I downloaded Dropbox from the official site and then installed it via Ubuntu's software installer. A message advised me to restart my session, so I logged out and in. No Dropbox.  So I chose Dropbox by searching it and the clicking via Activities. The message about installing Dropbox and then about restarting Nautilus appeared. I made my choices, but no Dropbox.  From command line, I chose dopbox running - no Dropbox. dropbox start gives the following message:  Starting Dropbox...Traceback (most recent call last):   File "/usr/bin/dropbox", line 1535, in &lt;module&gt;     ret = main(sys.argv)   File "/usr/bin/dropbox", line 1524, in main     result = commands[argv[i]](argv[i+1:])   File "/usr/bin/dropbox", line 1395, in start     if not start_dropbox():   File "/usr/bin/dropbox", line 732, in start_dropbox     stderr=sys.stderr, stdout=f, close_fds=True)   File "/usr/lib/python2.7/subprocess.py", line 390, in __init__     errread, errwrite)   File "/usr/lib/python2.7/subprocess.py", line 1025, in _execute_child     raise child_exception OSError: [Errno 8] Exec format error   I've tried this over and over with exactly the same result. Anybody know how to install Dropbox?
Since a while, 2 weeks, Dropbox does not startup anymore on my laptop running Ubuntu 12.04 LTS with GNOME shell.  When I run dropbox start -i in the console I get the following output.    Starting Dropbox...Traceback (most recent call last):   File "/usr/bin/dropbox", line 1387, in &lt;module&gt;     ret = main(sys.argv)   File "/usr/bin/dropbox", line 1376, in main     result = commands[argv[i]](argv[i+1:])   File "/usr/bin/dropbox", line 1247, in start     if not start_dropbox():   File "/usr/bin/dropbox", line 731, in start_dropbox     stderr=sys.stderr, stdout=f, close_fds=True)   File "/usr/lib/python2.7/subprocess.py", line 679, in __init__     errread, errwrite)   File "/usr/lib/python2.7/subprocess.py", line 1249, in _execute_child     raise child_exception   OSError: [Errno 8] Exec format error   I already removed Dropbox and reinstalled it. What should I do to fix this?
How do I transfer data and settings from one Apple Watch to another? I have an Apple Watch. I have had it for a while. I just bought a new Apple Watch. (Both are Series 1, just different sizes.)  I would like to transfer all my data and settings from my old Apple Watch to my new Apple Watch and then sell my old Apple Watch.  Is it possible to migrate my profile from one Apple Watch to another?  If so, what is the procedure?  All the search results I have found have to do with moving an Apple Watch to a new iPhone or restoring a backup to the same Apple Watch. Perhaps it is possible to restore a backup from an old Apple Watch onto a new one? Clarify an idiom in a political text Please carefully read the text below:     On 24 November, 1993, a meeting of Leftist intellectuals occurred in   London under the auspices of the Institute for Public Policy   Research (IPPR), which is a Labour-leaning think-tank.  A short document   was circulated in advance of the said meeting to clarify its   purpose.        Among other things, the document declared that the task of the   IPPR was: "To do what the Right did in the seventies, namely to break   through the prevailing parameters of debate and offer a new   perspective on contemporary British politics."    The explanatory document also said, "Our concern is not to engage in a   philosophical debate about foundations of socialism."      If this meant that those foundations were not the appropriate thing to   talk about at the 24 November meeting, then that might have been   right; not every thing has to be discussed at every meeting.  But if   what was meant was that discussion of philosophical foundations is not   what the Left now needs, then I disagree, and if that indeed is what   was meant, then it is curious that the breakthrough by the Right should   have been invoked as an achievement for the left to emulate, for if   there is a lesson for the Left in the Right's breakthrough, it is that   the Left must repossess itself of its traditional foundations on   pain of continuing along its present, politically feeble, reactive   course.  If the Left turns its back on its foundations, it will be   unable to make statements that are truly its own.   Since I've heard only one definition of the part identified in bold, I am at a dead end.  As you know, and according to Oxford's dictionary, the verb "repossess" means: To take back property or goods from SB who has arranged to buy them and can not pay.  Here, the object of verb is a thing not a person, but in the text, first,itself comes before of and its traditional foundations. As a result, I thought that this phrase might be an idiom and so has a different meaning with the original verb.  