Track Repairs

Old railway lines easily break down and need regular maintenance. Without that, weeds and trees grow on the line. Trains crash. Similarly, DNA is unstable and can break up. Now, it appears that some of these mutations can be repaired.

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The 2015 Nobel Prize in Chemistry has been awarded to Tomas Lindahl and Paul Modrich and Aziz Sancar for discoveries in DNA repair. They aim to put right some familiar mutations.
Their work uncovered mechanisms used by cells to repair damaged DNA – a fundamental process in living cells and important in cancer. Tomas Lindahl is from the UK’s Francis Crick Institute.

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Damaged sites in the chromosomal DNA can result in cell death or cancer, but may be corrected by DNA repair enzymes prior to phenotypic expression.

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The prize-winners investigated properties of several nuclear enzymes that remove harmful lesions or local aberrant structures from DNA. The absence of such DNA repair factors may result in an increased frequency of malignant transformation, or in some cases may be detected as immunological deficiencies.

Elements

Periodic Tales is at Compton Verney, Warwickshire until December 13th. It shows cultural experiments with some elements of the periodic table. The show is said to contain “Something common in the universe but rare on earth” or it may be more mysterious philosophically.

Antony Gormley, FUSE, 2011, Cast Iron, Photography by Stephen White, © Image Courtesy of White Cube

Antony Gormley, FUSE, 2011, Cast Iron, Photography by Stephen White, (c) Image Courtesy of White Cube JPEG RES

Kate Williams and John Lloyd, Nuclear Power Stations © The Artist

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Cornelia Parker, Thirty Pieces of Silver (Exhaled), 2003, 30 silver plated items crushed by 250 ton industrial press, metal, wire © Image Courtesy the artist & Frith Street Gallery, London

Cornelia Parker, Thirty Pieces of Silver , 2003, 30 silver plated items crushed by 250 ton industrial press copy

John Newling, Mine, 2005 © The Artist

John Newling, Mine, 2005

The show is curated by H Aldersley-Williams, with most objects made of a single element that is central to their role.

Uncle Oliver

The novelist and neurologist Oliver Sacks died this week (1933 – August 30 2015).

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Oliver Sacks worked on the medical effects of neurotransmitters such as  L- Dopa. This can be synthesised and added to biochemical pathways in human nerve cells. The pathway shown here is involved with Parkinson’s Disease.

Recently Sacks wrote: “I find my thoughts drifting to the Sabbath, the day of rest, the seventh day of the week, and perhaps the seventh day of one’s life as well, when one can feel that one’s work is done, and one may, in good conscience, rest.”

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Aurora

An aurora has been spotted outside our Solar System for the first time. The light display is around a brown dwarf about 18 light years away in the Lyra constellation. Its luminous glow looks like the Northern Lights, but is up to a million times brighter and more red than green in colour.

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This artist’s impression (above left) shows the brown dwarf’s aurora, which is red and extremely bright. The photograph (above right) is of the Northern Lights on Earth.

The findings are reported by G Hallinan et al in the journal Nature 523, 568-572 July 2015.

On Earth, shimmering auroras give dazzling displays. The glows can also appear around all the planets in our Solar System. They are caused when charged particles from the Sun interact with the atmosphere.
But the illuminated brown dwarf, an object which is too small to have become a star but too massive to be a planet, lies further out in the galaxy.
Called LSR J1835, it was observed using the Very Large Array radio telescope and the Hale and Keck optical telescopes.

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On Earth, the green hue is caused when the Sun’s charged particles interact with oxygen in the atmosphere
The dwarf’s aurora is mainly red in colour because the charged particles are mainly interacting with hydrogen in its atmosphere. On Earth, the greenish glow is caused as the electrons from the Sun hit oxygen atoms.

The brown dwarf is a sort of failed star itself, and has no other star like the Sun nearby to blast it with charged particles.
Either, the aurora is made from material being stripped off the surface of the brown dwarf to produce its own electrons, or an undetected planet or moon around the dwarf is throwing off material to light it up.

Some of Jupiter’s auroras are produced in this way, as charged particles are emitted from volcanoes on its moon Io –

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Limpets

Like most animals, the limpet (marine mollusc species of the genus Patella) has teeth and a tongue as part of the mouth:

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The tongue with its tiny teeth scrapes food off rocks and into the mouth, and it often swallows particles of rock in the process. The teeth are made of a mineral-protein composite, which has recently been tested in the laboratory.

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In the latest edition of Royal Society Interface, A Barber reports that limpets’ teeth consist of the strongest biological material ever tested. He suggests that the secret to the material’s strength is the thinness of its tightly packed mineral fibres – a discovery that could help improve the man-made composites used to build aircraft, cars and boats, as well as dental fillings.

In 1831, Sarah Hoare wrote: Poems on Conchology and Botany, strong statements of Victorian confidence give a different spin on the limpet’s adhesive strength:

Patella to the rock adheres,

Not of the raging tempest fears

The most tremendous power;

And though assail’d on every side,

Close to the guardian will abide,

Her strength, her fortress, and her pride,

Her never failing tower.

Gas

Across Britain, the old gas holders are being demolished to release inner-city space for re-development.

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For a century the national grid was supplied from these structures, a crude mixture of carbon monoxide and other volatile products from black coal, mined from abundant Carboniferous deposits.

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The holders encouraged their own design and architecture

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Now, natural gas is transmitted under pressure over long distances and there is no need for local storage systems.

The planet Neptune stores gas differently, the metal inside and the gas out:

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Beneath clouds of the outer atmosphere (1, above) there is also gas (2), ammonia, methane and hydrogen. Layer (3) is solid water and other ice. The core (4) is solid rock of silicates and metals.

[pictures from BBC]

Gas on Mars

Today’s newspaper headlines claim there is life on Mars, but all NASA have detected is the occasional puff of methane, as announced in Science magazine.

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On Earth the gas is not so romantic, for methane is a major greenhouse gas.

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In the same issue of Science, NASA announce that they may also have seen waves on the sea of Saturn’s moon Titan. What’s more, the sea is not made of water, but methane – below right.

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(Gas-Mask Skull at galleryhip.com; Drill Pipe by Greg Evans at evansart.com)

At least, NASA’s announcement has generated enough interest to justify further funding to find out more.