bluuebunny/crossref_metadata_2025_split huggingface dataset:
AtCCX3 Is an Arabidopsis Endomembrane H+-Dependent K+ Transporter
Authors: Morris Jay , Tian Hui , Park Sunghun , Sreevidya Coimbatore S. , Ward John M. , Hirschi Kendal D. 
Published: September 2008

Abstract
The Arabidopsis (Arabidopsis thaliana) cation calcium exchangers (CCXs) were recently identified as a subfamily of cation transporters; however, no plant CCXs have been functionally characterized. Here, we show that Arabidopsis AtCCX3 (At3g14070) and AtCCX4 (At1g54115) can suppress yeast mutants defective in Na+, K+, and Mn2+ transport. We also report high-capacity uptake of 86Rb+ in tonoplast-enriched vesicles from yeast expressing AtCCX3. Cation competition studies showed inhibition of 86Rb+ uptake in AtCCX3 cells by excess Na+, K+, and Mn2+. Functional epitope-tagged AtCCX3 fusion proteins were localized to endomembranes in plants and yeast. In Arabidopsis, AtCCX3 is primarily expressed in flowers, while AtCCX4 is expressed throughout the plant. Quantitative polymerase chain reaction showed that expression of AtCCX3 increased in plants treated with NaCl, KCl, and MnCl2. Insertional mutant lines of AtCCX3 and AtCCX4 displayed no apparent growth defects; however, overexpression of AtCCX3 caused increased Na+ accumulation and increased 86Rb+ transport. Uptake of 86Rb+ increased in tonoplast-enriched membranes isolated from Arabidopsis lines expressing CCX3 driven by the cauliflower mosaic virus 35S promoter. Overexpression of AtCCX3 in tobacco (Nicotiana tabacum) produced lesions in the leaves, stunted growth, and resulted in the accumulation of higher levels of numerous cations. In summary, these findings suggest that AtCCX3 is an endomembrane-localized H+-dependent K+ transporter with apparent Na+ and Mn2+ transport properties distinct from those of previously characterized plant transporters.
The F-Box Gene Family Is Expanded in Herbaceous Annual Plants Relative to Woody Perennial Plants
Authors: Yang Xiaohan , Kalluri Udaya C. , Jawdy Sara , Gunter Lee E. , Yin Tongming , Tschaplinski Timothy J. , Weston David J. , Ranjan Priya , Tuskan Gerald A. 
Published: September 2008

Abstract
F-box proteins are generally responsible for substrate recognition in the Skp1-Cullin-F-box complexes that are involved in protein degradation via the ubiquitin-26S proteasome pathway. In plants, F-box genes influence a variety of biological processes, such as leaf senescence, branching, self-incompatibility, and responses to biotic and abiotic stresses. The number of F-box genes in Populus (Populus trichocarpa; approximately 320) is less than half that found in Arabidopsis (Arabidopsis thaliana; approximately 660) or Oryza (Oryza sativa; approximately 680), even though the total number of genes in Populus is equivalent to that in Oryza and 1.5 times that in Arabidopsis. We performed comparative genomics analysis between the woody perennial plant Populus and the herbaceous annual plants Arabidopsis and Oryza in order to explicate the functional implications of this large gene family. Our analyses reveal interspecific differences in genomic distribution, orthologous relationship, intron evolution, protein domain structure, and gene expression. The set of F-box genes shared by these species appear to be involved in core biological processes essential for plant growth and development; lineage-specific differences primarily occurred because of an expansion of the F-box genes via tandem duplications in Arabidopsis and Oryza. The number of F-box genes in the newly sequenced woody species Vitis (Vitis vinifera; 156) and Carica (Carica papaya; 139) is similar to that in Populus, supporting the hypothesis that the F-box gene family is expanded in herbaceous annual plants relative to woody perennial plants. This study provides insights into the relationship between the structure and composition of the F-box gene family in herbaceous and woody species and their associated developmental and physiological features.
Terpene Biosynthesis in Glandular Trichomes of Hop
Authors: Wang Guodong , Tian Li , Aziz Naveed , Broun Pierre , Dai Xinbin , He Ji , King Andrew , Zhao Patrick X. , Dixon Richard A. 
Published: September 2008

