness made possible by a tragic situation? I frequently find myself needing a word to express happiness that acknowledges a tragic or unfortunate circumstance underpinning that happiness. Preferably the word could have both adjective and verb forms. For example, "Gregory [verb-ed | felt adjective about] the balmy February day, suspecting it was yet another consequence of catastrophic and irreversible climate change."  "Bittersweet" is close, but not precisely right. It implies ambivalence rather than genuine gladness. "Schadenfreude" is also in the neighborhood, but I don't want to imply that the tragic part of the situation is what causes the pleasure. (Also, I recognize that the word may not quite exist in English, and I don't know if this is forbidden for this forum, but I'd welcome a loan word or phrase if there's a better one.) LIKE uses index, CHARINDEX does not? How tipe are this series?  $$\sum_{n=2}^\infty \frac 1 {n^2\ln n}$$ But $$\sum_{n=2}^\infty \frac 1 {n\ln n\ln(\ln n)}$$ I used Condensation Test, but I stack after that. Thanks! disable clickable landmark on google map On the bash command-line, ↑ gives me the previous command. On the command-lines in ipython or matlab, when I type a few characters, ↑ gives me the previously entered command starting with those characters. How can I enable exactly this behaviour in bash? I am aware of more advanced ways of searching through the command-line history, but sometimes a simple way is more convenient. How to disable the "Your site has updated to WordPress x.y.z" admin email? Using the automatic update of my self-hosted WordPress blogs, I configured automatic updates of both the WordPress core as well as WordPress plugins and themes ().  Whenever a core update occurs, I get an email like:     Your site has updated to WordPress 3.9.2      Howdy! Your site at  has been updated automatically   to WordPress 3.9.2.      No further action is needed on your part. For more on version 3.9.2,   see the About WordPress screen:       If you experience any issues or need support, the volunteers in the   WordPress.org support forums may be able to help.         The WordPress Team   I understand that I can  but I would prefer to only disable the above notification.  Therefore my question is:  How to disable update notification emails in WordPress? What happened to Charles Xavier after X-Men 3? I remember watching X-Men 3 and seeing Charles Xavier get disintegrated by Phoenix, however the post-credits scene and his appearance in later movies indicate that he actually survived. How is that possible? Playing a remote movie on the remote computer I often see $I(t)\propto |E(t)|^2$. What is the exact form ? Which constants are missing to make this an equality and why are they so often omitted ? Trying to remember the name of a grade-school book about an alien in a cereal box When I was a kid (Grade school, Elementary, can't remember the exact grade, but it was between 1992 and 1999) I read a book about a kid who found an alien in his cereal.  This alien informed him that he was there to defeat an evil threat to Earth, that took the form of the school's most popular student.  The alien came with a gun that did nothing, and the alien in the popular kid disguise had the power to make the kid's fingernails bleed by damaging his nerve endings.  In the end, it was revealed that the evil alien had a huge craving for, and vulnerability towards, pizza flakes, and was defeated by gorging himself on them and then exploding. Install on Second Hard Drive with startup boot option? In theory, what I want to do is very simple, but I've done some google research and read some posts on this site and I'm still confused.   I want to keep win7 on my primary C:\ drive, and install Ubuntu (12.10) on a secondary drive (that I have yet to buy or install. I just want to be certain that I'm successful when I do this). If at all possible I'd also like it if when I start the computer I have the option to boot either Win7 or Ubuntu, like an account log in type thing where I just pick which drive I'm running with that day. And just to reiterate, I do not want to partition my C:\ drive or alter, change, or affect my Win7 system in any way.  The reason I'm still fairly uncertain about all of this, is that a lot of the guides I've read have been for earlier versions of Ubuntu. Also the vast majority of guides are about partitioning one drive to fit both OS'. I want two separate OS running from two separate drives that I can pick at boot. The guides I did find mentioned that there is some issue with the grub being installed on C:\ but the rest of the OS being installed on the other drive. Is this still the case? How do I avoid that?  Also, if it helps, I've been running 12.04lts on my laptop for a few months now in and out of class and I love it.  Finally, if you could please point me to a guide or write your answer in the form of a guide for a two year old that'd be awesome. I'm still an Ubuntu novice and I don't want to mess up my win7. Uninstall apps locked by phone vendor I'm using a Samsung I9000 and I have some annoying apps that came pre installed by the phone vendor, like a music store, a custom web browser and other memory leaking apps.  