Bobby McFerrin, Yo-Yo Ma, and Sergei Rachmaninoff

It’s been quite a hiatus – who knew residency could be busy? Today, my girlfriend sent me the most interesting collaboration I’ve seen since Martha and Snoop’s Potluck Dinner Party: Bobby McFerrin and Yo-Yo Ma performing selections from their collaborative album Hush on The Tonight Show.

It’s jaw-dropping this was a live performance! Between Bobby McFerrin’s perfect pitch while arpeggiating and Yo-Yo Ma’s dulcet handling of the melody, their version of “Ave Maria” is one of my all-time favorites. Meanwhile, I’m certain Two-Set Violin would be taken aback by McFerrin’s vocal agility in “Flight of the Bumblebee.” I ended up listening to the whole album as an energizing backdrop to pre-rounding.

This performance totally upended my view of Bobby McFerrin, who I previously only knew for the chart-topping “Don’t Worry, Be Happy.” Every time I heard that song on the radio, I found the faux Jamaican accent and vapid lyrics incredibly grating. After all “put a smile on your face/don’t bring everybody down like this,” is probably some of the least useful advice one can provide to somebody already struggling. Much to my amusement, McFerrin once said his accent in the song was actually “heavily influenced by Juan’s Mexican Restaurant, which was just around the corner from the studio.

However, after more listening, turns out McFerrin is a wizard. Not only does he have perfect pitch, but also has also mastered overtone singing, vocal percussion, and using the audience as an instrument. As Vox might describe – for McFerrin, the human voice is the ultimate instrument. Even “Don’t Worry, Be Happy” was more impressive than first meets the ear. The song was the first (and only) a capella song to ever hit #1 on the Billboard Hot 100, with McFerrin producing all the sounds heard on the entire track.

A lovely demonstration of leveraging the audience’s musical intuition. For a different take on the audience-choir from Jacob Collier, watch here.

My favorite song on Hush was probably Rachmaninoff’s Vocalise. Having played it on violin as a child, I’ve always been quite partial to this piece. McFerrin relies on no vocal tricks – just the melody beautifully rendered – and the interplay between voice and cello is absolutely seamless. For some other gorgeous renditions, try this theremin version by Gregoire LeBlanc, cello version by Rostropovich (arranged by Heifetz), or original version performed by Kiri Te Kanawa.

Side Note: There was an interesting comment I saw from the Pentatonic Scale video that pointed out that “This is made more amazing after realizing he’s moving left to right in the traditional low to high pitches in the audience perspective, but contrary to his own. In other words, as he moves to HIS left, the “notes” raise in pitch, but this is to the right in the audience perspective, so he’s switching it in his own mind.” As someone that has played a little piano, my intuition agrees that left to right generally corresponds to moving from lower to higher pitches. However, I’m unsure if this is a generally agreed-upon correspondence (some kind of widely-used orientational metaphor a la Lakoff) or if it’s more a narrowly culturally bound construction.

It’s all Greek to me…

Today, I read E. D. A. Morshead’s translation of Aeschylus’ Agamemnon. Although my copy is a Harvard Classics from 1982, the first printing was in 1902, and the translation itself dates from the 1880s (as per this mostly positive review in The Saturday Review). Still, I was surprised by the number of words I had to look up. And it’s not just my poor vocabulary at work, Wikipedia corroborates that Morshead’s “language is often archaic.”After my second time having to log into the OED just to find a definition, I decided to compile a list of the more obscure words (found at the end of the post).

I found the word choice often got in the way of actually enjoying the play from both dramatic and literary standpoints. For example, the only line I knew from the play was RFK’s misquote of Edith Hamilton’s translation – delivered during an impromptu speech in Indianapolis in the wake of MLK’s assassination.

Even in our sleep, pain which cannot forget falls drop by drop upon the heart until, in our own despair, against our will, comes wisdom through the awful grace of God.

Robert F. Kennedy

The original translation was actually “Even in our sleep, pain that cannot forget, falls drop by drop upon the heart, and in our own despite, against our will, comes wisdom to us by the awful grace of God.” In this context as a noun, despite means “contempt, malice, or spite.” Remarkably close though- and as one Reddit comment put it: “who the hell has Aeschylus in their back pocket?” Morshead’s translation in verse is a little less evocative, with “A boon, I wot…” just sounding silly.

In visions of the night, like dropping rain,

Descend the many memories of pain

Before the spirit’s sight: through tears and dole

comes wisdom o’er the unwilling soul –

A boon, I wot of all Divinity,

that holds its sacred throne in strength, above the sky!

