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ESA ACT

Materials Today : The top ten advances in materials science - 0 views

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    What are the defining discoveries, moments of inspiration, or shifts in understanding that have shaped the dynamic field of materials science we know today. Here's what we think are the most significant.
jcunha

Dynamic flat lens with metasurface actuated with MEMS - 2 views

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    Great engineering feat from Capasso's idea - an integrated flat lens electrically controlled enabling dynamic beam steering. Reconfigurabilility is the aim. The lens can be used microscope systems, holographic and projection imaging, LIDAR and laser printing. Besides working now on the mid-IR, visible light is the target.
jaihobah

Boston Dynamics Atlas updated - 3 views

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    Apparently Atlas became a ninja and I missed it: https://youtu.be/fRj34o4hN4I
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    he looks way more elegant than most humans when running :D
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    I'll try not to take that personally...
Annalisa Riccardi

New structures self-assemble in synchronized dance - 3 views

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    With self-assembly guiding the steps and synchronization providing the rhythm, a new class of materials forms dynamic, moving structures in an intricate dance. Researchers have demonstrated tiny spheres that synchronize their movements as they self-assemble into a spinning microtube.
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    This is quite similar to the following paper. Here they show how tiny variations of particle parameters can produce clearly distinct structures: Thermal and Athermal Swarms of Self-Propelled Particles --> http://arxiv.org/abs/1201.0180
Marcus Maertens

Pouring Milk All Over Yourself: The Next Extremely Bizarre Trend? - 1 views

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    So... who is in?
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    I thought you were supposed to do this with petrol... |:-[ It's by the way cool to see how the milk seems to flow very differently from what one might expect from water: it seems to flow in a few thick streams instead of wetting the whole person... Since the surface tension of milk seems to be lower than that of water (http://journals.cambridge.org/action/displayAbstract;jsessionid=908B02C3825E97162B9D60DA615EAC96.journals?fromPage=online&aid=5146540) this is surprising. It might very well be an effect of the colloidal nature of milk as it is water in which semi-solid fat particles are suspended. So like the cornstarch mix that we have seen in the office there might be some dynamic jamming going on leading to a higher viscosity (at high shear rates). After all they might be doing science...
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    nice comment Johannes ... if you add a bit of Kleopatre, e.g. why bathing in milk helped her fool Marcus Antonius, your comment would be fully interdisciplinary :-)
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    you mean it would include History or Psychology? I would understand why Marcus Antonius might get fooled by a bathing beauty - but milk? DONKEY MILK?!? That's just wrong... :-[
aborgg

Carbon-rich nanorods harvest water from the air - 0 views

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    Nanometre-sized rods of carbon can expel water in puffs of vapour when the air is already humid. Materials such as carbon and silica gels typically pick up moisture as humidity increases. But Satish Nune and his colleagues at the Pacific Northwest National Laboratory in Richland, Washington, found that their carbon-based nanorods take up water at low humidity and then give off about half of it when the relative humidity exceeds 50-80%. The team thinks that water condenses between adjacent rods and then capillary forces draw the rods together until the water bursts from the ends of the rods and evaporates.
Luís F. Simões

Ville Vivante: The Dynamic Dimension of Geneva - 3 views

  • Every mobile phone leaves digital traces permanently, while interacting with the mobile infrastructure. It can be seen as a mobile sensor that allows to define the geographic position of the subscription holder, almost in real-time.
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    beautiful and hypnotic, but I'd like to know exactly what it is they are visualizing. These don't seem to be the changes in people's locations during phone calls...
LeopoldS

GTOC problem announced! - 0 views

"This year's problem is the global mapping of Jupiter's Galilean satellites, Io, Europa, Ganymede, and Callisto, by means of close flybys. A trajectory must be designed for a low-thrust spacecraft ...

