Liverpool unveils the ins and outs of Klopp’s talks at half-time

first_imgLiverpool have revealed how Jürgen Klopp and his team of assistants work during the talks at the break of the games. Through Peter Krawietz, Klopp’s assistant coach, Liverpool have published on their website the methods used to influence players during breaks.With the help of two analysts, Harrison Kingston and Mark Leyland, Krawietz spends the first 45 minutes of games identifying “the tactical nuances” that players have to focus on at halftime., both positive and negative.Obviously this is a task that also falls to Klopp and his assistant Pepijn Lijnders, but Krawietz focuses “on the visual aspect”, producing video clips that support the explanations of the German technician.Krawietz, who has already accompanied Klopp in Mainz and Borussia Dortmund, explains that the talks at half-time are already prepared throughout the week, with an analysis of the rival and the team itself. The assistant sits with Klopp on the bench and makes notes during the match in a notebook, trying to glimpse how they can help the team, what the players are failing and what they are hitting. “Three or four minutes before the break, I go to the locker room. There I meet Harry and Mark and we choose the best video clips that I have identified during the meeting. I see them again and we decide if they are valid,” Krawietz explained. “The coach has about five or six minutes to talk, so we may find the right clip to show the players and to support Jürgen’s talk.”Krawietz indicated that three or four clips are used at most, with which it is intended to have an incidence in the second part. “One possibility is that if everything went well in the first part, it is to reiterate the pre-match strategy. Another possibility is that we have not found solutions, so we will try to give the players an image of the spaces in which we can play.”One of the examples Krawietz uses is the Premier League match against Southampton last February that ended with a 4-0 victory for the ‘Reds’. “Southampton played very well. In the end we won 4-0, but the match was very even and they prepared very well. We had problems in the first half, they created chances and we did not play well.” “The break talk was about continuing to attack as we have done so far. The message was’ keep trying and you will see what happens,” he said.last_img read more

Calabar, Camperdown clash in crucial game three

first_imgDefending champions Calabar High and Camperdown High square off today in the decisive game of the ISSA Southern Conference Under-19 best-of-three schools basketball final series at the National Indoor Sports Centre. Tip-off time is 6 p.m.Calabar levelled the series last Friday after they initially won Game One, which was ruled null and void after both teams had problems with their identification cards.Camperdown returned to win the replay and the lead in the series, however, the champions tied the series 1-1, and following that win, coach Ludlow Barker believes his charges are now mentally ready for the challenge.”We had a rough week, but we came back, fought hard, and I am really proud of them … Camperdown did a lot of things right the first game and we did a lot of things wrong. They were better, and we had to really dig deep and come up good Game Two,” he said.He anticipates and an even more testing match from the Oneil Brown-coached Camperdown today.”I expect them to come even harder, but we’ll be ready. We’ll be prepared as the players are more mentally ready to get the job done,” he added..Brown is of the view that Calabar’s talisman Maliek McCarthy was the difference in Game Two and he credited the Calabar star for his “composure and decision making under pressure”. However, he said that his team is fired up for today’s match.”I am 100 per cent confident that we are going to take Game Three. We have everything in place and we have something new to the table as we will be bringing in a new player. He has not played all season long and he should make a big difference to the guard position. So we are very confident we are going to take Game Three,” he said.last_img read more

