Category Archives: Science

Books Feminism History Politics Science

Podcast: The Right to Live in Health

On the New Books Network, a history of late 19th and 20th-century Cuba, of which I confess I knew exactly nothing. After a hideous late Spanish colonial period, when perhaps 10% of the population died as the colonialists tried to starve out rebels, public health was seen as an antic-colonial weapon, including in the American colonial period.

The 1940 constitution was the first to state public health and healthcare as a basic right. Possibly helped by the fact that there was an effective oversupply of doctors, so there was less resistance to the socialisation of medicine than in the US or UK.

Also very interesting, and sadly still highly relevant, on the gendered approach to public health, blaming poor women for particularly childhood mortality – their “lack of knowledge”, rather than the practical realities of their lives that they just had to navigate as best they could with scant resources.

Books Science

Podcast: Philosophy of Immunology

Fascinating listening again on the New Books Network, and a reminder of how much I was taught in a science degree 30 years ago has totally been swept aside. Makes sense when you think about it – the idea that the immune system acts against “non-self” makes little sense given how much we know about the microbiome – and that the body acts to regulate the balance of that. While thinking of auto-immune diseases as the body “attacking itself” ignores the fact that it needs to do that in cleaning up and tidying damaged cells and tissues all the time.

Whilst I remember being taught only vertebrates had immune systems, it is now clear even single celled organisms have them.

Pradeu suggests an individual is an immunologically unified chimera, and suggests big implications for our understanding of cognition and psychiatric illness.

And – nice! – the e-book is available for free.

Books Environmental politics Science

Notes from The Inside Out of Flies by Erica McAlister

p. 226 The digestive tract of flies has to cope with a variety of food sources. Often the same individual is feeding on both blood and nectar, so the interior has been divided into a series of distinct regions, for consuming and processing meals, then for nutrient absorption, and finally for excretion or waste removal, the length and size of the different parts varying with species and food type.”

p. 227 The mid gut has been poorly studied, which is quite remarkable considering how essential a good diet is to the fly. Flues, like us, have a variety of micro-organisms that live inside them to aid difestion. It has been suggested that the number … could be greater than the number of cells in their entire body… it is more than likely .. the larvae of the mosquito Aedes aegypytii don’t start off with any gut fauna and the poor things can’t actually grow if they are prevented from establishing a healthy microbe environment, cultured from microbes they would have consumed from their environment.

The midgut bacteria have been shown to strengthen the immune response in mosquiots and protect them against any unwelcome pathogens… The bacteria in the gut of adult Anopheles mosquitos inhibits Plasmodium infection – it alerts the immune system of the mosquito to let tit know that these parasites have arrived and the mosquito needs to do something about it, but these bacteria are also directly attacking the Plasmodum by producing enzymes and toxins. Studying which bacteria are the most effective at tackling this will aid our war against malaria. As mosquitos are smaller, and less complicated than us humans, they also make a great model for understanding the interactions between the host, the good bacteria and the bad pathogens.

p. 231 There are further issues to overcome when feeding. Mosquitos and other blood-feeding species have to cope with the high internal temperatures of their hosts … many blood-feeding species are heterothermic ie they vary between self-regulating their temperature and using the external environment to regulate it. The ANopheles genus does this by excreting fluid droplets from the end of their abdomens. This reduces the temperature of the internal fluid by a process of evaporative gooling, where the external air cools the fluid. This mechanism prevents all gut symbionts, as well as the mosquito, from overheating.

p. 278 Many species of fly will allow themselves to fall into a coma to protect themselves during times of extreme temperature… they can take their bodies below freezing point without all the internal cells becoming solid. This allows them to survive during periods of extreme cold, by inducing a state called a chill-coma. Some species have glycerol in their cells that acts as antifreeze. One such fly is Chymomyza constata… another species of drosophilid… subjected the largae of this species to a series of lower and lower temperatures.. (t) cryopreservation at -196C (-321F). And some survived – to be fair there was quite a high death rate in the individuals at -196C 0 but still, some survived, which means that these flies are the most complex animals able to do so.”