  1. bale-fire – bonfire
  2. soothliest – truthfully. Even sooth as a noun “was in common use down to the first half of the 17th cent.; after this apparently obsolete (except perhaps in sense 4c) until revived as a literary archaism, chiefly by Scott and contemporary writers.”
  3. doughty – courageous, determined, bold, brave
  4. oarage – “they wheel with the oarage of their wings” – movement of limbs [or wings] etc. in a manner resembling that of oars
  5. eyas – a young hawk taken from the nest for the purpose of training, or whose training is incomplete
  6. rapine – seizing the property of others
  7. spilth – spilled
  8. unmeet – unfit
  9. twy-coloured – this one gave me trouble. The “twy-” parasynthetic combination with a noun + ED is a less popular variant of the “twi-” combination; both of these mean “having two.”
  10. minished – diminished
  11. wot – know
  12. refluent – flowing back or flowing again
  13. welter – confusion, upheaval, turmoil
  14. recreant – a person who has been defeated… (hence) cowardly, faint-hearted, craven, afraid
  15. well-a-day – alas! (as an interjection)
  16. fore-sorrow As in “foreknowledge is fore-sorrow.” Definitely a neologism, even the OED doesn’t have an entry for fore-sorrow.
  17. stripling – a young man
  18. trammel – a long narrow fishing net
  19. wight – epithet applied to supernatural beings. (I knew this word, but once, unfortunately, confused it with “waif” in conversation).
  20. pinion – wings of a bird in flight, terminal segment of a bird’s wing that bears the primary flight feathers
  21. meed – reward for labor or service
  22. guerdon – reward
  23. horrent – “A curse that clung to our sodden garb/ and hair as horrent as a wild beast’s fell.” In this sense, horrent means bristling (as in standing up as bristles).
  24. fell – Covering of hair/wool.
  25. leal – loyal, honest, true
  26. coppice – shrubbed area
  27. fulsome – excessively complimentary
  28. obtrude – “How nor a fulsome praise obtrude, nor stint the meed of gratitude?” – become noticeable in an unpleasant way
  29. trace-horse – “A trusty trace-horse bound upon my car…” A horse which draws in traces, as distinct from a shaft-horse. A trace is the pair of ropes by which the collar of a draught-animal is connected with the splinter-bar or swingletree. A swingletree is a crossbar used to balance the pull of the horse.
  30. haply – maybe, perhaps
  31. gauds – “such footclothes and all gauds aside…” In this sense probably meaning a piece of finery or gewgaw. It can also mean a trick or prank, as well as an ornamental bead placed between the ‘aves’ in a rosary.
  32. fain – “I fain would fare unvexed by fear.” Wish, desire.
  33. appanage – the provision made for the maintenance of younger children of royalty
  34. lustral – pertaining to purificatory sacrifice
  35. hies – hastens
  36. rede – advice or counsel
  37. plash – sound produced by liquid striking something, splash
  38. plight – “I plighted troth, then foiled the god.” To pledge solemnly, to be engaged to be married.
  39. glozes – makes excuses for
  40. charnel – associated with death. As part of the phrase “charnel house” – a vault where corpses are piled or a place associated with violent death
  41. nard – spikenard, a costly aromatic ointment
  42. laver – “[The body of Agamemnon lies, muffled in a long robe, within a silver-sided laver]”. A basin or container used for washing oneself
  43. reck – pay heed to something
  44. requital- something given in return or compensation
  45. aver – state or assert
  46. lorn – lonely, abandoned, forlorn
  47. caparisoned – a horse decked out in rich decorative coverings
  48. losel – worthless person
  49. quittance – release or discharge from debt or obligation
  50. exeunt – stage direction in a printed play to indicate a group of characters leave the stage

And finally, an apt summary of the whole sordid tale of the House of Atreus…

Lo! sin by sin and sorrow dogg’d by sorrow –

And who the end can know?

The slayer of today shall die tomorrow –

The wage of wrong is woe


  1. Eliot, Charles & Morshead, E. D. A. (1982). The Harvard Classics: Nine Greek Dramas. Grolier Enterprises Corp.

Greek surnames: suffixes and places of origin

During a recent visit to Crete, a local student told me that last name suffixes in Greek often reflected a person’s ancestral origin. For example, the diminutive “-akis” (-άκης) was common for Cretans, the patronymic “-opoulos” (-όπουλος) for those from the Peloponnese, “-as” (-ᾶς) from Epirus and Macedonia, and the patronymic “-oglou” (-όγλου) for those originally from Anatolia.*

Distribution of the Mitsotakis surname, using a website that visualizes the frequency of phone number registrations with given surnames. Outside of Athens (the big red cluster in Attica), the surname is relatively common in Crete.

For some specific examples:

  1. The current prime minister of Greece (as of May 2022), Kyriakos Mitsotakis, was born in Athens. However, his father (and former PM), Konstantinos Mitsotakis, was born in Chania, Crete.
  2. The former PM, Alexis Tsipras, was also born in Athens; however, his father hailed from Epirus.
  3. The dictator and Nazi collaborator, Georgios Papadopoulos, was born in a small village in the Peloponnese.
  4. Nikitaras Stamatelopoulos, a revolutionary in the Greek War of Independence, was similarly born in the Peloponnese. Even today, the last name Stamatelopoulos is most commonly found in the Peloponnese.
Distribution of the Stamatelopoulos surname, as gleaned from phone number registrations. Note the numerous clusters across the Peloponnese.

