Energy consumption for ion transport in a segmented Paul trap

There is recent interest in determining energy costs of shortcuts to adiabaticity (STA), but different definitions of "cost" have been used. We demonstrate the importance of taking into account the Control System (CS) for a fair assessment of energy flows and consumptions. We model the energy consumption and power to transport an ion by a STA protocol in a multisegmented Paul trap. The ion is driven by an externally controlled, moving harmonic oscillator. Even if no net ion- energy is gained at destination, setting the time-dependent control parameters is a macroscopic operation that costs energy and results in energy dissipation for the short time scales implied by the intrinsically fast STA processes. The potential minimum is displaced by modulating the voltages on control (dc) electrodes. A secondary effect of the modulation, usually ignored as it does not affect the ion dynamics, is the time- dependent energy shift of the potential minimum. The non trivial part of the energy consumption is due to the electromotive forces to set the electrode voltages through the low-pass filters required to preserve the electronic noise from decohering the ion's motion. The results for the macroscopic CS (the Paul trap) are compared to the microscopic power and energy of the ion alone. Similarities are found -and may be used quantitatively to minimize costs- only when the CS-dependent energy shift of the harmonic oscillator is included in the ion energy

Design and energy consumption of invariant based shortcuts to adiabaticity

140 p.Esta tesis consta de dos ramas de investigación. La primera se centra en el diseño de operaciones para controlar los sistemas cuánticos basándose en los atajos a la adiabaticidad. La otra rama es el análisis del consumo energético en estas operaciones, y en particular, cómo afecta ese coste al rendimiento de los motores cuánticos

Design and energy consumption of invariant based shortcuts to adiabaticity

140 p.Esta tesis consta de dos ramas de investigación. La primera se centra en el diseño de operaciones para controlar los sistemas cuánticos basándose en los atajos a la adiabaticidad. La otra rama es el análisis del consumo energético en estas operaciones, y en particular, cómo afecta ese coste al rendimiento de los motores cuánticos

A network-based approach for predicting key enzymes explaining metabolite abundance alterations in a disease phenotype

<p>Background The study of metabolism has attracted much attention during the last years due to its relevance in various diseases. The advance in metabolomics platforms allows us to detect an increasing number of metabolites in abnormal high/low concentration in a disease phenotype. Finding a mechanistic interpretation for these alterations is important to understand pathophysiological processes, however it is not an easy task. The availability of genome scale metabolic networks and Systems Biology techniques open new avenues to address this question.</p> <p>Results In this article we present a novel mathematical framework to find enzymes whose malfunction explains the accumulation/depletion of a given metabolite in a disease phenotype. Our approach is based on a recently introduced pathway concept termed Carbon Flux Paths (CFPs), which extends classical topological definition by including network stoichiometry. Using CFPs, we determine the Connectivity Curve of an altered metabolite, which allows us to quantify changes in its pathway structure when a certain enzyme is removed. The influence of enzyme removal is then ranked and used to explain the accumulation/depletion of such metabolite. For illustration, we center our study in the accumulation of two metabolites (L-Cystine and Homocysteine) found in high concentration in the brain of patients with mental disorders. Our results were discussed based on literature and found a good agreement with previously reported mechanisms. In addition, we hypothesize a novel role of several enzymes for the accumulation of these metabolites, which opens new strategies to understand the metabolic processes underlying these diseases.</p> <p>Conclusions With personalized medicine on the horizon, metabolomic platforms are providing us with a vast amount of experimental data for a number of complex diseases. Our approach provides a novel apparatus to rationally investigate and understand metabolite alterations under disease phenotypes. This work contributes to the development of Systems Medicine, whose objective is to answer clinical questions based on theoretical methods and high-throughput “omics” data.</p&gt

Shortcut to Equilibration of an Open Quantum System

We present a procedure to accelerate the relaxation of an open quantum system towards its equilibrium state. The control protocol, termed Shortcut to Equilibration, is obtained by reverse-engineering the non-adiabatic master equation. This is a non-unitary control task aimed at rapidly changing the entropy of the system. Such a protocol serves as a shortcut to an abrupt change in the Hamiltonian, i.e., a quench. As an example, we study the thermalization of a particle in a harmonic well. We observe that for short protocols there is a three orders of magnitude improvement in accuracy

