bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Glucosylation Reaction on Anthocyanins Catalyzed by Acyl-Glucose–Dependent Glucosyltransferase in the Petals of Carnation and Delphinium
Authors: Matsuba Yuki , Sasaki Nobuhiro , Tera Masayuki , Okamura Masachika , Abe Yutaka , Okamoto Emi , Nakamura Haruka , Funabashi Hisakage , Takatsu Makoto , Saito Mikako , Matsuoka Hideaki , Nagasawa Kazuo , Ozeki Yoshihiro 
Published: October 2010

Abstract
Glucosylation of anthocyanin in carnations (Dianthus caryophyllus) and delphiniums (Delphinium grandiflorum) involves novel sugar donors, aromatic acyl-glucoses, in a reaction catalyzed by the enzymes acyl-glucose–dependent anthocyanin 5(7)-O-glucosyltransferase (AA5GT and AA7GT). The AA5GT enzyme was purified from carnation petals, and cDNAs encoding carnation Dc AA5GT and the delphinium homolog Dg AA7GT were isolated. Recombinant Dc AA5GT and Dg AA7GT proteins showed AA5GT and AA7GT activities in vitro. Although expression of Dc AA5GT in developing carnation petals was highest at early stages, AA5GT activity and anthocyanin accumulation continued to increase during later stages. Neither Dc AA5GT expression nor AA5GT activity was observed in the petals of mutant carnations; these petals accumulated anthocyanin lacking the glucosyl moiety at the 5 position. Transient expression of Dc AA5GT in petal cells of mutant carnations is expected to result in the transfer of a glucose moiety to the 5 position of anthocyanin. The amino acid sequences of Dc AA5GT and Dg AA7GT showed high similarity to glycoside hydrolase family 1 proteins, which typically act as β-glycosidases. A phylogenetic analysis of the amino acid sequences suggested that other plant species are likely to have similar acyl-glucose–dependent glucosyltransferases.
A Maize Thiamine Auxotroph Is Defective in Shoot Meristem Maintenance
Authors: Woodward John B. , Abeydeera N. Dinuka , Paul Debamita , Phillips Kimberly , Rapala-Kozik Maria , Freeling Michael , Begley Tadhg P. , Ealick Steven E. , McSteen Paula , Scanlon Michael J. 
Published: October 2010

AbstractPlant shoots undergo organogenesis throughout their life cycle via the perpetuation of stem cell pools called shoot apical meristems (SAMs). SAM maintenance requires the coordinated equilibrium between stem cell division and differentiation and is regulated by integrated networks of gene expression, hormonal signaling, and metabolite sensing. Here, we show that the maize (Zea mays) mutant bladekiller1-R (blk1-R) is defective in leaf blade development and meristem maintenance and exhibits a progressive reduction in SAM size that results in premature shoot abortion. Molecular markers for stem cell maintenance and organ initiation reveal that both of these meristematic functions are progressively compromised in blk1-R mutants, especially in the inflorescence and floral meristems. Positional cloning of blk1-R identified a predicted missense mutation in a highly conserved amino acid encoded by thiamine biosynthesis2 (thi2). Consistent with chromosome dosage studies suggesting that blk1-R is a null mutation, biochemical analyses confirm that the wild-type THI2 enzyme copurifies with a thiazole precursor to thiamine, whereas the mutant enzyme does not. Heterologous expression studies confirm that THI2 is targeted to chloroplasts. All blk1-R mutant phenotypes are rescued by exogenous thiamine supplementation, suggesting that blk1-R is a thiamine auxotroph. These results provide insight into the role of metabolic cofactors, such as thiamine, during the proliferation of stem and initial cell populations.
RAD5A, RECQ4A, and MUS81 Have Specific Functions in Homologous Recombination and Define Different Pathways of DNA Repair inArabidopsis thaliana
Authors: Mannuss Anja , Dukowic-Schulze Stefanie , Suer Stefanie , Hartung Frank , Pacher Michael , Puchta Holger 
Published: October 2010

