Spatial structures and Information Processing in Nonlinear Optical Cavities

Tesis doctoral de la Universidad de las Islas Baleares y del Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC-CSIC).- Fecha de lectura: 05-02-2008.Nonlinear optics is the study of phenomena that occur as a consequence of the modification of the optical properties of a material by the presence of light. Such nonlinear e ects usually occur with high intensities of light, that can only be achieved with lasers. In fact, the beginning of nonlinear optics is often considered to be the experiment of Second Harmonic Generation by Franken and coworkers in 1961, shortly after the demonstration of the first working laser by Maiman in 1960.Esta tesis fué realizada en el Instituto de Fisica Interdisciplinar y Sistemas Complejos (IFISC, CSIC-UIB) y financiada por una beca FPU del Ministerio de Ciencia e Innovación.Peer reviewe

Optical Image Processing in Second-Harmonic Generation

The original publication is available at Springer website: http://www.springer.com/physics/optics/book/978-0-387-33818-7

Chaos-Based Optical Communications: Encryption Versus Nonlinear Filtering

7 pages, 8 figures.Several chaos encoding schemes codify the message in such a way that the mean value of the transmitted signal (carrier with the message) is different for bits “0” and “1”. We present a nonlinear filtering method that is able to detect very small changes in the mean value of a signal and therefore recover this kind of messages if its amplitude is larger than the chaotic fluctuations in the mean over the length of a bit.We also introduce a new codification method in which the mean value of the transmitted signal, over the length of each bit, is preserved and we show how it is able to beat the decryption scheme.This work was supported by MEC (Spain) and Feder under Projects TEC2006-1009/MIC (PhoDECC), TEC-2006-28105-E, and FIS2007-60327 (FISICOS); from EC Project PICASSO Grant IST-2005- 34551. The work of M. C. Soriano was supported by the MEC under a “Juan de la Cierva” contract.Peer reviewe

Solving Large Problem Sizes of Index-Digit Algorithms on GPU: FFT and Tridiagonal System Solvers

[Abstract] Current Graphics Processing Units (GPUs) are capable of obtaining high computational performance in scientific applications. Nevertheless, programmers have to use suitable parallel algorithms for these architectures and usually have to consider optimization techniques in the implementation in order to achieve said performance. There are many efficient proposals for limited-size problems which fit directly in the shared memory of CUDA GPUs, however, there are few GPU proposals that tackle the design of efficient algorithms for large problem sizes that exceed shared memory storage capacity. In this work, we present a tuning strategy that addresses this problem for some parallel prefix algorithms that can be represented according to a set of common permutations of the digits of each of its element indices [1], denoted as Index-Digit (ID) algorithms. Specifically, our strategy has been applied to develop flexible Multi-Stage (MS) algorithms for the Fast Fourier Transform (FFT) algorithm (MS-ID-FFT) and a tridiagonal system solver (MS-ID-TS) on the GPU. The resulting implementation is compact and outperforms other well-known and commonly used state-of-the-art libraries, with an improvement of up to 1.47x with respect to NVIDIA's complex CUFFT, and up to 33.2x in comparison with NVIDIA's CUSPARSE for real data tridiagonal systems

Implementación de una cola de prioridad con variables parametrizables para mejorar la QoS

