bluuebunny/crossref_metadata_2025 huggingface dataset:
Depletion of organic phosphorus from Oxisols in relation to phosphatase activities in the rhizosphere
Authors: George T. S. , Turner B. L. , Gregory P. J. , Cade‐Menun B. J. , Richardson A. E.
Published: January 2006

Phosphorus (P) deficiency is a major limitation to agricultural production in many parts of the world. It is therefore desirable to identify plants with enhanced abilities to utilize P more efficiently. Exudation of phosphatase from roots may improve P availability, yet there is little direct evidence for this. Here we report the dynamics of organic P in the rhizosphere of plants that have enhanced rhizosphere phosphatase activity. Agroforestry species and transgenic subterranean clover (engineered to produce phytase) were compared with crop and wild‐type plant controls, respectively. Depletion of organic P was measured in pools defined by chemical extraction, solution 31P NMR spectroscopy, and microbial immobilization of radio‐isotopic P. Plants that had greater extracellular phosphatase activity depleted more organic P from P‐deficient Oxisols than control plants. Depleted organic P forms were primarily phosphate monoesters. Plants with enhanced extracellular phosphatase activity also had access to a pool of soil P that was less isotopically exchangeable. Transgenic subterranean clover that expresses a microbial phytase gene appeared to have greater access to recently immobilized P, whereas plants expressing endogenous phosphatases utilized the unlabelled portion of soil organic P to a greater extent. Collectively, these results indicate that the enhancement of phosphatase activity in the rhizosphere of plants is implicated in the depletion of organic P forms from soils, most notably orthophosphate monoesters, whilst also suggesting that there is some exclusivity to the pools of organic P utilized by plants and microorganisms.
Comparison of methods for measuring metal desorption from soils for parameterizing rhizosphere models
Authors: Molina Millán I. , Fitz W. J. , Unterbrunner R. , Wenzel W. W.
Published: January 2006

Sorption curves are commonly used to predict the partitioning of ions between the soil solid and solution in ion transport and rhizosphere models. We review methods for measuring metal desorption for such purposes, and we illustrate the problems involved by means of measurements of Ni desorption from a contaminated soil as an example. We find that measurements of metal concentration in shaken soil suspensions at a range of solution:soil ratios give similar desorption curves to the more tedious method of repeated extraction at a constant, smaller and therefore more realistic solution:soil ratio. We also find that desorption is sensitive to the nature and concentration of the background electrolyte used, and to interactions between these and additions of organic chelating agents of the sort excreted by roots and rhizosphere microbes.
Distributional patterns of freshwater taxa (fishes, crustaceans and plants) from the Mexican Transition Zone
Authors: Huidobro Leticia , Morrone Juan J. , Villalobos José Luis , Álvarez Fernando
Published: January 2006

Aim To test whether distributional patterns of Neotropical freshwater taxa fit the generalized tracks already postulated for terrestrial groups occurring in the Mexican Transition Zone.

Location The study units comprised 17 hydrological basins located along the Pacific coast of the Americas from Mexico to Panama, and in the Gulf of Mexico from the Papaloapan to the Grijalva–Usumacinta basin.

Methods Distributional data for 22 fish species, 34 crab species of the tribe Pseudothelphusini, and 22 strictly freshwater species of angiosperms were analysed. Parsimony analysis of endemicity is based on presence/absence data of these taxa and uses the computer programs Winclada and NONA.

Results Three generalized tracks were obtained: (1) Mexican North Pacific, (2) Mexican Central Pacific, and (3) Southern Mexico–Guatemala. A node resulted at the intersection of the first two tracks, coinciding with the Neovolcanic Axis in central Mexico.

Main conclusions Freshwater generalized tracks with an altitudinal distribution below 1000 m, mainly including fishes and angiosperms, are close to the Tropical Mesoamerican generalized track. Generalized tracks above 1000 m, including freshwater crabs, have a stronger affinity with the Mountain Mesoamerican track. The Isthmus of Tehuantepec represents a node for the Neotropical freshwater and terrestrial biota. These results seem to indicate that common geobiotic processes have induced these patterns.
Three‐dimensional volume reconstruction of extracellular matrix proteins in uveal melanoma from fluorescent confocal laser scanning microscope images
Authors: BAJCSY P. , LEE S‐C. , LIN A. , FOLBERG R.
Published: January 2006

The distribution of looping patterns of laminin in uveal melanomas and other tumours has been associated with adverse outcome. Moreover, these patterns are generated by highly invasive tumour cells through the process of vasculogenic mimicry and are not therefore blood vessels. Nevertheless, these extravascular matrix patterns conduct plasma. The three‐dimensional (3D) configuration of these laminin‐rich patterns compared with blood vessels has been the subject of speculation and intensive investigation. We have developed a method for the 3D reconstruction of volume for these extravascular matrix proteins from serial paraffin sections cut at 4 µm thicknesses and stained with a fluorescently labelled antibody to laminin (Maniotis et al., 2002). Each section was examined via confocal laser‐scanning focal microscopy (CLSM) and 13 images were recorded in the Z‐dimension for each slide. The input CLSM imagery is composed of a set of 3D subvolumes (stacks of 2D images) acquired at multiple confocal depths, from a sequence of consecutive slides. Steps for automated reconstruction included (1) unsupervised methods for selecting an image frame from a subvolume based on entropy and contrast criteria, (2) a fully automated registration technique for image alignment and (3) an improved histogram equalization method that compensates for spatially varying image intensities in CLSM imagery due to photo‐bleaching. We compared image alignment accuracy of a fully automated method with registration accuracy achieved by human subjects using a manual method. Automated 3D volume reconstruction was found to provide significant improvement in accuracy, consistency of results and performance time for CLSM images acquired from serial paraffin sections.
A step by step guide to phylogeny reconstruction
Authors: Jill Harrison C. , Langdale Jane A.
Published: January 2006

