Sampling Theorem and Discrete Fourier Transform on the Hyperboloid

Using Coherent-State (CS) techniques, we prove a sampling theorem for holomorphic functions on the hyperboloid (or its stereographic projection onto the open unit disk $\mathbb D_1$), seen as a homogeneous space of the pseudo-unitary group SU(1,1). We provide a reconstruction formula for bandlimited functions, through a sinc-type kernel, and a discrete Fourier transform from $N$ samples properly chosen. We also study the case of undersampling of band-unlimited functions and the conditions under which a partial reconstruction from $N$ samples is still possible and the accuracy of the approximation, which tends to be exact in the limit $N\to\infty$.Comment: 22 pages, 2 figures. Final version published in J. Fourier Anal. App

Tuning ubiquinone position in biomimetic monolayer membranes

Artificial lipid bilayers have been extensively studied as models that mimic natural membranes (biomimetic membranes). Several attempts of biomimetic membranes inserting ubiquinone (UQ) have been performed to enlighten which the position of UQ in the lipid layer is, although obtaining contradictory results. In this work, pure components (DPPC and UQ) and DPPC:UQ mixtures have been studied using surface pressure-area isotherms and Langmuir-Blodgett (LB) films of the same compounds have been transferred onto solid substrates being topographically characterized on mica using atomic force microscopy and electrochemically on indium tin oxide slides. DPPC:UQ mixtures present less solid-like physical state than pure DPPC indicating a higher-order degree for the latter. UQ influences considerably DPPC during the fluid state, but it is mainly expelled after the phase transition at ˜˜ 26 mN·m^-1 for the 5:1 ratio and at ˜˜ 21 mN·m^-1 for lower UQ content. The thermodynamic studies confirm the stability of the DPPC:UQ mixtures before that event, although presenting a non-ideal behaviour. The results indicate that UQ position can be tuned by means of the surface pressure applied to obtain LB films and the UQ initial content. The UQ positions in the biomimetic membrane are distinguished by their formal potential: UQ located in “diving” position with the UQ placed in the DPPC matrix in direct contact with the electrode surface ( -0.04±0.02 V), inserted between lipid chains without contact to the substrate ( 0.00±0.01 V) and parallel to the substrate, above the lipid chains ( 0.09±0.02 V).Peer ReviewedPostprint (author's final draft

A Combined Clinical and Langmuir Film Study of Natural Tear Films

The Langmuir technique has been applied to the study of natural tears and the results obtained from surface pressure-area isotherms have been correlated with those of clinical tests (the Schirmer and the TFBUT tests). The population studied only included people aged over 45. Natural tears were collected from Schirmer strips, which were placed in contact with the water subphase of a Langmuir trough for recording the surface pressure-area isotherms. These isotherms have been classified as good or weak according to the characteristics obtained. From the isotherms, characteristic values such as plimit, CS-1max and pmax were also obtained. The analysis from the Chi-squared test indicates dependence between the Schirmer test and the type of isotherms (P0.05 indicates that the independence cannot be discarded with the significance criteria imposed. Working with the same criteria of significance, we obtain moderate or good Pearson correlation coefficients with statistical significance (P0.05) between the values of the TFBUT test and the plimit, CS-1max and pmax values.Peer ReviewedPostprint (published version

Prototype of a GBAS ground station. Implementation of the differential corrections according to CAT I MOPS ED-114

The accuracy that GNSS and GBAS can provide is the key to improve air traffic where bottlenecks appear: terminal areas surrounding main airports. Its implementation would represent lower budgets in cost and maintenance in comparison to current guidance systems that would remain as backup. This project focuses on processing raw satellite data and producing a standard output to increase air traffic navigation, approach and landing capacities in terminal areas. This involves tasks such as algorithm prototyping in Matlab and -integrity monitoring testing- with bad ephemeris data to check the output response. The impact of known errors will be analyzed to obtain a robust and scalable system. The next step will be the GBAS message codification and generation (Type 1) for a GBAS station. This station will be made up of four reference receivers located in the proximity of airport's Runways to accomplish CAT (I) requirements and provide the best measurements in approach and landing maneuvers. The project is located in the base of an ambitious bigger scheme (CATGOS) under development by Indra, which aims to implement and certificate a GBAS station for an airport environment in a four-year prospect

“Zombie attack” a new way to teach Chemistry

The Higher Education requires new models which allow training people able to adapt and survive in changing environments. It is based on the use of technologies and the adaptation of knowledge to people. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people. One of the main difficulties that lecturers find in the classroom is how to maintain students' attention and interest in their subject, especially when students also think that the subject is not important for their training. In order to motivate these students, innovation in educational techniques and methodologies, such as experiential learning, are progressively being imposed to and/or coordinated with the traditional ones. Escape Room is a very modern concept in education, based on the development of mental skills for the solution of enigmas and problems. It is a tool to develop the cooperative, cognitive, deductive and logical reasoning skills of the students. In this work, an educational gamification experience based on the escape room concept is presented. The students have 1 hour and 30 minutes to carry out this activity. They will have to solve four puzzles and enigmas that will give them the key to open a treasure chest and finally let them escape from the classroom. Logic, ingenuity and teamwork will allow participants to develop not only chemical competence, but also other basic skills. The story that is told throughout the escape room is a zombie attack: the city has been infected (with a virus) and only the occupants of the room where the activity takes place have not been infected. In addition, they can all protect themselves if they are able to open the chest where the antidote is located. The aim of this activity is to enhance the knowledge acquired throughout the semester as well as the development of skills.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Control de agarre y posicionamiento en una plataforma robot con sensores táctiles

En este artículo se presenta una plataforma formada por un brazo robot de 5 grados de libertad y una pinza robot de 1 sólo grado de libertad, con superficies táctiles. Este sistema obtiene, en tiempo real, las distribuciones de presión cuando un objeto ha sido agarrado, produciendo una realimentación del control de la posición y fuerza