bluuebunny/crossref_metadata_2025 huggingface dataset:
Sons and daughters of foster carers and the impact of fostering on their everyday life
Authors: Höjer Ingrid
Published: September 2006

The paper presents results from a study of sons and daughters of foster carers, and the impact of fostering on their lives. Children and young people participated in focus groups and discussion groups, and 684 answered a questionnaire. Eight were interviewed in‐depth. The results from the study showed that sons and daughters of foster carers were highly involved in the fostering assignment. Most children and young people valued their relationship with foster children, but even though relations to foster children were good, fostering could imply complicated changes of everyday life. Sons and daughters of foster carers may have to cope with conflicts connected to behavioural disorders of foster children, and they gained knowledge about foster children’s problematic lives. Fostering also implied contact with natural parents of foster children. Such contact could challenge children’s and young people’s’ perception of adequate parenthood. For some respondents it was hard to become aware of the dysfunctional parenting, abuse and/or neglect to which foster children might have been exposed. The results of the study provided evidence of the need to acknowledge the contribution to fostering made by sons and daughters of foster carers, and also to recognize the impact fostering may have on their lives.
A family affair? Kinship care and parental substance misuse: some dilemmas explored
Authors: Kroll Brynna
Published: September 2006

Both the Children Act 1989 and the Human Rights Act 1998 support the principle that children should remain within their birth families wherever possible and that this option must be considered when children are unable to live with their parents. Where parental substance misuse is an issue, family placements, whether formally or informally arranged, are increasingly being used and the support of grandparents, in particular, has been identified as a significant protective factor for children. This paper examines some of the issues that can arise with such placements, particularly in view of the part that substance misuse may play within the wider family system, the impact of parental drug and alcohol use on attachment and child development, and the complex dynamics that can ensue. Drawing on themes emerging from parental substance misuse literature and kinship care research, some practice dilemmas will be explored. While acknowledging the complex aetiology of substance misuse and the dangers of pathologizing family systems in which it is found, some hypotheses about potential risks and challenges will be debated. It will be argued that, although such placements can often provide children with a safe haven, they may demand a specific type of support and monitoring, if children’s welfare is to be safeguarded.
Phytoplankton communities and antecedent conditions: high resolution sampling in Esthwaite Water
Authors: MADGWICK G. , JONES I. D. , THACKERAY S. J. , ELLIOTT J. A. , MILLER H. J.
Published: September 2006

1. The succession of a phytoplankton community was investigated through an intensive period of sampling and related to physical, chemical and biological conditions sampled at an equal, or higher, temporal resolution.

2. Phytoplankton samples were taken on a weekly basis from June to September 2004 and analysed for diversity, species composition, and contribution of different functional groups to total biomass. Physical and chemical data were collected on the sampling days, and physical environmental factors were also logged continuously throughout the period by automatic measuring stations. This continuous logging allowed community structure to be compared with physical data averaged over periods from a day to a week before each sampling date.

3. The Schmidt stability of the lake, a measure of the strength of stratification calculated from thermal data, showed a negative correlation with phytoplankton species diversity. This is consistent with the hypothesis that mixing was preventing exclusion by species that would otherwise dominate in stratified conditions.

4. At a functional level, stress tolerant (S‐type) species dominated during the stratified summer conditions, with small, colonising species (C types) and ruderal, disturbance tolerant species (R types) contributing little to the overall biomass. Of the stress tolerant species, the faster growing (SC) phytoplankters were significantly favoured by more stable, stratified conditions and higher solar radiation. Increased abundance of this group resulted in decreased species diversity. Correlations were generally strongest when using the 6‐ to 7‐day averaged physical data, stressing the importance of continuous measurements of these drivers in phytoplankton studies.
Invasive grass reduces aboveground carbon stocks in shrublands of the Western US
Authors: BRADLEY BETHANY A. , HOUGHTON R. A. , MUSTARD JOHN F. , HAMBURG STEVEN P.
Published: September 2006

Understanding the terrestrial carbon budget, in particular the strength of the terrestrial carbon sink, is important in the context of global climate change. Considerable attention has been given to woody encroachment in the western US and the role it might play as a carbon sink; however, in many parts of the western US the reverse process is also occurring. The conversion of woody shrublands to annual grasslands involves the invasion of non‐native cheatgrass (Bromus tectorum) which in turn leads to increased frequency and extent of fires. We compared carbon storage in adjacent plots of invasive grassland and native shrubland. We scaled‐up the impact of this ecosystem shift using regional maps of the current invasion and of the risk of future invasion. The expansion of cheatgrass within the Great Basin has released an estimated 8±3 Tg C to the atmosphere, and will likely release another 50±20 Tg C in the coming decades. This ecosystem conversion has changed portions of the western US from a carbon sink to a source, making previous estimates of a western carbon sink almost certainly spurious. The growing importance of invasive species in driving land cover changes may substantially change future estimates of US terrestrial carbon storage.
The influence of predation on the chronic response of Artemia sp. populations to a toxicant
Authors: BEKETOV MIKHAIL A. , LIESS MATTHIAS
Published: September 2006

Environmental risk assessment of contaminants is conventionally based on toxic effects assessed in organism‐level test systems. We suggest that, for the prediction of toxicant effects, population‐ and community‐level effects should be considered. The aim of this study was to investigate how predation could alter a prey population's response to a toxicant to reveal effects at population and community levels.

