bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetically Modified Food Crops and Their Contribution to Human Nutrition and Food Quality
Authors: BLANCHFIELD J. R.
Published: November 2006

ABSTRACT: Modern genetic modification is one of the tools to help feed the world, now and in the future. Its particular value lies in its ability to produce results faster, to be targeted better than other methods, and, in some instances, to achieve results that cannot be effectively obtained by other means. Potential benefits include: greater crop output from reduced input (energy, labor, other costs); reduction in use of chemical pesticides; crops with improved nutrition characteristics; crops that can grow under inhospitable conditions; and crops with improved handling and processing characteristics. Like any new technology it has potential problems, some real, some speculative, and some imaginary. However, we are not disinterested bystanders on the sidelines noting problems and regarding them as possible reasons not to proceed. Science is society's tool for addressing and solving problems so that useful potentialities can be realized, especially for a growing population that needs to be adequately fed.
Physicochemical Changes in Alaska Pollock Surimi and Surimi Gel as Affected by Electron Beam
Authors: JACZYNSKI J. , PARK J. W.
Published: November 2006

ABSTRACT: Alaska pollock surimi and surimi gels (cooked) were subjected to various doses of electron beam (e‐beam). Shear stress of surimi gels increased as the dose increased up to 6 to 8 kGy and then decreased. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) showed gradual degradation of myosin heavy chain as the dose increased. The degradation was slower for frozen samples. The integrity of actin was slightly affected by high doses (25 kGy). The amount of sulfhydryl groups and the level of surface hydrophobicity of Alaska pollock surimi decreased as the dose increased, suggesting formation of disulfide bonds and hydrophobic interactions. The sulfhydryl groups and hydrophobicity of surimi gels increased as the dose increased up to 6 kGy and then decreased.
Biodosimetry of Escherichia coli UV Inactivation in Model Juices with Regard to Dose Distribution in Annular UV Reactors
Authors: OUTCHMA T. K , ARISI B. P
Published: November 2006

ABSTRACT: An annular ultraviolet (UV) reactor as a single vertical segment and 4 segments of variable length connected in series were used to study inactivation kinetics of Escherichia coli and UV‐dose distribution. Both configurations produced linear inactivation curves in model juices. The rate of inactivation decreased as the solution absorption coefficient increased. UV doses for 90% reduction were determined and varied from 4.5 to 6.5 mJ/cm2 in a vertical setup. To study the UV‐dose distribution within a reactor, E. coli was injected and yielded the range from 5.6 to 11.1 mJ/cm2. A modified biodosimetry method using the injection of bacteria as a tracer can be used to evaluate dose delivery in UV reactors.
Application in Restructured Fish Products of Transglutaminase Obtained by Strepto verticillum ladakanaum in Media Made from Hydrolysates of Sorghum Straw
Authors: TÉLLEZ‐LUIS S. J. , RAMÍREZ J. A. , VÁZQUEZ M.
Published: November 2006

ABSTRACT: The efficiency of microbial transglutaminase (MTG), obtained by Streptoverticillum ladakanaum in the fermentation of sorghum straw hydrolysates to increase mechanical properties of restructured fish products, was evaluated. Fish gels were obtained from Mexican flounder (Cyclopsetta chittendenni) by (1) adding MTG obtained in the fermentation of sorghum straw hydrolysates (SMTG) at 0.3 units/g; (2) adding commercial MTG (CMTG) at 0.3 units/g; (3) adding 0.4% calcium chloride to activate the endogenous TG; and (4) without additives as control sample. SMTG more efficiently increased the mechanical properties of restructured products and induced a low value of expressible water, similar to the control (6% to 7%). Results demonstrated the feasibility of producing an efficient MTG from agricultural wastes. Keywords: fish, transglutaminase, microbial, restructured, sorghum
Relationship Between Aerosolized Microbial Load and Contamination of Fully Cooked Then Frozen Meat Products
Authors: HELM‐ARCHER A. A. , KERTH C. R. , JONES W. R. , MCCASKEY T. A. , CONNER D. E.
Published: November 2006

ABSTRACT: The relationship between microbial loads in air and contamination of fully cooked meat products was investigated in a commercial processing facility. Air and product were sampled in the packaging area. No correlation existed between microbial counts from air samples and product samples (P > 0.05; r < 0.06). Microbial counts from air samples ranged from 0.30 to 2.54 log10 colony‐forming units (CFU)/500 L and from 0.30 to 3.78 log10 CFU/g in the product samples. These data suggest that no direct relationship exists between microbial air quality and product contamination, but other environmental conditions may account for up to 1/5 of the variation in air contamination and 1/3 of the variation in product contamination.
Improvement of Rheological and Baking Properties of Cake Batters with Emulsifier Gels
Authors: JYOTSNA R. , PRABHASANKAR P. , INDRANI D. , RAO G. VENKATESWARA
Published: November 2006

