Time-Resolved Measurements of Plasma Electron Number Density and Electron-Neutral Collision Frequency Using a Microwave Diagnostic Method

Microwave interferometry is an established non-perturbing plasma diagnostic technique. Compared with other diagnostic techniques, it can be more robust and reliable in experimental applications. This thesis studies a simple and accurate microwave diagnostic method to characterize the electron number density and electron-neutral collision frequency, which are crucial to understanding the behavior and transport coefficients of plasma. This method is based on a modern vector network analyzer and measures the attenuation and phase shift of a microwave signal when propagating through a plasma layer. These measured quantities are related to the real and imaginary parts of the plasma index of refraction, which is described by Appleton’s equation and characterized by plasma parameters, including the electron number density and collision frequency. One can numerically derive these plasma parameters from the measured quantities by using Appleton’s equation. Since the electron number density and collision frequency can be calculated from measured quantities, one need not know the electron energy distribution function, the electron kinetic temperature, or the electron energy-dependent cross section for the collision process. The experimental measurements focus on the time-averaged and time resolved parameters of commercial fluorescent lamp plasma and the One Atmosphere Uniform Glow Discharge Plasma (OAUGDPTM). The latter is an atmospheric pressure glow discharge developed at the UT Plasma Sciences Lab. Since the plasma properties should be periodic with the applied plasma driving frequency, 60 Hz for fluorescent lamp plasma and 2-10 KHz for OAUGDPTM plasma, time-resolved measurements are taken to exhibit the variation of electron number density and collision frequency during one 60 Hz cycle of the fluorescent lamp plasma. This time-resolved measurement is achieved by applying the external trigger feature of the network analyzer

Development of a Real-time Ultra-wideband See Through Wall Imaging Radar System

Ultra-Wideband (UWB) See-Through-Wall (STW) technology has emerged as a musthave enabling technology by both the military and commercial sectors. As a pioneer in this area, we have led the research in addressing many of the fundamental STW questions. This dissertation is to investigate and resolve a few hurdles in advancing this technology, and produce a realizable high performance STW platform system, which will aid the STW community to find the ultimate answer through experimental and theoretical work. The architectures of a realizable STW imaging system are thoroughly examined and studied. We present both a conceptual system based on RF instruments and a standalone real-time system based on custom design, which utilize reconfigurable design architecture and allows scaling down/up to a desired UWB operating frequency with little difficulty. The systems will serve as a high performance platform for STW study and other related UWB applications. Along the way to a complete STW system, we have developed a simplified transmission line model for wall characteristic prediction; we have developed a scalable synthetic aperture array including both the RF part and the switch control/synchronization part; we have proposed a cost-effective and efficient UWB data acquisition method for real-time STW application based on equivalent-time sampling method. The measurement results reported here include static image formation and tracking moveable targets behind the wall. Even though digital signal processing to generate radar images is not the focus of this research, simple methods for image formation have been implemented and results are very encouraging

Cooperative Fuzzy Games Approach to Setting Target Levels of ECs in Quality Function Deployment

Quality function deployment (QFD) can provide a means of translating customer requirements (CRs) into engineering characteristics (ECs) for each stage of product development and production. The main objective of QFD-based product planning is to determine the target levels of ECs for a new product or service. QFD is a breakthrough tool which can effectively reduce the gap between CRs and a new product/service. Even though there are conflicts among some ECs, the objective of developing new product is to maximize the overall customer satisfaction. Therefore, there may be room for cooperation among ECs. A cooperative game framework combined with fuzzy set theory is developed to determine the target levels of the ECs in QFD. The key to develop the model is the formulation of the bargaining function. In the proposed methodology, the players are viewed as the membership functions of ECs to formulate the bargaining function. The solution for the proposed model is Pareto-optimal. An illustrated example is cited to demonstrate the application and performance of the proposed approach

Genome-Wide Identification and Characterization of BrrTCP Transcription Factors in Brassica rapa ssp. rapa

