College Park, GA, United States
College Park, GA, United States

Agnes Scott College is a private liberal arts college in downtown Decatur, Georgia.The college was founded in 1889 as Decatur Female Seminary by Presbyterian minister Frank H. Gaines. In 1890, the name was changed to Agnes Scott Institute to honor the mother of the college's primary benefactor, Col. George Washington Scott. The name was changed again to Agnes Scott College in 1906, and remains today a women's college.Agnes Scott currently enrolls 914 students. In 2006, the student to faculty ratio was 10:1. Eighty-seven percent of the faculty are full-time, and 100% of the tenure-track faculty hold terminal degrees.The college offers 30 majors and 25 minors and is affiliated with numerous institutions, including Georgia Institute of Technology, Emory University School of Nursing, and Washington University. Students who graduate from Agnes Scott receive a Bachelor of Arts degree.Agnes Scott is affiliated with the Presbyterian Church and is considered one of the Seven Sisters of the South. The current mission of the college, adopted in 2002, states: Agnes Scott College educates women to think deeply, live honorably and engage the intellectual and social challenges of their times. Wikipedia.


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News Article | November 11, 2016
Site: www.sciencedaily.com

The compound huperzine A can increase resistance to induced seizures in mouse models of genetic epilepsy, scientists at Emory University School of Medicine have found. In particular, huperzine A shows potential for protecting against febrile seizures, which are a feature of both Dravet syndrome, a severe form of childhood epilepsy, and a related condition, GEFS+ (genetic epilepsy with febrile seizures plus). The findings were recently published in Frontiers in Pharmacology. Huperzine A comes from the club moss Huperzia serrata and has been used in traditional Chinese medicine. The compound has been tested for the treatment of inflammation and neurological disorders, including Alzheimer's disease and schizophrenia. Children with Dravet syndrome experience early-life seizures due to high fever as well as other types of seizures and developmental delays. Although the condition can be controlled with some antiepileptic drugs, most patients do not achieve adequate seizure control. Most cases of Dravet syndrome are caused by "de novo" (not inherited) mutations in a sodium channel gene called SCN1A. The channel allows sodium to quickly enter into the cell, and forms part of the molecular machinery that is critical for how an electrical signal forms and travels along a neuron. In Dravet syndrome, the mutations often inactivate the gene, while SCN1A mutations in GEFS+ change properties of the sodium channel without inactivating it completely. Both types of mutations lead to increased neuron excitability. "We think that huperzine A could normalize the balance between neuronal inhibition and excitation in patients with SCN1A mutations, thereby protecting against seizure generation," says senior author Andrew Escayg, PhD, associate professor of human genetics at Emory University School of Medicine. At Emory, Escayg and his colleagues have developed mice in which one copy of the SCN1A gene has been modified as mouse models for the study of Dravet syndrome and GEFS+. Co-first authors of the paper are postdoctoral fellow Jennifer Wong, PhD and Stacey Dutton, PhD, now an assistant professor of biology at Agnes Scott College. SCN1A mutant mice exhibit increased susceptibility to seizures induced by hyperthermia, which serves as a model of human febrile seizures. In the Frontiers paper, almost all SCN1A mutant mice exhibited a seizure when their core body temperature reached 40°C. In contrast, when the mice were pre-treated with huperzine A, they only experienced a seizure at significantly higher temperatures. Escayg's team also found that huperzine A can reduce the frequency and severity of electrically and chemically induced seizures, both in normal mice and in SCN1A-mutant mice. In these experiments, the scientists observed that the protective effect against electricity-induced seizures in normal mice diminishes after 12 days of daily huperzine A administration, but "complete protection" is maintained in the SCN1A-mutant mice. "The protection observed in normal mice suggest huperzine A might also increase seizure resistance in other forms of treatment-resistant epilepsy. While these results are encouraging, further research will be required to determine suitability of using huperzine A as a clinical treatment for epilepsy," Escayg says. Biscayne Pharmaceuticals has plans to begin a phase 1b clinical trial of huperzine A in adults with refractory complex partial epilepsy in 2017. Clinical studies in children with Dravet syndrome are planned after additional toxicology studies are performed, as required by regulatory authorities. Huperzine A is thought to work, in part, by inhibiting the enzyme acetylcholinesterase, which breaks down the neurotransmitter acetylcholine. Thus, huperzine A can increase the levels of acetylcholine in the brain. In mice, the scientists observed some transient side effects from huperzine A administration: hypothermia, muscle twitching and lethargy. However, they determined that hypothermia does not contribute to seizure protection. Previous clinical studies have reported side effects such as nausea and vomiting. Wong and Escayg are now testing whether huperzine A can reduce the frequency of spontaneous seizures in their mouse models.


