bluuebunny/crossref_metadata_2025_split huggingface dataset:
TheFLORAL ORGAN NUMBER4Gene Encoding a Putative Ortholog of Arabidopsis CLAVATA3 Regulates Apical Meristem Size in Rice
Authors: Chu Huangwei , Qian Qian , Liang Wanqi , Yin Changsong , Tan Hexin , Yao Xuan , Yuan Zheng , Yang Jun , Huang Hai , Luo Da , Ma Hong , Zhang Dabing 
Published: September 2006

AbstractTo understand the molecular mechanism regulating meristem development in the monocot rice (Oryza sativa), we describe here the isolation and characterization of three floral organ number4 (fon4) alleles and the cloning of the FON4 gene. The fon4 mutants showed abnormal enlargement of the embryonic and vegetative shoot apical meristems (SAMs) and the inflorescence and floral meristems. Likely due to enlarged SAMs, fon4 mutants produced thick culms (stems) and increased numbers of both primary rachis branches and floral organs. We identified FON4 using a map-based cloning approach and found it encodes a small putatively secreted protein, which is the putative ortholog of the Arabidopsis (Arabidopsis thaliana) CLAVATA3 (CLV3) gene. FON4 transcripts mainly accumulated in the small group of cells at the apex of the SAMs, whereas the rice ortholog of CLV1 (FON1) is expressed throughout the SAMs, suggesting that the putative FON4 ligand might be sequestered as a possible mechanism for rice meristem regulation. Exogenous application of the peptides FON4p and CLV3p corresponding to the CLV3/ESR-related (CLE) motifs of FON4 and CLV3, respectively, resulted in termination of SAMs in rice, and treatment with CLV3p caused consumption of both rice and Arabidopsis root meristems, suggesting that the CLV pathway in limiting meristem size is conserved in both rice and Arabidopsis. However, exogenous FON4p did not have an obvious effect on limiting both rice and Arabidopsis root meristems, suggesting that the CLE motifs of Arabidopsis CLV3 and FON4 are potentially functionally divergent.
The Cyclin-Dependent Kinase Inhibitor Orysa;KRP1 Plays an Important Role in Seed Development of Rice
Authors: Barrôco Rosa Maria , Peres Adrian , Droual Anne-Marie , De Veylder Lieven , Nguyen Le Son Long , De Wolf Joris , Mironov Vladimir , Peerbolte Rindert , Beemster Gerrit T.S. , Inzé Dirk , Broekaert Willem F. , Frankard Valerie 
Published: September 2006

AbstractKip-related proteins (KRPs) play a major role in the regulation of the plant cell cycle. We report the identification of five putative rice (Oryza sativa) proteins that share characteristic motifs with previously described plant KRPs. To investigate the function of KRPs in rice development, we generated transgenic plants overexpressing the Orysa;KRP1 gene. Phenotypic analysis revealed that overexpressed KRP1 reduced cell production during leaf development. The reduced cell production in the leaf meristem was partly compensated by an increased cell size, demonstrating the existence of a compensatory mechanism in monocot species by which growth rate is less reduced than cell production, through cell expansion. Furthermore, Orysa;KRP1 overexpression dramatically reduced seed filling. Sectioning through the overexpressed KRP1 seeds showed that KRP overproduction disturbed the production of endosperm cells. The decrease in the number of fully formed seeds was accompanied by a drop in the endoreduplication of endosperm cells, pointing toward a role of KRP1 in connecting endocycle with endosperm development. Also, spatial and temporal transcript detection in developing seeds suggests that Orysa;KRP1 plays an important role in the exit from the mitotic cell cycle during rice grain formation.
Regulation of Seed Size by Hypomethylation of Maternal and Paternal Genomes
Authors: Xiao Wenyan , Brown Roy C. , Lemmon Betty E. , Harada John J. , Goldberg Robert B. , Fischer Robert L. 
Published: September 2006

