17 Jan

Fall Fire Ant Control

first_imgThe one thing that makes fall the single best time to treat fire ants, Sparks said, is that it’sfollowed by winter. “You can use fire ant baits any time of the year. But they’re most effective when the ants areactively foraging for food,” Sparks said. “If I could treat fire ants only once a year, I’d do it in the fall,” said Beverly Sparks, aUniversity of Georgia scientist. “Actively foraging ants will pick up a bait and carry it into the nest within minutes,” she said.If the ants are inactive and don’t find the bait quickly, it will become rancid. By the time theants find it, it no longer appeals to them. “Baits take a long time to work,” she said. “They weaken colonies and make them less able torespond to the challenges of winter weather.” When you think of fire ants in the fall, “vulnerable” isn’t the first word that pops into yourmind. But it should be. First, they’re more active. That makes it easier to treat them with fire ant baits. That’s the first step in the ongoing program Sparks recommends for fire ant control. Use afresh bait, she said, and apply it by the label directions. Then treat individual problem moundswith an approved contact product. The final step is simply to repeat the first step once or twicea year. Fire ants are easier to kill in the fall for four main reasons, said Sparks, an Extension Serviceand research entomologist in the UGA College of Agricultural and Environmental Sciences. Another advantage unique to the fall is that you are treating when many of the fire ant coloniesin your yard are very young. That makes them easier to kill with a mound-drench, granular, dust or aerosol contactinsecticide. When you use those products, Sparks said, “it’s critical to treat when the queenand brood are close to the surface.”center_img “Quite often you don’t even know they’re there,” she said. “But if you don’t treat them,they’ll become the big mounds you see next year.” How do you treat them if you don’t know where they are? Broadcast a fire ant bait. The second reason fire ants are vulnerable in the cooler weather of fall is that they’re not toodeep in the ground. “Fire ants mate all during the year, but they’re most actively mating in the spring,” Sparkssaid. Mated queens fly off and establish new colonies. By fall, these colonies arewell-established but still very small. Extreme cold is tough on fire ants, she said. That makes baits even more effective in the fall. The networked tunnels of a fire ant mound are constantly collapsing, she said. Moving deeperinto the ground requires a lot of work. Anything you can do to reduce the number of antsavailable to gather food and maintain the mound structure makes the colony less able tosurvive winter weather. Fire ants are most active in spring and fall, when daytime temperatures are between 70 and 85degrees, she said. The young colonies are especially vulnerable, she said, because they don’t have manyworkers. So they can’t respond very quickly to the need to escape freezing temperatures. “Winter is an ally in controlling fire ants,” Sparks said. “Reducing their numbers in the fallcan help push them over the edge in the winter.”last_img read more

12 Jan

New political party to be launched soon

first_img– challenges existing parties to 2020 showdownA new political party, the self-dubbed Democratic National Congress (DNC), has announced its presence on the national landscape). On Sunday, it threw down the gauntlet to the existing political parties with general and regional elections slated for 2020.DNC leader, Craig Sylvester, noted in a statement that he has always been anLeader of the Democratic National Congress, Craig Sylvesteradvocate of new political parties. He noted that his DNC party will go toe-to-toe with the other parties in 2020 under the theme ‘Bringing Guyana into the 21st century’.“As a preliminary estimate, we only require twenty persons to assume ministerial portfolios for a resounding victory at the polls,” Sylvester said. “The party’s official launch and public discussion forum is due to be held soon.”“The Democratic National Congress will be committed to the principle (of) Guyana (being) governed as a democratic republic, where the authority of the state and its government is created and sustained by the consent of its people through their elected representatives,” Sylvester said, reeling off his party’s draft constitution.He also promised that a sound, effective political system for choosing and replacing governments through free and fair elections will be sustained.last_img read more