The aim of this paper is to enable those who have never reconstructed a phylogeny to do so from scratch. The paper does not attempt to be a comprehensive theoretical guide, but describes one rigorous way of obtaining phylogenetic trees. Those who follow the methods outlined should be able to understand the basic ideas behind the steps taken, the meaning of the phylogenetic trees obtained and the scope of questions that can be answered with phylogenetic methods. The protocols have been successfully tested by volunteers with no phylogenetic experience.
Oxylipin analysis methods
Authors: Mueller Martin J. , Mène‐Saffrané Laurent , Grun Christoph , Karg Kathrin , Farmer Edward E.
Published: January 2006

Practical guidelines for monitoring and measuring compounds such as jasmonates, ketols, ketodi(tri)enes and hydroxy‐fatty acids as well as detecting the presence of novel oxylipins are presented. Additionally, a protocol for the penetrant analysis of non‐enzymatic lipid oxidation is described. Each of the methods, which employ gas chromatography/mass spectrometry, can be applied without specialist knowledge or recourse to the latest analytical instrumentation. Additional information on oxylipin quantification and novel protocols for preparing oxygen isotope‐labelled internal standards are provided. Four developing areas of research are identified: (i) profiling of the unbound cellular pools of oxylipins; (ii) profiling of esterified oxylipins and/or monitoring of their release from parent lipids; (iii) monitoring of non‐enzymatic lipid oxidation; (iv) analysis of unstable and reactive oxylipins. The methods and protocols presented herein are designed to give technical insights into the first three areas and to provide a platform from which to enter the fourth area.
Gateway‐compatible vectors for plant functional genomics and proteomics
Authors: Earley Keith W. , Haag Jeremy R. , Pontes Olga , Opper Kristen , Juehne Tom , Song Keming , Pikaard Craig S.
Published: January 2006

Gateway cloning technology facilitates high‐throughput cloning of target sequences by making use of the bacteriophage lambda site‐specific recombination system. Target sequences are first captured in a commercially available ‘entry vector’ and are then recombined into various ‘destination vectors’ for expression in different experimental organisms. Gateway technology has been embraced by a number of plant laboratories that have engineered destination vectors for promoter specificity analyses, protein localization studies, protein/protein interaction studies, constitutive or inducible protein expression studies, gene knockdown by RNA interference, or affinity purification experiments. We review the various types of Gateway destination vectors that are currently available to the plant research community and provide links and references to enable additional information to be obtained concerning these vectors. We also describe a set of ‘pEarleyGate’ plasmid vectors for Agrobacterium‐mediated plant transformation that translationally fuse FLAG, HA, cMyc, AcV5 or tandem affinity purification epitope tags onto target proteins, with or without an adjacent fluorescent protein. The oligopeptide epitope tags allow the affinity purification, immunolocalization or immunoprecipitation of recombinant proteins expressed in vivo. We demonstrate the utility of pEarleyGate destination vectors for the expression of epitope‐tagged proteins that can be affinity captured or localized by immunofluorescence microscopy. Antibodies detecting the FLAG, HA, cMyc and AcV5 tags show relatively little cross‐reaction with endogenous proteins in a variety of monocotyledonous and dicotyledonous plants, suggesting broad utility for the tags and vectors.
Imaging the live plant cell
Authors: Shaw Sidney L.
Published: January 2006

Observing a biological event as it unfolds in the living cell provides unique insight into the nature of the phenomenon under study. Capturing live cell data differs from imaging fixed preparations because living plants respond to the intense light used in the imaging process. In addition, live plant cells are inherently thick specimens containing colored and fluorescent molecules often removed when the plant is fixed and sectioned. For fixed cells, the straightforward goal is to maximize contrast and resolution. For live cell imaging, maximizing contrast and resolution will probably damage the specimen or rapidly bleach the probe. Therefore, the goals are different. Live cell imaging seeks a balance between image quality and the information content that comes with increasing contrast and resolution. That ‘lousy’ live cell image may contain all the information needed to answer the question being posed –provided the investigator properly framed the question and imaged the cells appropriately. Successful data collection from live cells requires developing a specimen‐mounting protocol, careful selection and alignment of microscope components, and a clear understanding of how the microscope system generates contrast and resolution. This paper discusses general aspects of modern live cell imaging and the special considerations for imaging live plant specimens.
TILLING: practical single‐nucleotide mutation discovery
Authors: Comai Luca , Henikoff Steven
Published: January 2006

