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Spiralling backwards
Last words past and present at newscientist.com/lastword
THE LAST WORD Hay fever fever
an antigen and opens fire as if a microorganism is about to invade. The result varies, from scratching and nasal congestion to a life-threatening anaphylactic shock, and the underlying mechanism, which involves IgE antibodies, is called a Type I hypersensitivity reaction,
or allergic reaction – from ancient n While researching why a Greek (állos meaning “other” professional gardener like me and érgon meaning “work” should suffer from the or “activity”). inconvenient curse of hay fever, An allergy is a superfluous I found a paper that suggested reply to an otherwise innocuous that the allergic reaction of hay environmental antigen. Most fever was the immune system’s people react to them, but in a mild response to the pollen grains way that causes no symptoms and trying to “implant” in the wet goes unnoticed. Others have a membranes of the human eyes genetic predisposition for a and nose. fiercer response. These “atopic” The pollen grains release a individuals – from the Greek word cocktail of chemical signals atopía, meaning “placelessness” – and stimulants that are designed produce between 1000 and 10,000 times more IgE antibodies “I read that hay fever is the immune system’s response than non-atopic people. to pollen trying to implant Recent evidence indicates in human eyes” another possible evolutionary significance of allergy, as a part of our defence against toxins. to help the growth of a pollen It has been shown that repeated tube into the female part of the exposure to bee and viper flower, but have an irritating venom confers resistance against effect on the human mucus subsequent potentially fatal membranes. doses of these poisons, and Grass species are windthat happens via a Type I pollinated and release huge hypersensitivity reaction. amounts of pollen into the air – Even carcinogens like aflatoxin so it’s no surprise that some of it produce that kind of reaction, ends up trying to pollinate us. and maybe that is why allergyThe paper also suggested that prone people develop fewer the main hay fever culprit in the cancers in tissues of the body UK is pollen of a particular grass that communicate directly called “Timothy” (Phleum with the external environment. pratense). The bottom line is that either This is a common agricultural allergy is an immune system crop that grows twice as tall as false alarm or a physiological most wild grasses and accounts anti-toxin adaptation. But its for a large proportion of pollen most potent role seems to remain because of its abundance. What’s the irritation of thousands of more, its pollen is particularly noses every year. aggressive in its biochemical Ilias Nikolakopoulos amorousness. National and Kapodistrian Nicholas Hall University of Athens, Greece St Just, Cornwall, UK
The writers of answers that are published in the magazine will receive a cheque for £25 (or US$ equivalent). Answers should be concise. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and an email address if you have one. New Scientist retains total editorial control over the published content. New Scientist Ltd reserves all rights to reuse all question and answer material that has been
submitted by readers in any medium or in any format and at any time in the future. Send questions and answers to The Last Word, New Scientist, 110 High Holborn, London WC1V 6EU, UK, by email to [email protected] or visit www.newscientist.com/topic/lastword (please include a postal address in order to receive payment for answers). Unanswered questions can also be found at this URL.
With the Australian spring comes seasonal allergic rhinitis, or hay fever. But why do humans have a physiological response to pollen and dust? I can’t see any benefit to suffering from sore eyes, a scratchy throat and nasal congestion. So why does it occur?
n One of the main tasks of the human immune system is to orchestrate a response to infections by pathogenic microorganisms including bacteria, fungi and parasites. Immunoglobulin E (IgE) antibodies specialise in combating the latter. Pathogens are recognised by some characteristic molecules they possess called antigens, which, more often than not, are molecules of protein. But when a protein derived from a mould spore or plant pollen looks very much like a protein of a pathogen microorganism (a phenomenon called molecular mimicry), the immune system identifies it as
“Most people react to antigens in a mild way that causes no symptoms and goes unnoticed”
This week’s questions WATER WORKS
Is hard or soft water better at removing dirt and bacteria? Patrick Jamison Ascot, Berkshire, UK SPIRALLING BACKWARDS
If there’s no friction in space, why do the arms of spiral galaxies sweep backwards? John McIntyre Yackandandah, Victoria, Australia FEEL THE HEAT
We sweat to cool our bodies by evaporation, but when we wipe the sweat away – a natural reaction in humans – are we defeating that function and making ourselves hotter? Do we also hasten dehydration by making our bodies sweat more, to replace what we’ve wiped away? In other words, should we just leave the sweat to do its job? Howard Bobry Nehalem, Oregon, US APOCALYPSE THEN
In the book, The Hitchhiker’s Guide to the Galaxy, the Vogons demolished Earth. They said it would take approximately 2 minutes, so how much energy would they have needed to obliterate our planet? Would kicking the planet out of its orbit have been more energy efficient than simple destruction? Katka Kessler By email, no address supplied