News Article | November 10, 2016
Site: www.eurekalert.org

The compound huperzine A can increase resistance to induced seizures in mouse models of genetic epilepsy, scientists at Emory University School of Medicine have found. In particular, huperzine A shows potential for protecting against febrile seizures, which are a feature of both Dravet syndrome, a severe form of childhood epilepsy, and a related condition, GEFS+ (genetic epilepsy with febrile seizures plus). The findings were recently published in Frontiers in Pharmacology. Huperzine A comes from the club moss Huperzia serrata and has been used in traditional Chinese medicine. The compound has been tested for the treatment of inflammation and neurological disorders, including Alzheimer's disease and schizophrenia. Children with Dravet syndrome experience early-life seizures due to high fever as well as other types of seizures and developmental delays. Although the condition can be controlled with some antiepileptic drugs, most patients do not achieve adequate seizure control. Most cases of Dravet syndrome are caused by "de novo" (not inherited) mutations in a sodium channel gene called SCN1A. The channel allows sodium to quickly enter into the cell, and forms part of the molecular machinery that is critical for how an electrical signal forms and travels along a neuron. In Dravet syndrome, the mutations often inactivate the gene, while SCN1A mutations in GEFS+ change properties of the sodium channel without inactivating it completely. Both types of mutations lead to increased neuron excitability. "We think that huperzine A could normalize the balance between neuronal inhibition and excitation in patients with SCN1A mutations, thereby protecting against seizure generation," says senior author Andrew Escayg, PhD, associate professor of human genetics at Emory University School of Medicine. At Emory, Escayg and his colleagues have developed mice in which one copy of the SCN1A gene has been modified as mouse models for the study of Dravet syndrome and GEFS+. Co-first authors of the paper are postdoctoral fellow Jennifer Wong, PhD and Stacey Dutton, PhD, now an assistant professor of biology at Agnes Scott College. SCN1A mutant mice exhibit increased susceptibility to seizures induced by hyperthermia, which serves as a model of human febrile seizures. In the Frontiers paper, almost all SCN1A mutant mice exhibited a seizure when their core body temperature reached 40°C. In contrast, when the mice were pre-treated with huperzine A, they only experienced a seizure at significantly higher temperatures. Escayg's team also found that huperzine A can reduce the frequency and severity of electrically and chemically induced seizures, both in normal mice and in SCN1A-mutant mice. In these experiments, the scientists observed that the protective effect against electricity-induced seizures in normal mice diminishes after 12 days of daily huperzine A administration, but "complete protection" is maintained in the SCN1A-mutant mice. "The protection observed in normal mice suggest huperzine A might also increase seizure resistance in other forms of treatment-resistant epilepsy. While these results are encouraging, further research will be required to determine suitability of using huperzine A as a clinical treatment for epilepsy," Escayg says. Biscayne Pharmaceuticals has plans to begin a phase 1b clinical trial of huperzine A in adults with refractory complex partial epilepsy in 2017. Clinical studies in children with Dravet syndrome are planned after additional toxicology studies are performed, as required by regulatory authorities. Huperzine A is thought to work, in part, by inhibiting the enzyme acetylcholinesterase, which breaks down the neurotransmitter acetylcholine. Thus, huperzine A can increase the levels of acetylcholine in the brain. In mice, the scientists observed some transient side effects from huperzine A administration: hypothermia, muscle twitching and lethargy. However, they determined that hypothermia does not contribute to seizure protection. Previous clinical studies have reported side effects such as nausea and vomiting. Wong and Escayg are now testing whether huperzine A can reduce the frequency of spontaneous seizures in their mouse models. This research was supported by the National Institute of Neurological Disorders and Stroke (R01NS072221, R21NS098776, 2T32NS00748016). Biscayne Pharmaceuticals provided the Escayg laboratory with huperzine A.