In the post‐genomic sequencing era, an expanding portfolio of genomic technologies has been applied to the study of gene function. Reverse genetics approaches that provide targeted inactivation of genes identified by sequence analysis include TILLING (for Targeting Local Lesions IN Genomes). TILLING searches the genomes of mutagenized organisms for mutations in a chosen gene, typically single base‐pair substitutions. This review covers practical aspects of the technology, ranging from building the mutagenized population to mutation discovery, and discusses possible improvements to current protocols and the impact of new genomic methods for mutation discovery in relation to the future of the TILLING approach.
Sequence‐based typing reveals a novel DLA‐88 allele, DLA‐88*04501, in a beagle family
Authors: Hardt C. , Ferencik S. , Tak R. , Hoogerbrugge P. M. , Wagner V. , Grosse‐Wilde H.
Published: January 2006

The dog is an important animal model for solid organ as well as stem cell allo transplantation. Methods such as cellular and serological typing and more recently sequence‐based typing (SBT) have been used to discriminate tissue antigen disparity of donor and recipient. We applied SBT for the canine class I (DLA‐88) and class II (DLA‐DRB1) genes in beagle families prior stem cell transplantation. A novel DLA‐88 (DLA‐88*04501) allele in combination with a DLA‐DRB1*01901 allele was found. Sequence comparison of exons 2 and 3 of the novel allele revealed most sequence identity to the DLA‐88*01301 allele (96.15% identity at the nucleotide and 90.65% identity at the protein level).
Identification of a novel HLA‐A allele (A*1115) in the UK National External Quality Assessment Schemes for Histocompatibility and Immunogenetics' Educational Cell Exchange
Authors: Bendukidze N. , Day S. , Street J. , Hammond L. , Downing J. , Corbin S. , Dunn P. P. J. , Darke C.
Published: January 2006

The novel allele, HLA‐A*1115, was identified in an ‘Educational Scheme’ sample (ED03/03 – from a north‐western European Caucasoid blood donor) distributed by the UK National External Quality Assessment Schemes for Histocompatibility and Immunogenetics. ED03/03 was typed by serology, the polymerase chain reaction using sequence‐specific primers and sequence‐based typing. A*1115 is most similar to A*110101 with a single mismatch (G to C) at constant position 565, leading to a conservative amino acid change from valine (GTG) to leucine (CTG) at codon 165 in the α2 domain. This substitution has not been reported for any other HLA class I allele so far. The HLA‐A*1115‐bearing haplotype was B*350101; Cw*040101; DRB1*140101; DRB3*020201; DQA1*010401; DQB1*0503; DPA1*0103/07; DPB1*030101. Extensive serological typing indicated that this allele essentially encodes a ‘normal’ HLA‐A11 specificity.
HLA‐DRB1*0826 and HLA‐DQB1*0627, two novel class II alleles identified in blood stem cell donors of Caucasian origin
Authors: Brixner V. , Mosebach M. , Schmidt M. , Hermann S. , Seifried E. , Martin H. , Seidl C.
Published: January 2006

This report describes two novel HLA class II alleles, HLA‐DRB1*0826 and HLA‐DQB1*0627, that have been identified in two unrelated voluntary blood stem cell donors of Caucasian origin. HLA‐DRB1*0826 is characterized by a nucleotide substitution (G to T) in exon 2 at position 163, leading to an amino acid exchange from argenine to leucine. The donor phenotype is HLA‐A*0301,*2902; B*3501,*4403; Cw*0401,*1601; DRB1*0101,*0826; DQB1*0402, *0501. The HLA‐DQB1*0627 alleles contain a nucleotide substitution at position 184 (T to C) resulting in an amino acid exchange from tyrosine to histidine. Family segregation analysis revealed that the HLA‐DQB1*0627 allele belongs to the haplotype A*0101, B*1517, Cw*0701, DRB1*1302, DQB1*0627. The donor phenotype is HLA‐A*0101; B*0801,*1517; Cw*0701; DRB1*1302,*1501; DQB1*0602,*0627.
HLA‐A, ‐B, and ‐DRB1 polymorphism defined by sequence‐based typing of the Han population in Northern China
Authors: Yang G. , Deng Y.‐J. , Hu S.‐N. , Wu D.‐Y. , Li S.‐B. , Zhu J. , Zhu B.‐F. , Liu Y.
Published: January 2006

DNA typing for human leukocyte antigen (HLA)‐A, ‐B and ‐DRB1 was performed using polymerase chain reaction–sequence‐based typing method on 618 randomly selected healthy individuals of the Han population in Northern China. Allele frequencies and haplotypes were statistically analyzed. A total of 84 HLA‐A alleles, 143 B alleles, and 122 DRB1 alleles were detected, and 853 A‐B‐DRB1 haplotypes, 473 A‐B haplotypes, and 551 B‐DRB1 haplotypes were statistically inferred. Statistical analysis of three‐locus haplotypes showed that A*0207‐B*4601‐DRB1*0901 (3.06%) was the most predominant. Gene frequencies and haplotypic associations within HLA‐A, ‐B, and ‐DRB1 loci were determined at a high‐resolution (four digit) allelic level and should provide useful information in anthropology, bone marrow donor registry, legal medicine, and disease association studies.
Correlation of interleukin‐10 gene haplotype with hepatocellular carcinoma in Taiwan
Authors: Tseng L.‐H. , Lin M.‐T. , Shau W.‐Y. , Lin W.‐C. , Chang F.‐Y. , Chien K.‐L. , Hansen J. A. , Chen D.‐S. , Chen P.‐J.
Published: January 2006