THE LAST WORD Hay fever fever
an antigen and opens fire as if a microorganism is about to invade. The result varies, from scratching and nasal congestion to a life-threatening anaphylactic shock, and the underlying mechanism, which involves IgE antibodies, is called a Type I hypersensitivity reaction,
or allergic reaction – from ancient n While researching why a Greek (állos meaning “other” professional gardener like me and érgon meaning “work” should suffer from the or “activity”). inconvenient curse of hay fever, An allergy is a superfluous I found a paper that suggested reply to an otherwise innocuous that the allergic reaction of hay environmental antigen. Most fever was the immune system’s people react to them, but in a mild response to the pollen grains way that causes no symptoms and trying to “implant” in the wet goes unnoticed. Others have a membranes of the human eyes genetic predisposition for a and nose. fiercer response. These “atopic” The pollen grains release a individuals – from the Greek word cocktail of chemical signals atopía, meaning “placelessness” – and stimulants that are designed produce between 1000 and 10,000 times more IgE antibodies “I read that hay fever is the immune system’s response than non-atopic people. to pollen trying to implant Recent evidence indicates in human eyes” another possible evolutionary significance of allergy, as a part of our defence against toxins. to help the growth of a pollen It has been shown that repeated tube into the female part of the exposure to bee and viper flower, but have an irritating venom confers resistance against effect on the human mucus subsequent potentially fatal membranes. doses of these poisons, and Grass species are windthat happens via a Type I pollinated and release huge hypersensitivity reaction. amounts of pollen into the air – Even carcinogens like aflatoxin so it’s no surprise that some of it produce that kind of reaction, ends up trying to pollinate us. and maybe that is why allergyThe paper also suggested that prone people develop fewer the main hay fever culprit in the cancers in tissues of the body UK is pollen of a particular grass that communicate directly called “Timothy” (Phleum with the external environment. pratense). The bottom line is that either This is a common agricultural allergy is an immune system crop that grows twice as tall as false alarm or a physiological most wild grasses and accounts anti-toxin adaptation. But its for a large proportion of pollen most potent role seems to remain because of its abundance. What’s the irritation of thousands of more, its pollen is particularly noses every year. aggressive in its biochemical Ilias Nikolakopoulos amorousness. National and Kapodistrian Nicholas Hall University of Athens, Greece St Just, Cornwall, UK
The writers of answers that are published in the magazine will receive a cheque for £25 (or US$ equivalent). Answers should be concise. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and an email address if you have one. New Scientist retains total editorial control over the published content. New Scientist Ltd reserves all rights to reuse all question and answer material that has been
submitted by readers in any medium or in any format and at any time in the future. Send questions and answers to The Last Word, New Scientist, 110 High Holborn, London WC1V 6EU, UK, by email to [email protected] or visit www.newscientist.com/topic/lastword (please include a postal address in order to receive payment for answers). Unanswered questions can also be found at this URL.
With the Australian spring comes seasonal allergic rhinitis, or hay fever. But why do humans have a physiological response to pollen and dust? I can’t see any benefit to suffering from sore eyes, a scratchy throat and nasal congestion. So why does it occur?
n One of the main tasks of the human immune system is to orchestrate a response to infections by pathogenic microorganisms including bacteria, fungi and parasites. Immunoglobulin E (IgE) antibodies specialise in combating the latter. Pathogens are recognised by some characteristic molecules they possess called antigens, which, more often than not, are molecules of protein. But when a protein derived from a mould spore or plant pollen looks very much like a protein of a pathogen microorganism (a phenomenon called molecular mimicry), the immune system identifies it as
“Most people react to antigens in a mild way that causes no symptoms and goes unnoticed”
This week’s questions WATER WORKS
Is hard or soft water better at removing dirt and bacteria? Patrick Jamison Ascot, Berkshire, UK SPIRALLING BACKWARDS
If there’s no friction in space, why do the arms of spiral galaxies sweep backwards? John McIntyre Yackandandah, Victoria, Australia FEEL THE HEAT
We sweat to cool our bodies by evaporation, but when we wipe the sweat away – a natural reaction in humans – are we defeating that function and making ourselves hotter? Do we also hasten dehydration by making our bodies sweat more, to replace what we’ve wiped away? In other words, should we just leave the sweat to do its job? Howard Bobry Nehalem, Oregon, US APOCALYPSE THEN
In the book, The Hitchhiker’s Guide to the Galaxy, the Vogons demolished Earth. They said it would take approximately 2 minutes, so how much energy would they have needed to obliterate our planet? Would kicking the planet out of its orbit have been more energy efficient than simple destruction? Katka Kessler By email, no address supplied