Populations of the brine shrimp Artemia sp. were maintained in the laboratory with and without simulated predation. Individuals were exposed for 1 h to the pyrethroid insecticide esfenvalerate (0, 0·01, 0·04 and 0·08 µg L−1) and subsequently observed for 6 weeks.

Unpredated exposed populations showed a reduced population density compared with the control. However, even at the highest concentration of insecticide, populations were sustained until the end of the experiment. The lower density in the exposed populations led to reduced competition and subsequently to enhanced development of surviving individuals and an increased proportion of young individuals. In contrast, the combination of predation and short‐term toxicant exposure at concentrations of 0·04 and 0·08 µg L−1 produced extinction of the populations after 39 and 32 days of exposure, respectively.

Synthesis and applications. The response of populations of brine shrimp to toxicants at the community level may be stronger when predation is present than the response of populations without predation pressure, as the regulation capacity of the population (measured as an increased production of offspring at reduced population densities) is exhausted when predation is present. Future ecotoxicological risk assessment schemes should consider relevant community characteristics such as predation as part of an environmental risk assessment.
Modelling the quantitative effects of pre‐ and post‐dispersal seed predation inPinus sylvestrisL.
Authors: WORTHY FIONA R. , LAW RICHARD , HULME PHILIP E.
Published: September 2006

Despite three decades of intensive research on seed predation, rather little is known about how important a role it plays in plant demography. Here a balance sheet of seed predation is drawn up forPinus sylvestris, based on mortality caused by its main seed predators. This species is of special interest because trees carry seeds throughout the year and can therefore support specialist as well as generalist seed predators. Also, its regeneration in Scotland is weak and some of its main seed predators (red squirrels, crossbills, wood ants) are themselves threatened.

Field data from twoP. sylvestrisforests were used to estimate rates of predation on seeds due to pre‐ and post‐dispersal predators, including both specialists and generalists. The rates of predation changed systematically over time and were fitted to time‐dependent functions. The resulting functions were incorporated into a model, which was solved numerically to determine the fate of a cohort of seeds.

On average, approximately 20% of seeds in the cohort were consumed by pre‐dispersal seed predators, approximately 25% of seeds by post‐dispersal seed predators, and approximately 55% of seeds were still alive at the end of 2 years. This reduces the seed pool for regeneration ofP. sylvestris, but is unlikely to be a serious problem for regeneration.

Seed survival was most sensitive to the rate at which seeds became invulnerable to further seed predation, and to the rate of seed dispersal from cones on trees. Seed survival was less sensitive to seed predation. However, among seed predators, carabids feeding on loose seeds and birds eating seeds in open cones were the most important.

Cones open as they dry out, and the timing of seed dispersal is therefore weather‐dependent. Late opening of cones had a deleterious effect on seed survival because it led to an increase in pre‐dispersal seed predation. Thus, in a period of climate change, patterns of seed predation would be expected also to change, altering the success of regeneration.
The effect of starvation on the susceptibility of teneral and non‐teneral tsetse flies to trypanosome infection
Authors: KUBI C. , VAN DEN ABBEELE J. , DE DEKEN R. , MARCOTTY T. , DORNY P. , VAN DEN BOSSCHE P.
Published: September 2006

Abstract Transmission of vector‐borne diseases depends largely on the ability of the insect vector to become infected with the parasite. In tsetse flies, newly emerged or teneral flies are considered the most likely to develop a mature, infective trypanosome infection. This was confirmed during experimental infections where laboratory‐reared Glossina morsitans morsitans Westwood (Diptera: Glossinidae) were infected with Trypanosoma congolense or T. brucei brucei. The ability of mature adult tsetse flies to become infected with trypanosomes was significantly lower than that of newly emerged flies for both parasites. However, the nutritional status of the tsetse at the time of the infective bloodmeal affected its ability to acquire either a T. congolense or T. b. brucei infection. Indeed, an extreme period of starvation (3–4 days for teneral flies, 7 days for adult flies) lowers the developmental barrier for a trypanosome infection, especially at the midgut level of the tsetse fly. Adult G. m. morsitans became at least as susceptible as newly emerged flies to infection with T. congolense. Moreover, the susceptibility of adult flies, starved for 7 days, to an infection with T. b. brucei was also significantly increased, but only at the level of maturation of an established midgut infection to a salivary gland infection. The outcome of these experimental infections clearly suggests that, under natural conditions, nutritional stress in adult tsetse flies could contribute substantially to the epidemiology of tsetse‐transmitted trypanosomiasis.
Secretion by numbers: protein traffic in prokaryotes
Authors: Economou Anastasias , Christie Peter J. , Fernandez Rachel C. , Palmer Tracy , Plano Greg V. , Pugsley Anthony P.
Published: September 2006

Almost all aspects of protein traffic in bacteria were covered at the ASM‐FEMS meeting on the topic in Iraklio, Crete in May 2006. The studies presented ranged from mechanistic analysis of specific events leading proteins to their final destinations to the physiological roles of the targeted proteins. Among the highlights from the meeting that are reviewed here are the molecular dynamics of SecA protein, membrane protein insertion, type III secretion needles and chaperones, type IV secretion, the two partner and autosecretion systems, the ‘secretion competent state’, and the recently discovered type VI secretion system.
The Escherichia coli UvrD helicase is essential for Tus removal during recombination‐dependent replication restart from Ter sites
Authors: Bidnenko Vladimir , Lestini Roxane , Michel Bénédicte
Published: September 2006

