From Starbucks punch cards to credit cards that earn frequent flyer miles, everything’s becoming a game. Jesse Schell, a professor at Carnegie Mellon University and founder of Schell Games, thinks that this is only the beginning. In a presentation he recently gave at the DICE 2010 tech summit, he laid out the future “beyond Facebook,” where the psychological tricks used to persuade people to fork over real cash for virtual games like Farmville will infiltrate our lives much more deeply. The future that Schell envisions is high-tech, but not too far-fetched. As technology becomes cheaper and cheaper, it will become more prevalent and even disposable, he says. For example, sensors will be affixed to all sorts of cheap products – from soda cans to cereal boxes – that track our activities. Products will have CPUs, screens, and cameras that allow consumers to play games on the packaging, for instance, and then a Wi-Fi connector will upload the game scores or eating habits to the Internet. Why would you want to participate in this seemingly mundane game world? Because you get points, which can be reimbursed for real goods and money. Of course, you may have to go a little bit out of your way to appease the point-givers. For example, if you use public transportation, maybe you would earn points that could be used for tax incentives. If your kids get good grades, you might get good parenting points from a government-sponsored social program, or kids that participate in positive activities could earn points that go toward a college scholarship. Sensors in your shoes could determine how much you walk per day, and your health insurance company might give you points for walking certain distances or for getting your heart rate up. Maybe you could even get a digital tattoo that comes with a “Tatoogle adsense” agreement, and earn points from that. Jesse Schell’s presentation at DICE 2010.“I jokingly call this convergence of games into reality the ‘Gamepocalypse’: the moment when every moment of life is actually a game,” Schell said in a recent interview at CNN.If all this tracking and measuring sounds a bit dystopian, Schell argues that it’s just good old capitalism at work. After all, no one is required to participate in the games; the game-based society is more a form of highly interactive advertising and influence. Explore further A clip from the video below, showing Jesse Schell’s presentation on life as a game. More information: Schell’s blog: Gamepocalypse Nowvia: CNN Citation: Professor says the Gamepocalypse is coming, but it may have a bright side (w/ Video) (2010, April 13) retrieved 18 August 2019 from https://phys.org/news/2010-04-professor-gamepocalypse-bright-side-video.html Students Launch Audiball, an Xbox Community Game “Anybody who has a product that can sense that the product is being used … they’re going to want to create motivations for you to use the product,” Schell said. “So fundamentally, they’re going to make games out of it, because games are reward-based systems that motivate us to do things.”Schell notes several examples belonging to this game-based future that already exist today. A product called Green Goose that snaps onto your bicycle tracks how much you ride and has a system of rewards based on how much gas you save. An Oral-B toothbrush beeps when it’s time to switch jaw quadrants, and rewards you with a smiley face if you finish the entire three-minute brushing routine. Similarly, a bathroom scale with Wi-Fi that connects to the Internet uploads your weight to a database for tracking over time; the system can also be configured to tweet your weight. A GPS game called Foursquare has turned a practical device used for finding directions into a gaming device, where you get points based on the places you visit. You can even become “mayor” of a place if you visit there more than anyone else. Schell predicts that the next step for these games is when game designers start merging them all together.Listening to Schell describe these everyday devices-turned-games, the Gamepocalypse seems to be a logical next step for society. It’s nothing new that humans are quite a competitive species, even for seemingly trivial pursuits. Still, as Schell notes, these games will only work if the game design is done skillfully, such as by carefully tapping into the human psychology of how we rationalize spending money. Of course, the companies that hire game designers generally have only one goal in mind: profit.“The part that I worry about the most is sort of the perverse incentives that these systems are going to try to create,” Schell said, mentioning the example of tobacco companies. “Largely, the companies won’t be caring about our health and welfare. They’re going to be caring about, ‘Can I manipulate you into doing things that help the company?’”On the other hand, as Schell concludes in his DICE 2010 presentation, living in a world where everything we do is being watched could make us more conscientious and have a positive influence on our behavior.“It could be that these systems are just all crass commercialization and it’s terrible,” he said. “But it’s possible that they’ll inspire us to be better people – if the game systems are designed right.” © 2010 PhysOrg.com This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
