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From fins to limbs and water to land

first_imgIt’s hard to overstate how much of a game-changer it was when vertebrates first rose up from the waters and moved onshore about 390 million years ago. That transition led to the rise of the dinosaurs and all the land animals that exist today.“Being able to walk around on land essentially set the stage for all biodiversity and established modern terrestrial ecosystems,” said Stephanie Pierce, Thomas D. Cabot Associate Professor of Organismic and Evolutionary Biology and curator of vertebrate paleontology in the Museum of Comparative Zoology. “It represents an incredibly important period of time in evolutionary history.”Scientists have been trying for more than a century to unravel exactly how this remarkable shift took place, and their understanding of the process is largely based on a few rare, intact fossils with anatomical gaps between them. A new study from Pierce and Blake Dickson, Ph.D. ’20, looks to provide a more thorough view by zeroing in on a single bone: the humerus.The study, published today in Nature, shows how and when the first groups of land explorers became better walkers than swimmers. The analysis spans the fin-to-limb transition and reconstructs the evolution of terrestrial movement in early tetrapods. These are the four-limbed land vertebrates whose descendants include extinct and living amphibians, reptiles, and mammals.The researchers focused on the humerus, the long bone in the upper arm that runs down from the shoulder and connects with the lower arm at the elbow, to get around the dilemma of gaps between well-preserved fossils. Functionally, the humerus is invaluable for movement because it hosts key muscles that absorb much of the stress from quadrupedal locomotion. Most importantly, the bone is found in all tetrapods and the fishes they evolved from and is pretty common throughout the fossil record. The bone represents a time capsule of sorts, with which to reconstruct the evolution of locomotion since it can be examined across the fin-to-limb transition, the researchers said.“We went in with the idea that the humerus should be able to tell us about the functional evolution of locomotion as you go from being a fish that’s just swimming around and as you come onto land and start walking,” Dickson said.The researchers analyzed 40 3D fossil humeri for the study, including new fossils collected by collaborators at the University of Cambridge as part of the TW:eed Project. The team looked at how the bone changed over time and its effect on how these creatures likely moved.A fossil humeri from an aquatic fish (Eusthenopteron), a transitional tetrapod (Acanthostega), and a terrestrial tetrapod (Ophiacodon). Credit: Stephanie PierceThe analysis covered the transition from aquatic fishes to terrestrial tetrapods. It included an intermediate group of tetrapods with previously unknown locomotor capabilities. The researchers found that the emergence of limbs in this intermediate group coincided with a transition onto land, but that these early tetrapods weren’t very good at moving on it.To understand this, the team measured the functional trade-offs associated with adapting to different environments. They found that as these creatures moved from water to land, the humerus changed shape, resulting in new combinations of functional traits that proved more advantageous for life on land than in the water.That made sense to the researchers. “You can’t be good at everything,” Dickson said. “You have to give up something to go from being a fish to being a tetrapod on land.”The researchers captured the changes on a topographical map showing where these early tetrapods stood in relation to water-based or land-based living. The scientists said these changes were likely driven by environmental pressures as these creatures adapted to terrestrial life.The paper describes the transitional tetrapods as having an “L-shaped” humerus that provided some functional benefit for moving on land, but not much. These animals had a long way to go to develop the traits necessary to use their limbs on land to move with ease and skill.As the humerus continued to change shape, tetrapods improved their movement. The “L” shaped humerus transformed into a more robust, elongated, twisted form, leading to new combinations of functional traits. This change allowed for more effective gaits on land and helped trigger biological diversity and expansion into terrestrial ecosystems. It also helped establish complex food chains based on predators, prey, herbivores, and carnivores still seen today.Analysis took about four years to complete. Quantifying how the humerus changed shape and function took thousands of hours on a supercomputer. The researchers then analyzed how those changes impacted functional performance of the limb during locomotion and the trade-offs associated.The innovative approach represents a new way of viewing and analyzing the fossil record — an effort Pierce said was well worth it.“This study demonstrates how much information you can get from such a small part of an animal’s skeleton that’s been recorded in the fossil record and how it can help unravel one of the biggest evolutionary transformations that has ever occurred,” Pierce said. “This is really cutting-edge stuff.”This research was supported with funding from the Harvard Museum of Comparative Zoology, the Robert A. Chapman Fellowship, and the Natural Environment Research Council.last_img read more

