bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elliptic functions, theta function and hypersurfaces satisfying a basic equality
Authors: CHEN BANG-YEN , YANG JIE 
Published: July 2002

(Volume 125 (1999), 463–509)Case (x) in Theorem 6 is missing. The correct statement of Theorem 6 in the paper
should read as follows.THEOREM 6. Let x: Mn → Hn+1
(−1) ⊂ [ ]n+21 (n > 2) be an isometric immersion of
a conformally flat n-manifold. Then it satisfies equality (1·2) if and only if one of the
following ten cases occurs.
Studies of the presence of verocytotoxic Escherichia coli

O157 in bovine faeces submitted for diagnostic purposes in
England and Wales and on beef carcases in abattoirs in the United Kingdom
Authors: RICHARDS M. S. , CORKISH J. D. , SAYERS A. R. , McLAREN I. M. , EVANS S. J. , WRAY C. 
Published: July 2002

A survey of beef carcases in abattoirs in the UK was carried
out in order to estimate the
prevalence of contamination with verocytotoxin – producing
Escherichia coli (VTEC) serogroup
O157. Contamination with verocytotoxin-producing E. coli (VTEC)
O157 was confirmed in
0·47% of the 4067 (95% confidence limits 0·22–1·00%)

of neck muscle samples. A significant
tendency for carcases present in the same abattoir on the same day to have
similar results was
found, thus suggesting cross contamination.VTEC O157 was found in 0·83% of 6495 bovine faeces samples routinely
submitted for
diagnostic purposes to Veterinary Investigation Centres in England and
Wales. Of the samples
from cattle less than 6 months old, 3·7% of 68 samples from
animals without gastrointestinal
disease were positive for E. coli O157, in contrast to
0·75% of 2321 samples from cases of
gastrointestinal disease. No association with season or herd type (beef
or dairy) was found.
Modulation of the adrenocortical stress response in marine turtles (Cheloniidae): evidence for a hormonal tactic maximizing maternal reproductive investment
Authors: Jessop Tim S. 
Published: July 2002

AbstractThe relationships between reproductive condition, level of reproductive investment and adrenocortical modulation to capture stress in marine turtles form the basis of this study. When subjected to either capture or ecological stressors, nesting marine turtles have demonstrated adrenocortical responses that are both small in magnitude, and slow in responsiveness. These observations were further investigated to determine whether this minimal stress response was a physiological strategy to maximize reproductive investment in adult green Chelonia mydas and hawksbill Eretmochelys imbricata turtles. Female green and hawksbill turtles exhibited a decrease in adrenocortical responsiveness with progressive reproductive condition. Breeding turtles exhibited most suppression of their adrenocortical response to capture compared to both non‐breeding and pre‐breeding female counterparts. Nesting green turtles maintained a suppressed adrenocortical response to capture throughout the nesting season despite decreased reproductive investment. In contrast, male green and hawksbill turtles were less able to modulate their corticosterone (B) response to acute capture stress. During breeding, male turtles possessed significantly greater adrenocortical responses to capture than females. These results could indicate that the large reproductive investment necessary for female marine turtle reproduction might underlie the marked decrease in adrenocortical responsiveness. This hormonal mechanism could function as one strategy by which female marine turtles maximize their current reproductive event, even though under certain situations this mechanism could entail costs to female survival.
The Northern Ireland Conflict: New Wine in Old Bottles?
Authors: Wichert Sabine 
Published: July 2002