High-Resolution NMR Spectroscopy at Large Fields with Nitrogen Vacancy Centers

Ensembles of nitrogen-vacancy (NV) centers are used as sensors to detect NMR signals from micron-sized samples at room temperature. In this scenario, the regime of large magnetic fields is especially interesting as it leads to a large nuclear thermal polarisation -- thus, to a strong sensor response even in low concentration samples -- while chemical shifts and J-couplings become more accessible. Nevertheless, this regime remains largely unexplored owing to the difficulties to couple NV-based sensors with high-frequency nuclear signals. In this work, we circumvent this problem with a method that maps the relevant energy shifts in the amplitude of an induced nuclear spin signal that is subsequently transferred to the sensor. This stage is interspersed with free-precession periods of the sample nuclear spins where the sensor does not participate. Thus, our method leads to high spectral resolutions ultimately limited by the coherence of the nuclear spin signal.Comment: 6 pages, 3 figure

Analysis of cardiac response of soccer referees in competition: a case study

][Resumen] Los objetivos de este estudio fueron, por un lado, examinar la respuesta cardiaca de un árbitro de fútbol tanto durante un test de campo incremental como durante dos partidos en un torneo nacional de categoría cadete, y por otro lado, determinar las zonas de intensidad del árbitro durante los partidos atendiendo a su FCmax individual. Un árbitro de fútbol de categoría nacional fue equipado con un pulsómetro (Polar Electro Oy, Kempele, Finlandia) y su FC fue monitorizada durante la realización del Yo-Yo de recuperación intermitente nivel 1 (YYIR1) y durante dos partidos de un Torneo de Fútbol de categoría cadete. Las zonas de intensidad se establecieron atendiendo a la clasificación de Edwards (1993). La FCmax obtenida en el YYIR1 y en los partidos fue de 178 ppm y 161 ppm, respectivamente. Durante los partidos la FCmed registrada fue de 127 ± 1,03 ppm que corresponde a un 71,3% de la FCmax obtenida en el YYIR1. La distribución de la frecuencia cardiaca atendiendo a las zonas establecidas es la siguiente: 10 ± 1,95% (zona 1), 32 ± 1,65% (zona 2), 38 ± 5,14% (zona 3), 19 ± 4,31% (zona 4) y 1 ± 0,53% (zona 5). Los resultados obtenidos nos muestran que la FC más alta alcanzada en partidos de categoría cadete es inferior a la alcanzada en el YYIR1. Además, se observa que la carga interna, medida mediante FC obtenida en partidos, es inferior a la reportada en otros estudios con árbitros en partidos de categoría sénior[Abstract] The aims of this study were: at first, to examine the cardiac response of an soccer referee both during an incremental field test and during two matches in a national Tournament Under 16 (U16), and secondly, to identify the different intensities of the soccer referee during the matches attending to his maximal heart rate (HRmax). A soccer referee of national competitive-level was equipped with a heart rate monitor (Polar Electro Oy, Kempele, Finland) and the HR was monitored during the Yo-Yo intermittent recovery level 1 (YYIR1) and during two matches of U16 National Tournament. The intensities were established attending to Edwards classification (1993). The average of HR (HRav) obtained in the YYIR1 and in the matches was 178 bpm and 161 bpm, respectively. HRav registered during matches was 127 ± 1.03 bpm approximately at 71.3% of FCmax obtained in the YYIR1. The percentage of time spent at different intensities during the matches was: 10 ± 1.95% (zone 1), 32 ± 1.65% (zone 2), 38 ± 5.14% (zone 3), 19 ± 4.31% (zone 4) y 1 ± 0.53% (zone 5). Our findings show that the highest HR reached during matches, is lower than HRmax registered during the YYIR1. Likewise, we can observe that internal match load, measured as a FC obtained during matches, is lower than the results of other studies during senior competitive-level matches