The genetic diversities in salad rocket (Eruca Sativa) and their applications for healthy functional vegetable

Zhihao, Xu Kangwon National Univ. 2013 국내박사

Salad rocket (Eruca sativa Miller), is an annual herbaceous plant which belongs to the Brassicacea family. It is a nutrient rich vegetable with a distinctive taste. It contains a range of health-promoting phytochemicals including carotenoids (pro vitamin A), vitamin C, folate, fibres, polyphenols, flavonoids and glucosinolates (glucoerucin). Rocket is a traditional medicine plant in many countries for the therapeutic properties as astringent, diuretic, digestive, emollient, tonic, stomachic, depurative, laxative, rubefacient, stimulant and aphrodisiac. The modern scientific studies had approved some therapeutic effects, including anticancer and anti-diabetes. Rocket originated in the Miditerranean region and western Asia. These regions covered the north part of Africa, south of Europe, western Asia. The northwestern India, Tadzhikistan, Uzbekistan, western Tian-shan area of China and southwestern Asia are the subsequence centre area of original of rocket. Rocket is an easy naturalized plant and can be found in nature as weeds in other regions, covered south of Africa, north of Europe, far-east of Asia, Australasia and America. Currently, rocket is cultivated all around the world, but remains the most important in the Mediterranean region as salad vegetable. In some other regions, such as Sahel region in Africa, north India, west part of China, rocket is an important oil crop. All the information is applied to group the rocket genotypes tested as materials from native area or non-native area, and further the wild or cultivated materials, in this thesis. In the study of agronomical and morphological diversities in salad rockets, a total of 213 genotypes of rocket were tested. Among them, 152 genotypes are from native area and 61 genotypes from non-native area, while 196 genotypes are cultivated materials and 17 genotypes are wild materials. The data showed that large genotype diversities exist in rocket genotypes and in the population. In general, the growth of genotypes from native area was faster than those from non-native area, in the terms of leaf number, plant height and plant width. It was same for cultivated genotypes in comparison of wild genotypes. More cultivated genotypes and the genotypes from native area distributed in the higher range of leaf number, plant height and plant width, comparing to the wild genotypes and genotypes from non-native area. However, the length of bolting stem was shorter in cultivated genotypes and the genotypes from non-native area. These data could lead to a suggestion, despite of the complicate source history and variation among the genotypes, the cultivated genotypes and the genotypes of non-native area had received more human efforts which resulted from the farmer breeders, who tend to select the faster growth and later bolting plants for better crop production. The heavy hairy leaf is rare in the rocket genotypes, as this characteristics cause the rough feeling when consumed and it is possibly rejected during the seeds saving by farmers in the history. It is surprised that big proportion of rocket genotypes (about 41 % in 213 genotypes) started bolting with 4-5 leaves and some plants even had flower buds during period of middle of winter season (November) in glasshouse condition. Late bolting genotypes (21 % genotypes) or individuals were found in this experiment and can be used for selecting later bolting varieties. In the study of genotypic diversity of nitrate content in salad rockets, a total of 167 genotypes of rocket were used, which were from 16 countries. Among them, 141 genotypes are from native area and 26 genotypes from non-native area, while 152 genotypes are cultivated materials and 15 genotypes are wild materials. The data showed that large genotype diversity existed in rocket genotypes. The nitrate content ranged from 480.2 to 6175.3 mg kg-1 in fresh matter, and about 6.0% of genotypes had nitrate content less than 1000 mg kg-1 in fresh matter. Eight genotypes had nitrate content higher than 4500 mg kg-1 fm, which was about 4.8% in the total number of rockets tested. In general, the cultivated materials had higher nitrate content than the wild ones, and the genotypes from native area had higher nitrate content than those from non-native area. The genetic diversity of α-glucosidase inhibitory activity was studied. We measured 190 genotypes of rocket, which 128 genotypes are original from native area and 62 from non-native area, while 14 genotypes are wild materials and 176 genotypes are cultivated materials. The α-glucosidase inhibitory rate was ranged from 0.3 to 32.6%, with an average of 14.3%. Within these 190 genotypes, about 17.4% genotypes showed strong α-glucosidase