Once a week.
Subscribe to our weekly newsletter.
Mosquitoes' taste for blood is finally explained
Mosquitoes can taste your blood using unique sensory abilities. Can we use that to keep them off us?
- A recent study demonstrates that mosquito brains react to the taste of human blood in strange ways.
- Some neurons only activated when presented with all four flavor elements. This is thought to be a unique adaptation.
- The findings may lead to novel ways to prevent mosquito bites.
Mosquitoes suck. The diseases that they spread kill 500,000 people a year, and some of them, such as Malaria and Zika, are noted for being remarkably unpleasant even when they don't kill you.
Female mosquitoes don't usually suck blood—they sustain themselves on nectar, but switch to the red stuff when they need to lay eggs. They work harder to drink blood than nectar, drawing it in with much greater force. How they know the difference between the two has remained unknown, until now.
A new study published in Neuron sheds light on how mosquitoes determine what they're eating and offers a potential solution to their disease spreading ways.
Like many things, it's all a matter of taste.
In a move dubbed a "tour de force" by other scientists involved in mosquito research, the researchers genetically modified mosquitoes so that specific neurons associated with taste lit up florescent tags when activated. They then offered these Franken-mosquitos a variety of tempting drinks to see if they would consume them and, if so, what taste neurons activated.
Sheep's blood was found to appeal to the insects, which consumed it with delight. However, attempts to get them interested in saline or sugar water mixtures that had only single components of blood didn't work, even when the signatures of animals like carbon dioxide or heat (typically used by the parasites as guides towards sources of blood) were added.
To draw them back, the researchers whipped up a blood-like concoction of glucose (sugar), sodium bicarbonate (present in both blood and baking soda), sodium chloride (salt), and adenosine triphosphate, or ATP, a compound that provides energy to cells which is found in all known forms of life. This was a success, and the little parasites flocked to it.
Next, the scientists offered the mosquitoes small tastes of each of the flavor components in the blood mixture to see which neurons reacted. While giving them glucose did not activate any of the neurons associated with the blood-drinking system— perhaps because glucose is also found in nectar—small doses of salt, sodium bicarbonate, and ATP did. Each flavor activated its own set of neurons, similar to how our taste buds react to a specific flavor element.
However, one large cluster of neurons only activated when all four ingredients were present.
According to lead author Veronica Jové, this detection of combinations rather than taste components is a unique adaptation. She explained, "These neurons break the rules of traditional taste coding, thought to be conserved from flies to humans."
And for the curious, the researchers did sample the ATP mixture they prepared in the lab. They didn't taste anything. Presumably, the taste of human blood to mosquitoes is akin to the sight of a flower in all its ultra-violet glory to a honey bee. It's just something we can't sense or hope to grasp. Though, given the sugar and salt element, perhaps to them it is like the sweet and salty flavor of salted caramels or saltwater taffy.
So, can we use this to finally destroy mosquitoes once and for all?
Not quite, but by increasing our understanding of how mosquitoes work, we can figure out how to keep them off us.
Co-author Dr. Leslie B. Vosshall suggests that, just as we give our pets medicine to keep fleas, ticks, and mosquitoes at bay, this discovery may lead to a drug that makes human blood unappealing to mosquitoes for use by those going into infested areas. If they can't taste blood, they may not bite in a way that can spread disease.
Mosquitoes are also known to prefer O type blood over all other types. This study may lead to further ones which help explain why. Additionally, because many neurons did not activate at all when the insects fed on blood or its components, further research will have to investigate if they are associated with still other flavors, or if they are related to the act of feeding on blood in different ways.
- Taste test: how mosquitoes tell nectar from human blood : Research ... ›
- Mosquitoes' taste for blood traced to four types of neurons ... ›
- Mosquitoes' Taste for Blood Traced to Four Types of Neurons ... ›
- Scientists discover mosquitoes' unique blood-taste detectors ›
- Why A Dangerous Mosquito Has A Taste For Human Blood : Goats ... ›
- The Taste of Blood in Mosquitoes | bioRxiv ›
Northwell Health is using insights from website traffic to forecast COVID-19 hospitalizations two weeks in the future.
- The machine-learning algorithm works by analyzing the online behavior of visitors to the Northwell Health website and comparing that data to future COVID-19 hospitalizations.
- The tool, which uses anonymized data, has so far predicted hospitalizations with an accuracy rate of 80 percent.
- Machine-learning tools are helping health-care professionals worldwide better constrain and treat COVID-19.
The value of forecasting<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTA0Njk2OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMzM2NDQzOH0.rid9regiDaKczCCKBsu7wrHkNQ64Vz_XcOEZIzAhzgM/img.jpg?width=980" id="2bb93" class="rm-shortcode" data-rm-shortcode-id="31345afbdf2bd408fd3e9f31520c445a" data-rm-shortcode-name="rebelmouse-image" data-width="1546" data-height="1056" />
Northwell emergency departments use the dashboard to monitor in real time.
