bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in root water flow properties of solution culture‐grown trembling aspen (Populus tremuloides) seedlings under different intensities of water‐deficit stress
Authors: Siemens J. Aurea , Zwiazek Janusz J.
Published: April 2004

To study the effects of water‐deficit stress on root water flow properties in trembling aspen (Populus tremuloides Michx.), seedlings were grown in solution culture and subjected to water‐deficit stress by placing their roots in sealed high humidity chambers. After 17 h of stress treatment, seedlings showed mild stress (MS) symptoms with a decline in shoot water potentials. Within 20 h, shoot water potentials rapidly declined, and severe stress (SS) symptoms were present. Root hydraulic conductivity (Lpr) increased more than two‐fold and the relative concentration of apoplastic tracer dye trisodium 3‐hydroxy‐5, 8, 10‐pyrenetrisulphonate (PTS3) in xylem exudate decreased by 73.6% in MS seedlings. Conversely, Lpr decreased (55.3%) and PTS3 increased (28.6%) in SS seedlings. Treatment of roots with 0.1 mM mercuric chloride decreased root volume flow density (Jv) by about 29.0% in control and MS plants with no decrease measured in SS seedlings. Mercuric chloride also increased PTS3 concentration in xylem exudate of control (59%) and MS (86%) seedlings with no change observed in SS plants. The results suggest that aquaporin‐mediated transport is important in the regulation of root water flow under drought stress and that root water flow properties are strongly affected by the stress level. Regulation of root water flow may represent an important drought‐stress resistance mechanism.
Lignification and structural biomass production in tobacco with suppressed caffeic/5‐hydroxy ferulic acid‐O‐methyl transferase activity under ambient and elevated CO2 concentrations
Authors: Blaschke Lothar , Legrand Michel , Mai Carsten , Polle Andrea
Published: April 2004

To investigate the relationship between growth, biomass partitioning and lignification we used tobacco (Nicotiana tabacum) in which O‐methyl transferase (OMT) activity, an enzyme involved in the pathway of sinapyl alcohol formation for lignin synthesis, was suppressed by antisense transformation. To modulate growth, controls and transformed tobacco plants were grown under ambient (approximately 380 p.p.m) or elevated CO2 (700 p.p.m), respectively. Lignin concentrations and composition were determined with spectrophotometric methods (thioglycolate and acetyl bromide) and Fourier transform infrared (FTIR) spectroscopy, respectively. A comparison of the thioglycolate and acetylbromide method suggested that the thioglycolate method was sensitive to changes in the syringyl/guaiacyl (S/G)‐ratio in lignin and therefore not suitable for quantification in tissues with altered lignin composition. Growth under elevated CO2 increased leaf and stem biomass of both genotypes by 40 and 20%, respectively, compared with ambient CO2 and had no effect on root biomass. OMT suppression did not affect lignin concentrations in the leaves but caused a shift in biomass partitioning from the structural to the non‐structural fraction. Elevated CO2 caused a shift towards production of structural compounds resulting in decreased foliar lignin concentrations and indicating that the lignin/structural mass ratio is flexible in leaves. By contrast, the lignin concentrations of stems were unaffected by elevated CO2 or OMT suppression and increased about three‐fold from the apex to the base. Antisense‐OMT plants produced more stem biomass than controls but showed no changes of the relative partitioning of biomass to the different pools. This indicates that the metabolic control of carbon fluxes to the production of structural versus non‐structural fractions is tighter in stems than in leaves. FTIR spectroscopy indicated a relative increase in guaiacyl‐ as compared with syringyl‐units in antisense‐OMT tobacco, which was more pronounced under elevated as compared with ambient CO2. Since there was no evidence for decreased lignin concentrations in the antisense‐OMT plants but increased biomass formation we suggest that less methylated lignins are ‘cheaper’ in biosynthetic carbon and energy demand and, thus, may enable plants to allocate increased resources to growth.
Peroxidase activity associated with suberization processes of the muskmelon (Cucumis melo) rind
Authors: Keren‐Keiserman Alexandra , Tanami Zaccharia , Shoseyov Oded , Ginzberg Idit
Published: April 2004

The rind of fruits of muskmelon (Cucumis melo L. var. reticulatus) contains a network of suberized tissue referred to as the ‘netting’, and peroxidase (EC 1.11.1.7) activity is necessary to the polymerization of the aromatic domain of suberin. Peroxidase activity increased dramatically during the early stages of melon fruit netting, and in fruits exhibiting incomplete netting, peroxidase activity was significantly higher in netted than in non‐netted regions of the same fruit. Moreover, analysis of peroxidase activity in three varieties of smooth‐rind melons (Cucumis melo var. inodorous) indicated lower levels of the activity in rind samples, taken throughout fruit development, than in rinds of netted varieties. Netting‐associated anionic peroxidase (NAPOD) was isolated from the melon rind at an early stage of netting development, partially purified, microsequenced and its cDNA was cloned. It was found to be a single‐copy gene within the genome of netted and smooth melon varieties, and highly homologous to other Cucurbitaceous anionic peroxidases. A high transcript level was only detected in the rind of the netted variety. Monitoring the gene expression of netting‐associated anionic peroxidase, together with other enzymes involved in the netting will shed light on the molecular control of the suberization processes in the melon rind and in plants in general.
Flowering genes in Metrosideros fit a broad herbaceous model encompassing Arabidopsis and Antirrhinum
Authors: Sreekantan Lekha , Clemens John , McKenzie Marian J. , Lenton John R. , Croker Steve J. , Jameson Paula E.
Published: April 2004

