53 research outputs found
Molecular mechanisMaster for maintenance of primary root apical meristem along aging in Arabidopsis
No full textRoot apical meristem, Quiescent Center, Cell division and differentiation, Auxin, ORESARA 15prohibitionAbstract i
Table of contents iii
List of Figures and Tables v
Abbreviations viii
Chapter I General Introduction - 1 -
1.1 Overview of plant senescence - 1 -
1.2 Regulation of senescence - 2 -
1.3 Senescence of organs - 3 -
1.3.1 Root senescence - 4 -
1.4 Objectives - 10 -
Chapter II. Characterization of changes in molecular, cellular, and physiological characteristics in primary RAM along age - 11 -
2.1 Introduction - 11 -
2.2 Materials and Methods - 15 -
2.3 Results - 19 -
2.3.1 The rates of cell division and auxin and cytokinin responses in the primary RAM change as the root ages - 19 -
2.3.2 Size of QC cells and expression of QC cell-specific marker genes in the primary RAM are temporally changed - 21 -
2.3.3 Genotoxic stress tolerance of QC cells decreases with root age - 25 -
2.3.4 QC cells protect theMasterelves from genotoxic stress via mechanisMaster other than asymmetric chromosomal segregation (ACS) - 27 -
2.3.5 The rate of QC cell division is temporally regulated - 32 -
2.4 Discussion and conclusion - 37 -
Chapter III. ORESARA 15 (ORE15) is a temporal regulator of maintenance of primary RAM along age - 41 -
3.1 Introduction - 41 -
3.2 Materials and methods - 44 -
3.3 Results - 52 -
3.3.1 ORE15 shows temporal decrease in expression level in primary RAM - 52 -
3.3.2 ORE15 regulates the size of RAM - 54 -
3.3.3 ORE15 regulates the dynamics of meristem size along age - 56 -
3.3.4 ORE15 regulates the dynamics of root growth rate along age - 58 -
3.3.5 ORE15 controls the cell size in RAM and other zones in root - 62 -
3.3.6 ORE15 regulate cell division in proximal RAM and stem-cell niche - 64 -
3.3.7 ORE15 is a temporal regulator of cell division dynamics in RAM - 71 -
3.3.8 ORE15 is invloved in the auxin hormonal regulation of RAM - 76 -
3.3.9 ORE15 modulates the process of auxin transportation in RAM - 81 -
3.3.10 ORE15 and auxin positively feedback each other - 85 -
3.3.11 Downstream targets of ORE15 - 87 -
3.4 Discussion - 94 -
Summary in Korean - 109 -
Acknowledgement - 112 -
Curriculum Vitae - 113 -DoctordCollectio
Role of Alternatively Spliced Transcripts of ANAC083 in Arabidopsis
No full textMasterANAC083 is a member of a NAC [No apical meristem (NAM), Arabidopsis transcription activation factor (ATAF), Cup-shaped cotyledon (CUC)] transcription factor gene family in Arabidopsis. ANAC083 has been reported to be an important linker between environmental signaling and senescence. It has also been established as negative regulator of xylem vessel development. However, till date the regulation of ANAC083 is unknown. In this study, it was found that ANAC083 undergoes intron retention type of alternative splicing. The intron retained transcript ANAC083’ could produce truncated protein, ANAC083,’ consisting of only N terminal domain with intact protein dimerization domain but lacking DNA functional DNA binding domain. The truncated ANAC083’ protein showed dimerization with full length ANAC083 protein and its other ANAC interaction partners also. This nonfunctional dimerization could possibly lead to dominant negative effect to attenuate the transcriptional activity of ANAC083 and thus repression of its target genes. The T-DNA insertion mutant line of ANAC083 (GABI-799H09), capable of producing only truncated ANAC083’ protein, showed weak delayed senescence phenotype compared to wild type. Thus this study establishes alternative splicing as an important post-transcriptional regulatory mechanism for ANAC083 gene
From Iteration to System Failure: Characterizing the FITness of Periodic Weakly-Hard Systems
No full textEstimating metrics such as the Mean Time To Failure (MTTF) or its inverse, the Failures-In-Time (FIT), is a central problem in reliability estimation of safety-critical systems. To this end, prior work in the real-time and embedded systems community has focused on bounding the probability of failures in a single iteration of the control loop, resulting in, for example, the worst-case probability of a message transmission error due to electromagnetic interference, or an upper bound on the probability of a skipped or an incorrect actuation. However, periodic systems, which can be found at the core of most safety-critical real-time systems, are routinely designed