Abstract
Hop (Humulus lupulus L. Cannabaceae) is an economically important crop for the brewing industry, where it is used to impart flavor and aroma to beer, and has also drawn attention in recent years due to its potential pharmaceutical applications. Essential oils (mono- and sesquiterpenes), bitter acids (prenylated polyketides), and prenylflavonoids are the primary phytochemical components that account for these traits, and all accumulate at high concentrations in glandular trichomes of hop cones. To understand the molecular basis for terpene accumulation in hop trichomes, a trichome cDNA library was constructed and 9,816 cleansed expressed sequence tag (EST) sequences were obtained from random sequencing of 16,152 cDNA clones. The ESTs were assembled into 3,619 unigenes (1,101 contigs and 2,518 singletons). Putative functions were assigned to the unigenes based on their homology to annotated sequences in the GenBank database. Two mono- and two sesquiterpene synthases identified from the EST collection were expressed in Escherichia coli. Hop MONOTERPENE SYNTHASE2 formed the linear monterpene myrcene from geranyl pyrophosphate, whereas hop SESQUITERPENE SYNTHASE1 (HlSTS1) formed both caryophyllene and humulene from farnesyl pyrophosphate. Together, these enzymes account for the production of the major terpene constituents of the hop trichomes. HlSTS2 formed the minor sesquiterpene constituent germacrene A, which was converted to β-elemene on chromatography at elevated temperature. We discuss potential functions for other genes expressed at high levels in developing hop trichomes.
Extremely High-Level and Rapid Transient Protein Production in Plants without the Use of Viral Replication
Authors: Sainsbury Frank , Lomonossoff George P. 
Published: September 2008

AbstractPlant-based overexpression of heterologous proteins has attracted much interest and development in recent years. To date, the most efficient vectors have been based on RNA virus-derived replicons. A system based on a disabled version of cowpea mosaic virus RNA-2 has been developed, which overcomes limitations on insert size and introduces biocontainment. This system involves positioning a gene of interest between the 5′ leader sequence and 3′ untranslated region (UTR) of RNA-2, thereby emulating a presumably stable mRNA for efficient translation. Thus far, the sequence of the 5′ UTR has been preserved to maintain the ability of the modified RNA-2 to be replicated by RNA-1. However, high-level expression may be achieved in the absence of RNA-1-derived replication functions using Agrobacterium-mediated transient transformation. To investigate those features of the 5′ UTR necessary for efficient expression, we have addressed the role of two AUG codons found within the 5′ leader sequence upstream of the main initiation start site. Deletion of an in-frame start codon upstream of the main translation initiation site led to a massive increase in foreign protein accumulation. By 6 d postinfiltration, a number of unrelated proteins, including a full-size IgG and a self-assembling virus-like particle, were expressed to &gt;10% and 20% of total extractable protein, respectively. Thus, this system provides an ideal vehicle for high-level expression that does not rely on viral replication of transcripts.
Transcriptome Analyses Show Changes in Gene Expression to Accompany Pollen Germination and Tube Growth in Arabidopsis
Authors: Wang Yi , Zhang Wen-Zheng , Song Lian-Fen , Zou Jun-Jie , Su Zhen , Wu Wei-Hua 
Published: September 2008