Correa N.M.,National University of Rio Cuarto | Silber J.J.,National University of Rio Cuarto | Riter R.E.,Agnes Scott College | Levinger N.E.,Colorado State University
Chemical Reviews | Year: 2012

The self-assembly of amphiphiles in the absence of water is studied. The assembly of amphiphiles into microemulsions and reverse micelles in nonpolar solvents while sequestering a polar nonaqueous core is discussed. Fletcher et al. used dynamic light scattering (DLS) and viscosimetry to study thermodynamically stable AOT stabilized dispersions of GY in n-heptane. Sarkar and co-workers have probed GY/AOT/isooctane reverse micelles through steady-state and time-resolved fluorescence spectroscopy of two solvatochromic dyes, coumarin 480 and coumarin 490. Martino and Kaler reported the effect on microemulsion phase behavior and microstructure occurring when replacing water with PG, GY, and their mixtures in systems made with the nonionic surfactants pentaethylene glycol mono-n-decyl ether (C10E5). Mehta et al. have explored phase diagrams for several nonaqueous polar solvents in AOT/hexane.


News Article | December 15, 2015
Site: phys.org

Rather than relying on the amount of light reflecting off metal particles, this novel process, to be presented in the journal eLife, involves delivering light energy to silver or gold nanoparticles deposited on neurons and imaging the higher energy levels resulting from their vibrations, known as surface plasmons. This technique is particularly effective as the light emitted from metal particles is resistant to fading, meaning that decades-old tissue samples achieved through other processes, such as the Golgi stain method from the late 1880s, can be imaged repeatedly. The new process was achieved by using spectral detection on a Laser Scanning Confocal Microscope (LSCM), first made available in the late 1980s and, until now, used most extensively for fluorescent imaging. Paired with such methods, silver- and gold-based cell labeling is poised to unlock new information in a myriad of archived specimens. Furthermore, silver-impregnated preparations should retain their high image quality for a century or more, allowing for archivability that could aid in clinical research and disease-related diagnostic techniques for cancer and neurological disorders. "For the purposes of medical diagnostics, older and newer specimens could be compared with the knowledge that signal intensity would remain fairly uniform regardless of sample age or repeated light exposure," says contributing author Karen Mesce from the University of Minnesota. "With the prediction that superior resolution microscopic techniques will continue to evolve, older archived samples could be reimagined with newer technologies and with the confidence that the signal in question was preserved. The progression or stability of a cancer or other disease could therefore be charted with accuracy over long periods of time." To appreciate the enhanced image quality produced by the new technique, the team first examined a conventional brightfield image of a metal-labelled neuron within a grasshopper's abdominal ganglion, a type of mini-brain which, even at that size, presented out-of-focus structures. They then imaged the same ganglion with the spectral LSCM adjusted to the manufacturer's traditional fluorescence settings, resulting only in strong natural fluorescence and a collective dark blur in place of the silver-labelled neurons. However, after collecting the light energy emitted from vibrating surface plasmons in the spectral LSCM, the team obtained spectacular three-dimensional computer images of silver and gold-impregnated neurons. This holds enormous potential for stimulating a re-examination of archived preparations, including Golgi-stained and cobalt/silver-labelled nervous systems. Additionally, by using a number of different metal-based cell-labeling techniques in combination with the new LSCM protocols, tissue and cell specimens can be generated and imaged with ease and in great three-dimensional detail. Changes in even small structural details of neurons can be identified, which are often important indicators of neurological disease, learning and memory, and brain development. "Both new and archived preparations are essentially permanent and the information gathered from them increases the data available for characterizing neurons as individuals or as members of classes for comparative studies, adding to emerging neuronal banks," says co-first author Karen Thompson from Agnes Scott College. "Just as plasmon resonance can explain the continued intensity of the red (caused by silver nanoparticles) and yellow (gold nanoparticles) colors in centuries-old medieval stained glass and other works of art, metal-impregnated neurons are also likely never to fade, neither in the information they provide nor in their intrinsic beauty," adds Mesce. More information: Karen J Thompson et al. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope, eLife (2015). DOI: 10.7554/eLife.09388


