All of a flutter over the blues
QUESTION Is blue the rarest colour in nature?
A LACK of blue pigments in nature makes it the rarest colour in the plant and animal world.
Fauna and flora that appear blue, including peacocks, butterflies, bluebells and irises, are performing a sleight of hand using physics or complex chemistry.
Most colours in the plant and animal kingdoms are derived from pigments — coloured chemicals that absorb certain wavelengths of light. Granules of melanin help keep bird feathers strong and protect human skin from the sun. Chlorophyll allows plants to trap light energy for photosynthesis and gives them their green colour.
Many animals absorb pigments from plants and eventually display them. In the case of flamingos, which are born grey, their diet of blue-green algae and brine shrimp, which contain pigments called carotenoids, turns them pink.
Likewise, wild salmon consume small fish and crustaceans, accumulating enough carotenoids to turn pink. Farmed salmon are fed colour additives to achieve deeper shades of red and pink.
Humans will turn orange if they consume too many carrots.
The blue colour displayed by some animals are usually due to the structure of their external molecules and the way they reflect light, a process known as coherent scattering.
The blue morpho butterfly from Latin America gets its colour from the fact its wing scales are arrayed in ridges that cause sunlight to bend in such a way that a vibrant blue light, at just the right wavelength, makes it to our eye.
If you were to grind up the butterfly’s wing, it would be robbed of its reflective prism and appear as grey dust.
Birds such as the blue jay get their colour through a different process: each feather is made up of light- scattering, microscopic beads spaced in a way that everything except blue light is cancelled out. The only exception is the
South American obrina olivewing butterfly. It’s the only known creature that can produce a blue pigment: a bile pigment called pterobilin.
Plants that appear blue use naturally red pigments known as anthocyanins that they alter by increasing its PH.
Vanessa Gower, Malvern, Worcs.
QUESTION Did an Irish missionary introduce competitive distance running to Kenya?
YES, an Irish missionary was inspired by the brother of Olympian Sir Brendan Foster to train students in distance running, helping to make Kenya famous for the sport.
Brother Colm O’Connell was born near Mallow, County Cork, in 1948. A geography teacher, he travelled to Kenya in 1976 for what was supposed to be a short stay at St Patrick’s High School in Iten, a small town in the Rift Valley.
There he was introduced to longdistance running by Peter Foster, the brother of 10,000m runner Sir Brendan. Peter was in temporary charge of track and field at the school on behalf of Voluntary Service Overseas and introduced a sporting regime of interval training and hill work.
He pointed out to Brother Colm the remarkable potential of many of the students. When Foster returned home, Brother Colm took over coaching duties.
What he lacked in experience he made up for in an uncanny ability to get the best out of his pupils.
Alongside standard training methods, he became expert at spotting talent, honing an athlete’s mental strength and boosting their confidence. Brother Colm is acknowledged as the world’s most successful coach of endurance running, having trained five Olympic gold medallists and 25 world champions. Thanks to his tutelage, Peter Rono won 1,500m gold at the 1988 Olympics and Matthew Birir won 3,000m steeplechase gold at the 1992 Olympics. He also trained female world champion Sally Barsosio and marathon winner Rose Cheruiyot. However, he’s most famed for discovering two of the most prodigious talents in middle- distance running: Wilson Kipketer and David Rudisha. Brother Colm was headmaster of St Patrick’s High School from 1986 to 1991. In 2003, he established an Aids awareness programme at a Kenyan teacher’s college. He still lives at St Patrick’s, where he is admired for his compassion, humility and loyalty. Peter Oliver, Beddgelert, Gwynedd.
QUESTION What is the gellike substance used to preserve the Covid test swab?
TESTING methods for Covid-19 rely on the detection of RNA (ribonucleic acid) using a polymerase chain reaction test that checks for genetic material of the virus in the sample.
RNA is sensitive to external factors, such as the presence of ribonucleases (enzymes that break up Rna) and changes in temperature and acidity or alkalinity (PH).
Due to the high volume of testing required during the pandemic, viral RNA in nose and mouth swabs and sputum needs to be kept stable by commercial viral transport media.
These vary between manufacturer, but are typically based on balanced salt or saline solutions with a buffering capacity to maintain a near neutral PH, an antimicrobial agent to suppress the growth of contaminating bacteria and fungi, and a protein supplement to enhance the stability of the RNA.
Bovine serum albumin is a popular choice because it’s a heavy globular protein that is stable and doesn’t interfere with biological reactions.
Dr Ian Smith, Cambridge.
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