Blocking replication forks in the Escherichia coli chromosome by ectopic Ter sites renders the RecBCD pathway of homologous recombination and SOS induction essential for viability. In this work, we show that the E. coli helicase II (UvrD) is also essential for the growth of cells where replication forks are arrested at ectopic Ter sites. We propose that UvrD is required for Tus removal from Ter sites. The viability of a SOS non‐inducible Ter‐blocked strain is fully restored by the expression of the two SOS‐induced proteins UvrD and RecA at high level, indicating that these are the only two SOS‐induced proteins required for replication across Ter/Tus complexes. Several observations suggest that UvrD acts in concert with homologous recombination and we propose that UvrD is associated with recombination‐initiated replication forks and that it removes Tus when a PriA‐dependent, restarted replication fork goes across the Ter/Tus complex. Finally, expression of the UvrD homologue from Bacilus subtilis PcrA restores the growth of uvrD‐deficient Ter‐blocked cells, indicating that the capacity to dislodge Tus is conserved in this distant bacterial species.
Transmission of stridulatory signals of the burrower bugs, Scaptocoris castanea and Scaptocoris carvalhoi (Heteroptera: Cydnidae) through the soil and soybean
Authors: C̆OKL ANDREJ , NARDI CRISTIANE , BENTO JOSÉ MAURICIO SIMÕES , HIROSE EDSON , PANIZZI ANTÔNIO RICARDO
Published: September 2006

Abstract Males and females of the burrower bug species Scaptocoris castanea Perty and Scaptocoris carvalhoi Becker emit stridulatory signals when on the roots of soybean. The substrate‐borne components of the signal can be recorded on the plant but not on the surrounding soil surface. The stridulatory apparatus is composed of the tergal plectrum (lima) and the stridulitrum (stridulatory vein) on the underside of the hind wings. The male plectrum has one ridge and the female lima has 13 ridges. Stridulitra of different species differ in the length and in the number of teeth. Rubbing of plectrum (lima) ridges over the stridulitrum in one or both directions produces pulse trains. The velocity of signals that are recorded less than 0.5 cm from the bug is below 0.013 mm s−1 on the soil and below 0.066 mm s−1 on the leaf surface. Broadband spectra have a dominant frequency of less than 1 kHz and subdominant peaks extending up to 7 kHz. The dominant frequency of the stridulatory signal transmitted through a plant decreases together with the proportion of its higher frequency spectral components. Signals are attenuated for 3–9 dB cm−1 when transmitted through the soil or soybean leaf and for approximately 1 dB cm−1 when transmitted through soybean stem.
Experimental Autoimmune Encephalomyelitis Develops in CC Chemokine Receptor 7‐deficient Mice with Altered T‐cell Responses
Authors: Pahuja A. , Maki R. A. , Hevezi P. A. , Chen A. , Verge G. M. , Lechner S. M. , Roth R. B. , Zlotnik A. , Alleva D. G.
Published: September 2006

CC chemokine receptor 7 (CCR7) is involved in the initiation of immune responses by mediating the migration of naïve T cells and mature dendritic cells to T‐cell‐rich zones of secondary lymphoid organs where antigen presentation occurs. To address whether CCR7 plays a role in the development of autoimmunity, we induced experimental autoimmune encephalomyelitis in CCR7‐deficient mice on a C57BL/6 background (CCR7−/−) using the neuroantigen, myelin oligodendrocyte glycoprotein 35–55 amino acid peptide (MOG(35−55)) and Bordetella pertussis toxin (PTX). CCR7−/− mice acquired disease with an intensity similar to wild‐type littermates. MOG(35−55)‐specific lymphocyte responses were dominant in the spleen of CCR7−/− mice, rather than in lymph nodes as observed in wild‐type mice. These results indicate that effective immune responses (with altered kinetics) can develop in the absence of CCR7 but develop in the spleen rather than lymph nodes as CCR7 is necessary for T and dendritic cells to enter lymph nodes.
Evaluation of Recombinant Serine‐rich 45‐kDa Antigen (ML0411) for Detection of Antibodies in Leprosy Patients
Authors: Parkash O. , Kumar A. , Nigam A. , Franken K. L. M. C. , Ottenhoff T. H. M.
Published: September 2006

The potential of the recombinant serine‐rich 45‐kDa antigen (ML0411) of Mycobacterium leprae to aid in detecting M. leprae‐specific serum antibodies was assessed by an enzyme‐linked immunosorbent assay (ELISA) in leprosy patients and controls comprising of tuberculosis patients, other unrelated skin‐diseased patients and healthy individuals from India. All 18 multibacillary (MB) and 18/38 (47.4%) of the paucibacillary (PB) leprosy patients were found positive. None of the controls was positive, yielding complete (0/49) specificity in the series tested here. On the other hand, an anti‐phenolic glycolipid‐1 (PGL‐I) antibody‐detecting assay yielded detectable responses in 94.4% (17/18) of MB and 36.8% (14/38) of PB leprosy patients. Only two of 49 (4.1%) controls were positive, giving a specificity of 95.9%. Further, there was a good concordance (agreement of 83.8%; χ2 = 40.3, P < 0.001; κ = 0.63) between the two assays. Thus, the 45‐kDa‐based assay was slightly better than anti‐PGL‐I antibody‐detecting assay. Interestingly, when combining the results of both the assays together for all leprosy patients (MB + PB), the combined sensitivity was significantly higher than that of the anti‐PGL‐I antibody‐detecting ELISA alone (73.2% versus 55.4%; P < 0.05), but not (P > 0.05) compared with the 45‐kDa antigen‐based assay alone. Similarly, in case of PB patients, using both assays in combination, the sensitivity was significantly higher compared with anti‐PGL‐I antibody‐detecting assay alone (60.5% versus 36.8%; P < 0.05). While adopting the combinatorial approach, the specificity remained invariably high (>95%). In conclusion, the results of the present study indicate that the M. leprae 45‐kDa protein is a potent B‐cell antigen and may be a useful serodiagnostic reagent.
A Differential Association of Interferon‐γ High‐Producing Allele T and Low‐Producing Allele A (+874 A/T) with Hashimoto's Thyroiditis and Graves’ Disease
Authors: Rekha P. L. , Ishaq M. , Valluri V.
Published: September 2006

Cytokines play a crucial role in the pathogenesis of autoimmune thyroid disease. The aim of this study was to investigate the relationship of the single base change polymorphic variants identified in the first intron of interferon‐gamma (IFN‐γ) (+874 T/A) with susceptibility to thyroid dysfunctions. A total of 340 subjects were included in the study comprising of 190 patients (104 patients with Hashimoto's thyroiditis, 26 with non‐Hashimoto's hypothyroidism and 60 Graves’ disease) and 150 controls. Genotyping was done by amplification refractory mutation system‐polymerase chain reaction using a set of sequence‐specific primers. Statistical analysis revealed a significant association between high IFN‐γ‐producing genotype TT and Hashimoto's thyroiditis compared to controls (P value < 0.001). On the other hand, the frequency of genotype TT was decreased in patients with Graves’ hyperthyroidism with a significant increase in low IFN‐γ‐producing genotype AA among this group (P = 0.03). To conclude the results of the study suggest a differential association of high‐ and low‐producing alleles of IFN‐γ gene with Hashimoto's thyroiditis and Graves’ disease. The high IFN‐γ‐producing allele T was observed to be associated with Hashimoto's thyroiditis in the present study where as in Graves’ hyperthyroidism the association was observed to be stronger with the low producing allele A.
Combined Costimulation Blockade Prevents Rejection of Allogeneic Islets in Mice
Authors: Malm H. , Påhlman C. , Veress B. , Corbascio M. , Ekberg H.
Published: September 2006

There is a need for immunosuppressive protocols in islet transplantation that are neither nephrotoxic nor diabetogenic. We have examined blockade of the CD28‐B7, CD40‐CD40L and ICAM‐LFA‐1 pathways in a model of allogeneic islet transplantation in mice to determine the efficacy of this blockade in prolongation of graft survival. Histological evidences of inflammation and function were evaluated in grafts that had been functioning for 100 days. Treatment with a combination of all three drugs, or with CTLA4Ig and anti‐CD40L, administered four times during the first six postoperative days, resulted in an excellent graft survival. All animals had a graft survival of >100 days (i.e. indefinitely). Mice treated with CTLA4Ig and anti‐CD40L all showed well‐preserved islets without signs of degeneration or destruction. There were no signs of rejection, as evidenced by the absence of infiltrating lymphocytes. This group had the least amount of rejection/inflammation changes according to ranking of all grafts. In conclusion, a short induction treatment with anti‐CD40L and CTLA4Ig totally prevents rejection and preserves the allogeneic islets transplanted to mice. The addition of anti‐LFA‐1 did not confer any benefit.
Chimera and other fertilization errors
Authors: Malan V , Vekemans M , Turleau C
Published: September 2006

The finding of a mixture of 46,XX and 46,XY cells in an individual has been rarely reported in literature. It usually results in individuals with ambiguous genitalia. Approximately 10% of true human hermaphrodites show this type of karyotype. However, the underlying mechanisms are poorly understood. It may be the result of mosaicism or chimerism. By definition, a chimera is produced by the fusion of two different zygotes in a single embryo, while a mosaic contains genetically different cells issued from a single zygote. Several mechanisms are involved in the production of chimera. Stricto sensu, chimerism occurs from the post‐zygotic fusion of two distinct embryos leading to a tetragametic chimera. In addition, there are other entities, which are also referred to as chimera: parthenogenetic chimera and chimera resulting from fertilization of the second polar body. Furthermore, a particular type of chimera called ‘androgenetic chimera’ recently described in fetuses with placental mesenchymal dysplasia and in rare patients with Beckwith–Wiedemann syndrome is discussed. Strategies to study mechanisms leading to the production of chimera and mosaics are also proposed.
Photosynthesis, growth and structural characteristics of holm oak resprouts originated from plants grown under elevated CO2
Authors: Aranda Xavier , Agustí Cristina , Joffre Richard , Fleck Isabel
Published: September 2006

