bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and Characterization of a Novel Ribosome-Inactivating Protein from Root Cultures of Pokeweed and Its Mechanism of Secretion from Roots
Authors: Park Sang-Wook , Lawrence Christopher B. , Linden James C. , Vivanco Jorge M. 
Published: September 2002

Abstract
Ribosome-inactivating proteins are N-glycosidases that remove a specific adenine from the sarcin/ricin loop of the large rRNA, thus arresting protein synthesis at the translocation step. In the present study, a novel type I ribosome-inactivating protein, termed PAP-H, was purified from Agrobacterium rhizogenes-transformed hairy roots of pokeweed (Phytolacca americana). The protein was purified by anion- and cation-exchange chromatography. PAP-H has a molecular mass of 29.5 kD as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point was determined to be 7.8. Yeast (Saccharomyces cerevisiae) ribosomes incubated with PAP-H released the 360-nucleotide diagnostic fragment from the 26S rRNA upon aniline treatment, an indication of its ribosome-inactivating activity. Using immunofluorescence microscopy, PAP-H was found to be located in the cell walls of hairy roots and root border cells. PAP-H was determined to be constitutively secreted as part of the root exudates, with its secretion enhanced by a mechanism mediated by ethylene induction. Purified PAP-H did not show in vitro antifungal activity against soil-borne fungi. In contrast, root exudates containing PAP-H as well as additional chitinase, β-1,3-glucanase, and protease activities did inhibit the growth of soil-borne fungi. We found that PAP-H depurinates fungal ribosomes in vitro and in vivo, suggesting an additive mechanism that enables PAP-H to penetrate fungal cells.
VFL, the GrapevineFLORICAULA/LEAFYOrtholog, Is Expressed in Meristematic Regions Independently of Their Fate
Authors: Carmona Marı́a José , Cubas Pilar , Martı́nez-Zapater José M. 
Published: September 2002

AbstractThe flowering process in grapevine (Vitis vinifera) takes place in buds and extends for two consecutive growing seasons. To understand the genetic and molecular mechanisms underlying this process, we have characterized grapevine bud development, cloned the grapevineFLORICAULA/LEAFY (FLO/LFY) ortholog, VFL, and analyzed its expression patterns during vegetative and reproductive development. Flowering induction takes place during the first season. Upon induction, the shoot apical meristem begins to produce lateral meristems that will give rise to either inflorescences or tendrils. During the second season, after a winter dormancy period, buds reactivate and inflorescence meristems give rise to flower meristems. VFL is expressed in lateral meristems that give rise to inflorescence and flower meristems, consistent with a role in reproductive development. Furthermore,VFL is also detected in other meristematic regions such as the vegetative shoot apical meristem and the lateral meristems that will give rise to tendrils. VFL is also expressed in leaf primordia and in growing leaf margins until later stages of development. Accumulation of VFL transcripts in cell-proliferating regions suggests a role for VFL not only in flower meristem specification, but also in the maintenance of indeterminacy before the differentiation of derivatives of the apical meristem: flowers, leaves, or tendrils.
Biochemical Characterization of the Arabidopsis Protein Kinase SOS2 That Functions in Salt Tolerance
Authors: Gong Deming , Guo Yan , Jagendorf Andre T. , Zhu Jian-Kang 
Published: September 2002

Abstract
The Arabidopsis Salt Overly Sensitive 2(SOS2) gene encodes a serine/threonine (Thr) protein kinase that has been shown to be a critical component of the salt stress signaling pathway. SOS2 contains a sucrose-non-fermenting protein kinase 1/AMP-activated protein kinase-like N-terminal catalytic domain with an activation loop and a unique C-terminal regulatory domain with an FISL motif that binds to the calcium sensorSalt Overly Sensitive 3. In this study, we examined some of the biochemical properties of the SOS2 in vitro. To determine its biochemical properties, we expressed and isolated a number of active and inactive SOS2 mutants as glutathione S-transferase fusion proteins in Escherichia coli. Three constitutively active mutants, SOS2T168D, SOS2T168DΔF, and SOS2T168DΔ308, were obtained previously, which contain either the Thr-168 to aspartic acid (Asp) mutation in the activation loop or combine the activation loop mutation with removal of the FISL motif or the entire regulatory domain. These active mutants exhibited a preference for Mn2+ relative to Mg2+ and could not use GTP as phosphate donor for either substrate phosphorylation or autophosphorylation. The three enzymes had similar peptide substrate specificity and catalytic efficiency. Salt overly sensitive 3 had little effect on the activity of the activation loop mutant SOS2T168D, either in the presence or absence of calcium. The active mutant SOS2T168DΔ308 could not transphosphorylate an inactive protein (SOS2K40N), which indicates an intramolecular reaction mechanism of SOS2 autophosphorylation. Interestingly, SOS2 could be activated not only by the Thr-168 to Asp mutation but also by a serine-156 or tyrosine-175 to Asp mutation within the activation loop. Our results provide insights into the regulation and biochemical properties of SOS2 and the SOS2 subfamily of protein kinases.
Arabidopsis UVR8 Regulates Ultraviolet-B Signal Transduction and Tolerance and Contains Sequence Similarity to Human Regulator of Chromatin Condensation 1
Authors: Kliebenstein Daniel J. , Lim Jackie E. , Landry Laurie G. , Last Robert L. 
Published: September 2002

