Episode 59: Dead Dinosaurs, Cockroach Sperm, and Monkey Testicles – A Science Sampler Platter for the New Year

Image: Male genital hook (left) and acrosomes on sperm cells (right) on Supella dominicana, described from amber. (Source: Poiner 2022)
Our new episode is available from our Podcast host here: Episode 59
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Sources/Reading:
- “The Mesozoic terminated in boreal spring” (Nature, 2022) ***Discussed
- The Avatar movies
- “Why Avatar has the Most Ironic Soundtrack of All Time” (Sideways on YouTube, 2020)
- “Avatar: The Way of Water or how not to make Indigenous futurism movies” (Grist, 2022)
- Cockroach in amber
- “Oregon State amber researcher finds new species of cockroach, first fossilized roach sperm” (Oregon State University, 2022)
- “Supella dominicana, a new species of cockroach (Blattida: Ectobiidae) with developed spermatids in Dominican amber” (Biologia, 2022) ***Discussed
- Ultrasound as contraception
- “The efficacy of ultrasound treatment as a reversible male contraceptive in the rhesus monkey” (Reproductive Biology and Endocrinology, 2012) ***Discussed
- “The use of nonmetal electrodes in electroejaculation of restrained but unanesthetized macaques” (Journal of medical primatology, 1991)
- “Collection of Monkey Semen by Electroejaculation” (Proceedings of the Society for Experimental Biology and Medicine, 1963)
- On humans
- “Ultrasound as a New Method of Male Contraception” (Fertility and Sterility, 1977)
- “Rebecca Weiss designs ultrasound-powered male contraceptive device” (dezeen, 2021)
- “COSO – THE NEW WAY OF MALE CONTRACEPTION” (James Dyson Award, 2021)
- As a bonus on the topic of vasectomy, one podcast I enjoy is My Brother, My Brother and Me, and my favorite clips, ever, are when Justin talked about having a vasectomy consultation and then the follow-up.
- “NUCLEAR SALT WATER ROCKETS: HIGH THRUST AT 10,000 SEC ISP” (Journal of The British Interplanetary Society, 1991) ***Discussed
- “Experimental animal decompressions to a near-vacuum environment” (1965) ***Discussed
Transcript
Charles 0:23
Hello, and welcome to Assigned Scientist at Bachelor’s. I’m Charles and I’m an entomologist
Tessa 0:28
And I’m Tessa and I’m an astrobiologist.
Charles 0:30
And today’s just the two of us, and I thought it would be fun to offer up kind of a sampler platter of interesting science. And in the sense of – if you imagine that most of our episodes are kind of a meal, based around one topic or one interview subject, this is instead kind of a party table of snacks. Tessa, how about you start us off?
Tessa 0:56
So I have two different articles. Would you like to hear the more recent one first or the older one first?
Charles 1:02
Uh, dealer’s choice.
Tessa 1:04
I think the older one will segue into the some of the things that you’ve worked on. So I’ll save that for later. First one, though, just came out this past year, and you may have heard some of the buzz about it, or our listeners may have. So, they’ve managed to figure out what time of year the asteroid that wiped out the dinosaurs impacted, which is pretty wild given that was 66 million years.
Charles 1:25
Can you give us the like article name?
Tessa 1:28
Yeah, sure. It’s simply called, “the Mesozoic terminated in boreal spring.” Mesozoic, being the era of the dinosaurs, boreal means northern spring. And the way this discovery was made is, we know this from a site in North Dakota that was discovered about 10 years ago by a guy named Robert De Palma, who later turned out to be kind of sketch for unrelated reasons, but that’s a topic for another time. And the site is called Tanis. But it is a pretty extraordinary find in that it basically was formed as a direct consequence of the Chicxulub asteroid impacts that wiped out the dinosaurs 66 million years ago, there was a shallow Inland Sea that kind of went up the middle of North America before the Rocky Mountains formed.
The asteroid impacted in the Gulf of Mexico, and caused massive earthquakes all throughout North and South America. These earthquakes caused what are called ch waves, which is kind of a cousin of a tsunami. It’s a seismically induced, like water wave and flooded the riverbank and all the sediment deposited out. And 66 million years later, there’s this fossilized and entrapped, you know, all the organisms, mostly fish that you know, got swept up in that seatwave on the day of the impact and preserved them in time. So we have like a snapshot about like an hour or so after the asteroid hit, which in itself is extraordinarily high time resolution for you know, an event that is 66 million years ago.
Charles 3:00
This is… this may be outside of your base of knowledge. But I remember growing up, I think the idea that an asteroid wiped out the dinosaurs was still presented as like, this is one of several different hypotheses. Do you know at what point we kind of got to a resolution of like, this is we’ve all kind of agreed here?
