Page 10 - BBC Knowledge - October 2017 IN

Questions
& Answers
W H A T C O NNE C T S

…FROGS AND FRESH
MILK?
1

Frogs, like all
amphibians,
have thin,
porous skin that
they can breathe through.
But this also poses a risk
because it makes it easier
for bacteria to infect them.
2

DO SEAGULLS DRINK SEAWATER?
AND, IF SO, HOW DO THEY DEAL To protect
WITH THE SALT? themselves,
frogs secrete
All seabirds drink seawater – yet birds have less efficient kidneys than mammals, substances
and so excess salt is even more toxic to them than to us. Seabirds cope with this called cationic antimicrobial peptides
by using specialised salt glands next to their eye sockets. These look like miniature (CAMPs). Other animals secrete CAMPs
kidneys and work in a similar way, pumping salt ions out of the bloodstream against too, but frogs produce much more,
the normal flow of osmosis. The extra-salty water drips down the side of their beak. LV including some peptides that are
effective against multi-resistant bacteria.

HOW DO WE TALK CAN THE PLACEBO
3
IN OUR HEADS? EFFECT HARM YOU?

Milk goes off
because of
bacteria,
especially
species of
Lactobacilli and Pseudomonas. These
ferment the lactose in milk into lactic
acid, and hydrolyse milk proteins into
Talking in our heads is referred to various unpleasant tasting by-products.
by psychologists as ‘inner speech’.
It involves some similar processes to
‘overt’ speech – it recruits brain regions 4
involved in language, such as the
Broca’s and Wernicke’s areas, and is
even accompanied by minute muscle According to
movements in the larynx. However, there Just as the placebo effect causes Russian
are notable differences too, with brain positive results if you believe you are folklore,
areas useful in inhibiting overt speech taking beneficial medicine, there is putting a live
playing a greater role in inner speech. a negative version, called the nocebo frog in milk
The exact brain mechanisms involved effect. This creates harmful effects such would help it PHOTOS: SCIENCE PHOTO LIBRARY, SHUITTERSTOCK
may come down to why we are talking as pain, high blood pressure, dizziness stay fresh. Recent
in our heads in the first place. For and rashes if you believe that these are research has found
example, when we read a book, possible side effects of the medication that CAMPs from the Russian brown
brain regions involved in attention you have been given, even though it’s frog could kill the bacteria in milk
may be more active than when we are a placebo. LV and prevent it from turning.
mentally preparing for a race. AGr
10
OCTOBER 2017