My Writings. My Thoughts.

Carnivorous snails, so how does that work?

Written by: Captain Skellett // April 22nd, 2013 // Comments Off on Carnivorous snails, so how does that work? // Recent Research, The Realm of Bizzare

Perrottetia dermapyrrhosa, one of the newly described species from Thailand. Credit: Somsak Panha. License CC BY 3.0

Perrottetia dermapyrrhosa, one of the newly described species from Thailand. Credit: Somsak Panha. License CC BY 3.0

Three new species of brightly coloured carnivorous snail have been found in the limestone hills of Northern Thailand.

Each of the species is only found on one or a handful of hills, some of which have become limestone quarries. Pretty impressive, as a quarry is not a friendly habitat for an animal whose main predator is the boot.

As well as coming in a range of fancy colours, the new species are characterised by nothing less than the shape of their genitals. All from the Perrottetia aquilonaria has a club-shaped penis and penial hooks (sounds painful?), while P. dermapyrrhosa has a long penial sheath, long, scattered penial hooks and vaginal hooks.

It seems like snail penises are a common way to distinguish between species, and there must be quite an art to it. Take this rather lengthy description of P. aquilonaria’s junk.

“Genitalia with a long, slender penis; penial sheath short, about half of penis length; internal wall of introverted penis with black to brown penial hooks; vas deferens passes through a short section of penial sheath before connecting distally to penis; vagina and free oviduct short to long, vaginal hooks may be present; gametolytic duct and sac may not extend as far as albumin gland; seminal vesicle present with about the same length from vesicle to talon.”

If you click through to the complete article, published open-access on peer-reviewed ZooKeys, you can even see some pictures of penial hooks and vaginal corrugated folds. Come on, what else are you going to do with your day?

Perrottetia aquilonaria, another newly described species. Credit: Somsak Panha. CC BY 3.0

Perrottetia aquilonaria, another newly described species. Credit: Somsak Panha. CC BY 3.0

It all sounds rather saucy, and top-notch science research, but I got caught up on this idea of a carnivorous snail. I mean, what IS that? It sounds like something from an old Doctor Who episode, back when the creepy alien du jour was footage of maggots, zoomed in so they looked gigantic. These day’s it’s terrifying ghosts with their mouth all screamy and sideways and it looks like something from The Exorcism of Emily Rose.

They may not be lions and tigers, but carnivorous snails are nonetheless vicious. Some of the species we have in Australia are small and are probably in your garden right now, others are big black ones that live in the Victorian rainforest.

Carnivorous snails hunt other snails, following their slime trail until they catch up with them. Now, most snails have a tongue like a rasp, and they eat lettuce leaves and such by simply licking them away with their tongue-which-works-like-teeth. Carnivorous snails upsize the rasp for big-ass hooks, and when they catch up with their prey they give them a lick and stick their hooks in.

If you’ve ever poked a snail, you know they slip inside their shell and produce gross foam to stop you poking them (no means no). Unfortunately they try the same trick when they get licked by a carnivorous snail, and the attacker has already shoved its hooks in so the snail unwittingly sucks the hunter right into its shell with it. Then the predator just licks away until there’s nothing left.

Actually, that does sound like a creepy Doctor Who episode.

Carnivorous snails also hunt worms, hooking ’em and eating ’em like spaghetti. There’s a great discussion of carnivorous worms on land and sea here on the ABC Radio website.

The research was performed by Chulalongkorn University, Bangkok and the Natural History Museum, London.

ResearchBlogging.orgSiriboon, T., Sutcharit, C., Naggs, F., & Panha, S. (2013). Three new species of the carnivorous snail genus Perrottetia Kobelt, 1905 from Thailand (Pulmonata, Streptaxidae) ZooKeys, 287, 41-57 DOI: 10.3897/zookeys.287.4572

Observations on a sedated cat, and links to Chlorpromazine, an antipsychotic in humans

Written by: Captain Skellett // April 10th, 2013 // Comments Off on Observations on a sedated cat, and links to Chlorpromazine, an antipsychotic in humans // Drugs

What a year! I’ve been around the world (Canada, USA, Argentina, Chile, Denmark, Germany, France, Ireland, England, Hong Kong) to be finally reunited with my kitty cat Phobos back in Adelaide, Australia. I know most pirates have a parrot, but I prefer my pets fluffy.

I had just over a month in my home town (during which time I haven’t blogged so much, as I was seeing everybody back home and the house I was staying in didn’t have internet access), and then had to move again. This time to Melbourne, a larger city full of trendy coffee shops, where my partner is studying at University.