Molecular studies were conducted on Metrosideros excelsa to determine if the current genetic models for flowering with regard to inflorescence and floral meristem identity genes in annual plants were applicable to a woody perennial. MEL, MESAP1 and METFL1, the fragments of LEAFY (LFY), APETALA1 (AP1) and TERMINAL FLOWER1 (TFL1) equivalents, respectively, were isolated from M. excelsa. Temporal expression patterns showed that MEL and MESAP1 exhibited a bimodal pattern of expression. Expression exhibited during early floral initiation in autumn was followed by down‐regulation during winter, and up‐regulation in spring as floral organogenesis occurred. Spatial expression patterns of MEL showed that it had greater similarity to FLORICAULA (FLO) than to LFY, whereas MESAP1 was more similar to AP1 than SQUAMOSA. The interaction between MEL and METFL1 was more similar to the interaction between FLO and CENTRORADIALIS than that between LFY and TFL1. Consequently, the three genes from M. excelsa fit a broader herbaceous model encompassing Antirrhinum as well as Arabidopsis, but with differences, such as the bimodal pattern of expression seen with MEL and MESAP1. In mid‐winter, at the time when both MEL and MESAP1 were down‐regulated, GA1 was below the level of detection in M. excelsa buds. Even though application of gibberellin inhibits flowering in members of the Myrtaceae, MEL was responsive to gibberellin with expression in juvenile plants up‐regulated by GA3. However, MESAP1 was not up‐regulated indicating that meristem competence was also probably required to promote flowering in M. excelsa.
Regulation of self‐glycosylation of reversibly glycosylated polypeptides from Solanum tuberosum
Authors: Testasecca Pamela , Wald Flavia A. , Cozzarín María E. , Moreno Silvia
Published: April 2004

Reversibly glycosylated polypeptides (RGPs) belong to a family of self‐glycosylating proteins believed to be involved in plant polysaccharide synthesis. The precise function of these enzymes remains to be elucidated. Our results showed that the RGP 38‐kDa subunit is phosphorylated in potato extracts (Solanum tuberosum L.). An increase in the self‐glycosylation of Solanum tuberosum RGP (StRGP) 38‐kDa subunit was observed after alkaline phosphatase (AP) treatment. Our results suggest that phosphorylation of StRGP appears to regulate its self‐glycosylation. It was determined that when the StRGP reaction was carried out in the presence of UDP‐[14C]Glc as the sugar donor and then 1 mM UDP was added in a chase‐out experiment, radioactive UDP‐Glc was obtained indicating that StRGP reaction seems to be reversible. The anomeric configuration of transferred sugars to StRGP protein was also studied.
Modeling Growth and Reduction of Microorganisms in Foods as Functions of Temperature and Time
Authors: McMasters Robert L. , Todd Ewen C.
Published: April 2004

Food safety objectives (FSOs) are established in order to minimize the risk of foodborne illnesses to consumers, but these have not yet been incorporated into regulatory policy. An FSO states the maximum frequency and/or concentration of a microbiological hazard in a food at the time of consumption that provides an acceptable level of protection to the public and leads to a performance criterion for industry. However, in order to be implemented as a regulation, this criterion has to be achievable by the affected industry. In order to determine an FSO, the steps to produce and store that food need to be known, especially where they have an impact on contamination, growth, and destruction. This article uses existing models for growth of Listeria monocytogenes in conjunction with calculations of FSOs to approximate the outcome of more than one introduction of the foodborne organism throughout the food‐processing path from the farm to the consumer. Most models for the growth and reduction of foodborne illnesses are logarithmic in nature, which fits the nature of the growth of microorganisms, spanning many orders of magnitude. However, these logarithmic models are normally limited to a single introduction step and a single reduction step. The model presented as part of this research addresses more than one introduction of food contamination, each of which can be separated by a substantial amount of time. The advantage of treating the problem this way is the accommodation of multiple introductions of foodborne pathogens over a range of time durations and conditions.
Waste Package Performance Evaluations for the Proposed High‐Level Nuclear Waste Repository at Yucca Mountain
Authors: Mon Kevin G. , Bullard Bryan E. , Mehta Sunil , Lee Joon H.
Published: April 2004