ABSTRACT: Effect of emulsifier gels prepared using sodium stearoyl‐2 lactylate (SSL), distilled glycerol monostearate (DGMS), propylene glycol monostearate (PGMS), polysorbate‐60 (PS‐60), and sorbitan monostearate (SMS) in shortening medium and on the physical properties of cake batter and the quality of cake were studied. Both storage modulus (G') and loss modulus (G”) of batters containing emulsifier gels increased compared with the control. The evaluation of cake batters for batter density showed that the emulsifier gels decreased the batter density from 0.95 g/cm3 for the control to 0.85 g/cm3. The photomicrographs of cake batters with different emulsifier gels showed an increase in the number of air bubbles, which were evenly distributed when compared with the control, indicating a lighter batter and better air incorporation. Among the emulsifier gels, cakes with PS‐60 gel showed a maximum increase in specific volume followed by cakes with SSL, DGMS, PGMS, and SMS gels.
Physicochemical Characterization and Consumer Acceptance by Asian Consumers of Aromatic Jasmine Rice
Authors: SUWANSRI S. , MEULLENET J. F.
Published: November 2006

ABSTRACT: Physicochemical properties and acceptance by Asian consumers in the United States of 3 commercially U. S.‐grown and 12 imported jasmine rice samples were evaluated. Rice kernels, flour, and starch were characterized for physical, chemical, pasting, and thermal properties. Amylose content, gel type, hardness‐to‐stickiness ratio, surface fat, protein, and pasting properties significantly affected the eating and cooking qualities and physical appearances of the rice samples; these variables were key to distinguishing the major quality differences and to differentiating U. S.‐grown from imported jasmine rice. Data collected from this study could be useful to rice producers, importers, or rice breeders for understanding the physicochemical characteristics of aromatic jasmine rice and its acceptance by Asian consumers.
Comparing the efficacy of agri‐environment schemes to enhance bumble bee abundance and diversity on arable field margins
Authors: CARVELL C. , MEEK W. R. , PYWELL R. F. , GOULSON D. , NOWAKOWSKI M.
Published: November 2006

Declines in abundance and diversity of bumble bees (Bombus spp.) in Europe have been linked to agricultural intensification and the resulting loss of suitable foraging and nesting habitats. Environmental Stewardship (ES) is a new scheme in England offering the opportunity to restore habitats of value for these important pollinators to agricultural land. Scientific evaluation of the options prescribed within the scheme is essential to ensure that their objectives are met and that the benefits can be realized by the full bumble bee species assemblage.

We compared the efficacy of different ES options for field margins on arable land in enhancing the abundance and diversity of flowering resources and foraging bumble bees. Our study was conducted over 3 years using a multisite experiment.

Overall, uncropped margins sown with mixtures containing nectar and pollen‐producing plants were more effective in providing bumble bee forage than margins sown with a grass mix, allowed to regenerate naturally or managed as conservation headlands.

A mixture of agricultural legumes established quickly and attracted on average the highest total abundance and diversity of bumble bees, including the rare long‐tongued species Bombus ruderatus and Bombus muscorum. However, marked differences were observed between species and sexes in their responses to field margin management over time.

A diverse mixture of native wildflowers attracted more of the shorter‐tongued Bombus spp. and provided greater continuity of forage resources, especially early in the season. Allowing Cirsium spp. to flower on such margins also increased their attractiveness to male bumble bees.

Synthesis and applications. Our results suggest that the legume‐based ‘pollen and nectar flower mix’, as prescribed under Entry Level Stewardship in England, can quickly provide a highly attractive forage resource for bumble bees, but that issues of seasonal flowering phenology and longevity of the mixture need to be addressed. Establishment of ‘floristically enhanced margins’ under Higher Level Stewardship will be important to provide diverse perennial communities of forage plants and to support a greater range of Bombus spp. and other pollinators. The population‐level responses of bumble bees to introduced seed mixtures and other agri‐environment options require further study in order to maximize the benefits of such schemes in intensively farmed landscapes.
Ecogenomic approach to the role of herbivore‐induced plant volatiles in community ecology
Authors: SNOEREN TJEERD A. L. , DE JONG PETER W. , DICKE MARCEL
Published: November 2006

Linking new developments in genomics with ecology provides interesting novel tools to address ecological questions in ways that have not been possible up to now. In this paper we address this issue for the ecology of infochemicals and plant–insect interactions in a food web context.

Plants are at the basis of most terrestrial food webs and insects are a dominant animal group interacting with plants. Insect–plant communities are characterized by direct and indirect interactions, many of which are mediated by infochemicals. Plants respond to insect herbivory with the production of volatiles that attract the enemies of the herbivores, such as insect predators and parasitoids. Moreover, the plant volatiles may be exploited by any organism in the environment and this results in many more infochemically mediated interactions. Thus, a food web is overlaid with an infochemical web.

In the past, several manipulative tools have been developed to investigate the role of infochemicals. The rapid advancement of molecular genetics and ‘‐omics’ technologies results in interesting new tools. A recent development is the use of well‐characterized genotypes that are modified in the mechanisms underlying the induced plant volatiles. These genotypes produce precisely manipulated phenotypes that often differ in only a single gene, and can be used to investigate the effect of particular genes on specific interactions. Moreover, these genotypes can be introduced into a natural community to assess the effects of the genetic change and its resulting phenotypic change on interactions with the entire natural community.

Furthermore, with the progress in microarray technology it becomes possible to assess the expressed genotype of plants in the field, which can be exploited to investigate expressed genetic variation under field conditions.

These developments are expected to be only the beginning of a successful integration of ‐omics technologies, such as transcriptomics and metabolomics, with community ecology into the new research field of ecogenomics.

