A Terrible Life Choice

I saw this on The Simpsons a long time ago. Talk about hitting the nail on the head! LOL.

On Thin Ice

When it comes to charismatic megafauna, polar bears are right up there in terms of cute stuff people like to like. Lately they have also been the poster-bear against climate change. That makes sense, considering that polar bears (Ursus maritimus) occur only in the Northern Hemisphere and are dependent on sea ice for access to their marine mammal prey, mainly seals. Declines in summer sea ice have been associated with declining physical stature, declining physical condition, poorer survival rates, and declining population sizes for these bears. This sea ice decline has been linked to these declines.

A new paper this week in Nature uses projections of twenty-first century global mean surface air temperature (GMAT) and data from the Community Climate System Model (CCSM3) to test the hypothesis that a tipping point will lead to irreversible loss of seasonal ice habitat as GMAT increases. Basically, that there are some elements/variables within a system that, when changed enough, cause habitats that support cold-dependent species to disappear abruptly and irreversibly. Namely when a particular GMAT is exceeded.
 
In a nutshell, they tested whether mitigating the rise in greenhouse gases could improve the outlook for polar bears.
 
Now, a USGS study in 2007 concluded that two-thirds of the world's polar bears could disappear by 2050 if atmospheric temperatures continue to increase due to greenhouse gases. Their model was a general circulation model (GCM) that projected losses of Arctic sea ice based on the Special Report on Emissions Scenarios (SRES) and a "business as usual" greenhouse gas emissions scenario, where emissions continue to increase and the carbon dioxide concentration reaches 689 parts per million (ppm) by the end of the century. However, they did not consider the possible benefits of greenhouse gas mitigation. Think about that in terms of tipping points. If you mitigate too little and/or too late then you get no conservation benefits for polar bears as their ice would already be gone. If you mitigate more and/or soon enough then you save the ice and the bears. That's the thought anyway. So the researchers modeled 5 different scenarios that ranged from "business as usual" all the way to aggressive cuts that reduce carbon dioxide concentrations to 368 ppm, those seen in the year 2000.
 
The study concludes that mitigating the rise in greenhouse gases will result in substantially more sea ice habitat being retained. The business-as-usual-model shows a 50% loss of sea ice by 2050 whereas the aggressive-mitigation-model shows only a 20% loss. They also show that this habitat retention, in turn, will allow polar bears to persist throughout the century in greater numbers and in more areas. The business-as-usual-model shows a 50-80% chance of polar bears disappearing from these habitats whereas the aggressive-mitigation-model shows only a 25-50% chance. However, the models did not give the thresholds or tipping point values that will lead to irreversible ice loss. They found that sea ice will decline at a steady rate as global mean annual temperature rises.
 
The paper also addresses positive feedback in this system. Its all about albedo, or how strongly a surface reflects light. Its really a quite logical scenario. Ice reflects light very well, warmer temperatures cause ice to melt, retreating ice means less reflective surface, retreating ice also means more exposed water, the darker water absorbs more sunlight, more absorbed light increases temperatures, increased temperatures melt more ice. And so on and so on. In this paper they test models that might counter this feedback mechanism. They specifically refer to rapid ice-loss events (RILEs). These rapid freezes result from going from open water to cold conditions reappearing in the Fall, and these compensate for the effects that are working to provide the potential tipping points.
 
Polar bears are not out of the woods yet. After all, we are still running the business-as-usual-model. And, in the past, models predicting sea ice loss have fallen short. But this paper shows us some good news, that with proper mitigation we can potentially slow down the decline.
 