Observer elects next top editor

first_imgThe Observer General Board elected Associate Sports Editor Greg Hadley to the position of Editor-in-Chief for 2015-2016 on Wednesday.Hadley, a junior resident of Carroll Hall, is a double major in Political Science and American Studies with a minor in Journalism, Ethics and Democracy. The Rockville, Maryland, native has served as both Baraka Bouts and Bengal Bouts editor in 2013-2014 and covered the Notre Dame women’s basketball team and men’s lacrosse team during their Final Four runs last season.“This position is both an honor and an opportunity, and I am very grateful to have it,” Hadley said. “The Editorial Board this year has done tremendous work, and I’m really looking forward to building off all that they’ve accomplished.”Hadley has also covered Notre Dame women’s golf, men’s tennis, women’s soccer, cross country and track and field, and spent the past year helping to coordinate all of The Observer’s sports coverage.“Greg has become an absolutely indispensable member of the staff this year, and I know he will do a fantastic job leading The Observer in the coming year,” outgoing Editor-in-Chief Ann Marie Jakubowski said. “I can’t wait to see what he accomplishes with his great talent, passion and work ethic.”“We have a great group of people on staff, and I am confident that we will continue to be an outstanding news source for the rest of campus,” Hadley said. “I will continue to look for ways to improve and learn as much as I can.”Hadley will take on his new position March 1.Tags: Editor-in-Chieflast_img read more

Chinese coal company planning world’s largest solar-powered hydrogen plant

first_imgChinese coal company planning world’s largest solar-powered hydrogen plant FacebookTwitterLinkedInEmailPrint分享PV Magazine:Chinese coal miner Baofeng Energy has announced the start of construction of what it claims will be the world’s largest solar-powered hydrogen plant, in the Ningxia Hui autonomous region of northwest China.The RMB1.4 billion ($199 million) electrolysis project is intended to produce 160 million cubic meters of hydrogen per year plus 80 million cubic meters of oxygen. Baofeng said the use of solar electricity to power the facility would save 254,000 tons of coal consumption annually, leading to a 445,000-ton reduction in carbon emissions.The project will feature two 10,000m3/hr electrolyzers powered by two 100 MW solar plants plus a 1,000kg/day hydrogenation station and two petrol stations will be converted to also supply natural gas and hydrogen for transport purposes. The solar panels will be installed over wolfberry and alfalfa crops which will generate extra revenue, according to Baofeng.Work on the project started this month and is slated for completion this year, with hydrogen production to start next year.[Vincent Shaw]More: Chinese coal miner starts work on world’s biggest solar-powered hydrogen facilitylast_img read more