In this review we present the current status and discuss the prospects for the future of an ecogenomic approach to the role of herbivore‐induced plant volatiles in insect–plant community ecology.
Bistability with Hysteresis in the Activity of Vasopressin Cells
Authors: Sabatier N. , Leng G.
Published: November 2006

Magnocellular vasopressin neurones generate distinctive ‘phasic’ patterns of electrical activity during which periods of spiking activity (bursts) alternate with periods of no spikes or occasional spikes. The mechanisms of burst termination in vivo are still not clearly understood. We recorded from single phasic vasopressin cells in vivo and here we show that burst terminations in some phasic cells is preceded by transient increases in activity, consistent with bursts ending as a result of activity‐dependent inhibition. We show that extrinsically imposed increases in activity, evoked by brief stimulation of the organum vasculosum of the lamina terminalis, can either trigger bursts if given when a cell is silent, or stop bursts if given when a cell is active. Thus, the magnocellular vasopressin system is a population of independent bistable oscillators. The population as a whole is insensitive to transient changes in input level, whether these are excitatory or inhibitory. The vasopressin cell population thus acts like a ‘low‐pass filter’; although brief large changes in input rate have little overall effect, the population responds very effectively to small, sustained changes in input rate by evolving a pattern of discharge activity that efficiently maintains secretion. We note that these filtering characteristics are the opposite of the filtering characteristics that are typically associated with neurones.
Evidence for subdivision within the M molecular form of Anopheles gambiae
Authors: SLOTMAN M. A. , TRIPET F. , CORNEL A. J. , MENESES C. R. , LEE Y. , REIMER L. J. , THIEMANN T. C. , FONDJO E. , FOFANA A. , TRAORÉ S. F. , LANZARO G. C.
Published: November 2006

The principal vector of malaria in sub‐Saharan Africa, Anopheles gambiae is subdivided into two molecular forms M and S. Additionally, several chromosomal forms, characterized by the presence of various inversion polymorphisms, have been described. The molecular forms M and S each contain several chromosomal forms, including the Savanna, Mopti and Forest forms. The M and S molecular forms are now considered to be the reproductive units within A. gambiae and it has recently been argued that a low recombination rate in the centromeric region of the X chromosome has facilitated isolation between these forms. The status of the chromosomal forms remains unclear however. Therefore, we studied genetic differentiation between Savanna S, Forest S, Forest M and Mopti M populations using microsatellites. Genetic differentiation between Savanna S and Forest S populations is very low (FST = 0.0053 ± 0.0049), even across large distances. In comparison, the Mopti M and Forest M populations show a relatively high degree of genetic differentiation (FST = 0.0406 ± 0.0054) indicating that the M molecular form may not be a single entity, but could be subdivided into at least two distinct chromosomal forms. Previously it was proposed that inversions have played a role in the origin of species within the A. gambiae complex. We argue that a possible subdivision within the M molecular form could be understood through this process, with the acquisition of inversions leading to the expansion of the M molecular form into new habitat, dividing it into two distinct chromosomal forms.
MHC‐DRB3 variation in a free‐living population of the European bison, Bison bonasus
Authors: RADWAN J. , KAWAŁKO A. , WÓJCIK J. M. , BABIK W.
Published: November 2006

MHC genes play a crucial role in pathogen recognition and are the most polymorphic genes in vertebrates. Loss of variation in these genes in bottlenecked species is thought to put their survival at risk. We examined variation at the MHC II DRB3 locus in the European bison, Bison bonasus, a species that has undergone an extreme bottleneck: the current population originated from only 12 founders. We also tested for the association of DRB3 genes with the incidence of posthitis, a disease affecting the reproductive organs of bulls and posing a new threat to the survival of the species. We found very limited MHC diversity, with only four alleles segregating in a sample of 172 individuals from a free‐ranging Białowieża population. The alleles were highly divergent and revealed the hallmark of positive selection acting on them in the past, that is, a significant excess of nonsynonymous substitutions. This excess was concentrated in putative antigen‐binding sites, suggesting that selection was driven by pathogens. However, we did not observe departures from Hardy–Weinberg equilibrium, an indicator of strong ongoing selection. Neither have we found a significant association between DRB3 alleles or genotypes and susceptibility to posthitis. Alleles conferring resistance to males may have been lost during the extreme bottleneck the species had undergone.
Impact of selective logging on inbreeding and gene dispersal in an Amazonian tree population of Carapa guianensis Aubl.
Authors: CLOUTIER D. , KANASHIRO M. , CIAMPI A. Y. , SCHOEN D. J.
Published: November 2006

Selective logging may impact patterns of genetic diversity within populations of harvested forest tree species by increasing distances separating conspecific trees, and modifying physical and biotic features of the forest habitat. We measured levels of gene diversity, inbreeding, pollen dispersal and spatial genetic structure (SGS) of an Amazonian insect‐pollinated Carapa guianensis population before and after commercial selective logging. Similar levels of gene diversity and allelic richness were found before and after logging in both the adult and the seed generations. Pre‐ and post‐harvest outcrossing rates were high, and not significantly different from one another. We found no significant levels of biparental inbreeding either before or after logging. Low levels of pollen pool differentiation were found, and the pre‐ vs. post‐harvest difference was not significant. Pollen dispersal distance estimates averaged between 75 m and 265 m before logging, and between 76 m and 268 m after logging, depending on the value of tree density and the dispersal model used. There were weak and similar levels of differentiation of allele frequencies in the adults and in the pollen pool, before and after logging occurred, as well as weak and similar pre‐ and post‐harvest levels of SGS among adult trees. The large neighbourhood sizes estimated suggest high historical levels of gene flow. Overall our results indicate that there is no clear short‐term genetic impact of selective logging on this population of C. guianensis.
Hybridization between multiple fence lizard lineages in an ecotone: locally discordant variation in mitochondrial DNA, chromosomes, and morphology
Authors: LEACHÉ ADAM D. , COLE CHARLES J.
Published: November 2006

We investigated a hybrid zone between two major lineages of fence lizards (Sceloporus cowlesiandSceloporus tristichus) in theSceloporus undulatusspecies complex in eastern Arizona. This zone occurs in an ecotone between Great Basin Grassland and Conifer Woodland habitats. We analysed spatial variation in mtDNA (N = 401; 969 bp), chromosomes (N = 217), and morphology (N = 312; 11 characters) to characterize the hybrid zone and assess species limits. A fine‐scale population level phylogenetic analysis refined the boundaries between these species and indicated that four nonsister mtDNA clades (three belonging toS. tristichusand one toS. cowlesi) are sympatric at the centre of the zone. Estimates of cytonuclear disequilibria in the population closest to the centre of the hybrid zone suggest that theS. tristichusclades are randomly mating, but that theS. cowlesihaplotype has a significant nonrandom association with nuclear alleles. Maximum‐likelihood cline‐fitting analyses suggest that the karyotype, morphology, and dorsal colour pattern clines are all coincident, but the mtDNA cline is skewed significantly to the south. A temporal comparison of cline centres utilizing karyotype data collected in the early 1970s and in 2002 suggests that the cline may have shifted by approximately 1.5 km to the north over a 30‐year period. The recent northward expansion of juniper trees into the Little Colorado River Basin resulting from intense cattle overgrazing provides a plausible mechanism for a shifting hybrid zone and the introgression of the mtDNA haplotypes, which appear to be selectively neutral. It is clear that complex interactions are operating simultaneously in this contact zone, including the formation of hybrids between populations withinS. tristichushaving diagnostic mtDNA, morphology, karyotypes, and dorsal colour patterns, and secondary contact between these and a distantly related yet morphologically cryptic mtDNA lineage (S. cowlesi).
Ribonucleotide reductase and the regulation of DNA replication: an old story and an ancient heritage
Authors: Herrick John , Sclavi Bianca
Published: November 2006

All organisms that synthesize their own DNA have evolved mechanisms for maintaining a constant DNA/cell mass ratio independent of growth rate. The DNA/cell mass ratio is a central parameter in the processes controlling the cell cycle. The co‐ordination of DNA replication with cell growth involves multiple levels of regulation. DNA synthesis is initiated at specific sites on the chromosome termed origins of replication, and proceeds bidirectionally to elongate and duplicate the chromosome. These two processes, initiation and elongation, therefore determine the total rate of DNA synthesis in the cell. In Escherichia coli, initiation depends on the DnaA protein while elongation depends on a multiprotein replication factory that incorporates deoxyribonucleotides (dNTPs) into the growing DNA chain. The enzyme ribonucleotide reductase (RNR) is universally responsible for synthesizing the necessary dNTPs. In this review we examine the role RNR plays in regulating the total rate of DNA synthesis in E. coli and, hence, in maintaining constant DNA/cell mass ratios during normal growth and under conditions of DNA stress.
Reduced action of polypeptide release factors induces mRNA cleavage and tmRNA tagging at stop codons in Escherichia coli
Authors: Li Xia , Yokota Teruaki , Ito Koichi , Nakamura Yoshikazu , Aiba Hiroji
Published: November 2006

Certain C‐terminal sequences of nascent peptide cause an efficient protein tagging by tmRNA system at stop codons in Escherichia coli. Here, we demonstrate that both mRNA cleavage and tmRNA tagging occur at UAG stop codon recognized specifically by polypeptide release factor 1 (RF‐1) when the activity of RF‐1 is reduced by a mutation in the prfA gene without requirement of particular C‐terminal sequences of nascent peptide. The tmRNA tagging and mRNA cleavage in the prfA mutant were eliminated when the wild‐type RF‐1 but not RF‐2 was supplied from plasmid. In addition, depletion of either RF‐1 or RF‐2 induces endonucleolytic cleavage and tmRNA tagging at UAG or UGA stop codons respectively. We conclude that ribosome stalling at the cognate stop codon caused by reduced activity or expression of RF‐1 or RF‐2 is responsible for mRNA cleavage. The present data along with our previous studies strongly suggest that ribosome stalling leads to endonucleolytic cleavage of mRNA in general resulting in non‐stop mRNA and that the 3′ end of non‐stop mRNA is probably only target for the tmRNA system.
In vivo contextual requirements for UAG translation as pyrrolysine
Authors: Longstaff David Gordon , Blight Sherry Kathleen , Zhang Liwen , Green‐Church Kari B. , Krzycki Joseph Adrian
Published: November 2006

Pyrrolysine and selenocysteine have infiltrated natural genetic codes via the translation of canonical stop codons. UGA translation as selenocysteine is absolutely dependent on message context. Here we describe the first experimental examination of contextual requirements for UAG translation as pyrrolysine. A hexahistidine‐tagged Methanosarcina barkeri mtmB1 gene, encoding monomethylamine methyltransferase MtmB1, was introduced into Methanosarcina acetivorans. Host mtmB expression was minimized by growth on methanol and recombinant mtmB1 products monitored by anti‐MtmB and anti‐hexahistidine immunoblotting. UAG translation was not compromised, as recombinant MtmB1 was 1% of cellular protein with only trace UAG‐terminated mtmB1 product detectable. Untranslated regions flanking mtmB1 were not required for UAG translation, but loss of a downstream pyrrolysine insertion sequence (PYLIS) significantly increased the UAG‐termination product of mtmB1 and decreased the UAG‐translation product, which nonetheless contained pyrrolysine. An in‐frame UAG within a bacterial uidA transcript was translated in the methanogen as pyrrolysine with 20% efficiency, suggesting UAG translation in the absence of evolved context. However, predominant UAG‐directed termination with enhancement of UAG translation by the PYLIS appears analogous to cis‐acting elements for UGA translation as selenocysteine, although different mechanisms may underlie these recoding events.
Haem recognition by a Staphylococcus aureus NEAT domain
Authors: Grigg Jason C. , Vermeiren Christie L. , Heinrichs David E. , Murphy Michael E. P.
Published: November 2006

Successful pathogenic organisms have developed mechanisms to thrive under extreme levels of iron restriction. Haem‐iron represents the largest iron reservoir in the human body and is a significant source of iron for some bacterial pathogens. NEAT (NEAr Transporter) domains are found exclusively in a family of cell surface proteins in Gram‐positive bacteria. Many NEAT domain‐containing proteins, including IsdA in Staphylococcus aureus, are implicated in haem binding. Here, we show that overexpression of IsdA in S. aureus enhances growth and an inactivation mutant of IsdA has a growth defect, compared with wild type, when grown in media containing haem as the sole iron source. Furthermore, the haem‐binding property of IsdA is contained within the NEAT domain. Crystal structures of the apo‐IsdA NEAT domain and in complex with haem were solved and reveal a clathrin adapter‐like β‐sandwich fold with a large hydrophobic haem‐binding pocket. Haem is bound with the propionate groups directed at the molecular surface and the iron is co‐ordinated solely by Tyr166. The phenol groups of Tyr166 and Tyr170 form an H‐bond that may function in regulating haem binding and release. An analysis of IsdA structure‐sequence alignments indicate that conservation of Tyr166 is a predictor of haem binding by NEAT domains.
Genome‐wide reprogramming of metabolism and regulatory networks of Arabidopsis in response to phosphorus
Authors: MORCUENDE ROSA , BARI RAJENDRA , GIBON YVES , ZHENG WENMING , PANT BIKRAM DATT , BLÄSING OLIVER , USADEL BJÖRN , CZECHOWSKI TOMASZ , UDVARDI MICHAEL K. , STITT MARK , SCHEIBLE WOLF‐RÜDIGER
Published: November 2006

Affymetrix ATH1 arrays, large‐scale real‐time reverse transcription PCR of ∼ 2200 transcription factor genes and other gene families, and analyses of metabolites and enzyme activities were used to investigate the response of Arabidopsis to phosphate (Pi) deprivation and re‐supply. Transcript data were analysed with MapMan software to identify coordinated, system‐wide changes in metabolism and other cellular processes. Phosphorus (P) deprivation led to induction or repression of > 1000 genes involved in many processes. A subset, including the induction of genes involved in P uptake, the mobilization of organic Pi, the conversion of phosphorylated glycolytic intermediates to carbohydrates and organic acids, the replacement of P‐containing phospholipids with galactolipids and the repression of genes involved in nucleotide/nucleic acid synthesis, was reversed within 3 h after Pi re‐supply. Analyses of 22 enzyme activities revealed that changes in transcript levels often, but not always, led to changes in the activities of the encoded enzymes in P‐deprived plants. Analyses of metabolites confirmed that P deprivation leads to a shift towards the accumulation of carbohydrates, organic acids and amino acids, and that Pi re‐supply leads to use of the latter. P‐deprived plants also showed large changes in the expression of many genes involved in, for example, secondary metabolism and photosynthesis. These changes were not reversed rapidly upon Pi re‐supply and were probably secondary in origin. Differentially expressed and highly P‐specific putative regulator genes were identified that presumably play central roles in coordinating the complex responses of plants to changes in P nutrition. The specific responses to Pi differ markedly from those found for nitrate, whereas the long‐term responses during P and N deprivation share common and non‐specific features.
Assessing environmental and physiological controls over water relations in a Scots pine (Pinus sylvestris L.) stand through analyses of stable isotope composition of water and organic matter
Authors: BRANDES ELKE , WENNINGER JOCHEN , KOENIGER PAUL , SCHINDLER DIRK , RENNENBERG HEINZ , LEIBUNDGUT CHRISTIAN , MAYER HELMUT , GESSLER ARTHUR
Published: November 2006

This study investigated the influence of meteorological, pedospheric and physiological factors on the water relations of Scots pine, as characterized by the origin of water taken up, by xylem transport as well as by carbon isotope discrimination (Δ13C) and oxygen isotope enrichment (Δ18O) of newly assimilated organic matter. For more than 1 year, we quantified δ2H and δ18O of potential water sources and xylem water as well as Δ13C and Δ18O in twig and trunk phloem organic matter biweekly, and related these values to continuously measured or modelled meteorological parameters, soil water content, stand transpiration (ST) and canopy stomatal conductance (Gs). During the growing season, δ18O and δ2H of xylem water were generally in a range comparable to soil water from a depth of 2–20 cm. Long residence time of water in the tracheids uncoupled the isotopic signals of xylem and soil water in winter. Δ18O but not Δ13C in phloem organic matter was directly indicative of recent environmental conditions during the whole year. Δ18O could be described applying a model that included 18O fractionation associated with water exchange between leaf and atmosphere, and with the production of organic matter as well as the influence of transpiration. Phloem Δ13C was assumed to be concertedly influenced by Gs and photosynthetically active radiation (PAR) (as a proxy for photosynthetic capacity). We conclude that isotope signatures can be used as effective tools (1) to characterize the seasonal dynamics in source and xylem water, and (2) to assess environmental effects on transpiration and Gs of Scots pine, thus helping to understand and predict potential impacts of climate change on trees and forest ecosystems.
Physiological girdling of pine trees via phloem chilling: proof of concept
Authors: JOHNSEN KURT , MAIER CHRIS , SANCHEZ FELIPE , ANDERSON PETER , BUTNOR JOHN , WARING RICHARD , LINDER SUNE
Published: November 2006

Quantifying below‐ground carbon (C) allocation is particularly difficult as methods usually disturb the root–mycorrhizal–soil continuum. We reduced C allocation below ground of loblolly pine trees by: (1) physically girdling trees and (2) physiologically girdling pine trees by chilling the phloem. Chilling reduced cambium temperatures by approximately 18 °C. Both methods rapidly reduced soil CO2efflux, and after approximately 10 days decreased net photosynthesis (Pn), the latter indicating feedback inhibition. Chilling decreased soil‐soluble C, indicating that decreased soil CO2efflux may have been mediated by a decrease in root C exudation that was rapidly respired by microbes. These effects were only observed in late summer/early autumn when above‐ground growth was minimal, and not in the spring when above‐ground growth was rapid. All of the effects were rapidly reversed when chilling was ceased. In fertilized plots, both chilling and physical girdling methods reduced soil CO2efflux by approximately 8%. Physical girdling reduced soil CO2efflux by 26% in non‐fertilized plots. This work demonstrates that phloem chilling provides a non‐destructive alternative to reducing the movement of recent photosynthate below the point of chilling to estimate C allocation below ground on large trees.
Occurrence of the R1 allele conferring resistance to late blight in potato R‐gene differentials and commercial cultivars
Authors: Trognitz B. R. , Trognitz F. Ch.
Published: November 2006

A total of 23 Scottish and 14 Dutch potato R‐gene differentials as well as five Austrian, two Dutch and two German commercial potato cultivars were screened for the R1 allele conferring resistance to Phytophthora infestans carrying Avr1, via PCR amplification and sequencing. A single 1400 bp fragment with complete sequence identity to the corresponding part of the R1 allele, was obtained from genomic DNA of all potato R‐gene differential clones whose denomination indicates R1 or a combination of R1 and other major resistance factors. The R1 allele was detected, as expected, in all these clones. This fragment also occurred in one Austrian and one German cultivar. Unexpectedly, the same R1 allele also was detected within all R5, R6 and R9 differentials.
Partial nucleotide sequence analysis of Turkish isolates of Beet necrotic yellow vein virus (BNYVV) RNA‐3
Authors: Kutluk Yilmaz N. D. , Meunier A. , Schmit J. F. , Stas A. , Bragard C.
Published: November 2006

A survey was carried out to detect Beet necrotic yellow vein virus (BNYVV) in soil samples using RT‐PCR and bait plant techniques from the sugar beet production area of Tokat, Turkey in 2001. More than 80% of the soil samples analyzed were found to be contaminated with the virus. The partial nucleotide sequence of cDNA corresponding to RNA‐3 of BNYVV isolates were analyzed for six different regions of Tokat province. All isolates were assigned to type A strains based on RFLP analysis and DNA sequences. Sequence comparison revealed differences at amino acid positions 35, 68, 71 and 179 of the P25 coding region amongst Turkish isolates. Additionally, all Turkish isolates were compared with Japanese, French, Kazakh, Italian and Belgian isolates.
Interaction of Cholera Toxin with Three Life‐cycle Stages of Schistosoma mansoni: Adult Worm, Egg and Cercaria
Authors: Akhiani A. A. , Deelder A. M. , Månsson J.‐E. , Nilsson L.‐Å.
Published: November 2006