Books Environmental politics History Science

Notes from Rain: Four Walks in English Weather by Melissa Harrison

p. 32 “One reaons we know how much rain has fallen where, and when is the British Rainfall Organisation: A quintessentially eccentric body and one of the first examples of what we now call ‘citizen science’. George James Symons, who began his working life in the Meteorological Department of the Board of Trade, set up the Association in the middle of the 19th century in response to public concern that rainfall was decreasing across the British Isles. He recruited a small network of initial observers, then wrote to The Times in 1853 listing the further locations he wanted, calling for observers ‘of both sexes and all ages’ and offering to subsidise the cost of instruments. By 1867 he had 1,300 observers, nad had to leave his post at the Board of Trade; by his death in 1900 there were 3,408, drawn from ‘nearly every social grade from peer to peasant’… In 1916 the BRO was called upon to determine whether the use of artillery on the Western Front was somehow responsible for one of the wettest winters on record… the opinion given … was that there was no connection. The following winter would prove less wet, despite the artillery barrage of the Somme, but bitterly cold .. continued to publish its records until 1991.”

p. 55 “The aptly named George Merryweather displayed his storm forecaster, the ‘Tempest Prognosticator’ at the Great Exhibition of 1851. Looking not unlike a miniature merry-go-round, it consisted of a circle of 12 pint bottles, each containing a little rainwater and a single leech. His idea was that, on sensing electrical activity in the atmosphere, the leeches would crawl to the top of the bottles, triggering whalebone levers connected to a bell on the topmost dome; the more times the bell rang, the greater the likelihood of an approaching storm. … believed that it could easily be connected to the telegraph network in a way that the bell in St Paul’s, London, could be rung to signal an approaching storm. But then, he also believed that arranging the bottles in a circle would allow the leeches to see one another and not become lonely.”

p. 62 “Because they need their food to be over 50% water, rabbits like to feed at dawn and dusk when the dew is down.”

p. 75 Dartmoor “became a vital source of sphagnum moss during the First World War when it was gathered in great quantities, dried and sent off to be used as wound dressings due to its abosrbency and healing properties; its been shown to slow the growth of fungi and bacteria. Twelves species are found on Dartmoor, and all can hold eight times their own weight in rain.”

p. 82 “A recent study by the Environment and Sustainability Institute, University of Exeter, showed that one square metre of inrtensively improved grassland held just 47 litres of grassland compared to the 269 litres per square metre held by unimproved ‘rhos’ pasture with its naturally occurring purple moor grass and sharp.flowered rush.”

Books Environmental politics Science

Notes from The Soil, By N.K. Davis, N. Walker, D.F. Ball and A.H. Fitter

p. 49 A mycorrhiza is a root infested with a particular type of generally beneficially fungus … The most widespread and ancient type, although not the most familiar, bears the cumbersome name of vesicular-arbuscular mycorrhiza (VAM)… form no visible external structures, so it is impossible to tell if a plant has the association without microscopic examination of stained roots. VAM are formed by a small group of fungi… can only survive in association with the roots of a plant. Their principal distinction is the size of their spores, which are quite enormous by fungal standards – in one species of Gigaspora they are over half a millimetre across, compared to a typical figure for most fungi of around 1/100th of a mm. … most plants that can form VAM do so nuder natural conditions because the fungus appears to offer a solution to an otherwise sever problem – the acquisition of the essential nutrient phosphorus… occurs in soil as phosphate ions which are so sparingly soluble that they move only very slowly through the soil… normally less than a millimetre through soil in a day … Remarkably, fossils of one of the first land plants Rhynia, about 400 million years old, have fungi associated with their rhizomes that appear almost identical to modern VAM fundgi.

p. 51 The best-known nonVAM mycorrhiza “is the ectomycorrhizal or sheathing mycorrhiza, characteristic of many forest trees, especially the Pinacae (pines, spruces, larchs firs), the Betlaceae (birches, alders) and the Fagacae (oaks, beeches).. almost all are toadstools, members of the Basidiomycetes. Some are well known and distinctive, such as fly agaric which forms a mycorrhiza with birch…. Ectomycorrhizal roots are stubby and often fork dichotomously, giving dense clusters. Each root tip is surrounded by a sheath of tightly woven fungal hyphae and other hyphae radiate away from this int the soil… The fine fungal threads penetrate the soil, picking up the immobile phosphate ions and transporting them back to the sheath. Meanwhile the fungal hyphae beneath the sheath, which are in contact with the root cells, obtain sugar from them to feed the fungal tissues.”