AbstractComplex DNA structures, such as double Holliday junctions and stalled replication forks, arise during DNA replication and DNA repair. Factors processing these intermediates include the endonuclease MUS81, helicases of the RecQ family, and the yeast SNF2 ATPase RAD5 and its Arabidopsis thaliana homolog RAD5A. By testing sensitivity of mutant plants to DNA-damaging agents, we defined the roles of these factors in Arabidopsis. rad5A recq4A and rad5A mus81 double mutants are more sensitive to cross-linking and methylating agents, showing that RAD5A is required for damage-induced DNA repair, independent of MUS81 and RECQ4A. The lethality of the recq4A mus81 double mutant indicates that MUS81 and RECQ4A also define parallel DNA repair pathways. The recq4A/mus81 lethality is suppressed by blocking homologous recombination (HR) through disruption of RAD51C, showing that RECQ4A and MUS81 are required for processing recombination-induced aberrant intermediates during replication. Thus, plants possess at least three different pathways to process DNA repair intermediates. We also examined HR-mediated double-strand break (DSB) repair using recombination substrates with inducible site-specific DSBs: MUS81 and RECQ4A are required for efficient synthesis-dependent strand annealing (SDSA) but only to a small extent for single-strand annealing (SSA). Interestingly, RAD5A plays a significant role in SDSA but not in SSA.
Fatigue crack detection in metallic plates with non‐linear Lamb wave modulation spectrum
Authors: Guili Gao , Dayong Li , Dequan Shi , Jingwei Dong 
Published: October 2010

PurposeThe purpose of this paper is to demonstrate by experiments that non‐linear Lamb wave modulation spectrum (NLWMS) will be a good indicator of fatigue cracks in a metallic plate.Design/methodology/approachA system composed of piezoelectric transducers, arbitrary waveform generator, power amplifier, laser vibrometer, digital oscilloscope and computer has been constructed, and using this system, three samples made of 7075‐T6 aluminium alloy plates are studied, respectively. One is with a fatigue crack, one is with a through hole and the other is intact.FindingsThe experimental results show that there are no significant harmonics and sidebands in the intact sample, and there are no modulation frequencies in the drilled‐hole sample. On the contrary, in the cracked sample, there is an abundance of the harmonics and sidebands. Therefore, these new modulation frequency components can be used to indicate the presence of the fatigue crack.Practical implicationsThis paper will provide a method for detecting fatigue crack in metallic plates, especially aluminium alloy plates for aerospace applications.Originality/valueUnder the excitation of two different frequency Lamb waves, experiments on 7075‐T6 alloy plates show that new rising modulation frequency components can be used to indicate the presence of the crack. So, the fatigue crack in metallic plates can be detected by NLWMS.
Minimum emission current of indium‐field emission electric propulsion thruster
Authors: Junyi Duan , Xiaoming Kang , Wansheng Zhao 
Published: October 2010

PurposeField emission electric propulsion (FEEP) thruster is a type of electric propulsion based on space‐proven indium liquid metal ion sources. The lifetime of FEEP thruster limits its application in space. A better method to improve its lifetime is the reduction of emission current. This paper aims to discuss the minimum emission current of operating FEEP thrusters.Design/methodology/approachIn this work, theoretical models, including fluid‐flow model and ion formation model, are analyzed. Current densities of these models are discussed and the minimum emission current is calculated.FindingsThere are few equilibrium states under low emission current conditions. However, the minimum emission current is the only stable state at which the FEEP thruster can operate.Research limitations/implicationsThis analysis is mainly based on the needle indium FEEP, which is compared indirectly with experiments of gallium.Practical implicationsThis paper attempts to help designers choose appropriate electric parameters to improve the lifetime of FEEP.Originality/valueBy introducing and analyzing theoretical models, this paper calculates the minimum emission current for stable operation of FEEP.
Longitudinal flight dynamic analysis of an agile UAV
Authors: Maqsood Adnan , Hiong Go Tiauw 
Published: October 2010