Abstract
Pollen germination, along with pollen tube growth, is an essential process for the reproduction of flowering plants. The germinating pollen with tip-growth characteristics provides an ideal model system for the study of cell growth and morphogenesis. As an essential step toward a detailed understanding of this important process, the objective of this study was to comprehensively analyze the transcriptome changes during pollen germination and pollen tube growth. Using Affymetrix Arabidopsis (Arabidopsis thaliana) ATH1 Genome Arrays, this study is, to our knowledge, the first to show the changes in the transcriptome from desiccated mature pollen grains to hydrated pollen grains and then to pollen tubes of Arabidopsis. The number of expressed genes, either for total expressed genes or for specifically expressed genes, increased significantly from desiccated mature pollen to hydrated pollen and again to growing pollen tubes, which is consistent with the finding that pollen germination and tube growth were significantly inhibited in vitro by a transcriptional inhibitor. The results of Gene Ontology analyses showed that expression of genes related to cell rescue, transcription, signal transduction, and cellular transport was significantly changed, especially for up-regulation, during pollen germination and tube growth. In particular, genes of the calmodulin/calmodulin-like protein, cation/hydrogen exchanger, and heat shock protein families showed the most significant changes during pollen germination and tube growth. These results demonstrate that the overall transcription of genes, both in the number of expressed genes and in the levels of transcription, was increased. Furthermore, the appearance of many novel transcripts during pollen germination as well as tube growth indicates that these newly expressed genes may function in this complex process.
ArabidopsisWRKY38 and WRKY62 Transcription Factors Interact with Histone Deacetylase 19 in Basal Defense
Authors: Kim Kang-Chang , Lai Zhibing , Fan Baofang , Chen Zhixiang 
Published: September 2008

AbstractArabidopsis thaliana WRKY38 and WRKY62, encoding two structurally similar type III WRKY transcription factors, are induced in a Nonexpressor of PR Gene1 (NPR1)–dependent manner by salicylic acid (SA) or by virulent Pseudomonas syringae. Disease resistance and SA-regulated Pathogenesis-Related1 (PR1) gene expression are enhanced in the wrky38 and wrky62 single mutants and, to a greater extent, in the double mutants. Overexpression of WRKY38 or WRKY62 reduces disease resistance and PR1 expression. Thus, WRKY38 and WRKY62 function additively as negative regulators of plant basal defense. WRKY38 and WRKY62 interact with Histone Deacetylase 19 (HDA19). Expression of HDA19 is also induced by P. syringae, and the stability of its induced transcripts depends on SA and NPR1 in infected plants. Disruption of HDA19 leads to compromised resistance, whereas its overexpression results in enhanced resistance to P. syringae. Thus, HDA19 has a role opposite from those of WRKY38 and WRKY62 in basal resistance to the bacterial pathogen. Both WRKY38 and WRKY62 are transcriptional activators in plant cells, but their activation activities are abolished by overexpressed HDA19. Interaction of WRKY38 and WRKY62 with HDA19 may act to fine-tune plant basal defense responses.
RNase-Based Self-Incompatibility: Puzzled byPollen S
Authors: Newbigin Ed , Paape Timothy , Kohn Joshua R. 
Published: September 2008

AbstractMany plants have a genetically determined self-incompatibility system in which the rejection of self pollen grains is controlled by alleles of an S locus. A common feature of these S loci is that separate pollen- and style-expressed genes (pollen S and style S, respectively) determine S allele identity. The long-held view has been that pollen S and style S must be a coevolving gene pair in order for allelic recognition to be maintained as new S alleles arise. In at least three plant families, the Solanaceae, Rosaceae, and Plantaginaceae, the style S gene has long been known to encode an extracellular ribonuclease called the S-RNase. Pollen S in these families has more recently been identified and encodes an F-box protein known as either SLF or SFB. In this perspective, we describe the puzzling evolutionary relationship that exists between the SLF/SFB and S-RNase genes and show that in most cases cognate pairs of genes are not coevolving in the expected manner. Because some pollen S genes appear to have arisen much more recently than their style S cognates, we conclude that either some pollen S genes have been falsely identified or that there is a major problem with our understanding of how the S locus evolves.
Comparative Genomics and Reverse Genetics Analysis Reveal Indispensable Functions of the Serine Acetyltransferase Gene Family in Arabidopsis
Authors: Watanabe Mutsumi , Mochida Keiichi , Kato Tomohiko , Tabata Satoshi , Yoshimoto Naoko , Noji Masaaki , Saito Kazuki 
Published: September 2008

