I am a South African passport holder and will be travelling to Mexico in May for 10 days. My flight is via a US airport, where I will be in transit for a few hours on the way to Mexico and then again when I return. I will not actually be visiting the US at all.  I understand that US tourist visa holders can enter Mexico as a tourist. I have 2 questions:   If I apply for a C1 US transit visa, can I still use this to enter Mexico? Or does only the B1/B2 US visa allow for entrance into Mexico? Once I get my US visa, do I have to separately apply for a Mexico tourist visa or can I just arrive in Mexico and show them my passport with the US visa in it – ie is this enough?
Can someone please confirm the following? I have a C1/D visa. I worked as a flight attendant (currently unemployed) and entered the US numerous times, and also visited Mexico in December 2017.  I am planning on visiting Mexico again for 3 weeks in due course. Will the C1/D allow for me to transit in the US and visit Mexico or do I need a B1/B2 visa? I had issues with CBP before as it seems to be a very grey area.  According to the Mexican Consulate in South Africa, the type of visa is irrelevant. As long as it is multiple-entry, I am good to go.  Can someone please confirm, as I cannot get a solid answer from anyone?  Thank you!
Where are the necessary places to be appended with % to remove unwanted spaces? I have  experience where empty spaces cause unwanted effects. It is not easy to trace the cause of these unwanted effects. In order to eliminate any doubt, I often overuse % as follows.   \usepackage% [% left=3cm, right=3cm% ]% {geometry}   or  \newcommand{\mycommand}% {% This is my command.% }   I got an extreme example that will break what Leo Liu said     In fact, only spaces which would be   output have to be removed by comment.   The following code does not produce output, but we cannot remove the % and leave a blank line between two elements of a list below.  \newpsstyle{gridstyle} { gridwidth=0.4pt, % griddots=0 }   Shortly speaking, where are the necessary places to be appended with % to remove unwanted spaces? Is the collapse of the wave function inherently time asymmetric? What are FML and BWSS? I see this ad sometimes and I would like to know what the acronyms are. Web sites can contain JPEG, GIF,PNG, SVG format graphics. Which ones should be used, and when? I am unable to find the link for downloading Ubuntu 16.04 onto my   desktop/laptop. I am able to see the link only for 18.04, but I need 16.04. Why some dragon claw doors do not open? What are your thoughts on epigraphs in theses? I am wondering if there is a general consensus as to the suitability of epigraphs in a thesis, either a single one at the start of the document, or an appropriate quote to begin every chapter.  For example, at the start of a technical chapter describing some code, I could write     Beware of bugs in the above code; I have only proved it correct, not tried it. - Donald E. Knuth   I am lucky to have complete freedom over how I choose to typeset my thesis (Master's thesis in astronomy) and I like the idea of a thematic quote to begin a chapter. However, I am wary of seeming unprofessional or tacky so I am curious to get some more thoughts on the matter. Consider these two sentences: "I gave him a pencil," and, "I gave a pencil to him."  Is it correct that the important part of the sentence is placed at the end? When we want to emphasize the pencil that I gave him, must we say, "I gave him a pencil?" When we want to emphasize that it is him to whom I gave a pencil, must we say, "I gave a pencil to him?" I want to check if points layer that I have intersect with polygons layer that I have, as Boolean column in the points dataframe. I have two GeoPandas dataframes, the first one is many points and looks like this: &gt;&gt;&gt;ID  geometry 0  12  POINT (5.0279 7.4547) 1  45  POINT (6.6539 12.139) ...  and the second dataframe is one layer of many different polygons  that looks something like this: &gt;&gt;&gt;name     code   geometry 0  Desert   12     POLYGON ((5.52013 13.8902, 5.5265 13.892,...) 1  Water    24     POLYGON ((5.53756 13.88472, 5.5291 13.8791,...) ...  I'm trying to check if there is any intersection between the points layer and the regions layer. For that I have determined the crs and then used intersects : regions=regions.to_crs({'init': 'epsg:4326'}) points=points.set_crs({'init': 'epsg:4326'}) inter=points.geometry.intersects(regions.geometry)  A The script runs with the following warnings:  FutureWarning: '+init=:' syntax is deprecated. ':' is the preferred initialization method. When making the change, be mindful of axis order changes: https://pyproj4.github.io/pyproj/stable/gotchas.html#axis-order-changes-in-proj-6 return _prepare_from_string(&quot; &quot;.join(pjargs)) /opt/conda/lib/python3.8/site-packages/geopandas/base.py:39: UserWarning: The indices of the two GeoSeries are different. warn(&quot;The indices of the two GeoSeries are different.