romunov’s blog et al

Zooxanthellae and their cnidarian (all (little) beasts with stinging cells) hosts live in mutualism, meaning they live in close contact and both reaping benefit from the association.

By defining the group, we must realize that this is a paraphyletic group. Various algae and other organisms have been grouped in this group “for convenience”. The word xanthos is Greek for yellow, you add zoo and with some degree of imagination, you have a working word. This describes the color that is characteristic for some “algae”, the dinoflagellates, from where the soon to be famous Symbiodinium comes from. I will use the term algae from now on, but I realize these are not algae per se.
These algae can be found in various groups of animals. Predominantly in cnidarians (corals, sea anemones, gorgonians…), but also in foraminiferans, radiolarians, ciliates, sponges, bristle worms, flat worms, mollusks (the famous giant Tridacna clams) and tunicates.

Zooxanthellae can get transferred to the host by at least two means – horizontal transfer, where they’re ingested from the water column or vertical, where the zooxanthellae are passed on from parents to their offspring.
Zooxanthellae live inside the host cells in special vacuoles. Exchange of gases and molecules is done by diffusion. Zooxanthellae are exposed to light, which powers their photosynthetic apparatus (made from chlorphyll) and form simple sugars. They pass at least some of these sugars to their host, and, in return, get some of the juicy metabolites that were meant to be thrown away (talk about one man’s garbage…). This is a source of carbon and other nutrients for the zooxanthellae.

Photosynthesis is very important for algae as well for the coral. When photosynthesis is running, major part of calcification of coral skeleton is taking place. The mechanism of calcification is far from certain, and various authors have introduced different models based on their results. A lot of work on transporters across the cells are done pharmacologically by various poisons. A lot of stuff in science is done by disfunction. To put it another way, you kill “something” (usually the target molecules of the poison is known) and see what happens.

Corals can form various pigments to protect their and algal cells from harmful sunlight (think UV light). This results in sometimes breath taking colors on coral reefs. Some pigments can be used for harnessing the light energy at different wavelengths, which gives corals another edge, because it enables them to colonize deeper waters.

When things become unfavorable, a host can expel some (all?) of the algae. This is probably because the algae are more sensitive to damage (by light, for example), and the process of dying forces the coral to dump the algae before they can cause any more damage to their cells. Coral bleaching has become a real problem in the past few decades. Most scientists contribute this “plague” to the elevated sea water temperatures (global warming, El Niño…). Animals losing the algae can recover, but the prognosis for such animals is dire. Dying corals mean direct shift in composition on coral reefs, which can have unforeseeable consequences on local, regional and, eventually, global scale.

Some light reading on this subject can be accessed in Eric Borneman’s book Corals. The author can be reached at MarineDepot forums here.

After my fresh install, I had to face the difficulty of mounting the hard drive that I disconnected just in case so that I don’t format anything “vital”. After turning the hard drive back on, I mounted the drive via System settings, but I couldn’t write to it. So something had to be done. I don’t recall where I got the link (perhaps it was some of the good people from #kubuntu on freenode) or a random google search, but I got this wiki page. I just followed the instructions that applied to my case and voila. I hope it will work on the next reboot as well.

A while back, Martin showed me some of the eye candy that he installed on his work station and the idea seemed interesting. I followed some guide on the internet and all I can say that I wrecked everything. My system was clogged up to the point where I wanted to jump out of the window. (After I got the thing working, I concluded that I used the wrong approach.) I decided to pull the plug and do a fresh install. After the install, I followed the tutorial found at Forlong’s blog and it works pretty nice. I get all the nice effects - wobbly windows, animated windows and many more. I installed emerald, and not compiz-kde/gnome. If you think you have the time and patience to go through the tutorial, give it a go. Chances are that it will work. Some cards are not supported, but he links to that as well, so you can check before you decide to take the plunge.

I imagine most of people out there may not relate to the next quote, but I find it very touching. I would just like to announce in advance that I’m not familiar with Shakespeare’s works - I just like the quote that follows. Thanks to Neddy’s Palaver for citing it for me. If you hop over to his/her page, you’ll notice that it’s a quote from a favorite mini series/book of mine - Band of brothers. It’s a story of men who fought for what they thought is right (or some other cause). Their stories are touching and worth the consideration and thus, your time.

From now until the end of the world, we and it shall be remembered. We few, we Band of Brothers. For he who sheds his blood with me shall be my brother. ~~ William Shakespeare (”King Henry V”)

Blessed thy who understands slovene, for you can see:

Light pollution is light emitted into the sky with no clear target to be illuminated. Some call us “Las Vegas” of Europe. On average, we waste almost 100 kWh/year/person, which is well above that of Europe (this costs us about 10 million euros). It effects animals, traffic safety, us and of course, our wallets.