Here's the paper:
Amstrup, Steven C. et al. (2010) Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence. Nature: 468, 955-958. (DOI: 10.1038/nature09653)

Additionally, I suggest reading this paper on polar bear and grizzly hybridization:
Kelly, Brendan P., Andrew Whiteley, and David Tallmon (2010) The Arctic Melting Pot. Nature: 468, 891. (DOI:  10.1038/468891a)
 
Story links:
http://news.sciencemag.org/sciencenow/2010/12/how-to-save-polar-bears.html
http://www.nature.com/news/2010/101215/full/news.2010.675.html
http://www.bbc.co.uk/news/science-environment-11986236
http://www.guardian.co.uk/environment/2010/dec/15/polar-bears-arctic-emissions
http://www.nytimes.com/gwire/2010/12/15/15greenwire-no-tipping-point-for-sea-ice-in-polar-bears-fu-29018.html
 
(image from metro.co.uk)

Rapping, Ecology Style

I don't know about you, but that's how I measure DBH.

Footprints in the Sand

This story is about tracks, specifically dinosaur tracks. Footprints can be very informative, giving so much more information than just the shape of the foot. They provide information on species, body posture, locomotor ability, sociality, preferential environments, and stratigraphic and geographic faunal diversity.

As you might guess, it isn't always easy to identify fossilized dinosaur tracks. Sure, some species are easier than others like sauropods, stegosaurs, and ceratopsians. The difficulty arises in distinguishing bipedal theropods (carnivores walking on two legs) and ornithopod dinosaurs ("bird-hipped" dinos, grazers walking/running on two legs). You can see how they might look pretty similar.

A new, in press, paper in Cretaceous Research takes a look at the Dinosaur Stampede National Monument at Lake Quarry Conservation Park in central-western Queensland, Australia. This monument contains thousands of fossilized footprints of dozens of dinosaurs from the mid-Cretaceous. Since the 1970's, the popular hypothesis regarding this area is that an Allosaurus-sized dinosaur chased a mixed herd of small-bodied dinosaurs, causing a stampede. Previous studies have identified this "predatory protagonist" as a large tridactyl (three-toed) dinosaur, a theropod (likely a Tyrannosauropus). This particular taxon has a bit of a checkered history, scientists have argued about it since the early 1920's. It has also been proposed that the tracks on the monument are attributable to a hadrosaurid ornithopod (a duck-billed dinosaur that walked on two legs).

Figure 1. The Winton Formation at Lark Quarry.

These authors applied a multivariate analysis to discriminate between theropod and ornithopod tracks in order to identify the track maker. Multivariate analysis allows you to analyze more than one statistical variable at a time and therefore you are able to test multiple dimensions while taking into account several variables. Why mention the statistical test used? Some people like statistics. No really, I mentioned it because this is the first time that multivariate analysis has been used to identify tracks on this valuable piece of biological history. To perform this analysis the researchers measured all of the tracks using published line drawings, catalogued photographs, latex peels, museum casts, and actually measured the real ones themselves. The variables for the analysis included track length and width, total digit lengths, basal digit length and width, middle digit widths, and the distance from heal to the interdigital (hypex) point.

The results showed that a majority of these measurements fell within the threshold expected for ornithopod dinosaurs. In fact, the authors conclude that of the known types of theropods from this region, none of the body fossils adequately match the measurements and analyses that they did.

So what type of ornithopod was the track maker? Well, the footprints are slightly longer than they are wide, they have symmetrical toes, have claws, and have a V-shaped central digit. Of the known large Cretaceous ornithopods, previous studies have concluded that it could be either Ambyldactylus, Caririchnium or Iguanodonipus. Of these, only the iguanodontian dinosaur, Amblydactylus, shares the distinctive features exhibited in the Lark Quarry tracks. The tracks are remarkably similar to ornithopod tracks from Canada named Amblydactylus gethingi and so the authors suggest re-naming the Lark Quarry tracks Amblydactlyus cf. A. gethingi. In all likelihood, the footprints were made by a large ornithopod standing approximately 2.5 meters tall at the hips, likely a more primitive member of the group, probably similar to Muttaburrasaurus langdoni. This species specifically because it has been found in similarly aged rocks only a few hundred kilometers from Lark Quarry. The stampede of the smaller dinosaurs also represented in these rocks was probably due to the approach of this larger dinosaur. A large herbivore spooking a group of smaller dinosaurs is not exactly as exciting as a predator chasing them down but, in this case, is more accurate.

