Category: Slimey stuff
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Why spiders’ silk is so much stronger than silkworms’
Spider silk and silkworm silk are almost identical in chemical composition and microscopic structure. And yet spider silk is far tougher. “One strand of pencil thick spider silk can stop a Boeing 747 in flight,” say Xiang Wu and colleagues at the National University of Singapore. Whereas a pencil thick strand of silkworm silk couldn’t.…
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The coming of age of hadrontherapy
There’s a problem with conventional radiotherapy for tumours: the body absorbs the radiation as it passes through. So zap a deep seated tumour with X-rays and the dose decreases exponentially with the depth of target. This means that both diseased and healthy tissue end up getting targeted. In 1946, Robert Wilson, a physicist at FermiLab…
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Glider guns created in chemical Game of Life
If you’ve ever played Conway’s Game of Life, you’ll be familiar with cellular automata and, more importantly, glider guns. So get this: a team of British chemists and computer scientists have created a chemical cocktail that behaves like a cellular automata and which reproduces this behavior: chemical guns firing chemical gliders across a chemical grid.…
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Fermi’s paradox solved?
We have little to guide us on the question of the existence intelligent life elsewhere in the universe. But the physicist Enrico Fermi came up with the most obvious question: if the universe is teeming with advanced civilizations, where are they? The so-called Fermi Paradox has haunted SETI researchers ever since. Not least because the…
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Rippling in muscles caused by molecular motors detaching
Muscle tissue is made of molecular engines called sarcomeres, which contract and expend when the muscle is flexed. In sarcomeres the business of contracting is carried out by molecular motors called myosins as they pull themselves along filaments of a protein called actin. When you flex your arm, it is these myosin molecular motors that…
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Is meditating good for the heart?
Let’s calm things down with some deep breaths: in…out…in…out. Relax. Feel your pulse rate slowing? We’ve known for some time that there’s more to pulse rate than beats per minute. Heart rate variability–the change in intervals between beats–can be used to distinguish healthy hearts from diseased and damaged ones. One sign of a healthy heart…
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Electronic nose spots anthrax bacteria by smell alone
In the last ten years or so electronic noses have become commercially available, based on a detection device known as a Taguchi sensor. These are heated semiconductor oxide films that change their resistance when they absorb gases. The gases break down inside the film and the various molecular species gather at grain boundaries within the…
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The waltz of the spherical algae
“Long after he made his great contributions to microscopy and started a revolution in biology, Antony van Leeuwenhoek peered into a drop of pond water and discovered one of nature’s geometrical marvels,” say Ray Goldstein and pals at the University of Cambridge in the UK. Val Leeuwenhoek had discovered Volvox, a spherical green algae that…
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How to spot vegetation on Earth-like planets
In December 1990, scientists analysing data from the Galileo spacecraft found compelling evidence for the existence of life in space. The data famously came from the craft’s first fly by of Earth, a planet on which life seemed a definite possibility. The exercise led to the establishment of a number of criteria that if found…
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First “movie” of fruitfly gene network aging
One of the major goals in biology is to reconstruct the complex genetic networks that operate inside cells, and to “film” how these networks evolve during the course of an organism’s development. Today, Eric Xing and buddies at Carnegie Mellon University in Pittsburgh claim to have worked out how the way patterns of gene expression…