4,061 research outputs found
On unitary convex decompositions of vectors in a -algebra
No full textsummary:By exploiting his recent results, the author further investigates the extent to which variation in the coefficients of a unitary convex decomposition of a vector in a unital -algebra permits the vector decomposable as convex combination of fewer unitaries; certain -algebra results due to M. Rørdam have been extended to the general setting of -algebras
Erratum: Half-supersymmetric solutions in five-dimensional supergravity (Journal of High Energy Physics (2007) 12 (025))
No full text[No abstract available]Gutowski JB, 2007, J HIGH ENERGY PHYS11
Surjective isometries between unitary sets of unital JB∗-algebras
No full textWe would like to thank Prof. Lajos Molnár for encouraging us to explore this problem.
We are also indebted to the anonymous reviewer for several useful comments.
First and fifth authors partially supported by the Spanish Ministry of Science, Innovation and Universities (MICINN) and European Regional Development Fund project
no. PGC2018-093332-B-I00, Programa Operativo FEDER 2014-2020 and Consejería de
Economía y Conocimiento de la Junta de Andalucía grant numbers A-FQM-242-UGR18
and FQM375. First author partially supported by EPSRC (UK) project “Jordan Algebras, Finsler Geometry and Dynamics” ref. no. EP/R044228/1. Second author partially
supported by JSPS KAKENHI Grant Number JP 21J21512. Fourth author partially
supported by JSPS KAKENHI (Japan) Grant Number JP 20K03650.
* Funding for open access charge: Universidad de Granada / CBUAThis paper is, in a first stage, devoted to establishing a topological–algebraic characterization of the principal component, U0(M), of the set of unitary elements, U(M), in a unital JB⁎-algebra M. We arrive to the conclusion that, as in the case of unital C⁎-algebras, U0(M)=M1−1∩U(M)={Ue⋯Ue(1):n∈N,hj∈Msa∀1≤j≤n}={u∈U(M): there exists w∈U0(M) with ‖u−w‖<2} is analytically arcwise connected. Actually, U0(M) is the smallest quadratic subset of U(M) containing the set eiM. Our second goal is to provide a complete description of the surjective isometries between the principal components of two unital JB⁎-algebras M and N. Contrary to the case of unital C⁎-algebras, we shall deduce the existence of connected components in U(M) which are not isometric as metric spaces. We shall also establish necessary and sufficient conditions to guarantee that a surjective isometry Δ:U(M)→U(N) admits an extension to a surjective linear isometry between M and N, a conclusion which is not always true. Among the consequences it is proved that M and N are Jordan ⁎-isomorphic if, and only if, their principal components are isometric as metric spaces if, and only if, there exists a surjective isometry Δ:U(M)→U(N) mapping the unit of M to an element in U0(N). These results provide an extension to the setting of unital JB⁎-algebras of the results obtained by O. Hatori for unital C⁎-algebras.CBUAConsejería de Economía y Conocimiento de la Junta de Andalucía
A-FQM-242-UGR18, FQM375Ministerio de Ciencia, Innovación y UniversidadesEngineering and Physical Sciences Research Council
EP/R044228/1Universidad de GranadaMinisterio de Ciencia e InnovaciónJapan Society for the Promotion of Science JP 20K03650, JP 21J21512European Regional Development Fund
PGC2018-093332-B-I0
Flexible time–space network formulation and hybrid metaheuristic for conflict-free and energy-efficient path planning of automated guided vehicles
No full textOperations of Automated Guided Vehicles (AGVs) are desired to be more energy-efficient while maintaining high transport productivity, motivated by the green production requirements. This paper investigates a new energy-efficient planning problem for determining conflict-free paths of the AGVs in its transport roadmap. In this problem, the vehicle path and transport time in the roadmap are jointly optimized, based on a flexible time–space network (FTSN). We provide the mathematical problem formulation of the energy-efficient path planning problem. The resulting optimization problem is proved to be a non-convex mixed-integer nonlinear programming which is computationally intractable. We further propose a hybrid metaheuristic that integrates the genetic algorithm and estimation of the distribution algorithm to improve its computational efficiency. Numerical results show the effectiveness of the developed algorithm based on the FTSN framework, compared to the existing metaheuristics, the conventional path planning method, and a commercial solver. The proposed method has a wide application in improving energy use of material handling, providing a guiding significance on promoting cleaner production of flexible manufacturing systems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport Engineering and Logistic
