3,027 research outputs found

    Interaction of CK1δ with γTuSC ensures proper microtubule assembly and spindle positioning.

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    Casein kinase 1δ (CK1δ) family members associate with microtubule-organizing centers (MTOCs) from yeast to humans, but their mitotic roles and targets have yet to be identified. We show here that budding yeast CK1δ, Hrr25, is a γ-tubulin small complex (γTuSC) binding factor. Moreover, Hrr25's association with γTuSC depends on its kinase activity and its noncatalytic central domain. Loss of Hrr25 kinase activity resulted in assembly of unusually long cytoplasmic microtubules and defects in spindle positioning, consistent with roles in regulation of γTuSC-mediated microtubule nucleation and the Kar9 spindle-positioning pathway, respectively. Hrr25 directly phosphorylated γTuSC proteins in vivo and in vitro, and this phosphorylation promoted γTuSC integrity and activity. Because CK1δ and γTuSC are highly conserved and present at MTOCs in diverse eukaryotes, similar regulatory mechanisms are expected to apply generally in eukaryotes

    Systems, computer-implemented methods, and tangible computer-readable storage media for wide-field interferometry

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    Disclosed herein are systems, computer-implemented methods, and tangible computer-readable storage media for wide field imaging interferometry. The method includes for each point in a two dimensional detector array over a field of view of an image: gathering a first interferogram from a first detector and a second interferogram from a second detector, modulating a path-length for a signal from an image associated with the first interferogram in the first detector, overlaying first data from the modulated first detector and second data from the second detector, and tracking the modulating at every point in a two dimensional detector array comprising the first detector and the second detector over a field of view for the image. The method then generates a wide-field data cube based on the overlaid first data and second data for each point. The method can generate an image from the wide-field data cube

    A platinum chloro (fluoroaryl)phosphine complex

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    trans-Dichloro bis[ tris(peritafluorophenyl)phosphine ]platinum(II), [PtCl_2{P(C_6F_5)_3}_2], M_r = 1330.29, triclinic, Pl, ɑ = 9.536 (4), b = 11.221 (2), c = 11.613 (1)Å, ɑ = 62.55 (1), β = 65.81 (2), y = 73.05 (2)º, V = 997.8 (4) Å^3, Z = 1, D_x = 2.21 g cm^(-3), λ(Mo Kɑ)= 0.71073 A, μ = 39.27 cm^(-1), F(000) = 628, room temperature, R = 0.034 for 3497 reflections with F_o^2 > 0. The molecule is centrosymmetric, with Pt-Cl distance 2.304 (2) and Pt-P 2.280 (1) Å, and P-Pt-Cl angle 94.8 (1)°. The C-P distances average 1.824 (4)Å, slightly longer than normal, and the pentafluoro-phenyl groups all have small [116.3 (3)º] angles at the c atom bonded to P

    Towards a fullerene-based quantum computer

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    Molecular structures appear to be natural candidates for a quantum technology: individual atoms can support quantum superpositions for long periods, and such atoms can in principle be embedded in a permanent molecular scaffolding to form an array. This would be true nanotechnology, with dimensions of order of a nanometre. However, the challenges of realising such a vision are immense. One must identify a suitable elementary unit and demonstrate its merits for qubit storage and manipulation, including input / output. These units must then be formed into large arrays corresponding to an functional quantum architecture, including a mechanism for gate operations. Here we report our efforts, both experimental and theoretical, to create such a technology based on endohedral fullerenes or 'buckyballs'. We describe our successes with respect to these criteria, along with the obstacles we are currently facing and the questions that remain to be addressed.Comment: 20 pages, 13 figs, single column forma

    Structure of trimethylplatinum(IV) with a tripod ligand

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    [1(η^5)-Cyclopentadienyl]-tris-µ-(dimethyl-phosphito-1κP:2κO)(trimethyl-2κ^3C)cobaltplatinum, [CoPt(C_2H_6O_3P)_3(C_5H_5)(CH_3)_3], M_r = 691.35, triclinic, P1, a = 9.106(3), b = 14.803(3), c = 15.147(3) Å, α = 112.95(2), β = 103.68(2), γ = 95.10(2)°, V = 1788.9(9) Å^3, Z = 3, D_x = 1.93 g cm^(-3), λ(Mo Kα) = 0.71073 Å, µ = 68.69 cm^(-1), F(000) = 1014, room temperature, R = 0.038 for 4620 reflections with F_o^2 > 3σ(F_o^2). The trimethylplatinum(IV) completes octahedral coordination by bonding to three O atoms of the tripod-shaped methoxy Kläui ligand. There are two independent molecules in the cell, one disordered about a center of symmetry. The ordered molecule has normal bond distances and angles; Pt-C = 2.001 (11) and Pt-O = 2.173(5) Å. Many distances in the disordered molecule are uncertain, particularly in the areas of the Cp C atoms and the CH_3 groups, which overlap in the two orientations

    Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill's epidemiologic criteria for causality

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    <p>Abstract</p> <p>Background</p> <p>Modern diets have been suggested to increase systemic acid load and net acid excretion. In response, alkaline diets and products are marketed to avoid or counteract this acid, help the body regulate its pH to prevent and cure disease. The objective of this systematic review was to evaluate causal relationships between dietary acid load and osteoporosis using Hill's criteria.</p> <p>Methods</p> <p>Systematic review and meta-analysis. We systematically searched published literature for randomized intervention trials, prospective cohort studies, and meta-analyses of the acid-ash or acid-base diet hypothesis with bone-related outcomes, in which the diet acid load was altered, or an alkaline diet or alkaline salts were provided, to healthy human adults. Cellular mechanism studies were also systematically examined.</p> <p>Results</p> <p>Fifty-five of 238 studies met the inclusion criteria: 22 randomized interventions, 2 meta-analyses, and 11 prospective observational studies of bone health outcomes including: urine calcium excretion, calcium balance or retention, changes of bone mineral density, or fractures, among healthy adults in which acid and/or alkaline intakes were manipulated or observed through foods or supplements; and 19 <it>in vitro </it>cell studies which examined the hypothesized mechanism. Urine calcium excretion rates were consistent with osteoporosis development; however calcium balance studies did not demonstrate loss of whole body calcium with higher net acid excretion. Several weaknesses regarding the acid-ash hypothesis were uncovered: No intervention studies provided direct evidence of osteoporosis progression (fragility fractures, or bone strength as measured using biopsy). The supporting prospective cohort studies were not controlled regarding important osteoporosis risk factors including: weight loss during follow-up, family history of osteoporosis, baseline bone mineral density, and estrogen status. No study revealed a biologic mechanism functioning at physiological pH. Finally, randomized studies did not provide evidence for an adverse role of phosphate, milk, and grain foods in osteoporosis.</p> <p>Conclusions</p> <p>A causal association between dietary acid load and osteoporotic bone disease is not supported by evidence and there is no evidence that an alkaline diet is protective of bone health.</p
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