Domain: doi.org
Stories and comments across the archive that link to doi.org.
Comments · 315
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Re:Math Fail
Of course, as the authors of the original article (probably login required) themselves admit, the confidence intervals are very wide. This is inevitable for a sample of only 12 individuals. However it indicates, that mutation rate is about 12/10149085=0.000001 (rounded at first non-zero digit).
I would expect mutation rate to be somehow adapted to changes in the environment. But this rate does seem very low. It translates to very long timescales of change.
I think a mutuation rate this low, gives more force to arguments for genetic engineering.
Interestingly, in genetic algorithms, it seems from a recent review that people usually use mutation rates much higher at the orders of 0.01 or 0.001. -
Nothing new
Saw a talk on this last year from some guys at Southampton who'd already done it: http://dx.doi.org/10.1016/j.biosystems.2006.09.016 Zauner is on a Microsoft Research fellowship though, so no doubt Slashdotters won't like it
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Relation to UCLA work from the 1970s
How is this different from what Walker, Kemmerer and Popek did in the 1970s with the UCLA Unix security kernel? See their 1980 paper.
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Really the first? ... historical-pedantry-dept.
See a lot of these "first" medical procedures usually originating in some press release from a clinic specialising in that particular area of treatment -- and wanting to promote their groundbreaking techniques. But are they the first?
At BMJ Case Reports we published a case of a web-connected implantable cardioverter defibrillator detecting digoxin toxicity a few months ago. An implantable cardioverter defibrillator is not a pacemaker of course but usually includes a quite sophisticated one along with the ability to do the DC shock.
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Link to caDNAno software
The research team that produced the paper in Science paper (link (subscription required to see more than the abstract)) described in the science daily writeup also published a paper in Nature (link) that more fully describes their method of creating three dimensional objects out of DNA (the newest paper expands these methods to construct more complicated objects with more precise curvature). Furthermore, they have published the open-source software that they used to design the DNA nanostructures (http://cadnano.org/). I was at a talk by the lead author of the Nature paper who said that, using their software, a high school student was able to design one of the structures they used in the paper as a summer project.
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Link to caDNAno software
The research team that produced the paper in Science paper (link (subscription required to see more than the abstract)) described in the science daily writeup also published a paper in Nature (link) that more fully describes their method of creating three dimensional objects out of DNA (the newest paper expands these methods to construct more complicated objects with more precise curvature). Furthermore, they have published the open-source software that they used to design the DNA nanostructures (http://cadnano.org/). I was at a talk by the lead author of the Nature paper who said that, using their software, a high school student was able to design one of the structures they used in the paper as a summer project.
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Re:Why?
The insulin molecule has two patches on its surface that are predominantly hydrophobic (water-hating) that likely help it to stick to the pure-carbon surface of (nano)diamond. The "nano" bit just insures there is a large amount of surface area for insulin to stick to per unit mass of diamond. The investigators only showed that their nanodiamonds can suck up a lot of insulin; they are far from proving their insulin-loaded nanodiamonds are useful for wound-healing. The investigators only speculate that insulin would act as a growth hormone (generally thought to be its minor function; the major function being the transsystem signal for organism-wide glucose homeostasis). They point out the pH in a typical wound could approach 10.5, which would facilitate insulin release from nanodiamonds. (Such increases in alkalinity in beta cells, the pacreatic cells that produce insulin, are thought to trigger its release.) Unfortunately, it might also compromise insulin's ability to dock with its receptor, a necessary requirement for its function (either as a growth hormone or in glucose regulation). Directly injecting insulin into wounds speeds healing (sometimes by 50%) (Zhang et al, J. Surg. Res. 142:90 (2007) link), so it seems like the investigators have a plausible path to follow.
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Re: Mosaic
My understanding of the article was that they sequenced DNA -- both strands -- not the RNA. But for reasons I don't understand, Schweitzer said it might be the consequences of RNA editing, to the messenger RNA.
From the paper published in the journal Human Genetics (subscription required), the authors sequenced the mRNA from aortic tissue and genomic DNA from the blood of individuals. To sequence mRNA, researchers must first extract the mRNA from cells and convert the mRNA into a DNA sequence (called complementary DNA or cDNA) using the enzyme Reverse Transcriptase. The reason why we do this is because DNA is much more stable than RNA (our bodies contain many enzymes that rapidly degrade RNA. These enzymes are secreted from our skin, so if you literaly touch an RNA sample it begins to degrade. I know because I work with RNA and it is a pain). Furthermore, sequencing procedures are optimized for sequencing DNA strands, not RNA strands. So, when the article refers to sequencing cDNA, it really means sequencing mRNA (indirectly).
Because the authors of the study looked only at the mRNA from the aortic tissue, they cannot exclude the possibility that the mutations in the mRNA arose from RNA editing, and not somatic mutation. It seems like it would have been fairly simple to sequence the genomic DNA from the aortic tissue, and I'm curious as to why the authors did not perform these analyses (perhaps they knew that other groups had made similar findings and wanted to rush the paper out before others could publish?).
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Original article
For those who are interested, the original article is published in Human Mutation journal, and can be found here: DOI It requires access to the journal to read beyond the abstract.
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Full article in Nature
http://dx.doi.org/10.1038/nature08134
Couldn't find anything in TFA or at ETH's website. Luckily, it was in a journal who's RSS feed I subscribe to! -
Re:Great news!I don't think the pillars are acting as antennas in the way you're thinking. It's simpler than that. The pillars are just providing a higher surface area of interface between the light-absorbing material and the conducting material, and creating a shorter path for the electron-hole-pairs (EHP) to reach their respective conducting materials. Basically one of the main limitations in photovoltaics of this type is the short lifetime of the EHP before it recombines... having the pillars penetrate into the absorbing layers means the EHP have a shorter path to travel. From the paper:
Conventional thin-film photovoltaics rely on the optical generation and separation of electron-hole pairs (EHPs) with an internal electric field, as shown in Fig. 1a. Among different factors, the absorption efficiency of the material and the minority carrier lifetime often determine the energy conversion efficiency15. In this regard, simulation studies have previously shown the advantages of three-dimensional (3D) cell structures, such as those using coaxially doped vertical nanopillar arrays, in improving the photocarrier separation and collection by orthogonalizing the direction of light absorption and EHPs separation (Fig. 1b)16.
Later in the paper they discuss the light-absorbing properties of these kinds of pillar arrays:
In addition, 3D nanopillar or nanowire arrays, similar to the ones used in this work, have been demonstrated in the past to exhibit unique optical absorption properties13,18. Similarly, we have observed reduced reflectivity from CdS nanopillar arrays especially when the inter-pillar distance is small (see Supplementary Fig. S6). This observation suggests that 3D nanopillar-based cell modules can potentially improve the light absorption while enhancing the carrier collection.