It’s a seven hour drive from Adelaide to Melbourne, and the cat would be coming too. Oh dear. Phobos is not one for cars. Like me, she prefers fresh air and sunshine to exhaust and headlights. She’s not good at hiding her displeasure. On the short trips we’ve taken before, she spends the entire time mewling most heartbreakingly, building up into a reverberating crescendo of “RAAAAAaaaaaaAAAAAaaaawaaarrrrr” and then panting for air. It’s quite upsetting.

That, for seven hours? Forget it! So we went to the vet and got some cat sedatives.

The vet gave us some ACP 10mg tablets, the active ingredient is Acepromazine. It is used for pets, including cats, dogs and sometimes horses. In the UK it’s not allowed to be used in horses intended for human consumption, which is hilarious in light of all the ruckus lately about humans eating horses without intending to. Perhaps a little anti-anxiety medication in the “steaks” would not have gone awry?

I shouldn’t jest, I was in the UK when the story broke and I’m pretty sure I accidentally ate horse. I must remember not to eat meat in the UK… you’d think we’d remember that from the mad cow outbreak in the 80’s. Speaking of mad cow, the fourth case in the US was identified in April 2012 in California, perhaps a month before I was there last year. Sure, it was in a dairy cow and bovine spongiform encephalopathy is not passed on by milk, but still…

Anyway, back to the cat! I gave her one tablet and within 15 minutes it had kicked in. Her eyes became unfocused and her third eyelids crept up. I’m glad the vet warned me of that one, it looked creepy – a layer of pinkish white arising from the corner of her nose and covering about a third of her eyes. The third eyelid has a protective function and it’s visible if the eye is injured, as a side effect of sedation, and during deep sleep.

Next she lost some motor control of her back legs and tail, like she had to move her whole hips to get her legs to move forward. Later she would start stepping backwards when she tried to curl into a ball, until she hit a wall and then stopped. She looked like a cowboy kitty.

The real test was when we got her in the car. She had a halfhearted meow or two, tried to look out the window, and then sat on my lap and rested quite peacefully. Acepromazine is an anti-anxiety drug, and she really didn’t seem anxious at all. Every hour or so she’d go for a little walk across our lap and quickly get worn out and go back to sitting with us or sleeping.

So it seemed good to me. She seemed less stressed.

Acepromazine

Acepromazine

As we were driving, and it’s a long drive, the topic changed to how much easier it was for the cat to be calm, not really for us but mostly for Phobos herself. What about with kids, then? We both knew that some kids are pretty loud and upset on plane flights (not all, but some), and we’ve heard of people who sedate their children with some cough medicine (or even stronger stuff.) It seems pretty unethical to me, on first glance and being childless myself. So why is it different to sedate a cat?

Perhaps it’s partly an age thing… I’m not sure I would sedate a kitten, for example. I have no problem with adult humans sedating themselves on flights, in fact I have a friend who does it due to extreme anxiety and sinus pain. But that’s also a question of consent, and even a grown cat can’t consent to taking drugs.

The next logical step in this conversation was “Do cat sedatives work on humans too?” And now I’m settled in Melbourne with high speed cable internet, I can tell you the answer for Acepromazine is yes, as it was used as an antipsychotic in humans during the 1950’s. However, it is no longer used in humans, and one of the reason’s that it is prescribed by vets is because it is much less likely to be misused recreationally than a morphine-based drug.

Chlorpromazine

Chlorpromazine

Although it’s no longer used as an antipsychotic, the closely related Chlorpromazine is. Chlorpromazine (or Thorazine in the US) has been used since the 1950’s, about the same time that Acepromazine was briefly used. The drug became very popular and was aggressively marketed, but it’s far from perfect. It’s one of the drugs given to patients in Ken Kesey’s book One Flew Over the Cuckoo’s Nest. That book is very critical of society’s reliance on drugs, and the overuse of medication to control mood and make patients compliant.

I agree, I think there is an overprescription of behavioural and mood drugs. All drugs have side-effects, and they should be taken seriously – especially if someone is taking a drug long-term. Also, in my opinion, western society today has a particularly strict view on “normal” and people who don’t fit in with the norm are medicalised.

Chlorpromazine is still used long-term as a treatment for schizophrenia, and I’d rather not give an opinion on that because it’s such a complex issue. However, a long-term usage as prescribed by doctors is surely different to the descriptions in One Flew which was decades ago, very extreme, and let’s not forget, fictional. Both are different again to a short-term one-dose of the closely related Acepromazine to a cat.