Polymorphisms in cytokine genes can influence immune responses, inflammation and tissue injury, and may affect the outcome of hepatitis B virus (HBV) infection. We analyzed single nucleotide polymorphisms (SNP) in the interleukin (IL)‐10 gene among 344 HBV carriers and 208 patients with hepatocellular carcinoma (HCC). Genotypes and haplotypes were tested for association with HCC. IL‐10/−592 C/C genotype was associated with a higher risk for HCC compared with IL‐10/−592 A/C and A/A genotypes [odds ratio (OR): 2.1, 95% confidence interval (CI): 1.2–3.6]. IL‐10/1927 A/A genotype was also associated with a higher risk for HCC compared with IL‐10/1927 A/C and C/C genotypes (OR: 1.5, 95% CI: 1.0–2.2). Haplotype analysis revealed that the homozygosity of the C‐A haplotype (defined by SNPs at positions −592 and 1927) of IL‐10 gene conveys the highest risk for HCC among HBV carriers compared with the homozygosity for the A‐C haplotype (OR: 2.6, 95% CI: 1.3–4.9). The results demonstrate that IL‐10 gene polymorphism can affect the outcome of chronic HBV infection. Further studies are necessary to clarify how variation in the IL‐10 gene affects IL‐10 function and risk of HCC.
Cloning of cDNAs encoding cell‐wall hydrolases from pear (Pyrus communis) fruit and their involvement in fruit softening and development of melting texture
Authors: Sekine Daisuke , Munemura Ikuko , Gao Mei , Mitsuhashi Wataru , Toyomasu Tomonobu , Murayama Hideki
Published: January 2006

‘La France’ pear (Pyrus communis L.) fruit stored at 1°C for 1 month (short‐term storage) before transfer to 20°C softened and developed a melting texture during ripening, whereas fruit stored for 5 months (long‐term storage) before transfer to 20°C softened but did not develop a melting texture. To clarify the mechanisms involved in fruit softening and textural changes, the cDNAs encoding cell‐wall hydrolases were isolated by RT‐PCR, and their expression and localization were investigated in ‘La France’ pears. Genes encoding three polygalacturonases (PG; EC 3.2.1.15), four pectin methylesterases (PME; EC 3.1.1.11), one α‐arabinofuranosidase (ARF; EC 3.2.1.55), three β‐galactosidases (GAL; EC 3.2.1.23), and two endo‐1,4‐β‐d‐glucanases (Cel; EC 3.2.1.4) were isolated. Among these 13 isolated genes, PcPG1 was the only gene for which the mRNA expression levels increased in both the short‐ and long‐term stored fruits. This suggested that PcPG1 is involved in fruit softening rather than in the development of the melting texture. In contrast, the expression levels of PcPG3, PcPME1, PcPME2, PcPME3, PcGAL1, PcGAL2, and PcCel2 increased during ripening only in the short‐term stored fruit. These genes might thus be involved in the development of the melting texture.
Protective cytokinin action switches to damaging during senescence of detached wheat leaves in continuous light
Authors: Vlčková Alexandra , Špundová Martina , Kotabová Eva , Novotný Radko , Doležal Karel , Nauš Jan
Published: January 2006

The effect of exogenous application of the cytokinin meta‐topolin [mT; N6‐(meta‐hydroxybenzyl)adenine] on artificial senescence of detached wheat leaves (Triticum aestivum L. cv. Hereward) was studied and compared in leaves senescing under continuous light (100 µmol photons m−2 s−1) and darkness. Senescence‐induced deterioration in structure and function of the photosynthetic apparatus was characterized by reduction in chlorophyll content, maximal efficiency of photosystem (PS) II photochemistry (Fv/Fm) and the rate of CO2 assimilation, by increase in the excitation pressure on PSII (1 − qP) and a level of lipid peroxidation and by modifications in chloroplast ultrastructure. While in darkened leaf segments mT effectively slowed senescence‐induced changes in all measured parameters, in light‐senescing segments the effect of mT changed into opposite a few days after detachment. We observed an overexcitation of photosynthetic apparatus, as indicated by pronounced increases in the excitation pressure on PSII and in a deepoxidation state of xanthophyll cycle pigments, marked starch grain accumulation in chloroplasts and stimulation of lipid peroxidation in light‐senescing leaf segments in mT. Possible mechanisms of acceleration of senescence‐accompanying decrease in photosynthetic function and increase in lipid peroxidation during mT influence are discussed. We propose that protective mT action in darkness becomes damaging during artificial senescence in continuous light due to overexcitation of photosynthetic apparatus resulting in oxidative damage.
Two MADS‐box genes from perennial ryegrass are regulated by vernalization and involved in the floral transition
Authors: Petersen Klaus , Kolmos Elsebeth , Folling Marianne , Salchert Klaus , Storgaard Morten , Jensen Christian S. , Didion Thomas , Nielsen Klaus K.
Published: January 2006