References 13,18 are:
L. Tsakalakos, J. Balch, J. Fronheiser, B. A. Korevaar, O. Sulima and J. Rand "Silicon nanowire solar cells". Appl. Phys. Lett. 91, 233117 (2007). doi 10.1063/1.2821113
Hu, L. and Chen, G. "Analysis of optical absorption in silicon nanowire arrays for photovoltaic applications". Nano Lett. 7, 3249-3252 (2007). doi 10.1021/nl071018b
Quoting from that second paper:We found that, in comparison to thin films, nanowire array based solar cells have an intrinsic antireflection effect that increases absorption in short wavelength range.
Essentially the nanowire arrays are acting as anti-reflection coatings and allowing the light to instead be absorbed.
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Re:Great news!I don't think the pillars are acting as antennas in the way you're thinking. It's simpler than that. The pillars are just providing a higher surface area of interface between the light-absorbing material and the conducting material, and creating a shorter path for the electron-hole-pairs (EHP) to reach their respective conducting materials. Basically one of the main limitations in photovoltaics of this type is the short lifetime of the EHP before it recombines... having the pillars penetrate into the absorbing layers means the EHP have a shorter path to travel. From the paper:
Conventional thin-film photovoltaics rely on the optical generation and separation of electron-hole pairs (EHPs) with an internal electric field, as shown in Fig. 1a. Among different factors, the absorption efficiency of the material and the minority carrier lifetime often determine the energy conversion efficiency15. In this regard, simulation studies have previously shown the advantages of three-dimensional (3D) cell structures, such as those using coaxially doped vertical nanopillar arrays, in improving the photocarrier separation and collection by orthogonalizing the direction of light absorption and EHPs separation (Fig. 1b)16.
Later in the paper they discuss the light-absorbing properties of these kinds of pillar arrays:
In addition, 3D nanopillar or nanowire arrays, similar to the ones used in this work, have been demonstrated in the past to exhibit unique optical absorption properties13,18. Similarly, we have observed reduced reflectivity from CdS nanopillar arrays especially when the inter-pillar distance is small (see Supplementary Fig. S6). This observation suggests that 3D nanopillar-based cell modules can potentially improve the light absorption while enhancing the carrier collection.
References 13,18 are:
L. Tsakalakos, J. Balch, J. Fronheiser, B. A. Korevaar, O. Sulima and J. Rand "Silicon nanowire solar cells". Appl. Phys. Lett. 91, 233117 (2007). doi 10.1063/1.2821113
Hu, L. and Chen, G. "Analysis of optical absorption in silicon nanowire arrays for photovoltaic applications". Nano Lett. 7, 3249-3252 (2007). doi 10.1021/nl071018b
Quoting from that second paper:We found that, in comparison to thin films, nanowire array based solar cells have an intrinsic antireflection effect that increases absorption in short wavelength range.
Essentially the nanowire arrays are acting as anti-reflection coatings and allowing the light to instead be absorbed.
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Re:Great news!
For those with access, here's the actual paper:
Fan, Zhiyong, Haleh Razavi, Jae-won Do, Aimee Moriwaki, Onur Ergen, Yu-Lun Chueh, Paul W. Leu, et al. "Three-dimensional nanopillar-array photovoltaics on low-cost and flexible substrates." Nature Materials advanced online publication (July 5, 2009). http://dx.doi.org/10.1038/nmat2493.
One of the cool things is that this new process results in a flexible photovoltaic. In the paper they show that efficiency is maintained even after repeated bending of the material. Even if the energy collection efficiency is lower than conventional silicon photovoltaics, there are tons of applications for flexible photovoltaics, like having tents coated in the material (both for things like camping, but could also be hugely useful for the military, for temporary tents for disaster relief, and so on...), clothing that generates power, and so on... (Maybe even fanciful things like kites that collect solar and wind power?)
It's not a commercial device yet (and oftentimes these kinds of lab devices just don't scale to mass production that well), but it's an encouraging step towards more robust solar cells, which would aid in the more widespread deployments of solar energy. -
Re:LaTeX
Although I agree with you in that LaTeX is widely used in the scientific community, and unambiguously offers the best typesetting facilities you'll find outside of a publishing house, is it still appropriate today?
The internet as we know it was created at CERN to facilitate the sharing of scientific information. Why are we still publishing in a format designed to be presented on dead trees?
Like it or not, a properly-formatted print article looks horrible on a screen. An article formatted for printing on A4 or Letter-sized paper will use the whole width of the page, be set in 10-point type, and use columns. Unfortunately, modern computer screens don't have nearly enough resolution to display the full width of the page alongside much else. Obviously, PDF files also don't have the ability to flow to fit the width of the screen.
LaTeX also doesn't give you the benefit of hypertext. Yes, there are various hacks you can use to add anchors and links to PDFs, although these are mere hacks on top of a broken format. Things such as high-resolution figures and hyperlinked references would be particularly beneficial for academic uses. It'd also be great to be able to see all articles linking back to what you happen to be reading. (This brings up all sorts of questions about the very nature of scientific publishing, although this is another debate entirely)
Wikipedia (more specifically, MediaWiki) actually offers a promising solution to these (and the original poster's) requirements. It provides a convenient and simplistic markup for multi-sectioned articles, flows to fit the width of the page, and also provides LaTeX's fantastic mathematical typesetting facilities. Hyperlinking to other parts of the Wiki (and to external sites) is excessively easy. I'm sure the DOI system could be integrated to allow linking back to other articles within the constraints of the existing academic publishing regime.
Google could very easily provide the "glue" to hold such a system together, although it would ultimately be better to put a public, non-profit entity in charge. It's absurd and hypocritical that so much of academic research (particularly the publishing part of it) is profit-driven.
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Re:hmm...Yeah you're right that quote was just about differentiating the contributions from van der Waals and capillary forces. Further in the paper they also explain:
Whereas the instability of ordinary liquid columns is driven by molecular surface tension, possible mechanisms for droplet formation in granular systems include hydrodynamic interactions with the surrounding gas, inelastic grain-grain collisions, and cohesive forces. Hydrodynamic interactions have indeed recently been associated with fluctuations in the profile of streams falling in air 9; however, from experiments across a wide range of ambient pressures down to 0.03 kPa we find that grain-gas interactions do not drive clustering (Supplementary Fig. S1), in agreement with earlier work 6.
(Emphasis added.)
For anyone curious, reference 6 is:
Mobius, M. E. Clustering instability in a freely falling granular jet. Phys. Rev. E 74, 051304 (2006). doi: 10.1103/PhysRevE.74.051304
If you don't have access to Phys. Rev. E., you can read a preprint of the same paper on ArXiv here.
That paper does measurements down to 0.03 kPa (1/5000 atmospheric pressure), and concludes:Clustering is observed down to the lowest pressure and the presence of air leads to larger clusters but does not initiate the cluster formation.
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Re:Pour sand in a vacuum
I thought the same thing, however, someone earlier posted a link to the original article, that requires a subscription to actually read, where apparently they say they tried it in a vacuum and achieved the same results
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Re:Meh...Nope. The researchers thought of that, too. But they ruled-out electrostatic charging. From the article (p. 1111):
In principle, cohesion might arise from a variety of sources, including electrostatic charging, capillary or van der Waals forces.
... a rough estimate of the cohesive strength ... gives values of a few nanoNewtons. To compare this to any electrostatic forces present, we obtain the distribution of charges on the grains by applying a uniform electric field perpendicular to the falling stream and tracking individual grain trajectories (see Supplementary Information). For both glass and copper, we find the streams are neutral overall but contain a small fraction of positively and negatively charged grains, up to a roughly q_max = +/- 100,000 electron charges per grain (Supplementary Fig. S2). Still, this gives attractive electrostatic forces a maximum F_max = (1/4*pi*e_0)q_max^2/d^2 ~= 0.1 nN for grains with diameter d = 100 micrometer, too weak to be the dominant cohesive force. (Here e_0 = 8.85 * 10^-12 C^2 N^-1 m^-2 is the permittivity of free space.) Furthermore, experiments with conductive, silver-coated 100-micrometer-diameter glass spheres produce clusters identical to experiments using uncoated spheres, emphasizing that electrostatic forces do not drive the observed clustering.(Note that I rewrote the equations in plaintext since Slashdot doesn't support all the necessary characters.)
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Re:hmm...The researchers did consider the effect of air. In fact, the ambient air has the opposite effect: the drag of the air as the droplets fall rips grains out of the droplets, thus working against whatever effect is aggregating them. In particular the authors say in their article (p. 1111):
For a rough estimate of the cohesive strength we track clusters as they fall and accelerate to a speed at which Stokes drag pulls individual grains off cluster protrusions. Correcting for slight changes in the air viscosity at reduced pressure, this gives values of a few nanoNewtons.
They then go on to measure more careful the strength of the clustering force, and ascribe it to both Van der Waals interaction and capillary forces. They did perform the experiment as a function of humidity to test the effect of water bridging (capillary forces) and found it to be significant. But they provide further data suggesting that Van der Waals forces also play a role. Again from the article (p. 1112):
It is difficult to distinguish van der Waals from capillary forces because we cannot rule out molecularly thin absorbed films that create tiny bridges between individual asperities24,25. However, we still observe clustering in glass grains stored under vacuum (0.05 kPa) at low humidity (,1%) and also in grains coated with hydrophobic silane.
The fact that clustering still occurs in vacuum suggests air is not crucial to the effect. The precise scaling they observe (e.g. the size and separation of the clusters as a function of time) is not consistent with simple inelastic collisions, and the effect of air would actually be to breakup the droplets, absent any attractive force. What they instead measured was a weak (but sufficient!) interaction between grains, which they ascribe to surface forces and capillary action.
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Re:hmm...
For those with access, the actual scientific article is:
John R. Royer, Daniel J. Evans, Loreto Oyarte, Qiti Guo, Eliot Kapit, Matthias E. MÃbius, Scott R. Waitukaitis & Heinrich M. Jaeger "High-speed tracking of rupture and clustering in freely falling granular streams" Nature, 459, 1110-1113 (25 June 2009) | doi:10.1038/nature08115.
The associated "News and Views" (Summary) is:
Detlef Lohse & Devaraj van der Meer "Granular media: Structures in sand streams" Nature, 459, 1064-1065 (25 June 2009) | doi:10.1038/4591064a
The previously-held belief in the field was that this breakup into droplets could be explained by inelastic collisions between the grains. That is, all the sand grains are bouncing off each other, but because these collisions are inelastic (the two particles slow down a bit relative to each other with the collision) the grains will, statistically, aggregate into larger structures.
However this new piece of work shows rather strikingly that the origin of the force is a very weak form of surface tension. In other words, the breakup into droplets occurs for the same reason as it does in water and other liquids... it's just the magnitude of the force that is much smaller. In addition to the high-speed photography the Slashdot summary mentions, they also used atomic force microscopy to directly measure the nanometer-scale cohesive forces between particles. In water, surface tension arises from the (rather strong) cohesive forces between water molecules (each water molecule 'sticks' to its neighbors). In sand, it appears that a very weak nano-scale cohesive force is nevertheless enough to generate macro-scale droplets out of micro-scale particles. The cohesive forces in sand arise from the weak Van der Waals forces (weak, but universal, surface attraction), and due to capillary forces. That is, ambient water bridges the sand particles and causes what is effectively an attractive force, which leads to an effective surface tension.
In the paper, they describe how they vary the particle type and ambient conditions, to demonstrate that these two effects are important. For instance varying humidity alters the cohesion and thus droplet formation. Also, altering the sand particles has an effect: e.g. rougher particles cannot stick to each other as much, thereby reducing this effect.
This is a neat piece of work because it involves just "known" physics. It is demonstrating that well-established physical effects (surface forces and capillary forces) can explain phenomena where their effect was previously assumed to be negligible. The surface tension in these granular media are about 100,000 times smaller than water, yet the exact same effects are observed: the surface tension, weak as it is, tries to minimize surface area. Coupled with well-known instabilities, this causes a breakup into droplets. -
Re:hmm...
For those with access, the actual scientific article is:
John R. Royer, Daniel J. Evans, Loreto Oyarte, Qiti Guo, Eliot Kapit, Matthias E. MÃbius, Scott R. Waitukaitis & Heinrich M. Jaeger "High-speed tracking of rupture and clustering in freely falling granular streams" Nature, 459, 1110-1113 (25 June 2009) | doi:10.1038/nature08115.
The associated "News and Views" (Summary) is:
Detlef Lohse & Devaraj van der Meer "Granular media: Structures in sand streams" Nature, 459, 1064-1065 (25 June 2009) | doi:10.1038/4591064a
The previously-held belief in the field was that this breakup into droplets could be explained by inelastic collisions between the grains. That is, all the sand grains are bouncing off each other, but because these collisions are inelastic (the two particles slow down a bit relative to each other with the collision) the grains will, statistically, aggregate into larger structures.