Mas ai

started by LeopoldS on 10 Sep 12 no follow-up yet
LeopoldS

Physical Review Letters - Extracting dynamical equations from experimental data is NP hard - 1 views

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    Something for Sante and Luis...
Tom Gheysens

Biomimicr-E: Nature-Inspired Energy Systems | AAAS - 4 views

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    some biomimicry used in energy systems... maybe it sparks some ideas
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    not much new that has not been shared here before ... BUT: we have done relativley little on any of them. for good reasons?? don't know - maybe time to look into some of these again more closely Energy Efficiency( Termite mounds inspired regulated airflow for temperature control of large structures, preventing wasteful air conditioning and saving 10% energy.[1] Whale fins shapes informed the design of new-age wind turbine blades, with bumps/tubercles reducing drag by 30% and boosting power by 20%.[2][3][4] Stingray motion has motivated studies on this type of low-effort flapping glide, which takes advantage of the leading edge vortex, for new-age underwater robots and submarines.[5][6] Studies of microstructures found on shark skin that decrease drag and prevent accumulation of algae, barnacles, and mussels attached to their body have led to "anti-biofouling" technologies meant to address the 15% of marine vessel fuel use due to drag.[7][8][9][10] Energy Generation( Passive heliotropism exhibited by sunflowers has inspired research on a liquid crystalline elastomer and carbon nanotube system that improves the efficiency of solar panels by 10%, without using GPS and active repositioning panels to track the sun.[11][12][13] Mimicking the fluid dynamics principles utilized by schools of fish could help to optimize the arrangement of individual wind turbines in wind farms.[14] The nanoscale anti-reflection structures found on certain butterfly wings has led to a model to effectively harness solar energy.[15][16][17] Energy Storage( Inspired by the sunlight-to-energy conversion in plants, researchers are utilizing a protein in spinach to create a sort of photovoltaic cell that generates hydrogen from water (i.e. hydrogen fuel cell).[18][19] Utilizing a property of genetically-engineered viruses, specifically their ability to recognize and bind to certain materials (carbon nanotubes in this case), researchers have developed virus-based "scaffolds" that
dejanpetkow

Photonic calculus with analog computer - 5 views

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    Weird.
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    This reminds me a 2013 paper on how to perform derivatives, integrals and even time reversal in optical fibres: http://www.nature.com/srep/2013/130403/srep01594/full/srep01594.html "The manipulation of dynamic Brillouin gratings in optical fibers is demonstrated to be an extremely flexible technique to achieve, with a single experimental setup, several all-optical signal processing functions. In particular, all-optical time differentiation, time integration and true time reversal are theoretically predicted, and then numerically and experimentally demonstrated."
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    Would this kind of computer be more space environment resistive?
Thijs Versloot

Real-time measurements inside a battery show dynamics of electrochemical processes (video) - 0 views

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    "As we start to sweep the potential, we didn't initially observe anything," said lead author Robert Sacci, a postdoctoral research fellow with ORNL's FIRST Energy Frontier Research Center. "Then we started seeing shadows-presumably polymeric SEI-forming into a dendritic pattern. It looks like a snowflake forming from the electrode." nice fractals.. as always
jmlloren

HUBbub 2013 - 0 views

shared by jmlloren on 21 Aug 13 - No Cached
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    HUBbub 2013 is the annual conference for researchers, educators, and IT professionals engaged in building and using cyberinfrastructure. Learn about the latest features in the HUBzero tool box and how they can be used to address the unique challenges of scientific pursuits.
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    It is probably more interesting to check the parent site: hubzero.org: HUBzero ® is a powerful, open source software platform for creating dynamic web sites that support scientific research and educational activities.
Beniamino Abis

Structure and Anonymity of the Bitcoin Transaction Graph - 1 views

shared by Beniamino Abis on 26 Sep 13 - No Cached
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    Bitcoin utilizes a peer-to-peer network to issue anonymous payment transactions between different users. Dynamical effects have been found, of which some increase anonymity while others decrease it. Most importantly, several parameters of the Bitcoin transaction graph seem to have become stationary over the last 12-18 months. The implications are discussed.
Athanasia Nikolaou

Nature Paper: Rivers and streams release more CO2 than previously believed - 6 views