However, the correspondence between surname and place is far from perfect, even long before today’s globalized and hypermobile world. Before the Greco-Turkish War of 1919-1922, some 2 million Greeks lived in modern-day Turkey. During the aftermath of the war, Greek and Turkey agreed to a “compulsory exchange” of populations, in which over a million surviving Greek Orthodox from Asia Minor and almost half a million Muslims from Greece were forcibly denaturalized and moved. The map below captures the most common surnames of Greek Orthodox refugees from this exchange. It clearly shows that Papadopoulos (yellow) was a very common name throughout the Greek-speaking world, far beyond what the “-opoulos” (Peloponnese) would suggest. However, were still a fair number of last names more typical of Asia Minor, such as Panagiotoglou, Terezoglou, and Papazoglou.

Map of the most common surnames by region of refugees from the Greek-Turkish population exchange of 1923. Yellow = Papadopoulos, Red = Ioannidis, Orange = Panagiotoglou, Pink= Terzoglou, Purple = Kypraios, Grey = Hartomantzoglou, Green = Karagiannis, Brown = Papazoglou, Blue = Kazakis. Credit: Alex Sakalis

Although some descendants of the population exchange have kept these more “Turkish” surnames, many others have opted to Hellenise their surnames using the Ancient Greek patronymic “-ides”. For those displaced from Greece to Turkey, even fewer traces remain of ancestral surname suffixes. The Surname Law of 1934 required all Turkish citizens to adopt a Turkish surname. Thus, those with Greek-sounding surnames had to change to more Turkish suffixes such as “-zade”, “oglu”, or “gil.”

*patronymic means a “name derived from that of a father or paternal ancestor, usually by the addition of a suffix or prefix meaning ‘son'”. Familiar examples include Fitzgerald (Fitz [Norman] = fils [modern French] = son of Gerald), MacDonald (son of Donald), and Peterson.



What do CODA and Bachianas Brasileiras have in common?

Short Answer: Both are related to musicians with the surname of Villalobos. Bernardo Villalobos (Eugenio Derbez) is a music teacher in the Best Picture nominee CODA and Heitor Villa-Lobos composed the Bachianas Brasileiras.

Sorry for the long hiatus, I’ve matched at Wills Eye Hospital, eaten lots of fantastic BBQ in Texas, and taken up rock climbing in the interim.

I heard a segment on The Intelligence a few days ago about Brazilian modernism that was highly related to my most recent blog post about Tarsilo do Amaral, Antropofagia, and modernism in Brazilian art. In brief, the podcast/article traces the course of Brazilian modernism in the century since the Modern Art Week (an arts festival to Brazilians “as important as the…Armory Show”) – discussing the Antropofagia movement, the architecture of Oscar Niemeyer, and the evolution of bossa nova. Of greatest interest to this post, it notes that Heitor Villa-Lobos presented some of his works at the Modern Art Week as well.

As a young man, Heitor Villa-Lobos (1887-1959) rebelled against his mother’s desire for him to become a doctor. He instead become a “musical vagabond” that played guitar and cello to support himself while traveling around Brazil. During this period, he absorbed Brazilian folk music, especially the Afro-Brazilian music of the country’s north. After his travels, he enrolled in the National Institute of Music in Rio de Janeiro where he seriously studied classical stalwarts such as Bach, Wagner, and Puccini. Among an extraordinarily prolific output (with ~2,000 credited works), his Bachianas Brasileiras (1930-1945) are probably some of the best known. These works uniquely blended Western classical music with Brazilian folk and popular music.

I’ve heard Bachianas Brasileiras No. 5 live twice in my life – once with Nicole Cabell and the Boston Symphony Orchestra in 2014- and the other time at a concert with a Stanford professor that refused to extend my funding for a research project. In any case, it’s quite sublime. For a recording helmed by Villa-Lobos himself:

CODA (child of deaf adults) is a coming-of-age comedy-drama directed by Sian Heder that is a remake of the 2014 French film La Famille Belier. Ruby (Emilia Jones), the only hearing member of her family, struggles to balance her passion for singing with her responsibilities to her family’s fishing business. The cast is rounded out by her inspirational music teacher Mr. Villalobos (Eugenio Derbez) and family (Troy Kotusr, Daniel Durant, and Marlee Matlin). It’s up for three Oscars (including Best Picture) in 2022. I would definitely recommend streaming on Apple TV or seeing it in theaters (for free!). You’ll never hear Judy Collins’ “Both Sides Now” the same after watching…

From CODA. Ruby’s audition for Berklee (actually filmed in Rockport, not Berklee).

Not totally related, but I also watched Soderbergh’s Kimi the other day in which Billie Eilish’s ‘Oxytocin’ was featured multiple times. Since then, another song from Happier Than Ever, Billie Bossa Nova has been totally stuck in my head. For some real bossa nova, I had a radio show from a few years ago also attempting to explore the evolution of Brazilian music here:

Track listings for the show can also be found on the website of WMBR 88.1.



