Eigenvalue Dynamics of a Central Wishart Matrix with Application to MIMO Systems

We investigate the dynamic behavior of the stationary random process defined by a central complex Wishart (CW) matrix ${\bf{W}}(t)$ as it varies along a certain dimension $t$. We characterize the second-order joint cdf of the largest eigenvalue, and the second-order joint cdf of the smallest eigenvalue of this matrix. We show that both cdfs can be expressed in exact closed-form in terms of a finite number of well-known special functions in the context of communication theory. As a direct application, we investigate the dynamic behavior of the parallel channels associated with multiple-input multiple-output (MIMO) systems in the presence of Rayleigh fading. Studying the complex random matrix that defines the MIMO channel, we characterize the second-order joint cdf of the signal-to-noise ratio (SNR) for the best and worst channels. We use these results to study the rate of change of MIMO parallel channels, using different performance metrics. For a given value of the MIMO channel correlation coefficient, we observe how the SNR associated with the best parallel channel changes slower than the SNR of the worst channel. This different dynamic behavior is much more appreciable when the number of transmit ($N_T$) and receive ($N_R$) antennas is similar. However, as $N_T$ is increased while keeping $N_R$ fixed, we see how the best and worst channels tend to have a similar rate of change.Comment: 15 pages, 9 figures and 1 table. This work has been accepted for publication at IEEE Trans. Inf. Theory. Copyright (c) 2014 IEEE. Personal use of this material is permitted. However, permission to use this material for any other purposes must be obtained from the IEEE by sending a request to [email protected]

A MATLAB program for the computation of the confluent hypergeometric function Φ2

We here present a sample MATLAB program for the numerical evaluation of the confluent hypergeometric function Φ2. This program is based on the calculation of the inverse Laplace transform using the algorithm suggested by Simon and Alouini in their reference textbook [1]

A Tractable Line-of-Sight Product Channel Model: Application to Wireless Powered Communications

We here present a general and tractable fading model for line-of-sight (LOS) scenarios, which is based on the product of two independent and non-identically distributed κ- μ shadowed random variables. Simple closed-form expressions for the probability density function and cumulative distribution function are derived, which are as tractable as the corresponding expressions derived from a product of Nakagami-m random variables. This newly proposed model simplifies the challenging characterization of LOS product channels, as well as combinations of LOS channels with non-LOS ones. Results are used to analyze performance measures of interest in the context of wireless powered communications.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Enzymatic preparation of structured triacylglycerides containing γ-linolenic acid

with the addition of molecular sieves (MS) at different addition times (3, 9, 12 and 15 h) and loads (2.5, 5, 10 and 15%, based on the total weight of substrates), the enrichment of GLA from evening primrose oil (EPO) and 1- butanol (BtOH) was improved via Candida rugosa lipase-catalysed esterification reactions. Secondly, the GLAenriched fraction was separated by thin-layer chromatography (TLC) to be further set to react during the third step in the presence of glycerol and Candida antarctica fraction B (CALB), under different enzyme loadings (5, 10, 15 and 20%, based on the total weight of substrates), temperatures (30, 40, 50 and 60 ◦C) and substrates molar ratios (1:1, 2:1, 3:1 and 4:1, GLA:glycerol). 60% of STAG containing 49 wt% of GLA were produced by using 15% of CALB at 60 ◦C and a 3:1 molar ratio.Conacyt: Beca no. 328716 UAEMex: Proyecto 3866/2015/PI

Bifocal dual reflectarray with curved main surface

This paper presents a novel approach to synthesizing curved reflectarrays using Geometrical Optics (GO). It introduces the concepts of virtual normal and path length shift, which enable a vector-based formulation of the problem that can be solved using ray tracing techniques. The formulation is applied for the design of two different versions of a Dual Bifocal Reflectarray with a parabolic main surface and a flat subreflectarray. The first version aims to enhance the performance of the multibeam antenna by providing a focal ring located at the feed cluster plane. The second version focuses on improving the scanning characteristics of the antenna in the horizontal plane by incorporating two foci. The synthesis procedure yields samples of the path length shift or its derivatives. To reconstruct the phase distribution, an interpolation scheme is employed and described in this paper. Numerical results are presented for both the focal-ring and two-foci configurations, demonstrating the feasibility of this solution for multibeam or scanning satellite antennas operating in the Ka.European Space Research and Technology Centre | Ref. 4000117113/16/NL/AFMinisterio de Economía y Competitividad | Ref. PDC2021-120959-C21/C22Ministerio de Ciencia e Innovación | Ref. RYC2021-033593-IXunta de Galicia | Ref. GRC-ED431C-2019/2

