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Comment: Analogy (Score 5, Insightful) 188

by TMB (#49156721) Attached to: One Astronomer's Quest To Reinstate Pluto As a Planet

Here's an analogy I gave my students last week...

Imagine you're an alien and you land on Earth in front of a pet store. You go inside and you start meeting dogs. Some are big with a loud deep "WOOF", some are small with a quieter higher "ruff" and there's one little one that goes "meow". Some of them have big floppy ears, some of them have little floppy ears, and that little one has sharp pointed ears with tufts on the end. You think "That little meowing dog with the pointed tufted ears is an unusual dog!"

Then you go onto the rest of the pet store and find a whole bunch more small meowing things with pointed tufted ears, and you say "Oh... I see. That wasn't a funny dog, that was just the first cat I met!"

Pluto was the first Trans-Neptunian Object we met, and so we originally called it by our existing language ("planet"). But once we had a much better lay of the land, it became clear that it was just the first example of a quite different type of object.

[TMB]

Comment: Re:I blame the FDA (Score 3, Interesting) 365

by reverseengineer (#49054763) Attached to: Smoking Is Even Deadlier Than Previously Thought

Nicotine is only distantly related structurally to the vitamin nicotinic acid (aka vitamin B3 or niacin). While nicotinic acid is an intermediate in tobacco's biosynthesis of nicotine, the final nicotine molecule also has an N-methylpyrrolidine ring not present in the vitamin. Nicotinic acid is the active form of vitamin B3, but the amide derivative (nicotinamide, as the parent notes) is also a bioavailable form, as it is converted in the body to nicotinic acid. Nicotinic acid is not named for a direct biological relationship to nicotine, but rather a synthetic chemical relationship. Nicotinic acid was first prepared synthetically by reacting nicotine with nitric acid; it was only later that nicotinic acid was isolated from biological systems, and was eventually found to be essential in the prevention of pellagra.

The physiological effects of nicotine are for the most part not due to its similarity with the vitamin niacin, but because it can bind to and activate a certain type of acetylcholine neuronal receptor: that is to say it mimics a neurotransmitter. Notably, nicotine does not bear much structural similarity to acetylcholine, but its agonist activity at these particular receptors is an identifying property of their type, to the point where they are called nicotinic acetylcholine receptors.

Comment: Re:TV = video (Score 1) 244

by TMB (#48985897) Attached to: Over the past 10 years, my TV-watching has..

There's a huge range of ambiguity these days.

How often do I watch a TV set that has a signal coming from an antenna, cable, or satellite receiver? Absolutely never.

How about if I stream an old TV show on Amazon instant video on my computer? How about if it's the latest (but not live) episode from the current season of a show? How about if I stream a live Canucks game on my computer? How about if I stream any of those onto a TV set via a Chromecast? I can't see a reasonable argument that sitting in front of a TV set watching a live sports event isn't "watching TV" --- but you can come up with plenty of industry definitions where it doesn't qualify.

Comment: Re:What, no MSDS? (Score 4, Interesting) 87

by reverseengineer (#48976427) Attached to: Novel Fluorinated Compounds Discovered In Firefighters' Blood

I don't know- I went looking for an MSDS for a modern firefighting foam, and the composition listed is:

Polyethylene glycol: 2.5-10%
Other components below reportable levels: Greater than 90%

Now, this is for Ansul-3 Fluoroprotein foam concentrate. It definitely contains some sort of fluorinated compound (fluoroprotein foam agents are at least known to contain a fluorinated surfactant and hydrolyzed protein); the MSDS has absolutely no mention of what it is. In the Environmental Handling section, all it says is "An environmental hazard cannot be excluded in the event of unprofessional handling or disposal." Nothing about how fluorinated surfactants are persistent environmental contaminants or can cause kidney damage in high doses. It is simply written like innocuous polyethylene glycol is the only component. I've seen material safety data sheets for shampoo that have far more information.

Now, in the specific case covered by the research paper, the "unknown compounds" aren't really that mysterious. They're all either metabolites, chemical precursors, or close chemical relatives (if you're making some some sort of octane derivative, you can expect some hexane to be in there too). And they're all given as 0.1%-1% of the main PFOS surfactant; certainly chemical manufacturers need to exert better control over their processes, minimize byproducts, perform long-term safety studies, etc. And that goes double for anyone making halogenated organic compounds, which now have a substantial record of turning out to be accumulative toxins. But I think if you look at many common manufactured products at trace levels with tandem mass spec, you're going to find some compounds that aren't in the literature.

Comment: Re:How are they rocky? (Score 2) 67

by reverseengineer (#48919285) Attached to: Kepler Discovers Solar System's Ancient 'Twin'

What's interesting about this star though, is that according to the paper, Kepler-444 is not some primordial supergiant, but a K dwarf (orange, of the same type as Alpha Centauri) with a smaller companion red dwarf (or possibly two companion red dwarf stars which are closely bound to each other).

Comment: Re:Yep it is a scam (Score 3, Insightful) 667

by forand (#48872073) Attached to: US Senate Set To Vote On Whether Climate Change Is a Hoax
I think you are confused. If there were no pipeline the oil would have to be refined nearby. This WOULD create lasting jobs and keep much more of the profits near where the oil is being extracted. The whole point of making a pipeline to the Gulf Coast is to enter the global crude oil market or more precisely to benefit the big oil companies who can ship the crude oil to countries with little or no environmental protections but cheaper refineries thereby keeping a larger share of the profits for themselves. The pipeline may not be directly bad for the environment but it is intended to avoid the costs and environmental regulations imposed by refining in Canada or the USA.

Comment: Line printers (Score 3, Interesting) 790

by Phil Karn (#48785225) Attached to: Ask Slashdot: Sounds We Don't Hear Any More?
Others have already mentioned the dot-matrix printer, but there was a big one before that: the high speed line printer. They were too expensive for individuals, but they certainly were a familiar sound to 1970s programming students like me.

There were two main types: the drum printer and the chain printer. The drum printer was cheaper and therefore much more common. The drum, which contained all the characters in a given font, rotated once for each row printed. An entire row was printed simultaneously; a separate solenoid-driven hammer in each column fired at the right instant to print the desired character in that column. You could easily tell from across the room whether your program had failed to compile or if execution ended with a core (!) dump. The burst pages between jobs had their own highly characteristic sound.

A related sound is that of ripping fanfold line printer paper to separate jobs. Who uses any kind of fanfold paper these days? Or even paper...?

Oh, and let's not forget the sound of the Hollerith (IBM punch card) reader...

Comment: Re:Hypocrisy. (Score 1) 153

by forand (#48778845) Attached to: Fewer Grants For Young Researchers Causing Brain Drain In Academia
I see it was the latter. Regardless, the government should be funding pie in the sky academic research. Currently the push is to fund marketable research. How does that benefit society? We all pay for the development of some clearly marketable product and don't actually retain any of the monetary benefit. If the government funded ONLY pie-in-the-sky research that was vetted by scientists we would be close to where we were in the 1950-1960s where dramatic increases in technology were occurring due to funding of basic research and the solving of problems needed to complete that research. You can claim it is is sucking on the government teat or you can realize that we would never have much of the technology we enjoy today if it weren't for funding of basic science.

Time to take stock. Go home with some office supplies.

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