Low-carb Locusts: Fighting a Modern-Day Plague

“By morning the wind had brought the locusts; they invaded all Egypt and settled down in every area of the country in great numbers...They covered all the ground until it was black. They devoured all that was left after the hail--everything growing in the fields and the fruit on the trees. Nothing green remained on tree or plant in all the land of Egypt.” (Exodus 10:13-15).

The plague of locusts is one of the most striking images from the Old Testament of the Bible. As punishment for Pharaoh’s enslavement of the Israelites, God unleashes a massive swarm of insects upon Egypt, so large that it blocks out the sun. The insects soon ate away all vegetation in the country, plunging Egypt into famine. And though it seems too bizarre and terrifying to be anything more than a biblical story, locusts are still a major threat to 10% of our world population today [1].

A desert locust [5].

Locusts are actually a type of grasshopper. However, out of the 20,000 species of grasshoppers in the world, only 19 of those species are capable of undergoing the locust transformation [2]. They are harmless in small numbers, just like the grasshoppers that you can catch in your own backyard. But when large numbers of these particular species are crowded together, they undergo a fascinating transformation that NPR’s Joe Palca describes on the podcast Short Wave. “...What happens is there’s a change, a physical change in the brain, the wing size, the coloration, that happens because certain species of grasshoppers when you pack them together, literally just pack them together...they turn into this thing that we know as locusts” [2]. Close proximity to other grasshoppers transforms harmless jumping insects into ravenous, destructive beasts, often likened to Dr. Jekyll and Mr. Hyde [2].

Map detailing the areas affected by the desert locust. Swarms (indicated by the red circles) are the most destructive [6].

Currently, a specific species known as the desert locust is a serious problem in the global south, specifically the horn of Africa, a region that includes Ethiopia, Somalia, and Kenya [3]. Recent heavy rainfall in the region has increased locust breeding, resulting in huge swarms of up to 80 million insects per square kilometer that can fly over 100 kilometers every day [1]. In Ethiopia, they devour up to 1.8 million tons of vegetation daily, and are on their way to becoming a plague of biblical proportions [1]. 

Threat level to crops of the desert locust in affected areas [7].

Because of the enormous threat that locust swarms pose to the food security of those living in the horn of Africa, as well as along the border between India and Pakistan further east, scientists are desperately searching for sustainable control measures. Pesticides aren’t practical: they can be toxic to farmers’ crops and livestock, and the locusts are too widespread to be greatly affected [2]. However, current research in a lab at Arizona State University has suggested that diet might be the key to controlling the plague. Arianne Cease, lead researcher and founder of the Global Locust Initiative, has found that locusts prefer a diet high in carbohydrates (sugars) compared to one high in protein [1,2]. Manipulation of the soil can control the carbohydrate-to-protein ratio in grain crops like millet: healthy soil produces protein-rich grain, while nutrient-poor soil produces grain that is high in carbohydrates [2]. Based on the locusts’ affinity for carbohydrates in a laboratory setting, Cease and her team believe that enriching the soil in affected areas could reduce damage to crops: “If the farmers can be talked into keeping their fields in good shape by fertilizing them and making sure there’s not a lot of runoff...it will be growing a crop that the locusts are less likely to eat” [2].

Is dieting really a feasible solution to the locust plague? The idea must be put to the test in the affected regions before we know for sure. Currently, a trial in Senegal is implementing new fertilization techniques to find out whether a high-protein diet reduces the impact of the Senegalese grasshopper, a locust that is less aggressive than the desert variety [2]. So far, the results look promising: early findings indicate that improving soil fertility can reduce locust numbers by half [1]. Hopefully by better equipping farmers to protect and nourish their land, we can bring the desert locust’s reign of terror to an end, forcing them to endure everyone’s worst nightmare: a strict no-carb diet.

References

1. Ahuja, A. (2019, December 17). Locust swarms refocus attention on an old enemy. Retrieved February 12, 2020, from Financial Times website: https://www.ft.com/content/32c66414-20be-11ea-b8a1-584213ee7b2b. 