PurposeThe purpose of this paper is to describe the longitudinal dynamics of a hover‐capable rigid‐winged unmanned aerial vehicles (UAV) under various equilibrium flight conditions. The effects of the variable‐incidence wing in comparison with the fixed in‐incidence wing on the dynamics of UAV are also discussed.Design/methodology/approachThe aerodynamic modeling of the vehicle covers both pre‐stall and post‐stall regimes using a three‐dimensional vortex lattice method incorporating viscous corrections. The trim states across a velocity spectrum are evaluated using a nonlinear constrained optimization scheme based on sequential quadratic programming. Then linearized dynamic analysis around trim states is carried out in order to compare the characteristics of the conventional platform with the modified platform incorporating variable‐incidence wing.FindingsIt is found that with the variable‐incidence wing, the longitudinal equilibrium flights can be achieved with reduced thrust‐to‐weight ratio demands and lower elevator deflection. However, the use of the variable‐incidence wing changes the dynamic characteristics of the vehicle considerably as indicated through the linear dynamic analysis.Research limitations/implicationsThe results presented in this paper are based on linear dynamic analysis about static trim point data. Further analysis taking into account nonlinearity, the unsteady aerodynamic effects and associated cross‐coupling because of asymmetric forces may be needed to reveal the true dynamics of the vehicle under unsteady maneuvers.Practical implicationsThe variable‐incidence wing is a useful design feature to reduce the thrust‐to‐weight ratio requirements and to increase elevator control authority, however its effect on the dynamics warrants further investigation.Originality/valueThis is the first paper highlighting the effects of variable‐incidence wing on an agile hover‐capable UAV.
Integrated waypoint path generation and following of an unmanned aerial vehicle
Authors: Lee Sanghyo , Cho Am , Kee Changdon 
Published: October 2010

PurposeThe purpose of this paper is to present an efficient method to integrate path generation and following for an unmanned aerial vehicle.Design/methodology/approachThe shortest path is briefly reviewed using a straight line and a circular arc in a horizontal plane. Based on shortest paths, various path generation algorithms using oriented waypoints are described. Path design unit, which is structured concatenations of line segments and circular arcs, is proposed to represent different paths as one structure. Simple path following controller to follow a straight line and a circle was also implemented with linear‐quadratic regulator control laws. Some flight tests were conducted to verify the efficiency of proposed algorithm.FindingsProposed method represents various paths between given waypoints efficiently by a small number of parameters. It does not need a large amount of memory storage and computation time to run in real time on a low‐cost microprocessor.Originality/valueThis paper provides new structured method to generate different paths efficiently including Dubins' set, which makes path following easy by simple switching logic. It needs small computational time to run in real time. The proposed algorithm in this paper could be used as a basis of other applications such as air traffic control and curved landing approach, which require more accurate path control.
The flying laboratory for aeronautics students' education
Authors: Tomczyk Andrzej 
Published: October 2010

PurposeThe main targets of the work are analysis and simulation of flying laboratory performance. In particular, synthesis of control system for handling qualities change and evaluation in flight are taken into consideration.Design/methodology/approachModification of handling qualities is obtained by applying indirect flight control system (FBW). The properties of the optimal controller are calculated through the indirect (implicit) model‐following method. In particular, the modified version based on the computer simulations is used.FindingsCalculation and simulation concern the synthesis of desired handling qualities of the general aviation aircraft PZL‐M20 “Mewa” equipped with indirect (FBW) experimental flight control system. Results of the simulation show that the flying laboratory has the same properties as modeled aircraft, and it is possible to say that handling properties concern attitude orientation of the experimental aircraft is similar to modeled commuter aircraft.Practical implicationsThe result of research can be implemented on a project of the flying laboratory based on general aviation aircraft PZL M20 “Mewa”.Originality/valueThe paper presents the practical approach for synthesis of the “Simplified total in flight simulator” performance which can be used for analysis of handling qualities of general aviation aircraft equipped with FBW. Research of this type focuses on military and transport airplanes however, there are no published works in the area of small aircraft so far.
Documentary tools in everyday life: the wedding planner
Authors: McKenzie Pamela J. , Davies Elisabeth 
Published: October 2010

