“Does beer and ice cream make gas?”

I get some odd Google searches hitting this site. Once in a while, however, I see one asking a question of vital importance and great usefulness to the general public. Today’s brief topic is this query: “Does beer and ice cream make gas?”.

I’m assuming the searcher did not mean gasoline. Biodiesel is all well and good, but who the heck would waste perfectly good beer and ice cream on such a thing? No, I assume the searcher wanted to know if eating these two fine foods together would expose one to the risk of increased flatulence.

Sad to say, the answer is most likely “yes”.

Flatulence gas (from humans, at least) is made up mostly of carbon dioxide and hydrogen gas[1], and for some people (but apparently not all!) methane. It’s worth noting that none of these components have any odor. All of the offensive smell comes from comparatively tiny amounts of sulfur-containing chemicals – most notably plain old Hydrogen Sulfide, and maybe a few molecules of indole-type compounds such as skatole which can make the origin of the stench obvious.

These main gases come from two sources – swallowed gases (air and carbonated beverages) and microbial fermentation. Obviously this is one place beer comes in – the carbonation adds to the amount of gas entering the digestive tract. Secondly, the beer probably contains some amount of remaining malt which some intestinal bacteria, like the yeast that made the beer in the first place, can break down and eat, possibly generating more carbon dioxide in the process. Beer also has small amounts of sulfur compounds in it which give it some of its flavors. It’s possible that some of this sulfur can end up as smelly by-products of microbial action as well.

I tend to assume that problems one might have with ice cream are mainly related to the lactose from the cream. Lactose is actually a combination of two kinds of “simple” sugar molecules linked together in pairs – glucose and galactose. Many unfortunate human beings are cursed with a lack of production of lactase, which is an enzyme that breaks lactose into its two simple sugars which can be easily absorbed and digested. Many bacteria which can live in the human intestine, on the other hand, make their own lactase. If the human eating the ice cream doesn’t make their own lactase so as to absorb and use up the simple sugars, it all gets down to the intestines where the intestinal bacteria can turn it into a major feast. Many bacteria generate a lot of carbon dioxide when eating these sugars, too, and this adds to the gases that build up in the intestine. This is similar to the issue with beans[2] and similarly ‘indigestible’ substances which can appear in food[3] – humans don’t use them up, so the bacteria get it all and make a huge amount of gas in the process of eating it.

Milk also has at least some sulfur in it[4], like just about any protein-containing food, but I’m not sure if it’s enough to add to the smell problem.

So, yes, beer and ice cream probably do make gas.

Incidentally, it seems as though methane production in humans only happens in some people. Methane is only produced by certain kinds of archaea, and not all humans have them growing in their intestines along with the regular bacteria. Don’t quote me on this, but I would tend to suspect that this would actually reduce the amount of gas that actually results in the end. Methanogens actually make the methane out of the other two major flatulence gases: carbon dioxide and hydrogen. I haven’t looked up the biochemistry, but I suspect the other byproduct is water. Since the pressure of a particular bubble of gas (and therefore its volume when your container is stretchable, like an intestine) is dependent on the number of actual molecules of any kind of gas in it, if you have methanogenic archaea in your intestines they should be taking a molecule of carbon dioxide plus more than one molecule of hydrogen gas, and producing just one molecule of methane out of it (plus some liquid water), so where you once had three or more molecules of gas you end up with just one. I’m sure somebody somewhere has done some kind of study on this, maybe I’ll go dig for it at some point. While I’m at it, perhaps I should look at patenting the use of archaeal “natural flora” as a probiotic?…

The picture at the head of this post, incidentally, came from this blog post of odd signs – apparently this one’s from an advertisement for some kind of backache treatment. Still, I couldn’t pass up putting it here…

[1] Furne JK, Levitt MD: “Factors influencing frequency of flatus emission by healthy subjects.” Digestive Diseases and Sciences, 1996; 41:8; pp 1631-1635
[2] Rockland LB, Gardiner BL, Pieczarka D: “Stimulation of Gas Production and Growth of Clostridium perfringens Type A (No. 3624) by Legumes.” Journal of Food Science; 1996; 34 (5); pp 411–414.
[3] Cummings JH, Macfarlane GT, Englyst HN: “Prebiotic digestion and fermentation” American Journal of Clinical Nutrition; 2001; 73(2); pp 415-420
[4] Ramsdell GA, Whittier GO: “Composition of Casein in Milk” Journal of Biological Chemistry; 1944; 154; pp 413-419

More Search Amusements. (p.s. I Ain’t Dead Yet.)