BanKo takes Game 1 of PVL semis, denies PayMaya

first_imgBicol riders extend help to Taal evacuees Don’t miss out on the latest news and information. LeBron speaks with Cavs as free agency opens Jury of 7 men, 5 women selected for Harvey Weinstein rape trial Tim Cone, Ginebra set their sights on elusive All-Filipino crown Volcano watch: Island fissures steaming, lake water receding MOST READ Cloudy skies over Luzon due to amihan Sports Related Videospowered by AdSparcRead Next In fight vs corruption, Duterte now points to Ayala, MVP companies as ‘big fish’center_img Christopher Tolkien, son of Lord of the Rings author, dies aged 95 Taal victims get help from Kalayaan town Lights inside SMX hall flicker as Duterte rants vs Ayala, Pangilinan anew Carpio hits red carpet treatment for China Coast Guard PLAY LIST 02:14Carpio hits red carpet treatment for China Coast Guard02:56NCRPO pledges to donate P3.5 million to victims of Taal eruption00:56Heavy rain brings some relief in Australia02:37Calm moments allow Taal folks some respite03:23Negosyo sa Tagaytay City, bagsak sa pag-aalboroto ng Bulkang Taal01:13Christian Standhardinger wins PBA Best Player award Both teams were scorching on the offensive end with BanKo having a slim 62-57 advantage in terms of spikes, and that was what head coach Dong Dela Cruz preached to his team.“I told them that we have to work, earn every point because we all know that PayMaya is a strong team,” said Dela Cruz in Filipino. “I have to commend the players because they really showed their heart in this one.”FEATURED STORIESSPORTSGinebra beats Meralco again to capture PBA Governors’ Cup titleSPORTSAfter winning title, time for LA Tenorio to give back to Batangas folkSPORTSTim Cone, Ginebra set their sights on elusive All-Filipino crown“I told my setter to, if there’s a chance, distribute the ball but we needed those points so she constantly gave it to the imports.”Grethcel Soltones had 16 points to help Rountree and the High Flyers. View comments LATEST STORIES Photo by Tristan Tamayo/INQUIRER.netBanKo dealt the first blow in its three-game semifinals series against PayMaya, taking a four-set win, 25-19, 26-28, 25-23, 25-23, in the Premier Volleyball League Reinforced Conference Sunday at Filoil Flying V Centre.Jutarat Montripila of the Perlas Spikers and the High Flyers’ Tess Rountree put on a duel putting up 31 points apiece to lead their respective teams but BanKo had a better support in Lakia Bright, who tallied 23 points.ADVERTISEMENTlast_img read more

UCLA Tailback possible Heisman candidate

first_imgA little more than two hours after UCLA tailback Maurice Drew compiled his latest one-game highlight film, the e-mails began flowing from the sports information staff touting the junior as a Heisman Trophy candidate. After the final play of the most memorable game the Bruins played under third-year coach Karl Dorrell, players followed suit by claiming Drew, who matched his school record with five touchdowns, is Heisman campaign worthy. “Maurice Drew is so elusive, so shifty, and he makes so many big plays,” Bruins receiver Marcus Everett said. “I think he’s the best player in the Pac-10. He’s just a great player.” Drew’s 299 all-purpose yards 65 rushing, 52 receiving, 20 on kickoff returns and 162 on punt returns was the second-highest total in the Division I this season, and earned him the Walker Camp offensive player of the week award. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!center_img AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREThe top 10 theme park moments of 2019 In UCLA’s 47-40 victory against the then No. 10 Cal at the Rose Bowl on Saturday, he averaged 14.2 yards in his 21 touches. His effort enabled UCLA to climb eight spots in the Associated Press poll to No. 12, its highest ranking since 2001. The Bruins are also No. 12 in the coaches’ poll, and according to the release sent out by UCLA, “Drew is playing himself into Heisman Trophy consideration.” Drew is eighth nationally in all-purpose yards at 172.4 per game, tied for the NCAA lead with 14.4 points per game and leads the nation in punt returns at 33.8 yards per attempt. “That dude is amazing,” said UCLA tight end Marcedes Lewis, an All-America candidate. “I don’t know the word for that guy. He’s the real deal. When you have a running back like that, it makes everyone’s job easier. He does everything. What can’t he do? Return team, running back, receiver? He can do it all.” Drew’s 12 touchdowns match his career high, and his average scoring play is 28.4 yards. His three punt-return touchdowns this season, and four in his career, tie Pacific-10 and school records. And more special things could be on the way. Dorrell hinted Drew could join the kick return unit permanently. last_img read more

