1,386 research outputs found
Experimental measurements of the ground cloud growth during the 11 February 1974, Titan-Centaur launch at Kennedy Space Center
The Titan-Centaur was launched from Kennedy Space Center on February 11, 1974 at 0948 eastern daylight time. Ground level effluent measurements were obtained from the solid rocket motors for comparison with NASA diffusion models for predicting effluent ground level concentrations and cloud behavior. The results obtained provide a basis for an evaluation of such key model inputs such as cloud rise rate, stabilization altitude, crosswind growth, volume expansion, and cloud trajectory. Ground level effluent measurements were limited because of changing meteorological conditions, incorrect instrument location, and operational problems. Based on the measurement results, operational changes are defined. Photographs of the ground exhaust clouds are shown. The chemical composition of the exhaust gases was analyzed and is given
The Role of Intrusive Imagery in Hoarding Disorder
Despite the incidence of trauma in the histories of people with Hoarding Disorder (HD), reexperiencing symptoms, namely intrusive images, have not been investigated in the condition. To address this, 27 individuals who met DSM-5 criteria for HD and 28 community controls (CCs) were interviewed about (a) their everyday experiences of intrusive imagery, and (b) the unexpected images they experience when discarding high- and low-value possessions. Compared to CCs, everyday images described by the HD group were more frequent, had a greater negative valence, and were associated with greater interference in everyday life and attempts to avoid the imagery. With regard to discard-related imagery, a MANOVA followed up with mixed ANOVAs showed that HD participants reported more negative experiences of intrusive imagery in comparison with CCs during recent episodes of discarding objects of low subjective value. However, HD and CC participants both experienced positive imagery when discarding high-value objects. CC participants reported greater avoidance of imagery in the high-value object condition, but imagery-avoidance did not change between conditions for HD participants. The findings are discussed, particularly in relation to the potential of imagery-based interventions for HD
Global properties of dilatonic Gauss-Bonnet black holes
We study the phase space of the spherically symmetric solutions of Einstein
Gauss-Bonnet system nonminimally coupled to a scalar field and show that in
four dimensions the only regular black hole solutions are asymptotically flatComment: 12 pages, plain TeX; v.2: phase space is described in more detai
Altered calcium signaling in cancer cells
It is the nature of the calcium signal, as determined by the coordinated activity of a suite of calcium channels, pumps, exchangers and binding proteins that ultimately guides a cell's fate. Deregulation of the calcium signal is often deleterious and has been linked to each of the 'cancer hallmarks'. Despite this, we do not yet have a full understanding of the remodeling of the calcium signal associated with cancer. Such an understanding could aid in guiding the development of therapies specifically targeting altered calcium signaling in cancer cells during tumorigenic progression. Findings from some of the studies that have assessed the remodeling of the calcium signal associated with tumorigenesis and/or processes important in invasion and metastasis are presented in this review. The potential of new methodologies is also discussed. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers
Structural transitions, octahedral rotations, and electronic properties of NiO rare-earth nickelates under high pressure
Motivated by the recent observation of superconductivity with K
in pressurized La3Ni2O7 [Nature 621, 493 (2023)], we explore the structural and
electronic properties in A3Ni2O7 bilayer nickelates (A=La-Lu, Y, Sc) as a
function of hydrostatic pressure (0-150 GPa) from first principles including a
Coulomb repulsion term. At GPa, we observe an
orthorhombic-to-tetragonal transition in LaNiO at variance with
recent x-ray diffraction data, which points to so-far unresolved complexities
at the onset of superconductivity, e.g., charge doping by variations in the
oxygen stoichiometry. We compile a structural phase diagram with particular
emphasis on the ratio, octahedral anisotropy, and octahedral rotations.
Intriguingly, chemical and external pressure emerge as two distinct and
counteracting control parameters. We find unexpected correlations between
and the in-plane Ni-O-Ni bond angles for LaNiO. Moreover, two novel
structural phases with significant octahedral rotations and in-plane bond
disproportionations are uncovered for A=Nd-Lu, Y, Sc that exhibit a surprising
pressure-driven electronic reconstruction in the Ni manifold. By
disentangling the involvement of basal versus apical oxygen states at the Fermi
surface, we identify TbNiO as an interesting candidate for
superconductivity at ambient pressure. These results suggest a profound
tunability of the structural and electronic phases in this novel materials
class and are key for a fundamental understanding of the superconductivity
mechanism.Comment: 12 pages, 5 figure
Differential effects of two-pore channel protein 1 and 2 silencing in MDA-MB-468 breast cancer cells
Two-pore channel proteins, TPC1 and TPC2, are calcium permeable ion channels found localized to the membranes of endolysosomal calcium stores. There is increasing interest in the role of TPC-mediated intracellular signaling in various pathologies; however their role in breast cancer has not been extensively evaluated. TPC1 and TPC2 mRNA was present in all non-tumorigenic and tumorigenic breast cell lines assessed. Silencing of TPC2 but not TPC1 attenuated epidermal growth factor-induced vimentin expression in MDA-MB-468 breast cancer cells. This effect was not due to a general inhibition of epithelial to mesenchymal transition (EMT) as TPC2 silencing had no effect on epidermal growth factor (EGF)-induced changes on E-cadherin expression. TPC1 and TPC2 were also shown to differentially regulate cyclopiazonic acid (CPA)-mediated changes in cytosolic free Ca. These findings indicate potential differential regulation of signaling processes by TPC1 and TPC2 in breast cancer cells
Gauss-Bonnet Black Holes and Heavy Fermion Metals
We consider charged black holes in Einstein-Gauss-Bonnet Gravity with
Lifshitz boundary conditions. We find that this class of models can reproduce
the anomalous specific heat of condensed matter systems exhibiting
non-Fermi-liquid behaviour at low temperatures. We find that the temperature
dependence of the Sommerfeld ratio is sensitive to the choice of Gauss-Bonnet
coupling parameter for a given value of the Lifshitz scaling parameter. We
propose that this class of models is dual to a class of models of
non-Fermi-liquid systems proposed by Castro-Neto et.al.Comment: 17 pages, 6 figures, pdfLatex; small corrections to figure 10 in this
versio
Identification of hip fracture patients from radiographs using Fourier analysis of the trabecular structure: a cross-sectional study
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