Credit: Northwell Health<p>One unique benefit of forecasting COVID-19 hospitalizations is that it allows health systems to better prepare, manage and allocate resources. For example, if the tool forecasted a surge in COVID-19 hospitalizations in two weeks, Northwell Health could begin:</p><ul><li>Making space for an influx of patients</li><li>Moving personal protective equipment to where it's most needed</li><li>Strategically allocating staff during the predicted surge</li><li>Increasing the number of tests offered to asymptomatic patients</li></ul><p>The health-care field is increasingly using machine learning. It's already helping doctors develop <a href="https://care.diabetesjournals.org/content/early/2020/06/09/dc19-1870" target="_blank">personalized care plans for diabetes patients</a>, improving cancer screening techniques, and enabling mental health professionals to better predict which patients are at <a href="https://healthitanalytics.com/news/ehr-data-fuels-accurate-predictive-analytics-for-suicide-risk" target="_blank" rel="noopener noreferrer">elevated risk of suicide</a>, to name a few applications.</p><p>Health systems around the world have already begun exploring how <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315944/" target="_blank" rel="noopener noreferrer">machine learning can help battle the pandemic</a>, including better COVID-19 screening, diagnosis, contact tracing, and drug and vaccine development.</p><p>Cruzen said these kinds of tools represent a shift in how health systems can tackle a wide variety of problems.</p><p>"Health care has always used the past to predict the future, but not in this mathematical way," Cruzen said. "I think [Northwell Health's new predictive tool] really is a great first example of how we should be attacking a lot of things as we go forward."</p>
Making machine-learning tools openly accessible<p>Northwell Health has made its predictive tool <a href="https://github.com/northwell-health/covid-web-data-predictor" target="_blank">available for free</a> to any health system that wishes to utilize it.</p><p>"COVID is everybody's problem, and I think developing tools that can be used to help others is sort of why people go into health care," Dr. Cruzen said. "It was really consistent with our mission."</p><p>Open collaboration is something the world's governments and health systems should be striving for during the pandemic, said Michael Dowling, Northwell Health's president and CEO.</p><p>"Whenever you develop anything and somebody else gets it, they improve it and they continue to make it better," Dowling said. "As a country, we lack data. I believe very, very strongly that we should have been and should be now working with other countries, including China, including the European Union, including England and others to figure out how to develop a health surveillance system so you can anticipate way in advance when these things are going to occur."</p><p>In all, Northwell Health has treated more than 112,000 COVID patients. During the pandemic, Dowling said he's seen an outpouring of goodwill, collaboration, and sacrifice from the community and the tens of thousands of staff who work across Northwell.</p><p>"COVID has changed our perspective on everything—and not just those of us in health care, because it has disrupted everybody's life," Dowling said. "It has demonstrated the value of community, how we help one another."</p>
"You dream about these kinds of moments when you're a kid," said lead paleontologist David Schmidt.
- The triceratops skull was first discovered in 2019, but was excavated over the summer of 2020.
- It was discovered in the South Dakota Badlands, an area where the Triceratops roamed some 66 million years ago.
- Studying dinosaurs helps scientists better understand the evolution of all life on Earth.
Credit: David Schmidt / Westminster College<p style="margin-left: 20px;">"We had to be really careful," Schmidt told St. Louis Public Radio. "We couldn't disturb anything at all, because at that point, it was under law enforcement investigation. They were telling us, 'Don't even make footprints,' and I was thinking, 'How are we supposed to do that?'"</p><p>Another difficulty was the mammoth size of the skull: about 7 feet long and more than 3,000 pounds. (For context, the largest triceratops skull ever unearthed was about <a href="https://www.tandfonline.com/doi/abs/10.1080/02724634.2010.483632" target="_blank">8.2 feet long</a>.) The skull of Schmidt's dinosaur was likely a <em>Triceratops prorsus, </em>one of two species of triceratops that roamed what's now North America about 66 million years ago.</p>
Credit: David Schmidt / Westminster College<p>The triceratops was an herbivore, but it was also a favorite meal of the T<em>yrannosaurus rex</em>. That probably explains why the Dakotas contain many scattered triceratops bone fragments, and, less commonly, complete bones and skulls. In summer 2019, for example, a separate team on a dig in North Dakota made <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">headlines</a> after unearthing a complete triceratops skull that measured five feet in length.</p><p>Michael Kjelland, a biology professor who participated in that excavation, said digging up the dinosaur was like completing a "multi-piece, 3-D jigsaw puzzle" that required "engineering that rivaled SpaceX," he jokingly told the <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">New York Times</a>.</p>
Morrison Formation in Colorado
James St. John via Flickr
|Credit: Nobu Tamura/Wikimedia Commons|
Archaeologists discover a cave painting of a wild pig that is now the world's oldest dated work of representational art.
- Archaeologists find a cave painting of a wild pig that is at least 45,500 years old.
- The painting is the earliest known work of representational art.
- The discovery was made in a remote valley on the Indonesian island of Sulawesi.
Oldest Cave Art Found in Sulawesi<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a9734e306f0914bfdcbe79a1e317a7f0"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/b-wAYtBxn7E?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The Persian polymath and philosopher of the Islamic Golden Age teaches us about self-awareness.