探花直播 of Cambridge - parasite

Medieval monks were 鈥榬iddled with worms鈥�, study finds

fpjl2 — Fri, 19 Aug 2022 07:20:44 +0000

A new analysis of remains from medieval Cambridge shows that local Augustinian friars were almost twice as likely as the city鈥檚 general population to be infected by intestinal parasites.

This is despite most Augustinian monasteries of the period having latrine blocks and hand-washing facilities, unlike the houses of ordinary working people.

Researchers from the 探花直播 of Cambridge鈥檚 Department of Archaeology say the difference in parasitic infection may be down to monks manuring crops in friary gardens with their own faeces, or purchasing fertiliser containing human or pig excrement.

探花直播study, published today in the International Journal of Paleopathology, is the first to compare parasite prevalence in people from the same medieval community who were living different lifestyles, and so might have differed in their infection risk.聽

探花直播population of medieval Cambridge consisted of residents of monasteries, friaries and nunneries of various major Christian orders, along with merchants, traders, craftsmen, labourers, farmers, and staff and students at the early university.

Cambridge archaeologists investigated samples of soil taken from around the pelvises of adult remains from the former cemetery of All Saints by the Castle parish church, as well as from the grounds where the city鈥檚 Augustinian Friary once stood.

Most of the parish church burials date from the 12-14th century, and those interred within were primarily of a lower socio-economic status, mainly agricultural workers.

探花直播Augustinian friary in Cambridge was an international study house, known as a studium generale, where clergy from across Britain and Europe would come to read manuscripts. It was founded in the 1280s and lasted until 1538 before suffering the fate of most English monasteries: closed or destroyed as part of Henry VIII鈥檚 break with the Roman Church.聽聽

探花直播researchers tested 19 monks from the friary grounds and 25 locals from All Saints cemetery, and found that 11 of the friars (58%) were infected by worms, compared with just eight of the general townspeople (32%).

They say these rates are likely the minimum, and that actual numbers of infections would have been higher, but some traces of worm eggs in the pelvic sediment would have been destroyed over time by fungi and insects.聽

探花直播32% prevalence of parasites among townspeople is in line with studies of medieval burials in other European countries, suggesting this is not particularly low 鈥� but rather the infection rates in the monastery were remarkably high.

鈥� 探花直播friars of medieval Cambridge appear to have been riddled with parasites,鈥� said study lead author Dr Piers Mitchell from Cambridge鈥檚 Department of Archaeology. 鈥淭his is the first time anyone has attempted to work out how common parasites were in people following different lifestyles in the same medieval town.鈥�

Cambridge researcher Tianyi Wang, who did the microscopy to spot the parasite eggs, said: 鈥淩oundworm was the most common infection, but we found evidence for whipworm infection as well. These are both spread by poor sanitation.鈥�

Standard sanitation in medieval towns relied on the cesspit toilet: holes in the ground used for faeces and household waste. In monasteries, however, running water systems were a common feature 鈥� including to rinse out the latrine 鈥� although that has yet to be confirmed at the Cambridge site, which is only partly excavated.聽

Not all people buried in Augustinian friaries were actually clergy, as wealthy people from the town could pay to be interred there. However, the team could tell which graves belonged to friars from the remains of their clothing.

鈥� 探花直播friars were buried wearing the belts they wore as standard clothing of the order, and we could see the metal buckles at excavation,鈥� said Craig Cessford of the Cambridge Archaeological Unit.

As roundworm and whipworm are spread by poor sanitation, researchers argue that the difference in infection rates between the friars and the general population must have been due to how each group dealt with their human waste.

鈥淥ne possibility is that the friars manured their vegetable gardens with human faeces, not unusual in the medieval period, and this may have led to repeated infection with the worms,鈥� said Mitchell.

Medieval records reveal how Cambridge residents may have understood parasites such as roundworm and whipworm. John Stockton, a medical practitioner in Cambridge who died in 1361, left a manuscript to Peterhouse college that included a section on De Lumbricis (鈥榦n worms鈥�).

It notes that intestinal worms are generated by excess of various kinds of mucus: 鈥淟ong round worms form from an excess of salt phlegm, short round worms from sour phlegm, while short and broad worms came from natural or sweet phlegm.鈥�

探花直播text prescribes 鈥渂itter medicinal plants鈥� such as aloe and wormwood, but recommends they are disguised with 鈥渉oney or other sweet things鈥� to help the medicine go down.

Another text 鈥� Tabula medicine 鈥� found favour with leading Cambridge doctors of the 15th century, and suggests remedies as recommended by individual Franciscan monks, such as Symon Welles, who advocated mixing a powder made from moles into a curative drink.

Overall, those buried in medieval England鈥檚 monasteries had lived longer than those in parish cemeteries, according to previous research, perhaps due to a more nourishing diet, a luxury of wealth.聽

Research examining traces of parasites in the remains of medieval Cambridge residents suggests that local friars were almost twice as likely as ordinary working townspeople to have intestinal worms 鈥� despite monasteries of the period having far more sanitary facilities.聽聽

One possibility is that the friars manured their vegetable gardens with human faeces

Piers Mitchell

Cambridge Archaeological Unit

Augustinian friars being excavated by the Cambridge Archaeological Unit.

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright 漏探花直播 of Cambridge and licensors/contributors as identified.聽 All rights reserved. We make our image and video content available in a number of ways 鈥� as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Ancient faeces reveal how 鈥榤arsh diet鈥� left Bronze Age Fen folk infected with parasites

fpjl2 — Thu, 15 Aug 2019 23:53:31 +0000

New research published today in the journal Parasitology shows how the prehistoric inhabitants of a settlement in the freshwater marshes of eastern England were infected by intestinal worms caught from foraging for food in the lakes and waterways around their homes.

探花直播Bronze Age settlement at Must Farm, located near what is now the fenland city of Peterborough, consisted of wooden houses built on stilts above the water. Wooden causeways connected islands in the marsh, and dugout canoes were used to travel along water channels.聽聽

探花直播village burnt down in a catastrophic fire around 3,000 years ago, with artefacts from the houses preserved in mud below the waterline, including food, cloth, and jewellery. 探花直播site has been called 鈥淏ritain鈥檚 Pompeii鈥�.

Also preserved in the surrounding mud were waterlogged coprolites聽鈥� pieces of human and animal聽faeces 鈥� that have now been collected and analysed by archaeologists at the 探花直播 of Cambridge. They used microscopy techniques to detect ancient parasite eggs within the faeces and surrounding sediment.

Very little is known about the intestinal diseases of Bronze Age Britain. 探花直播one previous study, of a farming village in Somerset, found evidence of roundworm and whipworm: parasites spread through contamination of food by human faeces.

探花直播ancient excrement of the Anglian marshes tells a different story. 鈥淲e have found the earliest evidence for fish tapeworm, Echinostoma worm, and giant kidney worm in Britain,鈥� said study lead author Dr Piers Mitchell of Cambridge鈥檚 Department of Archaeology.

鈥淭hese parasites are spread by eating raw aquatic animals such as fish, amphibians and molluscs. Living over slow-moving water may have protected the inhabitants from some parasites, but put them at risk of others if they ate fish or frogs.鈥�

Disposal of human and animal waste into the water around the settlement likely prevented direct faecal pollution of the fenlanders鈥� food, and so prevented infection from roundworm 鈥� the eggs of which have been found at Bronze Age sites across Europe.

However, water in the fens would have been quite stagnant, due in part to thick reed beds, leaving waste accumulating in the surrounding channels. Researchers say this likely provided fertile ground for other parasites to infect local wildlife, which 鈥� if eaten raw or poorly cooked 鈥� then spread to village residents.

鈥� 探花直播dumping of excrement into the freshwater channel in which the settlement was built, and consumption of aquatic organisms from the surrounding area, created an ideal nexus for infection with various species of intestinal parasite,鈥� said study first author Marissa Ledger, also from Cambridge鈥檚 Department of Archaeology.聽

Fish tapeworms can reach 10m in length, and live coiled up in the intestines. Heavy infection can lead to anaemia. Giant kidney worms can reach up to a metre in length. They gradually destroy the organ as they become larger, leading to kidney failure. Echinostoma worms are much smaller, up to 1cm in length. Heavy infection can lead to inflammation of the intestinal lining.

鈥淎s writing was only introduced to Britain centuries later with the Romans, these people were unable to record what happened to them during their lives. This research enables us for the first time to clearly understand the infectious diseases experienced by prehistoric people living in the Fens,鈥� said Ledger.

探花直播Cambridge team worked with colleagues at the 探花直播 of Bristol鈥檚 Organic Chemistry Unit to determine whether coprolites excavated from around the houses were human or animal. While some were human, others were from dogs.

鈥淏oth humans and dogs were infected by similar parasitic worms, which suggests the humans were sharing their food or leftovers with their dogs,鈥� said Ledger.

Other parasites that infect animals were also found at the site, including pig whipworm and Capillaria worm. It is thought that they originated from the butchery and consumption of the intestines of farmed or hunted animals, but probably did not cause humans any harm.

探花直播researchers compared their latest data with previous studies on ancient parasites from both the Bronze Age and Neolithic. Must Farm tallies with the trend of fewer parasite species found at Bronze Age compared with Neolithic sites.

鈥淥ur study fits with the broader pattern of a shrinking of the parasite ecosystem through time,鈥� said Mitchell. 鈥淐hanges in diet, sanitation and human-animal relationships over millennia have affected rates of parasitic infection.鈥� Although he points out that infections from the fish tapeworm found at Must Farm have seen a recent resurgence due to the popularity of sushi, smoked salmon and ceviche.

鈥淲e now need to study other sites in prehistoric Britain where people lived different lifestyles, to help us understand how our ancestors鈥� way of life affected their risk of developing infectious diseases,鈥� added Mitchell.

探花直播Must Farm site is an exceptionally well-preserved settlement dating to 900-800 BC (the Late Bronze Age).聽探花直播site was first discovered in 1999. 探花直播Cambridge Archaeological Unit carried out a major excavation between 2015 and 2016, funded by Historic England and Forterra Building Products Ltd.

Coprolites聽from the Must Farm archaeological excavation in East Anglia shows the prehistoric inhabitants were infected by parasitic worms that can be spread by eating raw fish, frogs and shellfish.

Consumption of aquatic organisms from the surrounding area created an ideal nexus for infection

Marissa Ledger

Left: Marissa Ledger. Right: D. Webb

Left: Microscopic egg of a fish tapeworm. Right: Must Farm excavation.

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Ancient faeces reveal parasites described in earliest Greek medical texts

fpjl2 — Fri, 15 Dec 2017 04:15:11 +0000

Ancient faeces from prehistoric burials on the Greek island of Kea have provided the first archaeological evidence for the parasitic worms described 2,500 years ago in the writings of Hippocrates 鈥� the most influential works of classical medicine.

探花直播 of Cambridge researchers Evilena Anastasiou and Piers Mitchell used microscopy to study soil formed from decomposed faeces recovered from the surface of pelvic bones of skeletons buried in the Neolithic (4th millennium BC), Bronze Age (2nd millennium BC) and Roman periods (146 BC 鈥� 330 AD).

探花直播Cambridge team worked on this project with Anastasia Papathanasiou and Lynne Schepartz, who are experts in the archaeology and anthropology of ancient Greece, and were based in Athens.

They found that eggs from two species of parasitic worm (helminths) were present: whipworm (Trichuris trichiura), and roundworm (Ascaris lumbricoides). Whipworm was present from the Neolithic, and roundworm from the Bronze Age.

Hippocrates was a medical practitioner from the Greek island of Cos, who lived in the 5th and 4th centuries BC. He became famous for developing the concept of humoural theory to explain why people became ill.

This theory 鈥� in which a healthy body has a balance of four 鈥榟umours鈥�: black bile, yellow bile, blood and phlegm 鈥� remained the accepted explanation for disease followed by doctors in Europe until the 17th century, over 2,000 years later.

Hippocrates and his students described many diseases in their medical texts, and historians have been trying to work out which diseases they were. Until now, they had to rely on the original written descriptions of intestinal worms to estimate which parasites may have infected the ancient Greeks. 探花直播Hippocratic texts called these intestinal worms Helmins strongyle, Ascaris, and Helmins plateia.

探花直播researchers say that this new archaeological evidence identifies beyond doubt some of the species of parasites that infected people in the region. 探花直播findings are published today in the Journal of Archaeological Science: Reports.聽

鈥� 探花直播Helmins strongyle worm in the ancient Greek texts is likely to have referred to roundworm, as found at Kea. 探花直播Ascaris worm described in the ancient medical texts may well have referred to two parasites, pinworm and whipworm, with the latter being found at Kea,鈥� said study leader Piers Mitchell, from Cambridge鈥檚 Department of Archaeology.

鈥淯ntil now we only had estimates from historians as to what kinds of parasites were described in the ancient Greek medical texts. Our research confirms some aspects of what the historians thought, but also adds new information that the historians did not expect, such as that whipworm was present鈥�.

探花直播mention of infections by these parasites in the Hippocratic Corpus includes symptoms of vomiting up worms, diarrhoea, fevers and shivers, heartburn, weakness, and swelling of the abdomen.

Descriptions of treatment for intestinal worms in the Corpus were mainly through medicines, such as the crushed root of the wild herb seseli mixed with water and honey taken as a drink.

鈥淔inding the eggs of intestinal parasites as early as the Neolithic period in Greece is a key advance in our field,鈥� said Evilena Anastasiou, one of the study鈥檚 authors. 鈥淭his provides the earliest evidence for parasitic worms in ancient Greece.鈥�

鈥淭his research shows how we can bring together archaeology and history to help us better understand the discoveries of key early medical practitioners and scientists,鈥� added Mitchell.

Earliest archaeological evidence of intestinal parasitic worms infecting the ancient inhabitants of Greece confirms descriptions found in writings associated with Hippocrates, the early physician and 鈥榝ather of Western medicine鈥�.聽聽聽

This research shows how we can bring together archaeology and history to help us better understand the discoveries of key early medical practitioners and scientists

Piers Mitchell

Left: Piers Mitchell/Elsevier. Right: Department of Classics, 探花直播 of Cincinnati.

Left: whipworm egg taken from ancient Greek faecal matter. Right: excavation of the Bronze Age site of Ayia Irini on the island of Kea.

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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探花直播reed warbler and the cuckoo: an escalating game of trickery and defence

amb206 — Mon, 22 Feb 2016 10:45:59 +0000

Reed warblers are a little smaller than sparrows and each one weighs no more than a large envelope. As autumn begins they migrate some 5,000 km from Britain to West Africa, a journey they might make just two or three times in their short lives. In April they fly north to breed in the watery landscapes of northern Europe where they raise their young in nests suspended from reeds. Sometimes they are tricked into raising cuckoo chicks which grow to four times their size.聽

In his book聽聽Cuckoo - Cheating by Nature, Nick Davies (Department of Zoology) describes what it鈥檚 like to watch reed warblers at the Cambridgeshire nature reserve of Wicken Fen. He carefully parts the reeds until he can see a pair of warblers feeding their young in a nest. He senses the parents鈥� urgency in collecting insects for their chicks while keeping them warm and staying alert for signs of danger. When several hours later he stands up, the intimate world of the warbler disappears into the great expanse of fenland and the wide East Anglian skies.

Observation remains vital to learning more about the world, believes Davies. 鈥淭here鈥檚 still plenty more to learn from going out into nature and watching carefully,鈥� he says. 鈥淚 get most of my ideas by watching animals and simply asking 鈥業 wonder why they鈥檙e doing that?鈥� 探花直播key to research is coming up with a good question and devising an experiment to answer it.鈥�

Davies, who gives this week's Darwin Lecture (Games Animals Play), has been studying reed warblers at Wicken Fen for more than 30 years. He thinks of them as 鈥榟is鈥� warblers and calls his interest in their lives, and their fragile niche within a changing environment, a kind of obsession. In the process of countless early mornings, and dozens of experiments, he and his colleagues have gradually unlocked some of the secrets of warblers鈥� interactions with cuckoos, who 鈥榩arasitise鈥� other birds.

In an endless game of trickery and defence, the cuckoo and its hosts engage in an 鈥榓rms race鈥� involving mimicry of many kinds 鈥� from the patterning of eggs to the demanding twittering of chicks 鈥� as the two species weigh up the risks of being duped and discovered. Reed warblers sometimes reject eggs that don鈥檛 look like their own 鈥� but what evidence does a warbler need before it takes such drastic action?聽 Recent research reveals that warblers eject suspect eggs from their nests only when local information is reinforced by signals from a wider 鈥榥eighbourhood watch鈥�.

Davies鈥檚 fascination for birds stems from a childhood spent on the Lancashire coast where the skies were full of skeins of pink-footed geese and the sand dunes were home to croaking natter jack toads. He got his taste for patient observation, for asking difficult questions (why, for example, does the reed warbler accept a cuckoo chick so obviously different to one of its own?), and interest in detective work from Niko Tinbergen, a pioneer of scientific studies of animal behaviour. As an evolutionary biologist, Davies is also respectful of the observational studies of the early naturalists who laid the foundations for subsequent experimental work.

探花直播remarkable insights explored so vividly in Cuckoo - Cheating by Nature would have been impossible without research collaborations, often international. Birds migrate vast distances: to understand them, and how they鈥檙e shaped by evolution, requires an investigation of every aspect of their lives. Within the same species, there are behavioural variations which offer clues to their evolutionary pathways. To get a picture of the different 鈥榬aces鈥� of cuckoos (categorised by the species they parasitise to host their young) Davies has worked with biologists across the world.

He says: 鈥淪ome of the most exciting discoveries are now being made in Africa by Claire Spottiswoode and in Australia by Naomi Langmore. In both places, the arms race between cuckoos and hosts has been going on much longer and has escalated to new levels. For example, in Australia some hosts reject chicks unlike their own and their cuckoo has combated this by evolving a mimetic chick. And in Africa, cuckoo hosts have the most remarkable egg signatures in the form of individual spots and squiggles which makes it easier for them to detect a foreign egg.鈥�

In the accompanying podcast, Davies talks about the games animals play with particular reference to the dunnock, a small brown bird with a surprisingly inventive sex life. 聽

探花直播lecture Games Animals Play will take place in the Lady Mitchell Hall, Sidgwick Site, 探花直播 of Cambridge, on Friday, February 26, 2016 - 17:30 to 18:30. No booking required, no charge. Arrive in good time to secure a seat.

Main image: a reed warbler feeds a cuckoo fledgling (https://www.richardnicollphotography.co.uk/) Inset images:聽a clutch of reed warbler eggs with a larger cuckoo egg (Nick Davies); a meadow pipit feeds a cuckoo fledgling (Charles Tyler).

Professor Nick Davies, who gives this week鈥檚 Darwin Lecture, has been studying reed warblers for more than 30 years 鈥� and has unlocked many of the secrets of their interactions with the cuckoo. His work shines light on the evolutionary games played out in nature as species compete with environmental pressures, with other species, and with the opposite sex, to pass on their genes.

I get most of my ideas by watching animals and simply asking 鈥業 wonder why they鈥檙e doing that?鈥� 探花直播key to research is coming up with a good question and devising an experiment to answer it.

Nick Davies

Richard Nicoll

A reed warbler feeds a cuckoo fledgling

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Neighbourhood watch and more: how reed warblers watch out when there鈥檚 a cuckoo about

amb206 — Fri, 22 Jan 2016 12:00:00 +0000

It鈥檚 a risky business being a reed warbler. Not only do these tiny birds embark on an annual migration of some 5,000 km from their West African winter quarters聽to breeding grounds in the north, but they are also 鈥榟osts鈥� to the cuckoo, a species that lays its eggs in other birds鈥� nests and takes no further part in raising its offspring. When the cuckoo chick hatches, it pushes the reed warbler eggs and young out of the nest. As sole occupant, it tricks its warbler 鈥榩arents鈥� into supplying its voracious appetite until it fledges.

Cuckoos are expert tricksters: their eggs mimic those of their hosts in pattern though they are a little bigger. If the reed warbler detects an alien egg in its nest, or spots a cuckoo nearby, it may eject the odd-looking egg. But cuckoos are so swift in laying their eggs (only one is laid per nest and the process is over in as little as 10 seconds), and so clever at disguising their eggs, that warblers are often uncertain whether an odd egg in the clutch is a cuckoo egg or one of their own.

Research into the relationship between cuckoos and reed warblers has to date concentrated on the behaviour of individual birds and their interactions with cuckoos, described as parasites. A new study published today (22 January 2016) in Scientific Reports looks at wider interactions between neighbouring communities of reed warblers, their strategies for coping with cuckoos, and, in particular, how warblers assess levels of risk by gathering information from a variety of sources.

After two years of observation of warblers that spend the breeding season at Wicken Fen in Cambridgeshire, authors Rose Thorogood and Nicholas Davies (Department of Zoology) reveal that a kind of 鈥渘eighbourhood watch鈥� exists out in the reed beds, keeping birds up-to-date with the latest threats. Using a series of controlled experiments, involving model cuckoos and broadcasts of reed warbler alarm calls, the researchers revealed that reed warblers factored information gathered from close surveillance of the neighbourhood into their decision-making when assessing whether or not to eject an egg.

When reed warblers spot a cuckoo, they may mob it and emit alarm calls that carry up to 40 metres. These alarm calls attract neighbours, who come to investigate the cause of the commotion. But the sound of neighbourly mobbing of a cuckoo alone is insufficient to prompt warblers to eject a suspect egg from their own nests. They also need clues that suggest a more close-up and personal threat.

鈥淲e found that warbler pairs ejected an odd egg only when there was strong evidence that it might not be one of their own.聽 For action to be taken, the clues had to add up. 探花直播warblers needed to be alerted by their neighbours鈥� behaviour that there was a cuckoo at large in the neighbourhood 聽and they needed to be aware of a more local and imminent threat, by seeing 聽a cuckoo near their own nest. 鈥� said Thorogood.

鈥淣either personal encounters nor social encounters alone were sufficient to stimulate egg rejection. Instead, information was combined from both these sources. This is fascinating because we have assumed previously that animals favour one type of information over the other 鈥� for example, experiments show that some fish species will ignore where their shoal mates forage if they already have information about the location of food themselves, even when it is less profitable. Here we show that combining information is the best way to take the most appropriate course of action.鈥�

探花直播use of multiple sources of information has important consequences for cuckoos too. With their neighbourhood abuzz with information, cuckoos need to be wary of alarming potential hosts.

鈥淏ecause the information warfare between cuckoos and their hosts extends well beyond individual interactions, there鈥檚 pressure on cuckoos to be increasingly secretive, not only to avoid alerting their target host pair, but also other host pairs in the local neighbourhood鈥� said Thorogood.

Cuckoo numbers have declined by as much as 60% in the past 30 years for reasons that remain unclear. At Wicken Fen, where several hundred warblers arrive to breed each May, between 10% and 20% of reed warblers nests were used by cuckoos. Today only 2% of warbler nests at Wicken host cuckoos. This rapid drop in cuckoo numbers, which contrasts with a stable warbler population, has enabled Thorogood and Davies to track how the warblers have dropped their defences in concert with the dramatic decrease in cuckoo threat.

Davies has been researching cuckoos and their hosts at Wicken Fen since the 1980s. He said: 鈥淩eed warblers are much less likely to eject an egg from their nest today than they were in the 1980s. This makes complete sense. They have matched their behaviour to the changing level of risk. Most reed warblers have just one or two summers in which to breed. So every opportunity to mate, construct a nest and raise a clutch of eggs is precious. If a pair of warblers mistakenly identifies one of their own eggs as a cuckoo egg and chucks it out, or deserts the nest, the loss is great. Our work shows how they match their defences to the risk of parasitism.鈥�

A study of reed warbler behaviour reveals for the first time that in assessing the risks posed by cuckoos the birds combine information from multiple sources. An 鈥榠nformation highway鈥� provides one set of clues and personal encounters another. Only when both add up, do the birds take defensive action.

Warbler pairs ejected an odd egg only when there was strong evidence that it might not be one of their own. For action to be taken, the clues had to add up.

Rose Thorogood

Richard Nicholl

A cuckoo chick ejects a reed warbler egg from a nest

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Birds evolve 鈥榮ignature鈥� patterns to distinguish cuckoo eggs from their own

fpjl2 — Wed, 18 Jun 2014 09:36:32 +0000

For some birds, recognising their own eggs can be a matter of life or death.

In a new study, scientists have shown that many birds affected by the parasitic Common Cuckoo - which lays its lethal offspring in other birds鈥� nests - have evolved distinctive patterns on their eggs in order to distinguish them from those laid by a cuckoo cheat.

探花直播study reveals that these signature patterns provide a powerful defense against cuckoo trickery, helping host birds to reject cuckoo eggs before they hatch and destroy the host鈥檚 own brood.

To determine how a bird brain might perceive and recognize complex pattern information, Dr Mary Caswell Stoddard at Harvard 探花直播 and Professor Rebecca Kilner and Dr Christopher Town at the 探花直播 of Cambridge developed a new computer vision tool, NATUREPATTERNMATCH. 探花直播tool extracts and compares recognizable features in visual scenes, recreating processes known to be important for recognition tasks in vertebrates.

鈥淲e harnessed the same computer technology used for diverse pattern recognition tasks, like face recognition and image stitching, to determine what visual features on a bird鈥檚 eggs might be easily recognised,鈥� explained Stoddard.

Using the tool, the researchers studied the pigmentation patterns on hundreds of eggs laid by eight different bird species (hosts) targeted by the Common Cuckoo.

They discovered that some hosts, like the Brambling, have evolved highly recognisable egg patterns characterised by distinctive blotches and markings. By contrast, other hosts have failed to evolve recognisable egg patterns, instead laying eggs with few identifiable markings. Those hosts with the best egg pattern signatures, the researchers found, are those that have been subjected to the most intense cuckoo mimicry.

探花直播Common Cuckoo and its hosts are locked in different stages of a co-evolutionary arms race. If a particular host species 鈥� over evolutionary time 鈥� develops the ability to reject foreign cuckoo eggs, the cuckoo improves its ability to lay eggs that closely match the colour and patterning of those laid by its host.

鈥� 探花直播ability of Common Cuckoos to mimic the appearance of many of their hosts鈥� eggs has been known for centuries. 探花直播astonishing finding here is that hosts can fight back against cuckoo mimicry by evolving highly recognisable patterns on their own eggs, just like a bank might insert watermarks on its currency to deter counterfeiters,鈥� said Stoddard.

鈥� 探花直播surprising discovery of this study is that hosts achieve egg recognition in different ways鈥� said Kilner, from Cambridge鈥檚 Department of Zoology.

Some host species have evolved egg patterns that are highly repeatable within a single clutch, while other species have evolved eggs with patterns that differ dramatically from female to female in a population. Still other host species produce egg patterns with high visual complexity. Each strategy is effective, increasing the likelihood that a given host will identify and reject a foreign egg. 鈥淪ome species use two of these strategies, but none uses all three,鈥� continued Kilner. 鈥淎 signature like this would be too complex to be easily recognised鈥�.

探花直播patterns on bird eggs are just one type of visual signature. Identity signatures are common in the animal world, but how they are encoded and recognised is poorly understood. In the future, computational tools like NATUREPATTERNMATCH - which account for important aspects of visual and cognitive processing - will be crucial for understanding the evolution of visual signals in diverse biological populations.

探花直播findings of this study are reported in the journal Nature Communications.

Inset image: Reed Warbler caring for Cuckoo chick. Credit: David Kjaer

Using new 鈥榩attern recognition algorithm,鈥� latest research highlights how birds are 鈥榝ighting back鈥� against the parasitic Common Cuckoo in what scientists describe as an evolutionary 鈥榓rms race鈥�. They found that birds with the most sophisticated and distinctive egg patterning are those most intensely targeted by the cuckoo鈥檚 egg mimicry.

探花直播surprising discovery of this study is that hosts achieve egg recognition in different ways

Rebecca Kilner

Mary Caswell Stoddard/Natural History Museum

NATUREPATTERNMATCH extracts visual features, here represented by magenta vectors (left). Three eggs each (represented in different rows) laid by three different Great Reed Warblers are shown here (right).

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Cuckoos impersonate hawks by matching their 'outfits'

fpjl2 — Thu, 17 Oct 2013 09:11:54 +0000

New research shows that cuckoos have striped or 鈥渂arred鈥� feathers that resemble local birds of prey, such as sparrowhawks, that may be used to frighten birds into briefly fleeing their nest in order to lay their parasitic eggs.

By using the latest digital image analysis techniques, and accounting for 鈥渂ird vision鈥� - by converting images to the spectral sensitivity of birds - researchers have been able to show for the first time that the barred patterns on a cuckoo鈥檚 breast may allow it to impersonate dangerous birds of prey. This might enable cuckoos to frighten other avian hosts into leaving their nests exposed.

探花直播latest findings, published today in the journal Animal Behaviour, expand the cuckoo鈥檚 arsenal of evolutionary deceptions, which include egg mimicry and chick mimicry that allow it to trick other birds into incubating its eggs.

Importantly, the study shows that a wide variety of cuckoos have adapted different plumage patterns depending on the area they inhabit so that they match a local bird of prey species.

While scientists have previously looked at links in plumage patterns between the common cuckoo and Eurasian sparrowhawk, the new research shows that this type of impersonation of a more dangerous animal 鈥� called 鈥楤atesian mimicry鈥� 鈥� may be far more widespread in cuckoos. In addition, the dangerous bird of prey that cuckoos resemble goes beyond sparrowhawks to include such raptors as bazas and harrier-hawks - depending on the species prevalent in the cuckoo鈥檚 neighbourhood.聽聽聽聽

鈥淭here is no benefit in looking like a dangerous species your target is not familiar with,鈥� said lead researcher Thanh-Lan Gluckman from Cambridge鈥檚 Department of Zoology.聽聽聽聽聽聽

鈥淲e first established similarity in plumage pattern attributes between cuckoos and raptor species, and then showed that cuckoos look nothing like species from a different geographical area.鈥�

探花直播cuckoos also use their crafty 鈥榟awk impression鈥� to allow them to fly 鈥榰nder the radar鈥�, undetected as they scope out potential nests in which to deposit their parasitic eggs.

鈥� 探花直播barring on their plumage helps cuckoos conceal themselves while searching for potential nests, then when they approach, the host of the nest may mistake a cuckoo for a raptor coming to get them 鈥� giving them unfettered access to lay eggs,鈥� Gluckman said.聽

While previous studies have focused on Batesian mimicry in the common cuckoo and Eurasian sparrowhawk, this is the first time that the plumage patterns of cuckoos have been analysed using digital image analysis techniques. 探花直播study suggests that this form of mimicry may be widespread among many cuckoo species, and that they may be mimicking a variety of different types of birds of prey.聽

探花直播researchers were surprised to find no pattern matching between cuckoos and raptors that live in different geographical areas, showing that the visual similarity is highly localised to species in the immediate vicinity.

鈥淭hese findings underscore the importance of using digital image analysis to objectively quantify plumage patterning in mimicry 鈥� it is important not to make assumptions about even simple patterns such as these,鈥� added Gluckman.

鈥淲e hope this encourages other researchers to examine the function of barred plumage in parasitic cuckoos and raptors the world over.鈥�

Another interesting finding is that of the African cuckoo-hawk, a raptor so named because of its visual resemblance to cuckoos. This study objectively shows that the naming was an apt one, given that a local cuckoo matched the African cuckoo-hawk in all of the pattern attributes measured.

One of the earliest observers of the cuckoos鈥� invasive guile was Ancient Greek philosopher Aristotle, who noted some 2,300 years ago that it 鈥渓ays its eggs in the nest of smaller birds鈥�.