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    Another underestimated source of CO2, are turbulent waters. "The stronger the turbulences at the water's surface, the more CO2 is released into the atmosphere. The combination of maps and data revealed that, while the CO2 emissions from lakes and reservoirs are lower than assumed, those from rivers and streams are three times as high as previously believed." Alltogether the emitted CO2 equates to roughly one-fifth of the emissions caused by humans. Yet more stuff to model...
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    This could also be a mechanism to counter human CO2 emission ... the more we emit, the less turbulent rivers and stream, the less CO2 is emitted there ... makes sense?
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    I guess there is a natural equilibrium there. Once the climate warms up enough for all rivers and streams to evaporate they will not contribute CO2 anymore - which stops their contribution to global warming. So the problem is also the solution (as always).
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    "The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally." It is another source of CO2 this one, and the turbulence in the rivers is independent of our emissions in CO2 and just facilitates the process of releasing CO2 waters. Dario, if I understood correct you have in mind a finite quantity of CO2 that the atmosphere can accomodate, and to my knowledge this does not happen, so I cannot find a relevant feedback there. Johannes, H2O is a powerful greenhouse gas :-)
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    Nasia I think you did not get my point (a joke, really, that Johannes continued) .... by emitting more CO2 we warm up the planet thus drying up rivers and lakes which will, in turn emit less CO2 :) No finite quantity of CO2 in the atmosphere is needed to close this loop ... ... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ...
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    Really awkward joke explanation: I got the joke of Johannes, but maybe you did not get mine: by warming up the planet to get rid of the rivers and their problems, the water of the rivers will be accomodated in the atmosphere, therefore, the greenhouse gas of water.
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    from my previous post: "... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ..."
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    I guess the emphasis is on "could"... ;-) Also, everybody knows that rain is cold - so more water in the atmosphere makes the climate colder.
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    do you have the nature paper also? looks like very nice, meticulous typically german research lasting over 10 years with painstakingly many researchers from all over the world involved .... and while important the total is still only 20% of human emissions ... so a variation in it does not seem to change the overall picture
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    here is the nature paper : http://www.nature.com/nature/journal/v503/n7476/full/nature12760.html I appreciate Johannes' and Dario's jokes, since climate is the common ground that all of us can have an opinion, taking honours from experiencing weather. But, the same as if I am trying to make jokes for material science, or A.I. I take a high risk of failing(!) :-S Water is a greenhouse gas, rain rather releases latent heat to the environment in order to be formed, Johannes, nice trolling effort ;-) Between this and the next jokes to come, I would stop to take a look here, provided you have 10 minutes: how/where rain forms http://www.scribd.com/doc/58033704/Tephigrams-for-Dummies
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    omg
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    Nasia, I thought about your statement carefully - and I cannot agree with you. Water is not a greenhouse gas. It is instead a liquid. Also, I can't believe you keep feeding the troll! :-P But on a more topical note: I think it is an over-simplification to call water a greenhouse gas - water is one of the most important mechanisms in the way Earth handles heat input from the sun. The latent heat that you mention actually cools Earth: solar energy that would otherwise heat Earth's surface is ABSORBED as latent heat by water which consequently evaporates - the same water condenses into rain drops at high altitudes and releases this stored heat. In effect the water cycle is a mechanism of heat transport from low altitude to high altitude where the chance of infrared radiation escaping into space is much higher due to the much thinner layer of atmosphere above (including the smaller abundance of greenhouse gasses). Also, as I know you are well aware, the cloud cover that results from water condensation in the troposphere dramatically increases albedo which has a cooling effect on climate. Furthermore the heat capacity of wet air ("humid heat") is much larger than that of dry air - so any advective heat transfer due to air currents is more efficient in wet air - transporting heat from warm areas to a natural heat sink e.g. polar regions. Of course there are also climate heating effects of water like the absorption of IR radiation. But I stand by my statement (as defended in the above) that rain cools the atmosphere. Oh and also some nice reading material on the complexities related to climate feedback due to sea surface temperature: http://journals.ametsoc.org/doi/abs/10.1175/1520-0442(1993)006%3C2049%3ALSEOTR%3E2.0.CO%3B2
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    I enjoy trolling conversations when there is a gain for both sides at the end :-) . I had to check upon some of the facts in order to explain my self properly. The IPCC report states the greenhouse gases here, and water vapour is included: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-2-1.html Honestly, I read only the abstract of the article you posted, which is a very interesting hypothesis on the mechanism of regulating sea surface temperature, but it is very localized to the tropics (vivid convection, storms) a region of which I have very little expertise, and is difficult to study because it has non-hydrostatic dynamics. The only thing I can comment there is that the authors define constant relative humidity for the bottom layer, supplied by the oceanic surface, which limits the implementation of the concept on other earth regions. Also, we may confuse during the conversation the greenhouse gas with the Radiative Forcing of each greenhouse gas: I see your point of the latent heat trapped in the water vapour, and I agree, but the effect of the water is that it traps even as latent heat an amount of LR that would otherwise escape back to space. That is the greenhouse gas identity and an image to see the absorption bands in the atmosphere and how important the water is, without vain authority-based arguments that miss the explanation in the end: http://www.google.nl/imgres?imgurl=http://www.solarchords.com/uploaded/82/87-33833-450015_44absorbspec.gif&imgrefurl=http://www.solarchords.com/agw-science/4/greenhouse--1-radiation/33784/&h=468&w=458&sz=28&tbnid=x2NtfKh5OPM7lM:&tbnh=98&tbnw=96&zoom=1&usg=__KldteWbV19nVPbbsC4jsOgzCK6E=&docid=cMRZ9f22jbtYPM&sa=X&ei=SwynUq2TMqiS0QXVq4C4Aw&ved=0CDkQ9QEwAw
Thijs Versloot

