…denies robbery chargesTwenty-nine-year-old miner David Alexander of Lot 61 Hadfield Street, Lodge was yesterday arraigned in Georgetown Magistrate Judy Latchman’s court on a charge of escaping from Police custody.Particulars of the charge state that on May 19, 2018 at North Road, Georgetown, while being in Police custody for questioning in a robbery-with-aggravation offence, he escaped from lawful custody.He pleaded guilty with explanation, telling the court that he had been badly beaten by Police ranks, and was being taken to recover the items which he had reportedly stolen when he was left alone in the Police van; and fearing for his life, he escaped.However, Police Prosecutor Arvin Moore told the court that Alexander pushed an officer and made good his escape. He was later apprehended in a minibus at Industry, East Coast Demerara (ECD).As such, Alexander was jailed for 18 months on this charge.He denied two other charges brought against him, alleging that on May 19, 2018, at both Hincks Street and Regent Street, Georgetown, while being in the company of others, he robbed Junior Azim and Johnny Loham respectively of items with a total value of $25,000. These cases will continue on June 11.
The aroma of coffee, of a steak, of cherries – these smells are all composed of dozens if not hundreds of separate molecules, yet our brains immediately recognize them each as a coherent whole. How does the nose and the brain process all this information? This is the subject of an article in the Caltech magazine Engineering and Science1 by Gilles Laurent, Caltech professor and neurologist, who studies olfaction and also “how single neurons perform nonlinear operations such as multiplication.” Unlike vision and hearing, our olfactory sense does not allow us to decompose a composite input into its constituents. We perceive odors as single entities. Studies on insects by Laurent and his students show that this is because individual receptors fire in patterns that are mapped like a code to a large number of unique sensors called Kenyon cells. In insects, these cells reside in a part of the olfactory apparatus called the mushroom body (in vertebrates, it’s the olfactory cortex of the brain). Each Kenyon cell gets a very unique set of inputs from the receptors, and thus a distinct, composite signal from a highly diverse set of inputs. Laurent does the math to show the staggering number of possibilities for odor memory that this system permits:The locust has 800 projection neurons connecting to 50,000 Kenyon cells. With such a large mismatch in numbers, how are these nerve-cell populations interconnected? When Ron Jortner, a graduate student in my lab, recorded simultaneously from both projection neurons and individual Kenyon cells to assess the probability of connection between them he found, surprisingly, that the probability was about 0.5. In other words, each Kenyon cell seems to connect on average to half of the input population, that is, to 400 projection neurons. The number of ways in which 400 neurons can be selected out of 800—the number of possible connection patterns—is about 10240. It’s an enormous number. To put it in context, there are about 1010 seconds in a century, and there have been about 1019 seconds since the beginning of the universe. With 10240 possible combinations of projection neurons to choose from—assuming random connectivity—almost every Kenyon cell is likely to sample a combination of inputs that is very different from that sampled by the other Kenyon cells. Each cell will therefore gain a picture of the state of the projection neuron population very different from that gathered by any other Kenyon cell. It follows that the responses of individual Kenyon cells will be very specific; a given cell should respond only to particular combinations of activated projection neurons, maximally different on average from those experienced by the other Kenyon cells. (Emphasis added in all quotes.)Laurent noted at the beginning of the article that olfaction is a form of pattern recognition, and that “Brains solve pattern-recognition problems much better than any machine built today.” His lab tries to figure out “how brains solve these problems.” Most of the research by Laurent and his students is on insects, whose olfactory receptors are on their antennae. A fruit fly has 1300 receptor neurons, with 60 different receptor types, but some moths might have several hundred thousand receptor neurons. This gives them an amazing sensitivity to low concentrations of odors like pheromones. A diagram and electron micrograph on p. 44 shows what receptor neurons look like. They have dozens of cilia projecting into the nasal cavity. The reason dogs have superior sensitivity to smells, he explains, is that their nasal cavity contains much more surface area where the receptors project from sponge-like tissue called turbinate bone. Dogs have ten times as much turbinate bone as humans. He provides a fragrant illustration: “In a medium-size dog,” he says, “the turbinates have a total surface area the size of a large pizza. In humans, they’re the size of a large cookie.” Each receptor neuron has a single sensitivity dictated by the order of the amino acids in its multi-folded receptor proteins. The amino acid sequences of receptor proteins show