Search found 850 matches

by qetzal
Sun May 10, 2015 5:21 am UTC
Forum: Science
Topic: Contamination of insulin pump cartridges
Replies: 23
Views: 4283

Re: Contamination of insulin pump cartridges

Zinc has no effect on monomer stability. It's possible it has some effect on dimer stability, but I doubt it. Zinc is excluded from the dimer interface. Zinc is just the cation of choice because that is how insulin exists natively. I searched a bit but couldn't find a good explanation of why Zn is ...
by qetzal
Sat May 09, 2015 9:16 pm UTC
Forum: Science
Topic: Contamination of insulin pump cartridges
Replies: 23
Views: 4283

Re: Contamination of insulin pump cartridges

There's plenty on sodium already for charge neutralization. I'm pretty sure they wouldn't bother adding zinc just for that. Most likely the zinc helps stabilize the monomers or something. I'd also guess that someone in pharma and/or FDA (and their equivalents in other countries) have already conside...
by qetzal
Sat May 09, 2015 3:11 pm UTC
Forum: Science
Topic: Contamination of insulin pump cartridges
Replies: 23
Views: 4283

Re: Contamination of insulin pump cartridges

The US label for Novolog says the following: NovoLog is a sterile, aqueous, clear, and colorless solution, that contains insulin aspart 100 Units/mL, glycerin 16 mg/mL, phenol 1.50 mg/mL, metacresol 1.72 mg/mL, zinc 19.6 mcg/mL, disodium hydrogen phosphate dihydrate 1.25 mg/mL, sodium chloride 0.58 ...
by qetzal
Thu Apr 30, 2015 1:59 pm UTC
Forum: Serious Business
Topic: Genetic use restriction technology (Suicide Seeds)
Replies: 22
Views: 8474

Re: Genetic use restriction technology (Suicide Seeds)

@ahammel: I don't disagree with any of that. I'll just say again that all those concerns relate to the introduced genes or traits, not to the method of introductoon. If it were possible to introduce the same genes/traits by non-GMO methods, all those issues would still apply, right? @Autolykos: AFAI...
by qetzal
Thu Apr 09, 2015 10:28 pm UTC
Forum: Science
Topic: Motion mountain: crackpot?
Replies: 26
Views: 13955

Re: Motion mountain: crackpot?

I humbly submit that if there's this much disagreement over what specific passages even mean, it's a bad textbook. Even uf the author isn't a crackpot.
by qetzal
Wed Apr 01, 2015 12:13 am UTC
Forum: News & Articles
Topic: Anglo-Saxon apothecary’s unguent effective against MRSA
Replies: 8
Views: 3811

Re: Anglo-Saxon apothecary’s unguent effective against MRSA

Not sure this is so surprising. Here's a paper from 70 years ago showing that onion and garlic have antibacterial properties.
by qetzal
Fri Mar 06, 2015 3:00 pm UTC
Forum: Serious Business
Topic: Genetic use restriction technology (Suicide Seeds)
Replies: 22
Views: 8474

Re: Genetic use restriction technology (Suicide Seeds)

I don't think it was really a bullshit reason. At least, not for everyone. I don't doubt that Monsanto et al. recognized that mechanisms to prevent escape could also be used to retain control. But I also clearly recall a lot of academic GMO researchers back in the 80s were very concerned about escap...
by qetzal
Fri Mar 06, 2015 3:21 am UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

What happens if you recolonize adult germ-free mice with normal gut flora? Do they gain significant protection from pathogens? Is their immune dysfunction ameliorated at all?
by qetzal
Thu Mar 05, 2015 4:15 pm UTC
Forum: Serious Business
Topic: Genetic use restriction technology (Suicide Seeds)
Replies: 22
Views: 8474

Re: Genetic use restriction technology (Suicide Seeds)

Wouldn't it also be important to make sure that GMO crops aren't cross-pollinating with the "natural" versions surrounding the fields? We want to be ecologically safe, after all. Is that really specific to GMO crops though? Why is it necessary to prevent cross-pollination for GMOs, but no...
by qetzal
Sun Mar 01, 2015 5:18 am UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