Many plants in temperate regions have a requirement for vernalization in order to initiate the reproductive growth phase. In cereals, this requirement has been linked to the VRN1 locus, which encodes an APETALA1‐like (AP1‐like) MADS‐box gene. In perennial ryegrass (Lolium perenne L.), we have isolated two MADS‐box genes that are regulated by vernalization, LpMADS1, which co‐localize to the VRN1 locus in ryegrass, and LpMADS10, which is an SVP‐like MADS‐box gene. In the shoot apex, LpMADS1 is increasingly induced by cold exposure, whereas LpMADS10 is increasingly repressed. Comparison of LpMADS1 promoter regions from several ryegrass varieties, with and without vernalization requirement, suggests that a putative MADS‐box protein‐binding site (CArG‐box) might be important for the vernalization‐regulated expression of LpMADS1. Although the LpMADS10 expression pattern suggests it to be involved in floral repression, ectopic expression of LpMADS10 did neither affect flowering time significantly in Arabidopsis thaliana nor in L. perenne. Interestingly, we found that LpMADS1 interacts with LpMADS10 in a yeast two‐hybrid assay. This finding is discussed in regard to the regulation of vernalization response in perennial ryegrass.
Influence of ascorbate and pH on the activity of the diatom xanthophyll cycle‐enzyme diadinoxanthin de‐epoxidase
Authors: Grouneva Irina , Jakob Torsten , Wilhelm Christian , Goss Reimund
Published: January 2006

In this study, the enzyme activity of partially purified diadinoxanthin de‐epoxidase (DDE) from the diatom Cyclotella meneghiniana was investigated at different ascorbate concentrations and pH values. In comparison with spinach violaxanthin de‐epoxidase (VDE), we found a much higher affinity of the enzyme for the co‐substrate ascorbate. The Km value of DDE at pH 5 (0.7 mM) was significantly lower than that observed for VDE (2.3 mM). The pH‐optimum of DDE activity was found at pH 5 at low ascorbate concentrations. At high ascorbate concentrations, we observed a strong shift of the pH optimum towards higher pH values, and significant DDE activity was still present at almost neutral pH values. This is in contrast to VDE, where despite a slight shift towards higher pH values, enzyme activity was never observed above pH 6.5. The pH optimum of VDE was always found in a narrow range between pH 5 and 5.2, irrespective of the presence of high or low ascorbate concentrations. The high affinity of DDE for ascorbate indicates that, even at a limited availability of reduced ascorbate, high enzyme activity is possible at low pH values. At high ascorbate concentrations, on the other hand, DDE activity can be shifted towards neutral pH values, thereby facilitating a very fast and strong response to small pH changes in the thylakoid lumen. The importance of the high ascorbate affinity of DDE for the physiology of intact diatom cells is discussed.
Regulation of tocopherol biosynthesis through transcriptional control of tocopherol cyclase during cold hardening in Eucalyptus gunnii
Authors: El Kayal Walid , Keller Guylaine , Debayles Caroline , Kumar Rajeev , Weier Dagmar , Teulieres Chantal , Marque Christiane
Published: January 2006

A clone very similar to the maize sucrose export defective (SXD1) gene encoding a tocopherol cyclase (TC) was isolated from a Eucalyptus cold‐acclimation downregulated cDNA library and was designated EgSXD1 (Eucalyptus gunnii sucrose export defective 1). As expected, the synthesis of tocopherols (vitamin E) from 2,3‐dimethyl‐5‐phytyl‐1,4‐benzoquinol by the recombinant protein demonstrated that the EgSXD1 gene product is a TC. Northern hybridizations with RNA isolated from cell suspension cultures clearly showed a fast EgSXD1 downregulation by cold. This strong repression also evidenced by real‐time reverse transcription polymerase chain reaction analysis on plantlets was associated with both an increased cold tolerance and a slight but significant decrease in leaf tocopherol content. These results, contrary to the commonly reported tocopherol accumulation after drought or salt stress, raise the question of the role of this gene regulation in cold hardening, which is clearly different from a direct antioxidant protection.
The role of auxin‐induced peaks of α‐expansin expression during lateral root primordium formation in Pinus taeda
Authors: Greenwood Michael S. , Xu Fuyu , Hutchison Keith W.
Published: January 2006

Lateral root primordium (LRP) formation in the four vascular poles of 7‐ to 10‐day‐old loblolly pine (Pinus taeda L.) seedlings was promoted by the auxin α‐naphthalene acetic acid (NAA) and occurred closer to the root tip than in the controls. These observations support a role of auxin located within the vascular cylinder in the development of LRP. Adjacent LRP almost never occurred in the same vascular pole, but NAA increased the probability that this would happen by two‐ to six‐fold. Expression of genes for α‐expansin was induced by auxin in hypocotyls but occurred spontaneously in primary roots. In situ localization revealed that expansin was expressed in the vascular parenchyma where LRP formed spontaneously in roots, and where adventitious root meristems formed in auxin‐treated hypocotyls. Expansin expression was not uniform in the LRP‐forming zone of the primary root. The number of cells exhibiting expansin expression longitudinally occurred in distinct peaks, which were more frequent after auxin treatment. These peaks may reflect non‐uniform distribution of auxin in the stele or localization of cells with increased sensitivity to auxin. However, LRP were spaced about 10‐fold further apart than the peaks of expansin expression. Therefore, localized peak expansin expression did not always predict the location of LRP. We speculate that other factors must interact with locally high auxin concentrations to specify the location of LRP.
First Record of Bremia lactucae Infecting Sonchus oleraceus and Sonchus asper in Brazil and its Infectivity to Lettuce
Authors: Vieira B. S. , Barreto R. W.
Published: January 2006