(PhysOrg.com) — Silicon substrate LED’s are cool, but you won’t find them in your TV, or in the headlights of your car. They simply do not throw off enough light to be used in commercial applications. Or, at least they did not used to be able to. © 2010 PhysOrg.com Bridgelux Inc., a California-based developer of semiconductor technology and solid-state lighting, has demonstrated a silicon substrate LED with a light output of 135 lumens per watt. The company believes that this is the first time that anyone has created “commercial grade” performance from a silicon substrate LED.The performance of 135 lumen per watt came to fruition by using a single 1.5-mm diameter LED that is operated at 350-mA. The LED’s have a color correlated temperature (CCT) of 4730K. In order to function the LEDs require a 2.9-V at 350-mA and less than 3.25-V at 1-A.Instead of using the more commonly found sapphire or silicon carbide substrates to create the epitaxial wafers that are used to create the LED, Bridgelux decided to use the less expensive to produce, by growing, gallium nitride on low-cost silicon wafers. These grown wafers come in 150-, 200- and 300-mm diameters that can, according to Bridgelux, deliver a 75 percent improvement in cost.Products based on this technology are at least two to three years to come to market. Some of the potential applications for this technology include commercial and office lighting, residential lighting applications, and retrofit lamps that the company hopes will convert to the solid state lighting. No word as to any specifics as to when you can expect to buy a GaN-on-Silicon based LED lamp. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Bridgelux demonstrates silicon substrate LED that produces 135 lumens per watt (2011, March 9) retrieved 18 August 2019 from https://phys.org/news/2011-03-bridgelux-silicon-substrate-lumens-watt.html IMEC, AIXTRON set important step towards low-cost GaN power devices
Explore further (PhysOrg.com) — When comets and asteroids impact Earth, we’re usually most concerned with how the impact events have affected life here. But scientists have pointed out that these impact events can eject pieces of Earth’s crust containing biological organisms into space, and if ejected at the right velocities from the right location on Earth, the ejected material could collide with another planet and seed life elsewhere in the Solar System. By using new simulations to analyze the dynamics of these ejected particles, and by tripling the number of particles compared with previous studies to improve the statistics, researchers have found that particles could not only reach Venus, the Moon, and Mars, but for the first time they show that particles from Earth could also reach Jupiter. Citation: Simulation shows how Earth may have seeded life on other planets (2011, August 23) retrieved 18 August 2019 from https://phys.org/news/2011-08-simulation-earth-seeded-life-planets.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Auroral rocket observed flow of heat, particles and electromagnetic energy © 2011 PhysOrg.com More information: M. Reyes-Ruiz, et al. “Dynamics of escaping Earth ejecta and their collision probability with different Solar System bodies.” arXiv:1108.3375v1 [astro-ph.EP]via: Physics ArXiv Blog Out of 10,242 simulated particles ejected from Earth, these figures show the number of particles that collide with nearby planets at three different ejection velocities, and the collision times. In the top panel, the values corresponding to collisions with Venus and the Moon are 10 times the actual values, which are too small to be plotted. Image credit: M. Reyes-Ruiz, et al. Mauricio Reyes-Ruiz at the Universidad Nacional Autonoma de Mexico and coauthors have posted their study on the collision probabilities of particles ejected from Earth with other nearby planets at arXiv.org.In addition to showing that particles ejected from Earth could reach Jupiter, their simulations also showed that the number of particles ejected from Earth that collide with Mars is two orders of magnitude greater than previous studies have found. The researchers explain that both results have astrobiological significance, especially due to the evidence for life-sustaining environments on early Mars and on Jupiter’s moons Europa and Ganymede.In their simulations, the researchers analyzed 10,242 particles with a minimum ejection velocity of 11.2 km/s (which is required to escape Earth’s orbit). Different impact events throughout Earth’s history have ejected particles with a wide range of velocities, with the maximum determined by the speed of the impactor as it hits Earth. The researchers followed the simulated ejected particles for 30,000 years, which is the maximum estimated survival time for biological material in space.Calculations have shown that an ejection velocity of 11.62 km/s is needed to reach Mars and 14.28 km/s to reach the orbit of Jupiter. While particles with ejection velocities of around 11.2 km/s have the highest chance of falling back to Earth, particles with ejection velocities of greater than 16.4 km/s typically get launched entirely out of the Solar System. Since these particles spend a very short amount of time in the inner Solar System, their collision probability with other planets is negligible.The results of the simulation also showed that the probability of particles ejected from Earth colliding with other planets depends on the particular place on Earth from where the particles are ejected. Particles ejected from Earth’s leading face along its direction of motion, which are statistically more likely, have a higher probability of colliding with Mars and Jupiter, while particles ejected from the trailing face are more likely to impact Venus.The researchers note that, overall, the probability of particles ejected from Earth colliding with another planet is very small. Further studies will be needed to investigate the velocity distribution of the ejected particles, along with simulations that use a greater number of ejected particles to estimate collision rates that have greater statistical significance.