2. Davis, R., Le, V., Sofia, M., & Palca, J. (Producers). (2020, January 22). Can A Low-Carb Diet Prevent A Plague Of Locusts? NPR Short Wave. Podcast retrieved from https://www.npr.org/2020/01/21/798163143/can-a-low-carb-diet-prevent-a-plague-of-locusts.

3. Food and Agriculture Organization of the United Nations. (2020, February 10). Desert Locust situation update. Retrieved February 12, 2020, from Locust Watch website: http://www.fao.org/ag/locusts/en/info/info/index.html.

4. Nunn, D. (2014, March 14). Desert locust [Photograph]. Retrieved from https://www.flickr.com/photos/davidnunn. 

5. Kamal, R. (2020, January 22). Desert locust (Schistocerca gregaria) [Photograph]. Retrieved from https://www.npr.org/2020/01/21/798163143/can-a-low-carb-diet-prevent-a-plague-of-locusts.

6. Current desert locust situation [Image]. (2020, February 10). Retrieved from http://www.fao.org/ag/locusts/en/info/info/index.html. 

7. Situation & threat of desert locust [Image]. (2020, February 10). Retrieved from http://www.fao.org/ag/locusts/en/info/info/index.html.

Edgar Allan Poe and CO: The Dangers of Carbon Monoxide Poisoning

The year is 1849. On a rainy day in Baltimore, Joseph W. Walker, an editor for the Baltimore Sun, comes across a man lying in the gutter on the side of the road, delirious and barely conscious[1]. Recognizing him instantly, Walker seeks medical attention and writes a letter to one of the gentleman’s acquaintances in Baltimore asking for help [1]. Unfortunately, it is too late: he never regains consciousness, and dies just 4 days later [1]. Though the circumstances of his death are mysterious and intriguing by any standards, they are made even more so by the fact that the man was Edgar Allan Poe.

How did Poe, the esteemed writer and poet, master of mystery and the macabre, end up like a character in one of his own short stories? Multiple theories--some more plausible than others--attempt to explain the mystery, including alcoholism, heavy metal poisoning, rabies, and murder [1]. None have been proven. Yet one theory finds basis not only in Poe’s death, but his life as well: carbon monoxide poisoning.

Known as “the silent killer” due to its lack of color or odor, carbon monoxide gas acts by binding to hemoglobin, the protein in our blood responsible for carrying oxygen to the tissues [2]. Carbon monoxide has a much higher affinity for hemoglobin than oxygen, meaning that it binds more tightly and is able to outcompete oxygen for binding space [2]. As a result, there is less oxygen available for our brain and tissues, leading to disastrous consequences [2]. Short-term symptoms include headache, nausea, and weakness; long-term exposure can cause coma or death [2].

Ball-and-stick model of hemoglobin, the protein responsible for carrying oxygen in our blood.

It is very likely that Poe was exposed to carbon monoxide on a regular basis: light fixtures of the era functioned through the burning of coal, which produced fumes that contained high levels of CO [3]. Additionally, chronic, low-level carbon monoxide exposure often isn’t immediately diagnosed because symptoms are much more subtle and may manifest in diverse ways [2]. One of these symptoms is partial facial paralysis caused by nerve damage from a lack of oxygen [3]. Pictures of Poe’s face exhibit the tell-tale slanting of the eyes and mouth, a hallmark of low-grade CO exposure [4]. 

Photo of Poe taken in 1849, original and colorized, showing slight slanting of the eyes and mouth that is indicative of chronic CO exposure [6].

In addition, many of the characters in Poe’s works exhibit the delusion and paranoia that are symptomatic of CO poisoning[4]. In The Tell-Tale Heart, the narrator believes he can hear the beating heart of his victim underneath the floorboards. In The Black Cat, a man is haunted by the pet that he killed in a drunken rage. The list goes on[5]. Poe’s own delirium and vivid hallucinations just before his death might also have been a product of carbon monoxide exposure: in his last moments, the grisly and haunting stories of his works became his reality [1].

