A Version of James' Theorem for Numerical Radius

We prove that if all the rank-one bounded operators on a Banachspace X attain their numerical radii, then X must be reflexive,but the converse does not hold. In fact, every reflexive spacewith basis can be renormed in such a way that there is a rank-oneoperator not attaining the numerical radius. 1991 MathematicsSubject Classification 47A12, 46B10.     

Effect of Sample Pre-Contact on the Experimental Evaluation of Cartilage Mechanical Properties

Mechanical characterization of articular cartilage has been widely analyzed in the literature, both experimentally and numerically, since load support (strength) and deformability (compliance) are among the most important physiological functions of this living tissue. They are also important indicators of cartilage degradation and regeneration. Cartilage elastic properties (Young’s Modulus, Aggregate Modulus and Poisson ratio) are usually determined experimentally by uniaxial confined and unconfined compression tests. Relevant differences can be found in the literature for these variables even when similar experimental protocols are used. Before starting the actual compression test, a pre-contact protocol has to be carried out in order to obtain optimum contact between the test tool and the cartilage sample. The aim of this work is to analyze the effect of sample pre-contact on the test results comparing three different protocols available in the literature (predeformation of 4 and 10 % of the total thickness of the sample and a preload equivalent to 12.5 KPa). The implementation of these protocols achieved contact, but only the predeformation allowed normalized experiments and ensured repeatability of the tests. Additionally, under the predeformation protocols, the results and trends for uniaxial compression tests were consistent with the cartilage physiological function. However, for 10 % predeformation, the experimental data showed maximum dispersion at the final stress levels. The statistical treatment determined significant differences between the 10 % predeformation and the preload results (Aggregate Modulus and Poisson ratio), defining them as non comparable protocols. Finally, a new pre-contact protocol is proposed introducing an initial approximation point between the test tool and the cartilage sample, and followed by a predeformation of 4 % for confined and unconfined tests.     

Mechanism of the OH–propene–O2 reaction: An ab initio study

The reaction of OH radicals with olefins is known to be important in atmospheric chemistry. From experimental data a global mechanism has been proposed, but the regioselectivity of the products is uncertain. In this work, the OH–propene–O₂ reaction has been studied with ab initio molecular orbital techniques. Reactants, transition structures, intermediate species and products are optimized at the UMP2/6‐31G** level for the two possible addition paths. In the first step, OH adducts are obtained with the OH radical linked to either the terminal or the central C atoms. Consideration of the second step, the addition of O₂, is required to explain the observed experimental data. The selectivity of the total reaction is found to be temperature and pressure dependent, but independent of the preferred site for the OH attack. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet: 31: 29–36, 1999     

Large deviations for empirical measures of Markov chains

In this paper we obtain large-deviation upper and lower bounds for the empirical measure of a Markov chain with general state space, as well as for the associated multivariate empirical measure and empirical process. In each of these instances we improve in various ways the results in the literature.     

Search for large extra dimensions in the production of jets and missing transverse energy in pp collisions at square root of s = 1.96 TeV

We present the results of a search for new physics in the jets plus missing transverse energy data sample collected from 368 pb(-1) of pp collisions at square root of s = 1.96 TeV recorded by the Collider Detector at Fermilab. We compare the number of events observed in the data with a data-based estimate of the standard model backgrounds contributing to this signature. We observe no significant excess of events, and we interpret this null result in terms of lower limits on the fundamental Planck scale for a large extra dimensions scenario.     

Dicopper(II) Anthraquinophanes as Multielectron Reservoirs for Oxidation and Reduction: A Joint Experimental and Theoretical Study

Two new dinuclear copper(II) metallacyclophanes with 1,4‐disubstituted 9,10‐anthraquinonebis(oxamate) bridging ligands are reported that can reversibly take and release electrons at the redox‐active ligand and metal sites, respectively, to give the corresponding mono‐ and bis(semiquinonate and/or catecholate) Cu^II₂ species and mixed‐valent Cu^II/Cu^III and high‐valent Cu^III₂ ones. Density functional calculations allow us to give further insights on the dual ligand‐ and metal‐based character of the redox processes in this novel family of antiferromagnetically coupled di‐ copper(II) anthraquinophanes. This unique ability for charge storage could be the basis for the development of new kinds of molecular spintronic devices, referred to as molecular magnetic capacitors (MMCs).     

Sodium dodecyl sulfate free gel electrophoresis/electroelution sorting for peptide fractionation

Shotgun proteomics based on peptide fractionation by using liquid chromatography has become the common procedure for proteomic studies, although in the very beginning of the field, protein separation by using electrophoresis was the main tool. Nonetheless, during the last two decades, the electrophoretic techniques for peptide mixtures fractionation have evolved as a result of relevant technological improvements. We also proposed the combination of sodium dodecyl sulfate polyacrylamide gel electrophoresis for protein fractionation and sodium dodecyl sulfate free polyacrylamide gel electrophoresis for peptide separation as a novel procedure for proteomic studies. Here, we present an optimized device for sodium dodecyl sulfate free polyacrylamide gel electrophoresis improving peptide recoveries respect to the established electrophoretic technique off gel electrophoresis meanwhile conserving the excellent resolution described for the former technique in slab gel based systems. The device simultaneously allows the separation and the collection of fractionated peptides in solution.     

A multilinear Lindenstrauss theorem

We show that the set of N-linear mappings on a product of N Banach spaces such that all their Arens extensions attain their norms (at the same element) is norm dense in the space of all bounded N-linear mappings.     

Predictive modeling in a steelmaking process using optimized relevance vector regression and support vector regression

Annals of Operations Research - The existence of contaminants in metal alloys products is the main problem affecting the product quality, which is an important requirement for competitiveness in...