This article presents the implementation of a priority queue with simulated parameterized components on the scenario of a banking institution in which four main elements were used: 1) the dispenser, 2) the cashier(s), 3) the server that receives and assigns the priority of the turns, and 4) a screen that displays the order of the turns. In any banking institution, there is always a large number of users that require attention, so they implement special turns to give priority to customers, improving the quality of service. One of the important elements within the cycle of service provision is related to the waiting lines, commonly called queues. Basically one queue is managed with the First-In, First-Out discipline. In this aspect, disciplines such as queuing theory help to understand the behavior of queues by examining all the components of the waiting lists. One of the most used disciplines for the management of a queue, is the enqueue with priority. In a priority queue, the element with the highest priority is removed before any other elements. The research was carried out using mainly a quantitative approach. The main goal of this type of research is the formulation and demonstration of theories and seeks that the studies carried out can be replicated. The algorithm implemented highly parameterizable allowed the correct simulation of a priority queue that can be taken as a basis for a subsequent application in any type of organization.Este artículo presenta la implementación de una cola de prioridad con componentes parametrizables simulada sobre el escenario de una institución bancaria en la cual se utilizaron cuatro elementos principales: 1) el dispensador de turnos, 2) el cajero(s) encargado de la atención, 3) el servidor que recibe y asigna la prioridad de los turnos, y 4) una pantalla que visualiza el orden de los turnos. En cualquier institución bancaria, siempre hay un gran número de usuarios que requieren atención, por lo que implementan turnos especiales para dar prioridad a los clientes, mejorando la calidad del servicio. Uno de los elementos importantes dentro del ciclo de provisión de servicios está relacionado con las líneas de espera, comúnmente llamadas colas. Básicamente una cola se gestiona con la disciplina First-In, First-Out. En este aspecto, disciplinas como la teoría de colas ayudan a comprender el comportamiento de las colas al examinar todos los componentes de las listas de espera. Una de las disciplinas más utilizadas para la gestión de una cola, es el encolado con prioridad. En una cola de prioridad, el elemento con la prioridad más alta se elimina antes que cualquier otro elemento. La investigación se realizó utilizando principalmente un enfoque cuantitativo. El objetivo principal de este tipo de investigación es la formulación y demostración de teorías y busca que los estudios realizados puedan replicarse. El algoritmo implementado altamente parametrizable permitió la correcta simulación de una cola de prioridad que puede tomarse como base para una aplicación posterior en cualquier tipo de organización

Development of Nano-Emulsions of Essential Citrus Oil Stabilized with Mesquite Gum

The use of nano-emulsions has great advantages over conventional macro-emulsions since the small droplet size allows to expand the options of applications besides presenting a greater surface area. This chapter focuses on the formulation of nano-emulsions of citrus essential oils in water, stabilized with a natural gum (mesquite gum), using a high pressure microfluidic homogenizer to obtain appropriate physicochemical characteristics and kinetic stability. When establishing the general conditions of the methods for obtaining nano-emulsions by high pressure homogenization, several formulations presented stability and size corresponding to nano-emulsions, and these were monitored during 4 months in order to study their stability as a function of time. Taking into account the results of size and stability, the best nano-emulsion obtained had a composition of Persian lemon oil (9.86%), mesquite gum (4.93%) Tween 80 (4.89%), Span 20 (1.45%), and deionized water (78.86%) with an average droplet size of 40 nm. In addition, the antibacterial activity studies also showed that this formulation had the best performance against common bacteria such as Staphylococcus aureus and Escherichia coli. The analysis of the minimum inhibitory concentration (MIC) shows that it is possible to prevent the growth of these particular bacteria using 6.25% of the best nano-emulsion formulations