The physiological characteristics of holm oak (Quercus ilex L.) resprouts originated from plants grown under current CO2 concentration (350 μl l−1) (A‐resprouts) were compared with those of resprouts originated from plants grown under elevated CO2 (750 μl l−1) (E‐resprouts). At their respective CO2 growth concentration, no differences were observed in photosynthesis and chlorophyll fluorescence parameters between the two kinds of resprout. E‐resprouts appeared earlier and showed lower stomatal conductance, higher water‐use efficiency and increased growth (higher leaf, stem and root biomass and increased height). Analyses of leaf chemical composition showed the effect of elevated [CO2] on structural polysaccharide (higher cellulose content), but no accumulation of total non‐structural carbohydrate on area or dry weight basis was seen. Four months after appearance, downregulation of photosynthesis and electron transport components was observed in E‐resprouts: lower photosynthetic capacity, photosystem II quantum efficiency, photochemical quenching of fluorescence and relative electron transport rate. Reduction in ribulose‐1,5‐bisphosphate carboxylase/oxygenase (RuBisCo) activity, deduced from the maximum carboxylation velocity of RuBisCo, accounts for the observed acclimation. Increased susceptibility of photosynthetic apparatus to increasing irradiance was detected in E‐resprouts.
Using quantitative proteomics of Arabidopsis roots and leaves to predict metabolic activity
Authors: Mooney Brian P. , Miernyk Jan A. , Michael Greenlief C. , Thelen Jay J.
Published: September 2006

Proteins isolated from developing roots and leaves of Arabidopsis thaliana were separated by high‐resolution two‐dimensional (2‐D) electrophoresis. The resulting 2‐D proteome maps are markedly different. Quantitative analysis of root and leaf protein spot pairs revealed that in most instances there was at least a 1.5‐fold differential. Peptide mass fingerprint analysis of the 288 most abundant 2‐D spots from each organ allowed 156 and 126 protein assignments for roots and leaves, respectively, 54 of which were common. Metabolism‐related proteins accounted for 20% of assignments in samples from both organs, whereas energy‐related proteins comprised 25 and 18% of leaf and root samples, respectively. Proteins involved in disease resistance and defense encompass 13% of root proteins, but only 7% of leaf proteins. Comparison of protein abundance with transcript abundance, using previously reported microarray data, yielded a correlation coefficient of approximately 0.6, suggesting that it is inappropriate to make protein level or metabolic conclusions based solely upon data from transcript profiling. A comparative model of root and leaf metabolism was developed, based upon protein rather than transcript abundance. The model indicates elevated one‐carbon and tricarboxylic acid metabolism in roots relative to leaves.
The relationship of hydraulic conductance to root system characteristics of peach (Prunus persica) rootstocks
Authors: Solari Luis I. , Pernice Fulvio , DeJong Theodore M.
Published: September 2006

Specific rootstocks can differentially influence the vegetative growth and development of fruit trees. However, the physiological mechanism involved in this phenomenon has been elusive. Recent research comparing different peach (Prunus persica L. Batsch) rootstocks suggests that the rootstock effect on vegetative growth in peach trees is associated to water relations and more specifically to differences in rootstock hydraulic conductance. This study was intended to confirm differences in hydraulic characteristics of similar size peach trees grafted on different rootstocks and to examine root system characteristics that could be associated with rootstock hydraulic limitations. Trees on rootstocks that were known to have a size‐controlling effect when grown under field conditions had lower rootstock conductance than trees on the vigorous (control) rootstock when rootstock hydraulic conductance was measured with both the high‐pressure and evaporative flow methods. Rootstocks with the lowest hydraulic conductance had less fine root surface area and length per unit root dry weight than the more vigorous (control) rootstock. However, contrary to previous field studies, in this study there were no significant differences in dry matter production and distribution among trees on the different rootstocks suggesting that whatever the normal growth control mechanism was, it did not differentially influence growth under the specific conditions of this study. This research confirmed that peach rootstocks exhibiting size‐controlling behavior under field conditions differed in their hydraulic and morphological characteristics under controlled growth conditions even when those growth conditions negated the expression of the size‐controlling behavior.
International standards for minimum potency of anti‐A and anti‐B blood grouping reagents: evaluation of candidate preparations in an international collaborative study
Authors: Thorpe S. J. , Fox B. , Heath A. B. , Scott M. , De Haas M. , Kochman S. , Padilla A.
Published: September 2006

Background and Objectives  The aim of the study was to evaluate lyophilized monoclonal IgM anti‐A and anti‐B preparations for use as international standards (IS) to specify recommended minimum potencies of anti‐A and anti‐B blood grouping reagents in tube tests.

Materials and Methods  The candidate IS for minimum potency of anti‐A and anti‐B blood grouping reagents, codes 03/188 and 03/164, respectively, were evaluated against a wide range of commercial anti‐A and anti‐B blood grouping reagents in an international collaborative study involving 16 laboratories in nine countries. Laboratories titrated 03/188 and 03/164 in parallel with as many commercial anti‐A and anti‐B blood grouping reagents, respectively, as were available to them, in tube tests according to specified haemagglutination methodology. Three of these laboratories and a further laboratory also titrated 03/188 and 03/164 in parallel with currently available reference preparations for anti‐A and anti‐B. The ratios of the mean endpoint titres of the anti‐A and anti‐B reagents to those of 03/188 and 03/164, respectively, within each laboratory were calculated.