It’s hard (often impossible) to know what’s happening in an animal’s head. Hell, it’s hard enough to know what’s happening in your own head sometimes! It’s entirely possible that she hated the experience, that she felt vulnerable and dissociated and confused – but there’s no evidence that this was the case. However, I do know (as far as it is possible to know) that she hates being in a car when she’s not sedated because she cries and cries. So for such a long journey I think the benefits outweighed the risks.

Altogether, I was pleased with Acepromazine. Phobos has completely recovered and is back to her usual inquisitive, scampering self.

Visiting the Royal Institution of Great Britain

Written by: Captain Skellett // March 4th, 2013 // Comments Off on Visiting the Royal Institution of Great Britain // Science Communication

This story has been a month in the making, and I should have just posted it back then! I’ve been really busy with visiting Hong Kong and coming back to Adelaide and seeing friends and family again, excuses excuses. Still, here ’tis, better late than never.

One of the things I was most excited to see on my trip to London this month was the Royal Institution of Great Britain. Over 200 years of science history are within those walls, where Michael Faraday toyed with electricity and magnetism in the basement.

Today the basement is a museum, but it still has Faraday’s lab down there – at least a recreation – right opposite a mini modern lab all sterile white and bright. Personally I loved Faraday’s soft yellow lamplight on parchment and sprinkling of dark carbon… the old lived-in laboratory, where the mind is encouraged to jump between ideas and tinker with equipment. Give me a well-stocked garage over a chrome kitchen any day! I hate bright lights *hiss* *hides in the shadows*. I may be part vampire. I hear that’s trendy right now.

The museum wasn’t terribly interactive, but it was brilliantly nerdy – as in “ooh, this is the actual journal Michael Faraday wrote his results in.” That was cool actually, they had one journal full of experiences from taking different drugs (like laughing gas) where the scientist described what it felt like to be under the influence. There was a lot of drawings of Isaac Newton’s name (like a teenager might doodle in love hearts) – apparently he was an inspiration.

It’s a terribly fancy establishment, a nod to the days of top hats and cravats in illustrious May Fair. Right from the moment you walk through those big wooden doors you feel like you’ve stepped into a manor house, with proper marble busts of notable minds beside the staircase. If a cluttered desk of a scientist hides the lofty ideals of science, the Royal Institution sees to it that the art is esteemed and valued.

Painting by Thomas Hosmer Shepherd (1793-1864)

Nonetheless it’s not a stuffy sort of place, especially not in December when they hold the Christmas lectures – which are more like shows for students with explosions and bright colourful demonstrations. As much as it values brilliant minds, it values young ones too. Children are encouraged not just at Christmas time but in the standard lectures too, I’ll get to that shortly.

Apparently the beautiful building and new conference rooms and updated lecture halls have come with a hefty price tag, that has now put the RiGB into several million pounds worth of debt. There’s now an online petition for the Department of Business, Innovation and Skills to purchase the building (for 60 million pounds) to allow the RiGB to stay in their historic building indefinitely.

Off topic, it just occurs to me that a lot of Aboriginal Australians lost their historic land, and 60 million pounds would buy quite a lot of it back. Guess that’s not relevant though.

If you’re keen, you can read and sign the petition to save the Royal Institution of Great Britain.

I feel sure the government won’t let something as historic and important as the RiGB to simply be sold and moved. It would be such a waste. Even if they don’t buy the whole building, I’m sure they would sort something out.

On a snowy Friday night I was lucky enough to attend one of the monthly lectures, which was on biology and quantum physics titled “Quantum life: how physics can revolutionise biology”. It was one of those topics which is incredibly hard to wrap your head around, because the quantum world is so counterintuitive and downright weird that even Niels Bohr said “if you aren’t confused by quantum mechanics, you haven’t really understood it.”

For example, the speaker Prof Jim Al-Khalili said that during photosynthesis an energised electron will appear to take multiple paths through a cell to its destination, find out which is the most efficient, and then rewind time and decide it took the most efficient route all along. Say wha???

The part I most remember was a kid, probably 10 years old, asking at the end of the lecture whether a particle moving faster than the speed of light would constitute a paradox by Einstein’s theory and rip the fabric of space and time. No joke, a 10 year old. Mind. Blown. Everyone applauded, and Al-Khalili agreed it would, but fortunately that neutrino particle travelling faster than light which was announced a couple of years ago actually wasn’t, there was a mistake with the equipment. So the fabric is intact, no paradoxes have yet been found.

