bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Arabidopsis Transcription Factor MYB12 Is a Flavonol-Specific Regulator of Phenylpropanoid Biosynthesis
Authors: Mehrtens Frank , Kranz Harald , Bednarek Pawel , Weisshaar Bernd 
Published: May 2005

Abstract
Comprehensive functional data on plant R2R3-MYB transcription factors is still scarce compared to the manifold of their occurrence. Here, we identified the Arabidopsis (Arabidopsis thaliana) R2R3-MYB transcription factor MYB12 as a flavonol-specific activator of flavonoid biosynthesis. Transient expression in Arabidopsis protoplasts revealed a high degree of functional similarity between MYB12 and the structurally closely related factor P from maize (Zea mays). Both displayed similar target gene specificity, and both activated target gene promoters only in the presence of a functional MYB recognition element. The genes encoding the flavonoid biosynthesis enzymes chalcone synthase, chalcone flavanone isomerase, flavanone 3-hydroxylase, and flavonol synthase were identified as target genes. Hence, our observations further add to the general notion of a close relationship between structure and function of R2R3-MYB factors. High-performance liquid chromatography analyses of myb12 mutant plants and MYB12 overexpression plants demonstrate a tight linkage between the expression level of functional MYB12 and the flavonol content of young seedlings. Quantitative real time reverse transcription-PCR using these mutant plants showed MYB12 to be a transcriptional regulator of CHALCONE SYNTHASE and FLAVONOL SYNTHASE in planta, the gene products of which are indispensable for the biosynthesis of flavonols.
The Involvement of Gibberellin 20-Oxidase Genes in Phytochrome-Regulated Petiole Elongation of Arabidopsis
Authors: Hisamatsu Tamotsu , King Rod W. , Helliwell Chris A. , Koshioka Masaji 
Published: May 2005

Abstract
Long day (LD) exposure of rosette plants causes rapid stem/petiole elongation, a more vertical growth habit, and flowering; all changes are suggestive of a role for the gibberellin (GA) plant growth regulators. For Arabidopsis (Arabidopsis thaliana) L. (Heynh), we show that enhancement of petiole elongation by a far-red (FR)-rich LD is mimicked by a brief (10 min) end-of-day (EOD) FR exposure in short day (SD). The EOD response shows red (R)/FR photoreversibility and is not affected in a phytochrome (PHY) A mutant so it is mediated by PHYB and related PHYs. FR photoconversion of PHYB to an inactive form activates a signaling pathway, leading to increased GA biosynthesis. Of 10 GA biosynthetic genes, expression of the 20-oxidase, AtGA20ox2, responded most to FR (up to a 40-fold increase within 3 h). AtGA20ox1 also responded but to a lesser extent. Stimulation of petiole elongation by EOD FR is reduced in a transgenic AtGA20ox2 hairpin gene silencing line. By contrast, it was only in SD that a T-DNA insertional mutant of AtGA20ox1 (ga5-3) showed reduced response. Circadian entrainment to a daytime pattern provides an explanation for the SD expression of AtGA20ox1. Conversely, the strong EOD/LD FR responses of AtGA20ox2 may reflect its independence of circadian regulation. While FR acting via PHYB increases expression of AtGA20ox2, other GA biosynthetic genes are known to respond to R rather than FR light and/or to other PHYs. Thus, there must be different signal transduction pathways, one at least showing a positive response to active PHYB and another showing a negative response.
Interaction between Phosphate-Starvation, Sugar, and Cytokinin Signaling in Arabidopsis and the Roles of Cytokinin Receptors CRE1/AHK4 and AHK3
Authors: Franco-Zorrilla José Manuel , Martín Ana Carmen , Leyva Antonio , Paz-Ares Javier 
Published: May 2005