Watch: Irish-American supergroup celebrate glorious Glenties

first_imgIrish-American supergroup Cherish the Ladies are celebrating the beauty of Glenties in their new song and video filmed in Donegal.The Grammy-nominated band, who have close connections to Donegal, are singing the praises of the region online and across the US through the song ‘Glenties’.Written by Dublin singer/songwriter Maurice McGrath, the song is a nostalgic nod to the natural beauty and history of the village and the road from Fintown. Cherish the Ladies visited Donegal to record the latest music video for Glenties, which is included on their new album, Heart of the Home featuring Co. Clare songstress Kate Purcell on lead vocals.Watch the new music video here: The all-female supergroup is currently touring America celebrating the musical culture and traditions of Ireland with tracks from Heart Of The Home.Founded by Joanie Madden in New York City in 1985, the band have performed at venues all over the world for over three decades and have been invited guest artists at The White House and the Olympics. They have recorded a staggering 17 critically acclaimed albums. Cherish the LadiesThe band always maintains their close connection to home in Ireland too.Pianist and harmony vocalist Kathleen Boyle spends a lot of time in Dungloe when not touring with the band. She was born in Glasgow and her parents moved back to the West in 2007.Kathleen’s mum was Catherine Boyle, whose parents came from Annagry and Curransport. Her father is Hughie Boyle, originally from Cronashallog, Dungloe and a well-known musician in the area. Hughie’s father was the renowned fiddler Neillidh Boyle.On the band’s local links, Kathleen said: “Joanie and the girls always loved Glenties from visiting Tommy Sands cottage in the mountains and thought the area was so picturesque and one of the nicest towns in Ireland they’ve ever driven through.“I of course am totally biased and I just love North West Donegal and think there really is no place like it! Kathleen added: “One of my favourite views is looking down the road to Glenties from the Lough at Fintown, I often pull my car in there and just look at the beauty of the mountains, the lough and surrounding scenery.“That’s what this song is all about and he really captures that in the lyrics. So, we didn’t need too much persuasion to record this song and Kate Purcell does a beautiful job on it.”Other special guest voices on Heart of the Home include Nathan Carter, Galway balladeer Don Stiffe, Newfoundland’s Ennis Sisters and rising star, Molly O’Riordan.As their reputation and admiration from both fans and critics alike continue to grow, Cherish The Ladies are looking forward to blazing forward into another decade of music making. Watch: Irish-American supergroup celebrate glorious Glenties was last modified: March 16th, 2019 by Rachel McLaughlinShare this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)Click to share on Telegram (Opens in new window)Click to share on WhatsApp (Opens in new window)Click to share on Skype (Opens in new window)Click to print (Opens in new window)Tags:Cherish the ladiesGlentiesMUSIClast_img read more

A’s to finish suspended game with Detroit Tigers at Coliseum

first_imgThe A’s announced on Tuesday that the balance of a May 19 road game against the Tigers will be played on Sept. 6 in Oakland starting at 5:15 p.m. The May 19 game started at Comerica Park in Detroit but was suspended because of rain with the A’s leading 5-3 with no outs in the bottom of the seventh.The A’s will will bat in the top half of each inning as the visiting team.  They’ll switch back to home team for the regularly-scheduled Sept. 6 game at 7:07 p.m. or 30 minutes following the …last_img read more

