December 19

Nose Code Rockets Smell Discrimination

first_imgYou have a code in your nose.  Scientists working on fruit fly olfactory systems have found that a mapping mechanism between components maximizes the fly’s ability to discriminate smells.  The coding system provides a non-linear response that appears finely tuned to maximize the information content of odor inputs.    The components of this system (antennal lobe, olfactory bulb, glomeruli, projection neurons, Kenyon cells) were described in more detail in our 06/27/2005 entry.  Why is the input information passed through several stages that combine, sort and distribute their respective inputs?  It turns out that a kind of computational algorithm is being performed on the input that translates a highly-variable chemical code into a discrete neural code.  This is analogous to analog-to-digital conversion.  In the process, one part can average away uncorrelated variability, but amplify correlated signals.  The outputs are amplified in a non-linear fashion, providing the maximum discrimination between input smells, some of which might be very similar.  The system also allows the teasing out of information from very weak inputs.    Baranidharan Ramana and Mark Stopfer, writing in Current Biology,1 commented on a recent study by Bhandawat et al. who “used the relatively simple olfactory system of the fruitfly Drosophila to show how noisy, variable peripheral signals are transformed by early neural circuits into consistent, efficient and distinguishable odor representations.  In their review, they described how the coding is finely balanced:…Bhandawat et al. found that the responses of projection neurons were highly correlated with each other, as were responses within groups of ORNs [olfactory receptor neurons].  The existence of inhibitory and excitatory local neurons in the antennal lobe suggests that both competitive and associative interactions are possible.  Purely inhibitory interactions between projection neurons would tend to decorrelate their responses; in an extreme case – a fully connected network – such interactions would lead to a ‘winner-take-all’ competition, resulting in a coding capacity greatly reduced to the number of available output channels.  Purely excitatory interactions, on the other hand, would decrease the independence of channels to lower than what is available in their inputs.  Thus, the results of Bhandawat et al. suggest that the network connectivity of the antennal lobe is delicately balanced to optimize its coding capacity.By optimizing its coding capacity, they mean that the system is sensitive, consistent, efficient, and reliable – despite the “chaotic structures of odor plumes” that are the inputs.  They said that the system also includes a “‘high-pass’ filtering function [that] may allow flies to alter behaviors rapidly when stimulated by odors.”  In addition, the time variability of the input signals gives the system additional real-time information.    What’s the usefulness of studying a fruit fly antenna?  In short, the elegant solution seen here can inspire human engineers faced with similar information-processing problems:The work by Bhandawat et al. provides insights into the logic behind olfactory circuit design.  It will be interesting to analyze how these results generalize to a larger set of odorants, and to other species.  It will also be interesting to see whether these peripheral circuits play a role in insulating the neural signal-processing engine from the constant changes in the population of ORNs that occur throughout the lifetime of the animal.  These fundamental olfactory processing principles are not only important for understanding how the brain interprets odor signals, but are also necessary for engineering solutions inspired by biological computations for addressing high dimensional and non-linear problems.The authors noted that the coding system found in the fruit fly is similar to that used by many animals.  This prompted an evolutionary speculation: “This peripheral reorganization scheme is remarkably similar across species and phyla, suggesting a design optimized over evolutionary time to solve a common information processing problem.”1.  Baranidharan Ramana and Mark Stopfer, “Olfactory Coding: Non-Linear Amplification Separates Smells,” Current Biology, Volume 18, Issue 1, 8 January 2008, pages R29-R32; doi:10.1016/j.cub.2007.10.063.Scratch that last lame, useless, dull, insipid, witless remark about evolutionary time optimizing design.  Can anyone conceive of how many lucky mutations would be required for this multi-part system to evolve?  The inputs are correlated and decorrelated, converged and distributed, filtered and amplified through a remarkable series of stages that results in a non-linear fashion to gain the maximum amount of information from the input.  If any one of these stages failed, the whole system wouldn’t work.  This is more elaborate than the famous Honda Accord commercial in which a rolling lug nut as input moved a half-ton automobile as output by passing through a finely-tuned chain reaction of alternating strong and weak energetic events.    Don’t accept balderdash about miracles in evolutionary time brought about by random, mindless mutations that yield optimized designs by accident.  This story was about intelligent design from start to finish.  It should make us stand in awe of creation while we employ our creativity to imitate and apply the engineering for the improvement of human life.  That is the fragrance of science.(Visited 14 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