Citation: Teenager reportedly finds solution to 350 year old math and physics problem (2012, May 29) retrieved 18 August 2019 from https://phys.org/news/2012-05-teenager-reportedly-solution-year-math.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Image: Welt.de © 2012 Phys.Org Shouryya Ray, a modest student who just four years ago was living in Calcuta, has been on an accelerated learning course and is taking his Abitur exams two years early. His math equations won him first place in a state science competition and second place in the national Math and IT section at finals. He’s told the press that figuring out how to come up with his formulas was more due to school-boy naivety than genius, which the German press has been suggesting.Ray moved with his family to Germany when his father landed a job as a research assistant at the Technical University of Freiburg. He has apparently shown great aptitude for math from an early age, learning calculus from his dad when he was still just six years old. He’s told the press that he got the idea of trying to develop the two formulas after visiting Dresden University on a field trip where he was told that no one had been able to come up with equations to describe the two dynamics theories. Ray’s story has generated a lot of press around the world, highlighting the young lad’s ability to come up with a math formula that not even the great Isaac Newton could find, despite the fact that no one other than a few local people have seen the formulas he’s created; thus, in the math and physics world there remains a great deal of skepticism regarding what he’s actually accomplished and most are holding off judgment until the formulas are published and reviewed. More information: via Welt, IBTimes, Discovery (Phys.org) — In Isaac Newton’s Principia Mathematica published in 1687, the man many consider the most brilliant mathematician of all time used a mathematical formula to describe the path taken by an object when it is thrown through the air from one point to the next, i.e. an arc based on several factors such as the angle it is thrown at, velocity, etc. At the time, Newton explained that to get it completely right though, air resistance would need to be taken into account, though he could not figure out himself how to factor that in. Now, it appears a 16 year old immigrant to Germany has done just that, and to top off his work, he’s also apparently come up with an equation that describes the motion of an object when it strikes an immobile surface such as a wall, and bounces back. Explore further Revealed: The fish that nearly sank Isaac Newton
Citation: Invisibility cloak hides parts of objects, leaves other parts visible (2013, December 2) retrieved 18 August 2019 from https://phys.org/news/2013-12-invisibility-cloak-visible.html The new study marks the first time that scientists have designed and fabricated localized invisibility cloaks and illusion devices that cloak or change only the desired parts of an object, leaving the other parts visible. To do this, the researchers explain how they first divide the physical space to be cloaked into many subregions (because invisibility cloaks operate on circular regions, the space is divided along azimuthal and radial lines, like the lines of a dart board). Any of the subregions can be chosen to be cloaked or not cloaked. Next, the researchers map the subregions of the real object to the corresponding subregions in a localized cloak. To make a subregion invisible, the researchers fill it with a cloaking material. As in global invisibility cloaks, this cloaking material is an artificially engineered metamaterial that has the key properties of being inhomogeneous and anistropic. To make a subregion visible, the researchers fill it with a material that is related to the original object, to generate the scattering signals of some parts of the object.The researchers demonstrated the feasibility of localized cloaking through numerical simulations and experimental demonstrations, and plan to continue with more experiments in the future.”We proposed the idea of localized transformation optics devices in all parts of the electromagnetic spectrum, including microwave, optical, etc.,” Cui said. “As a special example, we fabricated and tested a direct-current localized invisibility cloak in circuits. In the near future, we plan to fabricate a localized invisibility cloak in microwave frequencies and design some more complex transformation optics devices.” (a) Illustration of a locally invisible object, in which the green subregions are visible and the white subregions are invisible. (b) The near-field distribution of the object enclosed by the localized invisibility cloak shows that the white subregions look like the background, while the green subregions have a solid (visible) appearance. Credit: Jiang, et al. ©2013 AIP Publishing LLC (Phys.org) —When Harry Potter walks around with a visible head but an invisible body, the performance seems strongly