Ultimately, there is no way to prove that either Poe’s inspiration for his works or his ultimate demise were results of chronic carbon monoxide poisoning. His cause of death was officially listed simply as “phrenitis,” or swelling of the brain[1]. However, understanding the subtle symptoms of CO exposure could be the key to saving a life in the present day. And even if it isn’t true, it is interesting to consider that the morbid and fantastical worlds imagined in Poe’s works could be rooted in science after all.

References:

1. Geiling, Natasha. "The (Still) Mysterious Death of Edgar Allan Poe." Smithsonian.com. Last modified October 7, 2014. Accessed December 2, 2019. https://www.smithsonianmag.com/history/still-mysterious-death-edgar-allan-poe-180952936/. 

2. Blumenthal, Ivan. "Carbon Monoxide Poisoning." Journal of the Royal Society of Medicine 94, no. 6 (June 2001). Accessed December 2, 2019. https://doi.org/10.1177/014107680109400604. 

3. Otterbein, Leo E. "Quoth the Raven: Carbon Monoxide and Nothing More." Medical Gas Research 3, no. 7 (March 6, 2013). Accessed December 2, 2019. https://doi.org/10.1186/2045-9912-3-7. 

4. "Edgar Allan Poe and the Tell-Tale Face of Carbon Monoxide Poisoning." Multiple Chemical Sensitivity. Last modified October 24, 2006. Accessed December 2, 2019. http://www.mcsrr.org/poe/. 

5. "An Exploration of Short Stories by Edgar Allan Poe." PoeStories.com. Accessed December 2, 2019. https://poestories.com/summaries.php. 

6. Pat. Edgar Allan Poe 1849. Photograph. Flickr. June 1, 2016. Accessed December 2, 2019. https://www.flickr.com/photos/patseg. 

7. Edumol Molecular Visualization. Hemoglobin. Image. Flickr. March 23, 2017. Accessed December 2, 2019. https://www.flickr.com/photos/edumendo.

Am I Speaking Too Fast?

If you have ever tried to listen to native speakers of a language you are learning, you probably had trouble understanding them because they seem to be speaking too fast. It turns out that this might not just be because you are new to the language. People who speak different languages actually voice syllables at different rates, so some languages are consistently spoken faster than others. However, this doesn't mean that speakers of these languages convey information faster, according to a new study published in Science Advances.

A study conducted by researchers from the University of Lyon found that languages are constrained by a tradeoff between speed and efficiency. Languages spoken faster will contain less information per syllable, so that universally, languages tend to convey information at the same rate of 39.15 bits per second. Despite the large differences between languages-for instance, English has almost 7,000 distinct syllables, while Japanese only has a few hundred-a combination of biological, cultural, and social factors constrain them to be more similar than you think.

 The study investigated 17 Eurasian languages, including Japanese, Mandarin, German, Vietnamese, Spanish, French, and Italian. For each language, the researchers estimated the information density (ID) for each language, or the amount of information that is contained in each syllable, calculated in bits per second. A bit in linguistics is the amount of information contained in a syllable that reduces uncertainty by half. For example, in conversation, if you could narrow a topic of a conversation down by half from a single syllable, that syllable would contain 1 bit of information.

The researchers also asked 10 speakers for each language to read 15 texts and measured the duration and number of syllables spoken. They then calculated the speech rate (SR), the speed at which syllables are produced. You can imagine that speech rate would depend largely on the individual speakers, but the researchers found that it varied more by language than by speaker within a language.

 The information rate for each language was then calculated by multiple information density (ID) with average speech rate (SR). The researchers found that languages are more similar to each other in information rate than in speech rate, and that information rate negatively correlated with information density. These findings extend the results from a previous study, which found that English had an information density of 0.91, while Japanese had a density of almost half, at 0.49. However, English was spoken slower, at 6.19 syllables per second, compared to 7.84 syllables per second for Japanese.

