Facebook WhatsApp By admin – April 27, 2018 Twitter Local News WhatsApp 2018 Autism SHARE WalkAutism SHARE Walk 2018 has been scheduled from 9 a.m. to 1 p.m. Saturday at Grande Communications Stadium, 5514 Champions Drive, Midland.Preregistration starts 11:30 a.m. to 1:30 p.m. and 4:30 p.m. to 7 p.m. today. Day of registration opens at 8:30 a.m.The Austism SHARE Walk starts at 10 a.m.This ninth annual walk is the largest fundraiser for SHARE, a local nonprofit dedicated to caring for families where there are children with special needs.Lunch, t-shirts, free kids activities and door prizes will be included. Sensory rooms will be on site. Awards will be presented for largest team, top fundraisers, best t-shirt, and pet.Adult t-shirts are $15 and child t-shirts are $10. Raffle tickets on sale now.Leashed pets, strollers, buggies, trikes and other walking/riding aids permitted. share logo Pinterest Twitter Previous articleFlowers, food highlight Ellen Noël eventNext articleFamily nature festival admin Pinterest Autism SHARE Walk Facebook
Everybody knows the shortest distance between two points is a straight line, and now Harvard researchers have evidence that sperm have been taking the familiar axiom to heart.Though competition among individual sperm is usually thought to be intense, with each racing for the chance to fertilize the egg, Harvard scientists say that in some species, sperm form cooperative groups that allow them to take a straighter path to potential fertilization.A new study, conducted by Heidi Fisher, a postdoctoral student working in the lab of Hopi Hoekstra, the Alexander Agassiz Professor of Zoology in the Museum of Comparative Zoology, and postdoctoral student Luca Giomi, who works with L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, professor of organismic and evolutionary biology, and of physics, shows that in Peromyscus maniculatus, a species of deer mouse known to be promiscuous, sperm clump together to swim in a more linear fashion. The study is described in a July paper in Proceedings of the Royal Society B.“We generally think that each individual sperm cell swims its little heart out to get to the egg. But it had been discovered that, in at least a handful of organisms, sperm will cooperate and swim as a group,” said Hoekstra, who is also a professor of organismic and evolutionary biology.Exactly why sperm clump together, however, had remained a mystery — until now.“We had some hints that cooperation was enhancing their swimming performance, but what we didn’t understand was how it was helping,” Fisher said. “With this study, we combined a mathematical model with much finer-scale measurements that looked at groups that ranged from single sperm cells to groups of as many as 30 cells. What we realized was that that while their overall speed wasn’t increasing at all, that the time it took them to go from point A to point B was decreasing — they swim in a straighter line.”The study also found that sperm from promiscuous mice were likelier to form clumps of the optimum size, and that, when compared with sperm from Peromyscus polionotus — a closely related, but monogamous, species of mouse — the trait is likely driven by sexual selection.The new paper builds on a 2010 study conducted in Hoekstra’s lab, which found that sperm cells preferentially clump with those produced by the same male. Spurred by that earlier paper, Mahadevan approached Hoekstra with the idea of creating a mathematical model to understand whether and how sperm received an advantage by forming groups.“I read the paper and thought we could make a quantitative theory of the observations they had made,” he said. “But of course, the only way to know whether any model was capable of anything predictive was to make it testable.“In this context … the question was: Is it possible to make the aggregate do better than the individual?” he continued. “One way to do that is to get all the tails to synchronize, but that doesn’t happen. The other way is to cancel out the random motion of the individuals in an aggregate because the sperm adhere to each other. Eventually, for large aggregates, the sperm point toward each other and thus cannot swim at all. This mechanism, when quantified in a model that Luca and I developed, led to testable predictions. When Heidi did the experiment, we found that this was essentially correct.”In addition to finding that sperm that band together swim in a more linear fashion, researchers identified the clump size at which sperm reaped the largest reward for grouping. Groups with too few cells, Hoekstra said, continued to swim along more meandering paths, while sperm in over-large groups often ended up swimming against each other.“What we found is that both species have an optimum at around eight, which was what the model predicted, but there were fewer groups that were too big or too small in the promiscuous species,” she said. “That is consistent with the idea that sexual selection is driving this trait in the promiscuous species, whereas in the monogamous species, where there’s not as much competitive pressure, things are a bit more relaxed, so we see more variance in the clump sizes.”In the end, Mahadevan said, the study represented an ideal collaboration between the theoretical and the empirical.“If you talk to evolutionary biologists, their approaches are often genetic, because they’re trying to understand what the genetic bases are for natural selection pressures,” he said. “From a theoretical point of view, the focus is on reproductive capacity. What’s interesting in this particular situation is we can take a question of reproductive capacity and add a physiological twist to it that’s associated with sperm motility, and then we can take that apart in the context of what happens when you change the shape of the sperm, or their ability to adhere to each other, or their ability to move.“In my view we haven’t so much answered the question as we’ve sharpened it,” he continued. “And we’ve done by that couching a conceptual notion of competition and cooperation in terms of physical and physiological variables that can be measured and lead to testable predictions.”