News Article | December 15, 2016
Site: www.csmonitor.com

—In 1989, two geophysicists theorized that extensive stores of water-ice exist just beneath the surface of Ceres. Their model suggested that the ice could be 10 to 100 meters (33 to 330 feet) beneath the surface near the equator and closer to the surface – just 1 to 10 meters (3 to 33 feet) deep – from the mid-latitudes to the poles. That model was created with data obtained from ground-based telescopes, but new data beamed back from NASA's Dawn spacecraft, which arrived at the the dwarf planet (sometimes characterized as an asteroid) in 2015, suggests that their model wasn't far off. "Lo and behold, they're right," Tom Prettyman, a co-investigator of the NASA Dawn mission and a researcher at the Planetary Science Institute, tells The Christian Science Monitor. "There is ice. And there's very strong evidence for it near the surface at high latitudes on Ceres." "This builds a lot of confidence in the models that we're using for ice stability," he says, which could help astronomers know where to look for water-ice in the rest of the solar system. Recent exploration of our solar system has turned up evidence of water on many different planetary bodies. Most are moons with subsurface oceans or icy crusts. But another famous dwarf planet, Pluto, also has water ice, and models hint at a subsurface ocean, too. "As we're continuing to explore [the solar system], water seems to be very present," Richard Binzel, a planetary scientist at the Massachusetts Institute of Technology who was not part of the research team, tells the Monitor. "'Water, water everywhere' is the key finding that keeps turning up everywhere we explore." And that could be a boon for scientists. Not only could studying the composition of planetary bodies like Ceres help clarify the early history of the solar system and our own planet, water is a key ingredient for life as we know it. That means that where there is water, there might be life. And any humans planning to venture out into space also need water to survive. The model Dr. Prettyman and his colleagues have devised from the new data is remarkably similar to the one proposed in 1989. According to the new model, described in a paper published Thursday in the journal Science, water ice on Ceres becomes abundant starting at latitudes of 40 degrees and could reach 30 percent of the composition of material at the poles. "The results of the paper confirm our best hopes about Ceres – that it does contain a significant amount of water," Dr. Binzel says. Previous studies of Ceres have been limited to imaging the surface of the dwarf planet, but the Gamma Ray and Neutron Detector (GRaND) on Dawn was able to peer about 1 meter below the surface. But, Prettyman notes, GRaND isn't sensing ice directly. "There's no gamma ray or neutron signature for ice, per se," he says. Instead, the team looks at measurements of elements like hydrogen and then calculates how much might be in the form of H2O. "The water content of Ceres' uppermost surface is from about 16 weight percent at the equator to almost 30 weight percent in the northern hemisphere, at the north pole," Prettyman says. But it may not all be in the form of water ice, he adds. "We think part of it is, and part of it is the form of minerals of hydration," he said, referring to minerals that have water embedded in their chemical structures. Scientists have debated for years whether any water on Ceres would be in pure water-ice form. One model had suggested Ceres was a water-ice sandwich, with a rocky topping over a layer of mostly pure water-ice atop a rocky core. And although this new research supports the idea of layers, they don't seem to be so clearly separated. Understanding Ceres' composition could help scientists understand how the dwarf planet formed, which in turn could yield