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  • richardmitnick 10:00 am on February 8, 2018 Permalink | Reply
    Tags: , , , Rapid Detection and Recovery: The Science of Hunting Meteorites, U Arizona   

    From University of Arizona: “Rapid Detection and Recovery: The Science of Hunting Meteorites” 

    U Arizona bloc

    University of Arizona

    Feb. 6, 2018
    Emily Walla

    Science contact
    Vishnu Reddy
    UA Lunar and Planetary Laboratory
    520-621-6963
    vishnureddy@email.arizona.edu

    1
    A sample of the Michigan meteorite recovered by citizen scientists using maps produced by UA assistant professor Vishnu Reddy’s Doppler radar technique (Photo: Vishnu Reddy)

    UA professor Vishnu Reddy is leading a NASA-funded project to find freshly fallen meteorites like the one in Michigan last month.

    2
    Composite image of weather radar signatures of the falling meteorite (Image: Marc Fries)

    At 8:10 p.m. on Jan. 16, hundreds of people in Michigan reported the bright glow of a meteor streaking through the sky, rattling windows as it broke the sound barrier. The meteor then broke apart in the Earth’s atmosphere, and its pieces rained quietly to the ground.

    Using predictions by the Rapid Detection and Recovery of Meteorites, or RADARMET, project, scientists and meteorite hunters were able to recover more than half a dozen fragments of the rock within two days of the fall.

    RADARMET is led by Vishnu Reddy, assistant professor in the University of Arizona’s Lunar and Planetary Laboratory. He procured funding from NASA to operate RADARMET, which uses National Weather Service Doppler radar data and computer models to locate meteorites within hours of their fall.

    “Historically, people would see a meteor in the sky and they would say, ‘I saw it go that way behind the tree,'” Reddy said. “Even if someone takes a picture of the meteor, using the image to trace a trajectory for the meteorite is difficult and can be quite time-consuming.”

    3
    Computed strewn field of the meteorite. The dark orange shows where the largest, heaviest pieces of the meteorite fell, and the yellow shows where the lightest and smallest pieces fell. (Image: Marc Fries)

    Upper-atmosphere winds make extrapolation challenging, Reddy said. For a meteor to survive the trip through the atmosphere and fall onto the ground as a meteorite, it has to slow from its cosmic velocity. The friction from the atmosphere makes the meteor glow visibly between 30 and 65 miles above ground.

    “Typically, meteorite-dropping meteors need to slow down to around 6,700 mph, the speed when they no longer glow brightly while descending into the atmosphere,” Reddy said.

    Falling at Terminal Velocity

    The meteor then enters a period known as “dark flight,” during which it falls at terminal velocity. During this dark flight, winds in the upper atmosphere can buffet the meteorite miles away from where its glowing bright flight ends.

    Marc Fries, Reddy’s co-investigator for RADARMET and a scientist at NASA’s Johnson Space Center, developed a method that can predict how a meteorite would travel during its dark flight. He also has developed software tools to calculate where meteorites land under the influence of winds, and to estimate the total mass that reaches the ground.

    Tanner Campbell, a UA graduate student in aerospace and mechanical engineering, adapted Fries’ dark flight model into a computer program that quickly and accurately determines where a meteorite will fall.

    “We can accomplish this because the kinetics of an object in near freefall are known quite well,” Campbell said. “Since these meteorites are typically fairly small, we can make some assumptions about how they travel through the atmosphere. We can then take whatever data can be gathered on the meteorite while it is glowing in the sky, and measured atmospheric data from near the event, and use it to predict the path to the ground.”

    Atmospheric data include wind speeds and information collected by weather radar stations, which detect anything falling through the air, whether it is rain, birds, airplanes or meteorites. Although the radar cannot distinguish between a sparrow and a space rock, the RADARMET team has a method to do just that.

    “The first trigger is eyewitness reports from the public,” Reddy said.

    Using an online tool on the American Meteor Society website, members of the public can log their location, which direction they were facing and how long the meteor was visible in the sky. When an event has corroborating videos and other evidence such as sonic booms, Reddy and his co-investigators download radar data from the nearest weather station and power up the dark flight model.

    Accuracy of Location Is Vital

    Within hours of the event, the RADARMET team can locate the exact area where meteorite fragments have fallen. The information is quickly shared with the public, including scientists and meteorite hunters. RADARMET’s method is so accurate that hunters have been able to travel to a location, park their cars and find meteorites within that parking lot.

    When hunting meteorites, time is of the essence. The sooner a sample is found, the more scientists can learn from it.

    “The longer a meteorite sits on the Earth, the less scientifically useful it becomes, because the weathering process degrades the minerals and destroys it,” Reddy said.

    Rain can dissolve and wash away minerals, microbes can contaminate any evidence of the building blocks of life, and oxygen can rust the iron in the meteorite within a day.

    Although recovering pieces of the Michigan meteorite took slightly more than a day, some samples were found in nearly pristine condition. One piece was found in ice, protected from exposure to liquid water. Pristine samples such as this one enable scientists to study materials that are easily destroyed or of astrobiological significance.

    Reddy and students in the UA Department of Planetary Sciences plan to be involved in the study of the meteorite.

    “While we’re not out there hunting the meteorites, we’re doing the science,” Reddy said.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

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  • richardmitnick 9:29 am on January 31, 2018 Permalink | Reply
    Tags: , , , TMDs--transition metal dichalcogenides, U Arizona   

    From University of Arizona: “UA Researchers Observe Electrons Zipping Around in Crystals” 

    U Arizona bloc

    University of Arizona

    Jan. 29, 2018
    Daniel Stolte

    For the first time, scientists have tracked electrons moving through exotic materials that may make up the next generation of computing hardware, revealing intriguing properties not found in conventional, silicon-based semiconductors.

    1
    Extreme conditions are used to protect and preserve the TMDs during the experiments. As shown here, all samples are stored and manipulated in a vacuum that is close to the conditions in space. (Photo: Kyle Mittan/UANews.)

    The end of the silicon age has begun. As computer chips approach the physical limits of miniaturization and power-hungry processors drive up energy costs, scientists are looking to a new crop of exotic materials that could foster a new generation of computing devices that promise to push performance to new heights while skimping on energy consumption.

    Unlike current silicon-based electronics, which shed most of the energy they consume as waste heat, the future is all about low-power computing. Known as spintronics, this technology relies on a quantum physical property of electrons — up or down spin — to process and store information, rather than moving them around with electricity as conventional computing does.

    On the quest to making spintronic devices a reality, scientists at the University of Arizona are studying an exotic crop of materials known as transition metal dichalcogenides, or TMDs. TMDs have exciting properties lending themselves to new ways of processing and storing information and could provide the basis of future transistors and photovoltaics — and potentially even offer an avenue toward quantum computing.

    2
    Calley Eads, a fifth-year doctoral student in the UA’s Department of Chemistry and Biochemistry, aligns a laser system used to track electrons on time-scales at the limits of what can be measured. In her research, she investigates materials that could one day bring faster computing and more efficient solar cells. (Photo: Kyle Mittan/UANews.

    For example, current silicon-based solar cells convert realistically only about 25 percent of sunlight into electricity, so efficiency is an issue, says Calley Eads, a fifth-year doctoral student in the UA’s Department of Chemistry and Biochemistry who studies some of the properties of these new materials. “There could be a huge improvement there to harvest energy, and these materials could potentially do this,” she says.

    There is a catch, however: Most TMDs show their magic only in the form of sheets that are very large, but only one to three atoms thin. Such atomic layers are challenging enough to manufacture on a laboratory scale, let alone in industrial mass production.

    Many efforts are underway to design atomically thin materials for quantum communication, low-power electronics and solar cells, according to Oliver Monti, a professor in the department and Eads’ adviser. Studying a TMD consisting of alternating layers of tin and sulfur, his research team recently discovered a possible shortcut, published in the journal Nature Communications.

    “We show that for some of these properties, you don’t need to go to the atomically thin sheets,” he says. “You can go to the much more readily accessible crystalline form that’s available off the shelf. Some of the properties are saved and survive.”

    Understanding Electron Movement

    This, of course, could dramatically simplify device design.

    “These materials are so unusual that we keep discovering more and more about them, and they are revealing some incredible features that we think we can use, but how do we know for sure?” Monti says. “One way to know is by understanding how electrons move around in these materials so we can develop new ways of manipulating them — for example, with light instead of electrical current as conventional computers do.”

    To do this research, the team had to overcome a hurdle that never had been cleared before: figure out a way to “watch” individual electrons as they flow through the crystals.

    “We built what is essentially a clock that can time moving electrons like a stopwatch,” Monti says. “This allowed us to make the first direct observations of electrons move in crystals in real time. Until now, that had only been done indirectly, using theoretical models.”

    The work is an important step toward harnessing the unusual features that make TMDs intriguing candidates for future processing technology, because that requires a better understanding of how electrons behave and move around in them.

    Monti’s “stopwatch” makes it possible to track moving electrons at a resolution of a mere attosecond — a billionth of a billionth of a second. Tracking electrons inside the crystals, the team made another discovery: The charge flow depends on direction, an observation that seems to fly in the face of physics.

    Collaborating with Mahesh Neupane, a computational physicist at Army Research Laboratories, and Dennis Nordlund, an X-ray spectroscopy expert at Stanford University’s SLAC National Accelerator Laboratory, Monti’s team used a tunable, high-intensity X-ray source to excite individual electrons in their test samples and elevate them to very high energy levels.

    “When an electron is excited in that way, it’s the equivalent of a car that is being pushed from going 10 miles per hour to thousands of miles per hour,” Monti explains. “It wants to get rid of that enormous energy and fall back down to its original energy level. That process is extremely short, and when that happens, it gives off a specific signature that we can pick up with our instruments.”

    The researchers were able to do this in a way that allowed them to distinguish whether the excited electrons stayed within the same layer of the material, or spread into adjacent layers across the crystal.

    “We saw that electrons excited in this way scattered within the same layer and did so extremely fast, on the order of a few hundred attoseconds,” Monti says.

    In contrast, electrons that did cross into adjacent layers took more than 10 times longer to return to their ground energy state. The difference allowed the researchers to distinguish between the two populations.

    “I was very excited to find that directional mechanism of charge distribution occurring within a layer, as opposed to across layers,” says Eads, the paper’s lead author. “That had never been observed before.”

    Closer to Mass Manufacturing

    The X-ray “clock” used to track electrons is not part of the envisioned applications but a means to study the behavior of electrons inside them, Monti explains, a necessary first step in getting closer toward technology with the desired properties that could be mass-manufactured.

    “One example of the unusual behavior we see in these materials is that an electron going to the right is not the same as an electron going to the left,” he says. “That shouldn’t happen — according to physics of standard materials, going to the left or the right is the exact same thing. However, for these materials that is not true.”

    This directionality is an example of what makes TMDs intriguing to scientists, because it could be used to encode information.

    “Moving to the right could be encoded as ‘one’ and going to the left as ‘zero,'” Monti says. “So if I can generate electrons that neatly go to the right, I’ve written a bunch of ones, and if I can generate electrons that neatly go to the left, I have generated a bunch of zeroes.”

    Instead of applying electrical current, engineers could manipulate electrons in this way using light such as a laser, to optically write, read and process information. And perhaps someday it may even become possible to optically entangle information, clearing the way to quantum computing.

    “Every year, more and more discoveries are occurring in these materials,” Eads says. “They are exploding in terms of what kinds of electronic properties you can observe in them. There is a whole spectrum of ways in which they can function, from superconducting, semiconducting to insulating, and possibly more.”

    The research described here is just one way of probing the unexpected, exciting properties of layered TMD crystals, according to Monti.

    “If you did this experiment in silicon, you wouldn’t see any of this,” he says. “Silicon will always behave like a three-dimensional crystal, no matter what you do. It’s all about the layering.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 7:59 am on January 17, 2018 Permalink | Reply
    Tags: , , , , , , Steward Observatory, U Arizona   

    From U Arizona: “Students Help Little Telescope Do Big Things” 

    U Arizona bloc

    University of Arizona

    Jan. 11, 2018
    Daniel Stolte

    A four-year effort involving UA students helped a team of astronomers measure the masses of a large sample of supermassive black holes in the farthest reaches of the universe. As part of a robotic telescope network in southern Arizona, instruments such as the Bok Telescope could play a crucial role in future “grand challenge” science endeavors.

    2.3-metre Bok Telescope at the Steward Observatory at Kitt Peak in Arizona, USA, altitude 2,096 m (6,877 ft)


    U Arizona Steward Observatory at Kitt Peak, AZ, USA, altitude 2,096 m (6,877 ft)

    The Bok Telescope on Kitt Peak is the largest telescope operated solely by the UA’s Steward Observatory. Named in honor of Bart Bok, who was Steward’s director from 1966-1969, the telescope operates every night of the year except Christmas Eve and a maintenance period scheduled during the summer rainy season.

    By today’s standards, the University of Arizona’s Bok Telescope, perched on Kitt Peak southwest of Tucson, is a small telescope: Its primary mirror stands a mere five inches taller than Dušan Ristić, the 7-foot center of the UA men’s basketball team.

    Yet, despite its modest size and advanced age of almost 50 years, the instrument keeps churning out big science, helping us unravel some of the biggest questions about the cosmos. Using observations made with the Bok Telescope, a team of astronomers managed to directly measure the masses of an unprecedented number of the universe’s most distant supermassive black holes, also called quasars. Lurking in the centers of nearly every large galaxy, these Leviathans range from 5 million to 1.7 billion times the mass of the sun.

    “This is the first time that we have directly measured masses for so many supermassive black holes so far away,” said Catherine Grier, a postdoctoral fellow at the Penn State University, who led the research. “These new measurements, and future measurements like them, will provide vital information for people studying how galaxies grow and evolve throughout cosmic time.”

    The results, presented at the American Astronomical Society meeting in National Harbor, Maryland, are published in The Astrophysical Journal and represent a major step forward in our ability to measure supermassive black hole masses in large numbers of distant quasars and galaxies. In addition to the Bok Telescope, the project used the Sloan Digital Sky Survey, or SDSS, and the Canada-France-Hawaii Telescope, or CFHT, atop Hawaii’s Mauna Kea volcano.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude 2,788 meters (9,147 ft)


    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft)


    CFHT Telescope, Maunakea, Hawaii, USA, at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    3
    An artist’s rendering of the inner regions of a quasar, with a supermassive black hole at the center surrounded by a disk of hot material falling in. The two light curves at the bottom illustrates how astronomers use reverberation to map black holes. (Image: Nahks Tr’Ehnl and Catherine Grier/Penn State, SDSS)

    “The Bok Telescope provided key data that allow measurement of how the quasars vary over time, which tells us about the size of the light-emitting region around the black hole,” said Xiaohui Fan, a Regents’ Professor of Astronomy at the UA’s Steward Observatory and a member of the Sloan Digital Sky Survey. “The data is then used to determine the mass of the black hole.”

    Producing ‘World-Class Results’

    The Bok Telescope’s large field of view, combined with the sensitive detectors, means that astronomers can monitor many quasars at the same time, a feat that is crucial to establish the large sample used in the study.

    “This result shows that the Bok can still produce world-class results,” said Ian McGreer, an assistant astronomer at Steward and one of the study’s authors, who managed the observations with the Bok Telescope. “We got involved because the SDSS did a survey of facilities that could support this program, and the Bok came out as one of the few with the required capabilities.”

    The Bok investment was quite substantial, McGreer explained, with more than 100 nights spread over four years so far.

    “The data in this paper are based on the first year, 2014, when the monitoring was the most intense,” he said. “Sixty nights that year were covered by a rotating cast of observers, many of whom were UA undergrads, grads and visiting students.

    “The Bok does not have a nighttime operator, which means the students received valuable training not only in collecting the data and operating the instrument, but in learning how to operate a telescope at night. This is a fairly rare opportunity these days.”

    As they suck in nearby dust and gas, supermassive black holes heat the material to such high temperatures that it glows brightly enough to be seen all the way across the universe. These bright disks of hot gas are known as quasars, and they are clear indicators of the presence of supermassive black holes. By studying these quasars, we learn not only about supermassive black holes, or SMBHs, but also about the distant galaxies they live in. But to do all of this requires measurements of the properties of the SMBHs, most importantly their masses.

    Measuring the masses of extragalactic SMBHs — in this study, up to 8 billion light-years away — is a daunting task and requires a technique called reverberation mapping. Reverberation mapping works by comparing the brightness of light coming from gas very close in to the black hole (referred to as the “continuum” light) to the brightness of light coming from fast-moving gas farther out. Changes occurring in the continuum region impact the outer region, but light takes time to travel outward, or “reverberate.” By measuring this time delay, astronomers can determine how far out the gas is from the black hole. Knowing that distance allows them to measure the mass of the supermassive black hole — even though they can’t see the details of the black hole itself.

    In this new work, the team used an industrial-scale application of the reverberation mapping technique, with the goal of measuring black hole masses in tens to hundreds of quasars. These new SDSS measurements increase the total number of active galaxies with SMBH mass measurements by about two-thirds, and push the measurements farther back in time to when the universe was only half of its current age.

    Faint Quasars Pose a Challenge

    The key to the success of the SDSS reverberation mapping project lies in the SDSS’ ability to study many quasars at once — the program is currently observing 850 quasars simultaneously. But even with the SDSS’ powerful telescope, this is a challenging task because these distant quasars are incredibly faint.

    “You have to calibrate these measurements very carefully to make sure you really understand what the quasar system is doing,” said Jon Trump, an assistant professor at the University of Connecticut and a member of the research team.

    Observing the quasars over the same season with the Bok Telescope and the CFHT improved these calibrations, allowing the team to find reverberation time delays for 44 quasars and use the time delay measurements to calculate black hole masses that range from about 5 million to 1.7 billion times the mass of our sun.

    In the words of McGreer, the future is bright for this kind of work, with plans to develop a robotic telescope network in southern Arizona using telescopes such as the Bok, which could help guide efforts to combine such a network with “grand challenge” science projects like the Large Synoptic Survey Telescope, or LSST.

    Slated to begin operations in 2023, the LSST will conduct an unprecedented 10-year survey, repeatedly imaging every part of the visible sky every few nights. The heart of the instrument, a 8.4-meter primary mirror, was cast and polished at the UA’s Richard F. Caris Mirror Lab.

    “The lessons learned from this reverberation mapping project serve as a pathfinder, or proof of concept, for something that could be done on a much larger scale when LSST arrives,” McGreer said.

    LSST


    LSST Camera, built at SLAC



    LSST telescope, currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 7:43 am on November 14, 2017 Permalink | Reply
    Tags: , Introducing Titin - the Protein That Rules Our Hearts, , U Arizona   

    From U Arizona: “Introducing Titin, the Protein That Rules Our Hearts” 

    U Arizona bloc

    University of Arizona

    Nov. 13, 2017
    Emily Walla

    UA scientists have solved a muscle mystery by proving that the protein titin acts as a molecular ruler, determining the length of muscle fibers and influencing the strength of the muscles that make our hearts beat and bodies move.

    1
    Henk Granzier: “Biologists have always wondered what makes (muscles) so precisely structured.” No image credit.

    Although scientists have long speculated that a protein named titin measures thick filaments — the proteins that make muscles contract — no one has been able to provide evidence to support their theories.

    No one, that is, until a team of researchers in the University of Arizona’s Department of Cellular and Molecular Medicine took on the case. In a recent study published in Nature Communications, the team presented definitive proof that titin acts as a molecular ruler for the muscle’s thick filament.

    Throughout the muscles of the heart and body, the thick filaments have precise, uniform lengths.

    “Functionally and clinically, it is very important to regulate the thick filament precisely, otherwise muscles would not function well,” said Henk Granzier, senior author of the study and professor of molecular and cellular medicine. “Biologists have always wondered what makes them so precisely structured.”

    Studying mice with certain mutations in the gene encoding the blueprint for the titin protein, the researchers found that when titin was shortened, so were the thick filaments, resulting in weakened muscles and dilated cardiomyopathy, a condition that leads to heart failure.

    “We genetically engineered a mouse that doesn’t have normal titin,” said Granzier, a member of the BIO5 Institute. “It has a piece from titin deleted. Since titin is involved in somehow regulating the thick filament, then you expect if you make titin shorter, the thick filament length will be altered as well. And, lo and behold, that is the case.”

    A typical protein is made of a few hundred amino acids linked in a chain. Though still microscopically small, titin is gigantic compared to other proteins. Comprised of more than 30,000 amino acids, the supersize protein is made from super-repeated structures. The amino acid super-repeats of titin are like tick marks on a yardstick, measuring out uniform sections of the thick filament.

    By altering the gene for titin, Granzier’s team was able to make a mouse whose titin was missing several of its super-repeats.

    The resulting mice showed symptoms of dilated cardiomyopathy, or DCM. This condition stretches out the muscle in the heart and prevents it from pumping efficiently. While the heart still contracts, the muscle is weak, so each contraction only moves a fraction of the blood pumped by a normal heart.

    In humans, the most frequent cause of DCM is a mutation in titin that shortens the protein. DCM affects 1 in 500 people, and often patients must undergo a heart transplant to survive. Understanding the cause of the condition can better arm researchers as they search for novel ways to combat it.

    Methods of Discovery

    “In science, if you want to do conclusive work, you have to test your hypothesis multiple ways and get consistent results,” Granzier said. This meant that any abnormalities detected in the genetically engineered mice had to be deeply investigated.

    After testing the strength of the mice, his team removed the muscles of interest to inspect them in a setting they controlled, instead of a setting controlled by the complex biological systems of the mice. To make certain that differences in the mice were caused by titin, the muscle tissues were observed in vitro by removing them from the animals and artificially stimulating them to show that they produced less force. In the body, muscles contract when activated by calcium; under the microscope, flooding the isolated muscle tissue with a calcium solution mimics this activation process.

    Using ultrasound, the team showed that the hearts of the engineered mice were larger than those of mice with normal titin. The next step was to investigate how this enlargement weakened the heart.

    How Titin Controls Strength

    “The sarcomere is the smallest muscle unit you can tease out and still have all the properties of muscle: force development and shortening,” Granzier said.

    The sarcomeres are linked end-to-end in a chain that spans the entirety of a muscle. Just as a strong chain is made from links that are well made and uniform, sarcomere health and uniformity is vital to muscle strength.

    Each sarcomere is comprised of three filaments: thick, thin and titin filaments. The motor driving contraction — myosin — is held at precise points within the thick filament, and it pulls the thick filament across the thin filament, causing muscle contraction. Muscles are strongest when the thick and thin filaments overlap at an optimal length — around 2 micrometers, or one ten-thousandth of an inch. Stretch out the muscle, and the filaments cannot reach the point of optimum overlap, so the muscle is weakened. Overstretch the muscle, and the filaments do not overlap at all; the muscle cannot exert any force.

    When titin is mutated and short, the resulting shortened fibers cannot reach the optimal point of overlap, and the muscle cannot exert much force. The muscle is further weakened because shorter thick filaments cannot hold the optimal number of myosin motors. The thin and thick filaments do not overlap properly nor contract effectively when the thick filament is short.

    Paula Tonino and Balazs Kiss, lead authors of the study and scientific investigators in Granzier’s lab, observed the muscle fibers under electron and super-resolution microscopes. They determined that in the muscles of engineered mice, not only were the thick filaments shortened, but also that they were shortened by precise, uniform lengths that corresponded to the size of the super-repeats removed from titin.

    “We showed that titin is the regulator of the thick filament,” Granzier said, confirming that titin determines the strength of muscles and health of hearts.

    “You might say titin rules.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 12:23 pm on September 14, 2017 Permalink | Reply
    Tags: , , , , , , U Arizona   

    From U Arizona: “After Farewell Kiss, Cassini Takes the Plunge” 

    U Arizona bloc

    University of Arizona

    Sept. 13, 2017
    Daniel Stolte

    1
    In the upper reaches of Saturn’s atmosphere, the Cassini spacecraft will use its thrusters to point its antenna toward Earth until it breaks up. (Credit: NASA/JPL-Caltech)

    For UA scientists who contributed to NASA’s Cassini-Huygens mission, the Grand Finale of humanity’s tour of the Saturn system marks the end of an era.

    When NASA’s Cassini spacecraft careens to its final destination, the upper atmosphere of Saturn, it will take with it a sizable chunk of University of Arizona space research history. After a journey of 4.9 billion miles, and one month shy of 20 years in space, the probe is programmed to end its voyage exploring the Saturnian system through a deliberate plunge into the second-largest planet of the solar system.

    The spacecraft’s fateful dive on Friday will be the final beat in the mission’s Grand Finale — 22 weekly dives, begun in late April, through the gap between Saturn and its rings. According to NASA, no spacecraft has ever ventured so close to the planet before.

    “Cassini-Huygens is a classic example of a ‘flagship’ mission, accomplishing tremendous science in many disciplines over many years,” said Alfred McEwen, a UA professor of planetary sciences, on Monday as he prepared to leave for Pasadena, California. There, at NASA’s Jet Propulsion Laboratory, he would attend the final moments of the mission, along with other UA planetary scientists who have participated in the project.

    2
    NASA’s Cassini spacecraft delivered this glorious view of Saturn on Dec. 18, 2012, taken while the spacecraft was in Saturn’s shadow. The cameras were turned toward Saturn and the sun so that the planet and rings are backlit. (Credit: NASA/JPL-Caltech/Space Science Institute)

    NASA chose to end the mission by safely disposing of the spacecraft, burning it up in Saturn’s atmosphere rather than allowing it to run out of fuel and committing its fate to an aimless tumble and potential crash onto one of Saturn’s moons. Mission scientists were especially concerned about contaminating Titan or Enceladus, the two Saturnian moons where life as we know it might be possible — a possibility discovered by Cassini’s multiple flybys.

    When it launched, Cassini-Huygens was the biggest, most complex interplanetary spacecraft ever flown. In 2004, it arrived in the Saturn system, carrying with it a robotic passenger in form of the Huygens probe, contributed to the mission by the European Space Agency, or ESA. On Jan. 14, 2005, Huygens would make history as the first — and, so far, only — humanmade object to touch down on a world in the outer solar system. Through the eyes of Huygens, an instrument built by UA scientists and engineers, people on Earth could watch as the probe hurtled through the opaque and hazy atmosphere enshrouding Titan.

    The probe was equipped with an instrument called DISR, short for Descent Imager/Spectral Radiometer. Led by Martin Tomasko, a now-retired research professor at the Lunar and Planetary Laboratory, UA scientists joined their ESA colleagues in Germany to follow Huygens with six science experiments as it descended through Titan’s thick atmosphere until it touched down on a virtually unseen surface. In addition to images taken with DISR, the lander recorded data that enabled LPL staff scientist Erich Karkoschka to gather surprising clues about Titan’s surface many years after the event.

    3
    Cassini-Huygens is a “flagship mission” and has the track record to show it. (Credit: NASA/JPL-Caltech)

    Monitoring the Moon Titan

    During many flybys, Cassini monitored the dynamic Titan using its camera suite and an instrument called VIMS, a Visual and Infrared Mapping Spectrometer. Built at Jet Propulsion Laboratory under the leadership of Robert Brown, operations for VIMS moved to the UA when Brown assumed a position as professor at LPL. According to Brown, VIMS has been taking spectra over areas of Saturn, its rings and moons so scientists can discover what these objects are made of.

    Those observations revealed details about the cycle of methane, which on Titan takes the role of water on Earth — forming clouds, raining down and forming lakes, as well as freezing into ice. In all those observations, Cassini’s cameras played an important role, said McEwen, who is a team member of the craft’s imaging science subsystem. Those cameras, over the years of photographing Saturn, its rings and moons, created some of the most visually beautiful images of the solar system.

    Cassini’s imaging team leader Carolyn Porco was appointed to the mission while on the faculty at LPL, where she had been working on NASA’s Voyager mission, and was a co-originator of the idea to use Voyager-1 to take portraits of the planets, including the famous Pale Blue Dot image of Earth.

    4
    Earthrise. Credit: NASA/JPL. https://www.wessexscene.co.uk/science/2017/01/29/the-pale-blue-dot/

    Surface observations on Titan are planned at LPL, and then sent to the Cassini Imaging Central Laboratory for Operations, or CICLOPS, at the University of Colorado, Boulder, which Porco heads as director.

    “From there, the necessary commands are sent to JPL and then to the spacecraft,” McEwen explains.

    Another one of Saturn’s moons, ice-clad Enceladus, rose to stardom during several flybys over the course of the mission. Enceladus plows along the orbit of the E Ring, Saturn’s second-from-outermost ring, which reaches extremely far out into space, brushing up against the orbit of Titan.

    “There was speculation that the moon had something to do with the E Ring,” McEwen says.

    During multiple close flybys, Cassini used its full science payload to detect and analyze water-rich plumes erupting from the moon’s south pole far into space, a spectacular discovery that McEwen considers one of the highlights of the entire mission.

    “We saw that these plumes are quite large and extensive,” he recalls. “Because we were able to measure their composition with Cassini’s instruments, we could show that (tiny particles from those eruptions) are the source of the E Ring.”

    The Last Closest Approach

    Evidence for subsurface oceans of water were discovered by Cassini inside both Enceladus and Titan, making them prime targets for future NASA missions.

    Cassini made its last closest approach to Titan on Sept. 11 at 12:04 p.m. PDT, at an altitude of 73,974 miles (119,049 kilometers) above the moon’s surface, causing the spacecraft to slingshot into its final approach to Saturn — but not before it would send final images from Titan to Earth, eagerly awaited by scientists, including McEwen.

    “Previously, we saw thunderstorms in Titan’s southern hemisphere when it was summer there,” he says, “and because it’s now the northern summer solstice, we are hoping to see cloud activity and perhaps thunderstorms in the northern hemisphere.”

    Cassini will be doing science even after being gripped by Saturn’s gravity, pulling it into destruction, by measuring the composition, temperature and other properties of Saturn’s atmosphere.

    “The spacecraft will be transmitting data until the very end, and we’ll be there when it stops,” McEwen says. “It won’t go very deep, because it is not a probe designed to go deep, but still deeper than anything else.”

    When Cassini arrived at Saturn, where one “year” lasts 29.5 Earth years, the gas giant went through northern winter, and Cassini was there to witness the planet’s change of seasons.

    The end of the mission, McEwen says, is “not unexpected,” adding that the plan to end with a solstice mission, followed by a plunge into Saturn, was put in place about seven years ago.

    Still, “this mission has been going for so long, it’s a little hard to believe that it’s over,” he says.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 7:39 am on September 14, 2017 Permalink | Reply
    Tags: , Crustacean diseases, Histopathology, , , Shrimp studies, U Arizona, Zoology   

    From U Arizona: “Global Shrimp Industry Depends on UA” 

    U Arizona bloc

    University of Arizona

    Sept. 11, 2017
    Susan McGinley
    UA College of Agriculture and Life Sciences

    1
    Shrimp at the wet lab (live animal) facility at the West Campus Agricultural Center (Photo: Bob Demers/UANews)

    The Aquaculture Pathology Laboratory tests shrimp samples, identifies diseases and certifies disease-free stock to help the nearly $40 billion farmed shrimp industry provide a safe food supply.