Tessa 3:24
The idea was first postulated in the 80s by a father and son team of scientists, Alvarez, I don’t remember their first names. And for a while it was just competing theory, then they found that the Chicxulub asteroid impact crater in the Gulf of Mexico. And that provided more evidence. However, for a long time, there was still some debate up until pretty recently, actually, personally, because the other thing that was happening about 66 million years ago was a massive volcanic episode in India. And we’re talking like 1000s of square kilometers of like lava fields erupting. It’s an event called a flood basalt volcanism that just kind of randomly happens about every 100 million years or so on the planet. And it was wondered if that could have contributed to the dinosaurs extinction, particularly since we know that another mass extinction. In fact, most mass extinctions coincide with those massive eruptions, like the great dying at the end of the Permian Triassic that wiped out like 90% of life on the planet was largely caused, at least initially by another one of these episodes of mass volcanism.
And the other thing is that if you look at the strata, you know, the layers of Earth and cutting the hillside or whatever, three meters below the boundary, that marks where that asteroid impacted. There hadn’t been a lot of dinosaur fossils found and this is actually referred to in paleontology as a three meter problem. And that made people wonder if well, there was these volcanoes erupting. Maybe dinosaurs are already on their way out, you know, likely due to the vault Kenick eruptions that I mentioned earlier. The fines at Tanis, though, do include dinosaur fossils, although they weren’t the focus of the paper we’ll be discussing. And that’s kind of suggested that the asteroid impact was the primary cause, you know, it’s possible that dinosaurs were already stressed out, ecologically speaking due to the volcanic eruption, but it really was the asteroid that that put the nail in the coffin for them as a clade. So basically, to answer your question, it was only really in the last 10 years that it was definitively decided that the asteroid was by far the largest contributor to the extinction of the dinosaurs.
Charles 5:41
So then, in this paper, what new thing have they done?
Tessa 5:45
Well, since they’ve been able to determine that, again, that this site almost certainly comes from like within a few hours of the impact. And partially that’s also because they literally found debris, molten rock that been injected into space by the impact on separable trajectories and then rained it back down into Earth, they found those pieces of debris in this like fossil layer or fossil collection. Most of the organisms fossilized that they found had been fish, unsurprisingly, because it was a river bank that got hit by sea tweet. And it turns out that most of the fish species are paddlefish, which are apparently a relative of modern day sturgeon. And the some of their teeth, and, like associated bones actually have growth rings, because they basically put on new bone plating every year. And by looking at these layers, how thin or thick they are, and also to degree, the isotopic composition, they’ve been able to determine that, you know, they hadn’t really fully formed that yours growth plate on their teeth, and therefore it must have happened in the springtime, because that’s when they would first be forming those growth layers. So basically, it’s tree rings, but with fish teeth, and by looking at the comparative width of the growth rings in the teeth, they’ve been able to determine that yeah, it was in the spring, and specifically the northern hemisphere spring, because that’s what the site was.
Charles 7:12
Wow. Is there? Do you know, is there any basically… we both know that science is a lot pettier and more contagious than a lot of people, I think, imagine, right? Like people…
Tessa 7:25
Oh, yeah, there’s lots of drama.
Charles 7:27
Just essentially subtweeting each other in publications all the time. Do you know if there is any of that, like how well received has this paper been?
Tessa 7:39
Um, this one has been well received, because it was by a different team led by Melanie during she’s considered legit. She doesn’t have any of the sketchiness that Robert dipalma has. So so so far as I know, it’s been pretty well accepted. Or at the very least, I haven’t heard anyone like sounding off against it, or like sub tweeting about it. So yeah, as far as I know, it’s been accepted.
Charles 8:04
You know, I don’t think that I could be a paleontologist because the responsibility of dealing with fossils, I think would.. absolutely freak my bean.
Tessa 8:16
Often very fragile fossils, yes, yes.
Charles 8:20
Just… an absolutely priceless artifact not only because not because of any like monetary value, but because it is a singular object, offering insight on a past that none of us will ever be able to access. Couldn’t be me.
Tessa 8:39
Yeah.
Charles 8:39
Couldn’t be ole Charles. [interstitial] There’s not a lot to talk about here so much, but there was a paper published – now, last year – “Supella dominicana, a new species of cockroach (Blattida: Ectobiidae) with developed spermatids in Dominican Amber,” which if you actually read the paper, which is probably difficult for most people like ASU doesn’t even have institutional access to it. What I had to do to get it was to sign up for a free trial on a paper reading website, and then use that to print the PDF and then I immediately cancelled the free trial, because they aren’t going to get me…
Tessa 9:21
I should note that our listeners if they’re in the bind should absolutely not seek out Sci Hub.
Charles 9:26
See, here’s the thing, I would never use sci hub, because I’m not a criminal. But even if I were to use sci hub, it’s not even… like it’s not even a paper that is available there.