Walking droplets (video) - 2 views

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    Wow, the two droplets that orbit each other are really cool - as is the explanation!
Nicholas Lan

Kerbal Space Program | Media - 2 views

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    what seems to be an impressively detailed space game
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    Yeah... 2011 called with the greetings. However, there was quite an interesting news about KSP recently... Perhaps it's been ACT's small failure to spot this opportunity? Considering we wrote space missions games ourselves...
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    This guy actually makes very detailed video tutorials about how to master the orbital dynamics in Kerbal. I think the level of detail (and sometimes realism) is quite impressive: https://www.youtube.com/channel/UCxzC4EngIsMrPmbm6Nxvb-A
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    I will have to try this definitely, looks like a lot of fun.. I also saw some crazy 'Insane Rocket Division' videos.. :)
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    @Marek: true, old news. But "opportunity"? For what? The games we write are always games with a scientific purpose (not training not educational) Kerbal Space programme is cool, but it is a game just like Microsoft Flight Simulator (but less accurate). Having ESA mission simulated in it is also cool but is it what we should or could do? Even more is it want we want to do? My personal opinion: No-No-No
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    > The games we write are always games with a scientific purpose (not training not educational) I'd say investigating how to get the crowd may be an important part of "science of crowdsourcing". So, an obvious example would be comparing how many participants the original ACT space mission game attracted versus a variant implemented in Kerbal and why. Easily made and easily publishable I think. But that's just an obvious example I can give on the spot. I think there is more potential than that, so would not dismiss the idea so definitively. But then, correct me if I'm wrong, social sciences are still not represented in the ACT... Perhaps an idea to revive during the upcoming retreat? ;-)
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    it's on sale on steam til tomorrow by the way if anyone's interested
jmlloren

Insect flight dynamics: Stability and control - 2 views

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    A recently published review on insect flight appeared in Review of Modern Physics. It might be of interest to the biomimetics unit.
tvinko

