Tag Archive | "Nature"


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Researchers Discover That European Starlings Flocking Patterns Behave Like Metals Being Magnetized

Posted on 15 March 2012 by admin


From FeelGuide.com

Scientists have long been captivated by the ability of large groups of animals to move in swift unison with one another — large schools of fish and flocks of birds to be most specific.  Now, sildenafil new research set to be published in the Proceedings of the National Academy of Sciences reveals a mindblowing discovery made by a European research team which studied the spectacular flocking abilities of European starlings.  As reported by Physorg, “The team noticed that some of the starlings’ abilities might be mathematically defined, and that the ability of the birds to change directions almost simultaneously follows the same model as metal when it becomes magnetized.”  The same research team had previously discovered that if just one single bird changed its speed, the change would propagate out to every other bird.  In their latest research they focused on orientation (i.e. how individual movements of birds in the flock caused changes in the direction of the flock as a whole.  Multiple cameras were set up around Rome, where starling flocks are legendary.  Both video and stereometric stills were taken in order to produce 3D imagery of the flock.  Two subsequent discoveries were made: 1) a change in path by one bird impacts precisely 7 birds surrounding it (regardless of the flock’s size), and 2) “changes in  for the flock as a whole happens very similarly to the way single electron spins within a metal line up when a  is created.”  To find out the fascinating implications of these discoveries be sure to visit Physorg.com



From PhysOrg.com

(PhysOrg.com) — Scientists and amateur enthusiasts alike have long been fascinated by the abilities of some groups of animals to move in lockstep with one another, most specifically with schools of fish and flocks of birds. Now, new research by a team of researchers studying the flocking abilities of European starlings has shown that some of their abilities might be mathematically defined, and that the ability of the birds to change directions almost simultaneously follows the same model as metal when it becomes magnetized. The team is set to publish the results of their study in the Proceedings of the National Academy of Sciences.

Prior research by the same team regarding the of the birds in a showed that if just a single bird changed its speed, that change would propagate out to all the other birds in the flock. In this new research, the team focused on orientation. They wanted to know how individual movements of birds in the flock caused changes in the direction of the flock as a whole.

To find out, they set up multiple cameras around Rome, where the huge size of starling flocks is legendary. They took both video and stereometric stills which produce 3D imagery to allow them to capture the positions of birds in a flock as well as to project where they were going and how fast.

In so doing, they discovered two things. The first is that a change in path by one bird impacts exactly seven birds surrounding it, regardless of the size of the flock. The second is that changes in for the flock as a whole happens very similarly to the way single electron spins within a metal line up when a is created.

The first finding demonstrates that birds having neighbors is what is important to the flock, not how close they are. The seven birds that are impacted by the movement of one bird, then cause a change in the seven birds around each of them and so on until the entire flock has changed its alignment.

The second finding demonstrates that at least some of the ways birds move in a flock can be defined mathematically, which means other models may be found as well. If so, they may lead to predicting how a flock will respond in various scenarios, which when combined with the way the birds impact their neighbors, may finally solve the age old mystery of how they fly in flocks the way they do.

More information: The study will be published in PNAS at DOI:10.1073/pnas.1118633109 (not available at this moment yet).

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Cloning and resurrecting the mammoth? Not so fast

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Cloning and resurrecting the mammoth? Not so fast

Posted on 14 March 2012 by admin


From ArsTechnica.com

Two teams of researchers have apparently gone on record as saying they plan on cloning the mammoth. In 2008, levitra when the mammoth genome was announced in the journal Nature, we took at look at that possibility, and concluded it wouldn’t work. Given the recent press attention, we thought we’d rerun an updated version of the relevant section from our original report.

Given that the genome is often called the blueprint for an organism, Nature took the liberty of commissioning an evaluation of what it would take to rebuild the mammoth using that blueprint. The challenge is enormous: each one of the mammoth’s chromosomes are likely to be over 100 million base pairs long; the average surviving fragment of DNA we’ve obtained from mammoth remains is under 200 bases long.

That means the sort of cloning technique that we use on currently living mammals wouldn’t work, since it relies on a genome that’s largely intact. The cloned cells can undoubtedly repair some DNA damage, but nothing like the scrambled fragments we have from mammoths. There’s always the chance that some mammoth remains contain larger fragments of DNA, but basic chemistry indicates that we’re unlikely to ever find anything close to an intact chromosome.

So the piece suggests starting from scratch, using a process similar to the one that constructed the first artificial genome. Unfortunately, that bacterial genome is about three orders of magnitude smaller than a single mammoth chromosome, and the techniques used are simply unlikely to scale. Mammoths also had dozens of chromosomes, and we’d need to get two copies of each into a single cell, safely encapsulated in a nucleus. We’ve only got techniques that work for some of this, and we’ve never tried any of the ones that work on a task approaching this scale.

Assuming we have two full sets of mammoth chromosomes together in a single nucleus, advances in stem cell research suggest we could reset them to an embryonic stem cell state using molecular tools. Unfortunately, we still don’t know how to get these stem cells to develop into adult organisms without implanting them into a viable egg or embryo. That would mean we’d need the embryo of a closely related species to work with.

It would obviously be best to do this with elephants (as the teams of researchers have realized), both as egg donors and surrogates. But, apparently thanks to an aquatic lifestyle in the elephant’s evolutionary past, they have a baroque reproductive tract and an internal organ arrangement that makes laparoscopy to harvest eggs a non-starter. So, the elephant represents yet another technical hurdle.

There are a host of other issues that are relatively minor in scale—we’d need a Y chromosome and sequence from enough individuals to create a diverse breeding population—but resurrecting the mammoth faces some technological obstacles that we haven’t yet even started to try to overcome. A more likely solution, Natureconcludes, would be to identify the regions of the genome that have diverged most significantly between elephants and mammoths, and engineer the mammoth equivalent back into an elephant’s DNA. Depending how well we can identify these, the mammophant that we produce may be at least physically indistinguishable from artists’ renderings we’re all familiar with.

Overall, Nature’s analysis is pretty persuasive. Given the technology we have now, it’s tough to imagine putting a mammoth together, even given the complete genome sequence.

But it’s difficult to predict how technology advances will proceed. The article quotes one of the researchers who lead the efforts to sequence the Neanderthal and Denisovan genomes, Svante Paabo, as saying he doesn’t expect to see anything more than a mammophant in his lifetime. Of course, Paabo’s in his 50s, and I’d imagine that, in his 20s, he wouldn’t have expected to see a Neanderthal genome completed in his lifetime. He has done just that.

Nature, 2008. DOI: 10.1038/456310a

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January 2022