Slashdot Mirror

Most of our conventional crops, including rice and wheat, assimilate atmospheric CO2 by the C3 pathway of photosynthesis, which takes place in the mesophyll cells of leaves. Photosynthetically, these plants are underachievers because, on the one hand, they assimilate atmospheric CO2 into sugars but, on the other hand, part of the potential for sugar production is lost by respiration in daylight, releasing CO2 into the atmosphere, a wasteful process termed photorespiration. This is due to the dual function of the key photosynthetic enzyme, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). High CO2 favors the carboxylase reaction and thus net photosynthesis; whereas high O2 promotes the oxygenase reaction leading to photorespiration. When plants first evolved, photorespiration was not a problem because the atmosphere then was high in CO2 and low in O2. As a byproduct of photosynthesis, O2 accumulated in the atmosphere and reached the present level a million years ago. Current atmospheric CO2 levels limit photosynthesis in C3 plants. Furthermore, photorespiration reduces net carbon gain and productivity of C3 plants by as much as 40%. This renders C3 plants less competitive in certain environments. In contrast, with some modifications in leaf anatomy, some tropical species (e.g., maize and sugarcane) have evolved a biochemical "CO2 pump," the C4 pathway of photosynthesis, to concentrate atmospheric CO2 in the leaf and thus overcome photorespiration. Therefore, C4 plants exhibit many desirable agronomic traits: high rate of photosynthesis, fast growth, and high efficiency in water and mineral use.

...and:

CO2 enrichment can also affect plant communities directly. For many plant species, increased CO2 concentrations lead to increased rates of net photosynthesis and improved water-use efficiency, resulting in larger plants. This effect is greatest in C3 plants and is typically small or negligible in C4 plants. Where plant communities consist of both C3 and C4 species, the different responses of these two groups can lead to changes in plant community composition over time.

Finally, IIRC, most of the biomass is C3 plants.

-- MarkusQ

A bit OT but funny: I once ordered a bunch of Freshettes in the US for the women of our Himalayan expedition. It was blocked at the Italian customs because they considered it "medical equipment". I had to jump through all kind of legal loops to get those little pieces of plastic without being a doctor...

So how do we get power down there ?

Yeah the stations on the high Antarctic plateau may not have too much power requirements but they use mainly diesel generators.

The Americans used a nuclear generator taken from a Sub years ago but they kept having problems with it and it's now been removed because the Antarctic Treaty forbids it.

In summer there's plenty of sun, so solar panels are used, but in winter there's none. In the center of Antarctica there's not too much wind (I studied at Dome C where most winds are 'born' and there's not enough to power a fan. On the other hand, on the coast you get demented winds that will break anything.

The French experimented with a heat transfer system that had it's highest efficiency in cold winds. The colder and faster the better. But it wasn't too conclusive.

And if you just want power for your palmtop, take L91 Lithium Energizer batteries, the only ones that work below -50C...

So how do we get power down there ?

Yeah the stations on the high Antarctic plateau may not have too much power requirements but they use mainly diesel generators.

The Americans used a nuclear generator taken from a Sub years ago but they kept having problems with it and it's now been removed because the Antarctic Treaty forbids it.

In summer there's plenty of sun, so solar panels are used, but in winter there's none. In the center of Antarctica there's not too much wind (I studied at Dome C where most winds are 'born' and there's not enough to power a fan. On the other hand, on the coast you get demented winds that will break anything.

The French experimented with a heat transfer system that had it's highest efficiency in cold winds. The colder and faster the better. But it wasn't too conclusive.

And if you just want power for your palmtop, take L91 Lithium Energizer batteries, the only ones that work below -50C...

University directories, such as those located at Colorado State and CU Boulder, are extremely well organized. The vCard option at CSU is very nice and I know that both of these directories can be plugged in to your favorite mail client and serve as an address book. Are there any University sysadmins reading this who can post more info?

It is a festival that is determined by the lunar calendar.As lunar months are shorter than solar months, the Muslim lunar year is shorter than the western solar year by about 11 days. Ramadan thus occurs about 11 days earlier each year and can thus occur at all times of the year.

