Africa Water, Sanitation & Hygiene 2014 Sept - Oct Vol. 9 No.5 | Page 42

Roundup
in such a way that
the unpolarized light
becomes polarized,
meaning the light
waves travel in one
direction.

Free online course on urban sanitation starts 13
October
By Cor Dietvorst
A team of instructors led by Christoph Lüthi from the
École Polytechnique Fédérale de Lausanne (EPFL) are
eager to teach you how to plan urban sanitation systems.
Together with Sandec/Eawag, EPFL has designed a 5
week online course introducing sector planning tools and
frameworks such as Sanitation 21, Community-Led Urban
Environmental Sanitation (CLUES) and the Sanitation
Systems Approach.
The course consists of lecture videos (English, with
French subtitles), practical exercises, a homework quiz
and a final exam. The questions and explanations for the
practical exercises, the homework quiz and the final exam
are offered in English and French.

Outlining their

Greater mouse-eared bat, Myotis myotis, findings in a study
from Bulgaria published by in Nature

Communications, the
researchers admit that they have no idea how the bats are
able to detect polarized light.

Mysterious crop circle on Bavarian wheat field attracts
many visitors

Cap Galaxy NGC

This is a newly released composite image of the spiral
galaxy NGC 4258, which is also known as M106. The image
was composed from X-ray data from NASA’s Chandra
X-ray Observatory, radio data from the National Science
Foundation’s Karl Jansky Very Large Array, optical data from
the Hubble Space Telescope as wells as infrared data from
NASA’s Spitzer Space Telescope. (NASA)

Bats Rely on Polarized Light to Reset Their Internal
Compasses
A species of bats, called Greater mouse-eared bats, use the
polarized light of the setting sun to calibrate their internal
magnetic compass, which helps the flying animals travel in
the right direction, according to a new report.
The sun usually gives off unpolarized light, which means
that the light waves bounce all over the place. However,
at sunset the light waves interact with the atmosphere
42

Africa Water, Sanitation & Hygiene • September - October 2014

On July 28, 2014 photo visitors walked through a crop
circle in a wheat field near Raisting, southern Germany. A
balloonist had discovered the crop circle earlier on. Since
then thousands of esoteric fans came to visit the circle
whose appearance is unknown. Farmer Christoph Huttner,
the owner of the field, said that he was not responsible for
the crop circle.

Arsenic in Water Supplies
Did you know that arsenic-contaminated water affects the
health of over 140 million people worldwide?
According to a quote by Allan Smith from the University
of California at Berkeley in an article on BBC news, “one
in every ten people with high concentrations of arsenic in
their water will die from it.” Arsenic consumption leads
to higher rates of some cancers, including tumors of the
lung, bladder, skin and other lung conditions. Some of
these effects show up decades after the first exposure.
This issue stems beyond drinking water. Especially in
developing countries, food grown in contaminated soil
can quickly spread disease throughout the population. For
example, rice is typically grown in paddy fields; flooded
with potentially contaminated water.