On the properties of zeros of Bessel series in the real line

For a given sequence of real numbers (Formula presented.), we define the function (Formula presented.) where (Formula presented.), (Formula presented.) denotes the Bessel function of order µ, and (Formula presented.) are the positive zeros of  (Formula presented.). In this paper, we study the function (Formula presented.) and some outstanding instances of it on the whole real line and propose a number of conjectures about its positive zeros

TOY: A System for Experimenting with Cooperation of Constraint Domains

AbstractThis paper presents, from a user point-of-view, the mechanism of cooperation between constraint domains that is currently part of the system TOY, an implementation of a constraint functional logic programming scheme. This implementation follows a cooperative goal solving calculus based on lazy narrowing. It manages the invocation of solvers for each domain, and projection operations for converting constraints into mate domains via mediatorial constraints. We implemented the cooperation among Herbrand, real arithmetic (R), finite domain (FD) and set (S) domains. We provide two mediatorial constraints: The first one relates the numeric domains FD and R, and the second one relates FD and S

Spacetime symmetries of the Lorentz-violating Maxwell-Chern-Simons model

The spacetime symmetries of classical electrodynamics supplemented with a Chern-Simons term that contains a constant nondynamical 4-vector are investigated. In addition to translation invariance and the expected three remaining Lorentz symmetries characterized by the little group of the external vector, the model possesses an additional spacetime symmetry if the nondynamical vector is lightlike. The conserved current associated with this invariance is determined, and the symmetry structure arising from this invariance and the usual little group ISO(2) is identified as SIM(2).Comment: 5 pages, 1 table, REVTeX

Characterizing of steel used in the construction of civil works in Almería

Se realizaron varios ensayos sobre las barras de acero utilizadas en la construcción de obra civil en Almería, durante el período comprendido entre 18/1/2000 y 7/05/2001, con el fin de caracterizar, mecánicamente, los diferentes tipos de aceros (soldables: B400S, B500S y soldable dúctil: B400SD) y, de esta fonua, determinar si existe alguna razón técnica para un incremento del consumo del acero soldable dúctil. Para ello, se ensayaron a tracción todas las muestras que llegaron al laboratorio, siguiendo las normas UNE 7474-1: 1992 y UNE 7474-2:1992. Los resultados indican que el acero B400SD cumple, sólo, en un 86 % los límites especificados en la norma UNE 36065:1999 -EX, frente al 95 y 94 % de los aceros B400S y B500S. Además, el acero soldable dúctil muestra unos valores medios inferiores al B400S. Este hecho discrepa de lo que se podría esperar según la norma que lo regulaVarious tests have be en conducted on the steel bars used in the construction of civil works in Almería (Spain) during the period 18 ]anuary 2000-7 May 2001, with the aim of mechanically characterizing the different types of steel (weldable: B400S, B500S and ductile weldable: B400SD) to determine whether there is a technical reason for the increase in the use of ductile weldable steel. For this, we have used a hydraulic machine to break by traction all the test samples that arrived to the laboratory, following the specifications of the UNE 7474-1:1992 and the UNE 7474-2:1992. The results indicate that only in 86 % of the cases does the steel B400SD satisfy the limits specified by the UNE 36065:1999-EX, as opposed to 95 and 94 % of the B400S and B500S steels. In addition, the ductile weldable steel registered mean values lower than those of B400S. This finding disagrees with expectations set by the specifications

Intrinsic Moment of Inertia of Membranes as bounds for the mass gap of Yang-Mills Theories

We obtain the precise condition on the potentials of Yang-Mills theories in 0+1 dimensions and D0 brane quantum mechanics ensuring the discretness of the spectrum. It is given in terms of a moment of inertia of the membrane. From it we obtain a bound for the mass gap of any D+1 Yang-Mills theory in the slow-mode regime. In particular we analyze the physical case D=3. The quantum mechanical behavior of the theories, concerning its spectrum, is determined by harmonic oscillators with frequencies given by the inertial tensor of the membrane. We find a class of quantum mechanic potential polynomials of any degree, with classical instabilities that at quantum level have purely discrete spectrum.Comment: 12pages, Latex, minor changes, more explanatory comment

Factors affecting mortality of shearwaters stranded by light pollution

Every year and across the world, thousands of fledglings of different petrel species crash into human structures because they are disorientated by artificial lights during their first flights. As this phenomenon is rather predictable, rescue cam- paigns are organized to help birds to reach the ocean, but unfortunately, a low proportion gets hurt or dies. Despite the huge number of affected individuals, and the fact that the problem was detected a long time ago, little is known on this source of mortality. We have studied the factors (i.e. body condition, plumage development, fledging date and sex) influencing the mortality of Cory’s Shearwa- ter Calonectris diomedea fledglings stranded inland due to light pollution in Ten- erife (Canary Islands) during two consecutive breeding seasons (2009 and 2010). Late fledglings showed lower values of a body condition index than early ones. No sex biases were detected, neither considering stranded birds overall, nor for recov- ery dates or in the body condition of rescued fledglings. Our results indicate that late birds stranded by lights showing abundant down are more susceptible to fatal collisions and that the lights do not selectively kill birds with lower body condition indices. An enhancement of veterinary care should be done during the last part of the fledging period when more fatal collisions occur, especially focused on fledg- lings with abundant down. More research to determine why some individuals end up disoriented around artificial lights and others do not is urgently needed to minimize or prevent fallouts.Peer reviewe