Tessa 9:36
Oh, wow, that is really obscure.
Charles 9:37
Yeah. Because I mean, part of that is that it’s a very boiler plate like… if you have read a taxonomic description of an insect species that the actual paper would not be surprising to you in any aspect, but it’s kind of noteworthy instead of just being like a standard, we found and described this species in amber.
I mean, first of all, the sort of the connection to what you’ve talked about, is it absolutely… when I consider Amber like insects trapped in amber, it is I can’t even process like how incredible that is. Because the it says in the paper, even that the dating of this, the site that the ampere was founded is a little bit controversial. So it’s a range of like 20 to 30 million years ago. But you can hold in your hand a 30 million year old… not even an imprint of it like a fossilized emperor, but the cockroach itself, which is absolutely wild.
Actually to take another tangent from that arguable tangent. We have been speaking with each other recently about avatar because the new Avatar movie came out. And I cannot get interested in the Avatar movies at all. Like I watched the trailer for the new one because I was like, maybe it is more interesting than I’m giving it credit for. And the thing that I feel when I watch clips from these movies, or trailers for these movies is just an overwhelming sense of boredom. It doesn’t feel like what they’re doing and like the science fictional space of creating new species and new worlds is actually interesting to me in any way. And my working hypothesis here is that as an entomologist, I see so much just random, absurd, cool stuff all the time that like some blue cat people do not impress me.
Tessa 11:36
Yeah, no, I get that like, a lot of the stuff in there isn’t gonna seem all that alien to you.
Charles 11:40
Maybe if James Cameron had made like an, like a planet of giant insectoids. Maybe I would have time for him. But he didn’t. He made like Blue Cat people. And I love cats, but even these cat people don’t do it for me.
Tessa 11:57
Well, speaking as an astrobiologist, the blue cat people are literally the least interesting thing about the like, the world they’ve imagined. Like whoever was doing design came up with some pretty alien looking like stuff. But then they’re like, Oh, well, we can’t make the protagonist characters look too weird, because they’ll freak people out. So we’ll make them just look like Blue Cat people, even though everything else on the planet has like, six limbs, separate openings for their lungs that aren’t their mouths… You know, four eyes…
Charles 12:27
Yeah, I mean, I guess there’s some interesting stuff there. It just is not. Like I just I’ve been meaning to play Disco Elysium for a long time, and there was like a more engaging and transcendent moment of science fiction in that game that is mostly about solving a murder, and also communism, than I have encountered in anything from the avatar movies that I’ve seen at all, but maybe that’s just me. I don’t know.
Tessa 12:56
Yeah, I mean, fair, I totally got that. Like I said, they are the least interesting thing about Avatar.
Charles 13:02
None of it feels… it doesn’t feel like there are any interesting ideas there to me, but maybe that’s just me being a skeptic. I don’t know.
Tessa 13:09
My wife’s big gripe about them is that canonically they don’t have DNA or RNA. And this makes no sense biologically. Like they never say, Oh, they just use different nucleotides. They just they apparently just don’t encode biological information at all.
Charles 13:25
Is that for all of the species on the planet, or just the Na’vi? I mean, I, you know, I don’t want to close my mind to the possibility of an alternative to DNA or RNA.
Tessa 13:34
I mean, there are other information storage storage rights that people have considered, but like, whoever was doing the world building was like, let’s make them sound extra weird by saying they don’t have DNA and then never explaining what they have instead.
Charles 13:47
Yeah, I can’t… sorry to James Cameron, but I’m also not too sorry, because I did read an article that mentioned that like, in his part of his inspiration for the first Avatar movie, he was thinking about the Lakota and was like, what if they had fought harder and won and it’s like, oh, bro… so maybe not sorry to James Cameron.
And so that’s that article and it mostly notable in that it wasn’t just I mean, it was just the cockroach, but it included, quote, “tip of abdomen show sperm bundles (spermatodesm) containing spermatozoa with dark acrosomes that are surrounded by mucopolysaccharides (gelatinous material).” And in – because you probably will not be able to find access to the article itself… there is a very good write up that will include all the information that’s going to be important to people who are not specifically invested in very detailed taxonomic descriptions of cockroach species, from Oregon State, and it is as far as anybody can tell the first fossil cockroach to be found with sperm cells.
Tessa 14:58
Interesting.
Charles 14:59
Isn’t it just? And in that description, sperm bundle, spermatozoa, the actual sperm cells with dark acrosomes – acrosomes are a trait that is present on most insect sperm cells. From “The Insects: Structure and Function,” the description being “the acrosome is a membrane bound structure of glycoprotein within most insects, a granular extrachromosomal layer and a rod or cone, the acrosome is probably involved with attachment of the sperm to the egg and possibly also with lysis of the egg membrane, thus permitting sperm entry.”