The teosinte branched1/cycloidea/proliferating cell factor (TCP) gene family is a plant-specific transcription factor that participates in the control of plant development by regulating cell proliferation. However, no report is currently available about this gene family in turnips (Brassica rapa ssp. rapa). In this study, a genome-wide analysis of TCP genes was performed in turnips. Thirty-nine TCP genes in turnip genome were identified and distributed on 10 chromosomes. Phylogenetic analysis clearly showed that the family was classified as two clades: class I and class II. Gene structure and conserved motif analysis showed that the same clade genes have similar gene structures and conserved motifs. The expression profiles of 39 TCP genes were determined through quantitative real-time PCR. Most CIN-type BrrTCP genes were highly expressed in leaf. The members of CYC/TB1 subclade are highly expressed in flower bud and weakly expressed in root. By contrast, class I clade showed more widespread but less tissue-specific expression patterns. Yeast two-hybrid data show that BrrTCP proteins preferentially formed heterodimers. The function of BrrTCP2 was confirmed through ectopic expression of BrrTCP2 in wild-type and loss-of-function ortholog mutant of Arabidopsis. Overexpression of BrrTCP2 in wild-type Arabidopsis resulted in the diminished leaf size. Overexpression of BrrTCP2 in triple mutants of tcp2/4/10 restored the leaf phenotype of tcp2/4/10 to the phenotype of wild type. The comprehensive analysis of turnip TCP gene family provided the foundation to further study the roles of TCP genes in turnips

The reversible effects of free fatty acids on sulfonylurea-stimulated insulin secretion are related to the expression and dynamin-mediated endocytosis of KATP channels in pancreatic β cells

Objective: Lipotoxicity-induced pancreatic β cell-dysfunction results in decreased insulin secretion in response to multiple stimulus. In this study, we i nvestigated the reversible effects of palmitate (PA) or oleate (OA) on insulin secretion and the relationship with pancreatic β-cell ATP-sensitive potassium (KATP) channels. Methods: MIN6 cells were treated with PA and OA for 48 h and then washed out for 24 h to determine the changes in expression and endocytosis of the KATP channels and glucose-stimulated insulin secretion (GSIS) and sulfonylurea-stimulated insulin secretion (SU-SIS). Results: MIN6 cells exposed to PA or OA showed both impaired GSIS and SU -SIS; the former was not restorable, while the latter was reversible with washout of PA or OA. Decreased expressions of both total and surface Kir6.2 and SUR1 and endocytosis of KATP channels were observed, which were also recoverable after wash out. When MIN6 cells exposed to free fatty acids (FFAs) were cotreated wi th 5-aminoimidazole- 4-carboxamide ribonucleotide (AICAR) or dynasore, we found that endocytosis of KATP channels did not change significantly by AICAR but was almost co mpletely blocked by dynasore. Meanwhile, the inhibition of endocytosis of K ATP channels after washout could be activated by PIP2. The recovery of SU-SIS after washout was significantly weakened by PIP2, but the decrease of SU-SIS induced by FFAs was not allevi ated by dynasore. Conclusions: FFAs can cause reversible impairment of SU-SIS on pancreatic β cells. The reversibility of the effects is partial because of the changes o f expression and endocytosis of Kir6.2 and SUR1 which was mediated by dynamin

Identification of novel mutations in Chinese Hans with autosomal dominant polycystic kidney disease

<p>Abstract</p> <p>Background</p> <p>Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disease with an incidence of 1 in 400 to 1000. The disease is genetically heterogeneous, with two genes identified: <it>PKD1 </it>(16p13.3) and <it>PKD2 </it>(4q21). Molecular diagnosis of the disease in at-risk individuals is complicated due to the structural complexity of <it>PKD1 </it>gene and the high diversity of the mutations. This study is the first systematic ADPKD mutation analysis of both <it>PKD1 </it>and <it>PKD2 </it>genes in Chinese patients using denaturing high-performance liquid chromatography (DHPLC).</p> <p>Methods</p> <p>Both <it>PKD1 </it>and <it>PKD2 </it>genes were mutation screened in each proband from 65 families using DHPLC followed by DNA sequencing. Novel variations found in the probands were checked in their family members available and 100 unrelated normal controls. Then the pathogenic potential of the variations of unknown significance was examined by evolutionary comparison, effects of amino acid substitutions on protein structure, and effects of splice site alterations using online mutation prediction resources.</p> <p>Results</p> <p>A total of 92 variations were identified, including 27 reported previously. Definitely pathogenic mutations (ten frameshift, ten nonsense, two splicing defects and one duplication) were identified in 28 families, and probably pathogenic mutations were found in an additional six families, giving a total detection level of 52.3% (34/65). About 69% (20/29) of the mutations are first reported with a recurrent mutation rate of 31%.</p> <p>Conclusions</p> <p>Mutation study of <it>PKD1 </it>and <it>PKD2 </it>genes in Chinese Hans with ADPKD may contribute to a better understanding of the genetic diversity between different ethnic groups and enrich the mutation database. Besides, evaluating the pathogenic potential of novel variations should also facilitate the clinical diagnosis and genetic counseling of the disease.</p