Can the pyruvate: ferredoxin oxidoreductase (PFOR) gene be used as an additional marker to discriminate among Blastocystis strains or subtypes?

Background Blastocystis spp. are the most prevalent intestinal eukaryotes identified in humans, with at least 17 genetic subtypes (ST) based on genes coding for the small-subunit ribosomal RNA (18S). It has been argued that the 18S gene should not be the marker of choice to discriminate between STs of these strains because this marker exhibits high intra-genomic polymorphism. By contrast, pyruvate:ferredoxin oxidoreductase (PFOR) is a relevant enzyme involved in the core energy metabolism of many anaerobic microorganisms such as Blastocystis, which, in other protozoa, shows more polymorphisms than the 18S gene and thus may offer finer discrimination when trying to identify Blastocystis ST. Therefore, the objective of the present study was to assess the suitability of the PFOR gene as an additional marker to discriminate among Blastocystis strains or subtypes from symptomatic carrier children. Methods Faecal samples from 192 children with gastrointestinal symptoms from the State of Mexico were submitted for coprological study. Twenty-one of these samples were positive only for Blastocystis spp.; these samples were analysed by PCR sequencing of regions of the 18S and PFOR genes. The amplicons were purified and sequenced; afterwards, both markers were assessed for genetic diversity. Results The 18S analysis showed the following frequencies of Blastocystis subtypes: ST3 = 43%; ST1 = 38%; ST2 = 14%; and ST7 = 5%. Additionally, using subtype-specific primer sets, two samples showed mixed Blastocystis ST1 and ST2 infection. For PFOR, Bayesian inference revealed the presence of three clades (I-III); two of them grouped different ST samples, and one grouped six samples of ST3 (III). Nucleotide diversity (π) and haplotype polymorphism (θ) for the 18S analysis were similar for ST1 and ST2 (π = ~0.025 and θ = ~0.036); remarkably, ST3 showed almost 10-fold lower values. For PFOR, a similar trend was found: clade I and II had π = ~0.05 and θ = ~0.05, whereas for clade III, the values were almost 6-fold lower. Conclusions Although the fragment of the PFOR gene analysed in the present study did not allow discrimination between Blastocystis STs, this marker grouped the samples in three clades with strengthened support, suggesting that PFOR may be under different selective pressures and evolutionary histories than the 18S gene. Interestingly, the ST3 sequences showed lower variability with probable purifying selection in both markers, meaning that evolutionary forces drive differential processes among Blastocystis STs

Desarrollo de nuevos Modelos de Edificios de progresiva dificultad, para el estudio de su representación gráfica, utilizando los sistemas de representación que permiten las aplicaciones de Cad

