UNH OCEAN MAPPERS DISCOVER SEAMOUNT IN PACIFIC OCEAN
From the FMS Global News Desk of Jeanne Hambleton
Released: 2-Sep-2014 12:00 PM EDT
Source Newsroom: University of New Hampshire
University of New Hampshire Center for Coastal and Ocean Mapping/Joint Hydrographic Center – University of New Hampshire scientists on a seafloor mapping mission have discovered a new seamount near the Johnson Atoll in the Pacific Ocean. The summit of the seamount rises 1,100 meters from the 5,100-meter-deep ocean floor.
Newswise — DURHAM, N.H. – University of New Hampshire scientists on a seafloor mapping mission have discovered a new seamount near the Johnson Atoll in the Pacific Ocean. The summit of the seamount rises 1,100 meters from the 5,100-meter-deep ocean floor.
The seamount was discovered in August when James Gardner, research professor in the UNH-NOAA Center for Coastal and Ocean Mapping/Joint Hydrographic Center, was leading a mapping mission aimed at helping delineate the outer limits of the U.S. continental shelf.
Working aboard the R/V Kilo Moana, an oceanographic research ship owned by the U.S. Navy and operated by the University of Hawaii, Gardner and his team were using multibeam echosounder technology to create detailed images of the seafloor when, late at night, the seamount appeared “out of the blue.”
The team was able to map the conical seamount in its entirety.
The yet-unnamed seamount, located about 300 kilometers southeast of the uninhabited Jarvis Island, lies in one of the least explored areas of the central Pacific Ocean. Because of that, Gardner was not particularly surprised by the discovery.
“These seamounts are very common, but we do not know about them because most of the places that we go out and map have never been mapped before,” he says.
Since only low-resolution satellite data exists for most of the Earth’s seafloor, many seamounts of this size are not resolved in the satellite data but advanced multibeam echosounder missions like this one can resolve them.
“Satellites just cannot see these features and we can,” Gardner adds.
While the mapping mission was in support of the U.S. Extended Continental Shelf Task Force, a multi-agency project to delineate the outer limits of the U.S. continental shelf, the volcanic seamount lies within the U.S. exclusive economic zone.
That means the U.S. has jurisdiction of the waters above it as well as the sediment and rocks of the seamount itself. The seamount’s impact remains unknown – for now. It is too deep (its summit lies nearly 4,000 meters beneath the surface of the ocean) to be a navigation hazard or to provide rich fisheries.
“It is probably 100 million years old,” Gardner says, “and it might have something in it we may be interested in 100 years from now.”
A world-renowned marine geologist, Gardner leads CCOM/JHC’s mapping efforts in support of U.S. claims to an extended continental shelf under the United Nations Law of the Sea Convention. He has participated in mapping cruises in the Atlantic, eastern and western Pacific, Gulf of Mexico, Gulf of Alaska and Beaufort Sea and published more than 200 scientific papers. Before joining UNH in 2003, he led the U.S. Geological Survey’s Pacific Mapping Group.
The UNH Center for Coastal and Ocean Mapping/Joint Hydrographic Center was founded in 1999 to develop tools to advance ocean mapping and hydrography and to train the next generation of hydrographers and ocean mappers. The JHC is a formal cooperative partnership between the University of New Hampshire and the National Oceanic and Atmospheric Administration (NOAA) whose aim is to create a national center for expertise in ocean mapping and hydrographic sciences.
The University of New Hampshire, founded in 1866, is a world-class public research university with the feel of a New England liberal arts college. A land, sea, and space-grant university, UNH is the state’s flagship public institution, enrolling 12,300 undergraduate and 2,200 graduate students.
Credit: University of New Hampshire Center for Coastal and Ocean Mapping/Joint Hydrographic Center –Three-dimensional view of the seamount area (southeast point of view and 3.5x vertical exaggeration) showing two volcanoes, in the foreground, with the discovered seamount in the background.
SCIENTISTS’ WORK MAY LEAD TO MISSION TO FIND OUT WHAT’S INSIDE ASTEROIDS
From the FMS Global News Desk of Jeanne Hambleton
Released: 2-Sep-2014 Source : University of Alabama Huntsville
Newswise — HUNTSVILLE, Ala. (Sept. 2, 2014) – Future asteroid mining operations and how we deal with an impending strike could be influenced by research on a potential NASA mission that’s being done by team that includes a University of Alabama in Huntsville (UAH) scientist.
“If you identify an asteroid coming toward us, how you deal with it could depend on its density and structure,” says Dr. Richard S. Miller, a UAH physics professor.
“Likewise, if this technique pans out, you could imagine sending out a specialized telescope to determine what the densities and interior structure of various asteroids are, then decide on the basis of that information what ones to mine.”
Little is now known about asteroid interior density and composition. Are they uniform or are they what astrophysicists call differentiated bodies, having denser and less-dense areas?
“Asteroids are time capsules of the early solar system,” Dr. Miller says.
