Why doesn't evolution converge on perfection?
Why do some bad traits evolve, and good ones don't?
Connect to a MySQL server over SSH in PHP How can I convert audio from MP4 or FLV video files to mp3? Is there an application that allows me to extract the audio from a MP4 or FLV video file and store it as an MP3 file for use in a portable media player? Is "National Socialism" always capitalized? So, I'm writing a paper on the rise of communism in China. At one point I write the following:     "Today, it is well known that communism is responsible for more deaths than even national socialism."   Then, Word corrects it by capitalizing "National Socialism."   Is it always meant to be capitalized? I am simply referencing the ideology, not necessarily the Third Reich. Word didn't bother to correct "communism." I suppose since there was only one instance of Nazism (on a national scale at least) it could be considered a proper noun. Repost it with a minimal working example for the amsmath must be loaded earlier than mathspec problem See the following mwe:  \documentclass{article} \usepackage{amsmath} \usepackage{mathspec} \usepackage{unicode-math}  \begin{document} \begin{equation*}   1 + 2 = 3  \end{equation*} \end{document}   Run the above code with xelatex will meet the following error:  ! Package mathspec Error: `amsmath' must be loaded earlier than `mathspec'.  See the mathspec package documentation for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                                l.54 \RequirePackage{amsmath}  ?    $ xelatex --version XeTeX 3.14159265-2.6-0.999991 (TeX Live 2019)  Regards This may be a generic OOP question. I wanted to do a generic comparison between an interface and an abstract class on the basis of their usage.   When would one want to use an interface and when would one want to use an abstract class? Make Chrome always execute with flags, for eg., directly opening an HTML file I want to run Chrome with a given set of flags, always  I created a shortcut and added the flag to it in the following way, so my target of the shortcut says:  C:\&lt;application-path&gt;\chrome.exe --user-data-dir=D:\Chrome   But when I double click an HTML file, or if any other application triggers Chrome, it looses the flag value. The result - A new chrome window opens with Default profile directory.  I want to make the flag permanent, so that its active irrespective of however Chrome executes.  I tried changing the following registry key:  HKEY_CLASSES_ROOT\ChromeHTML\shell\open\command   It was this earlier:  "C:\&lt;application-path&gt;\chrome.exe" -- "%1"    I changed to following attempts which did not work:  1. "C:\&lt;application-path&gt;\chrome.exe" -- "%1" --user-data-dir=D:\Chrome 2. "C:\&lt;application-path&gt;\chrome.exe" -- "%1" -- "user-data-dir=D:\Chrome" 3. "C:\&lt;application-path&gt;\chrome.exe" -- "%1 user-data-dir=D:\Chrome"   Conclusively, when I try to open a link from any application, it doesn't open in my current Chrome as a new tab, rather opens a new Chrome window with no plugins and extensions since its from other directory.  Why I have changed my default directory? - because the OS drive was getting low on memory due to heave Chrome caches and apps. After reading a couple of answers and comments on some SQL questions here, and also hearing that a friend of mine works at a place which has a policy which bans them, I'm wondering if there's anything wrong with using backticks around field names in MySQL.  That is:  SELECT `id`, `name`, `anotherfield` ... -- vs -- SELECT id, name, anotherfield ... Computing matrices of linear transformation under different basis Came across a problem in my textbook and I am having trouble with it, the book provides an answer but no workings. Looking to get an explanation of what is going on  help I prepare for an exam. If we let $T : \mathbb R^2 \to \mathbb R^2$ be a linear transformation. Consdider two bases $V$ and $W$ of the vector space $\mathbb R^2$, where $V=\{v_1,v_2\}$ with $ v_1 =  \begin{bmatrix} -2 \\1   \end{bmatrix}$ and  $ v_2 =  \begin{bmatrix} 1 \\1   \end{bmatrix}$ and where $W = \{w_1,w_2\}$ with  $ w_1 =  \begin{bmatrix} -1 \\4   \end{bmatrix}$ and  $ w_2 =  \begin{bmatrix} 0 \\1   \end{bmatrix}$. Suppose that  $ A =  \begin{bmatrix} 1&amp;2   \\-1 &amp;4    \end{bmatrix}$ is the matrix of $T$ under basis $W$. I need to find the matrix $B$ the matrix of $T$ under basis $V$.  