Low-complexity iterative receiver algorithms for multiple-input multiple-output underwater wireless communications

This dissertation proposes three low-complexity iterative receiver algorithms for multiple-input multiple-output (MIMO) underwater acoustic (UWA) communications. First is a bidirectional soft-decision feedback Turbo equalizer (Bi-SDFE) which harvests the time-reverse diversity in severe multipath MIMO channels. The Bi-SDFE outperforms the original soft-decision feedback Turbo equalizer (SDFE) while keeping its total computational complexity similar to that of the SDFE. Second, this dissertation proposes an efficient direct adaptation Turbo equalizer for MIMO UWA communications. Benefiting from the usage of soft-decision reference symbols for parameter adaptation as well as the iterative processing inside the adaptive equalizer, the proposed algorithm is efficient in four aspects: robust performance in tough channels, high spectral efficiency with short training overhead, time efficient with fast convergence and low complexity in hardware implementation. Third, a frequency-domain soft-decision block iterative equalizer combined with iterative channel estimation is proposed for the uncoded single carrier MIMO systems with high data efficiency. All the three new algorithms are evaluated by data recorded in real world ocean experiment or pool experiment. Finally, this dissertation also compares several Turbo equalizers in single-input single-output (SISO) UWA channels. Experimental results show that the channel estimation based Turbo equalizers are robust in SISO underwater transmission under harsh channel conditions --Abstract, page iv

Characterization of Human Coronavirus Etiology in Chinese Adults with Acute Upper Respiratory Tract Infection by Real-Time RT-PCR Assays

BACKGROUND: In addition to SARS associated coronaviruses, 4 non-SARS related human coronaviruses (HCoVs) are recognized as common respiratory pathogens. The etiology and clinical impact of HCoVs in Chinese adults with acute upper respiratory tract infection (URTI) needs to be characterized systematically by molecular detection with excellent sensitivity. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we detected 4 non-SARS related HCoV species by real-time RT-PCR in 981 nasopharyngeal swabs collected from March 2009 to February 2011. All specimens were also tested for the presence of other common respiratory viruses and newly identified viruses, human metapneumovirus (hMPV) and human bocavirus (HBoV). 157 of the 981 (16.0%) nasopharyngeal swabs were positive for HCoVs. The species detected were 229E (96 cases, 9.8%), OC43 (42 cases, 4.3%), HKU1 (16 cases, 1.6%) and NL63 (11 cases, 1.1%). HCoV-229E was circulated in 21 of the 24 months of surveillance. The detection rates for both OC43 and NL63 were showed significantly year-to-year variation between 2009/10 and 2010/11, respectively (P<0.001 and P = 0.003), and there was a higher detection frequency of HKU1 in patients aged over 60 years (P = 0.03). 48 of 157(30.57%) HCoV positive patients were co-infected. Undifferentiated human rhinoviruses and influenza (Flu) A were the most common viruses detected (more than 35%) in HCoV co-infections. Respiratory syncytial virus (RSV), human parainfluenza virus (PIV) and HBoV were detected in very low rate (less than 1%) among adult patients with URTI. CONCLUSIONS/SIGNIFICANCE: All 4 non-SARS-associated HCoVs were more frequently detected by real-time RT-PCR assay in adults with URTI in Beijing and HCoV-229E led to the most prevalent infection. Our study also suggested that all non-SARS-associated HCoVs contribute significantly to URTI in adult patients in China

O-GlcNAcylation of G6PD Promotes the Pentose Phosphate Pathway and Tumor Growth

The pentose phosphate pathway (PPP) plays a critical role in macromolecule biosynthesis and maintaining cellular redox homoeostasis in rapidly proliferating cells. Upregulation of the PPP has been shown in several types of cancer. However, how the PPP is regulated to confer a selective growth advantage on cancer cells is not well understood. Here we show that glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the PPP, is dynamically modified with an O-linked b-N-acetylglucosamine sugar in response to hypoxia. Glycosylation activates G6PD activity and increases glucose flux through the PPP, thereby providing precursors for nucleotide and lipid biosynthesis, and reducing equivalents for antioxidant defense. Blocking glycosylation of G6PD reduces cancer cell proliferation in vitro and impairs tumor growth in vivo. Importantly, G6PD glycosylation is increased in human lung cancers. Our findings reveal a mechanistic understanding of how O-glycosylation directly regulates the PPP to confer a selective growth advantage to tumours

Características litogeoquímicas y petrográficas en los bordes norte y sur del segmento Lima - Batolito de la Costa, comparada con el sureste de China - [Boletín D 35]