So an acrosome is just a dark feature that is present on like the end of the sperm cell whose purpose, as far as you know, we seem to be aware, is in helping the sperm attach to the egg, and possibly also get into the egg cell itself. And there is a picture actually, in the paper that shows the acrosomes themselves, which is an incredible, like, I don’t think anybody from 200 years ago was going to be saying, we’re going to be able to look at the small parts of sperm of a cockroach from 30 million years ago.
Tessa 16:17
Yeah, that’s pretty wild.
Charles 16:18
So that’s my first sperm paper. [interstitial] Speaking of sperm, I did kind of a mini dive on a paper that I’ve had saved for a long time, from 2012. “The efficacy of ultrasound treatment as a reversible male contraceptive in the rhesus monkey,” from Reproductive Biology and Endocrinology. And basically, this paper is one in a history of papers going back, at least to the 1950s or 60s of ultrasound being a potential form of contraception, for mammals with testicles.
So this one is [in] a long history of similar papers that specifically applied ultrasound treatment to a collection of rhesus monkeys. And the thing that California and Primate Research, there’s like a large Primate Research Facility in California, which is where they sourced the rhesus monkeys from, and the idea behind ultrasound treatment as a form of quote unquote, male contraception…
Because of course, the topic of quote unquote male contraception is one that has kind of been ongoing for a long time of the idea that like, there are two primary methods available to people who produce sperm one is wearing a condom, which is, in my understanding, not especially popular, first of all, and secondarily is subject to individual misuse. used correctly, condoms are extremely effective as a form of contraception, as well as preventing STI transmission of STIs that are primarily transferred via fluid. But the problem is that condoms are very, very, very easily not used perfectly…
Tessa 18:22
Right.
Charles 18:22
And imperfect use reduces their efficacy significantly. So that’s not perfect. And then the other major, the other major possibility is vasectomy, which is invasive, in that it is surgical, and it is theoretically reversible. But that’s not a guarantee. And I was reading this earlier. And I was thinking to myself, and you can tell me the episode if you want to, but I was thinking that you had also accomplished absolutely perfect contraception.
Tessa 18:57
This is true, I have, I have guaranteed that I will not directly produce any children.
Charles 19:05
Yeah. But unfortunately, the method that you use, which is total surgical removal and reconstruction of your genitals into vulva is, for some reason, not very popular.
Tessa 19:20
[both laughing] Yeah, yeah. I can’t imagine why.
Charles 19:23
So there are kind of three methods, but none of them are particularly popular and not… basically it, an alternative to condoms is necessary, because people don’t like wearing condoms.
Tessa 19:37
Yeah, pretty much, unfortunately.
Charles 19:39
And it’s like, you can’t reuse condoms. Yeah, there’s, so there’s like a waste problem. And sometimes people think that they can flush them down toilets, and that’s an issue. So there are a lot of problems with condoms. And so basically, the idea with ultrasound treatment as a form of contraceptive is, if you put the testicles in like a water bath and you just apply ultrasound waves to theml, that can disrupt spermatogenesis, ie the creation of sperm, such that alternately in different studies, the sheer number of sperm falls, or it disrupts the morphology of sperm so that they’re still present but they’re all goofed up. Like in the specifics of this specific study from 2012, there is a picture showing before treatment and after treatment, and the before treatment sperm all have very straight tails, they have pretty normal morphology, and then the after treatment, they are still present, like sperm are still created, but they have very, like twisty corkscrew tails, so they are inactivated effectively.
And the idea… and this is like an attractive potential because other than disrupting spermatogenesis, and like very temporary discomfort, you know, it doesn’t alter testosterone production or disrupt sort of the hormonal balance of the body overall. And in the studies that have been done, pretty much, as far as I can tell, without fail, over a period of weeks or months after the treatment, the effects essentially wear off and then you get back to normal. So the sort of the the promise of this, if it were gotten to a point where it were scalable and widely available, is that it doesn’t have the effects of hormonal birth control, it doesn’t have the sort of user failure of condoms, and it doesn’t have the irreversibility or invasiveness of discectomy.
So theoretically, like, a very good option, because also when we’re talking about quote, unquote, male birth control, ie birth control for people who produce sperm rather than eggs, it’s kind of a cliche talking point at this point where they have tried hormonal birth control for, as they put it, men before, but in trials side effects were such that the people who were enrolled in the like, didn’t want to keep doing it long term. Which is another problem that we have with hormonal birth control for people who produce eggs, but I think it’s a couple of… I mean, just purely speculatively, there are a couple of reasons why hormonal birth control for people who produce eggs has been ongoing and widely mainstreamed in that, (a) misogyny in health care where women’s side effects are not taken as seriously as those from people perceived as men. And then also, the burden of unplanned pregnancy is much harder on those who are producing eggs than those who are producing sperm, and therefore, are the ones getting pregnant. And so I imagine that if you are facing down, I am going to get pregnant, or, I might get somebody else pregnant, if you are the person who might have to deal with pregnancy, you’re probably willing to put up with more side effects to prevent that than if you aren’t. That’s just my speculation.
