Paleontologists Audition Modern Examples of Ancient Behavior

ScienceDaily (Apr. 18, 2011) — Paleontologists agree that it's difficult to observe behavior in fossil specimens that are dead -- even extinct -- and petrified. One method is to find a modern, living, species that has some similarities to the ancient animal.

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That's the strategy adopted by David L. Meyer, University of Cincinnati professor of geology and colleagues as they study a group of ancient shellfish known as brachiopods. Although they resemble clams or other shelled mollusks, brachiopods are more closely related to marine worms. Relatively rare today, brachiopods were a dominant species in Paleozoic seas.
In the fossil-rich rocks of the Cincinnati region, a group of brachiopods known as strophomenates are found fossilized surrounded by tiny "moats." It is believed that the brachiopods themselves made the moats, but it is not certain how they did so. Paleontologists think the animals needed to open their shells to a gape of more than 45 degrees to make the moats.
Meyer, along with Benjamin Dattilo of Indiana University Purdue University Fort Wayne (a Ph.D. graduate of UC's geology program), and two students went looking for a modern analogue to the Paleozoic brachiopods. They found a tiny modern brachiopod named Thecidellina meyeri in the waters off Curaçao in the southern Caribbean.
"It's a reasonably good analogue," Meyer said. "They gape widely, and the internal anatomy shows similar structures."
Meyer, Dattilo, and UC students Tanya Del Valle and Christine Rahtz collected a fragment of coral covered with more than 30 Thecidellina specimens, and placed it in a tank with running seawater in the lab in Curaçao.
"They rapidly recovered," Meyer said, "resumed normal feeding behaviors, and maintained a 90-degree gape."
With video cameras recording, the paleontologists measured the ability of the modern brachiopods to move water around, generating relatively sluggish feeding currents and relatively strong currents when they snapped their shells shut.
Sometimes, the brachiopods would snap shut, stay shut, and then slowly open. At other times, they would open partially and shut several times in rapid succession.
The behavior of the modern animals provides a clue to ancient behaviors.
"By analogy," Meyer said, "feeding currents of the ancient brachiopods were too weak to disturb sediments, allowing them to feed close to the sea floor.

New Method for Engineering Human Tissue Regeneration

ScienceDaily (May 13, 2011) — If pending clinical trials prove successful, a new discovery published in The FASEB Journal could represent a major scientific leap toward human tissue regeneration and engineering. In a research report appearing online, Yale scientists provide evidence to support a major paradigm shift in this specialty area from the idea that cells added to a graft before implantation are the building blocks of tissue, to a new belief that engineered tissue constructs can actually induce or augment the body's own reparative mechanisms, including complex tissue regeneration.

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"With the constant growing clinical demand for alternative vessels used for vascular reconstructive surgeries, a significant development for alternative grafts is currently the primary focus of many investigators worldwide," said Christopher K. Breuer, M.D., a researcher involved in the work from Yale University School of Medicine/Yale-New Haven Hospital in New Haven, CT. "We believe that through an understanding of human vascular biology, coupled with technologies such as tissue engineering, we can introduce biological grafts that mimic the functional properties of native vessels and that are capable of growing with the patients." Breuer also says that patients are currently being enrolled in a first-of-its-kind clinical trial at Yale University to evaluate the safety and growth potential of tissue-engineered vascular grafts in children undergoing surgery for congenital heart disease.
To make this discovery, Breuer and colleagues conducted a three-part study, starting with two groups of mice. The first group expressed a gene that made all of its cells fluorescent green and the second group was normal. Researchers extracted bone marrow cells from the "green" mice, added them to previously designed scaffolds, and implanted the grafts into the normal mice. The seeded bone marrow cells improved the performance of the graft; however, a rapid loss of green cells was noted and the cells that developed in the new vessel wall were not green, suggesting that the seeded cells promoted vessel development, but did not turn into vessel wall cells themselves.
These findings led to the second part of the study, which tested whether cells produced in the host's bone marrow might be a source for new cells. Scientists replaced the bone marrow cells of a female mouse with those of a male mouse before implanting the graft into female mice. The researchers found that the cells forming the new vessel were female, meaning they did not come from the male bone marrow cells. In the final experiment, researchers implanted a segment of male vessel attached to the scaffold into a female host. After analysis, the researchers found that the side of the graft next to the male segment developed with male vessel wall cells while the side of the graft attached to the female host's vessel formed from female cells, proving that the cells in the new vessel must have migrated from the adjacent normal vessel.
"There's a very good chance that this study will eventually have a major impact on many disorders that afflict humankind," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "These scientists have basically used the body's repair mechanisms to make new tissues through bioengineering. In years to come, starfish and salamanders will have nothing on us!"

Household Sewage: Not Waste, but a Vast New Energy Resource

ScienceDaily (Jan. 6, 2011) — In a finding that gives new meaning to the adage, "waste not, want not," scientists are reporting that household sewage has far more potential as an alternative energy source than previously thought. They say the discovery, which increases the estimated potential energy in wastewater by almost 20 percent, could spur efforts to extract methane, hydrogen and other fuels from this vast and, as yet, untapped resource.

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Their report appears in ACS' journal Environmental Science & Technology.
Elizabeth S. Heidrich and colleagues note that sewage treatment plants in the United States use about 1.5 percent of the nation's electrical energy to treat 12.5 trillion gallons of wastewater a year. Instead of just processing and dumping this water, they suggest that in the future treatment facilities could convert its organic molecules into fuels, transforming their work from an energy drain to an energy source. Based on their research, they estimate that one gallon of wastewater contains enough energy to power a 100-watt light bulb for five minutes.
Only one other study had been done on wastewater's energy potential, and Heidrich thought that the results were too low because some energy-rich compounds were lost to evaporation. In the new study, the scientists freeze-dried wastewater to conserve more of its energy-rich compounds. Using a standard device to measure energy content, they found that the wastewater they collected from a water treatment plant in Northeast England contained nearly 20 per cent more than reported previously.
The authors acknowledge funding from the Engineering and Physical Sciences Research Council, the School of Chemical Engineering and Advanced Materials, Newcastle University, and Northumbrian Water Limited.

Converting Sewage Into Drinking Water: Wave Of The Future?

ScienceDaily (Jan. 30, 2008) — Amid growing water shortages in parts of the United States, more communities are considering tapping their sewage treatment plants as a new source of drinking water.

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The conversion of wastewater into tap water could help meet increased demand for one of life's most essential resources, according to the article "Treating Sewage For Drinking Water" scheduled for the Jan. 28 issue of Chemical & Engineering News.
C&EN Associate Editor Jyllian Kemsley notes in the article that some communities have used recycled wastewater for decades to replenish their drinking water supplies and wastewater often finds agricultural use for irrigation. Droughts, environmental concerns, and population growth now are forcing water utilities to consider adapting or expanding the practice, Kemsley explains.
Earlier in January, for instance, California approved operation of the Advanced Water Purification Facility (AWPF), the largest water reclamation plant in the nation. It will yield 70 million gallons per day of drinkable water from sewage. That's about 10 percent of the district's daily water demand for its 2.3 million residents. Although AWPF's purification process is complex, it produces clean, pure water that meets or exceeds all drinking water standards, the article notes.