A bit longer of a delay between posts than I’d like, but here you go:

+ =?????

I am often amused (and regularly baffled) by the kinds of search queries that lead people to this blog.

I wrote a sloppy little script to parse the server’s access logs and figure out who’s searching for what, where. Since I added the ability to recognize Google Image Searches, it’s gotten even stranger.

I do get a lot of perfectly understandable hits – people looking for information about “heat-fixing slides”, expired jello, and looking for pictures of lactic-acid bacteria or whatnot. Some of them are pretty interesting questions…but first, some oddities.

At the top of my current wierd-o-meter: “carbonated leprechaun”…what??? What’s funnier is that this was a Google Image search – someone doesn’t just want information ABOUT carbonation of leprechauns, they want pictures. Now I can’t stop imagining a mash-up of “Darkman” and Leprechaun. Thanks a lot, whoever you are…”I needs me gold! ARGH! SUNLIGHT! [bubblebubblebubble…]”

Another recent one was just a search for the phrase “new england sucks”. As another Image search. Somebody not only doesn’t like New England, but they want pictures of “new england sucks”?…

Less risible but still kind of funny are searches influenced by unfamiliarity with the English language. I have no idea what the search for pictures related to “useful of DNA” was hoping to find. (Uses of DNA? How to “use” [work with] DNA? Diagrams of genetic processes?). I also see a number of searches just based on the name of the blog – people looking for information about furnishing “big rooms”. I have no idea what the search for “name of thing in room” was expected to turn up. This one’s another language issue, but even taking that into account I’m still baffled about this one. I wouldn’t expect google.de to return any useful information for “Sache im Zimmer” (the original search was actually from a Spanish-speaking area, but No Entiendo Espanol, so I’ll use a German analogy instead.)

Or from Sweden: “Aerobic Oxygen fraud”. Somebody’s figured out that we don’t actually need to breathe and that it’s all a ploy by the Oxygen Lobby to enslave us, I guess.

Maybe just because “chemicals” get mentioned here from time to time, I get the occasional hit from someone looking for illegal drug information (either technical or just news of drug busts or whatever). Note to “HILLBILLY METH” searcher: Hillbillies do moonshine. Meth comes from Rednecks. Jeez, doesn’t everyone have to do a semester of Rural Population Stereotype Taxonomy in college anymore?

There are some more relevant and interesting questions that show up here, too.

Oreo CookieI guess someone in southern California used an interesting analogy in their microbiology class, because I recently got a couple of searches from there looking for why the cell membrane is not like an Oreo® cookie. The answer: There’s no “creme” filling. No seriously – the membrane is two layers of the same kind of molecule stuck together. The phrase you’re looking for is “Phospholipid bilayer”. In a way, the molecules are a lot like detergents – they’ve got one end that “likes” water, and a long tail at the other end that doesn’t (much as oil doesn’t). Since the cell is surrounded by and full of water, you end up with one layer with all its hydrophilic ends touching the water outside the cell, and the other layer with its hydrophilic ends on the inside of the membrane touching the water inside the cell, and the hydrophobic ends of both layers all tangled up together in the middle – without anything between them. See? Not like an oreo cookie at all. Aside from this, cell membranes are also squishier and not chocolate flavored most of the time.

I’ll deal with “does beer and ice cream make gas” in another post later…

It’s over!

No you can't have $10,000. Not yours.

I am proud to announce that I am 5th Loser in this 2007 College Blogging Scholarship competition!