James Loughlin, The Ulster Question since 1945 (London: Macmillan, 1998), 151 pp., £10.99 (pb), ISBN 0–333–60616–7.David Harkness, Ireland in the Twentieth Century. Divided Island (London: Macmillan, 1996), 190 pp., £9.99 (pb), ISBN 0–333–56796–X.Thomas Hennessey, A History of Northern Ireland, 1920–1996 (London: Macmillan, 1997), 347 pp., £12.99 (pb), £40.00 (hb), ISBN 0–333–73162–X.Brian A. Follis, A State Under Siege. The Establishment of Northern Ireland, 1920–1925 (Oxford: Clarendon, 1995), 250 pp., £35.00 (hb), ISBN 0–198–20305–5.Dermot Keogh and Michael H. Haltzel, eds., Northern Ireland and the Politics of reconciliation (Cambridge: Cambridge University Press, 1994), 256 pp., £35.00 (hb), ISBN 0–521–44430–6.William Crotty and David Schmitt, eds., Ireland and the Politics of Change (London/New York: Longman, 1999), 264 pp., £17.99 (pb), ISBN 0–582–32894–2.David Miller, ed., Rethinking Northern Ireland. Culture, Ideology and Colonialism. (London/New York: Longman, 1999), 344 pp., £17.99 (pb), ISBN 0–582–30287–0.Anthony D. Buckley and Mary Catherine Kenney, Negotiating Identity: Rhetoric, Metaphor, and Social Identity in Northern Ireland (Washington: Smithonian Institution Press, 1996), 270 pp., £34.75 (hb), ISBN 1–560–98520–8.John D. Brewer, with Gareth I. Higgins, Anti-Catholicism in Northern Ireland, 1600–1998: the mote and the beam (London: Macmillan, 1998), 248 pp., £16.99 (pb), ISBN 0–333–74635–X.During the last three decades, and accompanying the ‘troubles’, the literature on
Northern Ireland has mushroomed. Within the last ten years two surveys have
attempted to summarise and categorise the major interpretations. John Whyte's
Interpreting Northern Ireland covered the 1970s and 1980s and came to the conclusion
that traditional Unionist and nationalist interpretations, with their emphasis on
external, that is British and Irish, forces as the cause for the problem, had begun to
lose out to ‘internal conflict’ interpretations. He felt, however, that this approach,
too, was coming to the end of its usefulness, and he expected the emergence of a new paradigm shortly.
Predicting road hazards caused by rain, freezing rain and wet surfaces and the role of weather radar
Authors: Symons Leslie , Perry Allen 
Published: July 2002

AbstractFreezing rain in the winter of 1995/96 has drawn attention to the severity of black‐ice problems on British roads, additional to the normal increased hazards presented to drivers by any form of precipitation. Disruption to traffic was considerable on several days. Weather radar provides improved nowcasting, for both winter and summer conditions, where available real time directly to highway engineers, but this is not yet generally the case in England and Wales. New developments from the Meteorological Office offer improved possibilities at reasonable costs. Copyright © 1997 Royal Meteorological Society.
The Biophysics of Leaf Growth in Salt-Stressed Barley. A Study at the Cell Level
Authors: Fricke Wieland , Peters Winfried S. 
Published: July 2002

Abstract
Biophysical parameters potentially involved in growth regulation were studied at the single-cell level in the third leaf of barley (Hordeum vulgare) after exposure to various degrees of NaCl stress for 3 to 5 d. Gradients of elongation growth were measured, and turgor pressure, osmolality, and water potentials (ψ) were determined (pressure probe and picoliter osmometry) in epidermal cells of the elongation zone and the mature blade. Cells in the elongation zone adjusted to decreasing external ψ through increases in cell osmolality that were accomplished by increased solute loads and reduced water contents. Cell turgor changed only slightly. In contrast, decreases in turgor also contributed significantly to ψ adjustment in the mature blade. Solute deposition rates in the elongation zone increased at moderate stress levels as compared with control conditions, but decreased again at more severe NaCl exposure. Growth-associated ψ gradients between expanding epidermal cells and the xylem were significant under control and moderate stress conditions (75 mm NaCl) but seemed negligible at severe stress (120 mm NaCl). We conclude that leaf cell elongation in NaCl-treated barley is probably limited by the rate at which solutes can be taken up to generate turgor, particularly at high NaCl levels.
Members of the c1/pl1 Regulatory Gene Family Mediate the Response of Maize Aleurone and Mesocotyl to Different Light Qualities and Cytokinins
Authors: Piazza Paolo , Procissi Antonia , Jenkins Gareth I. , Tonelli Chiara 
Published: July 2002

Abstract
We investigated the role of transcription factors (R, SN, C1, and PL) in the regulation of anthocyanin biosynthesis by different light qualities (white, red, blue, and ultraviolet) and by cytokinin in maize (Zea mays). We analyzed anthocyanin accumulation, structural gene expression, and regulatory gene expression in the seed aleurone and the seedling mesocotyl. In the mesocotyl, white, blue, and ultraviolet-B light strongly induced anthocyanin accumulation and expression of two key structural genes. In contrast, red light had little effect. Cytokinin enhanced the response to light but was not sufficient to induce anthocyanin accumulation in darkness. Plants with the pl-bol3 allele showed high levels of anthocyanin accumulation in response to light, whereas those with thepl-W22 allele did not, demonstrating the importance of pl1 in the light response. The expression of the pl-bol3 gene, encoding an MYB-related transcription factor, was induced by light and enhanced by cytokinin in a very similar manner to the structural genes and anthocyanin accumulation. Expression of the bHLH(basic helix-loop-helix) Sn1-bol3 gene was stimulated by several light qualities, but not enhanced by cytokinin, and was less well correlated with the induction of anthocyanin biosynthesis. In the aleurone, white, red, and blue light were effective in stimulating anthocyanin accumulation and expression of the MYB-related gene C1. ThebHLH R gene was constitutively expressed. We conclude that specific members of the MYB-relatedc1/pl1 gene family play important roles in the regulation of anthocyanin synthesis in maize in response to different light qualities and cytokinin.
Starches from A to C (Chlamydomonas reinhardtii as a Model Microbial System to Investigate the Biosynthesis of the Plant Amylopectin Crystal)
Authors: Buleon A. , Gallant D. J. , Bouchet B. , Mouille G. , D'Hulst C. , Kossmann J. , Ball S. 
Published: July 2002