Interesting that Knight says two people may share as little as 10% of their gut microbes. Does that suggest that the major beneficial functions are fulfilled by a small fraction that's common to everyone? Or that many different microbes can fulfill the same functions more or less equivalently?
by qetzal
Sun Feb 22, 2015 4:02 pm UTC
Forum: Serious Business
Topic: The Ethics of Genetic Engineering
Replies: 215
Views: 40703

Re: The Ethics of Genetic Engineering

That's the beauty of it. The next generation could do the same procedure again for the next few sets of changes. They'll probably manage much more then, and even more the next one after, quite possibly due to advances made to the procedure by performing it. But how will you know if you really have ...
by qetzal
Sun Feb 22, 2015 1:38 pm UTC
Forum: Serious Business
Topic: The Ethics of Genetic Engineering
Replies: 215
Views: 40703

Re: The Ethics of Genetic Engineering

jseah, The problem, IMO, is that transforming "as many in as you can" is still going to be highly limited. I agree we could likely do that with a small number of different SNPs. But how much of an intelligence increase would we expect with only a few such changes? Even under the best of co...
by qetzal
Sat Feb 21, 2015 4:06 am UTC
Forum: Serious Business
Topic: The Ethics of Genetic Engineering
Replies: 215
Views: 40703

Re: The Ethics of Genetic Engineering

As for claims that the human genome is too complex to understand, I would like to point out that we can already model large parts of it and we are coming to understand the more complicated interactions. While we clearly haven't mapped it all out, we do have the ability to just try. Understanding an...
by qetzal
Thu Feb 19, 2015 12:58 am UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

I don't think it's a secret at all. Actually, qetzal, there's a bunch of good info for you in that link about the myriad issues germ free animals face. I must have missed it before. Ah, thanks! That was useful - esp. slide 15 where it says: Germfree Effects and Onset of Disease • Elimination of gas...
by qetzal
Fri Feb 13, 2015 3:11 am UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

I do get the gist. I'm just trying to understand the actual implication of phrases like "aids in." Functional eyes and functional kidneys both aid in survival, but the latter are a lot more essential than the former. I'm trying to get a sense of where on that scale gut microbes fall.
by qetzal
Thu Feb 12, 2015 9:29 pm UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

Thanks for all the responses. @Izawwlgood: I'm completely on board with the idea that gut microbes are essential to normal health in humans. My question is really whether they are essential to survival. Of course, even that can be argued. So: if not having gut microbes was comparable to not having t...
by qetzal
Sun Feb 08, 2015 8:18 pm UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

I didn't say any of this in the other thread...? Your comment over there was: No one is disputing that some microfauna are required for metabolism. As for the semantics, if your argument is that normal gut microbiota are essential for normal health, fine. I agree that there's a lot of evidence to s...
by qetzal
Sun Feb 08, 2015 2:06 am UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

Fecal transplants work because they restore the micro biome that is neccesary but absent. If you managed to completely sterilize your gut, and somehow magically only eat sterile foods, you would probably be in pretty lousy shape nutritionally. Citations needed for italicized unsupported assertions....
by qetzal
Sat Feb 07, 2015 10:21 pm UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Re: Human Gut Microbiome: Essential or Not?

Well, I'm interested in whatever is the best case that can be made. However, the idea that a healthy microbiome protects from C. difficile doesn't really qualify as essential, IMO. By that measure, measles vaccines are essential, since they also protect from a sometimes fatal disease. I'm familiar w...
by qetzal
Sat Feb 07, 2015 6:03 pm UTC
Forum: Science
Topic: Human Gut Microbiome: Essential or Not?
Replies: 31
Views: 5844

Human Gut Microbiome: Essential or Not?

I occasionally see claims that the microbes in our gut are essential for survival. It came up tangentially in the recent MS thread, but I've seen it claimed in a number of other science-oriented venues. My problem is that I have yet to find someone who can back up that claim with actual evidence. No...
by qetzal
Sat Feb 07, 2015 2:14 am UTC
Forum: Science
Topic: Whats happening in MS patients?
Replies: 71
Views: 11910

Re: Whats happening in MS patients?