The evaluation studies of the proposed repository for long‐term storage of spent nuclear fuel and high‐level nuclear waste at Yucca Mountain, Nevada, are underway. Fulfillment of the requirements for limiting dose to the public, which includes containment of the radioactive waste emplaced in the proposed repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere, will rely on a robust waste container design, among other EBS components. Part of the evaluation process involves sensitivity studies aimed at elucidating which model parameters contribute most to the waste package and overlying drip shield degradation characteristics. The model parameters identified for this study include (1) general corrosion rate parameters and (2) stress corrosion cracking (SCC) parameters. Temperature dependence and parameter uncertainty are evaluated for the general corrosion rate model parameters while for the SCC model parameters, uncertainty treatment of stress intensity factor, crack initiation threshold, and manufacturing flaw orientations are evaluated. Based on these evaluations new uncertainty distributions are generated and recommended for future analyses. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters.
Interpretation of Monte Carlo Simulations Using Parameter Space Plots
Authors: Kennedy Christopher A.
Published: April 2004

Multimodal distribution functions that result from Monte Carlo simulations can be interpreted by superimposing joint probability density functions onto the contour space of the simulated calculations. The method is demonstrated by analysis of the pathway of a radioactive groundwater contaminant using an analytical solution to the transport equation. Simulated concentrations at a fixed time and distance produce multimodal histograms, which are understood with reference to the parameter space for the two random variables—velocity and dispersivity. Numerical integration under the joint density function up to the contour of the analytical solution gives the probability of contaminant exceeding a target concentration. This technique is potentially more efficient than Monte Carlo simulation for low probability events. Visualization of parameter space is restricted to two random variables. Nevertheless, analyzing the two most pertinent random variables in a simulation might still offer insights into the multimodal nature of output histograms.
The Precautionary Principle and/or Risk Assessment in World Trade Organization Decisions: A Possible Role for Risk Perception
Authors: Goldstein Bernard , Carruth Russellyn S.
Published: April 2004

Risk analysis has been recognized and validated in World Trade Organization (WTO) decision processes. In recent years the precautionary principle has been proposed as an additional or alternative approach to standard risk assessment. The precautionary principle has also been advocated by some who see it as part of postmodern democracy in which more power is given to the public on health and safety matters relative to the judgments of technocrats. A more cynical view is that the precautionary principle is particularly championed by the European Community as a means to erect trade barriers. The WTO ruling against the European Community's trade barrier against beef from hormone‐treated cattle seemed to support the use of risk assessment and appeared to reject the argument that the precautionary principle was a legitimate basis for trade barriers. However, a more recent WTO decision on asbestos contains language suggesting that the precautionary principle, in the form of taking into account public perception, may be acceptable as a basis for a trade barrier. This decision, if followed in future WTO trade disputes, such as for genetically modified foods, raises many issues central to the field of risk analysis. It is too early to tell whether the precautionary principle will become accepted in WTO decisions, either as a supplement or a substitute for standard risk assessment. But it would undermine the value of the precautionary principle if this principle were misused to justify unwarranted trade barriers.
Orange County Bankruptcy: Financial Contagion in the Municipal Bond and Bank Equity Markets
Authors: Halstead John M. , Hegde Shantaram , Klein Linda Schmid
Published: April 2004

We examine the spillover wealth effects of the Orange County, California bankruptcy announcement in December 1994 on municipal bonds, municipal bond funds, and bank stocks. This bankruptcy is prominent because of unprecedented losses and because it was caused by a highly leveraged derivatives strategy rather than a shortage of tax revenues and excess spending. We find contagion in the bond market with significantly negative abnormal returns for municipal bond funds without direct exposure to Orange County and for non‐Orange County municipal bonds. In addition, our findings suggest the contagion spills over to the common stocks of investment and commercial banks that deal in or use derivatives; however, the equities of banks unexposed to derivatives are not affected.
Biology of tumor necrosis factor‐α– implications for psoriasis
Authors: Schottelius Arndt J. G. , Moldawer Lyle L. , Dinarello Charles A. , Asadullah Khusru , Sterry Wolfram , Edwards Carl K.
Published: April 2004

Abstract:  Numerous recent investigations have pointed to a key role of the proinflammatory, pleiotropic cytokine tumor necrosis factor‐α (TNF‐α) in host defense and inflammatory processes. TNF overexpression has been found in lesional skin and in the circulation of psoriatic patients, and it was suggested that TNF‐α is crucial in this and other immune diseases. Several approaches to inhibit TNF‐α activity have been developed. These include three different neutralizing antibodies to TNF‐α as well as three different soluble TNF‐α receptors with characteristic properties designed to bind the 17‐KDa soluble trimeric TNF‐α and the 26‐KDa membrane‐bound form of TNF‐α. Clinical trials have demonstrated significant antipsoriatic effects, and it is likely that blocking TNF‐α will become an important therapeutic option. The data available from these trials contribute to further understanding of the disease by demonstrating the major role of TNF‐α. An in‐depth understanding of the regulation of TNF gene expression, protein production, receptor expression, and signaling pathways may lead to further, potentially important novel therapeutic strategies and antipsoriatic active small molecules, suitable for oral application in the future. Here we review the current knowledge of TNF biology, the approaches to inhibit TNF activity, and their clinical and immunological effects in psoriasis. In addition, the host‐defense effects and chronic TNF‐blocking activity are discussed.
The Basel Capital Accords and International Mortgage Markets: A Survey of the Literature
Authors: Allen Linda
Published: April 2004

This paper surveys the literature on the impacts of the Basel Capital Accords on banking market profitability, competitiveness, structure and risk‐taking. Special emphasis is applied to the evolution of mortgage markets throughout the world over almost two decades of international bank regulatory policies.
Intensive care nurses' experiences of assessing and dealing with patients' psychological needs
Authors: Price Ann M
Published: April 2004

• Several authors have highlighted the short‐ and long‐term psychological effects of an intensive care unit (ICU) stay

• Few authors have discussed the nurses' perceptions of psychological care

• In this research, 12 nurses, who currently work in ICU, were interviewed using a semi‐structured technique

• Six categories were developed about issues in psychological care

• Implications for practice included the important role of the family, need for improved communication and improved staff awareness of issues
Can nurses in cardiology areas prepare patients for implantable cardioverter defibrillator implant and life at home?
Authors: Tagney Jenny
Published: April 2004

• This study explored nurses' confidence and competence in preparing patients for having an implantable cardioverter defibrillator implanted and for life at home after discharge

• Whilst research has identified various physical and psychosocial effects to patients and their partners associated with device implant and subsequent lifestyle adjustments, no research has explored nurses' knowledge of the device or these effects

• A survey was designed using a purposive sample of 152 nurses from cardiology areas in four large teaching hospitals and a 28‐point postal questionnaire to explore knowledge of the device and its impact

• Most subjects were not confident in their abilities to prepare patients for implant or life at home after implant

• Knowledge of the device and its effects appeared poorly understood by all nurses, irrespective of additional qualifications, length of time since qualifying or area of work

• Many participants were aware of the poor knowledge level of nurses and identified it as a weakness in current care practices

• Lack of understanding may impair preparation of patients for implantation of or for living with an implantable cardioverter defibrillator, and feasible strategies to change this situation will require careful consideration and further investment
Introducing an early warning scoring system in a district general hospital
Authors: Sharpley Julie T , Holden Janet C
Published: April 2004

• One of the critical care outreach service's aims in this local hospital was to develop an assessment tool to help identify patients in danger of deterioration

• This paper describes the introduction of an early warning scoring system between April 2001 and March 2002 to the surgical unit of a district general hospital

• The informal and gradual approach used to optimize the effectiveness of introducing the early warning scoring system is highlighted

• Explanations are given of the training processes undertaken, the pilot evaluation and lessons learned from the process

• Using the experiences of the outreach service in introducing the early warning scoring system, this paper aims to provide thought for others considering a similar initiative in their area
Absorption of the cholic acid‐conjugated peptide hormone cholylsecretin from the rat ileum in vivo
Authors: McHarg S. , Morton J. S. , McGinn B. J. , Yasin M. , Morrison J. D.
Published: April 2004

Aims:  Previously, we demonstrated that gastrin peptides as long as 34 amino acids were absorbed from the ileum of rat after conjugation to the C24 position of cholic acid and that these peptides retained full biological activity. As absorption was specific to the ileum, it was inferred that the conjugated hormone was taken up by the bile salt transporters. We have now extended these experiments to a member of a different family of hormones, viz. secretin, a 27‐amino acid hormone that stimulates serous secretions from the exocrine pancreas.

Methods:  After conjugation to cholic acid, the degree of cholylsecretin absorption from the ileum of anaesthetized rats was assessed from the increase in pancreatic secretions.

Results:  A complication to the study was that intra‐ileal infusion of native secretin caused a transient increase in the levels of pancreatic secretions. This was in contrast to the effects of intra‐ileal infusion of cholylsecretin which did not cause this transient increase but, instead, gave rise to a delayed increase in pancreatic secretions which was sustained over several hours during which cholylsecretin was detected in plasma in high concentration by mass spectrometry. The pancreatic response to cholylsecretin was abolished by co‐infusion of 50 mm taurocholate, employed to compete with the bile salt transporters, although a transient increase in pancreatic secretions similar to that caused by secretin was now generated. This was shown to arise from an action of taurocholate per se causing the release of endogenous secretin which is present in rat ileum.

Conclusions:  We, therefore, concluded that cholylsecretin had been absorbed from the rat ileum by uptake by bile salt transporters.
Evaluation of effects of rofecoxib on platelet function in an in vitro model of thrombosis with circulating human blood
Authors: Hernandez M. R. , Tonda R. , Pino M. , Serradell M. , Arderiu G. , Escolar G.
Published: April 2004

Background  Cyclooxygenase (COX)‐2‐selective non‐steroidal anti‐inflammatory drugs have been used for anti‐inflammatory therapy. However, it has also been described that they may increase risk of cardiovascular events.

Objectives  To study the effects of COX2 inhibitor rofecoxib on platelet function using in vitro tests. Results were compared with those obtained in a parallel experiment with acetyl salicylic acid (ASA).

Methods  Studies of platelet aggregation, using different agonists, were performed by a turbidimetric method. Adhesive and cohesive function of platelets were analyzed by perfusion techniques, treated blood was exposed to thrombogenic surfaces and platelet interaction was morphometrically evaluated.