Lacking the emotional appeal and/or existing promotional network of the top scorers, I was pretty much up the creek without a plunger. Given the popularity contest format of the competition, I’m actually pretty pleased with how I did. My regular readers (judging by the hits to the RSS feed) have approximately tripled or quadrupled, and I did get a small but useful amount of feedback to help improve things. Oh, and hey, I seem to have readers in Berlin and somewhere in Chile, among other places, so now I can say I’m “world famous™”. Though the proportion of voters who actually did check out all of the blogs was pitifully low, it does still look like it was around 1-2% of the voters, which is actually higher than I would have predicted.

I get the impression that some of us running less well known blogs were a little disappointed about the format of the competition, but there’s really no reason to be. All it means is that rather than being a contest for “highest quality” blog, it was a contest for “most effective” blog. Certainly, being able to get your “vote for me” message out to a larger range of people is a valid measure of effectiveness, so the results seem reasonable to me. And I wasn’t the bottom scorer. Judging by the way my score moved, at least some portion of the people who were examining all of the blogs actually did like what they saw here as I was getting a couple of votes a day on average, so I’m doing something right at least.

The only complaint I really have about the “popularity contest” format is this: I think one of the major benefits to humanity of “blogging” is the fact that unlike mainstream media, a blogger can afford to present unusual, less broadly popular content which otherwise would never be made available. Not having to worry about the internet equivalent of “Nielsen Ratings”, we can afford to put up obscure or strange things that only a fraction of the world might be interested in, which is why if you poke around the internet, you can find something that isn’t the latest celebrity crap or badly-reported political scandal. I actually don’t know how much of a role it played in this particular competition, but this sort of approach in general strikes me as something that would be strongly biased towards “mainstream” content. I think a little more love for all of us off-center folks would be in order.

I also hope they’re offering runner-up prizes again this year. Even if *I* don’t win, at least one of “my people” (nerds, that is – hey, you don’t go for a PhD in Neuroscience without being at least a little bit of a nerd…) would get something again this year if they do.

This does mean, though, that I won’t have $10,000 to buy a microscope with. Woe is me. On the other hand, that means I’ve got no excuse not to try begging in front of scientific conferences. I figure that ought to be worth some entertainment, once I get some time to try it. Perhaps by this time next year, I’ll have a bit more fame and popularity and have a better shot at the prize.

Hey, scienceblogs.com, if you want to promote my blog next year when I’m (hopefully) in graduate school, I may have a shot at the prize next time around… (UPDATE: It may not be obvious, but this should be read as good-natured jealously, not some kind of complaint or accusation…)

And now that all that’s over, we’ll be returning once again to my usual nerdity. Stay tuned (some more).

Give a man a fish, and you feed him for a day…

…but teach a man to fish, and he’ll sit in a boat and drink beer all day.

-== We interrupt this blog post to bring you this important announcement: Happy Birthday, Dad!==-

(His birthday was actually yesterday, but this week of school has been grinding me pretty hard and I’d forgotten all about it. He must be so proud – his son can handle a couple of semesters of biochemistry, complex microbial science, working with dangerous chemicals in a lab…but doesn’t seem to know how to use a simple calendar…I am filled with shame.)

We now return you to your regularly scheduled blog post:

This here critter is our resident fish. “He” is a classic specimen of real, old-fashioned, Honest-to-Aquaman Carassius auratus auratus – the Goldfish. And not one of those poor mutant freaks who can barely swim, either. No this here fish was rescued from the overcrowded “feeder goldfish” tank of a local Wal-Mart®. Handsome, ain’t he? I had a tough time getting even this good of a picture – every time I get near the tank he swims back and forth in front of me frantically, perhaps worshipping me as the magical fishfood god. He’s been here for about three years now, so I think he’s having a much longer life than most of them.

I’ve had no time to get into it, but part of the reason for having a fish is that I have a casual interest in aquaculture. That is, while I don’t currently have any intention of becoming a professional full-scale fish-farmer, the subject is interesting and, I think, very important in the near future. Once we figure out where we’re going to end up living next year and get settled in somewhere, I have considered trying to do the aquaculture equivalent of a backyard garden, though.

