Uppermantle anisotropy and the oceanic lithosphere

Rayleigh wave and Love wave dispersion data for oceanic paths cannot be satisfied by an isotropic uppermantle, and it is incorrect to invert these two datasets independently for separate isotropic structures. Available phase and group velocity data are inverted for oceanic structure as a function of age taking into account anelastic dispersion, sphericity, and anisotropy. The resulting models are quite different from previous results which ignore the above effects and the extra parameters involved in proper anisotropic inversion. The models have a high-velocity nearly isotropic layer at the top of the mantle that thickens with age, and an anisotropic low-velocity zone with an age-dependent anisotropy. The LID, or seismic lithosphere, reaches a maximum thickness of 50 km which is about one-half the thickness obtained in previous isotropic or pseudo-isotropic inversions. The seismic lithosphere therefore may be comparable in thickness to the elastic or flexural lithosphere, raising the possibility that both are controlled by effects other than temperature, stress and time, such as mineralogy, crystal orientation or partial melting. The velocities in the low-velocity zone are higher than inferred by previous surface wave studies

1d-1-O-tert-Butyl­diphenyl­silyl-2,3,6-O-tris­(meth­oxy­methyl­ene)-myo-inositol 4,5-bis­(dibenzyl­phosphate)

The title compound [systematic name: tetra­benzyl (1R,2R,3S,4R,5R,6S)-4-(tert-butyl­diphenyl­sil­yloxy)-3,5,6-tris­(meth­oxy­meth­oxy)cyclo­hexane-1,2-diyl bis­phosphate], C56H68O15P2Si, was isolated as an inter­mediate in the preparation of a phosphatidylinositol phosphate for biological studies. In the crystal, the mol­ecules are connected via one methyl­ene C—H⋯π and two weak phen­yl–ether C—H⋯O inter­actions. One benz­yloxy group is disordered over two overlapping positions with an occupancy ratio of 0.649 (7):0.351 (7)

Speeding up protein folding: mutations that increase the rate at which Rop folds and unfolds by over four orders of magnitude

BackgroundThe dimeric four-helix-bundle protein Rop folds and unfolds extremely slowly. To understand the molecular basis for the slow kinetics, we have studied the folding and unfolding of wild-type Rop and a series of hydrophobic core mutants.ResultsMutation of the hydrophobic core creates stable, dimeric, and wild-type-like proteins with dramatically increased rates of both folding and unfolding. The increases in rates are dependent upon the number and position of repacked residues within the hydrophobic core.ConclusionRop folds by a rapid collision of monomers to form a dimeric intermediate with substantial helical content, followed by a slow rearrangement to the final native structure. Rop unfolding is a single extremely slow kinetic phase. The slow steps of both folding and unfolding are dramatically increased by hydrophobic core replacements, suggesting that their main effect is to substantially decrease the energy of the transition state

K’AAW NATASH WA CHƗ́MYANASHMA SHAPÁTTAWAX̱SHA KU SÁPSIKW’ASHA MYÁNASHMA ’WE ARE THE PARENTS RAISING AND TEACHING CHILDREN’: RAISING YAKAMA BABIES AND LANGUAGE TOGETHER

This project listens to parents of Yakama children who provide insight into the ways families are driving efforts of Ichishkíin language revitalization and cultivating movement toward creating a new generation of first-language speakers of Ichishkíin. As a non-Native researcher, I worked collaboratively with my Yakama partner to gather data through a shared survey and community conversations drawing from relationships and connections established through the years. My work builds on research in the fields of Language Revitalization and Education Studies, engaging Indigenous methodologies and Yakama specific frameworks to guide my process and analysis. The survey was open to all parents and caretakers of Yakama children and conversations focused on parents of Yakama babies and toddlers. These interactions shared insights around how Ichishkíin language is used daily in the lives of families as well as what types of supports are wanted to help to increase language use. Parents were generous in sharing their daily practices, challenges, and hopes for the future and this project illustrates the ways Yakama values and language continue to be shared intergenerationally. This project provides a snapshot of the work parents and families are doing on a daily basis to cultivate their language and culture with guidance for future projects, programming, research, and policy

Stationary intraoral tomosynthesis imaging for vertical root fracture detection

University of Minnesota M.S. thesis. August 2017. Major: Dentistry. Advisor: Scott McClanahan. 1 computer file (PDF); viii, 168 pages.The purpose of this study was to compare the radiographic detection of induced vertical root fractures among periapical, limited-FOV CBCT, and stationary intraoral tomosythesis imaging, as well as the relationship between these variables and their impact on evaluator confidence in diagnosis of vertical root fractures. Tomosynthesis imaging uses a multi-source X-ray carbon nanotube array that allows for a acquisition of multiple basis images and subsequent reconstruction of a 3D volume. Sixty fully developed extracted human premolar root samples were assigned two one of four groups based on being either obturated or unobturated and fractured or unfractured. Samples were mounted in artificial alveolar bone then imaged with two-dimensional periapical imaging, limited-FOV CBCT, and stationary intraoral tomosynthesis. Three blinded evaluators assessed for the presence of fractures (yes or no) as well as reported a level of confidence (1 through 5). Generalized estimated equations was used to analyze the data. Within the limitations of this study, it can be concluded that stationary intraoral tomosynthesis improves the sensitivity of detection of induced root fractures compared to a single radiograph. Limited-FOV CBCT is the most sensitive imaging modality for detection of fractures among obturated and unobturated root samples. There is no significant difference in specificity or overall accuracy in fracture detection among periapical, CBCT, and tomosynthesis imaging. The presence of obturation material has a statistically significant reduction in sensitivity of fracture detection and accuracy for periapical radiographs. Obturation status did not have a significant impact on sensitivity for tomosynthesis imaging. . Furthermore, tomosynthesis imaging is superior to periapical imaging in root fracture detection insofar as the presence of obturation material does not significantly reduce fracture detection

Global Mapping of the Uppermantle by Surface Wave Tomography

Surface wave tomography compliments detailed body wave studies by providing a global framework for the lateral variability of the uppermantle. In particular the method allows one to map the mantle beneath the lithosphere and to discuss the fate of overridden oceanic plates. Midocean ridges appear to extend to at least 400 km. By contrast, the very high velocities associated with shields are primarily much shallower. The Red Sea-Afar region is a pronounced and deep low-velocity anomaly. A significant uppermantle anomaly has been found in the central Pacific. This "Polynesian Anomaly" is surrounded by hotspots; Hawaii, Tahiti, Samoa and the Caroline Islands. This may be the site of the extensive Cretaceous volanism which generated the plateaus and seamounts in the western Pacific. Anisotropy indicates deep upwellings, >300 km depth, under midocean ridges, the Afar and the Polynesian Anomaly and downwelling under the western Pacific and the northeastern Indian Ocean. The large fast anomaly under the south Atlantic may represent overridden Pacific plate

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Constraining Galileon inflation

In this short paper, we present constraints on the Galileon inflationary model from the CMB bispectrum. We employ a principal-component analysis of the independent degrees of freedom constrained by data and apply this to the WMAP 9-year data to constrain the free parameters of the model. A simple Bayesian comparison establishes that support for the Galileon model from bispectrum data is at best weak