Those crappy apps can't be uninstalled neither by Manage applications tool, nor by editing the apps tiles in the front menu.  I guess I have to be a root user or something to get rid of those apps, but I don't know how. How can I get my external IP address in a shell script? I need to find my external IP address from a shell script. At the moment I use this function:   myip () {      lwp-request -o text checkip.dyndns.org | awk '{ print $NF }' }   But it depends on perl-libwww, perl-html-format, perl-html-tree installed. What other ways can I get my external IP? I'm having trouble with \includegraphics I'm using MacTeX Arithmetic operator overloading for a generic class in C# Two icons on Unity Launcher on non-standard application launch I have an application which doesn't come from any Ubuntu repo (neither official, nor PPA) but available as tgz and supposed to be unpacked and ready to use. To be precise it is .   The problem is the  application when launched shows its own icon in Unity Launcher. After making a custom .desktop file and placing shortcut onto Unity Launcher (by dragging from the dash) and launching it I see two icons - one placed by me and another one with real application.  This is the .desktop contents:  [Desktop Entry] Version=1.0 Type=Application Terminal=false Exec=/opt/LightTable/LightTable Name=Light Table Icon=/opt/LightTable/core/img/lticon.png   One more thing. The /opt/LightTable/LightTable is bash script file and eventually /opt/LightTable/ltbin is being launched. I think this is the problem but have no idea how to fix the problem. How to show the number of domains the disk is split into is $1+ C_n^2 + C_n^4$? Assuming there are n points on a circle, then there are $C_n^2$ chords. If any three chords don't intersect in circle. How to show the circle will be divided into $1+ C_n^2 + C_n^4$ domains?  Picture below is a example of 5 points on circle. Integrate $\int \frac{25 - x^2}{x^4} \operatorname d\!x$ A geometric reason why the square of the focal length of a hyperbola is equal to the sum of the squares of the axes? When I teach conics, I give a simple geometric argument for the Pythagorean relation for ellipses. (By "Pythagorean relation" I mean the fact that the square of the focal length $c$ is the difference of the squares of the semimajor and semiminor axes, i.e. $c^2=|a^2-b^2|$ for the ellipse defined by $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$.) The picture argument goes as follows: just draw the obvious isosceles triangle from the two foci to one of the two points at the end of the minor axis. We see two right triangles; in each, one leg is the focal length $c$ and the other leg is the semiminor axis, while the hypotenuse is the semimajor axis. The result follows from the Pythagorean theorem applied to this right triangle.  But when it comes to the Pythagorean relation for hyperbolas, I can't think of an equally convincing picture to draw. Instead I have to give a rather inelegant algebraic argument for the relation $c^2=a^2+b^2$ (for the hyperbola defined by $\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$, with focal length $c$), directly from the definition of the hyperbola. The messy details are below.*  Now, obviously there is an asymmetry between the argument for the ellipse and the argument for the hyperbola: the ellipse argument is almost trivial and doesn't involve working straight from the locus definition, but the hyperbola argument is tedious and does require working straight from the definition. So, my question:     Is there an equally persuasive picture I could draw to convince high   school students of the Pythagorean relation for hyperbolas -- without having to get technical with points at infinity, say?   The natural triangle to draw is the right triangle with legs from the center to a vertex and from that vertex to an asymptote, which has legs of length $a$ and $b$; but then the problem becomes why the length along the asymptote should be equal to $c$. I doubt there is a purely (Euclidean) geometrical reason because this triangle lies on the asymptote, not on the hyperbola itself; I suspect some sort of limiting procedure will be required.    [*] The tedious algebraic details:     The foci lie at $(\pm c,0)$.   Say $a&gt;b$. Then hyperbola is the locus of points $(x,y)$ such that       $$\left|\sqrt{(x+c)^2+y^2}-\sqrt{(x-c)^2+y^2}\right|=2a$$      Assume for simplicity the expression between the absolute value bars   is positive. (The algebra is even more tedious if we don't make such a   simplifying assumption.) Then moving the right root to the other side   and squaring gives      $$(x+c)^2+y^2=4a^2+(x-c)^2+y^2+4a\sqrt{(x-c)^2+y^2}$$      Simplifying gives      $$xc-a^2=a\sqrt{(x-c)^2+y^2}$$      and upon squaring again we have      $$x^2c^2-2xca^2+a^4=a^2(x^2-2xc+c^2+y^2)=a^2x^2-2xca^2+c^2a^2+a^2y^2$$      which reduces to      $$x^2(c^2-a^2)-y^2a^2=a^2(c^2-a^2)$$      Defining $b^2:=c^2-a^2$ brings the equation into the form   $x^2/a^2+y^2/b^2=1$, and the Pythagorean relation follows from the   definition of $b$.