13,280 research outputs found
On the sheaf-theoretic SL(2, C) Casson–Lin invariant
No full textWe prove that the (τ-weighted, sheaf-theoretic) SL(2, C) Casson–Lin invariant introduced by Manolescu and the first author is generically independent of the parameter τ and additive under connected sums of knots in integral homology 3-spheres. This addresses two questions asked by Manolescu and the first author. Our arguments involve a mix of topology and algebraic geometry, and rely crucially on the fact that the SL(2, C) Casson–Lin invariant admits an alternative interpretation via the theory of Behrend functions.</p
sel-11 and cdc-42, two negative modulators of LIN-12/Notch activity in C. elegans.
No full textLIN-12/Notch signaling is important for cell-cell interactions during development, and mutations resulting in constitutive LIN-12/Notch signaling can cause cancer. Loss of negative regulators of lin-12/Notch activity has the potential for influencing cell fate decisions during development and the genesis or aggressiveness of cancer.We describe two negative modulators of lin-12 activity in C. elegans. One gene, sel-11, was initially defined as a suppressor of a lin-12 hypomorphic allele; the other gene, cdc-42, is a well-studied Rho GTPase. Here, we show that SEL-11 corresponds to yeast Hrd1p and mammalian Synoviolin. We also show that cdc-42 has the genetic properties consistent with negative regulation of lin-12 activity during vulval precursor cell fate specification.Our results underscore the multiplicity of negative regulatory mechanisms that impact on lin-12/Notch activity and suggest novel mechanisms by which constitutive lin-12/Notch activity might be exacerbated in cancer
Expression and Androgen Regulation of C-Cam Cell Adhesion Molecule Isoforms in Rat Dorsal and Ventral Prostate
No full textC-CAM is an epithelial cell adhesion molecule with two major splice variants that differ in the length of the cytoplasmic domain. C-CAM1 (long (L)-form) strongly suppresses the tumorigenicity of human prostate carcinoma cells. In contrast, C-CAM2 (short (S)-form) does not exhibit tumor-suppressive activity. In the present study we have investigated the functional significance of L-form and S- form C-CAM in rat prostate by examining their expression and distribution in different prostate lobes and their response to androgen deprivation. RNase protection assays with a probe for both C-CAM isoforms detected high levels of C-CAM messages in the rat dorso-lateral prostate (DLP). L- and S- form proteins, localized by indirect immunofluorescence using isoform-specific antipeptide antibodies, were co- expressed on the apical surface of prostate epithelial cells in normal DLP. Androgen depletion did not significantly change the steady state levels of C-CAM message and protein expression in the DLP, although there was a change in the pattern of protein expression in these lobes. In contrast, C -CAM isoform messages and proteins were undetectable in normal ventral prostate (VP) but increased markedly in this lobe in response to castration, producing isoform ratios similar to those in DLP. These results demonstrate that coordinate expression of C- CAM isoforms is maintained in the VP following androgen depletion and suggest that androgen suppresses C-CAM expression in VP but not in DLP. These results suggest that balanced expression of L- and S-form C- CAM is important for normal prostate growth and differentiation
sj-docx-1-jpx-10.1177_23743735241240926 - Supplemental material for Alternative Payment Models and Patient-Reported Quality of Preparation for Discharge: A Retrospective Longitudinal Study
No full textSupplemental material, sj-docx-1-jpx-10.1177_23743735241240926 for Alternative Payment Models and Patient-Reported Quality of Preparation for Discharge: A Retrospective Longitudinal Study by Sunny C. Lin, Julia Adler-Milstein, John M. Hollingsworth and Andrew Ryan in Journal of Patient Experience</p
VMJ789783_Supplementary_Table_1 – Supplemental material for Association of HIV infection with age and symptomatic carotid atherosclerotic disease at the time of carotid intervention in the United States
No full textSupplemental material, VMJ789783_Supplementary_Table_1 for Association of HIV infection with age and symptomatic carotid atherosclerotic disease at the time of carotid intervention in the United States by Timothy C Lin, Brittany N Burton, Andrew Barleben, Martin Hoenigl and Rodney A Gabriel in Vascular Medicine</p
Directional effects of antiferromagnetic ordering on the electronic structure in NdSb
No full textThe recent discovery of unconventional surface state pairs, which give rise to Fermi arcs and spin textures, in antiferromagnetically ordered NdBi raised the interest in rare-earth monopnictides. Several scenarios of antiferromagnetic order have been suggested to explain the origin of these states with some of them being consistent with the presence of non-trivial topologies. In this study, we use angle-resolved photoemission spectroscopy (ARPES) and density-functional-theory (DFT) calculations to investigate the electronic structure of NdSb. We found the presence of distinct domains that have different electronic structure at the surface. These domains correspond to different orientations of magnetic moments in the AFM state with respect to the surface. We demonstrated remarkable agreement between DFT calculations and ARPES that capture all essential changes in the band structure caused by transition to a magnetically ordered state.This is a preprint from Kushnirenko, Yevhen, Brinda Kuthanazhi, Lin-Lin Wang, Benjamin Schrunk, Evan O'Leary, Andrew Eaton, P. C. Canfield, and Adam Kaminski. "Directional effects of antiferromagnetic ordering on the electronic structure in NdSb." arXiv preprint arXiv:2305.17085 (2023). doi: https://doi.org/10.48550/arXiv.2305.17085. Published as Kushnirenko, Yevhen, Brinda Kuthanazhi, Lin-Lin Wang, Benjamin Schrunk, Evan O'Leary, Andrew Eaton, Paul C. Canfield, and Adam Kaminski. "Directional effects of antiferromagnetic ordering on the electronic structure in NdSb." Physical Review B 108, no. 11 (2023): 115102. https://doi.org/10.1103/PhysRevB.108.115102
