6 research outputs found
A Test of General Relativity Using the LARES and LAGEOS Satellites and a GRACE Earth's Gravity Model
We present a test of General Relativity, the measurement of the Earth's
dragging of inertial frames. Our result is obtained using about 3.5 years of
laser-ranged observations of the LARES, LAGEOS and LAGEOS 2 laser-ranged
satellites together with the Earth's gravity field model GGM05S produced by the
space geodesy mission GRACE. We measure ,
where is the Earth's dragging of inertial frames normalized to its
General Relativity value, 0.002 is the 1-sigma formal error and 0.05 is the
estimated systematic error mainly due to the uncertainties in the Earth's
gravity model GGM05S. Our result is in agreement with the prediction of General
Relativity.Comment: 13 pages, 4 figures, published on EPJ
LARES Satellite Thermal Forces and a Test of General Relativity
We summarize a laser-ranged satellite test of frame-dragging, a prediction of
General Relativity, and then concentrate on the estimate of thermal thrust, an
important perturbation affecting the accuracy of the test. The frame dragging
study analysed 3.5 years of data from the LARES satellite and a longer period
of time for the two LAGEOS satellites. Using the gravity field GGM05S obtained
via the Grace mission, which measures the Earth's gravitational field, the
prediction of General Relativity is confirmed with a 1- formal error of
0.002, and a systematic error of 0.05. The result for the value of the frame
dragging around the Earth is = 0.994, compared to = 1 predicted by
General Relativity. The thermal force model assumes heat flow from the sun
(visual) and from Earth (IR) to the satellite core and to the fused silica
reflectors on the satellite, and reradiation into space. For a roughly current
epoch (days 1460 - 1580 after launch) we calculate an average along-track drag
of -0.50 .Comment: 6 pages, multiple figures in Proceedings of Metrology for Aerospace
(MetroAeroSpace), 2016 IEE
Identification of Inhibitors of Tubulin Polymerization Using a CRISPR-Edited Cell Line with Endogenous Fluorescent Tagging of β-Tubulin and Histone H1
Tubulin is a protein that plays a critical role in maintaining cellular structure and facilitating cell division. Inhibiting tubulin polymerization has been shown to be an effective strategy for inhibiting the proliferation of cancer cells. In the past, identifying compounds that could inhibit tubulin polymerization has required the use of in vitro assays utilizing purified tubulin or immunofluorescence of fixed cells. This study presents a novel approach for identifying tubulin polymerization inhibitors using a CRISPR-edited cell line that expresses fluorescently tagged β-tubulin and a nuclear protein, enabling the visualization of tubulin polymerization dynamics via high-content imaging analysis (HCI). The cells were treated with known tubulin polymerization inhibitors, colchicine, and vincristine, and the resulting phenotypic changes indicative of tubulin polymerization inhibition were confirmed using HCI. Furthermore, a library of 429 kinase inhibitors was screened, resulting in the identification of three compounds (ON-01910, HMN-214, and KX2-391) that inhibit tubulin polymerization. Live cell tracking analysis confirmed that compound treatment leads to rapid tubulin depolymerization. These findings suggest that CRISPR-edited cells with fluorescently tagged endogenous β-tubulin can be utilized to screen large compound libraries containing diverse chemical families for the identification of novel tubulin polymerization inhibitors
Identification of Inhibitors of Tubulin Polymerization Using a CRISPR-Edited Cell Line with Endogenous Fluorescent Tagging of β-Tubulin and Histone H1
Tubulin is a protein that plays a critical role in maintaining cellular structure and facilitating cell division. Inhibiting tubulin polymerization has been shown to be an effective strategy for inhibiting the proliferation of cancer cells. In the past, identifying compounds that could inhibit tubulin polymerization has required the use of in vitro assays utilizing purified tubulin or immunofluorescence of fixed cells. This study presents a novel approach for identifying tubulin polymerization inhibitors using a CRISPR-edited cell line that expresses fluorescently tagged β-tubulin and a nuclear protein, enabling the visualization of tubulin polymerization dynamics via high-content imaging analysis (HCI). The cells were treated with known tubulin polymerization inhibitors, colchicine, and vincristine, and the resulting phenotypic changes indicative of tubulin polymerization inhibition were confirmed using HCI. Furthermore, a library of 429 kinase inhibitors was screened, resulting in the identification of three compounds (ON-01910, HMN-214, and KX2-391) that inhibit tubulin polymerization. Live cell tracking analysis confirmed that compound treatment leads to rapid tubulin depolymerization. These findings suggest that CRISPR-edited cells with fluorescently tagged endogenous β-tubulin can be utilized to screen large compound libraries containing diverse chemical families for the identification of novel tubulin polymerization inhibitors