How are the Donner Party and Tarsila do Amaral related?

Short answer: Cannibalism. The Donner Party was a group of pioneers who were snowbound in the Sierra Nevada mountains and had to resort to cannibalism; Tarsila do Amaral was a Brazilian modernist painter instrumental in the formation of the aesthetic movement Antropofagia (cannibalism).

Abaporu by Tarsila do Amaral. Source: MALBA

One of the other residency applicants during my interview today was from Brazil. Separately, my friend sent me the most recent episode of “Great Art Explained” about Dali’s Persistence of Memory. Somehow these two things together reminded me of the magnificent work of Tarsila do Amaral (1886-1973).

Tarsila was the scion of coffee plantation owners in São Paulo and studied art in Brazil before leaving for Paris. There she studied with noted Cubists such as Fernand Leger and Andre Lhote- which helped inform her future work. In 1928, she painted Abaporu (oil painting on canvas) as a birthday present for her husband, the Brazilian writer Oswald de Andrade. In the Tupi language (an language formerly spoken by the aboriginal peoples of South and Southeast Brazil), abapor’u means “the man who eats man” from aba (man), poro (people) and u (eat). The painting itself was described by Tarsila as “a monstrous solitary figure, enormous feet, sitting on a green plain, the hand supporting the featherweight minuscule head. In front a cactus exploding in an absurd flower.”

Tupi or not Tupi: that is the question.

Oswald de Andrade in Manifesto Antropofago

When Oswald saw the painting, he was said to have exclaimed “That looks like a cannibal, a man of the earth.” This went on to inspire Oswald to write the Manifesto Antropofago (Anthropophagic [Cannibal] Manifesto”). The manifesto proposes that Brazil “cannibalize” European culture, ridding themselves of direct influences to create their own culture. In the short term, the ideas of the Manifesto were suppressed in the wake of the Brazilian revolution of 1930 and the dictatorship of Getulio Vargas. In the longer term, the Manifesto would help inspire figures in the Tropicalismo movement of the 1960s.

Abaporu was sold in 1999 for $1.5 million to a (gasp) Argentinian collector and sits in the MALBA in Buenos Aires. Today, it is valued at over $100 million. However, as Freakonomics noted in their second podcast on art this week, all value is theoretical until it comes time for auction… The most expensive Brazilian painting to actually sell at auction is Tarsila’s A caipirinha (Brazil’s national cocktail made with cahaca [sugarcane liquor], sugar, and lime). This painting was sold by court order and went for $9.25 million, beating out Alberto de Veiga Guignard’s Vaso de flores.

A Caipirinha - Tarsila do Amaral -
A Caparinha by Tarsila do Amaral. Source: Wikiart

The Donner Party was a group of unfortunate Illinois pioneers that attempted to join the westward migration to California in 1846. Consisting of the families and employees of brothers George and Jacob Donner and local businessman James Reed, the party started off around 30 people strong. Their journey was unremarkable at first, reaching Independence, Missouri in May and Fort Laramie, Wyoming in July. However, their party (along with 50 unfortunate others) split off from the main group in late July, intending to head to California instead of Oregon. Following the advice of the unreliable explorer Lansford Hastings (and later Major in the Confederate States Army – they truly hired the best and the brightest), the party pushed ahead into the Hastings Cutoff. This route was 125 miles longer than the established trail and cut through inhospitable deserts. The group lost valuable time over the next few months breaking new trails, fixing wagons, and searching for dying cattle. By late September, the Donner Party was the final migrant party heading towards California. On October 31st, the group finally reached Donner Pass… and found their route blocked by snow.

10 Things You Should Know About the Donner Party - HISTORY
Hastings Cutoff. Source:

The party then built makeshift cabins around a nearby lake (Donner Lake) and tried to subsist through the winter. Due to the harsh weather and inadequate food supplies, deaths soon occurred; this left the survivors to resort to cannibalism of the dead bodies. For those interested in a more detailed accounting, the Encyclopedia Britannica provides a great summary. Amazingly, the last survivor did not leave the camp until April 21, subsisting on cannibalism for weeks. Although harrowing, the misfortunes of the Donner party did nothing to slow the pace of migration to California. Today, Donner Lake is a gorgeous alternative to Lake Tahoe – I can personally attest it is a great place to boat, hike, and water-ski.

Donner Lake - Wikipedia
Donner Lake. Source



How are nine-dart finishes related to determining the composition of atoms?

Short Answer: Both are applications of the change-making problem.

Not exactly a nine-dart finish, but probably my favorite scene from Ted Lasso.

A leg (single game) of darts requires the player to score exactly 501 points, ending with either a double or the bullseye. Each shot consists of 3 darts, and each dart may at most score 60 points (triple 20). Therefore, the minimum number of darts necessary to finish a game is 9. The most traditional way to achieve this feat is by scoring a triple 20 on each of the first 6 throws, leaving 141 to score on the final three darts (known as the outshot). There are three preferred ways for performing the outshot:

  1. Triple 20, triple 19, and double 12
  2. Triple 20, triple 15, and double 18
  3. Triple 17, triple 18, and double 18

However, there are many more than 3 ways to achieve this score. As a matter of fact, Wikipedia provides a handy table showing there are 3944 ways of achieving such a finish (574 if double-in, double-out). Calculating the number of ways of achieving this score is an application of the change-making problem, itself a special case of the knapsack problem.

Ways to achieve a nine-dart finish (assuming one is not playing double-in, double-out like Ted and Rupert were).

The change-making problem seeks to find the fewest number of coins (of integer denominations) that add up to a given amount of money. This is directly analogous to finding the fewest number of darts (which are each worth integer scores) to reach 501 (the “given sum of money”). The change-making problem is a variation on the coin change problem – in which one wishes to find the possible ways of using infinite coins of prespecified denominations to make change for a specific amount of money. With a few constraints, it is easy to imagine how these problems relate to the nine-dart finish question. At first blush, it seems one could solve these problems by using as many of the largest denomination coin/dart as possible, then progressing to the next largest etc. This technique actually works for American coin denominations. However, this “greedy” algorithm does not work in general. For example, using 8 triple 20s (480), will leave a remainder of 21, which cannot be achieved with a double.

Instead, these problems may be solved in pseudo-polynomial time by using dynamic programming. Without going too much into technical details, this technique involves finding all combinations of smaller values that sum to the current threshold, then using this stored information to work up to the goal amount.

Another application of the change-making problem is in finding combinations of atoms that could comprise a mass/charge (m/z) peak in mass spectrometry (MS). In this case, the possible constituent atoms each have an integer mass/charge (denomination of coins) that we will try to sum up to an observed mass/charge peak (“given sum of money”).

Bonus questions:

  1. Who has the most televised nine-dart finishes in history?
  2. Who achieved the first televised nine-dart finish?
  3. Who plays Ted Lasso in Ted Lasso?


  1. Burns, Brian. Encyclopedia of Games: Rules and Strategies. Page 269.


  1. Phil Taylor with 11. Michael van Gerwen is in second with 7.
  2. John Lowe
  3. Jason Sudeikis

Why do humans (but not turtles) benefit from rapid chest compressions in CPR?

Short answer: Turtles have a shell, so chest compressions aren’t really possible. But it’s more interesting than that!

Medium answer: CPR in adult humans should be performed at a rate of 100-120/min. By contrast, turtles can survive at heart rates as low as 1 beat every 5-10 minutes. Human heart muscle is oxygenated by dedicated blood vessels (coronary vessels), whereas turtle heart muscle is directly oxygenated by the blood in the heart. The coronary arteries require a pressure gradient to fill, which can be achieved only by multiple compressions in a row. Therefore, the primary focus of human CPR focuses on keeping the heart perfused via compressions, whereas turtle CPR can focus more on oxygenation.

The adult out-of-hospital Chain of Survival. Source.

While reading about painted turtle physiology yesterday, I came across a line from Donald Jackson’s review: “Under [anaerobic and hypoxic] conditions, the turtle’s heart rate can be as low as 1 beat every 5–10 min.” This didn’t square at all with my understanding of human CPR, in which 30 chest compressions should be performed for every 2 rescue breaths.

The rationale behind 30 compressions is that a longer stretch of uninterrupted compressions leads to increased time of adequate blood flow (perfusion) to the heart muscle (myocardium). When spontaneous circulation stops, there is no longer a pressure gradient between arteries and veins. As chest compressions begin, this gradient begins to build up again due to resistance from arterioles. The heart relies on this pressure gradient to be perfused – during diastole (when the heart relaxes), back pressure from the arterioles allows some blood to flow backwards towards the heart. During this time, the aortic valve that connects the left ventricle to the aorta is closed, so blood will instead flow to the coronary vessels (blood vessels that supply the heart, whose entrances are at the aortic root). However, if there is no pressure gradient due to loss of spontaneous circulation (or the cessation of compressions), no blood will flow into the coronary arteries. This pressure gradient actually takes a few compressions to build up – as seen in the diagram below. There is actually a pretty substantial reserve of oxygen in the blood, so distributing that reserve is usually more important than giving more oxygen.

Figure 2 from Cunningham et al. shows that prolonged interruptions in chest compressions leads to a decrease in myocardial perfusion pressure that takes a while to build up again.

By contrast, turtle hearts are three-chambered and lack significant coronary circulation. Similar to fish hearts, turtle hearts are composed primarily of spongy myocardium that receives direct perfusion from the blood within. In addition, turtle hearts lack a complete septum between the left and the right ventricle. This contrasts with humans in which, the left and right ventricles are completely separated. Thus, turtle hearts can support both left-to-right shunts to better perfuse the body during exercise, as well as a right-to-left shunt to increase digestion and gastric acid secretion.