Changes in malaria epidemiology in a rural area of Cubal, Angola

Scarce information about malaria epidemiology in Angola has been published. The objective of this study is to describe the epidemiology of malaria at the Hospital Nossa Senhora da Paz (Cubal, Angola) and the fatality rate due to malaria (total and in children under five years) in the last five years. A retrospective, observational study was performed at the Hospital Nossa Senhora da Paz, a 400-bed rural hospital located in Benguela Province of Angola. The study population included all patients who attended the hospital from January 2009 to December 2013. Outcome variables were calculated as follows: the percentage of malaria cases (number of positive thick blood films, divided by the total thick blood films performed); the percentage of in-patients for malaria (number of in-patients diagnosed with malaria, divided by the total number of in-patients); and, the fatality rate (number of deaths due to malaria divided by the number of positive thick blood films). Overall, 23,106 thick blood films were performed, of which 3,279 (14.2%) were positive for Plasmodium falciparum infection. During this five-year period, a reduction of 40% (95% CI 37-43%, p < 0.001) in the malaria-positive slides was detected. Distribution of positive-malaria slides showed a seasonal distribution with a peak from December to March (rainy season). An average annual reduction of 52% (95% CI 50-54%, p < 0.001) in the admissions due to malaria was observed. The overall fatality rate due to malaria was 8.3%, and no significant differences in the annual fatality rate were found (p = 0.553). A reduction in the number of malaria cases and the number of admissions due to malaria has been observed at the Hospital Nossa Senhora da Paz, during the last five years, and incidence along the study period showed a seasonal distribution. All this information could be useful when deciding which malaria control strategies have to be implemented in this area

NK Cell Subsets Changes in Partial Remission and Early Stages of Pediatric Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic metabolic disease characterized by the autoimmune destruction of β-cells in the pancreatic islets. T1D is preceded by islet-specific inflammation led by several immune cells. Among them, natural killer (NK) cells are emerging as important players in T1D development. Human NK cells are characterized by CD56 and CD16 expression, which allows classifying NK cells into four subsets: 1) CD56 dim CD16 + or effector NK cells (NK); 2) CD56 bright CD16 − or regulatory NK cells (NK); 3) intermediate CD56 bright CD16 + NK cells; and 4) CD56 dim CD16 − NK cells, whose function is not well determined. Since many studies have shown that T1D progression is associated with changes in various immune cell types, we hypothesize that the kinetics of NK cell subsets in the blood could correlate with different stages of T1D. To that aim, pediatric patients newly diagnosed with T1D were recruited, and peripheral NK cell subsets were analyzed by flow cytometry at several disease checkpoints: disease onset, partial remission (PR), 8 months (for non-remitters), and 12 months of progression. Our results showed that total NK cells and their four subsets are altered at the early stages of T1D. A decrease in the counts and percentage of total NK cells and NK cells at the different disease stages was found when compared to controls. These results suggest the extravasation of these cells into the islets at disease onset, which is maintained throughout the follow-up. By contrast, NK cells increased during the early stages after T1D onset, and both intermediate NK cells and CD56 dim CD16 - NK cells diminished at the PR stage, which might reflect the immunoregulatory attempts and could be candidate biomarkers for this stage. Also, CD56 dim CD16 - NK cells increased during T1D progression. Finally, changes in CD16 expression were identified in the different T1D stages, highlighting a CD16 expression reduction in total NK cells and NK cells 1 year after diagnosis. That may reflect a state of exhaustion after multiple cell-to-cell interactions. Altogether, our preliminary data provide a longitudinal picture of peripheral NK cell subpopulations during the different T1D stages, which could be potential candidate biomarkers indicators of disease progression

Ponavljajuća spontana disekcija koronarnih arterija u bolesnice srednje životne dobi

SUMMARY Spontaneous coronary dissection is an infrequent but well-described cause of acute myocardial infarction. It is associated with women of reproductive age or patients with fibromuscular dysplasia. Treatment consists of controlling cardiovascular risk factors, vasodilators, and beta-blockers. We present a case of 48-year-old patient with myocardial infarction secondary to spontaneous dissection and recurrence due to disease extension at a later stage.SAŽETAK Spontana disekcija koronarnih arterija rijedak je, ali dobro poznat uzrok akutnog infarkta miokarda. Češća je u žena reproduktivne dobi i u bolesnika s fibromuskularnom displazijom. Liječenje se sastoji od kontrole čimbenika kardiovaskularnog rizika te primjene vazodilatatora i beta-blokatora. Predstavljamo slučaj 48-godišnje bolesnice s infarktom miokarda uzrokovanim spontanim disekcijom i ponovnom pojavom bolesti zbog njezina širenja u kasnijemu stadiju