When I was in Morocco about 13 years ago, it was in about April. 13 years later year, Ramadan is about 11 x 13 = 143 days earlier, or November-December, which is where it was last year.

http://www.colostate.edu/Orgs/MSA/events/Ramadan.h tml has some basic details.

From Mechanical Metallurgy by George E. Deiter 3rd Ed.

The hardness of a material is a poorly defined term which has many meanings depending upon the experience of the person involved. In general, hardness usually implies a resistance to deformation, and for metals the property is a measure of their resistance to permanent or plastic deformation. To a person concerned with the mechanics of material testing, hardness is most likely to mean the resistance to indentation, and to the design engineer it often means an easily measured and specified quantity which indicated something about the strength and heat treatment of the metal.

After that the chapter briefly discusses how the different tests work, and some light derivation including a special case of finding the tensile strength. (Incidently, this conversation is why I provided a link to Powell's collection of Mechanics of Materials texts; I wanted to avoid it.) A link to convert hardnesses for steel into tensile strength. I might remark that given strength is simply a load over an area for a certain event, and any hardness test also uses a load over a slightly more complicated area (with some other considerations) one might readily and correctly assume they can be related. I might further add, that MY contention that strength and hardness are related is not even addressed in any of your definitions. I feel little need to offer anything in the way of proof, but since you seem to require it, this web site might be illuminating. Also any materials, and most mechanical, engineering departments will have a similar poster in their hardness testing labs.

Don't think me cruel, as I don't intend it in this fashion, but I had noticed the ASM site had a section called "Ask ASM" where you can pose questions, and thought it clearly marked. I suppose you could also write your local physics, mechanical, civil, or materials engineering departments as they almost certainly answer all sorts of questions. They are typically given to grad students to answer in math and physics departments.

I'm sorry you didn't see the value in links that I hoped you would find useful. I tried my best to keep everything simple and accurate, I hoped others would find it interesting. But it would seem you have little if any interest in finding answers, which is fine. But if you're not going to seek illumination beyond that of a poor dictionary, for the life of me I can't see why you quibble with mine. The fact is they created a new phase of steel (I took this as an obvious point from the press release, clearly I was in error). If you still believe they did not, you MUST also believe glass and quartz are the same. Which is your perogative. A new phase is better than simply a new alloy, as their figure of 16 GPa certainly shows. As a final token, here is a Iron-Carbon (Steel) phase diagram, note the lack of an amorphous phase (I realize it is quite busy, but it at least shows what steel fundementally is). In closing, you see what everyone else does, what you want to. Maybe this is what I get for picking nits.

You'd be surprised what just dumping stuff into a cloud can do.

I say we nuke the RIAA from orbit.

It's the only way to be sure.

Much of that growth is reflected in the stat I did find--women are a substantial majority of new users. The same study indicated that the average age of Internet users was also growing, and not in the obviously meaningless way you described. The proportion of adults over 50 who used the net was growing, for example.

I looked again for the study I was thinking of, and did not find it. But I did find a study from 1998 that said, more or less, "this is starting to happen and will happen by 2002." http://www.colostate.edu/Depts/CoopExt/PUBS/OCTNEW S/oc980806.html

Enon

If these guys want to have a serious impact on the platforms in use, they will either have to surf the existing platforms with something like TIBET(tm) or they will have to create a radically new platform that is so much better than anything else that it will seed a new regime of technology. For that, IMNSHO they should team up with the optical associative processing guys at Colorado State, the Mozart guys in Europe and the Postgresql guys before taking off to do yet another BeOS.

http://www.cs.colostate.edu/~dzubera/2600faq.html# newgames

About the time I got my first K6-3D box, and was considering an early Athlon box, I looked into weather simulation programs as a fun thing to run in order to use up all the excess CPU cycles I now had. A number of different packages exist that will produce interesting results, though I don't know how easily they can be made to compile and run on Linux (the problem is finding a good Fortran compiler): NCAR/Pennstate mesoscale model MM5, NCAR Community Climate Model CCM3, and Colorado State RAMS model.