Abstract
DNA methylation is an epigenetic modification of cytosine that is important for silencing gene transcription and transposons, gene imprinting, development, and seed viability. DNA METHYLTRANSFERASE1 (MET1) is the primary maintenance DNA methyltransferase in Arabidopsis (Arabidopsis thaliana). Reciprocal crosses between antisense MET1 transgenic and wild-type plants show that DNA hypomethylation has a parent-of-origin effect on seed size. However, due to the dominant nature of the antisense MET1 transgene, the parent with a hypomethylated genome, its gametophyte, and both the maternal and paternal genomes of the F1 seed become hypomethylated. Thus, the distinct role played by hypomethylation at each generation is not known. To address this issue, we examined F1 seed from reciprocal crosses using a loss-of-function recessive null allele, met1-6. Crosses between wild-type and homozygous met1-6 parents show that hypomethylated maternal and paternal genomes result in significantly larger and smaller F1 seeds, respectively. Our analysis of crosses between wild-type and heterozygous MET1/met1-6 parents revealed that hypomethylation in the female or male gametophytic generation was sufficient to influence F1 seed size. A recessive mutation in another gene that dramatically reduces DNA methylation, DECREASE IN DNA METHYLATION1, also causes parent-of-origin effects on F1 seed size. By contrast, recessive mutations in genes that regulate a smaller subset of DNA methylation (CHROMOMETHYLASE3 and DOMAINS REARRANGED METHYLTRANSFERASES1 and 2) had little effect on seed size. Collectively, these results show that maternal and paternal genomes play distinct roles in the regulation of seed size in Arabidopsis.
Calcium Entry Mediated by GLR3.3, an Arabidopsis Glutamate Receptor with a Broad Agonist Profile
Authors: Qi Zhi , Stephens Nicholas R. , Spalding Edgar P. 
Published: September 2006

AbstractThe amino acids glutamate (Glu) and glycine (Gly) trigger large, rapid rises in cytosolic Ca2+ concentration and a concomitant rise in membrane potential (depolarization) in plants. The possibility that plant homologs of neuronal ionotropic glutamate receptors mediate these neuron-like ionic responses was tested in Arabidopsis (Arabidopsis thaliana) seedlings using a combination of Ca2+ measurements, electrophysiology, and reverse genetics. The membrane depolarization triggered by Glu was greatly reduced or completely blocked in some conditions by mutations in GLR3.3, one of the 20 GLR genes in Arabidopsis. The same mutations completely blocked the associated rise in cytosolic Ca2+. These results genetically demonstrate the participation of a glutamate receptor in the rapid ionic responses to an amino acid. The GLR3.3-independent component of the depolarization required Glu concentrations above 25 μ m, did not display desensitization, and was strongly suppressed by increasing extracellular pH. It is suggested to result from H+-amino acid symport. Six amino acids commonly present in soils (Glu, Gly, alanine, serine, asparagine, and cysteine) as well as the tripeptide glutathione (γ-glutamyl-cysteinyl-Gly) were found to be strong agonists of the GLR3.3-mediated responses. All other amino acids induced a small depolarization similar to the non-GLR, putative symporter component and in most cases evoked little or no Ca2+ rise. From these results it may be concluded that sensing of six amino acids in the rhizosphere and perhaps extracellular peptides is coupled to Ca2+ signaling through a GLR-dependent mechanism homologous to a fundamental component of neuronal signaling.
Arabidopsis FHY3 Specifically Gates Phytochrome Signaling to the Circadian Clock
Authors: Allen Trudie , Koustenis Athanasios , Theodorou George , Somers David E. , Kay Steve A. , Whitelam Garry C. , Devlin Paul F. 
Published: September 2006

Abstract
Circadian gating of light signaling limits the timing of maximum responsiveness to light to specific times of day. The fhy3 (for far-red elongated hypocotyl3) mutant of Arabidopsis thaliana is involved in independently gating signaling from a group of photoreceptors to an individual response. fhy3 shows an enhanced response to red light during seedling deetiolation. Analysis of two independent fhy3 alleles links enhanced inhibition of hypocotyl elongation in response to red light with an arrhythmic pattern of hypocotyl elongation. Both alleles also show disrupted rhythmicity of central-clock and clock-output gene expression in constant red light. fhy3 exhibits aberrant phase advances under red light pulses during the subjective day. Release-from-light experiments demonstrate clock disruption in fhy3 during the early part of the subjective day in constant red light, suggesting that FHY3 is important in gating red light signaling for clock resetting. The FHY3 gating function appears crucial in the early part of the day for the maintenance of rhythmicity under these conditions. However, unlike previously described Arabidopsis gating mutants that gate all light signaling, gating of direct red light–induced gene expression in fhy3 is unaffected. FHY3 appears to be a novel gating factor, specifically in gating red light signaling to the clock during daytime.
Tocopherols Play a Crucial Role in Low-Temperature Adaptation and Phloem Loading in Arabidopsis
Authors: Maeda Hiroshi , Song Wan , Sage Tammy L. , DellaPenna Dean 
Published: September 2006