We have previously reported that there is an immunological cross‐reactivity between Schistosoma mansoni and cholera toxin (CT). In this study, using an immunofluorescence technique with anti‐CT antibody, we provide further evidence for this cross‐reactivity by demonstrating an antigen, localized in the tegument of S. mansoni adult worms which is cross‐reactive with a CT antigen. Anti‐CT antibodies also reacted with structures in S. mansoni cercariae and eggs. Additionally, CT itself was found to bind strongly to the gut of the adult worm, gut cells of cercaria and the egg shell. The binding of CT to the parasite was blocked when parasite sections were incubated with CT which had been incubated with the ganglioside GM1. Lipid extraction and isolation of gangliosides demonstrated the presence of GM1 in adult worms. For further analysis of CT‐binding structures, the possible interaction of CT with two major schistosome gut antigens, circulating cathodic antigen (CCA) and circulating anodic antigen (CAA), was studied. We found that CT blocked the binding of anti‐CCA antibody to the gut of adult worms and that anti‐CCA blocked the binding of CT to the worm gut. These findings indicate that CT binds to CCA present in the gut of the parasite and thus has, in addition to GM1, a second binding specificity.
Inflammatory Cytokines in Relation to Adrenal Response Following Total Hip Replacement
Authors: Bjornsson G. L. , Thorsteinsson L. , Gudmundsson K. O. , Jonsson H. , Gudmundsson S. , Gudbjornsson B.
Published: November 2006

Our objective was to investigate the initiation and course of pro‐ and anti‐inflammatory cytokines in early inflammatory response and to elucidate the cytokine system in relation to the adrenal response caused by stress. Seven blood samples were collected, pre‐ and postoperatively (0–72 h) after total hip replacement (THR) due to osteoarthritis. The following cytokines were measured using Cytometric Bead Array: interleukin‐1β (IL‐1β), IL‐6, tumour necrosis factor‐α, IL‐8, IL‐12 and IL‐10 (B&D). Thirteen patients took part in the study (67 ± 9 years). C‐reactive protein increased from <6 to over 200 mg/l on the second post‐op day. The concentration of IL‐6 increased 10‐fold just 3 h post‐op (4–47 pg/ml) and reached its maximum value 6 h post‐op (77 pg/ml; Wilcoxon test P < 0.01) Repeated measurements were also significant (Friedman P < 0.05). The concentration of IL‐8 doubled the day of surgery but did not reach a significant level (Friedman test =0.069). None of the other cytokines showed any significant changes. The diurnal cortisol rhythm was interrupted after the surgery and there was a significant correlation between the cortisol secretion and IL‐6 response. This study demonstrates an isolated elevation in IL‐6 levels with only a minor elevation in IL‐8 following THR. This pro‐inflammatory response seemed to decline without activation of anti‐inflammatory cytokines (IL‐10), but cortisol seemed to play a complicated role in halting the acute inflammatory response.
The Late Jurassic Tithonian, a greenhouse phase in the Middle Jurassic–Early Cretaceous ‘cool’ mode: evidence from the cyclic Adriatic Platform, Croatia
Authors: HUSINEC ANTUN , FRED READ J.
Published: November 2006

Well‐exposed Mesozoic sections of the Bahama‐like Adriatic Platform along the Dalmatian coast (southern Croatia) reveal the detailed stacking patterns of cyclic facies within the rapidly subsiding Late Jurassic (Tithonian) shallow platform‐interior (over 750 m thick, ca 5–6 Myr duration). Facies within parasequences include dasyclad‐oncoid mudstone‐wackestone‐floatstone and skeletal‐peloid wackestone‐packstone (shallow lagoon), intraclast‐peloid packstone and grainstone (shoal), radial‐ooid grainstone (hypersaline shallow subtidal/intertidal shoals and ponds), lime mudstone (restricted lagoon), fenestral carbonates and microbial laminites (tidal flat). Parasequences in the overall transgressive Lower Tithonian sections are 1–4·5 m thick, and dominated by subtidal facies, some of which are capped by very shallow‐water grainstone‐packstone or restricted lime mudstone; laminated tidal caps become common only towards the interior of the platform. Parasequences in the regressive Upper Tithonian are dominated by peritidal facies with distinctive basal oolite units and well‐developed laminate caps. Maximum water depths of facies within parasequences (estimated from stratigraphic distance of the facies to the base of the tidal flat units capping parasequences) were generally <4 m, and facies show strongly overlapping depth ranges suggesting facies mosaics. Parasequences were formed by precessional (20 kyr) orbital forcing and form parasequence sets of 100 and 400 kyr eccentricity bundles. Parasequences are arranged in third‐order sequences that lack significant bounding disconformities, and are evident on accommodation (Fischer) plots of cumulative departure from average cycle thickness plotted against cycle number or stratigraphic position. Modelling suggests that precessional sea‐level changes were small (several metres) as were eccentricity sea‐level changes (or precessional sea‐level changes modulated by eccentricity), supporting a global, hot greenhouse climate for the Late Jurassic (Tithonian) within the overall ‘cool’ mode of the Middle Jurassic to Early Cretaceous.
The glauconite–Fe‐illite–Fe‐smectite problem: a critical review
Authors: Meunier Alain , El Albani Abderrazak
Published: November 2006