 Overall, languages occupy a range of information rates, which the researchers suggest are due to the communicative and cognitive limitations of both speakers and listeners. If a high information density language was spoken to fast (termed "high-fast"), this would require the speaker to vocalize more complex sounds and require cognitive planning. As you can imagine, listeners would also have a hard time listening and understanding such speech. On the other hand, "low-slow" languages, low ID languages spoken slowly, would be less efficient and also require speakers and listeners to use more memory.

The researchers hope to broaden their results by studying more languages across the world from regions in Africa and the Americas. They are also interested in extending these findings to conversational speech, not just read speech. Interestingly, this study also relates to previous studies that found that within a single language, faster speakers tend to be less informational. Our brains find a balance between cognitive limitations and communication requirements, so that we can get our points across effectively and efficiently.

References

1. Coupé, C.; Oh, Y.; Dediu, D.; Pellegrino, F. Different Languages, Similar Encoding Efficiency: Comparable Information Rates across the Human Communicative Niche. Science Advances 2019, 5 (9).

2. Kluger, J. Slow Down! Why Some Languages Sound So Fast. http://content.time.com/time/health/article/0,8599,2091477,00.html (accessed Oct 13, 2019).

Geoengineering: The Technology of Tomorrow

From melting icebergs and rising waters to California wildfires and Houston hurricanes, the effects of climate change are becoming more intense and more frequent every day with the advent of more natural disasters and consequences of climate change. So what can we do about this? In order to mitigate the damage that natural disasters and climate change do to our environment, a new possible solution has emerged: geoengineering. 

At first glance, geoengineering – a set of ways to alter the climate to stall or inhibit the repercussions of climate change – may seem counterintuitive. Why would we knowingly mess around with the climate after we have already caused irreparable damage? And yet, geoengineering may prove a viable solution to combat the environmental changes we are currently experiencing. 

For example, one solution to combat global warming involves imitating the capacity of a volcano to cool by introducing more sulfates into the atmosphere [1]. Yet another example of geoengineering is ocean seeding. Marine phytoplankton has the ability to take carbon dioxide from the air and “sequester” it, meaning that the carbon dioxide is carried via phytoplankton to the bottom of the ocean [2]. Iron has also been associated with phytoplankton “blooms” or proliferation, as well – ocean seeding involves introducing iron particles to fertilize phytoplankton and cause more growth.

Even though these scenarios might help alleviate some of the consequences of irreversible climate change, environmental groups still express hesitation about these concepts because they fear that we would be further harming the planet by attempting to artificially change environmental circumstances. In the example of ocean seeding, researchers are concerned that creating phytoplankton blooms in one area would create ocean “dead zones” in another region[2]. There’s also the problem of deep-sea organisms, which might be negatively affected by the sequestration of carbon dioxide.  

Another example of geoengineering that seems both promising and risky is putting satellites in the atmosphere to deflect the sun’s rays from Earth and reflect sunlight – this has been referred to colloquially as “space mirrors,” and is actually a component of presidential candidate Andrew Yang’s environmental plan. However, the problem with space mirrors is that they could cause uneven climate circumstances, such as less rainfall in one area but warm weather near the poles, neither of which is a desirable outcome [4].

Ultimately, there is a scientific consensus that the most effective solution to climate change would be to decrease our emissions of greenhouse gases. But in order to mitigate the worst effects of what damage we have already done, we may have to accept that we will need to significantly remodel what’s left of our ecosystem in order to survive. Further research in these areas is definitely necessary to fully evaluate these potential geoengineering methods. Hopefully, our situation on Earth will not come to a point where we will be forced to make such decisions to fundamentally change components of our planet’s climate.

References

1. Biello, D. What Is Geoengineering and Why Is It Considered a Climate Change Solution? https://www.scientificamerican.com/article/geoengineering-and-climate-change (accessed Oct 11, 2019).

