“Stir-Fried Stochasticity” podcast: pilot episode

Cornelia the Happy Mutt with a tennis ballI’m still not sure I know why I have a desire to push recordings of my voice onto a more or less innocent worldwide population, but I do. And now I have a real theme to wrap an attempt at a podcast (or as I prefer – “oggcast”) around: scientific papers.

I finally got annoyed at press-release-based science stories one too many times, and thought to myself “why does almost nobody who does these stories at least cite the dang thing so I can go look it up and see what’s really in it, if they can’t be bothered to actually read and report on it themselves rather than just the press-release?” The story in question was the recent one about how babies understand dog-language (or something like that). Since I consider the dog to be a philosophical role-model, I wanted to read the actual paper and see if it was as silly as the headlines made it sound or (as I suspected) less flashy but more solid…but even “Science Daily” didn’t cite it.

Finally talking myself out of putting off doing audio recording, I tracked down the original paper, read it, and whipped out a rough show discussing what I found in the paper. I had fun doing it, so I’d like to turn it into a series.

I’ve put up a utilitarian page at http://bigroom.org/stirfry with both a built-in <audio> tag interface and direct-download links for both Ogg Vorbis and MP3 versions.

I’m still deciding exactly how I’m going to decide on the papers to cover – should I pick obscure, forgotten ones that almost nobody else would ever read again without me stumbling on them and talking about them? Classic papers? Papers related to recent news stories like this one? All of the above? Depending on how long I end up trying to make the episodes, perhaps starting with some kind of scientific question and then reporting on a selection of papers I dig up to address the question, or just a selection of papers on the same subject? I’ve already gotten a request for an episode on the theme of prokaryotic extracellular polysaccharides…

The rate at which I can convince myself to try to crank these out (and improve their quality) is directly proportional to how much interest there might be out there in them, so please don’t hesitate to let me know if you think this might be interesting. Please don’t let me slack off! Also, feel free to correct me if I’m wrong about anything I mention in the show or the attached show notes.

If you don’t want to comment here, you can also email me at epicanis at bigroom.org.

Thank you, and good night…

“A small modification of Koch’s plating method.”

Only two more days for the Classic Papers Challenge, so if I’m going to get any more up, I’d better get my butt in gear.

Here’s a nice easy one:

Petri, R. J.:”Eine kleine Modification des Koch’schen Plattenverfahrens.” Centralblatt für Bacteriologie und Parasitenkunde; 1887; Vol. 1, pages 279-280.

The American Society for Microbiology has a translation available online. It’s only about a page-and-a-half of relatively large type – check it out.

There’s a trick we microbiologists use for growing bacteria. You make a solid (but wet) surface that contains whatever nutrients the microbe (bacteria, archaea, yeasts, mold spores…) you’re interested in need, and then you spread a diluted mixture of the microbe on it. The idea is that since the surface is solid the microbes can’t move around too much, and at any spot where a single cell starts initially, a whole pile of that cell and it’s genetically-identical (non-sexually-produced) clone-children will form until it gets big enough to see without a microscope. This cell-pile is called a “colony”, and you can poke or rub it with a sterile object, then stick the object into a sterile nutrient source. The end result is you have a “pure” culture of microbes that are effectively genetically identical. The solid material could be a lot of things – I’ve seen references to using slices of potato – though these days agar-agar gel mixed with nutrients is the preferred substance.

Koch (that is, Robert Koch of “Koch’s Postulates” fame, not Ed Koch the former mayor of New York City) used gelatin (so, hey, here’s another thing you can do with your expired Jell-O&reg;). He apparently used to have a stack of shallow bowls, and had to use a special pouring device to carefully dump the gelatin into each stacked bowl in turn, then cover the works with a bell jar in order to keep stuff from falling into them from the air and contaminating them.

This was kind of a pain to work with, so some clever guy named Julius came up with a modification of this method in 1887, using pairs of shallow dishes, one slightly larger than the other so that it could be turned upside down to use as a lid. Then, you don’t necessarily need the bell jar, and you don’t need to stack them so they’re easier to pour.

Julius Robert Petri’s idea was so useful that we still use it today. Oh, yeah, and they named the dish-and-lid combination after him.

How’s that for a “classic” paper?

Meanwhile, my “Mountain Dew® Wine” project is turning out to be substantially more educational and fascinating than I’d hoped. There seems to be a decent amount of information available on how benzoic acid affects yeasts. I intend to turn that into a post later, but first I’ll try to find at least one more old paper to post before tomorrow is over…