Tessa 23:02
No, I can believe that.
Charles 23:03
Anyway. So in this paper, what is most interesting to me is spoiler alert, nobody seems to know how or why exactly ultrasound appears to have this effect of like…
Tessa 23:18
It almost kind of makes me wonder how they even discovered this in the first place.
Charles 23:21
Right? And I did I, I know. So I did, try to go back in time and find the first instance of the application of ultrasound as a potential form of contraception. And I found a an article from 1977, which as far as I can tell, is the first instance of its application on humans. And I think the genesis of the idea is that ultrasound, which is quote, “a form of acoustic vibration with frequency is so high that it cannot be perceived by the human ear. Thus, frequencies under 1700 CPS are called sound while those above 1700 CPS are defined as ultrasound,” right. So sound can have physical effects on the body, and one of these effects is increased heat. And so in sort of consistently throughout the literature, you see the comparison of ultrasound treatment versus just placing testicles in like a very warm bath, because we know that heat can disrupt spermatogenesis by itself.
And so I think sort of the the beginning idea of like, what led people to thinking about this is the idea that will we know that he disrupts spermatogenesis because testicles need to be kept at a certain temperature? Yeah, where else to either external it’s weather external. And so what also produces heat is ultrasound. And so in this paper they specifically say quote, recently, we found that ultrasound was more effective as a suppressant of spermatogenesis in male rats at 39 degrees Celsius. Then we’re hot water 60 degrees Celsius, infrared and microwave. So I really think it was a combination of like, well, we know that heat messes this stuff up. And we know that different kinds of waves can do weird stuff to the body. Let’s check it out. And I really think that that was the beginning of of it.
In this paper, the methodology that they used for humans was the patients were sitting at a chair that had a cup attached at the front part of the seat, the cup was filled with water, the testicles were put in the middle of the cup they were held in place so that they wouldn’t move around. And then the ultrasound transducer was placed as the bottom. And basically, ultrasound was sent through the and in the way that they were able to do this was that the men involved in the study were scheduled for orchiectomies, like medically indicated orchiectomies, so they were in a situation where the men were having… they could get a histology of testicular tissue several weeks beforehand, and then they would have the biopsy of the, they would have the testicles available to them afterwards. They source that… I like, I don’t know, but I would really guess that these people had an idea, because this article also involves multiple other animals that they also try this on, and so my thinking is that they were doing the study, they knew some… they knew somebody in like a medical research branch, there were going to be several men getting orchiectomies, and they were like, Whoa, wait a minute.
Tessa 26:35
Yeah.
Charles 26:35
And they were like…
Tessa 26:36
Well, while they’re here here.
Charles 26:38
And what’s hilarious is that this was in 1977. And sort of spoiler alert for the you know, the takeaway, of like, where are we now, there is a product that won the James Dyson Award in 2021, for something of like a proposed that would like that would be a commercial product that people could have in their home. And it basically is the exact same thing of like, a little bath for your testicles, that ultrasound can, can be, can be put through. And there you go.
But yeah, in this specific… what is so what is interesting to me in the 2012 paper, “the efficacy of ultrasound treatment as a reversible male contraceptive, and the rhesus monkey,” is just that Primate Research really freaks me out. Because it is more difficult, I think, to imagine distance between us and other primates. Do you ever get the sense of like… I hate seeing other primates. Because it gives me very like that one cartoon of a dog staring in the mirror. And he’s like, angrily looking at his reflection and being like, what dog is that? I feel like that whenever I see another primate, basically, of like, who is…? What weird person is that? And so potentially just like my own bias as a primate of seeing primates held in captivity and being like, that feels wrong. But what’s especially wild is that in this study, the methodology is like, first they had to, they had to do multiple sperm collections. Right? And so then the question is like, Well, how do you get sperm from a monkey? And the answer is electro ejaculation. And you might be asking, Charles, how long have people been using electro ejaculation to get sperm from animals? And the answer is at least as far back as the 1930s.
Tessa 28:33
Oh, yeah, yeah, yeah. No, it’s been part of animal husbandry for a long time.
Charles 28:37
Yeah. Because the, most of the time electro ejaculation is used in sires, right, so like, in bulls… and the common methodology for those kinds of animals appears to be rectal stimulation. But for monkeys, they don’t do that. They have direct penile stimulation using electrical equipment, which is like, very weird to think about. There’s actually in the article that I found, in this article that I read, there is a diagram specifically of the setup of how the monkey was restrained because they were restrained, but not anesthetized. And it’s like, I don’t, it gives me a real feeling of, I don’t know that this is okay that we’re doing this.