areas of both high conservation and high variability between species. They loop seven times through the cell membrane, providing pockets where the odor molecules bind. Laurent describes something striking about how the receptor neurons map their inputs to ball-shaped structures called glomeruli (singular, glomerulus). “In an amazing feat of organization during development,” a picture caption states, “each type of receptor neuron… sends its axon to the same glomerulus….” He calls it a “surprise” that all the axons of the same receptor type (colored red in the diagram) converge so neatly to their exact counterparts. “By implication,” he continues, “this means there are about as many glomeruli as there are receptor types. And with the exception of the roundworm, this extraordinary organization is found in almost all the animal species that have so far been looked at.” From the glomeruli, the information is passed on to a smaller group of nerve cells called projection neurons, which have no axons but connect with a dozen or more glomeruli. “With 100,000 receptor neurons converging on just 800 projection neurons, what is being computed?” he asks. Experiments show that the precise timing of firing creates a kind of code from the multiple inputs, a pulse pattern that can be mapped and analyzed. He likens the result to the unique arrangement that billiard balls take after the player breaks them with the cue ball; two very similar initial setups, but with slightly different angles of attack, can produce initially similar but ultimately divergent patterns of balls on the table. (The billiard game in the nose is super-fast. He notes on p. 48, “This happens so quickly that the representations are optimally separated within 100 to 300 milliseconds.”) As a result, differences between very similar smells can be amplified by the system. “That’s basically what we think is taking place in the olfactory circuit,” he says. “The remarkable thing is that this near-chaotic process is very sensitive to the input, but very reliable nevertheless.” To recap, the receptor proteins in the cilia of the receptor neurons react to molecules in odors. These neurons fire their axons to the glomeruli. The glomeruli then pass their encoded information patterns to the projection neurons. That noise-reduced information is passed in very unique ways to the tens of thousands of Kenyon cells, which have a near infinite way to respond to the myriad possible combinations of smells. “Kenyon cells are so specific that they only recognize one, or at most a few, odors,” a caption explains on p. 51. He summed it up earlier (p. 46): “In other words, each odor is defined by a certain combination of receptors; the code is combinatorial…. The perception of an odor must therefore result from the brain’s interpretation of combinatorial activity patterns.” Why, though, do a large number of receptors map to few encoders, and then those few to a large number of interpreters? There’s a reason for everything:It seems wasteful that hundreds of thousands of olfactory receptor neurons converge on their respective glomeruli in an amazingly precise way, but that this precision is then thrown away when seemingly disordered patterns of activation are generated in the projection neurons. But there’s a good reason for it. A system that amplifies small differences in signals runs the risk of also amplifying noise, in this case the noise coming from the receptors. Noise fluctuations would make the output of the projection neurons unreliable: the averaging that results from this kind of convergent design is precisely one way to reduce such fluctuations.(p. 49; for more on the problem of noise reduction, see 12/20/2004 entry). The sense of smell, obviously, is “quite complex.” It involves many more receptor types than other senses, like vision, which uses only four types of photoreceptor. How did the code in the nose, and all the apparatus in the circuitry, come about? Early in the article he speculated briefly about this question, but his answer assumes a remarkable convergence rather than demonstrating the evolutionary steps:In parts of the looping receptor protein chain, the order in which the amino acids are strung together is so variable that some animals, such as the rat, have over 1,200 different receptor types. On average, mammals have about 1,000 types, fish and birds between 100 and 200, round- worms (Caenorhabditis elegans) 1,000, and fruit flies 60. Humans have only 600 different odorant receptor genes, but almost half of these are “pseudogenes” that no longer function, leaving us with only 350 receptor types in our nasal mucosa…. Interestingly, when the receptor genes of mammals, flies, and worms were compared, no sequence homology was found. In other words, the genes had probably not evolved from a common ancestor: different types of animals had come up with their own particular (but related) designs for olfactory receptors independently throughout evolutionary history. Such convergent evolution, as it’s called, happens a lot in biological systems. The single-lens eye design, for example, has evolved independently at least eight times in the animal kingdom.How that happened is left as an exercise, but for Laurent, his job is in the here and now, studying the sensitive yet reliable olfactory