Uso de hardware gráfico para la aceleración de métodos algebraicos de recontrucción

El objetivo de este proyecto ha sido implementar un algoritmo de reconstrucción algebraica (en paricular SART, Simultaneous Algebraic Reconstruction Technique) y acelerar su ejecución utilizando los recursos paralelos que ponen a disosición del programador las unidades de procesamiento gráfico de hoy en día. Para ello, primero se han desarrollado dos variantes del algoritmo que sólo utilizan la CPU, en las que nos hemos basado para posteriormente portar a la GPU las partes susceptibles de obtener una mejora substancial de velocidad. Por último, se ha analizado en ambas variantes la calidad de la reconstrucciones y el spedup obtenido respecto a las implementaciones en CPU, así como el impacto en la calidad de los diversos parámetros configurables del algoritmo. [ABSTRACT] The aim of our project has been the implementation of an algebraic reconstrution algorithm (known as SART, Simultaneous Algebraic Reconstruction Technique) and improvement of its running time by making use of the massively parallel computational resources which today's graphics processing units provide the programmer with. To this end, two variants of the algorithm have first been developed which are executed entirely on the CPU, and upon whch we have based our subsequent porting to the GPU of those parts having the potencial to enjoy a subsancial increase in speed. Finally, the quality of both variants' reconstructions has been analyzed, along with the speedup obtained over CPU implementations and the impact that various customizable parameters of the algorithm have on image quality

Finding Densest kk-Connected Subgraphs

Dense subgraph discovery is an important graph-mining primitive with a variety of real-world applications. One of the most well-studied optimization problems for dense subgraph discovery is the densest subgraph problem, where given an edge-weighted undirected graph $G=(V,E,w)$, we are asked to find $S\subseteq V$ that maximizes the density $d(S)$, i.e., half the weighted average degree of the induced subgraph $G[S]$. This problem can be solved exactly in polynomial time and well-approximately in almost linear time. However, a densest subgraph has a structural drawback, namely, the subgraph may not be robust to vertex/edge failure. Indeed, a densest subgraph may not be well-connected, which implies that the subgraph may be disconnected by removing only a few vertices/edges within it. In this paper, we provide an algorithmic framework to find a dense subgraph that is well-connected in terms of vertex/edge connectivity. Specifically, we introduce the following problems: given a graph $G=(V,E,w)$ and a positive integer/real $k$, we are asked to find $S\subseteq V$ that maximizes the density $d(S)$ under the constraint that $G[S]$ is $k$-vertex/edge-connected. For both problems, we propose polynomial-time (bicriteria and ordinary) approximation algorithms, using classic Mader's theorem in graph theory and its extensions

Immersive virtual reality to visualise the visible and infrared layer of a medieval altarpiece

[EN] This article describes the conception, development and implementation process of an interactive, immersive virtual reality experience for a museum environment, which allows viewers to virtually explore the 'Retablo de San Jorge del Centenar de la Ploma' in detail and in its entirety. This altarpiece is a pivotal work in the International Valencian Gothic style. It is also an example of Relocated Heritage, which has belonged to the Victoria & Albert Museum in London since 1864. Currently, it is exhibited there in the room housing the Raphael Cartoons. The fact that it is impossible to physically view this work in the Museo de Bellas Artes de Valencia along with other medieval Valencian Gothic altarpieces has motivated the creation of this virtual reality experience. This will enable researchers and visitors interested in this period to virtually examine the work. To produce this experience, different data-gathering technology has been used, such as visible and infrared radiation, photogrammetry and computer design programs like Blender and Unreal Engine. For the viewing, high-range computer equipment and virtual reality headsets have been implemented, which totally immerse the user in the created environment. In this experience, the viewer is taken on an aerial tour of virtually reconstructed 15th century Valencia and finally brought to the altarpiece, where a close examination can be made. This examination implements both the visible light spectrum and that of infrared radiation, enabling the contemplation of the iconography of each of its scenes and characters and the detailed study of the techniques used in the creative process of this emblematic altarpiece.Authors would like to thank the Victoria & Albert Museum - Research project by the Generalitat Valenciana titled: 'The International Valencian Gothic. The altarpiece of Saint George of Centenar de la Ploma and other related key works for study, scientific analysis and/or identification of the authors' (GV/2018/154) - Generalitat Valenciana (Presidencia de GVA - Direccion General de Patrimonio -IVCR+i) and Pascual Merce professional photographer, for the realization of the infrared photography.García, G.; Saiz Mauleón, MB.; Contreras, G.; Juanes, D.; Soriano, A. (2020). Immersive virtual reality to visualise the visible and infrared layer of a medieval altarpiece. European Journal of Science and Theology. 16(3):165-178. http://hdl.handle.net/10251/165726S16517816