Tessa 29:24
Yeah, yeah, no, I get that.
Charles 29:25
Especially because the electoral ejaculation is like literally, it’s it basically they’re saying as previously described in a source, and then I found the source where it was described methodology that they’re using is from a 1991 paper in the Journal of Med Primol, which I’m assuming is Medical Primatology. “The use of non metal electrodes and electro ejaculation on restrained but anesthetized macaques” – there is a positive electrode pad placed around the base of the penis, while the ground electrode pad is secured near the glands, right so you have Have two pads on different sizes of penis like different ends of the penis, right. And then so they form two rings one positive and one round. And they are moistened with conductive gel and fit, quote, snugly. To maximize contact, the penis itself is held between the index and the third finger, keeping the electrode separate by one of the researchers. And then the thumb of the fourth finger were used to hold the collection tube. So it’s basically you have the first and the third finger holding the penis itself. And then the fourth and the thumb holding the collection to which I’m like making that shape with my hand right now awkward. And then a quote a grass six physiological stimulator was preset for a pulse of 20 milliseconds duration and 18 pulses a second at 30 volts. And so then if they they start at the lowest voltage, and then they do sort of a stepwise increase to 50, and then to 80, and then to 100. If they don’t, if they aren’t able to collect semen at like the previous voltage, and it’s… if I were a rhesus monkey, I don’t think I would be happy about this.
Tessa 31:12
Yeah, it does sound a little…
Charles 31:13
And then that’s only one part of it. Because other than the electoral ejaculation, which they have to do multiple times, like at least twice before and after, and then multiple times afterwards, so that they can evaluate it for the amount and the morphology of sperm cells. And then they also have to apply the ultrasound to them with two different methods. One, the cut method, which we have already described, basically, you put the testicles in a cup. There you go, as well as the direct method of an application of a probe directly to the scrotum slashed testes surface in a continuous circular manner. And you’ll never guess, but the cup method is actually the more effective method, which I guess makes sense intuitively, but if you asked me to describe why it does, I couldn’t, I could not tell you. But essentially, what they found is that the ultrasound method was found to be effective at decreasing the number of sperm with normal morphology, as well as reduced sample the sample variability in the total number of normally shaped sperm. And the direct method appeared to have a more pronounced effect on sperm morphology by increasing the number of sperm with tail effects, the results that they found were like very promising in that it did reduce the number of sperm with normal morphology, therefore, the massive reduction in the availability of sperm that conceivably could result in fertilization.
And not only did this happen, but there were limited to no detectable side effects on the testicles, such as swelling, or redness, or behavioral changes, or I don’t think that they specifically looked at it in this study. But in other studies, there has also been found no disruption of testosterone production, right, which is sort of the big thing. Right, and where people talk about where like, you don’t want to mess up people’s hormone levels. But and then the other interesting thing, as already mentioned, is that it’s not quite, the actual mechanism by which ultrasound messes up sperm production is is still kind of up in the air, because it’s not just the result of heat, because higher heat, or the same amount of heat, doesn’t result in the same effects in disrupting spermatogenesis. So it’s, it’s, you know, and the, the final interesting thing is that the specifically, the way that they justify their choice of rhesus monkeys, is that the testicle size of rhesus monkeys is actually very comparable to the average testicle size of humans, which is hilarious, because the size of rhesus monkeys is much smaller.
Tessa 34:09
Yeah, it was about to say that means their testicles are going to be proportionately [huge] compared to the rest of them.
Charles 34:14
Compared to humans… But I mean, it’s very intricate, sometimes, like, it’s, there is not a direct one to one relationship between any given behavioral traits, or like particularly, you know, domination behavior or whatever, and testicle size. It’s… maybe we’ll do an episode on testicles someday. And like the, the variations of testicle size in mammals and what they indicate?
And then, you know, as a sort of a conclusion point of like, where are we now, this has not yet been scaled to regular human use. Sort of the closest that we’ve gotten and the reason that this paper has been saved for like the last year or so. Is that as mentioned, there is like a prototype products that won the James Dyson Award for something in 2021, called the COSO, which, if you look at it, it’s, I mean, their logo is hilarious, or at least the image that they show, because it’s a very minimalist outline, suggesting hanging scrotum. And it’s from a German design graduate, Rebecca Weiss basically looks like any kind of modern plastic hygiene product kind of, you know, smooth lines, very contemporary design. And the idea is that it would be available to people, there’s little waterbath, you just stick your testicles right in, it sends ultrasound in and then you’re good to go for potentially months at a time. And I, I cannot wait for this to be available to people because it’s very silly, and very funny.
