Can I charge my laptop through USB
Can I charge a computer through its USB port?
Step to step how to install Cinelerra I have some problems installing cinelerra on my Ubuntu.  How do I install it? Explain reflection laws at the atomic level Evolution of the (phenotypic) facial features of the indigenous people of (west/central) Africa I am not even remotely an expert in this field; I just got curious, so help me.   First of all, let us remove all human sentimental attributes from this question (such as connotations of  or emotional reactions thereof) and ask it from a purely scientific point of view. The typical facial feature of a West/Central African person (the so-called ) exhibits a wide nose, a lack of nasal bridge projection (similar to many Asian noses) and a prognathous skull shape that resembles more closely to our ancestor Homo Heidelbergensis than many other indigenous phenotypes from other parts of the world do.  I agree that this claim sounds anecdotal, and is certainly not true of all Africans (for example, Ethiopians), but one cannot dismiss it simply on grounds of ethical policing. I cannot help but notice that many of my African friends remind me of our shared ancestry (with no disrespect meant whatsoever), as is clear from the photographs below, one of a supposed Homo Heidelbergensis and one of a random African Homo Sapiens of today.     My question is the following. What is the reason behind this seeming resemblance? Is this appearance an illusion and possibly a construct of a prejudiced mind, or does this have a valid scientific answer? For example, are most Africans closer to our ancestors than the rest of humanity is? How does evolution answer this question?  Thank you for your help. Multigroup (CCK3) / FlexiField-like solution for compound fields? I've used  in the past to do multiply occurring series of field groups; now, working on a Drupal 7 project, I'm setting up a "Resume" content type and need a way to set up repetitive entries for education/work experience.   IE: for "Education", I need the ability to dynamically add new rows comprised of a combination of dates and places for each institution studied at.  What is the best way to accomplish CCK3 multigroup/FlexiField-like functionality in Drupal 7?  Thanks! Including Interaction Terms in Random Forest Suppose we have a response Y and predictors X1,....,Xn. If we were to try to fit Y via a linear model of X1,....,Xn, and it just so happened that the true relationship between Y and X1,...,Xn wasn't linear, we might be able to fix the model by transforming the X's somehow and then fitting the model. Moreover, if it just so happened that the X1,...,XN didn't affect y independent of the other features, we also might be able to improve the model by including interaction terms, x1*x3 or x1*x4*x7 or something of the like. So in the linear case, interaction terms might bring value by fixing non-linearity or independence violations between the response and the features.  However, Random Forests don't really make these assumptions. Is including interaction terms important when fitting a Random Forest? Or will just including the individual terms and choosing appropriate parameters allow Random Forests to capture these relationships? jQuery - setting the selected value of a select control via its text description I have a select control, and in a javascript variable I have a text string.  Using jQuery I want to set the selected element of the select control to be the item with the text description I have (as opposed to the value, which I don't have).  I know setting it by value is pretty trivial. e.g.  $("#my-select").val(myVal);   But I'm a bit stumped on doing it via the text description. I guess there must be a way of getting the value out from the text description, but my brain is too Friday afternoon-ed to be able to work it out. I went into Live CD and activated Terminal.  Then, I typed gksu nautilus to gain temporary access to my root directory. Once the Manager window opened, I clicked on File System and navigated to the /etc/default/grub directory. I then double clicked on the Grub file to make changes to the TIMEOUT and TIMEOUT_QUIET.  I saved the file after I made the changes. Then I went back to the terminal mode and typed:  gksu update-grub   The error message I got was:     Can not find a device for / (is /dev mounted?)   I'm not sure what to do at this point. How can I run update-grub to update the changes? Thanks in advance for your help. Please be very detailed and specific with your response as I am totally new to this environment. Installing Ubuntu on a SSD Going to install Ubuntu 10.10 on new intel x25M 80GB SSD. It will be fresh install. I have been googling for past few days and getting overwhelming articles/blogs/Q&amp;As. One particularly very useful being:     But with so many suggestions and differences of opinions (on different links) this simple OS install process seems to be daunting task to me and I really want to stick with Ubuntu (although have used for very short period of time).  