Method of Moments Optimization of Distributed Raman Amplification in Fibers with Randomly Variying Birefringence

In this work, we develop a vectorial model, for optical communications, using distributed Raman amplification (DRA) applied to vectorial soliton pulses in monomode fiber optics. The main result, a dependent polarization effective Raman gain coefficient, is calculated considering the random birefringence character of the fiber and the relative mismatch between the continuous wave (CW) pump and the signal. The Method of Moments allows the determination of the optimal initial conditions to achieve a better performance in our system. With these starting values, the simulations carried out with the Split-Step Fourier Method (SSFM) elucidate the influence of the peak power and prechirping initial phase control on the vectorial soliton propagation

Efficient on-axis SLM engineering of optical vector modes

This work presents a method for the efficient experimental generation of arbitrary polarized vector beam modes. The optical system employs two liquid-crystal on silicon (LCOS) spatial light modulators (SLM) in a common path architecture, avoiding the use of beam-splitters. Each SLM displays a different phase-only mask, each one encoding a different pattern onto two orthogonal linear polarization components of the input beam. These phase-only masks are designed using a recently proposed random technique to encode complex amplitude values. This encoding technique reconstructs the complex function on-axis, thus avoiding incorporating carrier phases. By addressing such properly designed phase-only holograms we demonstrate arbitrary scalar modes on each polarization component, whose superposition results in a vector beam mode. Different superpositions of Laguerre–Gaussian and Hermite–Gaussian modes are obtained and the generated vector beam modes are analyzed. Moreover, the addition of a phase-bias proves itself useful to perform a phase-shifting technique in order to evaluate the correct phase of the generated vector beam

Inventario Clark-Beck de Obsesión-Compulsión (C-BOCI) : validación para su uso en población española

The Clark-Beck Obsessive-Compulsive Inventory (C-BOCI) is a recent self-administered inventory (Clark y Beck, 2002), designed to offer a valid, specific and reliable tool for the screening of Obsessive-Compulsive Disorder (OCD): it assesses symptoms and their consequences, and takes into account the assumptions of current cognitive models about the disorder.  The aim of this study has been to examine the usefulness of the C-BOCI in a Spanish population. The questionnaire was completed together with other OCD, depression, and anxiety instruments by 506 adults without mental disorders and 44 OCD patients. The α values were ≥0.80 except for the obsessions subscale in the clinical sample. Concurrent and discriminant validity were adequate, especially for the total score (TS) and the compulsions subscale.  Criterion validity was calculated by the positive and negative predictive values (PPV, PNV) of several TS cut-off points. Total scores ≥ 30 (PPV= 100%; PNV= 99.02%) indicate a clinical OCD diagnosis.   El Clark-Beck Obsessive-Compulsive Inventory (C-BOCI) es un inventario auto-informado breve de reciente publicacion (Clark y Beck, 2002), disenado para proporcionar una herramienta valida, especifi ca, y potente de cribado del trastorno obsesivo-compulsivo (TOC), que tenga en cuenta los sintomas, sus consecuencias, e incorpore supuestos de los modelos cognitivos sobre el trastorno. Nuestro objetivo ha sido examinar la utilidad del C-BOCI en poblacion espanola. El cuestionario fue completado junto con otros instrumentos de TOC, depresion, y ansiedad por 506 adultos sin patologia mental y 44 pacientes con diagnostico principal de TOC. Todos los valores ¿¿ fueron . 0,80, excepto para la subescala de obsesiones (muestra clinica). La validez concurrente y la discriminante fueron adecuadas, en especial para la puntuacion total (PT) y la subescala de compulsiones. Para la validez criterial se calcularon los valores predictivos positivo y negativo (VPP y VPN) de varios puntos de corte de la PT. Puntuaciones totales . 30 (VPP = 100%; VPN = 99,02%) senalan un diagnostico clinico de TOC

Amphiphilic Gemini Pyridinium-mediated incorporation of Zn(II)meso-tetrakis(4-carboxyphenyl)porphyrin into water-soluble gold nanoparticles for photodynamic therapy

