A new coral reef species from the Gambier Islands, French Polynesia

July 26, 2013 — The new speciesEchinophyllia taraeis described from the remote and poorly studied Gambier Islands, French Polynesia. Although the new species is common in the lagoon of Gambier Islands, its occurrence elsewhere is unknown.Echinophyllia taraelives in protected reef habitats and was observed between 5 and 20 m depth. It is a zooxanthellate species which commonly grows on dead coral fragments, which are also covered by crustose coralline algae and fleshy macroalgae.Share This:This species can grow on well illuminated surfaces but also encrusts shaded underhangs and contributes to the formation of coral reefs in the Gambier. It is characterized by large polyps and bright often mottled colourations and it is very plastic in morphology like most hard corals. Patterns of partial death and recovery of the species were often observed and could be due to competition with other benthic invertebrates like the soft-bodied corallimorpharians or zoanthids which can co-occur with this species.Stony corals are currently under threat by the effects of global warming, ocean acidification and anthropogenic changes of reef structures. Although corals represent a relatively well studied group of charismatic marine invertebrates, much has still to be understood of their biology, evolution, diversity, and biogeography. The discovery of this new species in French Polynesia confirms that our knowledge of hard coral diversity is still incomplete and that the exploration efforts of recent scientific expeditions like Tara Oceans can lead to new insights in a remote and previously poorly studied locations.This species is named after the Tara vessel which allowed the exploration of coral reefs in Gambier. Moreover, the name “tara” in the Polynesian language may refer to a spiny, pointed object, which applies well to the new species typically featuring pointed skeletal structures. In the same language, Tara is also the name of a sea goddess.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Pensoft Publishers. The original story is licensed under a Creative Commons License. …

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High tooth replacement rates in largest dinosaurs contributed to their evolutionary success

July 17, 2013 — Rapid tooth replacement by sauropods, the largest dinosaurs in the fossil record, likely contributed to their evolutionary success, according to a research paper by Stony Brook University paleontologist Michael D’Emic, PhD, and colleagues. Published in PLOS ONE, the study also hypothesizes that differences in tooth replacement rates among the giant herbivores likely meant their diets varied, an important factor that allowed multiple species to share the same ecosystems for several million years.Paleontologists have long wondered how sauropods digested massive amounts of foliage that would have been necessary for their immense sizes. In “Evolution of high tooth replacement rates in sauropod dinosaurs,” the team of paleontologists reveal that their new research into the microscopic structure of sauropod teeth shows the dinosaurs formed and replaced teeth faster than any other type of dinosaurs — more like sharks and crocodiles — and this process kept teeth fresh given the immense amount of wear they underwent from clipping off enormous volumes of food required for them.”The microscopic structure of teeth and bones records aspects of an animal’s physiology, giving us a window into the biology of long-extinct animals,” said Dr. D’Emic, Research Instructor in the Department of Anatomical Sciences at Stony Brook University School of Medicine. “We determined that for the gigantic sauropods, each tooth took just a few months to form. Effectively, sauropods took a ‘quantity over quality’ approach.”Dr. D’Emic explained that unlike mammals and some other dinosaurs, sauropods did not chew their food. They snipped food into smaller pieces before swallowing.”At least twice during their evolution, sauropods evolved small, peg-like teeth that formed and replaced quickly,” said Dr. D’Emic. “This characteristic may have led to the evolutionary success of sauropods.”The team developed a novel method to estimate sauropod tooth formation and replacement rate without destructively sampling the teeth by making microscopic sections. …

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High sugar intake linked to low dopamine release in insulin resistant patients

June 10, 2013 — Using positron emission tomography (PET) imaging of the brain, researchers have identified a sweet spot that operates in a disorderly way when simple sugars are introduced to people with insulin resistance, a precursor to type 2 diabetes. For those who have the metabolic syndrome, a sugar drink resulted in a lower-than-normal release of the chemical dopamine in a major pleasure center of the brain. This chemical response may be indicative of a deficient reward system, which could potentially be setting the stage for insulin resistance. This research could revolutionize the medical community’s understanding of how food-reward signaling contributes to obesity, according to a study presented at the Society of Nuclear Medicine and Molecular Imaging’s 2013 Annual Meeting.”Insulin resistance is a significant contributor to obesity and diabetes,” said Gene-Jack Wang, MD, lead author of the study and Professor of Radiology at Stony Brook University and researcher at the U.S. Department of Energy’s Brookhaven National Laboratory in Upton, N.Y. “A better understanding of the cerebral mechanisms underlying abnormal eating behaviors with insulin resistance would help in the development of interventions to counteract the deterioration caused by overeating and subsequent obesity. We suggest that insulin resistance and its association with less dopamine release in a central brain reward region might promote overeating to compensate for this deficit.”An estimated one-third of Americans are obese, according to the U.S. Centers for Disease Control and Prevention. The American Diabetes Association estimates that about 26 million Americans are living with diabetes and another 79 million are thought to be prediabetic, including those with insulin resistance.The tendency to overeat may be caused by a complex biochemical relationship, as evidenced by preliminary research with rodents. Dr. …

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