Massively collaborative mathematics : Article : Nature - 28 views

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    peer-to-peer theorem-proving
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    Or: mathematicians catch up with open-source software developers :)
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    "Similar open-source techniques could be applied in fields such as [...] computer science, where the raw materials are informational and can be freely shared online." ... or we could reach the point, unthinkable only few years ago, of being able to exchange text messages in almost real time! OMG, think of the possibilities! Seriously, does the author even browse the internet?
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    I do not agree with you F., you are citing out of context! Sharing messages does not make a collaboration, nor does a forum, .... You need a set of rules and a common objective. This is clearly observable in "some team", where these rules are lacking, making team work inexistent. The additional difficulties here are that it involves people that are almost strangers to each other, and the immateriality of the project. The support they are using (web, wiki) is only secondary. What they achieved is remarkable, disregarding the subject!
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    I think we will just have to agree to disagree then :) Open source developers have been organizing themselves with emails since the early '90s, and most projects (e.g., the Linux kernel) still do not use anything else today. The Linux kernel mailing list gets around 400 messages per day, and they are managing just fine to scale as the number of contributors increases. I agree that what they achieved is remarkable, but it is more for "what" they achieved than "how". What they did does not remotely qualify as "massively" collaborative: again, many open source projects are managed collaboratively by thousands of people, and many of them are in the multi-million lines of code range. My personal opinion of why in the scientific world these open models are having so many difficulties is that the scientific community today is (globally, of course there are many exceptions) a closed, mostly conservative circle of people who are scared of changes. There is also the fact that the barrier of entry in a scientific community is very high, but I think that this should merely scale down the number of people involved and not change the community "qualitatively". I do not think that many research activities are so much more difficult than, e.g., writing an O(1) scheduler for an Operating System or writing a new balancing tree algorithm for efficiently storing files on a filesystem. Then there is the whole issue of scientific publishing, which, in its current form, is nothing more than a racket. No wonder traditional journals are scared to death by these open-science movements.
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    here we go ... nice controversy! but maybe too many things mixed up together - open science journals vs traditional journals, conservatism of science community wrt programmers (to me one of the reasons for this might be the average age of both groups, which is probably more than 10 years apart ...) and then using emailing wrt other collaboration tools .... .... will have to look at the paper now more carefully ... (I am surprised to see no comment from José or Marek here :-)
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    My point about your initial comment is that it is simplistic to infer that emails imply collaborative work. You actually use the word "organize", what does it mean indeed. In the case of Linux, what makes the project work is the rules they set and the management style (hierachy, meritocracy, review). Mailing is just a coordination mean. In collaborations and team work, it is about rules, not only about the technology you use to potentially collaborate. Otherwise, all projects would be successful, and we would noy learn management at school! They did not write they managed the colloboration exclusively because of wikipedia and emails (or other 2.0 technology)! You are missing the part that makes it successful and remarkable as a project. On his blog the guy put a list of 12 rules for this project. None are related to emails, wikipedia, forums ... because that would be lame and your comment would make sense. Following your argumentation, the tools would be sufficient for collaboration. In the ACT, we have plenty of tools, but no team work. QED
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    the question on the ACT team work is one that is coming back continuously and it always so far has boiled down to the question of how much there need and should be a team project to which everybody inthe team contributes in his / her way or how much we should leave smaller, flexible teams within the team form and progress, more following a bottom-up initiative than imposing one from top-down. At this very moment, there are at least 4 to 5 teams with their own tools and mechanisms which are active and operating within the team. - but hey, if there is a real will for one larger project of the team to which all or most members want to contribute, lets go for it .... but in my view, it should be on a convince rather than oblige basis ...
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    It is, though, indicative that some of the team member do not see all the collaboration and team work happening around them. We always leave the small and agile sub-teams to form and organize themselves spontaneously, but clearly this method leaves out some people (be it for their own personal attitude or be it for pure chance) For those cases which we could think to provide the possibility to participate in an alternative, more structured, team work where we actually manage the hierachy, meritocracy and perform the project review (to use Joris words).
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    I am, and was, involved in "collaboration" but I can say from experience that we are mostly a sum of individuals. In the end, it is always one or two individuals doing the job, and other waiting. Sometimes even, some people don't do what they are supposed to do, so nothing happens ... this could not be defined as team work. Don't get me wrong, this is the dynamic of the team and I am OK with it ... in the end it is less work for me :) team = 3 members or more. I am personally not looking for a 15 member team work, and it is not what I meant. Anyway, this is not exactly the subject of the paper.
