Artificial neural network algorithm for online glucose prediction from continuous glucose monitoring.

Background and Aims: Continuous glucose monitoring (CGM) devices could be useful for real-time management of diabetes therapy. In particular, CGM information could be used in real time to predict future glucose levels in order to prevent hypo-/hyperglycemic events. This article proposes a new online method for predicting future glucose concentration levels from CGM data. Methods: The predictor is implemented with an artificial neural network model (NNM). The inputs of the NNM are the values provided by the CGM sensor during the preceding 20 min, while the output is the prediction of glucose concentration at the chosen prediction horizon (PH) time. The method performance is assessed using datasets from two different CGM systems (nine subjects using the Medtronic [Northridge, CA] Guardian® and six subjects using the Abbott [Abbott Park, IL] Navigator®). Three different PHs are used: 15, 30, and 45 min. The NNM accuracy has been estimated by using the root mean square error (RMSE) and prediction delay. Results: The RMSE is around 10, 18, and 27 mg/dL for 15, 30, and 45 min of PH, respectively. The prediction delay is around 4, 9, and 14 min for upward trends and 5, 15, and 26 min for downward trends, respectively. A comparison with a previously published technique, based on an autoregressive model (ARM), has been performed. The comparison shows that the proposed NNM is more accurate than the ARM, with no significant deterioration in the prediction delay

Effects of in-plane magnetic fields on the electronic cyclotron effective mass and Landé factor in GaAs-(Ga,Al)As quantum wells

The dependence of the electron Landé g-factor on carrier confinement in quantum wells recently gained both experimental and theoretical interest. The g factor of electrons in GaAs-(Ga,Al)As quantum wells is of special interest, as it changes its sign at a certain value of the well width. In the present work, the effects of an in-plane magnetic field on the cyclotron effective mass and on the Landé g^-factor in single GaAs-(Ga,Al)As quantum wells are studied. Theoretical calculations are performed in the framework of the effective-mass and non-parabolic-band approximations. The Ogg-McCombe Hamiltonian is used for the conduction-band electrons in the semiconductor heterostructure, and the Landé g^-factor theoretically evaluated is found in good agrement with available experimental measurements.858861Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

On hidden broken nonlinear superconformal symmetry of conformal mechanics and nature of double nonlinear superconformal symmetry

We show that for positive integer values $l$ of the parameter in the conformal mechanics model the system possesses a hidden nonlinear superconformal symmetry, in which reflection plays a role of the grading operator. In addition to the even $so(1,2)\oplus u(1)$-generators, the superalgebra includes $2l+1$ odd integrals, which form the pair of spin-$(l+{1/2})$ representations of the bosonic subalgebra and anticommute for order $2l+1$ polynomials of the even generators. This hidden symmetry, however, is broken at the level of the states in such a way that the action of the odd generators violates the boundary condition at the origin. In the earlier observed double nonlinear superconformal symmetry, arising in the superconformal mechanics for certain values of the boson-fermion coupling constant, the higher order symmetry is of the same, broken nature.Comment: 8 pages; typos correcte

On the non-abelian superalgebra spanned by the conserved quantities of N=1 supersymmetric Korteweg-de Vries equation

We obtain an infinite sequence of bosonic non-local conserved quantities for the N=1 supersymmetric Korteweg-de Vries equation. It is generated from a bosonic non-local conserved quantity of Super Gardner equation. In distinction to the already known one with odd parity and dimension 1/2, it has even parity and dimension 1. It fits exactly in the supersymmetric cohomology in the space of conserved quantities that we also introduce here. Using results from this cohomology we obtain the Poisson bracket of several non-local conserved quantities, including the already known odd ones and the new even ones. The algebra closes in terms of polynomials of local and non-local conserved quantities. We prove that the bosonic non-local conserved quantities cannot be expressed as functions of the already known local and non-local conserved quantities of Super KdV equation.Comment: To be published in: Physics Letters A. 16 page

Superconformal mechanics and nonlinear supersymmetry

We show that a simple change of the classical boson-fermion coupling constant, $2\alpha \to 2\alpha n$, $n\in \N$, in the superconformal mechanics model gives rise to a radical change of a symmetry: the modified classical and quantum systems are characterized by the nonlinear superconformal symmetry. It is generated by the four bosonic integrals which form the so(1,2) x u(1) subalgebra, and by the 2(n+1) fermionic integrals constituting the two spin-n/2 so(1,2)-representations and anticommuting for the order n polynomials of the even generators. We find that the modified quantum system with an integer value of the parameter $\alpha$ is described simultaneously by the two nonlinear superconformal symmetries of the orders relatively shifted in odd number. For the original quantum model with $|\alpha|=p$, $p\in \N$, this means the presence of the order 2p nonlinear superconformal symmetry in addition to the osp(2|2) supersymmetry.Comment: 16 pages; misprints corrected, note and ref added, to appear in JHE