computer: “Finding the rules of such nonlinear dynamical problems is one of our goals” (p. 49). Concluding, he says, “Our research into olfaction is…giving some valuable insights into how such kinds of high-level synthetic representations arise from the organization and dynamics of neural circuits” (p. 51). The nose shows that “Classifying and recognizing patterns is, after all, what our brains do best.”1Gilles Laurent, “Olfaction: A Window into the Brain,” Engineering and Science (LXVIII:1/2), [summer] 2005, pp. 43-51 (PDF).This article is a good companion to the next one (see 06/25/2005 entry). The language is similar: circuitry, computation, communication, codes, signals, and information. The lead-in photo shows a man with a very satisfied look savoring a cup of coffee, probably unaware that he is sensing a cocktail of two to three hundred compounds. Did you have any idea how much computation and circuitry make that pleasant feeling possible? We joke about our noses and don’t usually give them the same respect we pay the eye or ear, but each sense is more wonderful than we could possibly realize. Werner Gitt, in his delightful book The Wonder of Man, elaborates on some wonders of our human sense of smell. We have between 10 and 25 million receptor cells where the odor molecules fit with the proteins like a lock and key. Each olfactory cell measures only 5 to 15 millionths of an inch. Past these cells waft about 12 cubic meters of air per day, as we inhale and exhale 12,000 times. Our olfactory sense is extremely sensitive, exceeding the capabilities of most technological measuring instruments. We can detect one ten million millionth of a gram of mercaptan, for instance, and even distinguish between left- and right-handed forms of the same molecule. Remarkable as that is, we all know how the animal kingdom relies even more heavily on the sense of smell, marking territory with scents, using scents for sexual attraction, and navigating by their noses. A dog has 220 million receptor cells, tenfold more than we do; think of how dogs can be trained to sniff out bombs in luggage and people trapped under rubble or avalanches, or how bloodhounds can follow the footsteps of a crook all the way from the crime scene to his shoes. Maybe it’s good we humans don’t have that TMI problem, but our olfactory sensitivity is nothing to sneeze at. Smells enhance the taste and flavor of our food, color our world, and influence the way we think and act in many subtle ways. They warn us of danger, or attract us to pleasurable sensations. “Our memory for odours is astounding,” Gitt says; “nothing can stir up old memories better than a certain scent.” The fresh air in a pine forest, the sunshine after the rain, the fragrance of a rose, the symphony of smells at a table of great food – how impoverished life would be without a sense of smell. Thank God for your nose. Laurent’s brief side trip into Fantasyland with Tinker Bell (see 03/11/2005 commentary) provided some comic relief for this intense and thought-provoking look at a system of mind-boggling complexity. Did you enjoy the Fairy Godmother’s song, the Ballad of Convergent Evolution?Impossible! for a random mutation to become a neural circuit;Impossible! for an unguided process to produce a code so perfect.And four DNA bases will never produce Code Morses,Such fol-de-rol and fiddle-dee-dee of course is:Impossible!But the world is full of zanies and foolswho don’t believe in sensible rulesand won’t believe what sensible people say…and because these daft and dewey eyed dopeskeep building up impossible hopesimpossible things are happening every day!Nothing like a magic wand named Natural Selection to do impossible things. Just wish… and believe. While the Darwinists are wishing upon a star in Fantasyland, design scientists are turning Frontierland into Tomorrowland.(Visited 15 times, 1 visits today)FacebookTwitterPinterestSave分享0
22 May 2013 The police have arrested at least 116 people this week in an operation involving a special intervention team aimed at ridding the community of Eldorado Park, south of Johannesburg, of drugs and drug-related crime. This follows last week’s visit by President Jacob Zuma, who promised swift action in the fight against drug abuse in the area. Of the 116 arrested, 43 were for drug-related crimes, 20 for driving under the influence of alcohol, 10 for assault, while the rest were for various crimes such as burglary, theft and possession of unlicensed firearms. A total of 20 drug dens, also known as “lolly lounges”, have also been closed down. Four addicted children, including an 8-year-old, found at various “lolly lounges”, have been taken to a place of safety. Police also confiscated drugs including cat, mandrax, cocaine, rock and nyaope.Special team on the ground An integrated special intervention team, which includes a police tactical response team, members of the flying squad and provincial officers, has been dispatched to the area to increase visibility and hunt down drug dealers. Their operations include vehicle checkpoints, stop-and-searches, and visits to identified houses of alleged dealers and “lolly lounges”, and are continuing on a 24-hour basis in the area. The operation comes just days after Zuma visited the area in an answer to a plea from desperate parents, who informed the President about how drugs have run rampant in the area while some local police looked on. Briefing the media on the government’s intervention on Wednesday, Gauteng Premier Nomvula Mokonyane said the seriousness of the problem in Eldorado Park was one which required swift action and expertise. Mokonyane, who was flanked by members of the steering committee appointed by President Zuma, said various government departments would be working in partnership with the police to tackle the widespread substance abuse in the area. “The plan is based on two key strategies, which are the Drug Master Plan, that is aimed at reducing demand, harm and supply, and the Gauteng Provincial Anti-Substance Abuse Strategy, which focuses more on prevention, early intervention, treatment and after-care and reintegration.” Outlining the strategy, Mokonyane said the plan was not only about “banging down doors to get to drug dealers”, but would also take a deeper look into the social problems besetting the area.Making schools safe for children The preliminary intervention, which aims to reduce the demand for drugs, has also seen the police carrying out raids at various schools in the area, where random drug and body searches have been conducted, and raids at the homes of suspected minor drug dealers. The druglords tend to use minors to peddle drugs, especially at schools. Mokonyane told the media they were working towards ensuring that schools were safe havens. “This will be done by regular inspection of vendors outside and inside school premises, impromptu drug searches, deploying patrollers in schools and at every strategic point.” They would also fix broken school fences, clear open spaces next to schools of shrubbery, and implement the Safer Schools strategy and the Adopt-a-Cop programme for all schools in the area, she said. Part of the schools plan will be to raise awareness by conducting door-to-door campaigns, increasing the number of learners that visit prisons, and running substance abuse prevention and social crime prevention workshops. A Youth Against Drugs forum will also be formed through the Department of Social Development to educate learners about the effects of drugs. The number of social workers available to both learners in schools and youngster in the broader community will also be increased.Increasing rehab options Part of the government’s plan, according to Mokonyane, will be looking at how children who are already addicted can be helped. The premier announced that they have teamed up with Chris Hani Baragwanath Hospital, which will set up a short-term (seven-day) intensive detoxification programme. Plans are also in place to increase funding of existing out-patient treatment centres, not only in the area but the province as well. “In support of the initiative, we shall enhance mobilisation through community dialogues, youth safety imbizos, Men as Safety Promoters programmes and others. We shall also establish committees of concerned parents through local anti-drug committees.” Plans are also in place to register unregistered treatment centres to ensure that they are operating within the prescribed norms and minimum standards.‘We are moving in the right direction’ In order to ensure swift justice in the area, the steering committee is also looking at opening dedicated drug courts. According to Police Minister Nathi Methethwa, these special courts would “ensure the rapid processing of drug-related cases”. Mthethwa, who applauded the community of Eldorado Park for standing up and partnering with the government to find solutions to their challenges, said the high police visibility and random searches and raids would remain in place until the criminals had been brought to book. Residents who spoke to SAnews said they were seeing the difference and were starting to feel safer. “We are impressed by the police visibility. Drugs and criminals had taken over our streets, and now we are taking them back. Enough is enough,” said resident Anton Lynch. Michelle Booysens, who said drugs had been a big component of crime in the area, said she was “seeing the light … Once again, I have hope for this community. Yes, it’s still early days, but I have hope that we are moving in the right direction. Things are changing, and united we will soldier on. “ Mokonyane said there was still more to be done to ensure that the community normalised. “It’s not going to be easy, but it is going to be in the best interests of our community.” She added that they would bring on board a number of other departments, such as Economic Development and Trade and Industry, to address the critical lack of employment opportunities and economic activities in the area. “Economic development will receive particular attention so that we are able to ensure that we develop alternative sustainable livelihoods for families in the area. This includes approaching businesses who could potentially invest in the area.” The Department of Sports, Arts, Culture and Recreation will also be roped in to initiate a number of projects geared towards youth development and social cohesion. “We will solicit support of influential individuals from disciplines such as arts, sports, music and culture to have dialogues on issues of identity, culture, diversity and a sense of belonging,” said Mokonyane. Source: SAnews.gov.za
Space Shuttle Discovery (source: NASA)ORIGINALLY POSTED 10/28/2010UPDATE 2/24/2011The Space Shuttle Discovery and its crew launched into orbit on February 24th, 2011. The mission was originally scheduled for late 2010. According to NASA, the official mission rockets the shuttle toward the International Space Station (ISS) to deliver a module and critical spare parts. The mission will also make geocaching history, again.NASA Astronaut and geocacher Michael Barratt (source: NASA)Astronaut Michael Reed Barratt is the flight-surgeon on the mission. Barratt is also a geocacher.According to geocacher, cosmonaut and video game developer Richard Garriott (Lord British), Barratt will spend part of his free-time in the extreme environment of the International Space Station going geocaching.Garriott tells Geocaching.com, “The mission takes the NASA orbiter to the International Space Station and the highest geocache in existence. In the two years that bug has waited on-board the ISS, it has sure made some distance!”Garriott contributed $30 million to the Russian Space program for a seat aboard a Soyuz rocket bound for the space station. While on the space station he hid the geocache “International Space Station” (GC1BE91) and placed a Travel Bug inside it.Richard GarriottThe ISS and the Travel Bug placed onboard travel at 17,500 miles an hour. So far the Trackable has moved more than 350 million miles since Garriott placed it in October of 2008.Garriott met Barratt during preparation for his trip to the ISS. According to Garriott, “I know Mike from my training time in Star City [Russia] as he was training there too. In fact, he was one of the very first Astronauts /Cosmonauts I met in Russia.”Garriott says Barratt already had one chance to grab the Travel Bug but missed it: “He has already flown once between the time I left the bug and this flight. He even saw the bug, but he was not a geocacher at the time, and so my hidden in plain sight worked!”Travel Bug aboard the ISSBarratt has a rare second chance to grab the Travel Bug. And Garriott says that Barratt is going to take it: “Now that he is a geocacher, he recognized the item immediately! I have spoken with him about his upcoming flight and intentions to recover the well traveled bug.”Garriott hopes the Travel Bug takes a final trip to his doorstep, “I do indeed hope that the bug finds its way back to me, that would be a real thrill.” Although he hopes that it experiences some more extreme conditions first: “I think Mike may have it visit the NASA undersea lab before it finishes its exotic journey to the heights and depths humanity can take it.”Watch the Lost & Found video below showcasing Garriott placing the ISS geocache. The video also details Garriott hiding the lowest geocache in the world. He placed the geocache “Rainbow Hydrothermal Vents” (GCG822) in 2002. It sits 2300 meters below the surface of the ocean.Share with your Friends:More SharePrint RelatedThe First Geocaching First-to-Find in SpaceNovember 18, 2013In “Community”Highest and Lowest Geocaches – Geocaching PresentsJune 1, 2010In “Community”Geocaching in Space FAQOctober 9, 2013In “Community”
South Africa’s star batsman AB de Villiers has said that there would be a question mark on India’s number one ranking if they falter in the three-match series starting on December 16.”There’s been this feeling and stats show it, that their batters score bigger and they generally perform better at home, which is normal. This will be a big test for them. There’s always been the label that they struggle in South Africa,” de Villiers told The Independent. “If they don’t have success here, there’ll definitely be a question mark about their No. 1 ranking,” he said.De Villiers said he admires Sachin Tendulkar in the Indian team but hoped that the batsman does not strike form in the three-Test series starting in Centurion.”Sachin is a legend of the game and I will always look up to him and it’s great that he is here. It might be his last series in South Africa, so you’ve got to enjoy having the man around, but I’m hoping he doesn’t score too many hundreds.”The 26-year-old de Villiers has scored 4,540 runs in 63 Tests and has been a mainstay of South Africa’s batting line-up.De Villiers said the visitors would gain from having South African Gary Kirsten as coach but the hosts have quality bowlers to contain their much-vaunted batting line-up.”He (Kirsten) has got a lot of knowledge of conditions here. They’ll have all the necessary information. They are a class team and they gave us a run for our money the last time they were here. I back our seam bowlers. Dale (Steyn) and Morne (Morkel) will be big danger men. We are playing at home and we should know the conditions,” he said.advertisementDe Villiers, who had scored an unbeaten 278 against Pakistan in November, to become the highest scorer for South Africa in Tests, said “I would like to achieve a lot more. I have my goals now and I just want to go out there and win games for the team.”About his captain, the star batsman said, “I am the type of guy that needs a boost every now and then from the coaching staff and the captain. Graeme Smith’s always been there for me, backed me 100 per cent, even during the bad times,” he said.- With PTI inputs