to be robust to a single fault or to occasional failures (case in point, control applications are usually robust to a few skipped or misbehaving control loop iterations). Thus, obtaining long-run reliability metrics like MTTF and FIT from single iteration estimates by calculating the time to first fault can be quite pessimistic. Instead, overall system failures for such systems are better characterized using multi-state models such as weakly-hard constraints. In this paper, we describe and empirically evaluate three orthogonal approaches, PMC, Mart, and SAp, for the sound estimation of system’s MTTF, starting from a periodic stochastic model characterizing the failure in a single iteration of a periodic system, and using weakly-hard constraints as a measure of system robustness. PMC and Mart are exact analyses based on Markov chain analysis and martingale theory, respectively, whereas SAp is a sound approximation based on numerical analysis. We evaluate these techniques empirically in terms of their accuracy and numerical precision, their expressiveness for different definitions of weakly-hard constraints, and their space and time complexities, which affect their scalability and applicability in different regions of the space of weakly-hard constraints
Structural defect engineering of SnS thin films for photovoltaics
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from PDF version of thesis.Includes bibliographical references (pages 126-137).Tin (II) sulfide (SnS) is a promising Earth-abundant, non-toxic alternative to commercially available thin-film photovoltaic (PV) materials because of its near-ideal bandgap, high absorption coefficient, and potential for facile manufacturing. However, SnS-based photovoltaic devices have reached a maximum experimental efficiency of only 4.4%, compared to a theoretical maximum of 32%, primarily due to a low minority-carrier lifetime. In this work, I assess the impact of structural defects and anisotropy on the minority-carrier lifetime and other key device parameters, shedding light on the path to high-efficiency SnS-based photovoltaics. SnS thin films are deposited by thermal evaporation in a range of growth temperatures with varying structural defect density. Extended structural defects including intragranular defects and grain boundaries are directly related to minority-carrier collection length using high-resolution correlative electron microscopy. The results suggest that intragranular point defects, as opposed to extended structural defects, are likely responsible for the short minority-carrier lifetimes in present-day SnS films. Inhomogeneities in the polycrystalline SnS thin films due to the anisotropic material properties of SnS may also impact the device performance. Device simulations taking into account the orientation-dependent electron affinity of SnS show that a uniform grain orientation distribution is optimal. As a route toward both uniform grain orientation and low structural defect density, the anisotropic surface energy of SnS is harnessed by growth on a van der Waals-terminated substrate. An enhancement in both orientation uniformity and minority-carrier lifetime is measured, showing a promising path toward the ideal SnS film. Lastly, the process of optimization to reduce structural defect density may be expedited by in-situ characterization of micro- and nanoscale defects under realistic processing conditions. Toward this end, an in-situ temperature stage for synchrotron X-ray spectromicrosopy is developed to track nanoscale defects up to a sample temperature of 600°C. The stage enables previously unattainable in-situ studies of defect kinetics, allowing both a deeper understanding of how process conditions affect defect characteristics and the ability to rapidly optimize process conditions toward a defect-free film.by Rupak Chakraborty.Ph. D
Front End to Back End- Compiler Design
No full textAbstract: This research article explains how source code is assessed at the Front End and Back End of the compiler and which sections source code must pass and parse in order to generate target code. Furthermore, this paper discusses the concept of Pre-processors, Translators, Linkers, and Loaders, as well as the mechanism for using them and produces the code for the target The focus of this paper is on the concept of Compiler and Compiler Phases.
Keywords: Macro, Token, Lexemes, Identifier, Operators, Operands, Sentinel, Prefix, Postfix, IC, IR, Binary program.