A Study on the Organizational Architecture and Standard System of the Data Sharing Network of Earth System Science in China

The aim of this paper is to discuss the organizational architecture and standard system for sharing research data at the national level. The Data Sharing Network of Earth System Science (DSNESS) is one of the nine pilot projects of the Scientific Data Sharing Project in China that has become a long-term operational research data-sharing platform in the National Science and Technology Infrastructure (NSTI) of China. First, a data sharing union mechanism was designed with the core principle being, “data come from research and will be reused in research”. Second, a data sharing organizational architecture was constructed that consists of three sections: data resource architecture, data management architecture, and data services architecture. A physical data sharing network was constructed that includes one general center and 15 distributed sub-centers based on the architecture. Third, a series of data sharing standards and specifications were designed and implemented in the DSNESS. The reference model of the DSNESS standard system includes three levels of standards: directive standards, general standards, and application standards. In total, 21 high level standards and specifications were developed and implemented in the DSNESS. Several core standards and specifications, such as the extensible metadata standard, data quality control specifications, and so on, were analyzed in detail. Finally, the data service effect was summarized in three aspects: dataset services, standard and specification services, and international cooperation services. This research shows that the organizational architecture and standard system is a very important soft environment for research data sharing. The practices of DSNESS will provide useful experiences for multi-disciplinary data sharing in Earth science and will help to eliminate the data gap between the rich and poor at the national level

Chromosome-level genome assembly of Murraya paniculata sheds light on biosynthesis of floral volatiles

Abstract Background Murraya paniculata (L.) Jack, commonly called orange jessamine in the family Rutaceae, is an important ornamental plant in tropical and subtropical regions which is famous for its strong fragrance. Although genome assemblies have been reported for many Rutaceae species, mainly in the genus Citrus, full genomic information has not been reported for M. paniculata, which is a prerequisite for in-depth genetic studies on Murraya and manipulation using genetic engineering techniques. Here, we report a high-quality chromosome-level genome assembly of M. paniculata and aim to provide insights on the molecular mechanisms of flower volatile biosynthesis. Results The genome assembly with a contig N50 of 18.25 Mb consists of 9 pseudomolecules and has a total length of 216.86 Mb. Phylogenetic analysis revealed that M. paniculata diverged from the common ancestor approximately 25 million years ago and has not undergone any species-specific whole genome duplication events. Genome structural annotation and comparative genomics analysis revealed that there are obvious differences in transposon contents among the genomes of M. paniculata and Citrus species, especially in the upstream regions of genes. Research on the flower volatiles of M. paniculata and C. maxima at three flowering stages revealed significant differences in volatile composition with the flowers of C. maxima lacking benzaldehyde and phenylacetaldehyde. Notably, there are transposons inserted in the upstream region of the phenylacetaldehyde synthase (PAAS) genes Cg1g029630 and Cg1g029640 in C. maxima, but not in the upstream region of three PAAS genes Me2G_2379, Me2G_2381, and Me2G_2382 in M. paniculata. Our results indicated that compared to the low expression levels of PAAS genes in C. maxima, the higher expression levels of the three PAAS genes in M. paniculata are the main factor affecting the phenylacetaldehyde biosynthesis and causing the content difference of phenylacetaldehyde. The phenylacetaldehyde synthetic activities of the enzymes encoded by M. paniculata PAAS genes were validated by in vitro analyses. Conclusions Our study provides useful genomic resources of M. paniculata for further research on Rutaceae plants, identifies new PAAS genes, and provides insights into how transposons contribute to variations in flower volatiles among Murraya and Citrus plants