“We know about their surface properties and we can also infer the mass of some asteroids. But what we want to do is actually probe the interior of asteroids and determine information about their structure, are there interior density gradients, what is the composition – is it solid or like Swiss cheese – and do they have cores or not? Is it a pile of rubble? It turns out this structure can tell us a great deal about the conditions present during the early epochs of solar system formation and its evolution.”
To find that out, the team’s scientists will be borrowing imaging technology concepts developed for medicine and high-energy physics.
They are developing a mission concept to probe asteroids using a technique similar to human computerized tomography (CT) scans. Dr. Miller is a co-investigator in a collaborative effort with the Planetary Science Institute (PSI), NASA’s Johnson Space Center, the Universities Space Research Association’s Arecibo Observatory (Arecibo/USRA) and the University of Houston to do the fundamental research and design that could lead to such a mission.
Led by principal investigator Dr. Tom Prettyman, senior scientist at PSI, the group has $500,000 in funding from the NASA Innovative Advanced Concepts (NIAC) Phase II program. The team’s two-year proposal, “Deep Mapping of Small Solar System Bodies with Galactic Cosmic Ray Secondary Particle Showers,” is one of only five projects selected for funding.
Other funded collaborators include Dr. Steven Koontz, NASA Johnson Space Center; Dr. Michael Nolan, Arecibo/USRA; Dr. Lawrence Pinsky, University of Houston; and Dr. Mark Sykes, PSI.
The team proposes using ever-present cosmic rays to perform its measurements. All objects in space are constantly bombarded by these particles, which are thought to be the remnants of massive supernovas and are primarily protons. On Earth, the atmosphere breaks them up and shields us from direct hits.
“In space, on contact with dense matter like the moon’s surface or other airless planetary bodies, they interact within the first few centimeters of depth and create a shower of particles,” Dr. Miller says.
Studying those interactions has provided us surface knowledge of asteroids.
“But cosmic rays also contain muons, which are particles similar to electrons, but which can go a lot farther into the asteroid, in some cases up to one kilometer.”
The idea is to position a telescope to orbit the asteroid and measure the number and trajectories of the muons passing through it.
“Muons are like an SUV,” says Dr. Miller.
“Once they are moving it is not easy to knock them off their course.”
An asteroid composed of varying densities of material would return a different pattern than one with a single density, just as a CT scan differentiates between densities of structures in the body.
Likewise, if an asteroid has a denser core, it will stop muons from passing through and the telescope will detect the change. That process is called muon tomography and is well understood.
Developed in the 1950s, it was even used in the 1960s by Luis Alvarez to map the Pyramid of Chephren.
“What is different about a CT scan is that instead of using cosmic rays and muons to determine densities, a CT scan uses x-rays,” Dr. Miller says.
To mature the concept, the scientists must first solve a number of fundamental challenges. They will be using computer modeling to work on:
• Detailed estimates of the particle signatures, including muons and other radiations that will be present in deep space and in the neighborhood of any asteroids;
• Doing the initial work on the muon telescope’s design and operation. There are competing ideas, and the team will evaluate a variety of performance tradeoffs;
• The development and implementation of advanced algorithms for asteroid structure reconstruction;
• Establishing the preliminary outlines of how a proposed NASA mission would be conducted, its feasibility and making predictions of the ultimate science return.
“What it has to do is detect those muons and give us a direction they are coming from,” Dr. Miller says of the telescope, but getting to that goal involves trade offs.
For example, the bigger the area the telescope can scan as it orbits, the less time it will take to get results encompassing an entire asteroid being studied. But the greater the telescope’s size, the more resources will be involved to launch the mission.
Also, to tell where the muons are coming from, the telescope will have to be able to tell directional “up” from “down.”
Dr. Miller says he was already exploring using muons to probe asteroids when he attended a conference and found that PSI’s Dr. Prettyman was working on the same thing.
“This is a good story of how you had two independent groups who were both looking at the same idea,” Dr. Miller says, “and we have joined forces to make a stronger project.”
STUDY SHOWS CELLULAR RNA CAN TEMPLATE DNA REPAIR IN YEAST
From the FMS Global News Desk of Jeanne Hambleton
Embargo expired: 3-Sep-2014 Citations Nature;
Source Newsroom: Georgia Institute of Technology
Newswise — The ability to accurately repair DNA damaged by spontaneous errors, oxidation or mutagens is crucial to the survival of cells. This repair is normally accomplished by using an identical or homologous intact sequence of DNA, but scientists have now shown that RNA produced within cells of a common budding yeast can serve as a template for repairing the most devastating DNA damage – a break in both strands of a DNA helix.
Earlier research had shown that synthetic RNA oligonucleotides introduced into cells could help repair DNA breaks, but the new study is believed to be the first to show that a cell’s own RNA could be used for DNA recombination and repair. The finding provides a better understanding of how cells maintain genomic stability, and if the phenomenon extends to human cells, could potentially lead to new therapeutic or prevention strategies for genetic-based disease.