Abstract
To further our understanding of how plants defend against the harmful effects of ultraviolet (UV) light, we characterized an Arabidopsis mutant hypersensitive to UV-B. This mutant, UV resistance locus 8-1 (uvr8-1), contains a single recessive mutation at the bottom of chromosome 5. Fine-scale mapping localized uvr8-1 to a 21-kb locus containing five predicted open reading frames. Sequencing of this entire region revealed that the uvr8-1 allele contains a 15-nucleotide deletion in a gene similar to the human guanine nucleotide exchange factor regulator of chromatin condensation 1. This mutation reduces the UV-B-mediated induction of flavonoids and blocks chalcone synthase mRNA and protein induction. In contrast, uvr8-1 has enhanced induction of PR1 and PR5 proteins in response to UV-B, an indication of increased UV-B injury. These results suggest that UVR8acts in a UV-B signal transduction pathway leading to induction of flavonoid biosynthesis.
Regulation of Transcript Levels of the Arabidopsis Cytochrome P450 Genes Involved in Brassinosteroid Biosynthesis
Authors: Bancosİ Simona , Nomura Takahito , Sato Tatsuro , Molnár Gergely , Bishop Gerard J. , Koncz Csaba , Yokota Takao , Nagy Ferenc , Szekeres Miklós 
Published: September 2002

Abstract
Cytochrome P450 enzymes of the closely related CYP90 and CYP85 families catalyze essential oxidative reactions in the biosynthesis of brassinosteroid (BR) hormones. Arabidopsis CYP90B1/DWF4 and CYP90A1/CPD are responsible for respective C-22 and C-23 hydroxylation of the steroid side chain and CYP85A1 catalyzes C-6 oxidation of 6-deoxo intermediates, whereas the functions of CYP90C1/ROT3, CYP90D1, and CYP85A2 are still unknown. Semiquantitative reverse transcriptase-polymerase chain reaction analyses show that transcript levels of CYP85 and CYP90genes are down-regulated by brassinolide, the end product of the BR biosynthesis pathway. Feedback control of the CYP90C1,CYP90D1, and CYP85A2 genes by brassinolide suggests that the corresponding enzymes might also participate in BR synthesis. CYP85 andCYP90 mRNAs show strong and transient accumulation during the 1st week of seedling development, as well as characteristic organ-specific distribution. Transcripts of CYP90A1 andCYP85A2 are preferentially represented in shoots andCYP90C1, CYP90D1, andCYP85A1 mRNAs are more abundant in roots, whereasCYP90B1 is ubiquitously expressed. Remarkably, the spatial pattern of CYP90A1 expression is maintained in the BR-insensitive cbb2 mutant, indicating the independence of organ-specific and BR-dependent regulation. Quantitative gas chromatography-mass spectrometry analysis of endogenous BRs in shoots and roots of Arabidopsis, pea (Pisum sativum), and tomato (Lycopersicon esculentum) reveal similar partitioning patterns of BR intermediates in these species. Inverse correlation between CYP90A1/CPDtranscript levels and the amounts of the CYP90A1 substrate 6-deoxocathasterone in shoots and roots suggests that transcriptional regulation plays an important role in controlling BR biosynthesis.
The Altered Pattern of Amylose Accumulation in the Endosperm of Low-Amylose Barley Cultivars Is Attributable to a Single Mutant Allele of Granule-Bound Starch Synthase I with a Deletion in the 5′-Non-Coding Region
Authors: Patron Nicola J. , Smith Alison M. , Fahy Brendan F. , Hylton Christopher M. , Naldrett Mike J. , Rossnagel Brian G. , Denyer Kay 
Published: September 2002