Zn-containing porphyrins are intensely investigated for their ability to form reactive oxygen species and thereby being potent photosensitizers for use in photodynamic therapy (PDT). Some of the drawbacks of the PDT approach, such as unspecific distribution, could be addressed by means of photosensitizer drug delivery systems. In this work, we synthesize and characterize new water-soluble gold nanoparticles (GNP) stabilized by a mixture of a polyethyleneglycol-containing thiol (to improve water solubility) and a new amphiphilic gemini-type pyridinium salt, which also acts as promotor of the incorporation of the anionic photosensitizer Na-ZnTCPP into the GNP. The obtained GNP have sizes between 7 and 10 nm, as observed by Transmission Electron Microscopy. The incorporation of the photosensitizer caused an increase in the hydrodynamic size, detected by Dynamic Light Scattering, as well as a shift in the Surface Plasmon Resonance peak on the GNP UV–vis absorption spectra. The presence of the photosensitizer in the GNP was corroborated using Fluorescence Spectroscopy. The amount of Na-ZnTCPP was found to be 327 molecules per GNP. The porphyrin-containing Na-ZnTCPP-1·GNP showed good enhanced ability to produce singlet oxygen, compared to free Na-ZnTCPP. Their cytotoxicity and phototoxicity were investigated in vitro using two different human breast cell lines, one of tumoral origin (SKBR-3) and another of normal epithelium origin (MCF-10A). SKBR-3 cells showed higher sensitivity to Na-ZnTCCP and Na-ZnTCPP-1·GNP in dark conditions. After irradiation, no significant differences were observed between both cell lines except for 1 μM Na-ZnTCCP-1·GNP where SKBR-3 cells were also more sensitive

Microbiome in paired root apices and periapical lesions and its association with clinical signs in persistent apical periodontitis using next-generation sequencing

The study was partly funded by the FEDER/Junta de Andalucía- Consejería de Economía y Conocimiento (Project ref: A1- CTS-174-UGR18) and the Ministry of Science and Innovation of Spain co-financed with European Regional Development Funds (Project ref: PID2020-120481RB-I00) and University of Almería (Project Ref: PPUENTE2021-006). Pérez-Carrasco V was supported by a fellowship from the Ministry of Universities, Spain (FPU20/03952).Aim To assess and compare the microbiome of paired root apices and periapical lesions from cases with failed endodontic treatment and to associate the microbiome and bacterial metabolic pathways in both sites with asymptomatic apical periodontitis (AAP) and symptomatic apical periodontitis (SAP), using next-generation sequencing (NGS). Methodology Matched root apices and periapical lesions of patients with failed root canal treatments were surgically extracted. Specimens were cryopulverized, bacterial DNA was extracted and the V3–V4 hypervariable regions of the 16 S rRNA gene were amplified and sequenced using the Illumina Miseq platform. Diversity and community composition were studied in the paired samples, as well as in AAP and SAP cases. Diversity indices were compared in each case by means of the Wilcoxon matched-pairs signed rank and Mann–Whitney U tests. Differences in the community composition were explored with multivariate statistical analysis and Linear discriminant analysis Effect Size (LEfSe). Bacterial functional study was performed through the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis. Results Twenty-one paired apices and lesions were successfully sequenced and analysed, identifying a total of 21 phyla and 600 genera. A higher alpha-diversity was observed in the periapical lesions, although no global differences in the community composition between the two sites were found (p = .87), the most prevalent genera being Fusobacterium, Porphyromonas and Streptococcus. Prevotella, Clostridiales_vadinBB60_group, Bosea, Phreatobacter, Afipia and Xanthobacteriaceae_unclassified were enriched in SAP samples, while Pseudopropionibacterium, Campylobacter and Peptoniphilus were significantly more abundant in AAP cases (p < .05). Metabolic pathways involved in the amino acid metabolism or degradation and flagellum assembly were more abundant in SAP samples, whereas glucose metabolism-related pathways were associated with AAP. Conclusions The bacterial community composition was similar in the apices and periapical lesions. The microbiome was different in AAP and SAP samples, gram-negative bacteria showing higher relative abundances in SAP cases. An association was observed between amino acid degradation and flagellum assembly pathways, and the development of tenderness to percussion or palpation.FEDER/Junta de Andalucía- Consejería de Economía y Conocimiento A1- CTS-174-UGR18Ministry of Science and Innovation of SpainEuropean Regional Development Funds PID2020-120481RB-I00University of Almería PPUENTE2021-006Ministry of Universities, Spain FPU20/0395

Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice

Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future