    A world-renowned laboratory in Tucson has a quiet presence at the University of Arizona, but within the global farmed shrimp and aquaculture industry it exerts a tremendous influence.

    The Aquaculture Pathology Laboratory, housed within the College of Agriculture and Life Sciences’ School of Animal and Comparative Biomedical Sciences, works with commercial shrimp farming enterprises, research institutions and nongovernmental organizations, or NGOs, from across the world to diagnose infectious diseases of penaeid shrimp and other crustaceans in samples delivered to the UA, certify pathogen-free stock, test feed ingredients, conduct research and train shrimp disease specialists.

    _________________________________________________________________________

    Extra Info

    Facts About the Shrimp Industry

    About 75 percent of world shrimp production is Penaeus vannamei (Pacific white shrimp or king prawn).
    Total world shrimp production in 2014 was approximately 4 million metric tons.
    The shrimp industry has a projected annual growth rate of 4.2 percent.
    The top shrimp producers worldwide are China, India, Thailand, Vietnam, Indonesia and Ecuador.
    EMS (early mortality syndrome) disease was detected for the first time in the U.S. in Texas in July, with the research work carried out in the Aquaculture Pathology Laboratory at the UA: http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=24597.

    _________________________________________________________________________

    Clients pay for these services, which in turn help them maintain the biosecurity of their products and ultimately the health and profitability of their industry. For example, baby and adult stocker shrimp can’t be sold to large shrimp operations around the world — in the U.S., Mexico, South America, the Middle East and Asia — unless they are certified. The laboratory conducts certification testing and validation.

    The laboratory can do this because it is a reference laboratory, the only one in North America, certified for crustacean diseases by the Office International des Epizooties in Paris. It is also an approved laboratory of the U.S. Department of Agriculture Animal and Plant Health Inspection Service.

    “This lab has done a wonderful job of addressing the needs of the shrimp industry in terms of disease diagnosis and disease prevention worldwide,” said Arun K. Dhar, associate professor of shrimp and other crustacean aquaculture and director of the lab since January. He succeeded longtime professor and founding director Donald V. Lightner, who developed and guided the lab for more than 30 years as it became a facility recognized around the world.

    “We identify the pathogen, we get the specifics,” Dhar said. “When a disease emerges, we jump on it to determine the etiology (cause), the methods to detect it and the tools to prevent the spread of the disease. Then we tell that story to various audiences.”

    Wet Lab and Diagnostics Lab

    The UA laboratory includes a wet lab (live animal) facility at the West Campus Agricultural Center and a diagnostics lab of histology (tissue diagnostics) and molecular detection on the main campus.

    A staff of three in the center maintains tanks of specific pathogen-free (SPF) or specific pathogen-resistant quarantined stocks at the wet lab for companies and agencies, and they evaluate live shrimp samples from across the world to detect (or rule out) diseases so virulent that they can’t be tested anywhere near coastal waters. The risk of contamination to commercial shrimp beds would be too great.

    “Because of this, our lab is in the desert. We deal with the worst of the worst in emerging pathogens,” said senior research specialist Brenda Noble, who dips her boots in water when entering and exiting the quarantined areas. “Acute hepatopancreatic necrosis disease, also called EMS — early mortality syndrome — is big now, killing a lot of animals on farms in Asia and Latin America. EMS is bacterial and kills up to 100 percent in a day at the lab, although not on farms, where it is spread out.”

    White spot disease, or WSD, is another highly contagious and lethal viral disease. Shrimp diseases do not infect humans.

    The staff conducts challenge studies on animals (mainly crustaceans) brought in from all over the world to find family lines that are resistant to disease, and also product challenges on SPF animals to find out if ingredients in those products — probiotics, for example — enhance their survival. Two shrimp species form the bulk of the commercial farmed shrimp supply: Penaeus vannamei, Pacific white shrimp or king prawn, and Penaeus monodon, giant tiger prawn or Asian tiger shrimp.

    At the dry lab on campus, a team of seven tests tissue samples sent from the wet lab and from national and international companies and agencies. Most are from Hawaii, Florida and Latin America. Clients specify the tests they want: viral, bacterial, fungus, prokaryote or protozoa.

    In the histology lab, a team of two works on diagnosis via histopathology. Each sample is dissected into pieces, put into a cassette, processed overnight and embedded in wax blocks that cool and harden. The blocks are cut into thin sections, put on racks, cooked in a tissue oven to affix them and then stained. Each section is put into a slide folder to be read and diagnosed.

    These tests are conducted for regular surveillance of a company’s stock, or as a general health check on shrimp to make sure the shrimp population is safe.

    “Our department consists of different labs, but we are a team of lab technicians, scientists and specialists who help diagnose diseases and send results to clients in an ongoing relationship,” research specialist Jasmine Millabas said.

    In the PCR lab, extracts of shrimp feed are run in PCR (polymerase chain reaction) machines to note any presence of disease. Each report includes a picture of the PCR result as a proof of testing.

    “We have run samples from 461 clinical cases so far this year in this lab,” postdoctoral research associate Siddhartha Kanrar said.

    Shrimp Pathology Short Course

    Along with diagnostics, treatment and biosecurity, faculty and staff in the Aquaculture Pathology Laboratory teach an intensive one-week shrimp pathology short course plus several workshops annually, in Tucson and in various countries. The class is for professionals who conduct testing for companies and institutions dealing mainly with farm-raised shrimp.

    Dhar recently taught classes at the Bangladesh Fisheries Research Institute in Bangladesh and at Yangon University in Myanmar. He said shrimp is dubbed “white gold” in Bangladesh because it is the country’s third-largest export in revenue.

    In addition to methods for detecting and diagnosing diseases in farmed shrimp, the hands-on course takes participants through the steps of preparing tissue samples precisely to ensure accurate results when the samples are sent to the Aquaculture Pathology Laboratory. The participants learn about what to look for in cells in diseased animals and how to follow the proper procedures to get the detection correct. The West Campus experimental lab has inoculum for all Office International des Epizooties pathogens, kept in freezer at minus 80 degrees Celsius (minus 112 Fahrenheit) from diseased shrimp to use for testing the real thing in class.

    Nearly every shrimp pathologist in the world has taken the course. In July, the class included 19 participants from nine countries on four continents, mainly from commercial aquaculture businesses.

    While students prepared slides, senior research specialist Luis Fernando Aranguren Caro pointed out areas of slides projected on a screen that showed diseases or abnormalities, noting that “the degree of infection depends on the extent of the disease revealed.” Jessica Fox, director of veterinary services and biosecurity for Tru-Shrimp, a freshwater shrimp production facility in Minnesota, brought three employees to the UA who will prepare the histology samples that are sent to Arizona.

    “We wanted to learn more about the shrimp diseases to help us understand what to watch for, what screening measures we need to do and to help us develop other biosecurity protocols,” Fox said. “Our whole group understands more together. There’s quite a bit of hands-on here. We know what to look for and have done this before in-house, but it’s good to have experts checking your work.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 10:53 am on August 31, 2017 Permalink | Reply
    Tags: A trial will look at whether a naturally occurring compound known as angiotensin 1-7 relieves cognitive deficits after heart bypass, Angiotensin 1-7, , , Some patients have a profound response to this procedure others a minor one, The human heart is not cut out for bypass surgery, U Arizona, UA Team Tackles Better Brain Health   

    From U Arizona: “UA Team Tackles Better Brain Health” 

    U Arizona bloc

    University of Arizona

    Aug. 30, 2017
    Robin Tricoles

    The human heart is not cut out for bypass surgery. It beats and it moves. So, it must be quieted beforehand.

