Comets
Mostrando 13-24 de 33 artigos, teses e dissertações.
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13. Constraints on nebular dynamics and chemistry based on observations of annealed magnesium silicate grains in comets and in disks surrounding Herbig Ae/Be stars
Understanding dynamic conditions in the Solar Nebula is the key to prediction of the material to be found in comets. We suggest that a dynamic, large-scale circulation pattern brings processed dust and gas from the inner nebula back out into the region of cometesimal formation—extending possibly hundreds of astronomical units (AU) from the sun—and t
The National Academy of Sciences.
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14. Aphelion clustering of “new” comets: Star tracks through Oort's cloud
An explanation is proposed for the observed and often discussed clustering of long-period comet aphelia on the sky. Poisson and several multinomial distributions are applied to the most conspicuous cluster, considering only the 80 “new” and 59 “intermediate” comets with the best-determined orbits. The observed number of aphelion points in adjacent ar
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15. Roles of NUDE and NUDF Proteins of Aspergillus nidulans: Insights from Intracellular Localization and Overexpression EffectsV⃞
The NUDF protein of the filamentous fungus Aspergillus nidulans functions in the cytoplasmic dynein pathway. It binds several proteins, including the NUDE protein. Green fluorescent protein-tagged NUDF and NUDA (dynein heavy chain) localize to linearly moving dashes (“comets”) that coincide with microtubule ends. Herein, deletion of the nudE gene did not
The American Society for Cell Biology.
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16. The large GTPase dynamin regulates actin comet formation and movement in living cells
The large GTPase dynamin (Dyn2) has been demonstrated by us and others to interact with several different actin-binding proteins. To define how Dyn2 might participate in actin dynamics in livings cells we have expressed green fluorescent protein (GFP)-tagged Dyn2 in cultured cells and observed labeling of comet-like vesicles and macropinosomes. The come
The National Academy of Sciences.
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17. Medical comets: scholarly contributions by medical undergraduates
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18. Myosin Motors and Not Actin Comets Are Mediators of the Actin-based Golgi-to-Endoplasmic Reticulum Protein TransportD⃞
We have previously reported that actin filaments are involved in protein transport from the Golgi complex to the endoplasmic reticulum. Herein, we examined whether myosin motors or actin comets mediate this transport. To address this issue we have used, on one hand, a combination of specific inhibitors such as 2,3-butanedione monoxime (BDM) and 1-[5-isoquino
The American Society for Cell Biology.
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19. Self-assembling amphiphilic molecules: Synthesis in simulated interstellar/precometary ices
Interstellar gas and dust constitute the primary material from which the solar system formed. Near the end of the hot early phase of star and planet formation, volatile, less refractory materials were transported into the inner solar system as comets and interplanetary dust particles. Once the inner planets had sufficiently cooled, late accretionary inf
The National Academy of Sciences.
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20. Chaos and stability of the solar system
Over the last two decades, there has come about a recognition that chaotic dynamics is pervasive in the solar system. We now understand that the orbits of small members of the solar system—asteroids, comets, and interplanetary dust—are chaotic and undergo large changes on geological time scales. Are the major planets' orbits also chaotic? The answer is n
The National Academy of Sciences.
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21. The development of pneumatisation in the postcranial skeleton of the domestic fowl.
The development of pneumatisation in the postcranial skeleton has been investigated in a flock of Golden Comet pullets from hatching to 182 days posthatching. The timing of development of pneumatisation in the vertebral column, vertebral ribs, sternum and humerus has been demonstrated. No pneumatisation was encountered in the sternal ribs, os coxae or coraco
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22. Entry of the Two Infectious Forms of Vaccinia Virus at the Plasma Membane Is Signaling-Dependent for the IMV but Not the EEV
The simpler of the two infectious forms of vaccinia virus, the intracellular mature virus (IMV) is known to infect cells less efficiently than the extracellular enveloped virus (EEV), which is surrounded by an additional, TGN-derived membrane. We show here that when the IMV binds HeLa cells, it activates a signaling cascade that is regulated by the GTPase ra
The American Society for Cell Biology.
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23. Centrosome maturation: Measurement of microtubule nucleation throughout the cell cycle by using GFP-tagged EB1
Understanding how cells regulate microtubule nucleation during the cell cycle has been limited by the inability to directly observe nucleation from the centrosome. To view nucleation in living cells, we imaged GFP-tagged EB1, a microtubule tip-binding protein, and determined rates of nucleation by counting the number of EB1-GFP comets emerging from the centr
National Academy of Sciences.
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24. Tumor necrosis factor alpha-induced apoptosis in cardiac myocytes. Involvement of the sphingolipid signaling cascade in cardiac cell death.
In the present study, it was shown that physiologically relevant levels of the proinflammatory cytokine TNFalpha induced apoptosis in rat cardiomyocytes in vitro, as quantified by single cell microgel electrophoresis of nuclei ("cardiac comets") as well as by morphological and biochemical criteria. It was also shown that TNFalpha stimulated production of the