jeskill

So I asked why they would add formaldehyde and the answer I was given is that it acts as a preservative. First, my friend says that the brewing standards at Efes are fairly low and the risk of contamination is fairly high. This I believe, because I've noticed that the beer does not always taste the same. Sometimes it tastes OK, other times the finish is really "dirty". (I don't know how else to describe it). Anyways ... formaldehyde is apparently added because contamination occurs frequently. Another reason is because the little shops that sell beer often don't refrigerate it. Instead, they leave the beer out in the sun all day. According to him, the changes in temperature change the beers flavour if there's no preservative. As for why Turkey would allows formaldehyde ... well ... the place is really not a beacon of impartiality. The people who make up the laws regarding what's allowed to be put in beer are the beermakers, namely Efes.

Yeah, but developing countries have been known to do this. For example, this was an issue with Chinese breweries a while back: http://www.cbc.ca/cp/world/050715/w071530.html

Here's the situation: I'm living in Istanbul, and I have a friend who is a brewer at the local microbrewery. He ranted to me once that the major brewery here (Efes Pilsen) adds formaldehyde to their beer, hence the nasty hangovers. I've done some superficial google searches and haven't found any evidence that formaldehyde is actually in the beer, although quite a few people seem to believe this online. So it'd be fun to test the beer. My question: How would one test the beer for formaldehyde in a low-budget way using common household chemicals? I know I can buy kits that'll test for formaldehyde but I thought it'd be more fun to do it the homegrown way. Also, most of the kits I've seen test formaldehyde in the air rather than in liquid. And they involve sending the kit away to a lab, which would be expensive for me. Any ideas???

I thought that the driving forces of microevolution (ie. the processes that drive the change in allele frequencies) are selection, genetic drift, migration and mutations.

Not to be pulling teeth but ... I think that saying something like speciation occurs when species1 --> species2 is inaccurate because it represents the idea of speciation as a linear progression. In this particular PNAS article, I thought they were referring to allopatric speciation, where both populations diverge from each other so that over time, they are reproductively isolated from each other. In other words, it's more like a V, with the original species at the bottom and the two daughter species at the top. This is important because sometimes the daughter species are reproductively isolated from each other, but not from the "original species". For example, those lizard-thingys in California that make a species ring around the state. Anyways, I don't think he's implying that mutation is the driving force behind evolution. I think he's just stating the obvious: you can't have natural selection unless variability already exists in the population. Variability is often caused by mutations in the genetic code.

We tend to see it as: 1) beneficial mutation occurs 2) natural selection acts to increase the proportion of that beneficial mutation within the population Assuming that only one mutation is necessary to cause speciation and that mutation is beneficial to individuals who possess it, then yes, natural selection can only act on the individuals who already possess a mutation.

OK, I'm in the process of reviewing potential Grad study options and I came across various "rotation PhD" programs. For those who haven't heard of this, the first year is spent in various different labs learning different techniques and meeting different profs. Then after the first year, you decide which prof you want to work with and you write up a proposal. So question: Has anyone done a rotation PhD here, or do you know of people who have done this? If so, did you/they like it? Do you/they recommend this type of program? Has anyone heard of rotation PhD programs for Eco/Evo majors? And finally, does anyone know much about the John Innes Centre in Norwich, UK? (i.e., is it difficult to get in, is the program as "prestigious" as they say it is etc) Thanks JES

Time and time again the evidence suggests: moderation is best. Although, is this study really telling us anything new? I would think that most people into sports or dance or any other physical activity know that excessively working out has a negative effect on performance as well as increasing fatigue and injury.

OK, just found a fairly good explanation here: http://courses.washington.edu/biomechs/lect25.pdf

I can't find the reasoning behind the "fourth power law" in my notes, nor a simple enough version of this on the web. This is what I have in my notes: "Fluid flow in animals can occur via diffusion or bulk flow. Diffusion is distance-limited, occurs in the fine capillary networks and has low hydraulic conductivity potential because of the fourth power law" I'm assuming the fourth power law has something to do with the radius of the capillary vs. the radius of a vein or artery. IOW, the reason bulk flow doesn't occur in capillaries is because they're too small. I'm just not sure why it has to be to the fourth power. Can anyone explain?

One other example of that is the sugar in maple tree sap. In the spring, sugars get shuttled into the xylem to increase osmotic potential. Water moves along the gradient into the xylem, the air bubbles that were in the xylem get pulled into solution, then the sugars are used for energy (via respiration) to aid in new leaf growth. This is an example of sugars being used as a) osmotic regulators and then b) energy. Respiration has to occur in this situation because there are no photosynthesizing leaves at this point in time.

As far as I remember (I don't have a textbook handy) one of the end products of photosynthesis is glucose, is it not? Glucose needs to be broken down to make energy -- this can be done very efficiently by mitochondria, which use oxidative phosphorylation to get 30 ATP from one molecule of glucose.

From what I read, the site looks great. I'm unable to participate due to essays and exams and whatnot, but I just wanted to lend my support to this endeavor. Is it kosher if I sign the letter without actually participating the in formation of the letter?

Bascule, you seem to be very knowledgable on this subject. What do you think are the best papers and studies on climate change? (This is open to anyone else who's read something of interest too)

I think this was actually posted by silkworm. That is indeed a silly question. Unfortunately, I think you're probably right on this one. Edit to add this picture: Probably not COMPLETELY on topic, but interesting nonetheless. This was sent to me by my bf. It's a poster from the Turkish Creationist Museum. The blood is a nice touch.

Which specific evidence are you talking about?

Yeah, it's slick, but doesn't give any new insights. It's also innaccurate and misleading. For example, it talks about how "adaptation" can occur within "kinds" due to DNA mutations and natural selection but evolution does not occur. What? Basically, evolution occurs, but it doesn't occur.

Ring species? I must admit I've never heard that term before.