En el proceso de la definición gráfica de un edificio, conviene utilizar los sistemas de representación apropiados para cada fin que se pretende: En la representación tradicional, se utilizan las plantas/secciones horizontales, que son los diagramas de definición y construcción del edificio, y se complementan con los alzados como visión compositiva y/o adecuación con el entorno, así como con los dibujos de detalles y/o secciones verticales, que dan idea de los sistemas constructivos, alturas, nº. plantas, etc., Las nuevas tecnologías como son las aplicaciones de Cad, en su utilización en la representación de Edificios, facilitan el uso de otros tipos de representaciones que pueden ser útiles para ilustrar la naturaleza de algunos edificios, como son las axonometrías o perspectivas, y mejorar la comunicación con imágenes, videos etc. En este trabajo se desarrollan objetos arquitectónicos, con un diseño centrado en primer lugar en el estudio de su representación gráfica, a través de las aplicaciones de Cad, para el mejor entendimiento/comprensión de volúmenes/formas y espacios exterior/interior, realizando ejercicios de aplicación gráfica con una nueva forma de usar los sistemas de representación, y en segundo lugar atendiendo a las connotaciones arquitectónicas de composición, funcionalidad, estructura etc. Se concreta la investigación, en las nuevas formas de usar los sistemas de representación, con definición de proyecto básico y no en la simple aplicación de CAD: A.-objetos, con volúmenes/formas compuestas, con la dificultad propia de los objetos sin espacio interior, por lo que no se utilizan más que los dibujos de alzados, e isométricas exteriores, con una primera parte, de descripción gráfica de cómo se componen estos volúmenes, ya sea con connotaciones teóricas tipo Sección Aurea, con razones geométricas, proporciones. Ejerc.A.-Dibujar/definir con Alzados un objeto B.-objetos con aparición de los espacios interiores, (ya aparece lo interior/exterior), con hincapié en elementos comunicación vertical (escaleras, rampas etc.) espacios en doble altura, etc.. Ejerc.B.-Dibujar/definir con secc.verticales/horiz. C.-objetos con aparición de nuevos elementos interiores/exteriores, cubiertas/escaleras/huecos de fachadas, que necesitan sistemas de representación más complejos. Ejerc. C.-Dibujar/definir con axonométricas seccionadas horiz y/o vert. La presentación/composición se realiza si es posible en un solo formato A-3 horizontal con su descripción/identificación a pié de página, con los dibujos en el resto del formato, procurando que la escala sea 1/100, por cada objeto arquitectónico

The effect of orthodontic forces on calcitonin gene-related peptide (CGRP) expression in the human periodontal ligament and its relationship with the human dental pulp

The purpose of this study was to quantify the effect of moderate and severe orthodontic forces on Calcitonin gene-related peptide (CGRP) expression in the healthy human periodontal ligament (PDL) and its possible relationship with the human dental pulp

A novel deep targeted sequencing method for minimal residual disease monitoring in acute myeloid leukemia

A high proportion of patients with acute myeloid leukemia who achieve minimal residual disease negative status ultimately relapse because a fraction of pathological clones remains undetected by standard methods. We designed and validated a high-throughput sequencing method for minimal residual disease assessment of cell clonotypes with mutations of NPM1, IDH1/2 and/or FLT3-single nucleotide variants. For clinical validation, 106 follow-up samples from 63 patients in complete remission were studied by sequencing, evaluating the level of mutations detected at diagnosis. The predictive value of minimal residual disease status by sequencing, multiparameter flow cytometry, or quantitative polymerase chain reaction analysis was determined by survival analysis. The sequencing method achieved a sensitivity of 10-4 for single nucleotide variants and 10-5 for insertions/deletions and could be used in acute myeloid leukemia patients who carry any mutation (86% in our diagnostic data set). Sequencing-determined minimal residual disease positive status was associated with lower disease-free survival (hazard ratio 3.4, P=0.005) and lower overall survival (hazard ratio 4.2, P<0.001). Multivariate analysis showed that minimal residual disease positive status determined by sequencing was an independent factor associated with risk of death (hazard ratio 4.54, P=0.005) and the only independent factor conferring risk of relapse (hazard ratio 3.76, P=0.012). This sequencing-based method simplifies and standardizes minimal residual disease evaluation, with high applicability in acute myeloid leukemia. It is also an improvement upon flow cytometry- and quantitative polymerase chain reaction-based prediction of outcomes of patients with acute myeloid leukemia and could be incorporated in clinical settings and clinical trials.This study was supported by the Subdirección General de Investigación Sanitaria (Instituto de Salud Carlos III, Spain) grants PI13/02387 and PI16/01530, and the CRIS against Cancer foundation grant 2014/0120. ML holds a postdoctoral fellowship of the Spanish Ministry of Economy and Competitiveness (FPDI-2013- 16409). PRP holds a postdoctoral fellowship of the Spanish Instituto de Salud Carlos III: Contrato Predoctoral de Formación en Investigación en Salud i-PFIS (IFI 14/00008).S