However this new piece of work shows rather strikingly that the origin of the force is a very weak form of surface tension. In other words, the breakup into droplets occurs for the same reason as it does in water and other liquids... it's just the magnitude of the force that is much smaller. In addition to the high-speed photography the Slashdot summary mentions, they also used atomic force microscopy to directly measure the nanometer-scale cohesive forces between particles. In water, surface tension arises from the (rather strong) cohesive forces between water molecules (each water molecule 'sticks' to its neighbors). In sand, it appears that a very weak nano-scale cohesive force is nevertheless enough to generate macro-scale droplets out of micro-scale particles. The cohesive forces in sand arise from the weak Van der Waals forces (weak, but universal, surface attraction), and due to capillary forces. That is, ambient water bridges the sand particles and causes what is effectively an attractive force, which leads to an effective surface tension.
In the paper, they describe how they vary the particle type and ambient conditions, to demonstrate that these two effects are important. For instance varying humidity alters the cohesion and thus droplet formation. Also, altering the sand particles has an effect: e.g. rougher particles cannot stick to each other as much, thereby reducing this effect.
This is a neat piece of work because it involves just "known" physics. It is demonstrating that well-established physical effects (surface forces and capillary forces) can explain phenomena where their effect was previously assumed to be negligible. The surface tension in these granular media are about 100,000 times smaller than water, yet the exact same effects are observed: the surface tension, weak as it is, tries to minimize surface area. Coupled with well-known instabilities, this causes a breakup into droplets. -
Re:Hmmm...
Wait, CO2 is a fundamental particle now? I told you those guys at CERN would mess something up!
The amount of carbon in the world may be constant, as might the amount of oxygen. But making new CO2 is a trivial task (baking soda + vinegar, glucose + oxygen, etc etc); destroying it is slightly easier but plants seem to manage it quite well. If current research on synthetic photosynthesis goes well, hopefully we'll be able to make machines do it efficiently soon too. [1], [2] -
Re:I've got the promo materials in front of me...
In the words of wikipedia, citation please?
http://dx.doi.org/10.1016/j.jnucmat.2004.04.004
But seriously, with the hedging language in the statement you've quoted, there's nothing controversial. Note the "up to" and "aiming ultimately". (Plus "prolonged" in this line of business means a few minutes.) Fusion scientists are cautious people, having made rosy predictions in the past that never came to fruition. And when you're cautious, it's hard to convince lawmakers to hand over the money.
On the other hand, ITER as a concept has been around since the '80s. If they had just gone ahead with it back then, we would have learned a lot by now. Same goes for the cancellation of the SSC.
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Re:Junk Science
Science is reported in journal articles not news outlets (even one with science in the name).
From http://dx.doi.org/10.1289/ehp.0900604
Furthermore, we assessed the impact of polycarbonate bottle use in a normal use setting.
The present study could be considered a conservative estimate of true use, as students did not
have access to dishwashers and were instructed to use their containers for cold beverages only,
whereas the storage of hot liquids is common, especially in outdoor recreation settings. Because
heating is thought to increase the amount of BPA leached from the polycarbonate (Le et al.
2008), we would anticipate higher urinary BPA concentrations after ingestion of hot beverages
stored in the same bottles.Much more conservative in the actual paper.
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Re:Replication is dangerous
'In any virus intended for therapeutic use in humans, allowing the virus to retain its reproductive mechanisms is just a bad idea.'
Not necessarily. Obviously there are risks (and this is just a proof of concept experiment), but as the original paper explains:
http://dx.doi.org/10.1371/journal.ppat.1000440
'Viruses have a highly successful history as prophylactic vaccines and are also being developed for their intrinsic anticancer activities. In both settings the ability to undergo restricted replication is highly desirable. Attenuated (but not killed) viral strains often represent the most effective viral vaccines, affording the possibility of persistent low level infection without significant pathology.'
In other words, you want the virus to replicate in a controlled way, so that (e.g.) it hits more cancer cells than a non-replicating vector. Traditionally, 'attenuated' viruses have been used for vaccines and for anti-tumour experiments, but this tends to make them less effective than they might otherwise be. The trick they've used in this paper is selective attenuation - they've inserted an 'off switch' that responds to a microRNA that's expressed in liver (where the virus might do harm), but not elsewhere (where the virus is needed). Also, the adenovirus used in these studies isn't some exotic replicating construct with a deadly payload, but a rather common virus that generally causes mild disease even in its unattenuated form. It may not even be necessary to deliver a foreign gene to the tumour - replication-selective but otherwise normal adenoviruses can have intrinsic anti-tumour ('oncolytic') activity if they are engineered to prefer replicating in tumour cells. One common strategy is to delete a viral gene normally used to evade the cell's p53 response. The virus can then only replicate in cells with an already damaged p53 pathway (like many tumour cells!):
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Re:deniers come out in 3 .. 2 .. 1 ..
According to wikipedia this paper seems to disagree with you.
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Re:LOTS of missing details from TFA:
No, these are the fragments that lasted just long enough for the D(-1) state to hold together in a laser beam for ATTOSECONDS. (That's what those little "as" annotations are on their viewgraph).
You didn't specify what viewgraph you were referring to (there are none in the links in the summary). Presumably you are looking at one of their papers. E.g. Figure 2 from:
S. Badiei, P. U. Andersson and L. Holmlid, "High-energy Coulomb explosions in ultra-dense deuterium: time-of-flight mass spectrometry with variable energy and flight length". Int. J. Mass Spectrom. 282 (2009) 70-76. doi:10.1016/j.ijms.2009.02.014
Yes, that graph marks points along the curve with "as" meaning "attoseconds", but that doesn't mean that the UDD has a lifetime of attoseconds. That graph is describing the "Coulomb explosion" technique they are using to measure the bond distances in UDD. Briefly, they excite the ultra-dense deuterium with a laser pulse that ionizes some of the atoms, which causes them to fly apart (due to Coulomb repulsion) with great energy. By measuring the ions that result from this explosion they can calculate the bond distances. This high-speed explosion, however, was artificially induced to make it possible to measure the inter-atomic distances. If they had not purposefully excited the UDD with a laser it would have lasted longer.
I'm not sure how much longer that would be, mind you. As far as I can tell from their papers, they have not yet measured the lifetime. So it may very well be a rather low lifetime. (Though some forms of Rydberg matter can have appreciable lifetimes.) If anyone has any actual data (with link) for the lifetime, I'd love to see it.IF stable enought to survives the time-of-flight from source to fusion reactor
For Intertially-Confined Fusion, which typically uses lasers to compress the target matter, one could design a system where the UDD state is produced in-situ and immediately laser-compressed.
single D(-1) pseudonucleons may well exist for nanoseconds per KURT9's thesis
This is another statement whose source is unclear. Who or what is "KURT9"?
