2,300 research outputs found

    IHY Operations: How the IHY is facilitated by the IHY Secretariat

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    In 1957 a program of international research, inspired by the International Polar Years of 1882 and 1932, was organized as the International Geophysical Year (IGY) to study global phenomena of the Earth and geospace. Fifty years later, the world s space science community will again come together for international programs of scientific collaboration: the International Heliophysical Year (MY), the Electronic Geophysical Year (eGY), and the International Polar Year (IPY) 2007. This time, research will extend out into the Heliosphere to focus on solar-terrestrial-plans for the IHY, eGY and IPY incorporate the activities of scientists in 191 nations, as well as the "IGY Gold" Historical Preservation initiative, plus a series of coordinated campaigns involving more than 100 instruments and models, education and public outreach programs, a developing nations instrument development program, and opportunities for supported research worldwide. The presentation will focus on the efforts and operations which will make these activities possible

    SDO/AIA Observation of Kelvin-Helmholtz Instability in the Solar Corona

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    We present observations of the formation, propagation and decay of vortex- shaped features in coronal images from the Solar Dynamics Observatory (SDO) associated with an eruption starting at about 2:30UT on Apr 8, 2010. The series of vortices formed along the interface between an erupting (dimming) region and the surrounding corona. They ranged in size from several to ten arcseconds, and traveled along the interface at 6-14 km/s. The features were clearly visible in six out of the seven different EUV wavebands of the Atmospheric Imaging Assembly (AIA). Based on the structure, formation, propagation and decay of these features, we identified these features as the first observations of the Kelvin-Helmholtz (KH) instability in the corona in EUV. The interpretation is supported by linear analysis and by MHD model of KH instability. We conclude that the instability is driven by the velocity shear between the erupting and closed magnetic field of the Coronal Mass Ejection (CME). The shear flow driven instability can play an important role in energy transfer processes in coronal plasma

    Consensual Qualitative Research: An Update

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    The authors reviewed the application of consensual qualitative research (CQR) in 27 studies published since the method’s introduction to the field in 1997 by C. E. Hill, B. J. Thompson, and E. N. Williams (1997). After first describing the core components and the philosophical underpinnings of CQR, the authors examined how it has been applied in terms of the consensus process, biases, research teams, data collection, data analysis, and writing up the results and discussion sections of articles. On the basis of problems that have arisen in each of these areas, the authors made recommendations for modifications of the method. The authors concluded that CQR is a viable qualitative method and suggest several ideas for research on the method itself

    Plans for the International Heliophysical Year (IHY)

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    The International Heliophysical Year (IHY), an international program of scientific collaboration to understand the external drivers of planetary environments, will be conducted in 2007. This will be a major international event of great interest to the member States. The IHY will involve the deployment of new instrumentation, new observations from the ground and in space, and an education component. The IHY 2007 will coincide with the fiftieth anniversary of the International Geophysical Year (IGY) in 1957. The IGY was organized to study global phenomena of the Earth and Geospace involving about thousands of scientists from many nations, working at thousands of stations, around the world to obtain simultaneous, global observations from the ground and space. Building on results obtained during IGY 1957, the IHY will expand to the study of universal processes in the solar system that affect the interplanetary and terrestrial environments. The study of energetic events in the solar system will pave the way for safe human space travel to the Moon and planets in the future, and it will serve to inspire the next generation of space physicists

    ON THE ORIGINS OF SOLAR EIT WAVES

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    Abstract : Approximately half of the large-scale coronal waves identified in images obtained by the Extreme-Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory from 1997 March to 1998 June were associated with small solar flares with soft X-ray intensities below C class. The probability of a given flare of this intensity having an associated EIT wave is low. For example, of ~8,000 B-class flares occurring during this 15 month period, only 1% were linked to EIT waves. These results indicate the need for a special condition that distinguishes flares with EIT waves from the vast majority of flares that lack wave association. Various lines of evidence, including the fact that EIT waves have recently been shown to be highly associated with coronal mass ejections (CMEs), suggest that this special condition is a CME. A CME is not a sufficient condition for a detectable EIT wave, however, because we calculate that 5 times as many front-side CMEs as EIT waves occurred during this period, after taking the various visibility factors for both phenomena into account. In general, EIT wave association increases with CME speed and width

    Conformational studies on substituted ε-caprolactams by X-ray crystallography and NMR spectroscopy