Life Leads the Way to Invention

first_imgHere’s a factoid for the party: a cell is 10,000 times more energy-efficient than a transistor.  PhysOrg tells us that “ In one second, a cell performs about 10 million energy-consuming chemical reactions, which altogether require about one picowatt (one millionth millionth of a watt) of power.”  This and other amazing facts lead to an obvious conclusion: inventors ought to look to life for ideas. Cell-inspired electronics:  The PhysOrg article, based on a press release from Massachusetts Institute of Technology, tells how “MIT’s Rahul Sarpeshkar is now applying architectural principles from these ultra-energy-efficient cells to the design of low-power, highly parallel, hybrid analog-digital electronic circuits.”  He calls this “cytomorphic” electronics – design inspired by cells.  Think computers are reaching the pinnacle of their efficiency?  Think again:Essentially, cells may be viewed as circuits that use molecules, ions, proteins and DNA instead of electrons and transistors.  That analogy suggests that it should be possible to build electronic chips – what Sarpeshkar calls “cellular chemical computers” – that mimic chemical reactions very efficiently and on a very fast timescale.. Notice that the design imitates the architecture and the interaction strategies, not the materials.  This is good news; it means that Moore’s Law has not approached the limit, and that smaller, greener, ultra-fast supercomputers could be in everyone’s future – thanks to the living cell.Bio-inspired networks:  A related story on PhysOrg reported that European researchers are trying to build bio-inspired networks to form distributed computers.  “Powerful computers made up of physically separate modules, self-organising networks, and computing inspired by biological systems are three hot research topics coming together in one European project,” the article began.  Modular elements called ubidules can explore their environment and share information with other agents.  These form a network of self-organizing networks that can help solve “scientific problems in which complexity arises from simple building blocks, such as in brains, stock markets, and the spread of new ideas.”  Modeling the complex neural networks of the brain is one example.  Another is the foraging problem: how to get distributed agents to a collection point.  A set of robots with colored beacons can converge on the solution using the distributed agent algorithms.    Even humans can provide biological inspiration.  Computer programmers and robot designers study how social networks act as collections of agents that can learn and share to solve problems: “as in an unfamiliar shopping mall where you might locate a particular store by following a trail of people carrying distinctive plastic bags.”  Social networks also exhibit emergent self-organizational effects due to the ability of individuals to learn, share and communicate.  The challenge, then, is to make robots and computers that model the collective problem-solving ability of intelligent agents able to communicate their ideas and learn from one another.See turtle run:  An amazing race happens at night on some beaches.  Baby sea turtles hatch from under the sand, and race to the water.  “Life can be scary for endangered loggerhead sea turtles immediately after they hatch,” reported Science Daily.  “After climbing out of their underground nest, the baby turtles must quickly traverse a variety of terrains for several hundred feet to reach the ocean.”  Fortunately, they are well equipped for their journey.  They have specially-designed flippers that provide “excellent mobility over dune grass, rigid obstacles and sand of varying compaction and moisture content.”  It’s so good, in fact, that researchers at the Georgia Institute of Technology are envisioning how to “build robots that can travel across complex environments.”  They built an artificial flipper to measure the stresses and strains as it pushes on sand.  Somehow, the newly-hatched turtles, who have never run the race before, know how to maintain a “balance between high speed, which requires large inertial forces, and the potential for failure through fluidization of the sand.”    Robot designers, instead of having to calculate the number of appendages to traverse complex surfaces, could save a lot of time by imitating how these baby turtles do it.  They could “just design a robot with a flat mitt and a claw like these turtles have,” the researchers concluded.  Speaking of loggerhead sea turtles, Science Daily reported on efforts to reduce accidental captures of the endangered species.  Spanish scientists are working on rules for fisherman that can reduce the turtles getting snagged in nets – a problem that not only hurts the 20,000 turtles that are accidentally caught each year, but also hurts the fisherman who must spend time freeing and releasing them.How to trap radioactivity:  To grab radioactive ions, make like a Venus flytrap.  That’s how PhysOrg said scientists at Argonne National Laboratory are strategizing.  They are designing chemical traps that snap shut on wandering ions, to sequester them and decontaminate areas of radioactive pollution.  To be successful, the strategy needs the discriminating abilities of the plant.  “Imagine the framework like a Venus flytrap,” one of the inventors said.  “When the plant jaws are open, you can drop a pebble in and the plant won’t close—it knows it isn’t food.  When a fly enters, however, the plant’s jaws snap shut.”  Experiments showed that metal sulfides with a negative charge show promise for trapping radioactive cesium ions.  “As far as we know, this Venus-flytrap process is unique,” he said.  “It also works over a large range of acidities—an essential property for cleanup at different sites around the world, where pH can range considerably.”  The article is adorned with pictures of the Venus flytrap to show how the molecular trap imitates its botanical inspiration.Some of the most dynamic and productive areas of scientific research today take their inspiration from the living world.  We should reverse the old General Electric slogan: not “we bring good things to life,” but “life brings good things to us.”Intelligent design should claim these initiatives.  Usually, there is no mention of evolution in the reports, and when it is mentioned, it is a useless appendage with no explanatory power or direction.  When you approach an observable function in nature – an adaptive flipper, an efficient network – you can imitate it on the assumption that its design, structure, and architecture were designed.  Then you design inventions to imitate that design.  Instead of the GIGO (garbage-in, garbage-out) algorithm of Darwinism, biomimetics works on the DIDO (design-in, design-out) principle.  It’s important that the D in DIDO be design, not Darwin, or else you get irrational results (see 04/26/2008 commentary).(Visited 10 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Proteas turn the tables on Australia