insight into the early solar system. When Prettyman and his colleagues examined composition clues from the GRaND data, they spotted less iron in this shallow subsurface than they had expected. "The lack of iron in the surface suggests that some of it may have gone deeper, perhaps even to the core of Ceres," Binzel says. That would imply that Ceres underwent a differentiation process, with the heavier elements sinking toward the planetary body's center. Water is a key piece of that process, says Josh Emery, a planetary scientist at the University of Tennessee, Knoxville who wasn't part of the research, in an interview with the Monitor. "As a body is forming, it gets pretty warm inside from radioactive isotopes that can heat the entire interior," he explains. "If there's ice there, it melts the ice into water and drives chemical reactions and can lead to separation by density, by different materials." And the low-iron content on the surface of Ceres, along with evidence of clays, suggest water was involved in the early history of Ceres, Binzel says. "Layering is something that we see very pervasively in our solar system," says Amy Lovell, an astronomer at Agnes Scott College in Decatur, Ga. who was not involved in the research. So finding evidence of differentiation in the queen of the asteroid belt isn't a surprise, she tells the Monitor. But one thing doesn't quite fit: Ceres' location in the solar system. Planetary bodies that got big enough to become differentiated and that are close to the sun, within what is called the snowline, have a metal core and a rocky crust, explains Andy Rivkin, a planetary astronomer at the Johns Hopkins University Applied Physics Laboratory who was not involved in the research. Further out in the solar system, bodies have an icy mantle over a rocky core. But, so close to the sun, and without a protective atmosphere, ice isn't stable at the surface of Ceres. The heat of the sun would cause any ice on the surface to sublimate away, he tells the Monitor. That's where Ceres' dusty surface comes in. It serves as a sort of "protective coating," as Dr. Lovell puts it, allowing the ice beneath to stay stable. So, Dr. Rivkin says, this new research "tells us about the nature of Ceres. It might be what you get if you took something like Enceladus [one of the moons of Saturn], took it out of orbit from Saturn, put it in the middle of the asteroid belt and just let it heat up and see what happened. You might end up with something kind of like Ceres." And scientists have already proposed that perhaps Ceres migrated from the middle of the solar system, perhaps as a moon of Jupiter or Saturn, to its current location. Understanding how and where Ceres formed could also hold provide clues into how Earth got its water, Rivkin adds. "There's some evidence that the Earth formed without a lot of water and without a lot of organic materials," he says. It's possible that something like Ceres may have hit early Earth, depositing ice and organics – the building blocks for life as we know it. On the hunt for water "Maybe it's not surprising after all" that H2O keeps showing up everywhere, Binzel admits, as hydrogen and oxygen are two of the three most common elements in the universe, "and they like to get together." But understanding the presence of water and its role in planetary building processes goes beyond our own solar system, Binzel says. "Understanding how the process works here, around our sun, helps us understand how this must be working around all these other stars that we're discovering in planetary systems." Plus, it has benefits beyond pure science, Dr. Emery adds. If humans are to become "a spacefaring people," he says, "water in any form will be a valuable commodity. To understand where water is and where we can get it in the solar system will be really valuable information."