There is only hope
... nothing but speculative wishes that such a material holds promise to D+D=4He reactions ...From the above-cited paper:
"Due to the high density of the D(1) material, a factor of 2×10^5 higher than for H(1), the transport of energetic particles through the material is strongly impeded. In fact, the deuterons at 2.3pm bond distance are close to the nuclear barrier, and a kinetic energy of 630 eV may be sufficient to give d-d fusion by tunneling."
I haven't looked into the theory enough yet to say whether their suggestion of tunneling is correct or not... but if true this would indeed vastly increase the rate of fusion reactions. If nothing else, the extremely high density of the nucleons will make all kinds of many-body and multi-step reactions much more viable.he fine department of Physics at Gothenberg for letting these two obviously talented, and quite frankly queer, researchers have their limelight.
Umm... what?
=smudge=
I guess you're trolling.
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Re:Paper or it didn't happen
doi:10.1016/j.neuro.2009.01.011
Malin Larssona, Bernard Weissb, Staffan Jansona, Jan Sundellc and Carl-Gustav Bornehag
Associations between indoor environmental factors and parental-reported autistic spectrum disorders in children 6-8 years of age -
Re:needs another tag
The original Van Eck article is here.
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Re:Rare metals scattered everywhere
Accurate satellite, balloon and mountain top observations made over the last three decades have not shown any significant change in the long term rate of increase in global temperatures.
You may have an interesting definition of significant change. The satellite data for temperatures shows an increase that is quite notable.
Average ground station readings do show a mild warming of 0.6 to 0.8C over the last 100 years, which is well within the natural variations recorded in the last millennium.
Most reconstructions of temperatures over the last millenium (and that includes many more than those offered by Mann and Bradley) show that the current observed warming is significant in terms of the rate at which it has occurred. Indeed, most show the current warming over the last 100 years as outside the range of reconstructed temperatures over the last millenium.
The ground station network suffers from an uneven distribution across the globe; the stations are preferentially located in growing urban and industrial areas ("heat islands"), which show substantially higher readings than adjacent rural areas ("land use effects").
Of course the land based records attempt to take such effects into account, but aside from that we also have the ocean temperature records (which agree closely with the land based records), and several studies which all conclude that UHI effects don't cause the warming observed: [Parker 2004], [Parker 2006], [Peterson 2003]. Not to mention that if we go back to the question of satellite temperatures we see that they show no significant difference in trend to land based observations.
Significant changes in climate have continually occurred throughout geologic time. For instance, the Medieval Warm Period, from around 1000 to1200 AD (when the Vikings farmed on Greenland) was followed by a period known as the Little Ice Age
Mention of the Vikings on Greenland wrt the medieval warm period being very warm is deceptive. If you actually look at where the viking settlements were (Eastern Settlement, Western Settlement), and then check satellite imagery of those areas (Eastern Settlement, Western Settlement), you'll see that they are in sheltered fjords that are naturally quite green and suitable for farming. Some photos of the Viking ruins will confirm this (eg. this, or this).
The "hockey stick", a poster boy of both the UN's IPCC and Canada's Environment Department, ignores historical recorded climatic swings, and has now also been proven to be flawed and statistically unreliable as well. It is a computer construct and a faulty one at that.
Of course, as noted earlier, the Mann, Bradley, Hughes temperature reconstruction of 1998 is far from the only such effort. The others produced qualitatively similar results. Further, while there has been dispute of the original 1998 piece, the National Academy of Science report on the subject concluded tha
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Re:Rare metals scattered everywhere
Accurate satellite, balloon and mountain top observations made over the last three decades have not shown any significant change in the long term rate of increase in global temperatures.
You may have an interesting definition of significant change. The satellite data for temperatures shows an increase that is quite notable.
Average ground station readings do show a mild warming of 0.6 to 0.8C over the last 100 years, which is well within the natural variations recorded in the last millennium.
Most reconstructions of temperatures over the last millenium (and that includes many more than those offered by Mann and Bradley) show that the current observed warming is significant in terms of the rate at which it has occurred. Indeed, most show the current warming over the last 100 years as outside the range of reconstructed temperatures over the last millenium.
The ground station network suffers from an uneven distribution across the globe; the stations are preferentially located in growing urban and industrial areas ("heat islands"), which show substantially higher readings than adjacent rural areas ("land use effects").
Of course the land based records attempt to take such effects into account, but aside from that we also have the ocean temperature records (which agree closely with the land based records), and several studies which all conclude that UHI effects don't cause the warming observed: [Parker 2004], [Parker 2006], [Peterson 2003]. Not to mention that if we go back to the question of satellite temperatures we see that they show no significant difference in trend to land based observations.
Significant changes in climate have continually occurred throughout geologic time. For instance, the Medieval Warm Period, from around 1000 to1200 AD (when the Vikings farmed on Greenland) was followed by a period known as the Little Ice Age
Mention of the Vikings on Greenland wrt the medieval warm period being very warm is deceptive. If you actually look at where the viking settlements were (Eastern Settlement, Western Settlement), and then check satellite imagery of those areas (Eastern Settlement, Western Settlement), you'll see that they are in sheltered fjords that are naturally quite green and suitable for farming. Some photos of the Viking ruins will confirm this (eg. this, or this).
The "hockey stick", a poster boy of both the UN's IPCC and Canada's Environment Department, ignores historical recorded climatic swings, and has now also been proven to be flawed and statistically unreliable as well. It is a computer construct and a faulty one at that.
Of course, as noted earlier, the Mann, Bradley, Hughes temperature reconstruction of 1998 is far from the only such effort. The others produced qualitatively similar results. Further, while there has been dispute of the original 1998 piece, the National Academy of Science report on the subject concluded tha
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High resolution but small volumeThe actual scientific paper is:
C. L. Degen, M. Poggio, H. J. Mamin, C. T. Rettner, D. Rugar Nanoscale magnetic resonance imaging PNAS 2009, doi: 10.1073/pnas.0812068106.
The abstract:We have combined ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve magnetic resonance imaging (MRI) with resolution <10 nm. The image reconstruction converts measured magnetic force data into a 3D map of nuclear spin density, taking advantage of the unique characteristics of the 'resonant slice' that is projected outward from a nanoscale magnetic tip. The basic principles are demonstrated by imaging the 1H spin density within individual tobacco mosaic virus particles sitting on a nanometer-thick layer of adsorbed hydrocarbons. This result, which represents a 100 million-fold improvement in volume resolution over conventional MRI, demonstrates the potential of MRFM as a tool for 3D, elementally selective imaging on the nanometer scale.
I think it's important to emphasize that this is a nanoscale magnetic imaging technique. The summary implies that they created a conventional MRI that has nanoscale resolution, as if they can now image a person's brain and pick out individual cells and molecules. That is not the case! And that is likely to never be possible (given the frequencies of radiation that MRI uses and the diffraction limit that applies to far-field imaging.
That having been said, this is still a very cool and noteworthy piece of science. Scientists use a variety of nanoscale imaging tools (atomic force microscopes, electron microscopes, etc.), but having the ability to do nanoscale magnetic imaging is amazing. In the article they do a 3D reconstruction of a tobacco mosaic virus. One of the great things about MRI is that is has some amount of chemical selectivity: there are different magnetic imaging modes that can differentiate based on makeup. This nanoscale analog can use similar tricks: instead of just getting images of surface topography or electron density, it could actually determine the chemical makeup within nanostructures. I expect this will become a very powerful technique for nano-imaging over the next decade. -
Orientation analysis in an image
The image analysis question is interesting. You are trying to read dial positions, so conventional OCR is probably useless (unless there is a package to do exactly that?).
What you can do is use image processing commands (in your favorite programming language; a shell script, Python, etc.) to crop the image to generate a small image for each dial. Then convert to grayscale (and maybe increase the contrast to highlight the dial). To then calculate the preferred orientation in the image, you calculate gradients along different directions. There will be a much higher value for the gradient along directions perpendicular to the preferred axis. This procedure is described very briefly in this paper:
Harrison, C.; Cheng, Z.; Sethuraman, S.; Huse, D. A.; Chaikin, P. M.; Vega, D. A.; Sebastian, J. M.; Register, R. A.; Adamson, D. H. "Dynamics of pattern coarsening in a two-dimensional smectic system" Physical Review E 2002, 66, (1), 011706. DOI: 10.1103/PhysRevE.66.011706
This is easiest to do if you use a graphics package that has directional gradients built-in (but coding it yourself probably wouldn't be too hard). Basically you create copies of the image and on one you do a differentiation in the x-direction, and for the other one a differentiation in the y-direction. Let's call these images DIFX and DIFY. Then you compose two new images:
NUMERATOR = 2*DIFX*DIFY
DENOMINATOR = DIFX^2-DIFY^2
Then you calculate a final image:
ANGLES = atan2( NUMERATOR, DENOMINATOR )
(All the above calculations are done in a pixel-by-pixel mode.) The final image will have an angle map (with values between -pi to pi) for the image. It should be easy to then use the avg or max over that image to pull out the preferred direction. You may also improve results by tweaking the initial thresholding, or by adding an initial "Sharpen Edges" step, or by blurring the NUMERATOR and DENOMINATOR images slightly before doing the next step.
In any case, the above procedure has worked for me when coding image analysis for orientation throughout an image (coding was done in Igor Pro in my case). So maybe it is useful for you. -
photodetectors-yes; solar cells-NO
If you read the journal articles http://dx.doi.org/10.1016/j.mseb.2006.10.002 you'll find that this process esentially creates a large number of impurity states at the center of the band gap, creating an impurity band. What this means is that light is absorbed very very fast, but then its also turned to to heat very very fast. In other words you can excite electrons but that electron will decay back down before it creates any current. This could still work for a photodetector because you can apply a voltage to sweep out the excited carriers before they recombine/decay but not for a solar cell since you want to generate power.
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Re:alternately....
Computational Statistics & Data Analysis recently devoted an entire issue to Excel 2007. A good example of general opinion can be seen in the paper by McCullough and Heiser (2008) "On the accuracy of statistical procedures in Microsoft Excel 2007". http://dx.doi.org/10.1016/j.csda.2008.03.004 From the abstract: "Excel 2007, like its predecessors, fails a standard set of intermediate-level accuracy tests in three areas: statistical distributions, random number generation, and estimation. Additional errors in specific Excel procedures are discussed. Microsoftâ(TM)s continuing inability to correctly fix errors is discussed. No statistical procedure in Excel should be used until Microsoft documents that the procedure is correct; it is not safe to assume that Microsoft Excelâ(TM)s statistical procedures give the correct answer. Persons who wish to conduct statistical analyses should use some other package."
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Clueless Reviewer
Its clear that the reviewer is not qualified to review this text. First, if they were familiar with scientific data analysis, they would not use Mathematica for their ridiculous comparison. Mathematica is also the wrong tool for the job. At least it does math correctly, something Excel cannot claim.
You haven't seen a book typeset in LaTeX recently? What scientific computing books do you read that allow you to avoid LaTeX for years?
Excel is not the right tool for the job. If you are going to put in the time to learn some new math, learning a better tool along the way makes sense.
Get a different book, and a different software package.
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Re:Other kinds of therapy
Your implication that there is a conspiracy to prevent individuals from obtaining a powerful treatment for PTSD is misguided.
EMDR is well publicized and well debated in the psychological community. It is essentially another form of exposure therapy (ET), similar in nature to the referenced VR technique. While EMDR shows positive results for PTSD treatment, it has not been found to be significantly different from more traditional exposure-based approaches. (see, for example this meta analysis.)
In particular, the importance of "eye-movement" is not conclusively explained or validated as necessary for treatment. Thus, "what is effective in EMDR is not new, and what is new is not effective"
The reason, perhaps, that EMDR is
/not/ widely used, is because it is costly to become a "certified" practitioner (and, frankly, has some quacky characteristics). Since evidence to date suggests you're not gaining anything over ET, why should a therapist spend the time and money? Should evidence become clearer or the theorized mechanism of EMDR be validated independently, I'm certain EMDR will be more widely accepted. Until then, ET and its traditional variants will likely remain the treatment of choice for those who prefer evidence-based practices.Cheers
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Some additional information...The parts of TFA that talk about "self-assembly" are referring to the recent advances in using "block copolymers" to take a given lithographic pattern and "multiply" it into a high-density pattern.