first_img24 February 2014 There are plenty of statistics in cricket. One thing that cannot be quantified, however, is character, but there was plenty of it on show in the second test in Port Elizabeth as South Africa thrashed Australia by 231 runs in four days to reverse a massive defeat in the first test. Graeme Smith and company are the world’s number one ranked team, but some had questioned their position after the Aussies, fresh off a 5-0 whitewash of England, had crushed the Proteas by 281 runs in Centurion. At St George’s Park starting last Thursday, South Africa completely turned the tables.Stunning victory It was a stunning victory for other reasons too. Before the game, the Proteas were forced into a number of changes, with Ryan McLaren missing out with a concussion and Alviro Petersen being ruled out because of illness. Then, early in the game, Wayne Parnell suffered an injury, thus removing one of the South Africans’ front-line bowlers from their attack. Still, they found a way to win. On the first day the pitch appeared slow and low, and scoring was difficult. The big question was how was either of the teams going to take 20 wickets to win the match. Then, on Sunday, having set Australia 448 for victory, the Aussies cruised to 126 without loss before losing their 10 wickets for the addition of only 90 runs. It was an incredible turnaround, spearheaded by Dale Steyn, who bowled superbly when the ball started to reverse swing. His two dismissals of Brad Haddin, almost carbon copies of one another, were brilliant examples of reverse swing, with Steyn sending the wicketkeeper’s middle stump cartwheeling on both occasions.Happy captain “We always know that Dale is one spell away from being able to create something for us and it’s nice to know you have people in your team like that,” Proteas captain Graeme Smith said at a post-match press conference. “The intensity we showed in both innings with the ball was impressive. On a wicket that probably didn’t offer that match, we worked hard at getting reverse swing and the bowlers responded.” Looking back on his side’s reversal of fortune, Smith added: “The week building up [to the second test] was a tough week for us. We needed to be smart. We needed to be clinical. We needed to have good ideas of how we were going to respond. “I don’t think many teams would have been able to respond like we did to the defeat we faced in Pretoria, and I’ve seen some terrific victories from this team and nine wickets in a session is really something special.”Questions answered In Port Elizabeth, a number of South African players whose form had been questioned answered their critics in style. JP Duminy, whose batting had come under the spotlight, notched his third test century and claimed two important wickets, including the one that set the Australian slide on its way in the second innings. He won the man of the match award, while Hashim Amla, who by his own standards had been strangely quiet against India and in the first test against the Australians, followed up a first innings duck with an unbeaten 127 second time out. Dean Elgar, who replaced Alviro Petersen at the top of the order, played a very important knock of 83 in South Africa’s first innings and did a fine job sharing the spinning duties with Duminy.Torrid form AB de Villiers continued his run of form with an assured first innings century, while Vernon Philander and Morne Morkel, who bowled as fast as he ever has, sometimes topping 150 km/h, both made telling contributions to the South African victory. As good as the Australians were at SuperSport Park, their performance in Port Elizabeth was sub-standard. Off-spinner Nathan Lyon was solid in South Africa’s first innings, sending down a mammoth 46 overs and picking up 5 for 130. On the batting side of things, David Warner sparkled with 70 and 66, although his efforts were helped by some poor South African catching, while fellow opener Chris Rogers stood firm while the Aussies’ second innings crumbled, scoring 107 out of their innings of 216, which also included 21 extras.Outplayed There was little else to enthuse about for the Australians and captain Michael Clarke, with typical forthrightness, admitted after the match that they had been outplayed in all three facets of the game. Outplayed they might have been, but the third test is a new game and if any other team besides South Africa is capable of dramatically reversing their fortunes, it is Australia. That’s what makes the forthcoming showdown such an exciting prospect for cricket fans. The third and final test takes place at Newlands in Cape Town, starting on Saturday, 1 March. The eyes of the cricket world will be watching.last_img read more