News Article | December 15, 2015
Site: www.rdmag.com

Researchers have discovered a dazzling new method of visualizing neurons that promises to benefit neuroscientists and cell biologists alike: by using spectral confocal microscopy to image tissues impregnated with silver or gold. Rather than relying on the amount of light reflecting off metal particles, this novel process, to be presented in the journal eLife, involves delivering light energy to silver or gold nanoparticles deposited on neurons and imaging the higher energy levels resulting from their vibrations, known as surface plasmons. This technique is particularly effective as the light emitted from metal particles is resistant to fading, meaning that decades-old tissue samples achieved through other processes, such as the Golgi stain method from the late 1880s, can be imaged repeatedly. The new process was achieved by using spectral detection on a Laser Scanning Confocal Microscope (LSCM), first made available in the late 1980s and, until now, used most extensively for fluorescent imaging. Paired with such methods, silver- and gold-based cell labeling is poised to unlock new information in a myriad of archived specimens. Furthermore, silver-impregnated preparations should retain their high image quality for a century or more, allowing for archivability that could aid in clinical research and disease-related diagnostic techniques for cancer and neurological disorders. "For the purposes of medical diagnostics, older and newer specimens could be compared with the knowledge that signal intensity would remain fairly uniform regardless of sample age or repeated light exposure," says contributing author Karen Mesce from the University of Minnesota. "With the prediction that superior resolution microscopic techniques will continue to evolve, older archived samples could be reimagined with newer technologies and with the confidence that the signal in question was preserved. The progression or stability of a cancer or other disease could therefore be charted with accuracy over long periods of time." To appreciate the enhanced image quality produced by the new technique, the team first examined a conventional brightfield image of a metal-labelled neuron within a grasshopper's abdominal ganglion, a type of mini-brain which, even at that size, presented out-of-focus structures. They then imaged the same ganglion with the spectral LSCM adjusted to the manufacturer's traditional fluorescence settings, resulting only in strong natural fluorescence and a collective dark blur in place of the silver-labelled neurons. However, after collecting the light energy emitted from vibrating surface plasmons in the spectral LSCM, the team obtained spectacular three-dimensional computer images of silver and gold-impregnated neurons. This holds enormous potential for stimulating a re-examination of archived preparations, including Golgi-stained and cobalt/silver-labelled nervous systems. Additionally, by using a number of different metal-based cell-labeling techniques in combination with the new LSCM protocols, tissue and cell specimens can be generated and imaged with ease and in great three-dimensional detail. Changes in even small structural details of neurons can be identified, which are often important indicators of neurological disease, learning and memory, and brain development. "Both new and archived preparations are essentially permanent and the information gathered from them increases the data available for characterizing neurons as individuals or as members of classes for comparative studies, adding to emerging neuronal banks," says co-first author Karen Thompson from Agnes Scott College. "Just as plasmon resonance can explain the continued intensity of the red (caused by silver nanoparticles) and yellow (gold nanoparticles) colors in centuries-old medieval stained glass and other works of art, metal-impregnated neurons are also likely never to fade, neither in the information they provide nor in their intrinsic beauty," adds Mesce.