Bremia lactucae is recorded for the first time causing downy mildew on common sowthistle (Sonchus oleraceus) and spiny sowthistle (Sonchus asper) in Brazil. The disease and etiological agent are described. Pathogencity of sporangia obtained from S. oleraceus was tested on 12 species belonging to the Asteraceae, already recorded in the literature as hosts of B. lactucae, and four commonly cultivated varieties of lettuce. All four cultivars of lettuce, S. oleraceus and S. asper showed symptoms of the disease and sporulation of the pathogen 5 days after inoculation. It has been observed that the disease occurs on Sonchus spp. throughout the year in Viçosa (state of Minas Gerais), being more common on these two hosts than on lettuce. Both weeds are very common invaders of vegetable growing areas in Brazil. This indicates that those two hosts for the fungus may be important inoculum reservoirs for disease occurring in lettuce, highlighting the need for control of these weeds as part of the procedures aimed at controlling this disease. These results are also in agreement with the views that B. lactucae is split into host‐specific infra‐specific taxa. Lettuce and sowthistles are regarded as closely related, belonging to the same subfamily and tribe in the Asteraceae (Subfamily Cichorioideae: Tribe Lactuceae).
Characteristics of Pustula tragopogonis (syn. Albugo tragopogonis) Newly Occurring on Cultivated Sunflower in Germany
Authors: Thines M. , Zipper R. , Schäuffele D. , Spring O.
Published: January 2006

In temperate climates, Pustula tragopogonis is rarely found on cultivated sunflower. In Europe, it was so far of little economic impact on other Asteraceae, except for some regions in the Mediterranean. In 2003, P. tragopogonis was found for the first time in sunflower fields in southern Germany. The pathogen has a widespread occurrence there, especially in the region around Stuttgart, BW. Fatty acid profiling, ultrastructural investigation and ITS sequencing revealed a high similarity to an 2002 isolate from southern Africa and an 2005 isolate from Australia, but revealed significant differences to P. tragopogonis s.l. on Cirsium arvense, a common weed, growing on or in the vicinity of sunflower fields in Germany. P. tragopogonis from this host can therefore be excluded from being the source of the reported infection.
Yellow Death: A Disease of Date Palm in Iran Caused by Fusarium solani
Authors: Mansoori B. , Kord M. H.
Published: January 2006

In December 2003, a severe general yellowing and death of the fronds of date palm (Phoenix dactylifera) occurred in a grove in the vicinity of Kazeron district, west of Fars province, Iran. Fusarium solani was isolated from the crown, and xylem rays sampled from the trunk 1.5 m above soil level. In pathogenicity tests using artificially infested soil and 1‐year‐old date palm seedlings, an isolate from the trunk (FST) induced general chlorosis and death of seedlings 25–28 days after inoculation. Similar results were obtained when seedlings were planted in naturally infested soil. In both procedures, distal portions of the roots and crown were affected. The fungus was re‐isolated from the crown and leaf bases of the inoculated seedlings. This is the first report of a serious disease of date palm, which we call yellow death, incited by F. solani in Iran.
National Identity and Citizenship in the People's Republic of China and the Republic of Korea
Authors: CHOE HYUN
Published: January 2006

Abstract This paper points out the limitations of culturalist approaches to the PRC and the ROK and deals with factors that contribute to the legal definition of citizenship in those two counties. The understanding of political and economic interests, rather than cultural aspects, is important in explaining the changes of the definition of citizenship there. China institutionalized a state‐centered national identity, while Korea constructed an ethnic‐centered national identity as they became integrated into the international order as nation‐states. However, both the PRC and ROK made important changes in their legal definitions of citizenship regardless of their distinct national identities in China and Korea.
Stand and Deliver: Private Property and the Politics of Global Dispossession
Authors: Andreasson Stefan
Published: January 2006

Property rights necessarily generate violent, and oftentimes lethal, processes of dispossession. While liberal theorists from Locke to Hayek consider property rights as an essential and emancipatory component of human freedom, they fail to consider societal power asymmetries impeding the ability of property rights to protect the interests of the weak and marginalised. If property rights produce freedom and prosperity, they do so very selectively. More obvious is the ongoing historical process of already propertied classes making ‘clever usurpation into an irrevocable right’ by extending private property regimes along two key dimensions – type and space. Examining various uses of private property over time reveals processes whereby relatively basic notions of private property, enforced by a Weberian state at the local level in the early era of industrialisation, are extended to encompass new and sophisticated forms of property that are enforced globally via international institutions. Two contemporary empirical cases of using property rights are examined in this paper: land reform in Southern Africa (specifically Zimbabwe) and intellectual property rights. In this context of ongoing dispossession, further privatisation and commodification can only exacerbate contemporary problems of marginalisation and dispossession.
The Politics of Electoral Reform Abolition: The Informed Process of Israel's Return to its Previous Electoral System
Authors: Rahat Gideon
Published: January 2006

This article examines the process that led to the repeal of Israeli electoral reform (1992–2001) and compares it with that of reform adoption (1987–92). The most significant difference between the two processes is in the kinds of information that were available in them. In the politics of reform adoption, information was susceptible to manipulation and its supply was a crucial part of the struggle itself. In the politics of reform abolition, the real consequences of reform were constantly unfolding. This substantial difference resulted in other differences – not in type but in extent. First, while both were ongoing processes in which coalitions of supporters and opponents had to be built and then rebuilt several times, the cohesion of the camps throughout the struggle for reform abolition was higher than in the struggle for reform adoption. Second, while office-seeking successfully served as a basis for understanding the behavior of most parliamentary actors, the actual perceptions of its exact contextual meaning was dependent upon different available information. The two processes also had two common characteristics: power was diffused in both arenas of the politics of reform and in both instances the selection of the right timing proved to be necessary for successfully promoting the initiatives against veto players who were interested in preserving the status quo.
Escaping the TRIPs’ Trap: The Political Economy of Free and Open Source Software in Africa
Authors: May Christopher
Published: January 2006