PurposeThis paper aims to analyze documentary planning tools for an everyday life project, the wedding, to study how “document work” is constructed in this setting.Design/methodology/approachUsing Law and Lynch's study of birdwatching guides for novices as a framework, nine commercially‐available wedding planning guides targeted toward the primary planner, almost universally the bride, were analyzed.FindingsAs Law and Lynch found, part of a novice's apprenticeship requires learning how to “see” in ways that are socially organized in and through texts. The paper shows how characteristics of birdwatching guides (naturalistic accountability, a picture theory of representation, and the strategic use of texts) are also evident in wedding planners, and how the very features that make these guides usable also occasion troubles for their users. Wedding planning guides treat the bride as a novice and instruct her in seeing wedding‐related tasks and times as amenable to management. However, planning a wedding requires multiple tasks and times that may be intertwined in ways that make both their representation and their execution highly complex.Research limitations/implicationsThe need for both temporal and thematic access highlights more general problems of knowledge organization in presenting a complex planning project in a linear and paper format.Originality/valueAs workplace principles of time and project management are increasingly applied to everyday life, this paper provides a needed case study of the ways that everyday recordkeeping contributes to the novice bride's gendered apprenticeship and embeds her work within broader organizational and ideological systems.
Opening and closing rituals of the virtual reference service of the Internet Public Library
Authors: Park Jung‐ran , Li Guisu , Burger Amy 
Published: October 2010

PurposeThe purpose of this paper is to explore the communicative rituals of opening and closing manifested in e‐mail‐based Internet Public Library's (IPL's) online reference interaction.Design/methodology/approachA total of 400 transcripts comprising user queries and responses by IPL librarians are examined. The opening and closing elements are identified to examine the way in which IPL librarians and users construct social space; that is, communicate their interpersonal and affective stances during the course of seeking and offering information.FindingsThe results of data analysis show regular patterns of verbal and structural politeness indicators of opening and closing e‐mail discourse. Linguistic elements such as greetings and acknowledgement are included in all the sampled transcripts; i.e. a 100 percent occurrence. Closing rituals have a 95 percent occurrence of linguistic features such as acknowledgement and invitation for follow‐up. In contrast, there is a low occurrence of personalized openings through greeting by user name (26 percent). This lack of personalization also occurs in closings: personalized farewell through use of librarian name appears in only 8 percent of closings.Research limitations/implicationsThe employment of the various politeness tactics in opening and closing reflects the librarian's attention and concern to user's information needs, interests and wants. Such communicative competence narrows social distance and brings forth close socio‐interpersonal space for interaction; this may, in turn, improve the overall quality of reference service. Research findings also indicate that more use of personal names may decrease the social distance between the librarian and user, resulting in increased solidarity and proximity.Originality/valueThe study provides new insights into linguistic politeness and the functions of address forms such as personal names with a view toward developing effective opening and closing rituals that contribute to the enhancement of virtual reference services.
The individual and social dynamics of knowledge sharing: an exploratory study
Authors: Cyr Sylvio , Wei Choo Chun 
Published: October 2010