News Article | December 15, 2016
Site: www.csmonitor.com

—In 1989, two geophysicists theorized that extensive stores of water-ice exist just beneath the surface of Ceres. Their model suggested that the ice could be 10 to 100 meters (33 to 330 feet) beneath the surface near the equator and closer to the surface – just 1 to 10 meters (3 to 33 feet) deep – from the mid-latitudes to the poles. That model was created with data obtained from ground-based telescopes, but new data beamed back from NASA's Dawn spacecraft, which arrived at the the dwarf planet (sometimes characterized as an asteroid) in 2015, suggests that their model wasn't far off. "Lo and behold, they're right," Tom Prettyman, a co-investigator of the NASA Dawn mission and a researcher at the Planetary Science Institute, tells The Christian Science Monitor. "There is ice. And there's very strong evidence for it near the surface at high latitudes on Ceres." "This builds a lot of confidence in the models that we're using for ice stability," he says, which could help astronomers know where to look for water-ice in the rest of the solar system. Recent exploration of our solar system has turned up evidence of water on many different planetary bodies. Most are moons with subsurface oceans or icy crusts. But another famous dwarf planet, Pluto, also has water ice, and models hint at a subsurface ocean, too. "As we're continuing to explore [the solar system], water seems to be very present," Richard Binzel, a planetary scientist at the Massachusetts Institute of Technology who was not part of the research team, tells the Monitor. "'Water, water everywhere' is the key finding that keeps turning up everywhere we explore." And that could be a boon for scientists. Not only could studying the composition of planetary bodies like Ceres help clarify the early history of the solar system and our own planet, water is a key ingredient for life as we know it. That means that where there is water, there might be life. And any humans planning to venture out into space also need water to survive. The model Dr. Prettyman and his colleagues have devised from the new data is remarkably similar to the one proposed in 1989. According to the new model, described in a paper published Thursday in the journal Science, water ice on Ceres becomes abundant starting at latitudes of 40 degrees and could reach 30 percent of the composition of material at the poles. "The results of the paper confirm our best hopes about Ceres – that it does contain a significant amount of water," Dr. Binzel says. Previous studies of Ceres have been limited to imaging the surface of the dwarf planet, but the Gamma Ray and Neutron Detector (GRaND) on Dawn was able to peer about 1 meter below the surface. But, Prettyman notes, GRaND isn't sensing ice directly. "There's no gamma ray or neutron signature for ice, per se," he says. Instead, the team looks at measurements of elements like hydrogen and then calculates how much might be in the form of H2O. "The water content of Ceres' uppermost surface is from about 16 weight percent at the equator to almost 30 weight percent in the northern hemisphere, at the north pole," Prettyman says. But it may not all be in the form of water ice, he adds. "We think part of it is, and part of it is the form of minerals of hydration," he said, referring to minerals that have water embedded in their chemical structures. Scientists have debated for years whether any water on Ceres would be in pure water-ice form. One model had suggested Ceres was a water-ice sandwich, with a rocky topping over a layer of mostly pure water-ice atop a rocky core. And although this new research supports the idea of layers, they don't seem to be so clearly separated. Understanding Ceres' composition could help scientists understand how the dwarf planet formed, which in turn could yield insight into the early solar system. When Prettyman and his colleagues examined composition clues from the GRaND data, they spotted less iron in this shallow subsurface than they had expected. "The lack of iron in the surface suggests that some of it may have gone deeper, perhaps even to the core of Ceres," Binzel says. That would imply that Ceres underwent a differentiation process, with the heavier elements sinking toward the planetary body's center. Water is a key piece of that process, says Josh Emery, a planetary scientist at the University of Tennessee, Knoxville who wasn't part of the research, in an interview with the Monitor. "As a body is forming, it gets pretty warm inside from radioactive isotopes that can heat the entire interior," he explains. "If there's ice there, it melts the ice into water and drives chemical reactions and can lead to separation by density, by different materials." And the low-iron content on the surface of Ceres, along with evidence of clays, suggest water was involved in the early history of Ceres, Binzel says. "Layering is something that we see very pervasively in our solar system," says Amy Lovell, an astronomer at Agnes Scott College in Decatur, Ga. who was not involved in the research. So finding evidence of differentiation in the queen of the asteroid belt isn't a surprise, she tells the Monitor. But one thing doesn't quite fit: Ceres' location in the solar system. Planetary bodies that got big enough to become differentiated and that are close to the sun, within what is called the snowline, have a metal core and a rocky crust, explains Andy Rivkin, a planetary astronomer at the Johns Hopkins University Applied Physics Laboratory who was not involved in the research. Further out in the solar system, bodies have an icy mantle over a rocky core. But, so close to the sun, and without a protective atmosphere, ice isn't stable at the surface of Ceres. The heat of the sun would cause any ice on the surface to sublimate away, he tells the Monitor. That's where Ceres' dusty surface comes in. It serves as a sort of "protective coating," as Dr. Lovell puts it, allowing the ice beneath to stay stable. So, Dr. Rivkin says, this new research "tells us about the nature of Ceres. It might be what you get if you took something like Enceladus [one of the moons of Saturn], took it out of orbit from Saturn, put it in the middle of the asteroid belt and just let it heat up and see what happened. You might end up with something kind of like Ceres." And scientists have already proposed that perhaps Ceres migrated from the middle of the solar system, perhaps as a moon of Jupiter or Saturn, to its current location. Understanding how and where Ceres formed could also hold provide clues into how Earth got its water, Rivkin adds. "There's some evidence that the Earth formed without a lot of water and without a lot of organic materials," he says. It's possible that something like Ceres may have hit early Earth, depositing ice and organics – the building blocks for life as we know it. On the hunt for water "Maybe it's not surprising after all" that H2O keeps showing up everywhere, Binzel admits, as hydrogen and oxygen are two of the three most common elements in the universe, "and they like to get together." But understanding the presence of water and its role in planetary building processes goes beyond our own solar system, Binzel says. "Understanding how the process works here, around our sun, helps us understand how this must be working around all these other stars that we're discovering in planetary systems." Plus, it has benefits beyond pure science, Dr. Emery adds. If humans are to become "a spacefaring people," he says, "water in any form will be a valuable commodity. To understand where water is and where we can get it in the solar system will be really valuable information."