rooted in fantasy. But in a new study, scientists have designed and fabricated an invisibility cloak that may make such a feat possible. The new cloak can conceal some arbitrarily chosen parts of objects while leaving other parts visible, making it a localized invisibility cloak. Nearly perfect, ultrathin invisibility cloak could have wide practical applications More information: Wei Xiang Jiang, et al. “Localized transformation optics devices.” Applied Physics Letters. DOI: 10.1063/1.4833279 The researchers, led by Professor Tie Jun Cui at Southeast University in Nanjing, China, have published their paper on localized transformation optics devices in a recent issue of Applied Physics Letters.”The potential application of a localized invisibility cloak is to make an object partly invisible and leave other parts visible,” Cui told Phys.org. “Although it is difficult to allow a person to be partly visible and partly invisible in current technology, we believe it is completely possible in the future.”Transformation optics devices, which control and guide electromagnetic fields, have been fabricated in many different forms since the concept was first proposed by John Pendry, et al., in 2006. For example, there are invisibility cloaks for microwave, infrared, and optical frequencies; ground-plane or carpet cloaks for hiding objects on a flat plane; and cloaks (also called illusion optical devices) for changing the scattering signals of objects so they appear as different objects.However, all of the devices that have been fabricated so far conceal and change the scattering signals of whole objects. As such, they can be thought of as global invisibility cloaks and illusion devices. Explore further © 2013 Phys.org. All rights reserved. Journal information: Applied Physics Letters (a) The original object (a car) can be enclosed by (b) a localized invisibility cloak so that part of the car is invisible or (c) a localized illusion device so that the part that was invisible in (b) appears as a minivan. Credit: Jiang, et al. ©2013 AIP Publishing LLC This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
© 2014 Phys.org. All rights reserved. More information: Hyunseok Jeong, Youngrong Lim, and M. S. Kim. “Coarsening Measurement References and the Quantum-to-Classical Transition.” Physical Review Letters, DOI: 10.1103/PhysRevLett.112.010402Also available at arXiv:1307.3746 [quant-ph] Quantum measurement carries information even when the measurement outcome is unread (Phys.org) —The quantum and classical worlds are clearly very different, but how a physical system transitions between them is much less clear. The most well-known attempt to explain the quantum-to-classical transition is decoherence, which is the idea that interactions with the environment destroy quantum coherence, causing a quantum system to become classical. Explore further Journal information: Physical Review Letters Citation: Quantum-to-classical transition may be explained by fuzziness of measurement references (2014, January 14) retrieved 18 August 2019 from https://phys.org/news/2014-01-quantum-to-classical-transition-fuzziness.html But in more recent years, physicists have been investigating alternative explanations based on an observer’s limited ability to control the precision of the measurements made on a system. The idea is that a system that appears to exhibit quantum behavior when observed with very precise measurements will appear to behave classically if the measurements are too coarse or fuzzy. In such a scenario, the coarsening of measurements forces the quantum-to-classical transition.The problem is, fuzziness in measurements does not always result in the quantum-to-classical transition, and physicists aren’t sure what exact conditions of the measurement process are necessary to definitively force the quantum-to-classical transition.In a new study published in Physical Review Letters, physicists Hyunseok Jeong and Youngrong Lim at Seoul National University in Seoul, Korea, and M. S. Kim at Imperial College London in the UK, have proposed an explanation. They explain that a complete measurement process is composed of two parts: one part is to set and control a measurement reference (such as timing or angle), and the other is the final detection. All of the previous studies have focused on coarsening the resolution of the final detection. Here, the physicists looked at both parts of the measurement process and found that their coarsening leads to completely different outcomes. Their main result is that coarsening the measurement reference always forces the quantum-to-classical transition, while coarsening the final detection does not. This is because increasing the “macroscopicity” of the system, such as by increasing the number of photons in an entangled photon state, can make up for the coarseness of the final detection, but not for the coarseness of the measurement reference.”Our results reveal a previously unknown yet very critical element in