Please explain the meaning of this phrase. How do open files behave on linux systems? Characteristic polynomial of companion matrix restore table from .frm and .ibd file? I have previously saved a copy of /var/lib/mysql/ddms directory ("ddms" is the schema name). Now I installed a new MySQL on a freshly installed Ubuntu 10.04.3 LTS by running apt-get install mysql-server, I believe version 5.1 was installed. After I copy the ddms directory under /var/lib/mysql, some of its tables work fine, these are the tables with an associated set of three files: a .frm file, a .MYD file and a .MYI file.  However, there are two tables with a different set of files: a .frm file and a .ibd file. These two tables didn't show up in the table list in phpMyAdmin. When I look at the error log, it says:  [ERROR] Cannot find or open table ddms/dictionary_item from the internal data dictionary of InnoDB though the .frm file for the table exists. Maybe you have deleted and recreated InnoDB data files but have forgotten to delete the corresponding .frm files of InnoDB tables, or you have moved .frm files to another database? or, the table contains indexes that this version of the engine doesn't support.   Please help with restoring these two tables. Thanks. MongoDB could not connect local server I had mongdb installed and evrything was working fine. I wanted to delete the mongodb lock. By mistake the directory /var/lib/mongodb/ got deleted.  So, I uninstalled mongo db and installed again. But now i always keep getting this error:  Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:145 exception: connect fail   The error remains same even if I try to login from terminal or rockmongo or my application. I am using ubuntu12.04 and have latest version of mongo. With slapd.conf you could globally disable anonymous binding and require authentication with the following static directives:  disallow bind_anon require authc   How can I achieve the same global settings, but using the new cn=config live configuration method? Scientific visualization - How to replicate instances around a sphere? I want to replicate a protein structure around an icosahedron. Basically a vesicle of protein structure is what we want:  When I am instancing the protein structure using each vertex of the icosahedron it looks like:  However, the tails are supposed to be directed towards the center. How can I make that work? Why is $\mathbb{R}^2$ not a subspace of $\mathbb{R}^3$? What causes Nova's Triple Tap to go on a short cooldown? This isn't about the level 20 ultimate talent.  There is a brief "arming phase" where Nova locks onto her target before shooting three bullets.  When something happens to her target during that phase (allied Devouring Maw, Divine Shield, etc.), sometimes Triple Tap is placed on the full 100 second cooldown, other times it is placed on a much shorter 10 second cooldown.  What triggers this 10 second cooldown?   Is this a timing issue?  I believe if she is interrupted after the shots start going out, Triple Tap is always put on the full cooldown.  Maybe I'm just seeing the ability get blocked right as the first shot goes out? Is this ability-specific?  Does stunning Nova have a different effect than a Devouring Maw or Void Prison on her target?  And is that different from a Divine Shield/Sanctification on the target? Is this determined by whether the line to the target was interrupted by an ally or an enemy hero?  For example, is there a difference between an allied Void Prison and an enemy Void Prison on the target? Why are there $|G/G'|$ 1-dimensional representations of $G$? Let $G'$ be the derived subgroup of a finite group $G$.   We have a correspondence $\{\mathrm{reps \ of \ G/G'}\} \longleftrightarrow \{\mathrm{reps \ of \ G \ with \ kernel \ containing \ G' }\} $  If we restrict to 1-dimensional reps, we get:  $\{\mathrm{1\ dimensional \ reps \ of \ G/G'}\} \longleftrightarrow \{\mathrm{1 \ dimensional \ reps \ of \ G \ with \ kernel \ containing \ G' }\} $  Now my notes say that there are $|G/G'|$ 1-dimensional reps of $G$. Since there are $|G/G'|$ 1-dimensional reps of $G/G'$, this must mean that all 1-dimensional reps of $G$ have kernel containing $G'$. Why is this so?  Thanks Where can I find Obsidian in the Pocket Edition? I have looked everywhere for lava or obsidian in 0.7.1. I've looked all the way from top to bottom and all around, in about a 100 block diameter, but I can't find any. Where can I get some? Retrieving Maxwell's equations from the minimum action principle I'm currently working at the start of Alexei Tsvelik's book Quantum Field Theory in Condensed Matter Physics. I'm kinda stumped on a few essential steps.  Starting with the action:  $$S = \int dt \int d^3 x \mathcal{L}_{\mathrm{EM}} = \int dt \int d^3 x \left( -\frac{1}{4} F_{\mu \nu} F^{\mu \nu} + j_\mu A^{\mu}\right).