282 research outputs found
Energy storage in Chlamydomonas reinhardtii measured with photoacoustic techniques
No full textThe energy storage efficiencies of the reaction centers in the intact cells of Chlamydomonas reinhardtii wild type cell, PSI-less mutants and PSII-less mutants in microsecond time window were determined using pulsed, time-resolved photoacoustic techniques. The heat emission from the photochemical reaction can result in the positive thermal expansion photoacoustic signal, opposing the negative thylokoid volume contraction signal caused by electrostriction during the charge separation. In this present research, we observed that PSI differed strongly from PSII, both in thermal expansion and volume contraction. Similar to the bacterial reaction centre, PSI is marked with the large volume contraction but small thermal expansion, in contrast to the large thermal expansion but small volume contraction in PSII. For wild type, the volume contraction signal is dominant over the thermal expansion signal upon low pulse energy illumination at room temperature. In microsecond time scale, the energy storage efficiencies were estimated to be 36%, 80±5%, and 50±14% per trap in wild type, PSI and PSII, respectively. The different energy conversion efficiencies are probably attributed to the escape of the bound counterions from the particle surface in PSI and rapid electron transfer in PSII. In the present work, we conducted the photoacoustic experiments to study the energy storage in different photosystem with the intact cells of PSI-less and PSII-less mutants, instead of using either specific wavelength excitation light or PSII inhibitors (e. g. DCMU), which were commonly applied in the previous studies. We also proved photoacoustic techniques’ usefulness and convenience in the photosynthesis research, especially in electron transfer and some related thermodynamics studies.M.S.Includes bibliographical references (p. 22-27)by Chengyi Ya
Two Retrotransposon Elements in Intron of Porcine BMPR1B Is Associated with Phenotypic Variation
No full textIt has been established that through binding to bone morphogenetic proteins (BMPs), bone morphogenetic protein receptor I B (BMPR1B) can mediate transforming growth factor β (TGF-β) signal transduction, and is involved in the regulation of several biological processes, such as bone and muscle formation and homeostasis, as well as folliculogenesis. Also known as FecB, BMPR1B has been reported as the major gene for sheep prolificacy. A number of previous studies have analyzed the relationship between single nucleotide polymorphisms (SNPs) in this gene and its related performance. In recent years, with the illustration of the effect of retrotransposon insertion on the expression of the proximal genes or phenotypic variation, retrotransposon insertion polymorphisms (RIPs) have been used as a novel type of molecular marker in the evaluation of evolution, population structure and breeding of plant and domestic animals. In this study, the RIPs in porcine BMPR1B gene were excavated, and thereafter verified using a comparative genome and polymerase chain reaction (PCR). The potential effects of phenotype, gene expression and functions related to RIPs were also explored. The results showed that 13 distinct RIPs were identified in introns of porcine BMPR1B. Among these, only BMPR1B-SINE-RIP9 and BMPR1B-LINE-RIP13 displayed a close relationship with the growth traits of Large White pigs. Moreover, the total number of BMPR1B-SINE+/+-RIP9 individuals born was found to be significantly higher than that of SINE−/− (p < 0.05). These two RIPs showed an obvious distribution pattern among Chinese indigenous breeds and Western commercial breeds. The expression of BMPR1B in ovaries of adult BMPR1B-SINE+/+-RIP9 Sushan pigs was found to be significantly higher in comparison to those of BMPR1B-SINE−/−-RIP9 (p < 0.05). SINE insertion of BMPR1B-SINE-RIP9 and LINE insertion of BMPR1B-LINE-RIP13 were observed to significantly increase the activity of Octamer binding transcription factor 4 (OCT4) minipromoter in CHO and C2C12 cells (p < 0.01). Therefore, these two RIPs could serve as useful molecular markers for modulating the growth or reproductive traits in assisted selection of pig breeding, while the mechanisms of the insertion function should be studied further
Intelligent control and optimization for heating, ventilating, and air-conditioning systems
No full textThis thesis presents the development of intelligent control and optimization technologies for Heating, Ventilating, and Air-Conditioning (HVAC) systems.DOCTOR OF PHILOSOPHY (EEE
DEVELOPMENT OF PEPTIDE-BASED METHODS FOR CONTROLLING THE STRUCTURES, COMPOSITIONS, AND PROPERTIES OF COMPLEX NANOPARTICLE SUPERSTRUCTURES
No full textThis dissertation describes the development of a nanoparticle assembly methodology based on the use of peptide conjugate molecules. The aim of this research was to explore how this methodology could be used to control the structure, metrics, and properties of product nanoparticle superstructures.
