conference carbon footprint

As a local organiser of the recent BNP 11 conference in Paris, and hence involved in setting and cleaning coffee breaks and [now famous] wine&cheese poster sessions, I was rather shocked by the amount of waste generated by those events, albeit aware of the importance of the social exchanges they induced… And thus got to wonder how the impact of those conference events could be reduced. One solution is the drastic one, namely to provide exactly nothing at all during the breaks between talks and expect anyone hungry or thirsty enough to bring one own’s food or drink. Another one, as suggested by my daughter at the dinner table, is to provide Ecocups, namely reusable plastic glasses that can given to all participants at the beginning of the conference. Or sold (or rented) to those who have not brought their own mug or bottle. (Of course, this may be a poor idea in that manufacturing and shipping a hard-plastic glass that most likely will be discarded after a few days may be more damaging than producing the equivalent number of “disposable” thin plastic glasses. And in the end all this agitation is peanuts compared with the impact of flying participants to the conference. For which I have no handy solution… As biking to the conference location is a privilege very few can enjoy.) Still, and even though this puts another stone in the already rocky organisers’ garden, I wish we could adopt more positive policies at the meetings we organise and sponsor.

a weird beamer feature…

As I was preparing my slides for my third year undergraduate stat course, I got a weird error that got a search on the Web to unravel:

! Extra }, or forgotten \endgroup.
\endframe ->\egroup
  \begingroup \def \@currenvir {frame}
l.23 \end{frame}
  \begin{slide}
?

which was related with a fragile environment

\begin{frame}[fragile]
\frametitle{simulation in practice}
\begin{itemize}
\item For a given distribution $F$, call the corresponding 
pseudo-random generator in an arbitrary computer language
\begin{verbatim}
> x=rnorm(10)
> x
 [1] -0.021573 -1.134735  1.359812 -0.887579
 [7] -0.749418  0.506298  0.835791  0.472144
\end{verbatim}
\item use the sample as a statistician would
\begin{verbatim}
> mean(x)
[1] 0.004892123
> var(x)
[1] 0.8034657
\end{verbatim}
to approximate quantities related with $F$
\end{itemize}
\end{frame}\begin{frame}

but not directly the verbatim part: the reason for the bug was that the \end{frame} command did not have a line by itself! Which is one rare occurrence where the carriage return has an impact in LaTeX, as far as I know… (The same bug appears when there is an indentation at the beginning of the line. Weird!) [Another annoying feature is wordpress turning > into > in the sourcecode environment…]