Iron silicate minerals are a significant component of sedimentary systems but their modes of formation remain controversial. Our analysis of published data identifies end‐member compositions and mixtures and allows us to recognize controls of formation of different mineral species. The compositional fields of glaucony, Fe‐illite, Fe–Al smectites are determined in the M+/4Si vs. Fe/Sum of octahedral cations (M+ = interlayer charge). Solid solutions could exist between these phases. The Fe–Al and Fe‐rich clay minerals form two distinct solid solutions. The earliest phases to be formed are Fe–Al smectites or berthierine depending on the sedimentation rate. Reductive microsystems appear in the vicinity of organic debris in unconsolidated sediments. The Fe is incorporated first in pyrite and then in silicates after oxidation. Potassium ions diffuse from the sea‐water–sediment interface. If not interrupted, the diffusion process is active until reaction completion is reached, i.e. formation of Fe‐illite or glauconite or a mineral assemblage (berthierine–nontronite) according to the available Al ion amounts in the microsystem. Mixed‐layer minerals are formed when the diffusion process is interrupted because of sedimentation, compaction or cementation. Despite the common belief of their value as palaeoenvironment indicators, these minerals can form in a variety of environments and over a period of millions of years during sediment burial.
The role of methionine recycling for ethylene synthesis in Arabidopsis
Authors: Bürstenbinder Katharina , Rzewuski Guillaume , Wirtz Markus , Hell Rüdiger , Sauter Margret
Published: November 2006

The methionine (Met) cycle contributes to sulfur metabolism through the conversion of methylthioadenosine (MTA) to Met at the expense of ATP. MTA is released as a by‐product of ethylene synthesis from S‐adenosylmethionine (AdoMet). Disruption of the Met cycle in the Arabidopsis mtk mutant resulted in an imbalance of AdoMet homeostasis at sulfur‐limiting conditions, irrespective of the sulfur source supplied to the plants. At a low concentration of 100 μm sulfate, the mtk mutant had reduced AdoMet levels and growth was retarded as compared with wild type. An elevated production of ethylene was measured in seedlings of the ethylene‐overproducing eto3 mutant. When Met cycle knockout and ethylene overproduction were combined in the mtk/eto3 double mutant, a reduced capacity for ethylene synthesis was observed in seedlings. Even though mature eto3 plants did not produce elevated ethylene levels, and AdoMet homeostasis in eto3 plants did not differ from that in wild type, shoot growth was severely retarded. The mtk/eto3 double mutant displayed a metabolic plant phenotype that was similar to mtk with reduced AdoMet levels at sulfur‐limiting conditions. We conclude from our data that the Met cycle contributes to the maintenance of AdoMet homeostasis, especially when de novo AdoMet synthesis is limited. Our data further showed that the Met cycle is required to sustain high rates of ethylene synthesis. Expression of the Met cycle genes AtMTN1, AtMTN2, AtMTK, AtARD1, AtARD2, AtARD3 and AtARD4 was not regulated by ethylene. This result is in contrast to that found in rice where OsARD1 and OsMTK are induced in response to ethylene. We hypothesize that the regulation of the Met cycle by ethylene may be restricted to plants that naturally produce high quantities of ethylene for a prolonged period of time.
Knowledge, attitude and practice study about blood donation in the urban population of Yazd, Iran, 2004
Authors: Javadzadeh Shahshahani H. , Yavari M. T. , Attar M. , Ahmadiyėh M. H.
Published: November 2006

summary The most important aim of all blood transfusion centres is to recruit blood donors from low‐risk groups of society to donate blood voluntarily and regularly to have a safe and continuous blood supply. The aim of this study was to assess the level of knowledge, attitude and practice regarding blood donation in the city of Yazd, Iran. In this cross‐sectional study, 1394 cases aged between 20 and 60 years were selected by clustering sampling method and asked to fill a specially formatted questionnaire. Data were analysed by analysis of variance, Sheffe test and t‐test. Less than half of the population under study was aware about the appropriate age for blood donation and certain deferral criteria. Only 98% of them believed that blood donation is a moral duty with a spiritual reward and 38% of the population under study (60% of men and 16% of women) had donated blood at least once in the past. There was a direct relationship between knowledge and performance (P= 0·000). Women and young people had the least levels of knowledge and performance. Although the attitude level of women was high, their performance level was very low. Increase in the level of knowledge of women and young should be the topmost priority. Barriers to donation of blood by women who comprise half of the population should be studied and evaluated, and steps must be taken to remove or decrease them as far as possible. Advertisements should be with the aim of increasing the level of awareness of the general population regarding specific factors of blood donation and keeping fresh the idea of regular voluntary blood donations in their minds.
DTP vaccination and child survival in observational studies with incomplete vaccination data
Authors: Aaby Peter , Benn Christine Stabell , Nielsen Jens , Lisse Ida Maria , Rodrigues Amabelia , Jensen Henrik
Published: November 2006

Background  Observational studies of diphtheria–tetanus–pertussis (DTP) vaccine from longitudinal study sites have reported divergent effects on child survival, ranging from 10‐fold reduction to threefold increased mortality. None of these studies had complete information on DTP vaccinations from both survivors and children who died. We reviewed the data analysis methodology to assess whether methodological differences could explain the divergent results.

Design  Studies have used case–control design, survival analysis with interval‐fixed vaccination status (landmark approach), and survival analysis with retrospective updating of vaccination status.

Results  Seven studies using a case–control design or a landmark approach found a negative effect of DTP on child survival. Eight of nine survival analyses with retrospective updating of vaccination status reported a beneficial effect. This beneficial effect of DTP increased with the length of the interval between data collection visits. Studies with long interval between visits had very high mortality rates among unvaccinated children, low mortality rate ratios for vaccinated compared with unvaccinated children, and strongly beneficial estimates of DTP.

Conclusion  The divergent results in observational studies of the impact of DTP on child survival are partly because of methodological differences. To assess the impact on mortality of routine vaccinations, observational study designs which minimize the effect of bias are warranted. Randomized trials should be considered.