Specifically, this document describes mechanistic studies aimed at understanding the key factors that govern the nanoparticle synthesis and assembly process. Using what we learned from these studies, we prepared high-quality helical nanoparticle superstructures and studied their chirooptical properties. We coupled theory and experiment to show how tuning the metrics and structure of the helices results in predictable and tailorable circular dichroism (CD) properties. We also describe how the composition of the peptide conjugate can influence both the structure of the nanoparticle assembly and detail how peptide conjugates can be utilized to prepare ‘hollow’ sub-100nm gold nanoparticle spheres. Finally, to expand the composition scope of our newly developed methodology, we present a new cobalt-binding peptide conjugate, which could be used to direct the synthesis and assembly of hollow CoPt nanospherical superstructures exhibiting electrocatalytic activity for methanol oxidation
SINE jumping contributes to large-scale polymorphisms in the pig genomes
No full textAbstract Background Molecular markers based on retrotransposon insertion polymorphisms (RIPs) have been developed and are widely used in plants and animals. Short interspersed nuclear elements (SINEs) exert wide impacts on gene activity and even on phenotypes. However, SINE RIP profiles in livestock remain largely unknown, and not be revealed in pigs. Results Our data revealed that SINEA1 displayed the most polymorphic insertions (22.5 % intragenic and 26.5 % intergenic), followed by SINEA2 (10.5 % intragenic and 9 % intergenic) and SINEA3 (12.5 % intragenic and 5.0 % intergenic). We developed a genome-wide SINE RIP mining protocol and obtained a large number of SINE RIPs (36,284), with over 80 % accuracy and an even distribution in chromosomes (14.5/Mb), and 74.34 % of SINE RIPs generated by SINEA1 element. Over 65 % of pig SINE RIPs overlap with genes, most of them (> 95 %) are in introns. Overall, about one forth (23.09 %) of the total genes contain SINE RIPs. Significant biases of SINE RIPs in the transcripts of protein coding genes were observed. Nearly half of the RIPs are common in these pig breeds. Sixteen SINE RIPs were applied for population genetic analysis in 23 pig breeds, the phylogeny tree and cluster analysis were generally consistent with the geographical distributions of native pig breeds in China. Conclusions Our analysis revealed that SINEA1–3 elements, particularly SINEA1, are high polymorphic across different pig breeds, and generate large-scale structural variations in the pig genomes. And over 35,000 SINE RIP markers were obtained. These data indicate that young SINE elements play important roles in creating new genetic variations and shaping the evolution of pig genome, and also provide strong evidences to support the great potential of SINE RIPs as genetic markers, which can be used for population genetic analysis and quantitative trait locus (QTL) mapping in pig
Taking on Proper Appearance and Putting It into Practice: Two Different Systems of Effort in Song and Ming Neo-Confucianism
No full textBoth “jianxing” 践形 (taking on proper appearance) and “jianxing” 践行 (putting into practice) were concepts coined by Confucians before the Qin Dynasty. They largely referred to similar things. But because the “Daxue” 大学 (“Great Learning”) was listed as one of the Sishu 四书 (The Four Books) during the Song Dynasty, different explanations and trends in terms of the “Great Learning” resulted in “taking on proper appearance” and “putting into practice” becoming two different systems of efforts. The former formed a vertical kind of representation and a complete system of practice by “developing the sincerity of intentions inside and taking on proper appearance and looks outside” in “shendu” 慎独 (self-discipline when alone) and “chengyi” 诚意 (developing the sincerity of intentions), and the latter developed into a horizontal system of practice through the interdependency of zhi 知 (knowing or knowledge) and xing 行 (doing or practice). The “interdependence between knowledge and practice” promoted by the Cheng brothers and Zhu Xi represented the vertical practice of moral understanding, while the “integration of knowing and doing” advocated by Wang Yangming represented using the way in “developing the sincerity of intentions” to adjust and transform the representation of the relationship between knowledge and practice. The ideas that were frequently stressed, such as “the same effort” and “naturally being so,” were all from “developing the sincerity of intentions” and “taking on proper appearance,” and they were all the representation of “really making intentions sincere.” In fact, the confusion over “the integration of knowing and doing” reflected the tension between two different systems and inconsistency in their thoughts.</jats:p
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