Results  The ratios of the mean titres of the anti‐A reagents to the mean titre of 03/188 within a laboratory fell within 0·062 and 4, i.e. the potencies of the anti‐A reagents were between a sixteenth to four times as strong as 03/188. The ratios of the mean titres of the anti‐B reagents to the mean titre of 03/164 within a laboratory also fell within 0·062 and 4, with one outlier.

Conclusions  By international consensus, a 1 in 8 dilution of the candidate IS for anti‐A, 03/188, and a 1 in 4 dilution of the candidate IS for anti‐B, 03/164, were considered appropriate to define the recommended minimum potencies of anti‐A and anti‐B blood grouping reagents, respectively, in tube tests. On the basis of these results, preparations 03/188 and 03/164 were established by the World Health Organization as International Standards for Minimum Potency of Anti‐A and Anti‐B Blood Grouping Reagents respectively, and by the US Food and Drug Administration Center for Biologics Evaluation and Research as Minimum Potency Reference Reagents.
Temporal Variation in Decisions about Parental Care in Bluegill, Lepomis macrochirus
Authors: Magee Sarah E. , Neff Bryan D.
Published: September 2006

Parental investment theory states that an individual will trade‐off present and future reproductive potential to maximize lifetime reproductive success. Only when parental care is costly in terms of reduced future reproductive potential should individuals be sensitive to changes in the value of current offspring and adjust their care. Here, we examine temporal variation in parental care decision‐making in bluegill (Lepomis macrochirus), in which care is provided by males called ‘parentals’. Previous research has shown that parentals that nest early in the breeding season are in higher energetic condition than those that nest later, and early nesting males appear not to pay an opportunity cost to their care in terms of reduced future reproductive potential. Early nesting males also may have higher paternity in their broods than later nesting males. To examine the parental care decisions made by early and mid‐season nesting parentals, we experimentally reduced males’ perceived paternity by swapping eggs between nests. We found that experimental males that nested early in the breeding season adjusted their brood defence behaviour similarly to control males, which had sham egg swaps performed. Conversely, experimental males that nested mid‐season significantly decreased their brood defence behaviour after the manipulation as compared with control males. Thus, unlike mid‐season nesting males, early nesting males appear relatively insensitive to changes in brood value (paternity), possibly because early nesting males pay little cost in terms of reduced future reproductive potential to providing full care or because these males have a predisposition to high paternity.
Symptomatic Evidence for Differential Root Invasion by Fusarium Crown and Root Rot Pathogens Between Common Tomato Lycopersicon esculentum and Its Varieties
Authors: Xu L. , Nonomura T. , Suzuki S. , Kitagawa Y. , Tajima H. , Okada K. , Kusakari S. , Matsuda Y. , Toyoda H.
Published: September 2006

The pathogenic isolates (Kin2001a, Kin2001b and Kin2003) of Fusarium oxysporum f. sp. radicis‐lycopersici were obtained from hydroponically cultured seedlings of pear tomato (Lycopersicon esculentum var. pyriforme) infected at different times and their pathogenicity examined in an in vitro assay system on cotyledonal seedlings of pear tomato, cherry tomato (L. esculentum var. cerasiforme) and common tomato (L. esculentum). With the in vitro assay, infection and subsequent disease progress could be microscopically observed. Pear and cherry tomatoes suppressed invasion by all isolates at the junctions of epidermal cells along the root, comparable with the resistant cultivars of common tomato. The pathogen entered pear and cherry tomatoes at the tips of lateral roots and tap roots, in contrast to infection of susceptible cultivars of common tomato. In Kin2003‐inoculated roots, the top of the lateral rootlets first became discoloured, followed by the cortical parenchyma, central xylem vessel and finally the crown. This dark‐brown discolouration expanded rapidly and severe rot developed in the discoloured regions. In contrast, the dark‐brown discolouration in Kin2001b‐infected roots expanded into the cortical parenchyma cells abutting the originally infected lateral rootlets and at a much slower rate. Kin2001a was in a new group that entered via the cortical cleavage formed by the emergence of lateral rootlets, in addition to the tips of taproots and lateral roots. In this in vitro assay system, the Japanese pathogenic isolates collected from different districts of Japan were characterized and classified by the mode of host invasion. Of 13 isolates, four were placed with Kin2003, six with Kin2001a and three with Kin2001b.
Measurement of Horizontal and Vertical Movement of Ralstonia solanacearum in Soil
Authors: Satou M. , Kubota M. , Nishi K.
Published: September 2006

Two model systems were constructed to measure horizontal and vertical movement of bacteria in soil. These systems were applied to measuring movement of Ralstonia solanacearum (race 1, biovar 3), a causal agent of bacterial wilt of tomato, in andosol and sand at 28°C. The first system was used to measure horizontal movement of the bacteria in soil packed in a narrow horizontal frame. Suspension of the pathogen was applied to soil at one end of the frame, and bacterial number per gram of soil was measured over distance from the inoculation point after 4 days. Horizontal movement of R. solanacearum in supersaturated soil, but without flow, was possibly due to diffusion and the front advanced at 2.2 cm/day in andosol, and at 8.1 cm/day in sand. Using the same experimental system, but applying water inflow to one end of the frame only, the bacterium was detected at the front of water in andosol and sand. The front of the distribution advanced at 20.4 cm/h in andosol and 66.3 cm/h in sand. In the second experimental system, a cylinder of soil packed in a short tube was soaked with water, and soil at the top of the tube was inoculated with bacterial suspension. Immediately, soil cylinders were turned upward, and the bacterial number per gram of soil was measured along vertical distance from the inoculation point after 7 days. Using the system with andosol, the capillary water front rose to 32.5 cm over 7 days after inoculation, and R. solanacearum reached to 18.8 cm height. In sand, capillary water rose to 20.0 cm and the bacteria reached to 16.3 cm height.
Phytophthora melonis Associated with Fruit and Vine Rot Disease of Pointed Gourd in India as Revealed by RFLP and Sequencing of ITS Region
Authors: Guharoy S. , Bhattacharyya S. , Mukherjee S. K. , Mandal N. , Khatua D. C.
Published: September 2006