the process of the quantum-to-classical transition,” Jeong told Phys.org. “In the previous research along this line, researchers have paid attention to coarsening of the measurement resolution (i.e., efficiency of the final detection) to explain the quantum-to-classical transition, but it does not result in the quantum-to-classical transition under certain conditions. On the other hand, coarsening of the measurement references provides a stronger mechanism to explain the quantum-to-classical transition, as far as we could see, without an exception. Our results provide new insights into the quantum-to-classical transition and deepen the understanding of the measurement process by revealing the importance of the observer’s ability in controlling the measurement references.”The researchers explain that coarsening and decoherence are complementary explanations of the same problem.”The approach based on coarsening of measurements enables one to explain a part of the quantum-to-classical transition that cannot be explained by decoherence and vice versa,” Jeong said. “They are not contradictory to each other, nor does one of them replace the other.”The analysis suggests that this finding holds true for a wide range of physical systems, such as optical, atomic, and mechanical, and for systems using various degrees of freedom. In the future, the researchers hope to further investigate the extent of these results.”We hope to provide a more general and complete picture of the quantum-to-classical transition in our future research,” Jeong said. “In our published work, we investigated several different types of physical systems in order to support our claim. There exists, however, an interesting open problem to formally prove our claim in a completely general way for arbitrary systems. In general, we will further explore the boundaries between the quantum and classical worlds to understand and clarify when and how quantum systems become classical and vice versa.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Quantum physics could make secure, single-use computer memories possible Journal information: Physical Review Letters “QDS provides essentially all features for which standard ‘classical’ digital signatures are used in modern communication—guaranteed authenticity, integrity and transferability of messages,” Erika Andersson at Heriot-Watt University in Edinburgh, UK, told Phys.org. “The need for these features is ubiquitous in the modern e-world. They are used regularly in, for example, online banking, email systems, and smart electrical grids.”However, all QDS schemes proposed so far require advanced quantum memories capable of storing millions of qubits for months or even years. In contrast, today’s state-of-the-art quantum memories cannot store information for longer than a few minutes, which makes all QDS schemes proposed so far unfeasible. Now in a new paper published in Physical Review Letters, Andersson and UK-based coauthors Vedran Dunjko and Petros Wallden from Croatia and Greece, respectively, have proposed a QDS scheme that does not require any quantum memory, making the scheme feasible with current technology.A generic QDS protocol consists of two stages: distribution and messaging. In the distribution stage, the sender sends pairs of quantum states—or quantum signatures—to multiple recipients. This stage is independent of the future message sent in the messaging stage, where classical messages are sent to one or more recipients. Sometimes, it may be months or years from the time the quantum signatures are sent to the time an actual message is sent, which is why quantum memories have been required. The new protocol differs from the generic one in both stages. In the distribution stage, the quantum signatures are converted to classical information through quantum measurements, but they still retain the same level of security guaranteed by quantum mechanics. Yet because the information is now classical, it can be stored in a classical memory instead of a quantum one. Similarly, in the messaging stage, only classical data is processed by the receivers. One receiver may authenticate a message received directly from the sender, and a second receiver may verify a message forwarded by the first receiver. The scientists showed that, in both cases—authentication and verification—the new scheme provides security against problems such as forgery, tampering, and repudiation (in which the second receiver rejects the forwarded message).By showing that it is possible to perform a QDS scheme by using classical correlations, while maintaining the same security that is guaranteed by quantum correlations, the results open the doors to the experimental realization of QDS systems.”We have, since the publishing of our work, already carried out an experimental demonstration of our scheme on a small scale, in collaboration with the group of Prof. Gerald Buller at Heriot-Watt University,” the physicists wrote. “This we also aim at