Therefore, “turtle CPR” focuses more on oxygenation. For those that ever have to resuscitate turtles, some pearls are:

  1. Turtle CPR is all about the airway. Small pieces of food can get stuck resulting in choking. In addition, turtles can indeed inhale water and drown – even in shallow water! This is despite the fact that turtles can oxygenate in water via cloacal (combined GI/GU tract) breathing…
  2. Get the turtle out of water
  3. Elevate the hind end of the turtle (to let gravity get rid of water)
  4. Straighten, then bend the front legs of the turtle. This may help squeeze out some more water from the lungs.
  5. Take the turtle to a vet afterwards! They will give oxygen (and usually antibiotics)

Also, everyone can benefit from a basic understanding of how to perform CPR. Dr. Glaucomflecken makes an excellent pitch here. And for those short on time to formally learn – remember to push hard and fast on the center of the chest (100-120/min, about the speed of Stayin’ Alive). Rescue breaths do not lead to better survival if you are not EMS trained. If you don’t believe that- even Walter White says so (don’t follow his example though -instead lock your elbows, use your core, and don’t hang out with psychotic drug lords)!


  2. Jackson DC. How a Turtle’s Shell Helps It Survive Prolonged Anoxic Acidosis. News Physiol Sci. 2000 Aug;15:181-185. doi: 10.1152/physiologyonline.2000.15.4.181. PMID: 11390905.
  3. Cunningham LM, Mattu A, O’Connor RE, Brady WJ. Cardiopulmonary resuscitation for cardiac arrest: the importance of uninterrupted chest compressions in cardiac arrest resuscitation. Am J Emerg Med. 2012 Oct;30(8):1630-8. doi: 10.1016/j.ajem.2012.02.015. Epub 2012 May 23. PMID: 22633716.
  4. Farmer CG, Hicks JW. The Intracardiac Shunt as a Source of Myocardial Oxygen in a Turtle, Trachemys scripta. Integr Comp Biol. 2002 Apr;42(2):208-15. doi: 10.1093/icb/42.2.208. PMID: 21708712.
  5. Farmer CG. On the evolution of arterial vascular patterns of tetrapods. J Morphol. 2011 Nov;272(11):1325-41. doi: 10.1002/jmor.10986. Epub 2011 Jun 27. PMID: 21710654.

How do painted turtles hibernate without oxygen for 3 months?

Short answer: Cutaneous respiration (breathing through their skin) and storing lactic acid in their shell.

Eastern Painted Turtle (Chrysemys picta picta).jpg
Eastern Painted Turtle (Chrysemys picta picta) Source: By Greg Schechter

While reading about green anoles and “hibernation” yesterday, I came across this intriguing line from Vitt and Caldwell’s Herpetology and felt compelled to read more:

Survival [of painted turtles during hibernation] is possible because of high tolerance for lactic acid buildup, which can be stored in the shell, and because their metabolic rate is reduced to 10–20% of their aerobic resting rate.

Painted turtles (Chrysemys picta) are the most abundant turtles in North America. There are four subspecies of the painted turtle, with the Western painted turtle being both the most colorful and common. Adult females are larger than adult males (10-25 cm vs 7-15 cm, weight 500g vs 300g). Painted turtles are named for their coloration and have red, orange, and yellow stripes found on their heads, necks, and tails. These turtles can live a long time – more than 40 years in the wild!

Painted turtles live in slow-moving freshwater. They bask for warmth on logs or rocks in the warmer seasons. In the winters, they hide and hibernate in the muddy bottoms of their freshwater habitats. Like many other reptiles, the sex of the hatchlings is determined by the temperature of the nest during the middle third of the incubation period (22-26 degrees C for males, >28 degrees C for females). Of course, global warming hurts these turtles’ chances for reproduction by causing more and more hatchlings to be female.

Metabolic rate depression during anoxic submergence of the painted turtle. Source

The hibernation of painted turtles is particularly interesting – they can survive in freezing waters (as low as 3 degrees Celsius) without oxygen for months at a time. Cold and anoxic environments allow the turtle to use a fraction of the energy of a similarly-sized aerobic mammal (e.g. < 0.01% of the ATP usage of a comparably sized rat). There are 2 possible limiting factors for the survival of a turtle facing such prolonged anoxia: 1) depletion of glycogen reserves and 2) buildup of lactic acid (a byproduct of anaerobic metabolism). As noted in the figure above, painted turtles can use as little as 0.01 kcal/kg/min in anoxic, cold environments. For a 500g turtle, this amounts to only 7.2 kcal/day. Painted turtles have high glycogen content in their livers, skeletal muscles, and heart – these stores are sufficient at this level of energy expenditure for the average turtle to last for 5.5 months! Clearly then, the major hurdle facing the anoxic turtle is the buildup of lactic acidosis.