Pointed gourd is an important tropical high value vegetable crop, which is mainly affected by fruit and vine rot disease in field conditions. Causal organism of this devastating disease is Phytophthora melonis as revealed through morphological criteria as well as by molecular tools based on the restriction fragment length polymorphism (RFLP) of non‐coding Internal Transcriber Spacer (ITS) region and ITS sequencing. Sequencing of ITS region of our Ph. melonis isolate has 100% similarity with the five isolates of GenBank including a Ph. sinensis. The pathogen, Ph. melonis, is a new report from India and as regards host ranges a possible new report globally.
Screening Study of Potential Lead Compounds for Natural Product‐based Fungicides Against Phytophthora Species
Authors: Fernández‐Acero F. J. , Carbú M. , Garrido C. , Collado I. G. , Cantoral J. , Vallejo I.
Published: September 2006

Phytophthora spp. is one of the phytopathogenic Oomycete responsible for many important crop losses. Relevant species are P. infestans (causing potato late blight) and P. capsici (causing blight in pepper). In recent years, the use of conventional fungicides has favoured the appearance of different resistant strains. This study analyses the effect of various compounds on these two Phytophthora species. Those compounds were designed on the basis of known structures of natural compounds to obtain a rational control of these fungal‐like species. All the analysed products showed a fungistatic activity against both strains, one of them reduced mycelial growth by over 46% at 100 p.p.m.
Development of a Real‐time Polymerase Chain Reaction for the Detection of Fusarium oxysporum f. sp. basilici from Basil Seed and Roots
Authors: Pasquali M. , Piatti P. , Gullino M. L. , Garibaldi A.
Published: September 2006

A real‐time polymerase chain reaction (PCR) assay using a TaqMan® probe was developed to detect the causal agent of wilt and crown rot of basil from infected plants and seed in Italy. The aim of the study was to diminish testing time, previously performed using nested‐PCR, and to create the conditions for future automation. The sensitivity of the assay was shown to be similar to the detection limit of the available nested‐PCR procedure. The advantages of real‐time PCR system include halving of the testing time, as well as the ability to identify both internally and externally infected seed to the sensitivity of 1 pg of genomic DNA. The assay was able to detect the presence of the pathogen in infected seed up to a sensitivity of 24 (SD: ±10) CFU per 100 seeds.
A Laboratory Leaf Assay of Carrot Susceptibility to Botrytis cinerea
Authors: Baranski R. , Krämer R. , Klocke E.
Published: September 2006

Laboratory experiments were conducted to develop an assay for evaluation of carrot (Daucus carota L.) leaf reaction to Botrytis cinerea Pers. ex Pers. The detached carrot leaflets were inoculated with the colonized agar plugs attached to the cut surface of the midrib or by spraying conidial suspension. The estimation of the infected leaflet area expressed as the area under the disease progress curve enabled the discrimination between carrot genotypes differing in their susceptibility to the pathogen. Evaluation based on the measurement of the length of the midrib lesion did not allow such differentiation. The inoculation of leaf surface with suspension of conidia was less reliable and the development of the disease symptoms was not reproducible. The established assay using colonized plugs enables a fast assessment of carrot leaf susceptibility to grey mould and can be particularly useful for a non‐destructive, preliminary evaluation of precious and limited source materials.
Morphological investigations of the frustule, perizonium and initial valves of the freshwater diatom Achnanthes crenulata Grunow (Bacillariophyceae)
Authors: Toyoda Kensuke , Williams David M. , Tanaka Jiro , Nagumo Tamotsu
Published: September 2006

The present study clarifies the fine structure of the vegetative frustules, initial valves and perizonium of Achnanthes crenulata Grunow. The valves of the vegetative cell are distinctly linear‐lanceolate with an undulate margin. The valve face is quite flat and in girdle view is smoothly curved as in species of Gephyria (Bacillariophyceae). However, the valve face of the initial cells is slightly rounded and does not have an undulate margin. Furthermore, the rapheless sternum is centrally positioned along the apical axis of the araphid initial valve. As this taxon develops from auxospore to initial valve, it forms only longitudinal perizonial bands; no transverse bands arise. The perizonium consists of three silicified bands: one large, central longitudinal plate and two bands that underlie this plate; these two bands are either open or closed. This taxon has several conspicuous structures compared to other marine species of Achnanthes, but the structure of the perizonium supports the position of A. crenulata within Achnanthes sensu stricto.
Observations on Fragilaria longifusiformis comb. nov. et nom. nov. (Bacillariophyceae), a widespread planktic diatom documented from North America and Europe
Authors: Siver Peter A. , Morales Eduardo A. , Van de Vijver Bart , Smits Michiel , Hamilton Paul B. , Lange‐Bertalot Horst , Hains John J.
Published: September 2006