Teeth whitening technique

first_img Share HealthLifestyle Teeth whitening technique by: – September 22, 2014 Oil pulling is an ancient Ayurvedic remedy for oral health and detoxification. It involves the use of pure oils as agents for pulling harmful bacteria, fungus, and other organisms out of the mouth, teeth, gums and even throat.How To Oil PullThe most effective oil pulling is done by placing around a tablespoon of cold pressed organic sesame oil into the mouth and swishing the oil around the mouth for approximately 10-15 minutes and then spitting it out. Other oils such as extra virgin cold pressed coconut, sunflower and olive oil have been used, although sesame oil is considered one of the best oils for this practice. It is recommended to alter oils every couple of days to get the full benefit. Putting high quality organic oils into the mouth has a multi-effect outcome. First, the oils mix with the saliva, turning it into a thin, white liquid. Lipids in the oils begin to pull out toxins from the saliva. As the oil is swished around the mouth, teeth, gums and tongue, the oil continues to absorb toxins, and usually ends up turning thick and viscous and white. Once the oil has reached this consistency, it is spit out before the toxins are reabsorbed. What Does Oil Pulling Do? Multiple scientific studies show the efficacy of oil pulling therapy. One study shows that oil pulling with sesame oil can boost overall oral health. Specifically, using sesame oil as an oral health agent helps to reduce the amount of S. mutans (germ) count in both teeth plaque and mouth saliva. Scientists believe that the lipids in the oil both pull out bacteria, as well as stop bacterial from sticking to the walls of the oral cavity. Oil pulling may also increase saponification in the mouth, creating a soapy environment that cleanses the mouth as vegetable fat is an emulsifier by nature. Most interesting is perhaps the ability of oil to cleanse out harmful bacteria, as well as reduce fungal overgrowth. These oils also possibly help in cellular restructuring, and are related to the proper functioning of the lymph nodes and other internal organs. Additional benefits of oil pulling for oral health: Overall strengthening of the teeth and gums and jaws Prevention of diseases of the gums and mouth, such as cavities and gingivitis Prevention for bad breath Potential holistic remedy for bleeding gums Prevention of dryness of the lips, mouth and throat Possible holistic treatment for TMJ and general soreness in the jaw area Benefits Beyond the Mouth? Ancient Ayurvedic health practitioners believed that oil pulling could reduce more than just diseases of the mouth and throat. Today, many holistic practitioners tout its use for a variety of health concerns. It is believed that these oils help the lymphatic system of the body as harmful bacteria are removed and beneficial microflora are given with a healthy environment to flourish. Because of this holistic perspective, oil pulling has been used as a preventative health measure for many other conditions. Other possible benefits of oil pulling for overall health include: Migraine headache relief Correcting hormone imbalances Reducing inflammation of arthritis May help with gastro-enteritis Aids in the reduction of eczema May reduce symptoms of bronchitis Helps support normal kidney function May help reduce sinus congestion Some people report improved vision Helps reduce insomnia Reduced hangover after alcohol consumption Aids in reducing pain Reduces the symptoms of allergies Helps detoxify the body of harmful metals and organisms Scientific Studies on Sesame Oil & Oil Pulling Sesame oil is particularly high in the antioxidantssesamol, sesamin, and sesamolin. It also holds a high concentration of Vitamin E and polyunsaturated fatty acids. These antioxidants have been found to stop the absorption of negative forms of cholesterol in the liver. Multiple studies have shown the antibacterial capacities of sesame oil. These studies support the use of oil pulling in the prevention of dental cavities and gingivitis. A 2007 study looking into the effect of oil pulling (with sunflower oil) on plaque and gingivitis on oral soft and hard tissues. Results found that after 45 days of oil pulling, subjects showed a statistically significant reduction in gingivitis. Another study, conducted in 2008 found a “remarkable reduction in the total count of bacteria” in the mouth, and an overall marked reduction in susceptibility dental cavities. The antibacterial activity of sesame oil was also studied and found to have an effect on the Streptococcus mutans in the mouth. In fact, these studies showed an overall reduction of bacteria from 10 to 33.4% in participants, and after 40 days of oil-pulling, participants were found to show 20% in average reduction in oral bacteria. Moreover, half of all participants in this case study showed a drastic reduction in susceptibility to dental caries. Here is one more fantastic tip. Peel off to get whiter teeth with the banana peel. Minerals found on the banana’s inside show an incredible effect on teeth. The magnesium, potassium and manganese soak up into teeth and then whiten them. This methodology is extremely simple to be followed. Simply rub the banana’s inside, gently for two minutes, around your teeth. Soon, you will be able to find that the bananas would become yellow and your teeth white. Trythis.com Tweet Sharing is caring!center_img 255 Views   no discussions Share Sharelast_img read more