December 18

Govt, Absa partner on technology

first_img20 March 2012 Banking group Absa and the Department of Science and Technology have signed an agreement to collaborate on a range of technology and agricultural business development programmes aimed at stimulating South Africa’s growth trajectory. Speaking in Pretoria on Monday after signing the memorandum of understanding, Science and Technology Minister Naledi Pandor said the partnership was in line with the government’s bid to find “sustainable strategies to increase investment in research and development, and also stimulate business to do the same”.Closing the ‘innovation chasm’ In terms of the agreement, the department and Absa will work together on human capital development, technology commercialisation, renewable energy technologies, information communication technology (ICT) and agricultural business development. Pandor said the partnership would help to address the “innovation chasm” in ICT, information security and renewable energy technologies. Underlying the collaboration was an attempt to create “synergies in the research, development and innovation enterprise,” Pandor said, adding that it was crucial for South Africa to promote a prosperous society that derived equitable benefits from science and technology.Partnerships for human development Absa’s chief executive for retail and business banking, Bobby Malabie, said Absa was committed to helping the government widen access to high-level graduate programmes in science and engineering. “Our role extends beyond that of a mere bank,” Malabie said. “We are a true partner in society as we take a step closer today towards realising the desired partnership with universities to attract quality graduates who will be able to advance the fields of science, engineering and technology. “It is only through industrial, governmental and educational partnerships that this can be achieved,” he said. Source: BuaNewslast_img read more

November 27

More 3 pointers from June Mar Fajardo? Don’t count on it, says San Miguel center

first_imgPrivate companies step in to help SEA Games hosting The three-pointer, though, wasn’t the only thing Fajardo did out of the ordinary.During the second half, with San Miguel holding a double-digit lead, Fajardo dribbled the ball between his legs and proceeded to shoot a fade-away jumper from the post.Unfortunately for Fajardo, the shot didn’t go in.Still, it was a moment of pure joy for Fajardo who got the moves from the Internet.“I got it by watching too much YouTube,” said Fajardo. “Coach Leo [Austria] just shook his head when I looked at him.”“It could’ve looked better if it went in, but it just missed. We’re also up by a big margin so I tried to do it but if the game’s close I won’t even think about doing it.”Sports Related Videospowered by AdSparcRead Next P2.5 B shabu seized in Makati sting, Chinese national nabbed Gennady Golovkin to return in June after signing deal with DAZN MOST READ P2.5 B shabu seized in Makati sting, Chinese national nabbed Trending Articles PLAY LIST 00:50Trending Articles01:42Despite decorated career, June Mar Fajardo is not yet done: ‘I don’t want to be stagnant’01:02Fajardo predicts there will be no sweep in PBA Finals02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games02:11Trump awards medals to Jon Voight, Alison Krauss View comments MANILA, Philippines—Don’t count on June Mar Fajardo shooting more threes any time in the PBA.FEATURED STORIESSPORTSPrivate companies step in to help SEA Games hostingSPORTSUrgent reply from Philippine ‍football chiefSPORTSPalace wants Cayetano’s PHISGOC Foundation probed over corruption chargesFajardo, who only has two made three-pointers in his career, shot his first three-point basket of the season in the first quarter of San Miguel’s 121-111 win over NLEX in the Philippine Cup Friday at Smart Araneta Coliseum.San Miguel’s joviant giant, however, said that he only took the outside shot since the shot clock was running out and the Beermen were up 28-4 after his conversion. Lacson backs proposal to elect president and vice president in tandem 1 dead, 3 injured in Quezon road crash Trump campaign, GOP groups attack Google’s new ad policy Hong Kong tunnel reopens, campus siege nears end SEA Games hosting troubles anger Duterte LATEST STORIES Don’t miss out on the latest news and information. “It’s no big deal, and I think it’d be just a one-time thing,” said Fajardo in Filipino. “It was also in the dying seconds so that’s just a fluke.”Fajardo, whose last three-point basket was in the 2016-17 season, always shoots his outside shots in San Miguel’s practices but he knows his advantage is inside the paint, and sometimes in the mid-range, so he stays to his strength in the PBA.And although Yeng Guiao, NLEX head coach and also Fajardo’s mentor in the national team, allows his big men to spread the floor, San Miguel’s 6-foot-10 center would much rather give that job to his teammates like Marcio Lassiter and Chris Ross.“Maybe in international play I’ll shoot from outside but in the PBA that’s not my game,” said Fajardo who finished with 27 points and 13 rebounds. “I’ll leave the shooting to Marcio and Chris.”“I think I’ll shoot a three in the dying seconds and it also depends if I’m free or not.”ADVERTISEMENTlast_img read more