Abstract
Cytokinins control key processes during plant growth and development, and cytokinin receptors CYTOKININ RESPONSE 1/WOODEN LEG/ARABIDOPSIS HISTIDINE KINASE 4 (CRE1/WOL/AHK4), AHK2, and AHK3 have been shown to play a crucial role in this control. The involvement of cytokinins in signaling the status of several nutrients, such as sugar, nitrogen, sulfur, and phosphate (Pi), has also been highlighted, although the full physiological relevance of this role remains unclear. To gain further insights into this aspect of cytokinin action, we characterized a mutant with reduced sensitivity to cytokinin repression of a Pi starvation-responsive reporter gene and show it corresponds to AHK3. As expected, ahk3 displayed reduced responsiveness to cytokinin in callus proliferation and plant growth assays. In addition, ahk3 showed reduced cytokinin repression of several Pi starvation-responsive genes and increased sucrose sensitivity. These effects of the ahk3 mutation were especially evident in combination with the cre1 mutation, indicating partial functional redundancy between these receptors. We examined the effect of these mutations on Pi-starvation responses and found that the double mutant is not significantly affected in long-distance systemic repression of these responses. Remarkably, we found that expression of many Pi-responsive genes is stimulated by sucrose in shoots and to a lesser extent in roots, and the sugar effect in shoots of Pi-starved plants was particularly enhanced in the cre1 ahk3 double mutant. Altogether, these results indicate the existence of multidirectional cross regulation between cytokinin, sugar, and Pi-starvation signaling, thus underlining the role of cytokinin signaling in nutrient sensing and the relative importance of Pi-starvation signaling in the control of plant metabolism and development.
Characterization of Markers to Determine the Extent and Variability of Leaf Senescence in Arabidopsis. A Metabolic Profiling Approach
Authors: Diaz Céline , Purdy Sarah , Christ Aurélie , Morot-Gaudry Jean-Francois , Wingler Astrid , Masclaux-Daubresse Céline 
Published: May 2005

Abstract
Comparison of the extent of leaf senescence depending on the genetic background of different recombinant inbred lines (RILs) of Arabidopsis (Arabidopsis thaliana) is described. Five RILs of the Bay-0 × Shahdara population showing differential leaf senescence phenotypes (from early senescing to late senescing) were selected to determine metabolic markers to discriminate Arabidopsis lines on the basis of senescence-dependent changes in metabolism. The proportion of γ-aminobutyric acid, leucine, isoleucine, aspartate, and glutamate correlated with (1) the age and (2) the senescence phenotype of the RILs. Differences were observed in the glycine/serine ratio even before any senescence symptoms could be detected in the rosettes. This could be used as predictive indicator for plant senescence behavior. Surprisingly, late-senescing lines appeared to mobilize glutamine, asparagine, and sulfate more efficiently than early-senescing lines. The physiological basis of the relationship between leaf senescence and flowering time was analyzed.
A Basic Helix-Loop-Helix Transcription Factor in Arabidopsis, MYC2, Acts as a Repressor of Blue Light–Mediated Photomorphogenic Growth
Authors: Yadav Vandana , Mallappa Chandrashekara , Gangappa Sreeramaiah N. , Bhatia Shikha , Chattopadhyay Sudip 
Published: May 2005

AbstractThe crosstalk of light signaling pathways with other signaling cascades has just started to be revealed. Here, we report the identification and functional characterization of a Z-box binding factor (ZBF1) in light signaling pathways. Arabidopsis thaliana ZBF1 encodes AtMYC2/JIN1, a basic helix-loop-helix transcription factor, which has recently been shown to be involved in abscisic acid (ABA), jasmonic acid (JA), and jasmonate-ethylene signaling pathways. We demonstrate that AtMYC2 interacts with the Z- and G-box light-responsive elements of minimal light–regulated promoters. AtMYC2 is expressed in various light-grown seedlings, including in red, far red, and blue light. Genetic analyses suggest that AtMYC2 acts as a negative regulator of blue light–mediated photomorphogenic growth and blue and far-red-light–regulated gene expression; however, it functions as a positive regulator of lateral root formation. Our results further demonstrate that atmyc2 mutants have compromised sensitivity to ABA- and JA-mediated responses. Taken together, these results demonstrate that AtMYC2 is a common transcription factor of light, ABA, and JA signaling pathways in Arabidopsis.
Neural-Cardiac Coupling in Threat-Evoked Anxiety
Authors: Dalton Kim M. , Kalin Ned H. , Grist Thomas M. , Davidson Richard J. 
Published: May 2005

Abstract
Anxiety is a debilitating symptom of many psychiatric disorders including generalized anxiety disorder, mood disorders, schizophrenia, and autism. Anxiety involves changes in both central and peripheral biology, yet extant functional imaging studies have focused exclusively on the brain. Here we show, using functional brain and cardiac imaging in sequential brain and cardiac magnetic resonance imaging (MRI) sessions in response to cues that predict either threat (a possible shock) or safety (no possibility of shock), that MR signal change in the amygdala and the prefrontal and insula cortices predicts cardiac contractility to the threat of shock. Participants with greater MR signal change in these regions show increased cardiac contractility to the threat versus safety condition, a measure of the sympathetic nervous system contribution to the myocardium. These findings demonstrate robust neural-cardiac coupling during induced anxiety and indicate that individuals with greater activation in brain regions identified with aversive emotion show larger magnitude cardiac contractility increases to threat.
Priming of Color and Position during Visual Search in Unilateral Spatial Neglect
Authors: Kristjánsson Árni , Vuilleumier Patrik , Malhotra Paresh , Husain Masud , Driver Jon 
Published: May 2005