I think aquaculture is going to become extremely important in the relatively near future, as we run into the combination of overfishing of natural stocks, water shortages, contamination of natural waters with pollutants that build up in naturally-existing populations of fish, and the overall effects of climate change. I think understanding how to raise healthy and nutritious aquatic food without wasting water or causing environmental problems is going to be a useful set of knowledge to have. (There, see, not only do I love kittens and puppies and want to make the world a better place, but I’m also interested in Sustainable Environmental Practices™. While feeding the hungry. [Uphill. In the snow. With no shoes…]).

You may be wondering what interest an ex-professional-computer-nerd microbiologist would have in tending a pond full of eukaryotes. Well, aside from the obvious “Hey, I can have more than one interest, you know”, there actually is a lot of microbiological activity involved in the natural processes of the fishes’ homes. Plus, of course, the aforementioned beer doesn’t ferment and bottle itself, you know.

Since one of my interests in this context is water conservation, my main interest is in figuring out how to maintain a healthy “closed” system. In an aquaculture context, a “closed” system is one that you don’t normally add substantial amounts of water to. (An example of an “open” system might include raising fish in pens floating in a natural lake, or having a constant stream of fresh ground or river water pumping through your tanks). This poses certain problems, since you have to feed the fish, and this adds an ever-increasing load of potentially uneaten fishfood and especially of eaten fishfood – that is, fish wastes.

Fishfood being digested by either fish or bacteria ends up adding ammonia to the water, which is poisonous to the fish (and crawdads and whatever else is in there). Also excreted is carbon dioxide, which makes the water more acidic, and unused food also dumps sulfur and phosphorous into the system.

If you’ve ever had a fishtank, you may know about the ammonia. Certain kinds of Oxygen-using bacteria can actually get some of their biochemical energy from turning reduced nitrogen into oxidized nitrogen, ultimately turning the ammonia (NH3) into much less poisonous nitrate (NO3). These bacteria tend to colonize the tank’s filter, where they do their thing using the oxygen in the water that flows through. Even nitrate is dangerous if it builds up too much, though. In an aquarium, they usually recommend just taking out some of the tank’s water and replacing it with fresh water every week or two to get rid of the build-up. I’d show you pictures of the bacteria, but I still can’t afford a decent microscope. (sniffle.)

Anyway, I want to build a denitrification column one of these days. There are bacteria that can “breathe” nitrate in place of oxygen, and in the process they can reduce the nitrate back down to plain old harmless nitrogen gas, which just bubbles out of the water. If you build a long, tall tube full of something like gravel that bacteria can grow on, and then pump the water through it slowly, oxygen-breathing bacteria near the bottom of the tube rapidly use up the oxygen in the water, leaving the nitrate. With no oxygen further up the tube, bacteria that can breathe the nitrate instead can grow like crazy, and exhale the extra nitrogen out of the system.

That’s one way of avoiding the need to use up as much fresh water as you’d need if you relied only on replacing the water to get rid of the nitrate.

I’ll save the sulfur and phosphorous parts for another day. Meanwhile, I think the next podcast or two will deal with MRSA, since it’s been in the news so much lately. I normally find the neglected non-medical microbiology more interesting, but the biochemistry and genetics involved with Methicillin Resistant Staphylococcus Aureus (not to mention S. aureus itself) is pretty interesting, and I find the media discussions of it unsatisfying.

Stay tuned…

Hello, College Blogging Scholarship reviewer and other casual viewers

I see the hits from people examining the finalist blogs (including this one) at the 2007 College Blogging Scholarship are up, presumably since this is the last weekend of voting (insert obligatory “please vote for me” plea here).

I have a favor to ask of you, and everyone else who happens to stumble on this blog one way or another (including my regular readers): Please tell me something about your impression of this blog. Even if all you have time for is a quick one-sentence comment, praise for something you like or thoughtful criticism of something you don’t like, or just something that you thought was noteworthy, it will help me improve the blog. No registration is necessary to comment.