For anyone with access, these two article's from today's issue of Science Magazine describe this research:- Ricardo Ruiz, Huiman Kang, François A. Detcheverry, Elizabeth Dobisz, Dan S. Kercher, Thomas R. Albrecht, Juan J. de Pablo, and Paul F. Nealey "Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly", Science 15 August 2008: 936-939, DOI: 10.1126/science.1157626
- Ion Bita, Joel K. W. Yang, Yeon Sik Jung, Caroline A. Ross, Edwin L. Thomas, and Karl K. Berggren "Graphoepitaxy of Self-Assembled Block Copolymers on Two-Dimensional Periodic Patterned Templates" Science 15 August 2008: 939-943. DOI: 10.1126/science.1159352
Block copolymers are polymers (long-chain molecules that make up, for example, plastics) that are designed in such a way that they spontaneously form well-defined nano-patterns when allowed to equilibrate. So for instance a block-copolymer cast as a coating might spontaneously form nano-sized cylinders inside it (where the 'cylinder' and 'matrix' are formed of two different components... the two 'blocks'). Depending on what kind of copolymer you synthesize, you can form nano-cylinders, nano-sheets, nano-spheres, and other shapes (check out this, and this for some examples of the morphologies one can obtain).
One of the problems with block-copolymers, however, is that although they form very well-defined shapes (of exceedingly small and regular size), that's useless if you can't put those nano-objects where you need them. That's where this new work in "Templated Self-Assembly" comes into play. Basically you create a conventional, big pattern using the tried-and-tested techniques used to make microchips (optical lithography, e-beam lithography, etc.). Then you use that as a template for the block-copolymer. It fills in the gaps in the big pattern with its much smaller-scale nano-objects... which are now placed at well-defined positions because of the larger-scale template. So basically you get "density multiplication" of whatever pattern you're able to make.
So if you can use normal lithography to make a pattern of 100 nm, the block-copolymer can fill in the gaps and give you a pattern with sizes of 20 nm. Also, this "self-assembly" process has a way of "healing" over defects, basically giving you a very well-defined pattern even if your original template wasn't perfect.
The patterns in question can be "chemical templates" (basically stripes of different chemicals on a surface), or "topographical templates" (physical channels), which is what the two above-mentioned papers deal with, respectively. (Other kinds of directed-assembly, like surface treatments, electric fields, or thermal fields, are also possible.)
The research is coming along very nicely, and Hitachi seems pretty serious about it. There's no guarantee that this will end up in real technology someday, but I'd say this is looking more and more viable as the research pours in.
(Disclosure: My research covers similar topics, and I've worked with some of the above-mentioned people on occasion.) -
Some additional information...The parts of TFA that talk about "self-assembly" are referring to the recent advances in using "block copolymers" to take a given lithographic pattern and "multiply" it into a high-density pattern.
For anyone with access, these two article's from today's issue of Science Magazine describe this research:- Ricardo Ruiz, Huiman Kang, François A. Detcheverry, Elizabeth Dobisz, Dan S. Kercher, Thomas R. Albrecht, Juan J. de Pablo, and Paul F. Nealey "Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly", Science 15 August 2008: 936-939, DOI: 10.1126/science.1157626
- Ion Bita, Joel K. W. Yang, Yeon Sik Jung, Caroline A. Ross, Edwin L. Thomas, and Karl K. Berggren "Graphoepitaxy of Self-Assembled Block Copolymers on Two-Dimensional Periodic Patterned Templates" Science 15 August 2008: 939-943. DOI: 10.1126/science.1159352
Block copolymers are polymers (long-chain molecules that make up, for example, plastics) that are designed in such a way that they spontaneously form well-defined nano-patterns when allowed to equilibrate. So for instance a block-copolymer cast as a coating might spontaneously form nano-sized cylinders inside it (where the 'cylinder' and 'matrix' are formed of two different components... the two 'blocks'). Depending on what kind of copolymer you synthesize, you can form nano-cylinders, nano-sheets, nano-spheres, and other shapes (check out this, and this for some examples of the morphologies one can obtain).
One of the problems with block-copolymers, however, is that although they form very well-defined shapes (of exceedingly small and regular size), that's useless if you can't put those nano-objects where you need them. That's where this new work in "Templated Self-Assembly" comes into play. Basically you create a conventional, big pattern using the tried-and-tested techniques used to make microchips (optical lithography, e-beam lithography, etc.). Then you use that as a template for the block-copolymer. It fills in the gaps in the big pattern with its much smaller-scale nano-objects... which are now placed at well-defined positions because of the larger-scale template. So basically you get "density multiplication" of whatever pattern you're able to make.
So if you can use normal lithography to make a pattern of 100 nm, the block-copolymer can fill in the gaps and give you a pattern with sizes of 20 nm. Also, this "self-assembly" process has a way of "healing" over defects, basically giving you a very well-defined pattern even if your original template wasn't perfect.
The patterns in question can be "chemical templates" (basically stripes of different chemicals on a surface), or "topographical templates" (physical channels), which is what the two above-mentioned papers deal with, respectively. (Other kinds of directed-assembly, like surface treatments, electric fields, or thermal fields, are also possible.)
The research is coming along very nicely, and Hitachi seems pretty serious about it. There's no guarantee that this will end up in real technology someday, but I'd say this is looking more and more viable as the research pours in.
(Disclosure: My research covers similar topics, and I've worked with some of the above-mentioned people on occasion.) -
Nature's Abstract
"the world's two leading scientific journals, Science and Nature, are expected to report the results this week."
You can find the Nature abstract here. And if you have a subscription, you can read the full research and see the data they collected from experiments.
According to the Ars Technica article on this, the Science link will be here.
There seems to be a few more papers and articles on this but if you're interested you can search for optical metamaterials with negative refractive indexes. -
Some context
The science article where the approach is described in detail is this one: "A Gene Wiki for Community Annotation of Gene Function", http://dx.doi.org/10.1371/journal.pbio.0060175 It has just come out in PLoS Biology, - an open access journal. The researchers/wikipedians have constructed a script called "Protein box bot" that runs on (the real) Wikipedia. It creates images and writes text, for example links to NCBI. The bot can do this both for existing articles, such as this one: http://en.wikipedia.org/wiki/HTR2A, or it can create new articles with a the box, a small summary and references. The "gene wiki" is making an impact on the science part of Wikipedia. I counted the number of outbound scientific citations from Wikipedia, and the new ones that the bot has created are now the majority. The details of this count are here: http://www2.imm.dtu.dk/pubdb/views/publication_details.php?id=5666
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What? I've eaten silver...My understanding is that no one has ever documented lead leaching out of a tin-lead solder into ground water. However, silver - which is commonly used in lead-free solders will leach out and is somewhere around 100x (at least) more toxic than the lead anyway. The concept of lead-free solder having anything to do with safety or environmentalism is downright silly... Where in the world did you get the idea that silver is more dangerous than lead? If you eat too much silver, you get argyria, which makes you turn grey and is pretty easy to spot before it really harms you. Lead poisoning by comparison is both vastly more common and far more subtle and difficult to detect.
