Blind Symbol Rate Estimation of Faster-than-Nyquist Signals Based on Higher-Order Statistics

Both faster-than-Nyquist (FTN) and cognitive radio go towards an efficient use of spectrum in radio communications systems at the cost of an added computational complexity at the receiver side. To gain the maximum potential from these techniques, non-data-aided receivers are of interest. In this paper, we use fourth-order statistics to perform blind symbol rate estimation of FTN signals. The estimator shows good performance results for moderate system's densities beyond the Nyquist rate and for a reasonable number of received samples

Closed-Form Expressions for Channel Shortening Receivers Using A Priori Information

Channel shortening has been studied in the context of ISI and MIMO channels as a means to compute a posteriori probabilities with a BCJR algorithm at a reduced computational complexity. This is done by considering an approximate channel response of reduced length. In a turbo receiver, soft a priori information can be linearly combined with the received sequence to form a new input to the BCJR trellis-based processing. In this letter, we provide closed-form expressions for the channel shortening filters using a generalized mutual information objective function. The proposed receiver allows a complexity reduction with respect to numerical optimization approaches which may also present stability, precision and convergence issues

On zero-forcing equalization for short-filtered multicarrier faster-than-Nyquist signaling

Within the context of faster-than-Nyquist signaling, a low-complexity multicarrier system based on short-length filters and zero-forcing turbo equalization is introduced. Short-length filters allow a reduced-size block processing while zero-forcing equalization allows a linear reduced-complexity implementation. Furthermore, rectangular and out-of-band energy minimization pulse shaping demonstrates competitive performance results over an additive white Gaussian noise channel while keeping a lower computational cost than other multicarrier faster-than-Nyquist systems

Faster-than-Nyquist Signaling: on Linear and Non-Linear Reduced-Complexity Turbo Equalization

In the framework of digital video broadcasting by satellite - second generation (DVB-S2), we analyze a faster-than-Nyquist (FTN) system based on turbo equalization and low-density parity-check (LDPC) codes. Truncated maximum a posteriori (MAP) and minimum mean square error (MMSE) equalizers provide a reduced-complexity implementation of the FTN system. On the other hand, LDPC codes allow us to demonstrate attractive performance results over an additive white Gaussian noise (AWGN) channel while increasing spectral efficiency beyond the Nyquist rate and keeping a complexity comparable to that of a current DVB-S2 mode

Genome-wide recruitment profiling of transcription factor Crz1 in response to high pH stress

Background: Exposure of the budding Saccharomyces cerevisiae to an alkaline environment produces a robust transcriptional response involving hundreds of genes. Part of this response is triggered by an almost immediate burst of calcium that activates the Ser/Thr protein phosphatase calcineurin. Activated calcineurin dephosphorylates the transcription factor (TF) Crz1, which moves to the nucleus and binds to calcineurin/Crz1 responsive gene promoters. In this work we present a genome-wide study of the binding of Crz1 to gene promoters in response to high pH stress. Results: Environmental alkalinization promoted a time-dependent recruitment of Crz1 to 152 intergenic regions, the vast majority between 1 and 5 min upon stress onset. Positional evaluation of the genomic coordinates combined with existing transcriptional studies allowed identifying 140 genes likely responsive to Crz1 regulation. Gene Ontology analysis confirmed the relevant impact of calcineurin/Crz1 on a set of genes involved in glucose utilization, and uncovered novel targets, such as genes responsible for trehalose metabolism. We also identified over a dozen of genes encoding TFs that are likely under the control of Crz1, suggesting a possible mechanism for amplification of the signal at the transcription level. Further analysis of the binding sites allowed refining the consensus sequence for Crz1 binding to gene promoters and the effect of chromatin accessibility in the timing of Crz1 recruitment to promoters. Conclusions: The present work defines at the genomic-wide level the kinetics of binding of Crz1 to gene promoters in response to alkaline stress, confirms diverse previously known Crz1 targets and identifies many putative novel ones. Because of the relevance of calcineurin/Crz1 in signaling diverse stress conditions, our data will contribute to understand the transcriptional response in other circumstances that also involve calcium signaling, such as exposition to sexual pheromones or saline stress

Oxidation processes at the surface of BaTiO3 thin films under environmental conditions

Altres ajuts: the ICN2 is funded by the CERCA programme/Generalitat de Catalunya. I. S. acknowledges support of the Secretaria d'Universitats i Recerca - Departament d'Empresa i Coneixement - Generalitat de Catalunya and the European Social Fund (ESF) (FI grant reference 2020 FI_B2 00157).Dissociation and adsorption of water on ferroelectric oxide surfaces play important role in the processes of screening and switching dynamics of ferroelectric polarization, as well as in catalytic processes which can be additionally coupled with light, temperature or vibration stimuli. In this work, we present XPS study of ferroelectric BaTiOthin films and determine the entanglement between surface chemistry, polarization direction and stability, by observing changes upon time exposure to environmental conditions, heating in Oatmosphere and irradiation in vacuum. We devote special attention to Ba 3d spectral region and identify two different oxidation states of O atoms in the compounds of Ba. While this second specie was generally attributed to Ba in surface compounds where it has different oxygen coordination than in the bulk, based on the XPS results of oxygen annealed thin films, we demonstrate that this so far neglected component, corresponds to barium peroxide (BaO) and identify it as important active specie for the study of screening mechanisms closely related with catalytic activity present in this ferroelectric material. Finally, we report on chemically assisted polarization switching in thin films induced by heating in vacuum or exposure to X-Ray radiation due to the formation of positive surface electric field created by oxygen or electron vacancies, respectively