Across sub-Saharan Africa, the promise of ‘informational development’ is proclaimed. The global governance of intellectual property rights (IPRs), however, currently structured through the Trade-Related Aspects of Intellectual Property Rights (TRIPs) agreement and overseen by the World Trade Organisation (WTO), makes much software expensive to deploy. There is an alternative: open-source and/or free software ameliorates many of the cost problems countries in Africa have anticipated as they have changed their laws to protect IPRs; using non-proprietary software will enable them to deploy extensive computerisation without making large payments to suppliers from the developed countries. By escaping the TRIPs’ trap, many Africans will be better able to enjoy the potential benefits of ‘informational development’.
Balancing Fundamental Rights and Common Market Freedoms in Union Law: Schmidberger and Omega in the Light of the European Constitution
Authors: Morijn John
Published: January 2006

Abstract:  This article deals with how the Court of Justice balances fundamental rights protection and Common Market freedoms. From the particular perspective of the Charter and the ECHR, whose legal status will be upgraded upon entry into force of the European Constitution, it studies the Court of Justice's approach to fundamental rights invocations by Member States in the context of Common Market freedoms. For this purpose the judgments in Schmidberger and Omega will be discussed both in the current setting and that envisioned by the European Constitution. It will emerge that the Court of Justice's reasoning in Schmidberger and Omega can be criticised on different levels, and alternative approaches are proposed. At a later stage some further elements for refining the methodology for assessing Member States’ fundamental rights invocations are addressed with a view to facilitating the Court of Justice more satisfactorily to take account of the current and likely future setting of fundamental rights protection in Union law.
Transformation or Dilution: Fundamental Rights in the EU Social Space
Authors: Fredman Sandra
Published: January 2006

Abstract:  This article argues that in developing social rights to counterbalance economic freedoms, the EU has begun to reformulate traditional notions of rights. Instead of creating rights in their traditional individualised, negative, judicially enforceable, and fault‐based form, a new proactive model is emerging, which aims at institutional change, based on the notion of the active citizen and the centrality of participation in both rule formation and enforcement. It is argued that while this model has important advantages, its weakness lies in its dependence on political will. The challenge is therefore to ensure that proactive strategies are firmly centred on fundamental rights rather than political discretion. Part I briefly sketches the development of social rights in the EU; Part II examines the applicability of Third Way ideology; Part III considers European employment strategy and gender mainstreaming, asking whether they represent a dynamic new manifestation of fundamental rights at work, or a betrayal. Part IV applies a similar evaluation to the EU Charter.
Open-Economy Inflation- Forecast Targeting
Authors: Leitemo Kai
Published: January 2006

We study simple inflation-forecast targeting in an open-economy setting. Simple inflation-forecast targeting implies setting an interest rate which, if kept unchanged throughout the forecast-targeting horizon, produces a conditional inflation forecast equal to the inflation target at the end of the horizon.We find that the optimal forecast-targeting horizon is relatively short (one year). A longer horizon does not consistently contribute to improved output stability, indeed it increases exchange rate variability and traded sector variability. The targeting procedure is substantially inferior to the optimal pre-commitment policy. Moreover, the targeting procedure does not necessarily determine the rational-expectations equilibrium and is subject to time inconsistency.
Does the Choice between Wage Inequality and Unemployment Affect Productivity Growth?
Authors: Arnold Lutz G.
Published: January 2006

We present a non-scale continuous-time overlapping-generations growth model that provides an explanation for why economies with relative wage rigidity feature higher unemployment, but not slower productivity growth, than economies with flexible wages. The compression of the wage distribution associated with relative wage rigidity slows down human capital accumulation and growth ceteris paribus. But unemployment among the low-skilled workers strengthens the incentives to invest in human capital and, hence, growth. The two effects are offsetting, and growth is independent of the prevailing degree of relative wage rigidity. This knife-edge result is robust with respect to some modifications of the model.
Absence of large‐diameter sensory fibres in a nerve to the cat humerus
Authors: Ivanusic Jason J. , Mahns David A. , Sahai Vineet , Rowe Mark J.
Published: January 2006

A fine branch of the median nerve innervates the periosteum and medullary cavity of the cat humerus. After branching to innervate the periosteum on the medial surface of the humerus, the nerve enters and supplies the medullary cavity via a nutrient foramen, accompanied by a small artery and vein. The composition of the fibres in the nerve was examined using electron microscopy. Myelinated fibres with diameters of 0.8–6.6 µm and unmyelinated fibres with diameters of 0.1–1.4 µm were observed. These diameters indicate that afferent fibres of this nerve are confined within the Group III and IV categories, and may therefore be nociceptive or mechanoreceptive in function. In addition, autonomic efferent fibres may also be present in these fibre groups. As no fibre diameters greater than 7 µm were noted, it appears that Group I and II fibres are absent in this nerve. The fibre distribution suggests that the principal role of this nerve is to relay bone‐related nociceptive or mechanoreceptive information to the central nervous system and to provide autonomic regulatory influences on the bone.
Perinatal development of the pancreatic islet microvasculature in rats
Authors: Johansson Magnus , Andersson Arne , Carlsson Per‐Ola , Jansson Leif
Published: January 2006