Can someone help me by answering few questions (yes, they are repeated because I couldn't comprehend the answers elsewhere)   Which file system (ext2/3/4 or something else)? (consider SSD life) Can it be changed after installation? Should I partition the disk? (as we do in traditional HDD) for now, no plan of dual booting. Only Ubuntu will live on scarce space of 80GB SSD. I have 2 GB RAM, should i still allocate swap space (if I don't allocate swap space, can I still hibernate the machine)? will swap space impact SSD life? Should I consider putting additional 1GB RAM to avoid swap space? What is partition aligning? Is it needed to be done before installing the Ubuntu OS or can be done later?   Intended usage - heavy browsing, programming, regular video/music and some other non-CPU/RAM-intensive programs. Will keep big files in an external hard drive.  laptop config - 3yr old Vaio, Core2 Duo, 2GB RAM  More references:        (resizing/creating does not seem a simple process after look this) XP Activation and Dual Booting I need to make Windows 7 STOP disabling the wifi adapter when the wired LAN is connected Determinant of a specially structured matrix ($a$'s on the diagonal, all other entries equal to $b$) $n!+1$ being a perfect square One observes that  \begin{equation*} 4!+1 =25=5^{2},~5!+1=121=11^{2}  \end{equation*} is a perfect square. Similarly for $n=7$ also we see that $n!+1$ is a perfect square. So one can ask the truth of this question:   Is $n!+1$ a perfect square for infinitely many $n$? If yes, then how to prove. I received a mail today from Academia.edu (a site I wasn't previously aware of), asking me to confirm that I co-authored a paper with a colleague.  Having looked into it a little it sounds like it might be a useful site - the idea of a "social network for scientists" is one I've seen the need for in the past. However, partly due to bad experiences with the seemingly similar ResearchGate, I'm also skeptical.* Without signing up for an academia.edu account the site doesn't offer much information, so I would like the following information:   What specific features does academia.edu offer to its users? Is it genuinely useful for any of the following purposes (each of which seems genuinely needed)   as a platform for networking with academics for discovering relevant research as an effective system for post-publication peer review for organising references among a small team of people working on a project  Will it send out mails to my colleagues without my express and explicit permission? (I.e. are the mails I received today the result of a deliberate action by my colleague, who is aware that I will be emailed and wishes me to join the site; or are they essentially spam from a social networking site aggressively trying to expand its user base?) It's clear from its  that it's a private, venture-capital funded company. What is its business model?   In short, is this a site that has some genuine utility for academics, or should I just ignore it?  *I've never signed up for ResearchGate but I regularly receive spam from it purporting to be from my colleagues, who aren't aware that it's being sent on their behalf. I would be mortified if my senior colleagues received such mails claiming to be from me, so I won't touch it with a barge pole. Hi Blender coders and artists.  I am updating one of my add-ons for Blender 2.8 and have run into some  issues finding the appropriate way to hide a collection that is added to my scene.  I want to deselect the eyeball on the toolbar with a python command in a script but I don't want to disable the collection in the view-port entirely as it is used as a collection in a particle system.   I just want to deselect the eyeball circled in green below.  Anyone know the python API for this? Summing Up A 2D Array Redirecting from http to https in Apache This is a  about redirecting from http to https in Apache Related:     I have an Appache web server which serves both http://example.com/ and https://example.com/. I want to redirect all http requests to https. Currently I'm using this .htaccess rule to redirect http requests to https. RewriteEngine On RewriteBase / RewriteCond %{HTTPS} off RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}   It's working as expected for example.com but the same rule is not working for sub links, when I access existing links, like example.com/about it will still load in http, no redirection happens for existing links. How can I make Apache redirect all http requests to https? Animating Dynamic Paint with noise texture Proving $\tan(\theta_1+\theta_2+\cdots+\theta_n)$ has the form $\frac{S_1-S_3+S_5+\cdots}{1-S_2+S_4+\cdots}$ $$\tan(\theta_1+\theta_2+\cdots+\theta_n)=\frac{S_1-S_3+S_5+\cdots}{1-S_2+S_4+\cdots}$$  where  $S_i$ denotes the sum of product of tangent of angles taken $i$ at a time.     For example,$$\tan(\theta_1+\theta_2)=\frac{S_1}{1-S_2}=\frac{\tan\theta_1+\tan\theta_2} {1-\tan\theta_1\tan\theta_2}$$   (This formula is given  in my textbook with no derivation or background)  How to derive this? Enable ADB and/or change USB connection mode on Galaxy S7 w/ broken screen Solving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException