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In this Dutch town, the euro’s fictional bridges are now real
The European currency features buildings that didn't exist, until Spijkenisse made them in concrete

Frankfurt may be the Eurozone's financial capital, Spijkenisse is where you can walk through the money.
- The euro banknotes feature seven different bridges – all of them fictional.
- They represent periods instead of places, so as not to offend anyone.
- But one Dutch town has turned monetary fiction into monumental fact.
Wonderful subcategory
Go to the end of this street to find Heartbreak Hotel.
Credit: Google Street View
In topography, there's a wonderful subcategory of places that existed first in the imagination before they materialized on the map. Examples range in size from the New York landmark of Agloe, a tiny map trap that accidentally became real (see #643) to the huge country of Pakistan, one man's dream turned into a home for millions (see #647).
For an example at the intersection of lyrical and whimsical, book a stay at Heartbreak Hotel. It's in Memphis, right across from Elvis Presley's Graceland mansion. The King of Rock 'n Roll had a hit with that title back in 1956. Today, as in the song, you'll find the hotel down at the end of Lonely Street.
Brightly-colored bridges
The euro bridges were designed to be transnational – but now they're all Dutch.
Credit: Google Maps, ECB (Graphics: Ruland Kolen)
And then there's the otherwise unassuming Dutch town of Spijkenisse, where you can take a walk across seven brightly-colored bridges which until recently only existed on banknotes.
You might recognize those bridges. If you've ever handled euro notes, you'll have seen them on the reverse of each of the seven denominations. Those bridges, however, are not real. Unlike other currencies, which often double as patriotic pamphlets and/or tourist teasers, the euro notes do not feature real-life landmarks or real-dead Europeans.
That would have involved favoring some countries and leaving out others, and in a multinational endeavor like the pan-European currency, that was a definite no-no.
So, what to do? It's a problem that had to be solved relatively recently, as the euro is the youngest of the world's major currencies. The look of the euro notes can be traced back to a European Council meeting in Dublin on December 13, 1996, when the European Monetary Institute (the precursor of today's European Central Bank) announced the winner of its competition to design the euro notes.
44 contenders
The five-euro bridge: Classical, and dirt-grey.
Credit: ScWikiSc, CC BY-SA 4.0
The prize went to Robert Kalina, a designer with the National Bank of Austria. His 'Ages and Styles of Europe' was chosen from among 44 contenders. Mr Kalina had some form in the matter. All Austrian banknotes from 1982 onwards were by his hand, as were notes he later designed for Bosnia-Herzegovina, Azerbaijan, and Syria.
Mr Kalina's euro designs scrupulously avoided any allusion to particular people or places, referring merely to abstract, supra-national style periods. The obverse of each note shows a window and a doorway, symbolizing Europe's spirit of openness. Each reverse shows a bridge, exemplifying communication and cooperation, both between the countries of Europe and between Europe and the rest of the world.
The architectural style of each note progresses chronologically as the value of the denomination increases. Most also feature a color from the rainbow spectrum.
The Elements
The ten-euro bridge, Romanesque in style and red in color.
Credit: ScWikiSc, CC BY-SA 4.0
- €5: Classical (as this was to be the most widely used note, grey was chosen to mask the dirt)
- €10: Romanesque (red)
- €20: Gothic (blue)
- €50: Renaissance (orange)
- €100: Baroque and Rococo (green)
- €200: 19th century Industrial (yellow)
- €500: 20th century Modern (purple)
These euro bridges would have remained fictional, were it not for Robin Stam. The Rotterdam-based artist got the idea of turning financial fiction into architectural fact in a pizza place, while fiddling with a euro note. "Suddenly it struck me how amazing it would be if these fictional bridges came to life," he said.
Mr Stam found a willing partner for his idea in the city council of Spijkenisse, his hometown, a suburb of Rotterdam. The plan was to build seven euro bridges across a canal that almost entirely surrounds an area called De Elementen ('The Elements').
Letter of approval
Gothic blue: the twenty-euro bridge
Credit: ScWikiSc, CC BY-SA 4.0
But before he got started, Mr Stam felt he needed the blessing of the European Central Bank. The euro notes scrupulously avoid favoring one member state over the other, but Mr Stam's euro bridges would all be in one country – the Netherlands. Would the ECB mind? Mr Stam sent them a letter. But he needn't have feared: out of Frankfurt came a kind reply with an official letter of approval. "Their main concern is counterfeiting. And you can't pay with a bridge," says the artist.
And so, 'The Bridges of Europe' got underway. Funded by the city and aided by local contractors, all seven bridges were installed between October 2011 and September 2013. They all preserve the color and shape of the 'originals'. All were made of concrete except the two most recent styles (€200 and €500 notes), which were made out of steel. In all the project cost around €1 million to complete.
"Kitschy facade"
The fifty-euro bridge, in Renaissance orange.
Credit: ScWikiSc, CC BY-SA 4.0
However, the euro bridges of Spijkenisse are not as monumental as their depiction on the notes suggests. In fact, they're pedestrian in more than one sense. Mr Kalina, who first drew the fictional bridges, while amused by the project, has said he would have liked the bridges to be built in the style in which each was designed, instead of their appearance being used as a "kitschy façade." So, it's perhaps more appropriate to call them 'follies', but then many have said the same about the euro itself.
From 2013 onwards, a second series of euro notes was published. This 'Europa' series–named after the Greek goddess who is watermarked into the notes–is a redesign by the German banknote designer Reinhold Gerstetter, who wanted the notes to be "more colorful, so they would appear friendlier".
Useful to criminals
If it's Baroque/Rococo and green, it must be the one-hundred-euro bridge.
Credit: ScWikiSc, CC BY-SA 4.0
The basic design of the first series, including the colors and bridges, has been maintained, with one notable exception. The Europa series no longer features a €500 note, out of concern that it appeared to be more useful to criminals than to law-abiding citizens.
The reason is its exceptionally high value. True, Switzerland has a 1,000-franc note (app. € 900, or US$ 1,075), but the euro is the only major currency to have a note this valuable. Compare the US dollar, which has the $100 bill as its highest denomination.
Because it is so valuable and was so relatively widespread, the €500 bill is ideal for transferring large amounts of money in a compact volume of notes. Turns out that quality was greatly appreciated by money launderers, drug smugglers, and tax dodgers.
'Bin Ladens'
Industrial and yellow – the two-hundred-euro bridge
Credit: ScWikiSc, CC BY-SA 4.0
The notes soon acquired the nickname 'Bin Ladens' because, despite their notoriety, they were rarely seen in public. One examination by the UK's Serious Organised Crime Agency noted 90% of the €500 bills distributed in the U.K. were in the hands of criminal organisations, who liked the note because it made it easier to launder money (the highest British denomination is £50). For that reason, the U.K. Bureaux de Change stopped trading €500 notes in 2010.
Old €500 notes will remain legal tender forever, as will other notes from the first series; but they will gradually be taken out of circulation. Spijkenisse for its part has as yet no plans to demolish the €500 bridge.
Strange Maps #1075
Got a strange map? Let me know at strangemaps@gmail.com.
Purple and modern, like the 'Bin Laden' note beloved by criminals: the five-hundred-euro bridge.
Credit: ScWikiSc, CC BY-SA 4.0
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Weird science shows unseemly way beetles escape after being eaten
Certain water beetles can escape from frogs after being consumed.
R. attenuata escaping from a black-spotted pond frog.
- A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
- The research suggests the beetle can get out in as little as 7 minutes.
- Most of the beetles swallowed in the experiment survived with no complications after being excreted.
In what is perhaps one of the weirdest experiments ever that comes from the category of "why did anyone need to know this?" scientists have proven that the Regimbartia attenuata beetle can climb out of a frog's butt after being eaten.
The research was carried out by Kobe University ecologist Shinji Sugiura. His team found that the majority of beetles swallowed by black-spotted pond frogs (Pelophylax nigromaculatus) used in their experiment managed to escape about 6 hours after and were perfectly fine.
"Here, I report active escape of the aquatic beetle R. attenuata from the vents of five frog species via the digestive tract," writes Sugiura in a new paper, adding "although adult beetles were easily eaten by frogs, 90 percent of swallowed beetles were excreted within six hours after being eaten and, surprisingly, were still alive."
One bug even got out in as little as 7 minutes.
Sugiura also tried putting wax on the legs of some of the beetles, preventing them from moving. These ones were not able to make it out alive, taking from 38 to 150 hours to be digested.
Naturally, as anyone would upon encountering such a story, you're wondering where's the video. Thankfully, the scientists recorded the proceedings:
The Regimbartia attenuata beetle can be found in the tropics, especially as pests in fish hatcheries. It's not the only kind of creature that can survive being swallowed. A recent study showed that snake eels are able to burrow out of the stomachs of fish using their sharp tails, only to become stuck, die, and be mummified in the gut cavity. Scientists are calling the beetle's ability the first documented "active prey escape." Usually, such travelers through the digestive tract have particular adaptations that make it possible for them to withstand extreme pH and lack of oxygen. The researchers think the beetle's trick is in inducing the frog to open a so-called "vent" controlled by the sphincter muscle.
"Individuals were always excreted head first from the frog vent, suggesting that R. attenuata stimulates the hind gut, urging the frog to defecate," explains Sugiura.
For more information, check out the study published in Current Biology.
We're creating pigs with human immune systems to study illness
Are "humanized" pigs the future of medical research?
The U.S. Food and Drug Administration requires all new medicines to be tested in animals before use in people. Pigs make better medical research subjects than mice, because they are closer to humans in size, physiology and genetic makeup.
In recent years, our team at Iowa State University has found a way to make pigs an even closer stand-in for humans. We have successfully transferred components of the human immune system into pigs that lack a functional immune system. This breakthrough has the potential to accelerate medical research in many areas, including virus and vaccine research, as well as cancer and stem cell therapeutics.
Existing biomedical models
Severe Combined Immunodeficiency, or SCID, is a genetic condition that causes impaired development of the immune system. People can develop SCID, as dramatized in the 1976 movie “The Boy in the Plastic Bubble." Other animals can develop SCID, too, including mice.
Researchers in the 1980s recognized that SCID mice could be implanted with human immune cells for further study. Such mice are called “humanized" mice and have been optimized over the past 30 years to study many questions relevant to human health.
Mice are the most commonly used animal in biomedical research, but results from mice often do not translate well to human responses, thanks to differences in metabolism, size and divergent cell functions compared with people.
Nonhuman primates are also used for medical research and are certainly closer stand-ins for humans. But using them for this purpose raises numerous ethical considerations. With these concerns in mind, the National Institutes of Health retired most of its chimpanzees from biomedical research in 2013.
Alternative animal models are in demand.
Swine are a viable option for medical research because of their similarities to humans. And with their widespread commercial use, pigs are met with fewer ethical dilemmas than primates. Upwards of 100 million hogs are slaughtered each year for food in the U.S.
Humanizing pigs
In 2012, groups at Iowa State University and Kansas State University, including Jack Dekkers, an expert in animal breeding and genetics, and Raymond Rowland, a specialist in animal diseases, serendipitously discovered a naturally occurring genetic mutation in pigs that caused SCID. We wondered if we could develop these pigs to create a new biomedical model.
Our group has worked for nearly a decade developing and optimizing SCID pigs for applications in biomedical research. In 2018, we achieved a twofold milestone when working with animal physiologist Jason Ross and his lab. Together we developed a more immunocompromised pig than the original SCID pig – and successfully humanized it, by transferring cultured human immune stem cells into the livers of developing piglets.
During early fetal development, immune cells develop within the liver, providing an opportunity to introduce human cells. We inject human immune stem cells into fetal pig livers using ultrasound imaging as a guide. As the pig fetus develops, the injected human immune stem cells begin to differentiate – or change into other kinds of cells – and spread through the pig's body. Once SCID piglets are born, we can detect human immune cells in their blood, liver, spleen and thymus gland. This humanization is what makes them so valuable for testing new medical treatments.
We have found that human ovarian tumors survive and grow in SCID pigs, giving us an opportunity to study ovarian cancer in a new way. Similarly, because human skin survives on SCID pigs, scientists may be able to develop new treatments for skin burns. Other research possibilities are numerous.
The ultraclean SCID pig biocontainment facility in Ames, Iowa. Adeline Boettcher, CC BY-SA
Pigs in a bubble
Since our pigs lack essential components of their immune system, they are extremely susceptible to infection and require special housing to help reduce exposure to pathogens.
SCID pigs are raised in bubble biocontainment facilities. Positive pressure rooms, which maintain a higher air pressure than the surrounding environment to keep pathogens out, are coupled with highly filtered air and water. All personnel are required to wear full personal protective equipment. We typically have anywhere from two to 15 SCID pigs and breeding animals at a given time. (Our breeding animals do not have SCID, but they are genetic carriers of the mutation, so their offspring may have SCID.)
As with any animal research, ethical considerations are always front and center. All our protocols are approved by Iowa State University's Institutional Animal Care and Use Committee and are in accordance with The National Institutes of Health's Guide for the Care and Use of Laboratory Animals.
Every day, twice a day, our pigs are checked by expert caretakers who monitor their health status and provide engagement. We have veterinarians on call. If any pigs fall ill, and drug or antibiotic intervention does not improve their condition, the animals are humanely euthanized.
Our goal is to continue optimizing our humanized SCID pigs so they can be more readily available for stem cell therapy testing, as well as research in other areas, including cancer. We hope the development of the SCID pig model will pave the way for advancements in therapeutic testing, with the long-term goal of improving human patient outcomes.
Adeline Boettcher earned her research-based Ph.D. working on the SCID project in 2019.
Christopher Tuggle, Professor of Animal Science, Iowa State University and Adeline Boettcher, Technical Writer II, Iowa State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
A new warning to sign to predict volcanic eruptions?
Satellite imagery can help better predict volcanic eruptions by monitoring changes in surface temperature near volcanoes.
Volcano erupting lava, volcanic sky active rock night Ecuador landscape
- A recent study used data collected by NASA satellites to conduct a statistical analysis of surface temperatures near volcanoes that erupted from 2002 to 2019.
- The results showed that surface temperatures near volcanoes gradually increased in the months and years prior to eruptions.
- The method was able to detect potential eruptions that were not anticipated by other volcano monitoring methods, such as eruptions in Japan in 2014 and Chile in 2015.
How can modern technology help warn us of impending volcanic eruptions?
One promising answer may lie in satellite imagery. In a recent study published in Nature Geoscience, researchers used infrared data collected by NASA satellites to study the conditions near volcanoes in the months and years before they erupted.
The results revealed a pattern: Prior to eruptions, an unusually large amount of heat had been escaping through soil near volcanoes. This diffusion of subterranean heat — which is a byproduct of "large-scale thermal unrest" — could potentially represent a warning sign of future eruptions.
Conceptual model of large-scale thermal unrestCredit: Girona et al.
For the study, the researchers conducted a statistical analysis of changes in surface temperature near volcanoes, using data collected over 16.5 years by NASA's Terra and Aqua satellites. The results showed that eruptions tended to occur around the time when surface temperatures near the volcanoes peaked.
Eruptions were preceded by "subtle but significant long-term (years), large-scale (tens of square kilometres) increases in their radiant heat flux (up to ~1 °C in median radiant temperature)," the researchers wrote. After eruptions, surface temperatures reliably decreased, though the cool-down period took longer for bigger eruptions.
"Volcanoes can experience thermal unrest for several years before eruption," the researchers wrote. "This thermal unrest is dominated by a large-scale phenomenon operating over extensive areas of volcanic edifices, can be an early indicator of volcanic reactivation, can increase prior to different types of eruption and can be tracked through a statistical analysis of little-processed (that is, radiance or radiant temperature) satellite-based remote sensing data with high temporal resolution."
Temporal variations of target volcanoesCredit: Girona et al.
Although using satellites to monitor thermal unrest wouldn't enable scientists to make hyper-specific eruption predictions (like predicting the exact day), it could significantly improve prediction efforts. Seismologists and volcanologists currently use a range of techniques to forecast eruptions, including monitoring for gas emissions, ground deformation, and changes to nearby water channels, to name a few.
Still, none of these techniques have proven completely reliable, both because of the science and the practical barriers (e.g. funding) standing in the way of large-scale monitoring. In 2014, for example, Japan's Mount Ontake suddenly erupted, killing 63 people. It was the nation's deadliest eruption in nearly a century.
In the study, the researchers found that surface temperatures near Mount Ontake had been increasing in the two years prior to the eruption. To date, no other monitoring method has detected "well-defined" warning signs for the 2014 disaster, the researchers noted.
The researchers hope satellite-based infrared monitoring techniques, combined with existing methods, can improve prediction efforts for volcanic eruptions. Volcanic eruptions have killed about 2,000 people since 2000.
"Our findings can open new horizons to better constrain magma–hydrothermal interaction processes, especially when integrated with other datasets, allowing us to explore the thermal budget of volcanoes and anticipate eruptions that are very difficult to forecast through other geophysical/geochemical methods."
Moral and economic lessons from Mario Kart
The design of a classic video game yields insights on how to address global poverty.