HealthInternationalLifestylePrint UNICEF: AIDS leading cause of death for African teenagers by: Associated Press – November 27, 2015 Tweet 190 Views no discussions Share Share Sharing is caring! Share JOHANNESBURG (AP) — The United Nations’ agency for children says AIDS is now the leading cause of death for African teenagers and the second most common killer for adolescents across the globe.At a conference in South Africa on Friday, UNICEF said despite gains made among adults and babies with HIV, the number of 10-to-19-year-olds dying from AIDS-related diseases has tripled since 2000.The chief of UNICEF’s HIV and AIDS division, Craig McClure, said children born with the virus were dying in their teens because there was not enough treatment aimed at adolescents.Mani Djelassem, a 17-year-old activist who was born HIV-positive, said it was essential to educate teenagers about the disease and the medication that has been vital to saving her own life.
Photos: Lakers defeat Trail Blazers in Game 4 of first-round playoff series Video: What LeBron James said about Jacob Blake … ‘Black people in America are scared’ Chris Paul, Russell Westbrook and other NBA stars pay tribute to Kobe Bryant “I think anytime you’re pushed to be at your best, it strengthens your group,” Coach Frank Vogel said Wednesday. “And I think that would apply with a strong first-round opponent.”The Clippers are playing a Dallas team that outshot them as the No. 1 offensive team in the league led by their rising star point guard Luka Doncic.“Best offensive team in history, right?” Coach Doc Rivers said Wednesday night after the series was set. “They have one of the young stars (Doncic). They’re a two-star team now. (Kristaps) Porzingis is playing great. I mean, I look at that, that’s a tough matchup in the first round, that’s what it is.”Teams are playing from the unusual position of not having a true home-court advantage, aside from graphics and recorded court sounds intended to give the slightest of edges to the “home” team. The playoffs also will be played in a compacted schedule without travel days — since there’s no travel and all games will be played in the bubble.Mon., Aug. 17: Mavericks at Clippers, Game 1, 6 p.m., ESPN For Lakers’ LeBron James, Jacob Blake’s shooting is bigger issue than a big Game 4 victory Tues., Aug. 18: TBD at Lakers, Game 1, 6 p.m., TNTWed., Aug. 19: Mavericks at Clippers, Game 2, 6 p.m., TNTThurs., Aug. 20: TBD at Lakers, Game 2, 6 p.m., ESPNFri., Aug. 21: Clippers at Mavericks, Game 3, 6 p.m., TNTSat., Aug. 22: Lakers at TBD, Game 3, 5:30 p.m., ABCSun., Aug. 23: Clippers at Mavericks, Game 4, ABCMon., Aug. 24: Lakers at TBD, Game 4, TNTTues., Aug. 25: Mavericks at Clippers, Game 5 (if necessary)Wed., Aug. 26: TBD at Lakers, Game 5 (if necessary)Thurs., Aug. 27: Clippers at Mavericks, Game 6 (if necessary)Fri., Aug. 28: Lakers at TBD, Game 6 (if necessary)Sat., Aug. 29: Mavericks at Clippers, Game 7 (if necessary)Sun., Aug. 30: TBD at Lakers, Game 7 (if necessary)Related Articles LAKE BUENA VISTA, Fla. — While the full field of the NBA playoffs remains to be set, the Lakers and Clippers now know when the playoffs start for them, and what days they’ll be playing for the next month.The top two seeds in the Western Conference will be playing late games at AdventHealth Arena, the largest venue on the Disney campus.The Clippers begin their series with Dallas on Monday night, the first day of the postseason, with a 6 p.m. (PDT) game on ESPN, while the Lakers will begin Tuesday with their Game 1 against the winner of the play-in: Memphis, Portland or Phoenix.Both the Clippers and the Lakers have said they have nerves heading into the postseason. The Lakers face the prospect of perhaps facing the red-hot Trail Blazers or Suns, who in the bubble have outperformed otherwise mediocre seasons. The Lakers will have a lot of down time over the weekend, which could either give them the rest they need, or disrupt their rhythm against a team that will have to keep fighting to stave off elimination on Saturday and possibly Sunday. On Mamba Night, the Lakers make short work of Blazers to take 3-1 series lead Newsroom GuidelinesNews TipsContact UsReport an Error