Abstract
Ser acetyltransferase (SERAT), which catalyzes O-acetyl-Ser (OAS) formation, plays a key role in sulfur assimilation and Cys synthesis. Despite several studies on SERATs from various plant species, the in vivo function of multiple SERAT genes in plant cells remains unaddressed. Comparative genomics studies with the five genes of the SERAT gene family in Arabidopsis thaliana indicated that all three Arabidopsis SERAT subfamilies are conserved across five plant species with available genome sequences. Single and multiple knockout mutants of all Arabidopsis SERAT gene family members were analyzed. All five quadruple mutants with a single gene survived, with three mutants showing dwarfism. However, the quintuple mutant lacking all SERAT genes was embryo-lethal. Thus, all five isoforms show functional redundancy in vivo. The developmental and compartment-specific roles of each SERAT isoform were also demonstrated. Mitochondrial SERAT2;2 plays a predominant role in cellular OAS formation, while plastidic SERAT2;1 contributes less to OAS formation and subsequent Cys synthesis. Three cytosolic isoforms, SERAT1;1, SERAT3;1, and SERAT3;2, may play a major role during seed development. Thus, the evolutionally conserved SERAT gene family is essential in cellular processes, and the substrates and products of SERAT must be exchangeable between the cytosol and organelles.
Determination and extrapolation of the glider load spectra
Authors: Rodzewicz Mirosław 
Published: September 2008

PurposeThe purpose of this paper is to present a study on methods for load spectrum (LS) determination and extrapolation, basing on data obtained from experiments.Design/methodology/approachA sequence of loads registered in flight becomes an object of analysis aimed to calculate full cycles of loads, and on this basis two possible types of LS are determined, i.e. as the transfer array, or in classic form (as the plot presenting appearances of load increments, called “incremental load spectrum”). While the use of incremental LS enables just application of deterministic extrapolation methods, the transfer array enables application of the stochastic method of extrapolation that consists of random redistribution of the transfer array cell values.FindingsThe paper presents a comparison between the results of application of deterministic or stochastic extrapolation methods. Attention was focused on the LS registered during thermal flights. The stochastic extrapolation method is less conservative than the deterministic ones, and enables better adjustment of estimated LS to the reality.Originality/valueThe novel extrapolation method consists of cumulation of the results of stochastic redistribution of the values in transfer array obtained from the experiment.
A new method for design cycle period management in aircraft design process
Authors: Soltanmohammad B. , Malaek S.M. 
Published: September 2008

PurposeThe purpose of this paper is to present research into reducing the aircraft design cycle period, by reducing the necessary number of design cycle iterations. The design cycle period is one of the main characteristics of the design process and design cycle iterations play a major role in the design cycle period.Design/methodology/approachTo achieve the above‐mentioned goal, the paper presents a mathematical model of iterations for the aircraft design process. This model describes the design coupled tasks as a discrete‐linear time invariant dynamic system. This model also helps identify tasks which are the most important for generating iterations. This new method basically helps break information cycles that create iterations among important tasks.FindingsStudies conducted on a general aviation (GA) airplane (FAJR‐3) design process show the success of the suggested approach. This procedure eventually leads to an expedited convergence rate for the design iterations. That is, through proper breaking of information cycles, the convergence rate of the most dominant design mode could be increased by up to 31 percent. The process also leads to decoupling of the so‐called “coupled parts of design process,” which in turn leads to a more modular design with relatively easier management.Practical implicationsThis method offers a new way of managing aircraft design processes while having to deal with constraints such as time and resources. The approach could be easily implemented as it manages any complex design‐process based on its resemblance to a dynamic system. The method can also be used as a component of an Integrated Airframe Design (IAD), as a tool for “Cycle time reduction”.Originality/valueThe advantage of this new approach, over other existing ones, lies in its ability to distinguish the important information cycles in a systematic manner. This helps to break the design process in a way that guarantees the increase in convergence speed of the whole design process.
Multiple specification controller design for F‐16 fighters
Authors: Fung Eric H.K. , Wong Y.K. , Liu Hugh H.T. , Li Y.C. 
Published: September 2008

