2,016 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
Assessment of jugular bulb variability based on 3D surface models: quantitative measurements and surgical implications.
No full textPURPOSE
High-riding jugular bulbs (JBs) among other anatomical variations can limit surgical access during lateral skull base surgery or middle ear surgery and must be carefully assessed preoperatively. We reconstruct 3D surface models to evaluate recent JB classification systems and assess the variability in the JB and surrounding structures.
METHODS
3D surface models were reconstructed from 46 temporal bones from computed tomography scans. Two independent raters visually assessed the height of the JB in the 3D models. Distances between the round window and the JB dome were measured to evaluate the spacing of this area. Additional distances between landmarks on surrounding structures were measured and statistically analyzed to describe the anatomical variability between and within subjects.
RESULTS
The visual classification revealed that 30% of the specimens had no JB, 63% a low JB, and 7% a high-riding JB. The measured mean distance from the round window to the jugular bulb ranges between 3.22 ± 0.97 mm and 10.34 ± 1.41 mm. The distance measurement (error rate 5%) was more accurate than the visual classification (error rate 15%). The variability of the JB was higher than for the surrounding structures. No systematic laterality was found for any structure.
CONCLUSION
Qualitative analysis in 3D models can contribute to a better spatial orientation in the lateral skull base and, thereby, have important implications during planning of middle ear and lateral skull base surgery
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
Mastoid Emissary Vein Canal Incidence and Its Relationship with Jugular Bulb and Sigmoid Sulcus Anatomical Variations
No full textObjective:We aimed to investigate the mastoid emissary vein (MEV) canal incidence and to identify its relationship with jugular bulb (JB) and sigmoid sulcus anatomical variations.Methods:We retrospectively reviewed 1,300 patients with temporal bone computed tomography (CT) scans in January 2016 to March 2020. The presence and the diameter of the MEV canal, and the anatomical variations of the sigmoid sulcus and the JB were reviewed by two radiologists. High riding JB, JB diverticulum, dehiscent JB, and anterior and lateral protrusion of the sigmoid sulcus were evaluated. All variables were summarized using descriptive statistics. The differences between the groups for categorical data were investigated using the chi-square test. Numeric variables were compared with the Mann-Whitney and the Kruskal-Wallis tests. Logistic regression models were constructed.Results:The study included 1,269 patients of whom 694 were female (54.7%) and 575 were male (45.3%). Their mean age was 39.01±18.47. Among them 915 (72.1%) had the right and 871 (68.6%) had the left MEV canal. Men were more likely to have the MEV canal on both sides. The presence of the right and left MEV canals was associated with the ipsilateral dominant JB/sigmoid sulcus. The left MEV canal was associated with the left high riding JB and right dehiscent JB.Conclusion:This is the largest patient population reported in the literature and allows a more precise estimate of the MEV canal incidence. We also classified the diameter of the MEV canal to identify clinically relevant, prominent MEV incidence. This is also the first study to demonstrate a relationship between the presence of the MEV canal, and the JB and sigmoid canal variations. Since both the prominent MEV and the JB variations may be symptomatic, knowing this association between them may have clinical relevance
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
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