WARNING The prior post pegs the bullshit meter. Please try a balanced site for a more informed view.

I challenge tippergore to cite, with supporting link, a single example of an "extremely harmful" GM prodcut ever making to the food supply. (Yes, there was a problem for some allergy sufferers when a Brazil nut gene was inserted into soybeen, but this was halted while still in research.)

please please educate yourself before lobbying for 2 million children a year to die of B1 deficiency.

yeah, i had thought of it after i had posted. you are correct, i spoke too fast, i'm sorry.

this still seems a contradiction or a clumsy statement at least:

In fact, every true male ant has wings, as well as the queen. This occurs when the ant colony has grown large enough to migrate.

what do you mean by this occurs ? it would be logical if you would refer to every male ant has wings by this. by saying occurs after that you seem to imply that male ants would only have wings if their colony becomes large enough (to migrate), which is not true and seems to contradict what you said in the preceding sentence. but what you are probably refering to with this is the case in which a colony becomes large enough to produce male ants.

btw. afaik being able to migrate is not a condition which needs to be met for male ants to be produced, the colony simply needs to be large enough. also not all male ants have wings
check this page if you like.

let's leave it here ok ? i made some mistakes in the discussion but i thought you presented some of the things you said in a confusing manner and besides, the discussion has gone completely ot.

cheers

Starting a sentence with but.
R. Murray

I always learned that you aren't supposed to start a sentence with 'and' or 'but', but sometimes I want to because it makes sense at the time. Can I break this rule?

Re: Starting a sentence with but.
Nick Carbone

R.

Guess what! You're in luck. In this case, the rule has changed. The prohibition against beginning a sentence with a co-ordinating conjunction--and, or, or but--has been lifted because despite the prohibition, writers quite often did begin sentences with one of the three. And so the new rule now states, according to Sidney Greenbaum in The Oxford English Grammar (1996, Oxford U. Press), "sentences may begin with a co-ordinating conjunction that points back to a previous sentence or set of sentences" (381).

[...]

I'm only pointing this out to you, grammar nazi, because I want you to be the best damn grammar nazi you can be!

Try this one for size:

Gameline was a service offered by Control Video Corporation that admitted the downloading of games to the the 2600 over regular phone lines. The Gameline used a variable 800-2000 baud modem, according to Kevin Horton's Gameline Page. The Gameline Master Module originally sold for $49.95 and there was a one-time membership fee of $15. Charges were about $.10 a game or $1 for up to an hour of play. Contest games were $1 and there was a $.50 charge to enter a score. On your birthday, not only were you given free play for a day, but you also received a Happy Birthday screen, complete with cake, candles and music. Atari 2600 trumps... well... anything else you can throw at it. It's the oldest, man!

Help spread the love! :)
http://www.vis.colostate.edu/~scriven/css/

Are there any single-cell bacteria that have converted themselves into multi-cell versions?

>Depends if you count slime-molds or not; they go back and forth! Your question makes no sense in scientific terms; according to evolution, multi-cellularity only has to arise once, and from there it is "variations on a theme".

slime-molds are not bacteria. They are myxomycota fungi - eukaryotes! they're our close relatives!. For a picture click here

and for more information about taxonomy click here

and scroll to the bottom of the page. The latter is a cool page. You should also be aware that there is considerable controversy about the classifaction of any of these things and that these ones rely upon the use of 18S large-subunit rRNA.

My general point is that nothing in evolution and its study is as certain and as solid as you are making out, and further, that most of the support for evolution comes from molecular genetics, not from the fossil record which can be interpreted in all sorts of ways.

You are being too dogmatic - especially with regard to your horse example. This was one of the most embarrasing examples of "evolution", it was always presented as a succession of smaller to larger through intermediate forms. This linear pattern was seized on by creationists and debunked. Embarrassing and uneccessary, there is no need for regular "trends" in evolution to obtain.