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    The synthesis and conformational analysis of ε-caprolactams containing a -COOMe group at the C-6 position is described. The influence of different C-2, C-6 and N substituents on ring conformation was studied using X-ray crystallography and NMR spectroscopy. The results provide evidence that all the analysed caprolactams adopt a chair type conformation with a planar lactam. In the 6-substituted caprolactam, the -COOMe residue prefers to reside in an equatorial position, but can be induced to occupy an axial orientation by the introduction of a bulky tert-butyloxycarbonyl (BOC) group on the lactam nitrogen or by C-2/C-3 ring desaturation. The BOC protected caprolactam was found to undergo exchange between two chair forms as detected by solution NMR, one with the C-6 ester equatorial (30%) and the other with it in the axial position (70%); the latter was observed by X-ray crystallography. For the C-2 dithiocarbamate substituted C-6 methyl ester seven-membered rings, a single chair form is observed for cis-isomers with both substituents equatorial. The analogous trans-isomers, however, exist as two chair forms in a 1 : 1 equilibrium ratio of 1,NC4 and 4C1,N conformers, where either substituent can occupy axial or equatorial positions. This journal i

    EUV Dimmings as a Diagnostic of CMEs and Related Phenomena

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    Large-scale coronal EUV dimmings, developing on timescaJes of minutes to hours in association with a flare or filament eruption, are known to exhibit a high correlation with coronal mass ejections. While most observations indicate that the decrease in emission in a dimming is due, at least in part, to a density decrease, a complete understanding requires us to examine at least four mechanisms that have been observed to cause darkened regions in the corona: 1) mass loss, 2) cooling, 3) heating, and 4) absorption/obscuration. Recent advances in automatic detection, observations with improved cadence and resolution, multi-viewpoint imaging, and spectroscopic studies have continued to shed light on dimming formation, evolution, and recovery. However, there are still some outstanding questions, including 1) Why do some CMEs show dimming and some do not? 2) What determines the location of a dimming? 3) What determines the temporal evolution of a dimming? 4) How does the post-eruption dimming connect to the ICME? 5) What is the relationship between dimmings and other CME-associated phenomena? The talk will emphasize the different formation mechanisms of dimmings and their relationship to CMEs and CME-associated phenomena

    Student Perceptions Of Integrated Vs. Separate Basic Science And Clinical Resources

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    For 20 years there has been a push to integrate the basic and clinical sciences in medical school curricula. Recently, studies have suggested that cognitive integration is achieved when the relationships between basic science and clinical domains are explicitly demonstrated. In order to investigate methods that promote cognitive integration we performed a pilot study to develop and test different learning resources. We then surveyed students’ perceptions of these resources and analyzed how the resources affected their note taking. Our study suggests that the type of resources can influence the type of note-taking done by students, and that the process of taking integrated notes can enhance learning and retention. This was a pilot study and is limited by its small sample size. Additional research is planned to confirm and expand on these results.https://dune.une.edu/cetl_minigrant_posters/1000/thumbnail.jp

    The Large GTPase Dynamin Associates with the Spindle Midzone and Is Required for Cytokinesis

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    AbstractCytokinesis involves the concerted efforts of the microtubule and actin cytoskeletons as well as vesicle trafficking and membrane remodeling to form the cleavage furrow and complete daughter cell separation (for reviews, see [1–6]). The exact mechanisms that support membrane remodeling during cytokinesis remain largely undefined. In this study, we report that the large GTPase dynamin, a protein involved in membrane tubulation and vesiculation [7, 8], is essential for successful cytokinesis. Using biochemical and morphological methods, we demonstrate that dynamin localizes to the spindle midzone and the subsequent intercellular bridge in mammalian cells and is also enriched in spindle midbody extracts. In Caenorhabditis elegans, dynamin localized to newly formed cleavage furrow membranes and accumulated at the midbody of dividing embryos in a manner similar to dynamin localization in mammalian cells. Further, dynamin function appears necessary for cytokinesis, as C. elegans embryos from a dyn-1 ts strain [9], as well as dynamin RNAi-treated embryos, showed a marked defect in the late stages of cytokinesis. These findings indicate that, during mitosis, conventional dynamin is recruited to the spindle midzone and the subsequent intercellular bridge, where it plays an essential role in the final separation of dividing cells
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