The solution is:   $ B = P^{-1}AP$ = $   \begin{bmatrix} -30&amp;22   \\-48 &amp; 35    \end{bmatrix} $  But I don't know why. Would the Animate Objects spell end an ongoing spell affecting the targeted object(s)? How do I install the latest version of EMACS and pick the appropriate UI? I'm running the latest Kubuntu (12.04 beta 2) and I would like to run the latest emacs (currently v24). The repos are one version behind. What's the best way to install v24 or later (and avoid future version conflicts)?  Also, is there any reason not to aways use the GUI version of emacs if X is running? For example, could I set the GUI emacs version as the default text editor and use it to edit cron jobs (crontab -e)? I'm assuming the answer is yes, but since I haven't done that yet (my default editor is nano), I want to check if there are reasons I should leave nano as the default editor.  Usually when I'm working on the command line I end up using nano. Now that I think about it, I have no idea why I keep doing that. Is there any downside to calling a GUI editor when working in an X terminal?  EDIT: I briefly tested these two versions   GNU Emacs 24.0.94.1 (x86_64-pc-linux-gnu, GTK+ Version 3.3.20) from  GNU Emacs 23.3.1 (x86_64-pc-linux-gnu) installed by default in Kubuntu.   .  Unfortunately (for me) the defaults installed version (23.3.1, 23.3+1-1ubuntu9) is the nox version.   Package: emacs23-nox Status: install ok installed Version: 23.3+1-1ubuntu9 Replaces: emacs23, emacs23-gtk, emacs23-lucid   The package with version 24 opens in GUI mode by default. That's what I prefer. Some of the version 24 changes that interest me are listed in the references below.   But there appear to be a multitude of different packages and versions I could install.  References:   What’s New In Emacs 24 (part 1) | Mastering Emacs  "    shell-mode uses pcomplete rules, with the standard completion UI.  Yowzah! There’s a lot of cool, new functionality hidden away in this gem of a change." EmacsWiki: Recent Changes Can I leave the Schengen Area (and come back) while my non-eea spouse resident card application is being processed? My wife and I recently moved to Germany. She's a Swedish citizen, and I'm American. It'll be December before I can actually apply for my residence card, because my appointment to register our address is so far out - the local police station was all booked out and we didn't get an apartment right away.  I imagine that I won't be getting my residence card until well after Christmas, by which time my 90/180 days will be passed. What if I want to leave to, say, London for the holidays? Will I be allowed back in? I hit day 90 around the 21st of December. I could maybe leave on day 89 and come back on day 90 (with my wife and our marriage cert), or use this Polish solution: , since I can't be expelled from Germany for overstaying my visa while my application is processing.  Both of those seem a bit risky though. Am I reading too far into it, or is this a legitimate concern? Will I get some sort of documentation saying I have a residence card application processing? Grep equivalent for Windows 7? Is there a command prompt  equivalent for Windows 7? That is, I want to filter out the results of a command:  Bash use:  ls | grep root  What would it be from a Windows command prompt? How to solve $x^3=-1$? How to solve $x^3=-1$? I got following:  $x^3=-1$   $x=(-1)^{\frac{1}{3}}$  $x=\frac{(-1)^{\frac{1}{2}}}{(-1)^{\frac{1}{6}}}=\frac{i}{(-1)^{\frac{1}{6}}}$... How do you kill the devil? REST Service API executor.executeAsync Call Ends in Failure Function in Sharepoint Hosted App Any Answers Will Help me to Forward and Gain Knowledge in SharePoint Development  While i am Trying to get the list Items Using Rest API Calls in SharePoint Hosted App Using Below Function  function loadingSamples()  {     var JobListName = "RRR Jobs #";     var executor;     // Initialize the RequestExecutor with the app web URL.     executor = new SP.RequestExecutor("/");      //Fetching the choice values from the Job Status Field, to show in the Dropdown field     executor.executeAsync     ({         url: "/_api/web/lists/getbytitle('" + encodeURIComponent(JobListName) + "')/fields/getbytitle('Job Status')?