Tessa 35:59
Yeah, you know, I was wondering like, how is this going to be commercially ever like applied, but ya know it, they did a good job with the product.
Charles 36:08
And of course, the relevant articles will be linked in our show notes. Yeah, that’s me on a real journey of unease over how we treat research primates.
Tessa 36:19
[interstitial] So this one is about a much less practical and frankly, in my opinion, well thought out media were designed, which is the nuclear saltwater rocket. So let’s say you’re in space for some reason, and you need to get somewhere else in space relatively quickly. Well, you do that by firing up a rocket engine, which objects material of some form or another, at high speed and due to laws pushes you in the opposite direction. Now, we, as a species, mostly use chemical rockets, which basically you combine hydrogen and oxygen or kerosene and oxygen and ignite them. And that produces thrust because you’ve got all these hot gases being ejected out of your rocket engine.
Well, a dude by the name of Robert Zubrin who’s also well known for being like, somewhat alarmingly obsessed with the colonization of Mars came up with a concept based off the fact that so uranium Plutonium can be produced in the form of salts like uranium nitrate, and that the salts like any other salt can be dissolved in water, until this idea was like okay, well, we’ll get some water and we’ll dissolve this, you know, enriched uranium salts in it. And then we’ll store it in tanks in such a way that it’s just barely not enough uranium to go critical, which is that is to say, sustain a nuclear reaction. And then when we want to make our spaceship go, we will move this radioactive enriched uranium containing saltwater from the tanks into the rocket engine, at which point it will have pools enough water at a high enough concentration, that uranium in the water will go critical. And the end result is basically like a continually exploding atomic weapon. Because when the stuff goes critical, it really goes critical, it explodes basically. And I mean, the upshot is that you can get a monstrously high thrust out of a design like this, like, you know, potentially up to depending on your design it up to like a fraction of the speed of light, which is very impressive for any sort of rocket engine.
Now of course, there are some pretty major drawbacks First off, this thing shoots out radioactive fission byproducts at an appreciable speed of light. So you can’t ever point it anywhere near a planet that has people or the things you care about on it, it has actually been nicknamed the deaths fewer. The other thing is Robert Zubrin has never really quite come up with a convincing argument to explain why this nuclear reaction you’ve started in the rocket engine won’t propagate up the pipes and into your tanks and just cause the whole thing to detonate at once, which would be bad for you. And it also means you absolutely absolutely cannot have any leaks in your tanks. Because if some of that saltwater leaks out and you know puddles somewhere, it could potentially also go critical and explode. So yes, but still, you know, it is certainly daring and outside the box idea, and it’s one that I do think of from time to time because it is just so extra.
Charles 39:53
I just… everything about space and being in space, it’s terrifying already. I, I just, I actually in a, in a weird way, this reminds me of… Instagram explorer keeps showing me videos of women who are either in the free birth movement, or like, tangential to it. Are you familiar with this?
Tessa 40:24
Um, I think I’ve heard of it in passing, but I’m not sure.
Charles 40:28
It’s the idea of, the sort of extreme step against medicalization of birth, effectively, of like, we treat birth too much as a medical event, rather than just like a natural process, right? And so it’s, it’s like a spectrum of crunchiness of, sometimes you just have people who are kind of, “they want you to do too many drugs.” And then you get people at the very far end who are like, even against midwives? Right.
Tessa 41:00
Okay, yeah.
Charles 41:00
And so I keep seeing, Instagram keeps showing me these videos. And I, my best friend, as mentioned before, is in an MD PhD program. So they are in medical school. And we talk a lot about how terrifying the human body is and the body horror of being alive, which are also just common themes on this podcast.
Tessa 41:24
Obviously, as listeners know, yeah.
Charles 41:28
And the thing that gets me that we have talked about, me and my best friend have talked about a lot, is how in denial, a lot of people seem to be about how dangerous being alive is, where a lot of the justification for free birth stuff is like, it doesn’t need to be in a medical environment, your body knows what to do. Which in one sense, is correct. People have been giving birth for much longer than people have organized and sustained information sharing about methods of giving birth. But on the other hand, the maternal mortality rate has never been lower.
Tessa 42:15
Yeah, yeah, used to be as high as like, 20%.
Charles 42:18
It’s so dangerous to give birth. And I wonder, this is where the connection is coming. I, I feel like the people who go into space have gotta have just a different brain than me that can put the extreme danger of space, and a little box inside their brain and put a little padlock on it, and not be consumed with it at all times.
Tessa 42:52
Yeah, no, that sounds about right.