inhibition activities, which α-glucosidase inhibition rate were higher than 20%. And about 31.6% genotypes had less than 10% of α-glucosidase inhibition rate. Among the top 10 genotypes with strongest α-glucosidase inhibitory activity (higher than 25% of inhibition rate), 9 genotypes were cultivated materials, 6 of them were from the native area where rocket is a popular folk medicine for diabetes. In the study of light-response curves of photosynthesis, 23 genotypes randomly selected for measuring the light-response curves of net photosynthetic rate across 10 incident irradiances as a series of photosynthetically active radiation (PAR) at 0, 50, 100, 200, 400, 600, 800, 1100, 1500 and 2000 μmol photons m-2 s-1. And three widely used models, non-rectangular hyperbola, rectangular hyperbola and single exponential equation, were applied to fit the photosynthesis-light response data of rocket genotypes. We found there are three photosynthesis-light response patterns. With the photosynthetically active photon flux density (PAR) increasing, the net photosynthetic rate increases without showing the saturation (as pattern A), showed the saturation trend (as pattern B) and showed their photosynthetic rates reached a certain peaks and decreased clearly (as pattern C). Computing results showed that these three widely used models (non-rectangular hyperbola, rectangular hyperbola and single exponential equation) fitted well for the photosynthesis-light response data of pattern A and pattern B, but failed for pattern C. In order to estimate the performance of photosynthetic rate in pattern C, we developed a new model. We assume the photosynthesis has two processes, increasing process (A1) and decreasing process (A2). For the increasing process (A1), the photosynthesis increases with increasing of light intensity followed a normal pattern, and it can be predicted by the non-rectangular hyperbola. For the decreasing process (A2), photosynthesis is reduced with the increase of light, due to the genetic background and environmental factors, and it can be predicted by a single exponential equation. The new model can be described as following equation: A= (Asat+PAR ×Qe- √(-4 × PAR × Qe × k×Asat+ (Asat+PAR ×Qe)^2 ))/(2 × k) -Rd-c ×(1-e^((d ×(PAR-PARt))) ) The computing results showed that our new model can fit well to the photosynthesis-light response data of all these three patterns, especial for pattern C. These results indicate our model may apply a new practical method for study of photosynthesis under light saturation or photo-inhibition conditions. In the study of genotypic diversity of photosynthetic rate, a total 173 genotypes of rocket were measured the photosynthetic rate in 4 incidences of photosynthetic active radiation at 0, 100, 800 and 2000 μmol photons m-2 s-1, which represented the different growing conditions in different seasons. The data showed that the average photosynthetic rate was -1.313, 3.079, 9.710 and 10.453 μmol CO2 m-2 s-1 for PAR of 0, 100, 800 and 2000 μmol photons m-2 s-1. The difference between maximum and minimum was 16.2, 8.84, 44.8 and 34.4 times for PAR of 0, 100, 800 and 2000 μmol photons m-2 s-1. In general, there were about 52.6% of genotypes had the characteristics of pattern A and 25.4 % for pattern B and 22.0 % for pattern C. Some extinguish typical genotypes with interested characteristics had been found. These data suggested that the large diversity among the genotypes of rocket could be a rich resource for variety selection in the existed genotypes, or for breeding for new health salad vegetable. Meanwhile, a breeding program is carried out to select rockets with low nitrate content and high α-glucosidase inhibitory. Two outstanding lines which considered to be used as Ssam and green for Bibimbap were finally selected in the spring of 2012, and labeled as Kangwondae Ssam and Chaoyongkang Girl respectively. Kangwondae Ssam is a new rocket line breed from a low nitrate content genotype (R131) after 5 generations. The young plants of Kangwondae Ssam have a big size of leaf and it can be used to wrap meat or fish. The pungency of leaf is mild and its α-glucosidase inhibitory is 14.9%. The up-erect growth habit allows this line can be grown in higher density to achieve higher yield per area. Chaoyongkang Girl is a new rocket line breed from a low nitrate content genotype (R96) after 5 generations. The young plants of Chaoyongkang Girl have a nice tooth type of leaf. The pungency of leaf is stronger. Its α-glucosidase inhibitory is high (29%) and considered as a good company with rice in Bibimbap, which can reduce the carbohydrates and sugar digestion. The up-erect growth habit allows this line can be grown in higher density and harvested mechanically. Keywords: α-glucosidase inhibitory, diversity, Eruca sativa, model, nitrate content, photosynthesis, salad rocket