&quot;)  Then when I check the results the only value is False, like all th epoints do not intersect: inter.unique().tolist() &gt;&gt;&gt;[False]  *I saw on QGIS that the there are points that intersect and there are points that do not so there is no way this result is true *I have checked the dtypes - each one of my geodataframes has one column that is geometry and called geometry. My end goal: to add new column in the points geodataframe that will tell if it intersects the regions or not. Piping data through arbitrary functions in Clojure Complement of maximal multiplicative set is a prime ideal Let $R$ be a commutative ring with identity. I've been trying to prove the following:     If $S \subset R$ is a maximal multiplicative set, then $R \setminus S$ is a prime ideal of $R$.   I have spent some time in it, but nothing is coming to my mind. Any idea/solution will be appreciated. A way of casting a base type to a derived type How to get time difference in minutes in PHP How to calculate minute difference between two date-times in PHP? I want to change my computer's password. Right now my password is abc123. I run this command:  sudo passwd   I entered my current password and then a new one but the change does not take effect. How can I resolve this problem ? Cruising the old questions I came across juantheron asking for $\int \frac {\sec x\tan x}{3x+5}\,dx$ He tried using $(3x+5)^{-1}$ for $U$ and $\sec x \tan x$ for $dv$while integrating by parts.  below is his work.  How can I calculate $$ \int {\sec\left(x\right)\tan\left(x\right)  \over 3x + 5}\,{\rm d}x $$  My Try:: $\displaystyle \int \frac{1}{3x+5}\left(\sec x\tan x \right)\,\mathrm dx$  Now Using Integration by Parts::  We get  $$= \frac{1}{3x+5}\sec x +\int  \frac{3}{(3x+5)^2}\sec x\,\mathrm  dx$$  Here he hit his road block.   I tried the opposite tactic   Taking the other approach by parts.   let $$U= \sec x \tan x$$ then$$ du= \tan^2 x \sec x +\sec^3 x$$ and $$dv=(3x+5)^{-1}$$ then $$v=\frac 1 3 \ln(3x+5)$$ Thus $$\int \frac {\sec x \tan x}{3x+5}\,dx= \frac {\ln(3x+5)\sec x \tan x}{3} - \int \frac {\ln(3x+5) [\tan^2 x \sec x +\sec^3 x]}{3} \,dx$$    As you can see I got no further than he did.   So how many times do you have to complete integration by parts to get the integral of the original $\frac {\sec x \tan x}{3x+5} \, dx$ or is there a better way? Join CSV file to shapefile I wanted to join a CSV file to a shapefile.  When I identified a field to facilitate the join, e.g.,   map &lt;- spChFIDs(map, as.character(map$ID))   it returned     Error in spChFIDs(SP, x) : lengths differ   Can anyone advise? For PhD applications, I have mentioned that I am interested in some research areas. Besides, I am thinking about mentioning some professors' names, so that it shows I have read their websites and I am not just sending out generic statements applicable to many schools.  But is it good to mention some professors' names in the statement of purpose, if I don't know them personally? In what cases is it good, and in what cases it isn't?  For example, is it good to only mention    those whose research directions are aligned with my research interests, or/and those whose books or notes I have heard of, or better, might have read some parts of, or/and those who are already established and famous (such as having certain titles), or/and those that are directing the PhD graduate programs, or/and those that are heads of the departments?    What will other professors who are not mentioned think? How will you do, if it were you? Trying to find a book about kids with 'sunguns' revolting against alien overlords I'm trying to identify a book (or possibly a series, as I seem to recall reading a sequel which still left the story unfinished).  I read the book or books in the early 90's and had picked them up from a jumble sale at school, so they were probably published in the 80's or possibly 70's. I guess you would class them as YA fiction, though that wasn't really such a thing back then...  As I recall the story began with a slave transport craft crash landing on an alien world, with only a handful of teenage and pre-teen humans surviving. They scraped together what they could, including a couple of functional 'sunguns' (basically, laser rifles) and began a low level guerilla rebellion against the alien race that were using humanity as slave labour on the planet.  I've googled 'sungun' repeatedly, thinking that this should be the best way of finding the story but the references that come up are all for other stories or conspiracy technologies.  Anyone got any vague recollections of a book or series like this? I'm Egyptian and flying to Cairo from Tbilisi, via Istanbul. The first flight Tbilisi-Istanbul is on Atlasjet, then from Istanbul to Cairo I am flying on Egyptair. For that, I have to recheck in at Istanbul to my Egyptair flight  Will I need to pass passport control at Istanbul airport to collect my bags and check in on Egyptair? Will I need a transit visa for that? Or it can be all done through neutral zone? Hide back faces in 3D View? How do you hide back faces so that you only see faces when its normal is facing the camera? When exporting it for use in a game, the face is rendered in only the direction of its normal, so this would be useful to have something similar.