The aim of the present study was to investigate possible changes in the islet microvasculature during the period of pronounced β‐cell growth seen perinatally in rats. We studied islet endothelial and β‐cell proliferation, as well as islet vascular density, in rats during this period. There was a progressive increase in islet vascular density from day −1 to day 7 postpartum, with values similar to those in adult rats seen at the latter time point. 3H‐thymidine‐labelled islet endothelial cells were extremely rare in adult rats, whereas such cells were much more frequent perinatally. The β‐cell labelling index was higher in all perinatal animals than in adult rats, with peak values seen on day 2. The proliferating endocrine cells were located very close to blood vessels at day 2 after birth. In conclusion, the pronounced growth of islet endocrine cells seen during the first week after birth coincides and co‐localizes with an even more pronounced increase in islet endothelial cell proliferation, which results in a marked increase in intra‐islet vascular density. This perinatal increase in islet blood vessel density may facilitate glucose sensing and islet hormonal delivery to the systemic circulation.
An in situ hybridization study of Runx2, Osterix, and Sox9 at the onset of condylar cartilage formation in fetal mouse mandible
Authors: Shibata Shunichi , Suda Naoto , Suzuki Shoichi , Fukuoka Hiroki , Yamashita Yasuo
Published: January 2006

Mandibular condylar cartilage is the principal secondary cartilage, differing from primary cartilage in its rapid differentiation from progenitor cells (preosteoblasts/skeletoblasts) to hypertrophic chondrocytes. The expression of three transcription factors related to bone and cartilage formation, namely Runx2, Osterix and Sox9, was investigated at the onset of mouse mandibular condylar cartilage formation by in situ hybridization. Messenger RNAs for these three molecules were expressed in the condylar anlage, consisting of preosteoblasts/skeletoblasts, at embryonic day (E)14. Hypertrophic chondrocytes appeared at E15 as soon as cartilage tissue appeared. Runx2 mRNA was expressed in the embryonic zone at the posterior position of the newly formed cartilage, in the bone collar and in the newly formed cartilage, but expression intensity in the newly formed cartilage was slightly weaker. Osterix mRNA was also expressed in the embryonic zone and in the bone collar, but was at markedly lower levels in the newly formed cartilage. Sox9 mRNA was continuously expressed from the embryonic zone to the newly formed cartilage. At this stage, Sox5 mRNA was expressed only in the newly formed cartilage. These results suggest that reduced expression of Osterix in combination with Sox9–Sox5 expression is important for the onset of condylar (secondary) cartilage formation.
Plasma membrane anion channels in higher plants and their putative functions in roots
Authors: Roberts Stephen K.
Published: January 2006

Recent years have seen considerable progress in identifying anion channel activities in higher plant cells. This review outlines the functional properties of plasma membrane anion channels in plant cells and discusses their likely roles in root function. Plant anion channels can be grouped according to their voltage dependence and kinetics: (1) depolarization‐activated anion channels which mediate either anion efflux (R and S types) or anion influx (outwardly rectifying type); (2) hyperpolarization‐activated anion channels which mediate anion efflux, and (3) anion channels activated by light or membrane stretch. These types of anion channel are apparent in root cells where they may function in anion homeostasis, membrane stabilization, osmoregulation, boron tolerance and regulation of passive salt loading into the xylem vessels. In addition, roots possess anion channels exhibiting unique properties which are consistent with them having specialized functions in root physiology. Most notable are the organic anion selective channels, which are regulated by extracellular Al3+or the phosphate status of the plant. Finally, although the molecular identities of plant anion channels remain elusive, the diverse electrophysiological properties of plant anion channels suggest that large and diverse multigene families probably encode these channels.ContentsSummary647I.Introduction648II.Overview of higher plant plasma membrane anion channels648III.Anion channels in higher plant roots655IV.Conclusions and prospects661Acknowledgements662References662
J. M. Keynes and the Postwar International Economic Order
Authors: Newton Scott
Published: January 2006

Keynes was at the heart of efforts to establish a reformed international economy after World War Two. But the outcome of his efforts left him a disappointed man. Although the postwar international economic architecture owed much to Keynes it fell short of his ideals. It is arguable that international politics had as much to do with the era of expansion as the Bretton Woods institutions, and that even today the world has not yet grasped the full extent of the Keynesian challenge.
Images of the Merovingians and Carolingians
Authors: Bouchard Constance B.
Published: January 2006

For over a millennium, the perception of the role and achievements of the Merovingian and Carolingian dynasties, those that ruled the Franks from the mid‐fifth to the late tenth century, was heavily shaped by writers working at the Carolingian court. These publicists sought to establish that the previous dynasty was made up of uncivilized incompetents, in strong contrast to their own ruling dynasty. Recently historians have begun examining this characterization not as a simple description of fact but rather as part of a conscious ninth‐century plan to glorify the Carolingians. The Merovingians are now seen less as barbarians and more as Romanized Christians. Although historians do not denigrate the quite real Carolingian achievements, they are now analyzing the many models, from the kings of ancient Israel to the Caesars, to which the emperors were compared by their publicists.