Since I’ve been back in Adelaide I’ve visited the sister institute, the RiAus a couple of times for Fringe events. It’s great to see it’s still going strong and thankfully a financially independent group that isn’t suffering the same issues as the RiGB. Though the RiAus is a bit smaller, I prefer the casual atmosphere it has and the fact that speakers are encouraged to mingle with the audience after a show. Just that fact is what makes science more accessible to the public, because it pulls down the boundaries and invites dialogue. I quite wanted to speak to Al-Khalili after the quantum life event, but he was taken into another room behind a curtain, and if he reappeared later I didn’t see it.

Toothbrushes and breath testers for tuberculosis

Written by: Captain Skellett // January 15th, 2013 // Comments Off on Toothbrushes and breath testers for tuberculosis // Recent Research

Far-advanced tuberculosis diagnosed by x-ray. Image from the CDC, accessed on Wikipedia.

Tuberculosis is a major health issue, with around a third of the world’s population infected with the bacteria mycobacterium tuberculosis. Not all these people actually have signs of illness, only 10% will go on to have any symptoms during their life. For the rest it remains latent, the bacteria is present but not causing any problems.

As tuberculosis is only contagious and dangerous when it’s active, that’s usually what people test for. Chest x-rays can check whether TB has affected the lungs, and are required for people travelling from high-TB countries to low-TB countries including Australia and the United Kingdom. The other avenue for diagnoses is the slightly grosser method of analysing the gunk people cough up, to see if there’s bacteria in it. For  mycobacterium tuberculosis, growing a sample in agar takes weeks.

A breath test would be a much safer and faster way to see if bacteria are present in the lungs, and that’s what our first paper is looking at. Researchers from the University of Vermont are finding out whether bacteria can be identified by their “chemical fingerprint,” a cocktail of chemicals that makes its way from the lungs to the breath. Their research is published in the Journal of Breath Research.

Now, it’s some time before police can pull you over for a quick TB test when you’ve been swerving off the road from a coughing fit. “Honestly, it’s just the flu!” But it’s got to be a cheaper option for many countries with low health care budgets.

TB poster, image from Wikipedia.

It is early research. They studied the tiny puffs from mice, rather than humans, and looked at two different bacteria that cause lung infections Pseudomonas aeruginosa and Staphylococcus aureus (Golden staph), neither of which are the TB bacteria. Clearly there is more research to be done, but it’s a promising start.

Read more about it here.

TB can be cured with a course of antibiotics, or more specifically a combination of several antibiotics that have to be taken for six months. Like Golden Staph, the bacteria that causes tuberculosis is becoming increasingly drug resistant. Drug resistant strains need different antibiotics and take 18 months or more to cure.

In Papua New Guinea, extensively drug resistant TB is a problem. A recent outbreak there and movement of patients to better health facilities in Queensland and the Torres Strait Islands has triggered alarm and, frankly, scaremongering media reports and political backlash. You can read about it on the Conversation, because I’ve been out of Aus too long to be in on the goss (but I’m back in a month, yay!)

The next weapon against drug resistant TB may come in the unlikely form of a traditional toothbrush. The South African toothbrush tree contains a compound called diospyrin, which inactivates an enzyme critical for bacteria reproduction (but does not affect the similar enzyme found in human cells.) The enzyme is a DNA gyrase… would you care to know how it works?

When DNA is replicated, the two strands normally joined in a double helix are broken apart, and you can imagine it’s like putting your fingers into a rope and pulling apart the strands. If this imaginary rope is a circle (as DNA in bacteria is) then it can’t just unwind itself at the ends. Instead, things will get messy, and the DNA will coil and twist up on itself. These “positive supercoils” are a bit like like twisting a shoelace until it bunches up, and is bad for the DNA. Gyrases relax the positive supercoils by cutting the DNA and moving one strand to the other side, then joining them up again.

Circular DNA supercoiling. Image by Richard Wheeler.

Circular DNA supercoiling. Image by Richard Wheeler.[/caption]

By stopping gyrase activity, the bacteria can’t replicate its DNA. The research by a team from the UK and South Africa described how this compound from the toothbrush tree interferes with gyrase, and importantly, that it acts in a different way to existing antibiotics. This will hopefully be a chink to exploit in the armour of drug resistant bacteria.

Here’s the paper from the Journal of Biological Chemistry and the press release.

When a joke tickles the Broca area in your brain…

Written by: Captain Skellett // December 30th, 2012 // Comments Off on When a joke tickles the Broca area in your brain… // Just for Fun

Ever wondered what happens when you hear a joke?

Cyanide and Happiness, a daily webcomic
Cyanide & Happiness @ Explosm.net








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