extending. Furthermore, we are developing new theoretical results which will make QDS even more efficient and feasible—everything can always be improved!” A communication protocol that uses quantum digital signatures (QDS) offers security guaranteed by quantum mechanics. A new QDS protocol that does not require quantum memories is the first scheme that may be feasible with current technology. Credit: Dunjko, et al. ©2014 American Physical Society © 2014 Phys.org. All rights reserved. Explore further (Phys.org) —Quantum mechanics offers the potential for creating communication technologies with an inherently higher security level than today’s classical technologies. Using quantum digital signatures (QDS), for example, messages can be sent to multiple recipients with the guarantee that the messages cannot be forged or tampered with. More information: Vedran Dunjko, et al. “Quantum Digital Signatures without Quantum Memory.” Physical Review Letters. DOI: 10.1103/PhysRevLett.112.040502Robert J. Collins, et al. “Optical realisation of Quantum Digital Signatures without quantum memory.” arXiv:1311.5760 [quant-ph] This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Quantum communication scheme provides guaranteed security without quantum memories (2014, February 17) retrieved 18 August 2019 from https://phys.org/news/2014-02-quantum-scheme-memories.html
Credit: Karen M. Davies et.al. pnas.org/content/108/34/14121.full More information: Cox17 is an auxiliary factor involved in the control of the mitochondrial contact site and cristae organizing system, The Journal of Biological Chemistry, First Published on April 27, 2015, DOI: 10.1074/jbc.M115.645069 . http://www.jbc.org/content/early/2015/04/27/jbc.M115.645069.full.pdf+html Explore further More power to the mitochondria: Cells’ energy plant also plays key role in stem cell development Citation: Controlling the internal structure of mitochondria (2015, May 5) retrieved 18 August 2019 from https://phys.org/news/2015-05-internal-mitochondria.html Perhaps the more difficult question here is which geometries correspond to which mitochondrial behaviors. The possible behaviors obviously include not just making ATP, but also everything from fatty acid oxidation, to synthesizing steroids, pigments, and other eclectic essentials for the host cell and organism. The possible membrane geometries, much like the various creatively-named models for the generation complex lipid membranes of myelinated nerves, come with descriptive brands like the original ‘infolding baffle model’ and the more modern ‘crista junction’ models. Crista junctions are the proteinaceous contacts made a specific critical points between the inner and outer membranes. These various folds transition in various contexts between tubular, lamellar, and helically wound sheets ( particularly common in certain protists).A couple of papers from the past week have reported on the roles of some of the more important proteins in shaping membranes. Of note, one published by Polish and German researchers in The Journal of Biological Chemistry found a critical new protein that controls formation of the so-called MICOS system (mitochondrial contact site and cristae organizing system). This protein, Cox17, was already known for its role as a chaperone in the assembly of respiratory complex IV on the inner membrane of mitochondria. Known as cytochrome c oxidase (COX), this is the terminal respiratory complex in the whole chain—the one that hands off the electrons to oxygen. Among other amenities, Cox17 has a series of critical cysteines which appear to involved in recruiting copper to the business end of the mitochondrially encoded COX subunits. (Phys.org)—One might think of mitochondria as devices for transporting electrons to their lowest energy state. Little bags of finely-tuned respiratory chain subunits which combine electrons extracted from food with oxygen, and ultimately excrete them as water. Others might justifiably fancy mitochondria tiny bundles of geometry. Their folded inner membranes pegged with various proteins complexes like the rolls of candy button paper we might have ate as kids. Actually mitochondria are both enzyme bags and geometrical objects: the latest research tells us that it is proteins which create the complex inner membrane geometry specific to each kind of mitochondria, and in turn, it is their precise geometry which permits the respiratory proteins to create useful work in the first place. Several researchers have previously found that this 600-kDa ATP-generating monster forms dimers that localize to the highly curved wells in the deepest recesses of the crista. These dimers (and sometimes higher order multimers), are found in everything from yeast to mammals, and align themselves in rows forming a ‘ridged ribbon’ across much of the mitochondria. In cross section, the dimers are in contact at an angle of about 90 degrees (between the long axis of the central symmetry axis of the sythase turbine), which