I have tried all the ones suggested here:  (among others) in a .replace(regex, "") JavaScript function, but they either remove characters with accents too or leave other invalid non-UTF-8 characters.  Use case: I'm fetching XML data from a Spanish client and some items contain invalid non-UTF-8 characters which make the XML not parsable (even making the GET request through Chrome gives me "Input is not proper UTF-8"), but I want to keep all characters with Spanish accents ("tildes"/"acentos")  Example of invalid symbols mixed with accented and non-accented letters (for testing):     muérdago áéíóúàèìòù F̸̡̢͓̳̜̪̟̳̠̻̖͐̂̍̅̔̂͋͂͐l̸̢̹̣̤̙͚̱͓̖̹̻̣͇͗͂̃̈͝a̸̢̡̬͕͕̰̖͍̮̪̬̍̏̎̕͘ͅv̸̢̛̠̟̄̿���
How can I use Unicode-aware regular expressions in JavaScript?  For example, there should be something akin to \w that can match any code-point in Letters or Marks category (not just the ASCII ones), and hopefully have filters like [[P*]] for punctuation, etc.
Explicit space character? I'm wondering about the best way to do an explicit space character (I don't even know what it's properly called), like the ones you get in the \begin{verbatim*} environment. The closest I've found is  \sqcup   in math mode, but it seems like a bit of a hack to me. Is there any text symbol for what I'm looking for? TestMethod do not support Web service callouts, test skipped Typeset an = with an ! above I've seen an equals sign with a small exclamation mark on top being used to say "equals because of data that was given in the problem", for example for a boundary condition or initial value in a differential equation.  A rough picture of what I mean:       ! f(x) = 4   How do I typeset this in LaTeX? I've tried $=^!$ (which doesn't produce the desired result) and looked through the "relations" section of the  without success. There is this puzzling thing that is called : paradoxically, warm (35°C) water freezes faster than cold (5°C) water.  As a physisist, I've been asked about it several times already. And I have no definite answer to that, apart from the standard: "there are many things that can influence it".  So, does anyone knows about the status or progress on that effect? Any recent reviews, publications or other references? Finding plane equation given two lines Determine an equation of the plane containing the lines $\frac{x-1}{2}=\frac{y+1}{-1}=\frac{z-5}{6}$; $r=\lt1,-1,5\gt+t\lt1,1,-3\gt$.   I calculated the cross product between the directional vector of both lines to find the normal vector $n$, but when I looked for an intersection point $r_0$ to apply the formula: $\lt r-r_0\gt \bullet \ \ n$, I did not find any.  Can I use the point $\lt1,-1,5\gt$ given in the line $r$? Or is it not possible to find an equation of the plane containing two lines that do not intersect? For example,      I like chocolate, vanilla, and lemon and orange ice cream.    Indicating "lemon and orange" is a combined flavor, as an item in the list needing an initial and. Shorter way to say "conversational partner" I'm looking for a proper English word to say "conversational partner".   Is "interlocutor" a word an average person would understand?  Are there any other words or shorter expressions which could describe a person you are having a conversation with, but who is not your friend and is basically unknown to you? I've read a number of the helpful Q&amp;As on photons that mention the mass/mass-less issue. Do I understand correctly that the idea of mass-less (a rest mass of 0) may be just a convention to make the equations work?  From a layperson's view, it's difficult to understand how a particle of light (photon) can be mass-less. A physical object (everyday world-large or quantum-small) must have a mass. Yet, if my understanding is correct, the mass of a moving object/particle increases in proportion to its speed/velocity...so that at the speed of light, its mass would be infinite. A photon travels at the speed of light, but it obviously doesn't have infinite mass, right? Can someone formulate a practical explanation that can be understood by middle-school to high school kids? Much thanks for the help.    Wow--your answers to my original Q below clear up much of my confusion. I now have the daunting task of going over these nuggets and working up an equation-less (hopefully) explanation of the mass-less photon for non-physicist types.  Yes, from a layperson's view, it does seem remarkable that an existing piece of matter-- which has to be made of physical substance--could have zero mass at rest (though a photon is never at rest). It would be almost understandable if a piece of matter made of nothing had zero mass, but that  seems to be an oxymoron, and "nothing" would equate to nonexistent, right?  In case you might find it interesting: I'm working on a writing project that posits we inhabit a universe that consists of matter (physical stuff) only, and that the NON-physical (aka supernatural) does not (and cannot) exist. For instance, if a purported supernatural phenomenon is found to actually exist, then by definition, its existence is proof that it is mundane/natural. All it would take to disprove this premise is reliable proof that ONE supernatural event has occurred. Despite thousands of such claims, that's never yet happened.  Who else better than physicists to confirm my premise? However, I do wish the TV physicists would explain the terms they throw about, some of which mislead/confuse their lay viewers. Case in point: "The universe is made up of matter and energy" (without properly defining the term "energy" as a property of matter).  