Evolutionary trick allows cuckoos to mimic the plumage of birds of prey, and may be used to scare mothers from their nests so that cuckoos can lay their eggs. Mimicry in cuckoos may be more much more widespread than previously thought.

There is no benefit in looking like a dangerous species your target is not familiar with

Thanh-Lan Gluckman

Thanh-Lan Gluckman/Gabriel A. Jamie

Left: Cuckoo compared to cuckoo-hawk plumage. Right: Cuckoo

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New tool in the fight against tropical diseases

gm349 — Wed, 27 Feb 2013 01:01:00 +0000

A novel tool exploits baker鈥檚 yeast to expedite the development of new drugs to fight multiple tropical diseases, including malaria, schistosomiasis, and African sleeping sickness. 探花直播unique screening method uses yeasts which have been genetically engineered to express parasite and human proteins to identify chemical compounds that target disease-causing parasites but do not affect their human hosts.

Parasitic diseases affect millions of people annually, often in the most deprived parts of the world. Every year, malaria alone infects over 200 million people, killing an estimated 655,000 individuals, mostly under the age of five. Unfortunately, our ability to treat malaria, which is caused by Plasmodium parasites, has been compromised by the emergence of parasites that are resistant to the most commonly used drugs. There is also a pressing need for new treatments targeting other parasitic diseases, which have historically been neglected.

Currently, drug-screening methods for these diseases use live, whole parasites. However, this method has several limitations. First, it may be extremely difficult or impossible to grow the parasite, or at least one of its life cycle stages, outside of an animal host. (For example, the parasite Plasmodium vivax, responsible for the majority of cases of malaria in South America and South-East Asia, cannot be continuously cultivated in laboratory conditions.) Second, the current methods give no insight into how the compound interacts with the parasite or the toxicity of the compound to humans.

In an effort to develop new drugs to fight parasitic diseases, scientists from the 探花直播 of Cambridge have collaborated with computer scientists at Manchester 探花直播 to create a cheaper and more efficient anti-parasitic drug-screening method. 探花直播clever screening method identifies chemical compounds which target the enzymes from parasites but not those from their human hosts, thus enabling the early elimination of compounds with potential side effects.

Professor Steve Oliver, from the Cambridge Systems Biology Centre and Department of Biochemistry at the 探花直播 of Cambridge, said: 鈥淥ur screening method provides a faster and cheaper approach that complements the use of whole parasites for screening. This means that fewer experiments involving the parasites themselves, often in infected animals, need to be carried out.鈥�

探花直播new method uses genetically engineered baker鈥檚 yeast, which either expresses important parasite proteins or their human counterparts. 探花直播different yeast cells are labelled with fluorescent proteins to monitor the growth of the individual yeast strains while they grow in competition with one another. High-throughput is provided by growing three to four different yeast strains together in the presence of each candidate compound. This approach also provides high sensitivity (since drug-sensitive yeasts will lose out to drug-resistant strains in the competition for nutrients), reduces costs, and is highly reproducible.

探花直播scientists can then identify the chemical compounds that inhibit the growth of the yeast strains carrying parasite-drug targets, but fail to inhibit the corresponding human protein (thus excluding compounds that would cause side-effects for humans taking the drugs). 探花直播compounds can then be explored for further development into anti-parasitic drugs.

In order to demonstrate the effectiveness of their screening tool, the scientists tested it on Trypanosoma brucei, the parasite that causes African sleeping sickness. By using the engineered yeasts to screen for chemicals that would be effective against this parasite, they identified potential compounds and tested them on live parasites cultivated in the lab. Of the 36 compounds tested, 60 per cent were able to kill or severely inhibit the growth of the parasites (under standard lab conditions).

Dr Elizabeth Bilsland, the lead author of the paper from the 探花直播 of Cambridge, said: 鈥淭his study is only a beginning. It demonstrates that we can engineer a model organism, yeast, to mimic a disease organism and exploit this technology to perform low-cost, fully-automated drug screens to select and optimise drug candidates as well as identify and validate novel drug targets.鈥�

鈥淚n the future, we hope to engineer entire pathways from pathogens into yeast and also to construct yeast strains that mimic diseased states of human cells.鈥�

探花直播research, which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), was published today, 27 February, in the journal Open Biology.

Screening method created to expedite the development of new drugs in the fight against tropical diseases such as malaria and African sleeping sickness.

Our screening method provides a faster and cheaper approach that complements the use of whole parasites for screening.

Steve Oliver

Harry J. Moss

Different yeast cells are labelled with fluorescent proteins to monitor the growth of the individual yeast strains

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