A 1000 time this ^^^. Very well said, HungryHobo. I hope the OP drops by again to read it.
by qetzal
Tue Feb 03, 2015 10:55 pm UTC
Forum: News & Articles
Topic: US measles outbreak as fewer parents vaccinate
Replies: 211
Views: 25243

Re: US measles outbreak as fewer parents vaccinate

So I want to be on the side that argues for making decisions based on significantly valid statistical data rather than fear-based hypothetical modeling. If we're going to be chiding Americans for not making voluntary choices that would otherwise benefit the common good, let's put more effort the ch...
by qetzal
Sun Feb 01, 2015 8:26 pm UTC
Forum: Logic Puzzles
Topic: Six statements. How many are true?
Replies: 20
Views: 6543

Re: Six statements. How many are true?

Except, if "This statement is false" is neither true nor false, then I don't see how B can be true. For B to be true, it would have to be the case that if at least 2 of C-F were true, then B would be false. But you've already stipulated that "This statement is false" is n...
by qetzal
Sun Feb 01, 2015 3:36 pm UTC
Forum: Logic Puzzles
Topic: Six statements. How many are true?
Replies: 20
Views: 6543

Re: Six statements. How many are true?

I'm having a major difficulty with this puzzle. Statement A is "This statement is true if and only if the next statement is true." I don't think you can determine that A is true just by showing (or assuming) that B is true. If that were the intent of the puzzle, then A should have been wor...
by qetzal
Sat Jan 17, 2015 2:26 am UTC
Forum: Science
Topic: Whats happening in MS patients?
Replies: 71
Views: 11910

Re: Whats happening in MS patients?

[this would mean that all patients would have Clostridium infections. All patients have Clostridium infections; it's impossible to properly metabolize indole compounds without certain Clostridia. I believe it's passed down in breastmilk. Do you have a citation for the claim that Clostridium is requ...
by qetzal
Sat Jan 17, 2015 12:06 am UTC
Forum: Science
Topic: Whats happening in MS patients?
Replies: 71
Views: 11910

Re: Whats happening in MS patients?

google Ioannidis hm, i wouldn't trust a study that claims most studys produce wrong results. Technically, the Ioannidis paper wasn't an empirical study. It was an analysis saying that if certain premises are true, then most novel findings in the literature must be false. I have my doubts about how ...
by qetzal
Fri Jan 16, 2015 11:30 pm UTC
Forum: Science
Topic: Whats happening in MS patients?
Replies: 71
Views: 11910

Re: Whats happening in MS patients?

[A]n organism which we know to be widespread produces a toxin which we know to cause symptoms very similar to MS. Except that we don't know that C. perfringens Type B is widespread in MS patients . In fact, your own link claims they are the first to isolate C. perfringens Type B from any human ever...
by qetzal
Wed Jan 07, 2015 1:58 am UTC
Forum: Science
Topic: Evolution: Random or intentional?
Replies: 187
Views: 25248

Re: Evolution: Random or intentional?

The proposed mechanism is a 'negative feedback loop closed trough the environment of the organism', and it it's been proposed to explain some behaviors of living organisms, including bacteria, better than a stimulus-response causal chain. How is the environment closing the negative feedback loop? T...
by qetzal
Tue Jan 06, 2015 3:25 am UTC
Forum: Science
Topic: Evolution: Random or intentional?
Replies: 187
Views: 25248

Re: Evolution: Random or intentional?

aph, Lett me be the 5th (?) card-carrying molecular biologist to say that your use of "intent" in this context is inappropriate. I don't disagree with a lot of your points about feedback loops. But it's just wrong to describe them as being intentional. If you're just doing it as short-hand...
by qetzal
Sat May 31, 2014 2:25 am UTC
Forum: Science
Topic: Inbreeding thought experiment
Replies: 7
Views: 2059

Re: Inbreeding thought experiment

Inbreeding could be a problem if the starting population is small. But it can't become a problem later if you're assuming the island van sustain infinite people!
by qetzal
Sat May 17, 2014 7:41 am UTC
Forum: Science
Topic: Henrietta Lacks
Replies: 7
Views: 2535