    1
    Shutterstock

    To accomplish this, a surgeon puts a patient in circulatory arrest — that is, the heart is stopped and the patient placed on a bypass machine. The machine takes the patient’s blood and circulates it through a pump and an oxygenator and then returns it to the patient. Instead of the heart and lungs doing the pumping and the oxygenating, the machine is doing the work.

    However, the human body is “incredibly sensitive,” says Dr. Nancy Sweitzer, director of the University of Arizona Sarver Heart Center and chief of cardiology at the UA College of Medicine – Tucson.

    “As the blood re-enters the body after passing through the machine, the body knows that the blood has been exposed to the plastic and the tubing and the metal,” Sweitzer says. “It senses something about that blood being different and then activates the body’s inflammatory mechanisms.”

    A trial will look at whether a naturally occurring compound, known as angiotensin 1-7, relieves cognitive deficits after heart bypass. The UA collaborators include a cardiologist, a physiologist and a psychologist.

    Some patients have a profound response to this procedure, others a minor one.

    “After bypass surgery, some people tell us that they feel different, they think differently and things have changed for them even though their heart is better,” Sweitzer says.

    Some people don’t notice anything all. Studies have shown, however, that if cognition and memory are carefully evaluated, tests detect cognitive deficits in a substantial number of people after bypass surgery, says Sweitzer, an expert in heart failure.

    The cognitive deficits may be so subtle that people don’t notice them, but some do, and so do their families. Other times, studies have shown significant or even permanent memory loss in patients who have undergone bypass surgery, says Meredith Hay, professor of physiology at the College of Medicine – Tucson.

    As it stands now, there are no effective treatments for cognitive impairments, including memory loss.

    Introducing: Angiotensin 1-7

    That’s why Sweitzer is collaborating with Hay and Lee Ryan, a UA professor of psychology and department head, on the Phase 2 trial to determine whether a particular peptide administered before and after coronary bypass surgery mitigates — or even reverses — cognitive deficits thought to be connected to the procedure.

    The peptide is known as angiotensin 1-7 — or ang 1-7, for short. A derivative of angiotensin 2, it is a naturally occurring compound that relaxes vascular tone, diminishes the dilation of blood vessels, decreases inflammation and is considered safe in normal amounts.

    “Our body makes angiotensin, which is cleaved to angiotensin 2,” Hay explains.

    Angiotensin 2 is involved in the body’s water balance, an important matter. Many patients with high blood pressure have too much angiotensin 2. However, our bodies have the ability to break down angiotensin 2 into angiotensin 1-7.

    “It was discovered around 20 years ago that there’s this beautiful yin-yang relationship between angiotensin 2 (a vasoconstrictor that raises blood pressure and increases inflammation) and angiotensin 1-7 (which decreases inflammation),” Hay says.

    “People who have studied cardiovascular sciences have studied angiotensin 2 for years,” she says. “We know that angiotensin 1-7 is anti-inflammatory, and we know that it’s protective of the brain. People have studied it in the kidneys, in the heart, in the blood vessels, but nobody has studied its effect on memory function.”

    Until very recently, that is.

    The UA researchers are just starting the Phase 2 clinical trial, involving patients who come to Banner – University Medical Center Tucson in need of bypass surgery. Last month, the researchers enrolled their first participant.


    John Konhilas, UA associate professor of physiology; Carol Barnes, director of the UA Evelyn F. McKnight Brain Institute and Regents’ Professor of Psychology, and Hay previously conducted preclinical studies in mice with heart failure that laid the foundation for the human trial. These pivotal studies showed that angiotensin 1-7 reversed memory loss in mice with heart failure.

    “Important to our understanding of why disease in the heart results in memory loss requires scientists and doctors from different disciplines to work together,” Hay says.

    Generally speaking, cardiologists and cardiac surgeons make sure the heart is working, so careful evaluation for brain function may not occur. Meanwhile, neurologists are concentrating on the brain and not the heart.

    “We want to see what happens when we bring these two important areas of science and medicine together — the brain and the heart — and study the patient as a whole,” Hay says.

    Quality of Patient Health at Stake

    Researchers know that when patients have cognitive impairment, it can significantly affect the quality of their health, says Ryan, a clinical neuropsychologist and expert in neuroimaging and the aging brain.

    “Patients who have cognitive impairment after bypass surgery are less likely to maintain their regimens of medication, to engage in self-care, are more likely to be re-hospitalized, and have a higher mortality rate,” says Ryan, who is heading up the study’s cognitive testing and brain imaging.

    “We think ang 1-7 has a specific impact on an area of the brain called the hippocampus,” she says.

    Based on animal studies, researchers know the kinds of memories that should be most affected by damage to the hippocampus. Ryan will use targeted neurological tests that will tap into what the researchers think ang 1-7 might be doing.

    In the double-blind, clinical trial, participants will be given ang 1-7 or a placebo two hours before bypass surgery and will take the drug or placebo every day for 21 days thereafter.

    “The drug has got to be onboard and dispersed throughout the body before the patient goes on cardiopulmonary bypass,” notes Dr. David Bull, chief of cardiothoracic surgery in the College of Medicine – Tucson. Bull and Dr. Zain Khalpey, associate professor of surgery in the College of Medicine – Tucson, are the partner surgeons in the Phase 2 study.

    “Participants in the trial are going to be patients whose bypass is elective because there are requirements for certain lab tests and imaging,” Bull says. “With someone who needs urgent surgery, there isn’t going to be enough time to get the testing done before they have to have surgery.”

    In fact, participants will undergo a series of tests to evaluate their memory before surgery and periodically following surgery, with the last test administered one year after bypass. Imaging of the brain with MRI scans also will take place before and after surgery.

    Nothing Ventured, Nothing Gained

    “We don’t know if the drug is going to work in humans,” Hay says. “But if we don’t do a study like this, we won’t know if it will work or not.”

    But even if it doesn’t work, Ryan says, “we’re going to have a really strong dataset, and a broad and in-depth analysis of these participants pre- to post-surgery. The whole connection between cardiovascular health and brain health is relatively new, but it’s a major focus of the National Heart, Lung and Blood Institute, which funded the study.”

    Says Sweitzer: “I’ve never done anything with memory and heart disease. But right after I moved to Arizona, Lee and Meredith came to my office and said, ‘We have this compound, and we think it’s ready to move into humans, but we don’t have any expertise in doing human clinical trial studies.’ And that’s what I do.

    “I think it’s a great Arizona story that we had this confluence of expertise across very different and complementary disciplines. This isn’t one of those situations where if we don’t hurry somebody else will do this. Nobody else can do this. We have this unique combination of expertise right here in Tucson.”

    See the full article here .

    Please help promote STEM in your local schools.

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 10:12 am on August 15, 2017 Permalink | Reply
    Tags: , , , , LCOGT Las Cumbres Observatory Global Telescope Network, SN 2017cbv, , U Arizona   

    From U Arizona: “In Hunting Supernovae, ‘Get Them While They’re Young'” 

    U Arizona bloc

    University of Arizona

    1
    Bright blue dot: Supernovae such as SN 2017cbv appear as “stars that weren’t there before,” which is why multiple images taken over time are necessary to reveal their true identity. SN 2017cbv lies in the outskirts of a spiral galaxy called NGC 5643 that lies about 55 million light-years away and has about the same diameter as the Milky Way (~100,000 light-years). Data are from the Las Cumbres Observatory Global Supernova Project and the Carnegie-Irvine Galaxy Survey. (Credit: B.J. Fulton/Caltech).

    Thanks to a global network of telescopes, astronomers have caught the fleeting explosion of a Type Ia supernova in unprecedented detail. Because this type of supernova is commonly used as a cosmic yardstick, a better understanding of how they form could have implications for future dark energy measurements.

    8
    The Las Cumbres Global Telescope Network map.

    Not many people can say they have watched a star explode before their eyes, but David Sand can.