Results  Twenty‐five µM of rofecoxib induced a prolonged lag time and a reduction in the percentage of aggregation when arachidonic acid, ADP or collagen were used as agonists. In perfusion studies with parallel chamber rofecoxib 50 µM and ASA 500 µM reduced overall platelet interaction with the collagen surface (17·4 ± 3·7, P < 0·05; vs. 32·1 ± 2·6%P < 0·05 and 17·9 ± 2·4, vs. 31·9 ± 3·24, P < 0·05, respectively). In studies performed on annular chambers, 25 µM of rofecoxib reduced platelet interaction; values of the thrombus and covered surface were 17·4 ± 4·5%; P < 0·05 and 21·1 ± 4·1%; P < 0·05, respectively, vs. 30·4 ± 7·5% and 33·5 ± 6·5 in the control. ASA did also impair thrombus formation but differences did not reach the levels of statistical significance. Moreover, rofecoxib but not ASA reduced significantly thrombus height and thrombus area (7·4 ± 0·5 µM; P < 0·005 and 96·0 ± 21·2 µM2; P < 0·05 vs. control 11·2 ± 0·9 µM and 220·0 ± 47·7µM2, respectively).

Conclusion  We conclude that under our experimental conditions, rofecoxib diminished platelet aggregation induced by different agonists and inhibited platelet‐mediated thrombogenesis in an in vitro model of thrombosis.
2004 Spring Scientific Meeting of the British Endodontic Society
Authors: Desai M. , Gulabivala K. , Ng Y.‐L. , Spratt D.
Published: April 2004

Co‐aggregation studies on bacteria from infected root canals

Aim  Co‐aggregation phenomena may play a crucial role in root canal colonization and subsequent infection, and may be an important aspect of the selection process taking place. The aims were to determine intracanal and intercanal co‐aggregation partners in bacterial strains isolated from infected root canal systems.

Methodology  Bacterial strains isolated from the root canals of four intact teeth, and one strain of Fusobacterium nucleatum from a separate tooth were selected for the study. The isolates were grown in static culture at 37 °C in brain heart infusion broth. The cells were harvested by centrifugation and prepared for the co‐aggregation study in an appropriate buffer. Aliquots (100 µL) of each pair of isolates (all combinations) were placed in a durham tube, mixed and left to settle. A visual co‐aggregation assay was performed after 1–2 h after pairing and again 6–7 h later. Co‐aggregation was judged by a predetermined 5‐point visual assessment scale, which showed good reproducibility.

Results  Co‐aggregation results were identical at the different time points. Physical interaction between bacterial cells within a genus and between different genera was surprisingly infrequent; where it manifested in auto‐aggregation (within strain) or co‐aggregation, it was found to be species‐ and strain‐specific. Actinomyces viscosus, Rothia dentocariosa, Streptomyces scabei, Neiserria mucosa and two unidentified strains displayed auto‐aggregation. Intrageneric and intergeneric co‐aggregation was observed both between strains from the same tooth and those from different teeth. Sometimes, strains that showed no intracanal co‐aggregation were identified as co‐aggregation partners with strains from different teeth. Intrageneric co‐aggregation occurred between Streptococcus species, and intergeneric co‐aggregation involved Abiotrophia adiacens, A. naeslundii, Pediococcus urinaeequii, R. dentocariosa, S. scabei, Streptococcus gordonii and S. mitis. The F. nucleatum strain tested for co‐aggregation did not auto‐aggregate or co‐aggregate with any of the isolates it was paired with.

Conclusions  This study showed that co‐aggregation is species‐ and strain‐dependent, and was surprisingly infrequent among the various pairings. The renowned associations between root canal isolates may be dominated by interactions other than physical, such as nutritional and physiological dependence.
Utilization of relevant nutritional resources by root canal isolates
Authors: Khot A. , Spratt D. , Ng Y.‐L. , Gulabivala K.
Published: April 2004

Aim  To identify nutritional sources potentially available within the root canal systems that may allow the growth of bacteria.

Methodology  All the cultivable bacterial species (Aerococcus viridans, Actinomyces viscosus, Rothia dentocariosa, Streptococcus mitis, Corynebacterium durum, Pediococcus urinaeequi, Campylobacter gracilis, Fusobacterium nucleatum and Prevotella corporis) from a single tooth infection were used. The nutrient sources tested included those potentially available from teeth (enamel, dentine, cementum, pulp tissue, saliva, serum and blood), artificial media (reduced transport fluid (RTF), brain heart infusion (BHI) and nutrient broth) and a control (phosphate‐buffered saline (PBS)). Each medium was inoculated with each of the bacterial isolates in microtitre plates in doubling dilution series. All experiments were carried out in triplicate. The plates were incubated either aerobically or anaerobically, as appropriate. Bacterial growth was assessed as a function of relative optical densities (ODs) at different nutrient dilutions measured by spectrophotometry at 24 and 48 h. Mean values were calculated (n = 3) and the resultant data were analysed to determine the presence or absence of growth.