Abstract
Reasons for the variable amylose content of endosperm starch from waxy cultivars of barley (Hordeum vulgare) were investigated. The mature grains of most such cultivars contain some amylose, although amounts are much lower than in wild-type cultivars. In these low-amylose cultivars, amylose synthesis starts relatively late in grain development. Starch granules in the outer cell layers of the endosperm contain more amylose than those in the center. This distribution corresponds to that of granule-bound starch synthase I (GBSSI), which is more severely reduced in amount in the center of the endosperm than in the outer cell layers, relative to wild-type cultivars. A second GBSSI in the barley plant, GBSSIb, is not detectable in the endosperm and cannot account for amylose synthesis in the low-amylose cultivars. The change in the expression of GBSSI in the endosperm of the low-amylose cultivars appears to be due to a 413-bp deletion of part of the promoter and 5′-untranslated region of the gene. Although these cultivars are of diverse geographical origin, all carry this same deletion, suggesting that the low-amylose cultivars have a common waxyancestor. Records suggest a probable source in China, first recorded in the 16th century. Two further families of waxy cultivars have no detectable amylose in the endosperm starch. These amylose-free cultivars were selected in the 20th century from chemically mutagenized populations of wild-type barley. In both cases, 1-bp alterations in the GBSSI gene completely eliminate GBSSI activity.
elongated mesocotyl1, a Phytochrome-Deficient Mutant of Maize
Authors: Sawers Ruairidh J.H. , Linley Philip J. , Farmer Phyllis R. , Hanley Nicole P. , Costich Denise E. , Terry Matthew J. , Brutnell Thomas P. 
Published: September 2002

Abstract
To begin the functional dissection of light signal transduction pathways of maize (Zea mays), we have identified and characterized the light-sensing mutant elm1(elongated mesocotyl1). Seedlings homozygous forelm1 are pale green, show pronounced elongation of the mesocotyl, and fail to de-etiolate under red or far-red light. Etiolated elm1 mutants contain no spectrally active phytochrome and do not deplete levels of phytochrome A after red-light treatment. High-performance liquid chromatography analyses show that elm1 mutants are unable to convert biliverdin IXα to 3Z-phytochromobilin, preventing synthesis of the phytochrome chromophore. Despite the impairment of the phytochrome photoreceptors, elm1 mutants can be grown to maturity in the field. Mature plants retain aspects of the seedling phenotype and flower earlier than wild-type plants under long days. Thus, theelm1 mutant of maize provides the first direct evidence for phytochrome-mediated modulation of flowering time in this agronomically important species.
Cloning and Functional Characterization of a β-Pinene Synthase from Artemisia annua That Shows a Circadian Pattern of Expression
Authors: Lu Shan , Xu Ran , Jia Jun-Wei , Pang Jihai , Matsuda Seiichi P.T. , Chen Xiao-Ya 
Published: September 2002

Abstract
Artemisia annua plants produce a broad range of volatile compounds, including monoterpenes, which contribute to the characteristic fragrance of this medicinal species. A cDNA clone, QH6, contained an open reading frame encoding a 582-amino acid protein that showed high sequence identity to plant monoterpene synthases. The prokaryotically expressed QH6 fusion protein converted geranyl diphosphate to (−)-β-pinene and (−)-α-pinene in a 94:6 ratio. QH6 was predominantly expressed in juvenile leaves 2 weeks postsprouting. QH6 transcript levels were transiently reduced following mechanical wounding or fungal elicitor treatment, suggesting that this gene is not directly involved in defense reaction induced by either of these treatments. Under a photoperiod of 12 h/12 h (light/dark), the abundance of QH6 transcripts fluctuated in a diurnal pattern that ebbed around 3 h before daybreak (9th h in the dark phase) and peaked after 9 h in light (9th h in the light phase). The contents of (−)-β-pinene in juvenile leaves and in emitted volatiles also varied in a diurnal rhythm, correlating strongly with mRNA accumulation. WhenA. annua was entrained by constant light or constant dark conditions, QH6 transcript accumulation continued to fluctuate with circadian rhythms. Under constant light, advanced cycles of fluctuation of QH6 transcript levels were observed, and under constant dark, the cycle was delayed. However, the original diurnal pattern could be regained when the plants were returned to the normal light/dark (12 h/12 h) photoperiod. This is the first report that monoterpene biosynthesis is transcriptionally regulated in a circadian pattern.
Trends in BB/pellet gun injuries in children and teenagers in the United States, 1985–99
Authors: Nguyen M H , Annest J L , Mercy J A , Ryan G W , Fingerhut L A 
Published: September 2002