Abstract
Wide-angle powder x-ray diffraction analysis was carried out on starch extracted from wild-type and mutant Chlamydomonas reinhardtii cells. Strains containing no defective starch synthases as well as mutants carrying a disrupted granule-bound starch synthase structural gene displayed the A type of diffraction pattern with a high degree of crystallinity. Mutants carrying a defect for the major soluble starch synthase (SSS), SSS II, were characterized by a switch to the B type of diffraction pattern with very low crystallinity. Mutant strains carrying SSS I as the only glucan elongation enzyme regained some of their crystallinity but switched to the C type of diffraction pattern. Differential scanning calorimetry analysis correlated tightly with the x-ray diffraction results. Together with the electron microscopy analyses, these results establish C. reinhardtii as a microbial model system displaying all aspects of cereal starch synthesis and structure. We further show that SSS II is the major enzyme involved in the synthesis of crystalline structures in starch and demonstrate that SSS I alone builds a new type of amylopectin structure.
The Small, Methionine-Rich Chloroplast Heat-Shock Protein Protects Photosystem II Electron Transport during Heat Stress1
Authors: Heckathorn Scott A. , Downs Craig A. , Sharkey Thomas D. , Coleman James S. 
Published: July 2002

Abstract
Evidence suggests that the small chloroplast heat-shock protein (Hsp) is involved in plant thermotolerance but its site of action is unknown. Functional disruption of this Hsp using anti-Hsp antibodies or addition of purified Hsp to chloroplasts indicated that (a) this Hsp protects thermolabile photosystem II and, consequently, whole-chain electron transport during heat stress; and (b) this Hsp completely accounted for heat acclimation of electron transport in pre-heat-stressed plants. Therefore, this Hsp is a major adaptation to acute heat stress in plants.
Plastid Ontogeny during Petal Development in Arabidopsis1
Authors: Pyke Kevin A. , Page Anton M. 
Published: July 2002

Abstract
Imaging of chlorophyll autofluorescence by confocal microscopy in intact whole petals ofArabidopsis thaliana has been used to analyze chloroplast development and redifferentiation during petal development. Young petals dissected from unopened buds contained green chloroplasts throughout their structure, but as the upper part of the petal lamina developed and expanded, plastids lost their chlorophyll and redifferentiated into leukoplasts, resulting in a white petal blade. Normal green chloroplasts remained in the stalk of the mature petal. In epidermal cells the chloroplasts were normal and green, in stark contrast with leaf epidermal cell plastids. In addition, the majority of these chloroplasts had dumbbell shapes, typical of dividing chloroplasts, and we suggest that the rapid expansion of petal epidermal cells may be a trigger for the initiation of chloroplast division. In petals of the Arabidopsis plastid division mutantarc6, the conversion of chloroplasts into leukoplasts was unaffected in spite of the greatly enlarged size and reduced number of arc6 chloroplasts in cells in the petal base, resulting in few enlarged leukoplasts in cells from the white lamina ofarc6 petals.
Comparative Biochemistry of the Oxidative Burst Produced by Rose and French Bean Cells Reveals Two Distinct Mechanisms1
Authors: Bolwell G. Paul , Davies Dewi R. , Gerrish Chris , Auh Chung-Kyoon , Murphy Terence M. 
Published: July 2002