Hydroformylation of synthetic naphtha catalyzed by a dinuclear gem-dithiolato-bridged rhodium(I) complex

This work focuses on the use of a gem-dithiolato-bridged rhodium(I) Rh 2(µ-S 2CBn 2)(cod) 2 complex (cod = 1,5-cyclooctadiene, Bn 2CS 2 2- = 1,3-diphenyl-2,2-dithiolatopropane) dissolved in toluene in the presence of monodentate phosphite P-donor ligand (P(OPh) 3) under carbon monoxide/hydrogen (1:1, syngas) atmosphere as an effective catalyst for hydroformylation of some olefins (oxo-reactions). The capability of this system to catalyze the hydroformylation of hex-1-ene, cyclohexene, 2,3-dimethyl-but-1-ene and 2-methyl-pent-2-ene and their quaternary mixture (synthetic naphtha) has been demonstrated. This innovative method to perform the in situ hydroformylation of the olefins present in naphthas to oxygenated products would be a promissory work for a future industrial catalytic process applicable to gasoline improving based on oxo-reactions. An important observation is that variation of CO/H 2 pressure (6.8-34.0 atm), temperature (60-80 oC), reaction time (2-10 h), rhodium concentration ((1.0-1.8)x10 -3 mol/L) affect hydroformylation reaction rates. Optimal conversion to oxygenated products were achieved under Rh = 1.8 x10 -2 mol/L, P(CO/H 2) = 34 atm (CO/H 2 = 1:1) at 80 oC for 10 h

Towards an in-plane methodology to track breast lesions using mammograms and patient-specific finite-element simulations

In breast cancer screening or diagnosis, it is usual to combine different images in order to locate a lesion as accurately as possible. These images are generated using a single or several imaging techniques. As x-ray-based mammography is widely used, a breast lesion is located in the same plane of the image (mammogram), but tracking it across mammograms corresponding to different views is a challenging task for medical physicians. Accordingly, simulation tools and methodologies that use patient-specific numerical models can facilitate the task of fusing information from different images. Additionally, these tools need to be as straightforward as possible to facilitate their translation to the clinical area. This paper presents a patient-specific, finite-element-based and semi-automated simulation methodology to track breast lesions across mammograms. A realistic three-dimensional computer model of a patient''s breast was generated from magnetic resonance imaging to simulate mammographic compressions in cranio-caudal (CC, head-to-toe) and medio-lateral oblique (MLO, shoulder-to-opposite hip) directions. For each compression being simulated, a virtual mammogram was obtained and posteriorly superimposed to the corresponding real mammogram, by sharing the nipple as a common feature. Two-dimensional rigid-body transformations were applied, and the error distance measured between the centroids of the tumors previously located on each image was 3.84 mm and 2.41 mm for CC and MLO compression, respectively. Considering that the scope of this work is to conceive a methodology translatable to clinical practice, the results indicate that it could be helpful in supporting the tracking of breast lesions

Supersymmetry from a braided point of view

We show that one-dimensional superspace is isomorphic to a non-trivial but consistent limit as $q\to-1$ of the braided line. Supersymmetry is identified as translational invariance along this line. The supertranslation generator and covariant derivative are obtained in the limit in question as the left and right derivatives of the calculus on the braided line.Comment: LateX file. 10 pages. To appear in Phys. Lett.

Establishing the relationship between cortical atrophy and semantic deficits in Alzheimer's disease and Mild Cognitive Impairment patients through Voxel-Based Morphometry

The aim of this study was to determine the brain areas responsible for the semantic impairment observed in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI) patients. Thirteen AD, 14 MCI patients, and 13 matched healthy older adults were assessed with a test battery aimed to study their semantic competence. Different subtasks were designed to study their semantic knowledge related to objects and faces in the context of semantic retrieval- and semantic association-dependent tasks. Aggregate scores obtained in the different tests were entered into voxel-based regression analyses with grey matter volume values obtained from three-dimensional brain MRI scans. Areas of significant correlation between volume loss and poor semantic scores were restricted to the temporal lobe in the AD group, while in the MCI and control groups significant associations were found with lower grey matter volume values in a widely distributed network of bilateral fronto-temporo-parietal regions. Our results suggest that degradation of partially overlapping and widely distributed neural networks, mainly including temporal regions, subserve semantic deficits related to objects and faces in AD and MCI patients