Synedra planktonica was originally described by Hains and Sebring from a freshwater locality in the south‐eastern USA using light and transmission electron microscopy. The authors placed S. planktonica into the genus Synedra Ehrenberg because of its solitary habit and lack of marginal linking spines. Since the original description of S. planktonica, the concepts of Synedra and the related genus Fragilaria Lyngbye have undergone significant change and debate. Today, details of the areolae, apical pore fields, cingulum and rimoportulae, all lacking in the original description of S. planktonica, are now commonly used to distinguish between taxa in Fragilaria, Synedra and related genera. We provide details of these ultrastructural characters for S. planktonica based on specimens collected from the type locality, along with observations of cells from other sites in North America and Europe. Based on these findings, an emended description is presented for S. planktonica and the taxon is transferred to Fragilaria, as F. longifusiformis comb. nov. et nom. nov. According to the International Code of Botanical Nomenclature, the epithet planktonica could not be applied because it was previously used to describe a marine species of Fragilaria. We discuss the relationship of S. planktonica with morphologically similar taxa, including the genus Reimerothrix Prasad.
Serial replacement of a diatom endosymbiont in the marine dinoflagellate Peridinium quinquecorne (Peridiniales, Dinophyceae)
Authors: Horiguchi Takeo , Takano Yoshihito
Published: September 2006

To infer the phylogeny of both the host and the endosymbiont of Peridinium quinquecorne Abé, the small subunit (SSU) ribosomal DNA (rDNA) from the host and two genes of endosymbiont origin (plastid‐encoded rbcL and nuclear‐encoded SSU rDNA) were determined. The phylogenetic analysis of the host revealed that the marine dinoflagellate P. quinquecorne formed a clade with other diatom‐harbouring dinoflagellates, including Kryptoperidinium foliaceum (Stein) Lindeman, Durinskia baltica (Levander) Carty et Cox and Galeidinium rugatum Tamura et Horiguchi, indicating a single endosymbiotic event for this lineage. Phylogenetic analyses of the endosymbiont in these organisms revealed that the endosymbiont of P. quinquecorne formed a clade with a centric diatom (SSU data indicated it to be closely related to Chaetoceros), whereas the endosymbionts of other three dinoflagellates formed a clade with a pennate diatom. The discrepancy between the host and the endosymbiont phylogenies suggests a secondary replacement of the endosymbiont from a pennate to a centric diatom in P. quinquecorne.
Diversity and evolution of photosynthetic antenna systems in green plants
Authors: Yoshii Yukie
Published: September 2006

Photosynthetic antenna systems are mainly involved in the absorption of light energy required for photosynthesis. The typical green plants arrange chlorophylls a and b and carotenoids, including lutein and 9′‐cis neoxanthin, in their antenna systems; such antenna systems have prospered on earth. Therefore, these antenna systems should be highly evolved and should adapt to the photoenvironments in which plants grow. However, little information is available on the diversity and evolution of antenna systems in green plants as a whole. To approach this, the present study focused on the antenna systems in the Prasinophyceae, an assemblage of early diverging lineages of green plants and analyzed their photosynthetic pigments in detail. In the present study, various novel blue–green light‐absorbing siphonaxanthin series were detected in the early diverging species of the Prasinophyceae and the distribution of these carotenoids was revealed. Additionally, to clarify the evolution of antenna systems in the Ulvophyceae, a highly developed green algal group that specializes in inhabiting various aquatic environments, members of the Cladophorales belonging to this class were selected and their carotenoid compositions were determined to compare them with the molecular phylogenetic tree constructed on the basis of the 18S rRNA gene sequences of the Cladophorales. In this review, these data will be summarized and the remarkable variation of photosynthetic pigments will be presented. A possible scenario detailing the evolution of antenna systems in green plants will be elucidated.
Psychosocial impact of amblyopia and its treatment: a multidisciplinary study
Authors: Koklanis Konstandina , Abel Larry A , Aroni Rosalie
Published: September 2006

Abstract

Background:  To explore the meaning of amblyopia from both parents’ and children’s perspectives and to seek correlations between the experiential aspects of the condition and its treatment, the clinical characteristics of amblyopia and any apparent psychopathology.

Methods:  Children with amblyopia and their parents were engaged in semistructured in‐depth interviews. Children also underwent a vision assessment and, where applicable, parents and children completed a psychological inventory, the Behaviour Assessment System for Children.

Results:  Dealing with stigma and the perceptions and responses of peers were found to be of central significance to the experience of amblyopia therapy. This had adverse consequences for some children’s identity and psychosocial well‐being. The clinical manifestations of amblyopia did not correlate with the social implications of the condition. However, children with strabismus were noted to have significantly greater conduct and externalizing problems.

Conclusions:  Given that amblyopia can affect children’s psychosocial well‐being, health outcomes need to integrate both vision and psychosocial implications of treatment. Although treatment should aim to reverse amblyopia and restore visual acuity, efforts to minimise any negative psychosocial consequences of treatment should be made. A way to balance managing amblyopia and ensuring children’s psychosocial well‐being should to be considered by clinicians and included in treatment guidelines.