Price bubbles in Shanghai housing market

Jiang, Zhihao Graduate School of International Studies, Yonsei U 2007 국내석사

This paper investigates housing price bubble level in Shanghai by identifying price movements owing to fundamental components and speculative components, using multiple regressions.This paper first introduces background of China's real estate development process and the economic bubbles. Then previous and recent studies on Shanghai housing price bubbles are presented, followed with discussion on Shanghai housing price bubble using statistical model. The results show that there are severe price bubbles in the housing market in year 2004 and 2005.Finally, several policy implications are presented.

All-in-one platform for rapid enrichment of plant-derived exosomes by depleting pathogenic bacteria

Wen, Zhihao Graduate School, Yonsei University 2023 국내석사

Plant-derived exosomes (PDEs) exhibit a range of benefits, including high biocompatibility, improvement of skin conditions, and the properties of anti-aging. However, traditional methods of PDEs isolation from plants, are complicated, time-consuming, and even rely on high technology and special equipment. Therefore, it is important for developing a simple method of purely isolating natural substances from plants. Here, an all-in-one platform for removing impurities to purify PDEs is designed and fabricated. The proposed platform comprises three parts: (i) transferring part for the inflow of samples, (ii) enrichment part for the depletion of impurities, and (iii) collection part for the obtainment of PDEs. The platform is designed to operate under the action of gravity without any electric control. The depletion of impurities could be achieved through the platform, such as the pathogenic bacteria in PDEs, by capturing magnetic beads coated with Concanavalin A (Con A). Notably, the PDEs purified using the Con A-coated magnetic beads provide better cell uptake and wound recovery than the commercialized extract PDEs. Accordingly, the fresh PDEs purified using the all-in-one platform have clear and practical significance for therapeutic effects and provide great prospects for the cosmeceutical and therapeutic field.

쇼트클립 광고의 메시지 특성과 광고 전달자의 신뢰성이 광고효과에 미치는 영향

He, Zhihao 경희대학교 대학원 2021 국내석사

This research aims to identify the effect of the short clips advertising, the innovation and practicability of advertising contents generate influence on the value of advertisements. We conducted a survey though a questionnaire completed by 267 users and select the most presentative Tik Tok short clips as the survey object to explore the factors of advertising value, the theoretical model respecting the impact of the Novelty, Utility and Entertainment of short clips advertising and the Expertise, Trustworthiness and Goodwill of advertising model on the advertising value and consumers' arousal effect and persuasive ability. Research results show that the advertising model generate greater impact on consumers than advertising, particularly the influence respecting authenticity. Furthermore, the positive impact of the interest of the short clips advertising on advertising value supported greatly. Structural equation model (SEM) was used to analyze the relationship among variables in this study.

Research on Consumers' intention of Purchase Green Products of Agricultural under The Background of The COVID-19 Epidemic

ZHIHAO LIU 가천대학교 일반대학원 2022 국내박사

Since the outbreak of COVID-19, local governments have responded to the call of the government and successively introduced measures to restrict the entry of closed communities, traffic control, stop production, waiting for work, family isolation, and home office. Therefore, different industries have been impacted to a certain extent, among which the agricultural product industry is also inevitable.Xu Wencheng (2017) pointed out that Chinese consumers also have an increasing demand for the quality of agricultural products transported in the COVID-19 epidemic.The No.1 document of the CPC Central Committee in 2021 clearly pointed out that the quality of agricultural products and food safety level should be comprehensively improved.At the same time, with China's grain output growing year after year, the enhancement of national economic strength, the upgrading of national consumption capacity, and the improvement of residents' environmental protection and health awareness, people no longer worry about the quantity and insufficient supply of agricultural products, but pay more attention to the quality and safety of agricultural products.Green products of agricultural are becoming more and more favored by the public with their unique safety and health characteristics.This paper mainly explores the influence of consumers' health awareness of green products of agricultural, consumer subjective norms and the traceability of green products of agricultural, and introduces the Stimulus-Organism-Response (S-O-R) theory, thus exploring the mutual influence relationship between these influencing factors and perceived value and willingness to purchase them.The first issue mainly studied in this paper is the relationship between consumer health awareness, subjective norms, and the traceability of green products of agricultural and consumers' perceived value of green products of agricultural.The second problem is the relationship between consumers 'perceived value of green products of agricultural and consumers' purchase intention green products of agricultural.The third question is whether the epidemic, as an environmental perceived risk, plays a regulatory role between consumers 'perceived value of green products of agricultural and consumers' purchase intention green products of agricultural.To answer these questions, this paper builds the research framework model and raises relevant assumptions based on SOR theory.The research method used in this paper is mainly literature method and questionnaire method. Taking the green products of agricultural consumers as the main research object, the data were collected by questionnaire, a total of 351 valid questionnaires, and then the SPSS26 software was used to analyze the test data and verify the hypothesis, so as to draw the research conclusion and complete the writing of this article.

Near-Source Wind Development and Pollution Dispersion over Complex Terrain

Li, Zhihao Carnegie Mellon University ProQuest Dissertations 2021 해외박사(DDOD)

Affine Grassmannians and Splitting Models for Triality Groups

Zhao, Zhihao Michigan State University ProQuest Dissertations & 2021 해외박사(DDOD)

Automated Discovery of Machine Learning Optimizations

Jia, Zhihao ProQuest Dissertations & Theses Stanford Universit 2020 해외박사(DDOD)

It's not just fluff: mechanisms underlying the ability of Saccharomyces cerevisiae to build complex multicellular colonies

Tan, Zhihao University of Washington 2014 해외박사(DDOD)