The authors state that if this identification is correct then it removes any published evidence that a large theropod dinosaur existed in the Australian Cretaceous. However, I do recall posting an article about a new theropod discovered in Australia from 110 million years ago - which I'm pretty sure is the Cretaceous period (144 to 65 million years ago?) - so I'm not sure about this wiping out all evidence thing. Just sayin'.

This is the paper:
Romilio, Anthony and Steven W. Salisbury (2010). A reassessment of large theropod dinosaur tracks from the mid-Cretaceous (late Albian-Cenomanian) Winton Formation of Lark Quarry, central-western Queensland, Australia: A case for mistaken identity. Cretaceous Research: in press. (DOI: 10.1016/j.cretres.2010.11.003)

And here's some more reading material on the subject:
http://www.uq.edu.au/news/?article=22416
http://www.smh.com.au/world/science/giant-vegetarian-set-off-dinosaur-stampede-20101217-190qn.html
http://www.uq.edu.au/news/index.html?article=21805
http://www.uq.edu.au/dinosaurs/

Body by Google

Google. Love Google. It does so much, including powering this blog. They are known for their great mapping technologies such as Google Earth. Now they tackle a new mapping challenge: The human body. Last Thursday marked the release of Body Browser.

Body Browser uses 3D graphics application programming interface WebGL running within a browser to create a three-dimensional model that allows users to zoom in and out of the human body, remove layers, and generally explore. It is searchable and clickable, giving all sorts of info on how the body is put together.

Body Browser doesn't require Java or Flash, but you will need a browser that supports WebGL. Google recommends using the most recent version of Chrome, but Safari and Firefox/4.0b1 work as well. Body Browser is still in beta and has not been officially released, but users are able to try it out and report problems and bugs. So keep an eye out for this program to become fully operational.

Enjoy!

Here's the Body Browser site: http://bodybrowser.googlelabs.com/

http://www.informationweek.com/news/storage/virtualization/showArticle.jhtml?articleID=228800812&cid=RSSfeed_IWK_All#

http://www.pcmag.com/article2/0,2817,2374438,00.asp

http://www.pcmag.com/article2/0,2817,2374462,00.asp

http://healthland.time.com/2010/12/17/google-takes-a-peek-inside-your-body/

http://blog.chromium.org/2010/12/chrome-is-ready-for-business.html

A Year in Reviews

 No kidding, three people sent this one to me today. I can see why. It's fantastic. It's a review of peer reviews. Here are a few of my favorites:

• Alfachetoglutarate
• Season's Greetings! I apologise for my slow response but a roast goose prevented me from answering emails for a few days.
•  I started to review this but could not get much past the abstract.
• I suppose that I should be happy that I don't have to spend a lot of time reviewing this dreadful paper; however I am depressed that people are performing such bad science.
•  I feel like a curmudgeon, but I still have problems with this paper.
• Preliminary and intriguing results that should be published elsewhere.
• Reject – More holes than my grandad's string vest!

Read the complete list here:
Referees' quotes - 2010. (2010) Environmental Microbiology: 12(12), 3303-3304. (DOI: 10.1111/j.1462-2920.2010.02394.x) or click HERE

Having so thoroughly enjoyed this list I looked to see if there were any more. As it turns out the same journal publishes this type of list annually. I freely admit that I like the negative reviews best, you gotta admit they are the funniest. Here are a few of my favorites from years past, and at the end is the references/links so you can read the complete lists.

From 2009:

• Some self citations may be easily taken out without harming the paper.
• The peaceful atmosphere between Christmas and New Year was transiently disrupted by reading this manuscript.
• Ribosomes do not contain DNA.
• Page 3, line 28 –‘arqueobacteria’?
• I am afraid this current version looks too much like another manuscript saying ‘gee whiz we looked in a strange place and found some new microbes’.
• The writing style is flowery and has an air of Oscar Wilde about it.
• The trees are crap but, besides this, excellent work.