gives them the rough appearance of a V-8 engine. Now, the method to the madness here is that the cristae can act as ‘proton traps’: the respiratory chain complexes form the proton sources, and the ATP synthases form the proton sinks at the apex of each local crista compartment. Under proton limited conditions the optimal flow of ions set up in this geometry would then allow for efficient ATP synthesis.It is not yet understood what drives synthase dimerization. It has been suggested that the spontaneous formation of dimer rows is driven more by the reduction in the membrane elastic energy than by direct protein contacts. Depending on which ATP synthase subunits are deleted, different experimental effects on mitochondrial geometry can be acheived. Deletion of subunits ‘E’ or ‘G’, which control dimerization, result in layers of onion-like inner membranes instead of the typical cristae. In some cases, the cristae are balloon-shaped and the lone synthase monomers take on a random distribution. Other research has drawn parallels between certain kinds of cristae geomtry and optimization for different kinds of metabolic activites like for example synthesis of steroids. In this case the convential wisdom is that steroid generating mitochondria are presumed to have higher crista tubularity while more typical mitochondria retain more lamellar crista instead.Perhaps more intriguing is the recent observation in fruit flies that while ATP synthase plays a key role in germ cell differentiation, that role is completely independent of oxidative phosphorylation. In other words, when any one of ATP sythase’s 13 key proteins were blocked, the manipulation stalled egg development, however, blocking other enzymes required for ATP production did not. Each organ develops it’s own preferred style of mitochondria, but it may be the retina which provides the best place to try to answer the ‘how and the why’ geometry is optimized according to cell type and function. Not only can a stimulus be precisely controlled and oxygen consumption easily measured for the retina, but the precise anatomical differences of rods verses cones are now known in great detail. For example, research by Marc Ellisworth has defined the connectivity and tubularity in crista structure for mitochondria found in the inner segments of photoreceptors, and correlated it with their known spiking characteristics and presumed signalling efficiency. In asking basic structure-function questions as we have before for whether a neuron should fire or not fire—ie. polarize or hyperpolarize in response to some event— like light, the costs and benefits associated with specific mitochondrial geometeries should not be ignored.It may be a small insight to appreciate, for example, that ‘rods are metabolically less costly than cones because cones don’t saturate in bright light and also use more ATP in their downstream signalling pathways,’ but to be able to see that directly in the mitochondria, through nothing but bare membrane geometry is a good beginning. Journal information: Journal of Biological Chemistry © 2015 Phys.org In addition to defining a key role for Cox17 in establishing the MICOS, the researchers found that copper itself may regulate the interaction between the two. Truth be told, that point is probably not a very big deal. The MICOS seems to be a fairly sensitive assembly—if just one of its six protein subunits is missing the membrane contact points will detach. The MICOS works together with the crista junctions to maintain the deeply fissured profile of the crista. You might asking yourself about now, what exactly is the point of this peculiar clefted geometry? For that we need to look at the heavy hitter of mitochondrial proteins, the F1F0-ATP synthase. This is the guy that gets all the hard-core creationists up in a bunch for no apparent reason other than because it is simply that cool. Structure of ATPase dimers. Credit Karen M. Davies et. al. PNAS This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Explore further More information: Olga Shishkov et al. Black soldier fly larvae feed by forming a fountain around food, Journal of The Royal Society Interface (2019). DOI: 10.1098/rsif.2018.0735 A team of researchers at the Georgia Institute of Technology has found that black soldier fly larvae maximize their eating efficiency by pushing non-eaters out of the way, causing the emergence of a fountain shape made up of larvae bodies. In their paper published in Journal of the Royal Society Interface, the group describes their study of black fly larvae and their eating habits, and what they learned. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Explore further New study of Avebury monument suggests it started out as a single-family home A team of researchers at the University of Salford in the U.K. has revealed how voices would have sounded 4,000 years ago inside of the Stonehenge monument. The group made a recording of their efforts and posted the results on SoundCloud.