Decoupling of genome size and sequence divergence in a symbiotic bacterium
No full textAuthor Posting. © American Society for Microbiology, 2000. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Journal of Bacteriology 182 (2000): 3867-3869, doi:10.1128/JB.182.13.3867-3869.2000.In contrast to genome size variation in most bacterial taxa, the small genome size of Buchnera sp. was shown to be highly conserved across genetically diverse isolates (630 to 643 kb). This exceptional size conservation may reflect the inability of this obligate mutualist to acquire foreign DNA and reduced selection for genetic novelty within a static intracellular environment.Financial support was provided by a National Institute of Health
postdoctoral training grant to J.J.W. (Center for Insect Science, University
of Arizona) and a National Science Foundation grant (DEB-
9815413) to N.A.M
Vertical transmission of biosynthetic plasmids in aphid endosymbionts (Buchnera)
No full textAuthor Posting. © American Society for Microbiology, 2001. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Journal of Bacteriology 183 (2001): 785-790, doi:10.1128/JB.183.2.785-790.2001.This study tested for horizontal transfer of plasmids among Buchnera aphidicola strains associated with
ecologically and phylogenetically related aphid hosts (Uroleucon species). Phylogenetic congruence of Buchnera
plasmid (trpEG and leuABC) and chromosomal (dnaN and trpB) genes supports strictly vertical long-term transmission
of plasmids, which persist due to their contributions to host nutrition rather than capacity for infectious
transfer. Synonymous divergences indicate elevated mutation on plasmids relative to chromosomal genes.This work was supported by a National Institutes of Health postdoctoral
training grant in Molecular Insect Science (Center for Insect
Science, University of Arizona) to J.J.W. and a National Science Foundation
grant (DEB-9815413) to N.A.M
Tn5 synaptic complex formation : role of transposase residue W450
No full textAuthor Posting. © American Society for Microbiology, 2008. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Journal of Bacteriology 190 (2008): 1484-1487, doi:10.1128/JB.01488-07.A series of Tn5 transposases (Tnp's) with mutations at the conserved amino acid position W450, which was structurally predicted to be important for synapsis, have been generated and characterized. This study demonstrates that W450 is involved in hydrophobic (and possibly aromatic) contacts within the Tnp monomer that negatively regulate synaptic complex formation.This work was supported by the NIH (grant no. GM50693) and the University of Wisconsin—Madison (grant no. WIS04792) and through the Evelyn Mercer Professorship in Biochemistry and Molecular Biology
Automatic extension of Gene Ontology with flexible identification of candidate terms
No full textThis is a pre-copy-editing, author-produced PDF of an article accepted for publication in Bioinformatics following peer review. The definitive publisher-authenticated version is available online at: http://bioinformatics.oxfordjournals.org/cgi/reprint/22/6/665Motivation: Gene Ontology (GO) has been manually developed to provide a controlled vocabulary for gene product attributes. It continues to evolve with new concepts that are compiled mostly from existing concepts in a compositional way. If we consider the relatively slow growth rate of GO in the face of the fast accumulation of the biological data, it is much desirable to provide an automatic means for predicting new concepts from the existing ones. Results: We present a novel method that predicts more detailed concepts by utilizing syntactic relations among the existing concepts. We propose a validation measure for the automatically predicted concepts by matching the concepts to biomedical articles. We also suggest how to find a suitable direction for the extension of a constantly growing ontology such as GO.This work was supported by MOST/KOSEF through AITrc
The potential of umbilical cord cells, autologous bone marrow stromal cells and autologous chondrocytes for bone and cartilage repair