    On the evening of March 10, the astronomer happened to be on duty to monitor results coming in from an automated survey scanning faraway galaxies for evidence of such events. Sand was about to go to bed, when the software algorithm alerted him to a point of light where none had been just a few hours earlier, in a galaxy called NGC 5643, located in the constellation Lupus, 55 million light-years from Earth.

    “As I was looking at this image, it was clear to me a supernova had just gone off,” said Sand, who joined the University of Arizona’s Steward Observatory just this month as a new assistant professor. “I took another image right away to get a confirmation.”

    2
    Smoking gun: Unlike “regular” supernovae, whose change in ultraviolet brightness follows the gray curve, this one increased in brightness faster over the first two days, before slowing down (blue curve). This bump in the light curve likely reflects the slamming of material from the exploding white dwarf into a companion star. (Credit: Griffin Hosseinzadeh)

    Because some blips of light that show up unexpectedly in the observations turn out to be asteroids passing in front of the star-studded background and not stellar cataclysms, Sand sent a remote command to the telescope, located at the Cerro Tololo Observatory in Chile, to snap another image. The blip was still there.

    Within minutes of discovery, Sand activated observations with the global network of 18 robotic telescopes of the Las Cumbres Observatory.

    LCOGT Las Cumbres Observatory Global Telescope Network, Haleakala Hawaii, USA

    3
    Las Cumbres Observatory site at the SAAO observing station at Sutherland, South Africa

    They are spaced around the globe so that there is always one on the night side of the Earth, ready to conduct astronomical observations. This allowed the team to take immediate and near-continuous observations.

    “In a galaxy like our Milky Way, a supernova goes off, on average, about once per century,” Sand said. “We were fortunate to see this phenomenon that never had been observed before.”

    Sand’s discovery, designated SN 2017cbv, likely marks the first detailed observation of a cosmic event that astronomers only had glimpses of before: a supernova and its explosive ejecta slamming into a nearby companion star. The discovery was made possible by a specialized survey taking advantage of recent advances in linking telescopes across the globe into a robotic network.

    At 55 million light-years, SN 2017cbv was one of the closest supernovae discovered in recent years. It was found by the DLT40 survey, which stands for “Distance Less Than 40 Megaparsecs” or 120 million light-years. The survey uses the PROMPT telescope in Chile, which monitors roughly 500 galaxies nightly.

    55
    PROMPT telescope in Chile

    “This was one of the earliest catches ever — within a day, perhaps even hours, of its explosion,” said Sand, who created the DLT40 survey together with Stefano Valenti, an assistant professor at the University of California, Davis. Both were previously postdoctoral researchers at Las Cumbres Observatory, or LCO.

    Dead Stars Go Thermonuclear

    SN 2017cbv is a thermonuclear (Type Ia) supernova, the type astronomers use to measure the acceleration of the expansion of the universe. Type Ia supernovae are known to be the explosions of white dwarfs, the dead cores of what used to be normal stars.

    Across the cosmic abyss, a supernova tells of its existence by appearing like a star that wasn’t there before. Its brightness peaks within a matter of days to weeks and then slowly fades over weeks or months.

    “To turn into a Type Ia supernova, a white dwarf can’t be by itself,” explained Sand, who serves as the principal investigator of the DLT40 survey. “It has to have some kind of companion, and we are trying to figure out what that companion is.”

    The identity of this companion has been hotly debated for more than 50 years.

    6
    In one of two possible scenarios leading to a Type Ia supernova, two white dwarf stars orbit each other and lose energy via gravitational radiation, eventually resulting in a merger between the two stars. Because the total mass of this merger exceeds the weight limit for a white dwarf, the merged star is unstable and explodes as a Type Ia supernova. (Illustration: NASA/CXC/M.Weiss)

    7
    In the second scenario, which is likely the one that triggered the supernova described in this study, gas is being pulled from a sunlike star onto a white dwarf via a red disk. When the amount of material accreted onto the white dwarf causes the weight limit for this star to be exceeded, it explodes as a Type Ia supernova. (Illustration: NASA/CXC/M.Weiss)

    The prevailing theory over the last few years is that the supernovae happen when two white dwarfs spiral in toward each other and merge in a cataclysmic explosion. The other scenario involves a normal star that is not a white dwarf.

    Key to the observations reported in this study is a small bump in the light curve emitted by SN 2017cbv within the first three to four days, a feature that would have been missed were it not for the almost instantaneous reaction times that are the hallmark of the DLT40 survey: a fleeting blue glow from the interaction at an unprecedented level of detail, revealing the surprising identity of the mysterious companion star.

    “We think what happened here was likely scenario number two,” Sand said. “The bump in the light curve could be caused by material from the exploding white dwarf as it slams into the companion star.”

    This study infers that the white dwarf was stealing matter from a much larger companion star, approximately 20 times the radius of the sun. This caused the white dwarf to explode, and the collision of the supernova with the companion star shocked the supernova material, heating it to a blue glow that was heavy in ultraviolet light. Such a shock could not have been produced if the companion were another white dwarf star, the study’s authors say.

    “We’ve been looking for this effect — a supernova crashing into its companion star — since it was predicted in 2010,” said Griffin Hosseinzadeh, a doctoral student at the University of California, Santa Barbara, who led the study, which is soon to be published in the Astrophysical Journal Letters. “Hints have been seen before, but this time the evidence is overwhelming. The data are beautiful!

    “With Las Cumbres Observatory’s ability to monitor the supernova every few hours, we were able to see the full extent of the rise and fall of the blue glow for the first time,” he added. “Conventional telescopes would have had only a data point or two and missed it.”

    Eighteen telescopes, spread over eight sites around the world, form the heart of the Las Cumbres Observatory. At any given moment, it is nighttime somewhere in the network, which ensures that a supernova can be observed without interruption.

    Cosmology’s ’60-Watt Lightbulb’

    Because of their uniform brightness, Type Ia supernovae are akin to a “standard 60-watt lightbulb for cosmology,” and scientists use them as yardsticks to measure distances across the universe.

    Because of their rare and fleeting appearance, a targeted observational campaign such as the DLT40 survey and an automated network of observatories such as the LCO are critical to the discovery and study of Type Ia supernovae. Funded by the National Science Foundation, the DLT40 survey started in October 2016 and is scheduled to continue over the next three years.

    “The secret sauce to this are the connected telescopes of the Las Cumbres Observatory,” Sand said, adding that the survey is not about quantity. “We’d rather focus on a precious few than hundreds of them.”

    It is likely that Type Ia supernovae come from both types of progenitor systems — two white dwarfs or one white dwarf and a “normal” interacting star — and the goal of these studies is to figure out which of the two processes is more common, Sand explained.

    “Observing supernovae such as SN 2017cbv is an important step in this direction,” he said. “If we get them really young, we can get a better idea of these processes, which hold implications for our understanding of the cosmos, including dark energy.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 12:25 pm on July 6, 2017 Permalink | Reply
    Tags: , , Project POEM - Project-Based Learning Opportunities and Exploration of Mentorship for Students With Visual Impairments in STEM, U Arizona, U Arizona NASA Mars Reconnaisance HIRISE Camera, UA Trains Visually Impaired Youth for STEM   

    From U Arizona: “UA Trains Visually Impaired Youth for STEM” 

    U Arizona bloc

    University of Arizona

    July 5, 2017
    La Monica Everett-Haynes

    1
    Images and data from the UA’s Mars HiRISE camera are being used to help visually impaired students gain interest in scientific exploration and study. No image credit.

    U Arizona NASA Mars Reconnaisance HIRISE Camera

    The NSF-funded Project POEM was launched to better understand and advance the awareness and persistence toward STEM-related careers by middle and high school students with visual impairments.

    Using images and data from the University of Arizona’s Mars HiRISE camera, Sunggye Hong and Stephen Kortenkamp are creating educational experiences and tactile tools about the Red Planet to help students gain insight and interest in scientific exploration and study — and motivate students to imagine their future as scientists.

    Their interdisciplinary work at the UA has gained the attention of the National Science Foundation, which has provided a grant at more than $1 million to fund a research and engagement project.