From 2008:

• Mouldy bread. Unfortunately there are too many technical flaws in this one. Too bad because the potential was high.
• Great organism. Great scientists. Terrible manuscript.
• I am fed up with people ignoring totally the instructions for authors.
• The Abstract describes results that I could not find in the Results section.
• I wonder if you and I do not have better things to do than help people who can't help themselves.
• They were not the first to have done this, but they don't seem to know that.
• I have found this ms. boring to death.
• ‘Hijacked’ is a very dramatic word; maybe the bacteria are more polite with their biosynthesis.
• Page X, line Y claims both ‘rare’ and ‘unusual.’ Madonna and Tony Blair might use both in the same sentence.

From 2007:

• I felt like I was teaching my grandmother to suck eggs. Accept with minor revision.
• The paper is full of wild speculation linked by a few random experiments.
• A bad paper containing a good idea.
• Hundreds of commas are missing!
• A highly relevant, beautifully and concisely written cross-disciplinary report that unfortunately comes with a dull abstract.
• Use of the term remarkably borders on dramatization.
• For this crucial initial step, authors behaved like a cook who is in charge of preparing an ‘haute cuisine’ meal for the 40th wedding anniversary for 100 guests and consults the first cookbook for kiddies to get some idea.
• I nearly said reject. But then I recalled that I have a hangover and I am feeling grumpy.

 From 2006:

• I have taken out my earlier comment that the authors retake Chemistry 101, that is probably not allowable.
• The authors assume. . . . All assumptions are wrong.
• The authors need to remember that adverbs in English tend to end in -ly.
• The work is basically sound but unfortunately the presentation is a bit of a dog's breakfast.
• This is an essentially unreadable paper sent to the wrong journal.
• Fig. 1a looks a bit hand-drawn, 1b has more axes than display area.
• There is no apparent study concept other than ‘we went out to the campus pond one day and took 2 samples for sequencing’.

From 2005:

• This is depressing! So much work with so little science.
• They have no clue what they write about.
• The authors are quite creative in using different statistical approaches.
• This paper is the very expression of what happens when one tries to chop up one piece of work into as many publications as possible.
• Why don’t the percentages . . . add up to 100%?
• Almost all references used by the authors are from the last century.

Since I'm only posting a subset of each list I went ahead and looked at 5 years. There are more, and they get addictive once you start reading. So if you like them then look up some more, they are always published in the last issue of December. Have fun!

Referees' quotes - 2009. (2009) Environmental Microbiology: 11(12), 3309-3310. (DOI: 10.1111/j.1462-2920.2009.02120.x) or click HERE

Referees' quotes - 2008. (2008) Environmental Microbiology: 10(12), 3425-3426. (DOI: 10.1111/j.1462-2920.2008.01813.x) or click HERE

Referees' quotes - 2007. (2007) Environmental Microbiology: 9(12), 3153-3154.(DOI: 10.1111/j.1462-2920.2007.01484.x) or click HERE

Referees' quotes - 2006. (2006) Environmental Microbiology: 8(12), 2233-2234. (DOI: 10.1111/j.1462-2920.2006.01157.x) or click HERE

Referees' quotes - 2006. (2005) Environmental Microbiology: 7(12), 2036. (DOI: 10.1111/j.1462-2920.2005.00953.x) or click HERE

(image from cellbiochem.ca)

And We Have Liftoff!

This video is really long, but at the same time really interesting. It is a narrated video from NASA showing the best of the ground-based Space Shuttle motion imagery from STS-114, STS-117, and STS-124 missions. Such imagery is taken during each mission in order to visually identify off-nominal events and conditions requiring corrective action to ensure mission safety and success. So celebrate 30 years of the Space Shuttle Program by learning a little more about the Space Shuttle Program.