Abstract
Cultured cells of rose (Rosa damascena) treated with an elicitor derived from Phytophthora spp. and suspension-cultured cells of French bean (Phaseolus vulgaris) treated with an elicitor derived from the cell walls of Colletotrichum lindemuthianum both produced H2O2. It has been hypothesized that in rose cells H2O2is produced by a plasma membrane NAD(P)H oxidase (superoxide synthase), whereas in bean cells H2O2 is derived directly from cell wall peroxidases following extracellular alkalinization and the appearance of a reductant. In the rose/Phytophthoraspp. system treated with N,N-diethyldithiocarbamate, superoxide was detected by a N,N′-dimethyl-9,9′-biacridium dinitrate-dependent chemiluminescence; in contrast, in the bean/C. lindemuthianum system, no superoxide was detected, with or withoutN,N-diethyldithiocarbamate. When rose cells were washed free of medium (containing cell wall peroxidase) and then treated with Phytophthora spp. elicitor, they accumulated a higher maximum concentration of H2O2 than when treated without the washing procedure. In contrast, a washing treatment reduced the H2O2 accumulated by French bean cells treated with C. lindemuthianum elicitor. Rose cells produced reductant capable of stimulating horseradish (Armoracia lapathifolia) peroxidase to form H2O2but did not have a peroxidase capable of forming H2O2 in the presence of reductant. Rose and French bean cells thus appear to be responding by different mechanisms to generate the oxidative burst.
The Never ripe Mutant Provides Evidence That Tumor-Induced Ethylene Controls the Morphogenesis ofAgrobacterium tumefaciens-Induced Crown Galls on Tomato Stems1,2
Authors: Aloni Roni , Wolf Asnat , Feigenbaum Pua , Avni Adi , Klee Harry J. 
Published: July 2002

Abstract
We confirm the hypothesis thatAgrobacterium tumefaciens-induced galls produce ethylene that controls vessel differentiation in the host stem of tomato (Lycopersicon esculentum Mill.). Using an ethylene-insensitive mutant, Never ripe(Nr), and its isogenic wild-type parent we show that infection by A. tumefaciens results in high rates of ethylene evolution from the developing crown galls. Ethylene evolution from isolated internodes carrying galls was up to 50-fold greater than from isolated internodes of control plants when measured 21 and 28 d after infection. Tumor-induced ethylene substantially decreased vessel diameter in the host tissues beside the tumor in wild-type stems but had a very limited effect in the Nr stems. Ethylene promoted the typical unorganized callus shape of the gall, which maximized the tumor surface in wild-type stems, whereas the galls on the Nr stems had a smooth surface. The combination of decreased vessel diameter in the host and increased tumor surface ensured water-supply priority to the growing gall over the host shoot. These results indicate that in addition to the well-defined roles of auxin and cytokinin, there is a critical role for ethylene in determining crown-gall morphogenesis.
Characterization of Starch-Debranching Enzymes in Pea Embryos
Authors: Zhu Zhi-Ping , Hylton Christopher M. , Rössner Ute , Smith Alison M. 
Published: July 2002

Abstract
Two distinct types of debranching enzymes have been identified in developing pea (Pisum sativum L.) embryos using native gel analysis and tests of substrate preference on purified or partially purified activities. An isoamylase-like activity capable of hydrolyzing amylopectin and glycogen but not pullulan is present throughout development and is largely or entirely confined to the plastid. Activities capable of hydrolyzing pullulan are present both inside and outside of the plastid, and extraplastidial activity increases relative to the plastidial activity during development. Both types of debranching enzyme are also present in germinating embryos. We argue that debranching enzymes are likely to have a role in starch metabolism in the plastid of the developing embryo and in starch degradation during germination.
Domains of a Transit Sequence Required for in Vivo Import in Arabidopsis Chloroplasts
Authors: Rensink Willem Albert , Pilon Marinus , Weisbeek Peter 
Published: July 2002

Abstract
Nuclear-encoded precursors of chloroplast proteins are synthesized with an amino-terminal cleavable transit sequence, which contains the information for chloroplastic targeting. To determine which regions of the transit sequence are most important for its function, the chloroplast uptake and processing of a full-length ferredoxin precursor and four mutants with deletions in adjacent regions of the transit sequence were analyzed. Arabidopsis was used as an experimental system for both in vitro and in vivo import. The full-length wild-type precursor translocated efficiently into isolated Arabidopsis chloroplasts, and upon expression in transgenic Arabidopsis plants only mature-sized protein was detected, which was localized inside the chloroplast. None of the deletion mutants was imported in vitro. By analyzing transgenic plants, more subtle effects on import were observed. The most N-terminal deletion resulted in a fully defective transit sequence. Two deletions in the middle region of the transit sequence allowed translocation into the chloroplast, although with reduced efficiencies. One deletion in this region strongly reduced mature protein accumulation in older plants. The most C-terminal deletion was translocated but resulted in defective processing. These results allow the dissection of the transit sequence into separate functional regions and give an in vivo basis for a domain-like structure of the ferredoxin transit sequence.
The Sensitivity of Barley Aleurone Tissue to Gibberellin Is Heterogeneous and May Be Spatially Determined1
Authors: Ritchie Sian , McCubbin Andrew , Ambrose Genevieve , Kao Teh-hui , Gilroy Simon 
Published: July 2002