Charles 42:54
In the same way, that people who don’t even want to just have the hospital on speed dial, or maybe, because it’s… Although at the same time, like I do have sympathy for a lot of people who don’t want to go to the hospital to give birth, because, for example, it is it is still common practice for Child Protective Services to get called on Indigenous parents, like immediately, right? So I’m not saying that there is no good reason to want to avoid institutional settings. I’m specifically talking about overwhelmingly, if not exclusively, white, middle class women who have completely like compartmentalised or just forgotten… because one very common line of questioning will be, well, but if people people have been giving birth forever, why is it only so medicalized now? And it’s like, people have been dying from giving birth forever? Yeah, way more than they do now. I’m just so hyper aware of the fragility of life all the time that people who can kind of propose a rocket that would almost certainly kill everybody, and be like, we’ll figure it out. I just can’t, I just cannot imagine it.
Tessa 44:13
I mean, like I said, you know, it even within the space community, it’s considered, yeah, dubious, to say the least. But on the other hand, it’s just so out there that it does have a special place in my heart, not that I’d ever want to be within about 1000 kilometers, and one that’s been active.
Charles 44:31
Yeah, I mean, to be fair, also, though, that specific idea may be niche. But we did send people into space. We didn’t have computers, and we put somebody in space, and he came back.
Tessa 44:46
People do wild things sometimes.
Charles 44:48
[interstitial] Actually, the way we set this up is great, because my final article is also very, very brief, but I read… I recently fact checked a script on what would happen if you got ejected into the vacuum of space, like how quickly would you die and how would you die. And one of the things that really stuck out to me is that we have not done this to anybody, like we have not pushed any human being out into the vacuum of space without a spacesuit, so we don’t have observed empirical information on what would happen to the human body in the vacuum of space so it’s, it’s based on extrapolations from what we do know, as well as there have been a couple of incidents where people have accidentally been in effectively vacuum light conditions and we’ve been able to see what happened to them.
But one thing that really, really, really stood out to me is how much information about documented observations of the effects of a vacuum-like amount of air pressure on organic bodies we have from animal experimentation in the mid 20th century. And this is just another story of the whole electro ejaculation and then ultrasound testicle bath situation for the rhesus monkeys cannot be great. But that still had to go through, like, rigorous ethical review. And the primate centers that we have in the United States have very rigorously controlled living conditions for the primates. And if they are held in very small spaces, it’s only temporarily if they need medical care or if they’re specifically in an experiment, etc, etc. very temporary, potentially large, discomfort, but overall, pretty sweet setup. But we also eventually have to do an episode about the wildest research people got away with before the imposition of ethical review boards.
Tessa 46:55
Oh, yeah, there’s a lot there.
Charles 46:57
There was specifically a study that I read, that was published in 1967, called Experimental animal decompressions to a near vacuum environment, where they literally just took dogs 126 animals were rapidly decompressed, to absolute pressures, near vacuum conditions. And they literally took dogs, rapidly decompress them to near vacuum conditions, let them stay there, and then saw what happened.
Tessa 47:28
Which turns out is a lot of them, a lot of them died. Who would have thought?
Charles 47:32
Well. It’s… it’s so they had. So that’s the first thing is, that they put them in these conditions to begin with, which is not great. And then secondarily, they did not take any efforts to resuscitate them or reoxygenate them because they wanted to observe how long it would take for them to get back to normal conditions also. So that’s the second thing. And then depending on the conditions, because they did you know, they’re scientists, they had varied environmental conditions, they vary the length of time that the specific dogs were kept in these near vacuum conditions. Quote, “all dogs exposed to the near vacuum environment for less than 120 seconds, survived with essentially uneventful recoveries despite evidence of severe but transitory lung involvement. On the other hand, exposure times ranging from 120 to 180 seconds resulted in mortality rates of about 15% to more than 80%, respectively, as shown in figure two.” So they literally, in the 60s, took 126 dogs, put them in near vacuum environments for multiple minutes. And a bunch of them died. And that got published. And then people did a bunch of other studies doing very similar things.
Tessa 48:49
Yeah, yeah. I mean, it’s just, you could… they could just come up with any idea you wanted. And as long as it had something vaguely to do with national defense, you could just go do it.
Charles 48:58
You could just go do it.
[interstitial] So that was an episode of Assigned Scientist at Bachelor’s. My hope and my plan for 2023 is that we can have a more steady release schedule. If you are trans in science and you are interested in being a guest on the show you can email us at asabpod@gmail.com or fill out our guest interest form, which is linked on our website, or in the show notes. We’re still on Twitter @ASABpod, who knows for how long but we’re there. And you can also find show notes and transcripts for every episode at our website, asabpodcast.com. And if people want to find you Tessa, where should they look?
Tessa 49:42
They can check out my website tessafisher.com or while Twitter still exists. I am on Twitter @spacermase.
Charles 49:51
Thank you to Nicole Petcovich, friend of the show and former guest, for our music and if you liked the show, please tell people about it because word of mouth is the number one way that podcasts grow.
Tessa 50:00
And until next time, keep on science-ing.