There is controversy here and you are doing rationality and science no favours by trivializing and ignoring objections. Regards, Crush

Supports all Web technologies huh? If you can view this text file in IE, I will give you a doughnut. http://holly.colostate.edu/~je rbaker/misc/readme.doc

While the cost of change can be drastic in any situation, there comes a time when one must decide whether the paying the cost now, is worth it in the longrun. For instance, the deciding to pay the cost to switch over to fibre cable, and not stick with copper, while costly, was the best decision.

Zillions of tests and user-testaments over the years can't be wrong - maybe it is time to switch over to the Dvorak keyboard? Not convinced? Check out the following URLs:

Introducing DVORAK
The Curse of QWERYTY
Mavis Beacon's History of DVORAK


There are similar reasons why the metric systems hasn't been adopted world wide.

While this is slightly off-topic, and i apoligize, i find it worthy to point out that the Metric system has been officially adopted in every country except the U.S.
For more information on the metric system, and how it pertains to the U.S., try : The US Metric Association, and the WSDOT Metrics Page.


.------------ - - -
| big bad mr. frosty
`------------ - - -

The US switched to the Metric system in the year 1866

Here are links to the appropriate legal documents:

Metric Act of 1866 page 1

Metric Act of 1866 page 2

You can get a chronology of the metric system here:

Timeline

Reading academic journals is a good way to get immersed in that ultra-dry writing style.

Even though your school doesn't offer graduate-level programs, your profs had to have taken some at a point in their scholastic history. Find a good one -- as many other people pointed out and I missed, a good advisor is worth their weight in gold -- and look into doing an independent study with them and learning the advanced versions of some topics.

Perhaps if you can find a project on which a professor is working and you can help out, perhaps you'll be able to get to help out on writing the final article, and being published is a great thing when you're applying to grad schools.

Good luck to you, Kurtz!

Sam Jooky
sapienza@holly.colostate.edu

Grad Schools are really competitive, so right now while you have plenty of time left as an undergrad, start improving your chances of getting in. You can do this in lots of ways.

Remember, though, that grad schools really pay attention to letters of references from past professors that show how well you can do work (and possibly research). Meet a professor in your department who is doing research on something you find interesting and offer them your services. Learn a little bit about CS research.

When you get up to senior-status, talk to some professors about taking on a class as a non-teaching TA. Profs and GTAs always appreciate all the help you can offer. TA one of the introductory CS classes with 100 people.

Both of these things will help you get better letters of recommendation, and at the same time, you will get a much better idea of whether or not the grad student life is for you.

Also, when you start to get into the higher-level courses, take some graduate-level courses. Most schools won't let you take the higher-level grad courses, but the introductory ones should be accessible. This will help prepare for the amount of reading and work that your classes will involve in grad school.

If I think of other helpful tips, I'll respond to my message again. :)

Sam Jooky
sapienza@holly.colostate.edu

When you're selecting a grad school don't just put a bunch of school names on a dartboard and throw a dart to choose. Figure out what interests you in CS. Which subfield makes you cream your jeans? AI? Parallel Processing? Computer Graphics? You need to have a semi-narrow choice.

Once you've figured that part out, then start looking at grad schools. Don't go pick a school and then figure out what you want to study. That's a recipe for unhappiness.

Most CS departments list on their webpages which fields they specialize in. Find the profs at the school who teach your interest and email them about the sort of program of study they offer.

And don't forget to use the profs at your current school. They're in the field and can probably point you in a good direction for a good school, and if not, they're in a better position than you to find out where the best [insert your interest here] school is located.

Talk to the grad students at your school, too. They've been through this process before and can probably offer you good advice.

In short, don't just jump into a CS grad program because you like the school -- make sure they'll teach you what you want to learn.

And if you're interested in AI, Software Engineering or Parallel and Distributed Computation, come out to Colorado State University! :)

Hope this was semi-helpful and not totally redundant.

Sam Jooky

Of course, these are a hell of a lot more dangerous than Super Soakers, and even more dangerous than paintball guns. But they're great fun if you don't hurt living creatures with them! :)

Shameless plug: My mini-spudgun page

I've got a really small version that would work wonders in a food fight, too... It goes "poot" when it fires. :)