darkoshi: (Default)
Why can we smell metal? - it's not actually the metal that smells.

I was wondering last week why my hand smelled bad, then realized it was from simply having touched the metal zipper pull on an old duffle bag. (Yet when I later sniffed the zipper, it didn't smell). Certain metals like that (not sure what kind, but generally the yellowish/bronze colored ones) make my hands smell so horrible that I have to wash them to get rid of the smell. Then I wondered if other people could smell metal too, which led to me finding the above information.

genetics

Wednesday, September 18th, 2013 08:44 pm
darkoshi: (Default)
DNA Double Take - genetic chimerism and mosaicism is much more common that previously thought.

cool air

Thursday, July 18th, 2013 12:17 am
darkoshi: (Default)
Info about the phasing out of freon (R22), and its replacement by R410a (aka "puron"):

R-22 to R-410A - Understanding the Differences

What You Should Know about Refrigerants When Purchasing or Repairing a Residential A/C System or Heat Pump


Info about the potential phase-out of puron, and its replacement by other refrigerants:

Cooling: Rethinking Refrigerants
darkoshi: (Default)
Several times now, when I've been searching for scientific information, I've come across research papers with relevant/interesting sounding abstracts. In many cases, the sites hosting the papers have restricted access to the full text of the papers - one needs an account to view them. In order to get an account, one must be a member of a medical or educational institution, etc. In some cases, the sites in question also offer the ability for other people to buy/download the full paper, for a fee. If the fee were small (under $5), I'd consider it. But the fees I've seen so far are more in the range of $30.

So I end up doing a web search on the paper's title, to see if I can find it elsewhere. On more than one occasion, I've found the full paper freely available on Google Docs.

So I wonder:
1. Why do sites have fees / restrictions for viewing the papers in the first place? Who gets the money - is it used for site maintenance costs, or for what? Do the authors of the papers get any of the money?
2. Why does Google Docs have the papers freely available, when they aren't freely available elsewhere? Are these documents on Google Docs by mistake, or on purpose?

(no subject)

Wednesday, March 9th, 2011 11:52 pm
darkoshi: (Default)
Study identifies changes to DNA in major depression and suicide - interesting... I want to read more about this turning on and off of DNA somewhen; I've heard about it before but don't understand it well.
"We have about 40,000 genes in every cell and the main reason a brain cell is a brain cell is because only a small fraction of the genes are turned on. The remaining genes that are not expressed are shut down by an epigenetic process called DNA methylation."

via [personal profile] andrewducker
darkoshi: (Default)
How the inventor of the pill changed the world for women - about Carl Djerassi, one of the inventors of the Pill.

[regarding a male birth control pill] The first question a man would ask is: would it affect my potency? There have been clinical trials – it has no effect on potency. The second question is erection.

I can't figure out what the word "potency" means in that context. A male BC pill would obviously affect fertility, as that is the point of a BC pill. So potency doesn't seem to mean fertility. And it doesn't seem to mean the ability to get an erection, since that is the 2nd question, not the first. What does it mean?

"How many acts of sexual intercourse would you guess occur every 24 hours?" he asks. "I often do this with my students, and they say a billion. I say: 'No, no, no, you're dreaming. There are six billion people. Well, you need two for sexual intercourse, so there are only three billion. And some of them are five years old, so they're out.' So then they say a million. Well, now you're underestimating, because you're sitting here and you're not having sex. It's actually 100m, every 24 hours. And they produce about a million conceptions, about half of which are unexpected. Of the 500,000, half of them are unwanted. As a result, every 24 hours, 150,000 abortions occur; of these, over 50,000 are illegal."

Interview with Carl Djerassi

Some parts of this don't make sense to me. Having a male BC pill doesn't take away a woman's control over her fertility, it rather gives a man more control over his. But the comment about the female BC pill making men less willing to use condoms is intriguing.

Djerassi suggests that in the future we will freeze our sperm and eggs, get sterilised and check out our sperm and eggs from the bank when we want them later. 'Then you might as well forget about contraception'.

Interesting idea. Maybe the actual eggs and sperm won't even need to be stored in the future. Maybe their DNA sequences will be scanned and saved as data, and maybe it will be possible to re-create an egg or sperm using that data. It wouldn't even really be necessary to extract and scan actual eggs and sperm... one could take the person's DNA and have a computer randomly select half the chromosomes to make virtual gametes. It will surely be possible to check the DNA for hereditary diseases, and to make corrections to prevent those diseases.

Once all that is possible, it would theoretically be possible for people to decide that they want to have a child using someone else's DNA (a celebrity, for instance), rather than their own. Or using a combination of multiple people's DNA. I wonder how much legal control people will have over their own DNA... will it be similar to copyright, and after a certain length of time after a person dies, will other people will be able to use that person's DNA? Or will only people directly descended from that person be allowed to use it? Will you be able to sell your DNA sequence for specific uses?


Response - I never blamed the pill for the fall in family size ... I didn't know that the birth control pill wasn't legal in Japan until 1999.

Birth control in Japan - mostly via condoms.

(no subject)

Saturday, April 19th, 2008 10:17 pm
darkoshi: (Default)
This is an interesting article about what "false positive rate" really means. I was interpreting it wrongly myself. This is good to know if you have a medical test come back positive for something.
http://languagelog.ldc.upenn.edu/nll/?p=12

(no subject)

Sunday, March 23rd, 2008 01:28 pm
darkoshi: (Default)
This vegan ice cream line (Wheeler's Black Label) has a lot of flavors. I wonder where it is sold.

The Scientific American website has a lot of interesting articles. I seem to remember reading some of their magazines when I was a kid. I might have had a subscription for a while; I can't quite recall. I do remember the National Geographic subscriptions my dad paid for, as well as a subscription to an astronomy magazine which I believe I signed up for myself. I bought StarLog magazines at bookstores.

I find myself uncomfortable when I read a scientific article and am finding it interesting, and then it mentions animal experiments being done or having been done, as part of the research. I am against animal experimentation when it involves forced confinement, mutilation, induced illness and/or death. If it's not right to do certain kinds of research on humans, I feel it isn't right to do it on animals either. Yet I do find some of the results of such experiments fascinating... or rather they seem fascinating before I realize what was involved in gleaning the information; afterwards it merely seems interesting. I'm not against learning things and improving the human condition, but personally I feel we could be doing research and learning without treating animals as our disposable test subjects. We might not learn as much as quickly, using alternative research methods, but I think we would still continue learning.

It's one of those subjects there is no easy solution to. Some people will always, and perhaps rightly so, give human interests priority over other being's interests. Like, would it be right to deny humans access to certain places such as wildlife habitats, if they require it for their own subsistence, even if it ends up resulting in certain species or groups of animals dying out? In some cases, it is us versus them; there is no way of having every being on the planet thrive without having other beings suffer and die. In fact, even being vegan, much of my current existence - the products I buy, the things I use, the places I go - has probably in some way or other come at the expense of other beings' welfare.

(no subject)

Sunday, February 10th, 2008 02:36 pm
darkoshi: (Default)
Ah, :-)
to determine the type of metal something is, you can measure its density... it's weight, and water-displacement.

lead, ~11 grams/milliliter (1 milliliter is also 1 cubic centimter);
copper, ~9 g/ml;
iron/steel, ~8 g/ml;
titanium, ~4.5 g/ml;
aluminum, 2.7 g/ml

My pieces of metal, measured with low accuracy via a letter-scale and glass measuring cup, seem to have a density of about 3 g/ml, so they are probably aluminum!