Postulated mechanism of shell buffering of lactic acid in painted turtles. Source:

Painted turtles can build up plasma concentrations of lactic acid as high as 200mM (by contrast, a normal level in humans ranges between 2-4 mM). The painted turtles counteract this phenomenon in several ways:

  1. Direct body fluid buffering – painted turtles have high baseline plasma bicarbonate concentrations (40mM), with periotneal and pericardial fluid having concentrations of 80-120 mM.
  2. The turtle’s shell. The shell may release calcium carbonate, allowing for further buffering. In addition, lactate may be directly sequesterd by the shell. The lactate can then be flushed out later in normoxic conditions. Even during hibernation, turtles can switch between a normoxic and anoxic states (which may explain turtles swimming below the ice of frozen ponds). Apparently, this mechanism is not unique to the painted turtle, but generalizes to vertebrate bone, the carpace of crustaceans, and the shells of snails. As further proof, soft-shelled turtles fare much poorer in anoxic waters, lending more credence to the shell mechanism.
Western painted turtle. Photograph by Clay Showalter.

For those interested in more reading, I’d recommend looking into the work of Professor Donald Jackson. He passed away in 2020, but he seems to have written much of the seminal work on painted turtle physiology during his time at Brown.

As a final note, adult painted turtles cannot survive truly freezing temperatures (-1 to -2 degrees C). However, hatchling painted turtles can via supercooling – which I may discuss this further in the future… Also, stay tuned for a discussion tomorrow comparing turtle and human CPR!


  1. Vitt, L. J., & Caldwell, J. P. (2014). Herpetology: An introductory biology of amphibians and reptiles. Pages 203-227.
  2. Taking the temperature of the painted turtle. Lab Anim (NY). 2013 Sep;42(9):315. doi: 10.1038/laban.376. PMID: 23965557.
  3. Jackson, D.C. Hibernating without oxygen: physiological adaptations of the painted turtle. J. Physiol. 543, 731–737 (2002).
  4. Jackson DC. How a Turtle’s Shell Helps It Survive Prolonged Anoxic Acidosis. News Physiol Sci. 2000 Aug;15:181-185. doi: 10.1152/physiologyonline.2000.15.4.181. PMID: 11390905.

Why do green anoles (American chameleons) change color?

Short answer: It’s not entirely understood! Some factors inducing green-to-brown color change include increased light exposure, cooler temperatures, increased stress, and social interactions.

I was recently asked whether or not green anoles (Anolis carolinensis) change colors to brown when they “hibernate.” Green anoles are a tree-dwelling species of lizard native to the southeastern United States. They are known for being able to change colors between green and brown (see above). Pet stores sometimes refer to the green anole as the “American chameleon,” but this is a misnomer as it is not a true chameleon (which are Old World lizards). Not being from the southeastern United States, I haven’t seen many green anoles, so didn’t have a good prior on this question. In any case, doing some more reading, it seems green anoles don’t actually hibernate – instead they are just relatively inactive during the fall and winter.

It’s not fully understood why green anoles change colors. Some popular hypotheses for green-to-brown color change included as a response to increased light exposure, cooler temperatures, and increased stress. Additionally, some work suggests that brown coloration corresponds to subordinance, while green coloration indicates social dominance. During male-male interactions, the “winner” will usually be green while the “loser” will usually be brown. Interestingly, green anoles most likely do not change color to match their background. Field studies have actually observed that green anoles are mismatched to the surface they are sitting on more often than would be expected by chance. Although it’s still not entirely clear, I think the best answer to the question on green anole coloration during “hibernation” is that periods of inactivity and lower stress correspond to cooler temperatures, which in turn likely correlate with brown coloration.

By contrast, the how of green anole coloration is more clear. The green-to-brown transition occurs due to the stimulation of cells that contain melanin pigments (melanophores). Above these melanophores rest xanthophores (cells containing yellow pigment) and iridophores (cells containing “plates” that appear blue-green). Stimulation of melanophores (likely via hormonal mechanisms) causes upward migration of melanin, which blocks out light from xanthophores and iridophores. This results in the visible change of color from green to brown. Reaggregation of melanin within melanophores restores the original green color (Taylor et al.).

The green anole has spread to islands in the Pacific and Caribbean, where it is considered an invasive species. The changes in coloration make the green anole extra difficult to detect, requiring specialized field observers. In a recent paper, a group working in the Ogasawara Islands in Japan tried to combine remote sensing and machine learning to more efficiently detect these lizards. For those interested in more in-depth anole information, I recommend the Anole Annals run by Jonathan Losos from WUSTL.

Not really 100% related, but in my readings, I came across this fun figure from Herpetology with regards to dewlap color and head bobbing displays for male Anolis to attract females. After nodding my head for 6 hours straight in every ophthalmology interview – I certainly sympathize…

Figure 9.13 Three types of visual displays in Anolis lizards. Adapted from Echelle et al., 1971. from Herpetology.