The research was supported by the National Science Foundation, the National Institutes of Health and the Georgia Research Alliance. The results were scheduled to be reported September 3, 2014, in the journal Nature.
“We have found that genetic information can flow from RNA to DNA in a homology-driven manner, from cellular RNA to a homologous DNA sequence,” said Francesca Storici, an associate professor in the School of Biology at the Georgia Institute of Technology and senior author of the paper.
“This process is moving the genetic information in the opposite direction from which it normally flows. We have shown that when an endogenous RNA molecule can anneal to broken homologous DNA without being removed, the RNA can repair the damaged DNA. This finding reveals the existence of a novel mechanism of genetic recombination.”
Most newly-transcribed RNA is quickly exported from the nucleus to the cytoplasm of cells to perform its many essential roles in gene coding and expression, and in regulation of cell operations. Generally, RNA is kept away from – or removed from – nuclear DNA. In fact, it is known that annealing of RNA with complementary chromosomal DNA is dangerous for cells because it may impair transcription elongation and DNA replication, promoting genome instability.
This new study reveals that under conditions of genotoxic stress, such as a break in DNA, the role of RNA paired with complementary DNA may be different, and beneficial, for a cell.
“We discovered a mechanism in which transcript RNA anneals with complementary broken DNA and serves as a template for recombination and DNA repair, and thus has a role in both modifying and stabilizing the genome,” Storici explained.
DNA damage can arise from a variety of causes both inside and outside the cell. Because the DNA consists of two complementary strands, one strand can normally be used to repair damage to the other. However, if the cell sustains breakage in both strands – known as a double-strand break – the repair options are more limited. Simply rejoining the broken ends carries a high risk of unwanted mutations or chromosome rearrangement, which can cause undesirable effects including cancer.
Without successful repair, however, the cell may die or be unable to carry out important functions.
Beginning in 2007, Storici’s research team showed that synthetic RNA introduced into cells – including human cells – could repair DNA damage, but the process was inefficient and there were questions about whether the process could occur naturally.
To find out whether cells could use endogenous RNA transcripts to repair DNA damage, she and graduate students Havva Keskin and Ying Shen – who are first and second authors on the paper – devised experiments using the yeast Saccharomyces cerevisiae, which is widely used in the lab for genetics and genome engineering.
The researchers developed a strategy for distinguishing repair by endogenous RNA from repair by the normal DNA-based mechanisms in the budding yeast cells, including using mutants that lacked the ability to convert the RNA into a DNA copy.
They then induced a DNA double-strand break in the yeast genome and observed whether the organism could survive and grow by repairing the damage using only transcript RNA within the cells.
The DNA region that generates the transcript was constructed to contain a marker gene interrupted by an intron, which is a sequence that is removed only from the RNA during the process of transcription, explained Keskin.
Following intron removal, the transcript RNA sequence has no intron, while the DNA region that generates the transcript retains the intron; thus they are distinguishable. Only the repair templated by the transcript devoid of the intron can restore the function of a homologous marker gene in which the DNA double-strand break is induced, she added.
The researchers measured success by counting the number of yeast colonies growing on a Petri dish, indicating that the repair had been made by endogenous RNA. Testing was done on two types of breaks, one in the DNA from which the RNA transcript had been made, and the other in a homologous sequence from a different location in the DNA.
The research team, which also included scientists from Drexel University, found that proximity of the RNA to the broken DNA increased the efficiency of the repair and that the repair occurred via a homologous recombination process. Storici believes that the repair mechanism may operate in cells beyond yeast, and that many types of RNA can be used.
“We are showing that the flow of genetic information from RNA to DNA is not restricted to retro-elements and telomeres, but occurs with a generic cellular transcript, making it more of a general phenomenon than had been anticipated,” she explained. “Potentially, any RNA in the cell could have this function.”
For the future, Storici hopes to learn more about the mechanism, including what regulates it. She also wants to learn whether it takes place in human cells. If so, that could have implications for treating or preventing diseases that are caused by genetic damage.
“Cells synthesize lots of RNA transcripts during their life spans; therefore, RNA may have an unanticipated impact on genomic stability and plasticity,” said Storici, who is also a Georgia Research Alliance Distinguished Cancer Scientist.
“We need to understand in which situations cells would activate RNA-DNA recombination. Better understanding this molecular process could also help us manipulate mechanisms for therapy, allowing us to treat a disease or prevent it altogether.”
In addition to Storici, the paper’s authors include Alexander Mazin, a professor in the Department of Biochemistry and Molecular Biology at Drexel University; postdoctoral fellow Fei Huang and graduate student Mikir Patel, also from Drexel; Havva Keskin, a Georgia Tech graduate student; Ying Shen, a Ph.D. graduate from Georgia Tech who is now a postdoctoral fellow at Boston University School of Medicine; and graduate student Taehwan Yang and undergraduate student Katie Ashley from School of Biology at Georgia Tech.
Back tomorrow. Jeanne