The result is that laypersons are left with the impression that energy must therefore be something apart from or independent of matter (ie, nonphysical). Their use of the term "pure energy" without specifying exactly what that means adds to the confusion. (Thanks to your replies on this forum, I now understand that "pure energy" refers to photon particles.) However, "psychics" and other charlatans take advantage of such confusion by hijacking terms like energy (as in "psychic energy"), frequencies, vibrations, etc to give perceived scientific legitimacy to their claims that a supernatural spirit world, etc., exists. As you may realize, the majority of people in the US (per 2009 Harris Poll) and around the world believe in the existence of nonphysical/supernatural stuff such as ghosts and spirits.  My purpose is to give laypersons the information they need to distinguish what's real from what's not.  Thanks so much for help...And, PLEASE, add any further comments you think might be helpful/insightful to better inform laypersons. Why do cockroaches burst from soapy water? Math mode in tabular without having to use $...$ everywhere Why am I not getting a java.util.ConcurrentModificationException in this example? Grub rescue after installing Ubuntu on a external HDD from USB Best way to strip punctuation from a string It seems like there should be a simpler way than:  import string s = "string. With. Punctuation?" # Sample string  out = s.translate(string.maketrans("",""), string.punctuation)   Is there? garbled xml output If $\gcd(a,b)=1$, $\gcd(a,y)=1$ and $\gcd(b,x)=1$ then prove that $ax+by$ is prime to $ab$.  I tried assuming Diophantine Equations for all the relations and representing everything in terms of $a$, but that didn't lead me anywhere. There must be an intuitive and elegant approach right? Code in beamer presentation Good day! So, I need to present my disertation code to my thesis advisors, but I'm quite unsure how to actually do it in a proper way. I found  showing some ideas.  Is there a way of making the slides 48-67 in beamer without using tikz? Any ideas to implement the whole ideas the author propose?  Thanks in advance. How to preserve detail when downscaling scanned photos? I'm mixing analog with digital photography — I tend to take better photos when I can't look at a small digital screen, unconsciously forcing me to take the picture before I shoot instead of checking afterwards if it succeeded. I also like the grain film gives me.  However, most shots aren't worth spending much time in the darkroom, and scanning them is a lot faster. I'm wondering how best to convert the film to digital.  Scanning at lower than maximum (non-interpolated) resolution of my image scanner tends to exaggerate the contrast of the grain and screw up the mid-tones because of that.1 On the other hand, the resulting size of the scans are major overkill in most cases (I don't print them at A0 size), so I want to downscale the pictures. However, the grain confuses most methods and results in loss of detail and/or loss of the characteristic grain. For example, bicubic sharper tends to result in a "bigger" grain than the original. Now, the best compromise I've found so far is simply using bilinear interpolation, but I doubt that this is the best method to preserve both overall details and the look of the grain.  In short: when processing the scanned negative, how do I "best" preserve both image quality and the characteristic look of the grain?   As Stan Rogers pointed out below, there's a difference between truly scanning the grain of the film, and scanning the "grainy" character of film at lower resolutions. This question is about the latter; Stan Rogers explains how to do the first.  I'm looking for alternatives to the standard Photoshop options to try out, and reasons for each. Is the fact that every film has a different grain characteristic a problem? Are customized advanced noise reduction methods perhaps an option?  1. I'm using a Minolta DiMAGE Scan Elite 5400, using the software provided by Minolta.  As requested, here is a scanned picture with different resize methods. Just scanned this, scanning a B&amp;W negative to get better tonality range. I turned off grain dissolver, automatic dust and scratch removal, etc, for obvious reasons. On the right the pictures are upscaled again with Nearest Neighbor. I set the 8 bit scan to 16 bits before downscaling, assuming it reduces risks of banding if I choose to mess with curves, channel mixers, etc. No other modifications (usually I first retouch dust &amp; scratches, and in the end channel mix the picture to B&amp;W, then switch to 8 bits again). Can I ignore coefficients for non-significant levels of factors in a linear model? After seeking clarification about linear model coefficients  I have a follow up question concerning non-signficant (high p value) for coefficients of factor levels.  Example: If my linear model includes a factor with 10 levels, and only 3 of those levels have significant p values associated with them, when using the model to predict Y can I choose to not include the coefficient term if the subject falls in one of the non-signficant level?  More drastically, would it be wrong to lump the 7 non-significant levels into one level and re-analyze? Installing Wi-Fi driver for Realtek Semiconductor RTL8723DE Device [10ec:d723] On the three Stack Overflow chat servers, the  page displays the following image:    Is it from an actual episode, or is it a 'shop?