Most colonies formed by S.cerevisiae are simple domes, not surprising considering the yeast is a unicellular organism. However, certain S.cerevisiae strains are able to form complex and intricately patterned colonies that involve the formation of multicellular structures. The colony patterns formed by these strains are highly reproducible, indicating that they result from a well defined developmental path. Understanding this remarkable ability could give us insights into important biological phenomena such as biofilm formation, biological shape and pattern determination and the genetic architecture underlying complex traits. In this dissertation, the efforts taken to uncover the molecular mechanisms through which S.cerevisiae is able to achieve the formation of complex colony morphology are described. Through the thorough characterization of a novel switching phenomenon, we discover that the gain and loss of a single chromosome allows S.cerevisiae a quick, heritable and stable mechanism through which they are able to toggle their ability to form these complex colonies. This switch is made all the more remarkable with the realization that the phenotypic state of the colonies is able to confer fitness advantages in different conditions. The finding that the increased dosage of a single gene is sufficient for this switch then fuels an overexpression screen that uncovers novel suppressors of the trait. Through the further characterization of the transcriptome of several fluffy and smooth strains, we discover the importance of extracellular proteins for the formation of these colonies and how their expression is correlated with their molecular function. In summary, the findings described here not only newly implicate several proteins in the modulation of the trait and highlight the distinct transcriptional regulation of the mechanistic effectors of the trait, but also provide further insight into how aneuploidy is able to modulate the phenotypic state and fitness of an organism.

Conversion of three-dimensional nanostructured biosilica templates into non-oxide replicas

Bao, Zhihao Georgia Institute of Technology 2008 해외박사(DDOD)

Diatoms possess characteristics such as abundance, diversity, and high reproductivity, which make their nano-structured frustules (diatom frustules) attractive for a wide range of applications. To overcome the limitation of their silica based frustule composition, diatom frustules have been converted into a variety of materials including silicon, silicon carbide, silver, gold, palladium and carbon in the present study. The compositions and the extent of shape preservation of the replicas are examined and evaluated with different characterization methods such as X-ray diffraction, SEM, TEM and FTIR analyses. These replicas still retained the complex 3D structures and nano-scaled features of the starting diatom frustules. Some properties and possible applications of converted materials are explored and the kinetics and thermodynamics related to the successful replications (conversions) are also studied and discussed: (1) A low temperature (650°C) magnesiothermic reaction was used to convert three dimensional (3-D) nano-structured diatom frustules into microporous nanocrystalline silicon replicas. These silicon replicas possessed a very high surface area (>500 m2/g) and a large population of micropores (≤2 nm). The oxidized silicon frustule replicas exhibited photoluminescence under UV light. A microsensor fabricated from such a silicon frustule replica exhibited rapid (≤25 s) and sensitive nitric oxide gas detection (1 p.p.m.) with very low applied biased voltage (100 mV). This suggested a possible application in microscale gas sensing. The magnesium vapor partial pressure was the key parameter in controlling the products from the magnesiothermic reaction. Magnesium silicide is suggested as the source of magnesium gas to avoid the formation of a magnesium silicide product during the magnesiothermic reaction. (2) Metallic frustule replicas (e.g., Ag, Au, Pd) were obtained by immersing the microporous nanocrystalline silicon replicas in electroless plating solutions. Silicon carbide frustule replicas were synthesized with two steps. In the first step, the silicon frustule replicas were coated with carbon, either by resin coating or by pyrolysis of methane at 950°C. The coated carbon reacted with the silicon at 1200°C to form the silicon carbide frustule replicas. (3) A chlorine reaction process was used to convert the silicon carbide frustule replicas into carbon frustule replicas. This process also introduced micropores into the frustule replicas and, thus, the carbon frustules replicas possessed pores with sizes in various scales, which is important for catalysis. The carbon frustule replicas possessed high surface areas (e.g., 1368 m2/g) and micropore volumes (e.g., 0.386 cm3/g). Using a gas deposition method, Pt nanoparticles were successfully loaded into the nanopores of carbon frustule replicas, for possible catalytic application of carbon frustule replicas. The kinetics of the chlorine reaction process were also studied. Because the thickness of the formed carbon layer changed linearly with the reaction time but not the location, the rate-limiting step for the chlorine reaction process was found to be the reaction at the interface between the product carbon layer and the unreacted silicon carbide layer. The minimum time required for complete silicon removal from a silicon carbide frustule replica was also estimated, on the basis of the kinetic data from planar silicon carbide specimens. Considering the frustule diversity of extant diatom species and ongoing research to develop genetically-modified diatom frustules, diatoms (frustules) with precisely-controlled structures may be fabricated or cultured in the not-too-distant future. These structures may be converted into desired non-oxide compositions for specific applications through the synthetic chemical methods demonstrated in this dissertation. The control over 3-D microscale shape, nanoscale features, and chemistry afforded by such a process combining biology and synthetic chemistry should open the door to a wide variety of low-cost, high-performance electronic, optical, and chemical devices.