Results  The effectiveness of artificial media in supporting the growth of the isolates was confirmed; BHI supported the growth of all isolates, but nutrient broth supported the growth of only six strains. As expected, PBS and RTF did not support bacterial growth. Of the dental tissues, enamel and dentine did not support bacterial growth, but cementum supported the growth of C. durum and C. gracilis. Pulp tissue only supported the growth of A. viscosus and C. gracilis. The body fluids supported bacterial growth well. Blood supported growth of all bacterial isolates except C. gracilis. Serum supported the growth of all isolates except P. urinaeequi and C. gracilis. Saliva supported the growth of A. viridans, A. viscosus, R. dentocariosa, C. durum and P. urinaeequi.

Conclusions  The differential support of growth by the nutrient sources revealed in the present study support the conclusion that during root canal infection, the causative bacteria may derive nutrition from a variety of locally abundant key tissues, but the principal components of hard and soft tissue present within teeth support bacterial growth only to a limited extent or does not support at all. The principal requirements are body fluids.
Phylogeography of a game species: the red‐crested pochard (Netta rufina) and consequences for its management
Authors: Gay L. , Defos Du Rau P. , Mondain‐Monval J‐Y. , Crochet P‐A.
Published: April 2004

Western European populations of red‐crested pochard (Netta rufina) are characterized by low size and high fragmentation, which accentuate their sensitivity to hunting. Uncertainties regarding the demographic trends of these populations highlight the need for pertinent hunting regulations. This requires identification of the limits of the populations under exploitation, i.e. delimiting a management unit. We used the left domain of the mitochondrial control region and seven nuclear loci (four microsatellites and three introns) to assess the level of genetic structure and demographic independence between the fragmented Western European and the large Central Asian populations. The second objective was to investigate the colonization history of the Western European populations. This study demonstrated that the Western European populations of red‐crested pochard constitute a separate demographic conservation unit relative to the Asian population as a result of very low female dispersal (mitochondrial DNA: ΦST = 0.152). A morphometric analysis further suggested that Central Asian and Western European specimens of both sexes originate from different pools of individuals. Male dispersal seems higher than female dispersal, as suggested by the lack of clear genetic structure for the nuclear markers at this continental scale. Genetic data, in conjunction with historical demographic data, indicate that the current Western European populations probably originate from a recent colonization from Central Asia. As numbers of red‐crested pochards in Western Europe cannot be efficiently supplemented by immigration from the larger Asian populations, a management plan regulating the harvest in Western Europe is required.
Geographically specific heteroplasmy of mitochondrial DNA in the seaweed, Fucus serratus (Heterokontophyta: Phaeophyceae, Fucales)
Authors: Coyer J. A. , Hoarau G. , Stam W. T. , Olsen J. L.
Published: April 2004

The presence of more than one type of mitochondrial DNA within the same organism (mtDNA heteroplasmy) has been reported in vertebrates, invertebrates, basidiomycetes and some angiosperms, but never in marine (macro)algae. We examined sequence differences in a 135‐base pair (bp) region of the nad11 gene in mitochondria of the intertidal rockweed, Fucus serratus, using single‐strand conformation polymorphism (SSCP). Each of 70 and 22 individuals from Blushøj (Denmark) and Oskarshamn (Sweden), respectively, displayed haplotypes 2, 3, and 4 (= mtDNA heteroplasmy), whereas only haplotype 2 was found in each of 24 individuals from locations in Spain, France, Ireland, Iceland and Norway. As Blushøj and Oskarshamn were among the last areas to emerge from ice cover during the Last Glacial Maximum (18 000–20 000 years bp), the geographically specific heteroplasmy may represent a founder effect and therefore, a valuable marker for understanding the role of post‐Ice Age recolonization. Geographically specific heteroplasmy also has important implications in phylogeographical studies based on mtDNA sequences.
Natural hybridization and the evolution of domesticated, pest and disease organisms
Authors: Arnold Michael L.
Published: April 2004

The role of natural hybridization in the evolutionary history of numerous species is well recognized. The impact of introgressive hybridization and hybrid speciation has been documented especially in plant and animal assemblages. However, there remain certain areas of investigation for which natural hybridization and its consequences remain under‐studied and under‐appreciated. One such area involves the evolution of organisms that positively or negatively affect human populations. In this review, I highlight exemplars of how natural hybridization has contributed to the evolution of (i) domesticated plants and animals; (ii) pests; (iii) human disease vectors; and (iv) human pathogens. I focus on the effects from genetic exchange that may lead to the acquisition of novel phenotypes and thus increase the beneficial or detrimental (to human populations) aspects of the various taxa.
Population genetic structure of Arctic Charr, Salvelinus alpinus from northwest Europe on large and small spatial scales
Authors: Wilson A. J. , Gíslason D. , Skúlason S. , Snorrason S. S. , Adams C. E. , Alexander G. , Danzmann R. G. , Ferguson M. M.
Published: April 2004