Title: Front End to Back End- Compiler Design
Author: Mr. Rupak Kumar Gogoi, Mr. Abinash Borah, Ms. Chandrani Borah
International Journal of Computer Science and Information Technology Research
ISSN 2348-1196 (print), ISSN 2348-120X (online)
Vol. 10, Issue 2, April 2022 - June 2022
Page No: 97-106
Research Publish Journals
Website: www.researchpublish.com
Published Date: 25-June-2022
DOI: https://doi.org/10.5281/zenodo.6735151
Paper Download Link (Source)
https://www.researchpublish.com/papers/front-end-to-back-end--compiler-designInternational Journal of Computer Science and Information Technology Research, ISSN 2348-1196 (print), ISSN 2348-120X (online), Research Publish Journals, Website: www.researchpublish.co
MPC-based autonomous assignment algorithm for a swarm of satellites
No full textThis thesis was aimed for the Master of Science degree in Mechanical Engineering at The Delft University of Technology. The goal of this research was to formulate an assignment algorithm for autonomous guidance, control, and navigation system for spacecraft formation flying using a Model Predictive Control approach for estimation of fuel expenditure. This report is split into three parts. First, the earth's gravitation field and its variation are discussed. The relative motion in the orbit around the earth is briefly explained. The derivation of linearized relative dynamics by Clohessy-Wiltshire is presented. In the second part, the assignment problem is explained. The majority of the literature has been using the distance between the deployed state to the target state. A new approach is discussed using fuel as the assignment parameter including the framework for the assignment parameters is established. For the third part, fuel expenditure estimation using two types of control schemes is explained. The Artificial Potential Function approach is concisely explained. The choice of Model Predictive Control over Artificial Potential Function is discussed. The aim for the third part was the formulation of the control problem using the Model Predictive Control with a linearization dynamics model of the satellites. The system model used in the MPC formulation was constructed based on the Clohessy–Wiltshire relative equations of motion. The demonstrations were established using randomized positions. The simulations were performed and estimation of the fuel expenditure was explained based on the simulation results. The proposed assignment algorithm was tested using the fuel cost estimations from the MPC-based simulations. The results showed that the algorithm performed as designed. Lastly, the possible future research options are listed out.Mechanical Engineering | Vehicle Engineerin
Trends in IoT Research: A Bibliometric and Science mapping Analysis of Internet of Things
No full textInternet of Things (IoT) is about augmenting the existing power of the Internet beyond computers and smartphones to a whole range of other things, processes, and environments involving living or non-living species. It can bring life to the objects and enable them to communicate. This study presents the bibliometric analysis and science-mapping analysis on IoT. The data were extracted from the Web of Science (WoS) database from 1989–2019. In total 14,469 documents (articles, review, editorial material, proceedings, etc) were retrieved, which were further processed by VOSviewer software to perform advanced bibliometric analysis and science-mapping analysis. This research identifies the most productive or leading authors, countries, journals, institutions, keywords and to know their coauthorship pattern, co-citation pattern, bibliographic coupling pattern, the co-occurrence of keywords pattern in the research area of IoT. Results showed that Joel J.P.C Rodrigues was the most productive author, the People’s Republic of China was the most productive country, the Journal of EEE Access was the leading journal, Luigi Atzori was the most cited author. The main keywords more frequently occurred were Internet of things, and Internet, and Security. The analysis showed a collaboration relation between authors, countries and institutions. The visualizations conducted on this topic offer exploratory information on current status and trends on the scientific literature of IoT and provides insights for established and novice researchers in the understanding of this research topic
Science Mapping Analysis of Digital Humanities research: A scientometric study
No full textPurpose– The purpose of this paper is to use scientometric analysis to identify the current state of the academic literature regarding Digital humanities(DH) and analyze its knowledge base such as highly contributing researchers, countries, organizations, sources, keyword analysis and subject areas.
Design/methodology/approach– This study carried out a scientometric study on DH literature, 2909 records were retrieved from Scopus database, time span chosen as 2005-2020 as 15 years of study in DH research area. Retrieved data can be analyzed by using VOSviewer,Bibliometrix R package scientometric tools.
Findings – The findings suggested the enormous proliferation of DH research during last 15 years, social sciences scores highest position in subject category with (30.3%) publications. Hyvonen, Eero is the higly contributing author. USA is the most productive country. The King\u27s College London tops as the highly productive institutions in the DH research area. This study also shows strong co-authorship pattern between authors, countries and institutions. The most frequently used keyword in DH research is “Digital humanities”.
Originality/value– This study on scientometric analysis in DH literature may inform researchers and scholars of current trends and development in DH research area
Open Government Data (OGD) Initiative in India
No full textOpen Government Data (OGD) is a relevant discussion concerning transparency in governmental procedures. The chapter examines how India has followed up on the open data policy and constituted the Open Government Data (OGD) Platform and National Data Sharing and Accessibility Policy (NDSAP) to ensure that citizens can access data generated from public-funded governmental activities. The author has conducted an empirical examination of the status of the Open Government Data initiative in India, its scope, how the programme ranks against other countries, and has evaluated the same against the parameters of Democracy Index (33 out of 165), Open Data Barometer (43 out of 100) of Open Government Data and webometric analysis. India has taken proactive steps towards releasing government data to public domain. This can be seen in the rising growth in contribution of datasets and increase in OGD literature. The NDSAP and OGD Platform can be applauded as a healthy step on the part of the Government of India towards transparency and encouraging public participation in governance.</jats:p
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