Abstract
To test whether tocopherols (vitamin E) are essential in the protection against oxidative stress in plants, a series of Arabidopsis thaliana vitamin E (vte) biosynthetic mutants that accumulate different types and levels of tocopherols and pathway intermediates were analyzed under abiotic stress. Surprisingly subtle differences were observed between the tocopherol-deficient vte2 mutant and the wild type during high-light, salinity, and drought stresses. However, vte2, and to a lesser extent vte1, exhibited dramatic phenotypes under low temperature (i.e., increased anthocyanin levels and reduced growth and seed production). That these changes were independent of light level and occurred in the absence of photoinhibition or lipid peroxidation suggests that the mechanisms involved are independent of tocopherol functions in photoprotection. Compared with the wild type, vte1 and vte2 had reduced rates of photoassimilate export as early as 6 h into low-temperature treatment, increased soluble sugar levels by 60 h, and increased starch and reduced photosynthetic electron transport rate by 14 d. The rapid reduction in photoassimilate export in vte2 coincides with callose deposition exclusively in phloem parenchyma transfer cell walls adjacent to the companion cell/sieve element complex. Together, these results indicate that tocopherols have a more limited role in photoprotection than previously assumed but play crucial roles in low-temperature adaptation and phloem loading.
The Proteolytic Processing of Seed Storage Proteins inArabidopsisEmbryo Cells Starts in the Multivesicular Bodies
Authors: Otegui Marisa S. , Herder Rachel , Schulze Jan , Jung Rudolf , Staehelin L. Andrew 
Published: September 2006

AbstractWe have investigated the transport of storage proteins, their processing proteases, and the Vacuolar Sorting Receptor-1/Epidermal Growth Factor Receptor–Like Protein1 (VSR-1/ATELP1) receptor during the formation of protein storage vacuoles in Arabidopsis thaliana embryos by means of high-pressure freezing/freeze substitution, electron tomography, immunolabeling techniques, and subcellular fractionation. The storage proteins and their processing proteases are segregated from each other within the Golgi cisternae and packaged into separate vesicles. The storage protein–containing vesicles but not the processing enzyme–containing vesicles carry the VSR-1/ATELP1 receptor. Both types of secretory vesicles appear to fuse into a type of prevacuolar multivesicular body (MVB). We have also determined that the proteolytic processing of the 2S albumins starts in the MVBs. We hypothesize that the compartmentalized processing of storage proteins in the MVBs may allow for the sequential activation of processing proteases as the MVB lumen gradually acidifies.
INCREASED LEVEL OF POLYPLOIDY1, a Conserved Repressor of CYCLINA2 Transcription, Controls Endoreduplication in Arabidopsis
Authors: Yoshizumi Takeshi , Tsumoto Yuko , Takiguchi Tomoko , Nagata Noriko , Yamamoto Yoshiharu Y. , Kawashima Mika , Ichikawa Takanari , Nakazawa Miki , Yamamoto Naoki , Matsui Minami 
Published: September 2006

Abstract
Endoreduplication is a type of cell cycle in which DNA replication continues without cell division. We have isolated several dominant mutants from Arabidopsis thaliana activation tagging lines by flow cytometry. One of the mutants, increased level of polyploidy1-1D (ilp1-1D), showed increased polyploidy in both light- and dark-grown hypocotyls. The corresponding gene of ilp1-1D encodes a protein homologous to the C-terminal region of mammalian GC binding factor. We demonstrate that this protein functions as a transcriptional repressor in vivo. The expression of all members of the CYCLINA2 (CYCA2) family was reduced in an ILP1 overexpressing line, and the mouse (Mus musculus) homolog of ILP1 repressed cyclin A2 expression in mouse NIH3T3 cells. T-DNA insertion mutants of ILP1 showed reduced polyploidy and upregulated all CYCA2 expression. Furthermore, loss of CYCA2;1 expression induces an increase in polyploidy in Arabidopsis. We demonstrate that this protein regulates endoreduplication through control of CYCA2 expression in Arabidopsis.
LATTICE DIMENSIONS OF SOME SOLID SOLUTIONS IN THE SYSTEM MgO‐Al2O3*
Authors: CLARK G. L. , HOW E. E. , BADGER A. E. 
Published: October 2006

ABSTRACTThe lattice dimension of magnesia spinel was determined to be a0= 8.064 0.002 A.U. The lattice dimension of solid solutions of this spinel with αAl2O3 decreases progressively with increase of Al2O3.
ON THE THERMAL. ENDURANCE OF GLASS*
Authors: TABATA KOZO , MORIYA TARO 
Published: October 2006