To examine the population genetic structure of lake‐resident Arctic charr, Salvelinus alpinus from northwest Europe on multiple spatial scales, 2367 individuals from 43 lakes located in three geographical regions (Iceland, the British Isles and Scandinavia) were genotyped at six microsatellite loci. On a large scale, data provided little evidence to support clustering of populations according to geographical region. Hierarchical analysis of molecular variance indicated that, although statistically significant, only 2.17% of the variance in allelic frequencies was partitioned at the among‐region level. Within regions, high levels of genetic differentiation were typically found between lakes regardless of the geographical distance separating them. These results are consistent with the hypothesis of rapid postglacial recolonization of all of northwest Europe from a single charr lineage, with subsequent restriction of gene flow. On a smaller scale, there was evidence for close genetic relationships among lakes from within common drainage basins in Scotland. Thus, interlake genetic structure reflects localized patterns of recent (or contemporary) gene flow superimposed onto a larger scale structure that is largely a result of historical processes. There was also evidence for widespread genetic structuring at the within‐lake level, with sympatric populations detected in 10 lakes, and multilocus heterozygote deficits found in 23 lakes. This evidence of the Wahlund effect was found in all lakes known to contain discrete phenotypic morphs, as well as many others, suggesting that morphs may often represent separate breeding populations, and also that the phenomenon of polymorphism in this species may be more widespread than is currently realized.
Antimalarial efficacy of sulfadoxine–pyrimethamine, amodiaquine and a combination of chloroquine plus sulfadoxine–pyrimethamine in Bundi Bugyo, western Uganda
Authors: Checchi Francesco , Piola Patrice , Kosack Cara , Ardizzoni Elisa , Klarkowski Derryck , Kwezi Eric , Priotto Gerardo , Balkan Suna , Bakyaita Nathan , Brockman Alan , Guthmann Jean‐Paul
Published: April 2004

We report below an in vivo antimalarial efficacy study conducted in 2002 in Bundi Bugyo, a district of western Uganda housing a large displaced population. We tested sulfadoxine–pyrimethamine (SP), amodiaquine (AQ) and the combination chloroquine plus SP (CQ + SP). A total of 268 children with uncomplicated Plasmodium falciparum malaria were followed‐up for 28 days according to WHO recommendations, with PCR genotyping to distinguish late recrudescences from re‐infections. PCR‐adjusted failure proportions at day 28 were 37.0% (34/92, 95% CI 27.1–47.7) in the SP group, 20.6% (14/68, 95% CI 11.7–32.1) in the AQ group and 22.8% (18/79, 95% CI 14.1–33.6) in the CQ + SP group. Early failures were particularly frequent in the SP group (15.2%). Clearance of gametocytes was slower in the SP and CQ + SP groups than in the AQ group. This study suggests that, in Bundi Bugyo, CQ + SP (Uganda's first‐line regimen) will need to be replaced by a more efficacious regimen. Across Uganda, the deployment of SP containing combinations may not be a feasible long‐term strategy. For Bundi Bugyo, we recommend a combination of artesunate and AQ. Our study also confirms previous findings that resistance is considerably underestimated by 14‐day follow‐ups. Antimalarial policy decisions should therefore be based on 28‐day studies, with PCR adjustment to distinguish re‐infections.
Urinary tract infections and genitourinary abnormalities in Cameroonian men
Authors: Yuyun Matthew F. , Angwafo III Fru F. , Koulla‐Shiro Sinata , Zoung‐Kanyi Jimmy
Published: April 2004

Objective  To compare the prevalence of genitourinary abnormalities in men diagnosed with urinary tract infection (UTI) in a Cameroonian hospital and those without.

Patients and methods  Consecutive adult men aged 18–75 years, whose midstream urine samples were received for microscopy, culture and sensitivity at the microbiology laboratory of the Yaounde University Teaching Hospital, Cameroon, constituted the study population. Genitourinary abnormalities were diagnosed from history, physical examination, abdominal and transrectal ultrasonography, plain abdominal X‐ray, and if indicated urethrocystoscopy and biopsy.

Results  Of the 206 patients who qualified, 179 completed the study and 63 (35.2%) were found to have UTI. A total of 41 (65.1%) patients with UTI (mean age 69.2 years) had at least one genitourinary abnormality, compared to 13 (11.2%) of those without UTI (mean age 61.9 years) (P < 0.001). The age‐adjusted prevalence of genitourinary abnormalities was 59.4% in the UTI group and 12.1% in the non‐UTI group (P < 0.001). The most frequent genitourinary abnormality in men with UTI was benign prostatic enlargement, followed by urethral stricture. The crude odds ratio (95% confidence intervals) for UTI associated with genitourinary abnormality was 14.77 (6.80–32.05), and the adjusted odds ratio 11.51 (7.08–29.46).

Conclusion  Urological evaluation of Cameroonian men with UTI, using simple history taking, physical examination, ultrasound examination and plain abdominal X‐ray, could have significant clinical benefits in this tropical African region.
Duodenal gastric metaplasia and Helicobacter pylori infection in high and low duodenal ulcer‐prevalent areas in India
Authors: TOVEY FRANK I , HOBSLEY MICHAEL , KAUSHIK SATYENDRA P , PANDEY RAKESH , KURIAN GEORGE , SINGH KARTAR , SOOD AJIT , JEHANGIR ERNEST
Published: April 2004

Background:  Previous reports, based on surgery, showed duodenal ulcer (DU) to be more common in the rice‐eating areas of southern India than in the northern wheat‐eating areas.