Abstract
We examined priming of visual search by repeated target location or color in two patients with left visual neglect and extinction, following strokes centered on the right inferior parietal lobe. Both patients, like the healthy controls we tested, showed intact priming, with performance speeded when either the location or color of a singleton target was repeated over successive trials in a standard search condition (Experiment 1). This was observed both from and to targets on the contralesional (left) side. Moreover, priming of search was still observed even when a return of fixation back to display-center was required between successive trials (Experiment 2). When briefer displays were used (Experiment 3), the patients often failed to detect left targets. This situation revealed an important dissociation: Whereas location priming only arose from preceding left targets that had been consciously detected, color priming (possibly arising within the intact ventral stream) did not depend on awareness of the preceding target. There was considerable color priming from missed targets. These findings demonstrate relatively intact priming of visual search by color and location in patients with right parietal damage, and also reveal that location priming may differ from color priming in requiring awareness.
Hellenistic Instruction in Palestine and Egypt: Ben Sira and Papyrus Insinger
Authors: Goff Matthew 
Published: May 2005

AbstractBen Sira and the Demotic wisdom text Papyrus Insinger have numerous similarities. This is evident in terms of their practical instruction on topics such as shame, generosity, and moderation. They also have affinities regarding more speculative concerns, including theodicy and the nature of the cosmos. These affinities can often be attributed to the fact that each work draws on the native wisdom traditions of its own country, and there are broad similarities between the traditional wisdom of Israel and Egypt. Some of the points of contact between Ben Sira and Papyrus Insinger also reflect intellectual trends of the Hellenistic age.
The Letter of Aristeas: A New Exodus Story?
Authors: Hacham Noah 
Published: May 2005

AbstractA common opinion views the purpose of the Letter of Aristeas as strengthening the self-identity of Egyptian Diaspora Jewry by sanctifying the Greek translation of the Torah. As Orlinsky has shown, this view is supported by linguistic and thematic parallels between Aristeas and biblical descriptions of the giving of the Torah. The linguistic and thematic associations, however, do not only apply to this specific biblical episode, but also to the entire book of Exodus including the exodus story itself. The author of Aristeas transformed the biblical stories of the exodus and the giving of the Torah into a new foundation story of Egyptian Jewry. In doing so, the new story disregards the biblical hostility to Egypt and instead expresses sympathy for the Ptolemaic king who released the Jews from slavery, settled them in Egypt and initiated the Torah translation into Greek. The aim of Aristeas was to offer a religious justification for the residence of Jews in Egypt.
Tree thinning as an option to increase herbaceous yield of an encroached semi-arid savanna in South Africa
Authors: Smit Gert N 
Published: May 2005

Abstract

Background
The investigation was conducted in a savanna area covered by what was considered an undesirably dense stand of Colophospermum mopane trees, mainly because such a dense stand of trees often results in the suppression of herbaceous plants. The objectives of this study were to determine the influence of intensity of tree thinning on the dry matter yield of herbaceous plants (notably grasses) and to investigate differences in herbaceous species composition between defined subhabitats (under tree canopies, between tree canopies and where trees have been removed). Seven plots (65 × 180 m) were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0 %) to plots thinned to the equivalent of 10 %, 20%, 35 %, 50% and 75 % of the leaf biomass of a control plot (100 %) with a tree density of 2711 plants ha-1. The establishment of herbaceous plants (grasses and forbs) in response to reduced competition from the woody plants was measured during three full growing seasons following the thinning treatments.

Results
The grass component reacted positively to the tree thinning in terms of total dry matter (DM) yield, but forbs were negatively influenced. Rainfall interacted with tree density and the differences between grass DM yields in thinned plots during years of below average rainfall were substantially higher than those of the control. At high tree densities, yields differed little between seasons of varying rainfall. The relation between grass DM yield and tree biomass was curvilinear, best described by the exponential regression equation. Subhabitat differentiation by C. mopane trees did provide some qualitative benefits, with certain desirable grass species showing a preference for the subhabitat under tree canopies.

Conclusion
While it can be concluded from this study that high tree densities suppress herbaceous production, the decision to clear/thin the C. mopane trees should include additional considerations. Thinning of C. mopane with the exclusive objective of increasing productivity of the grass layer would thus invariably involve a compromise situation where some trees should be left for the sake of the qualitative benefits on the herbaceous layer, soil enrichment, provision of browse and stability of the ecosystem.
Critical clinical appraisal of the role of ultrasound guided fine needle aspiration cytology in the management of parotid tumours
Authors: Bajaj Y , Singh S , Cozens N , Sharp J 
Published: May 2005

Objective: Fine needle aspiration cytology is a well established tool for investigating many head and neck conditions. Its application in parotid tumours is, however, controversial. This article is aimed at defining the role of ultrasound guided fine needle aspiration cytology (FNAC) in the diagnostic work up of parotid tumours. The accuracy and utility of FNAC of parotid tumours was also assessed.Design: Retrospective case note review.Setting: District general hospital.Participants: Review of 69 patient records who had parotid surgery under one surgeon’s care (JS). Clinical opinion, FNAC results and final pathology findings were examined.Main outcome measures: The results of the FNAC were compared to the histopathological diagnosis obtained from the surgical specimen.Results: Histological evaluation revealed 13 malignant tumours and 56 benign lesions. The overall sensitivity of FNAC was 84.6 per cent and specificity was 96.4 per cent. We noted 11 true positive, 54 true negative, two false negative and two false positive results. Positive predictive value for diagnosing malignancy was 84.6 per cent and negative predictive value for malignancy was 96.4 per cent. The overall accuracy of FNAC of parotids in this study was 94.2 per cent.Conclusions: FNAC results provide useful preoperative information. FNAC enables more reliable patient counselling and reduces pathological surprises. Pre-operative recognition of malignant tumours may help prepare both the surgeon and patient for an appropriate surgical procedure. Its enhancement of the pre-operative recognition of malignant parotid tumours may alert more stringent attention to the operative margin and hence better tumour clearance. Ultrasound guided FNAC was found to be highly specific for malignancy and its sensitivity for malignancy was good.
Otologic side effects of drugs
Authors: Lee C A , Mistry D , Uppal S , Coatesworth A P 
Published: May 2005

Otolaryngologic symptoms are common and patients presenting to the otolaryngologist will often be taking drugs for the treatment of unrelated diseases. As a doctor, one must not forget the potential of these drugs to cause otologic side effects and, in some cases, to be the cause of the presenting symptom.We performed a comprehensive search of the British National Formulary and Electronic Medical Compendium websites to classify the otologic side effects caused by drugs. Not all the data were found at both websites. We have compiled all the data together, subclassified them and produced a review of the otologic side effects of drugs, in table form.
Thermisches Verhalten und Struktur von Copolymeren der Maleinsäure‐bzw. Fumarsäurehalbester
Authors: Rätzsch M. , Steinert V. , Seiler S. , Büttner B. 
Published: May 2005

AbstractDas thermische Verhalten von Maleinsäurehalbester‐Copolymeren, die durch Veresterung von Maleinsäureanhydrid‐Copolymeren hergestellt wurden, und der Copolymere der Malein‐ sowie Fumarsäurehalbester wird untersucht. Daraus werden Rückschlüsse auf die Struktur der Copolymere gezogen. Die Schwierigkeiten bei der experimentellen Durchführung der Cyclisierungsreaktion in Lösung, die zur Umsetzung in der Festphase geführt haben, werden beschrieben.
Zur Lichtstreuung an Polymerdispersionen. Teil 5. Theoretische Untersuchungen zur Auswertung von Streulichtmessungen im Bereich der Mie‐Streuung
Authors: Hartmann M. , Dautzenberg H. 
Published: May 2005

AbstractEin neues Verfahren zur Auswertung von experimentellen Streukurven im Bereich der Mie‐Streuung auf Basis der Mie‐Theorie unter Einbeziehung von Näherungsformeln der geometrischen Optik wird vorgestellt. Mit Hilfe dieser Methode ist es möglich, aus einem experimentell ermittelten Wertepaar von Streuintensität beim Streuwinkel 0° und Anfangsanstieg der Streukurve die dem gegebenen streuenden System entsprechenden Verteilungsparameter zu finden. Dies ist auch dann der Fall, wenn mehrere Zuordnungen (Mehrdeutigkeit der Mie‐Streuung) existieren.
Copolymerization of acrylonitrile with some transition metal acrylates. II. Determination of monomer reactivity ratios in radical copolymerization of acrylonitrile with cobalt, nickel and copper acrylates in dimethylformamide
Authors: Czerniawski T. , Wojtczak Z. 
Published: May 2005

AbstractThe results of the copolymerization of acrylonitrile with cobalt, nickel and copper acrylates in dimethylformamide solution at 60°C with AIBN as an initiator are presented. The copolymerization parameters are discussed.
Synthese und einige physiko‐chemische Eigenschaften makrovernetzter isoporöser Styrenpolymere mit Vernetzungsbrücken vom Diphenylmethantyp
Authors: Cjurupa M. P. , Lalaev V. V. , Davankov V. A. 
Published: May 2005

AbstractDie makrovernetzten isoporösen Polymere wurden durch Vernetzung von Polystyren in Lösung mit Dimethylformal in Gegenwart von Friedel‐Crafts‐Katalysatoren erhalten. Es wurden die Reaktionsbedingungen ermittelt (20°C, 5 h, 1 mol SnCl4 auf 1 mol Methylal), bei denen das Vernetzungsmittel praktisch vollständig zur Bildung von Diphenylmethanbrücken verbraucht wird. Die erhaltenen Polymere können sowohl in Lösungs‐ als auch Fällmitteln für lineares Polystyren quellen. Die innere spezifische Oberfläche stark vernetzter Proben erreicht 900 m2/g.
Über das mechanische schmelzen des supergitters von blockcopolymeren
Authors: Skazka V. S. , Ručin A. E. , Frenkel S. Ja. , Vilesov A. D. 
Published: May 2005

AbstractDie Temperaturabhängigkeit des photoelastischen Koeffizienten ϵ von ternären Blockcopolymeren aus Styren und Butadien mit verschiedenen Komponentenverhältnissen wird untersucht. Hierbei wird ein starker Einfluß des optischen Formeffektes auf die Abhängigkeit ϵ(T) nachgewiesen. Es wird gezeigt, daß die Störung der Regularität des Superkristallgitters des Blockcopolymers bei Temperaturen erfolgt, die erheblich oberhalb der höchsten Glastemperatur der Komponenten liegen. Dieser Prozeß wird als mechanisches „Schmelzen”︁ des Supergitters betrachtet.
Fraktographie von Polyamidfäden. I. Einfluß von Verstrecktemperatur, Verstreckgeschwindigkeit, Umgebungsmedium und Vorbehandlung
Authors: Hinrichsen G. , Altemeier G. , Renger M. 
Published: May 2005

AbstractEin unpigmentiertes Polyamid‐Filamentgarn wird unter Variation von Verstrecktemperatur, ‐geschwindigkeit und ‐medium bis zum Bruch verdehnt. Die entstandenen Bruchflächen werden mittels Rasterelektronenmikroskopie auf ihre Morphologie hin untersucht. Es werden für die jeweiligen Verstreckbedingungen charakteristische Bruchmorphologien nachgewiesen. Die Brüche starten durch ein Aufplatzen des Fasermantels.
InGaAlN and II–VI Systems for Blue–Green Light‐Emitting Devices
Authors: Matsuoka Takashi 
Published: May 2005

AbstractRecent progress in research on InGaAlN and II–VI systems has been remarkable, and this paper reviews the properties of these materials from the viewpoint of making reliable light‐emitting devices. The growth of these materials by molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE) is also reviewed, and the current status of both materials is reviewed with respect to light‐emitting devices.
Oligomeric arsenic nitrides
Authors: Schmid G. , Hättmann Katja 
Published: May 2005

Oligomeric AsN particleshave been synthesized as a first step towards forming polymeric (AsN)x, which is expected to be the arsenic nitride with the most important applications. The synthesis is described and the characterization of the resulting oligomers by X‐ray powder diffraction, mass spectrometry and DSC is presented which leads to the proposed structure of (AsN)12(AsCl2)6Cl6shown in the Figure.magnified image
A new approach to polybenzoid networks
Authors: Mindach Lutz , Müllen Klaus 
Published: May 2005

High‐carbon materials, which contain a high density of strong, directed CC bonds, are expected to exhibit some of the outstanding properties of diamond and graphite, e.g., hardness, thermal and electrical conductivity. The thermolysis of biphenylene‐containing monomers is demonstrated to offer a promising new approach to polybenzoid networks such as that shown in the Figure. magnified image