Fractional and integer stages of lithium ion-graphite systems: The role of electrostatic and elastic contributions

In the present work, we analyze the hot topic of integer and fractional stages of lithium-ion batteries by using Monte Carlo simulations. While fractional stages have been demonstrated through several experimental, simulation and theoretical measurements, in other experimental techniques, such as electrochemical ones, there is no evidence for them. In previous work, we have analyzed the thermodynamics and kinetics of lithium-ion intercalation using a potential based on empirical parameterization, where multiple stages (integer and fractional) were found and analyzed. The present simulations suggest that if we consider repulsive elastic interactions in addition to electrostatic ones, the Hamiltonian symmetry is broken and there is no evidence for fractional stages. The physical origin of these repulsive interactions is assigned to the increasing graphite layer separation during lithium-ion intercalation. In the light of these simulations, selected experimental data are revisited, validating the presented novel parameterization. The parametrization used here can be used for other kinds of intercalation compounds, such as those involving Na or K.Fil: Gavilán Arriazu, Edgardo Maximiliano. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Hümöller, Juan Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Pinto, Oscar Alejandro. Universidad Nacional de Santiago del Estero; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: De Mishima, B. A. López. Universidad Nacional de Santiago del Estero; ArgentinaFil: Leiva, Ezequiel Pedro M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Oviedo, Oscar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Impact and Learner Experience of a Technology Ecosystem as an Approach to Healthy Lifestyles: Erasmus+ SUGAPAS Project

The promotion of lifestyle habits in all ages is essential for the prevention of chronic non-communicable diseases. The aim of this study was to develop, validate, and disseminate an ecosystem that favors effective education on physical activity, a healthy lifestyle, and healthy nutritional habits. The sample consisted of 258 Spanish volunteer students. The evaluation of Ecosystem SUGAPAS was composed of two online surveys: MOOC and game surveys. The result of the MOOC survey reported a score above three points in all the sections (users’ opinion of the organization: 3.89 ± 0.71, 4.06 ± 0.64, and 4.01 ± 0.64; impact of the course on their day-to-day life: 3.62 ± 0.94; content present values: 3.96 ± 0.63, 3.69 ± 0.75, and 3.62 ± 0.94; usability of the platform: 3.75 ± 0.77, 3.96 ± 0.68, 4.06 ± 0.77, and 3.75 ± 0.84; relevance for professional development: 3.96 ± 0.63; overall opinion: 3.77 ± 0.57 points). The responses to all sections of the game evaluation reported a score between three and four points. A SUGAPAS ecosystem that includes new technologies for the promotion of a healthy lifestyle was developed, validated, and disseminated among the population. The users’ opinion, the impact of the ecosystem on their personal and professional development, and the usability of the platforms created make this ecosystem valid for its implementation for the proposed purposes

Kinetic Monte Carlo applied to the electrochemical study of the Li-ion graphite system

To delve deeper into the kinetics involved in the staging phenomena of lithium insertion into graphite, it is necessary to develop theoretical models that emulate the physical phenomenon involved. In the present work kinetic Monte Carlo simulations are used to carry out a thorough analysis of the Li-ion graphite system, with the twofold aim of providing atomistic support for interpretations based on several experimental electrochemical techniques commonly used in the laboratory and of making theoretical predictions for future experimental work. Cyclic voltammograms and chronoamperometric transients are obtained, and diffusion coefficients and exchange current densities are calculated at different Li loadings of graphite. These results are compared with selected experimental data from the literature. In this way, there emerge details that cannot be observed in ordinary experiments due to methodological/instrumental limitations. For example, it is found that chronoamperometric responses are different for intercalation and deintercalation, the latter being a faster process. The reason why these phenomena are different is revealed, supporting and widening experimental assumptions. The present results also suggest that the intrinsic hysteresis observed in experimental work (and in simulations) is due to kinetic factors.Fil: Gavilán Arriazu, Edgardo Maximiliano. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Teórica y Computacional; ArgentinaFil: Pinto, Oscar Alejandro. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: López de Mishima, Beatriz A.. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Barraco Diaz, Daniel Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Oviedo, Oscar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Leiva, Ezequiel Pedro M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin