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Will The Katy Prairie Save Houston Homes From Flooding

first_img 00:00 /04:02 Listen Share X Davis LandPrairie wetlands in the Katy Prairie retain water after Hurricane Harvey.Since 2015, the Katy Prairie Conservancy has been trying to build a berm that would protect homes in northwest Houston from flooding. The earthen wall would reach six feet high in some places, holding water inside the Katy Prairie, an area still wild with the native grasslands and wetlands much of Houston was built on. The prairie is naturally absorbent, retaining massive amounts of water in its root systems which often reach further into the ground than the plant stands high. If built, the berm – also known as Plan 5 of the Cypress Creek Overflow Project – would hopefully protect the Addicks and Barker Reservoirs from overflowing as they did during Harvey. The Katy Prairie is upstream of several tributaries to Addicks and Barker, and could keep water flow to a manageable level during major rain events. With Addicks and Barker coming close to overflow levels during Harvey, Plan 5 is gaining traction as a preventative measure. “They’re very similar to the engineered detention ponds that are built,” says Mary Anne Piacentini, Executive Director of the Katy Prairie Conservancy. Piacentini says that, unlike artificial detention ponds, grasslands offer wildlife habitats, recreational land, and water filtration. “When people say we can build these big detention ponds, the truth of the matter is we would be a lot better off saving the natural depressional wetlands,” she said. “They’re nature’s kidneys.” Davis LandMary Anne Piacentini, Executive Director of the Katy Prairie Conservancy, holds a four-inch-thick printed proposal for the Cypress Creek Overflow Project. The report estimates that Plan 5 will cost nearly 400 million dollars to complete.But while the Katy Prairie is poised to do some amount of good for the area, conservationists are worried they may be running out of time. Piacentini says development west of Houston is accelerating, and she’s worried the Conservancy may not be able to buy the land needed for the berm before developers. But some doubt the prairie can do more than artificial methods of flood control. “When we’re talking about catastrophic events,” says Phillip Magness, a professor of economics who studies public policy, “it’s the teacup trying to bail out the ocean.” When looking back through history, he says, “it’s a long standing problem of geography and topography,” not development. Magness sees the berm project as simply too costly for what it could accomplish, though he isn’t totally against it. The Katy Prairie Conservancy has taken some of that into account. Piacentini says the project’s planning committee was made up of both conservationists and developers. “The committee tried to work very hard to make sure that what this project was going to do was — yes it was going to save more land, but it was also going to protect lands south of Cypress Creek and that overflow region to be able to build,” she said.The group pushes back on the claim that prairie lands don’t retain enough water to be worth it. “It’s open ground, and open ground is obviously going to hold more water than paved ground,” said Wesley Newman, the group’s Conservation Director. The Conservancy knows Plan 5 is not the single, ultimate solution to Houston’s flooding problem, but they maintain that the project should be a part of it. “We just need to look at natural solutions as well as engineered solutions and a combination of the two, and it will help,” Newman said.For now, the Conservancy is hoping that renewed interested after Harvey will kickstart plans — and funding — for the berm. They hope that money from a federal aid package will help pay for the $400 million dollar project. Once funded, the berm could be completed within two years.  To embed this piece of audio in your site, please use this code:last_img read more

Scientists uncover clues to ATP mystery and how cells work

first_img Researchers uncover secrets of internal cell fine-tuning Although many parts of the cellular movement process are well-understood, there is still some mystery in the details. One mystery in particular is that long polymer chains of actin (called F-actin) have been observed to use ATP at a rate that is more than 40,000 times faster than that of individual monomers of actin (called G-actin). This gigantic rate difference has been experimentally investigated for more than 25 years without a solution.Now in a new paper in the Journal of the American Chemical Society, researchers Martin McCullagh, Marissa G. Saunders, and Gregory A. Voth at The University of Chicago have used quantum mechanics/molecular mechanics (QM/MM) simulations of G- and F-actin, guided by coarse-grained modeling, to investigate how the structural differences of the two types of actin may contribute to the rate difference at which they use ATP, a process called ATP hydrolysis.”I think this work provides a fundamental molecular understanding of how actin filaments catalyze ATP hydrolysis, which in turn is critical to their behavior,” Voth told Phys.org. “ATP hydrolysis modulates many actin properties, which in turn is very important to the behavior of the cellular cytoskeleton. Some of these properties are relevant to, e.g., the binding of anti-cancer drugs in targeting cancer cells.”In ATP hydrolysis, actin filaments use ATP by breaking off one of its three phosphate atoms. The chemical energy stored in the phosphate bond is released and can be used for many purposes. Here, the energy is used to change the properties of the actin filaments, after which the polymer can be disassembled. This continuous growth and disassembly is what causes cells to move. Basically, what the rate difference mystery means is that somehow actin polymerization accelerates ATP hydrolysis. In other words, as the actin forms a filament, the faster it can use ATP. The effect is cyclical, so that the higher the rate of ATP hydrolysis, the higher the rate at which actin can be depolymerized. This activity leads to a remarkable phenomenon called actin “treadmilling,” which is essential to cellular movement. Journal information: Journal of the American Chemical Society Water molecules can rotate more freely in G-actin than in F-actin. The F-actin snapshot (a) has a three-water wire, and the G-actin snapshot (b) has a six-water wire. Credit: McCullagh, et al. ©2014 American Chemical Society Citation: Scientists uncover clues to ATP mystery and how cells work (2014, September 23) retrieved 18 August 2019 from https://phys.org/news/2014-09-scientists-uncover-clues-atp-mystery.html Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: Martin McCullagh, et al. “Unraveling the Mystery of ATP Hydrolysis in Actin Filaments.” Journal of the American Chemical Society. DOI: 10.1021/ja507169f Artistic rendering of the actin structures and free energy surfaces calculated for ATP hydrolysis in G-actin and F-actin, computed using QM/MM simulations. Credit: McCullagh, et al. ©2014 American Chemical Society The new QM/MM simulations help explain the dramatic rate increase of ATP hydrolysis that occurs in F-actin compared to G-actin. The simulations show that certain key amino acids change position during polymerization, which promotes the rearrangement of nearby water molecules. The water molecules can rotate more freely, allowing them to easily align into shorter “water wires” that transport protons through the water very quickly—almost instantaneously, in fact. The resulting ease with which the protons can move corresponds to a lowering of the free energy barrier of that process. Since proton transport is a key step in ATP hydrolysis, overall less energy is required for F-actin to hydrolyze the ATP molecules.The simulations reveal a barrier height reduction that agrees well with the experimentally measured value, supporting the explanation that the favorable proton transport environment in F-actin plays an important role in the increased ATP hydrolysis rate. “There are many, many proteins that utilize ATP (or GTP) hydrolysis for modulate their behavior,” Voth said. “I think this work opens up the possibility to include that process more routinely in the computational study of proteins.” (Phys.org) —Strong, thin fibers called microfilaments, or actin filaments, are present in the cytoplasm of almost every cell in the body. By growing and shrinking, actin filaments play a major role in cellular movement. Since these processes require large amounts of energy, actin filaments use a lot of ATP (adenosine triphosphate), a molecule that is often called the energy currency of the cell. © 2014 Phys.orglast_img read more