Aims:  Does this difference persist? Can it be explained by risk factors other than diet?

Methods:  A total of 20 053 records from patients undergoing endoscopy for dyspepsia, and 590 endoscopy patients from two northern and two southern centers in India were studied prospectively. Records were scrutinized to determine the relative incidence of DU and non‐ulcer dyspepsia in wheat‐ and rice‐eating areas. Age, sex, length of history, smoking and medication were recorded. Three antral biopsies and one from each duodenal quadrant were taken. A rapid urease test was carried out on one of the antral biopsies; the others were examined for Helicobacter pylori, gastritis, duodenitis and duodenal gastric metaplasia.

Results:  The difference in diet‐associated prevalence persisted. No differences in smoking, Helicobacter pylori infection or duodenal gastric metaplasia were found between the two regions, but all three were more common in DU than in non‐ulcer dyspeptic patients from both dietary areas.

Conclusions:  The dietary differences between the regions remain the only factor to account for the differences in DU prevalence. A strong interrelationship between duodenal gastric metaplasia and cigarette smoking is demonstrated.
The impact of disclosure of HIV on the index patient's self‐defined family
Authors: Bor Robert , Du Plessis Peter , Russell Morris
Published: April 2004

For most people facing a serious illness, the family is regarded as the primary source of support. Research suggests that patterns of support may differ for people infected with HIV. Access to support normally requires disclosure of one's health problem to others. This study examined the impact of disclosure of HIV on the index patient's self‐defined family. Most participants were gay men attending a London HIV clinic. Both they and the care‐givers whom they identified to the researchers were interviewed. The results of this qualitative study highlight the fact that many gay men with HIV do not regard their biological family as their primary social support system. Friends and partners were commonly cited as primary care‐givers. Most of those interviewed who provided support to the infected individual clearly remembered the disclosure event. They also had a number of emotional reactions, over time, to disclosure. We argue that adjustment to illness among care‐givers is a complex two‐way, reciprocal process whereby the infected individual and care‐giver take subtle cues from one another in terms of how they appear to one another to cope. Some emotionally painful feelings may be experienced but not openly expressed. Therapists who work with families affected by illness should first learn from the patient who he or she defines as ‘family’. They should also enquire about the impact of disclosure of illness on all care‐givers as well as subsequent reactions and unexpressed feelings associated with this.
It is Possible to Just Give Money to the Poor
Authors: Hanlon Joseph
Published: April 2004

Meghnad Desai of the London School of Economics recently suggested that, rather than ‘giving fifty billion dollars of overseas aid’, we should simply ‘find the poor and give them one dollar a week … That would probably do more to relieve poverty than anything else’. Two experiences in Mozambique of simply handing out money show this is possible. Payments to demobilized soldiers over a two year period and single payments to flood victims were of the order of magnitude suggested by Desai. Rural people had no difficulty cashing cheques and used the money prudently. The money stimulated the rural economy and thus had a development impact. Administrative costs were between 5 and 10 per cent, much less than in other aid projects. Using the Mozambique experience, this article concludes by suggesting that Desai's proposed one dollar per person per week could be paid as a family grant bi‐monthly, which would keep administrative costs low.
Neoliberal Reform, Governance and Corruption in the South: Assessing the International Anti‐Corruption Crusade
Authors: Brown Ed , Cloke Jonathan
Published: April 2004

This paper presents a critique of current thinking on the causes and impacts of corruption and the measures designed to combat it. It begins by exploring the evolution of the current preoccupation with corruption and traces the growth in international initiatives designed to tackle the issue. It then moves on to consider the assumptions underlying the dominant schools of thought on corruption and alternative definitions of the phenomenon. The limitations of the dominant neoliberal perspective are explored in detail, focusing particularly on its blindness to the complex interplay between economic liberalisation, political power and institutional reform. An alternative framework that locates corruption at the systemic level is proposed. The paper concludes with some thoughts on potential directions for future geographical research on the topic.
Eletriptan for the Short‐term Prophylaxis of Cluster Headache
Authors: Zebenholzer Karin , Wöber Christian , Vigl Marion , Wessely Peter
Published: April 2004

Background.—A beneficial prophylactic effect from eletriptan 40 mg given to a single patient with cluster headache was observed.

Objective.—To further evaluate the efficacy of eletriptan in the short‐term prophylaxis of cluster headache.

Methods.—We treated 18 patients; mean age, 40.5 years (standard deviation [SD], 9.9). The number of cluster headache attacks was recorded during a baseline period of 6 days, and during 6 days of treatment with eletriptan 40 mg twice daily. The primary outcome measure was the reduction in the number of attacks during the treatment period.

Results.—In the 16 patients who completed the study (2 patients were lost to follow‐up), the mean total number of attacks decreased from 10.9 (SD, 5.6) during baseline to 6.3 (SD, 3.7) during treatment with eletriptan (P= .01) The reduction in the number of attacks exceeded 50% in 6 patients.

Conclusion.—This small open‐label study suggests that eletriptan 40 mg twice daily may be useful for the short‐term prophylaxis of cluster headache.