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Can I delete files or folders from /private/var/folders/? I have this folder /private/var/folders/bf/ with 3GB of what seems temporary files. Can I delete this folder? Are these plural or singular? I was surprised when I heard zero is plural, and even 1.00001 is plural.  Then, what about following numbers ?  (1) 1.00  which means the value measured  between 0.995-1.004, having possibility that it was exactly 1.  (2) 0.99999.....  which is mathematically equal to 1. Also, are others that are mathemattically equal to 1 than this, treated completely same as 1?  (3) -1  Is this singular? Or negative numbers are generally plural?  (4) i = square root of -1  I know it's weird to count things with imaginary numbers, nonetheless, if you were to count, which form, plural or singular, would you be to use?  That's it. When changing fields, should I focus more on describing past research or connecting it to the new area in my statement of purpose? I want to change my field from molecular biophysics to theoretical ecology. While they are basically required some same basic background (physics, math, programming), the rest is quite irrelevant. In my current draft of this part, about a half is about this the problem and the result of the work, another half is for my contribution and what I've learnt. Having said that, should I focus less on describing the work and leave space for the thing that will be useful for the next research?  Below is copy from .     What have you already done? What problems have you solved, or at least worked on? What independent projects have you been part of? What were your key contributions? What did you learn? What did you teach the world? How do your results compare to what was already known? What original ideas are you most proud of? Be specific, technical, credible, and confident (but not arrogant). Refer the reader to your web page for more details. Have a web page with more details: preprints, project reports, source code, videos, etc. What does a linear transformation do to a vector in $\mathbb{R}^2$ $\newcommand{\Reals}{\mathbb{R}}$Doing some linear algebra. This question has me intrigued. I imagine it causes the vector to rotates the $x$ axis. But I mean, is there more to it?  $$ T_{A(\theta)}: \Reals^2 \to \Reals^2,\qquad A(\theta) =  \left[\begin{array} {rr}\cos \theta &amp; -\sin \theta \\   \sin \theta &amp; \cos \theta \\ \end{array}\right]. $$ What, geometrically, does the linear transformation $T_{A(\theta)}$ do to a vector in $\Reals^2$? delaying moldy bread I always keep bread around, home-made or otherwise.  Is there a way to keep it from molding, or at least delay the process?  I've tried the fridge with some success (extra day or two), but I don't like my bread that cold to eat.  I've tried zip-top bags with no success (seems to mold faster).  Bread-box didn't seem to make any difference in time.  Thanks Platform diving: How deep does one go into the water? I am a platform diver. I am trying to figure out how deep in the water I go depending on which platform I dive from.  The platforms are 1m, 3m, 5m, 7.5m and 10m above the water surface.  By ignoring air resistance (we assume that I do not do any tricks) I can easily compute the energy that my 90 kg body has when it is hitting the water:  E = mgh = 0.5mv^2   My problem is to find the deceleration in water and thus how deep my feet will go into the water before coming to a halt. We can assume that I stand straight and fall straight down and have a height of 190cm.  How do I compute that? Test the convergence of the series For $a&gt;0$, test the convergence of the infinite series: $$\sum a^{\ln(n)}$$ Which test should be better to use here? I tried the D'Alembert's ratio test. $$\lim_{n\to \infty} {\frac{a^{\ln(n)}}{a^{\ln(n+1)}}}= \lim_{n\to \infty}a^{ln{\frac{n}{n+1}}}=a^0=1$$ So the test failed.  UPDATE: I observed that $${a^{\ln(n)}}=e^{{\ln(a)}{\ln(n)}}={n^{\ln(a)}}={{1\over n^{ln({1\over a})}} }$$Further by test of auxiliary series $$\sum \frac{1}{n^p}$$ we know that criterion for convergence is $p&gt;1$. Here $p=ln({1\over a})$.Hence the series will be convergent when $ln(a)&lt;-1$ i.e. when $0&lt;a&lt;1/e$, since $a&gt;0$ is already given.Finally this solved my question. How can you check for a #hash in a URL using JavaScript? What is a good way of parsing command line arguments in Java? What does the explicit keyword mean in C++? Neopronouns or trolling? It’s the  question: Am I looking at someone’s legitimate pronouns or trolling?   (It’s unfortunate I have to ask, but this is just where we are right now.)  I’ve seen “my pronouns are [insert ridiculous fake stuff here]” trolling recently (in posts) when before I never did. Also stuff that looks to be trolling, but could also maybe not be. Trolls deserve red flags while everyone else specifying pronouns does not, right?  (To clarify, the problem is not just about not wanting to use a troll's words. The purpose of some of this trolling is to try and convince people that transgender people—or their neopronouns—are stupid or unreasonable. Ignoring the trolls allows us to avoid the first problem, but not the second since it allows them to still reach people with their message, which is not something that I want to see promoted.)  Some neopronouns are clearly legitimate. Some trolling is clearly trolling. But unfortunately there’s a big grey area where it’s not clear to me what is what.   Does anyone have a good method for dealing with this? There just doesn’t even seem to be a good way to ask about someone’s specified pronouns in such a way that doesn’t sound insulting if the user isn’t trolling.     Note: A while ago, I did some research on neo-/third person pronouns which can be found . There are several important things I found:   There are more neopronouns than I could ever hope to keep track of The most popular neopronouns are very uncommon. On the other end of the spectrum, it looks like some neopronouns are neologisms used by a single person  Some neopronouns come from unlikely places, such as SciFi Prediction in Cox regression I am doing a multivariate Cox regression, I have my significant independent variables and beta values. The model fits to my data very well.   Now, I would like to use my model and predict the survival of a new observation. I am unclear how to do this with a Cox model. In a linear or logistic regression, it would be easy, just put the values of new observation in the regression and multiply them with betas and so I have the prediction of my outcome.  How can I determine my baseline hazard? I need it in addition to computing the prediction.  How is this done in a Cox model? Matlab Recursion Loop Simple past or past perfect with "by" and years What is the difference between      He became a star by 1990's.     He had become a star by 1990's.    Is the first sentence correct? If yes, then please tell me the difference between the two. Add an unnmbered section to the table of Contents in Lyx importing a multipage PDF file into InDesign CC When I place a multipage pdf file into InDesign CC, the pages go outside of my document settings, making this function useless.  What do I have to do to make the placed  pdf pages go within my document settings, which in this case is 11 in. Length X 8.5 in. width, .5 in. margins on all sides, with two columns per page. I would greatly appreciate an answer to this, Thank you. Accidentally deleted /etc/fstab file I accidentally deleted my /etc/fstab file by running sudo rm /etc/fstab. Without realising what I'd done, I shut down my Ubuntu OS.  Now I'm not able to boot.    My screen looks like this. In some cases, a purple screen appears. Please give me some solutions. Can anybody explain the UNABLE_TO_LOCK_ROW error? Problem with option border of class standalone I tested a MWE given in question . Following the documentation (page 9) I used the class option border={left right bottom top} with left=right=top=0pt and bottom=20pt (20pt only to show the effect here).  With the version 2012/09/15 v1.1b of standalone and the following MWE I get no 20 pt margin at the bottom of my picture.  What is the problem?  MWE:  \documentclass[% % border=1pt   border={0pt 0pt 20pt 0pt} %left right bottom top ]{standalone}% http://ctan.org/pkg/standalone \begin{document} $2^5 = x_5 \times y^8$ \end{document} Is there a way to get new dwellers with higher than normal stats?