299 research outputs found
Hypercontact structures and Floer homology
We introduce a new Floer theory associated to a pair consisting of a Cartan
hypercontact 3-manifold M and a hyperkaehler manifold X.Comment: 74 page
Evaluación del uso de los Encabezamientos de materia en el catálogo colectivo CIRBIC frente al uso de palabras de cualquier campo para la recuperación de la información
El objeto del estudio es evaluar la recuperaciĂłn temática de documentos en el catálogo CIRBIC-Libros partiendo de la bĂşsqueda en los ficheros de palabras PA (no controlado por generarse de cualquier campo bibliográfico), y PTL y PMT (controlados ya que provienen de encabezamientos normalizados: tĂtulos y series y encabezamientos de materia)
Commercial Production of Wild Rice
This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu
XMAP215 is a Processive Microtubule Polymerase
Fast growth of microtubules is essential for rapid assembly of the microtubule cytoskeleton during cell proliferation and differentiation. XMAP215 belongs to a conserved family of proteins that promote microtubule growth. To determine how XMAP215 accelerates growth, we developed a single-molecule assay to visualize directly XMAP215-GFP interacting with dynamic microtubules. XMAP215 binds free tubulin in a 1:1 complex that interacts with the microtubule lattice and targets the ends by a diffusion-facilitated mechanism. XMAP215 persists at the plus end for many rounds of tubulin subunit addition in a form of “tip-tracking.” These results show that XMAP215 is a processive polymerase that directly catalyzes the addition of up to 25 tubulin dimers to the growing plus end. Under some circumstances XMAP215 can also catalyze the reverse reaction, namely microtubule shrinkage. The similarities between XMAP215 and formins, actin polymerases, suggest that processive tip-tracking is a common mechanism for stimulating the growth of cytoskeletal polymers.Molecular and Cellular Biolog
Aurora A phosphorylation of TACC3/maskin is required for centrosome-dependent microtubule assembly in mitosis
Centrosomes act as sites of microtubule growth, but little is known about how the number and stability of microtubules emanating from a centrosome are controlled during the cell cycle. We studied the role of the TACC3–XMAP215 complex in this process by using purified proteins and Xenopus laevis egg extracts. We show that TACC3 forms a one-to-one complex with and enhances the microtubule-stabilizing activity of XMAP215 in vitro. TACC3 enhances the number of microtubules emanating from mitotic centrosomes, and its targeting to centrosomes is regulated by Aurora A–dependent phosphorylation. We propose that Aurora A regulation of TACC3 activity defines a centrosome-specific mechanism for regulation of microtubule polymerization in mitosis
All-optical switching due to state-filling in quantum dots
We report all-optical switching due to state-filling in quantum dots (QDs)
within a Mach-Zehnder Interferometric (MZI) switch. The MZI was fabricated
using InGaAsP/InP waveguides containing a single layer of InAs/InP QDs. A
1530-1570 nm probe beam is switched by optical excitation of one MZI-arm from
the top. By exciting below the InGaAsP bandgap, we prove that the refractive
index nonlinearity is only due to the QDs. The switching efficiency is 2
rad/(microW absorbed power). Probe wavelength insensitivity was obtained using
a broad distribution of QDs.Comment: 12 page
Wild rice production in Minnesota
40 pages; includes photographs and drawings. This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu
Tips for profitable small grain production
1 online resource (PDF, 4 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu
Pharmacological Evaluation of the Long-Term Effects of Xanomeline on the M1 Muscarinic Acetylcholine Receptor
Xanomeline is a unique agonist of muscarinic receptors that possesses functional selectivity at the M1 and M4 receptor subtypes. It also exhibits wash-resistant binding to and activation of the receptor. In the present work we investigated the consequences of this type of binding of xanomeline on the binding characteristics and function of the M1 muscarinic receptor. Pretreatment of CHO cells that stably express the M1 receptor for 1 hr with increasing concentrations of xanomeline followed by washing and waiting for an additional 23 hr in control culture media transformed xanomeline-induced inhibition of [3H]NMS binding from monophasic to biphasic. The high-affinity xanomeline binding site exhibited three orders of magnitude higher affinity than in the case of xanomeline added directly to the binding assay medium containing control cells. These effects were associated with a marked decrease in maximal radioligand binding and attenuation of agonist-induced increase in PI hydrolysis and were qualitatively similar to those caused by continuous incubation of cells with xanomeline for 24 hr. Attenuation of agonist-induced PI hydrolysis by persistently-bound xanomeline developed with a time course that parallels the return of receptor activation by prebound xanomeline towards basal levels. Additional data indicated that blockade of the receptor orthosteric site or the use of a non-functional receptor mutant reversed the long-term effects of xanomeline, but not its persistent binding at an allosteric site. Furthermore, the long-term effects of xanomeline on the receptor are mainly due to receptor down-regulation rather than internalization
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