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: GALACTIC ASTRONOMY PROGRAM | Award Amount: 201.89K | Year: 2012

Dr. De Pree and his team at Agnes Scott College perform observations with the Expanded Very Large Array (EVLA) to study massive star formation. In particular, they investigate radiation flux variations during massive star formation in HII regions (i.e., regions in the interstellar medium in which hydrogen is mainly present as ionized atoms). Massive stars drive processes that enrich the ISM in chemical elements and significantly impact the evolution of galaxies. The Sgr B2 region is one of the most source-rich massive star forming regions in the Milky Way. It contains many morphologically diverse HII regions, and the number of unusual broad line sources make it an ideal laboratory for testing theories of ultra-compact HII region evolution. Recent high-resolution, radiation-hydrodynamic simulations indicate that dense, rotating, accretion flows that are required to form massive stars quickly become gravitationally unstable. This changes the amount of trapped ionizing radiation and the sizes of the associated ultra-compact HII regions. The orbits of dense clumps and filaments near newly born massive stars thus may irregularly trap and expose their ionizing radiation. These objects are optically thick at a wavelength of 2 cm and thus size variations are also expressed as flux changes. Hence over time, a resulting HII region flickers in size between being hyper-compact and ultra-compact throughout the main star accretion phase, rather than monotonically expanding. The accretion flow continues for a period ten times longer than the free expansion timescale for an HII region, and the model can address why ultra-compact HII regions do not more rapidly expand and dissipate. It could also explain the observed distribution of morphologies.
The Sgr B2 region contains 49 regions that can be imaged at 1.3 cm wavelength, and 25 of these hyper-compact HII regions have physical diameters less than 5000 Astronomical Units. Dr. De Pree and his team will use the EVLA to reimage this large sample of ultra-compact HII regions to: (1) Determine the frequency and magnitude of ultra-compact HII region flux and size fluctuations over about a 20 year time baseline (since 1989) (2) Constrain and test the theoretical models, (3) Observe recombination lines with the improved spectral resolution and bandwidth of the new EVLA correlator, and characterize line profiles and velocity gradients, and (4) Examine the dynamics of sources with especially broad or multiply peaked line profiles.
The EVLA has the spatial and the spectral resolution to properly examine the Broad Line Recombination Objects in the crowded Sgr B2 region. Whether or not flickering is detected, these observations will provide the highest resolution, most sensitive radio image of this prototype massive star forming region, and the reduced data will be made publicly available. The EVLA observations will provide a definitive test of the flickering UC HII region model and will be the first attempt to make time-domain (20 year baseline) observations of a large sample of ultra-compact HII regions.
Agnes Scott College, with a 30% African American student body is the only womens college in the Southeastern Association for Research in Astronomy (SARA) consortium, and the Physics and Astronomy Department has a record of success in sending women on to graduate work and careers in the sciences. Dr. De Pree and his group are engaged in the well-established outreach program at Bradley Observatory at Agnes Scott College which is connected to area K12 institutions and hosting over 1500 students each year.


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: GALACTIC ASTRONOMY PROGRAM | Award Amount: 255.23K | Year: 2016

The team will use the Karl G. Jansky Very Large Array (VLA) to search for time-variable sources associated with massive stars. Such flickering sources at radio wavelengths suggest that the stars accrete gas in fits and starts. This surprising behavior was predicted from simulations. The expected changes in the radio signals are too small to measure from year to year. But they are big enough to measure from decade to decade. The longevity of the VLA means that the predictions can now be tested. The team will compare their new VLA measurements with those from two decades ago. Recent technical upgrades to this NSF facility will also let the team study the motions of the accreted gas. Undergraduates from underrepresented groups will be heavily involved in the research. The PI and his undergraduates will produce educational posters for middle-school students. They will also lecture at public events at the local campus observatory. The observatory is the well-known center of a scaled model of our Solar System spread throughout Atlanta, Georgia.

The team will use the VLAs exquisite spatial resolution and longevity to study W49A, a massive star-forming complex in our Galaxy. Their goals are to (1) search for variations in the size and flux density of its continuum sources of ionized (HII) gas; (2) test the predictions of the simulations; (3) characterize the properties of the spectral lines from the ionized gas; and (4) look for kinematic signatures of continuum flickering.


Grant
Agency: NSF | Branch: Standard Grant | Program: | Phase: S-STEM:SCHLR SCI TECH ENG&MATH | Award Amount: 196.00K | Year: 2012

The goal of this project is to develop, implement and evaluate problem-based (PB) laboratory experiments linked to process-oriented guided-inquiry learning (POGIL) activities for student learning of Fourier-transform infrared (FTIR) spectroscopy in analytical and physical chemistry. The POGIL activities focus on student understanding of key IR spectroscopic concepts. The PB laboratory experiments provide students with hands-on opportunities to explore fundamental techniques and measurements, including attenuated total reflectance (ATR) spectroscopy, as well as investigate advanced topics such as the characterization of surfaces. The FTIR with ATR accessory acquired through this grant is available for Agnes Scott Colleges undergraduate research program.

The intellectual merit of this project stems from the development and evaluation of new materials that integrate active-learning in-class activities and problem-based laboratories. Self-contained modules are designed to be used in any upper-level undergraduate course utilizing active learning methods to study FTIR spectroscopy. All activities and laboratory experiments are peer reviewed and classroom tested, which adds to the strength of the evaluation plan.

The broader impact includes the development of novel resources for upper-level undergraduate courses for any practitioner wishing to use active learning methods to study FTIR spectroscopy and/or fundamental principles illustrated by FTIR spectroscopy. Materials are disseminated on the POGIL website, a national repository for curricular materials employing this pedagogy, and through publications and workshops.

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