If you have time for a more detailed comment, some opinions as to what else you might be interested in seeing here would be helpful. For example, I’m considering trying to do a regular or semi-regular podcast. Would that be of interest? More pictures? More detailed discussions of scientific matters? Naked pictures of myself? (Okay, almost none of you would really want the latter…)

I’m actually more interested in your opinions than your votes, though if I can have both I would obviously be grateful…

I shall return again to the science nerdity intended for a broad not-necessarily-nerdy audience shortly. Thank you.

#1 on Google!

Over on scienceblogs.com’s The World’s Fair, the author has started an amusing meme.

It goes like this: the challenge is to find 5 sets of search terms for which your own blog or site is the #1 hit on a Google search. Note that it is acceptable to quote specific phrases but of course it’s more impressive if you don’t. Here are 8 that (as I type this) for which this blog is the #1 hit (links go to the blog address that is the hit):

There was at least one other which I’m having trouble remembering at the moment. Perhaps I’ll update later if I remember what it was.

My server’s going to walk funny for a week after this…

Someone posted a link to the “No, You Can’t Have A Cookie” image I put together a while back.

On Fark.com.

In a comment thread for an article that seems to involve the suggestion of a nude college girl.

The server logs have been scrolling by rapidly for quite a while now. Ow.

Incidentally, if you’re coming here from Fark.com, do me a favor and click on the “vote for me” image thing below. I promise if I win, I’ll use some of the money to get a TotalFark account…

UPDATE: The thread seems to be FINALLY winding down. Thank you, Farkers who noticed my plea and voted for me, I’m rapidly gaining on the 4th Loser position!

Hey, it beats last…and voting goes through Sunday this week, as I recall…

Microbial Fuel Cell netcast…

It’s only my first attempt at anything like this, so constructive comments are welcome…

(Hopefully you can see the embedded audio player here…)For those of you just tuning in, this is a 90-second explanation of Why Microbial Fuel Cells work. A longer (though still simple) explanation can be found at a slightly older post here.[Update: this was featured in the November 6, 2007 broadcast! Hooray, I can now claim to be an international “radio personality”!]Presuming hosting this file doesn’t kill my bandwidth, I’ll leave it up here. BelowAbove, you should see an embedded flash player (assuming you have Macromedia® Flash® player installed) which you should be able to click on to start the audio. I’ll also place a direct download link below. It should be noted that like everything else on this blog (unless otherwise specified), this audio is also available under the Creative Commons non-commercial/attribution/share-alike license, so as long as you have no problem with the terms of that license you are welcome to copy, redistribute, put up on bittorrent, host a public performance, turn into an interpretative dance art project, or whatever else you might want to do with it so long as you give me credit for it, don’t use it for commercial purposes, and distribute any derivative works of it under the same terms.

You can download the audio directly from here – right-click on the link and select “save link as…”. Ogg Vorbis format available on request…

Poor-boy science: should I build my own electrophoresis platform?

I want to build my own little electrophoresis gizmo to play with.

I did pick up a small tube of powdered graphite and some liquid tape. With this, I should be able to make a waterproof electrically-conducting glue that I can use for the electrodes. I’ve got numerous old “wall-wart”-type power adapters that I ought to be able to use for power supply.

The main thing I’m trying to work out in my head before I start trying to actually put this together is exactly how I’m going to arrange it so that I can have either a thin gel or a piece of paper or other fibrous material in between the electrodes so that I can best separate things.

I suppose it’s kind of bizarre, but this is actually part of the ongoing Expired JellO® projects. I was wondering to myself what actual changes might possibly occur in a packet of dry gelatin mix over time, and how would I be able to tell?  My previous experiments have shown no indication that there are any easily detectable differences (no obvious changes in taste or texture, no strange eerie glow, no acquisition of superpowers upon eating it…) so I’ll have to look more closely.