Objective:To characterize national trends in non-fatal BB/pellet gun related injury rates for persons aged 19 years or younger in relation to trends in non-fatal and fatal firearm related injury rates and discuss these trends in light of injury prevention and violence prevention efforts.Setting:The National Electronic Injury Surveillance System (NEISS) includes approximately 100 hospitals with at least six beds that provide emergency services. These hospitals comprise a stratified probability sample of all US hospitals with emergency departments. The National Vital Statistics System (NVSS) is a complete census of all death certificates filed by states and is compiled annually.Methods:National data on BB/pellet gun related injuries and injury rates were examined along with fatal and non-fatal firearm related injuries and injury rates. Non-fatal injury data for all BB/pellet gun related injury cases from 1985 through 1999, and firearm related injury cases from 1993 through 1999 were obtained from hospital emergency department records using the NEISS. Firearm related deaths from 1985 through 1999 were obtained from the NVSS.Results:BB/pellet gun related injury rates increased from age 3 years to a peak at age 13 years and declined thereafter. In contrast, firearm related injury and death rates increased gradually until age 13 and then increased sharply until age 18 years. For persons aged 19 years and younger, BB/pellet gun related injury rates increased from the late 1980s until the early 1990s and then declined until 1999; these injury rates per 100 000 population were 24.0 in 1988, 32.8 in 1992, and 18.3 in 1999. This trend was similar to those for fatal and non-fatal firearm related injury rates per 100 000 which were 4.5 in 1985, 7.8 in 1993, and 4.3 in 1999 (fatal) and 38.6 in 1993 and 16.3 in 1999 (non-fatal). In 1999, an estimated 14 313 (95% confidence interval (CI) 12 025 to 16 601) cases with non-fatal BB/pellet gun injuries and an estimated 12 748 (95% CI 7881–17 615) cases with non-fatal firearm related injuries among persons aged 19 years and younger were treated in US hospital emergency departments.Conclusions:BB/pellet gun related and firearm related injury rates show similar declines since the early 1990s. These declines coincide with a growing number of prevention efforts aimed at reducing injuries to children from unsupervised access to guns and from youth violence. Evaluations at the state and local level are needed to determine true associations.
Pediatric motor vehicle related injuries in the Navajo Nation: the impact of the 1988 child occupant restraint laws
Authors: Phelan K J , Khoury J , Grossman D C , Hu D , Wallace L J D , Bill N , Kalkwarf H 
Published: September 2002

Background:Navajo motor vehicle mortality is the highest among the 12 Indian Health Service (IHS) administrative areas. In July 1988, the Navajo Nation enacted a primary enforcement safety belt use and a child restraint law.Objective:Assess the impact of the laws on the rate and severity of pediatric (0–19 years) motor vehicle injury resulting in hospitalizations in the Navajo Nation.Methods:Hospitalizations associated with motor vehicle related injury discharges were identified byInternational Classification of Diseases, 9th revision, CM E codes, 810–825 (.0,.1) from the Navajo IHS hospital discharge database. Age specific rates for the period before the law, 1983–88, were compared with those after enactment and enforcement, 1991–95. Severity of injury, measured by the abbreviated injury scale (AIS) score and new injury severity score (NISS), was determined with ICDMAP-90 software. Wilcoxon rank sum and χ2tests were used for analysis.Results:Discharge rates (SE) for motor vehicle injury (per 100 000) decreased significantly in all age groups: 0–4 years (62 (7) to 28 (4)), 5–11 years (55.3 (6) to 26 (4)), and 15–19 years (139 (14) to 68 (7)); p=0.0001. In children 0–4 years, the median AIS score decreased from 1.5 (1,3) (25th, 75th centile) to 1 (1,2), p=0.06, and the median NISS decreased from 3.5 (1,9) to 2 (1,5), p=0.07. The proportion of children with NISS scores >4 decreased significantly for the 0–4 year age group (p=0.03).Conclusions:Concurrent with enactment of the Navajo Nation occupant and child restraint laws there was a reduction in the rate of motor vehicle related hospital discharges for children. Severity of injury declined in very young Navajo children. The effect of enactment and enforcement of this Native American child occupant restraint law may serve as an example of an effective injury control effort directed at Native American children.
How old is that child? Validating the accuracy of age assignments in observational surveys of vehicle restraint use
Authors: Moeller S , Berger L , Salvador J G , Helitzer D 
Published: September 2002