PurposeThe purpose of this paper is to show how to design effective and practical controllers that satisfy multiple simultaneous specifications (MSS) criteria concurrently.Design/methodology/approachIn automatic flight control system or autopilots, MSS such as good holding (small static altitude holding error), fast response, smooth transition (less oscillation, overshoot) are needed to be satisfied concurrently. So how to design the MSS controller effectively and practically is a very significant and challenging job. An MSS controller design method is proposed. The paper further applies the method together with the fine‐tuning technique to the 6 DoF non‐linear F‐16 fighter longitudinal control channel. Simulation results show its applicability to non‐linear flight control system.FindingsIt was found that the simulation results demonstrate that the MSS design method with controller fine‐tuning can be applied to the nonlinear F‐16 fighter longitudinal control system.Research limitations/implicationsThe practical implementation of this research work needs further investigation.Practical implicationsThe simplicity of the design algorithm facilitates the application of the design to other aircrafts by use of Matlab.Originality/valueThe simulation results presented demonstrate that the proposed MSS apply well to non‐linear F‐16 fighters.
Fuzzy logic‐based automated engine health monitoring for commercial aircraft
Authors: Demirci Seref , Hajiyev Chingiz , Schwenke Andreas 
Published: September 2008

PurposeThe purpose of this paper is to develop an automated engine health monitoring system (AEHMS) for commercial aircraft.Design/methodology/approachThe AEHMS is developed by using fuzzy logic. The input of the fuzzy logic is engine performance parameters gathered from aircraft for every flight during cruise. The fuzzy rule inference system for different engine faults is based on expert knowledge and real life data in the Turkish Airlines fleet. The very smallest is used for defuzzification, since it provides a more meaningful result than others. The complete loop of engine health monitoring (EHM) is automatically performed by the programs and Fuzzy Logic Toolbox in MATLAB. The system produces output values between 0 – faulty and 1 – not faulty for every fault or deterioration on a time series. The program triggers an alert if any output exceeds a specified value. Finally, the method is utilized for monitoring the engines in the Turkish Airlines fleet.FindingsHealth monitoring has been a very popular subject to increase aircraft availability with the minimum maintenance cost. Fuzzy logic is a very useful method for automated health monitoring strategies.Research limitations/implicationsIt does not provide long‐term engine maintenance decisions such as scheduling overhaul times, predicting the remaining life of the engine components.Originality/valueThe paper provides a robust method for EHM with the application to real aircraft data. The AEHMS can greatly simplify the EHM system for airlines and minimizes its drawbacks, such as extra labor hours, human error and requirement for engineering expertise.
Aircraft sustaining: a holistic and systemic approach establishing the various support components
Authors: Camelier Ivan A. , Lourenço Luis A. , Lourenço da Saúde José 
Published: September 2008

PurposeThe purpose of this paper is to describe the results of research into the support activities of commercial aircraft (A/C).Design/methodology/approachThe work is associated with A/C operations (OPS) providing a structure establishing the A/C sustaining during the in‐service phase. The process involved the implementation of a field survey in order to capture heuristically A/C support practices to enable one to identify system requirements. This part of the work utilized the collaboration of 21 A/C operators and maintenance repair and overhaul companies from various regions of the world.FindingsUsing systems engineering methodology, the research process led to the development of a prototype sustaining system. The solution comprises a tree of support functionalities (similar to a work breakdown structure). The result was verified by major local national airlines which confirmed the ability of the solution in terms of representing a viable structure establishing an A/C sustaining system.Originality/valueThe research initiative presented represents a contribution in the domain of A/C OPS, namely in terms of management aspects, by making available a solution that serves as a reference element, with a holistic nature, that integrates, normalizes and unifies commercial A/C support practices.
Autonomous orbit and attitude determination of satellite using SEMOI
Authors: Zhang Y. , Jing W.X. , Liu L.K. 
Published: September 2008

PurposeAn onboard autonomous technique can significantly reduce the costs of the mission. The purpose of this paper is to deal with the autonomous orbit determination and attitude determination of a satellite based on the sun, the earth and the moon sensors.Design/methodology/approachThe models of the conical earth scanner are presented, and its measurement with information from the sun and the moon sensors is processed to simultaneously acquire the orbit and attitude of the satellite via extended Kalman filter.FindingsThe numerical simulation shows that the presented method can obtain the orbit and attitude information precisely; even in the new moon period, it can be used to get the satisfied results.Originality/valueAutonomous orbit determination and attitude determination based on direction information of celestial objects, such as sun, earth and moon, are put forward. The method improves the survival ability of the satellite and decreases its reliance on the ground stations.