I've eaten a fair amount of silver in my day, with no harm done. Hindus eat a lot of it too. And I've applied silver-based cream to burns (makes 'em heal faster). Westerners used to mark cattle by slipping a silver dime into a cut, that way you could check with your fingers to see if somebody had re-branded cattle they'd rustled from your spread.
Silver's a doddle. And there most certainly is plenty of documentation and research on lead leaching into ground water. -
Re:Bunches of small drives
And, if you are an experimental scientist, build a shutter ('sorry, but you do need some sort of subscription to access the journal page).
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Re:NASA disaggrees with youEven NASA's data seems to disagree with you. NASA doesn't have any data for the last 150 years. We had twice your number since 1970 alone. If that were a long term trend, you might have a point. But you're not looking at the trend, you're looking at the difference in minima, and you're only looking at two full solar cycles at that. i.e., you're basically looking at noise.
If you look at the trend over the last 150 years or so, as I said, you find about 1 to 3 W/m^2 increase in irradiance, e.g. here or here. A 0.05% increase per decade, over a century, is 0.5%. Solar irradiance has not been increasing at a constant rate, either. Now it doesn't go the full 1.2% we'd need to explain the Global Warming (unless it went up as a different rate before), but it almost halves the effect we can blame ourselves for. This analysis has already been performed, far more carefully than your analysis, and does not support your conclusion. See, for instance, here, which I cited elsewhere in this thread. -
Re:Twisted Conclusion
is actually at the lowest end for plant survival
This is wrong. See for example here. CO2 concentration in the past were maybe half the current values, and this lead to specific adaptations in some plant species. For example, the carbon concentrating mechanism in C4 plants. Interestingly, this also explains why such plants (C4) do not benefit much from increases in atmospheric CO2.
I'm not saying CO2 is not limiting growth, but the effect is very much dependent on the species. Actually, google for Bunce for a nice correlation between growth rate at normal conditions and the stimulation by high CO2. To me, that seems like fast growing species (weeds) can benefit the most from the CO2. In any case, it will change the status quo.
To people in the know, this is a story, because it is very difficult to predict exactly what the outcome will be on a global scale. -
Re:The data measured is just noiseTo my surprise there was no clear winner or loser..
Forget what you *think* you're measuring (code quality). Instead, consider whether you're measuring anything at all. That is, is there any information in the data you've measured?
In the past other researchers have used a few of the metrics I used to measure what they called a system's maintainability, and they were able to match this with the subjective perceptions of developers at HP regarding the code's quality. So these measures are not just noise.For another indication, consider this figure, showing a trend that matches our expectations: how the maintainability of the FreeBSD system is, in general, falling over time. Again, this is derived from some of the metrics I used to compare the four kernels. These metrics do not yield noise.
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And the scientific article on CXV...And, for anyone interested (and who has a subscription), here's the article in Physical Review E that describes the scientific experiment and analysis of the recovered data:
Robert F. Berg, Michael R. Moldover, Minwu Yao, Gregory A. Zimmerli Shear thinning near the critical point of xenon, Phys. Rev. E 77, 041116 (2008) doi 10.1103/PhysRevE.77.041116.
In the article, they mention a bit about the data recovery: During the mission, the apparatus recorded 370 h of data, of which 85% were downlinked for real-time analysis. Fortunately, the hard disk drive was recovered from Columbia's debris in a condition that made 99% of the data available for analysis. Also quite interesting is an off-hand comment they make about the sample cell they used: Seven months after the Columbia disaster in 2003, the meniscus height was remeasured in the recovered sample cell... This suggests that in addition to getting the hard drive (and the data off the hard drive), the Columbia debris search also found the sample cell for their experiment, which allowed them to make some additional measurements for their data analysis. This is also quite impressive!
The data-recovery aspect is quite interesting. So is the fundamental science. They had to run the experiment in micro-gravity to eliminate the density stratification that occurs for any liquid or gas subject to gravity. Shear thinning is a well-established and fairly well-understood phenomena in "complex fluids" (e.g. mixtures of solvents and polymers, like paints, lubricants, etc.); but it is quite interesting to have measured the effect in a pure one-component atomic gas. It's hard to imagine a simpler fluid, and yet it exhibits this interesting viscosity effect!
I'm glad that this scientific experiment was salvaged from the otherwise tragic final mission of Challenger. -
Re:It's the Experience, Stupid
Actually that sounds rather more like the original Turing Test ( PDF version here and a very good read) and that is why it is an important operational test. Does it define intelligence? Probably not - it is certainly possible that there are intelligent beings who would not even recognize us as potentially intelligent or if they did, want to talk to us. Worse yet, we might not pass their Turing Test. But if we define intelligence as somehow being essential to humanness then the Turing Test is pretty good.
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Journal Reference
The journal article is available at http://dx.doi.org/10.1051/0004-6361:20078522
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Re:What, nobody's thought of the obvious?
and focus on Electric Cars powered by Hydrogen cells and NOT Hydrocarbons and not Hydrogen combustion engines... they are too inefficient.
You talk about efficiency and advocate hydrogen fuel cells in the same sentence? You do realize that hydrogen fuel cell vehicles are extremely inefficient, right? At low loads, fuel cell vehicles are typically 46% efficient at turning hydrogen in the tank into wheel torque and 36% in the NEDC driving cycle. On top of that, you have generation losses (modern power plants are 40-50%, older ~30%, and possibly up to 60% in the future), transmission losses (7.2% average in the US), electrolysis losses (80-85% efficiency if done in the most efficient manner possible, regeneratively on hot steam). Which makes hydrogen worse than gasoline in terms of a carbon footprint. You can also make it from methane reforming, but that's no better. You can grow it from bacteria, but that costs an utter fortune. There are direct sunlight to hydrogen cells, but they are expensive, very inefficient, and break down quickly.
The hydrogen economy is simply unrealistic. On the other hand, there is an awful lot of promise in electric vehicles. -
No, it's a display.
The BBC writeup isn't very good. Try Ars Technica's coverage and you'll see that it's a 100 cm^2, rewritable holographic display. Or you can read the scientific paper in Nature.
It really is a holographic display. It uses a mixture of two polymers and quite a few kilovolts to zap things into place, after which you get a nice little display. It takes about half a second to form the image, which then lasts for about 3 hours (compared to it vanishing in about as much time as it took to create the image before). The device is also a lot bigger than previous devices.
I covered all that in my submission, but I guess someone beat me to submitting the story. Oh well, I've got plenty of accepted submissions already, anyhow, and knowing Slashdot, they could use my submission for a dupe, tomorrow :-)
I Don't Believe in Imaginary Property