10 Jan

Croatia qualify for WCup with Greece draw

first_img0Shares0000Croatia’s Domagoj Vida celebrates with teammates after winning a World Cup 2018 qualifying match against Greece, on November 12, 2017 in Piraeus © AFP / LOUISA GOULIAMAKIPIRAEUS, Greece, Nov 13 – Croatia qualified for the 2018 World Cup on Sunday by holding Greece to a 0-0 draw in the second leg of their play-off in Piraeus for a 4-1 win on aggregate.Zlatko Dalic’s men will be playing in their fifth World Cup in Russia next year, having only once failed to qualify in 2010. “We had a good match in Zagreb but it was difficult here. If we had won 1-0 (in the first leg) it would have been very difficult tonight,” said Croatia coach Dalic, who only took over from the sacked Ante Cacic last month.“We are a very good team and it would not be just for us not to go to Russia.”A strong defensive performance, especially in the second half, was enough for Croatia to leave the Karaisiakis Stadium with a comfortable victory over the two legs after winning 4-1 on Thursday.“It was a tough match for us. We did not play at our level, but more important is the result,” said Real Madrid midfielder Luka Modric.“Greece played a good game tonight, it pushed us, but there was no serious opportunity (of a comeback).”Greece coach Michael Skibbe dropped half of his players from the disastrous first-leg showing in Zagreb, and the return of Roma defender Kostas Manolas kept Croatia striker Nikola Kalinic in check.“Unfortunately we had a very bad performance in Zagreb three days ago and we paid for it,” said German Skibbe.“We then made too many mistakes. Tonight we were excellent and Croatia were not good. The previous match happened the other way around.”For the first 30 minutes Greece were in control, but despite two good shots from Borussia Dortmund defender Sokratis Papastathopoulos and AEK Athens forward Anastasios Bakasetas, the home team failed to get the much-needed early goal.Greece came close to scoring four minutes before half-time when a cross from Kostas Mitroglou found midfielder Zeca, who headed the ball in front of the Croatian goalmouth, only for goalkeeper Danijel Subasic to tip the ball away with Panagiotis Retsos ready to head in.But the visitors nearly put the tie to bed when a left-footed blast by Inter Milan winger Ivan Perisic hit the post in the 43rd minute, after Barcelona midfielder Ivan Rakitic had earlier curled a free-kick over the crossbar.Greece continued to enjoy more of the ball in the second period but when it came to finishing off an attack, either a pass would go astray or a defender would step in.A shot on the turn by Mitroglou from just outside the penalty area just missed the post with an outstretched Subasic unable to reach it.Greece did put the ball in the net in the 79th minute, but substitute Dimitris Pelkas was correctly called offside.Bologna defender Vasilis Torosidis’ shot was blocked by Subasic with just three minutes left, denying Greece even a consolation strike.0Shares0000(Visited 1 times, 1 visits today)last_img read more