More information at http://www.temnonebo.org/

As you might have noticed (see below), Katja (my school mate) and I are writing a seminar for a class called Interaction of organisms, a seminar on alga-animal (more specifically zooxanthella-animal) relationship. During my search I’ve come across an article that talks about fatty acids and their role in thermal stress (Berkelmans & van Oppen 2006). A certain paragraph reads like this:

Thermal tolerance among different zooxanthella types is in large part due to thermal stability of the thylakoid lipid membranes of the chloroplasts, with sensitive types having lower concentrations of saturated polyunsaturated fatty acids and greater susceptibility to attack by reactive oxygen molecules which ultimately damages host cells.

Authors basically re-wrote verbatim with, what seems at first sight, no critical thinking. I’m not sure weather or not they’ve contacted the original author, but given that the fact reads the same as in the original, I would wage a guess that they haven’t.

The original work by Tchernov et al. (2004):

“Specifically, thermally tolerant, cultures Symbiodinium clones and zooxanthellae freshly isolated from corals that did not bleach after experimental thermal stress have a markedly lower concentration of the major polyunsaturated fatty acid, (delta)6,9,12,15-cis-octadecatetraenoic acid (18:4), in relation to (delta)9-cis-octadecatetraeonic (18:1) acid, independent of the experimental temperature. The differences in the lipid profile are statistically significant at the 0,001 level (ANOVA). The higher relative concentration of the saturated polyunsaturated fatty acid enhances thermal stability in eukaryotic thylakoid membranes and simultaneously reduces the susceptibility of the membrane lipid to attack by ROS.”

I have contacted the author and he confirmed my suspicion, that what was actually meant was the RATIO between saturated and polyunsaturated fatty acids. Looks like a : or / somehow got left out. I hear it happens (too) often!

Cited works:
Berkelmans, R. van Oppen, M. J. H. 2006. The role of zooxanthellae in the thermal tolerance of corals: a ‘nugget of hope’ for coral reefs in an era of climate change. Proc. R. Soc. B. 273, 2305-2312.

Tchernov, D., Gorbunov, M. Y., de Vargas. C., Narayan Yadav. S., Milligan, A. J., Häggblom, M., Falkowski, P. G. 2004. Membrane lipids of symbiotic algae are diagnostic of sensitivity to thermal bleaching in corals. Proc. Natl. Acad. Sci.. 101, 13531-13535 (doi:10.101073/pnas.0402907101).

I’ve been doing a lot of reading lately. I’m preparing a seminar on zooxanthella-animal symbiosis interactions, and I’ve downloaded (god bless remote access) a great deal of article.
I usually read the whole article, but due to time constraints, I had to abbreviate my task. I chose to cut out Materials and methods and Results, which left me only with Introduction and Discussion. While you may get good info - Introduction for writing ideas and Discussion for actual data - I’ve learned that passing the Results section may have set me back a bit. Especially, if one is searching or re-checking some facts found in another article. Once you’re “into” the business of a certain topic, reading the results, from what I’ve gathered, should give you enough information to set your arguments, latter reinforced in the Discussion section.

Along this work, I’ve found that reviews are not that good source for direct information, especially if you want to do things right. Reading a review is especially frustrating, because almost every information is cited, and you have to check the original article - which takes time, and I don’t have access to them all. I have been thinking of how to get around this, but haven’t found a sensible solution -yet. Keep in mind that I’m writing a <10 page seminar for internal purposes and not publicly available synthesis.
I really started to enjoy short works. Not as much for their brevity but because they usually yield the most information. Jumping to results usually gives you a pretty good idea of what they were doing, what their goal was and of course - the results. If I manage to pursue my publishing career, this is the type of work I’ll be doing, for sure!

Perhaps I need to explain to the reader or two why I haven’ been posting lately. With the school year in full swing, I spend most of my days at school and the work load has been piling daily. At the end of the day, when you come home, there is much to be done and when I run out of energy to work, there’s really little or nothing left to do anything else. I haven’t been following news for quite some time now, which, honestly, irritates me. I have no time to read other blogs and I’m blacked out from the blogosphere. I’m practically in a solitary confinement. I’m also going through a personal crisis which takes the will to live right out of me and slams it against the floor. As such, in the state that I am, the posting have become few in between. Hopefully, when my workload minimizes, hopefully by the end of the year, I’ll be back on track as much as possible. I have a few interesting subject (mostly my seminars) in store and I’ll be able to do a few posts just on that.

The US has been beating the war drums for quite some time against Iran and its alleged nuclear program that no one can prove it exists. With the NIE report coming out, the White House has snagged only a technical obstacle that probably won’t effect any long term plans (that have been drawn up back in the 2000, at least).
It seems only natural, that Iran will take some legal “soft” steps against the, still, verbal aggressor. I don’t know why they didn’t do this sooner. Iran has completely dropped the dollar as the currency in which oil is sold. Saddam tried to drop the dollar and look what happened. Can we expect something similar with Iran? The war machine is already mostly in place. All we need is a catalyzing event and off we go!
If that were to happen, I think we can expect a greater devaluation of the dollar. Be sure that I’ll be buying some cheap books from overseas by then! So, yeah George, keep it up…