2. Gramling , C. In a climate crisis, is geoengineering worth the risks? https://www.sciencenews.org/article/climate-change-crisis-geoengineering-worth-risks (accessed Oct 11, 2019)

3. Kaufman, R. Could Space Mirrors Stop Global Warming? https://www.livescience.com/22202-space-mirrors-global-warming.html (accessed Oct 11, 2019).

4. Phytoplankton blooms appear as a milky turquoise swirl in the Arctic’s Barents Sea in 2016 (https://www.sciencenews.org/article/climate-change-crisis-geoengineering-worth-risks) by Jeff Schmaltz/Joshua Stevens, Lance/Eosdis Rapid Response. Public Domain. (ScienceNews) 

5. Image: Phytoplankton blooms appear as a milky turquoise swirl in the Arctic’s Barents Sea in 2016 (https://www.sciencenews.org/article/climate-change-crisis-geoengineering-worth-risks) by Jeff Schmaltz/Joshua Stevens, Lance/Eosdis Rapid Response. Public Domain. (ScienceNews)

Prehistoric Canned Food: Bone Marrow Consumption at Qesem Cave

Nowadays, almost every food we eat has been preserved in some way - whether it’s a refrigerated bag of spinach, a package of ramen, or a bag of beef jerky. In contrast, our early ancestors had to rely on plants and animals that were currently available. This simple hunter-gatherer system promises times of hunger when food is scarce. However, one recent study has found evidence of early Paleolithic people saving animal bones for up to nine weeks before eating them around 420,000 to 200,000 years ago at Qesem cave near Tel Aviv [1]. These animal bones were saved for their valuable interiors: bone marrow, an important source of nutrition in a compact high-fat, high-calorie package.

In more recent times, bone marrow has been an important source of nutrition in the winter months for the Nunmiut Eskimo or processed from bison to make pemmican among Great Plains groups [1]. Within Qesem cave, the limbs and skulls of hunted animal carcasses, most commonly the fallow deer, were taken into the cave and saved while the rest of the carcass was processed on-site [1]. Archaeologists are able to distinguish the bones that were eaten immediately versus preserved by examining incision marks on the bones [1]. Here, the marrow-rich metapodials, one of the leg bones, were found with unique chopping marks that indicate that the marrow was consumed after it had been preserved. Additionally, these bones were likely stored with the skin still on in order to improve preservation. To further test this theory, archaeologists experimented on the preservation of bone marrow, finding that preserving bone with the skin in similar environmental conditions was feasible for up to nine weeks [1]. In this way, the bones represent “cans” that preserve the marrow for long periods of time. 

This changes our current understandings of hunter-gatherer practices: instead of early people living off whatever they caught that day and enduring periods of hunger when times were scarce, they had sophisticated systems of food storage and planning. As Professor Gopher, one of the archaeologists on the project, explained, evidence of these “food cans” indicate that prehistoric humans were “sophisticated enough, intelligent enough, and talented enough” to preserve these bones under specific conditions in order to plan for a food-scarce future [2]. This evidence of food-planning further represents an increasingly complex socioeconomic system as early humans adapted to their environments. So, when you pull out a bag of beef jerky or a can of corn from the cupboard, remember that our early ancestors were doing something very similar with a cache of bones.

References

1. Blasco, R.; Rosell, J.; Arilla, M.;, Margalida, A.; Villalba, D.; Gopher, A.; Barkai, R. Bone Marrow Storage and Delayed Consumption at Middle Pleistocene Qesem Cave, Israel (420 to 200 ka). Science Advances.  2019, Vol. 5, no. 10.

2. ScienceDaily. Prehistoric humans ate bone marrow like canned soup 400,000 years ago: Bone and skin preserved the nutritious marrow for later consumption. ScienceDaily. 2019. Retrieved 13 October 2019, from https://www.sciencedaily.com/releases/2019/10/191009142902.htm

3. Image: Cans Vectors by Vecteezy from https://www.vecteezy.com/free-vector/cans