Objectives:Many large scale observational studies of child restraint usage require observers to estimate the ages of the vehicle occupants. The accuracy of age assignments were assessed and possible methods to improve observational accuracy in research and field studies of child restraint use were identified.Methods:The validation study was performed at fast food restaurants in a metropolitan area. Three, two person teams observed 449 occupants of vehicles with at least one child passenger. The drivers were then interviewed to obtain the actual ages of the vehicle occupants. The primary outcome measure was the per cent of age assignments that were correct by age category (infant, toddler, school age, teen, adult). The observers had previously conducted a statewide child restraint observation study and were trained in estimating age categories.Results:A total of 391 (87%) of the 449 occupants were assigned to their correct age categories. Incorrect assignments were more common among infants (22% incorrect), but few infants (nine) were observed. The most frequent error was classifying adults (19 years and older) as teenagers (13–18 years).Conclusion:Trained, experienced observers approached 90% accuracy in their assignment of children to specific age categories. Additional study is required to determine whether these results are applicable to different age categories and observers.It is recommended that the National Highway Traffic Safety Administration, the Centers for Disease Control and Prevention, state and local agencies, and other sponsors of observational surveys consider observer competence as an important variable. The validity of age assignments can be assessed by randomly interviewing a sample of drivers. More accurate age estimates will improve decisions regarding prevention programs, funding, and policies.
ENGAGING TRADITION IN MODERN ARAB POETICS
Authors: Al-Musawi Muhsin Jassim 
Published: September 2002

AbstractThe modernist movement in Arabic literature develops its own poetics, especially pertaining to poetry, in dialogue with both the Arab literary legacy and modernity in its Western manifestations. In the face of many challenges after the Second World War, poets felt the need for a poetics of regeneration, a mythical method that could superimpose a totalizing vision on a seemingly dying land and civilization. T. S. Eliot's writings on tradition and his use of myth drew attention to pre-Islamic mythology, especially in its Babylonian and Phoenician manifestations. Tradition was manipulated, as well, in search of its dynamic impulse for innovation and change. Both al-Ma'arrī and al-Mutanabbī were re-discovered beyond their other attributes. Both foreshadow the modernist impulse for change, dissent, thought, reason and morality. Both make high claims for poetry. Although modern poets developed different commemorative strategies, recollection undergoes re-tailoring in view of each poet's commitment at a certain time. This essay discusses these strategies under four headings: Dialogization, Dedications, Exilic Space, Textual Apprenticeship.
Dye-sensitized Solar Cells Using Brookite Nanoparticle TiO2 Films as Electrodes
Authors: Jiang Ke-Jian , Kitamura Takayuki , Yin Hegbo , Ito Seigo , Yanagida Shozo 
Published: September 2002

Abstract
Mesoporous brookite-based TiO2 films, consisting of a certain amount of anatase, with thickness of about 2 and 5 μm were prepared by dip coating and screen printing techniques, respectively. Dye-sensitized solar cells based on both of these mesoporous brookite films using as electrodes, showed that the conversion efficiency of 2.6% and 4.1%, respectively.
Synthesis of Highly Ordered Long-range Lamellar Silica Composites
Authors: Xu An-Wu 
Published: September 2002

Abstract
Highly ordered long-range lamellar silica was prepared using silicone surfactant as the template. Lamellar silica has the largest lattice constant known for layered materials reported to date. The results show that silicone surfactants with flexible siloxane chain favor the formation of these unusual lamellar structures.
Arylated Mono- and Bifunctional 2-Aminothiophenes and 2-Aminothiazoles as a New Class of Hole Transport Materials
Authors: Kanitz Andreas , Schumann Jörg , Scheffel Marcus , Rajoelson Sambatra , Rogler Wolfgang , Hartmann Horst , Rohde Dirk 
Published: September 2002

Abstract
By using the well-known Hantzsch method and starting from some mono- and bifunctional aryl-substituted thioureas, thioacetamides, and bromoketones several new aryl-substituted 2-aminothiazoles and 2-aminothiophenes have been prepared and tested as hole transport materials for OLEDs.
Cyclohexynes. Generation from Iodonium Salts and Regioselective Reaction with Nucleophile
Authors: Fujita Morifumi , Sakanishi Yuichi , Kim Wan Hyeok , Okuyama Tadashi 
Published: September 2002

Abstract
Cyclohexynes are effectively generated by treatment of cyclohex-1-enyliodonium salts with a mild base such as acetate and fluoride ion in chloroform. Regioselectivity of the nucleophilic addition of acetate ion to cyclohexynes depends on the 4-substituent.