Durban: A place to visit

first_imgDurban is maturing into a trendsetting city with more to offer than just its goldenmile of beaches. (Image: Brand SA). Sulaiman PhilipDurban is stepping out of the shadow of Cape Town, traditionally South Africa’s tourist Mecca. Durbs, as it is affectionately known, is a melting pot of Zulu, British colonial and Indian culture – and it is seventh on the New York Times list of places to visit in 2015. In 1962, Nelson Mandela was captured and arrested in the town of Howick, outside Durban, and thus began his 27 years of incarceration. Mandela returned to KwaZulu-Natal to begin a new journey when he chose to cast his first vote in Inanda, Durban as a free man in 1994.Durban rocks. It’s not just the year-long balmy weather that allows you to sip cocktails on the pier, or the glamour of the Durban July or its International Film Festival. It is the attraction of the Blues festival and the long sub-tropical summers that allow you to sunbathe, swim and surf on the city’s famous beaches.Yet the beaches – described by the New York Times as “lovely” but “a touch gauche” – are not all Durban is about. According to the city’s tourism website, eThekwini is a trendsetter, a mature and ambitious liveable city “offering great lifestyle, speckled with adventure activities, blessed with natural beauty”.Africa’s busiest port is a gumbo flavoured by British explorers, Indian merchants and Zulu traditions. It can rightly claim to be South Africa’s most African city. You can enjoy a balmy evening listening to Zulu choirs practising in any open space they can find, or visit the Indian Spice Market in central Durban. The old City Hall with its wood panelled library, art museum – the first in the country to start collecting African art – and diorama-filled natural museum are housed in a building described as “bold and progressive” when it was built in 1903. The world’s tallest bungee swing is found at the Moses Mabhida Stadium.A World Cup host city, eThekwini began a major facelift while building its sleek stadium. It revitalised the beachfront to make it more pedestrian friendly. Once home to the biggest surfing event in Africa, Durban still claims the mantle of sporting capital of South Africa. Its wealth of stadiums and sports clubs and its butter yellow sand attest to a city best experienced outdoors. Whether it’s a lazy cycle along the new beachfront promenade or a soothing dip in the warm Indian Ocean after completing the Comrades Marathon, Durban offers everything for the active lifestyle. The Aliwal Shoal is considered as one of the world’s top diving sites.Laid out in a grid, the CBD has seen better days, but it has an abundance of impressive art deco constructions and extravagant colonial buildings. Daytime Durban is a buzzing, gritty city with a languorous African cadence.News network CNN described the city’s wharf side as “the sort of neighbourhood where movie mobsters might dispose of a corpse, but it’s both safe and worthwhile”. It is home to the BAT Centre, a community centre that celebrates the region’s artists and craftsmen. It also hosts a very successful Sunday Jazz Sundowners event that has sparked the live music scene back into life. The rickshaw was brought to Durban in 1893 by the sugar magnate Sir Marshall Campbell, from London. Rickshaw pullers, often dressed in traditional Zulu regalia, have been operating in Durban for more than 100 years.Florida Road is a moveable feast of cuisines but the city is famous for its bunny chow, a popular, convenient meal of curry overflowing its hollowed out white bread container. The bread is torn off in hunks to sop up the curry. The bread is there to help follow the only rule when it comes to bunny chow: you eat with your hands. The spiritual leader of the Indian independence movement, Mahatma Ghandi, began his political journey in Durban.Manilal Patel runs Patel’s, one of two Durban restaurants recognised with perfecting the bunny. He sells 500 bunnies a day out of his tiny shop, some to customers who travel from across the country to enjoy the vegetarian curries on which the shop has built a reputation over its 80-year existence.As the New Your Times says: “Familiar cities offer new reasons to visit.”last_img read more