20 Jul

Study Neural signal that urges to eat overpowers the one that says

first_imgReviewed by James Ives, M.Psych. (Editor)Sep 21 2018Almost everyone knows the feeling. You’re at a restaurant or a holiday meal, and your stomach is telling you it’s full, so logically you know you should stop eating.But what you’re eating tastes so good, or your friends and family are still eating, or you don’t get this treat very often. So you keep going.A new study explores the mystery of why this happens, at the most basic level in the brain. It shows that two tiny clusters of cells battle for control of feeding behavior — and the one that drives eating overpowers the one that says to stop.It also shows that the brain’s own natural opioid system gets involved – and that blocking it with the drug naloxone can stop over-eating.The researchers studied mice, not over-eating humans. But they do note that the findings could help inform the fight against the global obesity epidemic.The team, from the University of Michigan Molecular and Behavioral Neuroscience Institute, published their work in the Proceedings of the National Academy of Science.The two groups of brain cells they looked at, called POMC and AgRP, are next-door neighbors in a deep brain region called the arcuate nucleus, or Arc, within a larger region called the hypothalamus, which is a master regulator of motivated behaviors.Neuroscientist and U-M Department of Psychiatry professor Huda Akil, Ph.D., led the research team. She says the discovery involved a strong dose of serendipity.”We used a transgenic approach to specifically address the POMC neurons for optogenetic stimulation, and we expected to see a decrease in appetite. Instead, we saw a really remarkable effect,” she says. “The animals ate like crazy; during the half hour after stimulation, they ate a full day’s supply of food.”A tale of two genesPrevious research, including work done in several U-M laboratories, showed that the Arc region, and specifically POMC and AgRP neurons, play key roles in feeding behavior.The gene called POMC (short for pro-opiomelanocortin) has multiple functions: it encodes a stress hormone called ACTH, a natural opioid called beta-endoprhin, and several other molecules called melanocortins.The first mammalian gene to be cloned, it was also the first gene that scientists visualized in the brain of a mammal using a technique called in situ hybridization – work that was led by Stan Watson, M.D., Ph.D., who also co-authored the new paper. Another U-M researcher, Roger Cone, Ph.D., first cloned the receptors for POMC-produced melanocortins, and demonstrated their role in food intake, energy regulation and obesity.POMC’s products get opposition from products of the AgRP gene, whose name is short for Agouti-Gene-Related Peptide. Watson also mapped the location of AgRP cells in the brain, and Cone’s team determined their role in feeding and obesity.In general, POMC acts like a brake on feeding when it gets certain signals from the body, and AgRP acts like an accelerator pedal, especially when food is scarce or it’s been some time since a meal.But the new study shows for the first time how their activity relates to one another, thanks to a technique called optogenetics. By focusing on unique molecular features of a particular group of neurons, it makes it possible for scientists to target, or address, those cells specifically and activate them selectively.A hunt for answersThe serendipitous optogenetic finding about the over-eating mice set off a search for the reason why they overate, led by research scientist Qiang Wei, Ph.D., working with others in Akil’s lab.The answer was that while they were optogenetically stimulating the POMC cells, they were also unintentionally stimulating a subset of AgRP cells nearby. The two types of cells originate from the same parent cells during embryonic development. That common heritage meant that the transgenic approach Akil and her colleagues used to address POMC captured not only the POMC neurons but also a segment of the AgRP neuronal system.Related StoriesNeural pathways explain the relationship between imagination and willingness to helpAn active brain and body associated with reduced risk of dementiaNanoparticles used to deliver CRISPR gene editing tools into the cellIn other words, they had turned on both the brake and the gas pedal for eating. When both types of cell got activated, the “keep eating” signal from AgRP cells overpowered the “stop eating” signal from POMC cells. “When both are stimulated at once, AgRP steals the show,” says Akil.Then the researchers used a different technique, addressing the cells with an injected virus rather than a transgene, to focus the optogenetic stimulation on just POMC neurons and ensure that AgRP neurons didn’t get activated.They found that stimulating just POMC cells caused a significant decrease in eating – and were surprised at how rapidly it happened. Akil notes that past research had shown slow effects of POMC stimulation on eating – but in these previous experiments, mice had recently eaten, while the mice in the U-M study were slightly hungry.The team also used a new method called CLARITY to visualize in 3-D the pathways that start from POMC and AgRP neurons. These pathways of neurons, once activated, can trigger either a sense of feeling full – called satiety — or the drive to eat. They stitched together images of activated neurons in a computer, to create 3-D videos that show the neurons’ reach.Then, the researchers used a method called c-fos activation to dig deeper into the downstream effects of POMC and AgRP neuron activation – and showed that its effects spread throughout the brain, including in the cortex, which governs function like attention, perception, and memory.Since POMC encodes a natural opioid (B-Endorphin), the authors asked whether activation of this system triggers the body’s own natural painkiller system, called the endogenous opioid system. They found that activation of POMC blocked pain, but that this was reversed by the opioid antagonist drug naloxone.Interestingly, the activation of AgRP, which triggered feeding, also turned on the opioid system in the brain. “When we administered naloxone, which blocks opioid receptors, the feeding behavior stopped,” says Akil. “This suggests that the brain’s own endogenous opioid system may play a role in wanting to eat beyond what is needed.”More than just metabolic signalsThe involvement of the cortex and opioid systems lead Akil and her colleagues to think about how the results might relate to the human experience. Though mice and humans are very different, Akil speculates that the bombardment of our senses with sights and smells related to food, and the social interactions related to food, may be involved in encouraging overeating.Perhaps, she says, these factors combine to trigger us to become interested in eating when we’re not even hungry, and the battle between the “stop” and “keep going” signals is lost.”Our work shows that the signals of satiety – of having had enough food – are not powerful enough to work against the strong drive to eat, which has strong evolutionary value,” she says. She notes that other researchers are looking at opiate receptor blockers as potential diet aids, and that it’s also important to study the pathways that are activated by the products of both POMC and AgRP cells, as well as individual differences in all these systems.Many studies in humans have looked at the metabolic aspects of the drive to eat, and overeat – for instance, the metabolic signals that travel between the body and brain in the form of peptides such as leptin and ghrelin. But Akil says there appears to be a strong neural system involved in overeating that results from perceptual, emotional and social triggers, and that is not receiving sufficient scientific attention.”There’s a whole industry built on enticing you to eat, whether you need it or not, through visual cues, packaging, smells, emotional associations,” she says. “People get hungry just looking at them, and we need to study the neural signals involved in those attentional, perceptional mechanisms that drive us to eat.” Source:http://www.med.umich.edu/last_img read more