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    My opinion about this is that a research team, like the ACT, is a group of _people_ and not only brains. What I mean is that people have feelings, hate, anger, envy, sympathy, love, etc about the others. Unfortunately(?), this could lead to situations, where, in theory, a group of brains could work together, but not the same group of people. As far as I am concerned, this happened many times during my ACT period. And this is happening now with me in Delft, where I have the chance to be in an even more international group than the ACT. I do efficient collaborations with those people who are "close" to me not only in scientific interest, but also in some private sense. And I have people around me who have interesting topics and they might need my help and knowledge, but somehow, it just does not work. Simply lack of sympathy. You know what I mean, don't you? About the article: there is nothing new, indeed. However, why it worked: only brains and not the people worked together on a very specific problem. Plus maybe they were motivated by the idea of e-collaboration. No revolution.
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    Joris, maybe I made myself not clear enough, but my point was only tangentially related to the tools. Indeed, it is the original article mention of "development of new online tools" which prompted my reply about emails. Let me try to say it more clearly: my point is that what they accomplished is nothing new methodologically (i.e., online collaboration of a loosely knit group of people), it is something that has been done countless times before. Do you think that now that it is mathematicians who are doing it makes it somehow special or different? Personally, I don't. You should come over to some mailing lists of mathematical open-source software (e.g., SAGE, Pari, ...), there's plenty of online collaborative research going on there :) I also disagree that, as you say, "in the case of Linux, what makes the project work is the rules they set and the management style (hierachy, meritocracy, review)". First of all I think the main engine of any collaboration like this is the objective, i.e., wanting to get something done. Rules emerge from self-organization later on, and they may be completely different from project to project, ranging from almost anarchy to BDFL (benevolent dictator for life) style. Given this kind of variety that can be observed in open-source projects today, I am very skeptical that any kind of management rule can be said to be universal (and I am pretty sure that the overwhelming majority of project organizers never went to any "management school"). Then there is the social aspect that Tamas mentions above. From my personal experience, communities that put technical merit above everything else tend to remain very small and generally become irrelevant. The ability to work and collaborate with others is the main asset the a participant of a community can bring. I've seen many times on the Linux kernel mailing list contributions deemed "technically superior" being disregarded and not considered for inclusion in the kernel because it was clear that
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    hey, just catched up the discussion. For me what is very new is mainly the framework where this collaborative (open) work is applied. I haven't seen this kind of working openly in any other field of academic research (except for the Boinc type project which are very different, because relying on non specialists for the work to be done). This raise several problems, and mainly the one of the credit, which has not really been solved as I read in the wiki (is an article is written, who writes it, what are the names on the paper). They chose to refer to the project, and not to the individual researchers, as a temporary solution... It is not so surprising for me that this type of work has been first done in the domain of mathematics. Perhaps I have an ideal view of this community but it seems that the result obtained is more important than who obtained it... In many areas of research this is not the case, and one reason is how the research is financed. To obtain money you need to have (scientific) credit, and to have credit you need to have papers with your name on it... so this model of research does not fit in my opinion with the way research is governed. Anyway we had a discussion on the Ariadnet on how to use it, and one idea was to do this kind of collaborative research; idea that was quickly abandoned...
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    I don't really see much the problem with giving credit. It is not the first time a group of researchers collectively take credit for a result under a group umbrella, e.g., see Nicolas Bourbaki: http://en.wikipedia.org/wiki/Bourbaki Again, if the research process is completely transparent and publicly accessible there's no way to fake contributions or to give undue credit, and one could cite without problems a group paper in his/her CV, research grant application, etc.
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    Well my point was more that it could be a problem with how the actual system works. Let say you want a grant or a position, then the jury will count the number of papers with you as a first author, and the other papers (at least in France)... and look at the impact factor of these journals. Then you would have to set up a rule for classifying the authors (endless and pointless discussions), and give an impact factor to the group...?
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    it seems that i should visit you guys at estec... :-)
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    urgently!! btw: we will have the ACT christmas dinner on the 9th in the evening ... are you coming?
Beniamino Abis

Self-healing plastic that regenerates mimicking blood clots - 1 views

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    A vascular synthetic system that restores mechanical performance in response to large-scale damage. Gap-filling scaffolds are created through a two-stage polymer chemistry that initially forms a shape-conforming dynamic gel but later polymerizes to a solid structural polymer with robust mechanical properties.
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