PurposeThis paper aims to examine how knowledge sharing behavior is influenced by three sets of dynamics: a rational calculus that weighs the costs and benefits of sharing; a dispositional preference that favors certain patterns of sharing outcomes; and a relational effect based on working relationships.Design/methodology/approachConcepts from social exchange theory, social value orientation, and leader‐member exchange theory are applied to analyze behavioral intentions to share knowledge. The study population consists of employees of a large pension fund in Canada. Participants answered a survey that used allocation games and situational vignettes to measure social value orientation, propensity to share knowledge, and perception of cost and benefit.FindingsThe results suggest that personal preferences about the distribution of sharing outcomes, individual perceptions about costs and benefits, and structural relationship with knowledge recipients, all affect knowledge sharing behavior significantly. Notably, it was found that propensity to share knowledge is positively related to perceived benefit to the recipient, thus suggesting that evaluation of cost and benefit in social exchange is not limited to self‐interest, but is also influenced by perceived recipient benefit. Moreover, it was found that the relationship with the sharing target (superior or colleague) also influenced sharing.Originality/valueMost studies emphasize the organizational benefits of knowledge sharing. This study examines knowledge sharing from the perspective of the individual who approaches knowledge sharing as a social exchange that involves perceptions of costs and benefits, preferences about sharing outcomes, and relationship with the sharing target. The study also introduces innovative methods to measure social value orientation and propensity to share knowledge.
Managing documents at home for serious leisure: a case study of the hobby of gourmet cooking
Authors: Hartel Jenna 
Published: October 2010

PurposeThis paper aims to describe the way participants in the hobby of gourmet cooking in the USA manage culinary information in their homes.Design/methodology/approachThe study utilizes domain analysis and serious leisure as a conceptual framework and employs an ethnographic approach. In total 20 gourmet cooks in the USA were interviewed at home and then their culinary information collections were documented through a guided tour and photographic inventory. The resulting ethnographic record was analyzed using grounded theory and NVivo software.FindingsThe findings introduce the personal culinary library (PCL): a constellation of cooking‐related information resources and information structures in the home of the gourmet cook, and an associated set of upkeep activities that increase with the collection's size. PCLs are shown to vary in content, scale, distribution in space, and their role in the hobby. The personal libraries are characterized as small, medium or large and case studies of each extreme are presented. Larger PCLs are cast as a bibliographic pyramid distributed throughout the home in the form of a mother lode, zone, recipe collection, and binder.Practical implicationsInsights are provided into three areas: scientific ethnography as a methodology; a theory of documents in the hobby; and the changing role of information professionals given the increasing prevalence of home‐based information collections.Originality/valueThis project provides an original conceptual framework and research method for the study of information in personal spaces such as the home, and describes information phenomena in a popular, serious leisure, hobby setting.
A multilevel model of HIV/AIDS information/help network development
Authors: Veinot Tiffany 
Published: October 2010

PurposeThis paper aims to describe the personal information and help networks of people with HIV/AIDS (PHAs) in rural Canada, and to present a research‐based model of how and why these networks developed. This model seeks to consider the roles of PHAs, their family members/friends and formal health systems in network formation.Design/methodology/approachIn‐depth, semi‐structured interviews were conducted with 114 PHAs, their friends/family members (FFs) and formal caregivers in three rural regions of Canada. A network solicitation procedure elicited PHAs' HIV/AIDS information/help networks. Interviews were analyzed qualitatively, and network data were analyzed statistically. Documents describing health systems in each region were also analyzed. Analyses used social capital theory, supplemented by stress/coping and stigma management theories.FindingsPHAs' HIV/AIDS‐related information/help networks emphasized linking and bonding social capital with minimal bridging social capital. This paper presents a model that explains how and why such networks developed. The model shows that networks grew from the actions of PHAs, their FFs and health systems. PHAs experienced considerable stress, which led them to develop information/help networks to cope with HIV/AIDS – both individually and collaboratively. Because of stigmatization, many PHAs disclosed their illness selectively, thus constraining the size and composition of their networks. Health system actors created network‐building opportunities for PHAs by providing them with care, referrals and support programs.Originality/valueThis study describes and explains an understudied type of information behavior: information/help network development at individual, group and institutional levels. As such, it illuminates the complex dynamics that made individual acts of interpersonal information acquisition and sharing possible.