    “Opening up STEM careers through better awareness among pre-college-age students is a real need,” said UA President Robert C. Robbins. “I very much admire that UA faculty in the College of Education are helping create this awareness for students with visual impairments through their engaging approach to learning. This project and the NSF’s support for it are outstanding examples of what the UA can do for students through collaboration and the creativity of our faculty members.”

    Called Project POEM, short for Project-Based Learning Opportunities and Exploration of Mentorship for Students With Visual Impairments in STEM, the effort will involve 35 middle and high school students with visual impairments in a 14-month program meant to train them toward the science, technology, engineering and mathematics fields.

    “Mars is one of the most fascinating topics in the world of science today. If a student has an opportunity to study and to analyze data collected from Mars, that would be a very exciting and motivational component to helping students’ interest in science,” said Hong, associate professor in the UA College of Education’s Department of Disability and Psychoeducational Studies and principal investigator on the NSF grant.

    Other Project POEM collaborators are the UA Sky School, the UA Department of Mining and Geological Engineering, the UCAR Center for Science Education, the American Printing House for the Blind and Denver-based educational consultant McREL International.

    In developing the program, Hong and his partners were attentive and responsive to the Next Generation Science Standards, a multistate effort developed by a team of researchers commissioned by the Carnegie Foundation.

    Mentors to Lend Support

    As such, the program will be project-based, rich in content and complemented by the support of mentors — UA undergraduate and graduate students and also STEM industry professionals who have visual impairments.

    The educational tools being designed also address the problem of students with visual impairments having too little access to the types of resources that can help them understand complex scientific topics and drive their interests in science.

    “Much of the STEM curricula is so visual, so you must make appropriate adaptations and modifications for the materials to be used,” Hong said.

    “We know that there are these difficulties, but there are also techniques we can use to navigate such barriers,” he said. “If students are frustrated with not having properly modified materials, they can talk through problems with people who have gone through the same frustrations, and students with visual impairments can figure out ways to overcome those difficulties.”

    Using images and data from Mars sourced by the UA’s Lunar and Planetary Laboratory, the team led by Hong is also creating tactile, 3-D models of the surface of Mars that students can use to study the planet’s physical characteristics.

    Over the course of the program, the middle and high school students will learn about STEM concepts and Mars through learning models and other forms of engagement. They then will work alongside their mentors to develop and execute a research project about Mars, relying on adapted images and also data from the UA’s HiRISE camera currently operating on the Mars Reconnaissance Orbiter.

    The project draws heavily on the child education expertise of Kortenkamp, associate professor of practice in the Lunar and Planetary Laboratory in the College of Science, who also written and published children’s books on topical issues related to science.

    Kortenkamp also said he is especially dedicated to improving resources for students with visual impairments after having worked early in his UA career with a student who was blind.

    “Astronomy is such a visual field, so it became a challenge for me in how I was teaching the course,” Kortenkamp said. He began to more readily employ audio components and also introduced tactile tools — resources he would use for years.

    “Finding other ways of presenting the material, rather than just lecturing, is so fascinating. And putting that extra effort of finding materials and presenting them — whether your student can see them or not — helps to show that you are truly invested in learning,” Kortenkamp said.

    Also motivating Hong and Kortenkamp is the need for improved STEM-related educational resources and the problem of underemployment among individuals with disabilities, especially in STEM fields.

    Creating a ‘Set of Experiences’

    Individuals with visual impairments are highly underemployed, with the U.S. Census Bureau and the American Foundation for the Blind reporting that only 30 to 38 percent of that adult population is employed.

    “When you see 70 percent of a population unemployed, that is a huge problem,” Hong said. “Our idea was that if we could create a set of experiences for students with visual impairments to give them knowledge about STEM fields and find ways to keep them motivated in considering the STEM field as a potential occupation, we could raise their persistence toward STEM.”

    Ultimately, the team plans to develop curricula that K-12 teachers may use to replicate the program in other parts of Arizona and the nation.

    “Students with visual impairments are capable of becoming successful scientists — if all the pieces of the puzzle are given appropriately,” Hong said. “It is not the limitation of an individual, it is more about awareness of the public and working to bring STEM experiences to people with visual impairments.”

    Also, a research initiative is embedded within the project, and the team will be evaluating best approaches and methods for designing the effective and immersive experience to actively engage students.

    “Not everyone will become a scientist. But if they can gain interest in these technical areas, they may take a different route in life or have a deeper appreciation for the field and become more technologically savvy,” Kortenkamp said. “It never hurts to have some of that background, or at least be comfortable around science and math.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 11:23 am on June 27, 2017 Permalink | Reply
    Tags: Age-related macular degeneration, , L-dopa, , RPE - retinal pigment epithelium, U Arizona   

    From U Arizona: “Quest to End Macular Degeneration Continues With $1.7M Grant” 

    U Arizona bloc

    University of Arizona

    6.27.17
    Jean Spinelli

    1
    Age-related macular degeneration is more common in people with light-colored eyes, according to Prevent Blindness. No image credit.

    The UA’s Brian McKay will continue his work showing that l-dopa — used to treat Parkinson’s disease — can delay or prevent the sight-destroying eye disease.

    1
    Brian S. McKay (Photo: Kris Hanning/UAHS BioCommunications)

    After showing that individuals who take levodopa, or l-dopa, for movement disorders such as Parkinson’s disease are protected from developing macular degeneration, University of Arizona researcher Brian S. McKay is taking the next step in his quest to prevent the blinding eye disease, thanks to a $1.7 million grant from the National Eye Institute of the National Institutes of Health.

    Macular degeneration, also known as age-related macular degeneration, or AMD, is a degenerative disease of the retina that causes loss of central vision. L-dopa is a naturally occurring molecule made in all pigmented tissues, including the retinal pigment epithelium, or RPE, of the eye, where it has a role in maintaining a healthy macula — the part of the eye’s retina that provides the most high-acuity color vision.

    McKay’s discovery that the RPE expresses a receptor for l-dopa, and that this signaling pathway fosters the survival of the retina, led to a collaborative observational study that found that patients who take a synthesized form of l-dopa, a common treatment for Parkinson’s, were far less likely to develop macular degeneration. And if they did develop the disease, the onset was delayed by nearly 10 years.

    “We will follow up this critical observation with cell biological studies to determine how l-dopa’s effect occurs,” said McKay, associate professor of ophthalmology and vision science at the UA College of Medicine – Tucson. “This grant will help us determine whether we can repurpose l-dopa to halt the epidemic that age-related macular degeneration has become.”

    AMD is the most common cause of blindness in individuals older than 55 in developed countries, and more than 10 million people in the United States have AMD, according to the Foundation Fighting Blindness. AMD is particularly prevalent in the Southwest with its large retired population.

    “The cause of AMD isn’t known, so it’s difficult to develop strategies to prevent it,” McKay said. “There is no cure, and there are no treatments for early AMD, also known as ‘dry’ AMD. For the roughly 10 percent of AMD patients who develop ‘wet’ AMD, where abnormal blood vessels grow under the retina, there is an effective treatment. However, it requires repeated intraocular injections, which are expensive and associated with risks — and don’t stop the progression of the underlying disease.”

    McKay will test whether intersecting pathways related to dopamine signaling may be the actual driving force behind l-dopa’s protective effect rather than l-dopa itself.

    “This is a critical set of experiments because l-dopa is converted to dopamine in neurons and retinal pigment epithelial (RPE) cells,” McKay said. “Both RPE cells and the retinal neurons have dopamine receptors. We identified a signaling molecule, GPR143, that controls two RPE activities likely to protect from AMD, and showed that l-dopa could drive both activities.

    “The research will test whether GPR143 or other dopamine-related receptors bring about the protection from AMD in those taking l-dopa. Once the responsible receptors are identified, they can be targeted to develop new drugs or combination therapies to protect people from developing AMD.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
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