Medical Group Warns of Health Threats from White LED Street Lights

first_imgCan communities have more efficient lighting without causing health and safety problems? RELATED ARTICLES The American Medical Association (AMA) has just adopted an official policy statement about street lighting: cool it and dim it.The statement, adopted unanimously at the AMA’s annual meeting in Chicago on June 14, comes in response to the rise of new LED street lighting sweeping the country. An AMA committee issued guidelines on how communities can choose LED streetlights to “minimize potential harmful human health and environmental effects.”Municipalities are replacing existing streetlights with efficient and long-lasting LEDs to save money on energy and maintenance. Although the streetlights are delivering these benefits, the AMA’s stance reflects how important proper design of new technologies is and the close connection between light and human health.The AMA’s statement recommends that outdoor lighting at night, particularly street lighting, should have a color temperature of no greater than 3000° Kelvin (K). Color temperature (CT) is a measure of the spectral content of light from a source; how much blue, green, yellow and red there is in it. A higher CT rating generally means greater blue content, and the whiter the light appears. Two problems with LED street lightingAn incandescent bulb has a color temperature of 2400°K, which means it contains far less blue and far more yellow and red wavelengths. Before electric light, we burned wood and candles at night; this artificial light has a CT of about 1800°K, quite yellow/red and almost no blue. What we have now is very different.The new “white” LED street lighting which is rapidly being retrofitted in cities throughout the country has two problems, according to the AMA. The first is discomfort and glare. Because LED light is so concentrated and has high blue content, it can cause severe glare, resulting in pupillary constriction in the eyes. Blue light scatters more in the human eye than the longer wavelengths of yellow and red, and sufficient levels can damage the retina. This can cause problems seeing clearly for safe driving or walking at night.You can sense this easily if you look directly into one of the control lights on your new washing machine or other appliance: it is very difficult to do because it hurts. Street lighting can have this same effect, especially if its blue content is high and there is not appropriate shielding.The other issue addressed by the AMA statement is the impact on human circadian rhythmicity.Color temperature reliably predicts spectral content of light – that is, how much of each wavelength is present. It’s designed specifically for light that comes off the tungsten filament of an incandescent bulb.However, the CT rating does not reliably measure color from fluorescent and LED lights.Another system for measuring light color for these sources is called correlated color temperature (CCT). It adjusts the spectral content of the light source to the color sensitivity of human vision. Using this rating, two different 3000°K light sources could have fairly large differences in blue light content.Therefore, the AMA’s recommendation for CCT below 3000°K is not quite enough to be sure that blue light is minimized. The actual spectral irradiance of the LED – the relative amounts of each of the colors produced – should be considered, as well. Street lighting and human healthThe AMA has made three recommendations in its new policy statement:First, the AMA supports a “proper conversion to community based Light Emitting Diode (LED) lighting, which reduces energy consumption and decreases the use of fossil fuels.”Second, the AMA “encourage[s] minimizing and controlling blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare.”Third, the AMA “encourage[s] the use of 3000°K or lower lighting for outdoor installations such as roadways. All LED lighting should be properly shielded to minimize glare and detrimental human and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods.”There is almost never a completely satisfactory solution to a complex problem. We must have lighting at night, not only in our homes and businesses, but also outdoors on our streets. The need for energy efficiency is serious, but so too is minimizing human risk from bad lighting, both due to glare and to circadian disruption. LED technology can optimize both when properly designed. A white LED at CT 4000°K or 5000°K contains a high level of short-wavelength blue light; this has been the choice for a number of cities that have recently retrofitted their street lighting such as Seattle and New York.But in the wake of these installations have been complaints about the harshness of these lights. An extreme example is the city of Davis, California, where the residents demanded a complete replacement of these high color temperature LED street lights. Are LEDs Worth Their Extra Cost?Future of LEDs: Lower Cost, Higher EfficacyLEDs Could Get A Lot CheaperMartin’s 10 Rules of Lighting Richard G. ‘Bugs’ Stevens is a professor at the School of Medicine at the University of Connecticut. This post originally appeared at The Conversation. The reason lighting mattersThe AMA policy statement is particularly timely because the new World Atlas of Artificial Night Sky Brightness just appeared last week, and street lighting is an important component of light pollution. According to the AMA statement, one of the considerations of lighting the night is its impact on human health.In previous articles for The Conversation, I have described how lighting affects our normal circadian physiology, how this could lead to some serious health consequences and most recently how lighting the night affects sleep.In the case of white LED light, it is estimated to be five times more effective at suppressing melatonin at night than the high pressure sodium lamps (given the same light output) which have been the mainstay of street lighting for decades. Melatonin suppression is a marker of circadian disruption, which includes disrupted sleep.Bright electric lighting can also adversely affect wildlife by, for example, disturbing migratory patterns of birds and some aquatic animals which nest on shore.last_img read more