It occurred to me that just maybe over time the strands of protein that make up gelatin might get damaged by oxidation from the air in the pouch (or do they seal the pouch in a relatively inert gas, like argon or nitrogen?). This isn’t something one can really tell just by looking, obviously. One MIGHT be able to tell indirectly by making fresh and “expired” packets of gelatin with the same precisely-measured amount of water, poured on at the same precisely-measured temperature, and ideally with the same amount of mixing. Believe it or not, there are actually special scientific devices for measuring the firmness of gels like this. The hypothesis would be that expired gelatin might end up “degraded” into smaller strands of protein than a fresh packet, and that this would be reflected in a reduced firmness of the gel, or perhaps reduced water-holding capacity.

However, I don’t have access to precise devices for measuring things like that, and in any case since I suspect the difference would be pretty minimal, I’m not sure any difference in firmness would really be detectable with any kind of instrument I could cobble together on my own. What to do?…

I thought that if I had a way to subject a sample of dissolved gelatin to electrophoresis, I could then use a protein-staining substance to see how broad of a range of protein-fragment sizes were existent, or perhaps even spot distinct fragments if oxidative damage tended to happen at the juncture between particular amino acids or something.

I’m not quite sure why, but I have a strong desire to do this experiment from scratch as a “hillbilly biotech” exercise (including building the equipment and obtaining my supplies from grocery or hardware stores rather than specialty scientific supply places).

There are special protein staining compounds I can use at the end to see where my bits of protein ended up after electrophoresis. “Coomassie Brilliant Blue“, for example, but they don’t have that down at the grocery store. (And if you think that’s a funny name for a dye, consider “Light Green SF Yellowish”…)

Then, I ran into a post indirectly about henna over on scienceblogs.com. It seems the natural orange-staining ingredient in henna, called lawsone, may be specifically a protein-staining substance. I’m not certain about this, but a dark-orange protein-staining dye would work for my purposes I think. If so, that solves my need to get a protein stain from an ordinary store.

It’ll be a little while before I can try to put this plan into action, but I think I’ll be able to get to it in the next month or two.

In other news, I think I’ll try to post my “Microbial fuel cells in 90 seconds” audio sometime tomorrow. Then I can work on more. Anybody want to hear me attempting to explain something in 90 seconds? So far I’ve considered MRSA, and perhaps how cow flatulence threatens the world’s climate (which is also a microbiological topic). I’m sure there must be plenty of other possible topics. Any suggestions?

P.S. Who wants audio in Ogg Vorbis format in addition to mp3?

A short update…

I’ve got an Art History exam in the morning which has been consuming my time, but I wanted to get some kind of post up. Especially since it almost looks as though I just don’t post on Thursdays. I swear the recent several weeks of “no post on Thursday” is purely coincidental.

I’m still waiting to hear if This Week In Science got the audio file I sent them and whether or not they liked it. I did manage to find a legally-free embeddable flash-based audio player that I can use, so I’ll probably post it for listening to online or for downloading soon.

Meanwhile: One of my competitors in the College Blogging Scholarship 2007 competition had an interested post up the other day. Famous neuroscientist Shelley Batts of Retrospectacle posted about a bunch of computer people getting together to have a “hackfest”, where they all work on their projects and exchange ideas. She wonders if something similar might not be possible for scientists.

I have regularly found myself thinking about the possibility of a similar gathering for scientists. I wonder – would an international society of Peripatetic Scientists be feasible? What I envision would be a combination of “Science Cafe’” and “Semi-spontaneous field trip” (or even perhaps a “Flash Mob of Nerds”).

I picture groups of scientists, engineers, and other interested people converging on relatively short notice (say, no more than a week or so) to explore something together, whether it’s a section of a national park, or an observatory, or a grocery store, or even to just wander around in a public space discussing some topic. Rather than a carefully planned and organized event where people take turns “giving presentations”, I tend to suspect a more spontaneous exploration by a group of diverse people like this would result in much better horizontal meme transfer potential. It’s so much easier to participate and listen when one isn’t busy focusing on one’s own presentation material…

How many of you reading this might be interested in participating in this sort of thing?
(UPDATE: TO clarify, I mean how many of you, if you heard something like this was happening where you are, would be interested, not how many people are so incredibly impressed by me that they would travel across the world to be where I am…)