  1. Vaughan GL. Photosensitivity in the skin of the lizard, Anolis carolinensis. Photochem Photobiol. 1987;46(1):109-114. doi:10.1111/j.1751-1097.1987.tb04743.x
  2. Yabuta S. and Suzuki-Watanabe A. 2011. Function of body coloration in green anoles (Anolis carolinensis) at the beginning of the breeding season: advertisement signaling and thermoregulation. Curr. Herpetol. 30(2): 155–158.
  3. Summers CH, Greenberg N. Somatic correlates of adrenergic activity during aggression in the lizard, Anolis carolinensis. Horm Behav. 1994;28(1):29-40. doi:10.1006/hbeh.1994.1003
  4. Jane F.F. Boyer and Lindsey Swierk. Rapid body color brightening is associated with exposure to a stressor in an Anolis lizard. Canadian Journal of Zoology95(3): 213-219.
  7. Taylor, J.D., Hadley, M.E. Chromatophores and color change in the lizard, Anolis carolinensis . Z. Zellforsch. 104, 282–294 (1970).
  8. Aota, T., Ashizawa, K., Mori, H. et al. Detection of Anolis carolinensis using drone images and a deep neural network: an effective tool for controlling invasive species. Biol Invasions 23, 1321–1327 (2021).
  10. Vitt, L. J., & Caldwell, J. P. (2014). Herpetology: An introductory biology of amphibians and reptiles.

What’s the difference between Turkish coffee and Bosnian coffee?

Short answer: Sugar is added later when making Bosnian coffee.

“We [Bosnians] serve [our coffee] without sugar in the coffee pot.. because we have a less bitter life than Turkish people.”

Bosnian guide

I had some delicious Bosnian food for lunch today! We tried a combination plate with ćevapi (kebab-like minced meat), pljeskavica (spiced meat patty), chicken kebabs, sausages, lepinja (flatbread), and ajvar (relish), as well as a gulaš (goulash). Not quite Bosnian, but they also had a lovely rose hip soda from Slovenia! Unfortunately I didn’t get a nice photo of the combination plate (so that’s an image from Yelp), but the other two are actually from today…

They also had some interesting decorations. One was an advertisement for a free concert by Bijelo Dugme (White Button), the most popular rock band ever from Yugoslavia. This concert was a comeback attempt by the band, and the last performance before the lead guitarist’s (Bregovic) army duty. Between 70,000-100,000 people showed up to Kosutnjak in Belgrade, and it is considered a seminal event in Yugoslav rock. Another was a little placard about the Sebilj in Sarajevo, an Ottoman-style fountain in Bascarsija Square (Sarajevo’s old bazaar). According to local legend, visitors who drink water from this fountain will return to Sarajevo. No doubt the restaurant wishes a similar effect from the poster…

The owner of the restaurant noticed I was taking some photos of the poster and came by to show us a can of Coke. He proudly told us that the can was an original Coca-Cola from the Sarajevo Olympics in 1984! Amazingly, the can still contained some liquid after 37 years, although it was quite soft (probably from loss of carbonation and direct corrosive effect of phosphoric acid).

After lunch, we went to the attached Bosnian market. While shopping, I made a major mistake asking if they had “Turkish coffee.” The owner was appropriately insulted but did patiently direct us to the Bosnian coffee. We ended up getting 4 bags (as gifts), so the encounter ended with all smiles and some free Bananko (a Croatian candy of chocolate-covered banana foam). This did have me wondering what the difference between Turkish and Bosnian coffee was though.

Bosnian coffee grounds. Source: my own phot

Turkish and Bosnian coffee are both strong, unfiltered, and prepared with the same grounds. The preparation begins by boiling cold water in a copper pot (known variously as a dzezve, cezve, or ibrik). Turks add sugar to their water, while Bosnians do not. Once the water comes to a boil, coffee grounds are then added. This causes the characteristic foaming of Bosnian/Turkish coffee. Some additional hot water can be used to help sink the grounds. Alternatively, the foam may be stirred down with a spoon and the mixture slowly heated again to generate more foam. Bosnian and Turkish coffee are both served with a glass of water. Bosnian coffee will additionally be served with sugar cubes and rahat lokum (sweet jelly cubes coated in sugar).

How Bosnian Coffee Is Different from Turkish Coffee | MyRecipes
Bosnian coffee. Source

Bosnian coffee should first be poured out from the dzezve, then a little foam spooned on top. The drinker can then take a small nibble of a sugar cube then drink some coffee to let the two mix together in one’s mouth. This contrasts with Turkish coffee, which has already been sweetened during the preparation. In addition, in Bosnia, the dzezve is brought to the table; whereas Turkish coffee is served in a single cup. As for the taste – the two honestly are pretty similar…one BBC article notes “Bosnian coffee tasted indistinguishable from its Turkish counterpart, which is to say it was potent, bitter and as thick as mud.”

Bekrija si cijelo selo viče (The bohemian is shouting at the whole village) by Bijelmo Dugme. From the album Šta bi dao da si na mom mjestu (What Would You Give to Be in My Place).

Note: I don’t really (yet) understand the proper use of diacritical marks for Slavic languages, so sorry for missing a bunch of these!


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