Band structure and charge ordering of Dirac semimetal EuAl 4 at low temperatures
No full textEuAl4 is proposed to host a topological Hall state. This material also undergoes four consecutive antiferromagnetic (AFM) transitions upon cooling below TN1 = 15.4 K in the presence of charge density wave (CDW) order that sets in below TCDW = 140 K. We use angle-resolved photoemission spectroscopy and density-functional-theory calculations to study how magnetic ordering affects the electronic properties in EuAl4. We found changes in the band structure upon each of the four consecutive AFM transitions including band splitting, renormalizations, and appearance of new bands forming additional Fermi sheets. In addition we also found significant enhancement of the quasiparticles' lifetime due to suppression of spin flip scattering, similar to what was previously reported for ferromagnetic EuCd2As2. Surprisingly, we observe that most significant changes in electronic properties occur not at TN1, but instead at the AFM3 to AFM4 transition, which coincides with the largest drop in resistivity.This is a preprint from Eaton, Andrew, Brinda Kuthanazhi, Paul C. Canfield, Benjamin Schrunk, Na Hyun Jo, Yevhen Kushnirenko, Evan O'Leary, Lin-Lin Wang, and Adam Kaminski. "Band structure and charge ordering of Dirac semimetal EuAl4 at low temperatures." arXiv preprint arXiv:2409.16468 (2024). doi: https://doi.org/10.48550/arXiv.2409.16468. Published as Eaton, Andrew, Brinda Kuthanazhi, Paul C. Canfield, Benjamin Schrunk, Na Hyun Jo, Yevhen Kushnirenko, Evan O'Leary, Lin-Lin Wang, and Adam Kaminski. "Band structure and charge ordering of Dirac semimetal EuAl 4 at low temperatures." Physical Review B 110, no. 12 (2024): 125150. doi: https://doi.org/10.1103/PhysRevB.110.125150
Approaches for solving some scheduling and routing problems
No full textWe study approaches for finding good solutions, and lower bounds, for three difficult combinatorial optimisation problems.The supply ship travelling salesman problem is a simplification of a situation faced by a naval logistics coordinator who must direct a support vessel tasked with resupplying ships in a fleet. It is a generalisation of the travelling salesman problem in which the nodes are in motion, each following some predetermined route. We apply dynamic programming state-space relaxation
techniques, producing lower bounds for the problem that are 73% to 84% of the best solution, on average. We also apply heuristics to find good solutions to this NP-hard problem, showing that restricted dynamic programming approaches outperform simple 2-opt and 3-opt local search procedures
for instances with 20 nodes.We introduce the supply ship scheduling problem, another roblem inspired by a support vessel environment. We wish to minimise the number of mobile machines required to process a set of jobs; each job is in a different stationary location and features a fixed start time. Jobs may be simultaneously processed by multiple machines, obtaining a speed-up in processing time. We represent the problem as a directed graph and use the minimum flow in a transformed network to determine the minimum number of machines. We present a neighbourhood structure based on the maximum cut, applying it
within descent and tabu search procedures. We construct a restricted dynamic programming based approach, but this is outperformed by the tabu search algorithm.The task allocation problem, arising in distributed computing, is to assign a set of tasks to a set of processors so that the overall cost is minimised. Costs are incurred from processor usage, interprocessor communication and task execution. We construct, and try to improve, semidefinite programming relaxations to find lower bounds for variants of this NP-hard problem. We develop a branch-and-bound approach to find optimal solutions, but this is only effective for small instances
lin-31, a Caenorhabditis elegans HNF-3/fork head transcription factor homolog, specifies three alternative cell fates in vulva development
No full textLate events in the cell-cell signalling pathway that controls the specification of vulva cell fates in C. elegans are characterized. The lin-31 gene acts downstream of the ras homolog let-60 and encodes a member of the HNF-3/fork head family of DNA-binding transcription factors. lin-31 regulates how vulval precursor cells choose their fate and in lin-31 mutants, these cells do not properly choose which fate to express and therefore adopt any of the 3 possible vulval cell fates in a deregulated manner..RE: 68 ref.; SC: CA; PE; 0TSource type: Electronic(1) http://upei-resolver.asin-risa.ca?sid=SP:CABI&id=pmid:&id=&issn=0890-9369&isbn=&volume=7&issue=6&spage=933&pages=933-947&date=1993&title=Genes%20and%20Development&atitle=lin-31%2c%20a%20Caenorhabditis%20elegans%20HNF-3%2ffork%20head%20transcription%20factor%20homolog%2c%20specifies%20three%20alternative%20cell%20fates%20in%20vulva%20development.&aulast=Miller&pid=%3Cauthor%3EMiller%2c%20L%20M%3bGallegos%2c%20M%20E%3bMorisseau%2c%20B%20A%3bKim%2c%20S%20K%3C%2Fauthor%3E%3CAN%3E19932337278%3C%2FAN%3E%3CDT%3EJournal%20article%3C%2FDT%3
Inverse systems of spectra and generalizations of a theorem of W.H. Lin
No full textIn this thesis we generalize a theorem of W. H. Lin.
Lin's results are concerned with the homotopy and cohomotopy
of an inverse system of spectra {P-k }. Using the quadratic
construction we construct an inverse system of spectra {P-k(E)}
We generalize Lin's results by studying the homotopy and cohomotopy
of {P-k(E)}
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