ABSTRACTThe thermal endurance of borosilicate glasses in the form of perfectly annealed rods of five different diameters was studied. Temperature distribution in the rods, therma1 stress, relation between radius of rod and critical thermal shock are mathematically discussed from observed data. A new expression showing the relation between the radius of the rods and the minimum temperature difference to cause fracture in the rods is developed
THE CONSTITUTION OF GLASS*
Authors: MOREY GEORGE W. 
Published: October 2006

ABSTRACTGlass is to be regarded as a liquid which has a viscosity so great as to be practically rigid; and the glasses of commerce are all solutions undercooled far below their normal crystallizing temperatures. Nothing more is known regarding the constitution of these highly concentrated solutions than is known about the constitution of other concentrated solutions. The phase‐equilibrium diagram gives no information as to the compounds present in the liquid phase, for there is no known correlation between the properties of a homogeneous system and those of the heterogeneous system formed from it on crystallization. Evidence based on the rate of volatilization of alkali from alkali‐silicate glasses does not indicate compound formation. The discontinuous change of properties of a glass in the “annealing range” has been considered by some to be evidence that the glassy state is a fourth state of matter separated from the liquid state by this transition temperature; by others, as indicating that above this discontinuity the material is a liquid, below it, a brittle solid. These views are unsound, because they are based on measurements of physical properties made with changing temperature when those properties themselves not only change with temperature but also require at each temperature considerable time to reach their equilibrium value. When the measurements are made on glasses which have been held at constant temperature long enough for the equilibrium value of the property to be attained, no discontinuities are observed and there is no justification for calling glass a fourth state of matter or for separating a “brittle” from a “viscous” temperature range. Arguments, based on the variation of physical properties with composition in which it is considered that such variation is represented not by a continuous curve but by a series of straight lines determined by the composition of hypothetical compounds, are shown to be theoretically improbable and not in accord with the facts. Recent speculations on the constitution of glass based on X‐ray evidence and recent studies of glass by means of X‐rays indicate that the glassy state is distinguished by a random nonrepeating atomic network. This conclusion is in harmony with the view that glass is an undercooled liquid representing a solution in which definite compounds can not be identified.
THE SYSTEM Na2O‐B2O3, IV Vapor Pressures of Boric Oxide, Sodium Metaborate, and Sodium Diborate between 1150°C and 1400°C
Authors: Cole Sandford S. , Taylor Nelson W. 
Published: October 2006

ABSTRACTVapor pressures of B203, Na2O, B2O3, and Na2O.2B3O were obtained at 50°C intervals between 1150°C and 1400°C, utilizing the dynamic method with dry N2 under normal atmospheric pressure. Assuming normal vapor densities, the vapor pressures in millimeters of mercury at O°C were as follows:

Temperature, °C
B2O3
Na2O·B2O3
Na2O·2B2O3

1150

2.55
2.1

1200
0.83
7.2
5.5

1250
2.0
28.0
13.0

1300
3.4
62.0
25.5

1350
6.9
160.0

1400
12.0

The calculated boiling point was found to be 1860°C for B2O3, 1434°C for Na2O‐B2O3, and 1575°C for Na2O.2B2O3. The molal entropy of vaporization of B2O3 was found to be 32.2 calories per degree. The molal heat of vaporization was calculated to be B2O3, 65,600 cal.; NaZO.B2O3, 96,910 cal.; and Na2O.2B2O3, 72,410 cal.B2O3 and Na2O.B2O3 volatilized without change in composition, but Na2O.2B2O3 was found to dissociate at all temperatures studied. It yielded a vapor of calculated composition 51.6% Na2O, 48.4% B2O3. Vapor pressure data based on this composition are also reported.
THE EFFECT OF TEMPERATURE TREATMENT ON GLASS‐TO‐METAL SEALS*
Authors: Littleton J. T. 
Published: October 2006

ABSTRACTIt has been known for some time that glass cooled from temperatures well above the annealing temperature contracts at a rate depending upon its cooling rate and the temperature from which its cooling begins. Expansion measurements taken on the glass during later heating do not follow the original contraction curve. A photoelastic method is described which gives information on how the contraction of the glass is affected by these temperature conditions. The observations are of particular interest when applied to glass‐metal seals.
CONE FUSION STUDY OF MIXTURES OF ZIRCONIUM SILICATE, SILICA, AND ALUMINA*
Authors: Rea Robert F. 
Published: October 2006