Uso de fierro corrugado en la resistencia de viguetas de madera de entrepisos en Tumbes 2023

La presente investigación se realizó en la ciudad de Tumbes , en la Universidad Cesar Vallejo - Piura , se determinó la influencia del uso fierro corrugado en la resistencia de viguetas de madera para entrepisos en Tumbes 2023, En la ejecución de la tesis se recurrió a un diseño experimental, cuasi experimental; el muestreo fue no probabilístico por norma técnica (E.010 MADERA), (ITINTEC 251.107), (NTP.ISO.IEC.17025.2017), la recolección de datos se efectuó con la técnica de la Observación, el instrumento usado fue la guía de observación, para el análisis los datos se empleó una inferencia estadística. Problemática, la ciudad de Tumbes está situado en territorio sísmico motivo por lo cual se decidió mejorar la resistencia en las viguetas de madera adicionando fierro corrugado para dar mayor seguridad estructural y prevenir desastres con pérdidas humanas y mejorar las luces en ambientes, en una comparación de datos interpolados para las dos variables mencionadas los resultados arrojaron diferencias altamente significativas al ser sometidas a la prueba estadística t-studet, comprobándose una media de 900 para las testigos y 1663 para las experimentales, dando 30% de diferencia. En conclusión, las viguetas de madera más fierro, tuvo una diferencia altamente significativa

Complex pathogens in infective endocarditis

Endocarditis; Diagnosis; TreatmentEndocarditis; Diagnóstico; TratamientoEndocarditis; Diagnòstic; TractamentInfective endocarditis (IE) is a complex disease whose prognosis depends on the causative microorganism, among other factors. The latter can be difficult to identify and/or treat. In this narrative review, we identify knowledge gaps in the diagnosis and antimicrobial treatment of IE, and attempt to shed light on current questions. Specifically, we: (1) analyze the factors that may hinder the microbiological diagnosis of blood culture-negative IE, as well as the role of new imaging techniques, such as 18F-fluorodeoxyglucose ([18F]FDG PET/CT), in the diagnostic capacity of this disease, understanding their advantages and assuming their limitations; (2) discuss the therapeutic approach to various difficult-to-treat microorganisms. In particular, we focus on the treatment of staphylococcal IE since, at present, staphylococci are the most frequent cause of IE in developed countries and staphylococcal IE is one of those with the highest short- and long-term mortality. We critically evaluate the current evidence on combination therapy and address the occurrence of serious side effects, an aspect that is often overlooked owing to the severity of the infection; and (3) emphasize the need for home antimicrobial treatment of patients with IE, as these are fragile people who benefit from an early return to their environment. This poses undoubted logistical challenges and requires robust evidence to ensure the best short- and long-term outcomes.Laura Escolà-Vergé has a Juan Rodés contract in the call 2020 Strategic Action Health from the Instituto de Salud Carlos III of Spanish Health Ministry for the years 2021-2024. This research was supported by CIBER-Consorcio Centro de Investigación Biomédica en Red (CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea - NextGenerationEU

SETD7 regulates the differentiation of human embryonic stem cells

The successful use of specialized cells in regenerative medicine requires an optimization in the differentiation protocols that are currently used. Understanding the molecular events that take place during the differentiation of human pluripotent cells is essential for the improvement of these protocols and the generation of high quality differentiated cells. In an effort to understand the molecular mechanisms that govern differentiation we identify the methyltransferase SETD7 as highly induced during the differentiation of human embryonic stem cells and differentially expressed between induced pluripotent cells and somatic cells. Knock-down of SETD7 causes differentiation defects in human embryonic stem cell including delay in both the silencing of pluripotency-related genes and the induction of differentiation genes. We show that SETD7 methylates linker histone H1 in vitro causing conformational changes in H1. These effects correlate with a decrease in the recruitment of H1 to the pluripotency genes OCT4 and NANOG during differentiation in the SETD7 knockdown that might affect the proper silencing of these genes during differentiation.M.J.B. was partially supported by the Ramón y Cajal program of MEC (RYC-2007-01510). B.S. was a recipient of a predoctoral fellowship from MEC (BES-2008-009567). C.M. was supported by PT13/0001/0041 PRB2-ISCIII-SGEFI- FEDER-PE I+D+i 2013-2016. J.C. was partially supported by Fundación CELLEX. This work was partially supported by grant RD12/0019/0034 TERCEL-RETICS-ISCIII-MINECO-FEDER, grant SAF2009-08588 from MICINN to M.J.B and grant BFU2014-52237 to A.J.Peer Reviewe