Abstract
In cereals, gibberellin (GA) enhances the synthesis and secretion of hydrolytic enzymes from aleurone cells. These enzymes then mobilize the endosperm storage reserves that fuel germination. The dose-response curve of aleurone protoplasts to GA extends over a range of concentrations from 10−11 to more than 10−6m. One hypothesis is that subpopulations of cells have different sensitivities to GA, with each cell having a threshold concentration of GA above which it is switched on. The dose-response curve therefore reflects a gradual recruitment of cells to the pool exhibiting a full GA response. Alternatively, all cells may gradually increase their responses as the GA level is increased. In the present study we found that at increasing GA concentrations, increasing numbers of barley (Hordeum vulgare) cells showed the enhanced amylase secretion and vacuolation characteristic of the GA response. We also observed that the region of aleurone tissue closest to the embryo contains the highest proportion of cells activated at the GA concentrations thought to occur naturally in germinating grain. These data indicate that an aleurone layer contains cells of varying sensitivities to GA and that recruitment of these differentially responding pools of cells may explain the broad dose response to GA.
Genetic Analysis of Growth-Regulator-Induced Parthenocarpy in Arabidopsis
Authors: Vivian-Smith Adam , Koltunow Anna M. 
Published: July 2002

AbstractIn Arabidopsis, seedless silique development or parthenocarpy can be induced by the application of various plant growth regulators (PGRs) to unfertilized pistils. Ecotype-specific responses were observed in the Arabidopsis ecotypes Columbia and Landsberg relative to the type of PGR and level applied. The parthenocarpic response was greatest in ecotype Landsberg, and comparisons of fruit growth and morphology were studied primarily in this ecotype. Gibberellic acid application (10 μmol pistil−1) caused development similar to that in pollinated pistils, while benzyladenine (1 μmol pistil−1) and naphthylacetic acid (10 μmol pistil−1) treatment produced shorter siliques. Naphthylacetic acid primarily modified mesocarp cell expansion. Arabidopsis mutants were employed to examine potential dependencies on gibberellin biosynthesis (ga1-3,ga4-1, andga5-1) and perception (spy-4 and gai) during parthenocarpic silique development. Emasculated spy-4 pistils were neither obviously parthenocarpic nor deficient in PGR perception. By contrast, emasculated gai mutants did not produce parthenocarpic siliques following gibberellic acid application, but silique development occurred following pollination or application of auxin and cytokinin. Pollinated gai siliques had decreased cell numbers and morphologically resembled auxin-induced parthenocarpic siliques. This shows that a number of independent and possibly redundant pathways can direct hormone-induced parthenocarpy, and that endogenous gibberellins play a role in regulating cell expansion and promoting cell division in carpels.
Initial Binding of Preproteins Involving the Toc159 Receptor Can Be Bypassed during Protein Import into Chloroplasts
Authors: Chen Kunhua , Chen Xuejun , Schnell Danny J. 
Published: July 2002

Abstract
Two integral outer envelope GTPases, Toc34 and Toc86, are proposed to regulate the recognition and translocation of nuclear-encoded preproteins during the early stages of protein import into chloroplasts. Defining the precise roles of Toc86 and Toc34 has been complicated by the inability to distinguish their GTPase activities. Furthermore, the assignment of Toc86 function is rendered equivocal by recent reports suggesting that the standard protocol for the isolation of chloroplasts results in significant proteolysis of Toc86 (B. Bolter, T. May, J. Soll [1998] FEBS Lett 441: 59–62; G. Schatz [1998] Nature 395: 439–440). We demonstrate that Toc86 corresponds to a native protein of 159 kD in pea (Pisum sativum), designated Toc159. We take advantage of the proteolytic sensitivity of Toc159 to selectively remove its 100-kD cytoplasmic GTPase domain and thereby distinguish its activities from other import components. Proteolysis eliminates detectable binding of preproteins at the chloroplast surface, which is consistent with the proposed role of Toc159 as a receptor component. Remarkably, preprotein translocation across the outer membrane can occur in the absence of the Toc159 cytoplasmic domain, suggesting that binding can be bypassed. Translocation remains sensitive to GTP analogs in the absence of the Toc159 GTP-binding domain, providing evidence that Toc34 plays a key role in the regulation of translocation by GTP.