No full textAimsTo evaluate the in vitro potential of umbilical cord(UC)-derived cells as an allogeneic cell source that could be used ‘off-the-shelf’ in orthopaedics for bone and cartilage regeneration. The study also assesses the in-vivo efficacy of cell therapy in orthopaedics for the formation of de novo bone, cartilage and integration of both.Methods- In vitro potential of cells isolated from the four structural layers of the umbilical cord were characterised according to the criteria of the International Society for Cellular Therapy (ISCT). The differentiation potentials of these cell preparations, particularly for bone and cartilage formation, were also evaluated to ascertain their efficacy as potential cell sources for orthopaedic regenerative medicine.- Efficacy of autologous bone marrow-derived mesenchymal stromal cells (BMSC) for new bone formation in vivo for patients with lower limb long bone nonunions were assessed with a self-controlled randomised trial.- Efficacy and structural outcome of simultaneous autologous bone plug graft to restore subchondral bone with Autologous Chondrocyte Implantation (ACI) were evaluated to identify the quality and integration of the repair cartilage with the subchondral bone, described as the ‘Osplug’ technique.- Efficacy of concurrent realignment with ACI in patients with underlying chondral defects and idiopathic varus or valgus malalignments of the knee joint were studied to ascertain the outcome of simultaneous correction of the mechanical axis in patients receiving biological repair of the cartilage.Results- Potential of UC-derived cells in bone and cartilage formation: Cell preparations from four structural regions of umbilical cord were isolated via an in vitro explant culture technique. Osteogenic differentiation in these cell preparations correlated with a significant rise in alkaline phosphatase activity in the culture medium of the differentiated cells, in comparison to their respective controls. Following chondrogenic differentiation, a considerable variation in metachromasia was noted with toluidine blue staining, although type II collagen immunostaining was predominantly absent except in one sample of cells from Wharton’s Jelly. Cells from all the four layers of UC also expressed surface markers according to the ISCT criteria for Mesenchymal Stem Cells (MSC). However, it did not conform to the recommended standards quantitatively on fluorometric analysis.- New bone formation in nonunion: There was absence of significant increase in new bone formation on the side of BMSC insertion in cases with nonunion of fracture. Four predictors of successful fracture union in this study were shorter in-vitro cell doubling times of patient’s BMSC, the absence of diabetes, younger age and fewer operative procedures to treat the nonunion before the trial intervention.- Bone and cartilage healing in osteochondral defects: Significant improvement in clinical and functional outcome was found at mid-term follow-up after concurrent bone graft and ACI to restore subchondral bone and cartilage. Integration of the grafted bone had a direct correlation with the clinical outcome in these patients.- Cartilage repair with realignment: Simultaneous ACI with correction of malalignment led to significant improvement in clinical outcome, particularly in patients with varus deformity. Patients with valgus deformity were noted to fail relatively early with poor outcome.ConclusionThe current thesis extends from exploring the in vitro potential of UC to the clinical application of autologous chondrocytes and BMSC for cartilage and bone regeneration. UCderived cells were noted to have properties akin to MSC with trilineage differentiation capacity. However, regeneration of new bone with BMSC in nonunions remains challenging. Nonetheless, significant clinical improvement was noted in patients receiving ACI with underlying malalignment and subchondral bone defect when treated with concurrent realignment and bone graft respectively. Further work on the immunomodulatory effect of UC-derived cells in addition to longer-term follow-up of the patients receiving cell-based therapy is required to consolidate our understanding of future cell therapy in orthopaedics
Control of CydB and GltA1 Expression by the SenX3 RegX3 Two Component Regulatory System of Mycobacterium tuberculosis
No full textThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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