p. 52 It does seem that extomycorrhizal trees are better able to colonize poor soils than VAM trees, and this is probably because the former get more benefit from the more active fungi. Of course there is a cost to this: the ectomycorrhizal tree probably has to give up more of the carbon that it fixes than does the VAM tree so the latter may be at an advantage on better soils.
Another remarkable feature of mycorrhizas that has recently come to light is their ability to link plants together. .. BY labelling trees with radioactive isotopes, it has been found that materials can pass from plant to plant by means of these links… there is intriguing evidence that seedlings establish in swards more readily if they become mycorrhizal than if they remain uninfected… If this turns out to be widespread and important phenomenon t may force us to rethink our view of plant communities: ecologists have in the past tended to view them as dominated by intense competition between plants; it may be there is more cooperation than we thought.”

p. 57 Soil fauna – flatworms, rotifers or wheel animalcules, hairy backs, land nemerteans, eelworms, earthworms, bear animalcules (Tardigrada), woodlice, terrestrial sand-hopppers, mites, spiders, millipedes, centipedes.

pp. 158 Like an unpredictable genie, pesticides have proved to be a somewhat mixed blessing, for their overall effects can seldom be fully predicted. There are few if any pesticides that are completely specific to their target organisms: discrimination between harmful and harmless organisms is rarely adequate.

Books Environmental politics History Science

Notes from The Running Hare: The Secret of Farmland by John Lewis-Stempel

p. 25 All farms used to have an untidy corner where machinery went to die, and where thistles and nettles grew. Intensive farming has all but done away with these little no-man’s-land nature reserves; modern farms are as obsessively tidy as showroom Hygena kitchens.”

p. 26 “The Romans, who may well have introduced the hare to Britain, were keen hare-eaters. … Pliny the Elder advocated a diet of hare as a means of increasing sexual attractiveness…. Pliny’s ther proposition concerning hares was almost entirely contradictory: he declared the animals were hermaphrodites – a belief which eventually got worked into Christianity. Hares are a recurrent motif in British church architecture, standing for reproduction without loss of virginity .. p105 As with many animals sacred to older religions, medieval Christians changed the hair into an animal f ill-omen, saying witches shape-shifted into hare form to suck cows dry. Sailors considered hares so unlucky they could not be mentioned at sea. And not just sailors; country folk refused to call the hare by its name. p. 227 Hares have large hearts to enable them to achieve such speed. Up to 1.8% of body weight, compared to 0.3% for a rabbit.”

p. 56 “how ploughmen used to tell whether the earth was warm enough to sow (they’d drop their trousers and sit on the ground: if the bare bottom could bare the earth it was warm enough.”

p. 84 To walk behind a horse and harrow is to bring one into accord with all the ages. .. In harrowing half an acre Willow [Shetland pony] and I walk five miles. No one except kings and clergy was fat in the time of the horse… I am happy harrowing, an emotional state which may, according to scientists at the University of Bristol, be enhanced by soil itself. A specific soil bacterium, Mycobacteriyum vaccae, activates a set of serotonin-releasing neurons in the dorsal raphe nucles of the brain, the same ones targeted by Prozac. You can get an effective dose of Mycobacterim by walking in the wild, or gardening. “
p. 126 “The first wildflowers in my personal ploughland … are scarlet pimpernel, and common field speedwell, both delicate bejewelled creepers over ground, one red, the other blue. Their seed has been harboured safe in the earth for years: common field speedwell can germinate after 20 years. … as common on roadside verges as it is in arable fields, and travellers in years gone by sewed the flower into the lining of their coats as a charm.”

p. 137 Corn marigold is as old as British agriculture itself, since it was probably brought here by the Neolithic people. Arable farmers, however, have never warmed to its sunny splendour, since the fleshy leaves impeded the harvest reaping. Henry II issued an ordinance against “a certain plant called Gold”, requiring tenants t uproot it, which was probably the earliest enactment demanding the destruction of a weed. In A Boke of Husbandry, 1523, John Fitzherbert included ‘Gouldes’ in his blacklist of plants that ‘doe muche harme’.”
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