En el presente trabajo, se muestran los resultados obtenidos en el marco del convenio específico entre el Instituto Geológico Minero y Metalúrgico (INGEMMET) y el Servicio Geológico de China (CGS: China Geological Survey), entre los años 2017 y 2018. El área de estudio corresponde principalmente al Segmento Lima. En los cuerpos plutónicos del segmento Lima (128 a 33 Ma), se pueden observar con claridad las variaciones litológicas laterales asociadas a la diferenciación magmática directa, varían de dioritas a monzogranitos. Esto indica un desarrollo continuo en los ensambles magmáticos o super unidades. Las estructuras internas de los cuerpos intrusivos más característicos se pueden observar en cuerpos de monzogranitos de las super unidades Puscao, Tiabaya y Pativilca, donde se puede observar zonas de enclaves máficos: dispersos, a manera de capas (seudo estratificado) y diques sin magmáticos, estructuras asociadas principalmente a mezcla de magma. Para comprender la distribución temporal y espacial de la población de cristales de las rocas plutónicas del Batolito de la Costa, en el segmento Lima, se generó una base de datos composicional con las principales características petrográficas de cada roca, con ella, se generaron diagramas binarios MINEA (Minerales Esenciales y Accesorios). Donde se pudo observar, que las mayores concentraciones de feldespato potásico (K) están asociadas a rocas de la super unidades Linga, Tiabaya y Santa Rosa, asociados al magmatismo de 83.6 a 72.1 Ma. Por la gran extensión del área de trabajo, afinidad litológica y rango de edad antes definida (61-90 Ma), la Super Unidad Santa Rosa fue agrupada con otras super unidades (La Mina, San Jerónimo, Puscao) y definida como Superemsamble Santa Rosa, esto para el presente trabajo. En el análisis geoquímico, los diagramas de elementos trazas y elementos de tierras raras muestras una evolución de magmas mantélicos a muy diferenciados. Los magmas mantélicos están asociados a rocas de la Super Unidad Patap y los magmas diferenciados están asociados al Superensamble Santa Rosa y Super Unidad Catahuasi. Las mayores anomalías de HFSE, como Th y U, muestran las rocas del Superensamble Santa Rosa y Super Unidad Linga. Esto quiere decir que son rocas diferenciadas y de gran energía. Las rocas de este segmento muestran anomalías negativas de Nb y Ta, típicas de magmatismo de arco andino. A medida que el magma evoluciona, se observa un dominio de anfíboles y granate en los elementos de tierras raras pesadas evidenciada por la anomalía negativa mostrada en Y e Yb. Este último se puede asociar a ocurrencias de Cu-Mo y Mo, debido a que el Mo está controlado por la anomalía de Y en el fundido. Durante el año 2018, se obtuvieron 59 nuevas edades isotópicas U-Pb, estas se realizaron sobre zircones en rocas ígneas, principalmente en rocas plutónicas. Los estudios isotópicos fueron realizados por el Servicio Geológico de China del Centro de Nanjing

Application of Bayesian network structure learning to identify causal variant SNPs from resequencing data

Using single-nucleotide polymorphism (SNP) genotypes from the 1000 Genomes Project pilot3 data provided for Genetic Analysis Workshop 17 (GAW17), we applied Bayesian network structure learning (BNSL) to identify potential causal SNPs associated with the Affected phenotype. We focus on the setting in which target genes that harbor causal variants have already been chosen for resequencing; the goal was to detect true causal SNPs from among the measured variants in these genes. Examining all available SNPs in the known causal genes, BNSL produced a Bayesian network from which subsets of SNPs connected to the Affected outcome were identified and measured for statistical significance using the hypergeometric distribution. The exploratory phase of analysis for pooled replicates sometimes identified a set of involved SNPs that contained more true causal SNPs than expected by chance in the Asian population. Analyses of single replicates gave inconsistent results. No nominally significant results were found in analyses of African or European populations. Overall, the method was not able to identify sets of involved SNPs that included a higher proportion of true causal SNPs than expected by chance alone. We conclude that this method, as currently applied, is not effective for identifying causal SNPs that follow the simulation model for the GAW17 data set, which includes many rare causal SNPs

Effects of Fluorination on Fused Ring Electron Acceptor for Active Layer Morphology, Exciton Dissociation, and Charge Recombination in Organic Solar Cells

Fluorination is one of the effective approaches to alter the organic semiconductor properties that impact the performance of the organic solar cells (OSCs). Positive effects of fluorination are also revealed in the application of fused ring electron acceptors (FREAs). However, in comparison with the efforts allocated to the material designs and power conversion efficiency enhancement, understanding on the excitons and charge carriers' behaviors in high-performing OSCs containing FREAs is limited. Herein, the impact of fluorine substituents on the active layer morphology, and therefore exciton dissociation, charge separation, and charge carriers' recombination processes are examined by fabricating OSCs with PTO2 as the donor and two FREAs, O-IDTT-IC and its fluorinated analogue O-IDTT-4FIC, as the acceptors. With the presence of O-IDTT-4FIC in the devices, it is found that the excitons dissociate more efficiently, and the activation energy required to split the excitons to free charge carriers is much lower; the charge carriers live longer and suffer less extent of trap-assisted recombination; the trap density is 1 order of magnitude lower than that of the nonfluorinated counterpart. Overall, these findings provide information about the complex impacts of FREA fluorination on efficiently performed OSCs

Design and Research of Electron Cyclotron Resonance Heating and Current Dive System on HL-2M Tokamak

A research has been conducted to develop an 8MW electron cyclotron resonance heating and current drive (ECRH/ECCD) system on HL-2M tokamak. The ECRH system compromise eight 1MW gyrotrons, eight evacuated transmission lines and three launchers. The main purpose of the ECRH system was to suppress the neo-classical tearing modes and control the plasma profile. This paper presents an overview of the design and studies performed in this framework. Some primary test results of the critical components have been released in this paper, e.g. polarizers, power monitor and fast steering launchers

Single-cell chromatin accessibility profiling of cell-state-specific gene regulatory programs during mouse organogenesis

In mammals, early organogenesis begins soon after gastrulation, accompanied by specification of various type of progenitor/precusor cells. In order to reveal dynamic chromatin landscape of precursor cells and decipher the underlying molecular mechanism driving early mouse organogenesis, we performed single-cell ATAC-seq of E8.5-E10.5 mouse embryos. We profiled a total of 101,599 single cells and identified 41 specific cell types at these stages. Besides, by performing integrated analysis of scATAC-seq and public scRNA-seq data, we identified the critical cis-regulatory elements and key transcription factors which drving development of spinal cord and somitogenesis. Furthermore, we intersected accessible peaks with human diseases/traits-related loci and found potential clinical associated single nucleotide variants (SNPs). Overall, our work provides a fundamental source for understanding cell fate determination and revealing the underlying mechanism during postimplantation embryonic development, and expand our knowledge of pathology for human developmental malformations