AbstractAlumina and alumina‐silica mixtures have a strong fluxing effect on zirconium silicate A eutectic between ZrSiO3 and Al2O3 occurs at approximately 20% Al2O3 and melts at cone 31. The ternary eutectic has an approximate composition of 70% SiO2, 15% ZrSiO3, 15% A12O3, and a P.C.E. of cone 27.
SHRINKAGE RATES IN FIRING FIRE‐CLAY REFRACTORIES*
Authors: Stevens Donald K. , Bikch Raymond E. 
Published: October 2006

AbstractDirect optical measurements of length changes of five commercial fire‐clay refractories were made during a 72‐hour firing on a uniform heating schedule of 35°F. (20°C.) per hour. Data obtained from room temperature to 2700°F. (1480°C.) revealed three periods of high shrinkage rate. The shrinkage within these periods, emphasized by plotting the rate of change in length against temperature, showed maximum values at 950° to 1000°F., 1630° to 1680°F., and 1940° to 2040°F. (510°to 540°C.,890° to 915°C., and 1060° to 1115°C.). The magnitude of these peak values increased in the sameorder. The highest linear‐shrinkage rate observed was 2.4% per 100°F. (55°C.) temperature rise in the interval between 2018° and 2060°F. (1105° and 1125°C.).
ULTRAVIOLET‐TRANSMITTING GLASSES FOR MERCURY‐VAPOR LAMPS*
Authors: Nordberg M. E. 
Published: October 2006

AbstractThe ultraviolet transmission of Vycor brand glass No. 791 is compared with that of certain commercial glasses and fused silica. The loss in transmission after 230 hours of exposure to ultraviolet radiation (2537 a.u.) from a Hanovia arc was 2.5% for No. 791 glass and 32.5% for Pyrex brand glass No. 9741. The loss (approximately 12%), due to the darkened layer which forms on a glass surface in contact with a mercury arc, is smaller for No. 791 glass than for glasses in general. The decrease in 2537 a.u. output of experimental lamps was determined after operation times up to nearly 6000 hours; after 5000 hours, No. 791 glass showed 27% loss in hot cathode lamps and Pyrex brand No. 9741 showed 53%. Vycor brand glass No. 7911, developed for medium‐pressure arcs (such as sunlamps), is discussed. The electrical properties of Vycor brand No. 791 are resistivity at 350°C., 9.2 (log R, ohm‐cm.); loss factor at 1.0 mc., 0.00091; and dielectric constant, 3.8.
PROPERTIES OF ENAMEL SLIPS: II, SOLUBLE SALTS IN ENAMEL SLIPS*
Authors: King Burnham W. , Carter Herbert D. , Draker Harry C. 
Published: October 2006

AbstractThis paper contains data on the soluble salts to be found in mill liquors obtained on milling a number of different commercial porcelain‐enamel frits. The change in soluble salts on aging the enamel slips and the variation in pickup was also investigated. The mill liquors were found to contain chiefly Na2O, B2O3, and NaF. The effect of various proportions of these salts was studied by adding NaOH, Na2B4O7. 10H2O, and NaF to a slip composed of clay, water, and fine‐ground quartz. The correlation of the various data is discussed
RAPID METHOD FOR DETERMINING NICKEL ON THE SURFACE OF ENAMELING IRON*
Authors: Ikenberry L. c. , Canfield† J. J. 
Published: October 2006

AbstractA photometric method for determining nickel on nickel‐coated steel is described. The method is very rapid, requiring less than 5 minutes. The standard deviation (σ) has been found to be 0.0028 gm. of nickel per sq. ft. when testing a sheet carrying 0.10 gm. of nickel per sq. ft. The sample is obtained by dissolving the nickel coating on a small area with dilute nitric acid. The nitric acid is confined by using a weighted rubber ring and is withdrawn by suction into a 200‐ml. Erlenmeyer flask marked at 200 ml. A large excess of ammonium hydroxide is added, followed by ammonium persulfate and dimethylglyoxime. The solution is diluted to 200 ml. with water. After filtering off the ferric hydroxide, the intensity of the red color, which is proportional to the amount of nickel present, is measured by means of a photoelectric photometer.
IMPROVED APPARATUS FOR MEASURING VISCOSITY OF GLASSES IN ANNEALING RANGE OF TEMPERATURE*
Authors: Poole James P. 
Published: October 2006

AbstractAn instrument is described that has been found to be a valuable and precise tool for the measurement of viscosity in the annealing range of temperature. The outstanding feature of this apparatus is its high thermal inertia that makes it possible to maintain thermal equilibrium without auxiliary temperature‐control equipment.