$select=Choices",         method: "GET",         headers: { "Accept": "application/json; odata=verbose" },         success: successHandlerStatus,         error: errorHandler     }); } function successHandlerStatus(data)  {     alert("sucesss") }  function errorHandler(data, errorCode, errorMessage)  {     alert("errorMessage") }   It's always going to error function named errorHandler With  Error Code as -1002 and Error Message as Bad Request and Inside Data -> Body , the Error message is  {     "error":{            "code":"-1,Microsoft.SharePoint.Client.InvalidClientQueryException",         "message":{             "lang":"en-US",             "value":"The expression \"web/lists/getbytitle('DWR Jobs \" is not valid."         }     } }   Note :    This is working code in Sharepoint Hosted App that previously hosted in another Windows server. Now i hosted this App in New windows server,it's successfully hosted but it gives above mentioned Error in Rest Service Call. Why are disabled apps still running? Why can a discontinuous function not be differentiable? I don't really understand why a discontinuous function cannot be differentiable.  In Stewart's Calculus, the definition of a function $f$ being differentiable at $a$ is that $f'(a)$ exists. Earlier it gives the definition of the derivative as $f'(x)=\lim_{h\to0}\frac{f(x+h)-f(x)}{h}$. It also has a theorem that if $f$ is differentiable at $a$, then $f$ is continuous at $a$. There is also a definition that a functions $f$ is continuous at a number $a$ if $\lim_{x\to a}f(x)=f(a)$.  Take for example the very simple function:  $$ f(x)=\begin{cases} x+1 &amp; x\geq0, \\ x &amp; x&lt;0.  \end{cases} $$  It is discontinuous at $x=0$ (the limit $\lim_{x\to 0}f(x)$ does not exist and so does not equal $f(0)$), but if I find the derivative using the limit above, I get the left and right limits to equal $1$. So therefore, the derivative exists.  According to the book, the function shouldn't be differentiable at $x=0$ as it has a discontinuity (continuity is a necessary condition of differentiability). What am I doing/understanding wrong? Work done against gravity The work done against gravity is $mgh$, well at least that's what my textbook says. I have a question: I can apply a force say 50N, so total work done = $mgh + mah$. Where $ma$ = Force. But the truth is irrespective of the force applied, the work done against gravity is always $mgh$. Why?  For example, when I move an object with a force, the work done is more, so work depends on the Force. But in case of gravity it always depends upon the weight Number of ring homomorphisms from $\mathbb Z_{12}$ to $\mathbb Z_{28}$. Question:      Find the number of non trivial ring homomorphisms from $\mathbb Z_{12}$ to $\mathbb Z_{28}$. ($f$ is not necessarily unitary, i.e., $f(1)$ need not be $1$.)    Suppose $f$ is a ring homomorphism from $\mathbb Z_{12}$ to $\mathbb Z_{28}$.  Consider $f$ as a additive group homomorphism.  Let $k= |\ker f|$ and  $ t = |\operatorname{im}(f)|$. Then $k\mid 12$ and $t\mid 24$ and $kt=12$, by first isomorphism  theorem of groups.  There are two possibilities $k=3$, $t=4$   and $k=6$, $t=2$.  For the first case $f$ should map $1$ to an element of the subgroup generated by $7$ as there is a unique subgroup of $\mathbb Z_{28}$ of order $4$ generated by $7$. For the second case $1$ has to map to $14$, for the same reasoning.  So there are at most two ring homomorphisms from $\mathbb Z_{12}$ to $\mathbb Z_{28}$. Question is how to check the possible maps which are ring homomorphisms.  Thanks. Cannot translate vertice/edge will duplicate Most of the time when I try to move a vertex or an edge, instead of translating that, it extrudes it, it creates another face or, vertiex or whatever. I do not really get why it behaves like that. I hope I explained it in depth. I am sorry if this is a duplicate post but I could not find anything!