Re: Henrietta Lacks

Along those lines, google "devil facial tumor disease." Basically a cancer that developed in some Tasmanian devil at some point, but now is able to pass from one animal to another by biting. Definitely a new species if you ask me. There's another thing like that which affects dogs. Forget ...
by qetzal
Wed May 14, 2014 1:00 am UTC
Forum: Science
Topic: Henrietta Lacks
Replies: 7
Views: 2535

Re: Henrietta Lacks

Interestingly, you can reasonably argue that HeLa is a new species! It certainly is reproductively isolated from its ancestral species. It depends on human assistance to propagate, but there are lots of "natural" species that obligately depend on another.
by qetzal
Thu Apr 03, 2014 10:00 pm UTC
Forum: Science
Topic: cords coil. Why?
Replies: 15
Views: 3182

Re: cords coil. Why?

Maybe the outer plastic sheath changes size over time due to changes in temp, or gradual shrinkage, and that forces coiling?
by qetzal
Tue Jan 28, 2014 10:00 pm UTC
Forum: Science
Topic: Can dormant viruses survive meiosis?
Replies: 12
Views: 3026

Re: Can dormant viruses survive meiosis?

Indeed. My original comment was not meant to suggest that non-similar sequences can't recombine. Only that in such cases it's not homologous recombination. Sorry if I was unclear about that.
by qetzal
Tue Jan 28, 2014 8:23 pm UTC
Forum: Science
Topic: Can dormant viruses survive meiosis?
Replies: 12
Views: 3026

Re: Can dormant viruses survive meiosis?

Homologous recombination definitely requires similar sequences. E.g. see this online molecular genetics textbook by a biochem/mol bio professor at Penn State, which states: General or homologous recombination occurs between DNA molecules of very similar sequence, such as homologous chromosomes in di...
by qetzal
Tue Jan 28, 2014 1:18 am UTC
Forum: Science
Topic: Can dormant viruses survive meiosis?
Replies: 12
Views: 3026

Re: Can dormant viruses survive meiosis?

Technically, genes are homologous if they are derived from a common ancestor. But practically, homologous genes are those with similar DNA sequences. Homologous recombination only occurs between DNAs with similar base sequence. Your scenario of a viral sequence getting split in half can definitely h...
by qetzal
Mon Jan 27, 2014 2:39 am UTC
Forum: Science
Topic: Can dormant viruses survive meiosis?
Replies: 12
Views: 3026

Re: Can dormant viruses survive meiosis?

Yes, this has happened and is very well documented. Do a search on "human endogenous retroviruses." We all have something like 100,000 of these in our genomes, though most are fragmented or otherwise defective. Also, if there's a virus inserted on one chromosome but not on the homolog, hom...
by qetzal
Tue Dec 17, 2013 5:05 pm UTC
Forum: News & Articles
Topic: FDA forcing antibacterial soap makers to prove claims/safety
Replies: 40
Views: 6033

Re: FDA forcing antibacterial soap makers to prove claims/sa

I do not believe that antibiotics like penecillin form a normal part of antibacterial soap. Instead, "antibacterial" things include ingredients like Triclosan or ethyl alcohol. I believe these are distinct from the traditional medical antibiotics(though antibacterial soaps also see hospit...
by qetzal
Fri Dec 06, 2013 3:34 am UTC
Forum: Science
Topic: Bacteria in Spaaace
Replies: 14
Views: 3076

Re: Bacteria in Spaaace

1) No. As pointed out, all life on Earth requires water to grow and reproduce. No water, no reproduction. No reproduction, no adaption/evolution. 2) Surviving on the moon, yes, as others have noted. But it would be impossible to engineer any Earth life that could actually grow and reproduce without ...
by qetzal
Wed Oct 30, 2013 10:27 pm UTC
Forum: News & Articles
Topic: Chiro quackery - now on bebbies!
Replies: 275
Views: 21614

Re: Chiro quackery - now on bebbies!

So is that one part duck liver, 10^400 parts water? Is that how they measure that? I ask because assuming the volume of a duck liver to be 500 millilitres it would take 10^399 litres of water to achieve that level of dilution. According to wolframalpha the volume of the observable universe is 10^83...

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