$$  In the absence of any sources $j_\mu = 0$ and $c=1$, which after pulling in the negative sign implies  $$S = \frac{1}{2}\int dt \int d^3 x  \,\,\left(E^2 - B^2\right)$$ The next step is to take $\vec{E} = -\vec{\nabla} \phi + \partial_t \vec{A}$ and $\vec{B} = \vec{\nabla} \times \vec{A}$. Letting $\phi = 0$ and directly inserting these into the above yields:  $$S = \frac{1}{2} \int dt \int d^3 x  \,\left( (\partial_t \vec{A})^2 - (\vec{\nabla} \times \vec{A})^2 \right) $$  Now considering $\vec{A} = \vec{A}_0 + \delta \vec{A}$ as some minimal change in our vector potential, with $\vec{A}_0$ gives a minimum for the action and putting this into the above expression we have: $$\delta S = \int dt \int d^3 x \left(\partial_0 \vec{A}_0 \partial_0 \delta \vec{A} + \left(\vec{\nabla} \times \vec{A}_0\right)\cdot\left(\vec{\nabla} \times \delta \vec{A} \right) \right)+ \mathcal{O}(A^2)\,\,\,\,\,\,\, (1)$$ where I have the term  $$\mathcal{O}(A^2) = \int dt \int d^3 x \left( (\partial_0 \vec{A}_0)^2 + (\partial_0 \delta \vec{A})^2 - (\vec{\nabla}\times\vec{A}_0)^2-(\vec{\nabla}\times \delta\vec{A})^2\right)$$  The next step is where I lose our author and go from "Oh ok I get this" to "completely clueless". He rewrites $\delta S$ as:  $$\delta S =  \int dt \int d^3 (\delta x) \vec{A} \mathcal{F(\vec{A}_0)}+ \mathcal{O}(A^2)$$  where $\mathcal{F} = \frac{\delta S}{\delta A}$. What is the purpose of $x\to \delta x$ in the above expression? Is the functional derivative $\mathcal{F}$ a vector quantity? He has it bolded with a bolded $\vec{A}$ in the above expression. One last question takes the above expression further. We assume $\delta \vec{A}$ vanishes at infinity, as it should, and integration by parts yields:  $$\delta S =  -\int dt \int d^3 x \left( \partial^2_0 \vec{A}_0 - (\vec{\nabla} \times \vec{\nabla})\times \vec{A}_0  \right)\delta \vec{A}\,\,\,\,\,\,\,\, (2)$$ How exactly did we go from (1) to (2)? Thanks I appreciate your time! Sort a set of multidimensional arrays by array elements I was writing some Unit tests last week for a piece of code that generated some SQL statements.  I was trying to figure out a regex to match SELECT, INSERT and UPDATE syntax so I could verify that my methods were generating valid SQL, and after 3-4 hours of searching and messing around with various regex editors I gave up.  I managed to get partial matches but because a section in quotes can contain any characters it quickly expands to match the whole statement.  Any help would be appreciated, I'm not very good with regular expressions but I'd like to learn more about them.  By the way it's C# RegEx that I'm after.  Clarification  I don't want to need access to a database as this is part of a Unit test and I don't wan't to have to maintain a database to test my code. which may live longer than the project. Send email using the GMail SMTP server from a PHP page Biometrika journal style file not getting along with TeXLive-2020 I cannot compile styleguide.tex in biometrika.zip (see ). Here is a MWE which leads to the same error message, though not sure yet that I've not tossed baby out with bath water. \documentclass{article} \RequirePackage[thmmarks]{ntheorem}  \makeatletter \def\arabic#1{{\rm\expandafter\@arabic\csname c@#1\endcsname}} \theoremnumbering{arabic} \newtheorem{definition}{Definition} \makeatother  \begin{document}  \begin{definition} This is a definition. \end{definition}  \end{document}  Here is the output of pdflatex: % pdflatex styleguide This is pdfTeX, Version 3.14159265-2.6-1.40.21 (TeX Live 2020) (preloaded format=pdflatex)  restricted \write18 enabled. entering extended mode (./styleguide.tex LaTeX2e &lt;2020-02-02&gt; patch level 5 L3 programming layer &lt;2020-03-06&gt; (/usr/local/texlive/2020/texmf-dist/tex/latex/base/article.cls Document Class: article 2019/12/20 v1.4l Standard LaTeX document class (/usr/local/texlive/2020/texmf-dist/tex/latex/base/size10.clo)) (./ntheorem.sty  Style `ntheorem', Version 1.24 &lt;2004/09/20&gt; ) (/usr/local/texlive/2020/texmf-dist/tex/latex/l3backend/l3backend-pdfmode.def ) (./styleguide.aux) ! Use of \@item doesn't match its definition. \update@series@target@value #1-&gt;\def \reserved@a {                                                   #1}\ifx \target@meta@famil... l.13 T       his is a definition. ? q OK, entering \batchmode sudo apt upgrade error 18.04 (Broken Packages) Restoring MySQL database from physical files Is it possible to restore a MySQL database from the physical database files. I have a directory that has the following file types:  client.frm client.MYD client.MYI    but for about 20 more tables.  I usually use mysqldump or a similar tool to get everything in 1 SQL file so what is the way to deal with these types of files? Square of a second derivative is the fourth derivative I have a simple question for you guys, if I have this:  $$\left(\frac{d^2}{{dx}^2}\right)^2$$  Is it equal to this:  $$\frac{d^4}{{dx}^4}$$  Such that if I have an arbitrary function $f(x)$ I can get:  $$\left(\frac{d^2 f(x)}{{dx}^2}\right)^2 = \frac{d^4 f(x)}{{dx}^4}$$  Sorry if it's a pretty simple question, but I was trying to simplify something like this:  $$\left(a \cdot \frac{d^2}{{dx}^2} - f(x)\right)^2 g(x)$$ that's where it came up.