I am examining BMI effect on wage. I have included a lot of explanatory variables in the regression and all (most) coefficients were significant, but once I add ability which correlates with education (already in regression) slightly (34%) BMI measures turn insignificant.   Here is the question, what does it mean if BMI turns insignificant once we add another variable in the regression?   Estimated by OLS, cross sectional. Adj R  0.60, F=160.   PS: I added a variable and variable of interest turned insignificant, not vice versa.  Thank you for all the examples below, they address the same topic, but different issue.
I have what is probably a simple question, but it is baffling me right now, so I am hoping you can help me out.  I have a least squares regression model, with one independent variable and one dependent variable. The relationship is not significant. Now I add a second independent variable. Now the relationship between the first independent variable and the dependent variable becomes significant.  How does this work? This is probably demonstrating some issue with my understanding, but to me, but I do not see how adding this second independent variable can make the first significant.
I know it is defined as $ dP \wedge dx  $ or explicitly,  $$ \frac{\partial P }{\partial y } dy \wedge dx   . $$  The question is, could it be $dx \wedge d P $?  Or  $$  \frac{\partial P }{\partial y }  dx \wedge dy ?    $$  I know the question must be very naive or even stupid. But I am indeed confused. How to allow to run su instantly after I added the user to the appropriate group I have the su executable with the following permissions:  bash-4.2# ls -la /bin/su -rws--s--- 1 root wheel 59930 Sep 14  2012 ./su   When I am logged in as a user, not in the wheel group and try to run su, I get an error, which is correct:  bash-4.2$ su bash: /bin/su: Permission denied   After that I add this user to wheel group from root:  bash-4.2# usermod -a -G wheel user   But for the same terminal session I still can't run su:  bash-4.2$ su bash: /bin/su: Permission denied   For the new sessions I can run su. How to allow to run su instantly after I added the user to the appropriate group? In FreeBSD and also in Linux, how can I get the numerical chmod value of a file? For example, 644 instead of -rw-r--r--? I need an automatic way for a Bash script. Troubleshooting "Windows cannot be installed to this disk. The selected disk has an MBR partition table" How is it that questions posted to the Stack Overflow show up as #1 in Google search results just minutes after being submitted? What SEO practices are being used to generate this sort of up-to-the-minute accuracy? Why should the interface for a Java class be preferred? Let $T$ and $T^{'}$ be topologies on set $X$ such that $T \leq T^{'}$. If $(X,T^{'})$ is path-connected, is $(X,T)$ path connected? Let $T$ and $T^{'}$ be topologies on set $X$ such that $T \leq T^{'}$. If $(X,T^{'})$ is path-connected, is $(X,T)$ path-connected?  I think it is, and I tried to prove it by contradiction, but I got stuck. Any hint helps! Stripboard/veroboard/matrix board design software I'm prototyping a simple layout for a small project on matrix board, but figured there must be a better way than drawing it all out on paper. Are there any aimed at matrix board?  I've found the following software for stripboard, but nothing explicitly for matrix board:     Stripboard Magic (seems to be abandonware, but there's page about it )  Stripboard Editor Limited free version, designed to integrate well with     Any more I've missed? Any recommendations? Types of things vs. types of thing of a monic polynomial $f \in \mathbb F\left[x\right]$ in $1$ variable $x$ over a field $\mathbb F$ plays an important role in understanding the structure of finite dimensional $\mathbb F[x]$-modules.  It is an important fact that the characteristic polynomial and the minimal polynomial of $C(f)$ are both equal to $f$. This can be seen quite easily by induction on the degree of $f$.  Does anyone know a different proof of this fact? I would love to see a graph theoretic proof or a non inductive algebraic proof, but I would be happy with anything that makes it seem like more than a coincidence! Consider the following example:  \documentclass{article} \newtheorem{Theorem}{Theorem} \begin{document} \begin{Theorem} On the other hand, this one has only one claim. \end{Theorem} \begin{Theorem} \begin{enumerate} \item First claim \item Second claim \end{enumerate} \end{Theorem} \end{document}   Typesetting it results in:    Notice there is extra horizontal space before the first item in the list of the second theorem.     Is there a sensible way to get rid of that?   Ideally, the solution would work with amsthm, thmtools, enumitem.  N.B.: this is related to  but not quite the same. Easiest way to move my Windows installation to an SSD? I've taken the plunge and bought an SSD and want to move my existing Windows installation over. The current hard disk is 500Gb, but I've trimmed the contents down to about ~40Gb. I'm transferring it across to a 100Gb SSD and looking for the easiest way just to copy everything across and set the SSD up as a boot device.  I've looked at a few tools like Macrium Reflect, but they don't seem able to restore to a smaller drive. Do I need to go for something like  to do this? I'm trying to avoid scary Linux-based boot utilities if possible, does anyone know of an easier way? I have a SNP table looks like this  A N N N N N N N N N N N N C N N N C N N N N N N N N N N N N N N N N N N N C N N N C N N N N N N N N N N N N N N N N N N C C N N N N N N N N N N C C N N N C C N N N N N N N N N N N N N N N N N   I want to count total number of N in each row? any idea how to do that I want to refresh the entire service console on clicking of the save button on the visual force page. The button is an inline visual force page. Any ideas?  &lt;apex:includeScript value="/soap/ajax/26.0/connection.js"/&gt; &lt;apex:includeScript value="/support/console/26.0/integration.js"/&gt; &lt;script type="text/javascript"&gt; function focusAndSave() {     document.getElementById('focusMe').click(); }     &lt;/script&gt;     &lt;apex:form &gt;     &lt;apex:pageBlock id="pb"&gt;         &lt;apex:pageMessages id="errMsgsId"&gt;&lt;/apex:pageMessages&gt;         &lt;input type="text" id="focusMe" style="display:none" /&gt;         &lt;apex:pageBlockTable id="table" value="{!candidateMap}" var="c"&gt;             &lt;apex:column value="{!candidateMap[c].Contact__r.Name}"/&gt;             &lt;apex:column value="{!candidateMap[c].Submitted_at__c}"/&gt;             &lt;apex:column value="{!candidateMap[c].Interview_Availability__c}"/&gt;             &lt;apex:column value="{!candidateMap[c].Notice_Available__c}"/&gt;             &lt;apex:column headervalue="Stage"&gt;                 &lt;apex:outputfield value="{!candidateMap[c].Stage__c}"&gt;                     &lt;apex:inlineEditSupport event="ondblclick"/&gt;                 &lt;/apex:outputfield&gt;             &lt;/apex:column&gt;             &lt;apex:column headervalue="Ideally looking for"&gt;                 &lt;apex:outputfield value="{!candidateMap[c].Ideally_looking_for__c}"&gt;                     &lt;apex:inlineEditSupport event="ondblclick"/&gt;                 &lt;/apex:outputfield&gt;             &lt;/apex:column&gt;             &lt;apex:column headervalue="Action"&gt;                 &lt;apex:commandLink value="Save" action="{!saveCandidate}" rerender="errMsgsId,table" onclick="focusAndSave()" oncomplete="testGetFocusedPrimaryTabId()"&gt;                     &lt;apex:param name="candidateId" value="{!candidateMap[c].Id}" assignTo="{!candidateId}"/&gt;                 &lt;/apex:commandLink&gt;             &lt;/apex:column&gt;         &lt;/apex:pageBlockTable&gt;         &lt;apex:panelGrid columns="7" style="margin: 0 auto;"&gt;             &lt;apex:outputLabel value="{!noOfRecords} records found"&gt;&lt;/apex:outputLabel&gt;             &lt;apex:commandButton status="fetchStatus" reRender="pb" value="|&lt;" action="{!first}" disabled="{!!hasPrevious}" title="First Page"/&gt;             &lt;apex:commandButton status="fetchStatus" reRender="pb" value="&lt;" action="{!previous}" disabled="{!!hasPrevious}" title="Previous Page"/&gt;             &lt;apex:commandButton status="fetchStatus" reRender="pb" value="&gt;" action="{!next}" disabled="{!!hasNext}" title="Next Page"/&gt;             &lt;apex:commandButton status="fetchStatus" reRender="pb" value="&gt;|" action="{!last}" disabled="{!!hasNext}" title="Last Page"/&gt;             &lt;apex:outputLabel value="Page {!pageNumber} of {!pagecount}"&gt;&lt;/apex:outputLabel&gt;         &lt;/apex:panelGrid&gt;     &lt;/apex:pageBlock&gt; &lt;/apex:form&gt; I'm having trouble editing this file on Windows 7:  C:\Program Files (x86)\CMake 2.8.7\share\cmake-2.8\Modules\FindJNI.cmake   If I edit it in Cygwin (vi) or TextPad, those two programs see the changes, so it's getting written to disk somewhere.  But if I "type" the file in a DOS cmd shell, it looks like the file hasn't been changed at all.  One thing I noticed is that in the cmd shell, the owner is Administrators, but in Cygwin's bash shell, the owner is Dan:  C:\Program Files (x86)\CMake 2.8.7\share\cmake-2.8\Modules&gt;dir /Q FindJ*  Volume in drive C is Windows7_OS  Volume Serial Number is 92CA-8707   Directory of C:\Program Files (x86)\CMake 2.8.7\share\cmake-2.8\Modules  12/30/2011  09:45 AM             1,480 BUILTIN\Administrators FindJasper.cmake 12/30/2011  09:45 AM             7,951 BUILTIN\Administrators FindJava.cmake 12/30/2011  09:45 AM            10,632 BUILTIN\Administrators FindJNI.cmake 12/30/2011  09:45 AM             1,669 BUILTIN\Administrators FindJPEG.cmake                4 File(s)         21,732 bytes                0 Dir(s)  132,524,654,592 bytes free   Dan@home /c/Program Files (x86)/CMake 2.8.7/share/cmake-2.8/Modules $ ls -al FindJ* -rwx------+ 1 Dan            None 10636 Jan 30 13:57 FindJNI.cmake -rwx------+ 1 Administrators None  1669 Dec 30 09:45 FindJPEG.cmake -rwx------+ 1 Administrators None  1480 Dec 30 09:45 FindJasper.cmake -rwx------+ 1 Administrators None  7951 Dec 30 09:45 FindJava.cmake   How can this be?  It's like there are two different files with the same name in the same directory. A required field that isn't really required? ...the email field in my clients data entry system is required but users of the system are allowed to enter na@na.com if the customer refuses or doesn't have an email address. Is this best practice? Have any suggestions or workarounds for their solution? What should I do when a hacker gives me hacked money? I was peacefully playing GTA Online (yeah, was killing someone coming out of ls customs) then a hacker came and killed me using explosive ammos, I called him a hacker and he teleported to me and gave me 790k. I know that people get banned for receiving this kind of money, what should I do to avoid the ban? How to find application's path from command line? For example, I have git installed on my system. But I don't remember where I installed it, so which command is fit to find this out? Can I use a 23 W CFL in a fixture that's rated for a 60 W incandescent? I have a lamp that is rated at 60 Watts for an incandescent bulb with a disclaimer to use a 13 Watt bulb instead when using a CFL replacement. Do I really need to respect that disclaimer? Would not a 23 Watt CFL be just as safe to use? It still draws less power than a 60 Watt incandescent, right? Can I write the output the of time difference command to a file?